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Diffstat (limited to 'gcc/ada/gcc-interface/decl.cc')
| -rw-r--r-- | gcc/ada/gcc-interface/decl.cc | 10661 |
1 files changed, 10661 insertions, 0 deletions
diff --git a/gcc/ada/gcc-interface/decl.cc b/gcc/ada/gcc-interface/decl.cc new file mode 100644 index 0000000..39a9092 --- /dev/null +++ b/gcc/ada/gcc-interface/decl.cc @@ -0,0 +1,10661 @@ +/**************************************************************************** + * * + * GNAT COMPILER COMPONENTS * + * * + * D E C L * + * * + * C Implementation File * + * * + * Copyright (C) 1992-2021, Free Software Foundation, Inc. * + * * + * GNAT is free software; you can redistribute it and/or modify it under * + * terms of the GNU General Public License as published by the Free Soft- * + * ware Foundation; either version 3, or (at your option) any later ver- * + * sion. GNAT is distributed in the hope that it will be useful, but WITH- * + * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * + * for more details. You should have received a copy of the GNU General * + * Public License along with GCC; see the file COPYING3. If not see * + * <http://www.gnu.org/licenses/>. * + * * + * GNAT was originally developed by the GNAT team at New York University. * + * Extensive contributions were provided by Ada Core Technologies Inc. * + * * + ****************************************************************************/ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "target.h" +#include "tree.h" +#include "gimple-expr.h" +#include "stringpool.h" +#include "diagnostic-core.h" +#include "alias.h" +#include "fold-const.h" +#include "stor-layout.h" +#include "tree-inline.h" +#include "demangle.h" + +#include "ada.h" +#include "types.h" +#include "atree.h" +#include "elists.h" +#include "namet.h" +#include "nlists.h" +#include "repinfo.h" +#include "snames.h" +#include "uintp.h" +#include "urealp.h" +#include "fe.h" +#include "sinfo.h" +#include "einfo.h" +#include "ada-tree.h" +#include "gigi.h" + +/* The "stdcall" convention is really supported on 32-bit x86/Windows only. + The following macro is a helper to avoid having to check for a Windows + specific attribute throughout this unit. */ + +#if TARGET_DLLIMPORT_DECL_ATTRIBUTES +#ifdef TARGET_64BIT +#define Has_Stdcall_Convention(E) \ + (!TARGET_64BIT && Convention (E) == Convention_Stdcall) +#else +#define Has_Stdcall_Convention(E) (Convention (E) == Convention_Stdcall) +#endif +#else +#define Has_Stdcall_Convention(E) 0 +#endif + +#define STDCALL_PREFIX "_imp__" + +/* Stack realignment is necessary for functions with foreign conventions when + the ABI doesn't mandate as much as what the compiler assumes - that is, up + to PREFERRED_STACK_BOUNDARY. + + Such realignment can be requested with a dedicated function type attribute + on the targets that support it. We define FOREIGN_FORCE_REALIGN_STACK to + characterize the situations where the attribute should be set. We rely on + compiler configuration settings for 'main' to decide. */ + +#ifdef MAIN_STACK_BOUNDARY +#define FOREIGN_FORCE_REALIGN_STACK \ + (MAIN_STACK_BOUNDARY < PREFERRED_STACK_BOUNDARY) +#else +#define FOREIGN_FORCE_REALIGN_STACK 0 +#endif + +/* The largest TYPE_ARRAY_MAX_SIZE value we set on an array type. + It's an artibrary limit (256 MB) above which we consider that + the allocation is essentially unbounded. */ + +#define TYPE_ARRAY_SIZE_LIMIT (1 << 28) + +struct incomplete +{ + struct incomplete *next; + tree old_type; + Entity_Id full_type; +}; + +/* These variables are used to defer recursively expanding incomplete types + while we are processing a record, an array or a subprogram type. */ +static int defer_incomplete_level = 0; +static struct incomplete *defer_incomplete_list; + +/* This variable is used to delay expanding types coming from a limited with + clause and completed Taft Amendment types until the end of the spec. */ +static struct incomplete *defer_limited_with_list; + +typedef struct subst_pair_d { + tree discriminant; + tree replacement; +} subst_pair; + + +typedef struct variant_desc_d { + /* The type of the variant. */ + tree type; + + /* The associated field. */ + tree field; + + /* The value of the qualifier. */ + tree qual; + + /* The type of the variant after transformation. */ + tree new_type; + + /* The auxiliary data. */ + tree aux; +} variant_desc; + + +/* A map used to cache the result of annotate_value. */ +struct value_annotation_hasher : ggc_cache_ptr_hash<tree_int_map> +{ + static inline hashval_t + hash (tree_int_map *m) + { + return htab_hash_pointer (m->base.from); + } + + static inline bool + equal (tree_int_map *a, tree_int_map *b) + { + return a->base.from == b->base.from; + } + + static int + keep_cache_entry (tree_int_map *&m) + { + return ggc_marked_p (m->base.from); + } +}; + +static GTY ((cache)) hash_table<value_annotation_hasher> *annotate_value_cache; + +/* A map used to associate a dummy type with a list of subprogram entities. */ +struct GTY((for_user)) tree_entity_vec_map +{ + struct tree_map_base base; + vec<Entity_Id, va_gc_atomic> *to; +}; + +void +gt_pch_nx (Entity_Id &) +{ +} + +void +gt_pch_nx (Entity_Id *x, gt_pointer_operator op, void *cookie) +{ + op (x, NULL, cookie); +} + +struct dummy_type_hasher : ggc_cache_ptr_hash<tree_entity_vec_map> +{ + static inline hashval_t + hash (tree_entity_vec_map *m) + { + return htab_hash_pointer (m->base.from); + } + + static inline bool + equal (tree_entity_vec_map *a, tree_entity_vec_map *b) + { + return a->base.from == b->base.from; + } + + static int + keep_cache_entry (tree_entity_vec_map *&m) + { + return ggc_marked_p (m->base.from); + } +}; + +static GTY ((cache)) hash_table<dummy_type_hasher> *dummy_to_subprog_map; + +static void prepend_one_attribute (struct attrib **, + enum attrib_type, tree, tree, Node_Id); +static void prepend_one_attribute_pragma (struct attrib **, Node_Id); +static void prepend_attributes (struct attrib **, Entity_Id); +static tree elaborate_expression (Node_Id, Entity_Id, const char *, bool, bool, + bool); +static tree elaborate_expression_1 (tree, Entity_Id, const char *, bool, bool); +static tree elaborate_expression_2 (tree, Entity_Id, const char *, bool, bool, + unsigned int); +static tree elaborate_reference (tree, Entity_Id, bool, tree *); +static tree gnat_to_gnu_component_type (Entity_Id, bool, bool); +static tree gnat_to_gnu_subprog_type (Entity_Id, bool, bool, tree *); +static int adjust_packed (tree, tree, int); +static tree gnat_to_gnu_field (Entity_Id, tree, int, bool, bool); +static enum inline_status_t inline_status_for_subprog (Entity_Id); +static tree gnu_ext_name_for_subprog (Entity_Id, tree); +static void set_nonaliased_component_on_array_type (tree); +static void set_reverse_storage_order_on_array_type (tree); +static bool same_discriminant_p (Entity_Id, Entity_Id); +static bool array_type_has_nonaliased_component (tree, Entity_Id); +static bool compile_time_known_address_p (Node_Id); +static bool flb_cannot_be_superflat (Node_Id); +static bool range_cannot_be_superflat (Node_Id); +static bool constructor_address_p (tree); +static bool allocatable_size_p (tree, bool); +static bool initial_value_needs_conversion (tree, tree); +static tree update_n_elem (tree, tree, tree); +static int compare_field_bitpos (const PTR, const PTR); +static bool components_to_record (Node_Id, Entity_Id, tree, tree, int, bool, + bool, bool, bool, bool, bool, bool, tree, + tree *); +static Uint annotate_value (tree); +static void annotate_rep (Entity_Id, tree); +static tree build_position_list (tree, bool, tree, tree, unsigned int, tree); +static vec<subst_pair> build_subst_list (Entity_Id, Entity_Id, bool); +static vec<variant_desc> build_variant_list (tree, Node_Id, vec<subst_pair>, + vec<variant_desc>); +static tree maybe_saturate_size (tree, unsigned int align); +static tree validate_size (Uint, tree, Entity_Id, enum tree_code, bool, bool, + const char *, const char *); +static void set_rm_size (Uint, tree, Entity_Id); +static unsigned int validate_alignment (Uint, Entity_Id, unsigned int); +static unsigned int promote_object_alignment (tree, tree, Entity_Id); +static void check_ok_for_atomic_type (tree, Entity_Id, bool); +static bool type_for_atomic_builtin_p (tree); +static tree resolve_atomic_builtin (enum built_in_function, tree); +static tree create_field_decl_from (tree, tree, tree, tree, tree, + vec<subst_pair>); +static tree create_rep_part (tree, tree, tree); +static tree get_rep_part (tree); +static tree create_variant_part_from (tree, vec<variant_desc>, tree, + tree, vec<subst_pair>, bool); +static void copy_and_substitute_in_size (tree, tree, vec<subst_pair>); +static void copy_and_substitute_in_layout (Entity_Id, Entity_Id, tree, tree, + vec<subst_pair>, bool); +static tree associate_original_type_to_packed_array (tree, Entity_Id); +static const char *get_entity_char (Entity_Id); + +/* The relevant constituents of a subprogram binding to a GCC builtin. Used + to pass around calls performing profile compatibility checks. */ + +typedef struct { + Entity_Id gnat_entity; /* The Ada subprogram entity. */ + tree ada_fntype; /* The corresponding GCC type node. */ + tree btin_fntype; /* The GCC builtin function type node. */ +} intrin_binding_t; + +static bool intrin_profiles_compatible_p (const intrin_binding_t *); + +/* Given GNAT_ENTITY, a GNAT defining identifier node, which denotes some Ada + entity, return the equivalent GCC tree for that entity (a ..._DECL node) + and associate the ..._DECL node with the input GNAT defining identifier. + + If GNAT_ENTITY is a variable or a constant declaration, GNU_EXPR gives its + initial value (in GCC tree form). This is optional for a variable. For + a renamed entity, GNU_EXPR gives the object being renamed. + + DEFINITION is true if this call is intended for a definition. This is used + for separate compilation where it is necessary to know whether an external + declaration or a definition must be created if the GCC equivalent was not + created previously. */ + +tree +gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition) +{ + /* The construct that declared the entity. */ + const Node_Id gnat_decl = Declaration_Node (gnat_entity); + /* The object that the entity renames, if any. */ + const Entity_Id gnat_renamed_obj = Renamed_Object (gnat_entity); + /* The kind of the entity. */ + const Entity_Kind kind = Ekind (gnat_entity); + /* True if this is a type. */ + const bool is_type = IN (kind, Type_Kind); + /* True if this is an artificial entity. */ + const bool artificial_p = !Comes_From_Source (gnat_entity); + /* True if debug info is requested for this entity. */ + const bool debug_info_p = Needs_Debug_Info (gnat_entity); + /* True if this entity is to be considered as imported. */ + const bool imported_p + = (Is_Imported (gnat_entity) && No (Address_Clause (gnat_entity))); + /* True if this entity has a foreign convention. */ + const bool foreign = Has_Foreign_Convention (gnat_entity); + /* For a type, contains the equivalent GNAT node to be used in gigi. */ + Entity_Id gnat_equiv_type = Empty; + /* For a type, contains the GNAT node to be used for back-annotation. */ + Entity_Id gnat_annotate_type = Empty; + /* Temporary used to walk the GNAT tree. */ + Entity_Id gnat_temp; + /* Contains the GCC DECL node which is equivalent to the input GNAT node. + This node will be associated with the GNAT node by calling at the end + of the `switch' statement. */ + tree gnu_decl = NULL_TREE; + /* Contains the GCC type to be used for the GCC node. */ + tree gnu_type = NULL_TREE; + /* Contains the GCC size tree to be used for the GCC node. */ + tree gnu_size = NULL_TREE; + /* Contains the GCC name to be used for the GCC node. */ + tree gnu_entity_name; + /* True if we have already saved gnu_decl as a GNAT association. This can + also be used to purposely avoid making such an association but this use + case ought not to be applied to types because it can break the deferral + mechanism implemented for access types. */ + bool saved = false; + /* True if we incremented defer_incomplete_level. */ + bool this_deferred = false; + /* True if we incremented force_global. */ + bool this_global = false; + /* True if we should check to see if elaborated during processing. */ + bool maybe_present = false; + /* True if we made GNU_DECL and its type here. */ + bool this_made_decl = false; + /* Size and alignment of the GCC node, if meaningful. */ + unsigned int esize = 0, align = 0; + /* Contains the list of attributes directly attached to the entity. */ + struct attrib *attr_list = NULL; + + /* Since a use of an itype is a definition, process it as such if it is in + the main unit, except for E_Access_Subtype because it's actually a use + of its base type, and for E_Class_Wide_Subtype with an Equivalent_Type + because it's actually a use of the latter type. */ + if (!definition + && is_type + && Is_Itype (gnat_entity) + && Ekind (gnat_entity) != E_Access_Subtype + && !(Ekind (gnat_entity) == E_Class_Wide_Subtype + && Present (Equivalent_Type (gnat_entity))) + && !present_gnu_tree (gnat_entity) + && In_Extended_Main_Code_Unit (gnat_entity)) + { + /* Ensure that we are in a subprogram mentioned in the Scope chain of + this entity, our current scope is global, or we encountered a task + or entry (where we can't currently accurately check scoping). */ + if (!current_function_decl + || DECL_ELABORATION_PROC_P (current_function_decl)) + { + process_type (gnat_entity); + return get_gnu_tree (gnat_entity); + } + + for (gnat_temp = Scope (gnat_entity); + Present (gnat_temp); + gnat_temp = Scope (gnat_temp)) + { + if (Is_Type (gnat_temp)) + gnat_temp = Underlying_Type (gnat_temp); + + if (Ekind (gnat_temp) == E_Subprogram_Body) + gnat_temp + = Corresponding_Spec (Parent (Declaration_Node (gnat_temp))); + + if (Is_Subprogram (gnat_temp) + && Present (Protected_Body_Subprogram (gnat_temp))) + gnat_temp = Protected_Body_Subprogram (gnat_temp); + + if (Ekind (gnat_temp) == E_Entry + || Ekind (gnat_temp) == E_Entry_Family + || Ekind (gnat_temp) == E_Task_Type + || (Is_Subprogram (gnat_temp) + && present_gnu_tree (gnat_temp) + && (current_function_decl + == gnat_to_gnu_entity (gnat_temp, NULL_TREE, false)))) + { + process_type (gnat_entity); + return get_gnu_tree (gnat_entity); + } + } + + /* This abort means the itype has an incorrect scope, i.e. that its + scope does not correspond to the subprogram it is first used in. */ + gcc_unreachable (); + } + + /* If we've already processed this entity, return what we got last time. + If we are defining the node, we should not have already processed it. + In that case, we will abort below when we try to save a new GCC tree + for this object. We also need to handle the case of getting a dummy + type when a Full_View exists but be careful so as not to trigger its + premature elaboration. Likewise for a cloned subtype without its own + freeze node, which typically happens when a generic gets instantiated + on an incomplete or private type. */ + if ((!definition || (is_type && imported_p)) + && present_gnu_tree (gnat_entity)) + { + gnu_decl = get_gnu_tree (gnat_entity); + + if (TREE_CODE (gnu_decl) == TYPE_DECL + && TYPE_IS_DUMMY_P (TREE_TYPE (gnu_decl)) + && IN (kind, Incomplete_Or_Private_Kind) + && Present (Full_View (gnat_entity)) + && (present_gnu_tree (Full_View (gnat_entity)) + || No (Freeze_Node (Full_View (gnat_entity))))) + { + gnu_decl + = gnat_to_gnu_entity (Full_View (gnat_entity), NULL_TREE, + false); + save_gnu_tree (gnat_entity, NULL_TREE, false); + save_gnu_tree (gnat_entity, gnu_decl, false); + } + + if (TREE_CODE (gnu_decl) == TYPE_DECL + && TYPE_IS_DUMMY_P (TREE_TYPE (gnu_decl)) + && Ekind (gnat_entity) == E_Record_Subtype + && No (Freeze_Node (gnat_entity)) + && Present (Cloned_Subtype (gnat_entity)) + && (present_gnu_tree (Cloned_Subtype (gnat_entity)) + || No (Freeze_Node (Cloned_Subtype (gnat_entity))))) + { + gnu_decl + = gnat_to_gnu_entity (Cloned_Subtype (gnat_entity), NULL_TREE, + false); + save_gnu_tree (gnat_entity, NULL_TREE, false); + save_gnu_tree (gnat_entity, gnu_decl, false); + } + + return gnu_decl; + } + + /* If this is a numeric or enumeral type, or an access type, a nonzero Esize + must be specified unless it was specified by the programmer. Exceptions + are for access-to-protected-subprogram types and all access subtypes, as + another GNAT type is used to lay out the GCC type for them. */ + gcc_assert (!is_type + || Known_Esize (gnat_entity) + || Has_Size_Clause (gnat_entity) + || (!Is_In_Numeric_Kind (kind) + && !IN (kind, Enumeration_Kind) + && (!IN (kind, Access_Kind) + || kind == E_Access_Protected_Subprogram_Type + || kind == E_Anonymous_Access_Protected_Subprogram_Type + || kind == E_Access_Subtype + || type_annotate_only))); + + /* The RM size must be specified for all discrete and fixed-point types. */ + gcc_assert (!(Is_In_Discrete_Or_Fixed_Point_Kind (kind) + && !Known_RM_Size (gnat_entity))); + + /* If we get here, it means we have not yet done anything with this entity. + If we are not defining it, it must be a type or an entity that is defined + elsewhere or externally, otherwise we should have defined it already. + + In other words, the failure of this assertion typically arises when a + reference to an entity (type or object) is made before its declaration, + either directly or by means of a freeze node which is incorrectly placed. + This can also happen for an entity referenced out of context, for example + a parameter outside of the subprogram where it is declared. GNAT_ENTITY + is the N_Defining_Identifier of the entity, the problematic N_Identifier + being the argument passed to Identifier_to_gnu in the parent frame. + + One exception is for an entity, typically an inherited operation, which is + a local alias for the parent's operation. It is neither defined, since it + is an inherited operation, nor public, since it is declared in the current + compilation unit, so we test Is_Public on the Alias entity instead. */ + gcc_assert (definition + || is_type + || kind == E_Discriminant + || kind == E_Component + || kind == E_Label + || (kind == E_Constant && Present (Full_View (gnat_entity))) + || Is_Public (gnat_entity) + || (Present (Alias (gnat_entity)) + && Is_Public (Alias (gnat_entity))) + || type_annotate_only); + + /* Get the name of the entity and set up the line number and filename of + the original definition for use in any decl we make. Make sure we do + not inherit another source location. */ + gnu_entity_name = get_entity_name (gnat_entity); + if (!renaming_from_instantiation_p (gnat_entity)) + Sloc_to_locus (Sloc (gnat_entity), &input_location); + + /* For cases when we are not defining (i.e., we are referencing from + another compilation unit) public entities, show we are at global level + for the purpose of computing scopes. Don't do this for components or + discriminants since the relevant test is whether or not the record is + being defined. */ + if (!definition + && kind != E_Component + && kind != E_Discriminant + && Is_Public (gnat_entity) + && !Is_Statically_Allocated (gnat_entity)) + force_global++, this_global = true; + + /* Handle any attributes directly attached to the entity. */ + if (Has_Gigi_Rep_Item (gnat_entity)) + prepend_attributes (&attr_list, gnat_entity); + + /* Do some common processing for types. */ + if (is_type) + { + /* Compute the equivalent type to be used in gigi. */ + gnat_equiv_type = Gigi_Equivalent_Type (gnat_entity); + + /* Machine_Attributes on types are expected to be propagated to + subtypes. The corresponding Gigi_Rep_Items are only attached + to the first subtype though, so we handle the propagation here. */ + if (Base_Type (gnat_entity) != gnat_entity + && !Is_First_Subtype (gnat_entity) + && Has_Gigi_Rep_Item (First_Subtype (Base_Type (gnat_entity)))) + prepend_attributes (&attr_list, + First_Subtype (Base_Type (gnat_entity))); + + /* Compute a default value for the size of an elementary type. */ + if (Known_Esize (gnat_entity) && Is_Elementary_Type (gnat_entity)) + { + unsigned int max_esize; + + gcc_assert (UI_Is_In_Int_Range (Esize (gnat_entity))); + esize = UI_To_Int (Esize (gnat_entity)); + + if (IN (kind, Float_Kind)) + max_esize = fp_prec_to_size (LONG_DOUBLE_TYPE_SIZE); + else if (IN (kind, Access_Kind)) + max_esize = POINTER_SIZE * 2; + else + max_esize = Enable_128bit_Types ? 128 : LONG_LONG_TYPE_SIZE; + + if (esize > max_esize) + esize = max_esize; + } + } + + switch (kind) + { + case E_Component: + case E_Discriminant: + { + /* The GNAT record where the component was defined. */ + Entity_Id gnat_record = Underlying_Type (Scope (gnat_entity)); + + /* If the entity is a discriminant of an extended tagged type used to + rename a discriminant of the parent type, return the latter. */ + if (kind == E_Discriminant + && Present (Corresponding_Discriminant (gnat_entity)) + && Is_Tagged_Type (gnat_record)) + { + gnu_decl + = gnat_to_gnu_entity (Corresponding_Discriminant (gnat_entity), + gnu_expr, definition); + saved = true; + break; + } + + /* If the entity is an inherited component (in the case of extended + tagged record types), just return the original entity, which must + be a FIELD_DECL. Likewise for discriminants. If the entity is a + non-stored discriminant (in the case of derived untagged record + types), return the stored discriminant it renames. */ + if (Present (Original_Record_Component (gnat_entity)) + && Original_Record_Component (gnat_entity) != gnat_entity) + { + gnu_decl + = gnat_to_gnu_entity (Original_Record_Component (gnat_entity), + gnu_expr, definition); + /* GNU_DECL contains a PLACEHOLDER_EXPR for discriminants. */ + if (kind == E_Discriminant) + saved = true; + break; + } + + /* Otherwise, if we are not defining this and we have no GCC type + for the containing record, make one for it. Then we should + have made our own equivalent. */ + if (!definition && !present_gnu_tree (gnat_record)) + { + /* ??? If this is in a record whose scope is a protected + type and we have an Original_Record_Component, use it. + This is a workaround for major problems in protected type + handling. */ + Entity_Id Scop = Scope (Scope (gnat_entity)); + if (Is_Protected_Type (Underlying_Type (Scop)) + && Present (Original_Record_Component (gnat_entity))) + { + gnu_decl + = gnat_to_gnu_entity (Original_Record_Component + (gnat_entity), + gnu_expr, false); + } + else + { + gnat_to_gnu_entity (Scope (gnat_entity), NULL_TREE, false); + gnu_decl = get_gnu_tree (gnat_entity); + } + + saved = true; + break; + } + + /* Here we have no GCC type and this is a reference rather than a + definition. This should never happen. Most likely the cause is + reference before declaration in the GNAT tree for gnat_entity. */ + gcc_unreachable (); + } + + case E_Named_Integer: + case E_Named_Real: + { + tree gnu_ext_name = NULL_TREE; + + if (Is_Public (gnat_entity)) + gnu_ext_name = create_concat_name (gnat_entity, NULL); + + /* All references are supposed to be folded in the front-end. */ + gcc_assert (definition && gnu_expr); + + gnu_type = gnat_to_gnu_type (Etype (gnat_entity)); + gnu_expr = convert (gnu_type, gnu_expr); + + /* Build a CONST_DECL for debugging purposes exclusively. */ + gnu_decl + = create_var_decl (gnu_entity_name, gnu_ext_name, gnu_type, + gnu_expr, true, Is_Public (gnat_entity), + false, false, false, artificial_p, + debug_info_p, NULL, gnat_entity); + } + break; + + case E_Constant: + /* Ignore constant definitions already marked with the error node. See + the N_Object_Declaration case of gnat_to_gnu for the rationale. */ + if (definition + && present_gnu_tree (gnat_entity) + && get_gnu_tree (gnat_entity) == error_mark_node) + { + maybe_present = true; + break; + } + + /* Ignore deferred constant definitions without address clause since + they are processed fully in the front-end. If No_Initialization + is set, this is not a deferred constant but a constant whose value + is built manually. And constants that are renamings are handled + like variables. */ + if (definition + && !gnu_expr + && No (Address_Clause (gnat_entity)) + && !No_Initialization (gnat_decl) + && No (gnat_renamed_obj)) + { + gnu_decl = error_mark_node; + saved = true; + break; + } + + /* If this is a use of a deferred constant without address clause, + get its full definition. */ + if (!definition + && No (Address_Clause (gnat_entity)) + && Present (Full_View (gnat_entity))) + { + gnu_decl + = gnat_to_gnu_entity (Full_View (gnat_entity), gnu_expr, false); + saved = true; + break; + } + + /* If we have a constant that we are not defining, get the expression it + was defined to represent. This is necessary to avoid generating dumb + elaboration code in simple cases, and we may throw it away later if it + is not a constant. But do not do it for dispatch tables because they + are only referenced indirectly and we need to have a consistent view + of the exported and of the imported declarations of the tables from + external units for them to be properly merged in LTO mode. Moreover + simply do not retrieve the expression if it is an allocator because + the designated type might still be dummy at this point. Note that we + invoke gnat_to_gnu_external and not gnat_to_gnu because the expression + may contain N_Expression_With_Actions nodes and thus declarations of + objects from other units that we need to discard. Note also that we + need to do it even if we are only annotating types, so as to be able + to validate representation clauses using constants. */ + if (!definition + && !No_Initialization (gnat_decl) + && !Is_Dispatch_Table_Entity (gnat_entity) + && Present (gnat_temp = Expression (gnat_decl)) + && Nkind (gnat_temp) != N_Allocator + && (Is_Elementary_Type (Etype (gnat_entity)) || !type_annotate_only)) + gnu_expr = gnat_to_gnu_external (gnat_temp); + + /* ... fall through ... */ + + case E_Exception: + case E_Loop_Parameter: + case E_Out_Parameter: + case E_Variable: + { + const Entity_Id gnat_type = Etype (gnat_entity); + /* Always create a variable for volatile objects and variables seen + constant but with a Linker_Section pragma. */ + bool const_flag + = ((kind == E_Constant || kind == E_Variable) + && Is_True_Constant (gnat_entity) + && !(kind == E_Variable + && Present (Linker_Section_Pragma (gnat_entity))) + && !Treat_As_Volatile (gnat_entity) + && (((Nkind (gnat_decl) == N_Object_Declaration) + && Present (Expression (gnat_decl))) + || Present (gnat_renamed_obj) + || imported_p)); + bool inner_const_flag = const_flag; + bool static_flag = Is_Statically_Allocated (gnat_entity); + /* We implement RM 13.3(19) for exported and imported (non-constant) + objects by making them volatile. */ + bool volatile_flag + = (Treat_As_Volatile (gnat_entity) + || (!const_flag && (Is_Exported (gnat_entity) || imported_p))); + bool mutable_p = false; + bool used_by_ref = false; + tree gnu_ext_name = NULL_TREE; + tree gnu_ada_size = NULL_TREE; + + /* We need to translate the renamed object even though we are only + referencing the renaming. But it may contain a call for which + we'll generate a temporary to hold the return value and which + is part of the definition of the renaming, so discard it. */ + if (Present (gnat_renamed_obj) && !definition) + { + if (kind == E_Exception) + gnu_expr = gnat_to_gnu_entity (Renamed_Entity (gnat_entity), + NULL_TREE, false); + else + gnu_expr = gnat_to_gnu_external (gnat_renamed_obj); + } + + /* Get the type after elaborating the renamed object. */ + if (foreign && Is_Descendant_Of_Address (Underlying_Type (gnat_type))) + gnu_type = ptr_type_node; + else + gnu_type = gnat_to_gnu_type (gnat_type); + + /* For a debug renaming declaration, build a debug-only entity. */ + if (Present (Debug_Renaming_Link (gnat_entity))) + { + /* Force a non-null value to make sure the symbol is retained. */ + tree value = build1 (INDIRECT_REF, gnu_type, + build1 (NOP_EXPR, + build_pointer_type (gnu_type), + integer_minus_one_node)); + gnu_decl = build_decl (input_location, + VAR_DECL, gnu_entity_name, gnu_type); + SET_DECL_VALUE_EXPR (gnu_decl, value); + DECL_HAS_VALUE_EXPR_P (gnu_decl) = 1; + TREE_STATIC (gnu_decl) = global_bindings_p (); + gnat_pushdecl (gnu_decl, gnat_entity); + break; + } + + /* If this is a loop variable, its type should be the base type. + This is because the code for processing a loop determines whether + a normal loop end test can be done by comparing the bounds of the + loop against those of the base type, which is presumed to be the + size used for computation. But this is not correct when the size + of the subtype is smaller than the type. */ + if (kind == E_Loop_Parameter) + gnu_type = get_base_type (gnu_type); + + /* Reject non-renamed objects whose type is an unconstrained array or + any object whose type is a dummy type or void. */ + if ((TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE + && No (gnat_renamed_obj)) + || TYPE_IS_DUMMY_P (gnu_type) + || TREE_CODE (gnu_type) == VOID_TYPE) + { + gcc_assert (type_annotate_only); + if (this_global) + force_global--; + return error_mark_node; + } + + /* If an alignment is specified, use it if valid. Note that exceptions + are objects but don't have an alignment and there is also no point in + setting it for an address clause, since the final type of the object + will be a reference type. */ + if (Known_Alignment (gnat_entity) + && kind != E_Exception + && No (Address_Clause (gnat_entity))) + align = validate_alignment (Alignment (gnat_entity), gnat_entity, + TYPE_ALIGN (gnu_type)); + + /* Likewise, if a size is specified, use it if valid. */ + if (Known_Esize (gnat_entity)) + gnu_size + = validate_size (Esize (gnat_entity), gnu_type, gnat_entity, + VAR_DECL, false, Has_Size_Clause (gnat_entity), + NULL, NULL); + if (gnu_size) + { + gnu_type + = make_type_from_size (gnu_type, gnu_size, + Has_Biased_Representation (gnat_entity)); + + if (operand_equal_p (TYPE_SIZE (gnu_type), gnu_size, 0)) + gnu_size = NULL_TREE; + } + + /* If this object has self-referential size, it must be a record with + a default discriminant. We are supposed to allocate an object of + the maximum size in this case, unless it is a constant with an + initializing expression, in which case we can get the size from + that. Note that the resulting size may still be a variable, so + this may end up with an indirect allocation. */ + if (No (gnat_renamed_obj) + && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type))) + { + if (gnu_expr && kind == E_Constant) + { + gnu_size = TYPE_SIZE (TREE_TYPE (gnu_expr)); + gnu_ada_size = TYPE_ADA_SIZE (TREE_TYPE (gnu_expr)); + if (CONTAINS_PLACEHOLDER_P (gnu_size)) + { + /* If the initializing expression is itself a constant, + despite having a nominal type with self-referential + size, we can get the size directly from it. */ + if (TREE_CODE (gnu_expr) == COMPONENT_REF + && TYPE_IS_PADDING_P + (TREE_TYPE (TREE_OPERAND (gnu_expr, 0))) + && TREE_CODE (TREE_OPERAND (gnu_expr, 0)) == VAR_DECL + && (TREE_READONLY (TREE_OPERAND (gnu_expr, 0)) + || DECL_READONLY_ONCE_ELAB + (TREE_OPERAND (gnu_expr, 0)))) + { + gnu_size = DECL_SIZE (TREE_OPERAND (gnu_expr, 0)); + gnu_ada_size = gnu_size; + } + else + { + gnu_size + = SUBSTITUTE_PLACEHOLDER_IN_EXPR (gnu_size, + gnu_expr); + gnu_ada_size + = SUBSTITUTE_PLACEHOLDER_IN_EXPR (gnu_ada_size, + gnu_expr); + } + } + } + /* We may have no GNU_EXPR because No_Initialization is + set even though there's an Expression. */ + else if (kind == E_Constant + && Nkind (gnat_decl) == N_Object_Declaration + && Present (Expression (gnat_decl))) + { + tree gnu_expr_type + = gnat_to_gnu_type (Etype (Expression (gnat_decl))); + gnu_size = TYPE_SIZE (gnu_expr_type); + gnu_ada_size = TYPE_ADA_SIZE (gnu_expr_type); + } + else + { + gnu_size = max_size (TYPE_SIZE (gnu_type), true); + /* We can be called on unconstrained arrays in this mode. */ + if (!type_annotate_only) + gnu_ada_size = max_size (TYPE_ADA_SIZE (gnu_type), true); + mutable_p = true; + } + + /* If the size isn't constant and we are at global level, call + elaborate_expression_1 to make a variable for it rather than + calculating it each time. */ + if (!TREE_CONSTANT (gnu_size) && global_bindings_p ()) + gnu_size = elaborate_expression_1 (gnu_size, gnat_entity, + "SIZE", definition, false); + } + + /* If the size is zero byte, make it one byte since some linkers have + troubles with zero-sized objects. If the object will have a + template, that will make it nonzero so don't bother. Also avoid + doing that for an object renaming or an object with an address + clause, as we would lose useful information on the view size + (e.g. for null array slices) and we are not allocating the object + here anyway. */ + if (((gnu_size + && integer_zerop (gnu_size) + && !TREE_OVERFLOW (gnu_size)) + || (TYPE_SIZE (gnu_type) + && integer_zerop (TYPE_SIZE (gnu_type)) + && !TREE_OVERFLOW (TYPE_SIZE (gnu_type)))) + && !Is_Constr_Subt_For_UN_Aliased (gnat_type) + && No (gnat_renamed_obj) + && No (Address_Clause (gnat_entity))) + gnu_size = bitsize_unit_node; + + /* If this is an object with no specified size and alignment, and + if either it is full access or we are not optimizing alignment for + space and it is composite and not an exception, an Out parameter + or a reference to another object, and the size of its type is a + constant, set the alignment to the smallest one which is not + smaller than the size, with an appropriate cap. */ + if (!Known_Esize (gnat_entity) + && !Known_Alignment (gnat_entity) + && (Is_Full_Access (gnat_entity) + || (!Optimize_Alignment_Space (gnat_entity) + && kind != E_Exception + && kind != E_Out_Parameter + && Is_Composite_Type (gnat_type) + && !Is_Constr_Subt_For_UN_Aliased (gnat_type) + && !Is_Exported (gnat_entity) + && !imported_p + && No (gnat_renamed_obj) + && No (Address_Clause (gnat_entity)))) + && (TREE_CODE (TYPE_SIZE (gnu_type)) == INTEGER_CST || gnu_size)) + align = promote_object_alignment (gnu_type, gnu_size, gnat_entity); + + /* If the object is set to have atomic components, find the component + type and validate it. + + ??? Note that we ignore Has_Volatile_Components on objects; it's + not at all clear what to do in that case. */ + if (Has_Atomic_Components (gnat_entity)) + { + tree gnu_inner = (TREE_CODE (gnu_type) == ARRAY_TYPE + ? TREE_TYPE (gnu_type) : gnu_type); + + while (TREE_CODE (gnu_inner) == ARRAY_TYPE + && TYPE_MULTI_ARRAY_P (gnu_inner)) + gnu_inner = TREE_TYPE (gnu_inner); + + check_ok_for_atomic_type (gnu_inner, gnat_entity, true); + } + + /* If this is an aliased object with an unconstrained array nominal + subtype, make a type that includes the template. We will either + allocate or create a variable of that type, see below. */ + if (Is_Constr_Subt_For_UN_Aliased (gnat_type) + && Is_Array_Type (Underlying_Type (gnat_type)) + && !type_annotate_only) + { + tree gnu_array = gnat_to_gnu_type (Base_Type (gnat_type)); + gnu_type + = build_unc_object_type_from_ptr (TREE_TYPE (gnu_array), + gnu_type, + concat_name (gnu_entity_name, + "UNC"), + debug_info_p); + } + + /* ??? If this is an object of CW type initialized to a value, try to + ensure that the object is sufficient aligned for this value, but + without pessimizing the allocation. This is a kludge necessary + because we don't support dynamic alignment. */ + if (align == 0 + && Ekind (gnat_type) == E_Class_Wide_Subtype + && No (gnat_renamed_obj) + && No (Address_Clause (gnat_entity))) + align = get_target_system_allocator_alignment () * BITS_PER_UNIT; + +#ifdef MINIMUM_ATOMIC_ALIGNMENT + /* If the size is a constant and no alignment is specified, force + the alignment to be the minimum valid atomic alignment. The + restriction on constant size avoids problems with variable-size + temporaries; if the size is variable, there's no issue with + atomic access. Also don't do this for a constant, since it isn't + necessary and can interfere with constant replacement. Finally, + do not do it for Out parameters since that creates an + size inconsistency with In parameters. */ + if (align == 0 + && MINIMUM_ATOMIC_ALIGNMENT > TYPE_ALIGN (gnu_type) + && !FLOAT_TYPE_P (gnu_type) + && !const_flag && No (gnat_renamed_obj) + && !imported_p && No (Address_Clause (gnat_entity)) + && kind != E_Out_Parameter + && (gnu_size ? TREE_CODE (gnu_size) == INTEGER_CST + : TREE_CODE (TYPE_SIZE (gnu_type)) == INTEGER_CST)) + align = MINIMUM_ATOMIC_ALIGNMENT; +#endif + + /* Do not take into account aliased adjustments or alignment promotions + to compute the size of the object. */ + tree gnu_object_size = gnu_size ? gnu_size : TYPE_SIZE (gnu_type); + + /* If the object is aliased, of a constrained nominal subtype and its + size might be zero at run time, we force at least the unit size. */ + if (Is_Aliased (gnat_entity) + && !Is_Constr_Subt_For_UN_Aliased (gnat_type) + && Is_Array_Type (Underlying_Type (gnat_type)) + && !TREE_CONSTANT (gnu_object_size)) + gnu_size = size_binop (MAX_EXPR, gnu_object_size, bitsize_unit_node); + + /* Make a new type with the desired size and alignment, if needed. */ + if (gnu_size || align > 0) + { + tree orig_type = gnu_type; + + gnu_type = maybe_pad_type (gnu_type, gnu_size, align, gnat_entity, + false, definition, true); + + /* If the nominal subtype of the object is unconstrained and its + size is not fixed, compute the Ada size from the Ada size of + the subtype and/or the expression; this will make it possible + for gnat_type_max_size to easily compute a maximum size. */ + if (gnu_ada_size && gnu_size && !TREE_CONSTANT (gnu_size)) + SET_TYPE_ADA_SIZE (gnu_type, gnu_ada_size); + + /* If a padding record was made, declare it now since it will + never be declared otherwise. This is necessary to ensure + that its subtrees are properly marked. */ + if (gnu_type != orig_type && !DECL_P (TYPE_NAME (gnu_type))) + create_type_decl (TYPE_NAME (gnu_type), gnu_type, true, + debug_info_p, gnat_entity); + } + + /* Now check if the type of the object allows atomic access. */ + if (Is_Full_Access (gnat_entity)) + check_ok_for_atomic_type (gnu_type, gnat_entity, false); + + /* If this is a renaming, avoid as much as possible to create a new + object. However, in some cases, creating it is required because + renaming can be applied to objects that are not names in Ada. + This processing needs to be applied to the raw expression so as + to make it more likely to rename the underlying object. */ + if (Present (gnat_renamed_obj)) + { + /* If the renamed object had padding, strip off the reference to + the inner object and reset our type. */ + if ((TREE_CODE (gnu_expr) == COMPONENT_REF + && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (gnu_expr, 0)))) + /* Strip useless conversions around the object. */ + || gnat_useless_type_conversion (gnu_expr)) + { + gnu_expr = TREE_OPERAND (gnu_expr, 0); + gnu_type = TREE_TYPE (gnu_expr); + } + + /* Or else, if the renamed object has an unconstrained type with + default discriminant, use the padded type. */ + else if (type_is_padding_self_referential (TREE_TYPE (gnu_expr))) + gnu_type = TREE_TYPE (gnu_expr); + + /* If this is a constant renaming stemming from a function call, + treat it as a normal object whose initial value is what is being + renamed. RM 3.3 says that the result of evaluating a function + call is a constant object. Therefore, it can be the inner + object of a constant renaming and the renaming must be fully + instantiated, i.e. it cannot be a reference to (part of) an + existing object. And treat other rvalues the same way. */ + tree inner = gnu_expr; + while (handled_component_p (inner) || CONVERT_EXPR_P (inner)) + inner = TREE_OPERAND (inner, 0); + /* Expand_Dispatching_Call can prepend a comparison of the tags + before the call to "=". */ + if (TREE_CODE (inner) == TRUTH_ANDIF_EXPR + || TREE_CODE (inner) == COMPOUND_EXPR) + inner = TREE_OPERAND (inner, 1); + if ((TREE_CODE (inner) == CALL_EXPR + && !call_is_atomic_load (inner)) + || TREE_CODE (inner) == CONSTRUCTOR + || CONSTANT_CLASS_P (inner) + || COMPARISON_CLASS_P (inner) + || BINARY_CLASS_P (inner) + || EXPRESSION_CLASS_P (inner) + /* We need to detect the case where a temporary is created to + hold the return value, since we cannot safely rename it at + top level as it lives only in the elaboration routine. */ + || (TREE_CODE (inner) == VAR_DECL + && DECL_RETURN_VALUE_P (inner)) + /* We also need to detect the case where the front-end creates + a dangling 'reference to a function call at top level and + substitutes it in the renaming, for example: + + q__b : boolean renames r__f.e (1); + + can be rewritten into: + + q__R1s : constant q__A2s := r__f'reference; + [...] + q__b : boolean renames q__R1s.all.e (1); + + We cannot safely rename the rewritten expression since the + underlying object lives only in the elaboration routine. */ + || (TREE_CODE (inner) == INDIRECT_REF + && (inner + = remove_conversions (TREE_OPERAND (inner, 0), true)) + && TREE_CODE (inner) == VAR_DECL + && DECL_RETURN_VALUE_P (inner))) + ; + + /* Otherwise, this is an lvalue being renamed, so it needs to be + elaborated as a reference and substituted for the entity. But + this means that we must evaluate the address of the renaming + in the definition case to instantiate the SAVE_EXPRs. */ + else + { + tree gnu_init = NULL_TREE; + + if (type_annotate_only && TREE_CODE (gnu_expr) == ERROR_MARK) + break; + + gnu_expr + = elaborate_reference (gnu_expr, gnat_entity, definition, + &gnu_init); + + /* No DECL_EXPR might be created so the expression needs to be + marked manually because it will likely be shared. */ + if (global_bindings_p ()) + MARK_VISITED (gnu_expr); + + /* This assertion will fail if the renamed object isn't aligned + enough as to make it possible to honor the alignment set on + the renaming. */ + if (align) + { + const unsigned int ralign + = DECL_P (gnu_expr) + ? DECL_ALIGN (gnu_expr) + : TYPE_ALIGN (TREE_TYPE (gnu_expr)); + gcc_assert (ralign >= align); + } + + /* The expression might not be a DECL so save it manually. */ + gnu_decl = gnu_expr; + save_gnu_tree (gnat_entity, gnu_decl, true); + saved = true; + annotate_object (gnat_entity, gnu_type, NULL_TREE, false); + + /* If this is only a reference to the entity, we are done. */ + if (!definition) + break; + + /* Otherwise, emit the initialization statement, if any. */ + if (gnu_init) + add_stmt (gnu_init); + + /* If it needs to be materialized for debugging purposes, build + the entity as indirect reference to the renamed object. */ + if (Materialize_Entity (gnat_entity)) + { + gnu_type = build_reference_type (gnu_type); + const_flag = true; + volatile_flag = false; + + gnu_expr = build_unary_op (ADDR_EXPR, gnu_type, gnu_expr); + + create_var_decl (gnu_entity_name, gnu_ext_name, + TREE_TYPE (gnu_expr), gnu_expr, + const_flag, Is_Public (gnat_entity), + imported_p, static_flag, volatile_flag, + artificial_p, debug_info_p, attr_list, + gnat_entity, false); + } + + /* Otherwise, instantiate the SAVE_EXPRs if needed. */ + else if (TREE_SIDE_EFFECTS (gnu_expr)) + add_stmt (build_unary_op (ADDR_EXPR, NULL_TREE, gnu_expr)); + + break; + } + } + + /* If we are defining an aliased object whose nominal subtype is + unconstrained, the object is a record that contains both the + template and the object. If there is an initializer, it will + have already been converted to the right type, but we need to + create the template if there is no initializer. */ + if (definition + && !gnu_expr + && TREE_CODE (gnu_type) == RECORD_TYPE + && (TYPE_CONTAINS_TEMPLATE_P (gnu_type) + /* Beware that padding might have been introduced above. */ + || (TYPE_PADDING_P (gnu_type) + && TREE_CODE (TREE_TYPE (TYPE_FIELDS (gnu_type))) + == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P + (TREE_TYPE (TYPE_FIELDS (gnu_type)))))) + { + tree template_field + = TYPE_PADDING_P (gnu_type) + ? TYPE_FIELDS (TREE_TYPE (TYPE_FIELDS (gnu_type))) + : TYPE_FIELDS (gnu_type); + vec<constructor_elt, va_gc> *v; + vec_alloc (v, 1); + tree t = build_template (TREE_TYPE (template_field), + TREE_TYPE (DECL_CHAIN (template_field)), + NULL_TREE); + CONSTRUCTOR_APPEND_ELT (v, template_field, t); + gnu_expr = gnat_build_constructor (gnu_type, v); + } + + /* Convert the expression to the type of the object if need be. */ + if (gnu_expr && initial_value_needs_conversion (gnu_type, gnu_expr)) + gnu_expr = convert (gnu_type, gnu_expr); + + /* If this is a pointer that doesn't have an initializing expression, + initialize it to NULL, unless the object is declared imported as + per RM B.1(24). */ + if (definition + && (POINTER_TYPE_P (gnu_type) || TYPE_IS_FAT_POINTER_P (gnu_type)) + && !gnu_expr + && !Is_Imported (gnat_entity)) + gnu_expr = integer_zero_node; + + /* If we are defining the object and it has an Address clause, we must + either get the address expression from the saved GCC tree for the + object if it has a Freeze node, or elaborate the address expression + here since the front-end has guaranteed that the elaboration has no + effects in this case. */ + if (definition && Present (Address_Clause (gnat_entity))) + { + const Node_Id gnat_clause = Address_Clause (gnat_entity); + const Node_Id gnat_address = Expression (gnat_clause); + tree gnu_address = present_gnu_tree (gnat_entity) + ? TREE_OPERAND (get_gnu_tree (gnat_entity), 0) + : gnat_to_gnu (gnat_address); + + save_gnu_tree (gnat_entity, NULL_TREE, false); + + /* Convert the type of the object to a reference type that can + alias everything as per RM 13.3(19). */ + if (volatile_flag && !TYPE_VOLATILE (gnu_type)) + gnu_type = change_qualified_type (gnu_type, TYPE_QUAL_VOLATILE); + gnu_type + = build_reference_type_for_mode (gnu_type, ptr_mode, true); + gnu_address = convert (gnu_type, gnu_address); + used_by_ref = true; + const_flag + = (!Is_Public (gnat_entity) + || compile_time_known_address_p (gnat_address)); + volatile_flag = false; + gnu_size = NULL_TREE; + + /* If this is an aliased object with an unconstrained array nominal + subtype, then it can overlay only another aliased object with an + unconstrained array nominal subtype and compatible template. */ + if (Is_Constr_Subt_For_UN_Aliased (gnat_type) + && Is_Array_Type (Underlying_Type (gnat_type)) + && !type_annotate_only) + { + tree rec_type = TREE_TYPE (gnu_type); + tree off = byte_position (DECL_CHAIN (TYPE_FIELDS (rec_type))); + + /* This is the pattern built for a regular object. */ + if (TREE_CODE (gnu_address) == POINTER_PLUS_EXPR + && TREE_OPERAND (gnu_address, 1) == off) + gnu_address = TREE_OPERAND (gnu_address, 0); + + /* This is the pattern built for an overaligned object. */ + else if (TREE_CODE (gnu_address) == POINTER_PLUS_EXPR + && TREE_CODE (TREE_OPERAND (gnu_address, 1)) + == PLUS_EXPR + && TREE_OPERAND (TREE_OPERAND (gnu_address, 1), 1) + == off) + gnu_address + = build2 (POINTER_PLUS_EXPR, gnu_type, + TREE_OPERAND (gnu_address, 0), + TREE_OPERAND (TREE_OPERAND (gnu_address, 1), 0)); + + /* We make an exception for an absolute address but we warn + that there is a descriptor at the start of the object. */ + else if (TREE_CODE (gnu_address) == INTEGER_CST) + { + post_error_ne ("??aliased object& with unconstrained " + "array nominal subtype", gnat_clause, + gnat_entity); + post_error ("\\starts with a descriptor whose size is " + "given by ''Descriptor_Size", gnat_clause); + } + + else + { + post_error_ne ("aliased object& with unconstrained array " + "nominal subtype", gnat_clause, + gnat_entity); + post_error ("\\can overlay only aliased object with " + "compatible subtype", gnat_clause); + } + } + + /* If we don't have an initializing expression for the underlying + variable, the initializing expression for the pointer is the + specified address. Otherwise, we have to make a COMPOUND_EXPR + to assign both the address and the initial value. */ + if (!gnu_expr) + gnu_expr = gnu_address; + else + gnu_expr + = build2 (COMPOUND_EXPR, gnu_type, + build_binary_op (INIT_EXPR, NULL_TREE, + build_unary_op (INDIRECT_REF, + NULL_TREE, + gnu_address), + gnu_expr), + gnu_address); + } + + /* If it has an address clause and we are not defining it, mark it + as an indirect object. Likewise for Stdcall objects that are + imported. */ + if ((!definition && Present (Address_Clause (gnat_entity))) + || (imported_p && Has_Stdcall_Convention (gnat_entity))) + { + /* Convert the type of the object to a reference type that can + alias everything as per RM 13.3(19). */ + if (volatile_flag && !TYPE_VOLATILE (gnu_type)) + gnu_type = change_qualified_type (gnu_type, TYPE_QUAL_VOLATILE); + gnu_type + = build_reference_type_for_mode (gnu_type, ptr_mode, true); + used_by_ref = true; + const_flag = false; + volatile_flag = false; + gnu_size = NULL_TREE; + + /* No point in taking the address of an initializing expression + that isn't going to be used. */ + gnu_expr = NULL_TREE; + + /* If it has an address clause whose value is known at compile + time, make the object a CONST_DECL. This will avoid a + useless dereference. */ + if (Present (Address_Clause (gnat_entity))) + { + Node_Id gnat_address + = Expression (Address_Clause (gnat_entity)); + + if (compile_time_known_address_p (gnat_address)) + { + gnu_expr = gnat_to_gnu (gnat_address); + const_flag = true; + } + } + } + + /* If we are at top level and this object is of variable size, + make the actual type a hidden pointer to the real type and + make the initializer be a memory allocation and initialization. + Likewise for objects we aren't defining (presumed to be + external references from other packages), but there we do + not set up an initialization. + + If the object's size overflows, make an allocator too, so that + Storage_Error gets raised. Note that we will never free + such memory, so we presume it never will get allocated. */ + if (!allocatable_size_p (TYPE_SIZE_UNIT (gnu_type), + global_bindings_p () + || !definition + || static_flag) + || (gnu_size + && !allocatable_size_p (convert (sizetype, + size_binop + (EXACT_DIV_EXPR, gnu_size, + bitsize_unit_node)), + global_bindings_p () + || !definition + || static_flag))) + { + if (volatile_flag && !TYPE_VOLATILE (gnu_type)) + gnu_type = change_qualified_type (gnu_type, TYPE_QUAL_VOLATILE); + gnu_type = build_reference_type (gnu_type); + used_by_ref = true; + const_flag = true; + volatile_flag = false; + gnu_size = NULL_TREE; + + /* In case this was a aliased object whose nominal subtype is + unconstrained, the pointer above will be a thin pointer and + build_allocator will automatically make the template. + + If we have a template initializer only (that we made above), + pretend there is none and rely on what build_allocator creates + again anyway. Otherwise (if we have a full initializer), get + the data part and feed that to build_allocator. + + If we are elaborating a mutable object, tell build_allocator to + ignore a possibly simpler size from the initializer, if any, as + we must allocate the maximum possible size in this case. */ + if (definition && !imported_p) + { + tree gnu_alloc_type = TREE_TYPE (gnu_type); + + if (TREE_CODE (gnu_alloc_type) == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P (gnu_alloc_type)) + { + gnu_alloc_type + = TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (gnu_alloc_type))); + + if (TREE_CODE (gnu_expr) == CONSTRUCTOR + && CONSTRUCTOR_NELTS (gnu_expr) == 1) + gnu_expr = NULL_TREE; + else + gnu_expr + = build_component_ref + (gnu_expr, + DECL_CHAIN (TYPE_FIELDS (TREE_TYPE (gnu_expr))), + false); + } + + if (TREE_CODE (TYPE_SIZE_UNIT (gnu_alloc_type)) == INTEGER_CST + && !valid_constant_size_p (TYPE_SIZE_UNIT (gnu_alloc_type))) + post_error ("??Storage_Error will be raised at run time!", + gnat_entity); + + gnu_expr + = build_allocator (gnu_alloc_type, gnu_expr, gnu_type, + Empty, Empty, gnat_entity, mutable_p); + } + else + gnu_expr = NULL_TREE; + } + + /* If this object would go into the stack and has an alignment larger + than the largest stack alignment the back-end can honor, resort to + a variable of "aligning type". */ + if (definition + && TYPE_ALIGN (gnu_type) > BIGGEST_ALIGNMENT + && !imported_p + && !static_flag + && !global_bindings_p ()) + { + /* Create the new variable. No need for extra room before the + aligned field as this is in automatic storage. */ + tree gnu_new_type + = make_aligning_type (gnu_type, TYPE_ALIGN (gnu_type), + TYPE_SIZE_UNIT (gnu_type), + BIGGEST_ALIGNMENT, 0, gnat_entity); + tree gnu_new_var + = create_var_decl (create_concat_name (gnat_entity, "ALIGN"), + NULL_TREE, gnu_new_type, NULL_TREE, + false, false, false, false, false, + true, debug_info_p && definition, NULL, + gnat_entity); + + /* Initialize the aligned field if we have an initializer. */ + if (gnu_expr) + add_stmt_with_node + (build_binary_op (INIT_EXPR, NULL_TREE, + build_component_ref + (gnu_new_var, TYPE_FIELDS (gnu_new_type), + false), + gnu_expr), + gnat_entity); + + /* And setup this entity as a reference to the aligned field. */ + gnu_type = build_reference_type (gnu_type); + gnu_expr + = build_unary_op + (ADDR_EXPR, NULL_TREE, + build_component_ref (gnu_new_var, TYPE_FIELDS (gnu_new_type), + false)); + TREE_CONSTANT (gnu_expr) = 1; + + used_by_ref = true; + const_flag = true; + volatile_flag = false; + gnu_size = NULL_TREE; + } + + /* If this is an aggregate constant initialized to a constant, force it + to be statically allocated. This saves an initialization copy. */ + if (!static_flag + && const_flag + && gnu_expr + && TREE_CONSTANT (gnu_expr) + && AGGREGATE_TYPE_P (gnu_type) + && tree_fits_uhwi_p (TYPE_SIZE_UNIT (gnu_type)) + && !(TYPE_IS_PADDING_P (gnu_type) + && !tree_fits_uhwi_p (TYPE_SIZE_UNIT + (TREE_TYPE (TYPE_FIELDS (gnu_type)))))) + static_flag = true; + + /* If this is an aliased object with an unconstrained array nominal + subtype, we make its type a thin reference, i.e. the reference + counterpart of a thin pointer, so it points to the array part. + This is aimed to make it easier for the debugger to decode the + object. Note that we have to do it this late because of the + couple of allocation adjustments that might be made above. */ + if (Is_Constr_Subt_For_UN_Aliased (gnat_type) + && Is_Array_Type (Underlying_Type (gnat_type)) + && !type_annotate_only) + { + /* In case the object with the template has already been allocated + just above, we have nothing to do here. */ + if (!TYPE_IS_THIN_POINTER_P (gnu_type)) + { + /* This variable is a GNAT encoding used by Workbench: let it + go through the debugging information but mark it as + artificial: users are not interested in it. */ + tree gnu_unc_var + = create_var_decl (concat_name (gnu_entity_name, "UNC"), + NULL_TREE, gnu_type, gnu_expr, + const_flag, Is_Public (gnat_entity), + imported_p || !definition, static_flag, + volatile_flag, true, + debug_info_p && definition, + NULL, gnat_entity); + gnu_expr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_unc_var); + TREE_CONSTANT (gnu_expr) = 1; + + used_by_ref = true; + const_flag = true; + volatile_flag = false; + inner_const_flag = TREE_READONLY (gnu_unc_var); + gnu_size = NULL_TREE; + } + + tree gnu_array = gnat_to_gnu_type (Base_Type (gnat_type)); + gnu_type + = build_reference_type (TYPE_OBJECT_RECORD_TYPE (gnu_array)); + } + + /* Convert the expression to the type of the object if need be. */ + if (gnu_expr && initial_value_needs_conversion (gnu_type, gnu_expr)) + gnu_expr = convert (gnu_type, gnu_expr); + + /* If this name is external or a name was specified, use it, but don't + use the Interface_Name with an address clause (see cd30005). */ + if ((Is_Public (gnat_entity) && !Is_Imported (gnat_entity)) + || (Present (Interface_Name (gnat_entity)) + && No (Address_Clause (gnat_entity)))) + gnu_ext_name = create_concat_name (gnat_entity, NULL); + + /* Deal with a pragma Linker_Section on a constant or variable. */ + if ((kind == E_Constant || kind == E_Variable) + && Present (Linker_Section_Pragma (gnat_entity))) + prepend_one_attribute_pragma (&attr_list, + Linker_Section_Pragma (gnat_entity)); + + /* Now create the variable or the constant and set various flags. */ + gnu_decl + = create_var_decl (gnu_entity_name, gnu_ext_name, gnu_type, + gnu_expr, const_flag, Is_Public (gnat_entity), + imported_p || !definition, static_flag, + volatile_flag, artificial_p, + debug_info_p && definition, attr_list, + gnat_entity); + DECL_BY_REF_P (gnu_decl) = used_by_ref; + DECL_POINTS_TO_READONLY_P (gnu_decl) = used_by_ref && inner_const_flag; + DECL_CAN_NEVER_BE_NULL_P (gnu_decl) = Can_Never_Be_Null (gnat_entity); + + /* If we are defining an Out parameter and optimization isn't enabled, + create a fake PARM_DECL for debugging purposes and make it point to + the VAR_DECL. Suppress debug info for the latter but make sure it + will live in memory so that it can be accessed from within the + debugger through the PARM_DECL. */ + if (kind == E_Out_Parameter + && definition + && debug_info_p + && !optimize + && !flag_generate_lto) + { + tree param = create_param_decl (gnu_entity_name, gnu_type); + gnat_pushdecl (param, gnat_entity); + SET_DECL_VALUE_EXPR (param, gnu_decl); + DECL_HAS_VALUE_EXPR_P (param) = 1; + DECL_IGNORED_P (gnu_decl) = 1; + TREE_ADDRESSABLE (gnu_decl) = 1; + } + + /* If this is a loop parameter, set the corresponding flag. */ + else if (kind == E_Loop_Parameter) + DECL_LOOP_PARM_P (gnu_decl) = 1; + + /* If this is a constant and we are defining it or it generates a real + symbol at the object level and we are referencing it, we may want + or need to have a true variable to represent it: + - if the constant is public and not overlaid on something else, + - if its address is taken, + - if it is aliased, + - if optimization isn't enabled, for debugging purposes. */ + if (TREE_CODE (gnu_decl) == CONST_DECL + && (definition || Sloc (gnat_entity) > Standard_Location) + && ((Is_Public (gnat_entity) && No (Address_Clause (gnat_entity))) + || Address_Taken (gnat_entity) + || Is_Aliased (gnat_entity) + || (!optimize && debug_info_p))) + { + tree gnu_corr_var + = create_var_decl (gnu_entity_name, gnu_ext_name, gnu_type, + gnu_expr, true, Is_Public (gnat_entity), + !definition, static_flag, volatile_flag, + artificial_p, debug_info_p && definition, + attr_list, gnat_entity, false); + + SET_DECL_CONST_CORRESPONDING_VAR (gnu_decl, gnu_corr_var); + DECL_IGNORED_P (gnu_decl) = 1; + } + + /* If this is a constant, even if we don't need a true variable, we + may need to avoid returning the initializer in every case. That + can happen for the address of a (constant) constructor because, + upon dereferencing it, the constructor will be reinjected in the + tree, which may not be valid in every case; see lvalue_required_p + for more details. */ + if (TREE_CODE (gnu_decl) == CONST_DECL) + DECL_CONST_ADDRESS_P (gnu_decl) = constructor_address_p (gnu_expr); + + /* If this object is declared in a block that contains a block with an + exception handler, and we aren't using the GCC exception mechanism, + we must force this variable in memory in order to avoid an invalid + optimization. */ + if (Front_End_Exceptions () + && Has_Nested_Block_With_Handler (Scope (gnat_entity))) + TREE_ADDRESSABLE (gnu_decl) = 1; + + /* If this is a local variable with non-BLKmode and aggregate type, + and optimization isn't enabled, then force it in memory so that + a register won't be allocated to it with possible subparts left + uninitialized and reaching the register allocator. */ + else if (TREE_CODE (gnu_decl) == VAR_DECL + && !DECL_EXTERNAL (gnu_decl) + && !TREE_STATIC (gnu_decl) + && DECL_MODE (gnu_decl) != BLKmode + && AGGREGATE_TYPE_P (TREE_TYPE (gnu_decl)) + && !TYPE_IS_FAT_POINTER_P (TREE_TYPE (gnu_decl)) + && !optimize) + TREE_ADDRESSABLE (gnu_decl) = 1; + + /* If we are defining an object with variable size or an object with + fixed size that will be dynamically allocated, and we are using the + front-end setjmp/longjmp exception mechanism, update the setjmp + buffer. */ + if (definition + && Exception_Mechanism == Front_End_SJLJ + && get_block_jmpbuf_decl () + && DECL_SIZE_UNIT (gnu_decl) + && (TREE_CODE (DECL_SIZE_UNIT (gnu_decl)) != INTEGER_CST + || (flag_stack_check == GENERIC_STACK_CHECK + && compare_tree_int (DECL_SIZE_UNIT (gnu_decl), + STACK_CHECK_MAX_VAR_SIZE) > 0))) + add_stmt_with_node (build_call_n_expr + (update_setjmp_buf_decl, 1, + build_unary_op (ADDR_EXPR, NULL_TREE, + get_block_jmpbuf_decl ())), + gnat_entity); + + /* Back-annotate Esize and Alignment of the object if not already + known. Note that we pick the values of the type, not those of + the object, to shield ourselves from low-level platform-dependent + adjustments like alignment promotion. This is both consistent with + all the treatment above, where alignment and size are set on the + type of the object and not on the object directly, and makes it + possible to support all confirming representation clauses. */ + annotate_object (gnat_entity, TREE_TYPE (gnu_decl), gnu_object_size, + used_by_ref); + } + break; + + case E_Void: + /* Return a TYPE_DECL for "void" that we previously made. */ + gnu_decl = TYPE_NAME (void_type_node); + break; + + case E_Enumeration_Type: + /* A special case: for the types Character and Wide_Character in + Standard, we do not list all the literals. So if the literals + are not specified, make this an integer type. */ + if (No (First_Literal (gnat_entity))) + { + if (esize == CHAR_TYPE_SIZE && flag_signed_char) + gnu_type = make_signed_type (CHAR_TYPE_SIZE); + else + gnu_type = make_unsigned_type (esize); + TYPE_NAME (gnu_type) = gnu_entity_name; + + /* Set TYPE_STRING_FLAG for Character and Wide_Character types. + This is needed by the DWARF-2 back-end to distinguish between + unsigned integer types and character types. */ + TYPE_STRING_FLAG (gnu_type) = 1; + + /* This flag is needed by the call just below. */ + TYPE_ARTIFICIAL (gnu_type) = artificial_p; + + finish_character_type (gnu_type); + } + else + { + /* We have a list of enumeral constants in First_Literal. We make a + CONST_DECL for each one and build into GNU_LITERAL_LIST the list + to be placed into TYPE_FIELDS. Each node is itself a TREE_LIST + whose TREE_VALUE is the literal name and whose TREE_PURPOSE is the + value of the literal. But when we have a regular boolean type, we + simplify this a little by using a BOOLEAN_TYPE. */ + const bool is_boolean = Is_Boolean_Type (gnat_entity) + && !Has_Non_Standard_Rep (gnat_entity); + const bool is_unsigned = Is_Unsigned_Type (gnat_entity); + tree gnu_list = NULL_TREE; + Entity_Id gnat_literal; + + /* Boolean types with foreign convention have precision 1. */ + if (is_boolean && foreign) + esize = 1; + + gnu_type = make_node (is_boolean ? BOOLEAN_TYPE : ENUMERAL_TYPE); + TYPE_PRECISION (gnu_type) = esize; + TYPE_UNSIGNED (gnu_type) = is_unsigned; + set_min_and_max_values_for_integral_type (gnu_type, esize, + TYPE_SIGN (gnu_type)); + process_attributes (&gnu_type, &attr_list, true, gnat_entity); + layout_type (gnu_type); + + for (gnat_literal = First_Literal (gnat_entity); + Present (gnat_literal); + gnat_literal = Next_Literal (gnat_literal)) + { + tree gnu_value + = UI_To_gnu (Enumeration_Rep (gnat_literal), gnu_type); + /* Do not generate debug info for individual enumerators. */ + tree gnu_literal + = create_var_decl (get_entity_name (gnat_literal), NULL_TREE, + gnu_type, gnu_value, true, false, false, + false, false, artificial_p, false, + NULL, gnat_literal); + save_gnu_tree (gnat_literal, gnu_literal, false); + gnu_list + = tree_cons (DECL_NAME (gnu_literal), gnu_value, gnu_list); + } + + if (!is_boolean) + TYPE_VALUES (gnu_type) = nreverse (gnu_list); + + /* Note that the bounds are updated at the end of this function + to avoid an infinite recursion since they refer to the type. */ + goto discrete_type; + } + break; + + case E_Signed_Integer_Type: + /* For integer types, just make a signed type the appropriate number + of bits. */ + gnu_type = make_signed_type (esize); + goto discrete_type; + + case E_Ordinary_Fixed_Point_Type: + case E_Decimal_Fixed_Point_Type: + { + /* Small_Value is the scale factor. */ + const Ureal gnat_small_value = Small_Value (gnat_entity); + tree scale_factor = NULL_TREE; + + gnu_type = make_signed_type (esize); + + /* When encoded as 1/2**N or 1/10**N, describe the scale factor as a + binary or decimal scale: it is easier to read for humans. */ + if (UI_Eq (Numerator (gnat_small_value), Uint_1) + && (Rbase (gnat_small_value) == 2 + || Rbase (gnat_small_value) == 10)) + { + tree base + = build_int_cst (integer_type_node, Rbase (gnat_small_value)); + tree exponent + = build_int_cst (integer_type_node, + UI_To_Int (Denominator (gnat_small_value))); + scale_factor + = build2 (RDIV_EXPR, integer_type_node, + integer_one_node, + build2 (POWER_EXPR, integer_type_node, + base, exponent)); + } + + /* Use the arbitrary scale factor description. Note that we support + a Small_Value whose magnitude is larger than 64-bit even on 32-bit + platforms, so we unconditionally use a (dummy) 128-bit type. */ + else + { + const Uint gnat_num = Norm_Num (gnat_small_value); + const Uint gnat_den = Norm_Den (gnat_small_value); + tree gnu_small_type = make_unsigned_type (128); + tree gnu_num = UI_To_gnu (gnat_num, gnu_small_type); + tree gnu_den = UI_To_gnu (gnat_den, gnu_small_type); + + scale_factor + = build2 (RDIV_EXPR, gnu_small_type, gnu_num, gnu_den); + } + + TYPE_FIXED_POINT_P (gnu_type) = 1; + SET_TYPE_SCALE_FACTOR (gnu_type, scale_factor); + } + goto discrete_type; + + case E_Modular_Integer_Type: + { + /* Packed Array Impl. Types are supposed to be subtypes only. */ + gcc_assert (!Is_Packed_Array_Impl_Type (gnat_entity)); + + /* For modular types, make the unsigned type of the proper number + of bits and then set up the modulus, if required. */ + gnu_type = make_unsigned_type (esize); + + /* Get the modulus in this type. If the modulus overflows, assume + that this is because it was equal to 2**Esize. Note that there + is no overflow checking done on unsigned types, so we detect the + overflow by looking for a modulus of zero, which is invalid. */ + tree gnu_modulus = UI_To_gnu (Modulus (gnat_entity), gnu_type); + + /* If the modulus is not 2**Esize, then this also means that the upper + bound of the type, i.e. modulus - 1, is not maximal, so we create an + extra subtype to carry it and set the modulus on the base type. */ + if (!integer_zerop (gnu_modulus)) + { + TYPE_NAME (gnu_type) = create_concat_name (gnat_entity, "UMT"); + TYPE_MODULAR_P (gnu_type) = 1; + SET_TYPE_MODULUS (gnu_type, gnu_modulus); + tree gnu_high = fold_build2 (MINUS_EXPR, gnu_type, gnu_modulus, + build_int_cst (gnu_type, 1)); + gnu_type + = create_extra_subtype (gnu_type, TYPE_MIN_VALUE (gnu_type), + gnu_high); + } + } + goto discrete_type; + + case E_Signed_Integer_Subtype: + case E_Enumeration_Subtype: + case E_Modular_Integer_Subtype: + case E_Ordinary_Fixed_Point_Subtype: + case E_Decimal_Fixed_Point_Subtype: + + /* For integral subtypes, we make a new INTEGER_TYPE. Note that we do + not want to call create_range_type since we would like each subtype + node to be distinct. ??? Historically this was in preparation for + when memory aliasing is implemented, but that's obsolete now given + the call to relate_alias_sets below. + + The TREE_TYPE field of the INTEGER_TYPE points to the base type; + this fact is used by the arithmetic conversion functions. + + We elaborate the Ancestor_Subtype if it is not in the current unit + and one of our bounds is non-static. We do this to ensure consistent + naming in the case where several subtypes share the same bounds, by + elaborating the first such subtype first, thus using its name. */ + + if (!definition + && Present (Ancestor_Subtype (gnat_entity)) + && !In_Extended_Main_Code_Unit (Ancestor_Subtype (gnat_entity)) + && (!Compile_Time_Known_Value (Type_Low_Bound (gnat_entity)) + || !Compile_Time_Known_Value (Type_High_Bound (gnat_entity)))) + gnat_to_gnu_entity (Ancestor_Subtype (gnat_entity), gnu_expr, false); + + /* Set the precision to the Esize except for bit-packed arrays. */ + if (Is_Packed_Array_Impl_Type (gnat_entity)) + esize = UI_To_Int (RM_Size (gnat_entity)); + + /* Boolean types with foreign convention have precision 1. */ + if (Is_Boolean_Type (gnat_entity) && foreign) + { + gnu_type = make_node (BOOLEAN_TYPE); + TYPE_PRECISION (gnu_type) = 1; + TYPE_UNSIGNED (gnu_type) = 1; + set_min_and_max_values_for_integral_type (gnu_type, 1, UNSIGNED); + layout_type (gnu_type); + } + /* First subtypes of Character are treated as Character; otherwise + this should be an unsigned type if the base type is unsigned or + if the lower bound is constant and non-negative or if the type + is biased. However, even if the lower bound is constant and + non-negative, we use a signed type for a subtype with the same + size as its signed base type, because this eliminates useless + conversions to it and gives more leeway to the optimizer; but + this means that we will need to explicitly test for this case + when we change the representation based on the RM size. */ + else if (kind == E_Enumeration_Subtype + && No (First_Literal (Etype (gnat_entity))) + && Esize (gnat_entity) == RM_Size (gnat_entity) + && esize == CHAR_TYPE_SIZE + && flag_signed_char) + gnu_type = make_signed_type (CHAR_TYPE_SIZE); + else if (Is_Unsigned_Type (Underlying_Type (Etype (gnat_entity))) + || (Esize (Etype (gnat_entity)) != Esize (gnat_entity) + && Is_Unsigned_Type (gnat_entity)) + || Has_Biased_Representation (gnat_entity)) + gnu_type = make_unsigned_type (esize); + else + gnu_type = make_signed_type (esize); + TREE_TYPE (gnu_type) = get_unpadded_type (Etype (gnat_entity)); + + SET_TYPE_RM_MIN_VALUE + (gnu_type, elaborate_expression (Type_Low_Bound (gnat_entity), + gnat_entity, "L", definition, true, + debug_info_p)); + + SET_TYPE_RM_MAX_VALUE + (gnu_type, elaborate_expression (Type_High_Bound (gnat_entity), + gnat_entity, "U", definition, true, + debug_info_p)); + + if (TREE_CODE (gnu_type) == INTEGER_TYPE) + TYPE_BIASED_REPRESENTATION_P (gnu_type) + = Has_Biased_Representation (gnat_entity); + + /* Do the same processing for Character subtypes as for types. */ + if (TREE_CODE (TREE_TYPE (gnu_type)) == INTEGER_TYPE + && TYPE_STRING_FLAG (TREE_TYPE (gnu_type))) + { + TYPE_NAME (gnu_type) = gnu_entity_name; + TYPE_STRING_FLAG (gnu_type) = 1; + TYPE_ARTIFICIAL (gnu_type) = artificial_p; + finish_character_type (gnu_type); + } + + /* Inherit our alias set from what we're a subtype of. Subtypes + are not different types and a pointer can designate any instance + within a subtype hierarchy. */ + relate_alias_sets (gnu_type, TREE_TYPE (gnu_type), ALIAS_SET_COPY); + + /* One of the above calls might have caused us to be elaborated, + so don't blow up if so. */ + if (present_gnu_tree (gnat_entity)) + { + maybe_present = true; + break; + } + + /* Attach the TYPE_STUB_DECL in case we have a parallel type. */ + TYPE_STUB_DECL (gnu_type) + = create_type_stub_decl (gnu_entity_name, gnu_type); + + discrete_type: + + /* We have to handle clauses that under-align the type specially. */ + if ((Present (Alignment_Clause (gnat_entity)) + || (Is_Packed_Array_Impl_Type (gnat_entity) + && Present + (Alignment_Clause (Original_Array_Type (gnat_entity))))) + && UI_Is_In_Int_Range (Alignment (gnat_entity))) + { + align = UI_To_Int (Alignment (gnat_entity)) * BITS_PER_UNIT; + if (align >= TYPE_ALIGN (gnu_type)) + align = 0; + } + + /* If the type we are dealing with represents a bit-packed array, + we need to have the bits left justified on big-endian targets + and right justified on little-endian targets. We also need to + ensure that when the value is read (e.g. for comparison of two + such values), we only get the good bits, since the unused bits + are uninitialized. Both goals are accomplished by wrapping up + the modular type in an enclosing record type. */ + if (Is_Packed_Array_Impl_Type (gnat_entity)) + { + tree gnu_field_type, gnu_field, t; + + gcc_assert (Is_Bit_Packed_Array (Original_Array_Type (gnat_entity))); + TYPE_BIT_PACKED_ARRAY_TYPE_P (gnu_type) = 1; + + /* Make the original array type a parallel/debug type. */ + if (debug_info_p) + { + tree gnu_name + = associate_original_type_to_packed_array (gnu_type, + gnat_entity); + if (gnu_name) + gnu_entity_name = gnu_name; + } + + /* Set the RM size before wrapping up the original type. */ + SET_TYPE_RM_SIZE (gnu_type, + UI_To_gnu (RM_Size (gnat_entity), bitsizetype)); + + /* Create a stripped-down declaration, mainly for debugging. */ + t = create_type_decl (gnu_entity_name, gnu_type, true, debug_info_p, + gnat_entity); + + /* Now save it and build the enclosing record type. */ + gnu_field_type = gnu_type; + + gnu_type = make_node (RECORD_TYPE); + TYPE_NAME (gnu_type) = create_concat_name (gnat_entity, "JM"); + TYPE_PACKED (gnu_type) = 1; + TYPE_SIZE (gnu_type) = TYPE_SIZE (gnu_field_type); + TYPE_SIZE_UNIT (gnu_type) = TYPE_SIZE_UNIT (gnu_field_type); + SET_TYPE_ADA_SIZE (gnu_type, TYPE_RM_SIZE (gnu_field_type)); + + /* Propagate the alignment of the modular type to the record type, + unless there is an alignment clause that under-aligns the type. + This means that bit-packed arrays are given "ceil" alignment for + their size by default, which may seem counter-intuitive but makes + it possible to overlay them on modular types easily. */ + SET_TYPE_ALIGN (gnu_type, + align > 0 ? align : TYPE_ALIGN (gnu_field_type)); + + /* Propagate the reverse storage order flag to the record type so + that the required byte swapping is performed when retrieving the + enclosed modular value. */ + TYPE_REVERSE_STORAGE_ORDER (gnu_type) + = Reverse_Storage_Order (Original_Array_Type (gnat_entity)); + + relate_alias_sets (gnu_type, gnu_field_type, ALIAS_SET_COPY); + + /* Don't declare the field as addressable since we won't be taking + its address and this would prevent create_field_decl from making + a bitfield. */ + gnu_field + = create_field_decl (get_identifier ("OBJECT"), gnu_field_type, + gnu_type, NULL_TREE, bitsize_zero_node, 1, 0); + + /* We will output additional debug info manually below. */ + finish_record_type (gnu_type, gnu_field, 2, false); + TYPE_JUSTIFIED_MODULAR_P (gnu_type) = 1; + + /* Make the original array type a parallel/debug type. Note that + gnat_get_array_descr_info needs a TYPE_IMPL_PACKED_ARRAY_P type + so we use an intermediate step for standard DWARF. */ + if (debug_info_p) + { + if (gnat_encodings != DWARF_GNAT_ENCODINGS_ALL) + SET_TYPE_DEBUG_TYPE (gnu_type, gnu_field_type); + else if (DECL_PARALLEL_TYPE (t)) + add_parallel_type (gnu_type, DECL_PARALLEL_TYPE (t)); + } + } + + /* If the type we are dealing with has got a smaller alignment than the + natural one, we need to wrap it up in a record type and misalign the + latter; we reuse the padding machinery for this purpose. */ + else if (align > 0) + { + tree gnu_size = UI_To_gnu (RM_Size (gnat_entity), bitsizetype); + + /* Set the RM size before wrapping the type. */ + SET_TYPE_RM_SIZE (gnu_type, gnu_size); + + /* Create a stripped-down declaration, mainly for debugging. */ + create_type_decl (gnu_entity_name, gnu_type, true, debug_info_p, + gnat_entity); + + gnu_type + = maybe_pad_type (gnu_type, TYPE_SIZE (gnu_type), align, + gnat_entity, false, definition, false); + + TYPE_PACKED (gnu_type) = 1; + SET_TYPE_ADA_SIZE (gnu_type, gnu_size); + } + + break; + + case E_Floating_Point_Type: + /* The type of the Low and High bounds can be our type if this is + a type from Standard, so set them at the end of the function. */ + gnu_type = make_node (REAL_TYPE); + TYPE_PRECISION (gnu_type) = fp_size_to_prec (esize); + layout_type (gnu_type); + break; + + case E_Floating_Point_Subtype: + /* See the E_Signed_Integer_Subtype case for the rationale. */ + if (!definition + && Present (Ancestor_Subtype (gnat_entity)) + && !In_Extended_Main_Code_Unit (Ancestor_Subtype (gnat_entity)) + && (!Compile_Time_Known_Value (Type_Low_Bound (gnat_entity)) + || !Compile_Time_Known_Value (Type_High_Bound (gnat_entity)))) + gnat_to_gnu_entity (Ancestor_Subtype (gnat_entity), gnu_expr, false); + + gnu_type = make_node (REAL_TYPE); + TREE_TYPE (gnu_type) = get_unpadded_type (Etype (gnat_entity)); + TYPE_PRECISION (gnu_type) = fp_size_to_prec (esize); + TYPE_GCC_MIN_VALUE (gnu_type) + = TYPE_GCC_MIN_VALUE (TREE_TYPE (gnu_type)); + TYPE_GCC_MAX_VALUE (gnu_type) + = TYPE_GCC_MAX_VALUE (TREE_TYPE (gnu_type)); + layout_type (gnu_type); + + SET_TYPE_RM_MIN_VALUE + (gnu_type, elaborate_expression (Type_Low_Bound (gnat_entity), + gnat_entity, "L", definition, true, + debug_info_p)); + + SET_TYPE_RM_MAX_VALUE + (gnu_type, elaborate_expression (Type_High_Bound (gnat_entity), + gnat_entity, "U", definition, true, + debug_info_p)); + + /* Inherit our alias set from what we're a subtype of, as for + integer subtypes. */ + relate_alias_sets (gnu_type, TREE_TYPE (gnu_type), ALIAS_SET_COPY); + + /* One of the above calls might have caused us to be elaborated, + so don't blow up if so. */ + maybe_present = true; + break; + + /* Array Types and Subtypes + + In GNAT unconstrained array types are represented by E_Array_Type and + constrained array types are represented by E_Array_Subtype. They are + translated into UNCONSTRAINED_ARRAY_TYPE and ARRAY_TYPE respectively. + But there are no actual objects of an unconstrained array type; all we + have are pointers to that type. In addition to the type node itself, + 4 other types associated with it are built in the process: + + 1. the array type (suffix XUA) containing the actual data, + + 2. the template type (suffix XUB) containng the bounds, + + 3. the fat pointer type (suffix XUP) representing a pointer or a + reference to the unconstrained array type: + XUP = struct { XUA *, XUB * } + + 4. the object record type (suffix XUT) containing bounds and data: + XUT = struct { XUB, XUA } + + The bounds of the array type XUA (de)reference the XUB * field of a + PLACEHOLDER_EXPR for the fat pointer type XUP, so the array type XUA + is to be interpreted in the context of the fat pointer type XUB for + debug info purposes. */ + + case E_Array_Type: + { + const Entity_Id PAT = Packed_Array_Impl_Type (gnat_entity); + const bool convention_fortran_p + = (Convention (gnat_entity) == Convention_Fortran); + const int ndim = Number_Dimensions (gnat_entity); + tree gnu_template_type; + tree gnu_ptr_template; + tree gnu_template_reference, gnu_template_fields, gnu_fat_type; + tree *gnu_index_types = XALLOCAVEC (tree, ndim); + tree *gnu_temp_fields = XALLOCAVEC (tree, ndim); + tree gnu_max_size = size_one_node, tem, obj; + Entity_Id gnat_index; + int index; + tree comp_type; + + /* Create the type for the component now, as it simplifies breaking + type reference loops. */ + comp_type + = gnat_to_gnu_component_type (gnat_entity, definition, debug_info_p); + if (present_gnu_tree (gnat_entity)) + { + /* As a side effect, the type may have been translated. */ + maybe_present = true; + break; + } + + /* We complete an existing dummy fat pointer type in place. This both + avoids further complex adjustments in update_pointer_to and yields + better debugging information in DWARF by leveraging the support for + incomplete declarations of "tagged" types in the DWARF back-end. */ + gnu_type = get_dummy_type (gnat_entity); + if (gnu_type && TYPE_POINTER_TO (gnu_type)) + { + gnu_fat_type = TYPE_MAIN_VARIANT (TYPE_POINTER_TO (gnu_type)); + TYPE_NAME (gnu_fat_type) = NULL_TREE; + gnu_ptr_template = + TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (gnu_fat_type))); + gnu_template_type = TREE_TYPE (gnu_ptr_template); + + /* Save the contents of the dummy type for update_pointer_to. */ + TYPE_POINTER_TO (gnu_type) = copy_type (gnu_fat_type); + TYPE_FIELDS (TYPE_POINTER_TO (gnu_type)) + = copy_node (TYPE_FIELDS (gnu_fat_type)); + DECL_CHAIN (TYPE_FIELDS (TYPE_POINTER_TO (gnu_type))) + = copy_node (DECL_CHAIN (TYPE_FIELDS (gnu_fat_type))); + } + else + { + gnu_fat_type = make_node (RECORD_TYPE); + gnu_template_type = make_node (RECORD_TYPE); + gnu_ptr_template = build_pointer_type (gnu_template_type); + } + + /* Make a node for the array. If we are not defining the array + suppress expanding incomplete types. */ + gnu_type = make_node (UNCONSTRAINED_ARRAY_TYPE); + + if (!definition) + { + defer_incomplete_level++; + this_deferred = true; + } + + /* Build the fat pointer type. Use a "void *" object instead of + a pointer to the array type since we don't have the array type + yet (it will reference the fat pointer via the bounds). Note + that we reuse the existing fields of a dummy type because for: + + type Arr is array (Positive range <>) of Element_Type; + type Array_Ref is access Arr; + Var : Array_Ref := Null; + + in a declarative part, Arr will be frozen only after Var, which + means that the fields used in the CONSTRUCTOR built for Null are + those of the dummy type, which in turn means that COMPONENT_REFs + of Var may be built with these fields. Now if COMPONENT_REFs of + Var are also built later with the fields of the final type, the + aliasing machinery may consider that the accesses are distinct + if the FIELD_DECLs are distinct as objects. */ + if (COMPLETE_TYPE_P (gnu_fat_type)) + { + tem = TYPE_FIELDS (gnu_fat_type); + TREE_TYPE (tem) = ptr_type_node; + TREE_TYPE (DECL_CHAIN (tem)) = gnu_ptr_template; + TYPE_DECL_SUPPRESS_DEBUG (TYPE_STUB_DECL (gnu_fat_type)) = 0; + for (tree t = gnu_fat_type; t; t = TYPE_NEXT_VARIANT (t)) + SET_TYPE_UNCONSTRAINED_ARRAY (t, gnu_type); + } + else + { + /* We make the fields addressable for the sake of compatibility + with languages for which the regular fields are addressable. */ + tem + = create_field_decl (get_identifier ("P_ARRAY"), + ptr_type_node, gnu_fat_type, + NULL_TREE, NULL_TREE, 0, 1); + DECL_CHAIN (tem) + = create_field_decl (get_identifier ("P_BOUNDS"), + gnu_ptr_template, gnu_fat_type, + NULL_TREE, NULL_TREE, 0, 1); + finish_fat_pointer_type (gnu_fat_type, tem); + SET_TYPE_UNCONSTRAINED_ARRAY (gnu_fat_type, gnu_type); + } + + /* If the GNAT encodings are used, give the fat pointer type a name. + If this is a packed type implemented specially, tell the debugger + how to interpret the underlying bits by fetching the name of the + implementation type. But, in any case, mark it as artificial so + the debugger can skip it. */ + const Entity_Id gnat_name + = Present (PAT) && gnat_encodings == DWARF_GNAT_ENCODINGS_ALL + ? PAT + : gnat_entity; + tree xup_name + = gnat_encodings == DWARF_GNAT_ENCODINGS_ALL + ? create_concat_name (gnat_name, "XUP") + : gnu_entity_name; + create_type_decl (xup_name, gnu_fat_type, true, debug_info_p, + gnat_entity); + + /* Build a reference to the template from a PLACEHOLDER_EXPR that + is the fat pointer. This will be used to access the individual + fields once we build them. */ + tem = build3 (COMPONENT_REF, gnu_ptr_template, + build0 (PLACEHOLDER_EXPR, gnu_fat_type), + DECL_CHAIN (TYPE_FIELDS (gnu_fat_type)), NULL_TREE); + gnu_template_reference + = build_unary_op (INDIRECT_REF, gnu_template_type, tem); + TREE_READONLY (gnu_template_reference) = 1; + TREE_THIS_NOTRAP (gnu_template_reference) = 1; + + /* Now create the GCC type for each index and add the fields for that + index to the template. */ + for (index = (convention_fortran_p ? ndim - 1 : 0), + gnat_index = First_Index (gnat_entity); + IN_RANGE (index, 0, ndim - 1); + index += (convention_fortran_p ? - 1 : 1), + gnat_index = Next_Index (gnat_index)) + { + const bool is_flb + = Is_Fixed_Lower_Bound_Index_Subtype (Etype (gnat_index)); + tree gnu_index_type = get_unpadded_type (Etype (gnat_index)); + tree gnu_orig_min = TYPE_MIN_VALUE (gnu_index_type); + tree gnu_orig_max = TYPE_MAX_VALUE (gnu_index_type); + tree gnu_index_base_type = get_base_type (gnu_index_type); + tree gnu_lb_field, gnu_hb_field; + tree gnu_min, gnu_max, gnu_high; + char field_name[16]; + + /* Update the maximum size of the array in elements. */ + if (gnu_max_size) + gnu_max_size + = update_n_elem (gnu_max_size, gnu_orig_min, gnu_orig_max); + + /* Now build the self-referential bounds of the index type. */ + gnu_index_type = maybe_character_type (gnu_index_type); + gnu_index_base_type = maybe_character_type (gnu_index_base_type); + + /* Make the FIELD_DECLs for the low and high bounds of this + type and then make extractions of these fields from the + template. */ + sprintf (field_name, "LB%d", index); + gnu_lb_field = create_field_decl (get_identifier (field_name), + gnu_index_type, + gnu_template_type, NULL_TREE, + NULL_TREE, 0, 0); + Sloc_to_locus (Sloc (gnat_entity), + &DECL_SOURCE_LOCATION (gnu_lb_field)); + + field_name[0] = 'U'; + gnu_hb_field = create_field_decl (get_identifier (field_name), + gnu_index_type, + gnu_template_type, NULL_TREE, + NULL_TREE, 0, 0); + Sloc_to_locus (Sloc (gnat_entity), + &DECL_SOURCE_LOCATION (gnu_hb_field)); + + gnu_temp_fields[index] = chainon (gnu_lb_field, gnu_hb_field); + + /* We can't use build_component_ref here since the template type + isn't complete yet. */ + if (!is_flb) + { + gnu_orig_min = build3 (COMPONENT_REF, TREE_TYPE (gnu_lb_field), + gnu_template_reference, gnu_lb_field, + NULL_TREE); + TREE_READONLY (gnu_orig_min) = 1; + } + + gnu_orig_max = build3 (COMPONENT_REF, TREE_TYPE (gnu_hb_field), + gnu_template_reference, gnu_hb_field, + NULL_TREE); + TREE_READONLY (gnu_orig_max) = 1; + + gnu_min = convert (sizetype, gnu_orig_min); + gnu_max = convert (sizetype, gnu_orig_max); + + /* Compute the size of this dimension. See the E_Array_Subtype + case below for the rationale. */ + if (is_flb + && Nkind (gnat_index) == N_Subtype_Indication + && flb_cannot_be_superflat (gnat_index)) + gnu_high = gnu_max; + + else + gnu_high + = build3 (COND_EXPR, sizetype, + build2 (GE_EXPR, boolean_type_node, + gnu_orig_max, gnu_orig_min), + gnu_max, + TREE_CODE (gnu_min) == INTEGER_CST + ? int_const_binop (MINUS_EXPR, gnu_min, size_one_node) + : size_binop (MINUS_EXPR, gnu_min, size_one_node)); + + /* Make a range type with the new range in the Ada base type. + Then make an index type with the size range in sizetype. */ + gnu_index_types[index] + = create_index_type (gnu_min, gnu_high, + create_range_type (gnu_index_base_type, + gnu_orig_min, + gnu_orig_max), + gnat_entity); + + TYPE_NAME (gnu_index_types[index]) + = create_concat_name (gnat_entity, field_name); + } + + /* Install all the fields into the template. */ + TYPE_NAME (gnu_template_type) + = create_concat_name (gnat_entity, "XUB"); + gnu_template_fields = NULL_TREE; + for (index = 0; index < ndim; index++) + gnu_template_fields + = chainon (gnu_template_fields, gnu_temp_fields[index]); + finish_record_type (gnu_template_type, gnu_template_fields, 0, + debug_info_p); + TYPE_CONTEXT (gnu_template_type) = current_function_decl; + + /* If Component_Size is not already specified, annotate it with the + size of the component. */ + if (!Known_Component_Size (gnat_entity)) + Set_Component_Size (gnat_entity, + annotate_value (TYPE_SIZE (comp_type))); + + /* Compute the maximum size of the array in units. */ + if (gnu_max_size) + gnu_max_size + = size_binop (MULT_EXPR, gnu_max_size, TYPE_SIZE_UNIT (comp_type)); + + /* Now build the array type. */ + tem = comp_type; + for (index = ndim - 1; index >= 0; index--) + { + tem = build_nonshared_array_type (tem, gnu_index_types[index]); + TYPE_MULTI_ARRAY_P (tem) = (index > 0); + TYPE_CONVENTION_FORTRAN_P (tem) = convention_fortran_p; + if (index == ndim - 1 && Reverse_Storage_Order (gnat_entity)) + set_reverse_storage_order_on_array_type (tem); + if (array_type_has_nonaliased_component (tem, gnat_entity)) + set_nonaliased_component_on_array_type (tem); + } + + /* If this is a packed type implemented specially, then process the + implementation type so it is elaborated in the proper scope. */ + if (Present (PAT)) + gnat_to_gnu_entity (PAT, NULL_TREE, false); + + /* Otherwise, if an alignment is specified, use it if valid and, if + the alignment was requested with an explicit clause, state so. */ + else if (Known_Alignment (gnat_entity)) + { + SET_TYPE_ALIGN (tem, + validate_alignment (Alignment (gnat_entity), + gnat_entity, + TYPE_ALIGN (tem))); + if (Present (Alignment_Clause (gnat_entity))) + TYPE_USER_ALIGN (tem) = 1; + } + + /* Tag top-level ARRAY_TYPE nodes for packed arrays and their + implementation types as such so that the debug information back-end + can output the appropriate description for them. */ + TYPE_PACKED (tem) + = (Is_Packed (gnat_entity) + || Is_Packed_Array_Impl_Type (gnat_entity)); + + if (Treat_As_Volatile (gnat_entity)) + tem = change_qualified_type (tem, TYPE_QUAL_VOLATILE); + + /* Adjust the type of the pointer-to-array field of the fat pointer + and record the aliasing relationships if necessary. If this is + a packed type implemented specially, then use a ref-all pointer + type since the implementation type may vary between constrained + subtypes and unconstrained base type. */ + if (Present (PAT)) + TREE_TYPE (TYPE_FIELDS (gnu_fat_type)) + = build_pointer_type_for_mode (tem, ptr_mode, true); + else + TREE_TYPE (TYPE_FIELDS (gnu_fat_type)) = build_pointer_type (tem); + if (TYPE_ALIAS_SET_KNOWN_P (gnu_fat_type)) + record_component_aliases (gnu_fat_type); + + /* If the maximum size doesn't overflow, use it. */ + if (gnu_max_size + && TREE_CODE (gnu_max_size) == INTEGER_CST + && !TREE_OVERFLOW (gnu_max_size) + && compare_tree_int (gnu_max_size, TYPE_ARRAY_SIZE_LIMIT) <= 0) + TYPE_ARRAY_MAX_SIZE (tem) = gnu_max_size; + + /* See the above description for the rationale. */ + create_type_decl (create_concat_name (gnat_entity, "XUA"), tem, + artificial_p, debug_info_p, gnat_entity); + TYPE_CONTEXT (tem) = gnu_fat_type; + TYPE_CONTEXT (TYPE_POINTER_TO (tem)) = gnu_fat_type; + + /* Create the type to be designated by thin pointers: a record type for + the array and its template. We used to shift the fields to have the + template at a negative offset, but this was somewhat of a kludge; we + now shift thin pointer values explicitly but only those which have a + TYPE_UNCONSTRAINED_ARRAY attached to the designated RECORD_TYPE. + If the GNAT encodings are used, give it a name. */ + tree xut_name + = (gnat_encodings == DWARF_GNAT_ENCODINGS_ALL) + ? create_concat_name (gnat_name, "XUT") + : gnu_entity_name; + obj = build_unc_object_type (gnu_template_type, tem, xut_name, + debug_info_p); + + SET_TYPE_UNCONSTRAINED_ARRAY (obj, gnu_type); + TYPE_OBJECT_RECORD_TYPE (gnu_type) = obj; + + /* The result type is an UNCONSTRAINED_ARRAY_TYPE that indicates the + corresponding fat pointer. */ + TREE_TYPE (gnu_type) = gnu_fat_type; + TYPE_POINTER_TO (gnu_type) = gnu_fat_type; + TYPE_REFERENCE_TO (gnu_type) = gnu_fat_type; + SET_TYPE_MODE (gnu_type, BLKmode); + SET_TYPE_ALIGN (gnu_type, TYPE_ALIGN (tem)); + } + break; + + case E_Array_Subtype: + + /* This is the actual data type for array variables. Multidimensional + arrays are implemented as arrays of arrays. Note that arrays which + have sparse enumeration subtypes as index components create sparse + arrays, which is obviously space inefficient but so much easier to + code for now. + + Also note that the subtype never refers to the unconstrained array + type, which is somewhat at variance with Ada semantics. + + First check to see if this is simply a renaming of the array type. + If so, the result is the array type. */ + + gnu_type = TYPE_MAIN_VARIANT (gnat_to_gnu_type (Etype (gnat_entity))); + if (!Is_Constrained (gnat_entity)) + ; + else + { + const Entity_Id PAT = Packed_Array_Impl_Type (gnat_entity); + Entity_Id gnat_index, gnat_base_index; + const bool convention_fortran_p + = (Convention (gnat_entity) == Convention_Fortran); + const int ndim = Number_Dimensions (gnat_entity); + tree gnu_base_type = gnu_type; + tree *gnu_index_types = XALLOCAVEC (tree, ndim); + tree gnu_max_size = size_one_node; + bool need_index_type_struct = false; + int index; + + /* First create the GCC type for each index and find out whether + special types are needed for debugging information. */ + for (index = (convention_fortran_p ? ndim - 1 : 0), + gnat_index = First_Index (gnat_entity), + gnat_base_index + = First_Index (Implementation_Base_Type (gnat_entity)); + IN_RANGE (index, 0, ndim - 1); + index += (convention_fortran_p ? - 1 : 1), + gnat_index = Next_Index (gnat_index), + gnat_base_index = Next_Index (gnat_base_index)) + { + tree gnu_index_type = get_unpadded_type (Etype (gnat_index)); + tree gnu_orig_min = TYPE_MIN_VALUE (gnu_index_type); + tree gnu_orig_max = TYPE_MAX_VALUE (gnu_index_type); + tree gnu_index_base_type = get_base_type (gnu_index_type); + tree gnu_base_index_type + = get_unpadded_type (Etype (gnat_base_index)); + tree gnu_base_orig_min = TYPE_MIN_VALUE (gnu_base_index_type); + tree gnu_base_orig_max = TYPE_MAX_VALUE (gnu_base_index_type); + tree gnu_min, gnu_max, gnu_high; + + /* We try to create subtypes for discriminants used as bounds + that are more restrictive than those declared, by using the + bounds of the index type of the base array type. This will + make it possible to calculate the maximum size of the record + type more conservatively. This may have already been done by + the front-end (Exp_Ch3.Adjust_Discriminants), in which case + there will be a conversion that needs to be removed first. */ + if (CONTAINS_PLACEHOLDER_P (gnu_orig_min) + && TYPE_RM_SIZE (gnu_base_index_type) + && tree_int_cst_lt (TYPE_RM_SIZE (gnu_base_index_type), + TYPE_RM_SIZE (gnu_index_type))) + { + gnu_orig_min = remove_conversions (gnu_orig_min, false); + TREE_TYPE (gnu_orig_min) + = create_extra_subtype (TREE_TYPE (gnu_orig_min), + gnu_base_orig_min, + gnu_base_orig_max); + } + + if (CONTAINS_PLACEHOLDER_P (gnu_orig_max) + && TYPE_RM_SIZE (gnu_base_index_type) + && tree_int_cst_lt (TYPE_RM_SIZE (gnu_base_index_type), + TYPE_RM_SIZE (gnu_index_type))) + { + gnu_orig_max = remove_conversions (gnu_orig_max, false); + TREE_TYPE (gnu_orig_max) + = create_extra_subtype (TREE_TYPE (gnu_orig_max), + gnu_base_orig_min, + gnu_base_orig_max); + } + + /* Update the maximum size of the array in elements. Here we + see if any constraint on the index type of the base type + can be used in the case of self-referential bounds on the + index type of the array type. We look for a non-"infinite" + and non-self-referential bound from any type involved and + handle each bound separately. */ + if (gnu_max_size) + { + if (CONTAINS_PLACEHOLDER_P (gnu_orig_min)) + gnu_min = gnu_base_orig_min; + else + gnu_min = gnu_orig_min; + + if (TREE_CODE (gnu_min) != INTEGER_CST + || TREE_OVERFLOW (gnu_min)) + gnu_min = TYPE_MIN_VALUE (TREE_TYPE (gnu_min)); + + if (CONTAINS_PLACEHOLDER_P (gnu_orig_max)) + gnu_max = gnu_base_orig_max; + else + gnu_max = gnu_orig_max; + + if (TREE_CODE (gnu_max) != INTEGER_CST + || TREE_OVERFLOW (gnu_max)) + gnu_max = TYPE_MAX_VALUE (TREE_TYPE (gnu_max)); + + gnu_max_size + = update_n_elem (gnu_max_size, gnu_min, gnu_max); + } + + /* Convert the bounds to the base type for consistency below. */ + gnu_index_base_type = maybe_character_type (gnu_index_base_type); + gnu_orig_min = convert (gnu_index_base_type, gnu_orig_min); + gnu_orig_max = convert (gnu_index_base_type, gnu_orig_max); + + gnu_min = convert (sizetype, gnu_orig_min); + gnu_max = convert (sizetype, gnu_orig_max); + + /* See if the base array type is already flat. If it is, we + are probably compiling an ACATS test but it will cause the + code below to malfunction if we don't handle it specially. */ + if (TREE_CODE (gnu_base_orig_min) == INTEGER_CST + && TREE_CODE (gnu_base_orig_max) == INTEGER_CST + && tree_int_cst_lt (gnu_base_orig_max, gnu_base_orig_min)) + { + gnu_min = size_one_node; + gnu_max = size_zero_node; + gnu_high = gnu_max; + } + + /* Similarly, if one of the values overflows in sizetype and the + range is null, use 1..0 for the sizetype bounds. */ + else if (TREE_CODE (gnu_min) == INTEGER_CST + && TREE_CODE (gnu_max) == INTEGER_CST + && (TREE_OVERFLOW (gnu_min) || TREE_OVERFLOW (gnu_max)) + && tree_int_cst_lt (gnu_orig_max, gnu_orig_min)) + { + gnu_min = size_one_node; + gnu_max = size_zero_node; + gnu_high = gnu_max; + } + + /* If the minimum and maximum values both overflow in sizetype, + but the difference in the original type does not overflow in + sizetype, ignore the overflow indication. */ + else if (TREE_CODE (gnu_min) == INTEGER_CST + && TREE_CODE (gnu_max) == INTEGER_CST + && TREE_OVERFLOW (gnu_min) && TREE_OVERFLOW (gnu_max) + && !TREE_OVERFLOW + (convert (sizetype, + fold_build2 (MINUS_EXPR, + gnu_index_base_type, + gnu_orig_max, + gnu_orig_min)))) + { + TREE_OVERFLOW (gnu_min) = 0; + TREE_OVERFLOW (gnu_max) = 0; + gnu_high = gnu_max; + } + + /* Compute the size of this dimension in the general case. We + need to provide GCC with an upper bound to use but have to + deal with the "superflat" case. There are three ways to do + this. If we can prove that the array can never be superflat, + we can just use the high bound of the index type. */ + else if ((Nkind (gnat_index) == N_Range + && range_cannot_be_superflat (gnat_index)) + /* Bit-Packed Array Impl. Types are never superflat. */ + || (Is_Packed_Array_Impl_Type (gnat_entity) + && Is_Bit_Packed_Array + (Original_Array_Type (gnat_entity)))) + gnu_high = gnu_max; + + /* Otherwise, if the high bound is constant but the low bound is + not, we use the expression (hb >= lb) ? lb : hb + 1 for the + lower bound. Note that the comparison must be done in the + original type to avoid any overflow during the conversion. */ + else if (TREE_CODE (gnu_max) == INTEGER_CST + && TREE_CODE (gnu_min) != INTEGER_CST) + { + gnu_high = gnu_max; + gnu_min + = build_cond_expr (sizetype, + build_binary_op (GE_EXPR, + boolean_type_node, + gnu_orig_max, + gnu_orig_min), + gnu_min, + int_const_binop (PLUS_EXPR, gnu_max, + size_one_node)); + } + + /* Finally we use (hb >= lb) ? hb : lb - 1 for the upper bound + in all the other cases. Note that we use int_const_binop for + the shift by 1 if the bound is constant to avoid any unwanted + overflow. */ + else + gnu_high + = build_cond_expr (sizetype, + build_binary_op (GE_EXPR, + boolean_type_node, + gnu_orig_max, + gnu_orig_min), + gnu_max, + TREE_CODE (gnu_min) == INTEGER_CST + ? int_const_binop (MINUS_EXPR, gnu_min, + size_one_node) + : size_binop (MINUS_EXPR, gnu_min, + size_one_node)); + + /* Reuse the index type for the range type. Then make an index + type with the size range in sizetype. */ + gnu_index_types[index] + = create_index_type (gnu_min, gnu_high, gnu_index_type, + gnat_entity); + + /* We need special types for debugging information to point to + the index types if they have variable bounds, are not integer + types, are biased or are wider than sizetype. These are GNAT + encodings, so we have to include them only when all encodings + are requested. */ + if ((TREE_CODE (gnu_orig_min) != INTEGER_CST + || TREE_CODE (gnu_orig_max) != INTEGER_CST + || TREE_CODE (gnu_index_type) != INTEGER_TYPE + || (TREE_TYPE (gnu_index_type) + && TREE_CODE (TREE_TYPE (gnu_index_type)) + != INTEGER_TYPE) + || TYPE_BIASED_REPRESENTATION_P (gnu_index_type)) + && gnat_encodings == DWARF_GNAT_ENCODINGS_ALL) + need_index_type_struct = true; + } + + /* Then flatten: create the array of arrays. For an array type + used to implement a packed array, get the component type from + the original array type since the representation clauses that + can affect it are on the latter. */ + if (Is_Packed_Array_Impl_Type (gnat_entity) + && !Is_Bit_Packed_Array (Original_Array_Type (gnat_entity))) + { + gnu_type = gnat_to_gnu_type (Original_Array_Type (gnat_entity)); + for (index = ndim - 1; index >= 0; index--) + gnu_type = TREE_TYPE (gnu_type); + + /* One of the above calls might have caused us to be elaborated, + so don't blow up if so. */ + if (present_gnu_tree (gnat_entity)) + { + maybe_present = true; + break; + } + } + else + { + gnu_type = gnat_to_gnu_component_type (gnat_entity, definition, + debug_info_p); + + /* One of the above calls might have caused us to be elaborated, + so don't blow up if so. */ + if (present_gnu_tree (gnat_entity)) + { + maybe_present = true; + break; + } + } + + /* Compute the maximum size of the array in units. */ + if (gnu_max_size) + gnu_max_size + = size_binop (MULT_EXPR, gnu_max_size, TYPE_SIZE_UNIT (gnu_type)); + + /* Now build the array type. */ + for (index = ndim - 1; index >= 0; index --) + { + gnu_type = build_nonshared_array_type (gnu_type, + gnu_index_types[index]); + TYPE_MULTI_ARRAY_P (gnu_type) = (index > 0); + TYPE_CONVENTION_FORTRAN_P (gnu_type) = convention_fortran_p; + if (index == ndim - 1 && Reverse_Storage_Order (gnat_entity)) + set_reverse_storage_order_on_array_type (gnu_type); + if (array_type_has_nonaliased_component (gnu_type, gnat_entity)) + set_nonaliased_component_on_array_type (gnu_type); + + /* Kludge to remove the TREE_OVERFLOW flag for the sake of LTO + on maximally-sized array types designed by access types. */ + if (integer_zerop (TYPE_SIZE (gnu_type)) + && TREE_OVERFLOW (TYPE_SIZE (gnu_type)) + && Is_Itype (gnat_entity) + && (gnat_temp = Associated_Node_For_Itype (gnat_entity)) + && IN (Nkind (gnat_temp), N_Declaration) + && Is_Access_Type (Defining_Entity (gnat_temp)) + && Is_Entity_Name (First_Index (gnat_entity)) + && UI_To_Int (RM_Size (Entity (First_Index (gnat_entity)))) + == BITS_PER_WORD) + { + TYPE_SIZE (gnu_type) = bitsize_zero_node; + TYPE_SIZE_UNIT (gnu_type) = size_zero_node; + } + } + + /* Attach the TYPE_STUB_DECL in case we have a parallel type. */ + TYPE_STUB_DECL (gnu_type) + = create_type_stub_decl (gnu_entity_name, gnu_type); + + /* If this is a multi-dimensional array and we are at global level, + we need to make a variable corresponding to the stride of the + inner dimensions. */ + if (ndim > 1 && global_bindings_p ()) + { + tree gnu_arr_type; + + for (gnu_arr_type = TREE_TYPE (gnu_type), index = 1; + TREE_CODE (gnu_arr_type) == ARRAY_TYPE; + gnu_arr_type = TREE_TYPE (gnu_arr_type), index++) + { + tree eltype = TREE_TYPE (gnu_arr_type); + char stride_name[32]; + + sprintf (stride_name, "ST%d", index); + TYPE_SIZE (gnu_arr_type) + = elaborate_expression_1 (TYPE_SIZE (gnu_arr_type), + gnat_entity, stride_name, + definition, false); + + /* ??? For now, store the size as a multiple of the + alignment of the element type in bytes so that we + can see the alignment from the tree. */ + sprintf (stride_name, "ST%d_A_UNIT", index); + TYPE_SIZE_UNIT (gnu_arr_type) + = elaborate_expression_2 (TYPE_SIZE_UNIT (gnu_arr_type), + gnat_entity, stride_name, + definition, false, + TYPE_ALIGN (eltype)); + + /* ??? create_type_decl is not invoked on the inner types so + the MULT_EXPR node built above will never be marked. */ + MARK_VISITED (TYPE_SIZE_UNIT (gnu_arr_type)); + } + } + + /* Set the TYPE_PACKED flag on packed array types and also on their + implementation types, so that the DWARF back-end can output the + appropriate description for them. */ + TYPE_PACKED (gnu_type) + = (Is_Packed (gnat_entity) + || Is_Packed_Array_Impl_Type (gnat_entity)); + + TYPE_BIT_PACKED_ARRAY_TYPE_P (gnu_type) + = (Is_Packed_Array_Impl_Type (gnat_entity) + && Is_Bit_Packed_Array (Original_Array_Type (gnat_entity))); + + /* If the maximum size doesn't overflow, use it. */ + if (gnu_max_size + && TREE_CODE (gnu_max_size) == INTEGER_CST + && !TREE_OVERFLOW (gnu_max_size) + && compare_tree_int (gnu_max_size, TYPE_ARRAY_SIZE_LIMIT) <= 0) + TYPE_ARRAY_MAX_SIZE (gnu_type) = gnu_max_size; + + /* If we need to write out a record type giving the names of the + bounds for debugging purposes, do it now and make the record + type a parallel type. This is not needed for a packed array + since the bounds are conveyed by the original array type. */ + if (need_index_type_struct + && debug_info_p + && !Is_Packed_Array_Impl_Type (gnat_entity)) + { + tree gnu_bound_rec = make_node (RECORD_TYPE); + tree gnu_field_list = NULL_TREE; + tree gnu_field; + + TYPE_NAME (gnu_bound_rec) + = create_concat_name (gnat_entity, "XA"); + + for (index = ndim - 1; index >= 0; index--) + { + tree gnu_index = TYPE_INDEX_TYPE (gnu_index_types[index]); + tree gnu_index_name = TYPE_IDENTIFIER (gnu_index); + + /* Make sure to reference the types themselves, and not just + their names, as the debugger may fall back on them. */ + gnu_field = create_field_decl (gnu_index_name, gnu_index, + gnu_bound_rec, NULL_TREE, + NULL_TREE, 0, 0); + DECL_CHAIN (gnu_field) = gnu_field_list; + gnu_field_list = gnu_field; + } + + finish_record_type (gnu_bound_rec, gnu_field_list, 0, true); + add_parallel_type (gnu_type, gnu_bound_rec); + } + + /* If this is a packed array type, make the original array type a + parallel/debug type. Otherwise, if GNAT encodings are used, do + it for the base array type if it is not artificial to make sure + that it is kept in the debug info. */ + if (debug_info_p) + { + if (Is_Packed_Array_Impl_Type (gnat_entity)) + { + tree gnu_name + = associate_original_type_to_packed_array (gnu_type, + gnat_entity); + if (gnu_name) + gnu_entity_name = gnu_name; + } + + else if (gnat_encodings == DWARF_GNAT_ENCODINGS_ALL) + { + tree gnu_base_decl + = gnat_to_gnu_entity (Etype (gnat_entity), NULL_TREE, + false); + + if (!DECL_ARTIFICIAL (gnu_base_decl)) + add_parallel_type (gnu_type, + TREE_TYPE (TREE_TYPE (gnu_base_decl))); + } + } + + /* Set our alias set to that of our base type. This gives all + array subtypes the same alias set. */ + relate_alias_sets (gnu_type, gnu_base_type, ALIAS_SET_COPY); + + /* If this is a packed type implemented specially, then replace our + type with the implementation type. */ + if (Present (PAT)) + { + /* First finish the type we had been making so that we output + debugging information for it. */ + process_attributes (&gnu_type, &attr_list, false, gnat_entity); + if (Treat_As_Volatile (gnat_entity)) + { + const int quals + = TYPE_QUAL_VOLATILE + | (Is_Full_Access (gnat_entity) ? TYPE_QUAL_ATOMIC : 0); + gnu_type = change_qualified_type (gnu_type, quals); + } + /* Make it artificial only if the base type was artificial too. + That's sort of "morally" true and will make it possible for + the debugger to look it up by name in DWARF, which is needed + in order to decode the packed array type. */ + tree gnu_tmp_decl + = create_type_decl (gnu_entity_name, gnu_type, + !Comes_From_Source (Etype (gnat_entity)) + && artificial_p, debug_info_p, + gnat_entity); + /* Save it as our equivalent in case the call below elaborates + this type again. */ + save_gnu_tree (gnat_entity, gnu_tmp_decl, false); + + gnu_type = gnat_to_gnu_type (PAT); + save_gnu_tree (gnat_entity, NULL_TREE, false); + + /* Set the ___XP suffix for GNAT encodings. */ + if (gnat_encodings == DWARF_GNAT_ENCODINGS_ALL) + gnu_entity_name = DECL_NAME (TYPE_NAME (gnu_type)); + + tree gnu_inner = gnu_type; + while (TREE_CODE (gnu_inner) == RECORD_TYPE + && (TYPE_JUSTIFIED_MODULAR_P (gnu_inner) + || TYPE_PADDING_P (gnu_inner))) + gnu_inner = TREE_TYPE (TYPE_FIELDS (gnu_inner)); + + /* We need to attach the index type to the type we just made so + that the actual bounds can later be put into a template. */ + if ((TREE_CODE (gnu_inner) == ARRAY_TYPE + && !TYPE_ACTUAL_BOUNDS (gnu_inner)) + || (TREE_CODE (gnu_inner) == INTEGER_TYPE + && !TYPE_HAS_ACTUAL_BOUNDS_P (gnu_inner))) + { + if (TREE_CODE (gnu_inner) == INTEGER_TYPE) + { + /* The TYPE_ACTUAL_BOUNDS field is overloaded with the + TYPE_MODULUS for modular types so we make an extra + subtype if necessary. */ + if (TYPE_MODULAR_P (gnu_inner)) + gnu_inner + = create_extra_subtype (gnu_inner, + TYPE_MIN_VALUE (gnu_inner), + TYPE_MAX_VALUE (gnu_inner)); + + TYPE_HAS_ACTUAL_BOUNDS_P (gnu_inner) = 1; + + /* Check for other cases of overloading. */ + gcc_checking_assert (!TYPE_ACTUAL_BOUNDS (gnu_inner)); + } + + for (Entity_Id gnat_index = First_Index (gnat_entity); + Present (gnat_index); + gnat_index = Next_Index (gnat_index)) + SET_TYPE_ACTUAL_BOUNDS + (gnu_inner, + tree_cons (NULL_TREE, + get_unpadded_type (Etype (gnat_index)), + TYPE_ACTUAL_BOUNDS (gnu_inner))); + + if (Convention (gnat_entity) != Convention_Fortran) + SET_TYPE_ACTUAL_BOUNDS + (gnu_inner, nreverse (TYPE_ACTUAL_BOUNDS (gnu_inner))); + + if (TREE_CODE (gnu_type) == RECORD_TYPE + && TYPE_JUSTIFIED_MODULAR_P (gnu_type)) + TREE_TYPE (TYPE_FIELDS (gnu_type)) = gnu_inner; + } + } + } + break; + + case E_String_Literal_Subtype: + /* Create the type for a string literal. */ + { + Entity_Id gnat_full_type + = (Is_Private_Type (Etype (gnat_entity)) + && Present (Full_View (Etype (gnat_entity))) + ? Full_View (Etype (gnat_entity)) : Etype (gnat_entity)); + tree gnu_string_type = get_unpadded_type (gnat_full_type); + tree gnu_string_array_type + = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_string_type)))); + tree gnu_string_index_type + = get_base_type (TREE_TYPE (TYPE_INDEX_TYPE + (TYPE_DOMAIN (gnu_string_array_type)))); + tree gnu_lower_bound + = convert (gnu_string_index_type, + gnat_to_gnu (String_Literal_Low_Bound (gnat_entity))); + tree gnu_length + = UI_To_gnu (String_Literal_Length (gnat_entity), + gnu_string_index_type); + tree gnu_upper_bound + = build_binary_op (PLUS_EXPR, gnu_string_index_type, + gnu_lower_bound, + int_const_binop (MINUS_EXPR, gnu_length, + convert (gnu_string_index_type, + integer_one_node))); + tree gnu_index_type + = create_index_type (convert (sizetype, gnu_lower_bound), + convert (sizetype, gnu_upper_bound), + create_range_type (gnu_string_index_type, + gnu_lower_bound, + gnu_upper_bound), + gnat_entity); + + gnu_type + = build_nonshared_array_type (gnat_to_gnu_type + (Component_Type (gnat_entity)), + gnu_index_type); + if (array_type_has_nonaliased_component (gnu_type, gnat_entity)) + set_nonaliased_component_on_array_type (gnu_type); + relate_alias_sets (gnu_type, gnu_string_type, ALIAS_SET_COPY); + } + break; + + /* Record Types and Subtypes + + A record type definition is transformed into the equivalent of a C + struct definition. The fields that are the discriminants which are + found in the Full_Type_Declaration node and the elements of the + Component_List found in the Record_Type_Definition node. The + Component_List can be a recursive structure since each Variant of + the Variant_Part of the Component_List has a Component_List. + + Processing of a record type definition comprises starting the list of + field declarations here from the discriminants and the calling the + function components_to_record to add the rest of the fields from the + component list and return the gnu type node. The function + components_to_record will call itself recursively as it traverses + the tree. */ + + case E_Record_Type: + { + Node_Id record_definition = Type_Definition (gnat_decl); + + if (Has_Complex_Representation (gnat_entity)) + { + const Node_Id first_component + = First (Component_Items (Component_List (record_definition))); + tree gnu_component_type + = get_unpadded_type (Etype (Defining_Entity (first_component))); + gnu_type = build_complex_type (gnu_component_type); + break; + } + + Node_Id gnat_constr; + Entity_Id gnat_field, gnat_parent_type; + tree gnu_field, gnu_field_list = NULL_TREE; + tree gnu_get_parent; + /* Set PACKED in keeping with gnat_to_gnu_field. */ + const int packed + = Is_Packed (gnat_entity) + ? 1 + : Component_Alignment (gnat_entity) == Calign_Storage_Unit + ? -1 + : 0; + const bool has_align = Known_Alignment (gnat_entity); + const bool has_discr = Has_Discriminants (gnat_entity); + const bool is_extension + = (Is_Tagged_Type (gnat_entity) + && Nkind (record_definition) == N_Derived_Type_Definition); + const bool has_rep + = is_extension + ? Has_Record_Rep_Clause (gnat_entity) + : Has_Specified_Layout (gnat_entity); + const bool is_unchecked_union = Is_Unchecked_Union (gnat_entity); + bool all_rep = has_rep; + + /* See if all fields have a rep clause. Stop when we find one + that doesn't. */ + if (all_rep) + for (gnat_field = First_Entity (gnat_entity); + Present (gnat_field); + gnat_field = Next_Entity (gnat_field)) + if ((Ekind (gnat_field) == E_Component + || (Ekind (gnat_field) == E_Discriminant + && !is_unchecked_union)) + && No (Component_Clause (gnat_field))) + { + all_rep = false; + break; + } + + /* If this is a record extension, go a level further to find the + record definition. Also, verify we have a Parent_Subtype. */ + if (is_extension) + { + if (!type_annotate_only + || Present (Record_Extension_Part (record_definition))) + record_definition = Record_Extension_Part (record_definition); + + gcc_assert (Present (Parent_Subtype (gnat_entity)) + || type_annotate_only); + } + + /* Make a node for the record type. */ + gnu_type = make_node (tree_code_for_record_type (gnat_entity)); + TYPE_NAME (gnu_type) = gnu_entity_name; + TYPE_PACKED (gnu_type) = (packed != 0) || has_align || has_rep; + TYPE_REVERSE_STORAGE_ORDER (gnu_type) + = Reverse_Storage_Order (gnat_entity); + + /* If the record type has discriminants, pointers to it may also point + to constrained subtypes of it, so mark it as may_alias for LTO. */ + if (has_discr) + prepend_one_attribute + (&attr_list, ATTR_MACHINE_ATTRIBUTE, + get_identifier ("may_alias"), NULL_TREE, + gnat_entity); + + process_attributes (&gnu_type, &attr_list, true, gnat_entity); + + /* If we are not defining it, suppress expanding incomplete types. */ + if (!definition) + { + defer_incomplete_level++; + this_deferred = true; + } + + /* If both a size and rep clause were specified, put the size on + the record type now so that it can get the proper layout. */ + if (has_rep && Known_RM_Size (gnat_entity)) + TYPE_SIZE (gnu_type) + = UI_To_gnu (RM_Size (gnat_entity), bitsizetype); + + /* Always set the alignment on the record type here so that it can + get the proper layout. */ + if (has_align) + SET_TYPE_ALIGN (gnu_type, + validate_alignment (Alignment (gnat_entity), + gnat_entity, 0)); + else + { + SET_TYPE_ALIGN (gnu_type, 0); + + /* If a type needs strict alignment, then its type size will also + be the RM size (see below). Cap the alignment if needed, lest + it may cause this type size to become too large. */ + if (Strict_Alignment (gnat_entity) && Known_RM_Size (gnat_entity)) + { + unsigned int max_size = UI_To_Int (RM_Size (gnat_entity)); + unsigned int max_align = max_size & -max_size; + if (max_align < BIGGEST_ALIGNMENT) + TYPE_MAX_ALIGN (gnu_type) = max_align; + } + + /* Similarly if an Object_Size clause has been specified. */ + else if (Known_Esize (gnat_entity)) + { + unsigned int max_size = UI_To_Int (Esize (gnat_entity)); + unsigned int max_align = max_size & -max_size; + if (max_align < BIGGEST_ALIGNMENT) + TYPE_MAX_ALIGN (gnu_type) = max_align; + } + } + + /* If we have a Parent_Subtype, make a field for the parent. If + this record has rep clauses, force the position to zero. */ + if (Present (Parent_Subtype (gnat_entity))) + { + Entity_Id gnat_parent = Parent_Subtype (gnat_entity); + tree gnu_dummy_parent_type = make_node (RECORD_TYPE); + tree gnu_parent; + int parent_packed = 0; + + /* A major complexity here is that the parent subtype will + reference our discriminants in its Stored_Constraint list. + But those must reference the parent component of this record + which is precisely of the parent subtype we have not built yet! + To break the circle we first build a dummy COMPONENT_REF which + represents the "get to the parent" operation and initialize + each of those discriminants to a COMPONENT_REF of the above + dummy parent referencing the corresponding discriminant of the + base type of the parent subtype. */ + gnu_get_parent = build3 (COMPONENT_REF, gnu_dummy_parent_type, + build0 (PLACEHOLDER_EXPR, gnu_type), + build_decl (input_location, + FIELD_DECL, NULL_TREE, + gnu_dummy_parent_type), + NULL_TREE); + + if (has_discr) + for (gnat_field = First_Stored_Discriminant (gnat_entity); + Present (gnat_field); + gnat_field = Next_Stored_Discriminant (gnat_field)) + if (Present (Corresponding_Discriminant (gnat_field))) + { + tree gnu_field + = gnat_to_gnu_field_decl (Corresponding_Discriminant + (gnat_field)); + save_gnu_tree + (gnat_field, + build3 (COMPONENT_REF, TREE_TYPE (gnu_field), + gnu_get_parent, gnu_field, NULL_TREE), + true); + } + + /* Then we build the parent subtype. If it has discriminants but + the type itself has unknown discriminants, this means that it + doesn't contain information about how the discriminants are + derived from those of the ancestor type, so it cannot be used + directly. Instead it is built by cloning the parent subtype + of the underlying record view of the type, for which the above + derivation of discriminants has been made explicit. */ + if (Has_Discriminants (gnat_parent) + && Has_Unknown_Discriminants (gnat_entity)) + { + Entity_Id gnat_uview = Underlying_Record_View (gnat_entity); + + /* If we are defining the type, the underlying record + view must already have been elaborated at this point. + Otherwise do it now as its parent subtype cannot be + technically elaborated on its own. */ + if (definition) + gcc_assert (present_gnu_tree (gnat_uview)); + else + gnat_to_gnu_entity (gnat_uview, NULL_TREE, false); + + gnu_parent = gnat_to_gnu_type (Parent_Subtype (gnat_uview)); + + /* Substitute the "get to the parent" of the type for that + of its underlying record view in the cloned type. */ + for (gnat_field = First_Stored_Discriminant (gnat_uview); + Present (gnat_field); + gnat_field = Next_Stored_Discriminant (gnat_field)) + if (Present (Corresponding_Discriminant (gnat_field))) + { + tree gnu_field = gnat_to_gnu_field_decl (gnat_field); + tree gnu_ref + = build3 (COMPONENT_REF, TREE_TYPE (gnu_field), + gnu_get_parent, gnu_field, NULL_TREE); + gnu_parent + = substitute_in_type (gnu_parent, gnu_field, gnu_ref); + } + } + else + gnu_parent = gnat_to_gnu_type (gnat_parent); + + /* The parent field needs strict alignment so, if it is to + be created with a component clause below, then we need + to apply the same adjustment as in gnat_to_gnu_field. */ + if (has_rep && TYPE_ALIGN (gnu_type) < TYPE_ALIGN (gnu_parent)) + { + /* ??? For historical reasons, we do it on strict-alignment + platforms only, where it is really required. This means + that a confirming representation clause will change the + behavior of the compiler on the other platforms. */ + if (STRICT_ALIGNMENT) + SET_TYPE_ALIGN (gnu_type, TYPE_ALIGN (gnu_parent)); + else + parent_packed + = adjust_packed (gnu_parent, gnu_type, parent_packed); + } + + /* Finally we fix up both kinds of twisted COMPONENT_REF we have + initially built. The discriminants must reference the fields + of the parent subtype and not those of its base type for the + placeholder machinery to properly work. */ + if (has_discr) + { + /* The actual parent subtype is the full view. */ + if (Is_Private_Type (gnat_parent)) + { + if (Present (Full_View (gnat_parent))) + gnat_parent = Full_View (gnat_parent); + else + gnat_parent = Underlying_Full_View (gnat_parent); + } + + for (gnat_field = First_Stored_Discriminant (gnat_entity); + Present (gnat_field); + gnat_field = Next_Stored_Discriminant (gnat_field)) + if (Present (Corresponding_Discriminant (gnat_field))) + { + Entity_Id field; + for (field = First_Stored_Discriminant (gnat_parent); + Present (field); + field = Next_Stored_Discriminant (field)) + if (same_discriminant_p (gnat_field, field)) + break; + gcc_assert (Present (field)); + TREE_OPERAND (get_gnu_tree (gnat_field), 1) + = gnat_to_gnu_field_decl (field); + } + } + + /* The "get to the parent" COMPONENT_REF must be given its + proper type... */ + TREE_TYPE (gnu_get_parent) = gnu_parent; + + /* ...and reference the _Parent field of this record. */ + gnu_field + = create_field_decl (parent_name_id, + gnu_parent, gnu_type, + has_rep + ? TYPE_SIZE (gnu_parent) : NULL_TREE, + has_rep + ? bitsize_zero_node : NULL_TREE, + parent_packed, 1); + DECL_INTERNAL_P (gnu_field) = 1; + TREE_OPERAND (gnu_get_parent, 1) = gnu_field; + TYPE_FIELDS (gnu_type) = gnu_field; + } + + /* Make the fields for the discriminants and put them into the record + unless it's an Unchecked_Union. */ + if (has_discr) + for (gnat_field = First_Stored_Discriminant (gnat_entity); + Present (gnat_field); + gnat_field = Next_Stored_Discriminant (gnat_field)) + { + /* If this is a record extension and this discriminant is the + renaming of another discriminant, we've handled it above. */ + if (is_extension + && Present (Corresponding_Discriminant (gnat_field))) + continue; + + gnu_field + = gnat_to_gnu_field (gnat_field, gnu_type, packed, definition, + debug_info_p); + + /* Make an expression using a PLACEHOLDER_EXPR from the + FIELD_DECL node just created and link that with the + corresponding GNAT defining identifier. */ + save_gnu_tree (gnat_field, + build3 (COMPONENT_REF, TREE_TYPE (gnu_field), + build0 (PLACEHOLDER_EXPR, gnu_type), + gnu_field, NULL_TREE), + true); + + if (!is_unchecked_union) + { + DECL_CHAIN (gnu_field) = gnu_field_list; + gnu_field_list = gnu_field; + } + } + + /* If we have a derived untagged type that renames discriminants in + the parent type, the (stored) discriminants are just a copy of the + discriminants of the parent type. This means that any constraints + added by the renaming in the derivation are disregarded as far as + the layout of the derived type is concerned. To rescue them, we + change the type of the (stored) discriminants to a subtype with + the bounds of the type of the visible discriminants. */ + if (has_discr + && !is_extension + && Stored_Constraint (gnat_entity) != No_Elist) + for (gnat_constr = First_Elmt (Stored_Constraint (gnat_entity)); + gnat_constr != No_Elmt; + gnat_constr = Next_Elmt (gnat_constr)) + if (Nkind (Node (gnat_constr)) == N_Identifier + /* Ignore access discriminants. */ + && !Is_Access_Type (Etype (Node (gnat_constr))) + && Ekind (Entity (Node (gnat_constr))) == E_Discriminant) + { + const Entity_Id gnat_discr = Entity (Node (gnat_constr)); + tree gnu_discr_type = gnat_to_gnu_type (Etype (gnat_discr)); + tree gnu_ref + = gnat_to_gnu_entity (Original_Record_Component (gnat_discr), + NULL_TREE, false); + + /* GNU_REF must be an expression using a PLACEHOLDER_EXPR built + just above for one of the stored discriminants. */ + gcc_assert (TREE_TYPE (TREE_OPERAND (gnu_ref, 0)) == gnu_type); + + if (gnu_discr_type != TREE_TYPE (gnu_ref)) + TREE_TYPE (gnu_ref) + = create_extra_subtype (TREE_TYPE (gnu_ref), + TYPE_MIN_VALUE (gnu_discr_type), + TYPE_MAX_VALUE (gnu_discr_type)); + } + + /* If this is a derived type with discriminants and these discriminants + affect the initial shape it has inherited, factor them in. */ + if (has_discr + && !is_extension + && !Has_Record_Rep_Clause (gnat_entity) + && Stored_Constraint (gnat_entity) != No_Elist + && (gnat_parent_type = Underlying_Type (Etype (gnat_entity))) + && Is_Record_Type (gnat_parent_type) + && Is_Unchecked_Union (gnat_entity) + == Is_Unchecked_Union (gnat_parent_type) + && No_Reordering (gnat_entity) == No_Reordering (gnat_parent_type)) + { + tree gnu_parent_type + = TYPE_MAIN_VARIANT (gnat_to_gnu_type (gnat_parent_type)); + + if (TYPE_IS_PADDING_P (gnu_parent_type)) + gnu_parent_type = TREE_TYPE (TYPE_FIELDS (gnu_parent_type)); + + vec<subst_pair> gnu_subst_list + = build_subst_list (gnat_entity, gnat_parent_type, definition); + + /* Set the layout of the type to match that of the parent type, + doing required substitutions. Note that, if we do not use the + GNAT encodings, we don't need debug info for the inner record + types, as they will be part of the embedding variant record's + debug info. */ + copy_and_substitute_in_layout + (gnat_entity, gnat_parent_type, gnu_type, gnu_parent_type, + gnu_subst_list, + debug_info_p && gnat_encodings == DWARF_GNAT_ENCODINGS_ALL); + } + else + { + /* Add the fields into the record type and finish it up. */ + components_to_record (Component_List (record_definition), + gnat_entity, gnu_field_list, gnu_type, + packed, definition, false, all_rep, + is_unchecked_union, artificial_p, + debug_info_p, false, + all_rep ? NULL_TREE : bitsize_zero_node, + NULL); + + /* Empty classes have the size of a storage unit in C++. */ + if (TYPE_SIZE (gnu_type) == bitsize_zero_node + && Convention (gnat_entity) == Convention_CPP) + { + TYPE_SIZE (gnu_type) = bitsize_unit_node; + TYPE_SIZE_UNIT (gnu_type) = size_one_node; + compute_record_mode (gnu_type); + } + + /* If the type needs strict alignment, then no object of the type + may have a size smaller than the natural size, which means that + the RM size of the type is equal to the type size. */ + if (Strict_Alignment (gnat_entity)) + SET_TYPE_ADA_SIZE (gnu_type, TYPE_SIZE (gnu_type)); + + /* If there are entities in the chain corresponding to components + that we did not elaborate, ensure we elaborate their types if + they are itypes. */ + for (gnat_temp = First_Entity (gnat_entity); + Present (gnat_temp); + gnat_temp = Next_Entity (gnat_temp)) + if ((Ekind (gnat_temp) == E_Component + || Ekind (gnat_temp) == E_Discriminant) + && Is_Itype (Etype (gnat_temp)) + && !present_gnu_tree (gnat_temp)) + gnat_to_gnu_entity (Etype (gnat_temp), NULL_TREE, false); + } + + /* Fill in locations of fields. */ + annotate_rep (gnat_entity, gnu_type); + } + break; + + case E_Class_Wide_Subtype: + /* If an equivalent type is present, that is what we should use. + Otherwise, fall through to handle this like a record subtype + since it may have constraints. */ + if (gnat_equiv_type != gnat_entity) + { + gnu_decl = gnat_to_gnu_entity (gnat_equiv_type, NULL_TREE, false); + maybe_present = true; + break; + } + + /* ... fall through ... */ + + case E_Record_Subtype: + /* If Cloned_Subtype is Present it means this record subtype has + identical layout to that type or subtype and we should use + that GCC type for this one. The front-end guarantees that + the component list is shared. */ + if (Present (Cloned_Subtype (gnat_entity))) + { + gnu_decl = gnat_to_gnu_entity (Cloned_Subtype (gnat_entity), + NULL_TREE, false); + gnat_annotate_type = Cloned_Subtype (gnat_entity); + maybe_present = true; + break; + } + + /* Otherwise, first ensure the base type is elaborated. Then, if we are + changing the type, make a new type with each field having the type of + the field in the new subtype but the position computed by transforming + every discriminant reference according to the constraints. We don't + see any difference between private and non-private type here since + derivations from types should have been deferred until the completion + of the private type. */ + else + { + Entity_Id gnat_base_type = Implementation_Base_Type (gnat_entity); + + if (!definition) + { + defer_incomplete_level++; + this_deferred = true; + } + + tree gnu_base_type + = TYPE_MAIN_VARIANT (gnat_to_gnu_type (gnat_base_type)); + + if (present_gnu_tree (gnat_entity)) + { + maybe_present = true; + break; + } + + /* When the subtype has discriminants and these discriminants affect + the initial shape it has inherited, factor them in. But for an + Unchecked_Union (it must be an itype), just return the type. */ + if (Has_Discriminants (gnat_entity) + && Stored_Constraint (gnat_entity) != No_Elist + && Is_Record_Type (gnat_base_type) + && !Is_Unchecked_Union (gnat_base_type)) + { + vec<subst_pair> gnu_subst_list + = build_subst_list (gnat_entity, gnat_base_type, definition); + tree gnu_unpad_base_type; + + gnu_type = make_node (RECORD_TYPE); + TYPE_NAME (gnu_type) = gnu_entity_name; + TYPE_PACKED (gnu_type) = TYPE_PACKED (gnu_base_type); + TYPE_REVERSE_STORAGE_ORDER (gnu_type) + = Reverse_Storage_Order (gnat_entity); + process_attributes (&gnu_type, &attr_list, true, gnat_entity); + + /* Set the size, alignment and alias set of the type to match + those of the base type, doing required substitutions. */ + copy_and_substitute_in_size (gnu_type, gnu_base_type, + gnu_subst_list); + + if (TYPE_IS_PADDING_P (gnu_base_type)) + gnu_unpad_base_type = TREE_TYPE (TYPE_FIELDS (gnu_base_type)); + else + gnu_unpad_base_type = gnu_base_type; + + /* Set the layout of the type to match that of the base type, + doing required substitutions. We will output debug info + manually below so pass false as last argument. */ + copy_and_substitute_in_layout (gnat_entity, gnat_base_type, + gnu_type, gnu_unpad_base_type, + gnu_subst_list, false); + + /* Fill in locations of fields. */ + annotate_rep (gnat_entity, gnu_type); + + /* If debugging information is being written for the type and if + we are asked to output GNAT encodings, write a record that + shows what we are a subtype of and also make a variable that + indicates our size, if still variable. */ + if (debug_info_p + && gnat_encodings == DWARF_GNAT_ENCODINGS_ALL) + { + tree gnu_subtype_marker = make_node (RECORD_TYPE); + tree gnu_unpad_base_name + = TYPE_IDENTIFIER (gnu_unpad_base_type); + tree gnu_size_unit = TYPE_SIZE_UNIT (gnu_type); + + TYPE_NAME (gnu_subtype_marker) + = create_concat_name (gnat_entity, "XVS"); + finish_record_type (gnu_subtype_marker, + create_field_decl (gnu_unpad_base_name, + build_reference_type + (gnu_unpad_base_type), + gnu_subtype_marker, + NULL_TREE, NULL_TREE, + 0, 0), + 0, true); + + add_parallel_type (gnu_type, gnu_subtype_marker); + + if (definition + && TREE_CODE (gnu_size_unit) != INTEGER_CST + && !CONTAINS_PLACEHOLDER_P (gnu_size_unit)) + TYPE_SIZE_UNIT (gnu_subtype_marker) + = create_var_decl (create_concat_name (gnat_entity, + "XVZ"), + NULL_TREE, sizetype, gnu_size_unit, + true, false, false, false, false, + true, true, NULL, gnat_entity, false); + } + + /* Or else, if the subtype is artificial and GNAT encodings are + not used, use the base record type as the debug type. */ + else if (debug_info_p + && artificial_p + && gnat_encodings != DWARF_GNAT_ENCODINGS_ALL) + SET_TYPE_DEBUG_TYPE (gnu_type, gnu_unpad_base_type); + } + + /* Otherwise, go down all the components in the new type and make + them equivalent to those in the base type. */ + else + { + gnu_type = gnu_base_type; + + for (gnat_temp = First_Entity (gnat_entity); + Present (gnat_temp); + gnat_temp = Next_Entity (gnat_temp)) + if ((Ekind (gnat_temp) == E_Discriminant + && !Is_Unchecked_Union (gnat_base_type)) + || Ekind (gnat_temp) == E_Component) + save_gnu_tree (gnat_temp, + gnat_to_gnu_field_decl + (Original_Record_Component (gnat_temp)), + false); + } + } + break; + + case E_Access_Subprogram_Type: + case E_Anonymous_Access_Subprogram_Type: + /* Use the special descriptor type for dispatch tables if needed, + that is to say for the Prim_Ptr of a-tags.ads and its clones. + Note that we are only required to do so for static tables in + order to be compatible with the C++ ABI, but Ada 2005 allows + to extend library level tagged types at the local level so + we do it in the non-static case as well. */ + if (TARGET_VTABLE_USES_DESCRIPTORS + && Is_Dispatch_Table_Entity (gnat_entity)) + { + gnu_type = fdesc_type_node; + gnu_size = TYPE_SIZE (gnu_type); + break; + } + + /* ... fall through ... */ + + case E_Allocator_Type: + case E_Access_Type: + case E_Access_Attribute_Type: + case E_Anonymous_Access_Type: + case E_General_Access_Type: + { + /* The designated type and its equivalent type for gigi. */ + Entity_Id gnat_desig_type = Directly_Designated_Type (gnat_entity); + Entity_Id gnat_desig_equiv = Gigi_Equivalent_Type (gnat_desig_type); + /* Whether it comes from a limited with. */ + const bool is_from_limited_with + = (Is_Incomplete_Type (gnat_desig_equiv) + && From_Limited_With (gnat_desig_equiv)); + /* Whether it is a completed Taft Amendment type. Such a type is to + be treated as coming from a limited with clause if it is not in + the main unit, i.e. we break potential circularities here in case + the body of an external unit is loaded for inter-unit inlining. */ + const bool is_completed_taft_type + = (Is_Incomplete_Type (gnat_desig_equiv) + && Has_Completion_In_Body (gnat_desig_equiv) + && Present (Full_View (gnat_desig_equiv))); + /* The "full view" of the designated type. If this is an incomplete + entity from a limited with, treat its non-limited view as the full + view. Otherwise, if this is an incomplete or private type, use the + full view. In the former case, we might point to a private type, + in which case, we need its full view. Also, we want to look at the + actual type used for the representation, so this takes a total of + three steps. */ + Entity_Id gnat_desig_full_direct_first + = (is_from_limited_with + ? Non_Limited_View (gnat_desig_equiv) + : (Is_Incomplete_Or_Private_Type (gnat_desig_equiv) + ? Full_View (gnat_desig_equiv) : Empty)); + Entity_Id gnat_desig_full_direct + = ((is_from_limited_with + && Present (gnat_desig_full_direct_first) + && Is_Private_Type (gnat_desig_full_direct_first)) + ? Full_View (gnat_desig_full_direct_first) + : gnat_desig_full_direct_first); + Entity_Id gnat_desig_full + = Gigi_Equivalent_Type (gnat_desig_full_direct); + /* The type actually used to represent the designated type, either + gnat_desig_full or gnat_desig_equiv. */ + Entity_Id gnat_desig_rep; + /* We want to know if we'll be seeing the freeze node for any + incomplete type we may be pointing to. */ + const bool in_main_unit + = (Present (gnat_desig_full) + ? In_Extended_Main_Code_Unit (gnat_desig_full) + : In_Extended_Main_Code_Unit (gnat_desig_type)); + /* True if we make a dummy type here. */ + bool made_dummy = false; + /* The mode to be used for the pointer type. */ + scalar_int_mode p_mode; + /* The GCC type used for the designated type. */ + tree gnu_desig_type = NULL_TREE; + + if (!int_mode_for_size (esize, 0).exists (&p_mode) + || !targetm.valid_pointer_mode (p_mode)) + p_mode = ptr_mode; + + /* If either the designated type or its full view is an unconstrained + array subtype, replace it with the type it's a subtype of. This + avoids problems with multiple copies of unconstrained array types. + Likewise, if the designated type is a subtype of an incomplete + record type, use the parent type to avoid order of elaboration + issues. This can lose some code efficiency, but there is no + alternative. */ + if (Ekind (gnat_desig_equiv) == E_Array_Subtype + && !Is_Constrained (gnat_desig_equiv)) + gnat_desig_equiv = Etype (gnat_desig_equiv); + if (Present (gnat_desig_full) + && ((Ekind (gnat_desig_full) == E_Array_Subtype + && !Is_Constrained (gnat_desig_full)) + || (Ekind (gnat_desig_full) == E_Record_Subtype + && Ekind (Etype (gnat_desig_full)) == E_Record_Type))) + gnat_desig_full = Etype (gnat_desig_full); + + /* Set the type that's the representation of the designated type. */ + gnat_desig_rep + = Present (gnat_desig_full) ? gnat_desig_full : gnat_desig_equiv; + + /* If we already know what the full type is, use it. */ + if (Present (gnat_desig_full) && present_gnu_tree (gnat_desig_full)) + gnu_desig_type = TREE_TYPE (get_gnu_tree (gnat_desig_full)); + + /* Get the type of the thing we are to point to and build a pointer to + it. If it is a reference to an incomplete or private type with a + full view that is a record, an array or an access, make a dummy type + and get the actual type later when we have verified it is safe. */ + else if ((!in_main_unit + && !present_gnu_tree (gnat_desig_equiv) + && Present (gnat_desig_full) + && (Is_Record_Type (gnat_desig_full) + || Is_Array_Type (gnat_desig_full) + || Is_Access_Type (gnat_desig_full))) + /* Likewise if this is a reference to a record, an array or a + subprogram type and we are to defer elaborating incomplete + types. We do this because this access type may be the full + view of a private type. */ + || ((!in_main_unit || imported_p) + && defer_incomplete_level != 0 + && !present_gnu_tree (gnat_desig_equiv) + && (Is_Record_Type (gnat_desig_rep) + || Is_Array_Type (gnat_desig_rep) + || Ekind (gnat_desig_rep) == E_Subprogram_Type)) + /* If this is a reference from a limited_with type back to our + main unit and there's a freeze node for it, either we have + already processed the declaration and made the dummy type, + in which case we just reuse the latter, or we have not yet, + in which case we make the dummy type and it will be reused + when the declaration is finally processed. In both cases, + the pointer eventually created below will be automatically + adjusted when the freeze node is processed. */ + || (in_main_unit + && is_from_limited_with + && Present (Freeze_Node (gnat_desig_rep)))) + { + gnu_desig_type = make_dummy_type (gnat_desig_equiv); + made_dummy = true; + } + + /* Otherwise handle the case of a pointer to itself. */ + else if (gnat_desig_equiv == gnat_entity) + { + gnu_type + = build_pointer_type_for_mode (void_type_node, p_mode, + No_Strict_Aliasing (gnat_entity)); + TREE_TYPE (gnu_type) = TYPE_POINTER_TO (gnu_type) = gnu_type; + } + + /* If expansion is disabled, the equivalent type of a concurrent type + is absent, so we use the void pointer type. */ + else if (type_annotate_only && No (gnat_desig_equiv)) + gnu_type = ptr_type_node; + + /* If the ultimately designated type is an incomplete type with no full + view, we use the void pointer type in LTO mode to avoid emitting a + dummy type in the GIMPLE IR. We cannot do that in regular mode as + the name of the dummy type in used by GDB for a global lookup. */ + else if (Ekind (gnat_desig_rep) == E_Incomplete_Type + && No (Full_View (gnat_desig_rep)) + && flag_generate_lto) + gnu_type = ptr_type_node; + + /* Finally, handle the default case where we can just elaborate our + designated type. */ + else + gnu_desig_type = gnat_to_gnu_type (gnat_desig_equiv); + + /* It is possible that a call to gnat_to_gnu_type above resolved our + type. If so, just return it. */ + if (present_gnu_tree (gnat_entity)) + { + maybe_present = true; + break; + } + + /* Access-to-unconstrained-array types need a special treatment. */ + if (Is_Array_Type (gnat_desig_rep) && !Is_Constrained (gnat_desig_rep)) + { + /* If the processing above got something that has a pointer, then + we are done. This could have happened either because the type + was elaborated or because somebody else executed the code. */ + if (!TYPE_POINTER_TO (gnu_desig_type)) + build_dummy_unc_pointer_types (gnat_desig_equiv, gnu_desig_type); + + gnu_type = TYPE_POINTER_TO (gnu_desig_type); + } + + /* If we haven't done it yet, build the pointer type the usual way. */ + else if (!gnu_type) + { + /* Modify the designated type if we are pointing only to constant + objects, but don't do it for a dummy type. */ + if (Is_Access_Constant (gnat_entity) + && !TYPE_IS_DUMMY_P (gnu_desig_type)) + gnu_desig_type + = change_qualified_type (gnu_desig_type, TYPE_QUAL_CONST); + + gnu_type + = build_pointer_type_for_mode (gnu_desig_type, p_mode, + No_Strict_Aliasing (gnat_entity)); + } + + /* If the designated type is not declared in the main unit and we made + a dummy node for it, save our definition, elaborate the actual type + and replace the dummy type we made with the actual one. But if we + are to defer actually looking up the actual type, make an entry in + the deferred list instead. If this is from a limited with, we may + have to defer until the end of the current unit. */ + if (!in_main_unit && made_dummy) + { + if (TYPE_IS_FAT_POINTER_P (gnu_type) && esize == POINTER_SIZE) + gnu_type + = build_pointer_type (TYPE_OBJECT_RECORD_TYPE (gnu_desig_type)); + + process_attributes (&gnu_type, &attr_list, false, gnat_entity); + gnu_decl = create_type_decl (gnu_entity_name, gnu_type, + artificial_p, debug_info_p, + gnat_entity); + this_made_decl = true; + gnu_type = TREE_TYPE (gnu_decl); + save_gnu_tree (gnat_entity, gnu_decl, false); + saved = true; + + if (defer_incomplete_level == 0 + && !is_from_limited_with + && !is_completed_taft_type) + { + update_pointer_to (TYPE_MAIN_VARIANT (gnu_desig_type), + gnat_to_gnu_type (gnat_desig_equiv)); + } + else + { + struct incomplete *p = XNEW (struct incomplete); + struct incomplete **head + = (is_from_limited_with || is_completed_taft_type + ? &defer_limited_with_list : &defer_incomplete_list); + + p->old_type = gnu_desig_type; + p->full_type = gnat_desig_equiv; + p->next = *head; + *head = p; + } + } + } + break; + + case E_Access_Protected_Subprogram_Type: + case E_Anonymous_Access_Protected_Subprogram_Type: + /* If we are just annotating types and have no equivalent record type, + just use the void pointer type. */ + if (type_annotate_only && gnat_equiv_type == gnat_entity) + gnu_type = ptr_type_node; + + /* The run-time representation is the equivalent type. */ + else + { + gnu_type = gnat_to_gnu_type (gnat_equiv_type); + maybe_present = true; + } + + /* The designated subtype must be elaborated as well, if it does + not have its own freeze node. */ + if (Is_Itype (Directly_Designated_Type (gnat_entity)) + && !present_gnu_tree (Directly_Designated_Type (gnat_entity)) + && No (Freeze_Node (Directly_Designated_Type (gnat_entity))) + && !Is_Record_Type (Scope (Directly_Designated_Type (gnat_entity)))) + gnat_to_gnu_entity (Directly_Designated_Type (gnat_entity), + NULL_TREE, false); + + break; + + case E_Access_Subtype: + /* We treat this as identical to its base type; any constraint is + meaningful only to the front-end. */ + gnu_decl = gnat_to_gnu_entity (gnat_equiv_type, NULL_TREE, false); + maybe_present = true; + + /* The designated subtype must be elaborated as well, if it does + not have its own freeze node. But designated subtypes created + for constrained components of records with discriminants are + not frozen by the front-end and not elaborated here, because + their use may appear before the base type is frozen and it is + not clear that they are needed in gigi. With the current model, + there is no correct place where they could be elaborated. */ + if (Is_Itype (Directly_Designated_Type (gnat_entity)) + && !present_gnu_tree (Directly_Designated_Type (gnat_entity)) + && Is_Frozen (Directly_Designated_Type (gnat_entity)) + && No (Freeze_Node (Directly_Designated_Type (gnat_entity)))) + { + /* If we are to defer elaborating incomplete types, make a dummy + type node and elaborate it later. */ + if (defer_incomplete_level != 0) + { + struct incomplete *p = XNEW (struct incomplete); + + p->old_type + = make_dummy_type (Directly_Designated_Type (gnat_entity)); + p->full_type = Directly_Designated_Type (gnat_entity); + p->next = defer_incomplete_list; + defer_incomplete_list = p; + } + else if (!Is_Incomplete_Or_Private_Type + (Base_Type (Directly_Designated_Type (gnat_entity)))) + gnat_to_gnu_entity (Directly_Designated_Type (gnat_entity), + NULL_TREE, false); + } + break; + + /* Subprogram Entities + + The following access functions are defined for subprograms: + + Etype Return type or Standard_Void_Type. + First_Formal The first formal parameter. + Is_Imported Indicates that the subprogram has appeared in + an INTERFACE or IMPORT pragma. For now we + assume that the external language is C. + Is_Exported Likewise but for an EXPORT pragma. + Is_Inlined True if the subprogram is to be inlined. + + Each parameter is first checked by calling must_pass_by_ref on its + type to determine if it is passed by reference. For parameters which + are copied in, if they are Ada In Out or Out parameters, their return + value becomes part of a record which becomes the return type of the + function (C function - note that this applies only to Ada procedures + so there is no Ada return type). Additional code to store back the + parameters will be generated on the caller side. This transformation + is done here, not in the front-end. + + The intended result of the transformation can be seen from the + equivalent source rewritings that follow: + + struct temp {int a,b}; + procedure P (A,B: In Out ...) is temp P (int A,B) + begin { + .. .. + end P; return {A,B}; + } + + temp t; + P(X,Y); t = P(X,Y); + X = t.a , Y = t.b; + + For subprogram types we need to perform mainly the same conversions to + GCC form that are needed for procedures and function declarations. The + only difference is that at the end, we make a type declaration instead + of a function declaration. */ + + case E_Subprogram_Type: + case E_Function: + case E_Procedure: + { + tree gnu_ext_name + = gnu_ext_name_for_subprog (gnat_entity, gnu_entity_name); + const enum inline_status_t inline_status + = inline_status_for_subprog (gnat_entity); + bool public_flag = Is_Public (gnat_entity) || imported_p; + /* Subprograms marked both Intrinsic and Always_Inline need not + have a body of their own. */ + bool extern_flag + = ((Is_Public (gnat_entity) && !definition) + || imported_p + || (Is_Intrinsic_Subprogram (gnat_entity) + && Has_Pragma_Inline_Always (gnat_entity))); + tree gnu_param_list; + + /* A parameter may refer to this type, so defer completion of any + incomplete types. */ + if (kind == E_Subprogram_Type && !definition) + { + defer_incomplete_level++; + this_deferred = true; + } + + /* If the subprogram has an alias, it is probably inherited, so + we can use the original one. If the original "subprogram" + is actually an enumeration literal, it may be the first use + of its type, so we must elaborate that type now. */ + if (Present (Alias (gnat_entity))) + { + const Entity_Id gnat_alias = Alias (gnat_entity); + + if (Ekind (gnat_alias) == E_Enumeration_Literal) + gnat_to_gnu_entity (Etype (gnat_alias), NULL_TREE, false); + + gnu_decl = gnat_to_gnu_entity (gnat_alias, gnu_expr, false); + + /* Elaborate any itypes in the parameters of this entity. */ + for (gnat_temp = First_Formal_With_Extras (gnat_entity); + Present (gnat_temp); + gnat_temp = Next_Formal_With_Extras (gnat_temp)) + if (Is_Itype (Etype (gnat_temp))) + gnat_to_gnu_entity (Etype (gnat_temp), NULL_TREE, false); + + /* Materialize renamed subprograms in the debugging information + when the renamed object is known at compile time; we consider + such renamings as imported declarations. + + Because the parameters in generic instantiations are generally + materialized as renamings, we often end up having both the + renamed subprogram and the renaming in the same context and with + the same name; in this case, renaming is both useless debug-wise + and potentially harmful as name resolution in the debugger could + return twice the same entity! So avoid this case. */ + if (debug_info_p + && !artificial_p + && (Ekind (gnat_alias) == E_Function + || Ekind (gnat_alias) == E_Procedure) + && !(get_debug_scope (gnat_entity, NULL) + == get_debug_scope (gnat_alias, NULL) + && Name_Equals (Chars (gnat_entity), Chars (gnat_alias))) + && TREE_CODE (gnu_decl) == FUNCTION_DECL) + { + tree decl = build_decl (input_location, IMPORTED_DECL, + gnu_entity_name, void_type_node); + IMPORTED_DECL_ASSOCIATED_DECL (decl) = gnu_decl; + gnat_pushdecl (decl, gnat_entity); + } + + break; + } + + /* Get the GCC tree for the (underlying) subprogram type. If the + entity is an actual subprogram, also get the parameter list. */ + gnu_type + = gnat_to_gnu_subprog_type (gnat_entity, definition, debug_info_p, + &gnu_param_list); + if (DECL_P (gnu_type)) + { + gnu_decl = gnu_type; + gnu_type = TREE_TYPE (gnu_decl); + break; + } + + /* Deal with platform-specific calling conventions. */ + if (Has_Stdcall_Convention (gnat_entity)) + prepend_one_attribute + (&attr_list, ATTR_MACHINE_ATTRIBUTE, + get_identifier ("stdcall"), NULL_TREE, + gnat_entity); + + /* If we should request stack realignment for a foreign convention + subprogram, do so. Note that this applies to task entry points + in particular. */ + if (FOREIGN_FORCE_REALIGN_STACK && foreign) + prepend_one_attribute + (&attr_list, ATTR_MACHINE_ATTRIBUTE, + get_identifier ("force_align_arg_pointer"), NULL_TREE, + gnat_entity); + + /* Deal with a pragma Linker_Section on a subprogram. */ + if ((kind == E_Function || kind == E_Procedure) + && Present (Linker_Section_Pragma (gnat_entity))) + prepend_one_attribute_pragma (&attr_list, + Linker_Section_Pragma (gnat_entity)); + + /* If we are defining the subprogram and it has an Address clause + we must get the address expression from the saved GCC tree for the + subprogram if it has a Freeze_Node. Otherwise, we elaborate + the address expression here since the front-end has guaranteed + in that case that the elaboration has no effects. If there is + an Address clause and we are not defining the object, just + make it a constant. */ + if (Present (Address_Clause (gnat_entity))) + { + tree gnu_address = NULL_TREE; + + if (definition) + gnu_address + = (present_gnu_tree (gnat_entity) + ? get_gnu_tree (gnat_entity) + : gnat_to_gnu (Expression (Address_Clause (gnat_entity)))); + + save_gnu_tree (gnat_entity, NULL_TREE, false); + + /* Convert the type of the object to a reference type that can + alias everything as per RM 13.3(19). */ + gnu_type + = build_reference_type_for_mode (gnu_type, ptr_mode, true); + if (gnu_address) + gnu_address = convert (gnu_type, gnu_address); + + gnu_decl + = create_var_decl (gnu_entity_name, gnu_ext_name, gnu_type, + gnu_address, false, Is_Public (gnat_entity), + extern_flag, false, false, artificial_p, + debug_info_p, NULL, gnat_entity); + DECL_BY_REF_P (gnu_decl) = 1; + } + + /* If this is a mere subprogram type, just create the declaration. */ + else if (kind == E_Subprogram_Type) + { + process_attributes (&gnu_type, &attr_list, false, gnat_entity); + + gnu_decl + = create_type_decl (gnu_entity_name, gnu_type, artificial_p, + debug_info_p, gnat_entity); + } + + /* Otherwise create the subprogram declaration with the external name, + the type and the parameter list. However, if this a reference to + the allocation routines, reuse the canonical declaration nodes as + they come with special properties. */ + else + { + if (extern_flag && gnu_ext_name == DECL_NAME (malloc_decl)) + gnu_decl = malloc_decl; + else if (extern_flag && gnu_ext_name == DECL_NAME (realloc_decl)) + gnu_decl = realloc_decl; + else + gnu_decl + = create_subprog_decl (gnu_entity_name, gnu_ext_name, + gnu_type, gnu_param_list, + inline_status, public_flag, + extern_flag, artificial_p, + debug_info_p, + definition && imported_p, attr_list, + gnat_entity); + } + } + break; + + case E_Incomplete_Type: + case E_Incomplete_Subtype: + case E_Private_Type: + case E_Private_Subtype: + case E_Limited_Private_Type: + case E_Limited_Private_Subtype: + case E_Record_Type_With_Private: + case E_Record_Subtype_With_Private: + { + const bool is_from_limited_with + = (IN (kind, Incomplete_Kind) && From_Limited_With (gnat_entity)); + /* Get the "full view" of this entity. If this is an incomplete + entity from a limited with, treat its non-limited view as the + full view. Otherwise, use either the full view or the underlying + full view, whichever is present. This is used in all the tests + below. */ + const Entity_Id full_view + = is_from_limited_with + ? Non_Limited_View (gnat_entity) + : Present (Full_View (gnat_entity)) + ? Full_View (gnat_entity) + : IN (kind, Private_Kind) + ? Underlying_Full_View (gnat_entity) + : Empty; + + /* If this is an incomplete type with no full view, it must be a Taft + Amendment type or an incomplete type coming from a limited context, + in which cases we return a dummy type. Otherwise, we just get the + type from its Etype. */ + if (No (full_view)) + { + if (kind == E_Incomplete_Type) + { + gnu_type = make_dummy_type (gnat_entity); + gnu_decl = TYPE_STUB_DECL (gnu_type); + } + else + { + gnu_decl + = gnat_to_gnu_entity (Etype (gnat_entity), NULL_TREE, false); + maybe_present = true; + } + } + + /* Or else, if we already made a type for the full view, reuse it. */ + else if (present_gnu_tree (full_view)) + gnu_decl = get_gnu_tree (full_view); + + /* Or else, if we are not defining the type or there is no freeze + node on it, get the type for the full view. Likewise if this is + a limited_with'ed type not declared in the main unit, which can + happen for incomplete formal types instantiated on a type coming + from a limited_with clause. */ + else if (!definition + || No (Freeze_Node (full_view)) + || (is_from_limited_with + && !In_Extended_Main_Code_Unit (full_view))) + { + gnu_decl = gnat_to_gnu_entity (full_view, NULL_TREE, false); + maybe_present = true; + } + + /* Otherwise, make a dummy type entry which will be replaced later. + Save it as the full declaration's type so we can do any needed + updates when we see it. */ + else + { + gnu_type = make_dummy_type (gnat_entity); + gnu_decl = TYPE_STUB_DECL (gnu_type); + if (Has_Completion_In_Body (gnat_entity)) + DECL_TAFT_TYPE_P (gnu_decl) = 1; + save_gnu_tree (full_view, gnu_decl, false); + } + } + break; + + case E_Class_Wide_Type: + /* Class-wide types are always transformed into their root type. */ + gnu_decl = gnat_to_gnu_entity (gnat_equiv_type, NULL_TREE, false); + maybe_present = true; + break; + + case E_Protected_Type: + case E_Protected_Subtype: + case E_Task_Type: + case E_Task_Subtype: + /* If we are just annotating types and have no equivalent record type, + just return void_type, except for root types that have discriminants + because the discriminants will very likely be used in the declarative + part of the associated body so they need to be translated. */ + if (type_annotate_only && gnat_equiv_type == gnat_entity) + { + if (definition + && Has_Discriminants (gnat_entity) + && Root_Type (gnat_entity) == gnat_entity) + { + tree gnu_field_list = NULL_TREE; + Entity_Id gnat_field; + + /* This is a minimal version of the E_Record_Type handling. */ + gnu_type = make_node (RECORD_TYPE); + TYPE_NAME (gnu_type) = gnu_entity_name; + + for (gnat_field = First_Stored_Discriminant (gnat_entity); + Present (gnat_field); + gnat_field = Next_Stored_Discriminant (gnat_field)) + { + tree gnu_field + = gnat_to_gnu_field (gnat_field, gnu_type, false, + definition, debug_info_p); + + save_gnu_tree (gnat_field, + build3 (COMPONENT_REF, TREE_TYPE (gnu_field), + build0 (PLACEHOLDER_EXPR, gnu_type), + gnu_field, NULL_TREE), + true); + + DECL_CHAIN (gnu_field) = gnu_field_list; + gnu_field_list = gnu_field; + } + + finish_record_type (gnu_type, nreverse (gnu_field_list), 0, + false); + } + else + gnu_type = void_type_node; + } + + /* Concurrent types are always transformed into their record type. */ + else + gnu_decl = gnat_to_gnu_entity (gnat_equiv_type, NULL_TREE, false); + maybe_present = true; + break; + + case E_Label: + gnu_decl = create_label_decl (gnu_entity_name, gnat_entity); + break; + + case E_Block: + case E_Loop: + /* Nothing at all to do here, so just return an ERROR_MARK and claim + we've already saved it, so we don't try to. */ + gnu_decl = error_mark_node; + saved = true; + break; + + case E_Abstract_State: + /* This is a SPARK annotation that only reaches here when compiling in + ASIS mode. */ + gcc_assert (type_annotate_only); + gnu_decl = error_mark_node; + saved = true; + break; + + default: + gcc_unreachable (); + } + + /* If we had a case where we evaluated another type and it might have + defined this one, handle it here. */ + if (maybe_present && present_gnu_tree (gnat_entity)) + { + gnu_decl = get_gnu_tree (gnat_entity); + saved = true; + } + + /* If we are processing a type and there is either no DECL for it or + we just made one, do some common processing for the type, such as + handling alignment and possible padding. */ + if (is_type && (!gnu_decl || this_made_decl)) + { + const bool is_by_ref = Is_By_Reference_Type (gnat_entity); + + gcc_assert (!TYPE_IS_DUMMY_P (gnu_type)); + + /* Process the attributes, if not already done. Note that the type is + already defined so we cannot pass true for IN_PLACE here. */ + process_attributes (&gnu_type, &attr_list, false, gnat_entity); + + /* See if a size was specified, by means of either an Object_Size or + a regular Size clause, and validate it if so. + + ??? Don't set the size for a String_Literal since it is either + confirming or we don't handle it properly (if the low bound is + non-constant). */ + if (!gnu_size && kind != E_String_Literal_Subtype) + { + const char *size_s = "size for %s too small{, minimum allowed is ^}"; + const char *type_s = is_by_ref ? "by-reference type &" : "&"; + + if (Known_Esize (gnat_entity)) + gnu_size + = validate_size (Esize (gnat_entity), gnu_type, gnat_entity, + VAR_DECL, false, false, size_s, type_s); + + /* ??? The test on Has_Size_Clause must be removed when "unknown" is + no longer represented as Uint_0 (i.e. Use_New_Unknown_Rep). */ + else if (Known_RM_Size (gnat_entity) + || Has_Size_Clause (gnat_entity)) + gnu_size + = validate_size (RM_Size (gnat_entity), gnu_type, gnat_entity, + TYPE_DECL, false, Has_Size_Clause (gnat_entity), + size_s, type_s); + } + + /* If a size was specified, see if we can make a new type of that size + by rearranging the type, for example from a fat to a thin pointer. */ + if (gnu_size) + { + gnu_type + = make_type_from_size (gnu_type, gnu_size, + Has_Biased_Representation (gnat_entity)); + + if (operand_equal_p (TYPE_SIZE (gnu_type), gnu_size, 0) + && operand_equal_p (rm_size (gnu_type), gnu_size, 0)) + gnu_size = NULL_TREE; + } + + /* If the alignment has not already been processed and this is not + an unconstrained array type, see if an alignment is specified. + If not, we pick a default alignment for atomic objects. */ + if (align != 0 || TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE) + ; + else if (Known_Alignment (gnat_entity)) + { + align = validate_alignment (Alignment (gnat_entity), gnat_entity, + TYPE_ALIGN (gnu_type)); + + /* Warn on suspiciously large alignments. This should catch + errors about the (alignment,byte)/(size,bit) discrepancy. */ + if (align > BIGGEST_ALIGNMENT && Has_Alignment_Clause (gnat_entity)) + { + tree size; + + /* If a size was specified, take it into account. Otherwise + use the RM size for records or unions as the type size has + already been adjusted to the alignment. */ + if (gnu_size) + size = gnu_size; + else if (RECORD_OR_UNION_TYPE_P (gnu_type) + && !TYPE_FAT_POINTER_P (gnu_type)) + size = rm_size (gnu_type); + else + size = TYPE_SIZE (gnu_type); + + /* Consider an alignment as suspicious if the alignment/size + ratio is greater or equal to the byte/bit ratio. */ + if (tree_fits_uhwi_p (size) + && align >= tree_to_uhwi (size) * BITS_PER_UNIT) + post_error_ne ("??suspiciously large alignment specified for&", + Expression (Alignment_Clause (gnat_entity)), + gnat_entity); + } + } + else if (Is_Full_Access (gnat_entity) && !gnu_size + && tree_fits_uhwi_p (TYPE_SIZE (gnu_type)) + && integer_pow2p (TYPE_SIZE (gnu_type))) + align = MIN (BIGGEST_ALIGNMENT, + tree_to_uhwi (TYPE_SIZE (gnu_type))); + else if (Is_Full_Access (gnat_entity) && gnu_size + && tree_fits_uhwi_p (gnu_size) + && integer_pow2p (gnu_size)) + align = MIN (BIGGEST_ALIGNMENT, tree_to_uhwi (gnu_size)); + + /* See if we need to pad the type. If we did and built a new type, + then create a stripped-down declaration for the original type, + mainly for debugging, unless there was already one. */ + if (gnu_size || align > 0) + { + tree orig_type = gnu_type; + + gnu_type = maybe_pad_type (gnu_type, gnu_size, align, gnat_entity, + false, definition, false); + + if (gnu_type != orig_type && !gnu_decl) + create_type_decl (gnu_entity_name, orig_type, true, debug_info_p, + gnat_entity); + } + + /* Now set the RM size of the type. We cannot do it before padding + because we need to accept arbitrary RM sizes on integral types. */ + if (Known_RM_Size (gnat_entity)) + set_rm_size (RM_Size (gnat_entity), gnu_type, gnat_entity); + + /* Back-annotate the alignment of the type if not already set. */ + if (!Known_Alignment (gnat_entity)) + { + unsigned int double_align, align; + bool is_capped_double, align_clause; + + /* If the default alignment of "double" or larger scalar types is + specifically capped and this is not an array with an alignment + clause on the component type, return the cap. */ + if ((double_align = double_float_alignment) > 0) + is_capped_double + = is_double_float_or_array (gnat_entity, &align_clause); + else if ((double_align = double_scalar_alignment) > 0) + is_capped_double + = is_double_scalar_or_array (gnat_entity, &align_clause); + else + is_capped_double = align_clause = false; + + if (is_capped_double && !align_clause) + align = double_align; + else + align = TYPE_ALIGN (gnu_type) / BITS_PER_UNIT; + + Set_Alignment (gnat_entity, UI_From_Int (align)); + } + + /* Likewise for the size, if any. */ + if (!Known_Esize (gnat_entity) && TYPE_SIZE (gnu_type)) + { + tree size = TYPE_SIZE (gnu_type); + + /* If the size is self-referential, annotate the maximum value + after saturating it, if need be, to avoid a No_Uint value. + But do not do it for cases where Analyze_Object_Declaration + in Sem_Ch3 would build a default subtype for objects. */ + if (CONTAINS_PLACEHOLDER_P (size) + && !Is_Limited_Record (gnat_entity) + && !Is_Concurrent_Type (gnat_entity)) + { + const unsigned int align + = UI_To_Int (Alignment (gnat_entity)) * BITS_PER_UNIT; + size = maybe_saturate_size (max_size (size, true), align); + } + + /* If we are just annotating types and the type is tagged, the tag + and the parent components are not generated by the front-end so + alignment and sizes must be adjusted. */ + if (type_annotate_only && Is_Tagged_Type (gnat_entity)) + { + const bool derived_p = Is_Derived_Type (gnat_entity); + const Entity_Id gnat_parent + = derived_p ? Etype (Base_Type (gnat_entity)) : Empty; + /* The following test for Known_Alignment preserves the old behavior, + but is probably wrong. */ + const unsigned int inherited_align + = derived_p + ? (Known_Alignment (gnat_parent) + ? UI_To_Int (Alignment (gnat_parent)) * BITS_PER_UNIT + : 0) + : POINTER_SIZE; + const unsigned int align + = MAX (TYPE_ALIGN (gnu_type), inherited_align); + + Set_Alignment (gnat_entity, UI_From_Int (align / BITS_PER_UNIT)); + + /* If there is neither size clause nor representation clause, the + sizes need to be adjusted. */ + if (!Known_RM_Size (gnat_entity) + && !VOID_TYPE_P (gnu_type) + && (!TYPE_FIELDS (gnu_type) + || integer_zerop (bit_position (TYPE_FIELDS (gnu_type))))) + { + tree offset + = derived_p + ? UI_To_gnu (Esize (gnat_parent), bitsizetype) + : bitsize_int (POINTER_SIZE); + if (TYPE_FIELDS (gnu_type)) + offset + = round_up (offset, DECL_ALIGN (TYPE_FIELDS (gnu_type))); + size = size_binop (PLUS_EXPR, size, offset); + } + + size = maybe_saturate_size (round_up (size, align), align); + Set_Esize (gnat_entity, annotate_value (size)); + + /* Tagged types are Strict_Alignment so RM_Size = Esize. */ + if (!Known_RM_Size (gnat_entity)) + Set_RM_Size (gnat_entity, Esize (gnat_entity)); + } + + /* Otherwise no adjustment is needed. */ + else + Set_Esize (gnat_entity, No_Uint_To_0 (annotate_value (size))); + } + + /* Likewise for the RM size, if any. */ + if (!Known_RM_Size (gnat_entity) && TYPE_SIZE (gnu_type)) + Set_RM_Size (gnat_entity, + annotate_value (rm_size (gnu_type))); + + /* If we are at global level, GCC applied variable_size to the size but + this has done nothing. So, if it's not constant or self-referential, + call elaborate_expression_1 to make a variable for it rather than + calculating it each time. */ + if (TYPE_SIZE (gnu_type) + && !TREE_CONSTANT (TYPE_SIZE (gnu_type)) + && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type)) + && global_bindings_p ()) + { + tree orig_size = TYPE_SIZE (gnu_type); + + TYPE_SIZE (gnu_type) + = elaborate_expression_1 (TYPE_SIZE (gnu_type), gnat_entity, + "SIZE", definition, false); + + /* ??? For now, store the size as a multiple of the alignment in + bytes so that we can see the alignment from the tree. */ + TYPE_SIZE_UNIT (gnu_type) + = elaborate_expression_2 (TYPE_SIZE_UNIT (gnu_type), gnat_entity, + "SIZE_A_UNIT", definition, false, + TYPE_ALIGN (gnu_type)); + + /* ??? gnu_type may come from an existing type so the MULT_EXPR node + may not be marked by the call to create_type_decl below. */ + MARK_VISITED (TYPE_SIZE_UNIT (gnu_type)); + + /* For a record type, deal with the variant part, if any, and handle + the Ada size as well. */ + if (RECORD_OR_UNION_TYPE_P (gnu_type)) + { + tree variant_part = get_variant_part (gnu_type); + tree ada_size = TYPE_ADA_SIZE (gnu_type); + + if (variant_part) + { + tree union_type = TREE_TYPE (variant_part); + tree offset = DECL_FIELD_OFFSET (variant_part); + + /* If the position of the variant part is constant, subtract + it from the size of the type of the parent to get the new + size. This manual CSE reduces the data size. */ + if (TREE_CODE (offset) == INTEGER_CST) + { + tree bitpos = DECL_FIELD_BIT_OFFSET (variant_part); + TYPE_SIZE (union_type) + = size_binop (MINUS_EXPR, TYPE_SIZE (gnu_type), + bit_from_pos (offset, bitpos)); + TYPE_SIZE_UNIT (union_type) + = size_binop (MINUS_EXPR, TYPE_SIZE_UNIT (gnu_type), + byte_from_pos (offset, bitpos)); + } + else + { + TYPE_SIZE (union_type) + = elaborate_expression_1 (TYPE_SIZE (union_type), + gnat_entity, "VSIZE", + definition, false); + + /* ??? For now, store the size as a multiple of the + alignment in bytes so that we can see the alignment + from the tree. */ + TYPE_SIZE_UNIT (union_type) + = elaborate_expression_2 (TYPE_SIZE_UNIT (union_type), + gnat_entity, "VSIZE_A_UNIT", + definition, false, + TYPE_ALIGN (union_type)); + + /* ??? For now, store the offset as a multiple of the + alignment in bytes so that we can see the alignment + from the tree. */ + DECL_FIELD_OFFSET (variant_part) + = elaborate_expression_2 (offset, gnat_entity, + "VOFFSET", definition, false, + DECL_OFFSET_ALIGN + (variant_part)); + } + + DECL_SIZE (variant_part) = TYPE_SIZE (union_type); + DECL_SIZE_UNIT (variant_part) = TYPE_SIZE_UNIT (union_type); + } + + if (operand_equal_p (ada_size, orig_size, 0)) + ada_size = TYPE_SIZE (gnu_type); + else + ada_size + = elaborate_expression_1 (ada_size, gnat_entity, "RM_SIZE", + definition, false); + SET_TYPE_ADA_SIZE (gnu_type, ada_size); + } + } + + /* Similarly, if this is a record type or subtype at global level, call + elaborate_expression_2 on any field position. Skip any fields that + we haven't made trees for to avoid problems with class-wide types. */ + if (Is_In_Record_Kind (kind) && global_bindings_p ()) + for (gnat_temp = First_Entity (gnat_entity); Present (gnat_temp); + gnat_temp = Next_Entity (gnat_temp)) + if (Ekind (gnat_temp) == E_Component && present_gnu_tree (gnat_temp)) + { + tree gnu_field = get_gnu_tree (gnat_temp); + + /* ??? For now, store the offset as a multiple of the alignment + in bytes so that we can see the alignment from the tree. */ + if (!TREE_CONSTANT (DECL_FIELD_OFFSET (gnu_field)) + && !CONTAINS_PLACEHOLDER_P (DECL_FIELD_OFFSET (gnu_field))) + { + DECL_FIELD_OFFSET (gnu_field) + = elaborate_expression_2 (DECL_FIELD_OFFSET (gnu_field), + gnat_temp, "OFFSET", definition, + false, + DECL_OFFSET_ALIGN (gnu_field)); + + /* ??? The context of gnu_field is not necessarily gnu_type + so the MULT_EXPR node built above may not be marked by + the call to create_type_decl below. */ + MARK_VISITED (DECL_FIELD_OFFSET (gnu_field)); + } + } + + /* Now check if the type allows atomic access. */ + if (Is_Full_Access (gnat_entity)) + check_ok_for_atomic_type (gnu_type, gnat_entity, false); + + /* If this is not an unconstrained array type, set some flags. */ + if (TREE_CODE (gnu_type) != UNCONSTRAINED_ARRAY_TYPE) + { + /* Record the property that objects of tagged types are guaranteed to + be properly aligned. This is necessary because conversions to the + class-wide type are translated into conversions to the root type, + which can be less aligned than some of its derived types. */ + if (Is_Tagged_Type (gnat_entity) + || Is_Class_Wide_Equivalent_Type (gnat_entity)) + TYPE_ALIGN_OK (gnu_type) = 1; + + /* Record whether the type is passed by reference. */ + if (is_by_ref && !VOID_TYPE_P (gnu_type)) + TYPE_BY_REFERENCE_P (gnu_type) = 1; + + /* Record whether an alignment clause was specified. */ + if (Present (Alignment_Clause (gnat_entity))) + TYPE_USER_ALIGN (gnu_type) = 1; + + /* Record whether a pragma Universal_Aliasing was specified. */ + if (Universal_Aliasing (gnat_entity) && !TYPE_IS_DUMMY_P (gnu_type)) + TYPE_UNIVERSAL_ALIASING_P (gnu_type) = 1; + + /* If it is passed by reference, force BLKmode to ensure that + objects of this type will always be put in memory. */ + if (AGGREGATE_TYPE_P (gnu_type) && TYPE_BY_REFERENCE_P (gnu_type)) + SET_TYPE_MODE (gnu_type, BLKmode); + } + + /* If this is a derived type, relate its alias set to that of its parent + to avoid troubles when a call to an inherited primitive is inlined in + a context where a derived object is accessed. The inlined code works + on the parent view so the resulting code may access the same object + using both the parent and the derived alias sets, which thus have to + conflict. As the same issue arises with component references, the + parent alias set also has to conflict with composite types enclosing + derived components. For instance, if we have: + + type D is new T; + type R is record + Component : D; + end record; + + we want T to conflict with both D and R, in addition to R being a + superset of D by record/component construction. + + One way to achieve this is to perform an alias set copy from the + parent to the derived type. This is not quite appropriate, though, + as we don't want separate derived types to conflict with each other: + + type I1 is new Integer; + type I2 is new Integer; + + We want I1 and I2 to both conflict with Integer but we do not want + I1 to conflict with I2, and an alias set copy on derivation would + have that effect. + + The option chosen is to make the alias set of the derived type a + superset of that of its parent type. It trivially fulfills the + simple requirement for the Integer derivation example above, and + the component case as well by superset transitivity: + + superset superset + R ----------> D ----------> T + + However, for composite types, conversions between derived types are + translated into VIEW_CONVERT_EXPRs so a sequence like: + + type Comp1 is new Comp; + type Comp2 is new Comp; + procedure Proc (C : Comp1); + + C : Comp2; + Proc (Comp1 (C)); + + is translated into: + + C : Comp2; + Proc ((Comp1 &) &VIEW_CONVERT_EXPR <Comp1> (C)); + + and gimplified into: + + C : Comp2; + Comp1 *C.0; + C.0 = (Comp1 *) &C; + Proc (C.0); + + i.e. generates code involving type punning. Therefore, Comp1 needs + to conflict with Comp2 and an alias set copy is required. + + The language rules ensure the parent type is already frozen here. */ + if (kind != E_Subprogram_Type + && Is_Derived_Type (gnat_entity) + && !type_annotate_only) + { + Entity_Id gnat_parent_type = Underlying_Type (Etype (gnat_entity)); + /* For constrained packed array subtypes, the implementation type is + used instead of the nominal type. */ + if (kind == E_Array_Subtype + && Is_Constrained (gnat_entity) + && Present (Packed_Array_Impl_Type (gnat_parent_type))) + gnat_parent_type = Packed_Array_Impl_Type (gnat_parent_type); + relate_alias_sets (gnu_type, gnat_to_gnu_type (gnat_parent_type), + Is_Composite_Type (gnat_entity) + ? ALIAS_SET_COPY : ALIAS_SET_SUPERSET); + } + + /* Finally get to the appropriate variant, except for the implementation + type of a packed array because the GNU type might be further adjusted + when the original array type is itself processed. */ + if (Treat_As_Volatile (gnat_entity) + && !Is_Packed_Array_Impl_Type (gnat_entity)) + { + const int quals + = TYPE_QUAL_VOLATILE + | (Is_Full_Access (gnat_entity) ? TYPE_QUAL_ATOMIC : 0); + /* This is required by free_lang_data_in_type to disable the ODR. */ + if (TREE_CODE (gnu_type) == ENUMERAL_TYPE) + TYPE_STUB_DECL (gnu_type) + = create_type_stub_decl (TYPE_NAME (gnu_type), gnu_type); + gnu_type = change_qualified_type (gnu_type, quals); + } + + /* If we already made a decl, just set the type, otherwise create it. */ + if (gnu_decl) + { + TREE_TYPE (gnu_decl) = gnu_type; + TYPE_STUB_DECL (gnu_type) = gnu_decl; + } + else + gnu_decl = create_type_decl (gnu_entity_name, gnu_type, artificial_p, + debug_info_p, gnat_entity); + + /* For vector types, make the representative array the debug type. */ + if (VECTOR_TYPE_P (gnu_type)) + { + tree rep = TYPE_REPRESENTATIVE_ARRAY (gnu_type); + TYPE_NAME (rep) = DECL_NAME (gnu_decl); + SET_TYPE_DEBUG_TYPE (gnu_type, rep); + } + } + + /* Otherwise, for a type reusing an existing DECL, back-annotate values. */ + else if (is_type + && !TYPE_IS_DUMMY_P (TREE_TYPE (gnu_decl)) + && Present (gnat_annotate_type)) + { + if (!Known_Alignment (gnat_entity)) + Copy_Alignment (gnat_entity, gnat_annotate_type); + if (!Known_Esize (gnat_entity)) + Copy_Esize (gnat_entity, gnat_annotate_type); + if (!Known_RM_Size (gnat_entity)) + Copy_RM_Size (gnat_entity, gnat_annotate_type); + } + + /* If we haven't already, associate the ..._DECL node that we just made with + the input GNAT entity node. */ + if (!saved) + save_gnu_tree (gnat_entity, gnu_decl, false); + + /* Now we are sure gnat_entity has a corresponding ..._DECL node, + eliminate as many deferred computations as possible. */ + process_deferred_decl_context (false); + + /* If this is an enumeration or floating-point type, we were not able to set + the bounds since they refer to the type. These are always static. */ + if ((kind == E_Enumeration_Type && Present (First_Literal (gnat_entity))) + || (kind == E_Floating_Point_Type)) + { + tree gnu_scalar_type = gnu_type; + tree gnu_low_bound, gnu_high_bound; + + /* If this is a padded type, we need to use the underlying type. */ + if (TYPE_IS_PADDING_P (gnu_scalar_type)) + gnu_scalar_type = TREE_TYPE (TYPE_FIELDS (gnu_scalar_type)); + + /* If this is a floating point type and we haven't set a floating + point type yet, use this in the evaluation of the bounds. */ + if (!longest_float_type_node && kind == E_Floating_Point_Type) + longest_float_type_node = gnu_scalar_type; + + gnu_low_bound = gnat_to_gnu (Type_Low_Bound (gnat_entity)); + gnu_high_bound = gnat_to_gnu (Type_High_Bound (gnat_entity)); + + if (kind == E_Enumeration_Type) + { + /* Enumeration types have specific RM bounds. */ + SET_TYPE_RM_MIN_VALUE (gnu_scalar_type, gnu_low_bound); + SET_TYPE_RM_MAX_VALUE (gnu_scalar_type, gnu_high_bound); + } + else + { + /* Floating-point types don't have specific RM bounds. */ + TYPE_GCC_MIN_VALUE (gnu_scalar_type) = gnu_low_bound; + TYPE_GCC_MAX_VALUE (gnu_scalar_type) = gnu_high_bound; + } + } + + /* If we deferred processing of incomplete types, re-enable it. If there + were no other disables and we have deferred types to process, do so. */ + if (this_deferred + && --defer_incomplete_level == 0 + && defer_incomplete_list) + { + struct incomplete *p, *next; + + /* We are back to level 0 for the deferring of incomplete types. + But processing these incomplete types below may itself require + deferring, so preserve what we have and restart from scratch. */ + p = defer_incomplete_list; + defer_incomplete_list = NULL; + + for (; p; p = next) + { + next = p->next; + + if (p->old_type) + update_pointer_to (TYPE_MAIN_VARIANT (p->old_type), + gnat_to_gnu_type (p->full_type)); + free (p); + } + } + + /* If we are not defining this type, see if it's on one of the lists of + incomplete types. If so, handle the list entry now. */ + if (is_type && !definition) + { + struct incomplete *p; + + for (p = defer_incomplete_list; p; p = p->next) + if (p->old_type && p->full_type == gnat_entity) + { + update_pointer_to (TYPE_MAIN_VARIANT (p->old_type), + TREE_TYPE (gnu_decl)); + p->old_type = NULL_TREE; + } + + for (p = defer_limited_with_list; p; p = p->next) + if (p->old_type + && (Non_Limited_View (p->full_type) == gnat_entity + || Full_View (p->full_type) == gnat_entity)) + { + update_pointer_to (TYPE_MAIN_VARIANT (p->old_type), + TREE_TYPE (gnu_decl)); + if (TYPE_DUMMY_IN_PROFILE_P (p->old_type)) + update_profiles_with (p->old_type); + p->old_type = NULL_TREE; + } + } + + if (this_global) + force_global--; + + /* If this is a packed array type whose original array type is itself + an itype without freeze node, make sure the latter is processed. */ + if (Is_Packed_Array_Impl_Type (gnat_entity) + && Is_Itype (Original_Array_Type (gnat_entity)) + && No (Freeze_Node (Original_Array_Type (gnat_entity))) + && !present_gnu_tree (Original_Array_Type (gnat_entity))) + gnat_to_gnu_entity (Original_Array_Type (gnat_entity), NULL_TREE, false); + + return gnu_decl; +} + +/* Similar, but if the returned value is a COMPONENT_REF, return the + FIELD_DECL. */ + +tree +gnat_to_gnu_field_decl (Entity_Id gnat_entity) +{ + tree gnu_field = gnat_to_gnu_entity (gnat_entity, NULL_TREE, false); + + if (TREE_CODE (gnu_field) == COMPONENT_REF) + gnu_field = TREE_OPERAND (gnu_field, 1); + + return gnu_field; +} + +/* Similar, but GNAT_ENTITY is assumed to refer to a GNAT type. Return + the GCC type corresponding to that entity. */ + +tree +gnat_to_gnu_type (Entity_Id gnat_entity) +{ + tree gnu_decl; + + /* The back end never attempts to annotate generic types. */ + if (Is_Generic_Type (gnat_entity) && type_annotate_only) + return void_type_node; + + gnu_decl = gnat_to_gnu_entity (gnat_entity, NULL_TREE, false); + gcc_assert (TREE_CODE (gnu_decl) == TYPE_DECL); + + return TREE_TYPE (gnu_decl); +} + +/* Similar, but GNAT_ENTITY is assumed to refer to a GNAT type. Return + the unpadded version of the GCC type corresponding to that entity. */ + +tree +get_unpadded_type (Entity_Id gnat_entity) +{ + tree type = gnat_to_gnu_type (gnat_entity); + + if (TYPE_IS_PADDING_P (type)) + type = TREE_TYPE (TYPE_FIELDS (type)); + + return type; +} + +/* Return whether the E_Subprogram_Type/E_Function/E_Procedure GNAT_ENTITY is + a C++ imported method or equivalent. + + We use the predicate to find out whether we need to use METHOD_TYPE instead + of FUNCTION_TYPE for GNAT_ENTITY for the sake compatibility with C++. This + in turn determines whether the "thiscall" calling convention is used by the + back-end for GNAT_ENTITY on 32-bit x86/Windows. */ + +static bool +is_cplusplus_method (Entity_Id gnat_entity) +{ + /* A constructor is a method on the C++ side. We deal with it now because + it is declared without the 'this' parameter in the sources and, although + the front-end will create a version with the 'this' parameter for code + generation purposes, we want to return true for both versions. */ + if (Is_Constructor (gnat_entity)) + return true; + + /* Check that the subprogram has C++ convention. */ + if (Convention (gnat_entity) != Convention_CPP) + return false; + + /* And that the type of the first parameter (indirectly) has it too, but + we make an exception for Interfaces because they need not be imported. */ + Entity_Id gnat_first = First_Formal (gnat_entity); + if (No (gnat_first)) + return false; + Entity_Id gnat_type = Etype (gnat_first); + if (Is_Access_Type (gnat_type)) + gnat_type = Directly_Designated_Type (gnat_type); + if (Convention (gnat_type) != Convention_CPP && !Is_Interface (gnat_type)) + return false; + + /* This is the main case: a C++ virtual method imported as a primitive + operation of a tagged type. */ + if (Is_Dispatching_Operation (gnat_entity)) + return true; + + /* This is set on the E_Subprogram_Type built for a dispatching call. */ + if (Is_Dispatch_Table_Entity (gnat_entity)) + return true; + + /* A thunk needs to be handled like its associated primitive operation. */ + if (Is_Subprogram (gnat_entity) && Is_Thunk (gnat_entity)) + return true; + + /* Now on to the annoying case: a C++ non-virtual method, imported either + as a non-primitive operation of a tagged type or as a primitive operation + of an untagged type. We cannot reliably differentiate these cases from + their static member or regular function equivalents in Ada, so we ask + the C++ side through the mangled name of the function, as the implicit + 'this' parameter is not encoded in the mangled name of a method. */ + if (Is_Subprogram (gnat_entity) && Present (Interface_Name (gnat_entity))) + { + String_Pointer sp = { NULL, NULL }; + Get_External_Name (gnat_entity, false, sp); + + void *mem; + struct demangle_component *cmp + = cplus_demangle_v3_components (Name_Buffer, + DMGL_GNU_V3 + | DMGL_TYPES + | DMGL_PARAMS + | DMGL_RET_DROP, + &mem); + if (!cmp) + return false; + + /* We need to release MEM once we have a successful demangling. */ + bool ret = false; + + if (cmp->type == DEMANGLE_COMPONENT_TYPED_NAME + && cmp->u.s_binary.right->type == DEMANGLE_COMPONENT_FUNCTION_TYPE + && (cmp = cmp->u.s_binary.right->u.s_binary.right) != NULL + && cmp->type == DEMANGLE_COMPONENT_ARGLIST) + { + /* Make sure there is at least one parameter in C++ too. */ + if (cmp->u.s_binary.left) + { + unsigned int n_ada_args = 0; + do { + n_ada_args++; + gnat_first = Next_Formal (gnat_first); + } while (Present (gnat_first)); + + unsigned int n_cpp_args = 0; + do { + n_cpp_args++; + cmp = cmp->u.s_binary.right; + } while (cmp); + + if (n_cpp_args < n_ada_args) + ret = true; + } + else + ret = true; + } + + free (mem); + + return ret; + } + + return false; +} + +/* Return the inlining status of the GNAT subprogram SUBPROG. */ + +static enum inline_status_t +inline_status_for_subprog (Entity_Id subprog) +{ + if (Has_Pragma_No_Inline (subprog)) + return is_suppressed; + + if (Has_Pragma_Inline_Always (subprog)) + return is_required; + + if (Is_Inlined (subprog)) + { + tree gnu_type; + + /* This is a kludge to work around a pass ordering issue: for small + record types with many components, i.e. typically bit-fields, the + initialization routine can contain many assignments that will be + merged by the GIMPLE store merging pass. But this pass runs very + late in the pipeline, in particular after the inlining decisions + are made, so the inlining heuristics cannot take its outcome into + account. Therefore, we optimistically override the heuristics for + the initialization routine in this case. */ + if (Is_Init_Proc (subprog) + && flag_store_merging + && Is_Record_Type (Etype (First_Formal (subprog))) + && (gnu_type = gnat_to_gnu_type (Etype (First_Formal (subprog)))) + && !TYPE_IS_BY_REFERENCE_P (gnu_type) + && tree_fits_uhwi_p (TYPE_SIZE (gnu_type)) + && compare_tree_int (TYPE_SIZE (gnu_type), MAX_FIXED_MODE_SIZE) <= 0) + return is_prescribed; + + return is_requested; + } + + return is_default; +} + +/* Finalize the processing of From_Limited_With incomplete types. */ + +void +finalize_from_limited_with (void) +{ + struct incomplete *p, *next; + + p = defer_limited_with_list; + defer_limited_with_list = NULL; + + for (; p; p = next) + { + next = p->next; + + if (p->old_type) + { + update_pointer_to (TYPE_MAIN_VARIANT (p->old_type), + gnat_to_gnu_type (p->full_type)); + if (TYPE_DUMMY_IN_PROFILE_P (p->old_type)) + update_profiles_with (p->old_type); + } + + free (p); + } +} + +/* Return the equivalent type to be used for GNAT_ENTITY, if it's a kind + of type (such E_Task_Type) that has a different type which Gigi uses + for its representation. If the type does not have a special type for + its representation, return GNAT_ENTITY. */ + +Entity_Id +Gigi_Equivalent_Type (Entity_Id gnat_entity) +{ + Entity_Id gnat_equiv = gnat_entity; + + if (No (gnat_entity)) + return gnat_entity; + + switch (Ekind (gnat_entity)) + { + case E_Class_Wide_Subtype: + if (Present (Equivalent_Type (gnat_entity))) + gnat_equiv = Equivalent_Type (gnat_entity); + break; + + case E_Access_Protected_Subprogram_Type: + case E_Anonymous_Access_Protected_Subprogram_Type: + if (Present (Equivalent_Type (gnat_entity))) + gnat_equiv = Equivalent_Type (gnat_entity); + break; + + case E_Access_Subtype: + gnat_equiv = Etype (gnat_entity); + break; + + case E_Array_Subtype: + if (!Is_Constrained (gnat_entity)) + gnat_equiv = Etype (gnat_entity); + break; + + case E_Class_Wide_Type: + gnat_equiv = Root_Type (gnat_entity); + break; + + case E_Protected_Type: + case E_Protected_Subtype: + case E_Task_Type: + case E_Task_Subtype: + if (Present (Corresponding_Record_Type (gnat_entity))) + gnat_equiv = Corresponding_Record_Type (gnat_entity); + break; + + default: + break; + } + + return gnat_equiv; +} + +/* Return a GCC tree for a type corresponding to the component type of the + array type or subtype GNAT_ARRAY. DEFINITION is true if this component + is for an array being defined. DEBUG_INFO_P is true if we need to write + debug information for other types that we may create in the process. */ + +static tree +gnat_to_gnu_component_type (Entity_Id gnat_array, bool definition, + bool debug_info_p) +{ + const Entity_Id gnat_type = Component_Type (gnat_array); + const bool is_bit_packed = Is_Bit_Packed_Array (gnat_array); + tree gnu_type = gnat_to_gnu_type (gnat_type); + tree gnu_comp_size; + bool has_packed_components; + unsigned int max_align; + + /* If an alignment is specified, use it as a cap on the component type + so that it can be honored for the whole type, but ignore it for the + original type of packed array types. */ + if (No (Packed_Array_Impl_Type (gnat_array)) + && Known_Alignment (gnat_array)) + max_align = validate_alignment (Alignment (gnat_array), gnat_array, 0); + else + max_align = 0; + + /* Try to get a packable form of the component if needed. */ + if ((Is_Packed (gnat_array) || Has_Component_Size_Clause (gnat_array)) + && !is_bit_packed + && !Has_Aliased_Components (gnat_array) + && !Strict_Alignment (gnat_type) + && RECORD_OR_UNION_TYPE_P (gnu_type) + && !TYPE_FAT_POINTER_P (gnu_type) + && tree_fits_uhwi_p (TYPE_SIZE (gnu_type))) + { + gnu_type = make_packable_type (gnu_type, false, max_align); + has_packed_components = true; + } + else + has_packed_components = is_bit_packed; + + /* Get and validate any specified Component_Size. */ + gnu_comp_size + = validate_size (Component_Size (gnat_array), gnu_type, gnat_array, + has_packed_components ? TYPE_DECL : VAR_DECL, true, + Has_Component_Size_Clause (gnat_array), NULL, NULL); + + /* If the component type is a RECORD_TYPE that has a self-referential size, + then use the maximum size for the component size. */ + if (!gnu_comp_size + && TREE_CODE (gnu_type) == RECORD_TYPE + && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type))) + gnu_comp_size = max_size (TYPE_SIZE (gnu_type), true); + + /* If the array has aliased components and the component size is zero, force + the unit size to ensure that the components have distinct addresses. */ + if (!gnu_comp_size + && Has_Aliased_Components (gnat_array) + && integer_zerop (TYPE_SIZE (gnu_type))) + gnu_comp_size = bitsize_unit_node; + + /* Honor the component size. This is not needed for bit-packed arrays. */ + if (gnu_comp_size && !is_bit_packed) + { + tree orig_type = gnu_type; + unsigned int gnu_comp_align; + + gnu_type = make_type_from_size (gnu_type, gnu_comp_size, false); + if (max_align > 0 && TYPE_ALIGN (gnu_type) > max_align) + gnu_type = orig_type; + else + orig_type = gnu_type; + + /* We need to make sure that the size is a multiple of the alignment. + But we do not misalign the component type because of the alignment + of the array type here; this either must have been done earlier in + the packed case or should be rejected in the non-packed case. */ + if (TREE_CODE (gnu_comp_size) == INTEGER_CST) + { + const unsigned HOST_WIDE_INT int_size = tree_to_uhwi (gnu_comp_size); + gnu_comp_align = int_size & -int_size; + if (gnu_comp_align > TYPE_ALIGN (gnu_type)) + gnu_comp_align = 0; + } + else + gnu_comp_align = 0; + + gnu_type = maybe_pad_type (gnu_type, gnu_comp_size, gnu_comp_align, + gnat_array, true, definition, true); + + /* If a padding record was made, declare it now since it will never be + declared otherwise. This is necessary to ensure that its subtrees + are properly marked. */ + if (gnu_type != orig_type && !DECL_P (TYPE_NAME (gnu_type))) + create_type_decl (TYPE_NAME (gnu_type), gnu_type, true, debug_info_p, + gnat_array); + } + + /* This is a very special case where the array has aliased components and the + component size might be zero at run time. As explained above, we force at + least the unit size but we don't want to build a distinct padding type for + each invocation (they are not canonicalized if they have variable size) so + we cache this special padding type as TYPE_PADDING_FOR_COMPONENT. */ + else if (Has_Aliased_Components (gnat_array) + && TREE_CODE (gnu_type) == ARRAY_TYPE + && !TREE_CONSTANT (TYPE_SIZE (gnu_type))) + { + if (TYPE_PADDING_FOR_COMPONENT (gnu_type)) + gnu_type = TYPE_PADDING_FOR_COMPONENT (gnu_type); + else + { + gnu_comp_size + = size_binop (MAX_EXPR, TYPE_SIZE (gnu_type), bitsize_unit_node); + TYPE_PADDING_FOR_COMPONENT (gnu_type) + = maybe_pad_type (gnu_type, gnu_comp_size, 0, gnat_array, + true, definition, true); + gnu_type = TYPE_PADDING_FOR_COMPONENT (gnu_type); + create_type_decl (TYPE_NAME (gnu_type), gnu_type, true, debug_info_p, + gnat_array); + } + } + + /* Now check if the type of the component allows atomic access. */ + if (Has_Atomic_Components (gnat_array) || Is_Full_Access (gnat_type)) + check_ok_for_atomic_type (gnu_type, gnat_array, true); + + /* If the component type is a padded type made for a non-bit-packed array + of scalars with reverse storage order, we need to propagate the reverse + storage order to the padding type since it is the innermost enclosing + aggregate type around the scalar. */ + if (TYPE_IS_PADDING_P (gnu_type) + && !is_bit_packed + && Reverse_Storage_Order (gnat_array) + && Is_Scalar_Type (gnat_type)) + gnu_type = set_reverse_storage_order_on_pad_type (gnu_type); + + if (Has_Volatile_Components (gnat_array)) + { + const int quals + = TYPE_QUAL_VOLATILE + | (Has_Atomic_Components (gnat_array) ? TYPE_QUAL_ATOMIC : 0); + gnu_type = change_qualified_type (gnu_type, quals); + } + + return gnu_type; +} + +/* Return whether TYPE requires that formal parameters of TYPE be initialized + when they are Out parameters passed by copy. + + This just implements the set of conditions listed in RM 6.4.1(12). */ + +static bool +type_requires_init_of_formal (Entity_Id type) +{ + type = Underlying_Type (type); + + if (Is_Access_Type (type)) + return true; + + if (Is_Scalar_Type (type)) + return Has_Default_Aspect (type); + + if (Is_Array_Type (type)) + return Has_Default_Aspect (type) + || type_requires_init_of_formal (Component_Type (type)); + + if (Is_Record_Type (type)) + for (Entity_Id field = First_Entity (type); + Present (field); + field = Next_Entity (field)) + { + if (Ekind (field) == E_Discriminant && !Is_Unchecked_Union (type)) + return true; + + if (Ekind (field) == E_Component + && (Present (Expression (Parent (field))) + || type_requires_init_of_formal (Etype (field)))) + return true; + } + + return false; +} + +/* Return a GCC tree for a parameter corresponding to GNAT_PARAM, to be placed + in the parameter list of GNAT_SUBPROG. GNU_PARAM_TYPE is the GCC tree for + the type of the parameter. FIRST is true if this is the first parameter in + the list of GNAT_SUBPROG. Also set CICO to true if the parameter must use + the copy-in copy-out implementation mechanism. + + The returned tree is a PARM_DECL, except for the cases where no parameter + needs to be actually passed to the subprogram; the type of this "shadow" + parameter is then returned instead. */ + +static tree +gnat_to_gnu_param (Entity_Id gnat_param, tree gnu_param_type, bool first, + Entity_Id gnat_subprog, bool *cico) +{ + Mechanism_Type mech = Mechanism (gnat_param); + tree gnu_param_name = get_entity_name (gnat_param); + bool foreign = Has_Foreign_Convention (gnat_subprog); + bool in_param = (Ekind (gnat_param) == E_In_Parameter); + /* The parameter can be indirectly modified if its address is taken. */ + bool ro_param = in_param && !Address_Taken (gnat_param); + bool by_return = false, by_component_ptr = false; + bool by_ref = false; + bool forced_by_ref = false; + bool restricted_aliasing_p = false; + location_t saved_location = input_location; + tree gnu_param; + + /* Make sure to use the proper SLOC for vector ABI warnings. */ + if (VECTOR_TYPE_P (gnu_param_type)) + Sloc_to_locus (Sloc (gnat_subprog), &input_location); + + /* Builtins are expanded inline and there is no real call sequence involved. + So the type expected by the underlying expander is always the type of the + argument "as is". */ + if (Is_Intrinsic_Subprogram (gnat_subprog) + && Present (Interface_Name (gnat_subprog))) + mech = By_Copy; + + /* Handle the first parameter of a valued procedure specially: it's a copy + mechanism for which the parameter is never allocated. */ + else if (first && Is_Valued_Procedure (gnat_subprog)) + { + gcc_assert (Ekind (gnat_param) == E_Out_Parameter); + mech = By_Copy; + by_return = true; + } + + /* Or else, see if a Mechanism was supplied that forced this parameter + to be passed one way or another. */ + else if (mech == Default || mech == By_Copy || mech == By_Reference) + forced_by_ref + = (mech == By_Reference + && !foreign + && !TYPE_IS_BY_REFERENCE_P (gnu_param_type) + && !Is_Aliased (gnat_param)); + + /* Positive mechanism means by copy for sufficiently small parameters. */ + else if (mech > 0) + { + if (TREE_CODE (gnu_param_type) == UNCONSTRAINED_ARRAY_TYPE + || TREE_CODE (TYPE_SIZE (gnu_param_type)) != INTEGER_CST + || compare_tree_int (TYPE_SIZE (gnu_param_type), mech) > 0) + mech = By_Reference; + else + mech = By_Copy; + } + + /* Otherwise, it's an unsupported mechanism so error out. */ + else + { + post_error ("unsupported mechanism for&", gnat_param); + mech = Default; + } + + /* Either for foreign conventions, or if the underlying type is not passed + by reference and is as large and aligned as the original type, strip off + a possible padding type. */ + if (TYPE_IS_PADDING_P (gnu_param_type)) + { + tree inner_type = TREE_TYPE (TYPE_FIELDS (gnu_param_type)); + + if (foreign + || (mech != By_Reference + && !must_pass_by_ref (inner_type) + && (mech == By_Copy || !default_pass_by_ref (inner_type)) + && ((TYPE_SIZE (inner_type) == TYPE_SIZE (gnu_param_type) + && TYPE_ALIGN (inner_type) >= TYPE_ALIGN (gnu_param_type)) + || Is_Init_Proc (gnat_subprog)))) + gnu_param_type = inner_type; + } + + /* For foreign conventions, pass arrays as pointers to the element type. + First check for unconstrained array and get the underlying array. */ + if (foreign && TREE_CODE (gnu_param_type) == UNCONSTRAINED_ARRAY_TYPE) + gnu_param_type + = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_param_type)))); + + /* Arrays are passed as pointers to element type for foreign conventions. */ + if (foreign && mech != By_Copy && TREE_CODE (gnu_param_type) == ARRAY_TYPE) + { + /* Strip off any multi-dimensional entries, then strip + off the last array to get the component type. */ + while (TREE_CODE (TREE_TYPE (gnu_param_type)) == ARRAY_TYPE + && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_param_type))) + gnu_param_type = TREE_TYPE (gnu_param_type); + + gnu_param_type = TREE_TYPE (gnu_param_type); + gnu_param_type = build_pointer_type (gnu_param_type); + by_component_ptr = true; + } + + /* Fat pointers are passed as thin pointers for foreign conventions. */ + else if (foreign && TYPE_IS_FAT_POINTER_P (gnu_param_type)) + gnu_param_type + = make_type_from_size (gnu_param_type, size_int (POINTER_SIZE), 0); + + /* Use a pointer type for the "this" pointer of C++ constructors. */ + else if (Chars (gnat_param) == Name_uInit && Is_Constructor (gnat_subprog)) + { + gcc_assert (mech == By_Reference); + gnu_param_type = build_pointer_type (gnu_param_type); + by_ref = true; + } + + /* If we were requested or muss pass by reference, do so. + If we were requested to pass by copy, do so. + Otherwise, for foreign conventions, pass In Out or Out parameters + or aggregates by reference. For COBOL and Fortran, pass all + integer and FP types that way too. For Convention Ada, use + the standard Ada default. */ + else if (mech == By_Reference + || must_pass_by_ref (gnu_param_type) + || (mech != By_Copy + && ((foreign + && (!in_param || AGGREGATE_TYPE_P (gnu_param_type))) + || (foreign + && (Convention (gnat_subprog) == Convention_Fortran + || Convention (gnat_subprog) == Convention_COBOL) + && (INTEGRAL_TYPE_P (gnu_param_type) + || FLOAT_TYPE_P (gnu_param_type))) + || (!foreign + && default_pass_by_ref (gnu_param_type))))) + { + /* We take advantage of 6.2(12) by considering that references built for + parameters whose type isn't by-ref and for which the mechanism hasn't + been forced to by-ref allow only a restricted form of aliasing. */ + restricted_aliasing_p + = !TYPE_IS_BY_REFERENCE_P (gnu_param_type) && mech != By_Reference; + gnu_param_type = build_reference_type (gnu_param_type); + by_ref = true; + } + + /* Pass In Out or Out parameters using copy-in copy-out mechanism. */ + else if (!in_param) + *cico = true; + + input_location = saved_location; + + if (mech == By_Copy && (by_ref || by_component_ptr)) + post_error ("??cannot pass & by copy", gnat_param); + + /* If this is an Out parameter that isn't passed by reference and whose + type doesn't require the initialization of formals, we don't make a + PARM_DECL for it. Instead, it will be a VAR_DECL created when we + process the procedure, so just return its type here. Likewise for + the _Init parameter of an initialization procedure or the special + parameter of a valued procedure, never pass them in. */ + if (Ekind (gnat_param) == E_Out_Parameter + && !by_ref + && !by_component_ptr + && (!type_requires_init_of_formal (Etype (gnat_param)) + || Is_Init_Proc (gnat_subprog) + || by_return)) + { + Set_Mechanism (gnat_param, By_Copy); + return gnu_param_type; + } + + gnu_param = create_param_decl (gnu_param_name, gnu_param_type); + TREE_READONLY (gnu_param) = ro_param || by_ref || by_component_ptr; + DECL_BY_REF_P (gnu_param) = by_ref; + DECL_FORCED_BY_REF_P (gnu_param) = forced_by_ref; + DECL_BY_COMPONENT_PTR_P (gnu_param) = by_component_ptr; + DECL_POINTS_TO_READONLY_P (gnu_param) + = (ro_param && (by_ref || by_component_ptr)); + DECL_CAN_NEVER_BE_NULL_P (gnu_param) = Can_Never_Be_Null (gnat_param); + DECL_RESTRICTED_ALIASING_P (gnu_param) = restricted_aliasing_p; + Sloc_to_locus (Sloc (gnat_param), &DECL_SOURCE_LOCATION (gnu_param)); + + /* If no Mechanism was specified, indicate what we're using, then + back-annotate it. */ + if (mech == Default) + mech = (by_ref || by_component_ptr) ? By_Reference : By_Copy; + + Set_Mechanism (gnat_param, mech); + return gnu_param; +} + +/* Associate GNAT_SUBPROG with GNU_TYPE, which must be a dummy type, so that + GNAT_SUBPROG is updated when GNU_TYPE is completed. + + Ada 2012 (AI05-019) says that freezing a subprogram does not always freeze + the corresponding profile, which means that, by the time the freeze node + of the subprogram is encountered, types involved in its profile may still + be not yet frozen. That's why we need to update GNAT_SUBPROG when we see + the freeze node of types involved in its profile, either types of formal + parameters or the return type. */ + +static void +associate_subprog_with_dummy_type (Entity_Id gnat_subprog, tree gnu_type) +{ + gcc_assert (TYPE_IS_DUMMY_P (gnu_type)); + + struct tree_entity_vec_map in; + in.base.from = gnu_type; + struct tree_entity_vec_map **slot + = dummy_to_subprog_map->find_slot (&in, INSERT); + if (!*slot) + { + tree_entity_vec_map *e = ggc_alloc<tree_entity_vec_map> (); + e->base.from = gnu_type; + e->to = NULL; + *slot = e; + } + + /* Even if there is already a slot for GNU_TYPE, we need to set the flag + because the vector might have been just emptied by update_profiles_with. + This can happen when there are 2 freeze nodes associated with different + views of the same type; the type will be really complete only after the + second freeze node is encountered. */ + TYPE_DUMMY_IN_PROFILE_P (gnu_type) = 1; + + vec<Entity_Id, va_gc_atomic> *v = (*slot)->to; + + /* Make sure GNAT_SUBPROG is not associated twice with the same dummy type, + since this would mean updating twice its profile. */ + if (v) + { + const unsigned len = v->length (); + unsigned int l = 0, u = len; + + /* Entity_Id is a simple integer so we can implement a stable order on + the vector with an ordered insertion scheme and binary search. */ + while (l < u) + { + unsigned int m = (l + u) / 2; + int diff = (int) (*v)[m] - (int) gnat_subprog; + if (diff > 0) + u = m; + else if (diff < 0) + l = m + 1; + else + return; + } + + /* l == u and therefore is the insertion point. */ + vec_safe_insert (v, l, gnat_subprog); + } + else + vec_safe_push (v, gnat_subprog); + + (*slot)->to = v; +} + +/* Update the GCC tree previously built for the profile of GNAT_SUBPROG. */ + +static void +update_profile (Entity_Id gnat_subprog) +{ + tree gnu_param_list; + tree gnu_type = gnat_to_gnu_subprog_type (gnat_subprog, true, + Needs_Debug_Info (gnat_subprog), + &gnu_param_list); + if (DECL_P (gnu_type)) + { + /* Builtins cannot have their address taken so we can reset them. */ + gcc_assert (fndecl_built_in_p (gnu_type)); + save_gnu_tree (gnat_subprog, NULL_TREE, false); + save_gnu_tree (gnat_subprog, gnu_type, false); + return; + } + + tree gnu_subprog = get_gnu_tree (gnat_subprog); + + TREE_TYPE (gnu_subprog) = gnu_type; + + /* If GNAT_SUBPROG is an actual subprogram, GNU_SUBPROG is a FUNCTION_DECL + and needs to be adjusted too. */ + if (Ekind (gnat_subprog) != E_Subprogram_Type) + { + tree gnu_entity_name = get_entity_name (gnat_subprog); + tree gnu_ext_name + = gnu_ext_name_for_subprog (gnat_subprog, gnu_entity_name); + + DECL_ARGUMENTS (gnu_subprog) = gnu_param_list; + finish_subprog_decl (gnu_subprog, gnu_ext_name, gnu_type); + } +} + +/* Update the GCC trees previously built for the profiles involving GNU_TYPE, + a dummy type which appears in profiles. */ + +void +update_profiles_with (tree gnu_type) +{ + struct tree_entity_vec_map in; + in.base.from = gnu_type; + struct tree_entity_vec_map *e = dummy_to_subprog_map->find (&in); + gcc_assert (e); + vec<Entity_Id, va_gc_atomic> *v = e->to; + e->to = NULL; + + /* The flag needs to be reset before calling update_profile, in case + associate_subprog_with_dummy_type is again invoked on GNU_TYPE. */ + TYPE_DUMMY_IN_PROFILE_P (gnu_type) = 0; + + unsigned int i; + Entity_Id *iter; + FOR_EACH_VEC_ELT (*v, i, iter) + update_profile (*iter); + + vec_free (v); +} + +/* Return the GCC tree for GNAT_TYPE present in the profile of a subprogram. + + Ada 2012 (AI05-0151) says that incomplete types coming from a limited + context may now appear as parameter and result types. As a consequence, + we may need to defer their translation until after a freeze node is seen + or to the end of the current unit. We also aim at handling temporarily + incomplete types created by the usual delayed elaboration scheme. */ + +static tree +gnat_to_gnu_profile_type (Entity_Id gnat_type) +{ + /* This is the same logic as the E_Access_Type case of gnat_to_gnu_entity + so the rationale is exposed in that place. These processings probably + ought to be merged at some point. */ + Entity_Id gnat_equiv = Gigi_Equivalent_Type (gnat_type); + const bool is_from_limited_with + = (Is_Incomplete_Type (gnat_equiv) + && From_Limited_With (gnat_equiv)); + Entity_Id gnat_full_direct_first + = (is_from_limited_with + ? Non_Limited_View (gnat_equiv) + : (Is_Incomplete_Or_Private_Type (gnat_equiv) + ? Full_View (gnat_equiv) : Empty)); + Entity_Id gnat_full_direct + = ((is_from_limited_with + && Present (gnat_full_direct_first) + && Is_Private_Type (gnat_full_direct_first)) + ? Full_View (gnat_full_direct_first) + : gnat_full_direct_first); + Entity_Id gnat_full = Gigi_Equivalent_Type (gnat_full_direct); + Entity_Id gnat_rep = Present (gnat_full) ? gnat_full : gnat_equiv; + const bool in_main_unit = In_Extended_Main_Code_Unit (gnat_rep); + tree gnu_type; + + if (Present (gnat_full) && present_gnu_tree (gnat_full)) + gnu_type = TREE_TYPE (get_gnu_tree (gnat_full)); + + else if (is_from_limited_with + && ((!in_main_unit + && !present_gnu_tree (gnat_equiv) + && Present (gnat_full) + && (Is_Record_Type (gnat_full) + || Is_Array_Type (gnat_full) + || Is_Access_Type (gnat_full))) + || (in_main_unit && Present (Freeze_Node (gnat_rep))))) + { + gnu_type = make_dummy_type (gnat_equiv); + + if (!in_main_unit) + { + struct incomplete *p = XNEW (struct incomplete); + + p->old_type = gnu_type; + p->full_type = gnat_equiv; + p->next = defer_limited_with_list; + defer_limited_with_list = p; + } + } + + else if (type_annotate_only && No (gnat_equiv)) + gnu_type = void_type_node; + + else + gnu_type = gnat_to_gnu_type (gnat_equiv); + + /* Access-to-unconstrained-array types need a special treatment. */ + if (Is_Array_Type (gnat_rep) && !Is_Constrained (gnat_rep)) + { + if (!TYPE_POINTER_TO (gnu_type)) + build_dummy_unc_pointer_types (gnat_equiv, gnu_type); + } + + return gnu_type; +} + +/* Return true if TYPE contains only integral data, recursively if need be. */ + +static bool +type_contains_only_integral_data (tree type) +{ + switch (TREE_CODE (type)) + { + case RECORD_TYPE: + case UNION_TYPE: + case QUAL_UNION_TYPE: + for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) + if (!type_contains_only_integral_data (TREE_TYPE (field))) + return false; + return true; + + case ARRAY_TYPE: + case COMPLEX_TYPE: + return type_contains_only_integral_data (TREE_TYPE (type)); + + default: + return INTEGRAL_TYPE_P (type); + } + + gcc_unreachable (); +} + +/* Return a GCC tree for a subprogram type corresponding to GNAT_SUBPROG. + DEFINITION is true if this is for a subprogram being defined. DEBUG_INFO_P + is true if we need to write debug information for other types that we may + create in the process. Also set PARAM_LIST to the list of parameters. + If GNAT_SUBPROG is bound to a GCC builtin, return the DECL for the builtin + directly instead of its type. */ + +static tree +gnat_to_gnu_subprog_type (Entity_Id gnat_subprog, bool definition, + bool debug_info_p, tree *param_list) +{ + const Entity_Kind kind = Ekind (gnat_subprog); + const bool method_p = is_cplusplus_method (gnat_subprog); + const bool variadic = IN (Convention (gnat_subprog), Convention_C_Variadic); + Entity_Id gnat_return_type = Etype (gnat_subprog); + Entity_Id gnat_param; + tree gnu_type = present_gnu_tree (gnat_subprog) + ? TREE_TYPE (get_gnu_tree (gnat_subprog)) : NULL_TREE; + tree gnu_return_type; + tree gnu_param_type_list = NULL_TREE; + tree gnu_param_list = NULL_TREE; + /* Non-null for subprograms containing parameters passed by copy-in copy-out + (In Out or Out parameters not passed by reference), in which case it is + the list of nodes used to specify the values of the In Out/Out parameters + that are returned as a record upon procedure return. The TREE_PURPOSE of + an element of this list is a FIELD_DECL of the record and the TREE_VALUE + is the PARM_DECL corresponding to that field. This list will be saved in + the TYPE_CI_CO_LIST field of the FUNCTION_TYPE node we create. */ + tree gnu_cico_list = NULL_TREE; + tree gnu_cico_return_type = NULL_TREE; + tree gnu_cico_field_list = NULL_TREE; + bool gnu_cico_only_integral_type = true; + /* Although the semantics of "pure" units in Ada essentially match those of + "const" in GNU C, the semantics of the Is_Pure flag in GNAT do not say + anything about access to global memory, that's why it needs to be mapped + to "pure" instead of "const" in GNU C. The property is orthogonal to the + "nothrow" property only if the EH circuitry is explicit in the internal + representation of the middle-end: if we are to completely hide the EH + circuitry from it, we need to declare that calls to pure Ada subprograms + that can throw have side effects, since they can trigger an "abnormal" + transfer of control; therefore they cannot be "pure" in the GCC sense. */ + bool pure_flag = Is_Pure (gnat_subprog) && Back_End_Exceptions (); + bool return_by_direct_ref_p = false; + bool return_by_invisi_ref_p = false; + bool return_unconstrained_p = false; + bool incomplete_profile_p = false; + int num; + + /* Look into the return type and get its associated GCC tree if it is not + void, and then compute various flags for the subprogram type. But make + sure not to do this processing multiple times. */ + if (Ekind (gnat_return_type) == E_Void) + gnu_return_type = void_type_node; + + else if (gnu_type + && FUNC_OR_METHOD_TYPE_P (gnu_type) + && !TYPE_IS_DUMMY_P (TREE_TYPE (gnu_type))) + { + gnu_return_type = TREE_TYPE (gnu_type); + return_unconstrained_p = TYPE_RETURN_UNCONSTRAINED_P (gnu_type); + return_by_direct_ref_p = TYPE_RETURN_BY_DIRECT_REF_P (gnu_type); + return_by_invisi_ref_p = TREE_ADDRESSABLE (gnu_type); + } + + else + { + /* For foreign convention/intrinsic subprograms, return System.Address + as void * or equivalent; this comprises GCC builtins. */ + if ((Has_Foreign_Convention (gnat_subprog) + || Is_Intrinsic_Subprogram (gnat_subprog)) + && Is_Descendant_Of_Address (Underlying_Type (gnat_return_type))) + gnu_return_type = ptr_type_node; + else + gnu_return_type = gnat_to_gnu_profile_type (gnat_return_type); + + /* If this function returns by reference, make the actual return type + the reference type and make a note of that. */ + if (Returns_By_Ref (gnat_subprog)) + { + gnu_return_type = build_reference_type (gnu_return_type); + return_by_direct_ref_p = true; + } + + /* If the return type is an unconstrained array type, the return value + will be allocated on the secondary stack so the actual return type + is the fat pointer type. */ + else if (TREE_CODE (gnu_return_type) == UNCONSTRAINED_ARRAY_TYPE) + { + gnu_return_type = TYPE_REFERENCE_TO (gnu_return_type); + return_unconstrained_p = true; + } + + /* This is the same unconstrained array case, but for a dummy type. */ + else if (TYPE_REFERENCE_TO (gnu_return_type) + && TYPE_IS_FAT_POINTER_P (TYPE_REFERENCE_TO (gnu_return_type))) + { + gnu_return_type = TYPE_REFERENCE_TO (gnu_return_type); + return_unconstrained_p = true; + } + + /* Likewise, if the return type requires a transient scope, the return + value will also be allocated on the secondary stack so the actual + return type is the reference type. */ + else if (Requires_Transient_Scope (gnat_return_type)) + { + gnu_return_type = build_reference_type (gnu_return_type); + return_unconstrained_p = true; + } + + /* If the Mechanism is By_Reference, ensure this function uses the + target's by-invisible-reference mechanism, which may not be the + same as above (e.g. it might be passing an extra parameter). */ + else if (kind == E_Function && Mechanism (gnat_subprog) == By_Reference) + return_by_invisi_ref_p = true; + + /* Likewise, if the return type is itself By_Reference. */ + else if (TYPE_IS_BY_REFERENCE_P (gnu_return_type)) + return_by_invisi_ref_p = true; + + /* If the type is a padded type and the underlying type would not be + passed by reference or the function has a foreign convention, return + the underlying type. */ + else if (TYPE_IS_PADDING_P (gnu_return_type) + && (!default_pass_by_ref + (TREE_TYPE (TYPE_FIELDS (gnu_return_type))) + || Has_Foreign_Convention (gnat_subprog))) + gnu_return_type = TREE_TYPE (TYPE_FIELDS (gnu_return_type)); + + /* If the return type is unconstrained, it must have a maximum size. + Use the padded type as the effective return type. And ensure the + function uses the target's by-invisible-reference mechanism to + avoid copying too much data when it returns. */ + if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_return_type))) + { + tree orig_type = gnu_return_type; + tree max_return_size = max_size (TYPE_SIZE (gnu_return_type), true); + + /* If the size overflows to 0, set it to an arbitrary positive + value so that assignments in the type are preserved. Their + actual size is independent of this positive value. */ + if (TREE_CODE (max_return_size) == INTEGER_CST + && TREE_OVERFLOW (max_return_size) + && integer_zerop (max_return_size)) + { + max_return_size = copy_node (bitsize_unit_node); + TREE_OVERFLOW (max_return_size) = 1; + } + + gnu_return_type = maybe_pad_type (gnu_return_type, max_return_size, + 0, gnat_subprog, false, definition, + true); + + /* Declare it now since it will never be declared otherwise. This + is necessary to ensure that its subtrees are properly marked. */ + if (gnu_return_type != orig_type + && !DECL_P (TYPE_NAME (gnu_return_type))) + create_type_decl (TYPE_NAME (gnu_return_type), gnu_return_type, + true, debug_info_p, gnat_subprog); + + return_by_invisi_ref_p = true; + } + + /* If the return type has a size that overflows, we usually cannot have + a function that returns that type. This usage doesn't really make + sense anyway, so issue an error here. */ + if (!return_by_invisi_ref_p + && TYPE_SIZE_UNIT (gnu_return_type) + && TREE_CODE (TYPE_SIZE_UNIT (gnu_return_type)) == INTEGER_CST + && !valid_constant_size_p (TYPE_SIZE_UNIT (gnu_return_type))) + { + post_error ("cannot return type whose size overflows", gnat_subprog); + gnu_return_type = copy_type (gnu_return_type); + TYPE_SIZE (gnu_return_type) = bitsize_zero_node; + TYPE_SIZE_UNIT (gnu_return_type) = size_zero_node; + } + + /* If the return type is incomplete, there are 2 cases: if the function + returns by reference, then the return type is only linked indirectly + in the profile, so the profile can be seen as complete since it need + not be further modified, only the reference types need be adjusted; + otherwise the profile is incomplete and need be adjusted too. */ + if (TYPE_IS_DUMMY_P (gnu_return_type)) + { + associate_subprog_with_dummy_type (gnat_subprog, gnu_return_type); + incomplete_profile_p = true; + } + + if (kind == E_Function) + Set_Mechanism (gnat_subprog, return_unconstrained_p + || return_by_direct_ref_p + || return_by_invisi_ref_p + ? By_Reference : By_Copy); + } + + /* A procedure (something that doesn't return anything) shouldn't be + considered pure since there would be no reason for calling such a + subprogram. Note that procedures with Out (or In Out) parameters + have already been converted into a function with a return type. + Similarly, if the function returns an unconstrained type, then the + function will allocate the return value on the secondary stack and + thus calls to it cannot be CSE'ed, lest the stack be reclaimed. */ + if (VOID_TYPE_P (gnu_return_type) || return_unconstrained_p) + pure_flag = false; + + /* Loop over the parameters and get their associated GCC tree. While doing + this, build a copy-in copy-out structure if we need one. */ + for (gnat_param = First_Formal_With_Extras (gnat_subprog), num = 0; + Present (gnat_param); + gnat_param = Next_Formal_With_Extras (gnat_param), num++) + { + const bool mech_is_by_ref + = Mechanism (gnat_param) == By_Reference + && !(num == 0 && Is_Valued_Procedure (gnat_subprog)); + tree gnu_param_name = get_entity_name (gnat_param); + tree gnu_param, gnu_param_type; + bool cico = false; + + /* For a variadic C function, do not build unnamed parameters. */ + if (variadic + && num == (Convention (gnat_subprog) - Convention_C_Variadic_0)) + break; + + /* Fetch an existing parameter with complete type and reuse it. But we + didn't save the CICO property so we can only do it for In parameters + or parameters passed by reference. */ + if ((Ekind (gnat_param) == E_In_Parameter || mech_is_by_ref) + && present_gnu_tree (gnat_param) + && (gnu_param = get_gnu_tree (gnat_param)) + && !TYPE_IS_DUMMY_P (TREE_TYPE (gnu_param))) + { + DECL_CHAIN (gnu_param) = NULL_TREE; + gnu_param_type = TREE_TYPE (gnu_param); + } + + /* Otherwise translate the parameter type and act accordingly. */ + else + { + Entity_Id gnat_param_type = Etype (gnat_param); + + /* For foreign convention/intrinsic subprograms, pass System.Address + as void * or equivalent; this comprises GCC builtins. */ + if ((Has_Foreign_Convention (gnat_subprog) + || Is_Intrinsic_Subprogram (gnat_subprog)) + && Is_Descendant_Of_Address (Underlying_Type (gnat_param_type))) + gnu_param_type = ptr_type_node; + else + gnu_param_type = gnat_to_gnu_profile_type (gnat_param_type); + + /* If the parameter type is incomplete, there are 2 cases: if it is + passed by reference, then the type is only linked indirectly in + the profile, so the profile can be seen as complete since it need + not be further modified, only the reference type need be adjusted; + otherwise the profile is incomplete and need be adjusted too. */ + if (TYPE_IS_DUMMY_P (gnu_param_type)) + { + Node_Id gnat_decl; + + if (mech_is_by_ref + || (TYPE_REFERENCE_TO (gnu_param_type) + && TYPE_IS_FAT_POINTER_P + (TYPE_REFERENCE_TO (gnu_param_type))) + || TYPE_IS_BY_REFERENCE_P (gnu_param_type)) + { + gnu_param_type = build_reference_type (gnu_param_type); + gnu_param + = create_param_decl (gnu_param_name, gnu_param_type); + TREE_READONLY (gnu_param) = 1; + DECL_BY_REF_P (gnu_param) = 1; + DECL_POINTS_TO_READONLY_P (gnu_param) + = (Ekind (gnat_param) == E_In_Parameter + && !Address_Taken (gnat_param)); + Set_Mechanism (gnat_param, By_Reference); + Sloc_to_locus (Sloc (gnat_param), + &DECL_SOURCE_LOCATION (gnu_param)); + } + + /* ??? This is a kludge to support null procedures in spec taking + a parameter with an untagged incomplete type coming from a + limited context. The front-end creates a body without knowing + anything about the non-limited view, which is illegal Ada and + cannot be supported. Create a parameter with a fake type. */ + else if (kind == E_Procedure + && (gnat_decl = Parent (gnat_subprog)) + && Nkind (gnat_decl) == N_Procedure_Specification + && Null_Present (gnat_decl) + && Is_Incomplete_Type (gnat_param_type)) + gnu_param = create_param_decl (gnu_param_name, ptr_type_node); + + else + { + /* Build a minimal PARM_DECL without DECL_ARG_TYPE so that + Call_to_gnu will stop if it encounters the PARM_DECL. */ + gnu_param + = build_decl (input_location, PARM_DECL, gnu_param_name, + gnu_param_type); + associate_subprog_with_dummy_type (gnat_subprog, + gnu_param_type); + incomplete_profile_p = true; + } + } + + /* Otherwise build the parameter declaration normally. */ + else + { + gnu_param + = gnat_to_gnu_param (gnat_param, gnu_param_type, num == 0, + gnat_subprog, &cico); + + /* We are returned either a PARM_DECL or a type if no parameter + needs to be passed; in either case, adjust the type. */ + if (DECL_P (gnu_param)) + gnu_param_type = TREE_TYPE (gnu_param); + else + { + gnu_param_type = gnu_param; + gnu_param = NULL_TREE; + } + } + } + + /* If we have a GCC tree for the parameter, register it. */ + save_gnu_tree (gnat_param, NULL_TREE, false); + if (gnu_param) + { + gnu_param_type_list + = tree_cons (NULL_TREE, gnu_param_type, gnu_param_type_list); + DECL_CHAIN (gnu_param) = gnu_param_list; + gnu_param_list = gnu_param; + save_gnu_tree (gnat_param, gnu_param, false); + + /* A pure function in the Ada sense which takes an access parameter + may modify memory through it and thus cannot be considered pure + in the GCC sense, unless it's access-to-function. Likewise it if + takes a by-ref In Out or Out parameter. But if it takes a by-ref + In parameter, then it may only read memory through it and can be + considered pure in the GCC sense. */ + if (pure_flag + && ((POINTER_TYPE_P (gnu_param_type) + && TREE_CODE (TREE_TYPE (gnu_param_type)) != FUNCTION_TYPE) + || TYPE_IS_FAT_POINTER_P (gnu_param_type))) + pure_flag = DECL_POINTS_TO_READONLY_P (gnu_param); + } + + /* If the parameter uses the copy-in copy-out mechanism, allocate a field + for it in the return type and register the association. */ + if (cico && !incomplete_profile_p) + { + if (!gnu_cico_list) + { + gnu_cico_return_type = make_node (RECORD_TYPE); + + /* If this is a function, we also need a field for the + return value to be placed. */ + if (!VOID_TYPE_P (gnu_return_type)) + { + tree gnu_field + = create_field_decl (get_identifier ("RETVAL"), + gnu_return_type, + gnu_cico_return_type, NULL_TREE, + NULL_TREE, 0, 0); + Sloc_to_locus (Sloc (gnat_subprog), + &DECL_SOURCE_LOCATION (gnu_field)); + gnu_cico_field_list = gnu_field; + gnu_cico_list + = tree_cons (gnu_field, void_type_node, NULL_TREE); + if (!type_contains_only_integral_data (gnu_return_type)) + gnu_cico_only_integral_type = false; + } + + TYPE_NAME (gnu_cico_return_type) = get_identifier ("RETURN"); + /* Set a default alignment to speed up accesses. But we should + not increase the size of the structure too much, lest it does + not fit in return registers anymore. */ + SET_TYPE_ALIGN (gnu_cico_return_type, + get_mode_alignment (ptr_mode)); + } + + tree gnu_field + = create_field_decl (gnu_param_name, gnu_param_type, + gnu_cico_return_type, NULL_TREE, NULL_TREE, + 0, 0); + Sloc_to_locus (Sloc (gnat_param), + &DECL_SOURCE_LOCATION (gnu_field)); + DECL_CHAIN (gnu_field) = gnu_cico_field_list; + gnu_cico_field_list = gnu_field; + gnu_cico_list = tree_cons (gnu_field, gnu_param, gnu_cico_list); + if (!type_contains_only_integral_data (gnu_param_type)) + gnu_cico_only_integral_type = false; + } + } + + /* If the subprogram uses the copy-in copy-out mechanism, possibly adjust + and finish up the return type. */ + if (gnu_cico_list && !incomplete_profile_p) + { + /* If we have a CICO list but it has only one entry, we convert + this function into a function that returns this object. */ + if (list_length (gnu_cico_list) == 1) + gnu_cico_return_type = TREE_TYPE (TREE_PURPOSE (gnu_cico_list)); + + /* Do not finalize the return type if the subprogram is stubbed + since structures are incomplete for the back-end. */ + else if (Convention (gnat_subprog) != Convention_Stubbed) + { + finish_record_type (gnu_cico_return_type, + nreverse (gnu_cico_field_list), + 0, false); + + /* Try to promote the mode if the return type is fully returned + in integer registers, again to speed up accesses. */ + if (TYPE_MODE (gnu_cico_return_type) == BLKmode + && gnu_cico_only_integral_type + && !targetm.calls.return_in_memory (gnu_cico_return_type, + NULL_TREE)) + { + unsigned int size + = TREE_INT_CST_LOW (TYPE_SIZE (gnu_cico_return_type)); + unsigned int i = BITS_PER_UNIT; + scalar_int_mode mode; + + while (i < size) + i <<= 1; + if (int_mode_for_size (i, 0).exists (&mode)) + { + SET_TYPE_MODE (gnu_cico_return_type, mode); + SET_TYPE_ALIGN (gnu_cico_return_type, + GET_MODE_ALIGNMENT (mode)); + TYPE_SIZE (gnu_cico_return_type) + = bitsize_int (GET_MODE_BITSIZE (mode)); + TYPE_SIZE_UNIT (gnu_cico_return_type) + = size_int (GET_MODE_SIZE (mode)); + } + } + + /* But demote the mode if the return type is partly returned in FP + registers to avoid creating problematic paradoxical subregs. + Note that we need to cater to historical 32-bit architectures + that incorrectly use the mode to select the return mechanism. */ + else if (INTEGRAL_MODE_P (TYPE_MODE (gnu_cico_return_type)) + && !gnu_cico_only_integral_type + && BITS_PER_WORD >= 64 + && !targetm.calls.return_in_memory (gnu_cico_return_type, + NULL_TREE)) + SET_TYPE_MODE (gnu_cico_return_type, BLKmode); + + if (debug_info_p) + rest_of_record_type_compilation (gnu_cico_return_type); + } + + gnu_return_type = gnu_cico_return_type; + } + + /* The lists have been built in reverse. */ + gnu_param_type_list = nreverse (gnu_param_type_list); + if (!variadic) + gnu_param_type_list = chainon (gnu_param_type_list, void_list_node); + gnu_param_list = nreverse (gnu_param_list); + gnu_cico_list = nreverse (gnu_cico_list); + + /* Turn imported C++ constructors into their callable form as done in the + front-end, i.e. add the "this" pointer and void the return type. */ + if (method_p + && Is_Constructor (gnat_subprog) + && !VOID_TYPE_P (gnu_return_type)) + { + tree gnu_param_type + = build_pointer_type (gnat_to_gnu_profile_type (gnat_return_type)); + tree gnu_param_name = get_identifier (Get_Name_String (Name_uInit)); + tree gnu_param + = build_decl (input_location, PARM_DECL, gnu_param_name, + gnu_param_type); + gnu_param_type_list + = tree_cons (NULL_TREE, gnu_param_type, gnu_param_type_list); + DECL_CHAIN (gnu_param) = gnu_param_list; + gnu_param_list = gnu_param; + gnu_return_type = void_type_node; + } + + /* If the profile is incomplete, we only set the (temporary) return and + parameter types; otherwise, we build the full type. In either case, + we reuse an already existing GCC tree that we built previously here. */ + if (incomplete_profile_p) + { + if (gnu_type && FUNC_OR_METHOD_TYPE_P (gnu_type)) + ; + else + gnu_type = make_node (method_p ? METHOD_TYPE : FUNCTION_TYPE); + TREE_TYPE (gnu_type) = gnu_return_type; + TYPE_ARG_TYPES (gnu_type) = gnu_param_type_list; + TYPE_RETURN_UNCONSTRAINED_P (gnu_type) = return_unconstrained_p; + TYPE_RETURN_BY_DIRECT_REF_P (gnu_type) = return_by_direct_ref_p; + TREE_ADDRESSABLE (gnu_type) = return_by_invisi_ref_p; + } + else + { + if (gnu_type && FUNC_OR_METHOD_TYPE_P (gnu_type)) + { + TREE_TYPE (gnu_type) = gnu_return_type; + TYPE_ARG_TYPES (gnu_type) = gnu_param_type_list; + if (method_p) + { + tree gnu_basetype = TREE_TYPE (TREE_VALUE (gnu_param_type_list)); + TYPE_METHOD_BASETYPE (gnu_type) + = TYPE_MAIN_VARIANT (gnu_basetype); + } + TYPE_CI_CO_LIST (gnu_type) = gnu_cico_list; + TYPE_RETURN_UNCONSTRAINED_P (gnu_type) = return_unconstrained_p; + TYPE_RETURN_BY_DIRECT_REF_P (gnu_type) = return_by_direct_ref_p; + TREE_ADDRESSABLE (gnu_type) = return_by_invisi_ref_p; + TYPE_CANONICAL (gnu_type) = gnu_type; + layout_type (gnu_type); + } + else + { + if (method_p) + { + tree gnu_basetype = TREE_TYPE (TREE_VALUE (gnu_param_type_list)); + gnu_type + = build_method_type_directly (gnu_basetype, gnu_return_type, + TREE_CHAIN (gnu_param_type_list)); + } + else + gnu_type + = build_function_type (gnu_return_type, gnu_param_type_list); + + /* GNU_TYPE may be shared since GCC hashes types. Unshare it if it + has a different TYPE_CI_CO_LIST or flags. */ + if (!fntype_same_flags_p (gnu_type, gnu_cico_list, + return_unconstrained_p, + return_by_direct_ref_p, + return_by_invisi_ref_p)) + { + gnu_type = copy_type (gnu_type); + TYPE_CI_CO_LIST (gnu_type) = gnu_cico_list; + TYPE_RETURN_UNCONSTRAINED_P (gnu_type) = return_unconstrained_p; + TYPE_RETURN_BY_DIRECT_REF_P (gnu_type) = return_by_direct_ref_p; + TREE_ADDRESSABLE (gnu_type) = return_by_invisi_ref_p; + } + } + + if (pure_flag) + gnu_type = change_qualified_type (gnu_type, TYPE_QUAL_RESTRICT); + + if (No_Return (gnat_subprog)) + gnu_type = change_qualified_type (gnu_type, TYPE_QUAL_VOLATILE); + + /* If this subprogram is expectedly bound to a GCC builtin, fetch the + corresponding DECL node and check the parameter association. */ + if (Is_Intrinsic_Subprogram (gnat_subprog) + && Present (Interface_Name (gnat_subprog))) + { + tree gnu_ext_name = create_concat_name (gnat_subprog, NULL); + tree gnu_builtin_decl = builtin_decl_for (gnu_ext_name); + + /* If we have a builtin DECL for that function, use it. Check if + the profiles are compatible and warn if they are not. Note that + the checker is expected to post diagnostics in this case. */ + if (gnu_builtin_decl) + { + if (fndecl_built_in_p (gnu_builtin_decl, BUILT_IN_NORMAL)) + { + const enum built_in_function fncode + = DECL_FUNCTION_CODE (gnu_builtin_decl); + + switch (fncode) + { + case BUILT_IN_SYNC_FETCH_AND_ADD_N: + case BUILT_IN_SYNC_FETCH_AND_SUB_N: + case BUILT_IN_SYNC_FETCH_AND_OR_N: + case BUILT_IN_SYNC_FETCH_AND_AND_N: + case BUILT_IN_SYNC_FETCH_AND_XOR_N: + case BUILT_IN_SYNC_FETCH_AND_NAND_N: + case BUILT_IN_SYNC_ADD_AND_FETCH_N: + case BUILT_IN_SYNC_SUB_AND_FETCH_N: + case BUILT_IN_SYNC_OR_AND_FETCH_N: + case BUILT_IN_SYNC_AND_AND_FETCH_N: + case BUILT_IN_SYNC_XOR_AND_FETCH_N: + case BUILT_IN_SYNC_NAND_AND_FETCH_N: + case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_N: + case BUILT_IN_SYNC_LOCK_TEST_AND_SET_N: + case BUILT_IN_ATOMIC_EXCHANGE_N: + case BUILT_IN_ATOMIC_LOAD_N: + case BUILT_IN_ATOMIC_ADD_FETCH_N: + case BUILT_IN_ATOMIC_SUB_FETCH_N: + case BUILT_IN_ATOMIC_AND_FETCH_N: + case BUILT_IN_ATOMIC_NAND_FETCH_N: + case BUILT_IN_ATOMIC_XOR_FETCH_N: + case BUILT_IN_ATOMIC_OR_FETCH_N: + case BUILT_IN_ATOMIC_FETCH_ADD_N: + case BUILT_IN_ATOMIC_FETCH_SUB_N: + case BUILT_IN_ATOMIC_FETCH_AND_N: + case BUILT_IN_ATOMIC_FETCH_NAND_N: + case BUILT_IN_ATOMIC_FETCH_XOR_N: + case BUILT_IN_ATOMIC_FETCH_OR_N: + /* This is a generic builtin overloaded on its return + type, so do type resolution based on it. */ + if (!VOID_TYPE_P (gnu_return_type) + && type_for_atomic_builtin_p (gnu_return_type)) + gnu_builtin_decl + = resolve_atomic_builtin (fncode, gnu_return_type); + else + { + post_error + ("??cannot import type-generic 'G'C'C builtin!", + gnat_subprog); + post_error + ("\\?use a supported result type", + gnat_subprog); + gnu_builtin_decl = NULL_TREE; + } + break; + + case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_N: + /* This is a generic builtin overloaded on its third + parameter type, so do type resolution based on it. */ + if (list_length (gnu_param_type_list) >= 4 + && type_for_atomic_builtin_p + (list_third (gnu_param_type_list))) + gnu_builtin_decl + = resolve_atomic_builtin + (fncode, list_third (gnu_param_type_list)); + else + { + post_error + ("??cannot import type-generic 'G'C'C builtin!", + gnat_subprog); + post_error + ("\\?use a supported third parameter type", + gnat_subprog); + gnu_builtin_decl = NULL_TREE; + } + break; + + case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_N: + case BUILT_IN_SYNC_LOCK_RELEASE_N: + case BUILT_IN_ATOMIC_STORE_N: + post_error + ("??unsupported type-generic 'G'C'C builtin!", + gnat_subprog); + gnu_builtin_decl = NULL_TREE; + break; + + default: + break; + } + } + + if (gnu_builtin_decl) + { + const intrin_binding_t inb + = { gnat_subprog, gnu_type, TREE_TYPE (gnu_builtin_decl) }; + + if (!intrin_profiles_compatible_p (&inb)) + post_error + ("??profile of& doesn''t match the builtin it binds!", + gnat_subprog); + + return gnu_builtin_decl; + } + } + + /* Inability to find the builtin DECL most often indicates a genuine + mistake, but imports of unregistered intrinsics are sometimes used + on purpose to allow hooking in alternate bodies; we post a warning + conditioned on Wshadow in this case, to let developers be notified + on demand without risking false positives with common default sets + of options. */ + if (warn_shadow) + post_error ("'G'C'C builtin not found for&!??", gnat_subprog); + } + } + + *param_list = gnu_param_list; + + return gnu_type; +} + +/* Return the external name for GNAT_SUBPROG given its entity name. */ + +static tree +gnu_ext_name_for_subprog (Entity_Id gnat_subprog, tree gnu_entity_name) +{ + tree gnu_ext_name = create_concat_name (gnat_subprog, NULL); + + /* If there was no specified Interface_Name and the external and + internal names of the subprogram are the same, only use the + internal name to allow disambiguation of nested subprograms. */ + if (No (Interface_Name (gnat_subprog)) && gnu_ext_name == gnu_entity_name) + gnu_ext_name = NULL_TREE; + + return gnu_ext_name; +} + +/* Set TYPE_NONALIASED_COMPONENT on an array type built by means of + build_nonshared_array_type. */ + +static void +set_nonaliased_component_on_array_type (tree type) +{ + TYPE_NONALIASED_COMPONENT (type) = 1; + if (TYPE_CANONICAL (type)) + TYPE_NONALIASED_COMPONENT (TYPE_CANONICAL (type)) = 1; +} + +/* Set TYPE_REVERSE_STORAGE_ORDER on an array type built by means of + build_nonshared_array_type. */ + +static void +set_reverse_storage_order_on_array_type (tree type) +{ + TYPE_REVERSE_STORAGE_ORDER (type) = 1; + if (TYPE_CANONICAL (type)) + TYPE_REVERSE_STORAGE_ORDER (TYPE_CANONICAL (type)) = 1; +} + +/* Return true if DISCR1 and DISCR2 represent the same discriminant. */ + +static bool +same_discriminant_p (Entity_Id discr1, Entity_Id discr2) +{ + while (Present (Corresponding_Discriminant (discr1))) + discr1 = Corresponding_Discriminant (discr1); + + while (Present (Corresponding_Discriminant (discr2))) + discr2 = Corresponding_Discriminant (discr2); + + return + Original_Record_Component (discr1) == Original_Record_Component (discr2); +} + +/* Return true if the array type GNU_TYPE, which represents a dimension of + GNAT_TYPE, has a non-aliased component in the back-end sense. */ + +static bool +array_type_has_nonaliased_component (tree gnu_type, Entity_Id gnat_type) +{ + /* If the array type has an aliased component in the front-end sense, + then it also has an aliased component in the back-end sense. */ + if (Has_Aliased_Components (gnat_type)) + return false; + + /* If this is a derived type, then it has a non-aliased component if + and only if its parent type also has one. */ + if (Is_Derived_Type (gnat_type)) + { + tree gnu_parent_type = gnat_to_gnu_type (Etype (gnat_type)); + if (TREE_CODE (gnu_parent_type) == UNCONSTRAINED_ARRAY_TYPE) + gnu_parent_type + = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_parent_type)))); + return TYPE_NONALIASED_COMPONENT (gnu_parent_type); + } + + /* For a multi-dimensional array type, find the component type. */ + while (TREE_CODE (TREE_TYPE (gnu_type)) == ARRAY_TYPE + && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_type))) + gnu_type = TREE_TYPE (gnu_type); + + /* Consider that an array of pointers has an aliased component, which is + sort of logical and helps with Taft Amendment types in LTO mode. */ + if (POINTER_TYPE_P (TREE_TYPE (gnu_type))) + return false; + + /* Otherwise, rely exclusively on properties of the element type. */ + return type_for_nonaliased_component_p (TREE_TYPE (gnu_type)); +} + +/* Return true if GNAT_ADDRESS is a value known at compile-time. */ + +static bool +compile_time_known_address_p (Node_Id gnat_address) +{ + /* Handle reference to a constant. */ + if (Is_Entity_Name (gnat_address) + && Ekind (Entity (gnat_address)) == E_Constant) + { + gnat_address = Constant_Value (Entity (gnat_address)); + if (No (gnat_address)) + return false; + } + + /* Catch System'To_Address. */ + if (Nkind (gnat_address) == N_Unchecked_Type_Conversion) + gnat_address = Expression (gnat_address); + + return Compile_Time_Known_Value (gnat_address); +} + +/* Return true if GNAT_INDIC, a N_Subtype_Indication node for the index of a + FLB, cannot yield superflat objects, i.e. if the inequality HB >= LB - 1 + is true for these objects. LB and HB are the low and high bounds. */ + +static bool +flb_cannot_be_superflat (Node_Id gnat_indic) +{ + const Entity_Id gnat_type = Entity (Subtype_Mark (gnat_indic)); + const Entity_Id gnat_subtype = Etype (gnat_indic); + Node_Id gnat_scalar_range, gnat_lb, gnat_hb; + tree gnu_lb, gnu_hb, gnu_lb_minus_one; + + /* This is a FLB so LB is fixed. */ + if ((Ekind (gnat_subtype) == E_Signed_Integer_Subtype + || Ekind (gnat_subtype) == E_Modular_Integer_Subtype) + && (gnat_scalar_range = Scalar_Range (gnat_subtype))) + { + gnat_lb = Low_Bound (gnat_scalar_range); + gcc_assert (Nkind (gnat_lb) == N_Integer_Literal); + } + else + return false; + + /* The low bound of the type is a lower bound for HB. */ + if ((Ekind (gnat_type) == E_Signed_Integer_Subtype + || Ekind (gnat_type) == E_Modular_Integer_Subtype) + && (gnat_scalar_range = Scalar_Range (gnat_type))) + { + gnat_hb = Low_Bound (gnat_scalar_range); + gcc_assert (Nkind (gnat_hb) == N_Integer_Literal); + } + else + return false; + + /* We need at least a signed 64-bit type to catch most cases. */ + gnu_lb = UI_To_gnu (Intval (gnat_lb), sbitsizetype); + gnu_hb = UI_To_gnu (Intval (gnat_hb), sbitsizetype); + if (TREE_OVERFLOW (gnu_lb) || TREE_OVERFLOW (gnu_hb)) + return false; + + /* If the low bound is the smallest integer, nothing can be smaller. */ + gnu_lb_minus_one = size_binop (MINUS_EXPR, gnu_lb, sbitsize_one_node); + if (TREE_OVERFLOW (gnu_lb_minus_one)) + return true; + + return !tree_int_cst_lt (gnu_hb, gnu_lb_minus_one); +} + +/* Return true if GNAT_RANGE, a N_Range node, cannot be superflat, i.e. if the + inequality HB >= LB - 1 is true. LB and HB are the low and high bounds. */ + +static bool +range_cannot_be_superflat (Node_Id gnat_range) +{ + Node_Id gnat_lb = Low_Bound (gnat_range), gnat_hb = High_Bound (gnat_range); + Node_Id gnat_scalar_range; + tree gnu_lb, gnu_hb, gnu_lb_minus_one; + + /* If the low bound is not constant, take the worst case by finding an upper + bound for its type, repeatedly if need be. */ + while (Nkind (gnat_lb) != N_Integer_Literal + && (Ekind (Etype (gnat_lb)) == E_Signed_Integer_Subtype + || Ekind (Etype (gnat_lb)) == E_Modular_Integer_Subtype) + && (gnat_scalar_range = Scalar_Range (Etype (gnat_lb))) + && (Nkind (gnat_scalar_range) == N_Signed_Integer_Type_Definition + || Nkind (gnat_scalar_range) == N_Range)) + gnat_lb = High_Bound (gnat_scalar_range); + + /* If the high bound is not constant, take the worst case by finding a lower + bound for its type, repeatedly if need be. */ + while (Nkind (gnat_hb) != N_Integer_Literal + && (Ekind (Etype (gnat_hb)) == E_Signed_Integer_Subtype + || Ekind (Etype (gnat_hb)) == E_Modular_Integer_Subtype) + && (gnat_scalar_range = Scalar_Range (Etype (gnat_hb))) + && (Nkind (gnat_scalar_range) == N_Signed_Integer_Type_Definition + || Nkind (gnat_scalar_range) == N_Range)) + gnat_hb = Low_Bound (gnat_scalar_range); + + /* If we have failed to find constant bounds, punt. */ + if (Nkind (gnat_lb) != N_Integer_Literal + || Nkind (gnat_hb) != N_Integer_Literal) + return false; + + /* We need at least a signed 64-bit type to catch most cases. */ + gnu_lb = UI_To_gnu (Intval (gnat_lb), sbitsizetype); + gnu_hb = UI_To_gnu (Intval (gnat_hb), sbitsizetype); + if (TREE_OVERFLOW (gnu_lb) || TREE_OVERFLOW (gnu_hb)) + return false; + + /* If the low bound is the smallest integer, nothing can be smaller. */ + gnu_lb_minus_one = size_binop (MINUS_EXPR, gnu_lb, sbitsize_one_node); + if (TREE_OVERFLOW (gnu_lb_minus_one)) + return true; + + return !tree_int_cst_lt (gnu_hb, gnu_lb_minus_one); +} + +/* Return true if GNU_EXPR is (essentially) the address of a CONSTRUCTOR. */ + +static bool +constructor_address_p (tree gnu_expr) +{ + while (TREE_CODE (gnu_expr) == NOP_EXPR + || TREE_CODE (gnu_expr) == CONVERT_EXPR + || TREE_CODE (gnu_expr) == NON_LVALUE_EXPR) + gnu_expr = TREE_OPERAND (gnu_expr, 0); + + return (TREE_CODE (gnu_expr) == ADDR_EXPR + && TREE_CODE (TREE_OPERAND (gnu_expr, 0)) == CONSTRUCTOR); +} + +/* Return true if the size in units represented by GNU_SIZE can be handled by + an allocation. If STATIC_P is true, consider only what can be done with a + static allocation. */ + +static bool +allocatable_size_p (tree gnu_size, bool static_p) +{ + /* We can allocate a fixed size if it is a valid for the middle-end. */ + if (TREE_CODE (gnu_size) == INTEGER_CST) + return valid_constant_size_p (gnu_size); + + /* We can allocate a variable size if this isn't a static allocation. */ + else + return !static_p; +} + +/* Return true if GNU_EXPR needs a conversion to GNU_TYPE when used as the + initial value of an object of GNU_TYPE. */ + +static bool +initial_value_needs_conversion (tree gnu_type, tree gnu_expr) +{ + /* Do not convert if the object's type is unconstrained because this would + generate useless evaluations of the CONSTRUCTOR to compute the size. */ + if (TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE + || CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type))) + return false; + + /* Do not convert if the object's type is a padding record whose field is of + self-referential size because we want to copy only the actual data. */ + if (type_is_padding_self_referential (gnu_type)) + return false; + + /* Do not convert a call to a function that returns with variable size since + we want to use the return slot optimization in this case. */ + if (TREE_CODE (gnu_expr) == CALL_EXPR + && return_type_with_variable_size_p (TREE_TYPE (gnu_expr))) + return false; + + /* Do not convert to a record type with a variant part from a record type + without one, to keep the object simpler. */ + if (TREE_CODE (gnu_type) == RECORD_TYPE + && TREE_CODE (TREE_TYPE (gnu_expr)) == RECORD_TYPE + && get_variant_part (gnu_type) + && !get_variant_part (TREE_TYPE (gnu_expr))) + return false; + + /* In all the other cases, convert the expression to the object's type. */ + return true; +} + +/* Add the contribution of [MIN, MAX] to the current number of elements N_ELEM + of an array type and return the result, or NULL_TREE if it overflowed. */ + +static tree +update_n_elem (tree n_elem, tree min, tree max) +{ + /* First deal with the empty case. */ + if (TREE_CODE (min) == INTEGER_CST + && TREE_CODE (max) == INTEGER_CST + && tree_int_cst_lt (max, min)) + return size_zero_node; + + min = convert (sizetype, min); + max = convert (sizetype, max); + + /* Compute the number of elements in this dimension. */ + tree this_n_elem + = size_binop (PLUS_EXPR, size_one_node, size_binop (MINUS_EXPR, max, min)); + + if (TREE_CODE (this_n_elem) == INTEGER_CST && TREE_OVERFLOW (this_n_elem)) + return NULL_TREE; + + /* Multiply the current number of elements by the result. */ + n_elem = size_binop (MULT_EXPR, n_elem, this_n_elem); + + if (TREE_CODE (n_elem) == INTEGER_CST && TREE_OVERFLOW (n_elem)) + return NULL_TREE; + + return n_elem; +} + +/* Given GNAT_ENTITY, elaborate all expressions that are required to + be elaborated at the point of its definition, but do nothing else. */ + +void +elaborate_entity (Entity_Id gnat_entity) +{ + switch (Ekind (gnat_entity)) + { + case E_Signed_Integer_Subtype: + case E_Modular_Integer_Subtype: + case E_Enumeration_Subtype: + case E_Ordinary_Fixed_Point_Subtype: + case E_Decimal_Fixed_Point_Subtype: + case E_Floating_Point_Subtype: + { + Node_Id gnat_lb = Type_Low_Bound (gnat_entity); + Node_Id gnat_hb = Type_High_Bound (gnat_entity); + + /* ??? Tests to avoid Constraint_Error in static expressions + are needed until after the front stops generating bogus + conversions on bounds of real types. */ + if (!Raises_Constraint_Error (gnat_lb)) + elaborate_expression (gnat_lb, gnat_entity, "L", true, false, + Needs_Debug_Info (gnat_entity)); + if (!Raises_Constraint_Error (gnat_hb)) + elaborate_expression (gnat_hb, gnat_entity, "U", true, false, + Needs_Debug_Info (gnat_entity)); + break; + } + + case E_Record_Subtype: + case E_Private_Subtype: + case E_Limited_Private_Subtype: + case E_Record_Subtype_With_Private: + if (Has_Discriminants (gnat_entity) && Is_Constrained (gnat_entity)) + { + Node_Id gnat_discriminant_expr; + Entity_Id gnat_field; + + for (gnat_field + = First_Discriminant (Implementation_Base_Type (gnat_entity)), + gnat_discriminant_expr + = First_Elmt (Discriminant_Constraint (gnat_entity)); + Present (gnat_field); + gnat_field = Next_Discriminant (gnat_field), + gnat_discriminant_expr = Next_Elmt (gnat_discriminant_expr)) + /* Ignore access discriminants. */ + if (!Is_Access_Type (Etype (Node (gnat_discriminant_expr)))) + elaborate_expression (Node (gnat_discriminant_expr), + gnat_entity, get_entity_char (gnat_field), + true, false, false); + } + break; + + } +} + +/* Prepend to ATTR_LIST an entry for an attribute with provided TYPE, + NAME, ARGS and ERROR_POINT. */ + +static void +prepend_one_attribute (struct attrib **attr_list, + enum attrib_type attrib_type, + tree attr_name, + tree attr_args, + Node_Id attr_error_point) +{ + struct attrib * attr = (struct attrib *) xmalloc (sizeof (struct attrib)); + + attr->type = attrib_type; + attr->name = attr_name; + attr->args = attr_args; + attr->error_point = attr_error_point; + + attr->next = *attr_list; + *attr_list = attr; +} + +/* Prepend to ATTR_LIST an entry for an attribute provided by GNAT_PRAGMA. */ + +static void +prepend_one_attribute_pragma (struct attrib **attr_list, Node_Id gnat_pragma) +{ + const Node_Id gnat_arg = First (Pragma_Argument_Associations (gnat_pragma)); + Node_Id gnat_next_arg = Next (gnat_arg); + tree gnu_arg1 = NULL_TREE, gnu_arg_list = NULL_TREE; + enum attrib_type etype; + + /* Map the pragma at hand. Skip if this isn't one we know how to handle. */ + switch (Get_Pragma_Id (Chars (Pragma_Identifier (gnat_pragma)))) + { + case Pragma_Linker_Alias: + etype = ATTR_LINK_ALIAS; + break; + + case Pragma_Linker_Constructor: + etype = ATTR_LINK_CONSTRUCTOR; + break; + + case Pragma_Linker_Destructor: + etype = ATTR_LINK_DESTRUCTOR; + break; + + case Pragma_Linker_Section: + etype = ATTR_LINK_SECTION; + break; + + case Pragma_Machine_Attribute: + etype = ATTR_MACHINE_ATTRIBUTE; + break; + + case Pragma_Thread_Local_Storage: + etype = ATTR_THREAD_LOCAL_STORAGE; + break; + + case Pragma_Weak_External: + etype = ATTR_WEAK_EXTERNAL; + break; + + default: + return; + } + + /* See what arguments we have and turn them into GCC trees for attribute + handlers. The first one is always expected to be a string meant to be + turned into an identifier. The next ones are all static expressions, + among which strings meant to be turned into an identifier, except for + a couple of specific attributes that require raw strings. */ + if (Present (gnat_next_arg)) + { + gnu_arg1 = gnat_to_gnu (Expression (gnat_next_arg)); + gcc_assert (TREE_CODE (gnu_arg1) == STRING_CST); + + const char *const p = TREE_STRING_POINTER (gnu_arg1); + const bool string_args + = strcmp (p, "target") == 0 || strcmp (p, "target_clones") == 0; + gnu_arg1 = get_identifier (p); + if (IDENTIFIER_LENGTH (gnu_arg1) == 0) + return; + gnat_next_arg = Next (gnat_next_arg); + + while (Present (gnat_next_arg)) + { + tree gnu_arg = gnat_to_gnu (Expression (gnat_next_arg)); + if (TREE_CODE (gnu_arg) == STRING_CST && !string_args) + gnu_arg = get_identifier (TREE_STRING_POINTER (gnu_arg)); + gnu_arg_list + = chainon (gnu_arg_list, build_tree_list (NULL_TREE, gnu_arg)); + gnat_next_arg = Next (gnat_next_arg); + } + } + + prepend_one_attribute (attr_list, etype, gnu_arg1, gnu_arg_list, + Present (Next (gnat_arg)) + ? Expression (Next (gnat_arg)) : gnat_pragma); +} + +/* Prepend to ATTR_LIST the list of attributes for GNAT_ENTITY, if any. */ + +static void +prepend_attributes (struct attrib **attr_list, Entity_Id gnat_entity) +{ + Node_Id gnat_temp; + + /* Attributes are stored as Representation Item pragmas. */ + for (gnat_temp = First_Rep_Item (gnat_entity); + Present (gnat_temp); + gnat_temp = Next_Rep_Item (gnat_temp)) + if (Nkind (gnat_temp) == N_Pragma) + prepend_one_attribute_pragma (attr_list, gnat_temp); +} + +/* Given a GNAT tree GNAT_EXPR, for an expression which is a value within a + type definition (either a bound or a discriminant value) for GNAT_ENTITY, + return the GCC tree to use for that expression. S is the suffix to use + if a variable needs to be created and DEFINITION is true if this is done + for a definition of GNAT_ENTITY. If NEED_VALUE is true, we need a result; + otherwise, we are just elaborating the expression for side-effects. If + NEED_FOR_DEBUG is true, we need a variable for debugging purposes even + if it isn't needed for code generation. */ + +static tree +elaborate_expression (Node_Id gnat_expr, Entity_Id gnat_entity, const char *s, + bool definition, bool need_value, bool need_for_debug) +{ + tree gnu_expr; + + /* If we already elaborated this expression (e.g. it was involved + in the definition of a private type), use the old value. */ + if (present_gnu_tree (gnat_expr)) + return get_gnu_tree (gnat_expr); + + /* If we don't need a value and this is static or a discriminant, + we don't need to do anything. */ + if (!need_value + && (Compile_Time_Known_Value (gnat_expr) + || (Nkind (gnat_expr) == N_Identifier + && Ekind (Entity (gnat_expr)) == E_Discriminant))) + return NULL_TREE; + + /* If it's a static expression, we don't need a variable for debugging. */ + if (need_for_debug && Compile_Time_Known_Value (gnat_expr)) + need_for_debug = false; + + /* Otherwise, convert this tree to its GCC equivalent and elaborate it. */ + gnu_expr = elaborate_expression_1 (gnat_to_gnu (gnat_expr), gnat_entity, s, + definition, need_for_debug); + + /* Save the expression in case we try to elaborate this entity again. Since + it's not a DECL, don't check it. Don't save if it's a discriminant. */ + if (!CONTAINS_PLACEHOLDER_P (gnu_expr)) + save_gnu_tree (gnat_expr, gnu_expr, true); + + return need_value ? gnu_expr : error_mark_node; +} + +/* Similar, but take a GNU expression and always return a result. */ + +static tree +elaborate_expression_1 (tree gnu_expr, Entity_Id gnat_entity, const char *s, + bool definition, bool need_for_debug) +{ + const bool expr_public_p = Is_Public (gnat_entity); + const bool expr_global_p = expr_public_p || global_bindings_p (); + bool expr_variable_p, use_variable; + + /* If GNU_EXPR contains a placeholder, just return it. We rely on the fact + that an expression cannot contain both a discriminant and a variable. */ + if (CONTAINS_PLACEHOLDER_P (gnu_expr)) + return gnu_expr; + + /* If GNU_EXPR is neither a constant nor based on a read-only variable, make + a variable that is initialized to contain the expression when the package + containing the definition is elaborated. If this entity is defined at top + level, replace the expression by the variable; otherwise use a SAVE_EXPR + if this is necessary. */ + if (TREE_CONSTANT (gnu_expr)) + expr_variable_p = false; + else + { + /* Skip any conversions and simple constant arithmetics to see if the + expression is based on a read-only variable. */ + tree inner = remove_conversions (gnu_expr, true); + + inner = skip_simple_constant_arithmetic (inner); + + if (handled_component_p (inner)) + inner = get_inner_constant_reference (inner); + + expr_variable_p + = !(inner + && TREE_CODE (inner) == VAR_DECL + && (TREE_READONLY (inner) || DECL_READONLY_ONCE_ELAB (inner))); + } + + /* We only need to use the variable if we are in a global context since GCC + can do the right thing in the local case. However, when not optimizing, + use it for bounds of loop iteration scheme to avoid code duplication. */ + use_variable = expr_variable_p + && (expr_global_p + || (!optimize + && definition + && Is_Itype (gnat_entity) + && Nkind (Associated_Node_For_Itype (gnat_entity)) + == N_Loop_Parameter_Specification)); + + /* If the GNAT encodings are not used, we don't need a variable for debug + info purposes if the expression is a constant or another variable, but + we must be careful because we do not generate debug info for external + variables so DECL_IGNORED_P is not stable across units. */ + if (need_for_debug + && gnat_encodings != DWARF_GNAT_ENCODINGS_ALL + && (TREE_CONSTANT (gnu_expr) + || (!expr_public_p + && DECL_P (gnu_expr) + && !DECL_IGNORED_P (gnu_expr)))) + need_for_debug = false; + + /* Now create it, possibly only for debugging purposes. */ + if (use_variable || need_for_debug) + { + /* The following variable creation can happen when processing the body + of subprograms that are defined outside of the extended main unit and + inlined. In this case, we are not at the global scope, and thus the + new variable must not be tagged "external", as we used to do here as + soon as DEFINITION was false. And note that we test Needs_Debug_Info + here instead of NEED_FOR_DEBUG because, once the variable is created, + whether or not debug information is generated for it is orthogonal to + the reason why it was created in the first place. */ + tree gnu_decl + = create_var_decl (create_concat_name (gnat_entity, s), NULL_TREE, + TREE_TYPE (gnu_expr), gnu_expr, true, + expr_public_p, !definition && expr_global_p, + expr_global_p, false, true, + Needs_Debug_Info (gnat_entity), + NULL, gnat_entity, false); + + /* Using this variable for debug (if need_for_debug is true) requires + a proper location. The back-end will compute a location for this + variable only if the variable is used by the generated code. + Returning the variable ensures the caller will use it in generated + code. Note that there is no need for a location if the debug info + contains an integer constant. */ + if (use_variable || (need_for_debug && !TREE_CONSTANT (gnu_expr))) + return gnu_decl; + } + + return expr_variable_p ? gnat_save_expr (gnu_expr) : gnu_expr; +} + +/* Similar, but take an alignment factor and make it explicit in the tree. */ + +static tree +elaborate_expression_2 (tree gnu_expr, Entity_Id gnat_entity, const char *s, + bool definition, bool need_for_debug, unsigned int align) +{ + tree unit_align = size_int (align / BITS_PER_UNIT); + return + size_binop (MULT_EXPR, + elaborate_expression_1 (size_binop (EXACT_DIV_EXPR, + gnu_expr, + unit_align), + gnat_entity, s, definition, + need_for_debug), + unit_align); +} + +/* Structure to hold internal data for elaborate_reference. */ + +struct er_data +{ + Entity_Id entity; + bool definition; + unsigned int n; +}; + +/* Wrapper function around elaborate_expression_1 for elaborate_reference. */ + +static tree +elaborate_reference_1 (tree ref, void *data) +{ + struct er_data *er = (struct er_data *)data; + char suffix[16]; + + /* This is what elaborate_expression_1 does if NEED_DEBUG is false. */ + if (TREE_CONSTANT (ref)) + return ref; + + /* If this is a COMPONENT_REF of a fat pointer, elaborate the entire fat + pointer. This may be more efficient, but will also allow us to more + easily find the match for the PLACEHOLDER_EXPR. */ + if (TREE_CODE (ref) == COMPONENT_REF + && TYPE_IS_FAT_POINTER_P (TREE_TYPE (TREE_OPERAND (ref, 0)))) + return build3 (COMPONENT_REF, TREE_TYPE (ref), + elaborate_reference_1 (TREE_OPERAND (ref, 0), data), + TREE_OPERAND (ref, 1), NULL_TREE); + + /* If this is the displacement of a pointer, elaborate the pointer and then + displace the result. The actual purpose here is to drop the location on + the expression, which may be problematic if replicated on references. */ + if (TREE_CODE (ref) == POINTER_PLUS_EXPR + && TREE_CODE (TREE_OPERAND (ref, 1)) == INTEGER_CST) + return build2 (POINTER_PLUS_EXPR, TREE_TYPE (ref), + elaborate_reference_1 (TREE_OPERAND (ref, 0), data), + TREE_OPERAND (ref, 1)); + + sprintf (suffix, "EXP%d", ++er->n); + return + elaborate_expression_1 (ref, er->entity, suffix, er->definition, false); +} + +/* Elaborate the reference REF to be used as renamed object for GNAT_ENTITY. + DEFINITION is true if this is done for a definition of GNAT_ENTITY and + INIT is set to the first arm of a COMPOUND_EXPR present in REF, if any. */ + +static tree +elaborate_reference (tree ref, Entity_Id gnat_entity, bool definition, + tree *init) +{ + struct er_data er = { gnat_entity, definition, 0 }; + return gnat_rewrite_reference (ref, elaborate_reference_1, &er, init); +} + +/* Given a GNU tree and a GNAT list of choices, generate an expression to test + the value passed against the list of choices. */ + +static tree +choices_to_gnu (tree gnu_operand, Node_Id gnat_choices) +{ + tree gnu_result = boolean_false_node, gnu_type; + + gnu_operand = maybe_character_value (gnu_operand); + gnu_type = TREE_TYPE (gnu_operand); + + for (Node_Id gnat_choice = First (gnat_choices); + Present (gnat_choice); + gnat_choice = Next (gnat_choice)) + { + tree gnu_low = NULL_TREE, gnu_high = NULL_TREE; + tree gnu_test; + + switch (Nkind (gnat_choice)) + { + case N_Range: + gnu_low = gnat_to_gnu (Low_Bound (gnat_choice)); + gnu_high = gnat_to_gnu (High_Bound (gnat_choice)); + break; + + case N_Subtype_Indication: + gnu_low = gnat_to_gnu (Low_Bound (Range_Expression + (Constraint (gnat_choice)))); + gnu_high = gnat_to_gnu (High_Bound (Range_Expression + (Constraint (gnat_choice)))); + break; + + case N_Identifier: + case N_Expanded_Name: + /* This represents either a subtype range or a static value of + some kind; Ekind says which. */ + if (Is_Type (Entity (gnat_choice))) + { + tree gnu_type = get_unpadded_type (Entity (gnat_choice)); + + gnu_low = TYPE_MIN_VALUE (gnu_type); + gnu_high = TYPE_MAX_VALUE (gnu_type); + break; + } + + /* ... fall through ... */ + + case N_Character_Literal: + case N_Integer_Literal: + gnu_low = gnat_to_gnu (gnat_choice); + break; + + case N_Others_Choice: + break; + + default: + gcc_unreachable (); + } + + /* Everything should be folded into constants at this point. */ + gcc_assert (!gnu_low || TREE_CODE (gnu_low) == INTEGER_CST); + gcc_assert (!gnu_high || TREE_CODE (gnu_high) == INTEGER_CST); + + if (gnu_low && TREE_TYPE (gnu_low) != gnu_type) + gnu_low = convert (gnu_type, gnu_low); + if (gnu_high && TREE_TYPE (gnu_high) != gnu_type) + gnu_high = convert (gnu_type, gnu_high); + + if (gnu_low && gnu_high) + gnu_test + = build_binary_op (TRUTH_ANDIF_EXPR, boolean_type_node, + build_binary_op (GE_EXPR, boolean_type_node, + gnu_operand, gnu_low, true), + build_binary_op (LE_EXPR, boolean_type_node, + gnu_operand, gnu_high, true), + true); + else if (gnu_low == boolean_true_node + && TREE_TYPE (gnu_operand) == boolean_type_node) + gnu_test = gnu_operand; + else if (gnu_low) + gnu_test + = build_binary_op (EQ_EXPR, boolean_type_node, gnu_operand, gnu_low, + true); + else + gnu_test = boolean_true_node; + + if (gnu_result == boolean_false_node) + gnu_result = gnu_test; + else + gnu_result + = build_binary_op (TRUTH_ORIF_EXPR, boolean_type_node, gnu_result, + gnu_test, true); + } + + return gnu_result; +} + +/* Adjust PACKED setting as passed to gnat_to_gnu_field for a field of + type FIELD_TYPE to be placed in RECORD_TYPE. Return the result. */ + +static int +adjust_packed (tree field_type, tree record_type, int packed) +{ + /* If the field is an array of variable size, we'd better not pack it because + this would misalign it and, therefore, probably cause large temporarie to + be created in case we need to take its address. See addressable_p and the + notes on the addressability issues for further details. */ + if (TREE_CODE (field_type) == ARRAY_TYPE + && type_has_variable_size (field_type)) + return 0; + + /* In the other cases, we can honor the packing. */ + if (packed) + return packed; + + /* If the alignment of the record is specified and the field type + is over-aligned, request Storage_Unit alignment for the field. */ + if (TYPE_ALIGN (record_type) + && TYPE_ALIGN (field_type) > TYPE_ALIGN (record_type)) + return -1; + + /* Likewise if the maximum alignment of the record is specified. */ + if (TYPE_MAX_ALIGN (record_type) + && TYPE_ALIGN (field_type) > TYPE_MAX_ALIGN (record_type)) + return -1; + + return 0; +} + +/* Return a GCC tree for a field corresponding to GNAT_FIELD to be + placed in GNU_RECORD_TYPE. + + PACKED is 1 if the enclosing record is packed or -1 if the enclosing + record has Component_Alignment of Storage_Unit. + + DEFINITION is true if this field is for a record being defined. + + DEBUG_INFO_P is true if we need to write debug information for types + that we may create in the process. */ + +static tree +gnat_to_gnu_field (Entity_Id gnat_field, tree gnu_record_type, int packed, + bool definition, bool debug_info_p) +{ + const Node_Id gnat_clause = Component_Clause (gnat_field); + const Entity_Id gnat_record_type = Underlying_Type (Scope (gnat_field)); + const Entity_Id gnat_field_type = Etype (gnat_field); + tree gnu_field_type = gnat_to_gnu_type (gnat_field_type); + tree gnu_field_id = get_entity_name (gnat_field); + const bool is_aliased = Is_Aliased (gnat_field); + const bool is_full_access + = (Is_Full_Access (gnat_field) || Is_Full_Access (gnat_field_type)); + const bool is_independent + = (Is_Independent (gnat_field) || Is_Independent (gnat_field_type)); + const bool is_volatile + = (Treat_As_Volatile (gnat_field) || Treat_As_Volatile (gnat_field_type)); + const bool is_by_ref = TYPE_IS_BY_REFERENCE_P (gnu_field_type); + const bool is_strict_alignment = Strict_Alignment (gnat_field_type); + /* We used to consider that volatile fields also require strict alignment, + but that was an interpolation and would cause us to reject a pragma + volatile on a packed record type containing boolean components, while + there is no basis to do so in the RM. In such cases, the writes will + involve load-modify-store sequences, but that's OK for volatile. The + only constraint is the implementation advice whereby only the bits of + the components should be accessed if they both start and end on byte + boundaries, but that should be guaranteed by the GCC memory model. + Note that we have some redundancies (is_full_access => is_independent, + is_aliased => is_independent and is_by_ref => is_strict_alignment) + so the following formula is sufficient. */ + const bool needs_strict_alignment = (is_independent || is_strict_alignment); + const char *field_s, *size_s; + tree gnu_field, gnu_size, gnu_pos; + bool is_bitfield; + + /* Force the type of the Not_Handled_By_Others field to be that of the + field in struct Exception_Data declared in raise.h instead of using + the declared boolean type. We need to do that because there is no + easy way to make use of a C compatible boolean type for the latter. */ + if (gnu_field_id == not_handled_by_others_name_id + && gnu_field_type == boolean_type_node) + gnu_field_type = char_type_node; + + /* The qualifier to be used in messages. */ + if (is_aliased) + field_s = "aliased&"; + else if (is_full_access) + { + if (Is_Volatile_Full_Access (gnat_field) + || Is_Volatile_Full_Access (gnat_field_type)) + field_s = "volatile full access&"; + else + field_s = "atomic&"; + } + else if (is_independent) + field_s = "independent&"; + else if (is_by_ref) + field_s = "& with by-reference type"; + else if (is_strict_alignment) + field_s = "& with aliased part"; + else + field_s = "&"; + + /* The message to be used for incompatible size. */ + if (is_aliased || is_full_access) + size_s = "size for %s must be ^"; + else if (field_s) + size_s = "size for %s too small{, minimum allowed is ^}"; + + /* If a field requires strict alignment, we cannot pack it (RM 13.2(7)). */ + if (needs_strict_alignment) + packed = 0; + else + packed = adjust_packed (gnu_field_type, gnu_record_type, packed); + + /* If a size is specified, use it. Otherwise, if the record type is packed, + use the official RM size. See "Handling of Type'Size Values" in Einfo + for further details. */ + if (Present (gnat_clause) || Known_Esize (gnat_field)) + gnu_size = validate_size (Esize (gnat_field), gnu_field_type, gnat_field, + FIELD_DECL, false, true, size_s, field_s); + else if (packed == 1) + { + gnu_size = rm_size (gnu_field_type); + if (TREE_CODE (gnu_size) != INTEGER_CST) + gnu_size = NULL_TREE; + } + else + gnu_size = NULL_TREE; + + /* Likewise for the position. */ + if (Present (gnat_clause)) + { + gnu_pos = UI_To_gnu (Component_Bit_Offset (gnat_field), bitsizetype); + is_bitfield = !value_factor_p (gnu_pos, BITS_PER_UNIT); + } + + /* If the record has rep clauses and this is the tag field, make a rep + clause for it as well. */ + else if (Has_Specified_Layout (gnat_record_type) + && Chars (gnat_field) == Name_uTag) + { + gnu_pos = bitsize_zero_node; + gnu_size = TYPE_SIZE (gnu_field_type); + is_bitfield = false; + } + + else + { + gnu_pos = NULL_TREE; + is_bitfield = false; + } + + /* If the field's type is a fixed-size record that does not require strict + alignment, and the record is packed or we have a position specified for + the field that makes it a bitfield or we have a specified size that is + smaller than that of the field's type, then see if we can get either an + integral mode form of the field's type or a smaller form. If we can, + consider that a size was specified for the field if there wasn't one + already, so we know to make it a bitfield and avoid making things wider. + + Changing to an integral mode form is useful when the record is packed as + we can then place the field at a non-byte-aligned position and so achieve + tighter packing. This is in addition required if the field shares a byte + with another field and the front-end lets the back-end handle the access + to the field, because GCC cannot handle non-byte-aligned BLKmode fields. + + Changing to a smaller form is required if the specified size is smaller + than that of the field's type and the type contains sub-fields that are + padded, in order to avoid generating accesses to these sub-fields that + are wider than the field. + + We avoid the transformation if it is not required or potentially useful, + as it might entail an increase of the field's alignment and have ripple + effects on the outer record type. A typical case is a field known to be + byte-aligned and not to share a byte with another field. */ + if (!needs_strict_alignment + && RECORD_OR_UNION_TYPE_P (gnu_field_type) + && !TYPE_FAT_POINTER_P (gnu_field_type) + && tree_fits_uhwi_p (TYPE_SIZE (gnu_field_type)) + && (packed == 1 + || is_bitfield + || (gnu_size + && tree_int_cst_lt (gnu_size, TYPE_SIZE (gnu_field_type))))) + { + tree gnu_packable_type + = make_packable_type (gnu_field_type, true, is_bitfield ? 1 : 0); + if (gnu_packable_type != gnu_field_type) + { + gnu_field_type = gnu_packable_type; + if (!gnu_size) + gnu_size = rm_size (gnu_field_type); + } + } + + /* Now check if the type of the field allows atomic access. */ + if (Is_Full_Access (gnat_field)) + { + const unsigned int align + = promote_object_alignment (gnu_field_type, NULL_TREE, gnat_field); + if (align > 0) + gnu_field_type + = maybe_pad_type (gnu_field_type, NULL_TREE, align, gnat_field, + false, definition, true); + check_ok_for_atomic_type (gnu_field_type, gnat_field, false); + } + + /* If a position is specified, check that it is valid. */ + if (gnu_pos) + { + Entity_Id gnat_parent = Parent_Subtype (gnat_record_type); + + /* Ensure the position doesn't overlap with the parent subtype if there + is one. It would be impossible to build CONSTRUCTORs and accessing + the parent could clobber the component in the extension if directly + done. We accept it with -gnatd.K for the sake of compatibility. */ + if (Present (gnat_parent) + && !(Debug_Flag_Dot_KK && Is_Fully_Repped_Tagged_Type (gnat_parent))) + { + tree gnu_parent = gnat_to_gnu_type (gnat_parent); + + if (TREE_CODE (TYPE_SIZE (gnu_parent)) == INTEGER_CST + && tree_int_cst_lt (gnu_pos, TYPE_SIZE (gnu_parent))) + post_error_ne_tree + ("position for& must be beyond parent{, minimum allowed is ^}", + Position (gnat_clause), gnat_field, TYPE_SIZE_UNIT (gnu_parent)); + } + + /* If this field needs strict alignment, make sure that the record is + sufficiently aligned and that the position and size are consistent + with the type. But don't do it if we are just annotating types and + the field's type is tagged, since tagged types aren't fully laid out + in this mode. Also, note that atomic implies volatile so the inner + test sequences ordering is significant here. */ + if (needs_strict_alignment + && !(type_annotate_only && Is_Tagged_Type (gnat_field_type))) + { + const unsigned int type_align = TYPE_ALIGN (gnu_field_type); + + if (TYPE_ALIGN (gnu_record_type) + && TYPE_ALIGN (gnu_record_type) < type_align) + SET_TYPE_ALIGN (gnu_record_type, type_align); + + /* If the position is not a multiple of the storage unit, then error + out and reset the position. */ + if (!integer_zerop (size_binop (TRUNC_MOD_EXPR, gnu_pos, + bitsize_unit_node))) + { + char s[128]; + snprintf (s, sizeof (s), "position for %s must be " + "multiple of Storage_Unit", field_s); + post_error_ne (s, First_Bit (gnat_clause), gnat_field); + gnu_pos = NULL_TREE; + } + + /* If the position is not a multiple of the alignment of the type, + then error out and reset the position. */ + else if (type_align > BITS_PER_UNIT + && !integer_zerop (size_binop (TRUNC_MOD_EXPR, gnu_pos, + bitsize_int (type_align)))) + { + char s[128]; + snprintf (s, sizeof (s), "position for %s must be multiple of ^", + field_s); + post_error_ne_num (s, First_Bit (gnat_clause), gnat_field, + type_align / BITS_PER_UNIT); + post_error_ne_num ("\\because alignment of its type& is ^", + First_Bit (gnat_clause), Etype (gnat_field), + type_align / BITS_PER_UNIT); + gnu_pos = NULL_TREE; + } + + if (gnu_size) + { + tree type_size = TYPE_SIZE (gnu_field_type); + int cmp; + + /* If the size is not a multiple of the storage unit, then error + out and reset the size. */ + if (!integer_zerop (size_binop (TRUNC_MOD_EXPR, gnu_size, + bitsize_unit_node))) + { + char s[128]; + snprintf (s, sizeof (s), "size for %s must be " + "multiple of Storage_Unit", field_s); + post_error_ne (s, Last_Bit (gnat_clause), gnat_field); + gnu_size = NULL_TREE; + } + + /* If the size is lower than that of the type, or greater for + atomic and aliased, then error out and reset the size. */ + else if ((cmp = tree_int_cst_compare (gnu_size, type_size)) < 0 + || (cmp > 0 && (is_aliased || is_full_access))) + { + char s[128]; + snprintf (s, sizeof (s), size_s, field_s); + post_error_ne_tree (s, Last_Bit (gnat_clause), gnat_field, + type_size); + gnu_size = NULL_TREE; + } + } + } + } + + else + { + /* If we are packing the record and the field is BLKmode, round the + size up to a byte boundary. */ + if (packed && TYPE_MODE (gnu_field_type) == BLKmode && gnu_size) + gnu_size = round_up (gnu_size, BITS_PER_UNIT); + } + + /* We need to make the size the maximum for the type if it is + self-referential and an unconstrained type. In that case, we can't + pack the field since we can't make a copy to align it. */ + if (TREE_CODE (gnu_field_type) == RECORD_TYPE + && !gnu_size + && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_field_type)) + && !Is_Constrained (Underlying_Type (gnat_field_type))) + { + gnu_size = max_size (TYPE_SIZE (gnu_field_type), true); + packed = 0; + } + + /* If a size is specified, adjust the field's type to it. */ + if (gnu_size) + { + tree orig_field_type; + + /* If the field's type is justified modular, we would need to remove + the wrapper to (better) meet the layout requirements. However we + can do so only if the field is not aliased to preserve the unique + layout, if it has the same storage order as the enclosing record + and if the prescribed size is not greater than that of the packed + array to preserve the justification. */ + if (!needs_strict_alignment + && TREE_CODE (gnu_field_type) == RECORD_TYPE + && TYPE_JUSTIFIED_MODULAR_P (gnu_field_type) + && TYPE_REVERSE_STORAGE_ORDER (gnu_field_type) + == Reverse_Storage_Order (gnat_record_type) + && tree_int_cst_compare (gnu_size, TYPE_ADA_SIZE (gnu_field_type)) + <= 0) + gnu_field_type = TREE_TYPE (TYPE_FIELDS (gnu_field_type)); + + /* Similarly if the field's type is a misaligned integral type, but + there is no restriction on the size as there is no justification. */ + if (!needs_strict_alignment + && TYPE_IS_PADDING_P (gnu_field_type) + && INTEGRAL_TYPE_P (TREE_TYPE (TYPE_FIELDS (gnu_field_type)))) + gnu_field_type = TREE_TYPE (TYPE_FIELDS (gnu_field_type)); + + orig_field_type = gnu_field_type; + gnu_field_type + = make_type_from_size (gnu_field_type, gnu_size, + Has_Biased_Representation (gnat_field)); + + /* If the type has been extended, we may need to cap the alignment. */ + if (!needs_strict_alignment + && gnu_field_type != orig_field_type + && tree_int_cst_lt (TYPE_SIZE (orig_field_type), gnu_size)) + packed = adjust_packed (gnu_field_type, gnu_record_type, packed); + + orig_field_type = gnu_field_type; + gnu_field_type = maybe_pad_type (gnu_field_type, gnu_size, 0, gnat_field, + false, definition, true); + + /* If a padding record was made, declare it now since it will never be + declared otherwise. This is necessary to ensure that its subtrees + are properly marked. */ + if (gnu_field_type != orig_field_type + && !DECL_P (TYPE_NAME (gnu_field_type))) + create_type_decl (TYPE_NAME (gnu_field_type), gnu_field_type, true, + debug_info_p, gnat_field); + } + + /* Otherwise (or if there was an error), don't specify a position. */ + else + gnu_pos = NULL_TREE; + + /* If the field's type is a padded type made for a scalar field of a record + type with reverse storage order, we need to propagate the reverse storage + order to the padding type since it is the innermost enclosing aggregate + type around the scalar. */ + if (TYPE_IS_PADDING_P (gnu_field_type) + && TYPE_REVERSE_STORAGE_ORDER (gnu_record_type) + && Is_Scalar_Type (gnat_field_type)) + gnu_field_type = set_reverse_storage_order_on_pad_type (gnu_field_type); + + gcc_assert (TREE_CODE (gnu_field_type) != RECORD_TYPE + || !TYPE_CONTAINS_TEMPLATE_P (gnu_field_type)); + + /* Now create the decl for the field. */ + gnu_field + = create_field_decl (gnu_field_id, gnu_field_type, gnu_record_type, + gnu_size, gnu_pos, packed, is_aliased); + Sloc_to_locus (Sloc (gnat_field), &DECL_SOURCE_LOCATION (gnu_field)); + DECL_ALIASED_P (gnu_field) = is_aliased; + TREE_SIDE_EFFECTS (gnu_field) = TREE_THIS_VOLATILE (gnu_field) = is_volatile; + + /* If this is a discriminant, then we treat it specially: first, we set its + index number for the back-annotation; second, we record whether it cannot + be changed once it has been set for the computation of loop invariants; + third, we make it addressable in order for the optimizer to more easily + see that it cannot be modified by assignments to the other fields of the + record (see create_field_decl for a more detailed explanation), which is + crucial to hoist the offset and size computations of dynamic fields. */ + if (Ekind (gnat_field) == E_Discriminant) + { + DECL_DISCRIMINANT_NUMBER (gnu_field) + = UI_To_gnu (Discriminant_Number (gnat_field), sizetype); + DECL_INVARIANT_P (gnu_field) + = No (Discriminant_Default_Value (gnat_field)); + DECL_NONADDRESSABLE_P (gnu_field) = 0; + } + + return gnu_field; +} + +/* Return true if at least one member of COMPONENT_LIST needs strict + alignment. */ + +static bool +components_need_strict_alignment (Node_Id component_list) +{ + Node_Id component_decl; + + for (component_decl = First_Non_Pragma (Component_Items (component_list)); + Present (component_decl); + component_decl = Next_Non_Pragma (component_decl)) + { + Entity_Id gnat_field = Defining_Entity (component_decl); + + if (Is_Independent (gnat_field) || Is_Independent (Etype (gnat_field))) + return true; + + if (Strict_Alignment (Etype (gnat_field))) + return true; + } + + return false; +} + +/* Return true if FIELD is an artificial field. */ + +static bool +field_is_artificial (tree field) +{ + /* These fields are generated by the front-end proper. */ + if (IDENTIFIER_POINTER (DECL_NAME (field)) [0] == '_') + return true; + + /* These fields are generated by gigi. */ + if (DECL_INTERNAL_P (field)) + return true; + + return false; +} + +/* Return true if FIELD is a non-artificial field with self-referential + size. */ + +static bool +field_has_self_size (tree field) +{ + if (field_is_artificial (field)) + return false; + + if (DECL_SIZE (field) && TREE_CODE (DECL_SIZE (field)) == INTEGER_CST) + return false; + + return CONTAINS_PLACEHOLDER_P (TYPE_SIZE (TREE_TYPE (field))); +} + +/* Return true if FIELD is a non-artificial field with variable size. */ + +static bool +field_has_variable_size (tree field) +{ + if (field_is_artificial (field)) + return false; + + if (DECL_SIZE (field) && TREE_CODE (DECL_SIZE (field)) == INTEGER_CST) + return false; + + return TREE_CODE (TYPE_SIZE (TREE_TYPE (field))) != INTEGER_CST; +} + +/* qsort comparer for the bit positions of two record components. */ + +static int +compare_field_bitpos (const PTR rt1, const PTR rt2) +{ + const_tree const field1 = * (const_tree const *) rt1; + const_tree const field2 = * (const_tree const *) rt2; + const int ret + = tree_int_cst_compare (bit_position (field1), bit_position (field2)); + + return ret ? ret : (int) (DECL_UID (field1) - DECL_UID (field2)); +} + +/* Sort the LIST of fields in reverse order of increasing position. */ + +static tree +reverse_sort_field_list (tree list) +{ + const int len = list_length (list); + tree *field_arr = XALLOCAVEC (tree, len); + + for (int i = 0; list; list = DECL_CHAIN (list), i++) + field_arr[i] = list; + + qsort (field_arr, len, sizeof (tree), compare_field_bitpos); + + for (int i = 0; i < len; i++) + { + DECL_CHAIN (field_arr[i]) = list; + list = field_arr[i]; + } + + return list; +} + +/* Reverse function from gnat_to_gnu_field: return the GNAT field present in + either GNAT_COMPONENT_LIST or the discriminants of GNAT_RECORD_TYPE, and + corresponding to the GNU tree GNU_FIELD. */ + +static Entity_Id +gnu_field_to_gnat (tree gnu_field, Node_Id gnat_component_list, + Entity_Id gnat_record_type) +{ + Entity_Id gnat_component_decl, gnat_field; + + if (Present (Component_Items (gnat_component_list))) + for (gnat_component_decl + = First_Non_Pragma (Component_Items (gnat_component_list)); + Present (gnat_component_decl); + gnat_component_decl = Next_Non_Pragma (gnat_component_decl)) + { + gnat_field = Defining_Entity (gnat_component_decl); + if (gnat_to_gnu_field_decl (gnat_field) == gnu_field) + return gnat_field; + } + + if (Has_Discriminants (gnat_record_type)) + for (gnat_field = First_Stored_Discriminant (gnat_record_type); + Present (gnat_field); + gnat_field = Next_Stored_Discriminant (gnat_field)) + if (gnat_to_gnu_field_decl (gnat_field) == gnu_field) + return gnat_field; + + return Empty; +} + +/* Issue a warning for the problematic placement of GNU_FIELD present in + either GNAT_COMPONENT_LIST or the discriminants of GNAT_RECORD_TYPE. + IN_VARIANT is true if GNAT_COMPONENT_LIST is the list of a variant. + DO_REORDER is true if fields of GNAT_RECORD_TYPE are being reordered. */ + +static void +warn_on_field_placement (tree gnu_field, Node_Id gnat_component_list, + Entity_Id gnat_record_type, bool in_variant, + bool do_reorder) +{ + if (!Comes_From_Source (gnat_record_type)) + return; + + Entity_Id gnat_field + = gnu_field_to_gnat (gnu_field, gnat_component_list, gnat_record_type); + gcc_assert (Present (gnat_field)); + + const char *msg1 + = in_variant + ? "??variant layout may cause performance issues" + : "??record layout may cause performance issues"; + const char *msg2 + = Ekind (gnat_field) == E_Discriminant + ? "??discriminant & whose length is not multiple of a byte" + : field_has_self_size (gnu_field) + ? "??component & whose length depends on a discriminant" + : field_has_variable_size (gnu_field) + ? "??component & whose length is not fixed" + : "??component & whose length is not multiple of a byte"; + const char *msg3 + = do_reorder + ? "??comes too early and was moved down" + : "??comes too early and ought to be moved down"; + + post_error (msg1, gnat_field); + post_error_ne (msg2, gnat_field, gnat_field); + post_error (msg3, gnat_field); +} + +/* Likewise but for every field present on GNU_FIELD_LIST. */ + +static void +warn_on_list_placement (tree gnu_field_list, Node_Id gnat_component_list, + Entity_Id gnat_record_type, bool in_variant, + bool do_reorder) +{ + for (tree gnu_tmp = gnu_field_list; gnu_tmp; gnu_tmp = DECL_CHAIN (gnu_tmp)) + warn_on_field_placement (gnu_tmp, gnat_component_list, gnat_record_type, + in_variant, do_reorder); +} + +/* Structure holding information for a given variant. */ +typedef struct vinfo +{ + /* The record type of the variant. */ + tree type; + + /* The name of the variant. */ + tree name; + + /* The qualifier of the variant. */ + tree qual; + + /* Whether the variant has a rep clause. */ + bool has_rep; + + /* Whether the variant is packed. */ + bool packed; + +} vinfo_t; + +/* Translate and chain GNAT_COMPONENT_LIST present in GNAT_RECORD_TYPE to + GNU_FIELD_LIST, set the result as the field list of GNU_RECORD_TYPE and + finish it up. Return true if GNU_RECORD_TYPE has a rep clause that affects + the layout (see below). When called from gnat_to_gnu_entity during the + processing of a record definition, the GCC node for the parent, if any, + will be the single field of GNU_RECORD_TYPE and the GCC nodes for the + discriminants will be on GNU_FIELD_LIST. The other call to this function + is a recursive call for the component list of a variant and, in this case, + GNU_FIELD_LIST is empty. Note that GNAT_COMPONENT_LIST may be Empty. + + PACKED is 1 if this is for a packed record or -1 if this is for a record + with Component_Alignment of Storage_Unit. + + DEFINITION is true if we are defining this record type. + + CANCEL_ALIGNMENT is true if the alignment should be zeroed before laying + out the record. This means the alignment only serves to force fields to + be bitfields, but not to require the record to be that aligned. This is + used for variants. + + ALL_REP is true if a rep clause is present for all the fields. + + UNCHECKED_UNION is true if we are building this type for a record with a + Pragma Unchecked_Union. + + ARTIFICIAL is true if this is a type that was generated by the compiler. + + DEBUG_INFO is true if we need to write debug information about the type. + + IN_VARIANT is true if the componennt list is that of a variant. + + FIRST_FREE_POS, if nonzero, is the first (lowest) free field position in + the outer record type down to this variant level. It is nonzero only if + all the fields down to this level have a rep clause and ALL_REP is false. + + P_GNU_REP_LIST, if nonzero, is a pointer to a list to which each field + with a rep clause is to be added; in this case, that is all that should + be done with such fields and the return value will be false. */ + +static bool +components_to_record (Node_Id gnat_component_list, Entity_Id gnat_record_type, + tree gnu_field_list, tree gnu_record_type, int packed, + bool definition, bool cancel_alignment, bool all_rep, + bool unchecked_union, bool artificial, bool debug_info, + bool in_variant, tree first_free_pos, + tree *p_gnu_rep_list) +{ + const bool needs_xv_encodings + = debug_info && gnat_encodings == DWARF_GNAT_ENCODINGS_ALL; + bool all_rep_and_size = all_rep && TYPE_SIZE (gnu_record_type); + bool variants_have_rep = all_rep; + bool layout_with_rep = false; + bool has_non_packed_fixed_size_field = false; + bool has_self_field = false; + bool has_aliased_after_self_field = false; + Entity_Id gnat_component_decl, gnat_variant_part; + tree gnu_field, gnu_next, gnu_last; + tree gnu_variant_part = NULL_TREE; + tree gnu_rep_list = NULL_TREE; + + /* For each component referenced in a component declaration create a GCC + field and add it to the list, skipping pragmas in the GNAT list. */ + gnu_last = tree_last (gnu_field_list); + if (Present (gnat_component_list) + && (Present (Component_Items (gnat_component_list)))) + for (gnat_component_decl + = First_Non_Pragma (Component_Items (gnat_component_list)); + Present (gnat_component_decl); + gnat_component_decl = Next_Non_Pragma (gnat_component_decl)) + { + Entity_Id gnat_field = Defining_Entity (gnat_component_decl); + Name_Id gnat_name = Chars (gnat_field); + + /* If present, the _Parent field must have been created as the single + field of the record type. Put it before any other fields. */ + if (gnat_name == Name_uParent) + { + gnu_field = TYPE_FIELDS (gnu_record_type); + gnu_field_list = chainon (gnu_field_list, gnu_field); + } + else + { + gnu_field = gnat_to_gnu_field (gnat_field, gnu_record_type, packed, + definition, debug_info); + + /* If this is the _Tag field, put it before any other fields. */ + if (gnat_name == Name_uTag) + gnu_field_list = chainon (gnu_field_list, gnu_field); + + /* If this is the _Controller field, put it before the other + fields except for the _Tag or _Parent field. */ + else if (gnat_name == Name_uController && gnu_last) + { + DECL_CHAIN (gnu_field) = DECL_CHAIN (gnu_last); + DECL_CHAIN (gnu_last) = gnu_field; + } + + /* If this is a regular field, put it after the other fields. */ + else + { + DECL_CHAIN (gnu_field) = gnu_field_list; + gnu_field_list = gnu_field; + if (!gnu_last) + gnu_last = gnu_field; + + /* And record information for the final layout. */ + if (field_has_self_size (gnu_field)) + has_self_field = true; + else if (has_self_field && DECL_ALIASED_P (gnu_field)) + has_aliased_after_self_field = true; + else if (!DECL_FIELD_OFFSET (gnu_field) + && !DECL_PACKED (gnu_field) + && !field_has_variable_size (gnu_field)) + has_non_packed_fixed_size_field = true; + } + } + + save_gnu_tree (gnat_field, gnu_field, false); + } + + /* At the end of the component list there may be a variant part. */ + if (Present (gnat_component_list)) + gnat_variant_part = Variant_Part (gnat_component_list); + else + gnat_variant_part = Empty; + + /* We create a QUAL_UNION_TYPE for the variant part since the variants are + mutually exclusive and should go in the same memory. To do this we need + to treat each variant as a record whose elements are created from the + component list for the variant. So here we create the records from the + lists for the variants and put them all into the QUAL_UNION_TYPE. + If this is an Unchecked_Union, we make a UNION_TYPE instead or + use GNU_RECORD_TYPE if there are no fields so far. */ + if (Present (gnat_variant_part)) + { + Node_Id gnat_discr = Name (gnat_variant_part), variant; + tree gnu_discr = gnat_to_gnu (gnat_discr); + tree gnu_name = TYPE_IDENTIFIER (gnu_record_type); + tree gnu_var_name + = concat_name (get_identifier (Get_Name_String (Chars (gnat_discr))), + "XVN"); + tree gnu_union_name + = concat_name (gnu_name, IDENTIFIER_POINTER (gnu_var_name)); + tree gnu_union_type; + tree this_first_free_pos, gnu_variant_list = NULL_TREE; + bool union_field_needs_strict_alignment = false; + auto_vec <vinfo_t, 16> variant_types; + vinfo_t *gnu_variant; + unsigned int variants_align = 0; + unsigned int i; + + /* Reuse the enclosing union if this is an Unchecked_Union whose fields + are all in the variant part, to match the layout of C unions. There + is an associated check below. */ + if (TREE_CODE (gnu_record_type) == UNION_TYPE) + gnu_union_type = gnu_record_type; + else + { + gnu_union_type + = make_node (unchecked_union ? UNION_TYPE : QUAL_UNION_TYPE); + + TYPE_NAME (gnu_union_type) = gnu_union_name; + SET_TYPE_ALIGN (gnu_union_type, 0); + TYPE_PACKED (gnu_union_type) = TYPE_PACKED (gnu_record_type); + TYPE_REVERSE_STORAGE_ORDER (gnu_union_type) + = TYPE_REVERSE_STORAGE_ORDER (gnu_record_type); + } + + /* If all the fields down to this level have a rep clause, find out + whether all the fields at this level also have one. If so, then + compute the new first free position to be passed downward. */ + this_first_free_pos = first_free_pos; + if (this_first_free_pos) + { + for (gnu_field = gnu_field_list; + gnu_field; + gnu_field = DECL_CHAIN (gnu_field)) + if (DECL_FIELD_OFFSET (gnu_field)) + { + tree pos = bit_position (gnu_field); + if (!tree_int_cst_lt (pos, this_first_free_pos)) + this_first_free_pos + = size_binop (PLUS_EXPR, pos, DECL_SIZE (gnu_field)); + } + else + { + this_first_free_pos = NULL_TREE; + break; + } + } + + /* We build the variants in two passes. The bulk of the work is done in + the first pass, that is to say translating the GNAT nodes, building + the container types and computing the associated properties. However + we cannot finish up the container types during this pass because we + don't know where the variant part will be placed until the end. */ + for (variant = First_Non_Pragma (Variants (gnat_variant_part)); + Present (variant); + variant = Next_Non_Pragma (variant)) + { + tree gnu_variant_type = make_node (RECORD_TYPE); + tree gnu_inner_name, gnu_qual; + bool has_rep; + int field_packed; + vinfo_t vinfo; + + Get_Variant_Encoding (variant); + gnu_inner_name = get_identifier_with_length (Name_Buffer, Name_Len); + TYPE_NAME (gnu_variant_type) + = concat_name (gnu_union_name, + IDENTIFIER_POINTER (gnu_inner_name)); + + /* Set the alignment of the inner type in case we need to make + inner objects into bitfields, but then clear it out so the + record actually gets only the alignment required. */ + SET_TYPE_ALIGN (gnu_variant_type, TYPE_ALIGN (gnu_record_type)); + TYPE_PACKED (gnu_variant_type) = TYPE_PACKED (gnu_record_type); + TYPE_REVERSE_STORAGE_ORDER (gnu_variant_type) + = TYPE_REVERSE_STORAGE_ORDER (gnu_record_type); + + /* Similarly, if the outer record has a size specified and all + the fields have a rep clause, we can propagate the size. */ + if (all_rep_and_size) + { + TYPE_SIZE (gnu_variant_type) = TYPE_SIZE (gnu_record_type); + TYPE_SIZE_UNIT (gnu_variant_type) + = TYPE_SIZE_UNIT (gnu_record_type); + } + + /* Add the fields into the record type for the variant but note that + we aren't sure to really use it at this point, see below. In the + case of an unchecked union, we force the fields with a rep clause + present in a nested variant to be moved to the outermost variant, + so as to flatten the rep-ed layout as much as possible, the reason + being that we cannot do any flattening when a subtype statically + selects a variant later on, for example for an aggregate. */ + has_rep + = components_to_record (Component_List (variant), gnat_record_type, + NULL_TREE, gnu_variant_type, packed, + definition, !all_rep_and_size, all_rep, + unchecked_union, true, needs_xv_encodings, + true, this_first_free_pos, + (all_rep || this_first_free_pos) + && !(in_variant && unchecked_union) + ? NULL : &gnu_rep_list); + + /* Translate the qualifier and annotate the GNAT node. */ + gnu_qual = choices_to_gnu (gnu_discr, Discrete_Choices (variant)); + Set_Present_Expr (variant, annotate_value (gnu_qual)); + + /* Deal with packedness like in gnat_to_gnu_field. */ + if (components_need_strict_alignment (Component_List (variant))) + { + field_packed = 0; + union_field_needs_strict_alignment = true; + } + else + field_packed + = adjust_packed (gnu_variant_type, gnu_record_type, packed); + + /* Push this variant onto the stack for the second pass. */ + vinfo.type = gnu_variant_type; + vinfo.name = gnu_inner_name; + vinfo.qual = gnu_qual; + vinfo.has_rep = has_rep; + vinfo.packed = field_packed; + variant_types.safe_push (vinfo); + + /* Compute the global properties that will determine the placement of + the variant part. */ + variants_have_rep |= has_rep; + if (!field_packed && TYPE_ALIGN (gnu_variant_type) > variants_align) + variants_align = TYPE_ALIGN (gnu_variant_type); + } + + /* Round up the first free position to the alignment of the variant part + for the variants without rep clause. This will guarantee a consistent + layout independently of the placement of the variant part. */ + if (variants_have_rep && variants_align > 0 && this_first_free_pos) + this_first_free_pos = round_up (this_first_free_pos, variants_align); + + /* In the second pass, the container types are adjusted if necessary and + finished up, then the corresponding fields of the variant part are + built with their qualifier, unless this is an unchecked union. */ + FOR_EACH_VEC_ELT (variant_types, i, gnu_variant) + { + tree gnu_variant_type = gnu_variant->type; + tree gnu_field_list = TYPE_FIELDS (gnu_variant_type); + + /* If this is an Unchecked_Union whose fields are all in the variant + part and we have a single field with no representation clause or + placed at offset zero, use the field directly to match the layout + of C unions. */ + if (TREE_CODE (gnu_record_type) == UNION_TYPE + && gnu_field_list + && !DECL_CHAIN (gnu_field_list) + && (!DECL_FIELD_OFFSET (gnu_field_list) + || integer_zerop (bit_position (gnu_field_list)))) + { + gnu_field = gnu_field_list; + DECL_CONTEXT (gnu_field) = gnu_record_type; + } + else + { + /* Finalize the variant type now. We used to throw away empty + record types but we no longer do that because we need them to + generate complete debug info for the variant; otherwise, the + union type definition will be lacking the fields associated + with these empty variants. */ + if (gnu_field_list && variants_have_rep && !gnu_variant->has_rep) + { + /* The variant part will be at offset 0 so we need to ensure + that the fields are laid out starting from the first free + position at this level. */ + tree gnu_rep_type = make_node (RECORD_TYPE); + tree gnu_rep_part; + TYPE_REVERSE_STORAGE_ORDER (gnu_rep_type) + = TYPE_REVERSE_STORAGE_ORDER (gnu_variant_type); + finish_record_type (gnu_rep_type, NULL_TREE, 0, debug_info); + gnu_rep_part + = create_rep_part (gnu_rep_type, gnu_variant_type, + this_first_free_pos); + DECL_CHAIN (gnu_rep_part) = gnu_field_list; + gnu_field_list = gnu_rep_part; + finish_record_type (gnu_variant_type, gnu_field_list, 0, + false); + } + + if (debug_info) + rest_of_record_type_compilation (gnu_variant_type); + create_type_decl (TYPE_NAME (gnu_variant_type), gnu_variant_type, + true, needs_xv_encodings, gnat_component_list); + + gnu_field + = create_field_decl (gnu_variant->name, gnu_variant_type, + gnu_union_type, + all_rep_and_size + ? TYPE_SIZE (gnu_variant_type) : 0, + variants_have_rep ? bitsize_zero_node : 0, + gnu_variant->packed, 0); + + DECL_INTERNAL_P (gnu_field) = 1; + + if (!unchecked_union) + DECL_QUALIFIER (gnu_field) = gnu_variant->qual; + } + + DECL_CHAIN (gnu_field) = gnu_variant_list; + gnu_variant_list = gnu_field; + } + + /* Only make the QUAL_UNION_TYPE if there are non-empty variants. */ + if (gnu_variant_list) + { + int union_field_packed; + + if (all_rep_and_size) + { + TYPE_SIZE (gnu_union_type) = TYPE_SIZE (gnu_record_type); + TYPE_SIZE_UNIT (gnu_union_type) + = TYPE_SIZE_UNIT (gnu_record_type); + } + + finish_record_type (gnu_union_type, nreverse (gnu_variant_list), + all_rep_and_size ? 1 : 0, needs_xv_encodings); + + /* If GNU_UNION_TYPE is our record type, this means that we must have + an Unchecked_Union whose fields are all in the variant part. Now + verify that and, if so, just return. */ + if (gnu_union_type == gnu_record_type) + { + gcc_assert (unchecked_union + && !gnu_field_list + && !gnu_rep_list); + return variants_have_rep; + } + + create_type_decl (TYPE_NAME (gnu_union_type), gnu_union_type, true, + needs_xv_encodings, gnat_component_list); + + /* Deal with packedness like in gnat_to_gnu_field. */ + if (union_field_needs_strict_alignment) + union_field_packed = 0; + else + union_field_packed + = adjust_packed (gnu_union_type, gnu_record_type, packed); + + gnu_variant_part + = create_field_decl (gnu_var_name, gnu_union_type, gnu_record_type, + all_rep_and_size + ? TYPE_SIZE (gnu_union_type) : 0, + variants_have_rep ? bitsize_zero_node : 0, + union_field_packed, 0); + + DECL_INTERNAL_P (gnu_variant_part) = 1; + } + } + + /* Scan GNU_FIELD_LIST and see if any fields have rep clauses. If they do, + pull them out and put them onto the appropriate list. + + Similarly, pull out the fields with zero size and no rep clause, as they + would otherwise modify the layout and thus very likely run afoul of the + Ada semantics, which are different from those of C here. + + Finally, if there is an aliased field placed in the list after fields + with self-referential size, pull out the latter in the same way. + + Optionally, if the reordering mechanism is enabled, pull out the fields + with self-referential size, variable size and fixed size not a multiple + of a byte, so that they don't cause the regular fields to be either at + self-referential/variable offset or misaligned. Note, in the latter + case, that this can only happen in packed record types so the alignment + is effectively capped to the byte for the whole record. But we don't + do it for packed record types if not all fixed-size fiels can be packed + and for non-packed record types if pragma Optimize_Alignment (Space) is + specified, because this can prevent alignment gaps from being filled. + + Optionally, if the layout warning is enabled, keep track of the above 4 + different kinds of fields and issue a warning if some of them would be + (or are being) reordered by the reordering mechanism. + + ??? If we reorder fields, the debugging information will be affected and + the debugger print fields in a different order from the source code. */ + const bool do_reorder + = (Convention (gnat_record_type) == Convention_Ada + && !No_Reordering (gnat_record_type) + && !(Is_Packed (gnat_record_type) + ? has_non_packed_fixed_size_field + : Optimize_Alignment_Space (gnat_record_type)) + && !Debug_Flag_Dot_R); + const bool w_reorder + = (Convention (gnat_record_type) == Convention_Ada + && Warn_On_Questionable_Layout + && !(No_Reordering (gnat_record_type) && GNAT_Mode)); + tree gnu_zero_list = NULL_TREE; + tree gnu_self_list = NULL_TREE; + tree gnu_var_list = NULL_TREE; + tree gnu_bitp_list = NULL_TREE; + tree gnu_tmp_bitp_list = NULL_TREE; + unsigned int tmp_bitp_size = 0; + unsigned int last_reorder_field_type = -1; + unsigned int tmp_last_reorder_field_type = -1; + +#define MOVE_FROM_FIELD_LIST_TO(LIST) \ + do { \ + if (gnu_last) \ + DECL_CHAIN (gnu_last) = gnu_next; \ + else \ + gnu_field_list = gnu_next; \ + \ + DECL_CHAIN (gnu_field) = (LIST); \ + (LIST) = gnu_field; \ + } while (0) + + gnu_last = NULL_TREE; + for (gnu_field = gnu_field_list; gnu_field; gnu_field = gnu_next) + { + gnu_next = DECL_CHAIN (gnu_field); + + if (DECL_FIELD_OFFSET (gnu_field)) + { + MOVE_FROM_FIELD_LIST_TO (gnu_rep_list); + continue; + } + + if (DECL_SIZE (gnu_field) && integer_zerop (DECL_SIZE (gnu_field))) + { + DECL_SIZE_UNIT (gnu_field) = size_zero_node; + DECL_FIELD_OFFSET (gnu_field) = size_zero_node; + SET_DECL_OFFSET_ALIGN (gnu_field, BIGGEST_ALIGNMENT); + DECL_FIELD_BIT_OFFSET (gnu_field) = bitsize_zero_node; + if (DECL_ALIASED_P (gnu_field)) + SET_TYPE_ALIGN (gnu_record_type, + MAX (TYPE_ALIGN (gnu_record_type), + TYPE_ALIGN (TREE_TYPE (gnu_field)))); + MOVE_FROM_FIELD_LIST_TO (gnu_zero_list); + continue; + } + + if (has_aliased_after_self_field && field_has_self_size (gnu_field)) + { + MOVE_FROM_FIELD_LIST_TO (gnu_self_list); + continue; + } + + /* We don't need further processing in default mode. */ + if (!w_reorder && !do_reorder) + { + gnu_last = gnu_field; + continue; + } + + if (field_has_self_size (gnu_field)) + { + if (w_reorder) + { + if (last_reorder_field_type < 4) + warn_on_field_placement (gnu_field, gnat_component_list, + gnat_record_type, in_variant, + do_reorder); + else + last_reorder_field_type = 4; + } + + if (do_reorder) + { + MOVE_FROM_FIELD_LIST_TO (gnu_self_list); + continue; + } + } + + else if (field_has_variable_size (gnu_field)) + { + if (w_reorder) + { + if (last_reorder_field_type < 3) + warn_on_field_placement (gnu_field, gnat_component_list, + gnat_record_type, in_variant, + do_reorder); + else + last_reorder_field_type = 3; + } + + if (do_reorder) + { + MOVE_FROM_FIELD_LIST_TO (gnu_var_list); + continue; + } + } + + else + { + /* If the field has no size, then it cannot be bit-packed. */ + const unsigned int bitp_size + = DECL_SIZE (gnu_field) + ? TREE_INT_CST_LOW (DECL_SIZE (gnu_field)) % BITS_PER_UNIT + : 0; + + /* If the field is bit-packed, we move it to a temporary list that + contains the contiguously preceding bit-packed fields, because + we want to be able to put them back if the misalignment happens + to cancel itself after several bit-packed fields. */ + if (bitp_size != 0) + { + tmp_bitp_size = (tmp_bitp_size + bitp_size) % BITS_PER_UNIT; + + if (last_reorder_field_type != 2) + { + tmp_last_reorder_field_type = last_reorder_field_type; + last_reorder_field_type = 2; + } + + if (do_reorder) + { + MOVE_FROM_FIELD_LIST_TO (gnu_tmp_bitp_list); + continue; + } + } + + /* No more bit-packed fields, move the existing ones to the end or + put them back at their original location. */ + else if (last_reorder_field_type == 2 || gnu_tmp_bitp_list) + { + last_reorder_field_type = 1; + + if (tmp_bitp_size != 0) + { + if (w_reorder && tmp_last_reorder_field_type < 2) + { + if (gnu_tmp_bitp_list) + warn_on_list_placement (gnu_tmp_bitp_list, + gnat_component_list, + gnat_record_type, in_variant, + do_reorder); + else + warn_on_field_placement (gnu_last, + gnat_component_list, + gnat_record_type, in_variant, + do_reorder); + } + + if (do_reorder) + gnu_bitp_list = chainon (gnu_tmp_bitp_list, gnu_bitp_list); + + gnu_tmp_bitp_list = NULL_TREE; + tmp_bitp_size = 0; + } + else + { + /* Rechain the temporary list in front of GNU_FIELD. */ + tree gnu_bitp_field = gnu_field; + while (gnu_tmp_bitp_list) + { + tree gnu_bitp_next = DECL_CHAIN (gnu_tmp_bitp_list); + DECL_CHAIN (gnu_tmp_bitp_list) = gnu_bitp_field; + if (gnu_last) + DECL_CHAIN (gnu_last) = gnu_tmp_bitp_list; + else + gnu_field_list = gnu_tmp_bitp_list; + gnu_bitp_field = gnu_tmp_bitp_list; + gnu_tmp_bitp_list = gnu_bitp_next; + } + } + } + + else + last_reorder_field_type = 1; + } + + gnu_last = gnu_field; + } + +#undef MOVE_FROM_FIELD_LIST_TO + + gnu_field_list = nreverse (gnu_field_list); + + /* If permitted, we reorder the fields as follows: + + 1) all (groups of) fields whose length is fixed and multiple of a byte, + 2) the remaining fields whose length is fixed and not multiple of a byte, + 3) the remaining fields whose length doesn't depend on discriminants, + 4) all fields whose length depends on discriminants, + 5) the variant part, + + within the record and within each variant recursively. */ + + if (w_reorder) + { + /* If we have pending bit-packed fields, warn if they would be moved + to after regular fields. */ + if (last_reorder_field_type == 2 + && tmp_bitp_size != 0 + && tmp_last_reorder_field_type < 2) + { + if (gnu_tmp_bitp_list) + warn_on_list_placement (gnu_tmp_bitp_list, + gnat_component_list, gnat_record_type, + in_variant, do_reorder); + else + warn_on_field_placement (gnu_field_list, + gnat_component_list, gnat_record_type, + in_variant, do_reorder); + } + } + + if (do_reorder) + { + /* If we have pending bit-packed fields on the temporary list, we put + them either on the bit-packed list or back on the regular list. */ + if (gnu_tmp_bitp_list) + { + if (tmp_bitp_size != 0) + gnu_bitp_list = chainon (gnu_tmp_bitp_list, gnu_bitp_list); + else + gnu_field_list = chainon (gnu_tmp_bitp_list, gnu_field_list); + } + + gnu_field_list + = chainon (gnu_field_list, + chainon (gnu_bitp_list, + chainon (gnu_var_list, gnu_self_list))); + } + + /* Otherwise, if there is an aliased field placed after a field whose length + depends on discriminants, we put all the fields of the latter sort, last. + We need to do this in case an object of this record type is mutable. */ + else if (has_aliased_after_self_field) + gnu_field_list = chainon (gnu_field_list, gnu_self_list); + + /* If P_REP_LIST is nonzero, this means that we are asked to move the fields + in our REP list to the previous level because this level needs them in + order to do a correct layout, i.e. avoid having overlapping fields. */ + if (p_gnu_rep_list && gnu_rep_list) + *p_gnu_rep_list = chainon (*p_gnu_rep_list, gnu_rep_list); + + /* Deal with the case of an extension of a record type with variable size and + partial rep clause, for which the _Parent field is forced at offset 0 and + has variable size. Note that we cannot do it if the field has fixed size + because we rely on the presence of the REP part built below to trigger the + reordering of the fields in a derived record type when all the fields have + a fixed position. */ + else if (gnu_rep_list + && !DECL_CHAIN (gnu_rep_list) + && TREE_CODE (DECL_SIZE (gnu_rep_list)) != INTEGER_CST + && !variants_have_rep + && first_free_pos + && integer_zerop (first_free_pos) + && integer_zerop (bit_position (gnu_rep_list))) + { + DECL_CHAIN (gnu_rep_list) = gnu_field_list; + gnu_field_list = gnu_rep_list; + gnu_rep_list = NULL_TREE; + } + + /* Otherwise, sort the fields by bit position and put them into their own + record, before the others, if we also have fields without rep clause. */ + else if (gnu_rep_list) + { + tree gnu_parent, gnu_rep_type; + + /* If all the fields have a rep clause, we can do a flat layout. */ + layout_with_rep = !gnu_field_list + && (!gnu_variant_part || variants_have_rep); + + /* Same as above but the extension itself has a rep clause, in which case + we need to set aside the _Parent field to lay out the REP part. */ + if (TREE_CODE (DECL_SIZE (gnu_rep_list)) != INTEGER_CST + && !layout_with_rep + && !variants_have_rep + && first_free_pos + && integer_zerop (first_free_pos) + && integer_zerop (bit_position (gnu_rep_list))) + { + gnu_parent = gnu_rep_list; + gnu_rep_list = DECL_CHAIN (gnu_rep_list); + } + else + gnu_parent = NULL_TREE; + + gnu_rep_type + = layout_with_rep ? gnu_record_type : make_node (RECORD_TYPE); + + /* Sort the fields in order of increasing bit position. */ + const int len = list_length (gnu_rep_list); + tree *gnu_arr = XALLOCAVEC (tree, len); + + gnu_field = gnu_rep_list; + for (int i = 0; i < len; i++) + { + gnu_arr[i] = gnu_field; + gnu_field = DECL_CHAIN (gnu_field); + } + + qsort (gnu_arr, len, sizeof (tree), compare_field_bitpos); + + gnu_rep_list = NULL_TREE; + for (int i = len - 1; i >= 0; i--) + { + DECL_CHAIN (gnu_arr[i]) = gnu_rep_list; + gnu_rep_list = gnu_arr[i]; + DECL_CONTEXT (gnu_arr[i]) = gnu_rep_type; + } + + /* Do the layout of the REP part, if any. */ + if (layout_with_rep) + gnu_field_list = gnu_rep_list; + else + { + TYPE_NAME (gnu_rep_type) + = create_concat_name (gnat_record_type, "REP"); + TYPE_REVERSE_STORAGE_ORDER (gnu_rep_type) + = TYPE_REVERSE_STORAGE_ORDER (gnu_record_type); + finish_record_type (gnu_rep_type, gnu_rep_list, 1, false); + + /* If FIRST_FREE_POS is nonzero, we need to ensure that the fields + without rep clause are laid out starting from this position. + Therefore, we force it as a minimal size on the REP part. */ + tree gnu_rep_part + = create_rep_part (gnu_rep_type, gnu_record_type, first_free_pos); + + /* If this is an extension, put back the _Parent field as the first + field of the REP part at offset 0 and update its layout. */ + if (gnu_parent) + { + const unsigned int align = DECL_ALIGN (gnu_parent); + DECL_CHAIN (gnu_parent) = TYPE_FIELDS (gnu_rep_type); + TYPE_FIELDS (gnu_rep_type) = gnu_parent; + DECL_CONTEXT (gnu_parent) = gnu_rep_type; + if (align > TYPE_ALIGN (gnu_rep_type)) + { + SET_TYPE_ALIGN (gnu_rep_type, align); + TYPE_SIZE (gnu_rep_type) + = round_up (TYPE_SIZE (gnu_rep_type), align); + TYPE_SIZE_UNIT (gnu_rep_type) + = round_up (TYPE_SIZE_UNIT (gnu_rep_type), align); + SET_DECL_ALIGN (gnu_rep_part, align); + } + } + + if (debug_info) + rest_of_record_type_compilation (gnu_rep_type); + + /* Chain the REP part at the beginning of the field list. */ + DECL_CHAIN (gnu_rep_part) = gnu_field_list; + gnu_field_list = gnu_rep_part; + } + } + + /* Chain the variant part at the end of the field list. */ + if (gnu_variant_part) + gnu_field_list = chainon (gnu_field_list, gnu_variant_part); + + if (cancel_alignment) + SET_TYPE_ALIGN (gnu_record_type, 0); + + TYPE_ARTIFICIAL (gnu_record_type) = artificial; + + finish_record_type (gnu_record_type, gnu_field_list, layout_with_rep ? 1 : 0, + debug_info && !in_variant); + + /* Chain the fields with zero size at the beginning of the field list. */ + if (gnu_zero_list) + TYPE_FIELDS (gnu_record_type) + = chainon (gnu_zero_list, TYPE_FIELDS (gnu_record_type)); + + return (gnu_rep_list && !p_gnu_rep_list) || variants_have_rep; +} + +/* Given GNU_SIZE, a GCC tree representing a size, return a Uint to be + placed into an Esize, Component_Bit_Offset, or Component_Size value + in the GNAT tree. */ + +static Uint +annotate_value (tree gnu_size) +{ + static int var_count = 0; + TCode tcode; + Node_Ref_Or_Val ops[3] = { No_Uint, No_Uint, No_Uint }; + struct tree_int_map in; + + /* See if we've already saved the value for this node. */ + if (EXPR_P (gnu_size) || DECL_P (gnu_size)) + { + struct tree_int_map *e; + + in.base.from = gnu_size; + e = annotate_value_cache->find (&in); + + if (e) + return (Node_Ref_Or_Val) e->to; + } + else + in.base.from = NULL_TREE; + + /* If we do not return inside this switch, TCODE will be set to the + code to be used in a call to Create_Node. */ + switch (TREE_CODE (gnu_size)) + { + case INTEGER_CST: + /* For negative values, build NEGATE_EXPR of the opposite. Such values + can appear for discriminants in expressions for variants. */ + if (tree_int_cst_sgn (gnu_size) < 0) + { + tree t = wide_int_to_tree (sizetype, -wi::to_wide (gnu_size)); + tcode = Negate_Expr; + ops[0] = UI_From_gnu (t); + } + else + return TREE_OVERFLOW (gnu_size) ? No_Uint : UI_From_gnu (gnu_size); + break; + + case COMPONENT_REF: + /* The only case we handle here is a simple discriminant reference. */ + if (DECL_DISCRIMINANT_NUMBER (TREE_OPERAND (gnu_size, 1))) + { + tree ref = gnu_size; + gnu_size = TREE_OPERAND (ref, 1); + + /* Climb up the chain of successive extensions, if any. */ + while (TREE_CODE (TREE_OPERAND (ref, 0)) == COMPONENT_REF + && DECL_NAME (TREE_OPERAND (TREE_OPERAND (ref, 0), 1)) + == parent_name_id) + ref = TREE_OPERAND (ref, 0); + + if (TREE_CODE (TREE_OPERAND (ref, 0)) == PLACEHOLDER_EXPR) + { + /* Fall through to common processing as a FIELD_DECL. */ + tcode = Discrim_Val; + ops[0] = UI_From_gnu (DECL_DISCRIMINANT_NUMBER (gnu_size)); + } + else + return No_Uint; + } + else + return No_Uint; + break; + + case VAR_DECL: + tcode = Dynamic_Val; + ops[0] = UI_From_Int (++var_count); + break; + + CASE_CONVERT: + case NON_LVALUE_EXPR: + return annotate_value (TREE_OPERAND (gnu_size, 0)); + + /* Now just list the operations we handle. */ + case COND_EXPR: tcode = Cond_Expr; break; + case MINUS_EXPR: tcode = Minus_Expr; break; + case TRUNC_DIV_EXPR: tcode = Trunc_Div_Expr; break; + case CEIL_DIV_EXPR: tcode = Ceil_Div_Expr; break; + case FLOOR_DIV_EXPR: tcode = Floor_Div_Expr; break; + case TRUNC_MOD_EXPR: tcode = Trunc_Mod_Expr; break; + case CEIL_MOD_EXPR: tcode = Ceil_Mod_Expr; break; + case FLOOR_MOD_EXPR: tcode = Floor_Mod_Expr; break; + case EXACT_DIV_EXPR: tcode = Exact_Div_Expr; break; + case NEGATE_EXPR: tcode = Negate_Expr; break; + case MIN_EXPR: tcode = Min_Expr; break; + case MAX_EXPR: tcode = Max_Expr; break; + case ABS_EXPR: tcode = Abs_Expr; break; + case TRUTH_ANDIF_EXPR: + case TRUTH_AND_EXPR: tcode = Truth_And_Expr; break; + case TRUTH_ORIF_EXPR: + case TRUTH_OR_EXPR: tcode = Truth_Or_Expr; break; + case TRUTH_XOR_EXPR: tcode = Truth_Xor_Expr; break; + case TRUTH_NOT_EXPR: tcode = Truth_Not_Expr; break; + case LT_EXPR: tcode = Lt_Expr; break; + case LE_EXPR: tcode = Le_Expr; break; + case GT_EXPR: tcode = Gt_Expr; break; + case GE_EXPR: tcode = Ge_Expr; break; + case EQ_EXPR: tcode = Eq_Expr; break; + case NE_EXPR: tcode = Ne_Expr; break; + + case PLUS_EXPR: + /* Turn addition of negative constant into subtraction. */ + if (TREE_CODE (TREE_OPERAND (gnu_size, 1)) == INTEGER_CST + && tree_int_cst_sign_bit (TREE_OPERAND (gnu_size, 1))) + { + tcode = Minus_Expr; + wide_int wop1 = -wi::to_wide (TREE_OPERAND (gnu_size, 1)); + ops[1] = annotate_value (wide_int_to_tree (sizetype, wop1)); + break; + } + + /* ... fall through ... */ + + case MULT_EXPR: + tcode = (TREE_CODE (gnu_size) == MULT_EXPR ? Mult_Expr : Plus_Expr); + /* Fold conversions from bytes to bits into inner operations. */ + if (TREE_CODE (TREE_OPERAND (gnu_size, 1)) == INTEGER_CST + && CONVERT_EXPR_P (TREE_OPERAND (gnu_size, 0))) + { + tree inner_op = TREE_OPERAND (TREE_OPERAND (gnu_size, 0), 0); + if (TREE_CODE (inner_op) == TREE_CODE (gnu_size) + && TREE_CODE (TREE_OPERAND (inner_op, 1)) == INTEGER_CST) + { + ops[0] = annotate_value (TREE_OPERAND (inner_op, 0)); + tree inner_op_op1 = TREE_OPERAND (inner_op, 1); + tree gnu_size_op1 = TREE_OPERAND (gnu_size, 1); + widest_int op1; + if (TREE_CODE (gnu_size) == MULT_EXPR) + op1 = (wi::to_widest (inner_op_op1) + * wi::to_widest (gnu_size_op1)); + else + { + op1 = (wi::to_widest (inner_op_op1) + + wi::to_widest (gnu_size_op1)); + if (wi::zext (op1, TYPE_PRECISION (sizetype)) == 0) + return ops[0]; + } + ops[1] = annotate_value (wide_int_to_tree (sizetype, op1)); + } + } + break; + + case BIT_AND_EXPR: + tcode = Bit_And_Expr; + /* For negative values in sizetype, build NEGATE_EXPR of the opposite. + Such values can appear in expressions with aligning patterns. */ + if (TREE_CODE (TREE_OPERAND (gnu_size, 1)) == INTEGER_CST) + { + wide_int wop1 = -wi::to_wide (TREE_OPERAND (gnu_size, 1)); + tree op1 = wide_int_to_tree (sizetype, wop1); + ops[1] = annotate_value (build1 (NEGATE_EXPR, sizetype, op1)); + } + break; + + case CALL_EXPR: + /* In regular mode, inline back only if symbolic annotation is requested + in order to avoid memory explosion on big discriminated record types. + But not in ASIS mode, as symbolic annotation is required for DDA. */ + if (List_Representation_Info >= 3 || type_annotate_only) + { + tree t = maybe_inline_call_in_expr (gnu_size); + return t ? annotate_value (t) : No_Uint; + } + else + return Uint_Minus_1; + + default: + return No_Uint; + } + + /* Now get each of the operands that's relevant for this code. If any + cannot be expressed as a repinfo node, say we can't. */ + for (int i = 0; i < TREE_CODE_LENGTH (TREE_CODE (gnu_size)); i++) + if (ops[i] == No_Uint) + { + ops[i] = annotate_value (TREE_OPERAND (gnu_size, i)); + if (ops[i] == No_Uint) + return No_Uint; + } + + Node_Ref_Or_Val ret = Create_Node (tcode, ops[0], ops[1], ops[2]); + + /* Save the result in the cache. */ + if (in.base.from) + { + struct tree_int_map **h; + /* We can't assume the hash table data hasn't moved since the initial + look up, so we have to search again. Allocating and inserting an + entry at that point would be an alternative, but then we'd better + discard the entry if we decided not to cache it. */ + h = annotate_value_cache->find_slot (&in, INSERT); + gcc_assert (!*h); + *h = ggc_alloc<tree_int_map> (); + (*h)->base.from = in.base.from; + (*h)->to = ret; + } + + return ret; +} + +/* Given GNAT_ENTITY, an object (constant, variable, parameter, exception) + and GNU_TYPE, its corresponding GCC type, set Esize and Alignment to the + size and alignment used by Gigi. Prefer SIZE over TYPE_SIZE if non-null. + BY_REF is true if the object is used by reference. */ + +void +annotate_object (Entity_Id gnat_entity, tree gnu_type, tree size, bool by_ref) +{ + if (by_ref) + { + if (TYPE_IS_FAT_POINTER_P (gnu_type)) + gnu_type = TYPE_UNCONSTRAINED_ARRAY (gnu_type); + else + gnu_type = TREE_TYPE (gnu_type); + } + + if (!Known_Esize (gnat_entity)) + { + if (TREE_CODE (gnu_type) == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P (gnu_type)) + size = TYPE_SIZE (TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (gnu_type)))); + else if (!size) + size = TYPE_SIZE (gnu_type); + + if (size) + Set_Esize (gnat_entity, No_Uint_To_0 (annotate_value (size))); + } + + if (!Known_Alignment (gnat_entity)) + Set_Alignment (gnat_entity, + UI_From_Int (TYPE_ALIGN (gnu_type) / BITS_PER_UNIT)); +} + +/* Return first element of field list whose TREE_PURPOSE is the same as ELEM. + Return NULL_TREE if there is no such element in the list. */ + +static tree +purpose_member_field (const_tree elem, tree list) +{ + while (list) + { + tree field = TREE_PURPOSE (list); + if (SAME_FIELD_P (field, elem)) + return list; + list = TREE_CHAIN (list); + } + return NULL_TREE; +} + +/* Given GNAT_ENTITY, a record type, and GNU_TYPE, its corresponding GCC type, + set Component_Bit_Offset and Esize of the components to the position and + size used by Gigi. */ + +static void +annotate_rep (Entity_Id gnat_entity, tree gnu_type) +{ + /* For an extension, the inherited components have not been translated because + they are fetched from the _Parent component on the fly. */ + const bool is_extension + = Is_Tagged_Type (gnat_entity) && Is_Derived_Type (gnat_entity); + + /* We operate by first making a list of all fields and their position (we + can get the size easily) and then update all the sizes in the tree. */ + tree gnu_list + = build_position_list (gnu_type, false, size_zero_node, bitsize_zero_node, + BIGGEST_ALIGNMENT, NULL_TREE); + + for (Entity_Id gnat_field = First_Entity (gnat_entity); + Present (gnat_field); + gnat_field = Next_Entity (gnat_field)) + if ((Ekind (gnat_field) == E_Component + && (is_extension || present_gnu_tree (gnat_field))) + || (Ekind (gnat_field) == E_Discriminant + && !Is_Unchecked_Union (Scope (gnat_field)))) + { + tree t = purpose_member_field (gnat_to_gnu_field_decl (gnat_field), + gnu_list); + if (t) + { + tree offset = TREE_VEC_ELT (TREE_VALUE (t), 0); + tree bit_offset = TREE_VEC_ELT (TREE_VALUE (t), 2); + + /* If we are just annotating types and the type is tagged, the tag + and the parent components are not generated by the front-end so + we need to add the appropriate offset to each component without + representation clause. */ + if (type_annotate_only + && Is_Tagged_Type (gnat_entity) + && No (Component_Clause (gnat_field))) + { + tree parent_bit_offset; + + /* For a component appearing in the current extension, the + offset is the size of the parent. */ + if (Is_Derived_Type (gnat_entity) + && Original_Record_Component (gnat_field) == gnat_field) + parent_bit_offset + = UI_To_gnu (Esize (Etype (Base_Type (gnat_entity))), + bitsizetype); + else + parent_bit_offset = bitsize_int (POINTER_SIZE); + + if (TYPE_FIELDS (gnu_type)) + parent_bit_offset + = round_up (parent_bit_offset, + DECL_ALIGN (TYPE_FIELDS (gnu_type))); + + offset + = size_binop (PLUS_EXPR, offset, + fold_convert (sizetype, + size_binop (TRUNC_DIV_EXPR, + parent_bit_offset, + bitsize_unit_node))); + } + + /* If the field has a variable offset, also compute the normalized + position since it's easier to do on trees here than to deduce + it from the annotated expression of Component_Bit_Offset. */ + if (TREE_CODE (offset) != INTEGER_CST) + { + normalize_offset (&offset, &bit_offset, BITS_PER_UNIT); + Set_Normalized_Position (gnat_field, + annotate_value (offset)); + Set_Normalized_First_Bit (gnat_field, + annotate_value (bit_offset)); + } + + Set_Component_Bit_Offset + (gnat_field, + annotate_value (bit_from_pos (offset, bit_offset))); + + Set_Esize + (gnat_field, + No_Uint_To_0 (annotate_value (DECL_SIZE (TREE_PURPOSE (t))))); + } + else if (is_extension) + { + /* If there is no entry, this is an inherited component whose + position is the same as in the parent type. */ + Entity_Id gnat_orig = Original_Record_Component (gnat_field); + + /* If we are just annotating types, discriminants renaming those of + the parent have no entry so deal with them specifically. */ + if (type_annotate_only + && gnat_orig == gnat_field + && Ekind (gnat_field) == E_Discriminant) + gnat_orig = Corresponding_Discriminant (gnat_field); + + if (Known_Normalized_Position (gnat_orig)) + { + Set_Normalized_Position (gnat_field, + Normalized_Position (gnat_orig)); + Set_Normalized_First_Bit (gnat_field, + Normalized_First_Bit (gnat_orig)); + } + + Set_Component_Bit_Offset (gnat_field, + Component_Bit_Offset (gnat_orig)); + + Set_Esize (gnat_field, Esize (gnat_orig)); + } + } +} + +/* Scan all fields in GNU_TYPE and return a TREE_LIST where TREE_PURPOSE is + the FIELD_DECL and TREE_VALUE a TREE_VEC containing the byte position, the + value to be placed into DECL_OFFSET_ALIGN and the bit position. The list + of fields is flattened, except for variant parts if DO_NOT_FLATTEN_VARIANT + is set to true. GNU_POS is to be added to the position, GNU_BITPOS to the + bit position, OFFSET_ALIGN is the present offset alignment. GNU_LIST is a + pre-existing list to be chained to the newly created entries. */ + +static tree +build_position_list (tree gnu_type, bool do_not_flatten_variant, tree gnu_pos, + tree gnu_bitpos, unsigned int offset_align, tree gnu_list) +{ + tree gnu_field; + + for (gnu_field = TYPE_FIELDS (gnu_type); + gnu_field; + gnu_field = DECL_CHAIN (gnu_field)) + { + tree gnu_our_bitpos = size_binop (PLUS_EXPR, gnu_bitpos, + DECL_FIELD_BIT_OFFSET (gnu_field)); + tree gnu_our_offset = size_binop (PLUS_EXPR, gnu_pos, + DECL_FIELD_OFFSET (gnu_field)); + unsigned int our_offset_align + = MIN (offset_align, DECL_OFFSET_ALIGN (gnu_field)); + tree v = make_tree_vec (3); + + TREE_VEC_ELT (v, 0) = gnu_our_offset; + TREE_VEC_ELT (v, 1) = size_int (our_offset_align); + TREE_VEC_ELT (v, 2) = gnu_our_bitpos; + gnu_list = tree_cons (gnu_field, v, gnu_list); + + /* Recurse on internal fields, flattening the nested fields except for + those in the variant part, if requested. */ + if (DECL_INTERNAL_P (gnu_field)) + { + tree gnu_field_type = TREE_TYPE (gnu_field); + if (do_not_flatten_variant + && TREE_CODE (gnu_field_type) == QUAL_UNION_TYPE) + gnu_list + = build_position_list (gnu_field_type, do_not_flatten_variant, + size_zero_node, bitsize_zero_node, + BIGGEST_ALIGNMENT, gnu_list); + else + gnu_list + = build_position_list (gnu_field_type, do_not_flatten_variant, + gnu_our_offset, gnu_our_bitpos, + our_offset_align, gnu_list); + } + } + + return gnu_list; +} + +/* Return a list describing the substitutions needed to reflect the + discriminant substitutions from GNAT_TYPE to GNAT_SUBTYPE. They can + be in any order. The values in an element of the list are in the form + of operands to SUBSTITUTE_IN_EXPR. DEFINITION is true if this is for + a definition of GNAT_SUBTYPE. */ + +static vec<subst_pair> +build_subst_list (Entity_Id gnat_subtype, Entity_Id gnat_type, bool definition) +{ + vec<subst_pair> gnu_list = vNULL; + Entity_Id gnat_discrim; + Node_Id gnat_constr; + + for (gnat_discrim = First_Stored_Discriminant (gnat_type), + gnat_constr = First_Elmt (Stored_Constraint (gnat_subtype)); + Present (gnat_discrim); + gnat_discrim = Next_Stored_Discriminant (gnat_discrim), + gnat_constr = Next_Elmt (gnat_constr)) + /* Ignore access discriminants. */ + if (!Is_Access_Type (Etype (Node (gnat_constr)))) + { + tree gnu_field = gnat_to_gnu_field_decl (gnat_discrim); + tree replacement + = elaborate_expression (Node (gnat_constr), gnat_subtype, + get_entity_char (gnat_discrim), + definition, true, false); + /* If this is a definition, we need to make sure that the SAVE_EXPRs + are instantiated on every possibly path in size computations. */ + if (definition && TREE_CODE (replacement) == SAVE_EXPR) + add_stmt (replacement); + replacement = convert (TREE_TYPE (gnu_field), replacement); + subst_pair s = { gnu_field, replacement }; + gnu_list.safe_push (s); + } + + return gnu_list; +} + +/* Scan all fields in {GNU_QUAL_UNION_TYPE,GNAT_VARIANT_PART} and return a list + describing the variants of GNU_QUAL_UNION_TYPE that are still relevant after + applying the substitutions described in SUBST_LIST. GNU_LIST is an existing + list to be prepended to the newly created entries. */ + +static vec<variant_desc> +build_variant_list (tree gnu_qual_union_type, Node_Id gnat_variant_part, + vec<subst_pair> subst_list, vec<variant_desc> gnu_list) +{ + Node_Id gnat_variant; + tree gnu_field; + + for (gnu_field = TYPE_FIELDS (gnu_qual_union_type), + gnat_variant + = Present (gnat_variant_part) + ? First_Non_Pragma (Variants (gnat_variant_part)) + : Empty; + gnu_field; + gnu_field = DECL_CHAIN (gnu_field), + gnat_variant + = Present (gnat_variant_part) + ? Next_Non_Pragma (gnat_variant) + : Empty) + { + tree qual = DECL_QUALIFIER (gnu_field); + unsigned int i; + subst_pair *s; + + FOR_EACH_VEC_ELT (subst_list, i, s) + qual = SUBSTITUTE_IN_EXPR (qual, s->discriminant, s->replacement); + + /* If the new qualifier is not unconditionally false, its variant may + still be accessed. */ + if (!integer_zerop (qual)) + { + tree variant_type = TREE_TYPE (gnu_field), variant_subpart; + variant_desc v + = { variant_type, gnu_field, qual, NULL_TREE, NULL_TREE }; + + gnu_list.safe_push (v); + + /* Annotate the GNAT node if present. */ + if (Present (gnat_variant)) + Set_Present_Expr (gnat_variant, annotate_value (qual)); + + /* Recurse on the variant subpart of the variant, if any. */ + variant_subpart = get_variant_part (variant_type); + if (variant_subpart) + gnu_list + = build_variant_list (TREE_TYPE (variant_subpart), + Present (gnat_variant) + ? Variant_Part + (Component_List (gnat_variant)) + : Empty, + subst_list, + gnu_list); + + /* If the new qualifier is unconditionally true, the subsequent + variants cannot be accessed. */ + if (integer_onep (qual)) + break; + } + } + + return gnu_list; +} + +/* If SIZE has overflowed, return the maximum valid size, which is the upper + bound of the signed sizetype in bits, rounded down to ALIGN. Otherwise + return SIZE unmodified. */ + +static tree +maybe_saturate_size (tree size, unsigned int align) +{ + if (TREE_CODE (size) == INTEGER_CST && TREE_OVERFLOW (size)) + { + size + = size_binop (MULT_EXPR, + fold_convert (bitsizetype, TYPE_MAX_VALUE (ssizetype)), + build_int_cst (bitsizetype, BITS_PER_UNIT)); + size = round_down (size, align); + } + + return size; +} + +/* UINT_SIZE is a Uint giving the specified size for an object of GNU_TYPE + corresponding to GNAT_OBJECT. If the size is valid, return an INTEGER_CST + corresponding to its value. Otherwise, return NULL_TREE. KIND is set to + VAR_DECL if we are specifying the size of an object, TYPE_DECL for the + size of a type, and FIELD_DECL for the size of a field. COMPONENT_P is + true if we are being called to process the Component_Size of GNAT_OBJECT; + this is used only for error messages. ZERO_OK is true if a size of zero + is permitted; if ZERO_OK is false, it means that a size of zero should be + treated as an unspecified size. S1 and S2 are used for error messages. */ + +static tree +validate_size (Uint uint_size, tree gnu_type, Entity_Id gnat_object, + enum tree_code kind, bool component_p, bool zero_ok, + const char *s1, const char *s2) +{ + Node_Id gnat_error_node; + tree old_size, size; + + /* Return 0 if no size was specified. */ + if (uint_size == No_Uint) + return NULL_TREE; + + /* Ignore a negative size since that corresponds to our back-annotation. */ + if (UI_Lt (uint_size, Uint_0)) + return NULL_TREE; + + /* Find the node to use for error messages. */ + if ((Ekind (gnat_object) == E_Component + || Ekind (gnat_object) == E_Discriminant) + && Present (Component_Clause (gnat_object))) + gnat_error_node = Last_Bit (Component_Clause (gnat_object)); + else if (Present (Size_Clause (gnat_object))) + gnat_error_node = Expression (Size_Clause (gnat_object)); + else if (Has_Object_Size_Clause (gnat_object)) + gnat_error_node = Expression (Object_Size_Clause (gnat_object)); + else + gnat_error_node = gnat_object; + + /* Get the size as an INTEGER_CST. Issue an error if a size was specified + but cannot be represented in bitsizetype. */ + size = UI_To_gnu (uint_size, bitsizetype); + if (TREE_OVERFLOW (size)) + { + if (component_p) + post_error_ne ("component size for& is too large", gnat_error_node, + gnat_object); + else + post_error_ne ("size for& is too large", gnat_error_node, + gnat_object); + return NULL_TREE; + } + + /* Ignore a zero size if it is not permitted. */ + if (!zero_ok && integer_zerop (size)) + return NULL_TREE; + + /* The size of objects is always a multiple of a byte. */ + if (kind == VAR_DECL + && !integer_zerop (size_binop (TRUNC_MOD_EXPR, size, bitsize_unit_node))) + { + if (component_p) + post_error_ne ("component size for& must be multiple of Storage_Unit", + gnat_error_node, gnat_object); + else + post_error_ne ("size for& must be multiple of Storage_Unit", + gnat_error_node, gnat_object); + return NULL_TREE; + } + + /* If this is an integral type or a bit-packed array type, the front-end has + already verified the size, so we need not do it again (which would mean + checking against the bounds). However, if this is an aliased object, it + may not be smaller than the type of the object. */ + if ((INTEGRAL_TYPE_P (gnu_type) || BIT_PACKED_ARRAY_TYPE_P (gnu_type)) + && !(kind == VAR_DECL && Is_Aliased (gnat_object))) + return size; + + /* If the object is a record that contains a template, add the size of the + template to the specified size. */ + if (TREE_CODE (gnu_type) == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P (gnu_type)) + size = size_binop (PLUS_EXPR, DECL_SIZE (TYPE_FIELDS (gnu_type)), size); + + old_size = (kind == VAR_DECL ? TYPE_SIZE (gnu_type) : rm_size (gnu_type)); + + /* If the old size is self-referential, get the maximum size. */ + if (CONTAINS_PLACEHOLDER_P (old_size)) + old_size = max_size (old_size, true); + + /* If this is an access type or a fat pointer, the minimum size is that given + by the smallest integral mode that's valid for pointers. */ + if (TREE_CODE (gnu_type) == POINTER_TYPE || TYPE_IS_FAT_POINTER_P (gnu_type)) + { + scalar_int_mode p_mode = NARROWEST_INT_MODE; + while (!targetm.valid_pointer_mode (p_mode)) + p_mode = GET_MODE_WIDER_MODE (p_mode).require (); + old_size = bitsize_int (GET_MODE_BITSIZE (p_mode)); + } + + /* Issue an error either if the default size of the object isn't a constant + or if the new size is smaller than it. */ + if (TREE_CODE (old_size) != INTEGER_CST + || (!TREE_OVERFLOW (old_size) && tree_int_cst_lt (size, old_size))) + { + char buf[128]; + const char *s; + + if (s1 && s2) + { + snprintf (buf, sizeof (buf), s1, s2); + s = buf; + } + else if (component_p) + s = "component size for& too small{, minimum allowed is ^}"; + else + s = "size for& too small{, minimum allowed is ^}"; + + post_error_ne_tree (s, gnat_error_node, gnat_object, old_size); + + return NULL_TREE; + } + + return size; +} + +/* Similarly, but both validate and process a value of RM size. This routine + is only called for types. */ + +static void +set_rm_size (Uint uint_size, tree gnu_type, Entity_Id gnat_entity) +{ + Node_Id gnat_attr_node; + tree old_size, size; + + /* Do nothing if no size was specified. */ + if (uint_size == No_Uint) + return; + + /* Only issue an error if a Value_Size clause was explicitly given for the + entity; otherwise, we'd be duplicating an error on the Size clause. */ + gnat_attr_node + = Get_Attribute_Definition_Clause (gnat_entity, Attr_Value_Size); + if (Present (gnat_attr_node) && Entity (gnat_attr_node) != gnat_entity) + gnat_attr_node = Empty; + + /* Get the size as an INTEGER_CST. Issue an error if a size was specified + but cannot be represented in bitsizetype. */ + size = UI_To_gnu (uint_size, bitsizetype); + if (TREE_OVERFLOW (size)) + { + if (Present (gnat_attr_node)) + post_error_ne ("Value_Size for& is too large", gnat_attr_node, + gnat_entity); + return; + } + + /* Ignore a zero size unless a Value_Size clause exists, or a size clause + exists, or this is an integer type, in which case the front-end will + have always set it. */ + if (No (gnat_attr_node) + && integer_zerop (size) + && !Has_Size_Clause (gnat_entity) + && !Is_Discrete_Or_Fixed_Point_Type (gnat_entity)) + return; + + old_size = rm_size (gnu_type); + + /* If the old size is self-referential, get the maximum size. */ + if (CONTAINS_PLACEHOLDER_P (old_size)) + old_size = max_size (old_size, true); + + /* Issue an error either if the old size of the object isn't a constant or + if the new size is smaller than it. The front-end has already verified + this for scalar and bit-packed array types. */ + if (TREE_CODE (old_size) != INTEGER_CST + || TREE_OVERFLOW (old_size) + || (AGGREGATE_TYPE_P (gnu_type) + && !BIT_PACKED_ARRAY_TYPE_P (gnu_type) + && !(TYPE_IS_PADDING_P (gnu_type) + && BIT_PACKED_ARRAY_TYPE_P (TREE_TYPE (TYPE_FIELDS (gnu_type)))) + && tree_int_cst_lt (size, old_size))) + { + if (Present (gnat_attr_node)) + post_error_ne_tree + ("Value_Size for& too small{, minimum allowed is ^}", + gnat_attr_node, gnat_entity, old_size); + return; + } + + /* Otherwise, set the RM size proper for integral types... */ + if ((TREE_CODE (gnu_type) == INTEGER_TYPE + && Is_Discrete_Or_Fixed_Point_Type (gnat_entity)) + || (TREE_CODE (gnu_type) == ENUMERAL_TYPE + || TREE_CODE (gnu_type) == BOOLEAN_TYPE)) + SET_TYPE_RM_SIZE (gnu_type, size); + + /* ...or the Ada size for record and union types. */ + else if (RECORD_OR_UNION_TYPE_P (gnu_type) + && !TYPE_FAT_POINTER_P (gnu_type)) + SET_TYPE_ADA_SIZE (gnu_type, size); +} + +/* ALIGNMENT is a Uint giving the alignment specified for GNAT_ENTITY, + a type or object whose present alignment is ALIGN. If this alignment is + valid, return it. Otherwise, give an error and return ALIGN. */ + +static unsigned int +validate_alignment (Uint alignment, Entity_Id gnat_entity, unsigned int align) +{ + unsigned int max_allowed_alignment = get_target_maximum_allowed_alignment (); + unsigned int new_align; + Node_Id gnat_error_node; + + /* Don't worry about checking alignment if alignment was not specified + by the source program and we already posted an error for this entity. */ + if (Error_Posted (gnat_entity) && !Has_Alignment_Clause (gnat_entity)) + return align; + + /* Post the error on the alignment clause if any. Note, for the implicit + base type of an array type, the alignment clause is on the first + subtype. */ + if (Present (Alignment_Clause (gnat_entity))) + gnat_error_node = Expression (Alignment_Clause (gnat_entity)); + + else if (Is_Itype (gnat_entity) + && Is_Array_Type (gnat_entity) + && Etype (gnat_entity) == gnat_entity + && Present (Alignment_Clause (First_Subtype (gnat_entity)))) + gnat_error_node = + Expression (Alignment_Clause (First_Subtype (gnat_entity))); + + else + gnat_error_node = gnat_entity; + + /* Within GCC, an alignment is an integer, so we must make sure a value is + specified that fits in that range. Also, there is an upper bound to + alignments we can support/allow. */ + if (!UI_Is_In_Int_Range (alignment) + || ((new_align = UI_To_Int (alignment)) > max_allowed_alignment)) + post_error_ne_num ("largest supported alignment for& is ^", + gnat_error_node, gnat_entity, max_allowed_alignment); + else if (!(Present (Alignment_Clause (gnat_entity)) + && From_At_Mod (Alignment_Clause (gnat_entity))) + && new_align * BITS_PER_UNIT < align) + { + unsigned int double_align; + bool is_capped_double, align_clause; + + /* If the default alignment of "double" or larger scalar types is + specifically capped and the new alignment is above the cap, do + not post an error and change the alignment only if there is an + alignment clause; this makes it possible to have the associated + GCC type overaligned by default for performance reasons. */ + if ((double_align = double_float_alignment) > 0) + { + Entity_Id gnat_type + = Is_Type (gnat_entity) ? gnat_entity : Etype (gnat_entity); + is_capped_double + = is_double_float_or_array (gnat_type, &align_clause); + } + else if ((double_align = double_scalar_alignment) > 0) + { + Entity_Id gnat_type + = Is_Type (gnat_entity) ? gnat_entity : Etype (gnat_entity); + is_capped_double + = is_double_scalar_or_array (gnat_type, &align_clause); + } + else + is_capped_double = align_clause = false; + + if (is_capped_double && new_align >= double_align) + { + if (align_clause) + align = new_align * BITS_PER_UNIT; + } + else + { + if (is_capped_double) + align = double_align * BITS_PER_UNIT; + + post_error_ne_num ("alignment for& must be at least ^", + gnat_error_node, gnat_entity, + align / BITS_PER_UNIT); + } + } + else + { + new_align = (new_align > 0 ? new_align * BITS_PER_UNIT : 1); + if (new_align > align) + align = new_align; + } + + return align; +} + +/* Promote the alignment of GNU_TYPE for an object with GNU_SIZE corresponding + to GNAT_ENTITY. Return a positive value on success or zero on failure. */ + +static unsigned int +promote_object_alignment (tree gnu_type, tree gnu_size, Entity_Id gnat_entity) +{ + unsigned int align, size_cap, align_cap; + + /* No point in promoting the alignment if this doesn't prevent BLKmode access + to the object, in particular block copy, as this will for example disable + the NRV optimization for it. No point in jumping through all the hoops + needed in order to support BIGGEST_ALIGNMENT if we don't really have to. + So we cap to the smallest alignment that corresponds to a known efficient + memory access pattern, except for a full access entity. */ + if (Is_Full_Access (gnat_entity)) + { + size_cap = UINT_MAX; + align_cap = BIGGEST_ALIGNMENT; + } + else + { + size_cap = MAX_FIXED_MODE_SIZE; + align_cap = get_mode_alignment (ptr_mode); + } + + if (!gnu_size) + gnu_size = TYPE_SIZE (gnu_type); + + /* Do the promotion within the above limits. */ + if (!tree_fits_uhwi_p (gnu_size) + || compare_tree_int (gnu_size, size_cap) > 0) + align = 0; + else if (compare_tree_int (gnu_size, align_cap) > 0) + align = align_cap; + else + align = ceil_pow2 (tree_to_uhwi (gnu_size)); + + /* But make sure not to under-align the object. */ + if (align <= TYPE_ALIGN (gnu_type)) + align = 0; + + /* And honor the minimum valid atomic alignment, if any. */ +#ifdef MINIMUM_ATOMIC_ALIGNMENT + else if (align < MINIMUM_ATOMIC_ALIGNMENT) + align = MINIMUM_ATOMIC_ALIGNMENT; +#endif + + return align; +} + +/* Verify that TYPE is something we can implement atomically. If not, issue + an error for GNAT_ENTITY. COMPONENT_P is true if we are being called to + process a component type. */ + +static void +check_ok_for_atomic_type (tree type, Entity_Id gnat_entity, bool component_p) +{ + Node_Id gnat_error_point = gnat_entity; + Node_Id gnat_node; + machine_mode mode; + enum mode_class mclass; + unsigned int align; + tree size; + + /* If this is an anonymous base type, nothing to check, the error will be + reported on the source type if need be. */ + if (!Comes_From_Source (gnat_entity)) + return; + + mode = TYPE_MODE (type); + mclass = GET_MODE_CLASS (mode); + align = TYPE_ALIGN (type); + size = TYPE_SIZE (type); + + /* Consider all aligned floating-point types atomic and any aligned types + that are represented by integers no wider than a machine word. */ + scalar_int_mode int_mode; + if ((mclass == MODE_FLOAT + || (is_a <scalar_int_mode> (mode, &int_mode) + && GET_MODE_BITSIZE (int_mode) <= BITS_PER_WORD)) + && align >= GET_MODE_ALIGNMENT (mode)) + return; + + /* For the moment, also allow anything that has an alignment equal to its + size and which is smaller than a word. */ + if (size + && TREE_CODE (size) == INTEGER_CST + && compare_tree_int (size, align) == 0 + && align <= BITS_PER_WORD) + return; + + for (gnat_node = First_Rep_Item (gnat_entity); + Present (gnat_node); + gnat_node = Next_Rep_Item (gnat_node)) + if (Nkind (gnat_node) == N_Pragma) + { + unsigned char pragma_id + = Get_Pragma_Id (Chars (Pragma_Identifier (gnat_node))); + + if ((pragma_id == Pragma_Atomic && !component_p) + || (pragma_id == Pragma_Atomic_Components && component_p)) + { + gnat_error_point = First (Pragma_Argument_Associations (gnat_node)); + break; + } + } + + if (component_p) + post_error_ne ("atomic access to component of & cannot be guaranteed", + gnat_error_point, gnat_entity); + else if (Is_Volatile_Full_Access (gnat_entity)) + post_error_ne ("volatile full access to & cannot be guaranteed", + gnat_error_point, gnat_entity); + else + post_error_ne ("atomic access to & cannot be guaranteed", + gnat_error_point, gnat_entity); +} + +/* Return true if TYPE is suitable for a type-generic atomic builtin. */ + +static bool +type_for_atomic_builtin_p (tree type) +{ + const enum machine_mode mode = TYPE_MODE (type); + if (GET_MODE_CLASS (mode) == MODE_FLOAT) + return true; + + scalar_int_mode imode; + if (is_a <scalar_int_mode> (mode, &imode) && GET_MODE_SIZE (imode) <= 16) + return true; + + return false; +} + +/* Return the GCC atomic builtin based on CODE and sized for TYPE. */ + +static tree +resolve_atomic_builtin (enum built_in_function code, tree type) +{ + const unsigned int size = resolve_atomic_size (type); + code = (enum built_in_function) ((int) code + exact_log2 (size) + 1); + + return builtin_decl_implicit (code); +} + +/* Helper for intrin_profiles_compatible_p, to perform compatibility checks + on the Ada/builtin argument lists for the INB binding. */ + +static bool +intrin_arglists_compatible_p (const intrin_binding_t *inb) +{ + function_args_iterator ada_iter, btin_iter; + + function_args_iter_init (&ada_iter, inb->ada_fntype); + function_args_iter_init (&btin_iter, inb->btin_fntype); + + /* Sequence position of the last argument we checked. */ + int argpos = 0; + + while (true) + { + tree ada_type = function_args_iter_cond (&ada_iter); + tree btin_type = function_args_iter_cond (&btin_iter); + + /* If we've exhausted both lists simultaneously, we're done. */ + if (!ada_type && !btin_type) + break; + + /* If the internal builtin uses a variable list, accept anything. */ + if (!btin_type) + break; + + /* If we're done with the Ada args and not with the internal builtin + args, or the other way around, complain. */ + if (ada_type == void_type_node && btin_type != void_type_node) + { + post_error ("??Ada parameter list too short!", inb->gnat_entity); + return false; + } + + if (btin_type == void_type_node && ada_type != void_type_node) + { + post_error_ne_num ("??Ada parameter list too long ('> ^)!", + inb->gnat_entity, inb->gnat_entity, argpos); + return false; + } + + /* Otherwise, check that types match for the current argument. */ + argpos++; + if (!types_compatible_p (ada_type, btin_type)) + { + /* For vector builtins, issue an error to avoid an ICE. */ + if (VECTOR_TYPE_P (btin_type)) + post_error_ne_num + ("intrinsic binding type mismatch on parameter ^", + inb->gnat_entity, inb->gnat_entity, argpos); + else + post_error_ne_num + ("??intrinsic binding type mismatch on parameter ^!", + inb->gnat_entity, inb->gnat_entity, argpos); + return false; + } + + + function_args_iter_next (&ada_iter); + function_args_iter_next (&btin_iter); + } + + return true; +} + +/* Helper for intrin_profiles_compatible_p, to perform compatibility checks + on the Ada/builtin return values for the INB binding. */ + +static bool +intrin_return_compatible_p (const intrin_binding_t *inb) +{ + tree ada_return_type = TREE_TYPE (inb->ada_fntype); + tree btin_return_type = TREE_TYPE (inb->btin_fntype); + + /* Accept function imported as procedure, common and convenient. */ + if (VOID_TYPE_P (ada_return_type) && !VOID_TYPE_P (btin_return_type)) + return true; + + /* Check return types compatibility otherwise. Note that this + handles void/void as well. */ + if (!types_compatible_p (btin_return_type, ada_return_type)) + { + /* For vector builtins, issue an error to avoid an ICE. */ + if (VECTOR_TYPE_P (btin_return_type)) + post_error ("intrinsic binding type mismatch on result", + inb->gnat_entity); + else + post_error ("??intrinsic binding type mismatch on result", + inb->gnat_entity); + return false; + } + + return true; +} + +/* Check and return whether the Ada and gcc builtin profiles bound by INB are + compatible. Issue relevant warnings when they are not. + + This is intended as a light check to diagnose the most obvious cases, not + as a full fledged type compatibility predicate. It is the programmer's + responsibility to ensure correctness of the Ada declarations in Imports, + especially when binding straight to a compiler internal. */ + +static bool +intrin_profiles_compatible_p (const intrin_binding_t *inb) +{ + /* Check compatibility on return values and argument lists, each responsible + for posting warnings as appropriate. Ensure use of the proper sloc for + this purpose. */ + + bool arglists_compatible_p, return_compatible_p; + location_t saved_location = input_location; + + Sloc_to_locus (Sloc (inb->gnat_entity), &input_location); + + return_compatible_p = intrin_return_compatible_p (inb); + arglists_compatible_p = intrin_arglists_compatible_p (inb); + + input_location = saved_location; + + return return_compatible_p && arglists_compatible_p; +} + +/* Return a FIELD_DECL node modeled on OLD_FIELD. FIELD_TYPE is its type + and RECORD_TYPE is the type of the parent. If SIZE is nonzero, it is the + specified size for this field. POS_LIST is a position list describing + the layout of OLD_FIELD and SUBST_LIST a substitution list to be applied + to this layout. */ + +static tree +create_field_decl_from (tree old_field, tree field_type, tree record_type, + tree size, tree pos_list, + vec<subst_pair> subst_list) +{ + tree t = TREE_VALUE (purpose_member (old_field, pos_list)); + tree pos = TREE_VEC_ELT (t, 0), bitpos = TREE_VEC_ELT (t, 2); + unsigned int offset_align = tree_to_uhwi (TREE_VEC_ELT (t, 1)); + tree new_pos, new_field; + unsigned int i; + subst_pair *s; + + if (CONTAINS_PLACEHOLDER_P (pos)) + FOR_EACH_VEC_ELT (subst_list, i, s) + pos = SUBSTITUTE_IN_EXPR (pos, s->discriminant, s->replacement); + + /* If the position is now a constant, we can set it as the position of the + field when we make it. Otherwise, we need to deal with it specially. */ + if (TREE_CONSTANT (pos)) + new_pos = bit_from_pos (pos, bitpos); + else + new_pos = NULL_TREE; + + new_field + = create_field_decl (DECL_NAME (old_field), field_type, record_type, + size, new_pos, DECL_PACKED (old_field), + !DECL_NONADDRESSABLE_P (old_field)); + + if (!new_pos) + { + normalize_offset (&pos, &bitpos, offset_align); + /* Finalize the position. */ + DECL_FIELD_OFFSET (new_field) = variable_size (pos); + DECL_FIELD_BIT_OFFSET (new_field) = bitpos; + SET_DECL_OFFSET_ALIGN (new_field, offset_align); + DECL_SIZE (new_field) = size; + DECL_SIZE_UNIT (new_field) + = convert (sizetype, + size_binop (CEIL_DIV_EXPR, size, bitsize_unit_node)); + layout_decl (new_field, DECL_OFFSET_ALIGN (new_field)); + } + + DECL_INTERNAL_P (new_field) = DECL_INTERNAL_P (old_field); + SET_DECL_ORIGINAL_FIELD_TO_FIELD (new_field, old_field); + DECL_DISCRIMINANT_NUMBER (new_field) = DECL_DISCRIMINANT_NUMBER (old_field); + TREE_THIS_VOLATILE (new_field) = TREE_THIS_VOLATILE (old_field); + + return new_field; +} + +/* Create the REP part of RECORD_TYPE with REP_TYPE. If MIN_SIZE is nonzero, + it is the minimal size the REP_PART must have. */ + +static tree +create_rep_part (tree rep_type, tree record_type, tree min_size) +{ + tree field; + + if (min_size && !tree_int_cst_lt (TYPE_SIZE (rep_type), min_size)) + min_size = NULL_TREE; + + field = create_field_decl (get_identifier ("REP"), rep_type, record_type, + min_size, NULL_TREE, 0, 1); + DECL_INTERNAL_P (field) = 1; + + return field; +} + +/* Return the REP part of RECORD_TYPE, if any. Otherwise return NULL. */ + +static tree +get_rep_part (tree record_type) +{ + tree field = TYPE_FIELDS (record_type); + + /* The REP part is the first field, internal, another record, and its name + starts with an 'R'. */ + if (field + && DECL_INTERNAL_P (field) + && TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE + && IDENTIFIER_POINTER (DECL_NAME (field)) [0] == 'R') + return field; + + return NULL_TREE; +} + +/* Return the variant part of RECORD_TYPE, if any. Otherwise return NULL. */ + +tree +get_variant_part (tree record_type) +{ + tree field; + + /* The variant part is the only internal field that is a qualified union. */ + for (field = TYPE_FIELDS (record_type); field; field = DECL_CHAIN (field)) + if (DECL_INTERNAL_P (field) + && TREE_CODE (TREE_TYPE (field)) == QUAL_UNION_TYPE) + return field; + + return NULL_TREE; +} + +/* Return a new variant part modeled on OLD_VARIANT_PART. VARIANT_LIST is + the list of variants to be used and RECORD_TYPE is the type of the parent. + POS_LIST is a position list describing the layout of fields present in + OLD_VARIANT_PART and SUBST_LIST a substitution list to be applied to this + layout. DEBUG_INFO_P is true if we need to write debug information. */ + +static tree +create_variant_part_from (tree old_variant_part, + vec<variant_desc> variant_list, + tree record_type, tree pos_list, + vec<subst_pair> subst_list, + bool debug_info_p) +{ + tree offset = DECL_FIELD_OFFSET (old_variant_part); + tree old_union_type = TREE_TYPE (old_variant_part); + tree new_union_type, new_variant_part; + tree union_field_list = NULL_TREE; + variant_desc *v; + unsigned int i; + + /* First create the type of the variant part from that of the old one. */ + new_union_type = make_node (QUAL_UNION_TYPE); + TYPE_NAME (new_union_type) + = concat_name (TYPE_NAME (record_type), + IDENTIFIER_POINTER (DECL_NAME (old_variant_part))); + + /* If the position of the variant part is constant, subtract it from the + size of the type of the parent to get the new size. This manual CSE + reduces the code size when not optimizing. */ + if (TREE_CODE (offset) == INTEGER_CST + && TYPE_SIZE (record_type) + && TYPE_SIZE_UNIT (record_type)) + { + tree bitpos = DECL_FIELD_BIT_OFFSET (old_variant_part); + tree first_bit = bit_from_pos (offset, bitpos); + TYPE_SIZE (new_union_type) + = size_binop (MINUS_EXPR, TYPE_SIZE (record_type), first_bit); + TYPE_SIZE_UNIT (new_union_type) + = size_binop (MINUS_EXPR, TYPE_SIZE_UNIT (record_type), + byte_from_pos (offset, bitpos)); + SET_TYPE_ADA_SIZE (new_union_type, + size_binop (MINUS_EXPR, TYPE_ADA_SIZE (record_type), + first_bit)); + SET_TYPE_ALIGN (new_union_type, TYPE_ALIGN (old_union_type)); + relate_alias_sets (new_union_type, old_union_type, ALIAS_SET_COPY); + } + else + copy_and_substitute_in_size (new_union_type, old_union_type, subst_list); + + /* Now finish up the new variants and populate the union type. */ + FOR_EACH_VEC_ELT_REVERSE (variant_list, i, v) + { + tree old_field = v->field, new_field; + tree old_variant, old_variant_subpart, new_variant, field_list; + + /* Skip variants that don't belong to this nesting level. */ + if (DECL_CONTEXT (old_field) != old_union_type) + continue; + + /* Retrieve the list of fields already added to the new variant. */ + new_variant = v->new_type; + field_list = TYPE_FIELDS (new_variant); + + /* If the old variant had a variant subpart, we need to create a new + variant subpart and add it to the field list. */ + old_variant = v->type; + old_variant_subpart = get_variant_part (old_variant); + if (old_variant_subpart) + { + tree new_variant_subpart + = create_variant_part_from (old_variant_subpart, variant_list, + new_variant, pos_list, subst_list, + debug_info_p); + DECL_CHAIN (new_variant_subpart) = field_list; + field_list = new_variant_subpart; + } + + /* Finish up the new variant and create the field. */ + finish_record_type (new_variant, nreverse (field_list), 2, debug_info_p); + create_type_decl (TYPE_NAME (new_variant), new_variant, true, + debug_info_p, Empty); + + new_field + = create_field_decl_from (old_field, new_variant, new_union_type, + TYPE_SIZE (new_variant), + pos_list, subst_list); + DECL_QUALIFIER (new_field) = v->qual; + DECL_INTERNAL_P (new_field) = 1; + DECL_CHAIN (new_field) = union_field_list; + union_field_list = new_field; + } + + /* Finish up the union type and create the variant part. Note that we don't + reverse the field list because VARIANT_LIST has been traversed in reverse + order. */ + finish_record_type (new_union_type, union_field_list, 2, debug_info_p); + create_type_decl (TYPE_NAME (new_union_type), new_union_type, true, + debug_info_p, Empty); + + new_variant_part + = create_field_decl_from (old_variant_part, new_union_type, record_type, + TYPE_SIZE (new_union_type), + pos_list, subst_list); + DECL_INTERNAL_P (new_variant_part) = 1; + + /* With multiple discriminants it is possible for an inner variant to be + statically selected while outer ones are not; in this case, the list + of fields of the inner variant is not flattened and we end up with a + qualified union with a single member. Drop the useless container. */ + if (!DECL_CHAIN (union_field_list)) + { + DECL_CONTEXT (union_field_list) = record_type; + DECL_FIELD_OFFSET (union_field_list) + = DECL_FIELD_OFFSET (new_variant_part); + DECL_FIELD_BIT_OFFSET (union_field_list) + = DECL_FIELD_BIT_OFFSET (new_variant_part); + SET_DECL_OFFSET_ALIGN (union_field_list, + DECL_OFFSET_ALIGN (new_variant_part)); + new_variant_part = union_field_list; + } + + return new_variant_part; +} + +/* Copy the size (and alignment and alias set) from OLD_TYPE to NEW_TYPE, + which are both RECORD_TYPE, after applying the substitutions described + in SUBST_LIST. */ + +static void +copy_and_substitute_in_size (tree new_type, tree old_type, + vec<subst_pair> subst_list) +{ + unsigned int i; + subst_pair *s; + + TYPE_SIZE (new_type) = TYPE_SIZE (old_type); + TYPE_SIZE_UNIT (new_type) = TYPE_SIZE_UNIT (old_type); + SET_TYPE_ADA_SIZE (new_type, TYPE_ADA_SIZE (old_type)); + SET_TYPE_ALIGN (new_type, TYPE_ALIGN (old_type)); + relate_alias_sets (new_type, old_type, ALIAS_SET_COPY); + + if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (new_type))) + FOR_EACH_VEC_ELT (subst_list, i, s) + TYPE_SIZE (new_type) + = SUBSTITUTE_IN_EXPR (TYPE_SIZE (new_type), + s->discriminant, s->replacement); + + if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE_UNIT (new_type))) + FOR_EACH_VEC_ELT (subst_list, i, s) + TYPE_SIZE_UNIT (new_type) + = SUBSTITUTE_IN_EXPR (TYPE_SIZE_UNIT (new_type), + s->discriminant, s->replacement); + + if (CONTAINS_PLACEHOLDER_P (TYPE_ADA_SIZE (new_type))) + FOR_EACH_VEC_ELT (subst_list, i, s) + SET_TYPE_ADA_SIZE + (new_type, SUBSTITUTE_IN_EXPR (TYPE_ADA_SIZE (new_type), + s->discriminant, s->replacement)); + + /* Finalize the size. */ + TYPE_SIZE (new_type) = variable_size (TYPE_SIZE (new_type)); + TYPE_SIZE_UNIT (new_type) = variable_size (TYPE_SIZE_UNIT (new_type)); +} + +/* Return true if DISC is a stored discriminant of RECORD_TYPE. */ + +static inline bool +is_stored_discriminant (Entity_Id discr, Entity_Id record_type) +{ + if (Is_Unchecked_Union (record_type)) + return false; + else if (Is_Tagged_Type (record_type)) + return No (Corresponding_Discriminant (discr)); + else if (Ekind (record_type) == E_Record_Type) + return Original_Record_Component (discr) == discr; + else + return true; +} + +/* Copy the layout from {GNAT,GNU}_OLD_TYPE to {GNAT,GNU}_NEW_TYPE, which are + both record types, after applying the substitutions described in SUBST_LIST. + DEBUG_INFO_P is true if we need to write debug information for NEW_TYPE. */ + +static void +copy_and_substitute_in_layout (Entity_Id gnat_new_type, + Entity_Id gnat_old_type, + tree gnu_new_type, + tree gnu_old_type, + vec<subst_pair> subst_list, + bool debug_info_p) +{ + const bool is_subtype = (Ekind (gnat_new_type) == E_Record_Subtype); + tree gnu_field_list = NULL_TREE; + tree gnu_variable_field_list = NULL_TREE; + bool selected_variant; + vec<variant_desc> gnu_variant_list; + + /* Look for REP and variant parts in the old type. */ + tree gnu_rep_part = get_rep_part (gnu_old_type); + tree gnu_variant_part = get_variant_part (gnu_old_type); + + /* If there is a variant part, we must compute whether the constraints + statically select a particular variant. If so, we simply drop the + qualified union and flatten the list of fields. Otherwise we will + build a new qualified union for the variants that are still relevant. */ + if (gnu_variant_part) + { + const Node_Id gnat_decl = Declaration_Node (gnat_new_type); + variant_desc *v; + unsigned int i; + + gnu_variant_list + = build_variant_list (TREE_TYPE (gnu_variant_part), + is_subtype + ? Empty + : Variant_Part + (Component_List (Type_Definition (gnat_decl))), + subst_list, + vNULL); + + /* If all the qualifiers are unconditionally true, the innermost variant + is statically selected. */ + selected_variant = true; + FOR_EACH_VEC_ELT (gnu_variant_list, i, v) + if (!integer_onep (v->qual)) + { + selected_variant = false; + break; + } + + /* Otherwise, create the new variants. */ + if (!selected_variant) + FOR_EACH_VEC_ELT (gnu_variant_list, i, v) + { + tree old_variant = v->type; + tree new_variant = make_node (RECORD_TYPE); + tree suffix + = concat_name (DECL_NAME (gnu_variant_part), + IDENTIFIER_POINTER (DECL_NAME (v->field))); + TYPE_NAME (new_variant) + = concat_name (TYPE_NAME (gnu_new_type), + IDENTIFIER_POINTER (suffix)); + TYPE_REVERSE_STORAGE_ORDER (new_variant) + = TYPE_REVERSE_STORAGE_ORDER (gnu_new_type); + copy_and_substitute_in_size (new_variant, old_variant, subst_list); + v->new_type = new_variant; + } + } + else + { + gnu_variant_list.create (0); + selected_variant = false; + } + + /* Make a list of fields and their position in the old type. */ + tree gnu_pos_list + = build_position_list (gnu_old_type, + gnu_variant_list.exists () && !selected_variant, + size_zero_node, bitsize_zero_node, + BIGGEST_ALIGNMENT, NULL_TREE); + + /* Now go down every component in the new type and compute its size and + position from those of the component in the old type and the stored + constraints of the new type. */ + Entity_Id gnat_field, gnat_old_field; + for (gnat_field = First_Entity (gnat_new_type); + Present (gnat_field); + gnat_field = Next_Entity (gnat_field)) + if ((Ekind (gnat_field) == E_Component + || (Ekind (gnat_field) == E_Discriminant + && is_stored_discriminant (gnat_field, gnat_new_type))) + && (gnat_old_field = is_subtype + ? Original_Record_Component (gnat_field) + : Corresponding_Record_Component (gnat_field)) + && Underlying_Type (Scope (gnat_old_field)) == gnat_old_type + && present_gnu_tree (gnat_old_field)) + { + Name_Id gnat_name = Chars (gnat_field); + tree gnu_old_field = get_gnu_tree (gnat_old_field); + if (TREE_CODE (gnu_old_field) == COMPONENT_REF) + gnu_old_field = TREE_OPERAND (gnu_old_field, 1); + tree gnu_context = DECL_CONTEXT (gnu_old_field); + tree gnu_field, gnu_field_type, gnu_size, gnu_pos; + tree gnu_cont_type, gnu_last = NULL_TREE; + variant_desc *v = NULL; + + /* If the type is the same, retrieve the GCC type from the + old field to take into account possible adjustments. */ + if (Etype (gnat_field) == Etype (gnat_old_field)) + gnu_field_type = TREE_TYPE (gnu_old_field); + else + gnu_field_type = gnat_to_gnu_type (Etype (gnat_field)); + + /* If there was a component clause, the field types must be the same + for the old and new types, so copy the data from the old field to + avoid recomputation here. Also if the field is justified modular + and the optimization in gnat_to_gnu_field was applied. */ + if (Present (Component_Clause (gnat_old_field)) + || (TREE_CODE (gnu_field_type) == RECORD_TYPE + && TYPE_JUSTIFIED_MODULAR_P (gnu_field_type) + && TREE_TYPE (TYPE_FIELDS (gnu_field_type)) + == TREE_TYPE (gnu_old_field))) + { + gnu_size = DECL_SIZE (gnu_old_field); + gnu_field_type = TREE_TYPE (gnu_old_field); + } + + /* If the old field was packed and of constant size, we have to get the + old size here as it might differ from what the Etype conveys and the + latter might overlap with the following field. Try to arrange the + type for possible better packing along the way. */ + else if (DECL_PACKED (gnu_old_field) + && TREE_CODE (DECL_SIZE (gnu_old_field)) == INTEGER_CST) + { + gnu_size = DECL_SIZE (gnu_old_field); + if (RECORD_OR_UNION_TYPE_P (gnu_field_type) + && !TYPE_FAT_POINTER_P (gnu_field_type) + && tree_fits_uhwi_p (TYPE_SIZE (gnu_field_type))) + gnu_field_type = make_packable_type (gnu_field_type, true, 0); + } + + else + gnu_size = TYPE_SIZE (gnu_field_type); + + /* If the context of the old field is the old type or its REP part, + put the field directly in the new type; otherwise look up the + context in the variant list and put the field either in the new + type if there is a selected variant or in one new variant. */ + if (gnu_context == gnu_old_type + || (gnu_rep_part && gnu_context == TREE_TYPE (gnu_rep_part))) + gnu_cont_type = gnu_new_type; + else + { + unsigned int i; + tree rep_part; + + FOR_EACH_VEC_ELT (gnu_variant_list, i, v) + if (gnu_context == v->type + || ((rep_part = get_rep_part (v->type)) + && gnu_context == TREE_TYPE (rep_part))) + break; + + if (v) + gnu_cont_type = selected_variant ? gnu_new_type : v->new_type; + else + /* The front-end may pass us zombie components if it fails to + recognize that a constrain statically selects a particular + variant. Discard them. */ + continue; + } + + /* Now create the new field modeled on the old one. */ + gnu_field + = create_field_decl_from (gnu_old_field, gnu_field_type, + gnu_cont_type, gnu_size, + gnu_pos_list, subst_list); + gnu_pos = DECL_FIELD_OFFSET (gnu_field); + + /* If the context is a variant, put it in the new variant directly. */ + if (gnu_cont_type != gnu_new_type) + { + if (TREE_CODE (gnu_pos) == INTEGER_CST) + { + DECL_CHAIN (gnu_field) = TYPE_FIELDS (gnu_cont_type); + TYPE_FIELDS (gnu_cont_type) = gnu_field; + } + else + { + DECL_CHAIN (gnu_field) = v->aux; + v->aux = gnu_field; + } + } + + /* To match the layout crafted in components_to_record, if this is + the _Tag or _Parent field, put it before any other fields. */ + else if (gnat_name == Name_uTag || gnat_name == Name_uParent) + gnu_field_list = chainon (gnu_field_list, gnu_field); + + /* Similarly, if this is the _Controller field, put it before the + other fields except for the _Tag or _Parent field. */ + else if (gnat_name == Name_uController && gnu_last) + { + DECL_CHAIN (gnu_field) = DECL_CHAIN (gnu_last); + DECL_CHAIN (gnu_last) = gnu_field; + } + + /* Otherwise, put it after the other fields. */ + else + { + if (TREE_CODE (gnu_pos) == INTEGER_CST) + { + DECL_CHAIN (gnu_field) = gnu_field_list; + gnu_field_list = gnu_field; + if (!gnu_last) + gnu_last = gnu_field; + } + else + { + DECL_CHAIN (gnu_field) = gnu_variable_field_list; + gnu_variable_field_list = gnu_field; + } + } + + /* For a stored discriminant in a derived type, replace the field. */ + if (!is_subtype && Ekind (gnat_field) == E_Discriminant) + { + tree gnu_ref = get_gnu_tree (gnat_field); + TREE_OPERAND (gnu_ref, 1) = gnu_field; + } + else + save_gnu_tree (gnat_field, gnu_field, false); + } + + /* Put the fields with fixed position in order of increasing position. */ + if (gnu_field_list) + gnu_field_list = reverse_sort_field_list (gnu_field_list); + + /* Put the fields with variable position at the end. */ + if (gnu_variable_field_list) + gnu_field_list = chainon (gnu_variable_field_list, gnu_field_list); + + /* If there is a variant list and no selected variant, we need to create the + nest of variant parts from the old nest. */ + if (gnu_variant_list.exists () && !selected_variant) + { + variant_desc *v; + unsigned int i; + + /* Same processing as above for the fields of each variant. */ + FOR_EACH_VEC_ELT (gnu_variant_list, i, v) + { + if (TYPE_FIELDS (v->new_type)) + TYPE_FIELDS (v->new_type) + = reverse_sort_field_list (TYPE_FIELDS (v->new_type)); + if (v->aux) + TYPE_FIELDS (v->new_type) + = chainon (v->aux, TYPE_FIELDS (v->new_type)); + } + + tree new_variant_part + = create_variant_part_from (gnu_variant_part, gnu_variant_list, + gnu_new_type, gnu_pos_list, + subst_list, debug_info_p); + DECL_CHAIN (new_variant_part) = gnu_field_list; + gnu_field_list = new_variant_part; + } + + gnu_variant_list.release (); + subst_list.release (); + + /* If NEW_TYPE is a subtype, it inherits all the attributes from OLD_TYPE. + Otherwise sizes and alignment must be computed independently. */ + finish_record_type (gnu_new_type, nreverse (gnu_field_list), + is_subtype ? 2 : 1, debug_info_p); + + /* Now go through the entities again looking for itypes that we have not yet + elaborated (e.g. Etypes of fields that have Original_Components). */ + for (Entity_Id gnat_field = First_Entity (gnat_new_type); + Present (gnat_field); + gnat_field = Next_Entity (gnat_field)) + if ((Ekind (gnat_field) == E_Component + || Ekind (gnat_field) == E_Discriminant) + && Is_Itype (Etype (gnat_field)) + && !present_gnu_tree (Etype (gnat_field))) + gnat_to_gnu_entity (Etype (gnat_field), NULL_TREE, false); +} + +/* Associate to the implementation type of a packed array type specified by + GNU_TYPE, which is the translation of GNAT_ENTITY, the original array type + if it has been translated. This association is a parallel type for GNAT + encodings or a debug type for standard DWARF. Note that for standard DWARF, + we also want to get the original type name and therefore we return it. */ + +static tree +associate_original_type_to_packed_array (tree gnu_type, Entity_Id gnat_entity) +{ + const Entity_Id gnat_original_array_type + = Underlying_Type (Original_Array_Type (gnat_entity)); + tree gnu_original_array_type; + + if (!present_gnu_tree (gnat_original_array_type)) + return NULL_TREE; + + gnu_original_array_type = gnat_to_gnu_type (gnat_original_array_type); + + if (TYPE_IS_DUMMY_P (gnu_original_array_type)) + return NULL_TREE; + + gcc_assert (TYPE_IMPL_PACKED_ARRAY_P (gnu_type)); + + if (gnat_encodings == DWARF_GNAT_ENCODINGS_ALL) + { + add_parallel_type (gnu_type, gnu_original_array_type); + return NULL_TREE; + } + else + { + SET_TYPE_ORIGINAL_PACKED_ARRAY (gnu_type, gnu_original_array_type); + + tree original_name = TYPE_NAME (gnu_original_array_type); + if (TREE_CODE (original_name) == TYPE_DECL) + original_name = DECL_NAME (original_name); + return original_name; + } +} + +/* Given a type T, a FIELD_DECL F, and a replacement value R, return an + equivalent type with adjusted size expressions where all occurrences + of references to F in a PLACEHOLDER_EXPR have been replaced by R. + + The function doesn't update the layout of the type, i.e. it assumes + that the substitution is purely formal. That's why the replacement + value R must itself contain a PLACEHOLDER_EXPR. */ + +tree +substitute_in_type (tree t, tree f, tree r) +{ + tree nt; + + gcc_assert (CONTAINS_PLACEHOLDER_P (r)); + + switch (TREE_CODE (t)) + { + case INTEGER_TYPE: + case ENUMERAL_TYPE: + case BOOLEAN_TYPE: + case REAL_TYPE: + + /* First the domain types of arrays. */ + if (CONTAINS_PLACEHOLDER_P (TYPE_GCC_MIN_VALUE (t)) + || CONTAINS_PLACEHOLDER_P (TYPE_GCC_MAX_VALUE (t))) + { + tree low = SUBSTITUTE_IN_EXPR (TYPE_GCC_MIN_VALUE (t), f, r); + tree high = SUBSTITUTE_IN_EXPR (TYPE_GCC_MAX_VALUE (t), f, r); + + if (low == TYPE_GCC_MIN_VALUE (t) && high == TYPE_GCC_MAX_VALUE (t)) + return t; + + nt = copy_type (t); + TYPE_GCC_MIN_VALUE (nt) = low; + TYPE_GCC_MAX_VALUE (nt) = high; + + if (TREE_CODE (t) == INTEGER_TYPE && TYPE_INDEX_TYPE (t)) + SET_TYPE_INDEX_TYPE + (nt, substitute_in_type (TYPE_INDEX_TYPE (t), f, r)); + + return nt; + } + + /* Then the subtypes. */ + if (CONTAINS_PLACEHOLDER_P (TYPE_RM_MIN_VALUE (t)) + || CONTAINS_PLACEHOLDER_P (TYPE_RM_MAX_VALUE (t))) + { + tree low = SUBSTITUTE_IN_EXPR (TYPE_RM_MIN_VALUE (t), f, r); + tree high = SUBSTITUTE_IN_EXPR (TYPE_RM_MAX_VALUE (t), f, r); + + if (low == TYPE_RM_MIN_VALUE (t) && high == TYPE_RM_MAX_VALUE (t)) + return t; + + nt = copy_type (t); + SET_TYPE_RM_MIN_VALUE (nt, low); + SET_TYPE_RM_MAX_VALUE (nt, high); + + return nt; + } + + return t; + + case COMPLEX_TYPE: + nt = substitute_in_type (TREE_TYPE (t), f, r); + if (nt == TREE_TYPE (t)) + return t; + + return build_complex_type (nt); + + case FUNCTION_TYPE: + case METHOD_TYPE: + /* These should never show up here. */ + gcc_unreachable (); + + case ARRAY_TYPE: + { + tree component = substitute_in_type (TREE_TYPE (t), f, r); + tree domain = substitute_in_type (TYPE_DOMAIN (t), f, r); + + if (component == TREE_TYPE (t) && domain == TYPE_DOMAIN (t)) + return t; + + nt = build_nonshared_array_type (component, domain); + SET_TYPE_ALIGN (nt, TYPE_ALIGN (t)); + TYPE_USER_ALIGN (nt) = TYPE_USER_ALIGN (t); + SET_TYPE_MODE (nt, TYPE_MODE (t)); + TYPE_SIZE (nt) = SUBSTITUTE_IN_EXPR (TYPE_SIZE (t), f, r); + TYPE_SIZE_UNIT (nt) = SUBSTITUTE_IN_EXPR (TYPE_SIZE_UNIT (t), f, r); + TYPE_MULTI_ARRAY_P (nt) = TYPE_MULTI_ARRAY_P (t); + TYPE_CONVENTION_FORTRAN_P (nt) = TYPE_CONVENTION_FORTRAN_P (t); + if (TYPE_REVERSE_STORAGE_ORDER (t)) + set_reverse_storage_order_on_array_type (nt); + if (TYPE_NONALIASED_COMPONENT (t)) + set_nonaliased_component_on_array_type (nt); + return nt; + } + + case RECORD_TYPE: + case UNION_TYPE: + case QUAL_UNION_TYPE: + { + bool changed_field = false; + tree field; + + /* Start out with no fields, make new fields, and chain them + in. If we haven't actually changed the type of any field, + discard everything we've done and return the old type. */ + nt = copy_type (t); + TYPE_FIELDS (nt) = NULL_TREE; + + for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field)) + { + tree new_field = copy_node (field), new_n; + + new_n = substitute_in_type (TREE_TYPE (field), f, r); + if (new_n != TREE_TYPE (field)) + { + TREE_TYPE (new_field) = new_n; + changed_field = true; + } + + new_n = SUBSTITUTE_IN_EXPR (DECL_FIELD_OFFSET (field), f, r); + if (new_n != DECL_FIELD_OFFSET (field)) + { + DECL_FIELD_OFFSET (new_field) = new_n; + changed_field = true; + } + + /* Do the substitution inside the qualifier, if any. */ + if (TREE_CODE (t) == QUAL_UNION_TYPE) + { + new_n = SUBSTITUTE_IN_EXPR (DECL_QUALIFIER (field), f, r); + if (new_n != DECL_QUALIFIER (field)) + { + DECL_QUALIFIER (new_field) = new_n; + changed_field = true; + } + } + + DECL_CONTEXT (new_field) = nt; + SET_DECL_ORIGINAL_FIELD_TO_FIELD (new_field, field); + + DECL_CHAIN (new_field) = TYPE_FIELDS (nt); + TYPE_FIELDS (nt) = new_field; + } + + if (!changed_field) + return t; + + TYPE_FIELDS (nt) = nreverse (TYPE_FIELDS (nt)); + TYPE_SIZE (nt) = SUBSTITUTE_IN_EXPR (TYPE_SIZE (t), f, r); + TYPE_SIZE_UNIT (nt) = SUBSTITUTE_IN_EXPR (TYPE_SIZE_UNIT (t), f, r); + SET_TYPE_ADA_SIZE (nt, SUBSTITUTE_IN_EXPR (TYPE_ADA_SIZE (t), f, r)); + return nt; + } + + default: + return t; + } +} + +/* Return the RM size of GNU_TYPE. This is the actual number of bits + needed to represent the object. */ + +tree +rm_size (tree gnu_type) +{ + /* For integral types, we store the RM size explicitly. */ + if (INTEGRAL_TYPE_P (gnu_type) && TYPE_RM_SIZE (gnu_type)) + return TYPE_RM_SIZE (gnu_type); + + /* If the type contains a template, return the padded size of the template + plus the RM size of the actual data. */ + if (TREE_CODE (gnu_type) == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P (gnu_type)) + return + size_binop (PLUS_EXPR, + bit_position (DECL_CHAIN (TYPE_FIELDS (gnu_type))), + rm_size (TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (gnu_type))))); + + /* For record or union types, we store the size explicitly. */ + if (RECORD_OR_UNION_TYPE_P (gnu_type) + && !TYPE_FAT_POINTER_P (gnu_type) + && TYPE_ADA_SIZE (gnu_type)) + return TYPE_ADA_SIZE (gnu_type); + + /* For other types, this is just the size. */ + return TYPE_SIZE (gnu_type); +} + +/* Return the name to be used for GNAT_ENTITY. If a type, create a + fully-qualified name, possibly with type information encoding. + Otherwise, return the name. */ + +static const char * +get_entity_char (Entity_Id gnat_entity) +{ + Get_Encoded_Name (gnat_entity); + return ggc_strdup (Name_Buffer); +} + +tree +get_entity_name (Entity_Id gnat_entity) +{ + Get_Encoded_Name (gnat_entity); + return get_identifier_with_length (Name_Buffer, Name_Len); +} + +/* Return an identifier representing the external name to be used for + GNAT_ENTITY. If SUFFIX is specified, the name is followed by "___" + and the specified suffix. */ + +tree +create_concat_name (Entity_Id gnat_entity, const char *suffix) +{ + const Entity_Kind kind = Ekind (gnat_entity); + const bool has_suffix = (suffix != NULL); + String_Template temp = {1, has_suffix ? (int) strlen (suffix) : 0}; + String_Pointer sp = {suffix, &temp}; + + Get_External_Name (gnat_entity, has_suffix, sp); + + /* A variable using the Stdcall convention lives in a DLL. We adjust + its name to use the jump table, the _imp__NAME contains the address + for the NAME variable. */ + if ((kind == E_Variable || kind == E_Constant) + && Has_Stdcall_Convention (gnat_entity)) + { + const int len = strlen (STDCALL_PREFIX) + Name_Len; + char *new_name = (char *) alloca (len + 1); + strcpy (new_name, STDCALL_PREFIX); + strcat (new_name, Name_Buffer); + return get_identifier_with_length (new_name, len); + } + + return get_identifier_with_length (Name_Buffer, Name_Len); +} + +/* Given GNU_NAME, an IDENTIFIER_NODE containing a name and SUFFIX, a + string, return a new IDENTIFIER_NODE that is the concatenation of + the name followed by "___" and the specified suffix. */ + +tree +concat_name (tree gnu_name, const char *suffix) +{ + const int len = IDENTIFIER_LENGTH (gnu_name) + 3 + strlen (suffix); + char *new_name = (char *) alloca (len + 1); + strcpy (new_name, IDENTIFIER_POINTER (gnu_name)); + strcat (new_name, "___"); + strcat (new_name, suffix); + return get_identifier_with_length (new_name, len); +} + +/* Initialize the data structures of the decl.c module. */ + +void +init_gnat_decl (void) +{ + /* Initialize the cache of annotated values. */ + annotate_value_cache = hash_table<value_annotation_hasher>::create_ggc (512); + + /* Initialize the association of dummy types with subprograms. */ + dummy_to_subprog_map = hash_table<dummy_type_hasher>::create_ggc (512); +} + +/* Destroy the data structures of the decl.c module. */ + +void +destroy_gnat_decl (void) +{ + /* Destroy the cache of annotated values. */ + annotate_value_cache->empty (); + annotate_value_cache = NULL; + + /* Destroy the association of dummy types with subprograms. */ + dummy_to_subprog_map->empty (); + dummy_to_subprog_map = NULL; +} + +#include "gt-ada-decl.h" |