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Diffstat (limited to 'gcc/ada/gcc-interface/decl.c')
| -rw-r--r-- | gcc/ada/gcc-interface/decl.c | 7648 |
1 files changed, 7648 insertions, 0 deletions
diff --git a/gcc/ada/gcc-interface/decl.c b/gcc/ada/gcc-interface/decl.c new file mode 100644 index 0000000..ebc2e5e --- /dev/null +++ b/gcc/ada/gcc-interface/decl.c @@ -0,0 +1,7648 @@ +/**************************************************************************** + * * + * GNAT COMPILER COMPONENTS * + * * + * D E C L * + * * + * C Implementation File * + * * + * Copyright (C) 1992-2008, 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 "tm.h" +#include "tree.h" +#include "flags.h" +#include "toplev.h" +#include "convert.h" +#include "ggc.h" +#include "obstack.h" +#include "target.h" +#include "expr.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 "stringt.h" +#include "uintp.h" +#include "fe.h" +#include "sinfo.h" +#include "einfo.h" +#include "hashtab.h" +#include "ada-tree.h" +#include "gigi.h" + +#ifndef MAX_FIXED_MODE_SIZE +#define MAX_FIXED_MODE_SIZE GET_MODE_BITSIZE (DImode) +#endif + +/* Convention_Stdcall should be processed in a specific way on Windows targets + only. The macro below is a helper to avoid having to check for a Windows + specific attribute throughout this unit. */ + +#if TARGET_DLLIMPORT_DECL_ATTRIBUTES +#define Has_Stdcall_Convention(E) (Convention (E) == Convention_Stdcall) +#else +#define Has_Stdcall_Convention(E) (0) +#endif + +/* Stack realignment for functions with foreign conventions is provided on a + per back-end basis now, as it is handled by the prologue expanders and not + as part of the function's body any more. It might be requested by way of a + dedicated function type attribute on the targets that support it. + + We need a way to avoid setting the attribute on the targets that don't + support it and use FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN for this purpose. + + It is defined on targets where the circuitry is available, and indicates + whether the realignment is needed for 'main'. We use this to decide for + foreign subprograms as well. + + It is not defined on targets where the circuitry is not implemented, and + we just never set the attribute in these cases. + + Whether it is defined on all targets that would need it in theory is + not entirely clear. We currently trust the base GCC settings for this + purpose. */ + +#ifndef FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN +#define FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN 0 +#endif + +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 an array, a record or a subprogram type. */ +static int defer_incomplete_level = 0; +static struct incomplete *defer_incomplete_list; + +/* This variable is used to delay expanding From_With_Type types until the + end of the spec. */ +static struct incomplete *defer_limited_with; + +/* These variables are used to defer finalizing types. The element of the + list is the TYPE_DECL associated with the type. */ +static int defer_finalize_level = 0; +static VEC (tree,heap) *defer_finalize_list; + +/* A hash table used to cache the result of annotate_value. */ +static GTY ((if_marked ("tree_int_map_marked_p"), + param_is (struct tree_int_map))) htab_t annotate_value_cache; + +static void copy_alias_set (tree, tree); +static tree substitution_list (Entity_Id, Entity_Id, tree, bool); +static bool allocatable_size_p (tree, bool); +static void prepend_one_attribute_to (struct attrib **, + enum attr_type, tree, tree, Node_Id); +static void prepend_attributes (Entity_Id, struct attrib **); +static tree elaborate_expression (Node_Id, Entity_Id, tree, bool, bool, bool); +static bool is_variable_size (tree); +static tree elaborate_expression_1 (Node_Id, Entity_Id, tree, tree, + bool, bool); +static tree make_packable_type (tree, bool); +static tree gnat_to_gnu_field (Entity_Id, tree, int, bool); +static tree gnat_to_gnu_param (Entity_Id, Mechanism_Type, Entity_Id, bool, + bool *); +static bool same_discriminant_p (Entity_Id, Entity_Id); +static bool array_type_has_nonaliased_component (Entity_Id, tree); +static void components_to_record (tree, Node_Id, tree, int, bool, tree *, + bool, bool, bool, bool); +static Uint annotate_value (tree); +static void annotate_rep (Entity_Id, tree); +static tree compute_field_positions (tree, tree, tree, tree, unsigned int); +static tree validate_size (Uint, tree, Entity_Id, enum tree_code, bool, bool); +static void set_rm_size (Uint, tree, Entity_Id); +static tree make_type_from_size (tree, tree, bool); +static unsigned int validate_alignment (Uint, Entity_Id, unsigned int); +static unsigned int ceil_alignment (unsigned HOST_WIDE_INT); +static void check_ok_for_atomic (tree, Entity_Id, bool); +static int compatible_signatures_p (tree ftype1, tree ftype2); +static void rest_of_type_decl_compilation_no_defer (tree); + +/* Return true if GNAT_ADDRESS is a compile time known value. + In particular catch System'To_Address. */ + +static bool +compile_time_known_address_p (Node_Id gnat_address) +{ + return ((Nkind (gnat_address) == N_Unchecked_Type_Conversion + && Compile_Time_Known_Value (Expression (gnat_address))) + || Compile_Time_Known_Value (gnat_address)); +} + +/* Given GNAT_ENTITY, an entity in the incoming GNAT tree, return a + GCC type corresponding to that entity. GNAT_ENTITY is assumed to + refer to an Ada type. */ + +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; + + /* Convert the ada entity type into a GCC TYPE_DECL node. */ + gnu_decl = gnat_to_gnu_entity (gnat_entity, NULL_TREE, 0); + gcc_assert (TREE_CODE (gnu_decl) == TYPE_DECL); + return TREE_TYPE (gnu_decl); +} + +/* Given GNAT_ENTITY, a GNAT defining identifier node, which denotes some Ada + entity, this routine returns the equivalent GCC tree for that entity + (an ..._DECL node) and associates 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 variables. + For renamed entities, GNU_EXPR gives the object being renamed. + + DEFINITION is nonzero if this call is intended for a definition. This is + used for separate compilation where it necessary to know whether an + external declaration or a definition should be created if the GCC equivalent + was not created previously. The value of 1 is normally used for a nonzero + DEFINITION, but a value of 2 is used in special circumstances, defined in + the code. */ + +tree +gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition) +{ + Entity_Id gnat_equiv_type = Gigi_Equivalent_Type (gnat_entity); + tree gnu_entity_id; + tree gnu_type = NULL_TREE; + /* Contains the gnu XXXX_DECL tree node which is equivalent to the input + GNAT tree. This node will be associated with the GNAT node by calling + the save_gnu_tree routine at the end of the `switch' statement. */ + tree gnu_decl = NULL_TREE; + /* true if we have already saved gnu_decl as a gnat association. */ + bool saved = false; + /* Nonzero if we incremented defer_incomplete_level. */ + bool this_deferred = false; + /* Nonzero if we incremented force_global. */ + bool this_global = false; + /* Nonzero if we should check to see if elaborated during processing. */ + bool maybe_present = false; + /* Nonzero if we made GNU_DECL and its type here. */ + bool this_made_decl = false; + struct attrib *attr_list = NULL; + bool debug_info_p = (Needs_Debug_Info (gnat_entity) + || debug_info_level == DINFO_LEVEL_VERBOSE); + Entity_Kind kind = Ekind (gnat_entity); + Entity_Id gnat_temp; + unsigned int esize + = ((Known_Esize (gnat_entity) + && UI_Is_In_Int_Range (Esize (gnat_entity))) + ? MIN (UI_To_Int (Esize (gnat_entity)), + IN (kind, Float_Kind) + ? fp_prec_to_size (LONG_DOUBLE_TYPE_SIZE) + : IN (kind, Access_Kind) ? POINTER_SIZE * 2 + : LONG_LONG_TYPE_SIZE) + : LONG_LONG_TYPE_SIZE); + tree gnu_size = 0; + bool imported_p + = (Is_Imported (gnat_entity) && No (Address_Clause (gnat_entity))); + unsigned int align = 0; + + /* Since a use of an Itype is a definition, process it as such if it + is not in a with'ed unit. */ + + if (!definition && Is_Itype (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 that 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 (IN (Ekind (gnat_temp), Subprogram_Kind) + && 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 + || (IN (Ekind (gnat_temp), Subprogram_Kind) + && present_gnu_tree (gnat_temp) + && (current_function_decl + == gnat_to_gnu_entity (gnat_temp, NULL_TREE, 0)))) + { + process_type (gnat_entity); + return get_gnu_tree (gnat_entity); + } + } + + /* This abort means the entity "gnat_entity" has an incorrect scope, + i.e. that its scope does not correspond to the subprogram in which + it is declared */ + gcc_unreachable (); + } + + /* If this is entity 0, something went badly wrong. */ + gcc_assert (Present (gnat_entity)); + + /* 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. */ + + if (present_gnu_tree (gnat_entity) + && (!definition || (Is_Type (gnat_entity) && imported_p))) + { + 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))) + { + gnu_decl = gnat_to_gnu_entity (Full_View (gnat_entity), + NULL_TREE, 0); + + 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. */ + gcc_assert (!Unknown_Esize (gnat_entity) + || Has_Size_Clause (gnat_entity) + || (!IN (kind, Numeric_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))); + + /* Likewise, RM_Size must be specified for all discrete and fixed-point + types. */ + gcc_assert (!IN (kind, Discrete_Or_Fixed_Point_Kind) + || !Unknown_RM_Size (gnat_entity)); + + /* 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. */ + gnu_entity_id = get_entity_name (gnat_entity); + Sloc_to_locus (Sloc (gnat_entity), &input_location); + + /* If we get here, it means we have not yet done anything with this + entity. If we are not defining it here, it must be external, + otherwise we should have defined it already. */ + gcc_assert (definition || Is_Public (gnat_entity) || type_annotate_only + || kind == E_Discriminant || kind == E_Component + || kind == E_Label + || (kind == E_Constant && Present (Full_View (gnat_entity))) + || IN (kind, Type_Kind)); + + /* 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. But do this for Imported functions or procedures in + all cases. */ + if ((!definition && Is_Public (gnat_entity) + && !Is_Statically_Allocated (gnat_entity) + && kind != E_Discriminant && kind != E_Component) + || (Is_Imported (gnat_entity) + && (kind == E_Function || kind == E_Procedure))) + force_global++, this_global = true; + + /* Handle any attributes directly attached to the entity. */ + if (Has_Gigi_Rep_Item (gnat_entity)) + prepend_attributes (gnat_entity, &attr_list); + + /* 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 (Is_Type (gnat_entity) && Base_Type (gnat_entity) != gnat_entity + && !Is_First_Subtype (gnat_entity) + && Has_Gigi_Rep_Item (First_Subtype (Base_Type (gnat_entity)))) + prepend_attributes (First_Subtype (Base_Type (gnat_entity)), &attr_list); + + switch (kind) + { + case E_Constant: + /* If this is a use of a deferred constant, get its full + declaration. */ + if (!definition && Present (Full_View (gnat_entity))) + { + gnu_decl = gnat_to_gnu_entity (Full_View (gnat_entity), + gnu_expr, 0); + saved = true; + break; + } + + /* If we have an external constant that we are not defining, get the + expression that is was defined to represent. We may throw that + expression away later if it is not a constant. Do not retrieve the + expression if it is an aggregate or allocator, because in complex + instantiation contexts it may not be expanded */ + if (!definition + && Present (Expression (Declaration_Node (gnat_entity))) + && !No_Initialization (Declaration_Node (gnat_entity)) + && (Nkind (Expression (Declaration_Node (gnat_entity))) + != N_Aggregate) + && (Nkind (Expression (Declaration_Node (gnat_entity))) + != N_Allocator)) + gnu_expr = gnat_to_gnu (Expression (Declaration_Node (gnat_entity))); + + /* Ignore deferred constant definitions; they are processed fully in the + front-end. For deferred constant references get the full definition. + On the other hand, constants that are renamings are handled like + variable renamings. If No_Initialization is set, this is not a + deferred constant but a constant whose value is built manually. */ + if (definition && !gnu_expr + && !No_Initialization (Declaration_Node (gnat_entity)) + && No (Renamed_Object (gnat_entity))) + { + gnu_decl = error_mark_node; + saved = true; + break; + } + else if (!definition && IN (kind, Incomplete_Or_Private_Kind) + && Present (Full_View (gnat_entity))) + { + gnu_decl = gnat_to_gnu_entity (Full_View (gnat_entity), + NULL_TREE, 0); + saved = true; + break; + } + + goto object; + + case E_Exception: + /* We used to special case VMS exceptions here to directly map them to + their associated condition code. Since this code had to be masked + dynamically to strip off the severity bits, this caused trouble in + the GCC/ZCX case because the "type" pointers we store in the tables + have to be static. We now don't special case here anymore, and let + the regular processing take place, which leaves us with a regular + exception data object for VMS exceptions too. The condition code + mapping is taken care of by the front end and the bitmasking by the + runtime library. */ + goto object; + + case E_Discriminant: + case E_Component: + { + /* The GNAT record where the component was defined. */ + Entity_Id gnat_record = Underlying_Type (Scope (gnat_entity)); + + /* If the variable is an inherited record component (in the case of + extended record types), just return the inherited entity, which + must be a FIELD_DECL. Likewise for discriminants. + For discriminants of untagged records which have explicit + stored discriminants, return the entity for the corresponding + stored discriminant. Also use Original_Record_Component + if the record has a private extension. */ + + 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); + saved = true; + break; + } + + /* If the enclosing record has explicit stored discriminants, + then it is an untagged record. If the Corresponding_Discriminant + is not empty then this must be a renamed discriminant and its + Original_Record_Component must point to the corresponding explicit + stored discriminant (i.e., we should have taken the previous + branch). */ + + else if (Present (Corresponding_Discriminant (gnat_entity)) + && Is_Tagged_Type (gnat_record)) + { + /* A tagged record has no explicit stored discriminants. */ + + gcc_assert (First_Discriminant (gnat_record) + == First_Stored_Discriminant (gnat_record)); + gnu_decl + = gnat_to_gnu_entity (Corresponding_Discriminant (gnat_entity), + gnu_expr, definition); + saved = true; + break; + } + + else if (Present (CR_Discriminant (gnat_entity)) + && type_annotate_only) + { + gnu_decl = gnat_to_gnu_entity (CR_Discriminant (gnat_entity), + gnu_expr, definition); + saved = true; + break; + } + + /* If the enclosing record has explicit stored discriminants, + then it is an untagged record. If the Corresponding_Discriminant + is not empty then this must be a renamed discriminant and its + Original_Record_Component must point to the corresponding explicit + stored discriminant (i.e., we should have taken the first + branch). */ + + else if (Present (Corresponding_Discriminant (gnat_entity)) + && (First_Discriminant (gnat_record) + != First_Stored_Discriminant (gnat_record))) + gcc_unreachable (); + + /* 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. */ + else 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 (Scop) + || (Is_Private_Type (Scop) + && Present (Full_View (Scop)) + && Is_Protected_Type (Full_View (Scop)))) + && Present (Original_Record_Component (gnat_entity))) + { + gnu_decl + = gnat_to_gnu_entity (Original_Record_Component + (gnat_entity), + gnu_expr, 0); + saved = true; + break; + } + + gnat_to_gnu_entity (Scope (gnat_entity), NULL_TREE, 0); + gnu_decl = get_gnu_tree (gnat_entity); + saved = true; + break; + } + + else + /* Here we have no GCC type and this is a reference rather than a + definition. This should never happen. Most likely the cause is a + reference before declaration in the gnat tree for gnat_entity. */ + gcc_unreachable (); + } + + case E_Loop_Parameter: + case E_Out_Parameter: + case E_Variable: + + /* Simple variables, loop variables, Out parameters, and exceptions. */ + object: + { + bool used_by_ref = false; + bool const_flag + = ((kind == E_Constant || kind == E_Variable) + && Is_True_Constant (gnat_entity) + && (((Nkind (Declaration_Node (gnat_entity)) + == N_Object_Declaration) + && Present (Expression (Declaration_Node (gnat_entity)))) + || Present (Renamed_Object (gnat_entity)))); + bool inner_const_flag = const_flag; + bool static_p = Is_Statically_Allocated (gnat_entity); + bool mutable_p = false; + tree gnu_ext_name = NULL_TREE; + tree renamed_obj = NULL_TREE; + tree gnu_object_size; + + if (Present (Renamed_Object (gnat_entity)) && !definition) + { + if (kind == E_Exception) + gnu_expr = gnat_to_gnu_entity (Renamed_Entity (gnat_entity), + NULL_TREE, 0); + else + gnu_expr = gnat_to_gnu (Renamed_Object (gnat_entity)); + } + + /* Get the type after elaborating the renamed object. */ + gnu_type = gnat_to_gnu_type (Etype (gnat_entity)); + + /* For a debug renaming declaration, build a pure debug entity. */ + if (Present (Debug_Renaming_Link (gnat_entity))) + { + rtx addr; + gnu_decl = build_decl (VAR_DECL, gnu_entity_id, gnu_type); + /* The (MEM (CONST (0))) pattern is prescribed by STABS. */ + if (global_bindings_p ()) + addr = gen_rtx_CONST (VOIDmode, const0_rtx); + else + addr = stack_pointer_rtx; + SET_DECL_RTL (gnu_decl, gen_rtx_MEM (Pmode, addr)); + 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 types are unconstrained arrays or + any object whose type is a dummy type or VOID_TYPE. */ + + if ((TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE + && No (Renamed_Object (gnat_entity))) + || 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 alignments. We must do this + before we validate the size, since the alignment can affect the + size. */ + if (kind != E_Exception && Known_Alignment (gnat_entity)) + { + gcc_assert (Present (Alignment (gnat_entity))); + align = validate_alignment (Alignment (gnat_entity), gnat_entity, + TYPE_ALIGN (gnu_type)); + gnu_type = maybe_pad_type (gnu_type, NULL_TREE, align, gnat_entity, + "PAD", false, definition, true); + } + + /* If we are defining the object, see if it has a Size value and + validate it if so. If we are not defining the object and a Size + clause applies, simply retrieve the value. We don't want to ignore + the clause and it is expected to have been validated already. Then + get the new type, if any. */ + if (definition) + gnu_size = validate_size (Esize (gnat_entity), gnu_type, + gnat_entity, VAR_DECL, false, + Has_Size_Clause (gnat_entity)); + else if (Has_Size_Clause (gnat_entity)) + gnu_size = UI_To_gnu (Esize (gnat_entity), bitsizetype); + + 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 value. 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 (Renamed_Object (gnat_entity)) + && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type))) + { + if (gnu_expr && kind == E_Constant) + { + tree size = TYPE_SIZE (TREE_TYPE (gnu_expr)); + if (CONTAINS_PLACEHOLDER_P (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 + && TREE_CODE (TREE_TYPE (TREE_OPERAND (gnu_expr, 0))) + == RECORD_TYPE + && 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)); + else + gnu_size + = SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, gnu_expr); + } + else + gnu_size = size; + } + /* We may have no GNU_EXPR because No_Initialization is + set even though there's an Expression. */ + else if (kind == E_Constant + && (Nkind (Declaration_Node (gnat_entity)) + == N_Object_Declaration) + && Present (Expression (Declaration_Node (gnat_entity)))) + gnu_size + = TYPE_SIZE (gnat_to_gnu_type + (Etype + (Expression (Declaration_Node (gnat_entity))))); + else + { + gnu_size = max_size (TYPE_SIZE (gnu_type), true); + mutable_p = true; + } + } + + /* If the size is zero bytes, make it one byte since some linkers have + trouble 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 (Etype (gnat_entity)) + || !Is_Array_Type (Etype (gnat_entity))) + && !Present (Renamed_Object (gnat_entity)) + && !Present (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 atomic 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 (!gnu_size && align == 0 + && (Is_Atomic (gnat_entity) + || (!Optimize_Alignment_Space (gnat_entity) + && kind != E_Exception + && kind != E_Out_Parameter + && Is_Composite_Type (Etype (gnat_entity)) + && !Is_Constr_Subt_For_UN_Aliased (Etype (gnat_entity)) + && !imported_p + && No (Renamed_Object (gnat_entity)) + && No (Address_Clause (gnat_entity)))) + && TREE_CODE (TYPE_SIZE (gnu_type)) == INTEGER_CST) + { + /* No point in jumping through all the hoops needed in order + to support BIGGEST_ALIGNMENT if we don't really have to. */ + unsigned int align_cap = Is_Atomic (gnat_entity) + ? BIGGEST_ALIGNMENT + : get_mode_alignment (word_mode); + + if (!host_integerp (TYPE_SIZE (gnu_type), 1) + || compare_tree_int (TYPE_SIZE (gnu_type), align_cap) >= 0) + align = align_cap; + else + align = ceil_alignment (tree_low_cst (TYPE_SIZE (gnu_type), 1)); + + /* 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 + } + + /* 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 (gnu_inner, gnat_entity, true); + } + + /* Now check if the type of the object allows atomic access. Note + that we must test the type, even if this object has size and + alignment to allow such access, because we will be going + inside the padded record to assign to the object. We could fix + this by always copying via an intermediate value, but it's not + clear it's worth the effort. */ + if (Is_Atomic (gnat_entity)) + check_ok_for_atomic (gnu_type, gnat_entity, false); + + /* If this is an aliased object with an unconstrained nominal subtype, + make a type that includes the template. */ + if (Is_Constr_Subt_For_UN_Aliased (Etype (gnat_entity)) + && Is_Array_Type (Etype (gnat_entity)) + && !type_annotate_only) + { + tree gnu_fat + = TREE_TYPE (gnat_to_gnu_type (Base_Type (Etype (gnat_entity)))); + + gnu_type + = build_unc_object_type_from_ptr (gnu_fat, gnu_type, + concat_id_with_name (gnu_entity_id, + "UNC")); + } + +#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 (Renamed_Object (gnat_entity)) + && !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 + + /* Make a new type with the desired size and alignment, if needed. + But do not take into account alignment promotions to compute the + size of the object. */ + gnu_object_size = gnu_size ? gnu_size : TYPE_SIZE (gnu_type); + if (gnu_size || align > 0) + gnu_type = maybe_pad_type (gnu_type, gnu_size, align, gnat_entity, + "PAD", false, definition, + gnu_size ? true : false); + + /* Make a volatile version of this object's type if we are to make + the object volatile. We also interpret 13.3(19) conservatively + and disallow any optimizations for an object covered by it. */ + if ((Treat_As_Volatile (gnat_entity) + || (Is_Exported (gnat_entity) + /* Exclude exported constants created by the compiler, + which should boil down to static dispatch tables and + make it possible to put them in read-only memory. */ + && (Comes_From_Source (gnat_entity) || !const_flag)) + || Is_Imported (gnat_entity) + || Present (Address_Clause (gnat_entity))) + && !TYPE_VOLATILE (gnu_type)) + gnu_type = build_qualified_type (gnu_type, + (TYPE_QUALS (gnu_type) + | TYPE_QUAL_VOLATILE)); + + /* If this is a renaming, avoid as much as possible to create a new + object. However, in several cases, creating it is required. + This processing needs to be applied to the raw expression so + as to make it more likely to rename the underlying object. */ + if (Present (Renamed_Object (gnat_entity))) + { + bool create_normal_object = false; + + /* 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 + && TREE_CODE (TREE_TYPE (TREE_OPERAND (gnu_expr, 0))) + == RECORD_TYPE + && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (gnu_expr, 0)))) + /* Strip useless conversions around the object. */ + || TREE_CODE (gnu_expr) == NOP_EXPR) + { + gnu_expr = TREE_OPERAND (gnu_expr, 0); + gnu_type = TREE_TYPE (gnu_expr); + } + + /* Case 1: 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. As a consequence, it can + be the inner object of a constant renaming. In this case, the + renaming must be fully instantiated, i.e. it cannot be a mere + reference to (part of) an existing object. */ + if (const_flag) + { + tree inner_object = gnu_expr; + while (handled_component_p (inner_object)) + inner_object = TREE_OPERAND (inner_object, 0); + if (TREE_CODE (inner_object) == CALL_EXPR) + create_normal_object = true; + } + + /* Otherwise, see if we can proceed with a stabilized version of + the renamed entity or if we need to make a new object. */ + if (!create_normal_object) + { + tree maybe_stable_expr = NULL_TREE; + bool stable = false; + + /* Case 2: If the renaming entity need not be materialized and + the renamed expression is something we can stabilize, use + that for the renaming. At the global level, we can only do + this if we know no SAVE_EXPRs need be made, because the + expression we return might be used in arbitrary conditional + branches so we must force the SAVE_EXPRs evaluation + immediately and this requires a function context. */ + if (!Materialize_Entity (gnat_entity) + && (!global_bindings_p () + || (staticp (gnu_expr) + && !TREE_SIDE_EFFECTS (gnu_expr)))) + { + maybe_stable_expr + = maybe_stabilize_reference (gnu_expr, true, &stable); + + if (stable) + { + gnu_decl = maybe_stable_expr; + /* ??? No DECL_EXPR is created so we need to mark + the expression manually lest it is shared. */ + if (global_bindings_p ()) + mark_visited (&gnu_decl); + save_gnu_tree (gnat_entity, gnu_decl, true); + saved = true; + break; + } + + /* The stabilization failed. Keep maybe_stable_expr + untouched here to let the pointer case below know + about that failure. */ + } + + /* Case 3: If this is a constant renaming and creating a + new object is allowed and cheap, treat it as a normal + object whose initial value is what is being renamed. */ + if (const_flag && Is_Elementary_Type (Etype (gnat_entity))) + ; + + /* Case 4: Make this into a constant pointer to the object we + are to rename and attach the object to the pointer if it is + something we can stabilize. + + From the proper scope, attached objects will be referenced + directly instead of indirectly via the pointer to avoid + subtle aliasing problems with non-addressable entities. + They have to be stable because we must not evaluate the + variables in the expression every time the renaming is used. + The pointer is called a "renaming" pointer in this case. + + In the rare cases where we cannot stabilize the renamed + object, we just make a "bare" pointer, and the renamed + entity is always accessed indirectly through it. */ + else + { + gnu_type = build_reference_type (gnu_type); + inner_const_flag = TREE_READONLY (gnu_expr); + const_flag = true; + + /* If the previous attempt at stabilizing failed, there + is no point in trying again and we reuse the result + without attaching it to the pointer. In this case it + will only be used as the initializing expression of + the pointer and thus needs no special treatment with + regard to multiple evaluations. */ + if (maybe_stable_expr) + ; + + /* Otherwise, try to stabilize and attach the expression + to the pointer if the stabilization succeeds. + + Note that this might introduce SAVE_EXPRs and we don't + check whether we're at the global level or not. This + is fine since we are building a pointer initializer and + neither the pointer nor the initializing expression can + be accessed before the pointer elaboration has taken + place in a correct program. + + These SAVE_EXPRs will be evaluated at the right place + by either the evaluation of the initializer for the + non-global case or the elaboration code for the global + case, and will be attached to the elaboration procedure + in the latter case. */ + else + { + maybe_stable_expr + = maybe_stabilize_reference (gnu_expr, true, &stable); + + if (stable) + renamed_obj = maybe_stable_expr; + + /* Attaching is actually performed downstream, as soon + as we have a VAR_DECL for the pointer we make. */ + } + + gnu_expr + = build_unary_op (ADDR_EXPR, gnu_type, maybe_stable_expr); + + gnu_size = NULL_TREE; + used_by_ref = true; + } + } + } + + /* If this is 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. */ + else if (definition + && TREE_CODE (gnu_type) == RECORD_TYPE + && (TYPE_CONTAINS_TEMPLATE_P (gnu_type) + /* Beware that padding might have been introduced + via maybe_pad_type above. */ + || (TYPE_IS_PADDING_P (gnu_type) + && TREE_CODE (TREE_TYPE (TYPE_FIELDS (gnu_type))) + == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P + (TREE_TYPE (TYPE_FIELDS (gnu_type))))) + && !gnu_expr) + { + tree template_field + = TYPE_IS_PADDING_P (gnu_type) + ? TYPE_FIELDS (TREE_TYPE (TYPE_FIELDS (gnu_type))) + : TYPE_FIELDS (gnu_type); + + gnu_expr + = gnat_build_constructor + (gnu_type, + tree_cons + (template_field, + build_template (TREE_TYPE (template_field), + TREE_TYPE (TREE_CHAIN (template_field)), + NULL_TREE), + NULL_TREE)); + } + + /* Convert the expression to the type of the object except in the + case where the object's type is unconstrained or the object's type + is a padded record whose field is of self-referential size. In + the former case, converting will generate unnecessary evaluations + of the CONSTRUCTOR to compute the size and in the latter case, we + want to only copy the actual data. */ + if (gnu_expr + && TREE_CODE (gnu_type) != UNCONSTRAINED_ARRAY_TYPE + && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type)) + && !(TREE_CODE (gnu_type) == RECORD_TYPE + && TYPE_IS_PADDING_P (gnu_type) + && (CONTAINS_PLACEHOLDER_P + (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS (gnu_type))))))) + gnu_expr = convert (gnu_type, gnu_expr); + + /* If this is a pointer and it does not have an initializing + expression, initialize it to NULL, unless the object is + imported. */ + if (definition + && (POINTER_TYPE_P (gnu_type) || TYPE_FAT_POINTER_P (gnu_type)) + && !Is_Imported (gnat_entity) && !gnu_expr) + gnu_expr = integer_zero_node; + + /* If we are defining the object and it has an Address clause we must + get the address expression from the saved GCC tree for the + object if the object 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. Note that + only the latter mechanism is currently in use. */ + if (definition && Present (Address_Clause (gnat_entity))) + { + tree 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); + + /* Ignore the size. It's either meaningless or was handled + above. */ + gnu_size = NULL_TREE; + /* Convert the type of the object to a reference type that can + alias everything as per 13.3(19). */ + 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 (Expression (Address_Clause + (gnat_entity))); + + /* 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 + (MODIFY_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))) + || (Is_Imported (gnat_entity) + && Has_Stdcall_Convention (gnat_entity))) + { + /* Convert the type of the object to a reference type that can + alias everything as per 13.3(19). */ + gnu_type + = build_reference_type_for_mode (gnu_type, ptr_mode, true); + 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; + } + } + + used_by_ref = 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_p) + || (gnu_size + && ! allocatable_size_p (gnu_size, + global_bindings_p () || !definition + || static_p))) + { + gnu_type = build_reference_type (gnu_type); + gnu_size = NULL_TREE; + used_by_ref = true; + const_flag = true; + + /* 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) + { + 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 (TREE_CHAIN (TYPE_FIELDS (gnu_alloc_type))); + + if (TREE_CODE (gnu_expr) == CONSTRUCTOR + && 1 == VEC_length (constructor_elt, + CONSTRUCTOR_ELTS (gnu_expr))) + gnu_expr = 0; + else + gnu_expr + = build_component_ref + (gnu_expr, NULL_TREE, + TREE_CHAIN (TYPE_FIELDS (TREE_TYPE (gnu_expr))), + false); + } + + if (TREE_CODE (TYPE_SIZE_UNIT (gnu_alloc_type)) == INTEGER_CST + && TREE_OVERFLOW (TYPE_SIZE_UNIT (gnu_alloc_type)) + && !Is_Imported (gnat_entity)) + post_error ("?Storage_Error will be raised at run-time!", + gnat_entity); + + gnu_expr = build_allocator (gnu_alloc_type, gnu_expr, gnu_type, + 0, 0, gnat_entity, mutable_p); + } + else + { + gnu_expr = NULL_TREE; + const_flag = false; + } + } + + /* 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 (!global_bindings_p () && !static_p && definition + && !imported_p && TYPE_ALIGN (gnu_type) > BIGGEST_ALIGNMENT) + { + /* 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); + tree gnu_new_var + = create_var_decl (create_concat_name (gnat_entity, "ALIGN"), + NULL_TREE, gnu_new_type, NULL_TREE, false, + false, false, false, NULL, gnat_entity); + + /* Initialize the aligned field if we have an initializer. */ + if (gnu_expr) + add_stmt_with_node + (build_binary_op (MODIFY_EXPR, NULL_TREE, + build_component_ref + (gnu_new_var, NULL_TREE, + 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, gnu_type, + build_component_ref (gnu_new_var, NULL_TREE, + TYPE_FIELDS (gnu_new_type), false)); + + gnu_size = NULL_TREE; + used_by_ref = true; + const_flag = true; + } + + if (const_flag) + gnu_type = build_qualified_type (gnu_type, (TYPE_QUALS (gnu_type) + | TYPE_QUAL_CONST)); + + /* Convert the expression to the type of the object except in the + case where the object's type is unconstrained or the object's type + is a padded record whose field is of self-referential size. In + the former case, converting will generate unnecessary evaluations + of the CONSTRUCTOR to compute the size and in the latter case, we + want to only copy the actual data. */ + if (gnu_expr + && TREE_CODE (gnu_type) != UNCONSTRAINED_ARRAY_TYPE + && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type)) + && !(TREE_CODE (gnu_type) == RECORD_TYPE + && TYPE_IS_PADDING_P (gnu_type) + && (CONTAINS_PLACEHOLDER_P + (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS (gnu_type))))))) + gnu_expr = convert (gnu_type, gnu_expr); + + /* If this name is external or there was a name specified, use it, + unless this is a VMS exception object since this would conflict + with the symbol we need to export in addition. Don't use the + Interface_Name if there is an address clause (see CD30005). */ + if (!Is_VMS_Exception (gnat_entity) + && ((Present (Interface_Name (gnat_entity)) + && No (Address_Clause (gnat_entity))) + || (Is_Public (gnat_entity) + && (!Is_Imported (gnat_entity) + || Is_Exported (gnat_entity))))) + gnu_ext_name = create_concat_name (gnat_entity, 0); + + /* If this is constant initialized to a static constant and the + object has an aggregate type, force it to be statically + allocated. */ + if (const_flag && gnu_expr && TREE_CONSTANT (gnu_expr) + && host_integerp (TYPE_SIZE_UNIT (gnu_type), 1) + && (AGGREGATE_TYPE_P (gnu_type) + && !(TREE_CODE (gnu_type) == RECORD_TYPE + && TYPE_IS_PADDING_P (gnu_type)))) + static_p = true; + + gnu_decl = create_var_decl (gnu_entity_id, gnu_ext_name, gnu_type, + gnu_expr, const_flag, + Is_Public (gnat_entity), + imported_p || !definition, + static_p, 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; + if (TREE_CODE (gnu_decl) == VAR_DECL && renamed_obj) + { + SET_DECL_RENAMED_OBJECT (gnu_decl, renamed_obj); + if (global_bindings_p ()) + { + DECL_RENAMING_GLOBAL_P (gnu_decl) = 1; + record_global_renaming_pointer (gnu_decl); + } + } + + if (definition && DECL_SIZE (gnu_decl) + && get_block_jmpbuf_decl () + && (TREE_CODE (DECL_SIZE (gnu_decl)) != INTEGER_CST + || (flag_stack_check && !STACK_CHECK_BUILTIN + && 0 < compare_tree_int (DECL_SIZE_UNIT (gnu_decl), + STACK_CHECK_MAX_VAR_SIZE)))) + add_stmt_with_node (build_call_1_expr + (update_setjmp_buf_decl, + build_unary_op (ADDR_EXPR, NULL_TREE, + get_block_jmpbuf_decl ())), + gnat_entity); + + /* If this is a public constant or we're not optimizing and we're not + making a VAR_DECL for it, make one just for export or debugger use. + Likewise if the address is taken or if either the object or type is + aliased. Make an external declaration for a reference, unless this + is a Standard entity since there no real symbol at the object level + for these. */ + if (TREE_CODE (gnu_decl) == CONST_DECL + && (definition || Sloc (gnat_entity) > Standard_Location) + && ((Is_Public (gnat_entity) + && !Present (Address_Clause (gnat_entity))) + || optimize == 0 + || Address_Taken (gnat_entity) + || Is_Aliased (gnat_entity) + || Is_Aliased (Etype (gnat_entity)))) + { + tree gnu_corr_var + = create_true_var_decl (gnu_entity_id, gnu_ext_name, gnu_type, + gnu_expr, true, Is_Public (gnat_entity), + !definition, static_p, NULL, + gnat_entity); + + SET_DECL_CONST_CORRESPONDING_VAR (gnu_decl, gnu_corr_var); + + /* As debugging information will be generated for the variable, + do not generate information for the constant. */ + DECL_IGNORED_P (gnu_decl) = true; + } + + /* If this is declared in a block that contains a block with an + exception handler, we must force this variable in memory to + suppress an invalid optimization. */ + if (Has_Nested_Block_With_Handler (Scope (gnat_entity)) + && Exception_Mechanism != Back_End_Exceptions) + TREE_ADDRESSABLE (gnu_decl) = 1; + + gnu_type = TREE_TYPE (gnu_decl); + + /* Back-annotate Alignment and Esize of the object if not already + known, except for when the object is actually a pointer to the + real object, since alignment and size of a pointer don't have + anything to do with those of the designated object. 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 confirming representation clauses in all cases. */ + + if (!used_by_ref && Unknown_Alignment (gnat_entity)) + Set_Alignment (gnat_entity, + UI_From_Int (TYPE_ALIGN (gnu_type) / BITS_PER_UNIT)); + + if (!used_by_ref && Unknown_Esize (gnat_entity)) + { + if (TREE_CODE (gnu_type) == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P (gnu_type)) + gnu_object_size + = TYPE_SIZE (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (gnu_type)))); + + Set_Esize (gnat_entity, annotate_value (gnu_object_size)); + } + } + break; + + case E_Void: + /* Return a TYPE_DECL for "void" that we previously made. */ + gnu_decl = void_type_decl_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 unsigned type. */ + if (No (First_Literal (gnat_entity))) + { + gnu_type = make_unsigned_type (esize); + TYPE_NAME (gnu_type) = gnu_entity_id; + + /* Set the TYPE_STRING_FLAG for Ada Character and + Wide_Character types. This is needed by the dwarf-2 debug writer to + distinguish between unsigned integer types and character types. */ + TYPE_STRING_FLAG (gnu_type) = 1; + break; + } + + /* Normal case of non-character type, or non-Standard character type */ + { + /* Here we have a list of enumeral constants in First_Literal. + We make a CONST_DECL for each and build into GNU_LITERAL_LIST + the list to be places into TYPE_FIELDS. Each node in the list + is a TREE_LIST node whose TREE_VALUE is the literal name + and whose TREE_PURPOSE is the value of the literal. + + Esize contains the number of bits needed to represent the enumeral + type, Type_Low_Bound also points to the first literal and + Type_High_Bound points to the last literal. */ + + Entity_Id gnat_literal; + tree gnu_literal_list = NULL_TREE; + + if (Is_Unsigned_Type (gnat_entity)) + gnu_type = make_unsigned_type (esize); + else + gnu_type = make_signed_type (esize); + + TREE_SET_CODE (gnu_type, ENUMERAL_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); + tree gnu_literal + = create_var_decl (get_entity_name (gnat_literal), NULL_TREE, + gnu_type, gnu_value, true, false, false, + false, NULL, gnat_literal); + + save_gnu_tree (gnat_literal, gnu_literal, false); + gnu_literal_list = tree_cons (DECL_NAME (gnu_literal), + gnu_value, gnu_literal_list); + } + + TYPE_VALUES (gnu_type) = nreverse (gnu_literal_list); + + /* Note that the bounds are updated at the end of this function + because to avoid an infinite recursion when we get the bounds of + this type, since those bounds are objects of this type. */ + } + break; + + case E_Signed_Integer_Type: + case E_Ordinary_Fixed_Point_Type: + case E_Decimal_Fixed_Point_Type: + /* For integer types, just make a signed type the appropriate number + of bits. */ + gnu_type = make_signed_type (esize); + break; + + case E_Modular_Integer_Type: + /* For modular types, make the unsigned type of the proper number of + bits and then set up the modulus, if required. */ + { + enum machine_mode mode; + tree gnu_modulus; + tree gnu_high = 0; + + if (Is_Packed_Array_Type (gnat_entity)) + esize = UI_To_Int (RM_Size (gnat_entity)); + + /* Find the smallest mode at least ESIZE bits wide and make a class + using that mode. */ + + for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT); + GET_MODE_BITSIZE (mode) < esize; + mode = GET_MODE_WIDER_MODE (mode)) + ; + + gnu_type = make_unsigned_type (GET_MODE_BITSIZE (mode)); + TYPE_PACKED_ARRAY_TYPE_P (gnu_type) + = (Is_Packed_Array_Type (gnat_entity) + && Is_Bit_Packed_Array (Original_Array_Type (gnat_entity))); + + /* Get the modulus in this type. If it overflows, assume it is because + it is equal to 2**Esize. Note that there is no overflow checking + done on unsigned type, so we detect the overflow by looking for + a modulus of zero, which is otherwise invalid. */ + gnu_modulus = UI_To_gnu (Modulus (gnat_entity), gnu_type); + + if (!integer_zerop (gnu_modulus)) + { + TYPE_MODULAR_P (gnu_type) = 1; + SET_TYPE_MODULUS (gnu_type, gnu_modulus); + gnu_high = fold_build2 (MINUS_EXPR, gnu_type, gnu_modulus, + convert (gnu_type, integer_one_node)); + } + + /* If we have to set TYPE_PRECISION different from its natural value, + make a subtype to do do. Likewise if there is a modulus and + it is not one greater than TYPE_MAX_VALUE. */ + if (TYPE_PRECISION (gnu_type) != esize + || (TYPE_MODULAR_P (gnu_type) + && !tree_int_cst_equal (TYPE_MAX_VALUE (gnu_type), gnu_high))) + { + tree gnu_subtype = make_node (INTEGER_TYPE); + + TYPE_NAME (gnu_type) = create_concat_name (gnat_entity, "UMT"); + TREE_TYPE (gnu_subtype) = gnu_type; + TYPE_MIN_VALUE (gnu_subtype) = TYPE_MIN_VALUE (gnu_type); + TYPE_MAX_VALUE (gnu_subtype) + = TYPE_MODULAR_P (gnu_type) + ? gnu_high : TYPE_MAX_VALUE (gnu_type); + TYPE_PRECISION (gnu_subtype) = esize; + TYPE_UNSIGNED (gnu_subtype) = 1; + TYPE_EXTRA_SUBTYPE_P (gnu_subtype) = 1; + TYPE_PACKED_ARRAY_TYPE_P (gnu_subtype) + = (Is_Packed_Array_Type (gnat_entity) + && Is_Bit_Packed_Array (Original_Array_Type (gnat_entity))); + layout_type (gnu_subtype); + + gnu_type = gnu_subtype; + } + } + break; + + 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 build_range_type since we would + like each subtype node to be distinct. This will be important + when memory aliasing is implemented. + + The TREE_TYPE field of the INTEGER_TYPE we make points to the + parent 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 always 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, 0); + + gnu_type = make_node (INTEGER_TYPE); + if (Is_Packed_Array_Type (gnat_entity) + && Is_Bit_Packed_Array (Original_Array_Type (gnat_entity))) + { + esize = UI_To_Int (RM_Size (gnat_entity)); + TYPE_PACKED_ARRAY_TYPE_P (gnu_type) = 1; + } + + TYPE_PRECISION (gnu_type) = esize; + TREE_TYPE (gnu_type) = get_unpadded_type (Etype (gnat_entity)); + + TYPE_MIN_VALUE (gnu_type) + = convert (TREE_TYPE (gnu_type), + elaborate_expression (Type_Low_Bound (gnat_entity), + gnat_entity, + get_identifier ("L"), definition, 1, + Needs_Debug_Info (gnat_entity))); + + TYPE_MAX_VALUE (gnu_type) + = convert (TREE_TYPE (gnu_type), + elaborate_expression (Type_High_Bound (gnat_entity), + gnat_entity, + get_identifier ("U"), definition, 1, + Needs_Debug_Info (gnat_entity))); + + /* 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; + } + + TYPE_BIASED_REPRESENTATION_P (gnu_type) + = Has_Biased_Representation (gnat_entity); + + /* This should be an unsigned type if the lower bound is constant + and non-negative or if the base type is unsigned; a signed type + otherwise. */ + TYPE_UNSIGNED (gnu_type) + = (TYPE_UNSIGNED (TREE_TYPE (gnu_type)) + || (TREE_CODE (TYPE_MIN_VALUE (gnu_type)) == INTEGER_CST + && TREE_INT_CST_HIGH (TYPE_MIN_VALUE (gnu_type)) >= 0) + || TYPE_BIASED_REPRESENTATION_P (gnu_type) + || Is_Unsigned_Type (gnat_entity)); + + layout_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. */ + copy_alias_set (gnu_type, TREE_TYPE (gnu_type)); + + /* If the type we are dealing with is to represent a 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 the + modular value in an enclosing struct. */ + if (Is_Packed_Array_Type (gnat_entity) + && Is_Bit_Packed_Array (Original_Array_Type (gnat_entity))) + { + tree gnu_field_type = gnu_type; + tree gnu_field; + + TYPE_RM_SIZE_NUM (gnu_field_type) + = UI_To_gnu (RM_Size (gnat_entity), bitsizetype); + gnu_type = make_node (RECORD_TYPE); + TYPE_NAME (gnu_type) = create_concat_name (gnat_entity, "JM"); + + /* Propagate the alignment of the modular type to the record. + This means that bitpacked arrays have "ceil" alignment for + their size, which may seem counter-intuitive but makes it + possible to easily overlay them on modular types. */ + TYPE_ALIGN (gnu_type) = TYPE_ALIGN (gnu_field_type); + TYPE_PACKED (gnu_type) = 1; + + /* Create a stripped-down declaration of the original type, mainly + for debugging. */ + create_type_decl (get_entity_name (gnat_entity), gnu_field_type, + NULL, true, debug_info_p, gnat_entity); + + /* Don't notify the field as "addressable", since we won't be taking + it's address and it would prevent create_field_decl from making a + bitfield. */ + gnu_field = create_field_decl (get_identifier ("OBJECT"), + gnu_field_type, gnu_type, 1, 0, 0, 0); + + finish_record_type (gnu_type, gnu_field, 0, false); + TYPE_JUSTIFIED_MODULAR_P (gnu_type) = 1; + SET_TYPE_ADA_SIZE (gnu_type, bitsize_int (esize)); + + copy_alias_set (gnu_type, gnu_field_type); + } + + /* 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 under-align + the latter. We reuse the padding machinery for this purpose. */ + else if (Known_Alignment (gnat_entity) + && UI_Is_In_Int_Range (Alignment (gnat_entity)) + && (align = UI_To_Int (Alignment (gnat_entity)) * BITS_PER_UNIT) + && align < TYPE_ALIGN (gnu_type)) + { + tree gnu_field_type = gnu_type; + tree gnu_field; + + gnu_type = make_node (RECORD_TYPE); + TYPE_NAME (gnu_type) = create_concat_name (gnat_entity, "PAD"); + + TYPE_ALIGN (gnu_type) = align; + TYPE_PACKED (gnu_type) = 1; + + /* Create a stripped-down declaration of the original type, mainly + for debugging. */ + create_type_decl (get_entity_name (gnat_entity), gnu_field_type, + NULL, true, debug_info_p, gnat_entity); + + /* Don't notify the field as "addressable", since we won't be taking + it's address and it would prevent create_field_decl from making a + bitfield. */ + gnu_field = create_field_decl (get_identifier ("OBJECT"), + gnu_field_type, gnu_type, 1, 0, 0, 0); + + finish_record_type (gnu_type, gnu_field, 0, false); + TYPE_IS_PADDING_P (gnu_type) = 1; + SET_TYPE_ADA_SIZE (gnu_type, bitsize_int (esize)); + + copy_alias_set (gnu_type, gnu_field_type); + } + + /* Otherwise reset the alignment lest we computed it above. */ + else + align = 0; + + break; + + case E_Floating_Point_Type: + /* If this is a VAX floating-point type, use an integer of the proper + size. All the operations will be handled with ASM statements. */ + if (Vax_Float (gnat_entity)) + { + gnu_type = make_signed_type (esize); + TYPE_VAX_FLOATING_POINT_P (gnu_type) = 1; + SET_TYPE_DIGITS_VALUE (gnu_type, + UI_To_gnu (Digits_Value (gnat_entity), + sizetype)); + break; + } + + /* 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: + if (Vax_Float (gnat_entity)) + { + gnu_type = gnat_to_gnu_type (Etype (gnat_entity)); + break; + } + + { + 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, 0); + + 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_MIN_VALUE (gnu_type) + = convert (TREE_TYPE (gnu_type), + elaborate_expression (Type_Low_Bound (gnat_entity), + gnat_entity, get_identifier ("L"), + definition, 1, + Needs_Debug_Info (gnat_entity))); + + TYPE_MAX_VALUE (gnu_type) + = convert (TREE_TYPE (gnu_type), + elaborate_expression (Type_High_Bound (gnat_entity), + gnat_entity, get_identifier ("U"), + definition, 1, + Needs_Debug_Info (gnat_entity))); + + /* 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; + } + + layout_type (gnu_type); + + /* Inherit our alias set from what we're a subtype of, as for + integer subtypes. */ + copy_alias_set (gnu_type, TREE_TYPE (gnu_type)); + } + break; + + /* Array and String Types and Subtypes + + Unconstrained array types are represented by E_Array_Type and + constrained array types are represented by E_Array_Subtype. There + are no actual objects of an unconstrained array type; all we have + are pointers to that type. + + The following fields are defined on array types and subtypes: + + Component_Type Component type of the array. + Number_Dimensions Number of dimensions (an int). + First_Index Type of first index. */ + + case E_String_Type: + case E_Array_Type: + { + tree gnu_template_fields = NULL_TREE; + tree gnu_template_type = make_node (RECORD_TYPE); + tree gnu_ptr_template = build_pointer_type (gnu_template_type); + tree gnu_fat_type = make_node (RECORD_TYPE); + int ndim = Number_Dimensions (gnat_entity); + int firstdim + = (Convention (gnat_entity) == Convention_Fortran) ? ndim - 1 : 0; + int nextdim + = (Convention (gnat_entity) == Convention_Fortran) ? - 1 : 1; + int index; + tree *gnu_index_types = (tree *) alloca (ndim * sizeof (tree *)); + tree *gnu_temp_fields = (tree *) alloca (ndim * sizeof (tree *)); + tree gnu_comp_size = 0; + tree gnu_max_size = size_one_node; + tree gnu_max_size_unit; + Entity_Id gnat_ind_subtype; + Entity_Id gnat_ind_base_subtype; + tree gnu_template_reference; + tree tem; + + TYPE_NAME (gnu_template_type) + = create_concat_name (gnat_entity, "XUB"); + + /* 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). */ + tem = chainon (chainon (NULL_TREE, + create_field_decl (get_identifier ("P_ARRAY"), + ptr_void_type_node, + gnu_fat_type, 0, 0, 0, 0)), + create_field_decl (get_identifier ("P_BOUNDS"), + gnu_ptr_template, + gnu_fat_type, 0, 0, 0, 0)); + + /* Make sure we can put this into a register. */ + TYPE_ALIGN (gnu_fat_type) = MIN (BIGGEST_ALIGNMENT, 2 * POINTER_SIZE); + + /* Do not finalize this record type since the types of its fields + are still incomplete at this point. */ + finish_record_type (gnu_fat_type, tem, 0, true); + TYPE_IS_FAT_POINTER_P (gnu_fat_type) = 1; + + /* 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), + TREE_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; + + /* Now create the GCC type for each index and add the fields for + that index to the template. */ + for (index = firstdim, gnat_ind_subtype = First_Index (gnat_entity), + gnat_ind_base_subtype + = First_Index (Implementation_Base_Type (gnat_entity)); + index < ndim && index >= 0; + index += nextdim, + gnat_ind_subtype = Next_Index (gnat_ind_subtype), + gnat_ind_base_subtype = Next_Index (gnat_ind_base_subtype)) + { + char field_name[10]; + tree gnu_ind_subtype + = get_unpadded_type (Base_Type (Etype (gnat_ind_subtype))); + tree gnu_base_subtype + = get_unpadded_type (Etype (gnat_ind_base_subtype)); + tree gnu_base_min + = convert (sizetype, TYPE_MIN_VALUE (gnu_base_subtype)); + tree gnu_base_max + = convert (sizetype, TYPE_MAX_VALUE (gnu_base_subtype)); + tree gnu_min_field, gnu_max_field, gnu_min, gnu_max; + + /* Make the FIELD_DECLs for the minimum and maximum of this + type and then make extractions of that field from the + template. */ + sprintf (field_name, "LB%d", index); + gnu_min_field = create_field_decl (get_identifier (field_name), + gnu_ind_subtype, + gnu_template_type, 0, 0, 0, 0); + field_name[0] = 'U'; + gnu_max_field = create_field_decl (get_identifier (field_name), + gnu_ind_subtype, + gnu_template_type, 0, 0, 0, 0); + + Sloc_to_locus (Sloc (gnat_entity), + &DECL_SOURCE_LOCATION (gnu_min_field)); + Sloc_to_locus (Sloc (gnat_entity), + &DECL_SOURCE_LOCATION (gnu_max_field)); + gnu_temp_fields[index] = chainon (gnu_min_field, gnu_max_field); + + /* We can't use build_component_ref here since the template + type isn't complete yet. */ + gnu_min = build3 (COMPONENT_REF, gnu_ind_subtype, + gnu_template_reference, gnu_min_field, + NULL_TREE); + gnu_max = build3 (COMPONENT_REF, gnu_ind_subtype, + gnu_template_reference, gnu_max_field, + NULL_TREE); + TREE_READONLY (gnu_min) = TREE_READONLY (gnu_max) = 1; + + /* Make a range type with the new ranges, but using + the Ada subtype. Then we convert to sizetype. */ + gnu_index_types[index] + = create_index_type (convert (sizetype, gnu_min), + convert (sizetype, gnu_max), + build_range_type (gnu_ind_subtype, + gnu_min, gnu_max), + gnat_entity); + /* Update the maximum size of the array, in elements. */ + gnu_max_size + = size_binop (MULT_EXPR, gnu_max_size, + size_binop (PLUS_EXPR, size_one_node, + size_binop (MINUS_EXPR, gnu_base_max, + gnu_base_min))); + + TYPE_NAME (gnu_index_types[index]) + = create_concat_name (gnat_entity, field_name); + } + + for (index = 0; index < ndim; index++) + gnu_template_fields + = chainon (gnu_template_fields, gnu_temp_fields[index]); + + /* Install all the fields into the template. */ + finish_record_type (gnu_template_type, gnu_template_fields, 0, false); + TYPE_READONLY (gnu_template_type) = 1; + + /* Now make the array of arrays and update the pointer to the array + in the fat pointer. Note that it is the first field. */ + tem = gnat_to_gnu_type (Component_Type (gnat_entity)); + + /* Try to get a smaller form of the component if needed. */ + if ((Is_Packed (gnat_entity) + || Has_Component_Size_Clause (gnat_entity)) + && !Is_Bit_Packed_Array (gnat_entity) + && !Has_Aliased_Components (gnat_entity) + && !Strict_Alignment (Component_Type (gnat_entity)) + && TREE_CODE (tem) == RECORD_TYPE + && host_integerp (TYPE_SIZE (tem), 1)) + tem = make_packable_type (tem, false); + + if (Has_Atomic_Components (gnat_entity)) + check_ok_for_atomic (tem, gnat_entity, true); + + /* Get and validate any specified Component_Size, but if Packed, + ignore it since the front end will have taken care of it. */ + gnu_comp_size + = validate_size (Component_Size (gnat_entity), tem, + gnat_entity, + (Is_Bit_Packed_Array (gnat_entity) + ? TYPE_DECL : VAR_DECL), + true, Has_Component_Size_Clause (gnat_entity)); + + /* If the component type is a RECORD_TYPE that has a self-referential + size, use the maxium size. */ + if (!gnu_comp_size && TREE_CODE (tem) == RECORD_TYPE + && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (tem))) + gnu_comp_size = max_size (TYPE_SIZE (tem), true); + + if (gnu_comp_size && !Is_Bit_Packed_Array (gnat_entity)) + { + tree orig_tem; + tem = make_type_from_size (tem, gnu_comp_size, false); + orig_tem = tem; + tem = maybe_pad_type (tem, gnu_comp_size, 0, gnat_entity, + "C_PAD", 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 (tem != orig_tem) + create_type_decl (TYPE_NAME (tem), tem, NULL, true, false, + gnat_entity); + } + + if (Has_Volatile_Components (gnat_entity)) + tem = build_qualified_type (tem, + TYPE_QUALS (tem) | TYPE_QUAL_VOLATILE); + + /* If Component_Size is not already specified, annotate it with the + size of the component. */ + if (Unknown_Component_Size (gnat_entity)) + Set_Component_Size (gnat_entity, annotate_value (TYPE_SIZE (tem))); + + gnu_max_size_unit = size_binop (MAX_EXPR, size_zero_node, + size_binop (MULT_EXPR, gnu_max_size, + TYPE_SIZE_UNIT (tem))); + gnu_max_size = size_binop (MAX_EXPR, bitsize_zero_node, + size_binop (MULT_EXPR, + convert (bitsizetype, + gnu_max_size), + TYPE_SIZE (tem))); + + for (index = ndim - 1; index >= 0; index--) + { + tem = build_array_type (tem, gnu_index_types[index]); + TYPE_MULTI_ARRAY_P (tem) = (index > 0); + if (array_type_has_nonaliased_component (gnat_entity, tem)) + TYPE_NONALIASED_COMPONENT (tem) = 1; + } + + /* If an alignment is specified, use it if valid. But ignore it for + types that represent the unpacked base type for packed arrays. If + the alignment was requested with an explicit user alignment clause, + state so. */ + if (No (Packed_Array_Type (gnat_entity)) + && Known_Alignment (gnat_entity)) + { + gcc_assert (Present (Alignment (gnat_entity))); + TYPE_ALIGN (tem) + = validate_alignment (Alignment (gnat_entity), gnat_entity, + TYPE_ALIGN (tem)); + if (Present (Alignment_Clause (gnat_entity))) + TYPE_USER_ALIGN (tem) = 1; + } + + TYPE_CONVENTION_FORTRAN_P (tem) + = (Convention (gnat_entity) == Convention_Fortran); + TREE_TYPE (TYPE_FIELDS (gnu_fat_type)) = build_pointer_type (tem); + + /* The result type is an UNCONSTRAINED_ARRAY_TYPE that indicates the + corresponding fat pointer. */ + TREE_TYPE (gnu_type) = TYPE_POINTER_TO (gnu_type) + = TYPE_REFERENCE_TO (gnu_type) = gnu_fat_type; + TYPE_MODE (gnu_type) = BLKmode; + TYPE_ALIGN (gnu_type) = TYPE_ALIGN (tem); + SET_TYPE_UNCONSTRAINED_ARRAY (gnu_fat_type, gnu_type); + + /* If the maximum size doesn't overflow, use it. */ + if (TREE_CODE (gnu_max_size) == INTEGER_CST + && !TREE_OVERFLOW (gnu_max_size)) + TYPE_SIZE (tem) + = size_binop (MIN_EXPR, gnu_max_size, TYPE_SIZE (tem)); + if (TREE_CODE (gnu_max_size_unit) == INTEGER_CST + && !TREE_OVERFLOW (gnu_max_size_unit)) + TYPE_SIZE_UNIT (tem) + = size_binop (MIN_EXPR, gnu_max_size_unit, + TYPE_SIZE_UNIT (tem)); + + create_type_decl (create_concat_name (gnat_entity, "XUA"), + tem, NULL, !Comes_From_Source (gnat_entity), + debug_info_p, gnat_entity); + + /* Give the fat pointer type a name. */ + create_type_decl (create_concat_name (gnat_entity, "XUP"), + gnu_fat_type, NULL, !Comes_From_Source (gnat_entity), + debug_info_p, gnat_entity); + + /* Create the type to be used as what a thin pointer designates: an + record type for the object and its template with the field offsets + shifted to have the template at a negative offset. */ + tem = build_unc_object_type (gnu_template_type, tem, + create_concat_name (gnat_entity, "XUT")); + shift_unc_components_for_thin_pointers (tem); + + SET_TYPE_UNCONSTRAINED_ARRAY (tem, gnu_type); + TYPE_OBJECT_RECORD_TYPE (gnu_type) = tem; + + /* Give the thin pointer type a name. */ + create_type_decl (create_concat_name (gnat_entity, "XUX"), + build_pointer_type (tem), NULL, + !Comes_From_Source (gnat_entity), debug_info_p, + gnat_entity); + } + break; + + case E_String_Subtype: + case E_Array_Subtype: + + /* This is the actual data type for array variables. Multidimensional + arrays are implemented in the gnu tree as arrays of arrays. Note + that for the moment 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 = gnat_to_gnu_type (Etype (gnat_entity)); + if (!Is_Constrained (gnat_entity)) + break; + else + { + int index; + int array_dim = Number_Dimensions (gnat_entity); + int first_dim + = ((Convention (gnat_entity) == Convention_Fortran) + ? array_dim - 1 : 0); + int next_dim + = (Convention (gnat_entity) == Convention_Fortran) ? -1 : 1; + Entity_Id gnat_ind_subtype; + Entity_Id gnat_ind_base_subtype; + tree gnu_base_type = gnu_type; + tree *gnu_index_type = (tree *) alloca (array_dim * sizeof (tree *)); + tree gnu_comp_size = NULL_TREE; + tree gnu_max_size = size_one_node; + tree gnu_max_size_unit; + bool need_index_type_struct = false; + bool max_overflow = false; + + /* First create the gnu types for each index. Create types for + debugging information to point to the index types if the + are not integer types, have variable bounds, or are + wider than sizetype. */ + + for (index = first_dim, gnat_ind_subtype = First_Index (gnat_entity), + gnat_ind_base_subtype + = First_Index (Implementation_Base_Type (gnat_entity)); + index < array_dim && index >= 0; + index += next_dim, + gnat_ind_subtype = Next_Index (gnat_ind_subtype), + gnat_ind_base_subtype = Next_Index (gnat_ind_base_subtype)) + { + tree gnu_index_subtype + = get_unpadded_type (Etype (gnat_ind_subtype)); + tree gnu_min + = convert (sizetype, TYPE_MIN_VALUE (gnu_index_subtype)); + tree gnu_max + = convert (sizetype, TYPE_MAX_VALUE (gnu_index_subtype)); + tree gnu_base_subtype + = get_unpadded_type (Etype (gnat_ind_base_subtype)); + tree gnu_base_min + = convert (sizetype, TYPE_MIN_VALUE (gnu_base_subtype)); + tree gnu_base_max + = convert (sizetype, TYPE_MAX_VALUE (gnu_base_subtype)); + tree gnu_base_type = get_base_type (gnu_base_subtype); + tree gnu_base_base_min + = convert (sizetype, TYPE_MIN_VALUE (gnu_base_type)); + tree gnu_base_base_max + = convert (sizetype, TYPE_MAX_VALUE (gnu_base_type)); + tree gnu_high; + tree gnu_this_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 + indications. */ + if ((TYPE_PRECISION (gnu_index_subtype) + > TYPE_PRECISION (sizetype) + || TYPE_UNSIGNED (gnu_index_subtype) + != TYPE_UNSIGNED (sizetype)) + && TREE_CODE (gnu_min) == INTEGER_CST + && TREE_CODE (gnu_max) == INTEGER_CST + && TREE_OVERFLOW (gnu_min) && TREE_OVERFLOW (gnu_max) + && (!TREE_OVERFLOW + (fold_build2 (MINUS_EXPR, gnu_index_subtype, + TYPE_MAX_VALUE (gnu_index_subtype), + TYPE_MIN_VALUE (gnu_index_subtype))))) + { + TREE_OVERFLOW (gnu_min) = 0; + TREE_OVERFLOW (gnu_max) = 0; + } + + /* Similarly, if the range is null, use bounds of 1..0 for + the sizetype bounds. */ + else if ((TYPE_PRECISION (gnu_index_subtype) + > TYPE_PRECISION (sizetype) + || TYPE_UNSIGNED (gnu_index_subtype) + != TYPE_UNSIGNED (sizetype)) + && TREE_CODE (gnu_min) == INTEGER_CST + && TREE_CODE (gnu_max) == INTEGER_CST + && (TREE_OVERFLOW (gnu_min) || TREE_OVERFLOW (gnu_max)) + && tree_int_cst_lt (TYPE_MAX_VALUE (gnu_index_subtype), + TYPE_MIN_VALUE (gnu_index_subtype))) + gnu_min = size_one_node, gnu_max = size_zero_node; + + /* Now compute the size of this bound. 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 subtype. If we can + prove that the low bound minus one can't overflow, we + can do this as MAX (hb, lb - 1). Otherwise, we have to use + the expression hb >= lb ? hb : lb - 1. */ + gnu_high = size_binop (MINUS_EXPR, gnu_min, size_one_node); + + /* See if the base array type is already flat. If it is, we + are probably compiling an ACVC test, but it will cause the + code below to malfunction if we don't handle it specially. */ + if (TREE_CODE (gnu_base_min) == INTEGER_CST + && TREE_CODE (gnu_base_max) == INTEGER_CST + && !TREE_OVERFLOW (gnu_base_min) + && !TREE_OVERFLOW (gnu_base_max) + && tree_int_cst_lt (gnu_base_max, gnu_base_min)) + gnu_high = size_zero_node, gnu_min = size_one_node; + + /* If gnu_high is now an integer which overflowed, the array + cannot be superflat. */ + else if (TREE_CODE (gnu_high) == INTEGER_CST + && TREE_OVERFLOW (gnu_high)) + gnu_high = gnu_max; + else if (TYPE_UNSIGNED (gnu_base_subtype) + || TREE_CODE (gnu_high) == INTEGER_CST) + gnu_high = size_binop (MAX_EXPR, gnu_max, gnu_high); + else + gnu_high + = build_cond_expr + (sizetype, build_binary_op (GE_EXPR, integer_type_node, + gnu_max, gnu_min), + gnu_max, gnu_high); + + gnu_index_type[index] + = create_index_type (gnu_min, gnu_high, gnu_index_subtype, + gnat_entity); + + /* Also compute the maximum size of the array. Here we + see if any constraint on the index type of the base type + can be used in the case of self-referential bound on + the index type of the subtype. We look for a non-"infinite" + and non-self-referential bound from any type involved and + handle each bound separately. */ + + if ((TREE_CODE (gnu_min) == INTEGER_CST + && !TREE_OVERFLOW (gnu_min) + && !operand_equal_p (gnu_min, gnu_base_base_min, 0)) + || !CONTAINS_PLACEHOLDER_P (gnu_min) + || !(TREE_CODE (gnu_base_min) == INTEGER_CST + && !TREE_OVERFLOW (gnu_base_min))) + gnu_base_min = gnu_min; + + if ((TREE_CODE (gnu_max) == INTEGER_CST + && !TREE_OVERFLOW (gnu_max) + && !operand_equal_p (gnu_max, gnu_base_base_max, 0)) + || !CONTAINS_PLACEHOLDER_P (gnu_max) + || !(TREE_CODE (gnu_base_max) == INTEGER_CST + && !TREE_OVERFLOW (gnu_base_max))) + gnu_base_max = gnu_max; + + if ((TREE_CODE (gnu_base_min) == INTEGER_CST + && TREE_OVERFLOW (gnu_base_min)) + || operand_equal_p (gnu_base_min, gnu_base_base_min, 0) + || (TREE_CODE (gnu_base_max) == INTEGER_CST + && TREE_OVERFLOW (gnu_base_max)) + || operand_equal_p (gnu_base_max, gnu_base_base_max, 0)) + max_overflow = true; + + gnu_base_min = size_binop (MAX_EXPR, gnu_base_min, gnu_min); + gnu_base_max = size_binop (MIN_EXPR, gnu_base_max, gnu_max); + + gnu_this_max + = size_binop (MAX_EXPR, + size_binop (PLUS_EXPR, size_one_node, + size_binop (MINUS_EXPR, gnu_base_max, + gnu_base_min)), + size_zero_node); + + if (TREE_CODE (gnu_this_max) == INTEGER_CST + && TREE_OVERFLOW (gnu_this_max)) + max_overflow = true; + + gnu_max_size + = size_binop (MULT_EXPR, gnu_max_size, gnu_this_max); + + if (!integer_onep (TYPE_MIN_VALUE (gnu_index_subtype)) + || (TREE_CODE (TYPE_MAX_VALUE (gnu_index_subtype)) + != INTEGER_CST) + || TREE_CODE (gnu_index_subtype) != INTEGER_TYPE + || (TREE_TYPE (gnu_index_subtype) + && (TREE_CODE (TREE_TYPE (gnu_index_subtype)) + != INTEGER_TYPE)) + || TYPE_BIASED_REPRESENTATION_P (gnu_index_subtype) + || (TYPE_PRECISION (gnu_index_subtype) + > TYPE_PRECISION (sizetype))) + 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_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 = array_dim - 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_type (Component_Type (gnat_entity)); + + /* 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; + } + + /* Try to get a smaller form of the component if needed. */ + if ((Is_Packed (gnat_entity) + || Has_Component_Size_Clause (gnat_entity)) + && !Is_Bit_Packed_Array (gnat_entity) + && !Has_Aliased_Components (gnat_entity) + && !Strict_Alignment (Component_Type (gnat_entity)) + && TREE_CODE (gnu_type) == RECORD_TYPE + && host_integerp (TYPE_SIZE (gnu_type), 1)) + gnu_type = make_packable_type (gnu_type, false); + + /* Get and validate any specified Component_Size, but if Packed, + ignore it since the front end will have taken care of it. */ + gnu_comp_size + = validate_size (Component_Size (gnat_entity), gnu_type, + gnat_entity, + (Is_Bit_Packed_Array (gnat_entity) + ? TYPE_DECL : VAR_DECL), true, + Has_Component_Size_Clause (gnat_entity)); + + /* If the component type is a RECORD_TYPE that has a + self-referential size, use the maxium 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 (gnu_comp_size && !Is_Bit_Packed_Array (gnat_entity)) + { + tree orig_gnu_type; + gnu_type + = make_type_from_size (gnu_type, gnu_comp_size, false); + orig_gnu_type = gnu_type; + gnu_type = maybe_pad_type (gnu_type, gnu_comp_size, 0, + gnat_entity, "C_PAD", 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_type != orig_gnu_type) + create_type_decl (TYPE_NAME (gnu_type), gnu_type, NULL, + true, false, gnat_entity); + } + + if (Has_Volatile_Components (Base_Type (gnat_entity))) + gnu_type = build_qualified_type (gnu_type, + (TYPE_QUALS (gnu_type) + | TYPE_QUAL_VOLATILE)); + } + + gnu_max_size_unit = size_binop (MULT_EXPR, gnu_max_size, + TYPE_SIZE_UNIT (gnu_type)); + gnu_max_size = size_binop (MULT_EXPR, + convert (bitsizetype, gnu_max_size), + TYPE_SIZE (gnu_type)); + + for (index = array_dim - 1; index >= 0; index --) + { + gnu_type = build_array_type (gnu_type, gnu_index_type[index]); + TYPE_MULTI_ARRAY_P (gnu_type) = (index > 0); + if (array_type_has_nonaliased_component (gnat_entity, gnu_type)) + TYPE_NONALIASED_COMPONENT (gnu_type) = 1; + } + + /* If we are at file level and this is a multi-dimensional array, we + need to make a variable corresponding to the stride of the + inner dimensions. */ + if (global_bindings_p () && array_dim > 1) + { + tree gnu_str_name = get_identifier ("ST"); + tree gnu_arr_type; + + for (gnu_arr_type = TREE_TYPE (gnu_type); + TREE_CODE (gnu_arr_type) == ARRAY_TYPE; + gnu_arr_type = TREE_TYPE (gnu_arr_type), + gnu_str_name = concat_id_with_name (gnu_str_name, "ST")) + { + tree eltype = TREE_TYPE (gnu_arr_type); + + TYPE_SIZE (gnu_arr_type) + = elaborate_expression_1 (gnat_entity, gnat_entity, + TYPE_SIZE (gnu_arr_type), + gnu_str_name, definition, 0); + + /* ??? 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. */ + TYPE_SIZE_UNIT (gnu_arr_type) + = build_binary_op + (MULT_EXPR, sizetype, + elaborate_expression_1 + (gnat_entity, gnat_entity, + build_binary_op (EXACT_DIV_EXPR, sizetype, + TYPE_SIZE_UNIT (gnu_arr_type), + size_int (TYPE_ALIGN (eltype) + / BITS_PER_UNIT)), + concat_id_with_name (gnu_str_name, "A_U"), + definition, 0), + size_int (TYPE_ALIGN (eltype) / BITS_PER_UNIT)); + + /* ??? 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)); + } + } + + /* If we need to write out a record type giving the names of + the bounds, do it now. */ + if (need_index_type_struct && debug_info_p) + { + tree gnu_bound_rec_type = make_node (RECORD_TYPE); + tree gnu_field_list = NULL_TREE; + tree gnu_field; + + TYPE_NAME (gnu_bound_rec_type) + = create_concat_name (gnat_entity, "XA"); + + for (index = array_dim - 1; index >= 0; index--) + { + tree gnu_type_name + = TYPE_NAME (TYPE_INDEX_TYPE (gnu_index_type[index])); + + if (TREE_CODE (gnu_type_name) == TYPE_DECL) + gnu_type_name = DECL_NAME (gnu_type_name); + + gnu_field = create_field_decl (gnu_type_name, + integer_type_node, + gnu_bound_rec_type, + 0, NULL_TREE, NULL_TREE, 0); + TREE_CHAIN (gnu_field) = gnu_field_list; + gnu_field_list = gnu_field; + } + + finish_record_type (gnu_bound_rec_type, gnu_field_list, + 0, false); + + TYPE_STUB_DECL (gnu_type) + = build_decl (TYPE_DECL, NULL_TREE, gnu_type); + + add_parallel_type + (TYPE_STUB_DECL (gnu_type), gnu_bound_rec_type); + } + + TYPE_CONVENTION_FORTRAN_P (gnu_type) + = (Convention (gnat_entity) == Convention_Fortran); + TYPE_PACKED_ARRAY_TYPE_P (gnu_type) + = (Is_Packed_Array_Type (gnat_entity) + && Is_Bit_Packed_Array (Original_Array_Type (gnat_entity))); + + /* If our size depends on a placeholder and the maximum size doesn't + overflow, use it. */ + if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type)) + && !(TREE_CODE (gnu_max_size) == INTEGER_CST + && TREE_OVERFLOW (gnu_max_size)) + && !(TREE_CODE (gnu_max_size_unit) == INTEGER_CST + && TREE_OVERFLOW (gnu_max_size_unit)) + && !max_overflow) + { + TYPE_SIZE (gnu_type) = size_binop (MIN_EXPR, gnu_max_size, + TYPE_SIZE (gnu_type)); + TYPE_SIZE_UNIT (gnu_type) + = size_binop (MIN_EXPR, gnu_max_size_unit, + TYPE_SIZE_UNIT (gnu_type)); + } + + /* Set our alias set to that of our base type. This gives all + array subtypes the same alias set. */ + copy_alias_set (gnu_type, gnu_base_type); + } + + /* If this is a packed type, make this type the same as the packed + array type, but do some adjusting in the type first. */ + + if (Present (Packed_Array_Type (gnat_entity))) + { + Entity_Id gnat_index; + tree gnu_inner_type; + + /* First finish the type we had been making so that we output + debugging information for it */ + gnu_type + = build_qualified_type (gnu_type, + (TYPE_QUALS (gnu_type) + | (TYPE_QUAL_VOLATILE + * Treat_As_Volatile (gnat_entity)))); + gnu_decl = create_type_decl (gnu_entity_id, gnu_type, attr_list, + !Comes_From_Source (gnat_entity), + debug_info_p, gnat_entity); + if (!Comes_From_Source (gnat_entity)) + DECL_ARTIFICIAL (gnu_decl) = 1; + + /* Save it as our equivalent in case the call below elaborates + this type again. */ + save_gnu_tree (gnat_entity, gnu_decl, false); + + gnu_decl = gnat_to_gnu_entity (Packed_Array_Type (gnat_entity), + NULL_TREE, 0); + this_made_decl = true; + gnu_type = TREE_TYPE (gnu_decl); + save_gnu_tree (gnat_entity, NULL_TREE, false); + + gnu_inner_type = gnu_type; + while (TREE_CODE (gnu_inner_type) == RECORD_TYPE + && (TYPE_JUSTIFIED_MODULAR_P (gnu_inner_type) + || TYPE_IS_PADDING_P (gnu_inner_type))) + gnu_inner_type = TREE_TYPE (TYPE_FIELDS (gnu_inner_type)); + + /* We need to point the type we just made to our index type so + the actual bounds can be put into a template. */ + + if ((TREE_CODE (gnu_inner_type) == ARRAY_TYPE + && !TYPE_ACTUAL_BOUNDS (gnu_inner_type)) + || (TREE_CODE (gnu_inner_type) == INTEGER_TYPE + && !TYPE_HAS_ACTUAL_BOUNDS_P (gnu_inner_type))) + { + if (TREE_CODE (gnu_inner_type) == INTEGER_TYPE) + { + /* The TYPE_ACTUAL_BOUNDS field is also used for the modulus. + If it is, we need to make another type. */ + if (TYPE_MODULAR_P (gnu_inner_type)) + { + tree gnu_subtype; + + gnu_subtype = make_node (INTEGER_TYPE); + + TREE_TYPE (gnu_subtype) = gnu_inner_type; + TYPE_MIN_VALUE (gnu_subtype) + = TYPE_MIN_VALUE (gnu_inner_type); + TYPE_MAX_VALUE (gnu_subtype) + = TYPE_MAX_VALUE (gnu_inner_type); + TYPE_PRECISION (gnu_subtype) + = TYPE_PRECISION (gnu_inner_type); + TYPE_UNSIGNED (gnu_subtype) + = TYPE_UNSIGNED (gnu_inner_type); + TYPE_EXTRA_SUBTYPE_P (gnu_subtype) = 1; + layout_type (gnu_subtype); + + gnu_inner_type = gnu_subtype; + } + + TYPE_HAS_ACTUAL_BOUNDS_P (gnu_inner_type) = 1; + } + + SET_TYPE_ACTUAL_BOUNDS (gnu_inner_type, NULL_TREE); + + for (gnat_index = First_Index (gnat_entity); + Present (gnat_index); gnat_index = Next_Index (gnat_index)) + SET_TYPE_ACTUAL_BOUNDS + (gnu_inner_type, + tree_cons (NULL_TREE, + get_unpadded_type (Etype (gnat_index)), + TYPE_ACTUAL_BOUNDS (gnu_inner_type))); + + if (Convention (gnat_entity) != Convention_Fortran) + SET_TYPE_ACTUAL_BOUNDS + (gnu_inner_type, + nreverse (TYPE_ACTUAL_BOUNDS (gnu_inner_type))); + + if (TREE_CODE (gnu_type) == RECORD_TYPE + && TYPE_JUSTIFIED_MODULAR_P (gnu_type)) + TREE_TYPE (TYPE_FIELDS (gnu_type)) = gnu_inner_type; + } + } + + /* Abort if packed array with no packed array type field set. */ + else + gcc_assert (!Is_Packed (gnat_entity)); + + break; + + case E_String_Literal_Subtype: + /* Create the type for a string literal. */ + { + Entity_Id gnat_full_type + = (IN (Ekind (Etype (gnat_entity)), Private_Kind) + && 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))); + int length = UI_To_Int (String_Literal_Length (gnat_entity)); + tree gnu_length = ssize_int (length - 1); + tree gnu_upper_bound + = build_binary_op (PLUS_EXPR, gnu_string_index_type, + gnu_lower_bound, + convert (gnu_string_index_type, gnu_length)); + tree gnu_range_type + = build_range_type (gnu_string_index_type, + gnu_lower_bound, gnu_upper_bound); + tree gnu_index_type + = create_index_type (convert (sizetype, + TYPE_MIN_VALUE (gnu_range_type)), + convert (sizetype, + TYPE_MAX_VALUE (gnu_range_type)), + gnu_range_type, gnat_entity); + + gnu_type + = build_array_type (gnat_to_gnu_type (Component_Type (gnat_entity)), + gnu_index_type); + copy_alias_set (gnu_type, gnu_string_type); + } + break; + + /* Record Types and Subtypes + + The following fields are defined on record types: + + Has_Discriminants True if the record has discriminants + First_Discriminant Points to head of list of discriminants + First_Entity Points to head of list of fields + Is_Tagged_Type True if the record is tagged + + Implementation of Ada records and discriminated records: + + 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: + if (Has_Complex_Representation (gnat_entity)) + { + gnu_type + = build_complex_type + (get_unpadded_type + (Etype (Defining_Entity + (First (Component_Items + (Component_List + (Type_Definition + (Declaration_Node (gnat_entity))))))))); + + break; + } + + { + Node_Id full_definition = Declaration_Node (gnat_entity); + Node_Id record_definition = Type_Definition (full_definition); + Entity_Id gnat_field; + tree gnu_field; + tree gnu_field_list = NULL_TREE; + tree gnu_get_parent; + /* Set PACKED in keeping with gnat_to_gnu_field. */ + int packed + = Is_Packed (gnat_entity) + ? 1 + : Component_Alignment (gnat_entity) == Calign_Storage_Unit + ? -1 + : (Known_Alignment (gnat_entity) + || (Strict_Alignment (gnat_entity) + && Known_Static_Esize (gnat_entity))) + ? -2 + : 0; + bool has_rep = Has_Specified_Layout (gnat_entity); + bool all_rep = has_rep; + bool is_extension + = (Is_Tagged_Type (gnat_entity) + && Nkind (record_definition) == N_Derived_Type_Definition); + + /* See if all fields have a rep clause. Stop when we find one + that doesn't. */ + for (gnat_field = First_Entity (gnat_entity); + Present (gnat_field) && all_rep; + gnat_field = Next_Entity (gnat_field)) + if ((Ekind (gnat_field) == E_Component + || Ekind (gnat_field) == E_Discriminant) + && No (Component_Clause (gnat_field))) + all_rep = false; + + /* 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 (type_annotate_only + || Present (Parent_Subtype (gnat_entity))); + } + + /* Make a node for the record. If we are not defining the record, + suppress expanding incomplete types. */ + gnu_type = make_node (tree_code_for_record_type (gnat_entity)); + TYPE_NAME (gnu_type) = gnu_entity_id; + TYPE_PACKED (gnu_type) = (packed != 0) || has_rep; + + if (!definition) + defer_incomplete_level++, this_deferred = true; + + /* If both a size and rep clause was specified, put the size in + the record type now so that it can get the proper mode. */ + if (has_rep && Known_Esize (gnat_entity)) + TYPE_SIZE (gnu_type) = UI_To_gnu (Esize (gnat_entity), sizetype); + + /* Always set the alignment here so that it can be used to + set the mode, if it is making the alignment stricter. If + it is invalid, it will be checked again below. If this is to + be Atomic, choose a default alignment of a word unless we know + the size and it's smaller. */ + if (Known_Alignment (gnat_entity)) + TYPE_ALIGN (gnu_type) + = validate_alignment (Alignment (gnat_entity), gnat_entity, 0); + else if (Is_Atomic (gnat_entity)) + TYPE_ALIGN (gnu_type) + = esize >= BITS_PER_WORD ? BITS_PER_WORD : ceil_alignment (esize); + /* If a type needs strict alignment, the minimum size will be the + type size instead of the RM size (see validate_size). Cap the + alignment, lest it causes this type size to become too large. */ + else if (Strict_Alignment (gnat_entity) + && Known_Static_Esize (gnat_entity)) + { + unsigned int raw_size = UI_To_Int (Esize (gnat_entity)); + unsigned int raw_align = raw_size & -raw_size; + if (raw_align < BIGGEST_ALIGNMENT) + TYPE_ALIGN (gnu_type) = raw_align; + } + else + TYPE_ALIGN (gnu_type) = 0; + + /* 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_parent; + + /* A major complexity here is that the parent subtype will + reference our discriminants in its Discriminant_Constraint + list. But those must reference the parent component of this + record which is 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, void_type_node, + build0 (PLACEHOLDER_EXPR, gnu_type), + build_decl (FIELD_DECL, NULL_TREE, + void_type_node), + NULL_TREE); + + if (Has_Discriminants (gnat_entity)) + for (gnat_field = First_Stored_Discriminant (gnat_entity); + Present (gnat_field); + gnat_field = Next_Stored_Discriminant (gnat_field)) + if (Present (Corresponding_Discriminant (gnat_field))) + save_gnu_tree + (gnat_field, + build3 (COMPONENT_REF, + get_unpadded_type (Etype (gnat_field)), + gnu_get_parent, + gnat_to_gnu_field_decl (Corresponding_Discriminant + (gnat_field)), + NULL_TREE), + true); + + /* Then we build the parent subtype. */ + gnu_parent = gnat_to_gnu_type (gnat_parent); + + /* 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_Discriminants (gnat_entity)) + 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 = Empty; + 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_list + = create_field_decl (get_identifier + (Get_Name_String (Name_uParent)), + gnu_parent, gnu_type, 0, + has_rep ? TYPE_SIZE (gnu_parent) : 0, + has_rep ? bitsize_zero_node : 0, 1); + DECL_INTERNAL_P (gnu_field_list) = 1; + TREE_OPERAND (gnu_get_parent, 1) = gnu_field_list; + } + + /* Make the fields for the discriminants and put them into the record + unless it's an Unchecked_Union. */ + if (Has_Discriminants (gnat_entity)) + 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 already + handled the discriminant above. */ + if (Present (Parent_Subtype (gnat_entity)) + && Present (Corresponding_Discriminant (gnat_field))) + continue; + + gnu_field + = gnat_to_gnu_field (gnat_field, gnu_type, packed, definition); + + /* Make an expression using a PLACEHOLDER_EXPR from the + FIELD_DECL node just created and link that with the + corresponding GNAT defining identifier. Then add to the + list of fields. */ + save_gnu_tree (gnat_field, + build3 (COMPONENT_REF, TREE_TYPE (gnu_field), + build0 (PLACEHOLDER_EXPR, + DECL_CONTEXT (gnu_field)), + gnu_field, NULL_TREE), + true); + + if (!Is_Unchecked_Union (gnat_entity)) + { + TREE_CHAIN (gnu_field) = gnu_field_list; + gnu_field_list = gnu_field; + } + } + + /* Put the discriminants into the record (backwards), so we can + know the appropriate discriminant to use for the names of the + variants. */ + TYPE_FIELDS (gnu_type) = gnu_field_list; + + /* Add the listed fields into the record and finish it up. */ + components_to_record (gnu_type, Component_List (record_definition), + gnu_field_list, packed, definition, NULL, + false, all_rep, false, + Is_Unchecked_Union (gnat_entity)); + + /* We used to remove the associations of the discriminants and + _Parent for validity checking, but we may need them if there's + Freeze_Node for a subtype used in this record. */ + TYPE_VOLATILE (gnu_type) = Treat_As_Volatile (gnat_entity); + TYPE_BY_REFERENCE_P (gnu_type) = Is_By_Reference_Type (gnat_entity); + + /* If it is a tagged record force the type to BLKmode to insure + that these objects will always be placed in memory. Do the + same thing for limited record types. */ + if (Is_Tagged_Type (gnat_entity) || Is_Limited_Record (gnat_entity)) + TYPE_MODE (gnu_type) = BLKmode; + + /* If this is a derived type, we must make the alias set of this type + the same as that of the type we are derived from. We assume here + that the other type is already frozen. */ + if (Etype (gnat_entity) != gnat_entity + && !(Is_Private_Type (Etype (gnat_entity)) + && Full_View (Etype (gnat_entity)) == gnat_entity)) + copy_alias_set (gnu_type, gnat_to_gnu_type (Etype (gnat_entity))); + + /* Fill in locations of fields. */ + annotate_rep (gnat_entity, gnu_type); + + /* If there are any 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, 0); + } + 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, 0); + 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, 0); + maybe_present = true; + } + + /* 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 having the position + computed by transforming every discriminant reference according + to the constraints. We don't see any difference between + private and nonprivate 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); + tree gnu_base_type; + tree gnu_orig_type; + + if (!definition) + defer_incomplete_level++, this_deferred = true; + + /* Get the base type initially for its alignment and sizes. But + if it is a padded type, we do all the other work with the + unpadded type. */ + gnu_base_type = gnat_to_gnu_type (gnat_base_type); + + if (TREE_CODE (gnu_base_type) == RECORD_TYPE + && TYPE_IS_PADDING_P (gnu_base_type)) + gnu_type = gnu_orig_type = TREE_TYPE (TYPE_FIELDS (gnu_base_type)); + else + gnu_type = gnu_orig_type = gnu_base_type; + + if (present_gnu_tree (gnat_entity)) + { + maybe_present = true; + break; + } + + /* When the type has discriminants, and these discriminants + affect the shape of what it built, factor them in. + + If we are making a subtype of an Unchecked_Union (must be an + Itype), just return the type. + + We can't just use Is_Constrained because private subtypes without + discriminants of full types with discriminants with default + expressions are Is_Constrained but aren't constrained! */ + + if (IN (Ekind (gnat_base_type), Record_Kind) + && !Is_For_Access_Subtype (gnat_entity) + && !Is_Unchecked_Union (gnat_base_type) + && Is_Constrained (gnat_entity) + && Stored_Constraint (gnat_entity) != No_Elist + && Present (Discriminant_Constraint (gnat_entity))) + { + Entity_Id gnat_field; + tree gnu_field_list = 0; + tree gnu_pos_list + = compute_field_positions (gnu_orig_type, NULL_TREE, + size_zero_node, bitsize_zero_node, + BIGGEST_ALIGNMENT); + tree gnu_subst_list + = substitution_list (gnat_entity, gnat_base_type, NULL_TREE, + definition); + tree gnu_temp; + + gnu_type = make_node (RECORD_TYPE); + TYPE_NAME (gnu_type) = gnu_entity_id; + TYPE_VOLATILE (gnu_type) = Treat_As_Volatile (gnat_entity); + + /* Set the size, alignment and alias set of the new type to + match that of the old one, doing required substitutions. + We do it this early because we need the size of the new + type below to discard old fields if necessary. */ + TYPE_SIZE (gnu_type) = TYPE_SIZE (gnu_base_type); + TYPE_SIZE_UNIT (gnu_type) = TYPE_SIZE_UNIT (gnu_base_type); + SET_TYPE_ADA_SIZE (gnu_type, TYPE_ADA_SIZE (gnu_base_type)); + TYPE_ALIGN (gnu_type) = TYPE_ALIGN (gnu_base_type); + copy_alias_set (gnu_type, gnu_base_type); + + if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type))) + for (gnu_temp = gnu_subst_list; + gnu_temp; gnu_temp = TREE_CHAIN (gnu_temp)) + TYPE_SIZE (gnu_type) + = substitute_in_expr (TYPE_SIZE (gnu_type), + TREE_PURPOSE (gnu_temp), + TREE_VALUE (gnu_temp)); + + if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE_UNIT (gnu_type))) + for (gnu_temp = gnu_subst_list; + gnu_temp; gnu_temp = TREE_CHAIN (gnu_temp)) + TYPE_SIZE_UNIT (gnu_type) + = substitute_in_expr (TYPE_SIZE_UNIT (gnu_type), + TREE_PURPOSE (gnu_temp), + TREE_VALUE (gnu_temp)); + + if (CONTAINS_PLACEHOLDER_P (TYPE_ADA_SIZE (gnu_type))) + for (gnu_temp = gnu_subst_list; + gnu_temp; gnu_temp = TREE_CHAIN (gnu_temp)) + SET_TYPE_ADA_SIZE + (gnu_type, substitute_in_expr (TYPE_ADA_SIZE (gnu_type), + TREE_PURPOSE (gnu_temp), + TREE_VALUE (gnu_temp))); + + 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) + && (Underlying_Type (Scope (Original_Record_Component + (gnat_field))) + == gnat_base_type) + && (No (Corresponding_Discriminant (gnat_field)) + || !Is_Tagged_Type (gnat_base_type))) + { + tree gnu_old_field + = gnat_to_gnu_field_decl (Original_Record_Component + (gnat_field)); + tree gnu_offset + = TREE_VALUE (purpose_member (gnu_old_field, + gnu_pos_list)); + tree gnu_pos = TREE_PURPOSE (gnu_offset); + tree gnu_bitpos = TREE_VALUE (TREE_VALUE (gnu_offset)); + tree gnu_field_type + = gnat_to_gnu_type (Etype (gnat_field)); + tree gnu_size = TYPE_SIZE (gnu_field_type); + tree gnu_new_pos = NULL_TREE; + unsigned int offset_align + = tree_low_cst (TREE_PURPOSE (TREE_VALUE (gnu_offset)), + 1); + tree gnu_field; + + /* If there was a component clause, the field types must be + the same for the type and subtype, 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 + (Original_Record_Component (gnat_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 + onto 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 (TYPE_MODE (gnu_field_type) == BLKmode + && TREE_CODE (gnu_field_type) == RECORD_TYPE + && host_integerp (TYPE_SIZE (gnu_field_type), 1)) + gnu_field_type + = make_packable_type (gnu_field_type, true); + } + + if (CONTAINS_PLACEHOLDER_P (gnu_pos)) + for (gnu_temp = gnu_subst_list; + gnu_temp; gnu_temp = TREE_CHAIN (gnu_temp)) + gnu_pos = substitute_in_expr (gnu_pos, + TREE_PURPOSE (gnu_temp), + TREE_VALUE (gnu_temp)); + + /* 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 below. */ + if (TREE_CONSTANT (gnu_pos)) + { + gnu_new_pos = bit_from_pos (gnu_pos, gnu_bitpos); + + /* Discard old fields that are outside the new type. + This avoids confusing code scanning it to decide + how to pass it to functions on some platforms. */ + if (TREE_CODE (gnu_new_pos) == INTEGER_CST + && TREE_CODE (TYPE_SIZE (gnu_type)) == INTEGER_CST + && !integer_zerop (gnu_size) + && !tree_int_cst_lt (gnu_new_pos, + TYPE_SIZE (gnu_type))) + continue; + } + + gnu_field + = create_field_decl + (DECL_NAME (gnu_old_field), gnu_field_type, gnu_type, + DECL_PACKED (gnu_old_field), gnu_size, gnu_new_pos, + !DECL_NONADDRESSABLE_P (gnu_old_field)); + + if (!TREE_CONSTANT (gnu_pos)) + { + normalize_offset (&gnu_pos, &gnu_bitpos, offset_align); + DECL_FIELD_OFFSET (gnu_field) = gnu_pos; + DECL_FIELD_BIT_OFFSET (gnu_field) = gnu_bitpos; + SET_DECL_OFFSET_ALIGN (gnu_field, offset_align); + DECL_SIZE (gnu_field) = gnu_size; + DECL_SIZE_UNIT (gnu_field) + = convert (sizetype, + size_binop (CEIL_DIV_EXPR, gnu_size, + bitsize_unit_node)); + layout_decl (gnu_field, DECL_OFFSET_ALIGN (gnu_field)); + } + + DECL_INTERNAL_P (gnu_field) + = DECL_INTERNAL_P (gnu_old_field); + SET_DECL_ORIGINAL_FIELD + (gnu_field, (DECL_ORIGINAL_FIELD (gnu_old_field) + ? DECL_ORIGINAL_FIELD (gnu_old_field) + : gnu_old_field)); + DECL_DISCRIMINANT_NUMBER (gnu_field) + = DECL_DISCRIMINANT_NUMBER (gnu_old_field); + TREE_THIS_VOLATILE (gnu_field) + = TREE_THIS_VOLATILE (gnu_old_field); + TREE_CHAIN (gnu_field) = gnu_field_list; + gnu_field_list = gnu_field; + save_gnu_tree (gnat_field, gnu_field, false); + } + + /* Now go through the entities again looking for Itypes that + we have not elaborated but should (e.g., Etypes of fields + that have Original_Components). */ + for (gnat_field = First_Entity (gnat_entity); + Present (gnat_field); gnat_field = Next_Entity (gnat_field)) + if ((Ekind (gnat_field) == E_Discriminant + || Ekind (gnat_field) == E_Component) + && !present_gnu_tree (Etype (gnat_field))) + gnat_to_gnu_entity (Etype (gnat_field), NULL_TREE, 0); + + /* Do not finalize it since we're going to modify it below. */ + gnu_field_list = nreverse (gnu_field_list); + finish_record_type (gnu_type, gnu_field_list, 2, true); + + /* Finalize size and mode. */ + TYPE_SIZE (gnu_type) = variable_size (TYPE_SIZE (gnu_type)); + TYPE_SIZE_UNIT (gnu_type) + = variable_size (TYPE_SIZE_UNIT (gnu_type)); + + compute_record_mode (gnu_type); + + /* Fill in locations of fields. */ + annotate_rep (gnat_entity, gnu_type); + + /* We've built a new type, make an XVS type to show what this + is a subtype of. Some debuggers require the XVS type to be + output first, so do it in that order. */ + if (debug_info_p) + { + tree gnu_subtype_marker = make_node (RECORD_TYPE); + tree gnu_orig_name = TYPE_NAME (gnu_orig_type); + + if (TREE_CODE (gnu_orig_name) == TYPE_DECL) + gnu_orig_name = DECL_NAME (gnu_orig_name); + + TYPE_NAME (gnu_subtype_marker) + = create_concat_name (gnat_entity, "XVS"); + finish_record_type (gnu_subtype_marker, + create_field_decl (gnu_orig_name, + integer_type_node, + gnu_subtype_marker, + 0, NULL_TREE, + NULL_TREE, 0), + 0, false); + + add_parallel_type (TYPE_STUB_DECL (gnu_type), + gnu_subtype_marker); + } + + /* Now we can finalize it. */ + rest_of_record_type_compilation (gnu_type); + } + + /* Otherwise, go down all the components in the new type and + make them equivalent to those in the base type. */ + else + 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: + /* 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_Anonymous_Access_Subprogram_Type: + /* If we are not defining this entity, and we have incomplete + entities being processed above us, make a dummy type and + fill it in later. */ + if (!definition && defer_incomplete_level != 0) + { + struct incomplete *p + = (struct incomplete *) xmalloc (sizeof (struct incomplete)); + + gnu_type + = build_pointer_type + (make_dummy_type (Directly_Designated_Type (gnat_entity))); + gnu_decl = create_type_decl (gnu_entity_id, gnu_type, attr_list, + !Comes_From_Source (gnat_entity), + 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; + + p->old_type = TREE_TYPE (gnu_type); + p->full_type = Directly_Designated_Type (gnat_entity); + p->next = defer_incomplete_list; + defer_incomplete_list = p; + 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: + { + Entity_Id gnat_desig_type = Directly_Designated_Type (gnat_entity); + Entity_Id gnat_desig_equiv = Gigi_Equivalent_Type (gnat_desig_type); + bool is_from_limited_with + = (IN (Ekind (gnat_desig_equiv), Incomplete_Kind) + && From_With_Type (gnat_desig_equiv)); + + /* 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, 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) + : (IN (Ekind (gnat_desig_equiv), Incomplete_Or_Private_Kind) + ? Full_View (gnat_desig_equiv) : Empty)); + Entity_Id gnat_desig_full_direct + = ((is_from_limited_with + && Present (gnat_desig_full_direct_first) + && IN (Ekind (gnat_desig_full_direct_first), Private_Kind)) + ? Full_View (gnat_desig_full_direct_first) + : gnat_desig_full_direct_first); + Entity_Id gnat_desig_full + = Gigi_Equivalent_Type (gnat_desig_full_direct); + + /* This the type actually used to represent the designated type, + either gnat_desig_full or gnat_desig_equiv. */ + Entity_Id gnat_desig_rep; + + /* Nonzero if this is a pointer to an unconstrained array. */ + bool is_unconstrained_array; + + /* We want to know if we'll be seeing the freeze node for any + incomplete type we may be pointing to. */ + bool in_main_unit + = (Present (gnat_desig_full) + ? In_Extended_Main_Code_Unit (gnat_desig_full) + : In_Extended_Main_Code_Unit (gnat_desig_type)); + + /* Nonzero if we make a dummy type here. */ + bool got_fat_p = false; + /* Nonzero if the dummy is a fat pointer. */ + bool made_dummy = false; + tree gnu_desig_type = NULL_TREE; + enum machine_mode p_mode = mode_for_size (esize, MODE_INT, 0); + + if (!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); + + /* Now set the type that actually marks the representation of + the designated type and also flag whether we have a unconstrained + array. */ + gnat_desig_rep = gnat_desig_full ? gnat_desig_full : gnat_desig_equiv; + is_unconstrained_array + = (Is_Array_Type (gnat_desig_rep) + && ! Is_Constrained (gnat_desig_rep)); + + /* If we are pointing to an incomplete type whose completion is an + unconstrained array, make a fat pointer type. The two types in our + fields will be pointers to dummy nodes and will be replaced in + update_pointer_to. Similarly, if the type itself is a dummy type or + an unconstrained array. Also make a dummy TYPE_OBJECT_RECORD_TYPE + in case we have any thin pointers to it. */ + if (is_unconstrained_array + && (Present (gnat_desig_full) + || (present_gnu_tree (gnat_desig_equiv) + && TYPE_IS_DUMMY_P (TREE_TYPE + (get_gnu_tree (gnat_desig_equiv)))) + || (No (gnat_desig_full) && ! in_main_unit + && defer_incomplete_level != 0 + && ! present_gnu_tree (gnat_desig_equiv)) + || (in_main_unit && is_from_limited_with + && Present (Freeze_Node (gnat_desig_rep))))) + { + tree gnu_old + = (present_gnu_tree (gnat_desig_rep) + ? TREE_TYPE (get_gnu_tree (gnat_desig_rep)) + : make_dummy_type (gnat_desig_rep)); + tree fields; + + /* Show the dummy we get will be a fat pointer. */ + got_fat_p = made_dummy = true; + + /* If the call above got something that has a pointer, that + pointer is our type. This could have happened either + because the type was elaborated or because somebody + else executed the code below. */ + gnu_type = TYPE_POINTER_TO (gnu_old); + if (!gnu_type) + { + tree gnu_template_type = make_node (ENUMERAL_TYPE); + tree gnu_ptr_template = build_pointer_type (gnu_template_type); + tree gnu_array_type = make_node (ENUMERAL_TYPE); + tree gnu_ptr_array = build_pointer_type (gnu_array_type); + + TYPE_NAME (gnu_template_type) + = concat_id_with_name (get_entity_name (gnat_desig_equiv), + "XUB"); + TYPE_DUMMY_P (gnu_template_type) = 1; + + TYPE_NAME (gnu_array_type) + = concat_id_with_name (get_entity_name (gnat_desig_equiv), + "XUA"); + TYPE_DUMMY_P (gnu_array_type) = 1; + + gnu_type = make_node (RECORD_TYPE); + SET_TYPE_UNCONSTRAINED_ARRAY (gnu_type, gnu_old); + TYPE_POINTER_TO (gnu_old) = gnu_type; + + Sloc_to_locus (Sloc (gnat_entity), &input_location); + fields + = chainon (chainon (NULL_TREE, + create_field_decl + (get_identifier ("P_ARRAY"), + gnu_ptr_array, + gnu_type, 0, 0, 0, 0)), + create_field_decl (get_identifier ("P_BOUNDS"), + gnu_ptr_template, + gnu_type, 0, 0, 0, 0)); + + /* Make sure we can place this into a register. */ + TYPE_ALIGN (gnu_type) + = MIN (BIGGEST_ALIGNMENT, 2 * POINTER_SIZE); + TYPE_IS_FAT_POINTER_P (gnu_type) = 1; + + /* Do not finalize this record type since the types of + its fields are incomplete. */ + finish_record_type (gnu_type, fields, 0, true); + + TYPE_OBJECT_RECORD_TYPE (gnu_old) = make_node (RECORD_TYPE); + TYPE_NAME (TYPE_OBJECT_RECORD_TYPE (gnu_old)) + = concat_id_with_name (get_entity_name (gnat_desig_equiv), + "XUT"); + TYPE_DUMMY_P (TYPE_OBJECT_RECORD_TYPE (gnu_old)) = 1; + } + } + + /* If we already know what the full type is, use it. */ + else 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, make a dummy type node 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) + && ! present_gnu_tree (gnat_desig_full) + && Is_Record_Type (gnat_desig_full)) + /* Likewise if we are pointing to a record or array and we + are to defer elaborating incomplete types. We do this + since this access type may be the full view of some + private type. Note that the unconstrained array case is + handled above. */ + || ((! 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)))) + /* 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 processed. In both cases, the + pointer eventually created below will be automatically + adjusted when the Freeze_Node is processed. Note that the + unconstrained array case is handled above. */ + || (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 build a dummy pointer type. */ + else if (type_annotate_only && No (gnat_desig_equiv)) + gnu_type = ptr_void_type_node; + + /* Finally, handle the straightforward case where we can just + elaborate our designated type and point to it. */ + 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; + } + + /* If we have a GCC type for the designated type, possibly modify it + if we are pointing only to constant objects and then make a pointer + to it. Don't do this for unconstrained arrays. */ + if (!gnu_type && gnu_desig_type) + { + if (Is_Access_Constant (gnat_entity) + && TREE_CODE (gnu_desig_type) != UNCONSTRAINED_ARRAY_TYPE) + { + gnu_desig_type + = build_qualified_type + (gnu_desig_type, + TYPE_QUALS (gnu_desig_type) | TYPE_QUAL_CONST); + + /* Some extra processing is required if we are building a + pointer to an incomplete type (in the GCC sense). We might + have such a type if we just made a dummy, or directly out + of the call to gnat_to_gnu_type above if we are processing + an access type for a record component designating the + record type itself. */ + if (TYPE_MODE (gnu_desig_type) == VOIDmode) + { + /* We must ensure that the pointer to variant we make will + be processed by update_pointer_to when the initial type + is completed. Pretend we made a dummy and let further + processing act as usual. */ + made_dummy = true; + + /* We must ensure that update_pointer_to will not retrieve + the dummy variant when building a properly qualified + version of the complete type. We take advantage of the + fact that get_qualified_type is requiring TYPE_NAMEs to + match to influence build_qualified_type and then also + update_pointer_to here. */ + TYPE_NAME (gnu_desig_type) + = create_concat_name (gnat_desig_type, "INCOMPLETE_CST"); + } + } + + gnu_type + = build_pointer_type_for_mode (gnu_desig_type, p_mode, + No_Strict_Aliasing (gnat_entity)); + } + + /* If we are not defining this object and we made a dummy pointer, + save our current definition, evaluate the actual type, and replace + the tentative type we made with the actual one. If we are to defer + actually looking up the actual type, make an entry in the + deferred list. If this is from a limited with, we have to defer + to the end of the current spec in two cases: first if the + designated type is in the current unit and second if the access + type is. */ + if ((! in_main_unit || is_from_limited_with) && made_dummy) + { + tree gnu_old_type + = TYPE_FAT_POINTER_P (gnu_type) + ? TYPE_UNCONSTRAINED_ARRAY (gnu_type) : TREE_TYPE (gnu_type); + + if (esize == POINTER_SIZE + && (got_fat_p || TYPE_FAT_POINTER_P (gnu_type))) + gnu_type + = build_pointer_type + (TYPE_OBJECT_RECORD_TYPE + (TYPE_UNCONSTRAINED_ARRAY (gnu_type))); + + gnu_decl = create_type_decl (gnu_entity_id, gnu_type, attr_list, + !Comes_From_Source (gnat_entity), + 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 + && (in_main_unit + || In_Extended_Main_Code_Unit (gnat_entity)))) + update_pointer_to (TYPE_MAIN_VARIANT (gnu_old_type), + gnat_to_gnu_type (gnat_desig_equiv)); + + /* Note that the call to gnat_to_gnu_type here might have + updated gnu_old_type directly, in which case it is not a + dummy type any more when we get into update_pointer_to. + + This may happen for instance when the designated type is a + record type, because their elaboration starts with an + initial node from make_dummy_type, which may yield the same + node as the one we got. + + Besides, variants of this non-dummy type might have been + created along the way. update_pointer_to is expected to + properly take care of those situations. */ + else + { + struct incomplete *p + = (struct incomplete *) xmalloc (sizeof + (struct incomplete)); + struct incomplete **head + = (is_from_limited_with + && (in_main_unit + || In_Extended_Main_Code_Unit (gnat_entity)) + ? &defer_limited_with : &defer_incomplete_list); + + p->old_type = gnu_old_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 (type_annotate_only && No (gnat_equiv_type)) + gnu_type = ptr_void_type_node; + else + { + /* The runtime representation is the equivalent type. */ + gnu_type = gnat_to_gnu_type (gnat_equiv_type); + maybe_present = 1; + } + + 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, 0); + + break; + + case E_Access_Subtype: + + /* We treat this as identical to its base type; any constraint is + meaningful only to the front end. + + The designated type must be elaborated as well, if it does + not have its own freeze node. Designated (sub)types created + for constrained components of records with discriminants are + not frozen by the front end and thus not elaborated by gigi, + because their use may appear before the base type is frozen, + and because it is not clear that they are needed anywhere in + Gigi. With the current model, there is no correct place where + they could be elaborated. */ + + gnu_type = gnat_to_gnu_type (Etype (gnat_entity)); + 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 not defining this entity, and we have incomplete + entities being processed above us, make a dummy type and + elaborate it later. */ + if (!definition && defer_incomplete_level != 0) + { + struct incomplete *p + = (struct incomplete *) xmalloc (sizeof (struct incomplete)); + tree gnu_ptr_type + = build_pointer_type + (make_dummy_type (Directly_Designated_Type (gnat_entity))); + + p->old_type = TREE_TYPE (gnu_ptr_type); + p->full_type = Directly_Designated_Type (gnat_entity); + p->next = defer_incomplete_list; + defer_incomplete_list = p; + } + else if (!IN (Ekind (Base_Type + (Directly_Designated_Type (gnat_entity))), + Incomplete_Or_Private_Kind)) + gnat_to_gnu_entity (Directly_Designated_Type (gnat_entity), + NULL_TREE, 0); + } + + maybe_present = true; + break; + + /* Subprogram Entities + + The following access functions are defined for subprograms (functions + or procedures): + + 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. + + In addition for function subprograms we have: + + Etype Return type of the function. + + 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: + { + /* The first GCC parameter declaration (a PARM_DECL node). The + PARM_DECL nodes are chained through the TREE_CHAIN field, so this + actually is the head of this parameter list. */ + tree gnu_param_list = NULL_TREE; + /* Likewise for the stub associated with an exported procedure. */ + tree gnu_stub_param_list = NULL_TREE; + /* The type returned by a function. If the subprogram is a procedure + this type should be void_type_node. */ + tree gnu_return_type = void_type_node; + /* List of fields in return type of procedure with copy-in copy-out + parameters. */ + tree gnu_field_list = NULL_TREE; + /* Non-null for subprograms containing parameters passed by copy-in + copy-out (Ada 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 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_return_list = NULL_TREE; + /* If an import pragma asks to map this subprogram to a GCC builtin, + this is the builtin DECL node. */ + tree gnu_builtin_decl = NULL_TREE; + /* For the stub associated with an exported procedure. */ + tree gnu_stub_type = NULL_TREE, gnu_stub_name = NULL_TREE; + tree gnu_ext_name = create_concat_name (gnat_entity, NULL); + Entity_Id gnat_param; + bool inline_flag = Is_Inlined (gnat_entity); + bool public_flag = Is_Public (gnat_entity) || imported_p; + bool extern_flag + = (Is_Public (gnat_entity) && !definition) || imported_p; + bool pure_flag = Is_Pure (gnat_entity); + bool volatile_flag = No_Return (gnat_entity); + bool returns_by_ref = false; + bool returns_unconstrained = false; + bool returns_by_target_ptr = false; + bool has_copy_in_out = false; + bool has_stub = false; + int parmnum; + + if (kind == E_Subprogram_Type && !definition) + /* A parameter may refer to this type, so defer completion + of any incomplete types. */ + 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))) + { + if (Ekind (Alias (gnat_entity)) == E_Enumeration_Literal) + gnat_to_gnu_entity (Etype (Alias (gnat_entity)), NULL_TREE, 0); + + gnu_decl = gnat_to_gnu_entity (Alias (gnat_entity), + gnu_expr, 0); + + /* 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, 0); + + break; + } + + /* If this subprogram is expectedly bound to a GCC builtin, fetch the + corresponding DECL node. + + We still want the parameter associations to take place because the + proper generation of calls depends on it (a GNAT parameter without + a corresponding GCC tree has a very specific meaning), so we don't + just break here. */ + if (Convention (gnat_entity) == Convention_Intrinsic) + gnu_builtin_decl = builtin_decl_for (gnu_ext_name); + + /* ??? What if we don't find the builtin node above ? warn ? err ? + In the current state we neither warn nor err, and calls will just + be handled as for regular subprograms. */ + + if (kind == E_Function || kind == E_Subprogram_Type) + gnu_return_type = gnat_to_gnu_type (Etype (gnat_entity)); + + /* If this function returns by reference, make the actual + return type of this function the pointer and mark the decl. */ + if (Returns_By_Ref (gnat_entity)) + { + returns_by_ref = true; + gnu_return_type = build_pointer_type (gnu_return_type); + } + + /* If the Mechanism is By_Reference, ensure the return type uses + the machine's by-reference mechanism, which may not the same + as above (e.g., it might be by passing a fake parameter). */ + else if (kind == E_Function + && Mechanism (gnat_entity) == By_Reference) + { + TREE_ADDRESSABLE (gnu_return_type) = 1; + + /* We expect this bit to be reset by gigi shortly, so can avoid a + type node copy here. This actually also prevents troubles with + the generation of debug information for the function, because + we might have issued such info for this type already, and would + be attaching a distinct type node to the function if we made a + copy here. */ + } + + /* If we are supposed to return an unconstrained array, + actually return a fat pointer and make a note of that. Return + a pointer to an unconstrained record of variable size. */ + else if (TREE_CODE (gnu_return_type) == UNCONSTRAINED_ARRAY_TYPE) + { + gnu_return_type = TREE_TYPE (gnu_return_type); + returns_unconstrained = true; + } + + /* If the type requires a transient scope, the result is allocated + on the secondary stack, so the result type of the function is + just a pointer. */ + else if (Requires_Transient_Scope (Etype (gnat_entity))) + { + gnu_return_type = build_pointer_type (gnu_return_type); + returns_unconstrained = true; + } + + /* If the type is a padded type and the underlying type would not + be passed by reference or this function has a foreign convention, + return the underlying type. */ + else if (TREE_CODE (gnu_return_type) == RECORD_TYPE + && TYPE_IS_PADDING_P (gnu_return_type) + && (!default_pass_by_ref (TREE_TYPE + (TYPE_FIELDS (gnu_return_type))) + || Has_Foreign_Convention (gnat_entity))) + gnu_return_type = TREE_TYPE (TYPE_FIELDS (gnu_return_type)); + + /* If the return type has a non-constant size, we convert the function + into a procedure and its caller will pass a pointer to an object as + the first parameter when we call the function. This can happen for + an unconstrained type with a maximum size or a constrained type with + a size not known at compile time. */ + if (TYPE_SIZE_UNIT (gnu_return_type) + && !TREE_CONSTANT (TYPE_SIZE_UNIT (gnu_return_type))) + { + returns_by_target_ptr = true; + gnu_param_list + = create_param_decl (get_identifier ("TARGET"), + build_reference_type (gnu_return_type), + true); + gnu_return_type = void_type_node; + } + + /* If the return type has a size that overflows, we cannot have + a function that returns that type. This usage doesn't make + sense anyway, so give an error here. */ + if (TYPE_SIZE_UNIT (gnu_return_type) + && TREE_CONSTANT (TYPE_SIZE_UNIT (gnu_return_type)) + && TREE_OVERFLOW (TYPE_SIZE_UNIT (gnu_return_type))) + { + post_error ("cannot return type whose size overflows", + gnat_entity); + gnu_return_type = copy_node (gnu_return_type); + TYPE_SIZE (gnu_return_type) = bitsize_zero_node; + TYPE_SIZE_UNIT (gnu_return_type) = size_zero_node; + TYPE_MAIN_VARIANT (gnu_return_type) = gnu_return_type; + TYPE_NEXT_VARIANT (gnu_return_type) = NULL_TREE; + } + + /* Look at all our parameters and get the type of + each. While doing this, build a copy-out structure if + we need one. */ + + /* Loop over the parameters and get their associated GCC tree. + While doing this, build a copy-out structure if we need one. */ + for (gnat_param = First_Formal_With_Extras (gnat_entity), parmnum = 0; + Present (gnat_param); + gnat_param = Next_Formal_With_Extras (gnat_param), parmnum++) + { + tree gnu_param_name = get_entity_name (gnat_param); + tree gnu_param_type = gnat_to_gnu_type (Etype (gnat_param)); + tree gnu_param, gnu_field; + bool copy_in_copy_out = false; + Mechanism_Type mech = Mechanism (gnat_param); + + /* 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 each argument "as is". */ + if (gnu_builtin_decl) + mech = By_Copy; + /* Handle the first parameter of a valued procedure specially. */ + else if (Is_Valued_Procedure (gnat_entity) && parmnum == 0) + mech = By_Copy_Return; + /* Otherwise, 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) + ; + else if (By_Descriptor_Last <= mech && mech <= By_Descriptor) + mech = By_Descriptor; + else if (mech > 0) + { + if (TREE_CODE (gnu_param_type) == UNCONSTRAINED_ARRAY_TYPE + || TREE_CODE (TYPE_SIZE (gnu_param_type)) != INTEGER_CST + || 0 < compare_tree_int (TYPE_SIZE (gnu_param_type), + mech)) + mech = By_Reference; + else + mech = By_Copy; + } + else + { + post_error ("unsupported mechanism for&", gnat_param); + mech = Default; + } + + gnu_param + = gnat_to_gnu_param (gnat_param, mech, gnat_entity, + Has_Foreign_Convention (gnat_entity), + ©_in_copy_out); + + /* 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 (gnu_param) + { + /* If it's an exported subprogram, we build a parameter list + in parallel, in case we need to emit a stub for it. */ + if (Is_Exported (gnat_entity)) + { + gnu_stub_param_list + = chainon (gnu_param, gnu_stub_param_list); + /* Change By_Descriptor parameter to By_Reference for + the internal version of an exported subprogram. */ + if (mech == By_Descriptor) + { + gnu_param + = gnat_to_gnu_param (gnat_param, By_Reference, + gnat_entity, false, + ©_in_copy_out); + has_stub = true; + } + else + gnu_param = copy_node (gnu_param); + } + + gnu_param_list = chainon (gnu_param, gnu_param_list); + Sloc_to_locus (Sloc (gnat_param), + &DECL_SOURCE_LOCATION (gnu_param)); + save_gnu_tree (gnat_param, gnu_param, false); + + /* If a parameter is a pointer, this function may modify + memory through it and thus shouldn't be considered + a pure function. Also, the memory may be modified + between two calls, so they can't be CSE'ed. The latter + case also handles by-ref parameters. */ + if (POINTER_TYPE_P (gnu_param_type) + || TYPE_FAT_POINTER_P (gnu_param_type)) + pure_flag = false; + } + + if (copy_in_copy_out) + { + if (!has_copy_in_out) + { + gcc_assert (TREE_CODE (gnu_return_type) == VOID_TYPE); + gnu_return_type = make_node (RECORD_TYPE); + TYPE_NAME (gnu_return_type) = get_identifier ("RETURN"); + has_copy_in_out = true; + } + + gnu_field = create_field_decl (gnu_param_name, gnu_param_type, + gnu_return_type, 0, 0, 0, 0); + Sloc_to_locus (Sloc (gnat_param), + &DECL_SOURCE_LOCATION (gnu_field)); + TREE_CHAIN (gnu_field) = gnu_field_list; + gnu_field_list = gnu_field; + gnu_return_list = tree_cons (gnu_field, gnu_param, + gnu_return_list); + } + } + + /* Do not compute record for out parameters if subprogram is + stubbed since structures are incomplete for the back-end. */ + if (gnu_field_list && Convention (gnat_entity) != Convention_Stubbed) + finish_record_type (gnu_return_type, nreverse (gnu_field_list), + 0, false); + + /* If we have a CICO list but it has only one entry, we convert + this function into a function that simply returns that one + object. */ + if (list_length (gnu_return_list) == 1) + gnu_return_type = TREE_TYPE (TREE_PURPOSE (gnu_return_list)); + + if (Has_Stdcall_Convention (gnat_entity)) + prepend_one_attribute_to + (&attr_list, ATTR_MACHINE_ATTRIBUTE, + get_identifier ("stdcall"), NULL_TREE, + gnat_entity); + + /* If we are on a target where stack realignment is needed for 'main' + to honor GCC's implicit expectations (stack alignment greater than + what the base ABI guarantees), ensure we do the same for foreign + convention subprograms as they might be used as callbacks from code + breaking such expectations. Note that this applies to task entry + points in particular. */ + if (FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN + && Has_Foreign_Convention (gnat_entity)) + prepend_one_attribute_to + (&attr_list, ATTR_MACHINE_ATTRIBUTE, + get_identifier ("force_align_arg_pointer"), NULL_TREE, + gnat_entity); + + /* The lists have been built in reverse. */ + gnu_param_list = nreverse (gnu_param_list); + if (has_stub) + gnu_stub_param_list = nreverse (gnu_stub_param_list); + gnu_return_list = nreverse (gnu_return_list); + + if (Ekind (gnat_entity) == E_Function) + Set_Mechanism (gnat_entity, + (returns_by_ref || returns_unconstrained + ? By_Reference : By_Copy)); + gnu_type + = create_subprog_type (gnu_return_type, gnu_param_list, + gnu_return_list, returns_unconstrained, + returns_by_ref, returns_by_target_ptr); + + if (has_stub) + gnu_stub_type + = create_subprog_type (gnu_return_type, gnu_stub_param_list, + gnu_return_list, returns_unconstrained, + returns_by_ref, returns_by_target_ptr); + + /* A subprogram (something that doesn't return anything) shouldn't + be considered Pure since there would be no reason for such a + subprogram. Note that procedures with Out (or In Out) parameters + have already been converted into a function with a return type. */ + if (TREE_CODE (gnu_return_type) == VOID_TYPE) + pure_flag = false; + + /* The semantics of "pure" in Ada essentially matches that of "const" + in the back-end. In particular, both properties are orthogonal to + the "nothrow" property. But this is true only if the EH circuitry + is explicit in the internal representation of the back-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 flow; thus + they can be neither "const" nor "pure" in the back-end sense. */ + gnu_type + = build_qualified_type (gnu_type, + TYPE_QUALS (gnu_type) + | (Exception_Mechanism == Back_End_Exceptions + ? TYPE_QUAL_CONST * pure_flag : 0) + | (TYPE_QUAL_VOLATILE * volatile_flag)); + + Sloc_to_locus (Sloc (gnat_entity), &input_location); + + if (has_stub) + gnu_stub_type + = build_qualified_type (gnu_stub_type, + TYPE_QUALS (gnu_stub_type) + | (Exception_Mechanism == Back_End_Exceptions + ? TYPE_QUAL_CONST * pure_flag : 0) + | (TYPE_QUAL_VOLATILE * volatile_flag)); + + /* If we have a builtin decl for that function, check the signatures + compatibilities. If the signatures are compatible, use the builtin + decl. If they are not, we expect the checker predicate to have + posted the appropriate errors, and just continue with what we have + so far. */ + if (gnu_builtin_decl) + { + tree gnu_builtin_type = TREE_TYPE (gnu_builtin_decl); + + if (compatible_signatures_p (gnu_type, gnu_builtin_type)) + { + gnu_decl = gnu_builtin_decl; + gnu_type = gnu_builtin_type; + break; + } + } + + /* 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_entity)) && gnu_ext_name == gnu_entity_id) + gnu_ext_name = NULL_TREE; + + /* 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 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_id, gnu_ext_name, gnu_type, + gnu_address, false, Is_Public (gnat_entity), + extern_flag, false, NULL, gnat_entity); + DECL_BY_REF_P (gnu_decl) = 1; + } + + else if (kind == E_Subprogram_Type) + gnu_decl = create_type_decl (gnu_entity_id, gnu_type, attr_list, + !Comes_From_Source (gnat_entity), + debug_info_p, gnat_entity); + else + { + if (has_stub) + { + gnu_stub_name = gnu_ext_name; + gnu_ext_name = create_concat_name (gnat_entity, "internal"); + public_flag = false; + } + + gnu_decl = create_subprog_decl (gnu_entity_id, gnu_ext_name, + gnu_type, gnu_param_list, + inline_flag, public_flag, + extern_flag, attr_list, + gnat_entity); + if (has_stub) + { + tree gnu_stub_decl + = create_subprog_decl (gnu_entity_id, gnu_stub_name, + gnu_stub_type, gnu_stub_param_list, + inline_flag, true, + extern_flag, attr_list, + gnat_entity); + SET_DECL_FUNCTION_STUB (gnu_decl, gnu_stub_decl); + } + + /* This is unrelated to the stub built right above. */ + DECL_STUBBED_P (gnu_decl) + = Convention (gnat_entity) == Convention_Stubbed; + } + } + 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: + { + /* 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. */ + Entity_Id full_view + = (IN (Ekind (gnat_entity), Incomplete_Kind) + && From_With_Type (gnat_entity)) + ? Non_Limited_View (gnat_entity) + : Present (Full_View (gnat_entity)) + ? Full_View (gnat_entity) + : Underlying_Full_View (gnat_entity); + + /* If this is an incomplete type with no full view, it must be a Taft + Amendment type, in which case we return a dummy type. Otherwise, + just get the type from its Etype. */ + if (No (full_view)) + { + if (kind == E_Incomplete_Type) + gnu_type = make_dummy_type (gnat_entity); + else + { + gnu_decl = gnat_to_gnu_entity (Etype (gnat_entity), + NULL_TREE, 0); + maybe_present = true; + } + break; + } + + /* 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); + break; + } + + /* Otherwise, if we are not defining the type now, get the type + from the full view. But always get the type from the full view + for define on use types, since otherwise we won't see them! */ + else if (!definition + || (Is_Itype (full_view) + && No (Freeze_Node (gnat_entity))) + || (Is_Itype (gnat_entity) + && No (Freeze_Node (full_view)))) + { + gnu_decl = gnat_to_gnu_entity (full_view, NULL_TREE, 0); + maybe_present = true; + break; + } + + /* For incomplete types, make a dummy type entry which will be + replaced later. */ + gnu_type = make_dummy_type (gnat_entity); + + /* Save this type as the full declaration's type so we can do any + needed updates when we see it. */ + gnu_decl = create_type_decl (gnu_entity_id, gnu_type, attr_list, + !Comes_From_Source (gnat_entity), + debug_info_p, gnat_entity); + save_gnu_tree (full_view, gnu_decl, 0); + break; + } + + /* Simple class_wide types are always viewed as their root_type + by Gigi unless an Equivalent_Type is specified. */ + case E_Class_Wide_Type: + gnu_decl = gnat_to_gnu_entity (gnat_equiv_type, NULL_TREE, 0); + maybe_present = true; + break; + + case E_Task_Type: + case E_Task_Subtype: + case E_Protected_Type: + case E_Protected_Subtype: + if (type_annotate_only && No (gnat_equiv_type)) + gnu_type = void_type_node; + else + gnu_type = gnat_to_gnu_type (gnat_equiv_type); + + maybe_present = true; + break; + + case E_Label: + gnu_decl = create_label_decl (gnu_entity_id); + 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; + + 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 ((!gnu_decl || this_made_decl) && IN (kind, Type_Kind)) + { + if (Is_Tagged_Type (gnat_entity) + || Is_Class_Wide_Equivalent_Type (gnat_entity)) + TYPE_ALIGN_OK (gnu_type) = 1; + + if (AGGREGATE_TYPE_P (gnu_type) && Is_By_Reference_Type (gnat_entity)) + TYPE_BY_REFERENCE_P (gnu_type) = 1; + + /* ??? 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) + gnu_size = validate_size (Esize (gnat_entity), gnu_type, gnat_entity, + TYPE_DECL, false, + Has_Size_Clause (gnat_entity)); + + /* 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 = 0; + } + + /* If the alignment hasn't already been processed and this is + not an unconstrained array, 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 as the type size has already + been adjusted to the alignment. */ + if (gnu_size) + size = gnu_size; + else if ((TREE_CODE (gnu_type) == RECORD_TYPE + || TREE_CODE (gnu_type) == UNION_TYPE + || TREE_CODE (gnu_type) == QUAL_UNION_TYPE) + && !TYPE_IS_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 (host_integerp (size, 1) + && align >= TREE_INT_CST_LOW (size) * BITS_PER_UNIT) + post_error_ne ("?suspiciously large alignment specified for&", + Expression (Alignment_Clause (gnat_entity)), + gnat_entity); + } + } + else if (Is_Atomic (gnat_entity) && !gnu_size + && host_integerp (TYPE_SIZE (gnu_type), 1) + && integer_pow2p (TYPE_SIZE (gnu_type))) + align = MIN (BIGGEST_ALIGNMENT, + tree_low_cst (TYPE_SIZE (gnu_type), 1)); + else if (Is_Atomic (gnat_entity) && gnu_size + && host_integerp (gnu_size, 1) + && integer_pow2p (gnu_size)) + align = MIN (BIGGEST_ALIGNMENT, tree_low_cst (gnu_size, 1)); + + /* See if we need to pad the type. If we did, and made a record, + the name of the new type may be changed. So get it back for + us when we make the new TYPE_DECL below. */ + if (gnu_size || align > 0) + gnu_type = maybe_pad_type (gnu_type, gnu_size, align, gnat_entity, + "PAD", true, definition, false); + + if (TREE_CODE (gnu_type) == RECORD_TYPE + && TYPE_IS_PADDING_P (gnu_type)) + { + gnu_entity_id = TYPE_NAME (gnu_type); + if (TREE_CODE (gnu_entity_id) == TYPE_DECL) + gnu_entity_id = DECL_NAME (gnu_entity_id); + } + + set_rm_size (RM_Size (gnat_entity), gnu_type, gnat_entity); + + /* If we are at global level, GCC will have applied variable_size to + the type, but that won't have done anything. So, if it's not + a constant or self-referential, call elaborate_expression_1 to + make a variable for the size rather than calculating it each time. + Handle both the RM size and the actual size. */ + if (global_bindings_p () + && TYPE_SIZE (gnu_type) + && !TREE_CONSTANT (TYPE_SIZE (gnu_type)) + && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type))) + { + if (TREE_CODE (gnu_type) == RECORD_TYPE + && operand_equal_p (TYPE_ADA_SIZE (gnu_type), + TYPE_SIZE (gnu_type), 0)) + { + TYPE_SIZE (gnu_type) + = elaborate_expression_1 (gnat_entity, gnat_entity, + TYPE_SIZE (gnu_type), + get_identifier ("SIZE"), + definition, 0); + SET_TYPE_ADA_SIZE (gnu_type, TYPE_SIZE (gnu_type)); + } + else + { + TYPE_SIZE (gnu_type) + = elaborate_expression_1 (gnat_entity, gnat_entity, + TYPE_SIZE (gnu_type), + get_identifier ("SIZE"), + definition, 0); + + /* ??? 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) + = build_binary_op + (MULT_EXPR, sizetype, + elaborate_expression_1 + (gnat_entity, gnat_entity, + build_binary_op (EXACT_DIV_EXPR, sizetype, + TYPE_SIZE_UNIT (gnu_type), + size_int (TYPE_ALIGN (gnu_type) + / BITS_PER_UNIT)), + get_identifier ("SIZE_A_UNIT"), + definition, 0), + size_int (TYPE_ALIGN (gnu_type) / BITS_PER_UNIT)); + + if (TREE_CODE (gnu_type) == RECORD_TYPE) + SET_TYPE_ADA_SIZE + (gnu_type, + elaborate_expression_1 (gnat_entity, + gnat_entity, + TYPE_ADA_SIZE (gnu_type), + get_identifier ("RM_SIZE"), + definition, 0)); + } + } + + /* If this is a record type or subtype, call elaborate_expression_1 on + any field position. Do this for both global and local types. + Skip any fields that we haven't made trees for to avoid problems with + class wide types. */ + if (IN (kind, Record_Kind)) + 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); + + /* ??? Unfortunately, GCC needs to be able to prove the + alignment of this offset and if it's a variable, it can't. + In GCC 3.4, we'll use DECL_OFFSET_ALIGN in some way, but + right now, we have to put in an explicit multiply and + divide by that value. */ + if (!CONTAINS_PLACEHOLDER_P (DECL_FIELD_OFFSET (gnu_field))) + { + DECL_FIELD_OFFSET (gnu_field) + = build_binary_op + (MULT_EXPR, sizetype, + elaborate_expression_1 + (gnat_temp, gnat_temp, + build_binary_op (EXACT_DIV_EXPR, sizetype, + DECL_FIELD_OFFSET (gnu_field), + size_int (DECL_OFFSET_ALIGN (gnu_field) + / BITS_PER_UNIT)), + get_identifier ("OFFSET"), + definition, 0), + size_int (DECL_OFFSET_ALIGN (gnu_field) / BITS_PER_UNIT)); + + /* ??? 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. */ + if (global_bindings_p ()) + mark_visited (&DECL_FIELD_OFFSET (gnu_field)); + } + } + + gnu_type = build_qualified_type (gnu_type, + (TYPE_QUALS (gnu_type) + | (TYPE_QUAL_VOLATILE + * Treat_As_Volatile (gnat_entity)))); + + if (Is_Atomic (gnat_entity)) + check_ok_for_atomic (gnu_type, gnat_entity, false); + + if (Present (Alignment_Clause (gnat_entity))) + TYPE_USER_ALIGN (gnu_type) = 1; + + if (Universal_Aliasing (gnat_entity)) + TYPE_UNIVERSAL_ALIASING_P (TYPE_MAIN_VARIANT (gnu_type)) = 1; + + if (!gnu_decl) + gnu_decl = create_type_decl (gnu_entity_id, gnu_type, attr_list, + !Comes_From_Source (gnat_entity), + debug_info_p, gnat_entity); + else + TREE_TYPE (gnu_decl) = gnu_type; + } + + if (IN (kind, Type_Kind) && !TYPE_IS_DUMMY_P (TREE_TYPE (gnu_decl))) + { + gnu_type = TREE_TYPE (gnu_decl); + + /* Back-annotate the Alignment of the type if not already in the + tree. Likewise for sizes. */ + if (Unknown_Alignment (gnat_entity)) + Set_Alignment (gnat_entity, + UI_From_Int (TYPE_ALIGN (gnu_type) / BITS_PER_UNIT)); + + if (Unknown_Esize (gnat_entity) && TYPE_SIZE (gnu_type)) + { + /* If the size is self-referential, we annotate the maximum + value of that size. */ + tree gnu_size = TYPE_SIZE (gnu_type); + + if (CONTAINS_PLACEHOLDER_P (gnu_size)) + gnu_size = max_size (gnu_size, true); + + Set_Esize (gnat_entity, annotate_value (gnu_size)); + + if (type_annotate_only && Is_Tagged_Type (gnat_entity)) + { + /* In this mode the tag and the parent components are not + generated by the front-end, so the sizes must be adjusted + explicitly now. */ + int size_offset, new_size; + + if (Is_Derived_Type (gnat_entity)) + { + size_offset + = UI_To_Int (Esize (Etype (Base_Type (gnat_entity)))); + Set_Alignment (gnat_entity, + Alignment (Etype (Base_Type (gnat_entity)))); + } + else + size_offset = POINTER_SIZE; + + new_size = UI_To_Int (Esize (gnat_entity)) + size_offset; + Set_Esize (gnat_entity, + UI_From_Int (((new_size + (POINTER_SIZE - 1)) + / POINTER_SIZE) * POINTER_SIZE)); + Set_RM_Size (gnat_entity, Esize (gnat_entity)); + } + } + + if (Unknown_RM_Size (gnat_entity) && rm_size (gnu_type)) + Set_RM_Size (gnat_entity, annotate_value (rm_size (gnu_type))); + } + + if (!Comes_From_Source (gnat_entity) && DECL_P (gnu_decl)) + DECL_ARTIFICIAL (gnu_decl) = 1; + + if (!debug_info_p && DECL_P (gnu_decl) + && TREE_CODE (gnu_decl) != FUNCTION_DECL + && No (Renamed_Object (gnat_entity))) + DECL_IGNORED_P (gnu_decl) = 1; + + /* 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); + + /* If this is an enumeral or floating-point type, we were not able to set + the bounds since they refer to the type. These bounds are always static. + + For enumeration types, also write debugging information and declare the + enumeration literal table, if needed. */ + + if ((kind == E_Enumeration_Type && Present (First_Literal (gnat_entity))) + || (kind == E_Floating_Point_Type && !Vax_Float (gnat_entity))) + { + tree gnu_scalar_type = gnu_type; + + /* If this is a padded type, we need to use the underlying type. */ + if (TREE_CODE (gnu_scalar_type) == RECORD_TYPE + && 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_type; + + TYPE_MIN_VALUE (gnu_scalar_type) + = gnat_to_gnu (Type_Low_Bound (gnat_entity)); + TYPE_MAX_VALUE (gnu_scalar_type) + = gnat_to_gnu (Type_High_Bound (gnat_entity)); + + if (TREE_CODE (gnu_scalar_type) == ENUMERAL_TYPE) + { + /* Since this has both a typedef and a tag, avoid outputting + the name twice. */ + DECL_ARTIFICIAL (gnu_decl) = 1; + rest_of_type_decl_compilation (gnu_decl); + } + } + + /* If we deferred processing of incomplete types, re-enable it. If there + were no other disables and we have some to process, do so. */ + if (this_deferred && --defer_incomplete_level == 0) + { + if (defer_incomplete_list) + { + struct incomplete *incp, *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. */ + incp = defer_incomplete_list; + defer_incomplete_list = NULL; + + /* For finalization, however, all types must be complete so we + cannot do the same because deferred incomplete types may end up + referencing each other. Process them all recursively first. */ + defer_finalize_level++; + + for (; incp; incp = next) + { + next = incp->next; + + if (incp->old_type) + update_pointer_to (TYPE_MAIN_VARIANT (incp->old_type), + gnat_to_gnu_type (incp->full_type)); + free (incp); + } + + defer_finalize_level--; + } + + /* All the deferred incomplete types have been processed so we can + now proceed with the finalization of the deferred types. */ + if (defer_finalize_level == 0 && defer_finalize_list) + { + unsigned int i; + tree t; + + for (i = 0; VEC_iterate (tree, defer_finalize_list, i, t); i++) + rest_of_type_decl_compilation_no_defer (t); + + VEC_free (tree, heap, defer_finalize_list); + } + } + + /* If we are not defining this type, see if it's in the incomplete list. + If so, handle that list entry now. */ + else if (!definition) + { + struct incomplete *incp; + + for (incp = defer_incomplete_list; incp; incp = incp->next) + if (incp->old_type && incp->full_type == gnat_entity) + { + update_pointer_to (TYPE_MAIN_VARIANT (incp->old_type), + TREE_TYPE (gnu_decl)); + incp->old_type = NULL_TREE; + } + } + + if (this_global) + force_global--; + + if (Is_Packed_Array_Type (gnat_entity) + && Is_Itype (Associated_Node_For_Itype (gnat_entity)) + && No (Freeze_Node (Associated_Node_For_Itype (gnat_entity))) + && !present_gnu_tree (Associated_Node_For_Itype (gnat_entity))) + gnat_to_gnu_entity (Associated_Node_For_Itype (gnat_entity), NULL_TREE, 0); + + 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, 0); + + if (TREE_CODE (gnu_field) == COMPONENT_REF) + gnu_field = TREE_OPERAND (gnu_field, 1); + + return gnu_field; +} + +/* Wrap up compilation of DECL, a TYPE_DECL, possibly deferring it. + Every TYPE_DECL generated for a type definition must be passed + to this function once everything else has been done for it. */ + +void +rest_of_type_decl_compilation (tree decl) +{ + /* We need to defer finalizing the type if incomplete types + are being deferred or if they are being processed. */ + if (defer_incomplete_level || defer_finalize_level) + VEC_safe_push (tree, heap, defer_finalize_list, decl); + else + rest_of_type_decl_compilation_no_defer (decl); +} + +/* Same as above but without deferring the compilation. This + function should not be invoked directly on a TYPE_DECL. */ + +static void +rest_of_type_decl_compilation_no_defer (tree decl) +{ + const int toplev = global_bindings_p (); + tree t = TREE_TYPE (decl); + + rest_of_decl_compilation (decl, toplev, 0); + + /* Now process all the variants. This is needed for STABS. */ + for (t = TYPE_MAIN_VARIANT (t); t; t = TYPE_NEXT_VARIANT (t)) + { + if (t == TREE_TYPE (decl)) + continue; + + if (!TYPE_STUB_DECL (t)) + { + TYPE_STUB_DECL (t) = build_decl (TYPE_DECL, DECL_NAME (decl), t); + DECL_ARTIFICIAL (TYPE_STUB_DECL (t)) = 1; + } + + rest_of_type_compilation (t, toplev); + } +} + +/* Finalize any From_With_Type incomplete types. We do this after processing + our compilation unit and after processing its spec, if this is a body. */ + +void +finalize_from_with_types (void) +{ + struct incomplete *incp = defer_limited_with; + struct incomplete *next; + + defer_limited_with = 0; + for (; incp; incp = next) + { + next = incp->next; + + if (incp->old_type != 0) + update_pointer_to (TYPE_MAIN_VARIANT (incp->old_type), + gnat_to_gnu_type (incp->full_type)); + free (incp); + } +} + +/* 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. If a type is supposed to + exist, but does not, abort unless annotating types, in which case + return Empty. If GNAT_ENTITY is Empty, return Empty. */ + +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: + gnat_equiv = Equivalent_Type (gnat_entity); + break; + + case E_Class_Wide_Type: + gnat_equiv = ((Present (Equivalent_Type (gnat_entity))) + ? Equivalent_Type (gnat_entity) + : Root_Type (gnat_entity)); + break; + + case E_Task_Type: + case E_Task_Subtype: + case E_Protected_Type: + case E_Protected_Subtype: + gnat_equiv = Corresponding_Record_Type (gnat_entity); + break; + + default: + break; + } + + gcc_assert (Present (gnat_equiv) || type_annotate_only); + return gnat_equiv; +} + +/* Return a GCC tree for a parameter corresponding to GNAT_PARAM and + using MECH as its passing mechanism, to be placed in the parameter + list built for GNAT_SUBPROG. Assume a foreign convention for the + latter if FOREIGN is true. 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 those 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, Mechanism_Type mech, + Entity_Id gnat_subprog, bool foreign, bool *cico) +{ + tree gnu_param_name = get_entity_name (gnat_param); + tree gnu_param_type = gnat_to_gnu_type (Etype (gnat_param)); + 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, by_ref = false; + tree gnu_param; + + /* Copy-return is used only for the first parameter of a valued procedure. + It's a copy mechanism for which a parameter is never allocated. */ + if (mech == By_Copy_Return) + { + gcc_assert (Ekind (gnat_param) == E_Out_Parameter); + mech = By_Copy; + by_return = true; + } + + /* If this is either a foreign function or if the underlying type won't + be passed by reference, strip off possible padding type. */ + if (TREE_CODE (gnu_param_type) == RECORD_TYPE + && TYPE_IS_PADDING_P (gnu_param_type)) + { + tree unpadded_type = TREE_TYPE (TYPE_FIELDS (gnu_param_type)); + + if (mech == By_Reference + || foreign + || (!must_pass_by_ref (unpadded_type) + && (mech == By_Copy || !default_pass_by_ref (unpadded_type)))) + gnu_param_type = unpadded_type; + } + + /* If this is a read-only parameter, make a variant of the type that is + read-only. ??? However, if this is an unconstrained array, that type + can be very complex, so skip it for now. Likewise for any other + self-referential type. */ + if (ro_param + && TREE_CODE (gnu_param_type) != UNCONSTRAINED_ARRAY_TYPE + && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_param_type))) + gnu_param_type = build_qualified_type (gnu_param_type, + (TYPE_QUALS (gnu_param_type) + | TYPE_QUAL_CONST)); + + /* 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)))); + + /* VMS descriptors are themselves passed by reference. */ + if (mech == By_Descriptor) + gnu_param_type + = build_pointer_type (build_vms_descriptor (gnu_param_type, + Mechanism (gnat_param), + gnat_subprog)); + + /* Arrays are passed as pointers to element type for foreign conventions. */ + else 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); + + by_component_ptr = true; + gnu_param_type = TREE_TYPE (gnu_param_type); + + if (ro_param) + gnu_param_type = build_qualified_type (gnu_param_type, + (TYPE_QUALS (gnu_param_type) + | TYPE_QUAL_CONST)); + + gnu_param_type = build_pointer_type (gnu_param_type); + } + + /* Fat pointers are passed as thin pointers for foreign conventions. */ + else if (foreign && TYPE_FAT_POINTER_P (gnu_param_type)) + gnu_param_type + = make_type_from_size (gnu_param_type, size_int (POINTER_SIZE), 0); + + /* If we must pass or were requested to 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 (must_pass_by_ref (gnu_param_type) + || mech == By_Reference + || (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))))) + { + 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; + + 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 isn't + a pointer or aggregate, 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. For the special parameter of a valued procedure, + never pass it in. + + An exception is made to cover the RM-6.4.1 rule requiring "by copy" + Out parameters with discriminants or implicit initial values to be + handled like In Out parameters. These type are normally built as + aggregates, hence passed by reference, except for some packed arrays + which end up encoded in special integer types. + + The exception we need to make is then for packed arrays of records + with discriminants or implicit initial values. We have no light/easy + way to check for the latter case, so we merely check for packed arrays + of records. This may lead to useless copy-in operations, but in very + rare cases only, as these would be exceptions in a set of already + exceptional situations. */ + if (Ekind (gnat_param) == E_Out_Parameter + && !by_ref + && (by_return + || (mech != By_Descriptor + && !POINTER_TYPE_P (gnu_param_type) + && !AGGREGATE_TYPE_P (gnu_param_type))) + && !(Is_Array_Type (Etype (gnat_param)) + && Is_Packed (Etype (gnat_param)) + && Is_Composite_Type (Component_Type (Etype (gnat_param))))) + return gnu_param_type; + + gnu_param = create_param_decl (gnu_param_name, gnu_param_type, + ro_param || by_ref || by_component_ptr); + DECL_BY_REF_P (gnu_param) = by_ref; + DECL_BY_COMPONENT_PTR_P (gnu_param) = by_component_ptr; + DECL_BY_DESCRIPTOR_P (gnu_param) = (mech == By_Descriptor); + DECL_POINTS_TO_READONLY_P (gnu_param) + = (ro_param && (by_ref || by_component_ptr)); + + /* 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; +} + +/* 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 specified by GNAT_TYPE and GNU_TYPE has + a non-aliased component in the back-end sense. */ + +static bool +array_type_has_nonaliased_component (Entity_Id gnat_type, tree gnu_type) +{ + /* If the type below this is a multi-array type, then + this does not have aliased components. */ + if (TREE_CODE (TREE_TYPE (gnu_type)) == ARRAY_TYPE + && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_type))) + return true; + + if (Has_Aliased_Components (gnat_type)) + return false; + + return type_for_nonaliased_component_p (TREE_TYPE (gnu_type)); +} + +/* 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 for avoiding static constraint error expression + is needed until the front stops generating bogus conversions + on bounds of real types. */ + + if (!Raises_Constraint_Error (gnat_lb)) + elaborate_expression (gnat_lb, gnat_entity, get_identifier ("L"), + 1, 0, Needs_Debug_Info (gnat_entity)); + if (!Raises_Constraint_Error (gnat_hb)) + elaborate_expression (gnat_hb, gnat_entity, get_identifier ("U"), + 1, 0, Needs_Debug_Info (gnat_entity)); + break; + } + + case E_Record_Type: + { + Node_Id full_definition = Declaration_Node (gnat_entity); + Node_Id record_definition = Type_Definition (full_definition); + + /* If this is a record extension, go a level further to find the + record definition. */ + if (Nkind (record_definition) == N_Derived_Type_Definition) + record_definition = Record_Extension_Part (record_definition); + } + break; + + case E_Record_Subtype: + case E_Private_Subtype: + case E_Limited_Private_Subtype: + case E_Record_Subtype_With_Private: + if (Is_Constrained (gnat_entity) + && Has_Discriminants (Base_Type (gnat_entity)) + && Present (Discriminant_Constraint (gnat_entity))) + { + Node_Id gnat_discriminant_expr; + Entity_Id gnat_field; + + for (gnat_field = First_Discriminant (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)) + /* ??? For now, ignore access discriminants. */ + if (!Is_Access_Type (Etype (Node (gnat_discriminant_expr)))) + elaborate_expression (Node (gnat_discriminant_expr), + gnat_entity, + get_entity_name (gnat_field), 1, 0, 0); + } + break; + + } +} + +/* Mark GNAT_ENTITY as going out of scope at this point. Recursively mark + any entities on its entity chain similarly. */ + +void +mark_out_of_scope (Entity_Id gnat_entity) +{ + Entity_Id gnat_sub_entity; + unsigned int kind = Ekind (gnat_entity); + + /* If this has an entity list, process all in the list. */ + if (IN (kind, Class_Wide_Kind) || IN (kind, Concurrent_Kind) + || IN (kind, Private_Kind) + || kind == E_Block || kind == E_Entry || kind == E_Entry_Family + || kind == E_Function || kind == E_Generic_Function + || kind == E_Generic_Package || kind == E_Generic_Procedure + || kind == E_Loop || kind == E_Operator || kind == E_Package + || kind == E_Package_Body || kind == E_Procedure + || kind == E_Record_Type || kind == E_Record_Subtype + || kind == E_Subprogram_Body || kind == E_Subprogram_Type) + for (gnat_sub_entity = First_Entity (gnat_entity); + Present (gnat_sub_entity); + gnat_sub_entity = Next_Entity (gnat_sub_entity)) + if (Scope (gnat_sub_entity) == gnat_entity + && gnat_sub_entity != gnat_entity) + mark_out_of_scope (gnat_sub_entity); + + /* Now clear this if it has been defined, but only do so if it isn't + a subprogram or parameter. We could refine this, but it isn't + worth it. If this is statically allocated, it is supposed to + hang around out of cope. */ + if (present_gnu_tree (gnat_entity) && !Is_Statically_Allocated (gnat_entity) + && kind != E_Procedure && kind != E_Function && !IN (kind, Formal_Kind)) + { + save_gnu_tree (gnat_entity, NULL_TREE, true); + save_gnu_tree (gnat_entity, error_mark_node, true); + } +} + +/* Set the alias set of GNU_NEW_TYPE to be that of GNU_OLD_TYPE. If this + is a multi-dimensional array type, do this recursively. */ + +static void +copy_alias_set (tree gnu_new_type, tree gnu_old_type) +{ + /* Remove any padding from GNU_OLD_TYPE. It doesn't matter in the case + of a one-dimensional array, since the padding has the same alias set + as the field type, but if it's a multi-dimensional array, we need to + see the inner types. */ + while (TREE_CODE (gnu_old_type) == RECORD_TYPE + && (TYPE_JUSTIFIED_MODULAR_P (gnu_old_type) + || TYPE_IS_PADDING_P (gnu_old_type))) + gnu_old_type = TREE_TYPE (TYPE_FIELDS (gnu_old_type)); + + /* We need to be careful here in case GNU_OLD_TYPE is an unconstrained + array. In that case, it doesn't have the same shape as GNU_NEW_TYPE, + so we need to go down to what does. */ + if (TREE_CODE (gnu_old_type) == UNCONSTRAINED_ARRAY_TYPE) + gnu_old_type + = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_old_type)))); + + if (TREE_CODE (gnu_new_type) == ARRAY_TYPE + && TREE_CODE (TREE_TYPE (gnu_new_type)) == ARRAY_TYPE + && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_new_type))) + copy_alias_set (TREE_TYPE (gnu_new_type), TREE_TYPE (gnu_old_type)); + + TYPE_ALIAS_SET (gnu_new_type) = get_alias_set (gnu_old_type); + record_component_aliases (gnu_new_type); +} + +/* Return a TREE_LIST describing the substitutions needed to reflect + discriminant substitutions from GNAT_SUBTYPE to GNAT_TYPE and add + them to GNU_LIST. If GNAT_TYPE is not specified, use the base type + of GNAT_SUBTYPE. The substitutions can be in any order. TREE_PURPOSE + gives the tree for the discriminant and TREE_VALUES is the replacement + value. They are in the form of operands to substitute_in_expr. + DEFINITION is as in gnat_to_gnu_entity. */ + +static tree +substitution_list (Entity_Id gnat_subtype, Entity_Id gnat_type, + tree gnu_list, bool definition) +{ + Entity_Id gnat_discrim; + Node_Id gnat_value; + + if (No (gnat_type)) + gnat_type = Implementation_Base_Type (gnat_subtype); + + if (Has_Discriminants (gnat_type)) + for (gnat_discrim = First_Stored_Discriminant (gnat_type), + gnat_value = First_Elmt (Stored_Constraint (gnat_subtype)); + Present (gnat_discrim); + gnat_discrim = Next_Stored_Discriminant (gnat_discrim), + gnat_value = Next_Elmt (gnat_value)) + /* Ignore access discriminants. */ + if (!Is_Access_Type (Etype (Node (gnat_value)))) + gnu_list = tree_cons (gnat_to_gnu_field_decl (gnat_discrim), + elaborate_expression + (Node (gnat_value), gnat_subtype, + get_entity_name (gnat_discrim), definition, + 1, 0), + gnu_list); + + return gnu_list; +} + +/* Return true if the size 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) +{ + HOST_WIDE_INT our_size; + + /* If this is not a static allocation, the only case we want to forbid + is an overflowing size. That will be converted into a raise a + Storage_Error. */ + if (!static_p) + return !(TREE_CODE (gnu_size) == INTEGER_CST + && TREE_OVERFLOW (gnu_size)); + + /* Otherwise, we need to deal with both variable sizes and constant + sizes that won't fit in a host int. We use int instead of HOST_WIDE_INT + since assemblers may not like very large sizes. */ + if (!host_integerp (gnu_size, 1)) + return false; + + our_size = tree_low_cst (gnu_size, 1); + return (int) our_size == our_size; +} + +/* Prepend to ATTR_LIST an entry for an attribute with provided TYPE, + NAME, ARGS and ERROR_POINT. */ + +static void +prepend_one_attribute_to (struct attrib ** attr_list, + enum attr_type attr_type, + tree attr_name, + tree attr_args, + Node_Id attr_error_point) +{ + struct attrib * attr = (struct attrib *) xmalloc (sizeof (struct attrib)); + + attr->type = attr_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 the list of attributes for GNAT_ENTITY, if any. */ + +static void +prepend_attributes (Entity_Id gnat_entity, struct attrib ** attr_list) +{ + Node_Id gnat_temp; + + for (gnat_temp = First_Rep_Item (gnat_entity); Present (gnat_temp); + gnat_temp = Next_Rep_Item (gnat_temp)) + if (Nkind (gnat_temp) == N_Pragma) + { + tree gnu_arg0 = NULL_TREE, gnu_arg1 = NULL_TREE; + Node_Id gnat_assoc = Pragma_Argument_Associations (gnat_temp); + enum attr_type etype; + + if (Present (gnat_assoc) && Present (First (gnat_assoc)) + && Present (Next (First (gnat_assoc))) + && (Nkind (Expression (Next (First (gnat_assoc)))) + == N_String_Literal)) + { + gnu_arg0 = get_identifier (TREE_STRING_POINTER + (gnat_to_gnu + (Expression (Next + (First (gnat_assoc)))))); + if (Present (Next (Next (First (gnat_assoc)))) + && (Nkind (Expression (Next (Next (First (gnat_assoc))))) + == N_String_Literal)) + gnu_arg1 = get_identifier (TREE_STRING_POINTER + (gnat_to_gnu + (Expression + (Next (Next + (First (gnat_assoc))))))); + } + + switch (Get_Pragma_Id (Chars (Pragma_Identifier (gnat_temp)))) + { + case Pragma_Machine_Attribute: + etype = ATTR_MACHINE_ATTRIBUTE; + break; + + case Pragma_Linker_Alias: + etype = ATTR_LINK_ALIAS; + break; + + case Pragma_Linker_Section: + etype = ATTR_LINK_SECTION; + break; + + case Pragma_Linker_Constructor: + etype = ATTR_LINK_CONSTRUCTOR; + break; + + case Pragma_Linker_Destructor: + etype = ATTR_LINK_DESTRUCTOR; + break; + + case Pragma_Weak_External: + etype = ATTR_WEAK_EXTERNAL; + break; + + default: + continue; + } + + + /* Prepend to the list now. Make a list of the argument we might + have, as GCC expects it. */ + prepend_one_attribute_to + (attr_list, + etype, gnu_arg0, + (gnu_arg1 != NULL_TREE) + ? build_tree_list (NULL_TREE, gnu_arg1) : NULL_TREE, + Present (Next (First (gnat_assoc))) + ? Expression (Next (First (gnat_assoc))) : gnat_temp); + } +} + +/* Get the unpadded version of a GNAT type. */ + +tree +get_unpadded_type (Entity_Id gnat_entity) +{ + tree type = gnat_to_gnu_type (gnat_entity); + + if (TREE_CODE (type) == RECORD_TYPE && TYPE_IS_PADDING_P (type)) + type = TREE_TYPE (TYPE_FIELDS (type)); + + return type; +} + +/* Called when we need to protect a variable object using a save_expr. */ + +tree +maybe_variable (tree gnu_operand) +{ + if (TREE_CONSTANT (gnu_operand) || TREE_READONLY (gnu_operand) + || TREE_CODE (gnu_operand) == SAVE_EXPR + || TREE_CODE (gnu_operand) == NULL_EXPR) + return gnu_operand; + + if (TREE_CODE (gnu_operand) == UNCONSTRAINED_ARRAY_REF) + { + tree gnu_result = build1 (UNCONSTRAINED_ARRAY_REF, + TREE_TYPE (gnu_operand), + variable_size (TREE_OPERAND (gnu_operand, 0))); + + TREE_READONLY (gnu_result) = TREE_STATIC (gnu_result) + = TYPE_READONLY (TREE_TYPE (TREE_TYPE (gnu_operand))); + return gnu_result; + } + else + return variable_size (gnu_operand); +} + +/* 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. GNU_NAME is the + qualification to use if an external name is appropriate and DEFINITION is + nonzero if this is a definition of GNAT_ENTITY. If NEED_VALUE is nonzero, + we need a result. Otherwise, we are just elaborating this for + side-effects. If NEED_DEBUG is nonzero we need the symbol for debugging + purposes even if it isn't needed for code generation. */ + +static tree +elaborate_expression (Node_Id gnat_expr, Entity_Id gnat_entity, + tree gnu_name, bool definition, bool need_value, + bool need_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. */ + else if (!need_value + && (Is_OK_Static_Expression (gnat_expr) + || (Nkind (gnat_expr) == N_Identifier + && Ekind (Entity (gnat_expr)) == E_Discriminant))) + return 0; + + /* Otherwise, convert this tree to its GCC equivalent. */ + gnu_expr + = elaborate_expression_1 (gnat_expr, gnat_entity, gnat_to_gnu (gnat_expr), + gnu_name, definition, need_debug); + + /* Save the expression in case we try to elaborate this entity again. Since + this is 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. */ + +static tree +elaborate_expression_1 (Node_Id gnat_expr, Entity_Id gnat_entity, + tree gnu_expr, tree gnu_name, bool definition, + bool need_debug) +{ + tree gnu_decl = NULL_TREE; + /* Skip any conversions and simple arithmetics to see if the expression + is a read-only variable. + ??? This really should remain read-only, but we have to think about + the typing of the tree here. */ + tree gnu_inner_expr + = skip_simple_arithmetic (remove_conversions (gnu_expr, true)); + bool expr_global = Is_Public (gnat_entity) || global_bindings_p (); + bool expr_variable; + + /* In most cases, we won't see a naked FIELD_DECL here because a + discriminant reference will have been replaced with a COMPONENT_REF + when the type is being elaborated. However, there are some cases + involving child types where we will. So convert it to a COMPONENT_REF + here. We have to hope it will be at the highest level of the + expression in these cases. */ + if (TREE_CODE (gnu_expr) == FIELD_DECL) + gnu_expr = build3 (COMPONENT_REF, TREE_TYPE (gnu_expr), + build0 (PLACEHOLDER_EXPR, DECL_CONTEXT (gnu_expr)), + gnu_expr, NULL_TREE); + + /* If GNU_EXPR is neither a placeholder nor a constant, nor a variable + that is read-only, make a variable that is initialized to contain the + bound when the package containing the definition is elaborated. If + this entity is defined at top level and a bound or discriminant value + isn't a constant or a reference to a discriminant, replace the bound + by the variable; otherwise use a SAVE_EXPR if needed. Note that we + rely here on the fact that an expression cannot contain both the + discriminant and some other variable. */ + + expr_variable = (!CONSTANT_CLASS_P (gnu_expr) + && !(TREE_CODE (gnu_inner_expr) == VAR_DECL + && (TREE_READONLY (gnu_inner_expr) + || DECL_READONLY_ONCE_ELAB (gnu_inner_expr))) + && !CONTAINS_PLACEHOLDER_P (gnu_expr)); + + /* If this is a static expression or contains a discriminant, we don't + need the variable for debugging (and can't elaborate anyway if a + discriminant). */ + if (need_debug + && (Is_OK_Static_Expression (gnat_expr) + || CONTAINS_PLACEHOLDER_P (gnu_expr))) + need_debug = false; + + /* Now create the variable if we need it. */ + if (need_debug || (expr_variable && expr_global)) + gnu_decl + = create_var_decl (create_concat_name (gnat_entity, + IDENTIFIER_POINTER (gnu_name)), + NULL_TREE, TREE_TYPE (gnu_expr), gnu_expr, + !need_debug, Is_Public (gnat_entity), + !definition, false, NULL, gnat_entity); + + /* We only need to use this variable if we are in global context since GCC + can do the right thing in the local case. */ + if (expr_global && expr_variable) + return gnu_decl; + else if (!expr_variable) + return gnu_expr; + else + return maybe_variable (gnu_expr); +} + +/* Create a record type that contains a SIZE bytes long field of TYPE with a + starting bit position so that it is aligned to ALIGN bits, and leaving at + least ROOM bytes free before the field. BASE_ALIGN is the alignment the + record is guaranteed to get. */ + +tree +make_aligning_type (tree type, unsigned int align, tree size, + unsigned int base_align, int room) +{ + /* We will be crafting a record type with one field at a position set to be + the next multiple of ALIGN past record'address + room bytes. We use a + record placeholder to express record'address. */ + + tree record_type = make_node (RECORD_TYPE); + tree record = build0 (PLACEHOLDER_EXPR, record_type); + + tree record_addr_st + = convert (sizetype, build_unary_op (ADDR_EXPR, NULL_TREE, record)); + + /* The diagram below summarizes the shape of what we manipulate: + + <--------- pos ----------> + { +------------+-------------+-----------------+ + record =>{ |############| ... | field (type) | + { +------------+-------------+-----------------+ + |<-- room -->|<- voffset ->|<---- size ----->| + o o + | | + record_addr vblock_addr + + Every length is in sizetype bytes there, except "pos" which has to be + set as a bit position in the GCC tree for the record. */ + + tree room_st = size_int (room); + tree vblock_addr_st = size_binop (PLUS_EXPR, record_addr_st, room_st); + tree voffset_st, pos, field; + + tree name = TYPE_NAME (type); + + if (TREE_CODE (name) == TYPE_DECL) + name = DECL_NAME (name); + + TYPE_NAME (record_type) = concat_id_with_name (name, "_ALIGN"); + + /* Compute VOFFSET and then POS. The next byte position multiple of some + alignment after some address is obtained by "and"ing the alignment minus + 1 with the two's complement of the address. */ + + voffset_st = size_binop (BIT_AND_EXPR, + size_diffop (size_zero_node, vblock_addr_st), + ssize_int ((align / BITS_PER_UNIT) - 1)); + + /* POS = (ROOM + VOFFSET) * BIT_PER_UNIT, in bitsizetype. */ + + pos = size_binop (MULT_EXPR, + convert (bitsizetype, + size_binop (PLUS_EXPR, room_st, voffset_st)), + bitsize_unit_node); + + /* Craft the GCC record representation. We exceptionally do everything + manually here because 1) our generic circuitry is not quite ready to + handle the complex position/size expressions we are setting up, 2) we + have a strong simplifying factor at hand: we know the maximum possible + value of voffset, and 3) we have to set/reset at least the sizes in + accordance with this maximum value anyway, as we need them to convey + what should be "alloc"ated for this type. + + Use -1 as the 'addressable' indication for the field to prevent the + creation of a bitfield. We don't need one, it would have damaging + consequences on the alignment computation, and create_field_decl would + make one without this special argument, for instance because of the + complex position expression. */ + + field = create_field_decl (get_identifier ("F"), type, record_type, + 1, size, pos, -1); + TYPE_FIELDS (record_type) = field; + + TYPE_ALIGN (record_type) = base_align; + TYPE_USER_ALIGN (record_type) = 1; + + TYPE_SIZE (record_type) + = size_binop (PLUS_EXPR, + size_binop (MULT_EXPR, convert (bitsizetype, size), + bitsize_unit_node), + bitsize_int (align + room * BITS_PER_UNIT)); + TYPE_SIZE_UNIT (record_type) + = size_binop (PLUS_EXPR, size, + size_int (room + align / BITS_PER_UNIT)); + + TYPE_MODE (record_type) = BLKmode; + + copy_alias_set (record_type, type); + return record_type; +} + +/* Return the result of rounding T up to ALIGN. */ + +static inline unsigned HOST_WIDE_INT +round_up_to_align (unsigned HOST_WIDE_INT t, unsigned int align) +{ + t += align - 1; + t /= align; + t *= align; + return t; +} + +/* TYPE is a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE that is being used + as the field type of a packed record if IN_RECORD is true, or as the + component type of a packed array if IN_RECORD is false. See if we can + rewrite it either as a type that has a non-BLKmode, which we can pack + tighter in the packed record case, or as a smaller type with BLKmode. + If so, return the new type. If not, return the original type. */ + +static tree +make_packable_type (tree type, bool in_record) +{ + unsigned HOST_WIDE_INT size = tree_low_cst (TYPE_SIZE (type), 1); + unsigned HOST_WIDE_INT new_size; + tree new_type, old_field, field_list = NULL_TREE; + + /* No point in doing anything if the size is zero. */ + if (size == 0) + return type; + + new_type = make_node (TREE_CODE (type)); + + /* Copy the name and flags from the old type to that of the new. + Note that we rely on the pointer equality created here for + TYPE_NAME to look through conversions in various places. */ + TYPE_NAME (new_type) = TYPE_NAME (type); + TYPE_JUSTIFIED_MODULAR_P (new_type) = TYPE_JUSTIFIED_MODULAR_P (type); + TYPE_CONTAINS_TEMPLATE_P (new_type) = TYPE_CONTAINS_TEMPLATE_P (type); + if (TREE_CODE (type) == RECORD_TYPE) + TYPE_IS_PADDING_P (new_type) = TYPE_IS_PADDING_P (type); + + /* If we are in a record and have a small size, set the alignment to + try for an integral mode. Otherwise set it to try for a smaller + type with BLKmode. */ + if (in_record && size <= MAX_FIXED_MODE_SIZE) + { + TYPE_ALIGN (new_type) = ceil_alignment (size); + new_size = round_up_to_align (size, TYPE_ALIGN (new_type)); + } + else + { + unsigned HOST_WIDE_INT align; + + /* Do not try to shrink the size if the RM size is not constant. */ + if (TYPE_CONTAINS_TEMPLATE_P (type) + || !host_integerp (TYPE_ADA_SIZE (type), 1)) + return type; + + /* Round the RM size up to a unit boundary to get the minimal size + for a BLKmode record. Give up if it's already the size. */ + new_size = TREE_INT_CST_LOW (TYPE_ADA_SIZE (type)); + new_size = round_up_to_align (new_size, BITS_PER_UNIT); + if (new_size == size) + return type; + + align = new_size & -new_size; + TYPE_ALIGN (new_type) = MIN (TYPE_ALIGN (type), align); + } + + TYPE_USER_ALIGN (new_type) = 1; + + /* Now copy the fields, keeping the position and size as we don't want + to change the layout by propagating the packedness downwards. */ + for (old_field = TYPE_FIELDS (type); old_field; + old_field = TREE_CHAIN (old_field)) + { + tree new_field_type = TREE_TYPE (old_field); + tree new_field, new_size; + + if (TYPE_MODE (new_field_type) == BLKmode + && (TREE_CODE (new_field_type) == RECORD_TYPE + || TREE_CODE (new_field_type) == UNION_TYPE + || TREE_CODE (new_field_type) == QUAL_UNION_TYPE) + && host_integerp (TYPE_SIZE (new_field_type), 1)) + new_field_type = make_packable_type (new_field_type, true); + + /* However, for the last field in a not already packed record type + that is of an aggregate type, we need to use the RM_Size in the + packable version of the record type, see finish_record_type. */ + if (!TREE_CHAIN (old_field) + && !TYPE_PACKED (type) + && (TREE_CODE (new_field_type) == RECORD_TYPE + || TREE_CODE (new_field_type) == UNION_TYPE + || TREE_CODE (new_field_type) == QUAL_UNION_TYPE) + && !TYPE_IS_FAT_POINTER_P (new_field_type) + && !TYPE_CONTAINS_TEMPLATE_P (new_field_type) + && TYPE_ADA_SIZE (new_field_type)) + new_size = TYPE_ADA_SIZE (new_field_type); + else + new_size = DECL_SIZE (old_field); + + new_field = create_field_decl (DECL_NAME (old_field), new_field_type, + new_type, TYPE_PACKED (type), new_size, + bit_position (old_field), + !DECL_NONADDRESSABLE_P (old_field)); + + DECL_INTERNAL_P (new_field) = DECL_INTERNAL_P (old_field); + SET_DECL_ORIGINAL_FIELD + (new_field, (DECL_ORIGINAL_FIELD (old_field) + ? DECL_ORIGINAL_FIELD (old_field) : old_field)); + + if (TREE_CODE (new_type) == QUAL_UNION_TYPE) + DECL_QUALIFIER (new_field) = DECL_QUALIFIER (old_field); + + TREE_CHAIN (new_field) = field_list; + field_list = new_field; + } + + finish_record_type (new_type, nreverse (field_list), 2, true); + copy_alias_set (new_type, type); + + /* If this is a padding record, we never want to make the size smaller + than what was specified. For QUAL_UNION_TYPE, also copy the size. */ + if ((TREE_CODE (type) == RECORD_TYPE && TYPE_IS_PADDING_P (type)) + || TREE_CODE (type) == QUAL_UNION_TYPE) + { + TYPE_SIZE (new_type) = TYPE_SIZE (type); + TYPE_SIZE_UNIT (new_type) = TYPE_SIZE_UNIT (type); + } + else + { + TYPE_SIZE (new_type) = bitsize_int (new_size); + TYPE_SIZE_UNIT (new_type) + = size_int ((new_size + BITS_PER_UNIT - 1) / BITS_PER_UNIT); + } + + if (!TYPE_CONTAINS_TEMPLATE_P (type)) + SET_TYPE_ADA_SIZE (new_type, TYPE_ADA_SIZE (type)); + + compute_record_mode (new_type); + + /* Try harder to get a packable type if necessary, for example + in case the record itself contains a BLKmode field. */ + if (in_record && TYPE_MODE (new_type) == BLKmode) + TYPE_MODE (new_type) + = mode_for_size_tree (TYPE_SIZE (new_type), MODE_INT, 1); + + /* If neither the mode nor the size has shrunk, return the old type. */ + if (TYPE_MODE (new_type) == BLKmode && new_size >= size) + return type; + + return new_type; +} + +/* Ensure that TYPE has SIZE and ALIGN. Make and return a new padded type + if needed. We have already verified that SIZE and TYPE are large enough. + + GNAT_ENTITY and NAME_TRAILER are used to name the resulting record and + to issue a warning. + + IS_USER_TYPE is true if we must complete the original type. + + DEFINITION is true if this type is being defined. + + SAME_RM_SIZE is true if the RM_Size of the resulting type is to be set + to SIZE too; otherwise, it's set to the RM_Size of the original type. */ + +tree +maybe_pad_type (tree type, tree size, unsigned int align, + Entity_Id gnat_entity, const char *name_trailer, + bool is_user_type, bool definition, bool same_rm_size) +{ + tree orig_rm_size = same_rm_size ? NULL_TREE : rm_size (type); + tree orig_size = TYPE_SIZE (type); + unsigned int orig_align = align; + tree record, field; + + /* If TYPE is a padded type, see if it agrees with any size and alignment + we were given. If so, return the original type. Otherwise, strip + off the padding, since we will either be returning the inner type + or repadding it. If no size or alignment is specified, use that of + the original padded type. */ + if (TREE_CODE (type) == RECORD_TYPE && TYPE_IS_PADDING_P (type)) + { + if ((!size + || operand_equal_p (round_up (size, + MAX (align, TYPE_ALIGN (type))), + round_up (TYPE_SIZE (type), + MAX (align, TYPE_ALIGN (type))), + 0)) + && (align == 0 || align == TYPE_ALIGN (type))) + return type; + + if (!size) + size = TYPE_SIZE (type); + if (align == 0) + align = TYPE_ALIGN (type); + + type = TREE_TYPE (TYPE_FIELDS (type)); + orig_size = TYPE_SIZE (type); + } + + /* If the size is either not being changed or is being made smaller (which + is not done here (and is only valid for bitfields anyway), show the size + isn't changing. Likewise, clear the alignment if it isn't being + changed. Then return if we aren't doing anything. */ + if (size + && (operand_equal_p (size, orig_size, 0) + || (TREE_CODE (orig_size) == INTEGER_CST + && tree_int_cst_lt (size, orig_size)))) + size = NULL_TREE; + + if (align == TYPE_ALIGN (type)) + align = 0; + + if (align == 0 && !size) + return type; + + /* If requested, complete the original type and give it a name. */ + if (is_user_type) + create_type_decl (get_entity_name (gnat_entity), type, + NULL, !Comes_From_Source (gnat_entity), + !(TYPE_NAME (type) + && TREE_CODE (TYPE_NAME (type)) == TYPE_DECL + && DECL_IGNORED_P (TYPE_NAME (type))), + gnat_entity); + + /* We used to modify the record in place in some cases, but that could + generate incorrect debugging information. So make a new record + type and name. */ + record = make_node (RECORD_TYPE); + TYPE_IS_PADDING_P (record) = 1; + + if (Present (gnat_entity)) + TYPE_NAME (record) = create_concat_name (gnat_entity, name_trailer); + + TYPE_VOLATILE (record) + = Present (gnat_entity) && Treat_As_Volatile (gnat_entity); + + TYPE_ALIGN (record) = align; + if (orig_align) + TYPE_USER_ALIGN (record) = align; + + TYPE_SIZE (record) = size ? size : orig_size; + TYPE_SIZE_UNIT (record) + = convert (sizetype, + size_binop (CEIL_DIV_EXPR, TYPE_SIZE (record), + bitsize_unit_node)); + + /* If we are changing the alignment and the input type is a record with + BLKmode and a small constant size, try to make a form that has an + integral mode. This might allow the padding record to also have an + integral mode, which will be much more efficient. There is no point + in doing so if a size is specified unless it is also a small constant + size and it is incorrect to do so if we cannot guarantee that the mode + will be naturally aligned since the field must always be addressable. + + ??? This might not always be a win when done for a stand-alone object: + since the nominal and the effective type of the object will now have + different modes, a VIEW_CONVERT_EXPR will be required for converting + between them and it might be hard to overcome afterwards, including + at the RTL level when the stand-alone object is accessed as a whole. */ + if (align != 0 + && TREE_CODE (type) == RECORD_TYPE + && TYPE_MODE (type) == BLKmode + && TREE_CODE (orig_size) == INTEGER_CST + && !TREE_CONSTANT_OVERFLOW (orig_size) + && compare_tree_int (orig_size, MAX_FIXED_MODE_SIZE) <= 0 + && (!size + || (TREE_CODE (size) == INTEGER_CST + && compare_tree_int (size, MAX_FIXED_MODE_SIZE) <= 0))) + { + tree packable_type = make_packable_type (type, true); + if (TYPE_MODE (packable_type) != BLKmode + && align >= TYPE_ALIGN (packable_type)) + type = packable_type; + } + + /* Now create the field with the original size. */ + field = create_field_decl (get_identifier ("F"), type, record, 0, + orig_size, bitsize_zero_node, 1); + DECL_INTERNAL_P (field) = 1; + + /* Do not finalize it until after the auxiliary record is built. */ + finish_record_type (record, field, 1, true); + + /* Set the same size for its RM_size if requested; otherwise reuse + the RM_size of the original type. */ + SET_TYPE_ADA_SIZE (record, same_rm_size ? size : orig_rm_size); + + /* Unless debugging information isn't being written for the input type, + write a record that shows what we are a subtype of and also make a + variable that indicates our size, if still variable. */ + if (TYPE_NAME (record) + && AGGREGATE_TYPE_P (type) + && TREE_CODE (orig_size) != INTEGER_CST + && !(TREE_CODE (TYPE_NAME (type)) == TYPE_DECL + && DECL_IGNORED_P (TYPE_NAME (type)))) + { + tree marker = make_node (RECORD_TYPE); + tree name = TYPE_NAME (record); + tree orig_name = TYPE_NAME (type); + + if (TREE_CODE (name) == TYPE_DECL) + name = DECL_NAME (name); + + if (TREE_CODE (orig_name) == TYPE_DECL) + orig_name = DECL_NAME (orig_name); + + TYPE_NAME (marker) = concat_id_with_name (name, "XVS"); + finish_record_type (marker, + create_field_decl (orig_name, integer_type_node, + marker, 0, NULL_TREE, NULL_TREE, + 0), + 0, false); + + add_parallel_type (TYPE_STUB_DECL (record), marker); + + if (size && TREE_CODE (size) != INTEGER_CST && definition) + create_var_decl (concat_id_with_name (name, "XVZ"), NULL_TREE, + bitsizetype, TYPE_SIZE (record), false, false, false, + false, NULL, gnat_entity); + } + + rest_of_record_type_compilation (record); + + /* If the size was widened explicitly, maybe give a warning. Take the + original size as the maximum size of the input if there was an + unconstrained record involved and round it up to the specified alignment, + if one was specified. */ + if (CONTAINS_PLACEHOLDER_P (orig_size)) + orig_size = max_size (orig_size, true); + + if (align) + orig_size = round_up (orig_size, align); + + if (size && Present (gnat_entity) + && !operand_equal_p (size, orig_size, 0) + && !(TREE_CODE (size) == INTEGER_CST + && TREE_CODE (orig_size) == INTEGER_CST + && tree_int_cst_lt (size, orig_size))) + { + Node_Id gnat_error_node = Empty; + + if (Is_Packed_Array_Type (gnat_entity)) + gnat_entity = Original_Array_Type (gnat_entity); + + if ((Ekind (gnat_entity) == E_Component + || Ekind (gnat_entity) == E_Discriminant) + && Present (Component_Clause (gnat_entity))) + gnat_error_node = Last_Bit (Component_Clause (gnat_entity)); + else if (Present (Size_Clause (gnat_entity))) + gnat_error_node = Expression (Size_Clause (gnat_entity)); + + /* Generate message only for entities that come from source, since + if we have an entity created by expansion, the message will be + generated for some other corresponding source entity. */ + if (Comes_From_Source (gnat_entity) && Present (gnat_error_node)) + post_error_ne_tree ("{^ }bits of & unused?", gnat_error_node, + gnat_entity, + size_diffop (size, orig_size)); + + else if (*name_trailer == 'C' && !Is_Internal (gnat_entity)) + post_error_ne_tree ("component of& padded{ by ^ bits}?", + gnat_entity, gnat_entity, + size_diffop (size, orig_size)); + } + + return record; +} + +/* Given a GNU tree and a GNAT list of choices, generate an expression to test + the value passed against the list of choices. */ + +tree +choices_to_gnu (tree operand, Node_Id choices) +{ + Node_Id choice; + Node_Id gnat_temp; + tree result = integer_zero_node; + tree this_test, low = 0, high = 0, single = 0; + + for (choice = First (choices); Present (choice); choice = Next (choice)) + { + switch (Nkind (choice)) + { + case N_Range: + low = gnat_to_gnu (Low_Bound (choice)); + high = gnat_to_gnu (High_Bound (choice)); + + /* There's no good type to use here, so we might as well use + integer_type_node. */ + this_test + = build_binary_op (TRUTH_ANDIF_EXPR, integer_type_node, + build_binary_op (GE_EXPR, integer_type_node, + operand, low), + build_binary_op (LE_EXPR, integer_type_node, + operand, high)); + + break; + + case N_Subtype_Indication: + gnat_temp = Range_Expression (Constraint (choice)); + low = gnat_to_gnu (Low_Bound (gnat_temp)); + high = gnat_to_gnu (High_Bound (gnat_temp)); + + this_test + = build_binary_op (TRUTH_ANDIF_EXPR, integer_type_node, + build_binary_op (GE_EXPR, integer_type_node, + operand, low), + build_binary_op (LE_EXPR, integer_type_node, + operand, high)); + break; + + case N_Identifier: + case N_Expanded_Name: + /* This represents either a subtype range, an enumeration + literal, or a constant Ekind says which. If an enumeration + literal or constant, fall through to the next case. */ + if (Ekind (Entity (choice)) != E_Enumeration_Literal + && Ekind (Entity (choice)) != E_Constant) + { + tree type = gnat_to_gnu_type (Entity (choice)); + + low = TYPE_MIN_VALUE (type); + high = TYPE_MAX_VALUE (type); + + this_test + = build_binary_op (TRUTH_ANDIF_EXPR, integer_type_node, + build_binary_op (GE_EXPR, integer_type_node, + operand, low), + build_binary_op (LE_EXPR, integer_type_node, + operand, high)); + break; + } + /* ... fall through ... */ + case N_Character_Literal: + case N_Integer_Literal: + single = gnat_to_gnu (choice); + this_test = build_binary_op (EQ_EXPR, integer_type_node, operand, + single); + break; + + case N_Others_Choice: + this_test = integer_one_node; + break; + + default: + gcc_unreachable (); + } + + result = build_binary_op (TRUTH_ORIF_EXPR, integer_type_node, + result, this_test); + } + + return 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 contains an item of variable size, we cannot pack it + because we cannot create temporaries of non-fixed size in case + we need to take the address of the field. See addressable_p and + the notes on the addressability issues for further details. */ + if (is_variable_size (field_type)) + return 0; + + /* If the alignment of the record is specified and the field type + is over-aligned, request Storage_Unit alignment for the field. */ + if (packed == -2) + { + if (TYPE_ALIGN (field_type) > TYPE_ALIGN (record_type)) + return -1; + else + return 0; + } + + return packed; +} + +/* 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, -1 if the enclosing + record has Component_Alignment of Storage_Unit, -2 if the enclosing + record has a specified alignment. + + DEFINITION is true if this field is for a record being defined. */ + +static tree +gnat_to_gnu_field (Entity_Id gnat_field, tree gnu_record_type, int packed, + bool definition) +{ + tree gnu_field_id = get_entity_name (gnat_field); + tree gnu_field_type = gnat_to_gnu_type (Etype (gnat_field)); + tree gnu_field, gnu_size, gnu_pos; + bool needs_strict_alignment + = (Is_Aliased (gnat_field) || Strict_Alignment (Etype (gnat_field)) + || Treat_As_Volatile (gnat_field)); + + /* If this field requires strict alignment, we cannot pack it because + it would very likely be under-aligned in the record. */ + 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 (Known_Static_Esize (gnat_field)) + gnu_size = validate_size (Esize (gnat_field), gnu_field_type, + gnat_field, FIELD_DECL, false, true); + else if (packed == 1) + gnu_size = validate_size (RM_Size (Etype (gnat_field)), gnu_field_type, + gnat_field, FIELD_DECL, false, true); + else + gnu_size = NULL_TREE; + + /* If we have a specified size that's smaller than that of the field type, + or a position is specified, and the field type is also a record that's + BLKmode, see if we can get either an integral mode form of the type or + a smaller BLKmode form. If we can, show a size was specified for the + field if there wasn't one already, so we know to make this a bitfield + and avoid making things wider. + + Doing this is first useful if the record is packed because we may 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 references, because + GCC does not handle BLKmode bitfields properly. + + 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. + + Besides, we don't even look the possibility of a transformation in cases + known to be in error already, for instance when an invalid size results + from a component clause. */ + + if (TREE_CODE (gnu_field_type) == RECORD_TYPE + && TYPE_MODE (gnu_field_type) == BLKmode + && host_integerp (TYPE_SIZE (gnu_field_type), 1) + && (packed == 1 + || (gnu_size + && (tree_int_cst_lt (gnu_size, TYPE_SIZE (gnu_field_type)) + || Present (Component_Clause (gnat_field)))))) + { + /* See what the alternate type and size would be. */ + tree gnu_packable_type = make_packable_type (gnu_field_type, true); + + bool has_byte_aligned_clause + = Present (Component_Clause (gnat_field)) + && (UI_To_Int (Component_Bit_Offset (gnat_field)) + % BITS_PER_UNIT == 0); + + /* Compute whether we should avoid the substitution. */ + bool reject + /* There is no point substituting if there is no change... */ + = (gnu_packable_type == gnu_field_type) + /* ... nor when the field is known to be byte aligned and not to + share a byte with another field. */ + || (has_byte_aligned_clause + && value_factor_p (gnu_size, BITS_PER_UNIT)) + /* The size of an aliased field must be an exact multiple of the + type's alignment, which the substitution might increase. Reject + substitutions that would so invalidate a component clause when the + specified position is byte aligned, as the change would have no + real benefit from the packing standpoint anyway. */ + || (Is_Aliased (gnat_field) + && has_byte_aligned_clause + && !value_factor_p (gnu_size, TYPE_ALIGN (gnu_packable_type))); + + /* Substitute unless told otherwise. */ + if (!reject) + { + gnu_field_type = gnu_packable_type; + + if (!gnu_size) + gnu_size = rm_size (gnu_field_type); + } + } + + /* 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); + + if (Present (Component_Clause (gnat_field))) + { + gnu_pos = UI_To_gnu (Component_Bit_Offset (gnat_field), bitsizetype); + gnu_size = validate_size (Esize (gnat_field), gnu_field_type, + gnat_field, FIELD_DECL, false, true); + + /* Ensure the position does not overlap with the parent subtype, + if there is one. */ + if (Present (Parent_Subtype (Underlying_Type (Scope (gnat_field))))) + { + tree gnu_parent + = gnat_to_gnu_type (Parent_Subtype + (Underlying_Type (Scope (gnat_field)))); + + if (TREE_CODE (TYPE_SIZE (gnu_parent)) == INTEGER_CST + && tree_int_cst_lt (gnu_pos, TYPE_SIZE (gnu_parent))) + { + post_error_ne_tree + ("offset of& must be beyond parent{, minimum allowed is ^}", + First_Bit (Component_Clause (gnat_field)), gnat_field, + TYPE_SIZE_UNIT (gnu_parent)); + } + } + + /* If this field needs strict alignment, ensure the record is + sufficiently aligned and that that position and size are + consistent with the alignment. */ + if (needs_strict_alignment) + { + TYPE_ALIGN (gnu_record_type) + = MAX (TYPE_ALIGN (gnu_record_type), TYPE_ALIGN (gnu_field_type)); + + if (gnu_size + && !operand_equal_p (gnu_size, TYPE_SIZE (gnu_field_type), 0)) + { + if (Is_Atomic (gnat_field) || Is_Atomic (Etype (gnat_field))) + post_error_ne_tree + ("atomic field& must be natural size of type{ (^)}", + Last_Bit (Component_Clause (gnat_field)), gnat_field, + TYPE_SIZE (gnu_field_type)); + + else if (Is_Aliased (gnat_field)) + post_error_ne_tree + ("size of aliased field& must be ^ bits", + Last_Bit (Component_Clause (gnat_field)), gnat_field, + TYPE_SIZE (gnu_field_type)); + + else if (Strict_Alignment (Etype (gnat_field))) + post_error_ne_tree + ("size of & with aliased or tagged components not ^ bits", + Last_Bit (Component_Clause (gnat_field)), gnat_field, + TYPE_SIZE (gnu_field_type)); + + gnu_size = NULL_TREE; + } + + if (!integer_zerop (size_binop + (TRUNC_MOD_EXPR, gnu_pos, + bitsize_int (TYPE_ALIGN (gnu_field_type))))) + { + if (Is_Aliased (gnat_field)) + post_error_ne_num + ("position of aliased field& must be multiple of ^ bits", + First_Bit (Component_Clause (gnat_field)), gnat_field, + TYPE_ALIGN (gnu_field_type)); + + else if (Treat_As_Volatile (gnat_field)) + post_error_ne_num + ("position of volatile field& must be multiple of ^ bits", + First_Bit (Component_Clause (gnat_field)), gnat_field, + TYPE_ALIGN (gnu_field_type)); + + else if (Strict_Alignment (Etype (gnat_field))) + post_error_ne_num + ("position of & with aliased or tagged components not multiple of ^ bits", + First_Bit (Component_Clause (gnat_field)), gnat_field, + TYPE_ALIGN (gnu_field_type)); + + else + gcc_unreachable (); + + gnu_pos = NULL_TREE; + } + } + + if (Is_Atomic (gnat_field)) + check_ok_for_atomic (gnu_field_type, gnat_field, false); + } + + /* 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 (Scope (gnat_field)) + && Chars (gnat_field) == Name_uTag) + { + gnu_pos = bitsize_zero_node; + gnu_size = TYPE_SIZE (gnu_field_type); + } + + else + gnu_pos = NULL_TREE; + + /* 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 (Etype (gnat_field)))) + { + 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) + { + /* 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 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) + && tree_int_cst_compare (gnu_size, TYPE_ADA_SIZE (gnu_field_type)) + <= 0) + gnu_field_type = TREE_TYPE (TYPE_FIELDS (gnu_field_type)); + + gnu_field_type + = make_type_from_size (gnu_field_type, gnu_size, + Has_Biased_Representation (gnat_field)); + gnu_field_type = maybe_pad_type (gnu_field_type, gnu_size, 0, gnat_field, + "PAD", false, definition, true); + } + + /* Otherwise (or if there was an error), don't specify a position. */ + else + gnu_pos = NULL_TREE; + + 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, + packed, gnu_size, gnu_pos, + Is_Aliased (gnat_field)); + Sloc_to_locus (Sloc (gnat_field), &DECL_SOURCE_LOCATION (gnu_field)); + TREE_THIS_VOLATILE (gnu_field) = Treat_As_Volatile (gnat_field); + + if (Ekind (gnat_field) == E_Discriminant) + DECL_DISCRIMINANT_NUMBER (gnu_field) + = UI_To_gnu (Discriminant_Number (gnat_field), sizetype); + + return gnu_field; +} + +/* Return true if TYPE is a type with variable size, a padding type with a + field of variable size or is a record that has a field such a field. */ + +static bool +is_variable_size (tree type) +{ + tree field; + + if (!TREE_CONSTANT (TYPE_SIZE (type))) + return true; + + if (TREE_CODE (type) == RECORD_TYPE + && TYPE_IS_PADDING_P (type) + && !TREE_CONSTANT (DECL_SIZE (TYPE_FIELDS (type)))) + return true; + + if (TREE_CODE (type) != RECORD_TYPE + && TREE_CODE (type) != UNION_TYPE + && TREE_CODE (type) != QUAL_UNION_TYPE) + return false; + + for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) + if (is_variable_size (TREE_TYPE (field))) + return true; + + return false; +} + +/* 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)); +} + +/* Return a GCC tree for a record type given a GNAT Component_List and a chain + of GCC trees for fields that are in the record and have already been + processed. When called from gnat_to_gnu_entity during the processing of a + record type definition, the GCC nodes for the discriminants will be on + the chain. The other calls to this function are recursive calls from + itself for the Component_List of a variant and the chain is empty. + + PACKED is 1 if this is for a packed record, -1 if this is for a record + with Component_Alignment of Storage_Unit, -2 if this is for a record + with a specified alignment. + + DEFINITION is true if we are defining this record. + + P_GNU_REP_LIST, if nonzero, is a pointer to a list to which each field + with a rep clause is to be added. If it is nonzero, that is all that + should be done with such fields. + + CANCEL_ALIGNMENT, if true, means the alignment should be zeroed before + laying out the record. This means the alignment only serves to force fields + to be bitfields, but not require the record to be that aligned. This is + used for variants. + + ALL_REP, if true, means a rep clause was found for all the fields. This + simplifies the logic since we know we're not in the mixed case. + + DO_NOT_FINALIZE, if true, means that the record type is expected to be + modified afterwards so it will not be sent to the back-end for finalization. + + UNCHECKED_UNION, if true, means that we are building a type for a record + with a Pragma Unchecked_Union. + + The processing of the component list fills in the chain with all of the + fields of the record and then the record type is finished. */ + +static void +components_to_record (tree gnu_record_type, Node_Id component_list, + tree gnu_field_list, int packed, bool definition, + tree *p_gnu_rep_list, bool cancel_alignment, + bool all_rep, bool do_not_finalize, bool unchecked_union) +{ + Node_Id component_decl; + Entity_Id gnat_field; + Node_Id variant_part; + tree gnu_our_rep_list = NULL_TREE; + tree gnu_field, gnu_last; + bool layout_with_rep = false; + bool all_rep_and_size = all_rep && TYPE_SIZE (gnu_record_type); + + /* For each variable within each component declaration create a GCC field + and add it to the list, skipping any pragmas in the list. */ + if (Present (Component_Items (component_list))) + for (component_decl = First_Non_Pragma (Component_Items (component_list)); + Present (component_decl); + component_decl = Next_Non_Pragma (component_decl)) + { + gnat_field = Defining_Entity (component_decl); + + if (Chars (gnat_field) == Name_uParent) + gnu_field = tree_last (TYPE_FIELDS (gnu_record_type)); + else + { + gnu_field = gnat_to_gnu_field (gnat_field, gnu_record_type, + packed, definition); + + /* If this is the _Tag field, put it before any discriminants, + instead of after them as is the case for all other fields. + Ignore field of void type if only annotating. */ + if (Chars (gnat_field) == Name_uTag) + gnu_field_list = chainon (gnu_field_list, gnu_field); + else + { + TREE_CHAIN (gnu_field) = gnu_field_list; + gnu_field_list = gnu_field; + } + } + + save_gnu_tree (gnat_field, gnu_field, false); + } + + /* At the end of the component list there may be a variant part. */ + variant_part = Variant_Part (component_list); + + /* 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 (variant_part)) + { + tree gnu_discriminant = gnat_to_gnu (Name (variant_part)); + Node_Id variant; + tree gnu_name = TYPE_NAME (gnu_record_type); + tree gnu_var_name + = concat_id_with_name (get_identifier (Get_Name_String + (Chars (Name (variant_part)))), + "XVN"); + tree gnu_union_type; + tree gnu_union_name; + tree gnu_union_field; + tree gnu_variant_list = NULL_TREE; + + if (TREE_CODE (gnu_name) == TYPE_DECL) + gnu_name = DECL_NAME (gnu_name); + + gnu_union_name = concat_id_with_name (gnu_name, + IDENTIFIER_POINTER (gnu_var_name)); + + /* Reuse an enclosing union if all fields are in the variant part + and there is no representation clause on the record, to match + the layout of C unions. There is an associated check below. */ + if (!gnu_field_list + && TREE_CODE (gnu_record_type) == UNION_TYPE + && !TYPE_PACKED (gnu_record_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; + TYPE_ALIGN (gnu_union_type) = 0; + TYPE_PACKED (gnu_union_type) = TYPE_PACKED (gnu_record_type); + } + + for (variant = First_Non_Pragma (Variants (variant_part)); + Present (variant); + variant = Next_Non_Pragma (variant)) + { + tree gnu_variant_type = make_node (RECORD_TYPE); + tree gnu_inner_name; + tree gnu_qual; + + Get_Variant_Encoding (variant); + gnu_inner_name = get_identifier (Name_Buffer); + TYPE_NAME (gnu_variant_type) + = concat_id_with_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. */ + TYPE_ALIGN (gnu_variant_type) = TYPE_ALIGN (gnu_record_type); + TYPE_PACKED (gnu_variant_type) = TYPE_PACKED (gnu_record_type); + + /* Similarly, if the outer record has a size specified and all fields + have record rep clauses, we can propagate the size into the + variant part. */ + 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); + } + + /* Create the record type for the variant. Note that we defer + finalizing it until after we are sure to actually use it. */ + components_to_record (gnu_variant_type, Component_List (variant), + NULL_TREE, packed, definition, + &gnu_our_rep_list, !all_rep_and_size, all_rep, + true, unchecked_union); + + gnu_qual = choices_to_gnu (gnu_discriminant, + Discrete_Choices (variant)); + + Set_Present_Expr (variant, annotate_value (gnu_qual)); + + /* If this is an Unchecked_Union and we have exactly one field, + use this field directly to match the layout of C unions. */ + if (unchecked_union + && TYPE_FIELDS (gnu_variant_type) + && !TREE_CHAIN (TYPE_FIELDS (gnu_variant_type))) + gnu_field = TYPE_FIELDS (gnu_variant_type); + else + { + /* Deal with packedness like in gnat_to_gnu_field. */ + int field_packed + = adjust_packed (gnu_variant_type, gnu_record_type, packed); + + /* Finalize the record type now. We used to throw away + empty records 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. */ + rest_of_record_type_compilation (gnu_variant_type); + + gnu_field = create_field_decl (gnu_inner_name, gnu_variant_type, + gnu_union_type, field_packed, + (all_rep_and_size + ? TYPE_SIZE (gnu_variant_type) + : 0), + (all_rep_and_size + ? bitsize_zero_node : 0), + 0); + + DECL_INTERNAL_P (gnu_field) = 1; + + if (!unchecked_union) + DECL_QUALIFIER (gnu_field) = gnu_qual; + } + + TREE_CHAIN (gnu_field) = gnu_variant_list; + gnu_variant_list = gnu_field; + } + + /* Only make the QUAL_UNION_TYPE if there are any 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, false); + + /* If GNU_UNION_TYPE is our record type, it means we must have an + Unchecked_Union with no fields. Verify that and, if so, just + return. */ + if (gnu_union_type == gnu_record_type) + { + gcc_assert (unchecked_union + && !gnu_field_list + && !gnu_our_rep_list); + return; + } + + /* Deal with packedness like in gnat_to_gnu_field. */ + union_field_packed + = adjust_packed (gnu_union_type, gnu_record_type, packed); + + gnu_union_field + = create_field_decl (gnu_var_name, gnu_union_type, gnu_record_type, + union_field_packed, + all_rep ? TYPE_SIZE (gnu_union_type) : 0, + all_rep ? bitsize_zero_node : 0, 0); + + DECL_INTERNAL_P (gnu_union_field) = 1; + TREE_CHAIN (gnu_union_field) = gnu_field_list; + gnu_field_list = gnu_union_field; + } + } + + /* Scan GNU_FIELD_LIST and see if any fields have rep clauses. If they + do, pull them out and put them into GNU_OUR_REP_LIST. We have to do this + in a separate pass since we want to handle the discriminants but can't + play with them until we've used them in debugging data above. + + ??? Note: if we then reorder them, debugging information will be wrong, + but there's nothing that can be done about this at the moment. */ + for (gnu_field = gnu_field_list, gnu_last = NULL_TREE; gnu_field; ) + { + if (DECL_FIELD_OFFSET (gnu_field)) + { + tree gnu_next = TREE_CHAIN (gnu_field); + + if (!gnu_last) + gnu_field_list = gnu_next; + else + TREE_CHAIN (gnu_last) = gnu_next; + + TREE_CHAIN (gnu_field) = gnu_our_rep_list; + gnu_our_rep_list = gnu_field; + gnu_field = gnu_next; + } + else + { + gnu_last = gnu_field; + gnu_field = TREE_CHAIN (gnu_field); + } + } + + /* If we have any items in our rep'ed field list, it is not the case that all + the fields in the record have rep clauses, and P_REP_LIST is nonzero, + set it and ignore the items. */ + if (gnu_our_rep_list && p_gnu_rep_list && !all_rep) + *p_gnu_rep_list = chainon (*p_gnu_rep_list, gnu_our_rep_list); + else if (gnu_our_rep_list) + { + /* Otherwise, sort the fields by bit position and put them into their + own record if we have any fields without rep clauses. */ + tree gnu_rep_type + = (gnu_field_list ? make_node (RECORD_TYPE) : gnu_record_type); + int len = list_length (gnu_our_rep_list); + tree *gnu_arr = (tree *) alloca (sizeof (tree) * len); + int i; + + for (i = 0, gnu_field = gnu_our_rep_list; gnu_field; + gnu_field = TREE_CHAIN (gnu_field), i++) + gnu_arr[i] = gnu_field; + + qsort (gnu_arr, len, sizeof (tree), compare_field_bitpos); + + /* Put the fields in the list in order of increasing position, which + means we start from the end. */ + gnu_our_rep_list = NULL_TREE; + for (i = len - 1; i >= 0; i--) + { + TREE_CHAIN (gnu_arr[i]) = gnu_our_rep_list; + gnu_our_rep_list = gnu_arr[i]; + DECL_CONTEXT (gnu_arr[i]) = gnu_rep_type; + } + + if (gnu_field_list) + { + finish_record_type (gnu_rep_type, gnu_our_rep_list, 1, false); + gnu_field = create_field_decl (get_identifier ("REP"), gnu_rep_type, + gnu_record_type, 0, 0, 0, 1); + DECL_INTERNAL_P (gnu_field) = 1; + gnu_field_list = chainon (gnu_field_list, gnu_field); + } + else + { + layout_with_rep = true; + gnu_field_list = nreverse (gnu_our_rep_list); + } + } + + if (cancel_alignment) + TYPE_ALIGN (gnu_record_type) = 0; + + finish_record_type (gnu_record_type, nreverse (gnu_field_list), + layout_with_rep ? 1 : 0, do_not_finalize); +} + +/* 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) +{ + int len = TREE_CODE_LENGTH (TREE_CODE (gnu_size)); + TCode tcode; + Node_Ref_Or_Val ops[3], ret; + int i; + int size; + struct tree_int_map **h = NULL; + + /* See if we've already saved the value for this node. */ + if (EXPR_P (gnu_size)) + { + struct tree_int_map in; + if (!annotate_value_cache) + annotate_value_cache = htab_create_ggc (512, tree_int_map_hash, + tree_int_map_eq, 0); + in.base.from = gnu_size; + h = (struct tree_int_map **) + htab_find_slot (annotate_value_cache, &in, INSERT); + + if (*h) + return (Node_Ref_Or_Val) (*h)->to; + } + + /* If we do not return inside this switch, TCODE will be set to the + code to use for a Create_Node operand and LEN (set above) will be + the number of recursive calls for us to make. */ + + switch (TREE_CODE (gnu_size)) + { + case INTEGER_CST: + if (TREE_OVERFLOW (gnu_size)) + return No_Uint; + + /* This may have come from a conversion from some smaller type, + so ensure this is in bitsizetype. */ + gnu_size = convert (bitsizetype, gnu_size); + + /* For negative values, use NEGATE_EXPR of the supplied value. */ + if (tree_int_cst_sgn (gnu_size) < 0) + { + /* The ridiculous code below is to handle the case of the largest + negative integer. */ + tree negative_size = size_diffop (bitsize_zero_node, gnu_size); + bool adjust = false; + tree temp; + + if (TREE_OVERFLOW (negative_size)) + { + negative_size + = size_binop (MINUS_EXPR, bitsize_zero_node, + size_binop (PLUS_EXPR, gnu_size, + bitsize_one_node)); + adjust = true; + } + + temp = build1 (NEGATE_EXPR, bitsizetype, negative_size); + if (adjust) + temp = build2 (MINUS_EXPR, bitsizetype, temp, bitsize_one_node); + + return annotate_value (temp); + } + + if (!host_integerp (gnu_size, 1)) + return No_Uint; + + size = tree_low_cst (gnu_size, 1); + + /* This peculiar test is to make sure that the size fits in an int + on machines where HOST_WIDE_INT is not "int". */ + if (tree_low_cst (gnu_size, 1) == size) + return UI_From_Int (size); + else + return No_Uint; + + case COMPONENT_REF: + /* The only case we handle here is a simple discriminant reference. */ + if (TREE_CODE (TREE_OPERAND (gnu_size, 0)) == PLACEHOLDER_EXPR + && TREE_CODE (TREE_OPERAND (gnu_size, 1)) == FIELD_DECL + && DECL_DISCRIMINANT_NUMBER (TREE_OPERAND (gnu_size, 1))) + return Create_Node (Discrim_Val, + annotate_value (DECL_DISCRIMINANT_NUMBER + (TREE_OPERAND (gnu_size, 1))), + No_Uint, No_Uint); + else + return No_Uint; + + 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 PLUS_EXPR: tcode = Plus_Expr; break; + case MINUS_EXPR: tcode = Minus_Expr; break; + case MULT_EXPR: tcode = Mult_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: tcode = Truth_Andif_Expr; break; + case TRUTH_ORIF_EXPR: tcode = Truth_Orif_Expr; break; + case TRUTH_AND_EXPR: tcode = Truth_And_Expr; break; + 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 BIT_AND_EXPR: tcode = Bit_And_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; + + 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 (i = 0; i < 3; i++) + ops[i] = No_Uint; + + for (i = 0; i < len; i++) + { + ops[i] = annotate_value (TREE_OPERAND (gnu_size, i)); + if (ops[i] == No_Uint) + return No_Uint; + } + + ret = Create_Node (tcode, ops[0], ops[1], ops[2]); + + /* Save the result in the cache. */ + if (h) + { + *h = GGC_NEW (struct tree_int_map); + (*h)->base.from = gnu_size; + (*h)->to = ret; + } + + return ret; +} + +/* Given GNAT_ENTITY, a record type, and GNU_TYPE, its corresponding + GCC type, set Component_Bit_Offset and Esize to the position and size + used by Gigi. */ + +static void +annotate_rep (Entity_Id gnat_entity, tree gnu_type) +{ + tree gnu_list; + tree gnu_entry; + Entity_Id gnat_field; + + /* We operate by first making a list of all fields and their positions + (we can get the sizes easily at any time) by a recursive call + and then update all the sizes into the tree. */ + gnu_list = compute_field_positions (gnu_type, NULL_TREE, + size_zero_node, bitsize_zero_node, + BIGGEST_ALIGNMENT); + + 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 (Scope (gnat_field))))) + { + tree parent_offset = bitsize_zero_node; + + gnu_entry = purpose_member (gnat_to_gnu_field_decl (gnat_field), + gnu_list); + + if (gnu_entry) + { + if (type_annotate_only && Is_Tagged_Type (gnat_entity)) + { + /* In this mode the tag and parent components have not been + generated, so we add the appropriate offset to each + component. 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_offset + = UI_To_gnu (Esize (Etype (Base_Type (gnat_entity))), + bitsizetype); + else + parent_offset = bitsize_int (POINTER_SIZE); + } + + Set_Component_Bit_Offset + (gnat_field, + annotate_value + (size_binop (PLUS_EXPR, + bit_from_pos (TREE_PURPOSE (TREE_VALUE (gnu_entry)), + TREE_VALUE (TREE_VALUE + (TREE_VALUE (gnu_entry)))), + parent_offset))); + + Set_Esize (gnat_field, + annotate_value (DECL_SIZE (TREE_PURPOSE (gnu_entry)))); + } + else if (Is_Tagged_Type (gnat_entity) + && Is_Derived_Type (gnat_entity)) + { + /* If there is no gnu_entry, this is an inherited component whose + position is the same as in the parent type. */ + Set_Component_Bit_Offset + (gnat_field, + Component_Bit_Offset (Original_Record_Component (gnat_field))); + Set_Esize (gnat_field, + Esize (Original_Record_Component (gnat_field))); + } + } +} + +/* Scan all fields in GNU_TYPE and build entries where TREE_PURPOSE is the + FIELD_DECL and TREE_VALUE a TREE_LIST with TREE_PURPOSE being the byte + position and TREE_VALUE being a TREE_LIST with TREE_PURPOSE the value to be + placed into DECL_OFFSET_ALIGN and TREE_VALUE the bit position. GNU_POS is + to be added to the position, GNU_BITPOS to the bit position, OFFSET_ALIGN is + the present value of DECL_OFFSET_ALIGN and GNU_LIST is a list of the entries + so far. */ + +static tree +compute_field_positions (tree gnu_type, tree gnu_list, tree gnu_pos, + tree gnu_bitpos, unsigned int offset_align) +{ + tree gnu_field; + tree gnu_result = gnu_list; + + for (gnu_field = TYPE_FIELDS (gnu_type); gnu_field; + gnu_field = TREE_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)); + + gnu_result + = tree_cons (gnu_field, + tree_cons (gnu_our_offset, + tree_cons (size_int (our_offset_align), + gnu_our_bitpos, NULL_TREE), + NULL_TREE), + gnu_result); + + if (DECL_INTERNAL_P (gnu_field)) + gnu_result + = compute_field_positions (TREE_TYPE (gnu_field), gnu_result, + gnu_our_offset, gnu_our_bitpos, + our_offset_align); + } + + return gnu_result; +} + +/* UINT_SIZE is a Uint giving the specified size for an object of GNU_TYPE + corresponding to GNAT_OBJECT. If size is valid, return a tree corresponding + to its value. Otherwise return 0. KIND is VAR_DECL is we are specifying + the size for 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 for error + message handling and to indicate to use the object size of GNU_TYPE. + 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. */ + +static tree +validate_size (Uint uint_size, tree gnu_type, Entity_Id gnat_object, + enum tree_code kind, bool component_p, bool zero_ok) +{ + Node_Id gnat_error_node; + tree type_size, size; + + if (kind == VAR_DECL + /* If a type needs strict alignment, a component of this type in + a packed record cannot be packed and thus uses the type size. */ + || (kind == TYPE_DECL && Strict_Alignment (gnat_object))) + type_size = TYPE_SIZE (gnu_type); + else + type_size = rm_size (gnu_type); + + /* Find the node to use for errors. */ + 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 + gnat_error_node = gnat_object; + + /* Return 0 if no size was specified, either because Esize was not Present or + the specified size was zero. */ + if (No (uint_size) || uint_size == No_Uint) + return NULL_TREE; + + /* Get the size as a tree. Give an error if a size was specified, but cannot + be represented as in sizetype. */ + size = UI_To_gnu (uint_size, bitsizetype); + if (TREE_OVERFLOW (size)) + { + post_error_ne (component_p ? "component size of & is too large" + : "size of & is too large", + gnat_error_node, gnat_object); + return NULL_TREE; + } + + /* Ignore a negative size since that corresponds to our back-annotation. + Also ignore a zero size unless a size clause exists. */ + else if (tree_int_cst_sgn (size) < 0 || (integer_zerop (size) && !zero_ok)) + 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& is not a multiple of Storage_Unit", + gnat_error_node, gnat_object); + else + post_error_ne ("size for& is not a multiple of Storage_Unit", + gnat_error_node, gnat_object); + return NULL_TREE; + } + + /* If this is an integral type or a packed array type, the front-end has + verified the size, so we need not do it here (which would entail + 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) || TYPE_IS_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); + + /* Modify the size of the type to be that of the maximum size if it has a + discriminant. */ + if (type_size && CONTAINS_PLACEHOLDER_P (type_size)) + type_size = max_size (type_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_FAT_POINTER_P (gnu_type)) + { + enum machine_mode p_mode; + + for (p_mode = GET_CLASS_NARROWEST_MODE (MODE_INT); + !targetm.valid_pointer_mode (p_mode); + p_mode = GET_MODE_WIDER_MODE (p_mode)) + ; + + type_size = bitsize_int (GET_MODE_BITSIZE (p_mode)); + } + + /* If the size of the object is a constant, the new size must not be + smaller. */ + if (TREE_CODE (type_size) != INTEGER_CST + || TREE_OVERFLOW (type_size) + || tree_int_cst_lt (size, type_size)) + { + if (component_p) + post_error_ne_tree + ("component size for& too small{, minimum allowed is ^}", + gnat_error_node, gnat_object, type_size); + else + post_error_ne_tree ("size for& too small{, minimum allowed is ^}", + gnat_error_node, gnat_object, type_size); + + if (kind == VAR_DECL && !component_p + && TREE_CODE (rm_size (gnu_type)) == INTEGER_CST + && !tree_int_cst_lt (size, rm_size (gnu_type))) + post_error_ne_tree_2 + ("\\size of ^ is not a multiple of alignment (^ bits)", + gnat_error_node, gnat_object, rm_size (gnu_type), + TYPE_ALIGN (gnu_type)); + + else if (INTEGRAL_TYPE_P (gnu_type)) + post_error_ne ("\\size would be legal if & were not aliased!", + gnat_error_node, gnat_object); + + 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) +{ + /* Only give an error if a Value_Size clause was explicitly given. + Otherwise, we'd be duplicating an error on the Size clause. */ + Node_Id gnat_attr_node + = Get_Attribute_Definition_Clause (gnat_entity, Attr_Value_Size); + tree old_size = rm_size (gnu_type); + tree size; + + /* Get the size as a tree. Do nothing if none was specified, either + because RM_Size was not Present or if the specified size was zero. + Give an error if a size was specified, but cannot be represented as + in sizetype. */ + if (No (uint_size) || uint_size == No_Uint) + return; + + size = UI_To_gnu (uint_size, bitsizetype); + if (TREE_OVERFLOW (size)) + { + if (Present (gnat_attr_node)) + post_error_ne ("Value_Size of & is too large", gnat_attr_node, + gnat_entity); + + return; + } + + /* Ignore a negative size since that corresponds to our back-annotation. + Also ignore a zero size unless a size clause exists, a Value_Size + clause exists, or this is an integer type, in which case the + front end will have always set it. */ + else if (tree_int_cst_sgn (size) < 0 + || (integer_zerop (size) && No (gnat_attr_node) + && !Has_Size_Clause (gnat_entity) + && !Is_Discrete_Or_Fixed_Point_Type (gnat_entity))) + return; + + /* 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 the size of the object is a constant, the new size must not be + smaller (the front end checks this for scalar types). */ + if (TREE_CODE (old_size) != INTEGER_CST + || TREE_OVERFLOW (old_size) + || (AGGREGATE_TYPE_P (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. */ + if (TREE_CODE (gnu_type) == INTEGER_TYPE + && Is_Discrete_Or_Fixed_Point_Type (gnat_entity)) + TYPE_RM_SIZE_NUM (gnu_type) = size; + else if (TREE_CODE (gnu_type) == ENUMERAL_TYPE) + TYPE_RM_SIZE_NUM (gnu_type) = size; + else if ((TREE_CODE (gnu_type) == RECORD_TYPE + || TREE_CODE (gnu_type) == UNION_TYPE + || TREE_CODE (gnu_type) == QUAL_UNION_TYPE) + && !TYPE_IS_FAT_POINTER_P (gnu_type)) + SET_TYPE_ADA_SIZE (gnu_type, size); +} + +/* Given a type TYPE, return a new type whose size is appropriate for SIZE. + If TYPE is the best type, return it. Otherwise, make a new type. We + only support new integral and pointer types. FOR_BIASED is nonzero if + we are making a biased type. */ + +static tree +make_type_from_size (tree type, tree size_tree, bool for_biased) +{ + unsigned HOST_WIDE_INT size; + bool biased_p; + tree new_type; + + /* If size indicates an error, just return TYPE to avoid propagating + the error. Likewise if it's too large to represent. */ + if (!size_tree || !host_integerp (size_tree, 1)) + return type; + + size = tree_low_cst (size_tree, 1); + + switch (TREE_CODE (type)) + { + case INTEGER_TYPE: + case ENUMERAL_TYPE: + biased_p = (TREE_CODE (type) == INTEGER_TYPE + && TYPE_BIASED_REPRESENTATION_P (type)); + + /* Only do something if the type is not a packed array type and + doesn't already have the proper size. */ + if (TYPE_PACKED_ARRAY_TYPE_P (type) + || (TYPE_PRECISION (type) == size && biased_p == for_biased)) + break; + + biased_p |= for_biased; + size = MIN (size, LONG_LONG_TYPE_SIZE); + + if (TYPE_UNSIGNED (type) || biased_p) + new_type = make_unsigned_type (size); + else + new_type = make_signed_type (size); + TREE_TYPE (new_type) = TREE_TYPE (type) ? TREE_TYPE (type) : type; + TYPE_MIN_VALUE (new_type) + = convert (TREE_TYPE (new_type), TYPE_MIN_VALUE (type)); + TYPE_MAX_VALUE (new_type) + = convert (TREE_TYPE (new_type), TYPE_MAX_VALUE (type)); + TYPE_BIASED_REPRESENTATION_P (new_type) = biased_p; + TYPE_RM_SIZE_NUM (new_type) = bitsize_int (size); + return new_type; + + case RECORD_TYPE: + /* Do something if this is a fat pointer, in which case we + may need to return the thin pointer. */ + if (TYPE_IS_FAT_POINTER_P (type) && size < POINTER_SIZE * 2) + return + build_pointer_type + (TYPE_OBJECT_RECORD_TYPE (TYPE_UNCONSTRAINED_ARRAY (type))); + break; + + case POINTER_TYPE: + /* Only do something if this is a thin pointer, in which case we + may need to return the fat pointer. */ + if (TYPE_THIN_POINTER_P (type) && size >= POINTER_SIZE * 2) + return + build_pointer_type (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type))); + break; + + default: + break; + } + + return type; +} + +/* 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. */ + if (Present (Alignment_Clause (gnat_entity))) + gnat_error_node = Expression (Alignment_Clause (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) + 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; +} + +/* Return the smallest alignment not less than SIZE. */ + +static unsigned int +ceil_alignment (unsigned HOST_WIDE_INT size) +{ + return (unsigned int) 1 << (floor_log2 (size - 1) + 1); +} + +/* Verify that OBJECT, a type or decl, is something we can implement + atomically. If not, give an error for GNAT_ENTITY. COMP_P is true + if we require atomic components. */ + +static void +check_ok_for_atomic (tree object, Entity_Id gnat_entity, bool comp_p) +{ + Node_Id gnat_error_point = gnat_entity; + Node_Id gnat_node; + enum machine_mode mode; + unsigned int align; + tree size; + + /* There are three case of what OBJECT can be. It can be a type, in which + case we take the size, alignment and mode from the type. It can be a + declaration that was indirect, in which case the relevant values are + that of the type being pointed to, or it can be a normal declaration, + in which case the values are of the decl. The code below assumes that + OBJECT is either a type or a decl. */ + if (TYPE_P (object)) + { + mode = TYPE_MODE (object); + align = TYPE_ALIGN (object); + size = TYPE_SIZE (object); + } + else if (DECL_BY_REF_P (object)) + { + mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (object))); + align = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (object))); + size = TYPE_SIZE (TREE_TYPE (TREE_TYPE (object))); + } + else + { + mode = DECL_MODE (object); + align = DECL_ALIGN (object); + size = DECL_SIZE (object); + } + + /* Consider all floating-point types atomic and any types that that are + represented by integers no wider than a machine word. */ + if (GET_MODE_CLASS (mode) == MODE_FLOAT + || ((GET_MODE_CLASS (mode) == MODE_INT + || GET_MODE_CLASS (mode) == MODE_PARTIAL_INT) + && GET_MODE_BITSIZE (mode) <= BITS_PER_WORD)) + 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 (!comp_p && Nkind (gnat_node) == N_Pragma + && (Get_Pragma_Id (Chars (Pragma_Identifier (gnat_node))) + == Pragma_Atomic)) + gnat_error_point = First (Pragma_Argument_Associations (gnat_node)); + else if (comp_p && Nkind (gnat_node) == N_Pragma + && (Get_Pragma_Id (Chars (Pragma_Identifier (gnat_node))) + == Pragma_Atomic_Components)) + gnat_error_point = First (Pragma_Argument_Associations (gnat_node)); + } + + if (comp_p) + post_error_ne ("atomic access to component of & cannot be guaranteed", + gnat_error_point, gnat_entity); + else + post_error_ne ("atomic access to & cannot be guaranteed", + gnat_error_point, gnat_entity); +} + +/* Check if FTYPE1 and FTYPE2, two potentially different function type nodes, + have compatible signatures so that a call using one type may be safely + issued if the actual target function type is the other. Return 1 if it is + the case, 0 otherwise, and post errors on the incompatibilities. + + This is used when an Ada subprogram is mapped onto a GCC builtin, to ensure + that calls to the subprogram will have arguments suitable for the later + underlying builtin expansion. */ + +static int +compatible_signatures_p (tree ftype1, tree ftype2) +{ + /* As of now, we only perform very trivial tests and consider it's the + programmer's responsibility to ensure the type correctness in the Ada + declaration, as in the regular Import cases. + + Mismatches typically result in either error messages from the builtin + expander, internal compiler errors, or in a real call sequence. This + should be refined to issue diagnostics helping error detection and + correction. */ + + /* Almost fake test, ensuring a use of each argument. */ + if (ftype1 == ftype2) + return 1; + + return 1; +} + +/* Given a type T, a FIELD_DECL F, and a replacement value R, return a new + type with all size expressions that contain F updated by replacing F + with R. If F is NULL_TREE, always make a new RECORD_TYPE, even if + nothing has changed. */ + +tree +substitute_in_type (tree t, tree f, tree r) +{ + tree new = t; + tree tem; + + switch (TREE_CODE (t)) + { + case INTEGER_TYPE: + case ENUMERAL_TYPE: + case BOOLEAN_TYPE: + if (CONTAINS_PLACEHOLDER_P (TYPE_MIN_VALUE (t)) + || CONTAINS_PLACEHOLDER_P (TYPE_MAX_VALUE (t))) + { + tree low = SUBSTITUTE_IN_EXPR (TYPE_MIN_VALUE (t), f, r); + tree high = SUBSTITUTE_IN_EXPR (TYPE_MAX_VALUE (t), f, r); + + if (low == TYPE_MIN_VALUE (t) && high == TYPE_MAX_VALUE (t)) + return t; + + new = build_range_type (TREE_TYPE (t), low, high); + if (TYPE_INDEX_TYPE (t)) + SET_TYPE_INDEX_TYPE + (new, substitute_in_type (TYPE_INDEX_TYPE (t), f, r)); + return new; + } + + return t; + + case REAL_TYPE: + if (CONTAINS_PLACEHOLDER_P (TYPE_MIN_VALUE (t)) + || CONTAINS_PLACEHOLDER_P (TYPE_MAX_VALUE (t))) + { + tree low = NULL_TREE, high = NULL_TREE; + + if (TYPE_MIN_VALUE (t)) + low = SUBSTITUTE_IN_EXPR (TYPE_MIN_VALUE (t), f, r); + if (TYPE_MAX_VALUE (t)) + high = SUBSTITUTE_IN_EXPR (TYPE_MAX_VALUE (t), f, r); + + if (low == TYPE_MIN_VALUE (t) && high == TYPE_MAX_VALUE (t)) + return t; + + t = copy_type (t); + TYPE_MIN_VALUE (t) = low; + TYPE_MAX_VALUE (t) = high; + } + return t; + + case COMPLEX_TYPE: + tem = substitute_in_type (TREE_TYPE (t), f, r); + if (tem == TREE_TYPE (t)) + return t; + + return build_complex_type (tem); + + case OFFSET_TYPE: + case METHOD_TYPE: + case FUNCTION_TYPE: + case LANG_TYPE: + /* Don't know how to do these yet. */ + 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; + + new = build_array_type (component, domain); + TYPE_SIZE (new) = 0; + TYPE_MULTI_ARRAY_P (new) = TYPE_MULTI_ARRAY_P (t); + TYPE_CONVENTION_FORTRAN_P (new) = TYPE_CONVENTION_FORTRAN_P (t); + layout_type (new); + TYPE_ALIGN (new) = TYPE_ALIGN (t); + TYPE_USER_ALIGN (new) = TYPE_USER_ALIGN (t); + + /* If we had bounded the sizes of T by a constant, bound the sizes of + NEW by the same constant. */ + if (TREE_CODE (TYPE_SIZE (t)) == MIN_EXPR) + TYPE_SIZE (new) + = size_binop (MIN_EXPR, TREE_OPERAND (TYPE_SIZE (t), 1), + TYPE_SIZE (new)); + if (TREE_CODE (TYPE_SIZE_UNIT (t)) == MIN_EXPR) + TYPE_SIZE_UNIT (new) + = size_binop (MIN_EXPR, TREE_OPERAND (TYPE_SIZE_UNIT (t), 1), + TYPE_SIZE_UNIT (new)); + return new; + } + + case RECORD_TYPE: + case UNION_TYPE: + case QUAL_UNION_TYPE: + { + tree field; + bool changed_field + = (f == NULL_TREE && !TREE_CONSTANT (TYPE_SIZE (t))); + bool field_has_rep = false; + tree last_field = NULL_TREE; + + tree new = copy_type (t); + + /* 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. */ + + TYPE_FIELDS (new) = NULL_TREE; + TYPE_SIZE (new) = NULL_TREE; + + for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field)) + { + tree new_field = copy_node (field); + + TREE_TYPE (new_field) + = substitute_in_type (TREE_TYPE (new_field), f, r); + + if (DECL_HAS_REP_P (field) && !DECL_INTERNAL_P (field)) + field_has_rep = true; + else if (TREE_TYPE (new_field) != TREE_TYPE (field)) + changed_field = true; + + /* If this is an internal field and the type of this field is + a UNION_TYPE or RECORD_TYPE with no elements, ignore it. If + the type just has one element, treat that as the field. + But don't do this if we are processing a QUAL_UNION_TYPE. */ + if (TREE_CODE (t) != QUAL_UNION_TYPE + && DECL_INTERNAL_P (new_field) + && (TREE_CODE (TREE_TYPE (new_field)) == UNION_TYPE + || TREE_CODE (TREE_TYPE (new_field)) == RECORD_TYPE)) + { + if (!TYPE_FIELDS (TREE_TYPE (new_field))) + continue; + + if (!TREE_CHAIN (TYPE_FIELDS (TREE_TYPE (new_field)))) + { + tree next_new_field + = copy_node (TYPE_FIELDS (TREE_TYPE (new_field))); + + /* Make sure omitting the union doesn't change + the layout. */ + DECL_ALIGN (next_new_field) = DECL_ALIGN (new_field); + new_field = next_new_field; + } + } + + DECL_CONTEXT (new_field) = new; + SET_DECL_ORIGINAL_FIELD (new_field, + (DECL_ORIGINAL_FIELD (field) + ? DECL_ORIGINAL_FIELD (field) : field)); + + /* If the size of the old field was set at a constant, + propagate the size in case the type's size was variable. + (This occurs in the case of a variant or discriminated + record with a default size used as a field of another + record.) */ + DECL_SIZE (new_field) + = TREE_CODE (DECL_SIZE (field)) == INTEGER_CST + ? DECL_SIZE (field) : NULL_TREE; + DECL_SIZE_UNIT (new_field) + = TREE_CODE (DECL_SIZE_UNIT (field)) == INTEGER_CST + ? DECL_SIZE_UNIT (field) : NULL_TREE; + + if (TREE_CODE (t) == QUAL_UNION_TYPE) + { + tree new_q = SUBSTITUTE_IN_EXPR (DECL_QUALIFIER (field), f, r); + + if (new_q != DECL_QUALIFIER (new_field)) + changed_field = true; + + /* Do the substitution inside the qualifier and if we find + that this field will not be present, omit it. */ + DECL_QUALIFIER (new_field) = new_q; + + if (integer_zerop (DECL_QUALIFIER (new_field))) + continue; + } + + if (!last_field) + TYPE_FIELDS (new) = new_field; + else + TREE_CHAIN (last_field) = new_field; + + last_field = new_field; + + /* If this is a qualified type and this field will always be + present, we are done. */ + if (TREE_CODE (t) == QUAL_UNION_TYPE + && integer_onep (DECL_QUALIFIER (new_field))) + break; + } + + /* If this used to be a qualified union type, but we now know what + field will be present, make this a normal union. */ + if (changed_field && TREE_CODE (new) == QUAL_UNION_TYPE + && (!TYPE_FIELDS (new) + || integer_onep (DECL_QUALIFIER (TYPE_FIELDS (new))))) + TREE_SET_CODE (new, UNION_TYPE); + else if (!changed_field) + return t; + + gcc_assert (!field_has_rep); + layout_type (new); + + /* If the size was originally a constant use it. */ + if (TYPE_SIZE (t) && TREE_CODE (TYPE_SIZE (t)) == INTEGER_CST + && TREE_CODE (TYPE_SIZE (new)) != INTEGER_CST) + { + TYPE_SIZE (new) = TYPE_SIZE (t); + TYPE_SIZE_UNIT (new) = TYPE_SIZE_UNIT (t); + SET_TYPE_ADA_SIZE (new, TYPE_ADA_SIZE (t)); + } + + return new; + } + + 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 integer types, this is the precision. For record types, we store + the size explicitly. For other types, this is just the size. */ + + if (INTEGRAL_TYPE_P (gnu_type) && TYPE_RM_SIZE (gnu_type)) + return TYPE_RM_SIZE (gnu_type); + else if (TREE_CODE (gnu_type) == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P (gnu_type)) + /* Return the rm_size of the actual data plus the size of the template. */ + return + size_binop (PLUS_EXPR, + rm_size (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (gnu_type)))), + DECL_SIZE (TYPE_FIELDS (gnu_type))); + else if ((TREE_CODE (gnu_type) == RECORD_TYPE + || TREE_CODE (gnu_type) == UNION_TYPE + || TREE_CODE (gnu_type) == QUAL_UNION_TYPE) + && !TYPE_IS_FAT_POINTER_P (gnu_type) + && TYPE_ADA_SIZE (gnu_type)) + return TYPE_ADA_SIZE (gnu_type); + else + return TYPE_SIZE (gnu_type); +} + +/* 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) +{ + Entity_Kind kind = Ekind (gnat_entity); + + const char *str = (!suffix ? "" : suffix); + String_Template temp = {1, strlen (str)}; + Fat_Pointer fp = {str, &temp}; + + Get_External_Name_With_Suffix (gnat_entity, fp); + + /* A variable using the Stdcall convention (meaning we are running + on a Windows box) live in a DLL. Here 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 char *prefix = "_imp__"; + int k, plen = strlen (prefix); + + for (k = 0; k <= Name_Len; k++) + Name_Buffer [Name_Len - k + plen] = Name_Buffer [Name_Len - k]; + strncpy (Name_Buffer, prefix, plen); + } + + return get_identifier (Name_Buffer); +} + +/* 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. */ + +tree +get_entity_name (Entity_Id gnat_entity) +{ + Get_Encoded_Name (gnat_entity); + return get_identifier (Name_Buffer); +} + +/* Given GNU_ID, an IDENTIFIER_NODE containing a name and SUFFIX, a + string, return a new IDENTIFIER_NODE that is the concatenation of + the name in GNU_ID and SUFFIX. */ + +tree +concat_id_with_name (tree gnu_id, const char *suffix) +{ + int len = IDENTIFIER_LENGTH (gnu_id); + + strncpy (Name_Buffer, IDENTIFIER_POINTER (gnu_id), len); + strncpy (Name_Buffer + len, "___", 3); + len += 3; + strcpy (Name_Buffer + len, suffix); + return get_identifier (Name_Buffer); +} + +#include "gt-ada-decl.h" |