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Diffstat (limited to 'gcc/ada/gcc-interface/trans.cc')
| -rw-r--r-- | gcc/ada/gcc-interface/trans.cc | 11009 |
1 files changed, 11009 insertions, 0 deletions
diff --git a/gcc/ada/gcc-interface/trans.cc b/gcc/ada/gcc-interface/trans.cc new file mode 100644 index 0000000..39059cb --- /dev/null +++ b/gcc/ada/gcc-interface/trans.cc @@ -0,0 +1,11009 @@ +/**************************************************************************** + * * + * GNAT COMPILER COMPONENTS * + * * + * T R A N S * + * * + * C Implementation File * + * * + * Copyright (C) 1992-2021, Free Software Foundation, Inc. * + * * + * GNAT is free software; you can redistribute it and/or modify it under * + * terms of the GNU General Public License as published by the Free Soft- * + * ware Foundation; either version 3, or (at your option) any later ver- * + * sion. GNAT is distributed in the hope that it will be useful, but WITH- * + * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * + * for more details. You should have received a copy of the GNU General * + * Public License distributed with GNAT; see file COPYING3. If not see * + * <http://www.gnu.org/licenses/>. * + * * + * GNAT was originally developed by the GNAT team at New York University. * + * Extensive contributions were provided by Ada Core Technologies Inc. * + * * + ****************************************************************************/ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "target.h" +#include "function.h" +#include "bitmap.h" +#include "tree.h" +#include "gimple-expr.h" +#include "stringpool.h" +#include "cgraph.h" +#include "predict.h" +#include "diagnostic.h" +#include "alias.h" +#include "fold-const.h" +#include "stor-layout.h" +#include "stmt.h" +#include "varasm.h" +#include "output.h" +#include "debug.h" +#include "libfuncs.h" /* For set_stack_check_libfunc. */ +#include "tree-iterator.h" +#include "gimplify.h" +#include "opts.h" +#include "common/common-target.h" +#include "gomp-constants.h" +#include "stringpool.h" +#include "attribs.h" +#include "tree-nested.h" + +#include "ada.h" +#include "adadecode.h" +#include "types.h" +#include "atree.h" +#include "namet.h" +#include "nlists.h" +#include "snames.h" +#include "stringt.h" +#include "uintp.h" +#include "urealp.h" +#include "fe.h" +#include "sinfo.h" +#include "einfo.h" +#include "gadaint.h" +#include "ada-tree.h" +#include "gigi.h" + +/* We should avoid allocating more than ALLOCA_THRESHOLD bytes via alloca, + for fear of running out of stack space. If we need more, we use xmalloc + instead. */ +#define ALLOCA_THRESHOLD 1000 + +/* Pointers to front-end tables accessed through macros. */ +Node_Header *Node_Offsets_Ptr; +any_slot *Slots_Ptr; +Node_Id *Next_Node_Ptr; +Node_Id *Prev_Node_Ptr; +struct Elist_Header *Elists_Ptr; +struct Elmt_Item *Elmts_Ptr; +struct String_Entry *Strings_Ptr; +Char_Code *String_Chars_Ptr; +struct List_Header *List_Headers_Ptr; + +/* Highest number in the front-end node table. */ +int max_gnat_nodes; + +/* True when gigi is being called on an analyzed but unexpanded + tree, and the only purpose of the call is to properly annotate + types with representation information. */ +bool type_annotate_only; + +/* List of N_Validate_Unchecked_Conversion nodes in the unit. */ +static vec<Node_Id> gnat_validate_uc_list; + +/* List of expressions of pragma Compile_Time_{Error|Warning} in the unit. */ +static vec<Node_Id> gnat_compile_time_expr_list; + +/* When not optimizing, we cache the 'First, 'Last and 'Length attributes + of unconstrained array IN parameters to avoid emitting a great deal of + redundant instructions to recompute them each time. */ +struct GTY (()) parm_attr_d { + int id; /* GTY doesn't like Entity_Id. */ + int dim; + tree first; + tree last; + tree length; +}; + +typedef struct parm_attr_d *parm_attr; + +/* Structure used to record information for a function. */ +struct GTY(()) language_function { + vec<parm_attr, va_gc> *parm_attr_cache; + bitmap named_ret_val; + vec<tree, va_gc> *other_ret_val; + int gnat_ret; +}; + +#define f_parm_attr_cache \ + DECL_STRUCT_FUNCTION (current_function_decl)->language->parm_attr_cache + +#define f_named_ret_val \ + DECL_STRUCT_FUNCTION (current_function_decl)->language->named_ret_val + +#define f_other_ret_val \ + DECL_STRUCT_FUNCTION (current_function_decl)->language->other_ret_val + +#define f_gnat_ret \ + DECL_STRUCT_FUNCTION (current_function_decl)->language->gnat_ret + +/* A structure used to gather together information about a statement group. + We use this to gather related statements, for example the "then" part + of a IF. In the case where it represents a lexical scope, we may also + have a BLOCK node corresponding to it and/or cleanups. */ + +struct GTY((chain_next ("%h.previous"))) stmt_group { + struct stmt_group *previous; /* Previous code group. */ + tree stmt_list; /* List of statements for this code group. */ + tree block; /* BLOCK for this code group, if any. */ + tree cleanups; /* Cleanups for this code group, if any. */ +}; + +static GTY(()) struct stmt_group *current_stmt_group; + +/* List of unused struct stmt_group nodes. */ +static GTY((deletable)) struct stmt_group *stmt_group_free_list; + +/* A structure used to record information on elaboration procedures + we've made and need to process. + + ??? gnat_node should be Node_Id, but gengtype gets confused. */ + +struct GTY((chain_next ("%h.next"))) elab_info { + struct elab_info *next; /* Pointer to next in chain. */ + tree elab_proc; /* Elaboration procedure. */ + int gnat_node; /* The N_Compilation_Unit. */ +}; + +static GTY(()) struct elab_info *elab_info_list; + +/* Stack of exception pointer variables. Each entry is the VAR_DECL + that stores the address of the raised exception. Nonzero means we + are in an exception handler. Not used in the zero-cost case. */ +static GTY(()) vec<tree, va_gc> *gnu_except_ptr_stack; + +/* In ZCX case, current exception pointer. Used to re-raise it. */ +static GTY(()) tree gnu_incoming_exc_ptr; + +/* Stack for storing the current elaboration procedure decl. */ +static GTY(()) vec<tree, va_gc> *gnu_elab_proc_stack; + +/* Stack of labels to be used as a goto target instead of a return in + some functions. See processing for N_Subprogram_Body. */ +static GTY(()) vec<tree, va_gc> *gnu_return_label_stack; + +/* Stack of variable for the return value of a function with copy-in/copy-out + parameters. See processing for N_Subprogram_Body. */ +static GTY(()) vec<tree, va_gc> *gnu_return_var_stack; + +/* Structure used to record information for a range check. */ +struct GTY(()) range_check_info_d { + tree low_bound; + tree high_bound; + tree disp; + bool neg_p; + tree type; + tree invariant_cond; + tree inserted_cond; +}; + +typedef struct range_check_info_d *range_check_info; + +/* Structure used to record information for a loop. */ +struct GTY(()) loop_info_d { + tree fndecl; + tree stmt; + tree loop_var; + tree low_bound; + tree high_bound; + tree omp_loop_clauses; + tree omp_construct_clauses; + enum tree_code omp_code; + vec<range_check_info, va_gc> *checks; + vec<tree, va_gc> *invariants; +}; + +typedef struct loop_info_d *loop_info; + +/* Stack of loop_info structures associated with LOOP_STMT nodes. */ +static GTY(()) vec<loop_info, va_gc> *gnu_loop_stack; + +/* The stacks for N_{Push,Pop}_*_Label. */ +static vec<Entity_Id> gnu_constraint_error_label_stack; +static vec<Entity_Id> gnu_storage_error_label_stack; +static vec<Entity_Id> gnu_program_error_label_stack; + +/* Map GNAT tree codes to GCC tree codes for simple expressions. */ +static enum tree_code gnu_codes[Number_Node_Kinds]; + +static void init_code_table (void); +static tree get_elaboration_procedure (void); +static void Compilation_Unit_to_gnu (Node_Id); +static bool empty_stmt_list_p (tree); +static void record_code_position (Node_Id); +static void insert_code_for (Node_Id); +static void add_cleanup (tree, Node_Id); +static void add_stmt_list (List_Id); +static tree build_stmt_group (List_Id, bool); +static inline bool stmt_group_may_fallthru (void); +static enum gimplify_status gnat_gimplify_stmt (tree *); +static void elaborate_all_entities (Node_Id); +static void process_freeze_entity (Node_Id); +static void process_decls (List_Id, List_Id, Node_Id, bool, bool); +static tree emit_check (tree, tree, int, Node_Id); +static tree build_unary_op_trapv (enum tree_code, tree, tree, Node_Id); +static tree build_binary_op_trapv (enum tree_code, tree, tree, tree, Node_Id); +static tree convert_with_check (Entity_Id, tree, bool, bool, Node_Id); +static bool addressable_p (tree, tree); +static tree assoc_to_constructor (Entity_Id, Node_Id, tree); +static tree pos_to_constructor (Node_Id, tree); +static void validate_unchecked_conversion (Node_Id); +static void set_expr_location_from_node (tree, Node_Id, bool = false); +static void set_gnu_expr_location_from_node (tree, Node_Id); +static bool set_end_locus_from_node (tree, Node_Id); +static int lvalue_required_p (Node_Id, tree, bool, bool); +static tree build_raise_check (int, enum exception_info_kind); +static tree create_init_temporary (const char *, tree, tree *, Node_Id); +static bool maybe_make_gnu_thunk (Entity_Id gnat_thunk, tree gnu_thunk); + +/* This makes gigi's file_info_ptr visible in this translation unit, + so that Sloc_to_locus can look it up when deciding whether to map + decls to instances. */ + +static struct File_Info_Type *file_map; + +/* Return the string of the identifier allocated for the file name Id. */ + +static const char* +File_Name_to_gnu (Name_Id Id) +{ + /* __gnat_to_canonical_file_spec translates file names from pragmas + Source_Reference that contain host style syntax not understood by GDB. */ + const char *name = __gnat_to_canonical_file_spec (Get_Name_String (Id)); + + /* Use the identifier table to make a permanent copy of the file name as + the name table gets reallocated after Gigi returns but before all the + debugging information is output. */ + return IDENTIFIER_POINTER (get_identifier (name)); +} + +/* This is the main program of the back-end. It sets up all the table + structures and then generates code. */ + +void +gigi (Node_Id gnat_root, + int max_gnat_node, + int number_name ATTRIBUTE_UNUSED, + Node_Header *node_offsets_ptr, + any_slot *slots_ptr, + Node_Id *next_node_ptr, + Node_Id *prev_node_ptr, + struct Elist_Header *elists_ptr, + struct Elmt_Item *elmts_ptr, + struct String_Entry *strings_ptr, + Char_Code *string_chars_ptr, + struct List_Header *list_headers_ptr, + Nat number_file, + struct File_Info_Type *file_info_ptr, + Entity_Id standard_boolean, + Entity_Id standard_integer, + Entity_Id standard_character, + Entity_Id standard_long_long_float, + Entity_Id standard_exception_type, + Int gigi_operating_mode) +{ + Node_Id gnat_iter; + Entity_Id gnat_literal; + tree t, ftype, int64_type; + struct elab_info *info; + int i; + + max_gnat_nodes = max_gnat_node; + + Node_Offsets_Ptr = node_offsets_ptr; + Slots_Ptr = slots_ptr; + Next_Node_Ptr = next_node_ptr; + Prev_Node_Ptr = prev_node_ptr; + Elists_Ptr = elists_ptr; + Elmts_Ptr = elmts_ptr; + Strings_Ptr = strings_ptr; + String_Chars_Ptr = string_chars_ptr; + List_Headers_Ptr = list_headers_ptr; + + type_annotate_only = (gigi_operating_mode == 1); + + if (Generate_SCO_Instance_Table != 0) + { + file_map = file_info_ptr; + maybe_create_decl_to_instance_map (number_file); + } + + for (i = 0; i < number_file; i++) + { + /* We rely on the order isomorphism between files and line maps. */ + if ((int) LINEMAPS_ORDINARY_USED (line_table) != i) + { + gcc_assert (i > 0); + error ("%s contains too many lines", + File_Name_to_gnu (file_info_ptr[i - 1].File_Name)); + } + + /* We create the line map for a source file at once, with a fixed number + of columns chosen to avoid jumping over the next power of 2. */ + linemap_add (line_table, LC_ENTER, 0, + File_Name_to_gnu (file_info_ptr[i].File_Name), 1); + linemap_line_start (line_table, file_info_ptr[i].Num_Source_Lines, 252); + linemap_position_for_column (line_table, 252 - 1); + linemap_add (line_table, LC_LEAVE, 0, NULL, 0); + } + + gcc_assert (Nkind (gnat_root) == N_Compilation_Unit); + + /* Declare the name of the compilation unit as the first global + name in order to make the middle-end fully deterministic. */ + t = create_concat_name (Defining_Entity (Unit (gnat_root)), NULL); + first_global_object_name = ggc_strdup (IDENTIFIER_POINTER (t)); + + /* Initialize ourselves. */ + init_code_table (); + init_gnat_decl (); + init_gnat_utils (); + + /* If we are just annotating types, give VOID_TYPE zero sizes to avoid + errors. */ + if (type_annotate_only) + { + TYPE_SIZE (void_type_node) = bitsize_zero_node; + TYPE_SIZE_UNIT (void_type_node) = size_zero_node; + } + + /* Enable GNAT stack checking method if needed */ + if (!Stack_Check_Probes_On_Target) + set_stack_check_libfunc ("_gnat_stack_check"); + + /* Retrieve alignment settings. */ + double_float_alignment = get_target_double_float_alignment (); + double_scalar_alignment = get_target_double_scalar_alignment (); + + /* Record the builtin types. Define `integer' and `character' first so that + dbx will output them first. */ + record_builtin_type ("integer", integer_type_node, false); + record_builtin_type ("character", char_type_node, false); + record_builtin_type ("boolean", boolean_type_node, false); + record_builtin_type ("void", void_type_node, false); + + /* Save the type we made for integer as the type for Standard.Integer. */ + save_gnu_tree (Base_Type (standard_integer), + TYPE_NAME (integer_type_node), + false); + + /* Likewise for character as the type for Standard.Character. */ + finish_character_type (char_type_node); + save_gnu_tree (Base_Type (standard_character), + TYPE_NAME (char_type_node), + false); + + /* Likewise for boolean as the type for Standard.Boolean. */ + save_gnu_tree (Base_Type (standard_boolean), + TYPE_NAME (boolean_type_node), + false); + gnat_literal = First_Literal (Base_Type (standard_boolean)); + t = UI_To_gnu (Enumeration_Rep (gnat_literal), boolean_type_node); + gcc_assert (t == boolean_false_node); + t = create_var_decl (get_entity_name (gnat_literal), NULL_TREE, + boolean_type_node, t, true, false, false, false, false, + true, false, NULL, gnat_literal); + save_gnu_tree (gnat_literal, t, false); + gnat_literal = Next_Literal (gnat_literal); + t = UI_To_gnu (Enumeration_Rep (gnat_literal), boolean_type_node); + gcc_assert (t == boolean_true_node); + t = create_var_decl (get_entity_name (gnat_literal), NULL_TREE, + boolean_type_node, t, true, false, false, false, false, + true, false, NULL, gnat_literal); + save_gnu_tree (gnat_literal, t, false); + + /* Declare the building blocks of function nodes. */ + void_list_node = build_tree_list (NULL_TREE, void_type_node); + void_ftype = build_function_type_list (void_type_node, NULL_TREE); + ptr_void_ftype = build_pointer_type (void_ftype); + + /* Now declare run-time functions. */ + malloc_decl + = create_subprog_decl (get_identifier ("__gnat_malloc"), NULL_TREE, + build_function_type_list (ptr_type_node, sizetype, + NULL_TREE), + NULL_TREE, is_default, true, true, true, false, + false, NULL, Empty); + DECL_IS_MALLOC (malloc_decl) = 1; + + free_decl + = create_subprog_decl (get_identifier ("__gnat_free"), NULL_TREE, + build_function_type_list (void_type_node, + ptr_type_node, NULL_TREE), + NULL_TREE, is_default, true, true, true, false, + false, NULL, Empty); + + realloc_decl + = create_subprog_decl (get_identifier ("__gnat_realloc"), NULL_TREE, + build_function_type_list (ptr_type_node, + ptr_type_node, sizetype, + NULL_TREE), + NULL_TREE, is_default, true, true, true, false, + false, NULL, Empty); + + /* This is used for 64-bit multiplication with overflow checking. */ + int64_type = gnat_type_for_size (64, 0); + mulv64_decl + = create_subprog_decl (get_identifier ("__gnat_mulv64"), NULL_TREE, + build_function_type_list (int64_type, int64_type, + int64_type, NULL_TREE), + NULL_TREE, is_default, true, true, true, false, + false, NULL, Empty); + + if (Enable_128bit_Types) + { + tree int128_type = gnat_type_for_size (128, 0); + mulv128_decl + = create_subprog_decl (get_identifier ("__gnat_mulv128"), NULL_TREE, + build_function_type_list (int128_type, + int128_type, + int128_type, + NULL_TREE), + NULL_TREE, is_default, true, true, true, false, + false, NULL, Empty); + } + + /* Name of the _Parent field in tagged record types. */ + parent_name_id = get_identifier (Get_Name_String (Name_uParent)); + + /* Name of the Not_Handled_By_Others field in exception record types. */ + not_handled_by_others_name_id = get_identifier ("not_handled_by_others"); + + /* Make the types and functions used for exception processing. */ + except_type_node = gnat_to_gnu_type (Base_Type (standard_exception_type)); + + for (t = TYPE_FIELDS (except_type_node); t; t = DECL_CHAIN (t)) + if (DECL_NAME (t) == not_handled_by_others_name_id) + { + not_handled_by_others_decl = t; + break; + } + gcc_assert (DECL_P (not_handled_by_others_decl)); + + jmpbuf_type + = build_array_type (gnat_type_for_mode (Pmode, 0), + build_index_type (size_int (5))); + record_builtin_type ("JMPBUF_T", jmpbuf_type, true); + jmpbuf_ptr_type = build_pointer_type (jmpbuf_type); + + /* Functions to get and set the jumpbuf pointer for the current thread. */ + get_jmpbuf_decl + = create_subprog_decl + (get_identifier ("system__soft_links__get_jmpbuf_address_soft"), + NULL_TREE, build_function_type_list (jmpbuf_ptr_type, NULL_TREE), + NULL_TREE, is_default, true, true, true, false, false, NULL, Empty); + + set_jmpbuf_decl + = create_subprog_decl + (get_identifier ("system__soft_links__set_jmpbuf_address_soft"), + NULL_TREE, build_function_type_list (void_type_node, jmpbuf_ptr_type, + NULL_TREE), + NULL_TREE, is_default, true, true, true, false, false, NULL, Empty); + + get_excptr_decl + = create_subprog_decl + (get_identifier ("system__soft_links__get_gnat_exception"), NULL_TREE, + build_function_type_list (build_pointer_type (except_type_node), + NULL_TREE), + NULL_TREE, is_default, true, true, true, false, false, NULL, Empty); + + /* setjmp returns an integer and has one operand, which is a pointer to + a jmpbuf. */ + setjmp_decl + = create_subprog_decl + (get_identifier ("__builtin_setjmp"), NULL_TREE, + build_function_type_list (integer_type_node, jmpbuf_ptr_type, + NULL_TREE), + NULL_TREE, is_default, true, true, true, false, false, NULL, Empty); + set_decl_built_in_function (setjmp_decl, BUILT_IN_NORMAL, BUILT_IN_SETJMP); + + /* update_setjmp_buf updates a setjmp buffer from the current stack pointer + address. */ + update_setjmp_buf_decl + = create_subprog_decl + (get_identifier ("__builtin_update_setjmp_buf"), NULL_TREE, + build_function_type_list (void_type_node, jmpbuf_ptr_type, NULL_TREE), + NULL_TREE, is_default, true, true, true, false, false, NULL, Empty); + set_decl_built_in_function (update_setjmp_buf_decl, BUILT_IN_NORMAL, + BUILT_IN_UPDATE_SETJMP_BUF); + + /* Indicate that it never returns. */ + ftype = build_function_type_list (void_type_node, + build_pointer_type (except_type_node), + NULL_TREE); + ftype = build_qualified_type (ftype, TYPE_QUAL_VOLATILE); + raise_nodefer_decl + = create_subprog_decl + (get_identifier ("__gnat_raise_nodefer_with_msg"), NULL_TREE, ftype, + NULL_TREE, is_default, true, true, true, false, false, NULL, Empty); + + set_exception_parameter_decl + = create_subprog_decl + (get_identifier ("__gnat_set_exception_parameter"), NULL_TREE, + build_function_type_list (void_type_node, ptr_type_node, ptr_type_node, + NULL_TREE), + NULL_TREE, is_default, true, true, true, false, false, NULL, Empty); + + /* Hooks to call when entering/leaving an exception handler. */ + ftype = build_function_type_list (ptr_type_node, + ptr_type_node, NULL_TREE); + begin_handler_decl + = create_subprog_decl (get_identifier ("__gnat_begin_handler_v1"), + NULL_TREE, ftype, NULL_TREE, + is_default, true, true, true, false, false, NULL, + Empty); + /* __gnat_begin_handler_v1 is not a dummy procedure, but we arrange + for it not to throw. */ + TREE_NOTHROW (begin_handler_decl) = 1; + + ftype = build_function_type_list (ptr_type_node, + ptr_type_node, ptr_type_node, + ptr_type_node, NULL_TREE); + end_handler_decl + = create_subprog_decl (get_identifier ("__gnat_end_handler_v1"), NULL_TREE, + ftype, NULL_TREE, + is_default, true, true, true, false, false, NULL, + Empty); + + ftype = build_function_type_list (void_type_node, ptr_type_node, NULL_TREE); + unhandled_except_decl + = create_subprog_decl (get_identifier ("__gnat_unhandled_except_handler"), + NULL_TREE, ftype, NULL_TREE, + is_default, true, true, true, false, false, NULL, + Empty); + + /* Indicate that it never returns. */ + ftype = build_qualified_type (ftype, TYPE_QUAL_VOLATILE); + reraise_zcx_decl + = create_subprog_decl (get_identifier ("__gnat_reraise_zcx"), NULL_TREE, + ftype, NULL_TREE, + is_default, true, true, true, false, false, NULL, + Empty); + + /* Dummy objects to materialize "others" and "all others" in the exception + tables. These are exported by a-exexpr-gcc.adb, so see this unit for + the types to use. */ + others_decl + = create_var_decl (get_identifier ("OTHERS"), + get_identifier ("__gnat_others_value"), + char_type_node, NULL_TREE, + true, false, true, false, false, true, false, + NULL, Empty); + + all_others_decl + = create_var_decl (get_identifier ("ALL_OTHERS"), + get_identifier ("__gnat_all_others_value"), + char_type_node, NULL_TREE, + true, false, true, false, false, true, false, + NULL, Empty); + + unhandled_others_decl + = create_var_decl (get_identifier ("UNHANDLED_OTHERS"), + get_identifier ("__gnat_unhandled_others_value"), + char_type_node, NULL_TREE, + true, false, true, false, false, true, false, + NULL, Empty); + + /* If in no exception handlers mode, all raise statements are redirected to + __gnat_last_chance_handler. No need to redefine raise_nodefer_decl since + this procedure will never be called in this mode. */ + if (No_Exception_Handlers_Set ()) + { + /* Indicate that it never returns. */ + ftype = build_function_type_list (void_type_node, + build_pointer_type (char_type_node), + integer_type_node, NULL_TREE); + ftype = build_qualified_type (ftype, TYPE_QUAL_VOLATILE); + tree decl + = create_subprog_decl + (get_identifier ("__gnat_last_chance_handler"), NULL_TREE, ftype, + NULL_TREE, is_default, true, true, true, false, false, NULL, + Empty); + for (i = 0; i < (int) ARRAY_SIZE (gnat_raise_decls); i++) + gnat_raise_decls[i] = decl; + } + else + { + /* Otherwise, make one decl for each exception reason. */ + for (i = 0; i < (int) ARRAY_SIZE (gnat_raise_decls); i++) + gnat_raise_decls[i] = build_raise_check (i, exception_simple); + for (i = 0; i < (int) ARRAY_SIZE (gnat_raise_decls_ext); i++) + gnat_raise_decls_ext[i] + = build_raise_check (i, + i == CE_Index_Check_Failed + || i == CE_Range_Check_Failed + || i == CE_Invalid_Data + ? exception_range : exception_column); + } + + /* Build the special descriptor type and its null node if needed. */ + if (TARGET_VTABLE_USES_DESCRIPTORS) + { + tree null_node = fold_convert (ptr_void_ftype, null_pointer_node); + tree field_list = NULL_TREE; + int j; + vec<constructor_elt, va_gc> *null_vec = NULL; + constructor_elt *elt; + + fdesc_type_node = make_node (RECORD_TYPE); + vec_safe_grow (null_vec, TARGET_VTABLE_USES_DESCRIPTORS, true); + elt = (null_vec->address () + TARGET_VTABLE_USES_DESCRIPTORS - 1); + + for (j = 0; j < TARGET_VTABLE_USES_DESCRIPTORS; j++) + { + tree field + = create_field_decl (NULL_TREE, ptr_void_ftype, fdesc_type_node, + NULL_TREE, NULL_TREE, 0, 1); + DECL_CHAIN (field) = field_list; + field_list = field; + elt->index = field; + elt->value = null_node; + elt--; + } + + finish_record_type (fdesc_type_node, nreverse (field_list), 0, false); + record_builtin_type ("descriptor", fdesc_type_node, true); + null_fdesc_node = gnat_build_constructor (fdesc_type_node, null_vec); + } + + longest_float_type_node + = get_unpadded_type (Base_Type (standard_long_long_float)); + + main_identifier_node = get_identifier ("main"); + + /* If we are using the GCC exception mechanism, let GCC know. */ + if (Back_End_Exceptions ()) + gnat_init_gcc_eh (); + + /* Initialize the GCC support for FP operations. */ + gnat_init_gcc_fp (); + + /* Install the builtins we might need, either internally or as user-available + facilities for Intrinsic imports. Note that this must be done after the + GCC exception mechanism is initialized. */ + gnat_install_builtins (); + + vec_safe_push (gnu_except_ptr_stack, NULL_TREE); + + gnu_constraint_error_label_stack.safe_push (Empty); + gnu_storage_error_label_stack.safe_push (Empty); + gnu_program_error_label_stack.safe_push (Empty); + + /* Process any Pragma Ident for the main unit. */ + if (Present (Ident_String (Main_Unit))) + targetm.asm_out.output_ident + (TREE_STRING_POINTER (gnat_to_gnu (Ident_String (Main_Unit)))); + + /* Force -fno-strict-aliasing if the configuration pragma was seen. */ + if (No_Strict_Aliasing_CP) + flag_strict_aliasing = 0; + + /* Save the current optimization options again after the above possible + global_options changes. */ + optimization_default_node + = build_optimization_node (&global_options, &global_options_set); + optimization_current_node = optimization_default_node; + + /* Now translate the compilation unit proper. */ + Compilation_Unit_to_gnu (gnat_root); + + /* Then process the N_Validate_Unchecked_Conversion nodes. We do this at + the very end to avoid having to second-guess the front-end when we run + into dummy nodes during the regular processing. */ + for (i = 0; gnat_validate_uc_list.iterate (i, &gnat_iter); i++) + validate_unchecked_conversion (gnat_iter); + gnat_validate_uc_list.release (); + + /* Finally see if we have any elaboration procedures to deal with. */ + for (info = elab_info_list; info; info = info->next) + { + tree gnu_body = DECL_SAVED_TREE (info->elab_proc); + + /* We should have a BIND_EXPR but it may not have any statements in it. + If it doesn't have any, we have nothing to do except for setting the + flag on the GNAT node. Otherwise, process the function as others. */ + tree gnu_stmts = gnu_body; + if (TREE_CODE (gnu_stmts) == BIND_EXPR) + gnu_stmts = BIND_EXPR_BODY (gnu_stmts); + if (!gnu_stmts || empty_stmt_list_p (gnu_stmts)) + Set_Has_No_Elaboration_Code (info->gnat_node, 1); + else + { + begin_subprog_body (info->elab_proc); + end_subprog_body (gnu_body); + rest_of_subprog_body_compilation (info->elab_proc); + } + } + + /* Destroy ourselves. */ + file_map = NULL; + destroy_gnat_decl (); + destroy_gnat_utils (); + + /* We cannot track the location of errors past this point. */ + Current_Error_Node = Empty; +} + +/* Return a subprogram decl corresponding to __gnat_rcheck_xx for the given + CHECK if KIND is EXCEPTION_SIMPLE, or else to __gnat_rcheck_xx_ext. */ + +static tree +build_raise_check (int check, enum exception_info_kind kind) +{ + tree result, ftype; + const char pfx[] = "__gnat_rcheck_"; + + strcpy (Name_Buffer, pfx); + Name_Len = sizeof (pfx) - 1; + Get_RT_Exception_Name ((enum RT_Exception_Code) check); + + if (kind == exception_simple) + { + Name_Buffer[Name_Len] = 0; + ftype + = build_function_type_list (void_type_node, + build_pointer_type (char_type_node), + integer_type_node, NULL_TREE); + } + else + { + tree t = (kind == exception_column ? NULL_TREE : integer_type_node); + + strcpy (Name_Buffer + Name_Len, "_ext"); + Name_Buffer[Name_Len + 4] = 0; + ftype + = build_function_type_list (void_type_node, + build_pointer_type (char_type_node), + integer_type_node, integer_type_node, + t, t, NULL_TREE); + } + + /* Indicate that it never returns. */ + ftype = build_qualified_type (ftype, TYPE_QUAL_VOLATILE); + result + = create_subprog_decl (get_identifier (Name_Buffer), NULL_TREE, ftype, + NULL_TREE, is_default, true, true, true, false, + false, NULL, Empty); + + return result; +} + +/* Return a positive value if an lvalue is required for GNAT_NODE, which is + an N_Attribute_Reference. */ + +static int +lvalue_required_for_attribute_p (Node_Id gnat_node) +{ + switch (Get_Attribute_Id (Attribute_Name (gnat_node))) + { + case Attr_Pred: + case Attr_Succ: + case Attr_First: + case Attr_Last: + case Attr_Range_Length: + case Attr_Length: + case Attr_Object_Size: + case Attr_Size: + case Attr_Value_Size: + case Attr_Component_Size: + case Attr_Descriptor_Size: + case Attr_Max_Size_In_Storage_Elements: + case Attr_Min: + case Attr_Max: + case Attr_Null_Parameter: + case Attr_Passed_By_Reference: + case Attr_Mechanism_Code: + case Attr_Machine: + case Attr_Model: + return 0; + + case Attr_Address: + case Attr_Access: + case Attr_Unchecked_Access: + case Attr_Unrestricted_Access: + case Attr_Code_Address: + case Attr_Pool_Address: + case Attr_Alignment: + case Attr_Bit_Position: + case Attr_Position: + case Attr_First_Bit: + case Attr_Last_Bit: + case Attr_Bit: + case Attr_Asm_Input: + case Attr_Asm_Output: + default: + return 1; + } +} + +/* Return a positive value if an lvalue is required for GNAT_NODE. GNU_TYPE + is the type that will be used for GNAT_NODE in the translated GNU tree. + CONSTANT indicates whether the underlying object represented by GNAT_NODE + is constant in the Ada sense. If it is, ADDRESS_OF_CONSTANT indicates + whether its value is the address of another constant. If it isn't, then + ADDRESS_OF_CONSTANT is ignored. + + The function climbs up the GNAT tree starting from the node and returns 1 + upon encountering a node that effectively requires an lvalue downstream. + It returns int instead of bool to facilitate usage in non-purely binary + logic contexts. */ + +static int +lvalue_required_p (Node_Id gnat_node, tree gnu_type, bool constant, + bool address_of_constant) +{ + Node_Id gnat_parent = Parent (gnat_node), gnat_temp; + + switch (Nkind (gnat_parent)) + { + case N_Reference: + return 1; + + case N_Attribute_Reference: + return lvalue_required_for_attribute_p (gnat_parent); + + case N_Parameter_Association: + case N_Function_Call: + case N_Procedure_Call_Statement: + /* If the parameter is by reference, an lvalue is required. */ + return (!constant + || must_pass_by_ref (gnu_type) + || default_pass_by_ref (gnu_type)); + + case N_Pragma_Argument_Association: + return lvalue_required_p (gnat_parent, gnu_type, constant, + address_of_constant); + + case N_Pragma: + if (Is_Pragma_Name (Chars (Pragma_Identifier (gnat_parent)))) + { + const unsigned char id + = Get_Pragma_Id (Chars (Pragma_Identifier (gnat_parent))); + return id == Pragma_Inspection_Point; + } + else + return 0; + + case N_Indexed_Component: + /* Only the array expression can require an lvalue. */ + if (Prefix (gnat_parent) != gnat_node) + return 0; + + /* ??? Consider that referencing an indexed component with a variable + index forces the whole aggregate to memory. Note that testing only + for literals is conservative, any static expression in the RM sense + could probably be accepted with some additional work. */ + for (gnat_temp = First (Expressions (gnat_parent)); + Present (gnat_temp); + gnat_temp = Next (gnat_temp)) + if (Nkind (gnat_temp) != N_Character_Literal + && Nkind (gnat_temp) != N_Integer_Literal + && !(Is_Entity_Name (gnat_temp) + && Ekind (Entity (gnat_temp)) == E_Enumeration_Literal)) + return 1; + + /* ... fall through ... */ + + case N_Selected_Component: + case N_Slice: + /* Only the prefix expression can require an lvalue. */ + if (Prefix (gnat_parent) != gnat_node) + return 0; + + return lvalue_required_p (gnat_parent, + get_unpadded_type (Etype (gnat_parent)), + constant, address_of_constant); + + case N_Object_Renaming_Declaration: + /* We need to preserve addresses through a renaming. */ + return 1; + + case N_Object_Declaration: + /* We cannot use a constructor if this is an atomic object because + the actual assignment might end up being done component-wise. */ + return (!constant + ||(Is_Composite_Type (Underlying_Type (Etype (gnat_node))) + && Is_Full_Access (Defining_Entity (gnat_parent))) + /* We don't use a constructor if this is a class-wide object + because the effective type of the object is the equivalent + type of the class-wide subtype and it smashes most of the + data into an array of bytes to which we cannot convert. */ + || Ekind ((Etype (Defining_Entity (gnat_parent)))) + == E_Class_Wide_Subtype); + + case N_Assignment_Statement: + /* We cannot use a constructor if the LHS is an atomic object because + the actual assignment might end up being done component-wise. */ + return (!constant + || Name (gnat_parent) == gnat_node + || (Is_Composite_Type (Underlying_Type (Etype (gnat_node))) + && Is_Entity_Name (Name (gnat_parent)) + && Is_Full_Access (Entity (Name (gnat_parent))))); + + case N_Unchecked_Type_Conversion: + if (!constant) + return 1; + + /* ... fall through ... */ + + case N_Type_Conversion: + case N_Qualified_Expression: + /* We must look through all conversions because we may need to bypass + an intermediate conversion that is meant to be purely formal. */ + return lvalue_required_p (gnat_parent, + get_unpadded_type (Etype (gnat_parent)), + constant, address_of_constant); + + case N_Explicit_Dereference: + /* We look through dereferences for address of constant because we need + to handle the special cases listed above. */ + if (constant && address_of_constant) + return lvalue_required_p (gnat_parent, + get_unpadded_type (Etype (gnat_parent)), + true, false); + + /* ... fall through ... */ + + default: + return 0; + } + + gcc_unreachable (); +} + +/* Return true if an lvalue should be used for GNAT_NODE. GNU_TYPE is the type + that will be used for GNAT_NODE in the translated GNU tree and is assumed to + be an aggregate type. + + The function climbs up the GNAT tree starting from the node and returns true + upon encountering a node that makes it doable to decide. lvalue_required_p + should have been previously invoked on the arguments and returned false. */ + +static bool +lvalue_for_aggregate_p (Node_Id gnat_node, tree gnu_type) +{ + Node_Id gnat_parent = Parent (gnat_node); + + switch (Nkind (gnat_parent)) + { + case N_Parameter_Association: + case N_Function_Call: + case N_Procedure_Call_Statement: + /* Even if the parameter is by copy, prefer an lvalue. */ + return true; + + case N_Simple_Return_Statement: + /* Likewise for a return value. */ + return true; + + case N_Indexed_Component: + case N_Selected_Component: + /* If an elementary component is used, take it from the constant. */ + if (!Is_Composite_Type (Underlying_Type (Etype (gnat_parent)))) + return false; + + /* ... fall through ... */ + + case N_Slice: + return lvalue_for_aggregate_p (gnat_parent, + get_unpadded_type (Etype (gnat_parent))); + + case N_Object_Declaration: + /* For an aggregate object declaration, return false consistently. */ + return false; + + case N_Assignment_Statement: + /* For an aggregate assignment, decide based on the size. */ + { + const HOST_WIDE_INT size = int_size_in_bytes (gnu_type); + return size < 0 || size >= param_large_stack_frame / 4; + } + + case N_Unchecked_Type_Conversion: + case N_Type_Conversion: + case N_Qualified_Expression: + return lvalue_for_aggregate_p (gnat_parent, + get_unpadded_type (Etype (gnat_parent))); + + case N_Allocator: + /* We should only reach here through the N_Qualified_Expression case. + Force an lvalue for aggregate types since a block-copy to the newly + allocated area of memory is made. */ + return true; + + default: + return false; + } + + gcc_unreachable (); +} + + +/* Return true if T is a constant DECL node that can be safely replaced + by its initializer. */ + +static bool +constant_decl_with_initializer_p (tree t) +{ + if (!TREE_CONSTANT (t) || !DECL_P (t) || !DECL_INITIAL (t)) + return false; + + /* Return false for aggregate types that contain a placeholder since + their initializers cannot be manipulated easily. */ + if (AGGREGATE_TYPE_P (TREE_TYPE (t)) + && !TYPE_IS_FAT_POINTER_P (TREE_TYPE (t)) + && type_contains_placeholder_p (TREE_TYPE (t))) + return false; + + return true; +} + +/* Return an expression equivalent to EXP but where constant DECL nodes + have been replaced by their initializer. */ + +static tree +fold_constant_decl_in_expr (tree exp) +{ + enum tree_code code = TREE_CODE (exp); + tree op0; + + switch (code) + { + case CONST_DECL: + case VAR_DECL: + if (!constant_decl_with_initializer_p (exp)) + return exp; + + return DECL_INITIAL (exp); + + case COMPONENT_REF: + op0 = fold_constant_decl_in_expr (TREE_OPERAND (exp, 0)); + if (op0 == TREE_OPERAND (exp, 0)) + return exp; + + return fold_build3 (COMPONENT_REF, TREE_TYPE (exp), op0, + TREE_OPERAND (exp, 1), NULL_TREE); + + case BIT_FIELD_REF: + op0 = fold_constant_decl_in_expr (TREE_OPERAND (exp, 0)); + if (op0 == TREE_OPERAND (exp, 0)) + return exp; + + return fold_build3 (BIT_FIELD_REF, TREE_TYPE (exp), op0, + TREE_OPERAND (exp, 1), TREE_OPERAND (exp, 2)); + + case ARRAY_REF: + case ARRAY_RANGE_REF: + /* If the index is not itself constant, then nothing can be folded. */ + if (!TREE_CONSTANT (TREE_OPERAND (exp, 1))) + return exp; + op0 = fold_constant_decl_in_expr (TREE_OPERAND (exp, 0)); + if (op0 == TREE_OPERAND (exp, 0)) + return exp; + + return fold (build4 (code, TREE_TYPE (exp), op0, TREE_OPERAND (exp, 1), + TREE_OPERAND (exp, 2), NULL_TREE)); + + case REALPART_EXPR: + case IMAGPART_EXPR: + case VIEW_CONVERT_EXPR: + op0 = fold_constant_decl_in_expr (TREE_OPERAND (exp, 0)); + if (op0 == TREE_OPERAND (exp, 0)) + return exp; + + return fold_build1 (code, TREE_TYPE (exp), op0); + + default: + return exp; + } + + gcc_unreachable (); +} + +/* Return true if TYPE and DEF_TYPE are compatible GNAT types for Gigi. */ + +static bool +Gigi_Types_Compatible (Entity_Id type, Entity_Id def_type) +{ + /* The trivial case. */ + if (type == def_type) + return true; + + /* A class-wide type is equivalent to a subtype of itself. */ + if (Is_Class_Wide_Type (type)) + return true; + + /* A packed array type is compatible with its implementation type. */ + if (Is_Packed (def_type) && type == Packed_Array_Impl_Type (def_type)) + return true; + + /* If both types are Itypes, one may be a copy of the other. */ + if (Is_Itype (def_type) && Is_Itype (type)) + return true; + + /* If the type is incomplete and comes from a limited context, then also + consider its non-limited view. */ + if (Is_Incomplete_Type (def_type) + && From_Limited_With (def_type) + && Present (Non_Limited_View (def_type))) + return Gigi_Types_Compatible (type, Non_Limited_View (def_type)); + + /* If the type is incomplete/private, then also consider its full view. */ + if (Is_Incomplete_Or_Private_Type (def_type) + && Present (Full_View (def_type))) + return Gigi_Types_Compatible (type, Full_View (def_type)); + + return false; +} + +/* Subroutine of gnat_to_gnu to translate gnat_node, an N_Identifier, + to a GCC tree, which is returned. GNU_RESULT_TYPE_P is a pointer + to where we should place the result type. */ + +static tree +Identifier_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p) +{ + /* The entity of GNAT_NODE and its type. */ + Node_Id gnat_entity = (Nkind (gnat_node) == N_Defining_Identifier + || Nkind (gnat_node) == N_Defining_Operator_Symbol) + ? gnat_node : Entity (gnat_node); + Node_Id gnat_entity_type = Etype (gnat_entity); + /* If GNAT_NODE is a constant, whether we should use the initialization + value instead of the constant entity, typically for scalars with an + address clause when the parent doesn't require an lvalue. */ + bool use_constant_initializer = false; + /* Whether we should require an lvalue for GNAT_NODE. Needed in + specific circumstances only, so evaluated lazily. < 0 means + unknown, > 0 means known true, 0 means known false. */ + int require_lvalue = -1; + Entity_Id gnat_result_type; + tree gnu_result, gnu_result_type; + + /* If the Etype of this node is not the same as that of the Entity, then + something went wrong, probably in generic instantiation. However, this + does not apply to types. Since we sometime have strange Ekind's, just + do this test for objects, except for discriminants because their type + may have been changed to a subtype by Exp_Ch3.Adjust_Discriminants. */ + gcc_assert (!Is_Object (gnat_entity) + || Ekind (gnat_entity) == E_Discriminant + || Etype (gnat_node) == gnat_entity_type + || Gigi_Types_Compatible (Etype (gnat_node), gnat_entity_type)); + + /* If this is a reference to a deferred constant whose partial view is an + unconstrained private type, the proper type is on the full view of the + constant, not on the full view of the type, which may be unconstrained. + + This may be a reference to a type, for example in the prefix of the + attribute Position, generated for dispatching code (see Make_DT in + exp_disp,adb). In that case we need the type itself, not is parent, + in particular if it is a derived type */ + if (Ekind (gnat_entity) == E_Constant + && Is_Private_Type (gnat_entity_type) + && (Has_Unknown_Discriminants (gnat_entity_type) + || (Present (Full_View (gnat_entity_type)) + && Has_Discriminants (Full_View (gnat_entity_type)))) + && Present (Full_View (gnat_entity))) + { + gnat_entity = Full_View (gnat_entity); + gnat_result_type = Etype (gnat_entity); + } + else + { + /* We use the Actual_Subtype only if it has already been elaborated, + as we may be invoked precisely during its elaboration, otherwise + the Etype. Avoid using it for packed arrays to simplify things, + except in a return statement because we need the actual size and + the front-end does not make it explicit in this case. */ + if ((Ekind (gnat_entity) == E_Constant + || Ekind (gnat_entity) == E_Variable + || Is_Formal (gnat_entity)) + && !(Is_Array_Type (Etype (gnat_entity)) + && Present (Packed_Array_Impl_Type (Etype (gnat_entity))) + && Nkind (Parent (gnat_node)) != N_Simple_Return_Statement) + && Present (Actual_Subtype (gnat_entity)) + && present_gnu_tree (Actual_Subtype (gnat_entity))) + gnat_result_type = Actual_Subtype (gnat_entity); + else + gnat_result_type = Etype (gnat_node); + } + + /* Expand the type of this identifier first, in case it is an enumeral + literal, which only get made when the type is expanded. There is no + order-of-elaboration issue here. */ + gnu_result_type = get_unpadded_type (gnat_result_type); + + /* If this is a non-imported elementary constant with an address clause, + retrieve the value instead of a pointer to be dereferenced unless + an lvalue is required. This is generally more efficient and actually + required if this is a static expression because it might be used + in a context where a dereference is inappropriate, such as a case + statement alternative or a record discriminant. There is no possible + volatile-ness short-circuit here since Volatile constants must be + imported per C.6. */ + if (Ekind (gnat_entity) == E_Constant + && Is_Elementary_Type (gnat_result_type) + && !Is_Imported (gnat_entity) + && Present (Address_Clause (gnat_entity))) + { + require_lvalue + = lvalue_required_p (gnat_node, gnu_result_type, true, false); + use_constant_initializer = !require_lvalue; + } + + if (use_constant_initializer) + { + /* If this is a deferred constant, the initializer is attached to + the full view. */ + if (Present (Full_View (gnat_entity))) + gnat_entity = Full_View (gnat_entity); + + gnu_result = gnat_to_gnu (Expression (Declaration_Node (gnat_entity))); + } + else + gnu_result = gnat_to_gnu_entity (gnat_entity, NULL_TREE, false); + + /* Some objects (such as parameters passed by reference, globals of + variable size, and renamed objects) actually represent the address + of the object. In that case, we must do the dereference. Likewise, + deal with parameters to foreign convention subprograms. */ + if (DECL_P (gnu_result) + && (DECL_BY_REF_P (gnu_result) + || (TREE_CODE (gnu_result) == PARM_DECL + && DECL_BY_COMPONENT_PTR_P (gnu_result)))) + { + const bool read_only = DECL_POINTS_TO_READONLY_P (gnu_result); + + /* If it's a PARM_DECL to foreign convention subprogram, convert it. */ + if (TREE_CODE (gnu_result) == PARM_DECL + && DECL_BY_COMPONENT_PTR_P (gnu_result)) + gnu_result + = convert (build_pointer_type (gnu_result_type), gnu_result); + + /* If it's a CONST_DECL, return the underlying constant like below. */ + else if (TREE_CODE (gnu_result) == CONST_DECL + && !(DECL_CONST_ADDRESS_P (gnu_result) + && lvalue_required_p (gnat_node, gnu_result_type, true, + true))) + gnu_result = DECL_INITIAL (gnu_result); + + /* Do the final dereference. */ + gnu_result = build_unary_op (INDIRECT_REF, NULL_TREE, gnu_result); + + if ((TREE_CODE (gnu_result) == INDIRECT_REF + || TREE_CODE (gnu_result) == UNCONSTRAINED_ARRAY_REF) + && No (Address_Clause (gnat_entity))) + TREE_THIS_NOTRAP (gnu_result) = 1; + + if (read_only) + TREE_READONLY (gnu_result) = 1; + } + + /* If we have a constant declaration and its initializer, try to return the + latter to avoid the need to call fold in lots of places and the need for + elaboration code if this identifier is used as an initializer itself. */ + if (constant_decl_with_initializer_p (gnu_result)) + { + bool constant_only = (TREE_CODE (gnu_result) == CONST_DECL + && !DECL_CONST_CORRESPONDING_VAR (gnu_result)); + bool address_of_constant = (TREE_CODE (gnu_result) == CONST_DECL + && DECL_CONST_ADDRESS_P (gnu_result)); + + /* If there is a (corresponding) variable or this is the address of a + constant, we only want to return the initializer if an lvalue isn't + required. Evaluate this now if we have not already done so. */ + if ((!constant_only || address_of_constant) && require_lvalue < 0) + require_lvalue + = lvalue_required_p (gnat_node, gnu_result_type, true, + address_of_constant) + || (AGGREGATE_TYPE_P (gnu_result_type) + && lvalue_for_aggregate_p (gnat_node, gnu_result_type)); + + /* Finally retrieve the initializer if this is deemed valid. */ + if ((constant_only && !address_of_constant) || !require_lvalue) + gnu_result = DECL_INITIAL (gnu_result); + } + + /* But for a constant renaming we couldn't do that incrementally for its + definition because of the need to return an lvalue so, if the present + context doesn't itself require an lvalue, we try again here. */ + else if (Ekind (gnat_entity) == E_Constant + && Is_Elementary_Type (gnat_result_type) + && Present (Renamed_Object (gnat_entity))) + { + if (require_lvalue < 0) + require_lvalue + = lvalue_required_p (gnat_node, gnu_result_type, true, false); + if (!require_lvalue) + gnu_result = fold_constant_decl_in_expr (gnu_result); + } + + /* The GNAT tree has the type of a function set to its result type, so we + adjust here. Also use the type of the result if the Etype is a subtype + that is nominally unconstrained. Likewise if this is a deferred constant + of a discriminated type whose full view can be elaborated statically, to + avoid problematic conversions to the nominal subtype. But remove any + padding from the resulting type. */ + if (FUNC_OR_METHOD_TYPE_P (TREE_TYPE (gnu_result)) + || Is_Constr_Subt_For_UN_Aliased (gnat_result_type) + || (Ekind (gnat_entity) == E_Constant + && Present (Full_View (gnat_entity)) + && Has_Discriminants (gnat_result_type) + && TREE_CODE (gnu_result) == CONSTRUCTOR)) + { + gnu_result_type = TREE_TYPE (gnu_result); + if (TYPE_IS_PADDING_P (gnu_result_type)) + gnu_result_type = TREE_TYPE (TYPE_FIELDS (gnu_result_type)); + } + + *gnu_result_type_p = gnu_result_type; + + return gnu_result; +} + +/* Subroutine of gnat_to_gnu to process gnat_node, an N_Pragma. Return + any statements we generate. */ + +static tree +Pragma_to_gnu (Node_Id gnat_node) +{ + tree gnu_result = alloc_stmt_list (); + Node_Id gnat_temp; + + /* Check for (and ignore) unrecognized pragmas. */ + if (!Is_Pragma_Name (Chars (Pragma_Identifier (gnat_node)))) + return gnu_result; + + const unsigned char id + = Get_Pragma_Id (Chars (Pragma_Identifier (gnat_node))); + + /* Save the expression of pragma Compile_Time_{Error|Warning} for later. */ + if (id == Pragma_Compile_Time_Error || id == Pragma_Compile_Time_Warning) + { + gnat_temp = First (Pragma_Argument_Associations (gnat_node)); + gnat_compile_time_expr_list.safe_push (Expression (gnat_temp)); + return gnu_result; + } + + /* Stop there if we are just annotating types. */ + if (type_annotate_only) + return gnu_result; + + switch (id) + { + case Pragma_Inspection_Point: + /* Do nothing at top level: all such variables are already viewable. */ + if (global_bindings_p ()) + break; + + for (gnat_temp = First (Pragma_Argument_Associations (gnat_node)); + Present (gnat_temp); + gnat_temp = Next (gnat_temp)) + { + Node_Id gnat_expr = Expression (gnat_temp); + tree gnu_expr = gnat_to_gnu (gnat_expr); + tree asm_constraint = NULL_TREE; +#ifdef ASM_COMMENT_START + char *comment; +#endif + gnu_expr = maybe_unconstrained_array (gnu_expr); + if (TREE_CODE (gnu_expr) == CONST_DECL + && DECL_CONST_CORRESPONDING_VAR (gnu_expr)) + gnu_expr = DECL_CONST_CORRESPONDING_VAR (gnu_expr); + gnat_mark_addressable (gnu_expr); + +#ifdef ASM_COMMENT_START + comment = concat (ASM_COMMENT_START, + " inspection point: ", + Get_Name_String (Chars (gnat_expr)), + " is at %0", + NULL); + asm_constraint = build_string (strlen (comment), comment); + free (comment); +#endif + gnu_expr = build5 (ASM_EXPR, void_type_node, + asm_constraint, + NULL_TREE, + tree_cons + (build_tree_list (NULL_TREE, + build_string (1, "m")), + gnu_expr, NULL_TREE), + NULL_TREE, NULL_TREE); + ASM_VOLATILE_P (gnu_expr) = 1; + set_expr_location_from_node (gnu_expr, gnat_node); + append_to_statement_list (gnu_expr, &gnu_result); + } + break; + + case Pragma_Loop_Optimize: + for (gnat_temp = First (Pragma_Argument_Associations (gnat_node)); + Present (gnat_temp); + gnat_temp = Next (gnat_temp)) + { + tree gnu_loop_stmt = gnu_loop_stack->last ()->stmt; + + switch (Chars (Expression (gnat_temp))) + { + case Name_Ivdep: + LOOP_STMT_IVDEP (gnu_loop_stmt) = 1; + break; + + case Name_No_Unroll: + LOOP_STMT_NO_UNROLL (gnu_loop_stmt) = 1; + break; + + case Name_Unroll: + LOOP_STMT_UNROLL (gnu_loop_stmt) = 1; + break; + + case Name_No_Vector: + LOOP_STMT_NO_VECTOR (gnu_loop_stmt) = 1; + break; + + case Name_Vector: + LOOP_STMT_VECTOR (gnu_loop_stmt) = 1; + break; + + default: + gcc_unreachable (); + } + } + break; + + case Pragma_Optimize: + switch (Chars (Expression + (First (Pragma_Argument_Associations (gnat_node))))) + { + case Name_Off: + if (optimize) + post_error ("must specify -O0??", gnat_node); + break; + + case Name_Space: + if (!optimize_size) + post_error ("must specify -Os??", gnat_node); + break; + + case Name_Time: + if (!optimize) + post_error ("insufficient -O value??", gnat_node); + break; + + default: + gcc_unreachable (); + } + break; + + case Pragma_Reviewable: + if (write_symbols == NO_DEBUG) + post_error ("must specify -g??", gnat_node); + break; + + case Pragma_Warning_As_Error: + case Pragma_Warnings: + { + Node_Id gnat_expr; + /* Preserve the location of the pragma. */ + const location_t location = input_location; + struct cl_option_handlers handlers; + unsigned int option_index; + diagnostic_t kind; + bool imply; + + gnat_temp = First (Pragma_Argument_Associations (gnat_node)); + + /* This is the String form: pragma Warning{s|_As_Error}(String). */ + if (Nkind (Expression (gnat_temp)) == N_String_Literal) + { + switch (id) + { + case Pragma_Warning_As_Error: + kind = DK_ERROR; + imply = false; + break; + + case Pragma_Warnings: + kind = DK_WARNING; + imply = true; + break; + + default: + gcc_unreachable (); + } + + gnat_expr = Expression (gnat_temp); + } + + /* This is the On/Off form: pragma Warnings (On | Off [,String]). */ + else if (Nkind (Expression (gnat_temp)) == N_Identifier) + { + switch (Chars (Expression (gnat_temp))) + { + case Name_Off: + kind = DK_IGNORED; + break; + + case Name_On: + kind = DK_WARNING; + break; + + default: + gcc_unreachable (); + } + + /* Deal with optional pattern (but ignore Reason => "..."). */ + if (Present (Next (gnat_temp)) + && Chars (Next (gnat_temp)) != Name_Reason) + { + /* pragma Warnings (On | Off, Name) is handled differently. */ + if (Nkind (Expression (Next (gnat_temp))) != N_String_Literal) + break; + + gnat_expr = Expression (Next (gnat_temp)); + } + else + { + gnat_expr = Empty; + + /* For pragma Warnings (Off), we save the current state... */ + if (kind == DK_IGNORED) + diagnostic_push_diagnostics (global_dc, location); + + /* ...so that, for pragma Warnings (On), we do not enable all + the warnings but just restore the previous state. */ + else + { + diagnostic_pop_diagnostics (global_dc, location); + break; + } + } + + imply = false; + } + + else + gcc_unreachable (); + + /* This is the same implementation as in the C family of compilers. */ + const unsigned int lang_mask = CL_Ada | CL_COMMON; + const char *arg = NULL; + if (Present (gnat_expr)) + { + tree gnu_expr = gnat_to_gnu (gnat_expr); + const char *option_string = TREE_STRING_POINTER (gnu_expr); + const int len = TREE_STRING_LENGTH (gnu_expr); + if (len < 3 || option_string[0] != '-' || option_string[1] != 'W') + break; + option_index = find_opt (option_string + 1, lang_mask); + if (option_index == OPT_SPECIAL_unknown) + { + post_error ("unknown -W switch??", gnat_node); + break; + } + else if (!(cl_options[option_index].flags & CL_WARNING)) + { + post_error ("-W switch does not control warning??", gnat_node); + break; + } + else if (!(cl_options[option_index].flags & lang_mask)) + { + post_error ("-W switch not valid for Ada??", gnat_node); + break; + } + if (cl_options[option_index].flags & CL_JOINED) + arg = option_string + 1 + cl_options[option_index].opt_len; + } + else + option_index = 0; + + set_default_handlers (&handlers, NULL); + control_warning_option (option_index, (int) kind, arg, imply, location, + lang_mask, &handlers, &global_options, + &global_options_set, global_dc); + } + break; + + default: + break; + } + + return gnu_result; +} + +/* Check the inline status of nested function FNDECL wrt its parent function. + + If a non-inline nested function is referenced from an inline external + function, we cannot honor both requests at the same time without cloning + the nested function in the current unit since it is private to its unit. + We could inline it as well but it's probably better to err on the side + of too little inlining. + + This must be done only on nested functions present in the source code + and not on nested functions generated by the compiler, e.g. finalizers, + because they may be not marked inline and we don't want them to block + the inlining of the parent function. */ + +static void +check_inlining_for_nested_subprog (tree fndecl) +{ + if (DECL_IGNORED_P (current_function_decl) || DECL_IGNORED_P (fndecl)) + return; + + if (DECL_DECLARED_INLINE_P (fndecl)) + return; + + tree parent_decl = decl_function_context (fndecl); + if (DECL_EXTERNAL (parent_decl) && DECL_DECLARED_INLINE_P (parent_decl)) + { + const location_t loc1 = DECL_SOURCE_LOCATION (fndecl); + const location_t loc2 = DECL_SOURCE_LOCATION (parent_decl); + + if (lookup_attribute ("always_inline", DECL_ATTRIBUTES (parent_decl))) + { + error_at (loc1, "subprogram %q+F not marked %<Inline_Always%>", + fndecl); + error_at (loc2, "parent subprogram cannot be inlined"); + } + else + { + warning_at (loc1, OPT_Winline, "subprogram %q+F not marked %<Inline%>", + fndecl); + warning_at (loc2, OPT_Winline, "parent subprogram cannot be inlined"); + } + + DECL_DECLARED_INLINE_P (parent_decl) = 0; + DECL_UNINLINABLE (parent_decl) = 1; + } +} + +/* Return an expression for the length of TYPE, an integral type, computed in + RESULT_TYPE, another integral type. + + We used to compute the length as MAX (hb - lb + 1, 0) which could overflow + when lb == TYPE'First. We now compute it as (hb >= lb) ? hb - lb + 1 : 0 + which would only overflow in much rarer cases, for extremely large arrays + we expect never to encounter in practice. Besides, the former computation + required the use of potentially constraining signed arithmetics while the + latter does not. Note that the comparison must be done in the original + base index type in order to avoid any overflow during the conversion. */ + +static tree +get_type_length (tree type, tree result_type) +{ + tree comp_type = get_base_type (result_type); + tree base_type = maybe_character_type (get_base_type (type)); + tree lb = convert (base_type, TYPE_MIN_VALUE (type)); + tree hb = convert (base_type, TYPE_MAX_VALUE (type)); + tree length + = build_binary_op (PLUS_EXPR, comp_type, + build_binary_op (MINUS_EXPR, comp_type, + convert (comp_type, hb), + convert (comp_type, lb)), + build_int_cst (comp_type, 1)); + length + = build_cond_expr (result_type, + build_binary_op (GE_EXPR, boolean_type_node, hb, lb), + convert (result_type, length), + build_int_cst (result_type, 0)); + return length; +} + +/* Subroutine of gnat_to_gnu to translate GNAT_NODE, an N_Attribute node, + to a GCC tree, which is returned. GNU_RESULT_TYPE_P is a pointer to + where we should place the result type. ATTRIBUTE is the attribute ID. */ + +static tree +Attribute_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p, int attribute) +{ + const Node_Id gnat_prefix = Prefix (gnat_node); + tree gnu_prefix = gnat_to_gnu (gnat_prefix); + tree gnu_type = TREE_TYPE (gnu_prefix); + tree gnu_expr, gnu_result_type, gnu_result = error_mark_node; + bool prefix_unused = false; + + /* If the input is a NULL_EXPR, make a new one. */ + if (TREE_CODE (gnu_prefix) == NULL_EXPR) + { + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + *gnu_result_type_p = gnu_result_type; + return build1 (NULL_EXPR, gnu_result_type, TREE_OPERAND (gnu_prefix, 0)); + } + + switch (attribute) + { + case Attr_Pred: + case Attr_Succ: + /* These just add or subtract the constant 1 since representation + clauses for enumeration types are handled in the front-end. */ + gnu_expr = gnat_to_gnu (First (Expressions (gnat_node))); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + gnu_type = maybe_character_type (gnu_result_type); + if (TREE_TYPE (gnu_expr) != gnu_type) + gnu_expr = convert (gnu_type, gnu_expr); + gnu_result + = build_binary_op (attribute == Attr_Pred ? MINUS_EXPR : PLUS_EXPR, + gnu_type, gnu_expr, build_int_cst (gnu_type, 1)); + break; + + case Attr_Address: + case Attr_Unrestricted_Access: + /* Conversions don't change the address of references but can cause + build_unary_op to miss the references below, so strip them off. + On the contrary, if the address-of operation causes a temporary + to be created, then it must be created with the proper type. */ + gnu_expr = remove_conversions (gnu_prefix, + !Must_Be_Byte_Aligned (gnat_node)); + if (REFERENCE_CLASS_P (gnu_expr)) + gnu_prefix = gnu_expr; + + /* If we are taking 'Address of an unconstrained object, this is the + pointer to the underlying array. */ + if (attribute == Attr_Address) + gnu_prefix = maybe_unconstrained_array (gnu_prefix); + + /* If we are building a static dispatch table, we have to honor + TARGET_VTABLE_USES_DESCRIPTORS if we want to be compatible + with the C++ ABI. We do it in the non-static case as well, + see gnat_to_gnu_entity, case E_Access_Subprogram_Type. */ + else if (TARGET_VTABLE_USES_DESCRIPTORS + && Is_Dispatch_Table_Entity (Etype (gnat_node))) + { + tree gnu_field, t; + /* Descriptors can only be built here for top-level functions. */ + bool build_descriptor = (global_bindings_p () != 0); + int i; + vec<constructor_elt, va_gc> *gnu_vec = NULL; + constructor_elt *elt; + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + /* If we're not going to build the descriptor, we have to retrieve + the one which will be built by the linker (or by the compiler + later if a static chain is requested). */ + if (!build_descriptor) + { + gnu_result = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_prefix); + gnu_result = fold_convert (build_pointer_type (gnu_result_type), + gnu_result); + gnu_result = build1 (INDIRECT_REF, gnu_result_type, gnu_result); + } + + vec_safe_grow (gnu_vec, TARGET_VTABLE_USES_DESCRIPTORS, true); + elt = (gnu_vec->address () + TARGET_VTABLE_USES_DESCRIPTORS - 1); + for (gnu_field = TYPE_FIELDS (gnu_result_type), i = 0; + i < TARGET_VTABLE_USES_DESCRIPTORS; + gnu_field = DECL_CHAIN (gnu_field), i++) + { + if (build_descriptor) + { + t = build2 (FDESC_EXPR, TREE_TYPE (gnu_field), gnu_prefix, + build_int_cst (NULL_TREE, i)); + TREE_CONSTANT (t) = 1; + } + else + t = build3 (COMPONENT_REF, ptr_void_ftype, gnu_result, + gnu_field, NULL_TREE); + + elt->index = gnu_field; + elt->value = t; + elt--; + } + + gnu_result = gnat_build_constructor (gnu_result_type, gnu_vec); + break; + } + + /* ... fall through ... */ + + case Attr_Access: + case Attr_Unchecked_Access: + case Attr_Code_Address: + /* Taking the address of a type does not make sense. */ + gcc_assert (TREE_CODE (gnu_prefix) != TYPE_DECL); + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + gnu_result + = build_unary_op (((attribute == Attr_Address + || attribute == Attr_Unrestricted_Access) + && !Must_Be_Byte_Aligned (gnat_node)) + ? ATTR_ADDR_EXPR : ADDR_EXPR, + gnu_result_type, gnu_prefix); + + /* For 'Code_Address, find an inner ADDR_EXPR and mark it so that we + don't try to build a trampoline. */ + if (attribute == Attr_Code_Address) + { + gnu_expr = remove_conversions (gnu_result, false); + + if (TREE_CODE (gnu_expr) == ADDR_EXPR) + TREE_NO_TRAMPOLINE (gnu_expr) = TREE_CONSTANT (gnu_expr) = 1; + + /* On targets for which function symbols denote a descriptor, the + code address is stored within the first slot of the descriptor + so we do an additional dereference: + result = *((result_type *) result) + where we expect result to be of some pointer type already. */ + if (targetm.calls.custom_function_descriptors == 0) + gnu_result + = build_unary_op (INDIRECT_REF, NULL_TREE, + convert (build_pointer_type (gnu_result_type), + gnu_result)); + } + + /* For 'Access, issue an error message if the prefix is a C++ method + since it can use a special calling convention on some platforms, + which cannot be propagated to the access type. */ + else if (attribute == Attr_Access + && TREE_CODE (TREE_TYPE (gnu_prefix)) == METHOD_TYPE) + post_error ("access to C++ constructor or member function not allowed", + gnat_node); + + /* For other address attributes applied to a nested function, + find an inner ADDR_EXPR and annotate it so that we can issue + a useful warning with -Wtrampolines. */ + else if (FUNC_OR_METHOD_TYPE_P (TREE_TYPE (gnu_prefix)) + && (gnu_expr = remove_conversions (gnu_result, false)) + && TREE_CODE (gnu_expr) == ADDR_EXPR + && decl_function_context (TREE_OPERAND (gnu_expr, 0))) + { + set_expr_location_from_node (gnu_expr, gnat_node); + + /* Also check the inlining status. */ + check_inlining_for_nested_subprog (TREE_OPERAND (gnu_expr, 0)); + + /* Moreover, for 'Access or 'Unrestricted_Access with non- + foreign-compatible representation, mark the ADDR_EXPR so + that we can build a descriptor instead of a trampoline. */ + if ((attribute == Attr_Access + || attribute == Attr_Unrestricted_Access) + && targetm.calls.custom_function_descriptors > 0 + && Can_Use_Internal_Rep (Underlying_Type (Etype (gnat_node)))) + FUNC_ADDR_BY_DESCRIPTOR (gnu_expr) = 1; + + /* Otherwise, we need to check that we are not violating the + No_Implicit_Dynamic_Code restriction. */ + else if (targetm.calls.custom_function_descriptors != 0) + Check_Implicit_Dynamic_Code_Allowed (gnat_node); + } + break; + + case Attr_Pool_Address: + { + tree gnu_ptr = gnu_prefix; + tree gnu_obj_type; + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + /* If this is fat pointer, the object must have been allocated with the + template in front of the array. So compute the template address; do + it by converting to a thin pointer. */ + if (TYPE_IS_FAT_POINTER_P (TREE_TYPE (gnu_ptr))) + gnu_ptr + = convert (build_pointer_type + (TYPE_OBJECT_RECORD_TYPE + (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (gnu_ptr)))), + gnu_ptr); + + gnu_obj_type = TREE_TYPE (TREE_TYPE (gnu_ptr)); + + /* If this is a thin pointer, the object must have been allocated with + the template in front of the array. So compute the template address + and return it. */ + if (TYPE_IS_THIN_POINTER_P (TREE_TYPE (gnu_ptr))) + gnu_ptr + = build_binary_op (POINTER_PLUS_EXPR, TREE_TYPE (gnu_ptr), + gnu_ptr, + fold_build1 (NEGATE_EXPR, sizetype, + byte_position + (DECL_CHAIN + TYPE_FIELDS ((gnu_obj_type))))); + + gnu_result = convert (gnu_result_type, gnu_ptr); + } + break; + + case Attr_Size: + case Attr_Object_Size: + case Attr_Value_Size: + case Attr_Max_Size_In_Storage_Elements: + /* Strip NOPs, conversions between original and packable versions, and + unpadding from GNU_PREFIX. Note that we cannot simply strip every + VIEW_CONVERT_EXPR because some of them may give the actual size, e.g. + for nominally unconstrained packed array. We use GNU_EXPR to see + if a COMPONENT_REF was involved. */ + while (CONVERT_EXPR_P (gnu_prefix) + || TREE_CODE (gnu_prefix) == NON_LVALUE_EXPR + || (TREE_CODE (gnu_prefix) == VIEW_CONVERT_EXPR + && TREE_CODE (TREE_TYPE (gnu_prefix)) == RECORD_TYPE + && TREE_CODE (TREE_TYPE (TREE_OPERAND (gnu_prefix, 0))) + == RECORD_TYPE + && TYPE_NAME (TREE_TYPE (gnu_prefix)) + == TYPE_NAME (TREE_TYPE (TREE_OPERAND (gnu_prefix, 0))))) + gnu_prefix = TREE_OPERAND (gnu_prefix, 0); + gnu_expr = gnu_prefix; + if (TREE_CODE (gnu_prefix) == COMPONENT_REF + && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (gnu_prefix, 0)))) + gnu_prefix = TREE_OPERAND (gnu_prefix, 0); + prefix_unused = true; + gnu_type = TREE_TYPE (gnu_prefix); + + /* Replace an unconstrained array type with the type of the underlying + array, except for 'Max_Size_In_Storage_Elements because we need to + return the (maximum) size requested for an allocator. */ + if (TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE) + { + gnu_type = TYPE_OBJECT_RECORD_TYPE (gnu_type); + if (attribute != Attr_Max_Size_In_Storage_Elements) + gnu_type = TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (gnu_type))); + } + + /* The type must be frozen at this point. */ + gcc_assert (COMPLETE_TYPE_P (gnu_type)); + + /* If we're looking for the size of a field, return the field size. */ + if (TREE_CODE (gnu_prefix) == COMPONENT_REF) + gnu_result = DECL_SIZE (TREE_OPERAND (gnu_prefix, 1)); + + /* Otherwise, if the prefix is an object, or if we are looking for + 'Object_Size or 'Max_Size_In_Storage_Elements, the result is the + GCC size of the type. We make an exception for padded objects, + as we do not take into account alignment promotions for the size. + This is in keeping with the object case of gnat_to_gnu_entity. */ + else if ((TREE_CODE (gnu_prefix) != TYPE_DECL + && !(TYPE_IS_PADDING_P (gnu_type) + && TREE_CODE (gnu_expr) == COMPONENT_REF + && pad_type_has_rm_size (gnu_type))) + || attribute == Attr_Object_Size + || attribute == Attr_Max_Size_In_Storage_Elements) + { + /* If this is a dereference and we have a special dynamic constrained + subtype on the prefix, use it to compute the size; otherwise, use + the designated subtype. */ + if (Nkind (gnat_prefix) == N_Explicit_Dereference) + { + Node_Id gnat_actual_subtype + = Actual_Designated_Subtype (gnat_prefix); + tree gnu_ptr_type + = TREE_TYPE (gnat_to_gnu (Prefix (gnat_prefix))); + + if (TYPE_IS_FAT_OR_THIN_POINTER_P (gnu_ptr_type) + && Present (gnat_actual_subtype)) + { + tree gnu_actual_obj_type + = gnat_to_gnu_type (gnat_actual_subtype); + gnu_type + = build_unc_object_type_from_ptr (gnu_ptr_type, + gnu_actual_obj_type, + get_identifier ("SIZE"), + false); + } + } + + gnu_result = TYPE_SIZE (gnu_type); + } + + /* Otherwise, the result is the RM size of the type. */ + else + gnu_result = rm_size (gnu_type); + + /* Deal with a self-referential size by qualifying the size with the + object or returning the maximum size for a type. */ + if (TREE_CODE (gnu_prefix) != TYPE_DECL) + gnu_result = SUBSTITUTE_PLACEHOLDER_IN_EXPR (gnu_result, gnu_prefix); + else if (CONTAINS_PLACEHOLDER_P (gnu_result)) + gnu_result = max_size (gnu_result, true); + + /* If the type contains a template, subtract the padded size of the + template, except for 'Max_Size_In_Storage_Elements because we need + to return the (maximum) size requested for an allocator. */ + if (TREE_CODE (gnu_type) == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P (gnu_type) + && attribute != Attr_Max_Size_In_Storage_Elements) + gnu_result + = size_binop (MINUS_EXPR, gnu_result, + bit_position (DECL_CHAIN (TYPE_FIELDS (gnu_type)))); + + /* For 'Max_Size_In_Storage_Elements, adjust the unit. */ + if (attribute == Attr_Max_Size_In_Storage_Elements) + gnu_result = size_binop (CEIL_DIV_EXPR, gnu_result, bitsize_unit_node); + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + break; + + case Attr_Alignment: + { + unsigned int align; + + if (TREE_CODE (gnu_prefix) == COMPONENT_REF + && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (gnu_prefix, 0)))) + gnu_prefix = TREE_OPERAND (gnu_prefix, 0); + + gnu_type = TREE_TYPE (gnu_prefix); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + prefix_unused = true; + + if (TREE_CODE (gnu_prefix) == COMPONENT_REF) + align = DECL_ALIGN (TREE_OPERAND (gnu_prefix, 1)) / BITS_PER_UNIT; + else + { + Entity_Id gnat_type = Etype (gnat_prefix); + unsigned int double_align; + bool is_capped_double, align_clause; + + /* If the default alignment of "double" or larger scalar types is + specifically capped and there is an alignment clause neither + on the type nor on the prefix itself, return the cap. */ + if ((double_align = double_float_alignment) > 0) + is_capped_double + = is_double_float_or_array (gnat_type, &align_clause); + else if ((double_align = double_scalar_alignment) > 0) + is_capped_double + = is_double_scalar_or_array (gnat_type, &align_clause); + else + is_capped_double = align_clause = false; + + if (is_capped_double + && Nkind (gnat_prefix) == N_Identifier + && Present (Alignment_Clause (Entity (gnat_prefix)))) + align_clause = true; + + if (is_capped_double && !align_clause) + align = double_align; + else + align = TYPE_ALIGN (gnu_type) / BITS_PER_UNIT; + } + + gnu_result = size_int (align); + } + break; + + case Attr_First: + case Attr_Last: + case Attr_Range_Length: + prefix_unused = true; + + if (INTEGRAL_TYPE_P (gnu_type) || SCALAR_FLOAT_TYPE_P (gnu_type)) + { + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + if (attribute == Attr_First) + gnu_result = TYPE_MIN_VALUE (gnu_type); + else if (attribute == Attr_Last) + gnu_result = TYPE_MAX_VALUE (gnu_type); + else + gnu_result = get_type_length (gnu_type, gnu_result_type); + break; + } + + /* ... fall through ... */ + + case Attr_Length: + { + int Dimension = (Present (Expressions (gnat_node)) + ? UI_To_Int (Intval (First (Expressions (gnat_node)))) + : 1), i; + struct parm_attr_d *pa = NULL; + Entity_Id gnat_param = Empty; + bool unconstrained_ptr_deref = false; + + gnu_prefix = maybe_padded_object (gnu_prefix); + gnu_prefix = maybe_unconstrained_array (gnu_prefix); + + /* We treat unconstrained array In parameters specially. We also note + whether we are dereferencing a pointer to unconstrained array. */ + if (!Is_Constrained (Etype (gnat_prefix))) + switch (Nkind (gnat_prefix)) + { + case N_Identifier: + /* This is the direct case. */ + if (Ekind (Entity (gnat_prefix)) == E_In_Parameter) + gnat_param = Entity (gnat_prefix); + break; + + case N_Explicit_Dereference: + /* This is the indirect case. Note that we need to be sure that + the access value cannot be null as we'll hoist the load. */ + if (Nkind (Prefix (gnat_prefix)) == N_Identifier + && Ekind (Entity (Prefix (gnat_prefix))) == E_In_Parameter) + { + if (Can_Never_Be_Null (Entity (Prefix (gnat_prefix)))) + gnat_param = Entity (Prefix (gnat_prefix)); + } + else + unconstrained_ptr_deref = true; + break; + + default: + break; + } + + /* If the prefix is the view conversion of a constrained array to an + unconstrained form, we retrieve the constrained array because we + might not be able to substitute the PLACEHOLDER_EXPR coming from + the conversion. This can occur with the 'Old attribute applied + to a parameter with an unconstrained type, which gets rewritten + into a constrained local variable very late in the game. */ + if (TREE_CODE (gnu_prefix) == VIEW_CONVERT_EXPR + && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (TREE_TYPE (gnu_prefix))) + && !CONTAINS_PLACEHOLDER_P + (TYPE_SIZE (TREE_TYPE (TREE_OPERAND (gnu_prefix, 0))))) + gnu_type = TREE_TYPE (TREE_OPERAND (gnu_prefix, 0)); + else + gnu_type = TREE_TYPE (gnu_prefix); + + prefix_unused = true; + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + if (TYPE_CONVENTION_FORTRAN_P (gnu_type)) + { + int ndim; + tree gnu_type_temp; + + for (ndim = 1, gnu_type_temp = gnu_type; + TREE_CODE (TREE_TYPE (gnu_type_temp)) == ARRAY_TYPE + && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_type_temp)); + ndim++, gnu_type_temp = TREE_TYPE (gnu_type_temp)) + ; + + Dimension = ndim + 1 - Dimension; + } + + for (i = 1; i < Dimension; i++) + gnu_type = TREE_TYPE (gnu_type); + + gcc_assert (TREE_CODE (gnu_type) == ARRAY_TYPE); + + /* When not optimizing, look up the slot associated with the parameter + and the dimension in the cache and create a new one on failure. + Don't do this when the actual subtype needs debug info (this happens + with -gnatD): in elaborate_expression_1, we create variables that + hold the bounds, so caching attributes isn't very interesting and + causes dependency issues between these variables and cached + expressions. */ + if (!optimize + && Present (gnat_param) + && !(Present (Actual_Subtype (gnat_param)) + && Needs_Debug_Info (Actual_Subtype (gnat_param)))) + { + FOR_EACH_VEC_SAFE_ELT (f_parm_attr_cache, i, pa) + if (pa->id == gnat_param && pa->dim == Dimension) + break; + + if (!pa) + { + pa = ggc_cleared_alloc<parm_attr_d> (); + pa->id = gnat_param; + pa->dim = Dimension; + vec_safe_push (f_parm_attr_cache, pa); + } + } + + /* Return the cached expression or build a new one. */ + if (attribute == Attr_First) + { + if (pa && pa->first) + { + gnu_result = pa->first; + break; + } + + gnu_result + = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (gnu_type))); + } + + else if (attribute == Attr_Last) + { + if (pa && pa->last) + { + gnu_result = pa->last; + break; + } + + gnu_result + = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (gnu_type))); + } + + else /* attribute == Attr_Range_Length || attribute == Attr_Length */ + { + if (pa && pa->length) + { + gnu_result = pa->length; + break; + } + + gnu_result + = get_type_length (TYPE_INDEX_TYPE (TYPE_DOMAIN (gnu_type)), + gnu_result_type); + } + + /* If this has a PLACEHOLDER_EXPR, qualify it by the object we are + handling. Note that these attributes could not have been used on + an unconstrained array type. */ + gnu_result = SUBSTITUTE_PLACEHOLDER_IN_EXPR (gnu_result, gnu_prefix); + + /* Cache the expression we have just computed. Since we want to do it + at run time, we force the use of a SAVE_EXPR and let the gimplifier + create the temporary in the outermost binding level. We will make + sure in Subprogram_Body_to_gnu that it is evaluated on all possible + paths by forcing its evaluation on entry of the function. */ + if (pa) + { + gnu_result + = build1 (SAVE_EXPR, TREE_TYPE (gnu_result), gnu_result); + switch (attribute) + { + case Attr_First: + pa->first = gnu_result; + break; + + case Attr_Last: + pa->last = gnu_result; + break; + + case Attr_Length: + case Attr_Range_Length: + pa->length = gnu_result; + break; + + default: + gcc_unreachable (); + } + } + + /* Otherwise, evaluate it each time it is referenced. */ + else + switch (attribute) + { + case Attr_First: + case Attr_Last: + /* If we are dereferencing a pointer to unconstrained array, we + need to capture the value because the pointed-to bounds may + subsequently be released. */ + if (unconstrained_ptr_deref) + gnu_result + = build1 (SAVE_EXPR, TREE_TYPE (gnu_result), gnu_result); + break; + + case Attr_Length: + case Attr_Range_Length: + /* Set the source location onto the predicate of the condition + but not if the expression is cached to avoid messing up the + debug info. */ + if (TREE_CODE (gnu_result) == COND_EXPR + && EXPR_P (TREE_OPERAND (gnu_result, 0))) + set_expr_location_from_node (TREE_OPERAND (gnu_result, 0), + gnat_node); + break; + + default: + gcc_unreachable (); + } + + break; + } + + case Attr_Bit_Position: + case Attr_Position: + case Attr_First_Bit: + case Attr_Last_Bit: + case Attr_Bit: + { + poly_int64 bitsize; + poly_int64 bitpos; + tree gnu_offset; + tree gnu_field_bitpos; + tree gnu_field_offset; + tree gnu_inner; + machine_mode mode; + int unsignedp, reversep, volatilep; + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + gnu_prefix = remove_conversions (gnu_prefix, true); + prefix_unused = true; + + /* We can have 'Bit on any object, but if it isn't a COMPONENT_REF, + the result is 0. Don't allow 'Bit on a bare component, though. */ + if (attribute == Attr_Bit + && TREE_CODE (gnu_prefix) != COMPONENT_REF + && TREE_CODE (gnu_prefix) != FIELD_DECL) + { + gnu_result = integer_zero_node; + break; + } + + else + gcc_assert (TREE_CODE (gnu_prefix) == COMPONENT_REF + || (attribute == Attr_Bit_Position + && TREE_CODE (gnu_prefix) == FIELD_DECL)); + + get_inner_reference (gnu_prefix, &bitsize, &bitpos, &gnu_offset, + &mode, &unsignedp, &reversep, &volatilep); + + if (TREE_CODE (gnu_prefix) == COMPONENT_REF) + { + gnu_field_bitpos = bit_position (TREE_OPERAND (gnu_prefix, 1)); + gnu_field_offset = byte_position (TREE_OPERAND (gnu_prefix, 1)); + + for (gnu_inner = TREE_OPERAND (gnu_prefix, 0); + TREE_CODE (gnu_inner) == COMPONENT_REF + && DECL_INTERNAL_P (TREE_OPERAND (gnu_inner, 1)); + gnu_inner = TREE_OPERAND (gnu_inner, 0)) + { + gnu_field_bitpos + = size_binop (PLUS_EXPR, gnu_field_bitpos, + bit_position (TREE_OPERAND (gnu_inner, 1))); + gnu_field_offset + = size_binop (PLUS_EXPR, gnu_field_offset, + byte_position (TREE_OPERAND (gnu_inner, 1))); + } + } + else if (TREE_CODE (gnu_prefix) == FIELD_DECL) + { + gnu_field_bitpos = bit_position (gnu_prefix); + gnu_field_offset = byte_position (gnu_prefix); + } + else + { + gnu_field_bitpos = bitsize_zero_node; + gnu_field_offset = size_zero_node; + } + + switch (attribute) + { + case Attr_Position: + gnu_result = gnu_field_offset; + break; + + case Attr_First_Bit: + case Attr_Bit: + gnu_result = size_int (num_trailing_bits (bitpos)); + break; + + case Attr_Last_Bit: + gnu_result = bitsize_int (num_trailing_bits (bitpos)); + gnu_result = size_binop (PLUS_EXPR, gnu_result, + TYPE_SIZE (TREE_TYPE (gnu_prefix))); + /* ??? Avoid a large unsigned result that will overflow when + converted to the signed universal_integer. */ + if (integer_zerop (gnu_result)) + gnu_result = integer_minus_one_node; + else + gnu_result + = size_binop (MINUS_EXPR, gnu_result, bitsize_one_node); + break; + + case Attr_Bit_Position: + gnu_result = gnu_field_bitpos; + break; + } + + /* If this has a PLACEHOLDER_EXPR, qualify it by the object we are + handling. */ + gnu_result = SUBSTITUTE_PLACEHOLDER_IN_EXPR (gnu_result, gnu_prefix); + break; + } + + case Attr_Min: + case Attr_Max: + { + tree gnu_lhs = gnat_to_gnu (First (Expressions (gnat_node))); + tree gnu_rhs = gnat_to_gnu (Next (First (Expressions (gnat_node)))); + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + /* The result of {MIN,MAX}_EXPR is unspecified if either operand is + a NaN so we implement the semantics of C99 f{min,max} to make it + predictable in this case: if either operand is a NaN, the other + is returned; if both operands are NaN's, a NaN is returned. */ + if (SCALAR_FLOAT_TYPE_P (gnu_result_type) + && !Machine_Overflows_On_Target) + { + const bool lhs_side_effects_p = TREE_SIDE_EFFECTS (gnu_lhs); + const bool rhs_side_effects_p = TREE_SIDE_EFFECTS (gnu_rhs); + tree t = builtin_decl_explicit (BUILT_IN_ISNAN); + tree lhs_is_nan, rhs_is_nan; + + /* If the operands have side-effects, they need to be evaluated + only once in spite of the multiple references in the result. */ + if (lhs_side_effects_p) + gnu_lhs = gnat_protect_expr (gnu_lhs); + if (rhs_side_effects_p) + gnu_rhs = gnat_protect_expr (gnu_rhs); + + lhs_is_nan = fold_build2 (NE_EXPR, boolean_type_node, + build_call_expr (t, 1, gnu_lhs), + integer_zero_node); + + rhs_is_nan = fold_build2 (NE_EXPR, boolean_type_node, + build_call_expr (t, 1, gnu_rhs), + integer_zero_node); + + gnu_result = build_binary_op (attribute == Attr_Min + ? MIN_EXPR : MAX_EXPR, + gnu_result_type, gnu_lhs, gnu_rhs); + gnu_result = fold_build3 (COND_EXPR, gnu_result_type, + rhs_is_nan, gnu_lhs, gnu_result); + gnu_result = fold_build3 (COND_EXPR, gnu_result_type, + lhs_is_nan, gnu_rhs, gnu_result); + + /* If the operands have side-effects, they need to be evaluated + before doing the tests above since the place they otherwise + would end up being evaluated at run time could be wrong. */ + if (lhs_side_effects_p) + gnu_result + = build2 (COMPOUND_EXPR, gnu_result_type, gnu_lhs, gnu_result); + + if (rhs_side_effects_p) + gnu_result + = build2 (COMPOUND_EXPR, gnu_result_type, gnu_rhs, gnu_result); + } + else + gnu_result = build_binary_op (attribute == Attr_Min + ? MIN_EXPR : MAX_EXPR, + gnu_result_type, gnu_lhs, gnu_rhs); + } + break; + + case Attr_Passed_By_Reference: + gnu_result = size_int (default_pass_by_ref (gnu_type) + || must_pass_by_ref (gnu_type)); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + break; + + case Attr_Component_Size: + gnu_prefix = maybe_padded_object (gnu_prefix); + gnu_type = TREE_TYPE (gnu_prefix); + + if (TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE) + gnu_type = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_type)))); + + while (TREE_CODE (TREE_TYPE (gnu_type)) == ARRAY_TYPE + && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_type))) + gnu_type = TREE_TYPE (gnu_type); + + gcc_assert (TREE_CODE (gnu_type) == ARRAY_TYPE); + + /* Note this size cannot be self-referential. */ + gnu_result = TYPE_SIZE (TREE_TYPE (gnu_type)); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + prefix_unused = true; + break; + + case Attr_Descriptor_Size: + gnu_type = TREE_TYPE (gnu_prefix); + gcc_assert (TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE); + + /* Return the padded size of the template in the object record type. */ + gnu_type = TYPE_OBJECT_RECORD_TYPE (gnu_type); + gnu_result = bit_position (DECL_CHAIN (TYPE_FIELDS (gnu_type))); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + prefix_unused = true; + break; + + case Attr_Null_Parameter: + /* This is just a zero cast to the pointer type for our prefix and + dereferenced. */ + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + gnu_result + = build_unary_op (INDIRECT_REF, NULL_TREE, + convert (build_pointer_type (gnu_result_type), + integer_zero_node)); + break; + + case Attr_Mechanism_Code: + { + Entity_Id gnat_obj = Entity (gnat_prefix); + int code; + + prefix_unused = true; + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + if (Present (Expressions (gnat_node))) + { + int i = UI_To_Int (Intval (First (Expressions (gnat_node)))); + + for (gnat_obj = First_Formal (gnat_obj); i > 1; + i--, gnat_obj = Next_Formal (gnat_obj)) + ; + } + + code = Mechanism (gnat_obj); + if (code == Default) + code = ((present_gnu_tree (gnat_obj) + && (DECL_BY_REF_P (get_gnu_tree (gnat_obj)) + || ((TREE_CODE (get_gnu_tree (gnat_obj)) + == PARM_DECL) + && (DECL_BY_COMPONENT_PTR_P + (get_gnu_tree (gnat_obj)))))) + ? By_Reference : By_Copy); + gnu_result = convert (gnu_result_type, size_int (- code)); + } + break; + + case Attr_Model: + /* We treat Model as identical to Machine. This is true for at least + IEEE and some other nice floating-point systems. */ + + /* ... fall through ... */ + + case Attr_Machine: + /* The trick is to force the compiler to store the result in memory so + that we do not have extra precision used. But do this only when this + is necessary, i.e. if FP_ARITH_MAY_WIDEN is true and the precision of + the type is lower than that of the longest floating-point type. */ + prefix_unused = true; + gnu_expr = gnat_to_gnu (First (Expressions (gnat_node))); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + gnu_result = convert (gnu_result_type, gnu_expr); + + if (TREE_CODE (gnu_result) != REAL_CST + && fp_arith_may_widen + && TYPE_PRECISION (gnu_result_type) + < TYPE_PRECISION (longest_float_type_node)) + { + tree rec_type = make_node (RECORD_TYPE); + tree field + = create_field_decl (get_identifier ("OBJ"), gnu_result_type, + rec_type, NULL_TREE, NULL_TREE, 0, 0); + tree rec_val, asm_expr; + + finish_record_type (rec_type, field, 0, false); + + rec_val = build_constructor_single (rec_type, field, gnu_result); + rec_val = build1 (SAVE_EXPR, rec_type, rec_val); + + asm_expr + = build5 (ASM_EXPR, void_type_node, + build_string (0, ""), + tree_cons (build_tree_list (NULL_TREE, + build_string (2, "=m")), + rec_val, NULL_TREE), + tree_cons (build_tree_list (NULL_TREE, + build_string (1, "m")), + rec_val, NULL_TREE), + NULL_TREE, NULL_TREE); + ASM_VOLATILE_P (asm_expr) = 1; + + gnu_result + = build_compound_expr (gnu_result_type, asm_expr, + build_component_ref (rec_val, field, + false)); + } + break; + + case Attr_Deref: + prefix_unused = true; + gnu_expr = gnat_to_gnu (First (Expressions (gnat_node))); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + /* This can be a random address so build an alias-all pointer type. */ + gnu_expr + = convert (build_pointer_type_for_mode (gnu_result_type, ptr_mode, + true), + gnu_expr); + gnu_result = build_unary_op (INDIRECT_REF, NULL_TREE, gnu_expr); + break; + + default: + /* This abort means that we have an unimplemented attribute. */ + gcc_unreachable (); + } + + /* If this is an attribute where the prefix was unused, force a use of it if + it has a side-effect. But don't do it if the prefix is just an entity + name. However, if an access check is needed, we must do it. See second + example in AARM 11.6(5.e). */ + if (prefix_unused + && TREE_SIDE_EFFECTS (gnu_prefix) + && !Is_Entity_Name (gnat_prefix)) + gnu_result + = build_compound_expr (TREE_TYPE (gnu_result), gnu_prefix, gnu_result); + + *gnu_result_type_p = gnu_result_type; + return gnu_result; +} + +/* Subroutine of gnat_to_gnu to translate gnat_node, an N_Case_Statement, + to a GCC tree, which is returned. */ + +static tree +Case_Statement_to_gnu (Node_Id gnat_node) +{ + tree gnu_result, gnu_expr, gnu_type, gnu_label; + Node_Id gnat_when; + location_t end_locus; + bool may_fallthru = false; + + gnu_expr = gnat_to_gnu (Expression (gnat_node)); + gnu_expr = convert (get_base_type (TREE_TYPE (gnu_expr)), gnu_expr); + gnu_expr = maybe_character_value (gnu_expr); + gnu_type = TREE_TYPE (gnu_expr); + + /* We build a SWITCH_EXPR that contains the code with interspersed + CASE_LABEL_EXPRs for each label. */ + if (!Sloc_to_locus (End_Location (gnat_node), &end_locus)) + end_locus = input_location; + gnu_label = create_artificial_label (end_locus); + start_stmt_group (); + + for (gnat_when = First_Non_Pragma (Alternatives (gnat_node)); + Present (gnat_when); + gnat_when = Next_Non_Pragma (gnat_when)) + { + bool choices_added_p = false; + Node_Id gnat_choice; + + /* First compile all the different case choices for the current WHEN + alternative. */ + for (gnat_choice = First (Discrete_Choices (gnat_when)); + Present (gnat_choice); + gnat_choice = Next (gnat_choice)) + { + tree gnu_low = NULL_TREE, gnu_high = NULL_TREE; + tree label = create_artificial_label (input_location); + + switch (Nkind (gnat_choice)) + { + case N_Range: + gnu_low = gnat_to_gnu (Low_Bound (gnat_choice)); + gnu_high = gnat_to_gnu (High_Bound (gnat_choice)); + break; + + case N_Subtype_Indication: + gnu_low = gnat_to_gnu (Low_Bound (Range_Expression + (Constraint (gnat_choice)))); + gnu_high = gnat_to_gnu (High_Bound (Range_Expression + (Constraint (gnat_choice)))); + break; + + case N_Identifier: + case N_Expanded_Name: + /* This represents either a subtype range or a static value of + some kind; Ekind says which. */ + if (Is_Type (Entity (gnat_choice))) + { + tree gnu_type = get_unpadded_type (Entity (gnat_choice)); + + gnu_low = TYPE_MIN_VALUE (gnu_type); + gnu_high = TYPE_MAX_VALUE (gnu_type); + break; + } + + /* ... fall through ... */ + + case N_Character_Literal: + case N_Integer_Literal: + gnu_low = gnat_to_gnu (gnat_choice); + break; + + case N_Others_Choice: + break; + + default: + gcc_unreachable (); + } + + /* Everything should be folded into constants at this point. */ + gcc_assert (!gnu_low || TREE_CODE (gnu_low) == INTEGER_CST); + gcc_assert (!gnu_high || TREE_CODE (gnu_high) == INTEGER_CST); + + if (gnu_low && TREE_TYPE (gnu_low) != gnu_type) + gnu_low = convert (gnu_type, gnu_low); + if (gnu_high && TREE_TYPE (gnu_high) != gnu_type) + gnu_high = convert (gnu_type, gnu_high); + + add_stmt_with_node (build_case_label (gnu_low, gnu_high, label), + gnat_choice); + choices_added_p = true; + } + + /* This construct doesn't define a scope so we shouldn't push a binding + level around the statement list. Except that we have always done so + historically and this makes it possible to reduce stack usage. As a + compromise, we keep doing it for case statements, for which this has + never been problematic, but not for case expressions in Ada 2012. */ + if (choices_added_p) + { + const bool is_case_expression + = (Nkind (Parent (gnat_node)) == N_Expression_With_Actions); + tree group + = build_stmt_group (Statements (gnat_when), !is_case_expression); + bool group_may_fallthru = block_may_fallthru (group); + add_stmt (group); + if (group_may_fallthru) + { + tree stmt = build1 (GOTO_EXPR, void_type_node, gnu_label); + SET_EXPR_LOCATION (stmt, end_locus); + add_stmt (stmt); + may_fallthru = true; + } + } + } + + /* Now emit a definition of the label the cases branch to, if any. */ + if (may_fallthru) + add_stmt (build1 (LABEL_EXPR, void_type_node, gnu_label)); + gnu_result = build2 (SWITCH_EXPR, gnu_type, gnu_expr, end_stmt_group ()); + + return gnu_result; +} + +/* Return true if we are in the body of a loop. */ + +static inline bool +inside_loop_p (void) +{ + return !vec_safe_is_empty (gnu_loop_stack); +} + +/* Find out whether EXPR is a simple additive expression based on the iteration + variable of some enclosing loop in the current function. If so, return the + loop and set *DISP to the displacement and *NEG_P to true if this is for a + subtraction; otherwise, return NULL. */ + +static struct loop_info_d * +find_loop_for (tree expr, tree *disp, bool *neg_p) +{ + tree var, add, cst; + bool minus_p; + struct loop_info_d *iter = NULL; + unsigned int i; + + if (is_simple_additive_expression (expr, &add, &cst, &minus_p)) + { + var = add; + if (disp) + *disp = cst; + if (neg_p) + *neg_p = minus_p; + } + else + { + var = expr; + if (disp) + *disp = NULL_TREE; + if (neg_p) + *neg_p = false; + } + + var = remove_conversions (var, false); + + if (TREE_CODE (var) != VAR_DECL) + return NULL; + + gcc_checking_assert (vec_safe_length (gnu_loop_stack) > 0); + + FOR_EACH_VEC_ELT_REVERSE (*gnu_loop_stack, i, iter) + if (iter->loop_var == var && iter->fndecl == current_function_decl) + break; + + return iter; +} + +/* Return the innermost enclosing loop in the current function. */ + +static struct loop_info_d * +find_loop (void) +{ + struct loop_info_d *iter = NULL; + unsigned int i; + + gcc_checking_assert (vec_safe_length (gnu_loop_stack) > 0); + + FOR_EACH_VEC_ELT_REVERSE (*gnu_loop_stack, i, iter) + if (iter->fndecl == current_function_decl) + break; + + return iter; +} + +/* Return true if VAL (of type TYPE) can equal the minimum value if MAX is + false, or the maximum value if MAX is true, of TYPE. */ + +static bool +can_equal_min_or_max_val_p (tree val, tree type, bool max) +{ + tree min_or_max_val = (max ? TYPE_MAX_VALUE (type) : TYPE_MIN_VALUE (type)); + + if (TREE_CODE (min_or_max_val) != INTEGER_CST) + return true; + + if (TREE_CODE (val) == NOP_EXPR) + val = (max + ? TYPE_MAX_VALUE (TREE_TYPE (TREE_OPERAND (val, 0))) + : TYPE_MIN_VALUE (TREE_TYPE (TREE_OPERAND (val, 0)))); + + if (TREE_CODE (val) != INTEGER_CST) + return true; + + if (max) + return tree_int_cst_lt (val, min_or_max_val) == 0; + else + return tree_int_cst_lt (min_or_max_val, val) == 0; +} + +/* Return true if VAL (of type TYPE) can equal the minimum value of TYPE. + If REVERSE is true, minimum value is taken as maximum value. */ + +static inline bool +can_equal_min_val_p (tree val, tree type, bool reverse) +{ + return can_equal_min_or_max_val_p (val, type, reverse); +} + +/* Return true if VAL (of type TYPE) can equal the maximum value of TYPE. + If REVERSE is true, maximum value is taken as minimum value. */ + +static inline bool +can_equal_max_val_p (tree val, tree type, bool reverse) +{ + return can_equal_min_or_max_val_p (val, type, !reverse); +} + +/* Replace EXPR1 and EXPR2 by invariant expressions if possible. Return + true if both expressions have been replaced and false otherwise. */ + +static bool +make_invariant (tree *expr1, tree *expr2) +{ + tree inv_expr1 = gnat_invariant_expr (*expr1); + tree inv_expr2 = gnat_invariant_expr (*expr2); + + if (inv_expr1) + *expr1 = inv_expr1; + + if (inv_expr2) + *expr2 = inv_expr2; + + return inv_expr1 && inv_expr2; +} + +/* Helper function for walk_tree, used by independent_iterations_p below. */ + +static tree +scan_rhs_r (tree *tp, int *walk_subtrees, void *data) +{ + bitmap *params = (bitmap *)data; + tree t = *tp; + + /* No need to walk into types or decls. */ + if (IS_TYPE_OR_DECL_P (t)) + *walk_subtrees = 0; + + if (TREE_CODE (t) == PARM_DECL && bitmap_bit_p (*params, DECL_UID (t))) + return t; + + return NULL_TREE; +} + +/* Return true if STMT_LIST generates independent iterations in a loop. */ + +static bool +independent_iterations_p (tree stmt_list) +{ + tree_stmt_iterator tsi; + bitmap params = BITMAP_GGC_ALLOC(); + auto_vec<tree, 16> rhs; + tree iter; + int i; + + if (TREE_CODE (stmt_list) == BIND_EXPR) + stmt_list = BIND_EXPR_BODY (stmt_list); + + /* Scan the list and return false on anything that is not either a check + or an assignment to a parameter with restricted aliasing. */ + for (tsi = tsi_start (stmt_list); !tsi_end_p (tsi); tsi_next (&tsi)) + { + tree stmt = tsi_stmt (tsi); + + switch (TREE_CODE (stmt)) + { + case COND_EXPR: + { + if (COND_EXPR_ELSE (stmt)) + return false; + if (TREE_CODE (COND_EXPR_THEN (stmt)) != CALL_EXPR) + return false; + tree func = get_callee_fndecl (COND_EXPR_THEN (stmt)); + if (!(func && TREE_THIS_VOLATILE (func))) + return false; + break; + } + + case MODIFY_EXPR: + { + tree lhs = TREE_OPERAND (stmt, 0); + while (handled_component_p (lhs)) + lhs = TREE_OPERAND (lhs, 0); + if (TREE_CODE (lhs) != INDIRECT_REF) + return false; + lhs = TREE_OPERAND (lhs, 0); + if (!(TREE_CODE (lhs) == PARM_DECL + && DECL_RESTRICTED_ALIASING_P (lhs))) + return false; + bitmap_set_bit (params, DECL_UID (lhs)); + rhs.safe_push (TREE_OPERAND (stmt, 1)); + break; + } + + default: + return false; + } + } + + /* At this point we know that the list contains only statements that will + modify parameters with restricted aliasing. Check that the statements + don't at the time read from these parameters. */ + FOR_EACH_VEC_ELT (rhs, i, iter) + if (walk_tree_without_duplicates (&iter, scan_rhs_r, ¶ms)) + return false; + + return true; +} + +/* Subroutine of gnat_to_gnu to translate gnat_node, an N_Loop_Statement, + to a GCC tree, which is returned. */ + +static tree +Loop_Statement_to_gnu (Node_Id gnat_node) +{ + const Node_Id gnat_iter_scheme = Iteration_Scheme (gnat_node); + struct loop_info_d *gnu_loop_info = ggc_cleared_alloc<loop_info_d> (); + tree gnu_loop_stmt = build4 (LOOP_STMT, void_type_node, NULL_TREE, + NULL_TREE, NULL_TREE, NULL_TREE); + tree gnu_loop_label = create_artificial_label (input_location); + tree gnu_cond_expr = NULL_TREE, gnu_low = NULL_TREE, gnu_high = NULL_TREE; + tree gnu_result; + + /* Push the loop_info structure associated with the LOOP_STMT. */ + gnu_loop_info->fndecl = current_function_decl; + gnu_loop_info->stmt = gnu_loop_stmt; + vec_safe_push (gnu_loop_stack, gnu_loop_info); + + /* Set location information for statement and end label. */ + set_expr_location_from_node (gnu_loop_stmt, gnat_node); + Sloc_to_locus (Sloc (End_Label (gnat_node)), + &DECL_SOURCE_LOCATION (gnu_loop_label)); + LOOP_STMT_LABEL (gnu_loop_stmt) = gnu_loop_label; + + /* Set the condition under which the loop must keep going. If we have an + explicit condition, use it to set the location information throughout + the translation of the loop statement to avoid having multiple SLOCs. + + For the case "LOOP .... END LOOP;" the condition is always true. */ + if (No (gnat_iter_scheme)) + ; + + /* For the case "WHILE condition LOOP ..... END LOOP;" it's immediate. */ + else if (Present (Condition (gnat_iter_scheme))) + { + LOOP_STMT_COND (gnu_loop_stmt) + = gnat_to_gnu (Condition (gnat_iter_scheme)); + + set_expr_location_from_node (gnu_loop_stmt, gnat_iter_scheme); + } + + /* Otherwise we have an iteration scheme and the condition is given by the + bounds of the subtype of the iteration variable. */ + else + { + Node_Id gnat_loop_spec = Loop_Parameter_Specification (gnat_iter_scheme); + Entity_Id gnat_loop_var = Defining_Entity (gnat_loop_spec); + Entity_Id gnat_type = Etype (gnat_loop_var); + tree gnu_type = get_unpadded_type (gnat_type); + tree gnu_base_type = maybe_character_type (get_base_type (gnu_type)); + tree gnu_one_node = build_int_cst (gnu_base_type, 1); + tree gnu_loop_var, gnu_loop_iv, gnu_first, gnu_last, gnu_stmt; + enum tree_code update_code, test_code, shift_code; + bool reverse = Reverse_Present (gnat_loop_spec), use_iv = false; + + gnu_low = convert (gnu_base_type, TYPE_MIN_VALUE (gnu_type)); + gnu_high = convert (gnu_base_type, TYPE_MAX_VALUE (gnu_type)); + + /* We must disable modulo reduction for the iteration variable, if any, + in order for the loop comparison to be effective. */ + if (reverse) + { + gnu_first = gnu_high; + gnu_last = gnu_low; + update_code = MINUS_NOMOD_EXPR; + test_code = GE_EXPR; + shift_code = PLUS_NOMOD_EXPR; + } + else + { + gnu_first = gnu_low; + gnu_last = gnu_high; + update_code = PLUS_NOMOD_EXPR; + test_code = LE_EXPR; + shift_code = MINUS_NOMOD_EXPR; + } + + /* We use two different strategies to translate the loop, depending on + whether optimization is enabled. + + If it is, we generate the canonical loop form expected by the loop + optimizer and the loop vectorizer, which is the do-while form: + + ENTRY_COND + loop: + TOP_UPDATE + BODY + BOTTOM_COND + GOTO loop + + This avoids an implicit dependency on loop header copying and makes + it possible to turn BOTTOM_COND into an inequality test. + + If optimization is disabled, loop header copying doesn't come into + play and we try to generate the loop form with the fewer conditional + branches. First, the default form, which is: + + loop: + TOP_COND + BODY + BOTTOM_UPDATE + GOTO loop + + It should catch most loops with constant ending point. Then, if we + cannot, we try to generate the shifted form: + + loop: + TOP_COND + TOP_UPDATE + BODY + GOTO loop + + which should catch loops with constant starting point. Otherwise, if + we cannot, we generate the fallback form: + + ENTRY_COND + loop: + BODY + BOTTOM_COND + BOTTOM_UPDATE + GOTO loop + + which works in all cases. */ + + if (optimize && !optimize_debug) + { + /* We can use the do-while form directly if GNU_FIRST-1 doesn't + overflow. */ + if (!can_equal_min_val_p (gnu_first, gnu_base_type, reverse)) + ; + + /* Otherwise, use the do-while form with the help of a special + induction variable in the unsigned version of the base type + or the unsigned version of the size type, whichever is the + largest, in order to have wrap-around arithmetics for it. */ + else + { + if (TYPE_PRECISION (gnu_base_type) + > TYPE_PRECISION (size_type_node)) + gnu_base_type + = gnat_type_for_size (TYPE_PRECISION (gnu_base_type), 1); + else + gnu_base_type = size_type_node; + + gnu_first = convert (gnu_base_type, gnu_first); + gnu_last = convert (gnu_base_type, gnu_last); + gnu_one_node = build_int_cst (gnu_base_type, 1); + use_iv = true; + } + + gnu_first + = build_binary_op (shift_code, gnu_base_type, gnu_first, + gnu_one_node); + LOOP_STMT_TOP_UPDATE_P (gnu_loop_stmt) = 1; + LOOP_STMT_BOTTOM_COND_P (gnu_loop_stmt) = 1; + } + else + { + /* We can use the default form if GNU_LAST+1 doesn't overflow. */ + if (!can_equal_max_val_p (gnu_last, gnu_base_type, reverse)) + ; + + /* Otherwise, we can use the shifted form if neither GNU_FIRST-1 nor + GNU_LAST-1 does. */ + else if (!can_equal_min_val_p (gnu_first, gnu_base_type, reverse) + && !can_equal_min_val_p (gnu_last, gnu_base_type, reverse)) + { + gnu_first + = build_binary_op (shift_code, gnu_base_type, gnu_first, + gnu_one_node); + gnu_last + = build_binary_op (shift_code, gnu_base_type, gnu_last, + gnu_one_node); + LOOP_STMT_TOP_UPDATE_P (gnu_loop_stmt) = 1; + } + + /* Otherwise, use the fallback form. */ + else + LOOP_STMT_BOTTOM_COND_P (gnu_loop_stmt) = 1; + } + + /* If we use the BOTTOM_COND, we can turn the test into an inequality + test but we have to add ENTRY_COND to protect the empty loop. */ + if (LOOP_STMT_BOTTOM_COND_P (gnu_loop_stmt)) + { + test_code = NE_EXPR; + gnu_cond_expr + = build3 (COND_EXPR, void_type_node, + build_binary_op (LE_EXPR, boolean_type_node, + gnu_low, gnu_high), + NULL_TREE, alloc_stmt_list ()); + set_expr_location_from_node (gnu_cond_expr, gnat_iter_scheme); + } + + /* Open a new nesting level that will surround the loop to declare the + iteration variable. */ + start_stmt_group (); + gnat_pushlevel (); + + /* If we use the special induction variable, create it and set it to + its initial value. Morever, the regular iteration variable cannot + itself be initialized, lest the initial value wrapped around. */ + if (use_iv) + { + gnu_loop_iv + = create_init_temporary ("I", gnu_first, &gnu_stmt, gnat_loop_var); + add_stmt (gnu_stmt); + gnu_first = NULL_TREE; + } + else + gnu_loop_iv = NULL_TREE; + + /* Declare the iteration variable and set it to its initial value. */ + gnu_loop_var = gnat_to_gnu_entity (gnat_loop_var, gnu_first, true); + if (DECL_BY_REF_P (gnu_loop_var)) + gnu_loop_var = build_unary_op (INDIRECT_REF, NULL_TREE, gnu_loop_var); + else if (use_iv) + { + gcc_assert (DECL_LOOP_PARM_P (gnu_loop_var)); + SET_DECL_INDUCTION_VAR (gnu_loop_var, gnu_loop_iv); + } + gnu_loop_info->loop_var = gnu_loop_var; + gnu_loop_info->low_bound = gnu_low; + gnu_loop_info->high_bound = gnu_high; + + /* Do all the arithmetics in the base type. */ + gnu_loop_var = convert (gnu_base_type, gnu_loop_var); + + /* Set either the top or bottom exit condition. */ + if (use_iv) + LOOP_STMT_COND (gnu_loop_stmt) + = build_binary_op (test_code, boolean_type_node, gnu_loop_iv, + gnu_last); + else + LOOP_STMT_COND (gnu_loop_stmt) + = build_binary_op (test_code, boolean_type_node, gnu_loop_var, + gnu_last); + + /* Set either the top or bottom update statement and give it the source + location of the iteration for better coverage info. */ + if (use_iv) + { + gnu_stmt + = build_binary_op (MODIFY_EXPR, NULL_TREE, gnu_loop_iv, + build_binary_op (update_code, gnu_base_type, + gnu_loop_iv, gnu_one_node)); + set_expr_location_from_node (gnu_stmt, gnat_iter_scheme); + append_to_statement_list (gnu_stmt, + &LOOP_STMT_UPDATE (gnu_loop_stmt)); + gnu_stmt + = build_binary_op (MODIFY_EXPR, NULL_TREE, gnu_loop_var, + gnu_loop_iv); + set_expr_location_from_node (gnu_stmt, gnat_iter_scheme); + append_to_statement_list (gnu_stmt, + &LOOP_STMT_UPDATE (gnu_loop_stmt)); + } + else + { + gnu_stmt + = build_binary_op (MODIFY_EXPR, NULL_TREE, gnu_loop_var, + build_binary_op (update_code, gnu_base_type, + gnu_loop_var, gnu_one_node)); + set_expr_location_from_node (gnu_stmt, gnat_iter_scheme); + LOOP_STMT_UPDATE (gnu_loop_stmt) = gnu_stmt; + } + + set_expr_location_from_node (gnu_loop_stmt, gnat_iter_scheme); + } + + /* If the loop was named, have the name point to this loop. In this case, + the association is not a DECL node, but the end label of the loop. */ + if (Present (Identifier (gnat_node))) + save_gnu_tree (Entity (Identifier (gnat_node)), gnu_loop_label, true); + + /* Make the loop body into its own block, so any allocated storage will be + released every iteration. This is needed for stack allocation. */ + LOOP_STMT_BODY (gnu_loop_stmt) + = build_stmt_group (Statements (gnat_node), true); + TREE_SIDE_EFFECTS (gnu_loop_stmt) = 1; + + /* If we have an iteration scheme, then we are in a statement group. Add + the LOOP_STMT to it, finish it and make it the "loop". */ + if (Present (gnat_iter_scheme) && No (Condition (gnat_iter_scheme))) + { + /* First, if we have computed invariant conditions for range (or index) + checks applied to the iteration variable, find out whether they can + be evaluated to false at compile time; otherwise, if there are not + too many of them, combine them with the original checks. If loop + unswitching is enabled, do not require the loop bounds to be also + invariant, as their evaluation will still be ahead of the loop. */ + if (vec_safe_length (gnu_loop_info->checks) > 0 + && (make_invariant (&gnu_low, &gnu_high) || optimize >= 3)) + { + struct range_check_info_d *rci; + unsigned int i, n_remaining_checks = 0; + + FOR_EACH_VEC_ELT (*gnu_loop_info->checks, i, rci) + { + tree low_ok, high_ok; + + if (rci->low_bound) + { + tree gnu_adjusted_low = convert (rci->type, gnu_low); + if (rci->disp) + gnu_adjusted_low + = fold_build2 (rci->neg_p ? MINUS_EXPR : PLUS_EXPR, + rci->type, gnu_adjusted_low, rci->disp); + low_ok + = build_binary_op (GE_EXPR, boolean_type_node, + gnu_adjusted_low, rci->low_bound); + } + else + low_ok = boolean_true_node; + + if (rci->high_bound) + { + tree gnu_adjusted_high = convert (rci->type, gnu_high); + if (rci->disp) + gnu_adjusted_high + = fold_build2 (rci->neg_p ? MINUS_EXPR : PLUS_EXPR, + rci->type, gnu_adjusted_high, rci->disp); + high_ok + = build_binary_op (LE_EXPR, boolean_type_node, + gnu_adjusted_high, rci->high_bound); + } + else + high_ok = boolean_true_node; + + tree range_ok + = build_binary_op (TRUTH_ANDIF_EXPR, boolean_type_node, + low_ok, high_ok); + + rci->invariant_cond + = build_unary_op (TRUTH_NOT_EXPR, boolean_type_node, range_ok); + + if (rci->invariant_cond == boolean_false_node) + TREE_OPERAND (rci->inserted_cond, 0) = rci->invariant_cond; + else + n_remaining_checks++; + } + + /* Note that loop unswitching can only be applied a small number of + times to a given loop (PARAM_MAX_UNSWITCH_LEVEL default to 3). */ + if (IN_RANGE (n_remaining_checks, 1, 3) + && optimize >= 2 + && !optimize_size) + FOR_EACH_VEC_ELT (*gnu_loop_info->checks, i, rci) + if (rci->invariant_cond != boolean_false_node) + { + TREE_OPERAND (rci->inserted_cond, 0) = rci->invariant_cond; + + if (optimize >= 3) + add_stmt_with_node_force (rci->inserted_cond, gnat_node); + } + } + + /* Second, if we have recorded invariants to be hoisted, emit them. */ + if (vec_safe_length (gnu_loop_info->invariants) > 0) + { + tree *iter; + unsigned int i; + FOR_EACH_VEC_ELT (*gnu_loop_info->invariants, i, iter) + add_stmt_with_node_force (*iter, gnat_node); + } + + /* Third, if loop vectorization is enabled and the iterations of the + loop can easily be proved as independent, mark the loop. */ + if (optimize >= 3 + && independent_iterations_p (LOOP_STMT_BODY (gnu_loop_stmt))) + LOOP_STMT_IVDEP (gnu_loop_stmt) = 1; + + add_stmt (gnu_loop_stmt); + gnat_poplevel (); + gnu_loop_stmt = end_stmt_group (); + } + + /* If we have an outer COND_EXPR, that's our result and this loop is its + "true" statement. Otherwise, the result is the LOOP_STMT. */ + if (gnu_cond_expr) + { + COND_EXPR_THEN (gnu_cond_expr) = gnu_loop_stmt; + TREE_SIDE_EFFECTS (gnu_cond_expr) = 1; + gnu_result = gnu_cond_expr; + } + else + gnu_result = gnu_loop_stmt; + + gnu_loop_stack->pop (); + + return gnu_result; +} + +/* This page implements a form of Named Return Value optimization modeled + on the C++ optimization of the same name. The main difference is that + we disregard any semantical considerations when applying it here, the + counterpart being that we don't try to apply it to semantically loaded + return types, i.e. types with the TYPE_BY_REFERENCE_P flag set. + + We consider a function body of the following GENERIC form: + + return_type R1; + [...] + RETURN_EXPR [<retval> = ...] + [...] + RETURN_EXPR [<retval> = R1] + [...] + return_type Ri; + [...] + RETURN_EXPR [<retval> = ...] + [...] + RETURN_EXPR [<retval> = Ri] + [...] + + where the Ri are not addressable and we try to fulfill a simple criterion + that would make it possible to replace one or several Ri variables by the + single RESULT_DECL of the function. + + The first observation is that RETURN_EXPRs that don't directly reference + any of the Ri variables on the RHS of their assignment are transparent wrt + the optimization. This is because the Ri variables aren't addressable so + any transformation applied to them doesn't affect the RHS; moreover, the + assignment writes the full <retval> object so existing values are entirely + discarded. + + This property can be extended to some forms of RETURN_EXPRs that reference + the Ri variables, for example CONSTRUCTORs, but isn't true in the general + case, in particular when function calls are involved. + + Therefore the algorithm is as follows: + + 1. Collect the list of candidates for a Named Return Value (Ri variables + on the RHS of assignments of RETURN_EXPRs) as well as the list of the + other expressions on the RHS of such assignments. + + 2. Prune the members of the first list (candidates) that are referenced + by a member of the second list (expressions). + + 3. Extract a set of candidates with non-overlapping live ranges from the + first list. These are the Named Return Values. + + 4. Adjust the relevant RETURN_EXPRs and replace the occurrences of the + Named Return Values in the function with the RESULT_DECL. + + If the function returns an unconstrained type, things are a bit different + because the anonymous return object is allocated on the secondary stack + and RESULT_DECL is only a pointer to it. Each return object can be of a + different size and is allocated separately so we need not care about the + addressability and the aforementioned overlapping issues. Therefore, we + don't collect the other expressions and skip step #2 in the algorithm. */ + +struct nrv_data +{ + bitmap nrv; + tree result; + Node_Id gnat_ret; + hash_set<tree> *visited; +}; + +/* Return true if T is a Named Return Value. */ + +static inline bool +is_nrv_p (bitmap nrv, tree t) +{ + return TREE_CODE (t) == VAR_DECL && bitmap_bit_p (nrv, DECL_UID (t)); +} + +/* Helper function for walk_tree, used by finalize_nrv below. */ + +static tree +prune_nrv_r (tree *tp, int *walk_subtrees, void *data) +{ + struct nrv_data *dp = (struct nrv_data *)data; + tree t = *tp; + + /* No need to walk into types or decls. */ + if (IS_TYPE_OR_DECL_P (t)) + *walk_subtrees = 0; + + if (is_nrv_p (dp->nrv, t)) + bitmap_clear_bit (dp->nrv, DECL_UID (t)); + + return NULL_TREE; +} + +/* Prune Named Return Values in BLOCK and return true if there is still a + Named Return Value in BLOCK or one of its sub-blocks. */ + +static bool +prune_nrv_in_block (bitmap nrv, tree block) +{ + bool has_nrv = false; + tree t; + + /* First recurse on the sub-blocks. */ + for (t = BLOCK_SUBBLOCKS (block); t; t = BLOCK_CHAIN (t)) + has_nrv |= prune_nrv_in_block (nrv, t); + + /* Then make sure to keep at most one NRV per block. */ + for (t = BLOCK_VARS (block); t; t = DECL_CHAIN (t)) + if (is_nrv_p (nrv, t)) + { + if (has_nrv) + bitmap_clear_bit (nrv, DECL_UID (t)); + else + has_nrv = true; + } + + return has_nrv; +} + +/* Helper function for walk_tree, used by finalize_nrv below. */ + +static tree +finalize_nrv_r (tree *tp, int *walk_subtrees, void *data) +{ + struct nrv_data *dp = (struct nrv_data *)data; + tree t = *tp; + + /* No need to walk into types. */ + if (TYPE_P (t)) + *walk_subtrees = 0; + + /* Change RETURN_EXPRs of NRVs to just refer to the RESULT_DECL; this is a + nop, but differs from using NULL_TREE in that it indicates that we care + about the value of the RESULT_DECL. */ + else if (TREE_CODE (t) == RETURN_EXPR + && TREE_CODE (TREE_OPERAND (t, 0)) == INIT_EXPR) + { + tree ret_val = TREE_OPERAND (TREE_OPERAND (t, 0), 1); + + /* Strip useless conversions around the return value. */ + if (gnat_useless_type_conversion (ret_val)) + ret_val = TREE_OPERAND (ret_val, 0); + + if (is_nrv_p (dp->nrv, ret_val)) + TREE_OPERAND (t, 0) = dp->result; + } + + /* Replace the DECL_EXPR of NRVs with an initialization of the RESULT_DECL, + if needed. */ + else if (TREE_CODE (t) == DECL_EXPR + && is_nrv_p (dp->nrv, DECL_EXPR_DECL (t))) + { + tree var = DECL_EXPR_DECL (t), init; + + if (DECL_INITIAL (var)) + { + init = build_binary_op (INIT_EXPR, NULL_TREE, dp->result, + DECL_INITIAL (var)); + SET_EXPR_LOCATION (init, EXPR_LOCATION (t)); + DECL_INITIAL (var) = NULL_TREE; + } + else + init = build_empty_stmt (EXPR_LOCATION (t)); + *tp = init; + + /* Identify the NRV to the RESULT_DECL for debugging purposes. */ + SET_DECL_VALUE_EXPR (var, dp->result); + DECL_HAS_VALUE_EXPR_P (var) = 1; + /* ??? Kludge to avoid an assertion failure during inlining. */ + DECL_SIZE (var) = bitsize_unit_node; + DECL_SIZE_UNIT (var) = size_one_node; + } + + /* And replace all uses of NRVs with the RESULT_DECL. */ + else if (is_nrv_p (dp->nrv, t)) + *tp = convert (TREE_TYPE (t), dp->result); + + /* Avoid walking into the same tree more than once. Unfortunately, we + can't just use walk_tree_without_duplicates because it would only + call us for the first occurrence of NRVs in the function body. */ + if (dp->visited->add (*tp)) + *walk_subtrees = 0; + + return NULL_TREE; +} + +/* Likewise, but used when the function returns an unconstrained type. */ + +static tree +finalize_nrv_unc_r (tree *tp, int *walk_subtrees, void *data) +{ + struct nrv_data *dp = (struct nrv_data *)data; + tree t = *tp; + + /* No need to walk into types. */ + if (TYPE_P (t)) + *walk_subtrees = 0; + + /* We need to see the DECL_EXPR of NRVs before any other references so we + walk the body of BIND_EXPR before walking its variables. */ + else if (TREE_CODE (t) == BIND_EXPR) + walk_tree (&BIND_EXPR_BODY (t), finalize_nrv_unc_r, data, NULL); + + /* Change RETURN_EXPRs of NRVs to assign to the RESULT_DECL only the final + return value built by the allocator instead of the whole construct. */ + else if (TREE_CODE (t) == RETURN_EXPR + && TREE_CODE (TREE_OPERAND (t, 0)) == INIT_EXPR) + { + tree ret_val = TREE_OPERAND (TREE_OPERAND (t, 0), 1); + + /* This is the construct returned by the allocator. */ + if (TREE_CODE (ret_val) == COMPOUND_EXPR + && TREE_CODE (TREE_OPERAND (ret_val, 0)) == INIT_EXPR) + { + tree rhs = TREE_OPERAND (TREE_OPERAND (ret_val, 0), 1); + + if (TYPE_IS_FAT_POINTER_P (TREE_TYPE (ret_val))) + ret_val = CONSTRUCTOR_ELT (rhs, 1)->value; + else + ret_val = rhs; + } + + /* Strip useless conversions around the return value. */ + if (gnat_useless_type_conversion (ret_val) + || TREE_CODE (ret_val) == VIEW_CONVERT_EXPR) + ret_val = TREE_OPERAND (ret_val, 0); + + /* Strip unpadding around the return value. */ + if (TREE_CODE (ret_val) == COMPONENT_REF + && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (ret_val, 0)))) + ret_val = TREE_OPERAND (ret_val, 0); + + /* Assign the new return value to the RESULT_DECL. */ + if (is_nrv_p (dp->nrv, ret_val)) + TREE_OPERAND (TREE_OPERAND (t, 0), 1) + = TREE_OPERAND (DECL_INITIAL (ret_val), 0); + } + + /* Adjust the DECL_EXPR of NRVs to call the allocator and save the result + into a new variable. */ + else if (TREE_CODE (t) == DECL_EXPR + && is_nrv_p (dp->nrv, DECL_EXPR_DECL (t))) + { + tree saved_current_function_decl = current_function_decl; + tree var = DECL_EXPR_DECL (t); + tree alloc, p_array, new_var, new_ret; + vec<constructor_elt, va_gc> *v; + vec_alloc (v, 2); + + /* Create an artificial context to build the allocation. */ + current_function_decl = decl_function_context (var); + start_stmt_group (); + gnat_pushlevel (); + + /* This will return a COMPOUND_EXPR with the allocation in the first + arm and the final return value in the second arm. */ + alloc = build_allocator (TREE_TYPE (var), DECL_INITIAL (var), + TREE_TYPE (dp->result), + Procedure_To_Call (dp->gnat_ret), + Storage_Pool (dp->gnat_ret), + Empty, false); + + /* The new variable is built as a reference to the allocated space. */ + new_var + = build_decl (DECL_SOURCE_LOCATION (var), VAR_DECL, DECL_NAME (var), + build_reference_type (TREE_TYPE (var))); + DECL_BY_REFERENCE (new_var) = 1; + + if (TYPE_IS_FAT_POINTER_P (TREE_TYPE (alloc))) + { + tree cst = TREE_OPERAND (alloc, 1); + + /* The new initial value is a COMPOUND_EXPR with the allocation in + the first arm and the value of P_ARRAY in the second arm. */ + DECL_INITIAL (new_var) + = build2 (COMPOUND_EXPR, TREE_TYPE (new_var), + TREE_OPERAND (alloc, 0), + CONSTRUCTOR_ELT (cst, 0)->value); + + /* Build a modified CONSTRUCTOR that references NEW_VAR. */ + p_array = TYPE_FIELDS (TREE_TYPE (alloc)); + CONSTRUCTOR_APPEND_ELT (v, p_array, + fold_convert (TREE_TYPE (p_array), new_var)); + CONSTRUCTOR_APPEND_ELT (v, DECL_CHAIN (p_array), + CONSTRUCTOR_ELT (cst, 1)->value); + new_ret = build_constructor (TREE_TYPE (alloc), v); + } + else + { + /* The new initial value is just the allocation. */ + DECL_INITIAL (new_var) = alloc; + new_ret = fold_convert (TREE_TYPE (alloc), new_var); + } + + gnat_pushdecl (new_var, Empty); + + /* Destroy the artificial context and insert the new statements. */ + gnat_zaplevel (); + *tp = end_stmt_group (); + current_function_decl = saved_current_function_decl; + + /* Chain NEW_VAR immediately after VAR and ignore the latter. */ + DECL_CHAIN (new_var) = DECL_CHAIN (var); + DECL_CHAIN (var) = new_var; + DECL_IGNORED_P (var) = 1; + + /* Save the new return value and the dereference of NEW_VAR. */ + DECL_INITIAL (var) + = build2 (COMPOUND_EXPR, TREE_TYPE (var), new_ret, + build1 (INDIRECT_REF, TREE_TYPE (var), new_var)); + /* ??? Kludge to avoid messing up during inlining. */ + DECL_CONTEXT (var) = NULL_TREE; + } + + /* And replace all uses of NRVs with the dereference of NEW_VAR. */ + else if (is_nrv_p (dp->nrv, t)) + *tp = TREE_OPERAND (DECL_INITIAL (t), 1); + + /* Avoid walking into the same tree more than once. Unfortunately, we + can't just use walk_tree_without_duplicates because it would only + call us for the first occurrence of NRVs in the function body. */ + if (dp->visited->add (*tp)) + *walk_subtrees = 0; + + return NULL_TREE; +} + +/* Apply FUNC to all the sub-trees of nested functions in NODE. FUNC is called + with the DATA and the address of each sub-tree. If FUNC returns a non-NULL + value, the traversal is stopped. */ + +static void +walk_nesting_tree (struct cgraph_node *node, walk_tree_fn func, void *data) +{ + for (node = first_nested_function (node); + node; node = next_nested_function (node)) + { + walk_tree_without_duplicates (&DECL_SAVED_TREE (node->decl), func, data); + walk_nesting_tree (node, func, data); + } +} + +/* Finalize the Named Return Value optimization for FNDECL. The NRV bitmap + contains the candidates for Named Return Value and OTHER is a list of + the other return values. GNAT_RET is a representative return node. */ + +static void +finalize_nrv (tree fndecl, bitmap nrv, vec<tree, va_gc> *other, Node_Id gnat_ret) +{ + struct nrv_data data; + walk_tree_fn func; + unsigned int i; + tree iter; + + /* We shouldn't be applying the optimization to return types that we aren't + allowed to manipulate freely. */ + gcc_assert (!TYPE_IS_BY_REFERENCE_P (TREE_TYPE (TREE_TYPE (fndecl)))); + + /* Prune the candidates that are referenced by other return values. */ + data.nrv = nrv; + data.result = NULL_TREE; + data.gnat_ret = Empty; + data.visited = NULL; + FOR_EACH_VEC_SAFE_ELT (other, i, iter) + walk_tree_without_duplicates (&iter, prune_nrv_r, &data); + if (bitmap_empty_p (nrv)) + return; + + /* Prune also the candidates that are referenced by nested functions. */ + walk_nesting_tree (cgraph_node::get_create (fndecl), prune_nrv_r, &data); + if (bitmap_empty_p (nrv)) + return; + + /* Extract a set of NRVs with non-overlapping live ranges. */ + if (!prune_nrv_in_block (nrv, DECL_INITIAL (fndecl))) + return; + + /* Adjust the relevant RETURN_EXPRs and replace the occurrences of NRVs. */ + data.nrv = nrv; + data.result = DECL_RESULT (fndecl); + data.gnat_ret = gnat_ret; + data.visited = new hash_set<tree>; + if (TYPE_RETURN_UNCONSTRAINED_P (TREE_TYPE (fndecl))) + func = finalize_nrv_unc_r; + else + func = finalize_nrv_r; + walk_tree (&DECL_SAVED_TREE (fndecl), func, &data, NULL); + delete data.visited; +} + +/* Return true if RET_VAL can be used as a Named Return Value for the + anonymous return object RET_OBJ. */ + +static bool +return_value_ok_for_nrv_p (tree ret_obj, tree ret_val) +{ + if (TREE_CODE (ret_val) != VAR_DECL) + return false; + + if (TREE_THIS_VOLATILE (ret_val)) + return false; + + if (DECL_CONTEXT (ret_val) != current_function_decl) + return false; + + if (TREE_STATIC (ret_val)) + return false; + + /* For the constrained case, test for addressability. */ + if (ret_obj && TREE_ADDRESSABLE (ret_val)) + return false; + + /* For the constrained case, test for overalignment. */ + if (ret_obj && DECL_ALIGN (ret_val) > DECL_ALIGN (ret_obj)) + return false; + + /* For the unconstrained case, test for bogus initialization. */ + if (!ret_obj + && DECL_INITIAL (ret_val) + && TREE_CODE (DECL_INITIAL (ret_val)) == NULL_EXPR) + return false; + + return true; +} + +/* Build a RETURN_EXPR. If RET_VAL is non-null, build a RETURN_EXPR around + the assignment of RET_VAL to RET_OBJ. Otherwise build a bare RETURN_EXPR + around RESULT_OBJ, which may be null in this case. */ + +static tree +build_return_expr (tree ret_obj, tree ret_val) +{ + tree result_expr; + + if (ret_val) + { + /* The gimplifier explicitly enforces the following invariant: + + RETURN_EXPR + | + INIT_EXPR + / \ + / \ + RET_OBJ ... + + As a consequence, type consistency dictates that we use the type + of the RET_OBJ as the operation type. */ + tree operation_type = TREE_TYPE (ret_obj); + + /* Convert the right operand to the operation type. Note that this is + the transformation applied in the INIT_EXPR case of build_binary_op, + with the assumption that the type cannot involve a placeholder. */ + if (operation_type != TREE_TYPE (ret_val)) + ret_val = convert (operation_type, ret_val); + + /* We always can use an INIT_EXPR for the return object. */ + result_expr = build2 (INIT_EXPR, void_type_node, ret_obj, ret_val); + + /* If the function returns an aggregate type, find out whether this is + a candidate for Named Return Value. If so, record it. Otherwise, + if this is an expression of some kind, record it elsewhere. */ + if (optimize + && !optimize_debug + && AGGREGATE_TYPE_P (operation_type) + && !TYPE_IS_FAT_POINTER_P (operation_type) + && TYPE_MODE (operation_type) == BLKmode + && aggregate_value_p (operation_type, current_function_decl)) + { + /* Strip useless conversions around the return value. */ + if (gnat_useless_type_conversion (ret_val)) + ret_val = TREE_OPERAND (ret_val, 0); + + /* Now apply the test to the return value. */ + if (return_value_ok_for_nrv_p (ret_obj, ret_val)) + { + if (!f_named_ret_val) + f_named_ret_val = BITMAP_GGC_ALLOC (); + bitmap_set_bit (f_named_ret_val, DECL_UID (ret_val)); + } + + /* Note that we need not care about CONSTRUCTORs here, as they are + totally transparent given the read-compose-write semantics of + assignments from CONSTRUCTORs. */ + else if (EXPR_P (ret_val)) + vec_safe_push (f_other_ret_val, ret_val); + } + } + else + result_expr = ret_obj; + + return build1 (RETURN_EXPR, void_type_node, result_expr); +} + +/* Subroutine of gnat_to_gnu to process gnat_node, an N_Subprogram_Body. We + don't return anything. */ + +static void +Subprogram_Body_to_gnu (Node_Id gnat_node) +{ + /* Defining identifier of a parameter to the subprogram. */ + Entity_Id gnat_param; + /* The defining identifier for the subprogram body. Note that if a + specification has appeared before for this body, then the identifier + occurring in that specification will also be a defining identifier and all + the calls to this subprogram will point to that specification. */ + Entity_Id gnat_subprog_id + = (Present (Corresponding_Spec (gnat_node)) + ? Corresponding_Spec (gnat_node) : Defining_Entity (gnat_node)); + /* The FUNCTION_DECL node corresponding to the subprogram spec. */ + tree gnu_subprog_decl; + /* Its RESULT_DECL node. */ + tree gnu_result_decl; + /* Its FUNCTION_TYPE node. */ + tree gnu_subprog_type; + /* The TYPE_CI_CO_LIST of its FUNCTION_TYPE node, if any. */ + tree gnu_cico_list; + /* The entry in the CI_CO_LIST that represents a function return, if any. */ + tree gnu_return_var_elmt = NULL_TREE; + tree gnu_result; + location_t locus; + struct language_function *gnu_subprog_language; + vec<parm_attr, va_gc> *cache; + + /* If this is a generic object or if it has been eliminated, + ignore it. */ + if (Ekind (gnat_subprog_id) == E_Generic_Procedure + || Ekind (gnat_subprog_id) == E_Generic_Function + || Is_Eliminated (gnat_subprog_id)) + return; + + /* If this subprogram acts as its own spec, define it. Otherwise, just get + the already-elaborated tree node. However, if this subprogram had its + elaboration deferred, we will already have made a tree node for it. So + treat it as not being defined in that case. Such a subprogram cannot + have an address clause or a freeze node, so this test is safe, though it + does disable some otherwise-useful error checking. */ + gnu_subprog_decl + = gnat_to_gnu_entity (gnat_subprog_id, NULL_TREE, + Acts_As_Spec (gnat_node) + && !present_gnu_tree (gnat_subprog_id)); + DECL_FUNCTION_IS_DEF (gnu_subprog_decl) = true; + gnu_result_decl = DECL_RESULT (gnu_subprog_decl); + gnu_subprog_type = TREE_TYPE (gnu_subprog_decl); + gnu_cico_list = TYPE_CI_CO_LIST (gnu_subprog_type); + if (gnu_cico_list && TREE_VALUE (gnu_cico_list) == void_type_node) + gnu_return_var_elmt = gnu_cico_list; + + /* If the function returns by invisible reference, make it explicit in the + function body. See gnat_to_gnu_entity, E_Subprogram_Type case. */ + if (TREE_ADDRESSABLE (gnu_subprog_type)) + { + TREE_TYPE (gnu_result_decl) + = build_reference_type (TREE_TYPE (gnu_result_decl)); + relayout_decl (gnu_result_decl); + } + + /* Set the line number in the decl to correspond to that of the body. */ + if (DECL_IGNORED_P (gnu_subprog_decl)) + locus = UNKNOWN_LOCATION; + else if (!Sloc_to_locus (Sloc (gnat_node), &locus, false, gnu_subprog_decl)) + locus = input_location; + DECL_SOURCE_LOCATION (gnu_subprog_decl) = locus; + + /* If the body comes from an expression function, arrange it to be inlined + in almost all cases. */ + if (Was_Expression_Function (gnat_node) && !Debug_Flag_Dot_8) + DECL_DISREGARD_INLINE_LIMITS (gnu_subprog_decl) = 1; + + /* Try to create a bona-fide thunk and hand it over to the middle-end. */ + if (Is_Thunk (gnat_subprog_id) + && maybe_make_gnu_thunk (gnat_subprog_id, gnu_subprog_decl)) + return; + + /* Initialize the information structure for the function. */ + allocate_struct_function (gnu_subprog_decl, false); + gnu_subprog_language = ggc_cleared_alloc<language_function> (); + DECL_STRUCT_FUNCTION (gnu_subprog_decl)->language = gnu_subprog_language; + DECL_STRUCT_FUNCTION (gnu_subprog_decl)->function_start_locus = locus; + set_cfun (NULL); + + begin_subprog_body (gnu_subprog_decl); + + /* If there are copy-in/copy-out parameters, we need to ensure that they are + properly copied out by the return statement. We do this by making a new + block and converting any return into a goto to a label at the end of the + block. */ + if (gnu_cico_list) + { + tree gnu_return_var = NULL_TREE; + + vec_safe_push (gnu_return_label_stack, + create_artificial_label (input_location)); + + start_stmt_group (); + gnat_pushlevel (); + + /* If this is a function with copy-in/copy-out parameters and which does + not return by invisible reference, we also need a variable for the + return value to be placed. */ + if (gnu_return_var_elmt && !TREE_ADDRESSABLE (gnu_subprog_type)) + { + tree gnu_return_type + = TREE_TYPE (TREE_PURPOSE (gnu_return_var_elmt)); + + gnu_return_var + = create_var_decl (get_identifier ("RETVAL"), NULL_TREE, + gnu_return_type, NULL_TREE, + false, false, false, false, false, + true, false, NULL, gnat_subprog_id); + TREE_VALUE (gnu_return_var_elmt) = gnu_return_var; + } + + vec_safe_push (gnu_return_var_stack, gnu_return_var); + + /* See whether there are parameters for which we don't have a GCC tree + yet. These must be Out parameters. Make a VAR_DECL for them and + put it into TYPE_CI_CO_LIST, which must contain an empty entry too. + We can match up the entries because TYPE_CI_CO_LIST is in the order + of the parameters. */ + for (gnat_param = First_Formal_With_Extras (gnat_subprog_id); + Present (gnat_param); + gnat_param = Next_Formal_With_Extras (gnat_param)) + if (!present_gnu_tree (gnat_param)) + { + tree gnu_cico_entry = gnu_cico_list; + tree gnu_decl; + + /* Skip any entries that have been already filled in; they must + correspond to In Out parameters. */ + while (gnu_cico_entry && TREE_VALUE (gnu_cico_entry)) + gnu_cico_entry = TREE_CHAIN (gnu_cico_entry); + + /* Do any needed dereferences for by-ref objects. */ + gnu_decl = gnat_to_gnu_entity (gnat_param, NULL_TREE, true); + gcc_assert (DECL_P (gnu_decl)); + if (DECL_BY_REF_P (gnu_decl)) + gnu_decl = build_unary_op (INDIRECT_REF, NULL_TREE, gnu_decl); + + /* Do any needed references for padded types. */ + TREE_VALUE (gnu_cico_entry) + = convert (TREE_TYPE (TREE_PURPOSE (gnu_cico_entry)), gnu_decl); + } + } + else + vec_safe_push (gnu_return_label_stack, NULL_TREE); + + /* Get a tree corresponding to the code for the subprogram. */ + start_stmt_group (); + gnat_pushlevel (); + + process_decls (Declarations (gnat_node), Empty, Empty, true, true); + + /* Generate the code of the subprogram itself. A return statement will be + present and any Out parameters will be handled there. */ + add_stmt (gnat_to_gnu (Handled_Statement_Sequence (gnat_node))); + gnat_poplevel (); + gnu_result = end_stmt_group (); + + /* Attempt setting the end_locus of our GCC body tree, typically a BIND_EXPR, + then the end_locus of our GCC subprogram declaration tree. */ + set_end_locus_from_node (gnu_result, gnat_node); + set_end_locus_from_node (gnu_subprog_decl, gnat_node); + + /* If we populated the parameter attributes cache, we need to make sure that + the cached expressions are evaluated on all the possible paths leading to + their uses. So we force their evaluation on entry of the function. */ + cache = gnu_subprog_language->parm_attr_cache; + if (cache) + { + struct parm_attr_d *pa; + int i; + + start_stmt_group (); + + FOR_EACH_VEC_ELT (*cache, i, pa) + { + if (pa->first) + add_stmt_with_node_force (pa->first, gnat_node); + if (pa->last) + add_stmt_with_node_force (pa->last, gnat_node); + if (pa->length) + add_stmt_with_node_force (pa->length, gnat_node); + } + + add_stmt (gnu_result); + gnu_result = end_stmt_group (); + + gnu_subprog_language->parm_attr_cache = NULL; + } + + /* If we are dealing with a return from an Ada procedure with parameters + passed by copy-in/copy-out, we need to return a record containing the + final values of these parameters. If the list contains only one entry, + return just that entry though. + + For a full description of the copy-in/copy-out parameter mechanism, see + the part of the gnat_to_gnu_entity routine dealing with the translation + of subprograms. + + We need to make a block that contains the definition of that label and + the copying of the return value. It first contains the function, then + the label and copy statement. */ + if (gnu_cico_list) + { + const Node_Id gnat_end_label + = End_Label (Handled_Statement_Sequence (gnat_node)); + + gnu_return_var_stack->pop (); + + add_stmt (gnu_result); + add_stmt (build1 (LABEL_EXPR, void_type_node, + gnu_return_label_stack->last ())); + + /* If this is a function which returns by invisible reference, the + return value has already been dealt with at the return statements, + so we only need to indirectly copy out the parameters. */ + if (TREE_ADDRESSABLE (gnu_subprog_type)) + { + tree gnu_ret_deref + = build_unary_op (INDIRECT_REF, NULL_TREE, gnu_result_decl); + tree t; + + gcc_assert (TREE_VALUE (gnu_cico_list) == void_type_node); + + for (t = TREE_CHAIN (gnu_cico_list); t; t = TREE_CHAIN (t)) + { + tree gnu_field_deref + = build_component_ref (gnu_ret_deref, TREE_PURPOSE (t), true); + gnu_result = build2 (MODIFY_EXPR, void_type_node, + gnu_field_deref, TREE_VALUE (t)); + add_stmt_with_node (gnu_result, gnat_end_label); + } + } + + /* Otherwise, if this is a procedure or a function which does not return + by invisible reference, we can do a direct block-copy out. */ + else + { + tree gnu_retval; + + if (list_length (gnu_cico_list) == 1) + gnu_retval = TREE_VALUE (gnu_cico_list); + else + gnu_retval + = build_constructor_from_list (TREE_TYPE (gnu_subprog_type), + gnu_cico_list); + + gnu_result = build_return_expr (gnu_result_decl, gnu_retval); + add_stmt_with_node (gnu_result, gnat_end_label); + } + + gnat_poplevel (); + gnu_result = end_stmt_group (); + } + + gnu_return_label_stack->pop (); + + /* On SEH targets, install an exception handler around the main entry + point to catch unhandled exceptions. */ + if (DECL_NAME (gnu_subprog_decl) == main_identifier_node + && targetm_common.except_unwind_info (&global_options) == UI_SEH) + { + tree t; + tree etype; + + t = build_call_expr (builtin_decl_explicit (BUILT_IN_EH_POINTER), + 1, integer_zero_node); + t = build_call_n_expr (unhandled_except_decl, 1, t); + + etype = build_unary_op (ADDR_EXPR, NULL_TREE, unhandled_others_decl); + etype = tree_cons (NULL_TREE, etype, NULL_TREE); + + t = build2 (CATCH_EXPR, void_type_node, etype, t); + gnu_result = build2 (TRY_CATCH_EXPR, TREE_TYPE (gnu_result), + gnu_result, t); + } + + end_subprog_body (gnu_result); + + /* Finally annotate the parameters and disconnect the trees for parameters + that we have turned into variables since they are now unusable. */ + for (gnat_param = First_Formal_With_Extras (gnat_subprog_id); + Present (gnat_param); + gnat_param = Next_Formal_With_Extras (gnat_param)) + { + tree gnu_param = get_gnu_tree (gnat_param); + bool is_var_decl = (TREE_CODE (gnu_param) == VAR_DECL); + + annotate_object (gnat_param, TREE_TYPE (gnu_param), NULL_TREE, + DECL_BY_REF_P (gnu_param)); + + if (is_var_decl) + save_gnu_tree (gnat_param, NULL_TREE, false); + } + + /* Disconnect the variable created for the return value. */ + if (gnu_return_var_elmt) + TREE_VALUE (gnu_return_var_elmt) = void_type_node; + + /* If the function returns an aggregate type and we have candidates for + a Named Return Value, finalize the optimization. */ + if (optimize && !optimize_debug && gnu_subprog_language->named_ret_val) + { + finalize_nrv (gnu_subprog_decl, + gnu_subprog_language->named_ret_val, + gnu_subprog_language->other_ret_val, + gnu_subprog_language->gnat_ret); + gnu_subprog_language->named_ret_val = NULL; + gnu_subprog_language->other_ret_val = NULL; + } + + /* If this is an inlined external function that has been marked uninlinable, + drop the body and stop there. Otherwise compile the body. */ + if (DECL_EXTERNAL (gnu_subprog_decl) && DECL_UNINLINABLE (gnu_subprog_decl)) + DECL_SAVED_TREE (gnu_subprog_decl) = NULL_TREE; + else + rest_of_subprog_body_compilation (gnu_subprog_decl); +} + +/* The type of an atomic access. */ + +typedef enum { NOT_ATOMIC, SIMPLE_ATOMIC, OUTER_ATOMIC } atomic_acces_t; + +/* Return true if GNAT_NODE references an Atomic entity. This is modeled on + the Is_Atomic_Object predicate of the front-end, but additionally handles + explicit dereferences. */ + +static bool +node_is_atomic (Node_Id gnat_node) +{ + Entity_Id gnat_entity; + + switch (Nkind (gnat_node)) + { + case N_Identifier: + case N_Expanded_Name: + gnat_entity = Entity (gnat_node); + if (Ekind (gnat_entity) != E_Variable) + break; + return Is_Atomic (gnat_entity) || Is_Atomic (Etype (gnat_entity)); + + case N_Selected_Component: + return Is_Atomic (Etype (gnat_node)) + || Is_Atomic (Entity (Selector_Name (gnat_node))); + + case N_Indexed_Component: + return Is_Atomic (Etype (gnat_node)) + || Has_Atomic_Components (Etype (Prefix (gnat_node))) + || (Is_Entity_Name (Prefix (gnat_node)) + && Has_Atomic_Components (Entity (Prefix (gnat_node)))); + + case N_Explicit_Dereference: + return Is_Atomic (Etype (gnat_node)); + + default: + break; + } + + return false; +} + +/* Return true if GNAT_NODE references a Volatile_Full_Access entity. This is + modeled on the Is_Volatile_Full_Access_Object predicate of the front-end, + but additionally handles explicit dereferences. */ + +static bool +node_is_volatile_full_access (Node_Id gnat_node) +{ + Entity_Id gnat_entity; + + switch (Nkind (gnat_node)) + { + case N_Identifier: + case N_Expanded_Name: + gnat_entity = Entity (gnat_node); + if (!Is_Object (gnat_entity)) + break; + return Is_Volatile_Full_Access (gnat_entity) + || Is_Volatile_Full_Access (Etype (gnat_entity)); + + case N_Selected_Component: + return Is_Volatile_Full_Access (Etype (gnat_node)) + || Is_Volatile_Full_Access (Entity (Selector_Name (gnat_node))); + + case N_Indexed_Component: + case N_Explicit_Dereference: + return Is_Volatile_Full_Access (Etype (gnat_node)); + + default: + break; + } + + return false; +} + +/* Return true if GNAT_NODE references a component of a larger object. */ + +static inline bool +node_is_component (Node_Id gnat_node) +{ + const Node_Kind k = Nkind (gnat_node); + return + (k == N_Indexed_Component || k == N_Selected_Component || k == N_Slice); +} + +/* Compute whether GNAT_NODE requires atomic access and set TYPE to the type + of access and SYNC according to the associated synchronization setting. + + We implement 3 different semantics of atomicity in this function: + + 1. the Ada 95/2005/2012 semantics of the Atomic aspect/pragma, + 2. the Ada 2022 semantics of the Atomic aspect/pragma, + 3. the semantics of the Volatile_Full_Access GNAT aspect/pragma. + + They are mutually exclusive and the FE should have rejected conflicts. */ + +static void +get_atomic_access (Node_Id gnat_node, atomic_acces_t *type, bool *sync) +{ + Node_Id gnat_parent, gnat_temp; + unsigned char attr_id; + + /* First, scan the parent to filter out irrelevant cases. */ + gnat_parent = Parent (gnat_node); + switch (Nkind (gnat_parent)) + { + case N_Attribute_Reference: + attr_id = Get_Attribute_Id (Attribute_Name (gnat_parent)); + /* Do not mess up machine code insertions. */ + if (attr_id == Attr_Asm_Input || attr_id == Attr_Asm_Output) + goto not_atomic; + + /* Nothing to do if we are the prefix of an attribute, since we do not + want an atomic access for things like 'Size. */ + + /* ... fall through ... */ + + case N_Reference: + /* The N_Reference node is like an attribute. */ + if (Prefix (gnat_parent) == gnat_node) + goto not_atomic; + break; + + case N_Object_Renaming_Declaration: + /* Nothing to do for the identifier in an object renaming declaration, + the renaming itself does not need atomic access. */ + goto not_atomic; + + default: + break; + } + + /* Now strip any type conversion from GNAT_NODE. */ + if (Nkind (gnat_node) == N_Type_Conversion + || Nkind (gnat_node) == N_Unchecked_Type_Conversion) + gnat_node = Expression (gnat_node); + + /* Up to Ada 2012, for Atomic itself, only reads and updates of the object as + a whole require atomic access (RM C.6(15)). But, starting with Ada 2022, + reads of or writes to a nonatomic subcomponent of the object also require + atomic access (RM C.6(19)). */ + if (node_is_atomic (gnat_node)) + { + bool as_a_whole = true; + + /* If we are the prefix of the parent, then the access is partial. */ + for (gnat_temp = gnat_node, gnat_parent = Parent (gnat_temp); + node_is_component (gnat_parent) && Prefix (gnat_parent) == gnat_temp; + gnat_temp = gnat_parent, gnat_parent = Parent (gnat_temp)) + if (Ada_Version < Ada_2022 || node_is_atomic (gnat_parent)) + goto not_atomic; + else + as_a_whole = false; + + /* We consider that partial accesses are not sequential actions and, + therefore, do not require synchronization. */ + *type = SIMPLE_ATOMIC; + *sync = as_a_whole ? Atomic_Sync_Required (gnat_node) : false; + return; + } + + /* Look for an outer atomic access of a nonatomic subcomponent. Note that, + for VFA, we do this before looking at the node itself because we need to + access the outermost VFA object atomically, unlike for Atomic where it is + the innermost atomic object (RM C.6(19)). */ + for (gnat_temp = gnat_node; + node_is_component (gnat_temp); + gnat_temp = Prefix (gnat_temp)) + if ((Ada_Version >= Ada_2022 && node_is_atomic (Prefix (gnat_temp))) + || node_is_volatile_full_access (Prefix (gnat_temp))) + { + *type = OUTER_ATOMIC; + *sync = false; + return; + } + + /* Unlike Atomic, accessing a VFA object always requires atomic access. */ + if (node_is_volatile_full_access (gnat_node)) + { + *type = SIMPLE_ATOMIC; + *sync = false; + return; + } + +not_atomic: + *type = NOT_ATOMIC; + *sync = false; +} + +/* Return true if GNAT_NODE requires simple atomic access and, if so, set SYNC + according to the associated synchronization setting. */ + +static inline bool +simple_atomic_access_required_p (Node_Id gnat_node, bool *sync) +{ + atomic_acces_t type; + get_atomic_access (gnat_node, &type, sync); + return type == SIMPLE_ATOMIC; +} + +/* Create a temporary variable with PREFIX and TYPE, and return it. */ + +static tree +create_temporary (const char *prefix, tree type) +{ + tree gnu_temp + = create_var_decl (create_tmp_var_name (prefix), NULL_TREE, + type, NULL_TREE, + false, false, false, false, false, + true, false, NULL, Empty); + return gnu_temp; +} + +/* Create a temporary variable with PREFIX and initialize it with GNU_INIT. + Put the initialization statement into GNU_INIT_STMT and annotate it with + the SLOC of GNAT_NODE. Return the temporary variable. */ + +static tree +create_init_temporary (const char *prefix, tree gnu_init, tree *gnu_init_stmt, + Node_Id gnat_node) +{ + tree gnu_temp = create_temporary (prefix, TREE_TYPE (gnu_init)); + + *gnu_init_stmt = build_binary_op (INIT_EXPR, NULL_TREE, gnu_temp, gnu_init); + set_expr_location_from_node (*gnu_init_stmt, gnat_node); + + return gnu_temp; +} + +/* Return true if TYPE is an array of scalar type. */ + +static bool +is_array_of_scalar_type (tree type) +{ + if (TREE_CODE (type) != ARRAY_TYPE) + return false; + + type = TREE_TYPE (type); + + return !AGGREGATE_TYPE_P (type) && !POINTER_TYPE_P (type); +} + +/* Helper function for walk_tree, used by return_slot_opt_for_pure_call_p. */ + +static tree +find_decls_r (tree *tp, int *walk_subtrees, void *data) +{ + bitmap decls = (bitmap) data; + + if (TYPE_P (*tp)) + *walk_subtrees = 0; + + else if (DECL_P (*tp)) + bitmap_set_bit (decls, DECL_UID (*tp)); + + return NULL_TREE; +} + +/* Return whether the assignment TARGET = CALL can be subject to the return + slot optimization, under the assumption that the called function be pure + in the Ada sense and return an array of scalar type. */ + +static bool +return_slot_opt_for_pure_call_p (tree target, tree call) +{ + /* Check that the target is a DECL. */ + if (!DECL_P (target)) + return false; + + const bitmap decls = BITMAP_GGC_ALLOC (); + call_expr_arg_iterator iter; + tree arg; + + /* Check that all the arguments have either a scalar type (we assume that + this means by-copy passing mechanism) or array of scalar type. */ + FOR_EACH_CALL_EXPR_ARG (arg, iter, call) + { + tree arg_type = TREE_TYPE (arg); + if (TREE_CODE (arg_type) == REFERENCE_TYPE) + arg_type = TREE_TYPE (arg_type); + + if (is_array_of_scalar_type (arg_type)) + walk_tree_without_duplicates (&arg, find_decls_r, decls); + + else if (AGGREGATE_TYPE_P (arg_type) || POINTER_TYPE_P (arg_type)) + return false; + } + + /* Check that the target is not referenced by the non-scalar arguments. */ + return !bitmap_bit_p (decls, DECL_UID (target)); +} + +/* Elaborate types referenced in the profile (FIRST_FORMAL, RESULT_TYPE). */ + +static void +elaborate_profile (Entity_Id first_formal, Entity_Id result_type) +{ + Entity_Id formal; + + for (formal = first_formal; + Present (formal); + formal = Next_Formal_With_Extras (formal)) + (void) gnat_to_gnu_type (Etype (formal)); + + if (Present (result_type) && Ekind (result_type) != E_Void) + (void) gnat_to_gnu_type (result_type); +} + +/* Subroutine of gnat_to_gnu to translate gnat_node, either an N_Function_Call + or an N_Procedure_Call_Statement, to a GCC tree, which is returned. + GNU_RESULT_TYPE_P is a pointer to where we should place the result type. + If GNU_TARGET is non-null, this must be a function call on the RHS of a + N_Assignment_Statement and the result is to be placed into that object. + ATOMIC_ACCESS is the type of atomic access to be used for the assignment + to GNU_TARGET. If, in addition, ATOMIC_SYNC is true, then the assignment + to GNU_TARGET requires atomic synchronization. */ + +static tree +Call_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p, tree gnu_target, + atomic_acces_t atomic_access, bool atomic_sync) +{ + const bool function_call = (Nkind (gnat_node) == N_Function_Call); + const bool returning_value = (function_call && !gnu_target); + /* The GCC node corresponding to the GNAT subprogram name. This can either + be a FUNCTION_DECL node if we are dealing with a standard subprogram call, + or an indirect reference expression (an INDIRECT_REF node) pointing to a + subprogram. */ + const Node_Id gnat_subprog = Name (gnat_node); + tree gnu_subprog = gnat_to_gnu (gnat_subprog); + /* The FUNCTION_TYPE node giving the GCC type of the subprogram. */ + tree gnu_subprog_type = TREE_TYPE (gnu_subprog); + /* The return type of the FUNCTION_TYPE. */ + tree gnu_result_type;; + const bool frontend_builtin + = (TREE_CODE (gnu_subprog) == FUNCTION_DECL + && DECL_BUILT_IN_CLASS (gnu_subprog) == BUILT_IN_FRONTEND); + auto_vec<tree, 16> gnu_actual_vec; + tree gnu_name_list = NULL_TREE; + tree gnu_stmt_list = NULL_TREE; + tree gnu_after_list = NULL_TREE; + tree gnu_retval = NULL_TREE; + tree gnu_call, gnu_result; + bool went_into_elab_proc; + bool pushed_binding_level; + bool variadic; + bool by_descriptor; + Entity_Id gnat_formal; + Entity_Id gnat_result_type; + Node_Id gnat_actual; + atomic_acces_t aa_type; + bool aa_sync; + + /* The only way we can make a call via an access type is if GNAT_NAME is an + explicit dereference. In that case, get the list of formal args from the + type the access type is pointing to. Otherwise, get the formals from the + entity being called. */ + if (Nkind (gnat_subprog) == N_Explicit_Dereference) + { + const Entity_Id gnat_prefix_type + = Underlying_Type (Etype (Prefix (gnat_subprog))); + + gnat_formal = First_Formal_With_Extras (Etype (gnat_subprog)); + gnat_result_type = Etype (Etype (gnat_subprog)); + variadic = IN (Convention (gnat_prefix_type), Convention_C_Variadic); + + /* If the access type doesn't require foreign-compatible representation, + be prepared for descriptors. */ + by_descriptor + = targetm.calls.custom_function_descriptors > 0 + && Can_Use_Internal_Rep (gnat_prefix_type); + } + + else if (Nkind (gnat_subprog) == N_Attribute_Reference) + { + /* Assume here that this must be 'Elab_Body or 'Elab_Spec. */ + gnat_formal = Empty; + gnat_result_type = Empty; + variadic = false; + by_descriptor = false; + } + + else + { + gcc_checking_assert (Is_Entity_Name (gnat_subprog)); + + gnat_formal = First_Formal_With_Extras (Entity (gnat_subprog)); + gnat_result_type = Etype (Entity_Id (gnat_subprog)); + variadic = IN (Convention (Entity (gnat_subprog)), Convention_C_Variadic); + by_descriptor = false; + + /* If we are calling a stubbed function, then raise Program_Error, but + elaborate all our args first. */ + if (Convention (Entity (gnat_subprog)) == Convention_Stubbed) + { + tree call_expr = build_call_raise (PE_Stubbed_Subprogram_Called, + gnat_node, N_Raise_Program_Error); + + for (gnat_actual = First_Actual (gnat_node); + Present (gnat_actual); + gnat_actual = Next_Actual (gnat_actual)) + add_stmt (gnat_to_gnu (gnat_actual)); + + if (returning_value) + { + gnu_result_type = TREE_TYPE (gnu_subprog_type); + *gnu_result_type_p = gnu_result_type; + return build1 (NULL_EXPR, gnu_result_type, call_expr); + } + + return call_expr; + } + } + + /* We must elaborate the entire profile now because, if it references types + that were initially incomplete,, their elaboration changes the contents + of GNU_SUBPROG_TYPE and, in particular, may change the result type. */ + elaborate_profile (gnat_formal, gnat_result_type); + + gcc_assert (FUNC_OR_METHOD_TYPE_P (gnu_subprog_type)); + gnu_result_type = TREE_TYPE (gnu_subprog_type); + + if (TREE_CODE (gnu_subprog) == FUNCTION_DECL) + { + /* For a call to a nested function, check the inlining status. */ + if (decl_function_context (gnu_subprog)) + check_inlining_for_nested_subprog (gnu_subprog); + + /* For a recursive call, avoid explosion due to recursive inlining. */ + if (gnu_subprog == current_function_decl) + DECL_DISREGARD_INLINE_LIMITS (gnu_subprog) = 0; + } + + /* The lifetime of the temporaries created for the call ends right after the + return value is copied, so we can give them the scope of the elaboration + routine at top level. */ + if (!current_function_decl) + { + current_function_decl = get_elaboration_procedure (); + went_into_elab_proc = true; + } + else + went_into_elab_proc = false; + + /* First, create the temporary for the return value when: + + 1. There is no target and the function has copy-in/copy-out parameters, + because we need to preserve the return value before copying back the + parameters. + + 2. There is no target and the call is made for neither the declaration + of an object (regular or renaming), nor a return statement, nor an + allocator, nor an aggregate, and the return type has variable size + because in this case the gimplifier cannot create the temporary, or + more generally is an aggregate type, because the gimplifier would + create the temporary in the outermost scope instead of locally here. + But there is an exception for an allocator of unconstrained record + type with default discriminant because we allocate the actual size + in this case, unlike in the other cases, so we need a temporary to + fetch the discriminant and we create it here. + + 3. There is a target and it is a slice or an array with fixed size, + and the return type has variable size, because the gimplifier + doesn't handle these cases. + + 4. There is a target which is a bit-field and the function returns an + unconstrained record type with default discriminant, because the + return may copy more data than the bit-field can contain. + + 5. There is no target and we have misaligned In Out or Out parameters + passed by reference, because we need to preserve the return value + before copying back the parameters. However, in this case, we'll + defer creating the temporary, see below. + + This must be done before we push a binding level around the call, since + we will pop it before copying the return value. */ + if (function_call + && ((!gnu_target && TYPE_CI_CO_LIST (gnu_subprog_type)) + || (!gnu_target + && Nkind (Parent (gnat_node)) != N_Object_Declaration + && Nkind (Parent (gnat_node)) != N_Object_Renaming_Declaration + && Nkind (Parent (gnat_node)) != N_Simple_Return_Statement + && (!(Nkind (Parent (gnat_node)) == N_Qualified_Expression + && Nkind (Parent (Parent (gnat_node))) == N_Allocator) + || type_is_padding_self_referential (gnu_result_type)) + && Nkind (Parent (gnat_node)) != N_Aggregate + && AGGREGATE_TYPE_P (gnu_result_type) + && !TYPE_IS_FAT_POINTER_P (gnu_result_type)) + || (gnu_target + && (TREE_CODE (gnu_target) == ARRAY_RANGE_REF + || (TREE_CODE (TREE_TYPE (gnu_target)) == ARRAY_TYPE + && TREE_CODE (TYPE_SIZE (TREE_TYPE (gnu_target))) + == INTEGER_CST)) + && TREE_CODE (TYPE_SIZE (gnu_result_type)) != INTEGER_CST) + || (gnu_target + && TREE_CODE (gnu_target) == COMPONENT_REF + && DECL_BIT_FIELD (TREE_OPERAND (gnu_target, 1)) + && DECL_SIZE (TREE_OPERAND (gnu_target, 1)) + != TYPE_SIZE (TREE_TYPE (gnu_target)) + && type_is_padding_self_referential (gnu_result_type)))) + { + gnu_retval = create_temporary ("R", gnu_result_type); + DECL_RETURN_VALUE_P (gnu_retval) = 1; + } + + /* If we don't need a value or have already created it, push a binding level + around the call. This will narrow the lifetime of the temporaries we may + need to make when translating the parameters as much as possible. */ + if (!returning_value || gnu_retval) + { + start_stmt_group (); + gnat_pushlevel (); + pushed_binding_level = true; + } + else + pushed_binding_level = false; + + /* Create the list of the actual parameters as GCC expects it, namely a + chain of TREE_LIST nodes in which the TREE_VALUE field of each node + is an expression and the TREE_PURPOSE field is null. But skip Out + parameters not passed by reference and that need not be copied in. */ + for (gnat_actual = First_Actual (gnat_node); + Present (gnat_actual); + gnat_formal = Next_Formal_With_Extras (gnat_formal), + gnat_actual = Next_Actual (gnat_actual)) + { + Entity_Id gnat_formal_type = Etype (gnat_formal); + tree gnu_formal_type = gnat_to_gnu_type (gnat_formal_type); + tree gnu_formal = present_gnu_tree (gnat_formal) + ? get_gnu_tree (gnat_formal) : NULL_TREE; + const bool in_param = (Ekind (gnat_formal) == E_In_Parameter); + const bool is_true_formal_parm + = gnu_formal && TREE_CODE (gnu_formal) == PARM_DECL; + const bool is_by_ref_formal_parm + = is_true_formal_parm + && (DECL_BY_REF_P (gnu_formal) + || DECL_BY_COMPONENT_PTR_P (gnu_formal)); + /* In the In Out or Out case, we must suppress conversions that yield + an lvalue but can nevertheless cause the creation of a temporary, + because we need the real object in this case, either to pass its + address if it's passed by reference or as target of the back copy + done after the call if it uses the copy-in/copy-out mechanism. + We do it in the In case too, except for an unchecked conversion + to an elementary type or a constrained composite type because it + alone can cause the actual to be misaligned and the addressability + test is applied to the real object. */ + const bool suppress_type_conversion + = ((Nkind (gnat_actual) == N_Unchecked_Type_Conversion + && (!in_param + || !is_by_ref_formal_parm + || (Is_Composite_Type (Underlying_Type (gnat_formal_type)) + && !Is_Constrained (Underlying_Type (gnat_formal_type))))) + || (Nkind (gnat_actual) == N_Type_Conversion + && Is_Composite_Type (Underlying_Type (gnat_formal_type)))); + Node_Id gnat_name = suppress_type_conversion + ? Expression (gnat_actual) : gnat_actual; + tree gnu_name = gnat_to_gnu (gnat_name), gnu_name_type; + + /* If it's possible we may need to use this expression twice, make sure + that any side-effects are handled via SAVE_EXPRs; likewise if we need + to force side-effects before the call. */ + if (!in_param && !is_by_ref_formal_parm) + { + tree init = NULL_TREE; + gnu_name = gnat_stabilize_reference (gnu_name, true, &init); + if (init) + gnu_name + = build_compound_expr (TREE_TYPE (gnu_name), init, gnu_name); + } + + /* If we are passing a non-addressable parameter by reference, pass the + address of a copy. In the In Out or Out case, set up to copy back + out after the call. */ + if (is_by_ref_formal_parm + && (gnu_name_type = gnat_to_gnu_type (Etype (gnat_name))) + && !addressable_p (gnu_name, gnu_name_type)) + { + tree gnu_orig = gnu_name, gnu_temp, gnu_stmt; + + /* Do not issue warnings for CONSTRUCTORs since this is not a copy + but sort of an instantiation for them. */ + if (TREE_CODE (remove_conversions (gnu_name, true)) == CONSTRUCTOR) + ; + + /* If the formal is passed by reference, a copy is not allowed. */ + else if (TYPE_IS_BY_REFERENCE_P (gnu_formal_type) + || Is_Aliased (gnat_formal)) + post_error ("misaligned actual cannot be passed by reference", + gnat_actual); + + /* If the mechanism was forced to by-ref, a copy is not allowed but + we issue only a warning because this case is not strict Ada. */ + else if (DECL_FORCED_BY_REF_P (gnu_formal)) + post_error ("misaligned actual cannot be passed by reference??", + gnat_actual); + + /* If the actual type of the object is already the nominal type, + we have nothing to do, except if the size is self-referential + in which case we'll remove the unpadding below. */ + if (TREE_TYPE (gnu_name) == gnu_name_type + && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_name_type))) + ; + + /* Otherwise remove the unpadding from all the objects. */ + else if (TREE_CODE (gnu_name) == COMPONENT_REF + && TYPE_IS_PADDING_P + (TREE_TYPE (TREE_OPERAND (gnu_name, 0)))) + gnu_orig = gnu_name = TREE_OPERAND (gnu_name, 0); + + /* Otherwise convert to the nominal type of the object if needed. + There are several cases in which we need to make the temporary + using this type instead of the actual type of the object when + they are distinct, because the expectations of the callee would + otherwise not be met: + - if it's a justified modular type, + - if the actual type is a smaller form of it, + - if it's a smaller form of the actual type. */ + else if ((TREE_CODE (gnu_name_type) == RECORD_TYPE + && (TYPE_JUSTIFIED_MODULAR_P (gnu_name_type) + || smaller_form_type_p (TREE_TYPE (gnu_name), + gnu_name_type))) + || (INTEGRAL_TYPE_P (gnu_name_type) + && smaller_form_type_p (gnu_name_type, + TREE_TYPE (gnu_name)))) + gnu_name = convert (gnu_name_type, gnu_name); + + /* If this is an In Out or Out parameter and we're returning a value, + we need to create a temporary for the return value because we must + preserve it before copying back at the very end. */ + if (!in_param && returning_value && !gnu_retval) + { + gnu_retval = create_temporary ("R", gnu_result_type); + DECL_RETURN_VALUE_P (gnu_retval) = 1; + } + + /* If we haven't pushed a binding level, push it now. This will + narrow the lifetime of the temporary we are about to make as + much as possible. */ + if (!pushed_binding_level && (!returning_value || gnu_retval)) + { + start_stmt_group (); + gnat_pushlevel (); + pushed_binding_level = true; + } + + /* Create an explicit temporary holding the copy. */ + /* Do not initialize it for the _Init parameter of an initialization + procedure since no data is meant to be passed in. */ + if (Ekind (gnat_formal) == E_Out_Parameter + && Is_Entity_Name (gnat_subprog) + && Is_Init_Proc (Entity (gnat_subprog))) + gnu_name = gnu_temp = create_temporary ("A", TREE_TYPE (gnu_name)); + + /* Initialize it on the fly like for an implicit temporary in the + other cases, as we don't necessarily have a statement list. */ + else + { + gnu_temp = create_init_temporary ("A", gnu_name, &gnu_stmt, + gnat_actual); + gnu_name = build_compound_expr (TREE_TYPE (gnu_name), gnu_stmt, + gnu_temp); + } + + /* Set up to move the copy back to the original if needed. */ + if (!in_param) + { + /* If the original is a COND_EXPR whose first arm isn't meant to + be further used, just deal with the second arm. This is very + likely the conditional expression built for a check. */ + if (TREE_CODE (gnu_orig) == COND_EXPR + && TREE_CODE (TREE_OPERAND (gnu_orig, 1)) == COMPOUND_EXPR + && integer_zerop + (TREE_OPERAND (TREE_OPERAND (gnu_orig, 1), 1))) + gnu_orig = TREE_OPERAND (gnu_orig, 2); + + gnu_stmt + = build_binary_op (MODIFY_EXPR, NULL_TREE, gnu_orig, gnu_temp); + set_expr_location_from_node (gnu_stmt, gnat_node); + + append_to_statement_list (gnu_stmt, &gnu_after_list); + } + } + + /* Start from the real object and build the actual. */ + tree gnu_actual = gnu_name; + + /* If atomic access is required for an In or In Out actual parameter, + build the atomic load. */ + if (is_true_formal_parm + && !is_by_ref_formal_parm + && Ekind (gnat_formal) != E_Out_Parameter + && simple_atomic_access_required_p (gnat_actual, &aa_sync)) + gnu_actual = build_atomic_load (gnu_actual, aa_sync); + + /* If this was a procedure call, we may not have removed any padding. + So do it here for the part we will use as an input, if any. */ + if (Ekind (gnat_formal) != E_Out_Parameter + && TYPE_IS_PADDING_P (TREE_TYPE (gnu_actual))) + gnu_actual + = convert (get_unpadded_type (Etype (gnat_actual)), gnu_actual); + + /* Put back the conversion we suppressed above in the computation of the + real object. And even if we didn't suppress any conversion there, we + may have suppressed a conversion to the Etype of the actual earlier, + since the parent is a procedure call, so put it back here. Note that + we might have a dummy type here if the actual is the dereference of a + pointer to it, but that's OK when the formal is passed by reference. + We also do not put back a conversion between an actual and a formal + that are unconstrained array types to avoid creating local bounds. */ + tree gnu_actual_type = get_unpadded_type (Etype (gnat_actual)); + if (TYPE_IS_DUMMY_P (gnu_actual_type)) + gcc_assert (is_true_formal_parm && DECL_BY_REF_P (gnu_formal)); + else if (suppress_type_conversion + && Nkind (gnat_actual) == N_Unchecked_Type_Conversion) + gnu_actual = unchecked_convert (gnu_actual_type, gnu_actual, + No_Truncation (gnat_actual)); + else if ((TREE_CODE (TREE_TYPE (gnu_actual)) == UNCONSTRAINED_ARRAY_TYPE + || (TREE_CODE (TREE_TYPE (gnu_actual)) == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (gnu_actual)))) + && TREE_CODE (gnu_formal_type) == UNCONSTRAINED_ARRAY_TYPE) + ; + else + gnu_actual = convert (gnu_actual_type, gnu_actual); + + gigi_checking_assert (!Do_Range_Check (gnat_actual)); + + /* First see if the parameter is passed by reference. */ + if (is_true_formal_parm && DECL_BY_REF_P (gnu_formal)) + { + if (!in_param) + { + /* In Out or Out parameters passed by reference don't use the + copy-in/copy-out mechanism so the address of the real object + must be passed to the function. */ + gnu_actual = gnu_name; + + /* If we have a padded type, be sure we've removed padding. */ + if (TYPE_IS_PADDING_P (TREE_TYPE (gnu_actual))) + gnu_actual = convert (get_unpadded_type (Etype (gnat_actual)), + gnu_actual); + + /* If we have the constructed subtype of an aliased object + with an unconstrained nominal subtype, the type of the + actual includes the template, although it is formally + constrained. So we need to convert it back to the real + constructed subtype to retrieve the constrained part + and takes its address. */ + if (TREE_CODE (TREE_TYPE (gnu_actual)) == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (gnu_actual)) + && Is_Constr_Subt_For_UN_Aliased (Etype (gnat_actual)) + && Is_Array_Type (Underlying_Type (Etype (gnat_actual)))) + gnu_actual = convert (gnu_actual_type, gnu_actual); + } + + /* There is no need to convert the actual to the formal's type before + taking its address. The only exception is for unconstrained array + types because of the way we build fat pointers. */ + if (TREE_CODE (gnu_formal_type) == UNCONSTRAINED_ARRAY_TYPE) + { + /* Put back the conversion we suppressed above for In Out or Out + parameters, since it may set the bounds of the actual. */ + if (!in_param && suppress_type_conversion) + gnu_actual = convert (gnu_actual_type, gnu_actual); + gnu_actual = convert (gnu_formal_type, gnu_actual); + } + + /* Take the address of the object and convert to the proper pointer + type. */ + gnu_formal_type = TREE_TYPE (gnu_formal); + gnu_actual = build_unary_op (ADDR_EXPR, gnu_formal_type, gnu_actual); + } + + /* Then see if the parameter is an array passed to a foreign convention + subprogram. */ + else if (is_true_formal_parm && DECL_BY_COMPONENT_PTR_P (gnu_formal)) + { + gnu_actual = maybe_padded_object (gnu_actual); + gnu_actual = maybe_unconstrained_array (gnu_actual); + + /* Take the address of the object and convert to the proper pointer + type. We'd like to actually compute the address of the beginning + of the array using an ADDR_EXPR of an ARRAY_REF, but there's a + possibility that the ARRAY_REF might return a constant and we'd be + getting the wrong address. Neither approach is exactly correct, + but this is the most likely to work in all cases. */ + gnu_formal_type = TREE_TYPE (gnu_formal); + gnu_actual = build_unary_op (ADDR_EXPR, gnu_formal_type, gnu_actual); + } + + /* Then see if the parameter is passed by copy. */ + else if (is_true_formal_parm) + { + if (!in_param) + gnu_name_list = tree_cons (NULL_TREE, gnu_name, gnu_name_list); + + gnu_actual = convert (gnu_formal_type, gnu_actual); + + /* If this is a front-end built-in function, there is no need to + convert to the type used to pass the argument. */ + if (!frontend_builtin) + gnu_actual = convert (DECL_ARG_TYPE (gnu_formal), gnu_actual); + } + + /* Then see if this is an unnamed parameter in a variadic C function. */ + else if (variadic) + { + /* This is based on the processing done in gnat_to_gnu_param, but + we expect the mechanism to be set in (almost) all cases. */ + const Mechanism_Type mech = Mechanism (gnat_formal); + + /* Strip off possible padding type. */ + if (TYPE_IS_PADDING_P (gnu_formal_type)) + gnu_formal_type = TREE_TYPE (TYPE_FIELDS (gnu_formal_type)); + + /* Arrays are passed as pointers to element type. First check for + unconstrained array and get the underlying array. */ + if (TREE_CODE (gnu_formal_type) == UNCONSTRAINED_ARRAY_TYPE) + gnu_formal_type + = TREE_TYPE + (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_formal_type)))); + + /* Arrays are passed as pointers to element type. */ + if (mech != By_Copy && TREE_CODE (gnu_formal_type) == ARRAY_TYPE) + { + gnu_actual = maybe_padded_object (gnu_actual); + gnu_actual = maybe_unconstrained_array (gnu_actual); + + /* Strip off any multi-dimensional entries, then strip + off the last array to get the component type. */ + while (TREE_CODE (TREE_TYPE (gnu_formal_type)) == ARRAY_TYPE + && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_formal_type))) + gnu_formal_type = TREE_TYPE (gnu_formal_type); + + gnu_formal_type = TREE_TYPE (gnu_formal_type); + gnu_formal_type = build_pointer_type (gnu_formal_type); + gnu_actual + = build_unary_op (ADDR_EXPR, gnu_formal_type, gnu_actual); + } + + /* Fat pointers are passed as thin pointers. */ + else if (TYPE_IS_FAT_POINTER_P (gnu_formal_type)) + gnu_formal_type + = make_type_from_size (gnu_formal_type, + size_int (POINTER_SIZE), 0); + + /* If we were requested or muss pass by reference, do so. + If we were requested to pass by copy, do so. + Otherwise, pass In Out or Out parameters or aggregates by + reference. */ + else if (mech == By_Reference + || must_pass_by_ref (gnu_formal_type) + || (mech != By_Copy + && (!in_param || AGGREGATE_TYPE_P (gnu_formal_type)))) + { + gnu_formal_type = build_reference_type (gnu_formal_type); + gnu_actual + = build_unary_op (ADDR_EXPR, gnu_formal_type, gnu_actual); + } + + /* Otherwise pass by copy after applying default C promotions. */ + else + { + if (INTEGRAL_TYPE_P (gnu_formal_type) + && TYPE_PRECISION (gnu_formal_type) + < TYPE_PRECISION (integer_type_node)) + gnu_formal_type = integer_type_node; + + else if (SCALAR_FLOAT_TYPE_P (gnu_formal_type) + && TYPE_PRECISION (gnu_formal_type) + < TYPE_PRECISION (double_type_node)) + gnu_formal_type = double_type_node; + } + + gnu_actual = convert (gnu_formal_type, gnu_actual); + } + + /* If we didn't create a PARM_DECL for the formal, this means that + it is an Out parameter not passed by reference and that need not + be copied in. In this case, the value of the actual need not be + read. However, we still need to make sure that its side-effects + are evaluated before the call, so we evaluate its address. */ + else + { + if (!in_param) + gnu_name_list = tree_cons (NULL_TREE, gnu_name, gnu_name_list); + + if (TREE_SIDE_EFFECTS (gnu_name)) + { + tree addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_name); + append_to_statement_list (addr, &gnu_stmt_list); + } + + continue; + } + + gnu_actual_vec.safe_push (gnu_actual); + } + + if (frontend_builtin) + { + tree pred_cst = build_int_cst (integer_type_node, PRED_BUILTIN_EXPECT); + enum internal_fn icode = IFN_BUILTIN_EXPECT; + + switch (DECL_FE_FUNCTION_CODE (gnu_subprog)) + { + case BUILT_IN_EXPECT: + break; + case BUILT_IN_LIKELY: + gnu_actual_vec.safe_push (boolean_true_node); + break; + case BUILT_IN_UNLIKELY: + gnu_actual_vec.safe_push (boolean_false_node); + break; + default: + gcc_unreachable (); + } + + gnu_actual_vec.safe_push (pred_cst); + + gnu_call + = build_call_expr_internal_loc_array (UNKNOWN_LOCATION, + icode, + gnu_result_type, + gnu_actual_vec.length (), + gnu_actual_vec.begin ()); + } + else + { + gnu_call + = build_call_array_loc (UNKNOWN_LOCATION, + gnu_result_type, + build_unary_op (ADDR_EXPR, NULL_TREE, + gnu_subprog), + gnu_actual_vec.length (), + gnu_actual_vec.begin ()); + CALL_EXPR_BY_DESCRIPTOR (gnu_call) = by_descriptor; + } + + set_expr_location_from_node (gnu_call, gnat_node); + + /* If we have created a temporary for the return value, initialize it. */ + if (gnu_retval) + { + tree gnu_stmt + = build_binary_op (INIT_EXPR, NULL_TREE, gnu_retval, gnu_call); + set_expr_location_from_node (gnu_stmt, gnat_node); + append_to_statement_list (gnu_stmt, &gnu_stmt_list); + gnu_call = gnu_retval; + } + + /* If this is a subprogram with copy-in/copy-out parameters, we need to + unpack the valued returned from the function into the In Out or Out + parameters. We deal with the function return (if this is an Ada + function) below. */ + if (TYPE_CI_CO_LIST (gnu_subprog_type)) + { + /* List of FIELD_DECLs associated with the PARM_DECLs of the copy-in/ + copy-out parameters. */ + tree gnu_cico_list = TYPE_CI_CO_LIST (gnu_subprog_type); + const int length = list_length (gnu_cico_list); + + /* The call sequence must contain one and only one call, even though the + function is pure. Save the result into a temporary if needed. */ + if (length > 1) + { + if (!gnu_retval) + { + tree gnu_stmt; + gnu_call + = create_init_temporary ("P", gnu_call, &gnu_stmt, gnat_node); + append_to_statement_list (gnu_stmt, &gnu_stmt_list); + } + + gnu_name_list = nreverse (gnu_name_list); + } + + /* The first entry is for the actual return value if this is a + function, so skip it. */ + if (function_call) + gnu_cico_list = TREE_CHAIN (gnu_cico_list); + + if (Nkind (gnat_subprog) == N_Explicit_Dereference) + gnat_formal = First_Formal_With_Extras (Etype (gnat_subprog)); + else + gnat_formal = First_Formal_With_Extras (Entity (gnat_subprog)); + + for (gnat_actual = First_Actual (gnat_node); + Present (gnat_actual); + gnat_formal = Next_Formal_With_Extras (gnat_formal), + gnat_actual = Next_Actual (gnat_actual)) + /* If we are dealing with a copy-in/copy-out parameter, we must + retrieve its value from the record returned in the call. */ + if (!(present_gnu_tree (gnat_formal) + && TREE_CODE (get_gnu_tree (gnat_formal)) == PARM_DECL + && (DECL_BY_REF_P (get_gnu_tree (gnat_formal)) + || DECL_BY_COMPONENT_PTR_P (get_gnu_tree (gnat_formal)))) + && Ekind (gnat_formal) != E_In_Parameter) + { + /* Get the value to assign to this In Out or Out parameter. It is + either the result of the function if there is only a single such + parameter or the appropriate field from the record returned. */ + tree gnu_result + = length == 1 + ? gnu_call + : build_component_ref (gnu_call, TREE_PURPOSE (gnu_cico_list), + false); + + /* If the actual is a conversion, get the inner expression, which + will be the real destination, and convert the result to the + type of the actual parameter. */ + tree gnu_actual + = maybe_unconstrained_array (TREE_VALUE (gnu_name_list)); + + /* If the result is padded, remove the padding. */ + gnu_result = maybe_padded_object (gnu_result); + + /* If the actual is a type conversion, the real target object is + denoted by the inner Expression and we need to convert the + result to the associated type. + We also need to convert our gnu assignment target to this type + if the corresponding GNU_NAME was constructed from the GNAT + conversion node and not from the inner Expression. */ + if (Nkind (gnat_actual) == N_Type_Conversion) + { + const Node_Id gnat_expr = Expression (gnat_actual); + + gigi_checking_assert (!Do_Range_Check (gnat_expr)); + + gnu_result + = convert_with_check (Etype (gnat_expr), gnu_result, + Do_Overflow_Check (gnat_actual), + Float_Truncate (gnat_actual), + gnat_actual); + + if (!Is_Composite_Type (Underlying_Type (Etype (gnat_formal)))) + gnu_actual = convert (TREE_TYPE (gnu_result), gnu_actual); + } + + /* Unchecked conversions as actuals for Out parameters are not + allowed in user code because they are not variables, but do + occur in front-end expansions. The associated GNU_NAME is + always obtained from the inner expression in such cases. */ + else if (Nkind (gnat_actual) == N_Unchecked_Type_Conversion) + gnu_result = unchecked_convert (TREE_TYPE (gnu_actual), + gnu_result, + No_Truncation (gnat_actual)); + else + { + gigi_checking_assert (!Do_Range_Check (gnat_actual)); + + if (!(!TREE_CONSTANT (TYPE_SIZE (TREE_TYPE (gnu_actual))) + && TREE_CONSTANT (TYPE_SIZE (TREE_TYPE (gnu_result))))) + gnu_result = convert (TREE_TYPE (gnu_actual), gnu_result); + } + + get_atomic_access (gnat_actual, &aa_type, &aa_sync); + + /* If an outer atomic access is required for an actual parameter, + build the load-modify-store sequence. */ + if (aa_type == OUTER_ATOMIC) + gnu_result + = build_load_modify_store (gnu_actual, gnu_result, gnat_node); + + /* Or else, if a simple atomic access is required, build the atomic + store. */ + else if (aa_type == SIMPLE_ATOMIC) + gnu_result + = build_atomic_store (gnu_actual, gnu_result, aa_sync); + + /* Otherwise build a regular assignment. */ + else + gnu_result = build_binary_op (MODIFY_EXPR, NULL_TREE, + gnu_actual, gnu_result); + + if (EXPR_P (gnu_result)) + set_expr_location_from_node (gnu_result, gnat_node); + append_to_statement_list (gnu_result, &gnu_stmt_list); + gnu_cico_list = TREE_CHAIN (gnu_cico_list); + gnu_name_list = TREE_CHAIN (gnu_name_list); + } + } + + /* If this is a function call, the result is the call expression unless a + target is specified, in which case we copy the result into the target + and return the assignment statement. */ + if (function_call) + { + /* If this is a function with copy-in/copy-out parameters, extract the + return value from it and update the return type. */ + if (TYPE_CI_CO_LIST (gnu_subprog_type)) + { + tree gnu_elmt = TYPE_CI_CO_LIST (gnu_subprog_type); + gnu_call + = build_component_ref (gnu_call, TREE_PURPOSE (gnu_elmt), false); + gnu_result_type = TREE_TYPE (gnu_call); + } + + /* If the function returns an unconstrained array or by direct reference, + we have to dereference the pointer. */ + if (TYPE_RETURN_UNCONSTRAINED_P (gnu_subprog_type) + || TYPE_RETURN_BY_DIRECT_REF_P (gnu_subprog_type)) + gnu_call = build_unary_op (INDIRECT_REF, NULL_TREE, gnu_call); + + if (gnu_target) + { + Node_Id gnat_parent = Parent (gnat_node); + enum tree_code op_code; + + gigi_checking_assert (!Do_Range_Check (gnat_node)); + + /* ??? If the return type has variable size, then force the return + slot optimization as we would not be able to create a temporary. + That's what has been done historically. */ + if (return_type_with_variable_size_p (gnu_result_type)) + op_code = INIT_EXPR; + + /* If this is a call to a pure function returning an array of scalar + type, try to apply the return slot optimization. */ + else if ((TYPE_READONLY (gnu_subprog_type) + || TYPE_RESTRICT (gnu_subprog_type)) + && is_array_of_scalar_type (gnu_result_type) + && TYPE_MODE (gnu_result_type) == BLKmode + && aggregate_value_p (gnu_result_type, gnu_subprog_type) + && return_slot_opt_for_pure_call_p (gnu_target, gnu_call)) + op_code = INIT_EXPR; + + else + op_code = MODIFY_EXPR; + + /* Use the required method to move the result to the target. */ + if (atomic_access == OUTER_ATOMIC) + gnu_call + = build_load_modify_store (gnu_target, gnu_call, gnat_node); + else if (atomic_access == SIMPLE_ATOMIC) + gnu_call = build_atomic_store (gnu_target, gnu_call, atomic_sync); + else + gnu_call + = build_binary_op (op_code, NULL_TREE, gnu_target, gnu_call); + + if (EXPR_P (gnu_call)) + set_expr_location_from_node (gnu_call, gnat_parent); + append_to_statement_list (gnu_call, &gnu_stmt_list); + } + else + *gnu_result_type_p = get_unpadded_type (Etype (gnat_node)); + } + + /* Otherwise, if this is a procedure call statement without copy-in/copy-out + parameters, the result is just the call statement. */ + else if (!TYPE_CI_CO_LIST (gnu_subprog_type)) + append_to_statement_list (gnu_call, &gnu_stmt_list); + + /* Finally, add the copy back statements, if any. */ + append_to_statement_list (gnu_after_list, &gnu_stmt_list); + + if (went_into_elab_proc) + current_function_decl = NULL_TREE; + + /* If we have pushed a binding level, pop it and finish up the enclosing + statement group. */ + if (pushed_binding_level) + { + add_stmt (gnu_stmt_list); + gnat_poplevel (); + gnu_result = end_stmt_group (); + } + + /* Otherwise, retrieve the statement list, if any. */ + else if (gnu_stmt_list) + gnu_result = gnu_stmt_list; + + /* Otherwise, just return the call expression. */ + else + return gnu_call; + + /* If we nevertheless need a value, make a COMPOUND_EXPR to return it. + But first simplify if we have only one statement in the list. */ + if (returning_value) + { + tree first = expr_first (gnu_result), last = expr_last (gnu_result); + if (first == last) + gnu_result = first; + gnu_result + = build_compound_expr (TREE_TYPE (gnu_call), gnu_result, gnu_call); + } + + return gnu_result; +} + +/* Subroutine of gnat_to_gnu to translate gnat_node, an + N_Handled_Sequence_Of_Statements, to a GCC tree, which is returned. */ + +static tree +Handled_Sequence_Of_Statements_to_gnu (Node_Id gnat_node) +{ + /* If just annotating, ignore all EH and cleanups. */ + const bool gcc_eh + = (!type_annotate_only + && Present (Exception_Handlers (gnat_node)) + && Back_End_Exceptions ()); + const bool fe_sjlj_eh + = (!type_annotate_only + && Present (Exception_Handlers (gnat_node)) + && Exception_Mechanism == Front_End_SJLJ); + const bool at_end = !type_annotate_only && Present (At_End_Proc (gnat_node)); + const bool binding_for_block = (at_end || gcc_eh || fe_sjlj_eh); + tree gnu_jmpsave_decl = NULL_TREE; + tree gnu_jmpbuf_decl = NULL_TREE; + tree gnu_inner_block; /* The statement(s) for the block itself. */ + tree gnu_result; + tree gnu_expr; + Node_Id gnat_temp; + + /* The GCC exception handling mechanism can handle both ZCX and SJLJ schemes + and the front-end has its own SJLJ mechanism. To call the GCC mechanism, + we call add_cleanup, and when we leave the binding, end_stmt_group will + create the TRY_FINALLY_EXPR construct. + + ??? The region level calls down there have been specifically put in place + for a ZCX context and currently the order in which things are emitted + (region/handlers) is different from the SJLJ case. Instead of putting + other calls with different conditions at other places for the SJLJ case, + it seems cleaner to reorder things for the SJLJ case and generalize the + condition to make it not ZCX specific. + + If there are any exceptions or cleanup processing involved, we need an + outer statement group (for front-end SJLJ) and binding level. */ + if (binding_for_block) + { + start_stmt_group (); + gnat_pushlevel (); + } + + /* If using fe_sjlj_eh, make the variables for the setjmp buffer and save + area for address of previous buffer. Do this first since we need to have + the setjmp buf known for any decls in this block. */ + if (fe_sjlj_eh) + { + gnu_jmpsave_decl + = create_var_decl (get_identifier ("JMPBUF_SAVE"), NULL_TREE, + jmpbuf_ptr_type, + build_call_n_expr (get_jmpbuf_decl, 0), + false, false, false, false, false, true, false, + NULL, gnat_node); + + /* The __builtin_setjmp receivers will immediately reinstall it. Now + because of the unstructured form of EH used by fe_sjlj_eh, there + might be forward edges going to __builtin_setjmp receivers on which + it is uninitialized, although they will never be actually taken. */ + suppress_warning (gnu_jmpsave_decl, OPT_Wuninitialized); + gnu_jmpbuf_decl + = create_var_decl (get_identifier ("JMP_BUF"), NULL_TREE, + jmpbuf_type, + NULL_TREE, + false, false, false, false, false, true, false, + NULL, gnat_node); + + set_block_jmpbuf_decl (gnu_jmpbuf_decl); + + /* When we exit this block, restore the saved value. */ + add_cleanup (build_call_n_expr (set_jmpbuf_decl, 1, gnu_jmpsave_decl), + Present (End_Label (gnat_node)) + ? End_Label (gnat_node) : gnat_node); + } + + /* If we are to call a function when exiting this block, add a cleanup + to the binding level we made above. Note that add_cleanup is FIFO + so we must register this cleanup after the EH cleanup just above. */ + if (at_end) + { + tree proc_decl = gnat_to_gnu (At_End_Proc (gnat_node)); + + /* When not optimizing, disable inlining of finalizers as this can + create a more complex CFG in the parent function. */ + if (!optimize || optimize_debug) + DECL_DECLARED_INLINE_P (proc_decl) = 0; + + /* If there is no end label attached, we use the location of the At_End + procedure because Expand_Cleanup_Actions might reset the location of + the enclosing construct to that of an inner statement. */ + add_cleanup (build_call_n_expr (proc_decl, 0), + Present (End_Label (gnat_node)) + ? End_Label (gnat_node) : At_End_Proc (gnat_node)); + } + + /* Now build the tree for the declarations and statements inside this block. + If this is SJLJ, set our jmp_buf as the current buffer. */ + start_stmt_group (); + + if (fe_sjlj_eh) + { + gnu_expr = build_call_n_expr (set_jmpbuf_decl, 1, + build_unary_op (ADDR_EXPR, NULL_TREE, + gnu_jmpbuf_decl)); + set_expr_location_from_node (gnu_expr, gnat_node); + add_stmt (gnu_expr); + } + + if (Present (First_Real_Statement (gnat_node))) + process_decls (Statements (gnat_node), Empty, + First_Real_Statement (gnat_node), true, true); + + /* Generate code for each statement in the block. */ + for (gnat_temp = (Present (First_Real_Statement (gnat_node)) + ? First_Real_Statement (gnat_node) + : First (Statements (gnat_node))); + Present (gnat_temp); gnat_temp = Next (gnat_temp)) + add_stmt (gnat_to_gnu (gnat_temp)); + + gnu_inner_block = end_stmt_group (); + + /* Now generate code for the two exception models, if either is relevant for + this block. */ + if (fe_sjlj_eh) + { + tree *gnu_else_ptr = 0; + tree gnu_handler; + + /* Make a binding level for the exception handling declarations and code + and set up gnu_except_ptr_stack for the handlers to use. */ + start_stmt_group (); + gnat_pushlevel (); + + vec_safe_push (gnu_except_ptr_stack, + create_var_decl (get_identifier ("EXCEPT_PTR"), NULL_TREE, + build_pointer_type (except_type_node), + build_call_n_expr (get_excptr_decl, 0), + false, false, false, false, false, + true, false, NULL, gnat_node)); + + /* Generate code for each handler. The N_Exception_Handler case does the + real work and returns a COND_EXPR for each handler, which we chain + together here. */ + for (gnat_temp = First_Non_Pragma (Exception_Handlers (gnat_node)); + Present (gnat_temp); gnat_temp = Next_Non_Pragma (gnat_temp)) + { + gnu_expr = gnat_to_gnu (gnat_temp); + + /* If this is the first one, set it as the outer one. Otherwise, + point the "else" part of the previous handler to us. Then point + to our "else" part. */ + if (!gnu_else_ptr) + add_stmt (gnu_expr); + else + *gnu_else_ptr = gnu_expr; + + gnu_else_ptr = &COND_EXPR_ELSE (gnu_expr); + } + + /* If none of the exception handlers did anything, re-raise but do not + defer abortion. */ + gnu_expr = build_call_n_expr (raise_nodefer_decl, 1, + gnu_except_ptr_stack->last ()); + set_expr_location_from_node + (gnu_expr, + Present (End_Label (gnat_node)) ? End_Label (gnat_node) : gnat_node); + + if (gnu_else_ptr) + *gnu_else_ptr = gnu_expr; + else + add_stmt (gnu_expr); + + /* End the binding level dedicated to the exception handlers and get the + whole statement group. */ + gnu_except_ptr_stack->pop (); + gnat_poplevel (); + gnu_handler = end_stmt_group (); + + /* If the setjmp returns 1, we restore our incoming longjmp value and + then check the handlers. */ + start_stmt_group (); + add_stmt_with_node (build_call_n_expr (set_jmpbuf_decl, 1, + gnu_jmpsave_decl), + gnat_node); + add_stmt (gnu_handler); + gnu_handler = end_stmt_group (); + + /* This block is now "if (setjmp) ... <handlers> else <block>". */ + gnu_result = build3 (COND_EXPR, void_type_node, + (build_call_n_expr + (setjmp_decl, 1, + build_unary_op (ADDR_EXPR, NULL_TREE, + gnu_jmpbuf_decl))), + gnu_handler, gnu_inner_block); + } + else if (gcc_eh) + { + tree gnu_handlers; + location_t locus; + + /* First make a block containing the handlers. */ + start_stmt_group (); + for (gnat_temp = First_Non_Pragma (Exception_Handlers (gnat_node)); + Present (gnat_temp); + gnat_temp = Next_Non_Pragma (gnat_temp)) + add_stmt (gnat_to_gnu (gnat_temp)); + gnu_handlers = end_stmt_group (); + + /* Now make the TRY_CATCH_EXPR for the block. */ + gnu_result = build2 (TRY_CATCH_EXPR, void_type_node, + gnu_inner_block, gnu_handlers); + /* Set a location. We need to find a unique location for the dispatching + code, otherwise we can get coverage or debugging issues. Try with + the location of the end label. */ + if (Present (End_Label (gnat_node)) + && Sloc_to_locus (Sloc (End_Label (gnat_node)), &locus)) + SET_EXPR_LOCATION (gnu_result, locus); + else + /* Clear column information so that the exception handler of an + implicit transient block does not incorrectly inherit the slocs + of a decision, which would otherwise confuse control flow based + coverage analysis tools. */ + set_expr_location_from_node (gnu_result, gnat_node, true); + } + else + gnu_result = gnu_inner_block; + + /* Now close our outer block, if we had to make one. */ + if (binding_for_block) + { + add_stmt (gnu_result); + gnat_poplevel (); + gnu_result = end_stmt_group (); + } + + return gnu_result; +} + +/* Subroutine of gnat_to_gnu to translate gnat_node, an N_Exception_Handler, + to a GCC tree, which is returned. This is the variant for front-end sjlj + exception handling. */ + +static tree +Exception_Handler_to_gnu_fe_sjlj (Node_Id gnat_node) +{ + /* Unless this is "Others" or the special "Non-Ada" exception for Ada, make + an "if" statement to select the proper exceptions. For "Others", exclude + exceptions where Handled_By_Others is nonzero unless the All_Others flag + is set. For "Non-ada", accept an exception if "Lang" is 'V'. */ + tree gnu_choice = boolean_false_node; + tree gnu_body = build_stmt_group (Statements (gnat_node), false); + Node_Id gnat_temp; + + for (gnat_temp = First (Exception_Choices (gnat_node)); + gnat_temp; gnat_temp = Next (gnat_temp)) + { + tree this_choice; + + if (Nkind (gnat_temp) == N_Others_Choice) + { + if (All_Others (gnat_temp)) + this_choice = boolean_true_node; + else + this_choice + = build_binary_op + (EQ_EXPR, boolean_type_node, + convert + (integer_type_node, + build_component_ref + (build_unary_op + (INDIRECT_REF, NULL_TREE, + gnu_except_ptr_stack->last ()), + not_handled_by_others_decl, + false)), + integer_zero_node); + } + + else if (Nkind (gnat_temp) == N_Identifier + || Nkind (gnat_temp) == N_Expanded_Name) + { + Entity_Id gnat_ex_id = Entity (gnat_temp); + tree gnu_expr; + + /* Exception may be a renaming. Recover original exception which is + the one elaborated and registered. */ + if (Present (Renamed_Object (gnat_ex_id))) + gnat_ex_id = Renamed_Object (gnat_ex_id); + + gnu_expr = gnat_to_gnu_entity (gnat_ex_id, NULL_TREE, false); + + this_choice + = build_binary_op + (EQ_EXPR, boolean_type_node, + gnu_except_ptr_stack->last (), + convert (TREE_TYPE (gnu_except_ptr_stack->last ()), + build_unary_op (ADDR_EXPR, NULL_TREE, gnu_expr))); + } + else + gcc_unreachable (); + + gnu_choice = build_binary_op (TRUTH_ORIF_EXPR, boolean_type_node, + gnu_choice, this_choice); + } + + return build3 (COND_EXPR, void_type_node, gnu_choice, gnu_body, NULL_TREE); +} + +/* Return true if no statement in GNAT_LIST can alter the control flow. */ + +static bool +stmt_list_cannot_alter_control_flow_p (List_Id gnat_list) +{ + if (No (gnat_list)) + return true; + + /* This is very conservative, we reject everything except for simple + assignments between identifiers or literals. */ + for (Node_Id gnat_node = First (gnat_list); + Present (gnat_node); + gnat_node = Next (gnat_node)) + { + if (Nkind (gnat_node) != N_Assignment_Statement) + return false; + + if (Nkind (Name (gnat_node)) != N_Identifier) + return false; + + Node_Kind nkind = Nkind (Expression (gnat_node)); + if (nkind != N_Identifier + && nkind != N_Integer_Literal + && nkind != N_Real_Literal) + return false; + } + + return true; +} + +/* Subroutine of gnat_to_gnu to translate gnat_node, an N_Exception_Handler, + to a GCC tree, which is returned. This is the variant for GCC exception + schemes. */ + +static tree +Exception_Handler_to_gnu_gcc (Node_Id gnat_node) +{ + tree gnu_etypes_list = NULL_TREE; + + /* We build a TREE_LIST of nodes representing what exception types this + handler can catch, with special cases for others and all others cases. + + Each exception type is actually identified by a pointer to the exception + id, or to a dummy object for "others" and "all others". */ + for (Node_Id gnat_temp = First (Exception_Choices (gnat_node)); + gnat_temp; + gnat_temp = Next (gnat_temp)) + { + tree gnu_expr, gnu_etype; + + if (Nkind (gnat_temp) == N_Others_Choice) + { + gnu_expr = All_Others (gnat_temp) ? all_others_decl : others_decl; + gnu_etype = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_expr); + } + else if (Nkind (gnat_temp) == N_Identifier + || Nkind (gnat_temp) == N_Expanded_Name) + { + Entity_Id gnat_ex_id = Entity (gnat_temp); + + /* Exception may be a renaming. Recover original exception which is + the one elaborated and registered. */ + if (Present (Renamed_Object (gnat_ex_id))) + gnat_ex_id = Renamed_Object (gnat_ex_id); + + gnu_expr = gnat_to_gnu_entity (gnat_ex_id, NULL_TREE, false); + gnu_etype = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_expr); + } + else + gcc_unreachable (); + + /* The GCC interface expects NULL to be passed for catch all handlers, so + it would be quite tempting to set gnu_etypes_list to NULL if gnu_etype + is integer_zero_node. It would not work, however, because GCC's + notion of "catch all" is stronger than our notion of "others". Until + we correctly use the cleanup interface as well, doing that would + prevent the "all others" handlers from being seen, because nothing + can be caught beyond a catch all from GCC's point of view. */ + gnu_etypes_list = tree_cons (NULL_TREE, gnu_etype, gnu_etypes_list); + } + + start_stmt_group (); + gnat_pushlevel (); + + /* Expand a call to the begin_handler hook at the beginning of the + handler, and arrange for a call to the end_handler hook to occur + on every possible exit path. GDB sets a breakpoint in the + begin_handler for catchpoints. + + A v1 begin handler saves the cleanup from the exception object, + and marks the exception as in use, so that it will not be + released by other handlers. A v1 end handler restores the + cleanup and releases the exception object, unless it is still + claimed, or the exception is being propagated (reraised). + + __builtin_eh_pointer references the exception occurrence being + handled or propagated. Within the handler region, it is the + former, but within the else branch of the EH_ELSE_EXPR, i.e. the + exceptional cleanup path, it is the latter, so we must save the + occurrence being handled early on, so that, should an exception + be (re)raised, we can release the current exception, or figure + out we're not to release it because we're propagating a reraise + thereof. + + We use local variables to retrieve the incoming value at handler + entry time (EXPTR), the saved cleanup (EXCLN) and the token + (EXVTK), and reuse them to feed the end_handler hook's argument + at exit. */ + + /* CODE: void *EXPTR = __builtin_eh_pointer (0); */ + tree gnu_current_exc_ptr + = build_call_expr (builtin_decl_explicit (BUILT_IN_EH_POINTER), + 1, integer_zero_node); + tree exc_ptr + = create_var_decl (get_identifier ("EXPTR"), NULL_TREE, + ptr_type_node, gnu_current_exc_ptr, + true, false, false, false, false, true, true, + NULL, gnat_node); + + tree prev_gnu_incoming_exc_ptr = gnu_incoming_exc_ptr; + gnu_incoming_exc_ptr = exc_ptr; + + /* begin_handler_decl must not throw, so we can use it as an + initializer for a variable used in cleanups. + + CODE: void *EXCLN = __gnat_begin_handler_v1 (EXPTR); */ + tree exc_cleanup + = create_var_decl (get_identifier ("EXCLN"), NULL_TREE, + ptr_type_node, + build_call_n_expr (begin_handler_decl, 1, + exc_ptr), + true, false, false, false, false, + true, true, NULL, gnat_node); + + /* Declare and initialize the choice parameter, if present. */ + if (Present (Choice_Parameter (gnat_node))) + { + tree gnu_param + = gnat_to_gnu_entity (Choice_Parameter (gnat_node), NULL_TREE, true); + + /* CODE: __gnat_set_exception_parameter (&choice_param, EXPTR); */ + add_stmt (build_call_n_expr + (set_exception_parameter_decl, 2, + build_unary_op (ADDR_EXPR, NULL_TREE, gnu_param), + gnu_incoming_exc_ptr)); + } + + /* CODE: <handler proper> */ + add_stmt_list (Statements (gnat_node)); + + tree call = build_call_n_expr (end_handler_decl, 3, + exc_ptr, + exc_cleanup, + null_pointer_node); + /* If the handler can only end by falling off the end, don't bother + with cleanups. */ + if (stmt_list_cannot_alter_control_flow_p (Statements (gnat_node))) + /* CODE: __gnat_end_handler_v1 (EXPTR, EXCLN, NULL); */ + add_stmt_with_node (call, gnat_node); + /* Otherwise, all of the above is after + CODE: try { + + The call above will appear after + CODE: } finally { + + And the code below will appear after + CODE: } else { + + The else block to a finally block is taken instead of the finally + block when an exception propagates out of the try block. */ + else + { + start_stmt_group (); + gnat_pushlevel (); + /* CODE: void *EXPRP = __builtin_eh_handler (0); */ + tree prop_ptr + = create_var_decl (get_identifier ("EXPRP"), NULL_TREE, + ptr_type_node, + build_call_expr (builtin_decl_explicit + (BUILT_IN_EH_POINTER), + 1, integer_zero_node), + true, false, false, false, false, + true, true, NULL, gnat_node); + + /* CODE: __gnat_end_handler_v1 (EXPTR, EXCLN, EXPRP); */ + tree ecall = build_call_n_expr (end_handler_decl, 3, + exc_ptr, + exc_cleanup, + prop_ptr); + + add_stmt_with_node (ecall, gnat_node); + + /* CODE: } */ + gnat_poplevel (); + tree eblk = end_stmt_group (); + tree ehls = build2 (EH_ELSE_EXPR, void_type_node, call, eblk); + add_cleanup (ehls, gnat_node); + } + + gnat_poplevel (); + + gnu_incoming_exc_ptr = prev_gnu_incoming_exc_ptr; + + return + build2 (CATCH_EXPR, void_type_node, gnu_etypes_list, end_stmt_group ()); +} + +/* Subroutine of gnat_to_gnu to generate code for an N_Compilation unit. */ + +static void +Compilation_Unit_to_gnu (Node_Id gnat_node) +{ + const Node_Id gnat_unit = Unit (gnat_node); + const bool body_p = (Nkind (gnat_unit) == N_Package_Body + || Nkind (gnat_unit) == N_Subprogram_Body); + const Entity_Id gnat_unit_entity = Defining_Entity (gnat_unit); + Entity_Id gnat_entity; + Node_Id gnat_pragma, gnat_iter; + /* Make the decl for the elaboration procedure. Emit debug info for it, so + that users can break into their elaboration code in debuggers. Kludge: + don't consider it as a definition so that we have a line map for its + body, but no subprogram description in debug info. In addition, don't + qualify it as artificial, even though it is not a user subprogram per se, + in particular for specs. Unlike, say, clones created internally by the + compiler, this subprogram materializes specific user code and flagging it + artificial would take elab code away from gcov's analysis. */ + tree gnu_elab_proc_decl + = create_subprog_decl + (create_concat_name (gnat_unit_entity, body_p ? "elabb" : "elabs"), + NULL_TREE, void_ftype, NULL_TREE, + is_default, true, false, false, true, false, NULL, gnat_unit); + struct elab_info *info; + + vec_safe_push (gnu_elab_proc_stack, gnu_elab_proc_decl); + DECL_ELABORATION_PROC_P (gnu_elab_proc_decl) = 1; + + /* Initialize the information structure for the function. */ + allocate_struct_function (gnu_elab_proc_decl, false); + set_cfun (NULL); + + current_function_decl = NULL_TREE; + + start_stmt_group (); + gnat_pushlevel (); + + /* For a body, first process the spec if there is one. */ + if (Nkind (gnat_unit) == N_Package_Body + || (Nkind (gnat_unit) == N_Subprogram_Body && !Acts_As_Spec (gnat_node))) + add_stmt (gnat_to_gnu (Library_Unit (gnat_node))); + + if (type_annotate_only && gnat_node == Cunit (Main_Unit)) + { + elaborate_all_entities (gnat_node); + + if (Nkind (gnat_unit) == N_Subprogram_Declaration + || Nkind (gnat_unit) == N_Generic_Package_Declaration + || Nkind (gnat_unit) == N_Generic_Subprogram_Declaration) + return; + } + + /* Then process any pragmas and declarations preceding the unit. */ + for (gnat_pragma = First (Context_Items (gnat_node)); + Present (gnat_pragma); + gnat_pragma = Next (gnat_pragma)) + if (Nkind (gnat_pragma) == N_Pragma) + add_stmt (gnat_to_gnu (gnat_pragma)); + process_decls (Declarations (Aux_Decls_Node (gnat_node)), Empty, Empty, + true, true); + + /* Process the unit itself. */ + add_stmt (gnat_to_gnu (gnat_unit)); + + /* Generate code for all the inlined subprograms. */ + for (gnat_entity = First_Inlined_Subprogram (gnat_node); + Present (gnat_entity); + gnat_entity = Next_Inlined_Subprogram (gnat_entity)) + { + Node_Id gnat_body; + + /* Without optimization, process only the required subprograms. */ + if (!optimize && !Has_Pragma_Inline_Always (gnat_entity)) + continue; + + /* The set of inlined subprograms is computed from data recorded early + during expansion and it can be a strict superset of the final set + computed after semantic analysis, for example if a call to such a + subprogram occurs in a pragma Assert and assertions are disabled. + In that case, semantic analysis resets Is_Public to false but the + entry for the subprogram in the inlining tables is stalled. */ + if (!Is_Public (gnat_entity)) + continue; + + gnat_body = Parent (Declaration_Node (gnat_entity)); + if (Nkind (gnat_body) != N_Subprogram_Body) + { + /* ??? This happens when only the spec of a package is provided. */ + if (No (Corresponding_Body (gnat_body))) + continue; + + gnat_body + = Parent (Declaration_Node (Corresponding_Body (gnat_body))); + } + + /* Define the entity first so we set DECL_EXTERNAL. */ + gnat_to_gnu_entity (gnat_entity, NULL_TREE, false); + add_stmt (gnat_to_gnu (gnat_body)); + } + + /* Process any pragmas and actions following the unit. */ + add_stmt_list (Pragmas_After (Aux_Decls_Node (gnat_node))); + add_stmt_list (Actions (Aux_Decls_Node (gnat_node))); + finalize_from_limited_with (); + + /* Then process the expressions of pragma Compile_Time_{Error|Warning} to + annotate types referenced therein if they have not been annotated. */ + for (int i = 0; gnat_compile_time_expr_list.iterate (i, &gnat_iter); i++) + (void) gnat_to_gnu_external (gnat_iter); + gnat_compile_time_expr_list.release (); + + /* Save away what we've made so far and finish it up. */ + set_current_block_context (gnu_elab_proc_decl); + gnat_poplevel (); + DECL_SAVED_TREE (gnu_elab_proc_decl) = end_stmt_group (); + set_end_locus_from_node (gnu_elab_proc_decl, gnat_unit); + gnu_elab_proc_stack->pop (); + + /* Record this potential elaboration procedure for later processing. */ + info = ggc_alloc<elab_info> (); + info->next = elab_info_list; + info->elab_proc = gnu_elab_proc_decl; + info->gnat_node = gnat_node; + elab_info_list = info; + + /* Force the processing for all nodes that remain in the queue. */ + process_deferred_decl_context (true); +} + +/* Mark COND, a boolean expression, as predicating a call to a noreturn + function, i.e. predict that it is very likely false, and return it. + + The compiler will automatically predict the last edge leading to a call + to a noreturn function as very unlikely taken. This function makes it + possible to extend the prediction to predecessors in case the condition + is made up of several short-circuit operators. */ + +static tree +build_noreturn_cond (tree cond) +{ + tree pred_cst = build_int_cst (integer_type_node, PRED_NORETURN); + return + build_call_expr_internal_loc (UNKNOWN_LOCATION, IFN_BUILTIN_EXPECT, + boolean_type_node, 3, cond, + boolean_false_node, pred_cst); +} + +/* Subroutine of gnat_to_gnu to translate GNAT_RANGE, a node representing a + range of values, into GNU_LOW and GNU_HIGH bounds. */ + +static void +Range_to_gnu (Node_Id gnat_range, tree *gnu_low, tree *gnu_high) +{ + /* GNAT_RANGE is either an N_Range or an identifier denoting a subtype. */ + switch (Nkind (gnat_range)) + { + case N_Range: + *gnu_low = gnat_to_gnu (Low_Bound (gnat_range)); + *gnu_high = gnat_to_gnu (High_Bound (gnat_range)); + break; + + case N_Expanded_Name: + case N_Identifier: + { + tree gnu_range_type = get_unpadded_type (Entity (gnat_range)); + tree gnu_range_base_type = get_base_type (gnu_range_type); + + *gnu_low + = convert (gnu_range_base_type, TYPE_MIN_VALUE (gnu_range_type)); + *gnu_high + = convert (gnu_range_base_type, TYPE_MAX_VALUE (gnu_range_type)); + } + break; + + default: + gcc_unreachable (); + } +} + +/* Subroutine of gnat_to_gnu to translate GNAT_NODE, an N_Raise_xxx_Error, + to a GCC tree and return it. GNU_RESULT_TYPE_P is a pointer to where + we should place the result type. */ + +static tree +Raise_Error_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p) +{ + const Node_Kind kind = Nkind (gnat_node); + const Node_Id gnat_cond = Condition (gnat_node); + const int reason = UI_To_Int (Reason (gnat_node)); + const bool with_extra_info + = Exception_Extra_Info + && !No_Exception_Handlers_Set () + && No (get_exception_label (kind)); + tree gnu_result = NULL_TREE, gnu_cond = NULL_TREE; + Node_Id gnat_rcond; + + /* The following processing is not required for correctness. Its purpose is + to give more precise error messages and to record some information. */ + switch (reason) + { + case CE_Access_Check_Failed: + if (with_extra_info) + gnu_result = build_call_raise_column (reason, gnat_node, kind); + break; + + case CE_Index_Check_Failed: + case CE_Range_Check_Failed: + case CE_Invalid_Data: + if (No (gnat_cond) || Nkind (gnat_cond) != N_Op_Not) + break; + gnat_rcond = Right_Opnd (gnat_cond); + if (Nkind (gnat_rcond) == N_In + || Nkind (gnat_rcond) == N_Op_Ge + || Nkind (gnat_rcond) == N_Op_Le) + { + const Node_Id gnat_index = Left_Opnd (gnat_rcond); + const Node_Id gnat_type = Etype (gnat_index); + tree gnu_index = gnat_to_gnu (gnat_index); + tree gnu_type = get_unpadded_type (gnat_type); + tree gnu_low_bound, gnu_high_bound, disp; + struct loop_info_d *loop; + bool neg_p; + + switch (Nkind (gnat_rcond)) + { + case N_In: + Range_to_gnu (Right_Opnd (gnat_rcond), + &gnu_low_bound, &gnu_high_bound); + break; + + case N_Op_Ge: + gnu_low_bound = gnat_to_gnu (Right_Opnd (gnat_rcond)); + gnu_high_bound = TYPE_MAX_VALUE (gnu_type); + break; + + case N_Op_Le: + gnu_low_bound = TYPE_MIN_VALUE (gnu_type); + gnu_high_bound = gnat_to_gnu (Right_Opnd (gnat_rcond)); + break; + + default: + gcc_unreachable (); + } + + gnu_type = maybe_character_type (gnu_type); + if (TREE_TYPE (gnu_index) != gnu_type) + { + gnu_low_bound = convert (gnu_type, gnu_low_bound); + gnu_high_bound = convert (gnu_type, gnu_high_bound); + gnu_index = convert (gnu_type, gnu_index); + } + + if (with_extra_info + && Known_Esize (gnat_type) + && UI_To_Int (Esize (gnat_type)) <= 32) + gnu_result + = build_call_raise_range (reason, gnat_node, kind, gnu_index, + gnu_low_bound, gnu_high_bound); + + /* If optimization is enabled and we are inside a loop, we try to + compute invariant conditions for checks applied to the iteration + variable, i.e. conditions that are independent of the variable + and necessary in order for the checks to fail in the course of + some iteration. If we succeed, we consider an alternative: + + 1. If loop unswitching is enabled, we prepend these conditions + to the original conditions of the checks. This will make it + possible for the loop unswitching pass to replace the loop + with two loops, one of which has the checks eliminated and + the other has the original checks reinstated, and a prologue + implementing a run-time selection. The former loop will be + for example suitable for vectorization. + + 2. Otherwise, we instead append the conditions to the original + conditions of the checks. At worse, if the conditions cannot + be evaluated at compile time, they will be evaluated as true + at run time only when the checks have already failed, thus + contributing negatively only to the size of the executable. + But the hope is that these invariant conditions be evaluated + at compile time to false, thus taking away the entire checks + with them. */ + if (optimize + && inside_loop_p () + && (!gnu_low_bound + || (gnu_low_bound = gnat_invariant_expr (gnu_low_bound))) + && (!gnu_high_bound + || (gnu_high_bound = gnat_invariant_expr (gnu_high_bound))) + && (loop = find_loop_for (gnu_index, &disp, &neg_p))) + { + struct range_check_info_d *rci = ggc_alloc<range_check_info_d> (); + rci->low_bound = gnu_low_bound; + rci->high_bound = gnu_high_bound; + rci->disp = disp; + rci->neg_p = neg_p; + rci->type = gnu_type; + rci->inserted_cond + = build1 (SAVE_EXPR, boolean_type_node, boolean_true_node); + vec_safe_push (loop->checks, rci); + gnu_cond = build_noreturn_cond (gnat_to_gnu (gnat_cond)); + if (optimize >= 3) + gnu_cond = build_binary_op (TRUTH_ANDIF_EXPR, + boolean_type_node, + rci->inserted_cond, + gnu_cond); + else + gnu_cond = build_binary_op (TRUTH_ANDIF_EXPR, + boolean_type_node, + gnu_cond, + rci->inserted_cond); + } + } + break; + + default: + break; + } + + /* The following processing does the real work, but we must nevertheless make + sure not to override the result of the previous processing. */ + if (!gnu_result) + gnu_result = build_call_raise (reason, gnat_node, kind); + set_expr_location_from_node (gnu_result, gnat_node); + + *gnu_result_type_p = get_unpadded_type (Etype (gnat_node)); + + /* If the type is VOID, this is a statement, so we need to generate the code + for the call. Handle a condition, if there is one. */ + if (VOID_TYPE_P (*gnu_result_type_p)) + { + if (Present (gnat_cond)) + { + if (!gnu_cond) + gnu_cond = gnat_to_gnu (gnat_cond); + if (integer_zerop (gnu_cond)) + return alloc_stmt_list (); + gnu_result = build3 (COND_EXPR, void_type_node, gnu_cond, gnu_result, + alloc_stmt_list ()); + } + } + else + { + /* The condition field must not be present when the node is used as an + expression form. */ + gigi_checking_assert (No (gnat_cond)); + gnu_result = build1 (NULL_EXPR, *gnu_result_type_p, gnu_result); + } + + return gnu_result; +} + +/* Return true if GNAT_NODE is on the LHS of an assignment or an actual + parameter of a call. */ + +static bool +lhs_or_actual_p (Node_Id gnat_node) +{ + const Node_Id gnat_parent = Parent (gnat_node); + const Node_Kind kind = Nkind (gnat_parent); + + if (kind == N_Assignment_Statement && Name (gnat_parent) == gnat_node) + return true; + + if ((kind == N_Procedure_Call_Statement || kind == N_Function_Call) + && Name (gnat_parent) != gnat_node) + return true; + + if (kind == N_Parameter_Association) + return true; + + return false; +} + +/* Return true if either GNAT_NODE or a view of GNAT_NODE is on the LHS + of an assignment or an actual parameter of a call. */ + +static bool +present_in_lhs_or_actual_p (Node_Id gnat_node) +{ + if (lhs_or_actual_p (gnat_node)) + return true; + + const Node_Kind kind = Nkind (Parent (gnat_node)); + + if ((kind == N_Type_Conversion || kind == N_Unchecked_Type_Conversion) + && lhs_or_actual_p (Parent (gnat_node))) + return true; + + return false; +} + +/* Return true if GNAT_NODE, an unchecked type conversion, is a no-op as far + as gigi is concerned. This is used to avoid conversions on the LHS. */ + +static bool +unchecked_conversion_nop (Node_Id gnat_node) +{ + Entity_Id from_type, to_type; + + /* The conversion must be on the LHS of an assignment or an actual parameter + of a call. Otherwise, even if the conversion was essentially a no-op, it + could de facto ensure type consistency and this should be preserved. */ + if (!lhs_or_actual_p (gnat_node)) + return false; + + from_type = Etype (Expression (gnat_node)); + + /* We're interested in artificial conversions generated by the front-end + to make private types explicit, e.g. in Expand_Assign_Array. */ + if (!Is_Private_Type (from_type)) + return false; + + from_type = Underlying_Type (from_type); + to_type = Etype (gnat_node); + + /* The direct conversion to the underlying type is a no-op. */ + if (to_type == from_type) + return true; + + /* For an array subtype, the conversion to the PAIT is a no-op. */ + if (Ekind (from_type) == E_Array_Subtype + && to_type == Packed_Array_Impl_Type (from_type)) + return true; + + /* For a record subtype, the conversion to the type is a no-op. */ + if (Ekind (from_type) == E_Record_Subtype + && to_type == Etype (from_type)) + return true; + + return false; +} + +/* Return true if GNAT_NODE represents a statement. */ + +static bool +statement_node_p (Node_Id gnat_node) +{ + const Node_Kind kind = Nkind (gnat_node); + + if (kind == N_Label) + return true; + + if (IN (kind, N_Statement_Other_Than_Procedure_Call)) + return true; + + if (kind == N_Procedure_Call_Statement) + return true; + + if (IN (kind, N_Raise_xxx_Error) && Ekind (Etype (gnat_node)) == E_Void) + return true; + + return false; +} + +/* This function is the driver of the GNAT to GCC tree transformation process. + It is the entry point of the tree transformer. GNAT_NODE is the root of + some GNAT tree. Return the root of the corresponding GCC tree. If this + is an expression, return the GCC equivalent of the expression. If this + is a statement, return the statement or add it to the current statement + group, in which case anything returned is to be interpreted as occurring + after anything added. */ + +tree +gnat_to_gnu (Node_Id gnat_node) +{ + const Node_Kind kind = Nkind (gnat_node); + tree gnu_result = error_mark_node; /* Default to no value. */ + tree gnu_result_type = void_type_node; + tree gnu_expr, gnu_lhs, gnu_rhs; + Node_Id gnat_temp; + atomic_acces_t aa_type; + bool went_into_elab_proc; + bool aa_sync; + + /* Save node number for error message and set location information. */ + Current_Error_Node = gnat_node; + Sloc_to_locus (Sloc (gnat_node), &input_location); + + /* If we are only annotating types and this node is a statement, return + an empty statement list. */ + if (type_annotate_only && statement_node_p (gnat_node)) + return alloc_stmt_list (); + + /* If we are only annotating types and this node is a subexpression, return + a NULL_EXPR, but filter out nodes appearing in the expressions attached + to packed array implementation types. */ + if (type_annotate_only + && IN (kind, N_Subexpr) + && !(((IN (kind, N_Op) && kind != N_Op_Expon) + || kind == N_Type_Conversion) + && Is_Integer_Type (Etype (gnat_node))) + && !(kind == N_Attribute_Reference + && (Get_Attribute_Id (Attribute_Name (gnat_node)) == Attr_Length + || Get_Attribute_Id (Attribute_Name (gnat_node)) == Attr_Size) + && Is_Constrained (Etype (Prefix (gnat_node))) + && !Is_Constr_Subt_For_U_Nominal (Etype (Prefix (gnat_node)))) + && kind != N_Expanded_Name + && kind != N_Identifier + && !Compile_Time_Known_Value (gnat_node)) + return build1 (NULL_EXPR, get_unpadded_type (Etype (gnat_node)), + build_call_raise (CE_Range_Check_Failed, gnat_node, + N_Raise_Constraint_Error)); + + /* If this is a statement and we are at top level, it must be part of the + elaboration procedure, so mark us as being in that procedure. */ + if ((statement_node_p (gnat_node) + || kind == N_Handled_Sequence_Of_Statements + || kind == N_Implicit_Label_Declaration) + && !current_function_decl) + { + current_function_decl = get_elaboration_procedure (); + went_into_elab_proc = true; + } + else + went_into_elab_proc = false; + + switch (kind) + { + /********************************/ + /* Chapter 2: Lexical Elements */ + /********************************/ + + case N_Identifier: + case N_Expanded_Name: + case N_Operator_Symbol: + case N_Defining_Identifier: + case N_Defining_Operator_Symbol: + gnu_result = Identifier_to_gnu (gnat_node, &gnu_result_type); + + /* If atomic access is required on the RHS, build the atomic load. */ + if (simple_atomic_access_required_p (gnat_node, &aa_sync) + && !present_in_lhs_or_actual_p (gnat_node)) + gnu_result = build_atomic_load (gnu_result, aa_sync); + break; + + case N_Integer_Literal: + { + tree gnu_type; + + /* Get the type of the result, looking inside any padding and + justified modular types. Then get the value in that type. */ + gnu_type = gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + if (TREE_CODE (gnu_type) == RECORD_TYPE + && TYPE_JUSTIFIED_MODULAR_P (gnu_type)) + gnu_type = TREE_TYPE (TYPE_FIELDS (gnu_type)); + + gnu_result = UI_To_gnu (Intval (gnat_node), gnu_type); + + /* If the result overflows (meaning it doesn't fit in its base type), + abort, unless this is for a named number because that's not fatal. + We would like to check that the value is within the range of the + subtype, but that causes problems with subtypes whose usage will + raise Constraint_Error and also with biased representation. */ + if (TREE_OVERFLOW (gnu_result)) + { + if (Nkind (Parent (gnat_node)) == N_Number_Declaration) + gnu_result = error_mark_node; + else + gcc_unreachable (); + } + } + break; + + case N_Character_Literal: + /* If a Entity is present, it means that this was one of the + literals in a user-defined character type. In that case, + just return the value in the CONST_DECL. Otherwise, use the + character code. In that case, the base type should be an + INTEGER_TYPE, but we won't bother checking for that. */ + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + if (Present (Entity (gnat_node))) + gnu_result = DECL_INITIAL (get_gnu_tree (Entity (gnat_node))); + else + gnu_result + = build_int_cst (gnu_result_type, + UI_To_CC (Char_Literal_Value (gnat_node))); + break; + + case N_Real_Literal: + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + /* If this is of a fixed-point type, the value we want is the value of + the corresponding integer. */ + if (Is_Fixed_Point_Type (Underlying_Type (Etype (gnat_node)))) + { + gnu_result = UI_To_gnu (Corresponding_Integer_Value (gnat_node), + gnu_result_type); + gcc_assert (!TREE_OVERFLOW (gnu_result)); + } + + else + { + Ureal ur_realval = Realval (gnat_node); + + /* First convert the value to a machine number if it isn't already. + That will force the base to 2 for non-zero values and simplify + the rest of the logic. */ + if (!Is_Machine_Number (gnat_node)) + ur_realval + = Machine (Base_Type (Underlying_Type (Etype (gnat_node))), + ur_realval, Round_Even, gnat_node); + + if (UR_Is_Zero (ur_realval)) + gnu_result = build_real (gnu_result_type, dconst0); + else + { + REAL_VALUE_TYPE tmp; + + gnu_result = UI_To_gnu (Numerator (ur_realval), gnu_result_type); + + /* The base must be 2 as Machine guarantees this, so we scale + the value, which we know can fit in the mantissa of the type + (hence the use of that type above). */ + gcc_assert (Rbase (ur_realval) == 2); + real_ldexp (&tmp, &TREE_REAL_CST (gnu_result), + - UI_To_Int (Denominator (ur_realval))); + gnu_result = build_real (gnu_result_type, tmp); + } + + /* Now see if we need to negate the result. Do it this way to + properly handle -0. */ + if (UR_Is_Negative (Realval (gnat_node))) + gnu_result + = build_unary_op (NEGATE_EXPR, get_base_type (gnu_result_type), + gnu_result); + } + + break; + + case N_String_Literal: + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + if (TYPE_PRECISION (TREE_TYPE (gnu_result_type)) == HOST_BITS_PER_CHAR) + { + String_Id gnat_string = Strval (gnat_node); + int length = String_Length (gnat_string); + int i; + char *string; + if (length >= ALLOCA_THRESHOLD) + string = XNEWVEC (char, length); + else + string = (char *) alloca (length); + + /* Build the string with the characters in the literal. Note + that Ada strings are 1-origin. */ + for (i = 0; i < length; i++) + string[i] = Get_String_Char (gnat_string, i + 1); + + gnu_result = build_string (length, string); + + /* Strings in GCC don't normally have types, but we want + this to not be converted to the array type. */ + TREE_TYPE (gnu_result) = gnu_result_type; + + if (length >= ALLOCA_THRESHOLD) + free (string); + } + else + { + /* Build a list consisting of each character, then make + the aggregate. */ + String_Id gnat_string = Strval (gnat_node); + int length = String_Length (gnat_string); + int i; + tree gnu_idx = TYPE_MIN_VALUE (TYPE_DOMAIN (gnu_result_type)); + tree gnu_one_node = convert (TREE_TYPE (gnu_idx), integer_one_node); + vec<constructor_elt, va_gc> *gnu_vec; + vec_alloc (gnu_vec, length); + + for (i = 0; i < length; i++) + { + tree t = build_int_cst (TREE_TYPE (gnu_result_type), + Get_String_Char (gnat_string, i + 1)); + + CONSTRUCTOR_APPEND_ELT (gnu_vec, gnu_idx, t); + gnu_idx = int_const_binop (PLUS_EXPR, gnu_idx, gnu_one_node); + } + + gnu_result = gnat_build_constructor (gnu_result_type, gnu_vec); + } + break; + + case N_Pragma: + gnu_result = Pragma_to_gnu (gnat_node); + break; + + /**************************************/ + /* Chapter 3: Declarations and Types */ + /**************************************/ + + case N_Subtype_Declaration: + case N_Full_Type_Declaration: + case N_Incomplete_Type_Declaration: + case N_Private_Type_Declaration: + case N_Private_Extension_Declaration: + case N_Task_Type_Declaration: + process_type (Defining_Entity (gnat_node)); + gnu_result = alloc_stmt_list (); + break; + + case N_Object_Declaration: + case N_Number_Declaration: + case N_Exception_Declaration: + gnat_temp = Defining_Entity (gnat_node); + gnu_result = alloc_stmt_list (); + + /* If we are just annotating types and this object has an unconstrained + or task type, don't elaborate it. */ + if (type_annotate_only + && (((Is_Array_Type (Etype (gnat_temp)) + || Is_Record_Type (Etype (gnat_temp))) + && !Is_Constrained (Etype (gnat_temp))) + || Is_Concurrent_Type (Etype (gnat_temp)))) + break; + + if (Present (Expression (gnat_node)) + && !(kind == N_Object_Declaration && No_Initialization (gnat_node)) + && (!type_annotate_only + || Compile_Time_Known_Value (Expression (gnat_node)))) + { + gigi_checking_assert (!Do_Range_Check (Expression (gnat_node))); + + gnu_expr = gnat_to_gnu (Expression (gnat_node)); + + /* First deal with erroneous expressions. */ + if (TREE_CODE (gnu_expr) == ERROR_MARK) + { + /* If this is a named number for which we cannot manipulate + the value, just skip the declaration altogether. */ + if (kind == N_Number_Declaration) + break; + else if (type_annotate_only) + gnu_expr = NULL_TREE; + } + + /* Then a special case: we do not want the SLOC of the expression + of the tag to pop up every time it is referenced somewhere. */ + else if (EXPR_P (gnu_expr) && Is_Tag (gnat_temp)) + SET_EXPR_LOCATION (gnu_expr, UNKNOWN_LOCATION); + } + else + gnu_expr = NULL_TREE; + + /* If this is a deferred constant with an address clause, we ignore the + full view since the clause is on the partial view and we cannot have + 2 different GCC trees for the object. The only bits of the full view + we will use is the initializer, but it will be directly fetched. */ + if (Ekind (gnat_temp) == E_Constant + && Present (Address_Clause (gnat_temp)) + && Present (Full_View (gnat_temp))) + save_gnu_tree (Full_View (gnat_temp), error_mark_node, true); + + /* If this object has its elaboration delayed, we must force evaluation + of GNU_EXPR now and save it for the freeze point. Note that we need + not do anything special at the global level since the lifetime of the + temporary is fully contained within the elaboration routine. */ + if (Present (Freeze_Node (gnat_temp))) + { + if (gnu_expr) + { + gnu_result = gnat_save_expr (gnu_expr); + save_gnu_tree (gnat_node, gnu_result, true); + } + } + else + gnat_to_gnu_entity (gnat_temp, gnu_expr, true); + break; + + case N_Object_Renaming_Declaration: + gnat_temp = Defining_Entity (gnat_node); + gnu_result = alloc_stmt_list (); + + /* Don't do anything if this renaming is handled by the front end and it + does not need debug info. Note that we consider renamings don't need + debug info when optimizing: our way to describe them has a + memory/elaboration footprint. + + Don't do anything neither if we are just annotating types and this + object has a composite or task type, don't elaborate it. */ + if ((!Is_Renaming_Of_Object (gnat_temp) + || (Needs_Debug_Info (gnat_temp) + && !optimize + && can_materialize_object_renaming_p + (Renamed_Object (gnat_temp)))) + && ! (type_annotate_only + && (Is_Array_Type (Etype (gnat_temp)) + || Is_Record_Type (Etype (gnat_temp)) + || Is_Concurrent_Type (Etype (gnat_temp))))) + gnat_to_gnu_entity (gnat_temp, + gnat_to_gnu (Renamed_Object (gnat_temp)), + true); + break; + + case N_Exception_Renaming_Declaration: + gnat_temp = Defining_Entity (gnat_node); + gnu_result = alloc_stmt_list (); + + if (Present (Renamed_Entity (gnat_temp))) + gnat_to_gnu_entity (gnat_temp, + gnat_to_gnu (Renamed_Entity (gnat_temp)), + true); + break; + + case N_Subprogram_Renaming_Declaration: + { + const Node_Id gnat_renaming = Defining_Entity (gnat_node); + const Node_Id gnat_renamed = Renamed_Entity (gnat_renaming); + + gnu_result = alloc_stmt_list (); + + /* Materializing renamed subprograms will only benefit the debugging + information as they aren't referenced in the generated code. So + skip them when they aren't needed. Avoid doing this if: + + - there is a freeze node: in this case the renamed entity is not + elaborated yet, + - the renamed subprogram is intrinsic: it will not be available in + the debugging information (note that both or only one of the + renaming and the renamed subprograms can be intrinsic). */ + if (!type_annotate_only + && Needs_Debug_Info (gnat_renaming) + && No (Freeze_Node (gnat_renaming)) + && Present (gnat_renamed) + && (Ekind (gnat_renamed) == E_Function + || Ekind (gnat_renamed) == E_Procedure) + && !Is_Intrinsic_Subprogram (gnat_renaming) + && !Is_Intrinsic_Subprogram (gnat_renamed)) + gnat_to_gnu_entity (gnat_renaming, gnat_to_gnu (gnat_renamed), true); + break; + } + + case N_Implicit_Label_Declaration: + gnat_to_gnu_entity (Defining_Entity (gnat_node), NULL_TREE, true); + gnu_result = alloc_stmt_list (); + break; + + case N_Package_Renaming_Declaration: + /* These are fully handled in the front end. */ + /* ??? For package renamings, find a way to use GENERIC namespaces so + that we get proper debug information for them. */ + gnu_result = alloc_stmt_list (); + break; + + /*************************************/ + /* Chapter 4: Names and Expressions */ + /*************************************/ + + case N_Explicit_Dereference: + /* Make sure the designated type is complete before dereferencing. */ + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + gnu_result = gnat_to_gnu (Prefix (gnat_node)); + gnu_result = build_unary_op (INDIRECT_REF, NULL_TREE, gnu_result); + + /* If atomic access is required on the RHS, build the atomic load. */ + if (simple_atomic_access_required_p (gnat_node, &aa_sync) + && !present_in_lhs_or_actual_p (gnat_node)) + gnu_result = build_atomic_load (gnu_result, aa_sync); + break; + + case N_Indexed_Component: + { + tree gnu_array_object = gnat_to_gnu ((Prefix (gnat_node))); + tree gnu_type; + int ndim, i; + Node_Id *gnat_expr_array; + + gnu_array_object = maybe_padded_object (gnu_array_object); + gnu_array_object = maybe_unconstrained_array (gnu_array_object); + + /* Convert vector inputs to their representative array type, to fit + what the code below expects. */ + if (VECTOR_TYPE_P (TREE_TYPE (gnu_array_object))) + { + if (present_in_lhs_or_actual_p (gnat_node)) + gnat_mark_addressable (gnu_array_object); + gnu_array_object = maybe_vector_array (gnu_array_object); + } + + /* The failure of this assertion will very likely come from a missing + expansion for a packed array access. */ + gcc_assert (TREE_CODE (TREE_TYPE (gnu_array_object)) == ARRAY_TYPE); + + /* First compute the number of dimensions of the array, then + fill the expression array, the order depending on whether + this is a Convention_Fortran array or not. */ + for (ndim = 1, gnu_type = TREE_TYPE (gnu_array_object); + TREE_CODE (TREE_TYPE (gnu_type)) == ARRAY_TYPE + && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_type)); + ndim++, gnu_type = TREE_TYPE (gnu_type)) + ; + + gnat_expr_array = XALLOCAVEC (Node_Id, ndim); + + if (TYPE_CONVENTION_FORTRAN_P (TREE_TYPE (gnu_array_object))) + for (i = ndim - 1, gnat_temp = First (Expressions (gnat_node)); + i >= 0; + i--, gnat_temp = Next (gnat_temp)) + gnat_expr_array[i] = gnat_temp; + else + for (i = 0, gnat_temp = First (Expressions (gnat_node)); + i < ndim; + i++, gnat_temp = Next (gnat_temp)) + gnat_expr_array[i] = gnat_temp; + + /* Start with the prefix and build the successive references. */ + gnu_result = gnu_array_object; + + for (i = 0, gnu_type = TREE_TYPE (gnu_array_object); + i < ndim; + i++, gnu_type = TREE_TYPE (gnu_type)) + { + gcc_assert (TREE_CODE (gnu_type) == ARRAY_TYPE); + gnat_temp = gnat_expr_array[i]; + gnu_expr = maybe_character_value (gnat_to_gnu (gnat_temp)); + + gnu_result + = build_binary_op (ARRAY_REF, NULL_TREE, gnu_result, gnu_expr); + } + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + /* If atomic access is required on the RHS, build the atomic load. */ + if (simple_atomic_access_required_p (gnat_node, &aa_sync) + && !present_in_lhs_or_actual_p (gnat_node)) + gnu_result = build_atomic_load (gnu_result, aa_sync); + } + break; + + case N_Slice: + { + tree gnu_array_object = gnat_to_gnu (Prefix (gnat_node)); + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + gnu_array_object = maybe_padded_object (gnu_array_object); + gnu_array_object = maybe_unconstrained_array (gnu_array_object); + + gnu_expr = TYPE_MIN_VALUE (TYPE_DOMAIN (gnu_result_type)); + gnu_expr = maybe_character_value (gnu_expr); + + /* If this is a slice with non-constant size of an array with constant + size, set the maximum size for the allocation of temporaries. */ + if (!TREE_CONSTANT (TYPE_SIZE_UNIT (gnu_result_type)) + && TREE_CONSTANT (TYPE_SIZE_UNIT (TREE_TYPE (gnu_array_object)))) + TYPE_ARRAY_MAX_SIZE (gnu_result_type) + = TYPE_SIZE_UNIT (TREE_TYPE (gnu_array_object)); + + gnu_result = build_binary_op (ARRAY_RANGE_REF, gnu_result_type, + gnu_array_object, gnu_expr); + } + break; + + case N_Selected_Component: + { + const Entity_Id gnat_prefix = Prefix (gnat_node); + Entity_Id gnat_field = Entity (Selector_Name (gnat_node)); + tree gnu_prefix = gnat_to_gnu (gnat_prefix); + + gnu_prefix = maybe_padded_object (gnu_prefix); + + /* gnat_to_gnu_entity does not save the GNU tree made for renamed + discriminants so avoid making recursive calls on each reference + to them by following the appropriate link directly here. */ + if (Ekind (gnat_field) == E_Discriminant) + { + /* For discriminant references in tagged types always substitute + the corresponding discriminant as the actual component. */ + if (Is_Tagged_Type (Underlying_Type (Etype (gnat_prefix)))) + while (Present (Corresponding_Discriminant (gnat_field))) + gnat_field = Corresponding_Discriminant (gnat_field); + + /* For discriminant references in untagged types always substitute + the corresponding stored discriminant. */ + else if (Present (Corresponding_Discriminant (gnat_field))) + gnat_field = Original_Record_Component (gnat_field); + } + + /* Handle extracting the real or imaginary part of a complex. + The real part is the first field and the imaginary the last. */ + if (TREE_CODE (TREE_TYPE (gnu_prefix)) == COMPLEX_TYPE) + gnu_result = build_unary_op (Present (Next_Entity (gnat_field)) + ? REALPART_EXPR : IMAGPART_EXPR, + NULL_TREE, gnu_prefix); + else + { + tree gnu_field = gnat_to_gnu_field_decl (gnat_field); + tree gnu_offset; + struct loop_info_d *loop; + + gnu_result + = build_component_ref (gnu_prefix, gnu_field, + (Nkind (Parent (gnat_node)) + == N_Attribute_Reference) + && lvalue_required_for_attribute_p + (Parent (gnat_node))); + + /* If optimization is enabled and we are inside a loop, we try to + hoist nonconstant but invariant offset computations outside of + the loop, since they very likely contain loads that could turn + out to be hard to move if they end up in active EH regions. */ + if (optimize + && inside_loop_p () + && TREE_CODE (gnu_result) == COMPONENT_REF + && (gnu_offset = component_ref_field_offset (gnu_result)) + && !TREE_CONSTANT (gnu_offset) + && (gnu_offset = gnat_invariant_expr (gnu_offset)) + && (loop = find_loop ())) + { + tree invariant + = build1 (SAVE_EXPR, TREE_TYPE (gnu_offset), gnu_offset); + vec_safe_push (loop->invariants, invariant); + tree field = TREE_OPERAND (gnu_result, 1); + tree factor + = size_int (DECL_OFFSET_ALIGN (field) / BITS_PER_UNIT); + /* Divide the offset by its alignment. */ + TREE_OPERAND (gnu_result, 2) + = size_binop (EXACT_DIV_EXPR, invariant, factor); + } + } + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + /* If atomic access is required on the RHS, build the atomic load. */ + if (simple_atomic_access_required_p (gnat_node, &aa_sync) + && !present_in_lhs_or_actual_p (gnat_node)) + gnu_result = build_atomic_load (gnu_result, aa_sync); + } + break; + + case N_Attribute_Reference: + { + /* The attribute designator. */ + const int attr = Get_Attribute_Id (Attribute_Name (gnat_node)); + + /* The Elab_Spec and Elab_Body attributes are special in that Prefix + is a unit, not an object with a GCC equivalent. */ + if (attr == Attr_Elab_Spec || attr == Attr_Elab_Body) + return + create_subprog_decl (create_concat_name + (Entity (Prefix (gnat_node)), + attr == Attr_Elab_Body ? "elabb" : "elabs"), + NULL_TREE, void_ftype, NULL_TREE, is_default, + true, true, true, true, false, NULL, + gnat_node); + + gnu_result = Attribute_to_gnu (gnat_node, &gnu_result_type, attr); + } + break; + + case N_Reference: + /* Like 'Access as far as we are concerned. */ + gnu_result = gnat_to_gnu (Prefix (gnat_node)); + gnu_result = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_result); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + break; + + case N_Aggregate: + case N_Extension_Aggregate: + { + tree gnu_aggr_type; + + /* Check that this aggregate has not slipped through the cracks. */ + gcc_assert (!Expansion_Delayed (gnat_node)); + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + if (TREE_CODE (gnu_result_type) == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P (gnu_result_type)) + gnu_aggr_type + = TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (gnu_result_type))); + else if (TREE_CODE (gnu_result_type) == VECTOR_TYPE) + gnu_aggr_type = TYPE_REPRESENTATIVE_ARRAY (gnu_result_type); + else + gnu_aggr_type = gnu_result_type; + + if (Null_Record_Present (gnat_node)) + gnu_result = gnat_build_constructor (gnu_aggr_type, NULL); + + else if (TREE_CODE (gnu_aggr_type) == RECORD_TYPE + || TREE_CODE (gnu_aggr_type) == UNION_TYPE) + gnu_result + = assoc_to_constructor (Etype (gnat_node), + First (Component_Associations (gnat_node)), + gnu_aggr_type); + else if (TREE_CODE (gnu_aggr_type) == ARRAY_TYPE) + gnu_result = pos_to_constructor (First (Expressions (gnat_node)), + gnu_aggr_type); + else if (TREE_CODE (gnu_aggr_type) == COMPLEX_TYPE) + gnu_result + = build_binary_op + (COMPLEX_EXPR, gnu_aggr_type, + gnat_to_gnu (Expression (First + (Component_Associations (gnat_node)))), + gnat_to_gnu (Expression + (Next + (First (Component_Associations (gnat_node)))))); + else + gcc_unreachable (); + + gnu_result = convert (gnu_result_type, gnu_result); + } + break; + + case N_Null: + if (TARGET_VTABLE_USES_DESCRIPTORS + && Ekind (Etype (gnat_node)) == E_Access_Subprogram_Type + && Is_Dispatch_Table_Entity (Etype (gnat_node))) + gnu_result = null_fdesc_node; + else + gnu_result = null_pointer_node; + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + break; + + case N_Type_Conversion: + case N_Qualified_Expression: + gnu_expr = maybe_character_value (gnat_to_gnu (Expression (gnat_node))); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + /* If this is a qualified expression for a tagged type, we mark the type + as used. Because of polymorphism, this might be the only reference to + the tagged type in the program while objects have it as dynamic type. + The debugger needs to see it to display these objects properly. */ + if (kind == N_Qualified_Expression && Is_Tagged_Type (Etype (gnat_node))) + used_types_insert (gnu_result_type); + + gigi_checking_assert (!Do_Range_Check (Expression (gnat_node))); + + gnu_result + = convert_with_check (Etype (gnat_node), gnu_expr, + Do_Overflow_Check (gnat_node), + kind == N_Type_Conversion + && Float_Truncate (gnat_node), gnat_node); + break; + + case N_Unchecked_Type_Conversion: + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + gnu_expr = maybe_character_value (gnat_to_gnu (Expression (gnat_node))); + + /* Skip further processing if the conversion is deemed a no-op. */ + if (unchecked_conversion_nop (gnat_node)) + { + gnu_result = gnu_expr; + gnu_result_type = TREE_TYPE (gnu_result); + break; + } + + /* If the result is a pointer type, see if we are improperly + converting to a stricter alignment. */ + if (STRICT_ALIGNMENT && POINTER_TYPE_P (gnu_result_type) + && Is_Access_Type (Etype (gnat_node))) + { + unsigned int align = known_alignment (gnu_expr); + tree gnu_obj_type = TREE_TYPE (gnu_result_type); + unsigned int oalign = TYPE_ALIGN (gnu_obj_type); + + if (align != 0 && align < oalign && !TYPE_ALIGN_OK (gnu_obj_type)) + post_error_ne_tree_2 + ("??source alignment (^) '< alignment of & (^)", + gnat_node, Designated_Type (Etype (gnat_node)), + size_int (align / BITS_PER_UNIT), oalign / BITS_PER_UNIT); + } + + /* If we are converting a descriptor to a function pointer, first + build the pointer. */ + if (TARGET_VTABLE_USES_DESCRIPTORS + && TREE_TYPE (gnu_expr) == fdesc_type_node + && POINTER_TYPE_P (gnu_result_type)) + gnu_expr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_expr); + + gnu_result = unchecked_convert (gnu_result_type, gnu_expr, + No_Truncation (gnat_node)); + break; + + case N_In: + case N_Not_In: + { + tree gnu_obj = gnat_to_gnu (Left_Opnd (gnat_node)); + tree gnu_low, gnu_high; + + Range_to_gnu (Right_Opnd (gnat_node), &gnu_low, &gnu_high); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + tree gnu_op_type = maybe_character_type (TREE_TYPE (gnu_obj)); + if (TREE_TYPE (gnu_obj) != gnu_op_type) + { + gnu_obj = convert (gnu_op_type, gnu_obj); + gnu_low = convert (gnu_op_type, gnu_low); + gnu_high = convert (gnu_op_type, gnu_high); + } + + /* If LOW and HIGH are identical, perform an equality test. Otherwise, + ensure that GNU_OBJ is evaluated only once and perform a full range + test. */ + if (operand_equal_p (gnu_low, gnu_high, 0)) + gnu_result + = build_binary_op (EQ_EXPR, gnu_result_type, gnu_obj, gnu_low); + else + { + tree t1, t2; + gnu_obj = gnat_protect_expr (gnu_obj); + t1 = build_binary_op (GE_EXPR, gnu_result_type, gnu_obj, gnu_low); + if (EXPR_P (t1)) + set_expr_location_from_node (t1, gnat_node); + t2 = build_binary_op (LE_EXPR, gnu_result_type, gnu_obj, gnu_high); + if (EXPR_P (t2)) + set_expr_location_from_node (t2, gnat_node); + gnu_result + = build_binary_op (TRUTH_ANDIF_EXPR, gnu_result_type, t1, t2); + } + + if (kind == N_Not_In) + gnu_result + = invert_truthvalue_loc (EXPR_LOCATION (gnu_result), gnu_result); + } + break; + + case N_Op_Divide: + gnu_lhs = gnat_to_gnu (Left_Opnd (gnat_node)); + gnu_rhs = gnat_to_gnu (Right_Opnd (gnat_node)); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + gnu_result = build_binary_op (FLOAT_TYPE_P (gnu_result_type) + ? RDIV_EXPR + : (Rounded_Result (gnat_node) + ? ROUND_DIV_EXPR : TRUNC_DIV_EXPR), + gnu_result_type, gnu_lhs, gnu_rhs); + break; + + case N_Op_Eq: + case N_Op_Ne: + case N_Op_Lt: + case N_Op_Le: + case N_Op_Gt: + case N_Op_Ge: + case N_Op_Add: + case N_Op_Subtract: + case N_Op_Multiply: + case N_Op_Mod: + case N_Op_Rem: + case N_Op_Rotate_Left: + case N_Op_Rotate_Right: + case N_Op_Shift_Left: + case N_Op_Shift_Right: + case N_Op_Shift_Right_Arithmetic: + case N_Op_And: + case N_Op_Or: + case N_Op_Xor: + case N_And_Then: + case N_Or_Else: + { + enum tree_code code = gnu_codes[kind]; + bool ignore_lhs_overflow = false; + location_t saved_location = input_location; + tree gnu_type, gnu_max_shift = NULL_TREE; + + /* Fix operations set up for boolean types in GNU_CODES above. */ + if (Is_Modular_Integer_Type (Underlying_Type (Etype (gnat_node)))) + switch (kind) + { + case N_Op_And: + code = BIT_AND_EXPR; + break; + case N_Op_Or: + code = BIT_IOR_EXPR; + break; + case N_Op_Xor: + code = BIT_XOR_EXPR; + break; + default: + break; + } + + gnu_lhs = gnat_to_gnu (Left_Opnd (gnat_node)); + gnu_rhs = gnat_to_gnu (Right_Opnd (gnat_node)); + gnu_type = gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + /* If this is a shift, take the count as unsigned since that is what + most machines do and will generate simpler adjustments below. */ + if (IN (kind, N_Op_Shift)) + { + tree gnu_count_type + = gnat_unsigned_type_for (get_base_type (TREE_TYPE (gnu_rhs))); + gnu_rhs = convert (gnu_count_type, gnu_rhs); + gnu_max_shift + = convert (TREE_TYPE (gnu_rhs), TYPE_SIZE (gnu_type)); + } + + /* Pending generic support for efficient vector logical operations in + GCC, convert vectors to their representative array type view and + fallthrough. */ + gnu_lhs = maybe_vector_array (gnu_lhs); + gnu_rhs = maybe_vector_array (gnu_rhs); + + /* If this is a comparison operator, convert any references to an + unconstrained array value into a reference to the actual array. */ + if (TREE_CODE_CLASS (code) == tcc_comparison) + { + gnu_lhs = maybe_unconstrained_array (gnu_lhs); + gnu_rhs = maybe_unconstrained_array (gnu_rhs); + + tree gnu_op_type = maybe_character_type (TREE_TYPE (gnu_lhs)); + if (TREE_TYPE (gnu_lhs) != gnu_op_type) + { + gnu_lhs = convert (gnu_op_type, gnu_lhs); + gnu_rhs = convert (gnu_op_type, gnu_rhs); + } + } + + /* If this is a shift whose count is not guaranteed to be correct, + we need to adjust the shift count. */ + if ((kind == N_Op_Rotate_Left || kind == N_Op_Rotate_Right) + && !Shift_Count_OK (gnat_node)) + gnu_rhs = build_binary_op (TRUNC_MOD_EXPR, TREE_TYPE (gnu_rhs), + gnu_rhs, gnu_max_shift); + else if (kind == N_Op_Shift_Right_Arithmetic + && !Shift_Count_OK (gnat_node)) + gnu_rhs + = build_binary_op (MIN_EXPR, TREE_TYPE (gnu_rhs), + build_binary_op (MINUS_EXPR, + TREE_TYPE (gnu_rhs), + gnu_max_shift, + build_int_cst + (TREE_TYPE (gnu_rhs), 1)), + gnu_rhs); + + /* For right shifts, the type says what kind of shift to do, + so we may need to choose a different type. In this case, + we have to ignore integer overflow lest it propagates all + the way down and causes a CE to be explicitly raised. */ + if (kind == N_Op_Shift_Right && !TYPE_UNSIGNED (gnu_type)) + { + gnu_type = gnat_unsigned_type_for (gnu_type); + ignore_lhs_overflow = true; + } + else if (kind == N_Op_Shift_Right_Arithmetic + && TYPE_UNSIGNED (gnu_type)) + { + gnu_type = gnat_signed_type_for (gnu_type); + ignore_lhs_overflow = true; + } + + if (gnu_type != gnu_result_type) + { + tree gnu_old_lhs = gnu_lhs; + gnu_lhs = convert (gnu_type, gnu_lhs); + if (TREE_CODE (gnu_lhs) == INTEGER_CST && ignore_lhs_overflow) + TREE_OVERFLOW (gnu_lhs) = TREE_OVERFLOW (gnu_old_lhs); + gnu_rhs = convert (gnu_type, gnu_rhs); + if (gnu_max_shift) + gnu_max_shift = convert (gnu_type, gnu_max_shift); + } + + /* For signed integer addition, subtraction and multiplication, do an + overflow check if required. */ + if (Do_Overflow_Check (gnat_node) + && (code == PLUS_EXPR || code == MINUS_EXPR || code == MULT_EXPR) + && !TYPE_UNSIGNED (gnu_type) + && !FLOAT_TYPE_P (gnu_type)) + gnu_result + = build_binary_op_trapv (code, gnu_type, gnu_lhs, gnu_rhs, + gnat_node); + else + { + /* Some operations, e.g. comparisons of arrays, generate complex + trees that need to be annotated while they are being built. */ + input_location = saved_location; + gnu_result = build_binary_op (code, gnu_type, gnu_lhs, gnu_rhs); + } + + /* If this is a logical shift with the shift count not verified, + we must return zero if it is too large. We cannot compensate + beforehand in this case. */ + if ((kind == N_Op_Shift_Left || kind == N_Op_Shift_Right) + && !Shift_Count_OK (gnat_node)) + gnu_result + = build_cond_expr (gnu_type, + build_binary_op (GE_EXPR, boolean_type_node, + gnu_rhs, gnu_max_shift), + build_int_cst (gnu_type, 0), + gnu_result); + } + break; + + case N_If_Expression: + { + tree gnu_cond = gnat_to_gnu (First (Expressions (gnat_node))); + tree gnu_true = gnat_to_gnu (Next (First (Expressions (gnat_node)))); + tree gnu_false + = gnat_to_gnu (Next (Next (First (Expressions (gnat_node))))); + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + gnu_result + = build_cond_expr (gnu_result_type, gnu_cond, gnu_true, gnu_false); + } + break; + + case N_Op_Plus: + gnu_result = gnat_to_gnu (Right_Opnd (gnat_node)); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + break; + + case N_Op_Not: + /* This case can apply to a boolean or a modular type. + Fall through for a boolean operand since GNU_CODES is set + up to handle this. */ + if (Is_Modular_Integer_Type (Underlying_Type (Etype (gnat_node)))) + { + gnu_expr = gnat_to_gnu (Right_Opnd (gnat_node)); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + gnu_result = build_unary_op (BIT_NOT_EXPR, gnu_result_type, + gnu_expr); + break; + } + + /* ... fall through ... */ + + case N_Op_Minus: + case N_Op_Abs: + gnu_expr = gnat_to_gnu (Right_Opnd (gnat_node)); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + /* For signed integer negation and absolute value, do an overflow check + if required. */ + if (Do_Overflow_Check (gnat_node) + && !TYPE_UNSIGNED (gnu_result_type) + && !FLOAT_TYPE_P (gnu_result_type)) + gnu_result + = build_unary_op_trapv (gnu_codes[kind], gnu_result_type, gnu_expr, + gnat_node); + else + gnu_result + = build_unary_op (gnu_codes[kind], gnu_result_type, gnu_expr); + break; + + case N_Allocator: + { + tree gnu_type, gnu_init; + bool ignore_init_type; + + gnat_temp = Expression (gnat_node); + + /* The expression can be either an N_Identifier or an Expanded_Name, + which must represent a type, or a N_Qualified_Expression, which + contains both the type and an initial value for the object. */ + if (Nkind (gnat_temp) == N_Identifier + || Nkind (gnat_temp) == N_Expanded_Name) + { + ignore_init_type = false; + gnu_init = NULL_TREE; + gnu_type = gnat_to_gnu_type (Entity (gnat_temp)); + } + + else if (Nkind (gnat_temp) == N_Qualified_Expression) + { + const Entity_Id gnat_desig_type + = Designated_Type (Underlying_Type (Etype (gnat_node))); + + ignore_init_type = Has_Constrained_Partial_View (gnat_desig_type); + + gnu_init = gnat_to_gnu (Expression (gnat_temp)); + gnu_init = maybe_unconstrained_array (gnu_init); + + gigi_checking_assert (!Do_Range_Check (Expression (gnat_temp))); + + if (Is_Elementary_Type (gnat_desig_type) + || Is_Constrained (gnat_desig_type)) + gnu_type = gnat_to_gnu_type (gnat_desig_type); + else + { + gnu_type = gnat_to_gnu_type (Etype (Expression (gnat_temp))); + if (TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE) + gnu_type = TREE_TYPE (gnu_init); + } + + /* See the N_Qualified_Expression case for the rationale. */ + if (Is_Tagged_Type (gnat_desig_type)) + used_types_insert (gnu_type); + + gnu_init = convert (gnu_type, gnu_init); + } + else + gcc_unreachable (); + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + return build_allocator (gnu_type, gnu_init, gnu_result_type, + Procedure_To_Call (gnat_node), + Storage_Pool (gnat_node), gnat_node, + ignore_init_type); + } + break; + + /**************************/ + /* Chapter 5: Statements */ + /**************************/ + + case N_Label: + gnu_result = build1 (LABEL_EXPR, void_type_node, + gnat_to_gnu (Identifier (gnat_node))); + break; + + case N_Null_Statement: + /* When not optimizing, turn null statements from source into gotos to + the next statement that the middle-end knows how to preserve. */ + if (!optimize && Comes_From_Source (gnat_node)) + { + tree stmt, label = create_label_decl (NULL_TREE, gnat_node); + DECL_IGNORED_P (label) = 1; + start_stmt_group (); + stmt = build1 (GOTO_EXPR, void_type_node, label); + set_expr_location_from_node (stmt, gnat_node); + add_stmt (stmt); + stmt = build1 (LABEL_EXPR, void_type_node, label); + set_expr_location_from_node (stmt, gnat_node); + add_stmt (stmt); + gnu_result = end_stmt_group (); + } + else + gnu_result = alloc_stmt_list (); + break; + + case N_Assignment_Statement: + /* Get the LHS and RHS of the statement and convert any reference to an + unconstrained array into a reference to the underlying array. */ + gnu_lhs = maybe_unconstrained_array (gnat_to_gnu (Name (gnat_node))); + + /* If the type has a size that overflows, convert this into raise of + Storage_Error: execution shouldn't have gotten here anyway. */ + if (TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (gnu_lhs))) == INTEGER_CST + && !valid_constant_size_p (TYPE_SIZE_UNIT (TREE_TYPE (gnu_lhs)))) + gnu_result = build_call_raise (SE_Object_Too_Large, gnat_node, + N_Raise_Storage_Error); + else if (Nkind (Expression (gnat_node)) == N_Function_Call) + { + get_atomic_access (Name (gnat_node), &aa_type, &aa_sync); + gnu_result + = Call_to_gnu (Expression (gnat_node), &gnu_result_type, gnu_lhs, + aa_type, aa_sync); + } + else + { + const Node_Id gnat_expr = Expression (gnat_node); + const Node_Id gnat_inner + = Nkind (gnat_expr) == N_Qualified_Expression + ? Expression (gnat_expr) + : gnat_expr; + const Entity_Id gnat_type + = Underlying_Type (Etype (Name (gnat_node))); + const bool use_memset_p + = Is_Array_Type (gnat_type) + && Nkind (gnat_inner) == N_Aggregate + && Is_Single_Aggregate (gnat_inner); + + /* If we use memset, we need to find the innermost expression. */ + if (use_memset_p) + { + gnat_temp = gnat_inner; + do { + gnat_temp + = Expression (First (Component_Associations (gnat_temp))); + } while (Nkind (gnat_temp) == N_Aggregate + && Is_Single_Aggregate (gnat_temp)); + gnu_rhs = gnat_to_gnu (gnat_temp); + } + else + gnu_rhs = maybe_unconstrained_array (gnat_to_gnu (gnat_expr)); + + gigi_checking_assert (!Do_Range_Check (gnat_expr)); + + get_atomic_access (Name (gnat_node), &aa_type, &aa_sync); + + /* If an outer atomic access is required on the LHS, build the load- + modify-store sequence. */ + if (aa_type == OUTER_ATOMIC) + gnu_result = build_load_modify_store (gnu_lhs, gnu_rhs, gnat_node); + + /* Or else, if a simple atomic access is required, build the atomic + store. */ + else if (aa_type == SIMPLE_ATOMIC) + gnu_result = build_atomic_store (gnu_lhs, gnu_rhs, aa_sync); + + /* Or else, use memset when the conditions are met. This has already + been validated by Aggr_Assignment_OK_For_Backend in the front-end + and the RHS is thus guaranteed to be of the appropriate form. */ + else if (use_memset_p) + { + tree value + = real_zerop (gnu_rhs) + ? integer_zero_node + : fold_convert (integer_type_node, gnu_rhs); + tree dest = build_fold_addr_expr (gnu_lhs); + tree t = builtin_decl_explicit (BUILT_IN_MEMSET); + /* Be extra careful not to write too much data. */ + tree size; + if (TREE_CODE (gnu_lhs) == COMPONENT_REF) + size = DECL_SIZE_UNIT (TREE_OPERAND (gnu_lhs, 1)); + else if (DECL_P (gnu_lhs)) + size = DECL_SIZE_UNIT (gnu_lhs); + else + size = TYPE_SIZE_UNIT (TREE_TYPE (gnu_lhs)); + size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, gnu_lhs); + if (TREE_CODE (value) == INTEGER_CST && !integer_zerop (value)) + { + tree mask + = build_int_cst (integer_type_node, + ((HOST_WIDE_INT) 1 << BITS_PER_UNIT) - 1); + value = int_const_binop (BIT_AND_EXPR, value, mask); + } + gnu_result = build_call_expr (t, 3, dest, value, size); + } + + /* Otherwise build a regular assignment. */ + else + gnu_result + = build_binary_op (MODIFY_EXPR, NULL_TREE, gnu_lhs, gnu_rhs); + + /* If the assignment type is a regular array and the two sides are + not completely disjoint, play safe and use memmove. But don't do + it for a bit-packed array as it might not be byte-aligned. */ + if (TREE_CODE (gnu_result) == MODIFY_EXPR + && Is_Array_Type (gnat_type) + && !Is_Bit_Packed_Array (gnat_type) + && !(Forwards_OK (gnat_node) && Backwards_OK (gnat_node))) + { + tree to = TREE_OPERAND (gnu_result, 0); + tree from = TREE_OPERAND (gnu_result, 1); + tree type = TREE_TYPE (from); + tree size + = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TYPE_SIZE_UNIT (type), from); + tree to_ptr = build_fold_addr_expr (to); + tree from_ptr = build_fold_addr_expr (from); + tree t = builtin_decl_explicit (BUILT_IN_MEMMOVE); + gnu_result = build_call_expr (t, 3, to_ptr, from_ptr, size); + } + } + break; + + case N_If_Statement: + { + tree *gnu_else_ptr; /* Point to put next "else if" or "else". */ + + /* Make the outer COND_EXPR. Avoid non-determinism. */ + gnu_result = build3 (COND_EXPR, void_type_node, + gnat_to_gnu (Condition (gnat_node)), + NULL_TREE, NULL_TREE); + COND_EXPR_THEN (gnu_result) + = build_stmt_group (Then_Statements (gnat_node), false); + TREE_SIDE_EFFECTS (gnu_result) = 1; + gnu_else_ptr = &COND_EXPR_ELSE (gnu_result); + + /* Now make a COND_EXPR for each of the "else if" parts. Put each + into the previous "else" part and point to where to put any + outer "else". Also avoid non-determinism. */ + if (Present (Elsif_Parts (gnat_node))) + for (gnat_temp = First (Elsif_Parts (gnat_node)); + Present (gnat_temp); gnat_temp = Next (gnat_temp)) + { + gnu_expr = build3 (COND_EXPR, void_type_node, + gnat_to_gnu (Condition (gnat_temp)), + NULL_TREE, NULL_TREE); + COND_EXPR_THEN (gnu_expr) + = build_stmt_group (Then_Statements (gnat_temp), false); + TREE_SIDE_EFFECTS (gnu_expr) = 1; + set_expr_location_from_node (gnu_expr, gnat_temp); + *gnu_else_ptr = gnu_expr; + gnu_else_ptr = &COND_EXPR_ELSE (gnu_expr); + } + + *gnu_else_ptr = build_stmt_group (Else_Statements (gnat_node), false); + } + break; + + case N_Case_Statement: + gnu_result = Case_Statement_to_gnu (gnat_node); + break; + + case N_Loop_Statement: + gnu_result = Loop_Statement_to_gnu (gnat_node); + break; + + case N_Block_Statement: + /* The only way to enter the block is to fall through to it. */ + if (stmt_group_may_fallthru ()) + { + start_stmt_group (); + gnat_pushlevel (); + process_decls (Declarations (gnat_node), Empty, Empty, true, true); + add_stmt (gnat_to_gnu (Handled_Statement_Sequence (gnat_node))); + gnat_poplevel (); + gnu_result = end_stmt_group (); + } + else + gnu_result = alloc_stmt_list (); + break; + + case N_Exit_Statement: + gnu_result + = build2 (EXIT_STMT, void_type_node, + (Present (Condition (gnat_node)) + ? gnat_to_gnu (Condition (gnat_node)) : NULL_TREE), + (Present (Name (gnat_node)) + ? get_gnu_tree (Entity (Name (gnat_node))) + : LOOP_STMT_LABEL (gnu_loop_stack->last ()->stmt))); + break; + + case N_Simple_Return_Statement: + { + tree gnu_ret_obj, gnu_ret_val; + + /* If the subprogram is a function, we must return the expression. */ + if (Present (Expression (gnat_node))) + { + tree gnu_subprog_type = TREE_TYPE (current_function_decl); + + /* If this function has copy-in/copy-out parameters parameters and + doesn't return by invisible reference, get the real object for + the return. See Subprogram_Body_to_gnu. */ + if (TYPE_CI_CO_LIST (gnu_subprog_type) + && !TREE_ADDRESSABLE (gnu_subprog_type)) + gnu_ret_obj = gnu_return_var_stack->last (); + else + gnu_ret_obj = DECL_RESULT (current_function_decl); + + /* Get the GCC tree for the expression to be returned. */ + gnu_ret_val = gnat_to_gnu (Expression (gnat_node)); + + /* Do not remove the padding from GNU_RET_VAL if the inner type is + self-referential since we want to allocate the fixed size. */ + if (TREE_CODE (gnu_ret_val) == COMPONENT_REF + && type_is_padding_self_referential + (TREE_TYPE (TREE_OPERAND (gnu_ret_val, 0)))) + gnu_ret_val = TREE_OPERAND (gnu_ret_val, 0); + + /* If the function returns by direct reference, return a pointer + to the return value. */ + if (TYPE_RETURN_BY_DIRECT_REF_P (gnu_subprog_type) + || By_Ref (gnat_node)) + gnu_ret_val = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_ret_val); + + /* Otherwise, if it returns an unconstrained array, we have to + allocate a new version of the result and return it. */ + else if (TYPE_RETURN_UNCONSTRAINED_P (gnu_subprog_type)) + { + gnu_ret_val = maybe_unconstrained_array (gnu_ret_val); + + /* And find out whether this is a candidate for Named Return + Value. If so, record it. */ + if (optimize + && !optimize_debug + && !TYPE_CI_CO_LIST (gnu_subprog_type)) + { + tree ret_val = gnu_ret_val; + + /* Strip useless conversions around the return value. */ + if (gnat_useless_type_conversion (ret_val)) + ret_val = TREE_OPERAND (ret_val, 0); + + /* Strip unpadding around the return value. */ + if (TREE_CODE (ret_val) == COMPONENT_REF + && TYPE_IS_PADDING_P + (TREE_TYPE (TREE_OPERAND (ret_val, 0)))) + ret_val = TREE_OPERAND (ret_val, 0); + + /* Now apply the test to the return value. */ + if (return_value_ok_for_nrv_p (NULL_TREE, ret_val)) + { + if (!f_named_ret_val) + f_named_ret_val = BITMAP_GGC_ALLOC (); + bitmap_set_bit (f_named_ret_val, DECL_UID (ret_val)); + if (!f_gnat_ret) + f_gnat_ret = gnat_node; + } + } + + gnu_ret_val = build_allocator (TREE_TYPE (gnu_ret_val), + gnu_ret_val, + TREE_TYPE (gnu_ret_obj), + Procedure_To_Call (gnat_node), + Storage_Pool (gnat_node), + gnat_node, false); + } + + /* Otherwise, if it returns by invisible reference, dereference + the pointer it is passed using the type of the return value + and build the copy operation manually. This ensures that we + don't copy too much data, for example if the return type is + unconstrained with a maximum size. */ + else if (TREE_ADDRESSABLE (gnu_subprog_type)) + { + tree gnu_ret_deref + = build_unary_op (INDIRECT_REF, TREE_TYPE (gnu_ret_val), + gnu_ret_obj); + gnu_result = build2 (INIT_EXPR, void_type_node, + gnu_ret_deref, gnu_ret_val); + add_stmt_with_node (gnu_result, gnat_node); + gnu_ret_val = NULL_TREE; + } + } + + else + gnu_ret_obj = gnu_ret_val = NULL_TREE; + + /* If we have a return label defined, convert this into a branch to + that label. The return proper will be handled elsewhere. */ + if (gnu_return_label_stack->last ()) + { + if (gnu_ret_val) + add_stmt_with_node (build_binary_op (MODIFY_EXPR, + NULL_TREE, gnu_ret_obj, + gnu_ret_val), + gnat_node); + + gnu_result = build1 (GOTO_EXPR, void_type_node, + gnu_return_label_stack->last ()); + + /* When not optimizing, make sure the return is preserved. */ + if (!optimize && Comes_From_Source (gnat_node)) + DECL_ARTIFICIAL (gnu_return_label_stack->last ()) = 0; + } + + /* Otherwise, build a regular return. */ + else + gnu_result = build_return_expr (gnu_ret_obj, gnu_ret_val); + } + break; + + case N_Goto_Statement: + gnu_expr = gnat_to_gnu (Name (gnat_node)); + gnu_result = build1 (GOTO_EXPR, void_type_node, gnu_expr); + TREE_USED (gnu_expr) = 1; + break; + + /***************************/ + /* Chapter 6: Subprograms */ + /***************************/ + + case N_Subprogram_Declaration: + /* Unless there is a freeze node, declare the entity. We consider + this a definition even though we're not generating code for the + subprogram because we will be making the corresponding GCC node. + When there is a freeze node, it is considered the definition of + the subprogram and we do nothing until after it is encountered. + That's an efficiency issue: the types involved in the profile + are far more likely to be frozen between the declaration and + the freeze node than before the declaration, so we save some + updates of the GCC node by waiting until the freeze node. + The counterpart is that we assume that there is no reference + to the subprogram between the declaration and the freeze node + in the expanded code; otherwise, it will be interpreted as an + external reference and very likely give rise to a link failure. */ + if (No (Freeze_Node (Defining_Entity (Specification (gnat_node))))) + gnat_to_gnu_entity (Defining_Entity (Specification (gnat_node)), + NULL_TREE, true); + gnu_result = alloc_stmt_list (); + break; + + case N_Abstract_Subprogram_Declaration: + /* This subprogram doesn't exist for code generation purposes, but we + have to elaborate the types of any parameters and result, unless + they are imported types (nothing to generate in this case). + + The parameter list may contain types with freeze nodes, e.g. not null + subtypes, so the subprogram itself may carry a freeze node, in which + case its elaboration must be deferred. */ + + /* Process the parameter types first. */ + if (No (Freeze_Node (Defining_Entity (Specification (gnat_node))))) + for (gnat_temp + = First_Formal_With_Extras + (Defining_Entity (Specification (gnat_node))); + Present (gnat_temp); + gnat_temp = Next_Formal_With_Extras (gnat_temp)) + if (Is_Itype (Etype (gnat_temp)) + && !From_Limited_With (Etype (gnat_temp))) + gnat_to_gnu_entity (Etype (gnat_temp), NULL_TREE, false); + + /* Then the result type, set to Standard_Void_Type for procedures. */ + { + Entity_Id gnat_temp_type + = Etype (Defining_Entity (Specification (gnat_node))); + + if (Is_Itype (gnat_temp_type) && !From_Limited_With (gnat_temp_type)) + gnat_to_gnu_entity (Etype (gnat_temp_type), NULL_TREE, false); + } + + gnu_result = alloc_stmt_list (); + break; + + case N_Defining_Program_Unit_Name: + /* For a child unit identifier go up a level to get the specification. + We get this when we try to find the spec of a child unit package + that is the compilation unit being compiled. */ + gnu_result = gnat_to_gnu (Parent (gnat_node)); + break; + + case N_Subprogram_Body: + Subprogram_Body_to_gnu (gnat_node); + gnu_result = alloc_stmt_list (); + break; + + case N_Function_Call: + case N_Procedure_Call_Statement: + gnu_result = Call_to_gnu (gnat_node, &gnu_result_type, NULL_TREE, + NOT_ATOMIC, false); + break; + + /************************/ + /* Chapter 7: Packages */ + /************************/ + + case N_Package_Declaration: + gnu_result = gnat_to_gnu (Specification (gnat_node)); + break; + + case N_Package_Specification: + + start_stmt_group (); + process_decls (Visible_Declarations (gnat_node), + Private_Declarations (gnat_node), Empty, true, true); + gnu_result = end_stmt_group (); + break; + + case N_Package_Body: + + /* If this is the body of a generic package - do nothing. */ + if (Ekind (Corresponding_Spec (gnat_node)) == E_Generic_Package) + { + gnu_result = alloc_stmt_list (); + break; + } + + start_stmt_group (); + process_decls (Declarations (gnat_node), Empty, Empty, true, true); + + if (Present (Handled_Statement_Sequence (gnat_node))) + add_stmt (gnat_to_gnu (Handled_Statement_Sequence (gnat_node))); + + gnu_result = end_stmt_group (); + break; + + /********************************/ + /* Chapter 8: Visibility Rules */ + /********************************/ + + case N_Use_Package_Clause: + case N_Use_Type_Clause: + /* Nothing to do here - but these may appear in list of declarations. */ + gnu_result = alloc_stmt_list (); + break; + + /*********************/ + /* Chapter 9: Tasks */ + /*********************/ + + case N_Protected_Type_Declaration: + gnu_result = alloc_stmt_list (); + break; + + case N_Single_Task_Declaration: + gnat_to_gnu_entity (Defining_Entity (gnat_node), NULL_TREE, true); + gnu_result = alloc_stmt_list (); + break; + + /*********************************************************/ + /* Chapter 10: Program Structure and Compilation Issues */ + /*********************************************************/ + + case N_Compilation_Unit: + /* This is not called for the main unit on which gigi is invoked. */ + Compilation_Unit_to_gnu (gnat_node); + gnu_result = alloc_stmt_list (); + break; + + case N_Subunit: + gnu_result = gnat_to_gnu (Proper_Body (gnat_node)); + break; + + case N_Entry_Body: + case N_Protected_Body: + case N_Task_Body: + /* These nodes should only be present when annotating types. */ + gcc_assert (type_annotate_only); + process_decls (Declarations (gnat_node), Empty, Empty, true, true); + gnu_result = alloc_stmt_list (); + break; + + case N_Subprogram_Body_Stub: + case N_Package_Body_Stub: + case N_Protected_Body_Stub: + case N_Task_Body_Stub: + /* Simply process whatever unit is being inserted. */ + if (Present (Library_Unit (gnat_node))) + gnu_result = gnat_to_gnu (Unit (Library_Unit (gnat_node))); + else + { + gcc_assert (type_annotate_only); + gnu_result = alloc_stmt_list (); + } + break; + + /***************************/ + /* Chapter 11: Exceptions */ + /***************************/ + + case N_Handled_Sequence_Of_Statements: + /* If there is an At_End procedure attached to this node, and the EH + mechanism is front-end, we must have at least a corresponding At_End + handler, unless the No_Exception_Handlers restriction is set. */ + gcc_assert (type_annotate_only + || !Front_End_Exceptions () + || No (At_End_Proc (gnat_node)) + || Present (Exception_Handlers (gnat_node)) + || No_Exception_Handlers_Set ()); + + gnu_result = Handled_Sequence_Of_Statements_to_gnu (gnat_node); + break; + + case N_Exception_Handler: + if (Back_End_Exceptions ()) + gnu_result = Exception_Handler_to_gnu_gcc (gnat_node); + else if (Exception_Mechanism == Front_End_SJLJ) + gnu_result = Exception_Handler_to_gnu_fe_sjlj (gnat_node); + else + gcc_unreachable (); + break; + + case N_Raise_Statement: + /* Only for reraise in back-end exceptions mode. */ + gcc_assert (No (Name (gnat_node)) && Back_End_Exceptions ()); + + start_stmt_group (); + + add_stmt_with_node (build_call_n_expr (reraise_zcx_decl, 1, + gnu_incoming_exc_ptr), + gnat_node); + + gnu_result = end_stmt_group (); + break; + + case N_Push_Constraint_Error_Label: + gnu_constraint_error_label_stack.safe_push (Exception_Label (gnat_node)); + break; + + case N_Push_Storage_Error_Label: + gnu_storage_error_label_stack.safe_push (Exception_Label (gnat_node)); + break; + + case N_Push_Program_Error_Label: + gnu_program_error_label_stack.safe_push (Exception_Label (gnat_node)); + break; + + case N_Pop_Constraint_Error_Label: + gnat_temp = gnu_constraint_error_label_stack.pop (); + if (Present (gnat_temp) + && !TREE_USED (gnat_to_gnu_entity (gnat_temp, NULL_TREE, false)) + && No_Exception_Propagation_Active ()) + Warn_If_No_Local_Raise (gnat_temp); + break; + + case N_Pop_Storage_Error_Label: + gnat_temp = gnu_storage_error_label_stack.pop (); + if (Present (gnat_temp) + && !TREE_USED (gnat_to_gnu_entity (gnat_temp, NULL_TREE, false)) + && No_Exception_Propagation_Active ()) + Warn_If_No_Local_Raise (gnat_temp); + break; + + case N_Pop_Program_Error_Label: + gnat_temp = gnu_program_error_label_stack.pop (); + if (Present (gnat_temp) + && !TREE_USED (gnat_to_gnu_entity (gnat_temp, NULL_TREE, false)) + && No_Exception_Propagation_Active ()) + Warn_If_No_Local_Raise (gnat_temp); + break; + + /******************************/ + /* Chapter 12: Generic Units */ + /******************************/ + + case N_Generic_Function_Renaming_Declaration: + case N_Generic_Package_Renaming_Declaration: + case N_Generic_Procedure_Renaming_Declaration: + case N_Generic_Package_Declaration: + case N_Generic_Subprogram_Declaration: + case N_Package_Instantiation: + case N_Procedure_Instantiation: + case N_Function_Instantiation: + /* These nodes can appear on a declaration list but there is nothing to + to be done with them. */ + gnu_result = alloc_stmt_list (); + break; + + /**************************************************/ + /* Chapter 13: Representation Clauses and */ + /* Implementation-Dependent Features */ + /**************************************************/ + + case N_Attribute_Definition_Clause: + gnu_result = alloc_stmt_list (); + + /* The only one we need to deal with is 'Address since, for the others, + the front-end puts the information elsewhere. */ + if (Get_Attribute_Id (Chars (gnat_node)) != Attr_Address) + break; + + /* And we only deal with 'Address if the object has a Freeze node. */ + gnat_temp = Entity (Name (gnat_node)); + if (Freeze_Node (gnat_temp)) + { + tree gnu_address = gnat_to_gnu (Expression (gnat_node)), gnu_temp; + + /* Get the value to use as the address and save it as the equivalent + for the object; when it is frozen, gnat_to_gnu_entity will do the + right thing. For a subprogram, put the naked address but build a + meaningfull expression for an object in case its address is taken + before the Freeze node is encountered; this can happen if the type + of the object is limited and it is initialized with the result of + a function call. */ + if (Is_Subprogram (gnat_temp)) + gnu_temp = gnu_address; + else + { + tree gnu_type = gnat_to_gnu_type (Etype (gnat_temp)); + /* Drop atomic and volatile qualifiers for the expression. */ + gnu_type = TYPE_MAIN_VARIANT (gnu_type); + gnu_type + = build_reference_type_for_mode (gnu_type, ptr_mode, true); + gnu_address = convert (gnu_type, gnu_address); + gnu_temp + = build_unary_op (INDIRECT_REF, NULL_TREE, gnu_address); + } + + save_gnu_tree (gnat_temp, gnu_temp, true); + } + break; + + case N_Enumeration_Representation_Clause: + case N_Record_Representation_Clause: + case N_At_Clause: + /* We do nothing with these. SEM puts the information elsewhere. */ + gnu_result = alloc_stmt_list (); + break; + + case N_Code_Statement: + if (!type_annotate_only) + { + tree gnu_template = gnat_to_gnu (Asm_Template (gnat_node)); + tree gnu_inputs = NULL_TREE, gnu_outputs = NULL_TREE; + tree gnu_clobbers = NULL_TREE, tail; + bool allows_mem, allows_reg, fake; + int ninputs, noutputs, i; + const char **oconstraints; + const char *constraint; + char *clobber; + + /* First retrieve the 3 operand lists built by the front-end. */ + Setup_Asm_Outputs (gnat_node); + while (Present (gnat_temp = Asm_Output_Variable ())) + { + tree gnu_value = gnat_to_gnu (gnat_temp); + tree gnu_constr = build_tree_list (NULL_TREE, gnat_to_gnu + (Asm_Output_Constraint ())); + + gnu_outputs = tree_cons (gnu_constr, gnu_value, gnu_outputs); + Next_Asm_Output (); + } + + Setup_Asm_Inputs (gnat_node); + while (Present (gnat_temp = Asm_Input_Value ())) + { + tree gnu_value = gnat_to_gnu (gnat_temp); + tree gnu_constr = build_tree_list (NULL_TREE, gnat_to_gnu + (Asm_Input_Constraint ())); + + gnu_inputs = tree_cons (gnu_constr, gnu_value, gnu_inputs); + Next_Asm_Input (); + } + + Clobber_Setup (gnat_node); + while ((clobber = (char *) Clobber_Get_Next ())) + gnu_clobbers + = tree_cons (NULL_TREE, + build_string (strlen (clobber) + 1, clobber), + gnu_clobbers); + + /* Then perform some standard checking and processing on the + operands. In particular, mark them addressable if needed. */ + gnu_outputs = nreverse (gnu_outputs); + noutputs = list_length (gnu_outputs); + gnu_inputs = nreverse (gnu_inputs); + ninputs = list_length (gnu_inputs); + oconstraints = XALLOCAVEC (const char *, noutputs); + + for (i = 0, tail = gnu_outputs; tail; ++i, tail = TREE_CHAIN (tail)) + { + tree output = TREE_VALUE (tail); + constraint + = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail))); + oconstraints[i] = constraint; + + if (parse_output_constraint (&constraint, i, ninputs, noutputs, + &allows_mem, &allows_reg, &fake)) + { + /* If the operand is going to end up in memory, + mark it addressable. Note that we don't test + allows_mem like in the input case below; this + is modeled on the C front-end. */ + if (!allows_reg) + { + output = remove_conversions (output, false); + if (TREE_CODE (output) == CONST_DECL + && DECL_CONST_CORRESPONDING_VAR (output)) + output = DECL_CONST_CORRESPONDING_VAR (output); + if (!gnat_mark_addressable (output)) + output = error_mark_node; + } + } + else + output = error_mark_node; + + TREE_VALUE (tail) = output; + } + + for (i = 0, tail = gnu_inputs; tail; ++i, tail = TREE_CHAIN (tail)) + { + tree input = TREE_VALUE (tail); + constraint + = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail))); + + if (parse_input_constraint (&constraint, i, ninputs, noutputs, + 0, oconstraints, + &allows_mem, &allows_reg)) + { + /* If the operand is going to end up in memory, + mark it addressable. */ + if (!allows_reg && allows_mem) + { + input = remove_conversions (input, false); + if (TREE_CODE (input) == CONST_DECL + && DECL_CONST_CORRESPONDING_VAR (input)) + input = DECL_CONST_CORRESPONDING_VAR (input); + if (!gnat_mark_addressable (input)) + input = error_mark_node; + } + } + else + input = error_mark_node; + + TREE_VALUE (tail) = input; + } + + gnu_result = build5 (ASM_EXPR, void_type_node, + gnu_template, gnu_outputs, + gnu_inputs, gnu_clobbers, NULL_TREE); + ASM_VOLATILE_P (gnu_result) = Is_Asm_Volatile (gnat_node); + } + else + gnu_result = alloc_stmt_list (); + + break; + + /****************/ + /* Added Nodes */ + /****************/ + + /* Markers are created by the ABE mechanism to capture information which + is either unavailable of expensive to recompute. Markers do not have + and runtime semantics, and should be ignored. */ + + case N_Call_Marker: + case N_Variable_Reference_Marker: + gnu_result = alloc_stmt_list (); + break; + + case N_Expression_With_Actions: + /* This construct doesn't define a scope so we don't push a binding + level around the statement list, but we wrap it in a SAVE_EXPR to + protect it from unsharing. Elaborate the expression as part of the + same statement group as the actions so that the type declaration + gets inserted there as well. This ensures that the type elaboration + code is issued past the actions computing values on which it might + depend. */ + start_stmt_group (); + add_stmt_list (Actions (gnat_node)); + gnu_expr = gnat_to_gnu (Expression (gnat_node)); + gnu_result = end_stmt_group (); + + gnu_result = build1 (SAVE_EXPR, void_type_node, gnu_result); + TREE_SIDE_EFFECTS (gnu_result) = 1; + + gnu_result + = build_compound_expr (TREE_TYPE (gnu_expr), gnu_result, gnu_expr); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + break; + + case N_Freeze_Entity: + start_stmt_group (); + process_freeze_entity (gnat_node); + process_decls (Actions (gnat_node), Empty, Empty, true, true); + gnu_result = end_stmt_group (); + break; + + case N_Freeze_Generic_Entity: + gnu_result = alloc_stmt_list (); + break; + + case N_Itype_Reference: + if (!present_gnu_tree (Itype (gnat_node))) + process_type (Itype (gnat_node)); + gnu_result = alloc_stmt_list (); + break; + + case N_Free_Statement: + gnat_temp = Expression (gnat_node); + + if (!type_annotate_only) + { + tree gnu_ptr, gnu_ptr_type, gnu_obj_type, gnu_actual_obj_type; + + const Entity_Id gnat_desig_type + = Designated_Type (Underlying_Type (Etype (gnat_temp))); + + /* Make sure the designated type is complete before dereferencing, + in case it is a Taft Amendment type. */ + (void) gnat_to_gnu_entity (gnat_desig_type, NULL_TREE, false); + + gnu_ptr = gnat_to_gnu (gnat_temp); + gnu_ptr_type = TREE_TYPE (gnu_ptr); + + /* If this is a thin pointer, we must first dereference it to create + a fat pointer, then go back below to a thin pointer. The reason + for this is that we need to have a fat pointer someplace in order + to properly compute the size. */ + if (TYPE_IS_THIN_POINTER_P (TREE_TYPE (gnu_ptr))) + gnu_ptr = build_unary_op (ADDR_EXPR, NULL_TREE, + build_unary_op (INDIRECT_REF, NULL_TREE, + gnu_ptr)); + + /* If this is a fat pointer, the object must have been allocated with + the template in front of the array. So pass the template address, + and get the total size; do it by converting to a thin pointer. */ + if (TYPE_IS_FAT_POINTER_P (TREE_TYPE (gnu_ptr))) + gnu_ptr + = convert (build_pointer_type + (TYPE_OBJECT_RECORD_TYPE + (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (gnu_ptr)))), + gnu_ptr); + + gnu_obj_type = TREE_TYPE (TREE_TYPE (gnu_ptr)); + + /* If this is a thin pointer, the object must have been allocated with + the template in front of the array. So pass the template address, + and get the total size. */ + if (TYPE_IS_THIN_POINTER_P (TREE_TYPE (gnu_ptr))) + gnu_ptr + = build_binary_op (POINTER_PLUS_EXPR, TREE_TYPE (gnu_ptr), + gnu_ptr, + fold_build1 (NEGATE_EXPR, sizetype, + byte_position + (DECL_CHAIN + TYPE_FIELDS ((gnu_obj_type))))); + + /* If we have a special dynamic constrained subtype on the node, use + it to compute the size; otherwise, use the designated subtype. */ + if (Present (Actual_Designated_Subtype (gnat_node))) + { + gnu_actual_obj_type + = gnat_to_gnu_type (Actual_Designated_Subtype (gnat_node)); + + if (TYPE_IS_FAT_OR_THIN_POINTER_P (gnu_ptr_type)) + gnu_actual_obj_type + = build_unc_object_type_from_ptr (gnu_ptr_type, + gnu_actual_obj_type, + get_identifier ("DEALLOC"), + false); + } + else + gnu_actual_obj_type = gnu_obj_type; + + tree gnu_size = TYPE_SIZE_UNIT (gnu_actual_obj_type); + gnu_size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (gnu_size, gnu_ptr); + + gnu_result + = build_call_alloc_dealloc (gnu_ptr, gnu_size, gnu_obj_type, + Procedure_To_Call (gnat_node), + Storage_Pool (gnat_node), + gnat_node); + } + break; + + case N_Raise_Constraint_Error: + case N_Raise_Program_Error: + case N_Raise_Storage_Error: + if (type_annotate_only) + gnu_result = alloc_stmt_list (); + else + gnu_result = Raise_Error_to_gnu (gnat_node, &gnu_result_type); + break; + + case N_Validate_Unchecked_Conversion: + /* The only validation we currently do on an unchecked conversion is + that of aliasing assumptions. */ + if (flag_strict_aliasing) + gnat_validate_uc_list.safe_push (gnat_node); + gnu_result = alloc_stmt_list (); + break; + + case N_Function_Specification: + case N_Procedure_Specification: + case N_Op_Concat: + case N_Component_Association: + /* These nodes should only be present when annotating types. */ + gcc_assert (type_annotate_only); + gnu_result = alloc_stmt_list (); + break; + + default: + /* Other nodes are not supposed to reach here. */ + gcc_unreachable (); + } + + /* If we are in the elaboration procedure, check if we are violating the + No_Elaboration_Code restriction by having a non-empty statement. */ + if (statement_node_p (gnat_node) + && !(TREE_CODE (gnu_result) == STATEMENT_LIST + && empty_stmt_list_p (gnu_result)) + && current_function_decl == get_elaboration_procedure ()) + Check_Elaboration_Code_Allowed (gnat_node); + + /* If we pushed the processing of the elaboration routine, pop it back. */ + if (went_into_elab_proc) + current_function_decl = NULL_TREE; + + /* When not optimizing, turn boolean rvalues B into B != false tests + so that we can put the location information of the reference to B on + the inequality operator for better debug info. */ + if (!optimize + && TREE_CODE (gnu_result) != INTEGER_CST + && TREE_CODE (gnu_result) != TYPE_DECL + && (kind == N_Identifier + || kind == N_Expanded_Name + || kind == N_Explicit_Dereference + || kind == N_Indexed_Component + || kind == N_Selected_Component) + && TREE_CODE (get_base_type (gnu_result_type)) == BOOLEAN_TYPE + && Nkind (Parent (gnat_node)) != N_Attribute_Reference + && Nkind (Parent (gnat_node)) != N_Pragma_Argument_Association + && Nkind (Parent (gnat_node)) != N_Variant_Part + && !lvalue_required_p (gnat_node, gnu_result_type, false, false)) + { + gnu_result + = build_binary_op (NE_EXPR, gnu_result_type, + convert (gnu_result_type, gnu_result), + convert (gnu_result_type, boolean_false_node)); + if (TREE_CODE (gnu_result) != INTEGER_CST) + set_gnu_expr_location_from_node (gnu_result, gnat_node); + } + + /* Set the location information on the result if it's not a simple name + or something that contains a simple name, for example a tag, because + we don"t want all the references to get the location of the first use. + Note that we may have no result if we tried to build a CALL_EXPR node + to a procedure with no side-effects and optimization is enabled. */ + else if (kind != N_Identifier + && !(kind == N_Selected_Component + && Chars (Selector_Name (gnat_node)) == Name_uTag) + && gnu_result + && EXPR_P (gnu_result)) + set_gnu_expr_location_from_node (gnu_result, gnat_node); + + /* If we're supposed to return something of void_type, it means we have + something we're elaborating for effect, so just return. */ + if (TREE_CODE (gnu_result_type) == VOID_TYPE) + return gnu_result; + + /* If the result is a constant that overflowed, raise Constraint_Error. */ + if (TREE_CODE (gnu_result) == INTEGER_CST && TREE_OVERFLOW (gnu_result)) + { + post_error ("??Constraint_Error will be raised at run time", gnat_node); + gnu_result + = build1 (NULL_EXPR, gnu_result_type, + build_call_raise (CE_Overflow_Check_Failed, gnat_node, + N_Raise_Constraint_Error)); + } + + /* If the result has side-effects and is of an unconstrained type, protect + the expression in case it will be referenced multiple times, i.e. for + its value and to compute the size of an object. But do it neither for + an object nor a renaming declaration, nor a return statement of a call + to a function that returns an unconstrained record type with default + discriminant, because there is no size to be computed in these cases + and this will create a useless temporary. We must do this before any + conversions. */ + if (TREE_SIDE_EFFECTS (gnu_result) + && (TREE_CODE (gnu_result_type) == UNCONSTRAINED_ARRAY_TYPE + || CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_result_type))) + && !(TREE_CODE (gnu_result) == CALL_EXPR + && type_is_padding_self_referential (TREE_TYPE (gnu_result)) + && (Nkind (Parent (gnat_node)) == N_Object_Declaration + || Nkind (Parent (gnat_node)) == N_Object_Renaming_Declaration + || Nkind (Parent (gnat_node)) == N_Simple_Return_Statement))) + gnu_result = gnat_protect_expr (gnu_result); + + /* Now convert the result to the result type, unless we are in one of the + following cases: + + 1. If this is the LHS of an assignment or an actual parameter of a + call, return the result almost unmodified since the RHS will have + to be converted to our type in that case, unless the result type + has a simpler size or for array types because this size might be + changed in-between. Likewise if there is just a no-op unchecked + conversion in-between. Similarly, don't convert integral types + that are the operands of an unchecked conversion since we need + to ignore those conversions (for 'Valid). + + 2. If we have a label (which doesn't have any well-defined type), a + field or an error, return the result almost unmodified. Similarly, + if the two types are record types with the same name, don't convert. + This will be the case when we are converting from a packable version + of a type to its original type and we need those conversions to be + NOPs in order for assignments into these types to work properly. + + 3. If the type is void or if we have no result, return error_mark_node + to show we have no result. + + 4. If this is a call to a function that returns with variable size and + the call is used as the expression in either an object or a renaming + declaration, return the result unmodified because we want to use the + return slot optimization in this case. + + 5. If this is a reference to an unconstrained array which is used as the + prefix of an attribute reference that requires an lvalue, return the + result unmodified because we want to return the original bounds. + + 6. Finally, if the type of the result is already correct. */ + + if (Present (Parent (gnat_node)) + && (lhs_or_actual_p (gnat_node) + || (Nkind (Parent (gnat_node)) == N_Unchecked_Type_Conversion + && unchecked_conversion_nop (Parent (gnat_node))) + || (Nkind (Parent (gnat_node)) == N_Unchecked_Type_Conversion + && !AGGREGATE_TYPE_P (gnu_result_type) + && !AGGREGATE_TYPE_P (TREE_TYPE (gnu_result)))) + && !(TYPE_SIZE (gnu_result_type) + && TYPE_SIZE (TREE_TYPE (gnu_result)) + && AGGREGATE_TYPE_P (gnu_result_type) + == AGGREGATE_TYPE_P (TREE_TYPE (gnu_result)) + && ((TREE_CODE (TYPE_SIZE (gnu_result_type)) == INTEGER_CST + && (TREE_CODE (TYPE_SIZE (TREE_TYPE (gnu_result))) + != INTEGER_CST)) + || (TREE_CODE (TYPE_SIZE (gnu_result_type)) != INTEGER_CST + && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_result_type)) + && (CONTAINS_PLACEHOLDER_P + (TYPE_SIZE (TREE_TYPE (gnu_result))))) + || (TREE_CODE (gnu_result_type) == ARRAY_TYPE + && TREE_CODE (TREE_TYPE (gnu_result)) == ARRAY_TYPE)) + && !(TREE_CODE (gnu_result_type) == RECORD_TYPE + && TYPE_JUSTIFIED_MODULAR_P (gnu_result_type)))) + { + /* Remove padding only if the inner object is of self-referential + size: in that case it must be an object of unconstrained type + with a default discriminant and we want to avoid copying too + much data. But do not remove it if it is already too small. */ + if (type_is_padding_self_referential (TREE_TYPE (gnu_result)) + && !(TREE_CODE (gnu_result) == COMPONENT_REF + && DECL_BIT_FIELD (TREE_OPERAND (gnu_result, 1)) + && DECL_SIZE (TREE_OPERAND (gnu_result, 1)) + != TYPE_SIZE (TREE_TYPE (gnu_result)))) + gnu_result = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_result))), + gnu_result); + } + + else if (TREE_CODE (gnu_result) == LABEL_DECL + || TREE_CODE (gnu_result) == FIELD_DECL + || TREE_CODE (gnu_result) == ERROR_MARK + || (TYPE_NAME (gnu_result_type) + == TYPE_NAME (TREE_TYPE (gnu_result)) + && TREE_CODE (gnu_result_type) == RECORD_TYPE + && TREE_CODE (TREE_TYPE (gnu_result)) == RECORD_TYPE)) + { + /* Remove any padding. */ + gnu_result = maybe_padded_object (gnu_result); + } + + else if (gnu_result == error_mark_node || gnu_result_type == void_type_node) + gnu_result = error_mark_node; + + else if (TREE_CODE (gnu_result) == CALL_EXPR + && Present (Parent (gnat_node)) + && (Nkind (Parent (gnat_node)) == N_Object_Declaration + || Nkind (Parent (gnat_node)) == N_Object_Renaming_Declaration) + && return_type_with_variable_size_p (TREE_TYPE (gnu_result))) + ; + + else if (TREE_CODE (gnu_result) == UNCONSTRAINED_ARRAY_REF + && Present (Parent (gnat_node)) + && Nkind (Parent (gnat_node)) == N_Attribute_Reference + && lvalue_required_for_attribute_p (Parent (gnat_node))) + ; + + else if (TREE_TYPE (gnu_result) != gnu_result_type) + gnu_result = convert (gnu_result_type, gnu_result); + + /* We don't need any NOP_EXPR or NON_LVALUE_EXPR on the result. */ + while ((TREE_CODE (gnu_result) == NOP_EXPR + || TREE_CODE (gnu_result) == NON_LVALUE_EXPR) + && TREE_TYPE (TREE_OPERAND (gnu_result, 0)) == TREE_TYPE (gnu_result)) + gnu_result = TREE_OPERAND (gnu_result, 0); + + return gnu_result; +} + +/* Similar to gnat_to_gnu, but discard any object that might be created in + the course of the translation of GNAT_NODE, which must be an "external" + expression in the sense that it will be elaborated elsewhere. */ + +tree +gnat_to_gnu_external (Node_Id gnat_node) +{ + const int save_force_global = force_global; + bool went_into_elab_proc; + + /* Force the local context and create a fake scope that we zap + at the end so declarations will not be stuck either in the + global varpool or in the current scope. */ + if (!current_function_decl) + { + current_function_decl = get_elaboration_procedure (); + went_into_elab_proc = true; + } + else + went_into_elab_proc = false; + force_global = 0; + gnat_pushlevel (); + + tree gnu_result = gnat_to_gnu (gnat_node); + + gnat_zaplevel (); + force_global = save_force_global; + if (went_into_elab_proc) + current_function_decl = NULL_TREE; + + /* Do not import locations from external units. */ + if (gnu_result && EXPR_P (gnu_result)) + SET_EXPR_LOCATION (gnu_result, UNKNOWN_LOCATION); + + return gnu_result; +} + +/* Return true if the statement list STMT_LIST is empty. */ + +static bool +empty_stmt_list_p (tree stmt_list) +{ + tree_stmt_iterator tsi; + + for (tsi = tsi_start (stmt_list); !tsi_end_p (tsi); tsi_next (&tsi)) + { + tree stmt = tsi_stmt (tsi); + + /* Anything else than an empty STMT_STMT counts as something. */ + if (TREE_CODE (stmt) != STMT_STMT || STMT_STMT_STMT (stmt)) + return false; + } + + return true; +} + +/* Record the current code position in GNAT_NODE. */ + +static void +record_code_position (Node_Id gnat_node) +{ + tree stmt_stmt = build1 (STMT_STMT, void_type_node, NULL_TREE); + + add_stmt_with_node (stmt_stmt, gnat_node); + save_gnu_tree (gnat_node, stmt_stmt, true); +} + +/* Insert the code for GNAT_NODE at the position saved for that node. */ + +static void +insert_code_for (Node_Id gnat_node) +{ + tree code = gnat_to_gnu (gnat_node); + + /* It's too late to remove the STMT_STMT itself at this point. */ + if (!empty_stmt_list_p (code)) + STMT_STMT_STMT (get_gnu_tree (gnat_node)) = code; + + save_gnu_tree (gnat_node, NULL_TREE, true); +} + +/* Start a new statement group chained to the previous group. */ + +void +start_stmt_group (void) +{ + struct stmt_group *group = stmt_group_free_list; + + /* First see if we can get one from the free list. */ + if (group) + stmt_group_free_list = group->previous; + else + group = ggc_alloc<stmt_group> (); + + group->previous = current_stmt_group; + group->stmt_list = group->block = group->cleanups = NULL_TREE; + current_stmt_group = group; +} + +/* Add GNU_STMT to the current statement group. If it is an expression with + no effects, it is ignored. */ + +void +add_stmt (tree gnu_stmt) +{ + append_to_statement_list (gnu_stmt, ¤t_stmt_group->stmt_list); +} + +/* Similar, but the statement is always added, regardless of side-effects. */ + +void +add_stmt_force (tree gnu_stmt) +{ + append_to_statement_list_force (gnu_stmt, ¤t_stmt_group->stmt_list); +} + +/* Like add_stmt, but set the location of GNU_STMT to that of GNAT_NODE. */ + +void +add_stmt_with_node (tree gnu_stmt, Node_Id gnat_node) +{ + if (Present (gnat_node)) + set_expr_location_from_node (gnu_stmt, gnat_node); + add_stmt (gnu_stmt); +} + +/* Similar, but the statement is always added, regardless of side-effects. */ + +void +add_stmt_with_node_force (tree gnu_stmt, Node_Id gnat_node) +{ + if (Present (gnat_node)) + set_expr_location_from_node (gnu_stmt, gnat_node); + add_stmt_force (gnu_stmt); +} + +/* Add a declaration statement for GNU_DECL to the current statement group. + Get the SLOC to be put onto the statement from GNAT_NODE. */ + +void +add_decl_expr (tree gnu_decl, Node_Id gnat_node) +{ + tree type = TREE_TYPE (gnu_decl); + tree gnu_stmt, gnu_init; + + /* If this is a variable that Gigi is to ignore, we may have been given + an ERROR_MARK. So test for it. We also might have been given a + reference for a renaming. So only do something for a decl. Also + ignore a TYPE_DECL for an UNCONSTRAINED_ARRAY_TYPE. */ + if (!DECL_P (gnu_decl) + || (TREE_CODE (gnu_decl) == TYPE_DECL + && TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)) + return; + + gnu_stmt = build1 (DECL_EXPR, void_type_node, gnu_decl); + + /* If we are external or global, we don't want to output the DECL_EXPR for + this DECL node since we already have evaluated the expressions in the + sizes and positions as globals and doing it again would be wrong. */ + if (DECL_EXTERNAL (gnu_decl) || global_bindings_p ()) + { + /* Mark everything as used to prevent node sharing with subprograms. + Note that walk_tree knows how to deal with TYPE_DECL, but neither + VAR_DECL nor CONST_DECL. This appears to be somewhat arbitrary. */ + MARK_VISITED (gnu_stmt); + if (TREE_CODE (gnu_decl) == VAR_DECL + || TREE_CODE (gnu_decl) == CONST_DECL) + { + MARK_VISITED (DECL_SIZE (gnu_decl)); + MARK_VISITED (DECL_SIZE_UNIT (gnu_decl)); + MARK_VISITED (DECL_INITIAL (gnu_decl)); + } + } + else + add_stmt_with_node (gnu_stmt, gnat_node); + + /* Mark our TYPE_ADA_SIZE field now since it will not be gimplified. */ + if (TREE_CODE (gnu_decl) == TYPE_DECL + && RECORD_OR_UNION_TYPE_P (type) + && !TYPE_FAT_POINTER_P (type)) + MARK_VISITED (TYPE_ADA_SIZE (type)); + + /* If this is a variable and an initializer is attached to it, it must be + valid for the context. Similar to init_const in create_var_decl. */ + if (TREE_CODE (gnu_decl) == VAR_DECL + && (gnu_init = DECL_INITIAL (gnu_decl)) + && (!gnat_types_compatible_p (type, TREE_TYPE (gnu_init)) + || (TREE_STATIC (gnu_decl) + && !initializer_constant_valid_p (gnu_init, + TREE_TYPE (gnu_init))))) + { + DECL_INITIAL (gnu_decl) = NULL_TREE; + if (TREE_READONLY (gnu_decl)) + { + TREE_READONLY (gnu_decl) = 0; + DECL_READONLY_ONCE_ELAB (gnu_decl) = 1; + } + + /* Remove any padding so the assignment is done properly. */ + gnu_decl = maybe_padded_object (gnu_decl); + + gnu_stmt = build_binary_op (INIT_EXPR, NULL_TREE, gnu_decl, gnu_init); + add_stmt_with_node (gnu_stmt, gnat_node); + } +} + +/* Callback for walk_tree to mark the visited trees rooted at *TP. */ + +static tree +mark_visited_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED) +{ + tree t = *tp; + + if (TREE_VISITED (t)) + *walk_subtrees = 0; + + /* Don't mark a dummy type as visited because we want to mark its sizes + and fields once it's filled in. */ + else if (!TYPE_IS_DUMMY_P (t)) + TREE_VISITED (t) = 1; + + /* The test in gimplify_type_sizes is on the main variant. */ + if (TYPE_P (t)) + TYPE_SIZES_GIMPLIFIED (TYPE_MAIN_VARIANT (t)) = 1; + + return NULL_TREE; +} + +/* Mark nodes rooted at T with TREE_VISITED and types as having their + sized gimplified. We use this to indicate all variable sizes and + positions in global types may not be shared by any subprogram. */ + +void +mark_visited (tree t) +{ + walk_tree (&t, mark_visited_r, NULL, NULL); +} + +/* Add GNU_CLEANUP, a cleanup action, to the current code group and + set its location to that of GNAT_NODE if present, but with column info + cleared so that conditional branches generated as part of the cleanup + code do not interfere with coverage analysis tools. */ + +static void +add_cleanup (tree gnu_cleanup, Node_Id gnat_node) +{ + if (Present (gnat_node)) + set_expr_location_from_node (gnu_cleanup, gnat_node, true); + + /* An EH_ELSE_EXPR must be by itself, and that's all we need when we + use it. The assert below makes sure that is so. Should we ever + need more than that, we could combine EH_ELSE_EXPRs, and copy + non-EH_ELSE_EXPR stmts into both cleanup paths of an + EH_ELSE_EXPR. */ + if (TREE_CODE (gnu_cleanup) == EH_ELSE_EXPR) + { + gcc_assert (!current_stmt_group->cleanups); + current_stmt_group->cleanups = gnu_cleanup; + } + else + { + gcc_assert (!current_stmt_group->cleanups + || (TREE_CODE (current_stmt_group->cleanups) + != EH_ELSE_EXPR)); + append_to_statement_list (gnu_cleanup, ¤t_stmt_group->cleanups); + } +} + +/* Set the BLOCK node corresponding to the current code group to GNU_BLOCK. */ + +void +set_block_for_group (tree gnu_block) +{ + gcc_assert (!current_stmt_group->block); + current_stmt_group->block = gnu_block; +} + +/* Return code corresponding to the current code group. It is normally + a STATEMENT_LIST, but may also be a BIND_EXPR or TRY_FINALLY_EXPR if + BLOCK or cleanups were set. */ + +tree +end_stmt_group (void) +{ + struct stmt_group *group = current_stmt_group; + tree gnu_retval = group->stmt_list; + + /* If this is a null list, allocate a new STATEMENT_LIST. Then, if there + are cleanups, make a TRY_FINALLY_EXPR. Last, if there is a BLOCK, + make a BIND_EXPR. Note that we nest in that because the cleanup may + reference variables in the block. */ + if (!gnu_retval) + gnu_retval = alloc_stmt_list (); + + if (group->cleanups) + gnu_retval = build2 (TRY_FINALLY_EXPR, void_type_node, gnu_retval, + group->cleanups); + + if (current_stmt_group->block) + gnu_retval = build3 (BIND_EXPR, void_type_node, BLOCK_VARS (group->block), + gnu_retval, group->block); + + /* Remove this group from the stack and add it to the free list. */ + current_stmt_group = group->previous; + group->previous = stmt_group_free_list; + stmt_group_free_list = group; + + return gnu_retval; +} + +/* Return whether the current statement group may fall through. */ + +static inline bool +stmt_group_may_fallthru (void) +{ + if (current_stmt_group->stmt_list) + return block_may_fallthru (current_stmt_group->stmt_list); + else + return true; +} + +/* Add a list of statements from GNAT_LIST, a possibly-empty list of + statements.*/ + +static void +add_stmt_list (List_Id gnat_list) +{ + Node_Id gnat_node; + + if (Present (gnat_list)) + for (gnat_node = First (gnat_list); Present (gnat_node); + gnat_node = Next (gnat_node)) + add_stmt (gnat_to_gnu (gnat_node)); +} + +/* Build a tree from GNAT_LIST, a possibly-empty list of statements. + If BINDING_P is true, push and pop a binding level around the list. */ + +static tree +build_stmt_group (List_Id gnat_list, bool binding_p) +{ + start_stmt_group (); + + if (binding_p) + gnat_pushlevel (); + + add_stmt_list (gnat_list); + + if (binding_p) + gnat_poplevel (); + + return end_stmt_group (); +} + +/* Generate GIMPLE in place for the expression at *EXPR_P. */ + +int +gnat_gimplify_expr (tree *expr_p, gimple_seq *pre_p, + gimple_seq *post_p ATTRIBUTE_UNUSED) +{ + tree expr = *expr_p; + tree type = TREE_TYPE (expr); + tree op; + + if (IS_ADA_STMT (expr)) + return gnat_gimplify_stmt (expr_p); + + switch (TREE_CODE (expr)) + { + case NULL_EXPR: + /* If this is an aggregate type, build a null pointer of the appropriate + type and dereference it. */ + if (AGGREGATE_TYPE_P (type) + || TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE) + *expr_p = build_unary_op (INDIRECT_REF, NULL_TREE, + convert (build_pointer_type (type), + integer_zero_node)); + /* Otherwise, just make a VAR_DECL. */ + else + { + *expr_p = create_tmp_var (type, NULL); + suppress_warning (*expr_p); + } + + gimplify_and_add (TREE_OPERAND (expr, 0), pre_p); + return GS_OK; + + case UNCONSTRAINED_ARRAY_REF: + /* We should only do this if we are just elaborating for side-effects, + but we can't know that yet. */ + *expr_p = TREE_OPERAND (*expr_p, 0); + return GS_OK; + + case ADDR_EXPR: + op = TREE_OPERAND (expr, 0); + + /* If we are taking the address of a constant CONSTRUCTOR, make sure it + is put into static memory. We know that it's going to be read-only + given the semantics we have and it must be in static memory when the + reference is in an elaboration procedure. */ + if (TREE_CODE (op) == CONSTRUCTOR && TREE_CONSTANT (op)) + { + tree addr = build_fold_addr_expr (tree_output_constant_def (op)); + *expr_p = fold_convert (type, addr); + return GS_ALL_DONE; + } + + /* Replace atomic loads with their first argument. That's necessary + because the gimplifier would create a temporary otherwise. */ + if (TREE_SIDE_EFFECTS (op)) + while (handled_component_p (op) || CONVERT_EXPR_P (op)) + { + tree inner = TREE_OPERAND (op, 0); + if (TREE_CODE (inner) == CALL_EXPR && call_is_atomic_load (inner)) + { + tree t = CALL_EXPR_ARG (inner, 0); + if (TREE_CODE (t) == NOP_EXPR) + t = TREE_OPERAND (t, 0); + if (TREE_CODE (t) == ADDR_EXPR) + TREE_OPERAND (op, 0) = TREE_OPERAND (t, 0); + else + TREE_OPERAND (op, 0) = build_fold_indirect_ref (t); + } + else + op = inner; + } + + return GS_UNHANDLED; + + case CALL_EXPR: + /* If we are passing a constant fat pointer CONSTRUCTOR, make sure it is + put into static memory; this performs a restricted version of constant + propagation on fat pointers in calls. But do not do it for strings to + avoid blocking concatenation in the caller when it is inlined. */ + for (int i = 0; i < call_expr_nargs (expr); i++) + { + tree arg = *(CALL_EXPR_ARGP (expr) + i); + + if (TREE_CODE (arg) == CONSTRUCTOR + && TREE_CONSTANT (arg) + && TYPE_IS_FAT_POINTER_P (TREE_TYPE (arg))) + { + tree t = CONSTRUCTOR_ELT (arg, 0)->value; + if (TREE_CODE (t) == NOP_EXPR) + t = TREE_OPERAND (t, 0); + if (TREE_CODE (t) == ADDR_EXPR) + t = TREE_OPERAND (t, 0); + if (TREE_CODE (t) != STRING_CST) + *(CALL_EXPR_ARGP (expr) + i) = tree_output_constant_def (arg); + } + } + + return GS_UNHANDLED; + + case VIEW_CONVERT_EXPR: + op = TREE_OPERAND (expr, 0); + + /* If we are view-converting a CONSTRUCTOR or a call from an aggregate + type to a scalar one, explicitly create the local temporary. That's + required if the type is passed by reference. */ + if ((TREE_CODE (op) == CONSTRUCTOR || TREE_CODE (op) == CALL_EXPR) + && AGGREGATE_TYPE_P (TREE_TYPE (op)) + && !AGGREGATE_TYPE_P (type)) + { + tree mod, new_var = create_tmp_var_raw (TREE_TYPE (op), "C"); + gimple_add_tmp_var (new_var); + + mod = build2 (INIT_EXPR, TREE_TYPE (new_var), new_var, op); + gimplify_and_add (mod, pre_p); + + TREE_OPERAND (expr, 0) = new_var; + return GS_OK; + } + + return GS_UNHANDLED; + + case DECL_EXPR: + op = DECL_EXPR_DECL (expr); + + /* The expressions for the RM bounds must be gimplified to ensure that + they are properly elaborated. See gimplify_decl_expr. */ + if ((TREE_CODE (op) == TYPE_DECL || TREE_CODE (op) == VAR_DECL) + && !TYPE_SIZES_GIMPLIFIED (TREE_TYPE (op))) + switch (TREE_CODE (TREE_TYPE (op))) + { + case INTEGER_TYPE: + case ENUMERAL_TYPE: + case BOOLEAN_TYPE: + case REAL_TYPE: + { + tree type = TYPE_MAIN_VARIANT (TREE_TYPE (op)), t, val; + + val = TYPE_RM_MIN_VALUE (type); + if (val) + { + gimplify_one_sizepos (&val, pre_p); + for (t = type; t; t = TYPE_NEXT_VARIANT (t)) + SET_TYPE_RM_MIN_VALUE (t, val); + } + + val = TYPE_RM_MAX_VALUE (type); + if (val) + { + gimplify_one_sizepos (&val, pre_p); + for (t = type; t; t = TYPE_NEXT_VARIANT (t)) + SET_TYPE_RM_MAX_VALUE (t, val); + } + + } + break; + + default: + break; + } + + /* ... fall through ... */ + + default: + return GS_UNHANDLED; + } +} + +/* Generate GIMPLE in place for the statement at *STMT_P. */ + +static enum gimplify_status +gnat_gimplify_stmt (tree *stmt_p) +{ + tree stmt = *stmt_p; + + switch (TREE_CODE (stmt)) + { + case STMT_STMT: + *stmt_p = STMT_STMT_STMT (stmt); + return GS_OK; + + case LOOP_STMT: + { + tree gnu_start_label = create_artificial_label (input_location); + tree gnu_cond = LOOP_STMT_COND (stmt); + tree gnu_update = LOOP_STMT_UPDATE (stmt); + tree gnu_end_label = LOOP_STMT_LABEL (stmt); + + /* Build the condition expression from the test, if any. */ + if (gnu_cond) + { + /* Deal with the optimization hints. */ + if (LOOP_STMT_IVDEP (stmt)) + gnu_cond = build3 (ANNOTATE_EXPR, TREE_TYPE (gnu_cond), gnu_cond, + build_int_cst (integer_type_node, + annot_expr_ivdep_kind), + integer_zero_node); + if (LOOP_STMT_NO_UNROLL (stmt)) + gnu_cond = build3 (ANNOTATE_EXPR, TREE_TYPE (gnu_cond), gnu_cond, + build_int_cst (integer_type_node, + annot_expr_unroll_kind), + integer_one_node); + if (LOOP_STMT_UNROLL (stmt)) + gnu_cond = build3 (ANNOTATE_EXPR, TREE_TYPE (gnu_cond), gnu_cond, + build_int_cst (integer_type_node, + annot_expr_unroll_kind), + build_int_cst (NULL_TREE, USHRT_MAX)); + if (LOOP_STMT_NO_VECTOR (stmt)) + gnu_cond = build3 (ANNOTATE_EXPR, TREE_TYPE (gnu_cond), gnu_cond, + build_int_cst (integer_type_node, + annot_expr_no_vector_kind), + integer_zero_node); + if (LOOP_STMT_VECTOR (stmt)) + gnu_cond = build3 (ANNOTATE_EXPR, TREE_TYPE (gnu_cond), gnu_cond, + build_int_cst (integer_type_node, + annot_expr_vector_kind), + integer_zero_node); + + gnu_cond + = build3 (COND_EXPR, void_type_node, gnu_cond, NULL_TREE, + build1 (GOTO_EXPR, void_type_node, gnu_end_label)); + } + + /* Set to emit the statements of the loop. */ + *stmt_p = NULL_TREE; + + /* We first emit the start label and then a conditional jump to the + end label if there's a top condition, then the update if it's at + the top, then the body of the loop, then a conditional jump to + the end label if there's a bottom condition, then the update if + it's at the bottom, and finally a jump to the start label and the + definition of the end label. */ + append_to_statement_list (build1 (LABEL_EXPR, void_type_node, + gnu_start_label), + stmt_p); + + if (gnu_cond && !LOOP_STMT_BOTTOM_COND_P (stmt)) + append_to_statement_list (gnu_cond, stmt_p); + + if (gnu_update && LOOP_STMT_TOP_UPDATE_P (stmt)) + append_to_statement_list (gnu_update, stmt_p); + + append_to_statement_list (LOOP_STMT_BODY (stmt), stmt_p); + + if (gnu_cond && LOOP_STMT_BOTTOM_COND_P (stmt)) + append_to_statement_list (gnu_cond, stmt_p); + + if (gnu_update && !LOOP_STMT_TOP_UPDATE_P (stmt)) + append_to_statement_list (gnu_update, stmt_p); + + tree t = build1 (GOTO_EXPR, void_type_node, gnu_start_label); + SET_EXPR_LOCATION (t, DECL_SOURCE_LOCATION (gnu_end_label)); + append_to_statement_list (t, stmt_p); + + append_to_statement_list (build1 (LABEL_EXPR, void_type_node, + gnu_end_label), + stmt_p); + return GS_OK; + } + + case EXIT_STMT: + /* Build a statement to jump to the corresponding end label, then + see if it needs to be conditional. */ + *stmt_p = build1 (GOTO_EXPR, void_type_node, EXIT_STMT_LABEL (stmt)); + if (EXIT_STMT_COND (stmt)) + *stmt_p = build3 (COND_EXPR, void_type_node, + EXIT_STMT_COND (stmt), *stmt_p, alloc_stmt_list ()); + return GS_OK; + + default: + gcc_unreachable (); + } +} + +/* Force a reference to each of the entities in GNAT_PACKAGE recursively. + + This routine is exclusively called in type_annotate mode, to compute DDA + information for types in withed units, for ASIS use. */ + +static void +elaborate_all_entities_for_package (Entity_Id gnat_package) +{ + Entity_Id gnat_entity; + + for (gnat_entity = First_Entity (gnat_package); + Present (gnat_entity); + gnat_entity = Next_Entity (gnat_entity)) + { + const Entity_Kind kind = Ekind (gnat_entity); + + /* We are interested only in entities visible from the main unit. */ + if (!Is_Public (gnat_entity)) + continue; + + /* Skip stuff internal to the compiler. */ + if (Is_Intrinsic_Subprogram (gnat_entity)) + continue; + if (kind == E_Operator) + continue; + if (IN (kind, Subprogram_Kind) + && (Present (Alias (gnat_entity)) + || Is_Intrinsic_Subprogram (gnat_entity))) + continue; + if (Is_Itype (gnat_entity)) + continue; + + /* Skip named numbers. */ + if (IN (kind, Named_Kind)) + continue; + + /* Skip generic declarations. */ + if (IN (kind, Generic_Unit_Kind)) + continue; + + /* Skip formal objects. */ + if (IN (kind, Formal_Object_Kind)) + continue; + + /* Skip package bodies. */ + if (kind == E_Package_Body) + continue; + + /* Skip limited views that point back to the main unit. */ + if (IN (kind, Incomplete_Kind) + && From_Limited_With (gnat_entity) + && In_Extended_Main_Code_Unit (Non_Limited_View (gnat_entity))) + continue; + + /* Skip types that aren't frozen. */ + if (IN (kind, Type_Kind) && !Is_Frozen (gnat_entity)) + continue; + + /* Recurse on real packages that aren't in the main unit. */ + if (kind == E_Package) + { + if (No (Renamed_Entity (gnat_entity)) + && !In_Extended_Main_Code_Unit (gnat_entity)) + elaborate_all_entities_for_package (gnat_entity); + } + else + gnat_to_gnu_entity (gnat_entity, NULL_TREE, false); + } +} + +/* Force a reference to each of the entities in packages withed by GNAT_NODE. + Operate recursively but check that we aren't elaborating something more + than once. + + This routine is exclusively called in type_annotate mode, to compute DDA + information for types in withed units, for ASIS use. */ + +static void +elaborate_all_entities (Node_Id gnat_node) +{ + Entity_Id gnat_with_clause; + + /* Process each unit only once. As we trace the context of all relevant + units transitively, including generic bodies, we may encounter the + same generic unit repeatedly. */ + if (!present_gnu_tree (gnat_node)) + save_gnu_tree (gnat_node, integer_zero_node, true); + + /* Save entities in all context units. A body may have an implicit_with + on its own spec, if the context includes a child unit, so don't save + the spec twice. */ + for (gnat_with_clause = First (Context_Items (gnat_node)); + Present (gnat_with_clause); + gnat_with_clause = Next (gnat_with_clause)) + if (Nkind (gnat_with_clause) == N_With_Clause + && !present_gnu_tree (Library_Unit (gnat_with_clause)) + && Library_Unit (gnat_with_clause) != Library_Unit (Cunit (Main_Unit))) + { + Node_Id gnat_unit = Library_Unit (gnat_with_clause); + Entity_Id gnat_entity = Entity (Name (gnat_with_clause)); + + elaborate_all_entities (gnat_unit); + + if (Ekind (gnat_entity) == E_Package + && No (Renamed_Entity (gnat_entity))) + elaborate_all_entities_for_package (gnat_entity); + + else if (Ekind (gnat_entity) == E_Generic_Package) + { + Node_Id gnat_body = Corresponding_Body (Unit (gnat_unit)); + + /* Retrieve compilation unit node of generic body. */ + while (Present (gnat_body) + && Nkind (gnat_body) != N_Compilation_Unit) + gnat_body = Parent (gnat_body); + + /* If body is available, elaborate its context. */ + if (Present (gnat_body)) + elaborate_all_entities (gnat_body); + } + } + + if (Nkind (Unit (gnat_node)) == N_Package_Body) + elaborate_all_entities (Library_Unit (gnat_node)); +} + +/* Do the processing of GNAT_NODE, an N_Freeze_Entity. */ + +static void +process_freeze_entity (Node_Id gnat_node) +{ + const Entity_Id gnat_entity = Entity (gnat_node); + const Entity_Kind kind = Ekind (gnat_entity); + tree gnu_old, gnu_new; + + /* If this is a package, generate code for the package body, if any. */ + if (kind == E_Package) + { + const Node_Id gnat_decl = Parent (Declaration_Node (gnat_entity)); + if (Present (Corresponding_Body (gnat_decl))) + insert_code_for (Parent (Corresponding_Body (gnat_decl))); + return; + } + + /* Don't do anything for class-wide types as they are always transformed + into their root type. */ + if (kind == E_Class_Wide_Type) + return; + + /* Check for an old definition if this isn't an object with address clause, + since the saved GCC tree is the address expression in that case. */ + gnu_old + = present_gnu_tree (gnat_entity) && No (Address_Clause (gnat_entity)) + ? get_gnu_tree (gnat_entity) : NULL_TREE; + + /* Don't do anything for subprograms that may have been elaborated before + their freeze nodes. This can happen, for example, because of an inner + call in an instance body or because of previous compilation of a spec + for inlining purposes. */ + if (gnu_old + && ((TREE_CODE (gnu_old) == FUNCTION_DECL + && (kind == E_Function || kind == E_Procedure)) + || (FUNC_OR_METHOD_TYPE_P (TREE_TYPE (gnu_old)) + && kind == E_Subprogram_Type))) + return; + + /* If we have a non-dummy type old tree, we have nothing to do, except for + aborting, since this node was never delayed as it should have been. We + let this happen for concurrent types and their Corresponding_Record_Type, + however, because each might legitimately be elaborated before its own + freeze node, e.g. while processing the other. */ + if (gnu_old + && !(TREE_CODE (gnu_old) == TYPE_DECL + && TYPE_IS_DUMMY_P (TREE_TYPE (gnu_old)))) + { + gcc_assert (Is_Concurrent_Type (gnat_entity) + || (Is_Record_Type (gnat_entity) + && Is_Concurrent_Record_Type (gnat_entity))); + return; + } + + /* Reset the saved tree, if any, and elaborate the object or type for real. + If there is a full view, elaborate it and use the result. And, if this + is the root type of a class-wide type, reuse it for the latter. */ + if (gnu_old) + { + save_gnu_tree (gnat_entity, NULL_TREE, false); + + if (Is_Incomplete_Or_Private_Type (gnat_entity) + && Present (Full_View (gnat_entity))) + { + Entity_Id full_view = Full_View (gnat_entity); + + save_gnu_tree (full_view, NULL_TREE, false); + + if (Is_Private_Type (full_view) + && Present (Underlying_Full_View (full_view))) + { + full_view = Underlying_Full_View (full_view); + save_gnu_tree (full_view, NULL_TREE, false); + } + } + + if (Is_Type (gnat_entity) + && Present (Class_Wide_Type (gnat_entity)) + && Root_Type (Class_Wide_Type (gnat_entity)) == gnat_entity) + save_gnu_tree (Class_Wide_Type (gnat_entity), NULL_TREE, false); + } + + if (Is_Incomplete_Or_Private_Type (gnat_entity) + && Present (Full_View (gnat_entity))) + { + Entity_Id full_view = Full_View (gnat_entity); + + if (Is_Private_Type (full_view) + && Present (Underlying_Full_View (full_view))) + full_view = Underlying_Full_View (full_view); + + gnu_new = gnat_to_gnu_entity (full_view, NULL_TREE, true); + + /* Propagate back-annotations from full view to partial view. */ + if (!Known_Alignment (gnat_entity)) + Copy_Alignment (gnat_entity, full_view); + + if (!Known_Esize (gnat_entity)) + Copy_Esize (gnat_entity, full_view); + + if (!Known_RM_Size (gnat_entity)) + Copy_RM_Size (gnat_entity, full_view); + + /* The above call may have defined this entity (the simplest example + of this is when we have a private enumeral type since the bounds + will have the public view). */ + if (!present_gnu_tree (gnat_entity)) + save_gnu_tree (gnat_entity, gnu_new, false); + } + else + { + tree gnu_init + = (Nkind (Declaration_Node (gnat_entity)) == N_Object_Declaration + && present_gnu_tree (Declaration_Node (gnat_entity))) + ? get_gnu_tree (Declaration_Node (gnat_entity)) : NULL_TREE; + + gnu_new = gnat_to_gnu_entity (gnat_entity, gnu_init, true); + } + + if (Is_Type (gnat_entity) + && Present (Class_Wide_Type (gnat_entity)) + && Root_Type (Class_Wide_Type (gnat_entity)) == gnat_entity) + save_gnu_tree (Class_Wide_Type (gnat_entity), gnu_new, false); + + /* If we have an old type and we've made pointers to this type, update those + pointers. If this is a Taft amendment type in the main unit, we need to + mark the type as used since other units referencing it don't see the full + declaration and, therefore, cannot mark it as used themselves. */ + if (gnu_old) + { + update_pointer_to (TYPE_MAIN_VARIANT (TREE_TYPE (gnu_old)), + TREE_TYPE (gnu_new)); + if (TYPE_DUMMY_IN_PROFILE_P (TREE_TYPE (gnu_old))) + update_profiles_with (TREE_TYPE (gnu_old)); + if (DECL_TAFT_TYPE_P (gnu_old)) + used_types_insert (TREE_TYPE (gnu_new)); + } +} + +/* Elaborate decls in the lists GNAT_DECLS and GNAT_DECLS2, if present. + We make two passes, one to elaborate anything other than bodies (but + we declare a function if there was no spec). The second pass + elaborates the bodies. + + GNAT_END_LIST gives the element in the list past the end. Normally, + this is Empty, but can be First_Real_Statement for a + Handled_Sequence_Of_Statements. + + We make a complete pass through both lists if PASS1P is true, then make + the second pass over both lists if PASS2P is true. The lists usually + correspond to the public and private parts of a package. */ + +static void +process_decls (List_Id gnat_decls, List_Id gnat_decls2, + Node_Id gnat_end_list, bool pass1p, bool pass2p) +{ + List_Id gnat_decl_array[2]; + Node_Id gnat_decl; + int i; + + gnat_decl_array[0] = gnat_decls, gnat_decl_array[1] = gnat_decls2; + + if (pass1p) + for (i = 0; i <= 1; i++) + if (Present (gnat_decl_array[i])) + for (gnat_decl = First (gnat_decl_array[i]); + gnat_decl != gnat_end_list; gnat_decl = Next (gnat_decl)) + { + /* For package specs, we recurse inside the declarations, + thus taking the two pass approach inside the boundary. */ + if (Nkind (gnat_decl) == N_Package_Declaration + && (Nkind (Specification (gnat_decl) + == N_Package_Specification))) + process_decls (Visible_Declarations (Specification (gnat_decl)), + Private_Declarations (Specification (gnat_decl)), + Empty, true, false); + + /* Similarly for any declarations in the actions of a + freeze node. */ + else if (Nkind (gnat_decl) == N_Freeze_Entity) + { + process_freeze_entity (gnat_decl); + process_decls (Actions (gnat_decl), Empty, Empty, true, false); + } + + /* Package bodies with freeze nodes get their elaboration deferred + until the freeze node, but the code must be placed in the right + place, so record the code position now. */ + else if (Nkind (gnat_decl) == N_Package_Body + && Present (Freeze_Node (Corresponding_Spec (gnat_decl)))) + record_code_position (gnat_decl); + + else if (Nkind (gnat_decl) == N_Package_Body_Stub + && Present (Library_Unit (gnat_decl)) + && Present (Freeze_Node + (Corresponding_Spec + (Proper_Body (Unit + (Library_Unit (gnat_decl))))))) + record_code_position + (Proper_Body (Unit (Library_Unit (gnat_decl)))); + + /* We defer most subprogram bodies to the second pass. */ + else if (Nkind (gnat_decl) == N_Subprogram_Body) + { + if (Acts_As_Spec (gnat_decl)) + { + Node_Id gnat_subprog_id = Defining_Entity (gnat_decl); + + if (Ekind (gnat_subprog_id) != E_Generic_Procedure + && Ekind (gnat_subprog_id) != E_Generic_Function) + gnat_to_gnu_entity (gnat_subprog_id, NULL_TREE, true); + } + } + + /* For bodies and stubs that act as their own specs, the entity + itself must be elaborated in the first pass, because it may + be used in other declarations. */ + else if (Nkind (gnat_decl) == N_Subprogram_Body_Stub) + { + Node_Id gnat_subprog_id + = Defining_Entity (Specification (gnat_decl)); + + if (Ekind (gnat_subprog_id) != E_Subprogram_Body + && Ekind (gnat_subprog_id) != E_Generic_Procedure + && Ekind (gnat_subprog_id) != E_Generic_Function) + gnat_to_gnu_entity (gnat_subprog_id, NULL_TREE, true); + } + + /* Concurrent stubs stand for the corresponding subprogram bodies, + which are deferred like other bodies. */ + else if (Nkind (gnat_decl) == N_Task_Body_Stub + || Nkind (gnat_decl) == N_Protected_Body_Stub) + ; + + /* Renamed subprograms may not be elaborated yet at this point + since renamings do not trigger freezing. Wait for the second + pass to take care of them. */ + else if (Nkind (gnat_decl) == N_Subprogram_Renaming_Declaration) + ; + + else + add_stmt (gnat_to_gnu (gnat_decl)); + } + + /* Here we elaborate everything we deferred above except for package bodies, + which are elaborated at their freeze nodes. Note that we must also + go inside things (package specs and freeze nodes) the first pass did. */ + if (pass2p) + for (i = 0; i <= 1; i++) + if (Present (gnat_decl_array[i])) + for (gnat_decl = First (gnat_decl_array[i]); + gnat_decl != gnat_end_list; gnat_decl = Next (gnat_decl)) + { + if (Nkind (gnat_decl) == N_Subprogram_Body + || Nkind (gnat_decl) == N_Subprogram_Body_Stub + || Nkind (gnat_decl) == N_Task_Body_Stub + || Nkind (gnat_decl) == N_Protected_Body_Stub) + add_stmt (gnat_to_gnu (gnat_decl)); + + else if (Nkind (gnat_decl) == N_Package_Declaration + && (Nkind (Specification (gnat_decl) + == N_Package_Specification))) + process_decls (Visible_Declarations (Specification (gnat_decl)), + Private_Declarations (Specification (gnat_decl)), + Empty, false, true); + + else if (Nkind (gnat_decl) == N_Freeze_Entity) + process_decls (Actions (gnat_decl), Empty, Empty, false, true); + + else if (Nkind (gnat_decl) == N_Subprogram_Renaming_Declaration) + add_stmt (gnat_to_gnu (gnat_decl)); + } +} + +/* Make a unary operation of kind CODE using build_unary_op, but guard + the operation by an overflow check. CODE can be one of NEGATE_EXPR + or ABS_EXPR. GNU_TYPE is the type desired for the result. Usually + the operation is to be performed in that type. GNAT_NODE is the gnat + node conveying the source location for which the error should be + signaled. */ + +static tree +build_unary_op_trapv (enum tree_code code, tree gnu_type, tree operand, + Node_Id gnat_node) +{ + gcc_assert (code == NEGATE_EXPR || code == ABS_EXPR); + + operand = gnat_protect_expr (operand); + + return emit_check (build_binary_op (EQ_EXPR, boolean_type_node, + operand, TYPE_MIN_VALUE (gnu_type)), + build_unary_op (code, gnu_type, operand), + CE_Overflow_Check_Failed, gnat_node); +} + +/* Make a binary operation of kind CODE using build_binary_op, but guard + the operation by an overflow check. CODE can be one of PLUS_EXPR, + MINUS_EXPR or MULT_EXPR. GNU_TYPE is the type desired for the result. + Usually the operation is to be performed in that type. GNAT_NODE is + the GNAT node conveying the source location for which the error should + be signaled. */ + +static tree +build_binary_op_trapv (enum tree_code code, tree gnu_type, tree left, + tree right, Node_Id gnat_node) +{ + const unsigned int precision = TYPE_PRECISION (gnu_type); + tree lhs = gnat_protect_expr (left); + tree rhs = gnat_protect_expr (right); + tree type_max = TYPE_MAX_VALUE (gnu_type); + tree type_min = TYPE_MIN_VALUE (gnu_type); + tree gnu_expr, check; + int sgn; + + /* Assert that the precision is a power of 2. */ + gcc_assert ((precision & (precision - 1)) == 0); + + /* Prefer a constant on the RHS to simplify checks. */ + if (TREE_CODE (rhs) != INTEGER_CST + && TREE_CODE (lhs) == INTEGER_CST + && (code == PLUS_EXPR || code == MULT_EXPR)) + { + tree tmp = lhs; + lhs = rhs; + rhs = tmp; + } + + gnu_expr = build_binary_op (code, gnu_type, lhs, rhs); + + /* If we can fold the expression to a constant, just return it. + The caller will deal with overflow, no need to generate a check. */ + if (TREE_CODE (gnu_expr) == INTEGER_CST) + return gnu_expr; + + /* If no operand is a constant, we use the generic implementation. */ + if (TREE_CODE (lhs) != INTEGER_CST && TREE_CODE (rhs) != INTEGER_CST) + { + /* First convert the operands to the result type like build_binary_op. + This is where the bias is made explicit for biased types. */ + lhs = convert (gnu_type, lhs); + rhs = convert (gnu_type, rhs); + + /* Never inline a 64-bit mult for a 32-bit target, it's way too long. */ + if (code == MULT_EXPR && precision == 64 && BITS_PER_WORD < 64) + { + tree int64 = gnat_type_for_size (64, 0); + return convert (gnu_type, build_call_n_expr (mulv64_decl, 2, + convert (int64, lhs), + convert (int64, rhs))); + } + + /* Likewise for a 128-bit mult and a 64-bit target. */ + else if (code == MULT_EXPR && precision == 128 && BITS_PER_WORD < 128) + { + tree int128 = gnat_type_for_size (128, 0); + return convert (gnu_type, build_call_n_expr (mulv128_decl, 2, + convert (int128, lhs), + convert (int128, rhs))); + } + + enum internal_fn icode; + + switch (code) + { + case PLUS_EXPR: + icode = IFN_ADD_OVERFLOW; + break; + case MINUS_EXPR: + icode = IFN_SUB_OVERFLOW; + break; + case MULT_EXPR: + icode = IFN_MUL_OVERFLOW; + break; + default: + gcc_unreachable (); + } + + tree gnu_ctype = build_complex_type (gnu_type); + tree call + = build_call_expr_internal_loc (UNKNOWN_LOCATION, icode, gnu_ctype, 2, + lhs, rhs); + tree tgt = save_expr (call); + gnu_expr = build1 (REALPART_EXPR, gnu_type, tgt); + check = fold_build2 (NE_EXPR, boolean_type_node, + build1 (IMAGPART_EXPR, gnu_type, tgt), + build_int_cst (gnu_type, 0)); + return + emit_check (check, gnu_expr, CE_Overflow_Check_Failed, gnat_node); + } + + /* If one operand is a constant, we expose the overflow condition to enable + a subsequent simplication or even elimination. */ + switch (code) + { + case PLUS_EXPR: + sgn = tree_int_cst_sgn (rhs); + if (sgn > 0) + /* When rhs > 0, overflow when lhs > type_max - rhs. */ + check = build_binary_op (GT_EXPR, boolean_type_node, lhs, + build_binary_op (MINUS_EXPR, gnu_type, + type_max, rhs)); + else if (sgn < 0) + /* When rhs < 0, overflow when lhs < type_min - rhs. */ + check = build_binary_op (LT_EXPR, boolean_type_node, lhs, + build_binary_op (MINUS_EXPR, gnu_type, + type_min, rhs)); + else + return gnu_expr; + break; + + case MINUS_EXPR: + if (TREE_CODE (lhs) == INTEGER_CST) + { + sgn = tree_int_cst_sgn (lhs); + if (sgn > 0) + /* When lhs > 0, overflow when rhs < lhs - type_max. */ + check = build_binary_op (LT_EXPR, boolean_type_node, rhs, + build_binary_op (MINUS_EXPR, gnu_type, + lhs, type_max)); + else if (sgn < 0) + /* When lhs < 0, overflow when rhs > lhs - type_min. */ + check = build_binary_op (GT_EXPR, boolean_type_node, rhs, + build_binary_op (MINUS_EXPR, gnu_type, + lhs, type_min)); + else + return gnu_expr; + } + else + { + sgn = tree_int_cst_sgn (rhs); + if (sgn > 0) + /* When rhs > 0, overflow when lhs < type_min + rhs. */ + check = build_binary_op (LT_EXPR, boolean_type_node, lhs, + build_binary_op (PLUS_EXPR, gnu_type, + type_min, rhs)); + else if (sgn < 0) + /* When rhs < 0, overflow when lhs > type_max + rhs. */ + check = build_binary_op (GT_EXPR, boolean_type_node, lhs, + build_binary_op (PLUS_EXPR, gnu_type, + type_max, rhs)); + else + return gnu_expr; + } + break; + + case MULT_EXPR: + sgn = tree_int_cst_sgn (rhs); + if (sgn > 0) + { + if (integer_onep (rhs)) + return gnu_expr; + + tree lb = build_binary_op (TRUNC_DIV_EXPR, gnu_type, type_min, rhs); + tree ub = build_binary_op (TRUNC_DIV_EXPR, gnu_type, type_max, rhs); + + /* When rhs > 1, overflow outside [type_min/rhs; type_max/rhs]. */ + check + = build_binary_op (TRUTH_ORIF_EXPR, boolean_type_node, + build_binary_op (LT_EXPR, boolean_type_node, + lhs, lb), + build_binary_op (GT_EXPR, boolean_type_node, + lhs, ub)); + } + else if (sgn < 0) + { + tree lb = build_binary_op (TRUNC_DIV_EXPR, gnu_type, type_max, rhs); + tree ub = build_binary_op (TRUNC_DIV_EXPR, gnu_type, type_min, rhs); + + if (integer_minus_onep (rhs)) + /* When rhs == -1, overflow if lhs == type_min. */ + check + = build_binary_op (EQ_EXPR, boolean_type_node, lhs, type_min); + else + /* When rhs < -1, overflow outside [type_max/rhs; type_min/rhs]. */ + check + = build_binary_op (TRUTH_ORIF_EXPR, boolean_type_node, + build_binary_op (LT_EXPR, boolean_type_node, + lhs, lb), + build_binary_op (GT_EXPR, boolean_type_node, + lhs, ub)); + } + else + return gnu_expr; + break; + + default: + gcc_unreachable (); + } + + return emit_check (check, gnu_expr, CE_Overflow_Check_Failed, gnat_node); +} + +/* GNU_COND contains the condition corresponding to an index, overflow or + range check of value GNU_EXPR. Build a COND_EXPR that returns GNU_EXPR + if GNU_COND is false and raises a CONSTRAINT_ERROR if GNU_COND is true. + REASON is the code that says why the exception is raised. GNAT_NODE is + the node conveying the source location for which the error should be + signaled. + + We used to propagate TREE_SIDE_EFFECTS from GNU_EXPR to the COND_EXPR, + overwriting the setting inherited from the call statement, on the ground + that the expression need not be evaluated just for the check. However + that's incorrect because, in the GCC type system, its value is presumed + to be valid so its comparison against the type bounds always yields true + and, therefore, could be done without evaluating it; given that it can + be a computation that overflows the bounds, the language may require the + check to fail and thus the expression to be evaluated in this case. */ + +static tree +emit_check (tree gnu_cond, tree gnu_expr, int reason, Node_Id gnat_node) +{ + tree gnu_call + = build_call_raise (reason, gnat_node, N_Raise_Constraint_Error); + return + fold_build3 (COND_EXPR, TREE_TYPE (gnu_expr), gnu_cond, + build2 (COMPOUND_EXPR, TREE_TYPE (gnu_expr), gnu_call, + SCALAR_FLOAT_TYPE_P (TREE_TYPE (gnu_expr)) + ? build_real (TREE_TYPE (gnu_expr), dconst0) + : build_int_cst (TREE_TYPE (gnu_expr), 0)), + gnu_expr); +} + +/* Return an expression that converts GNU_EXPR to GNAT_TYPE, doing overflow + checks if OVERFLOW_P is true. If TRUNCATE_P is true, do a fp-to-integer + conversion with truncation, otherwise round. GNAT_NODE is the GNAT node + conveying the source location for which the error should be signaled. */ + +static tree +convert_with_check (Entity_Id gnat_type, tree gnu_expr, bool overflow_p, + bool truncate_p, Node_Id gnat_node) +{ + tree gnu_type = get_unpadded_type (gnat_type); + tree gnu_base_type = get_base_type (gnu_type); + tree gnu_in_type = TREE_TYPE (gnu_expr); + tree gnu_in_base_type = get_base_type (gnu_in_type); + tree gnu_result = gnu_expr; + + /* If we are not doing any checks, the output is an integral type and the + input is not a floating-point type, just do the conversion. This is + required for packed array types and is simpler in all cases anyway. */ + if (!overflow_p + && INTEGRAL_TYPE_P (gnu_base_type) + && !FLOAT_TYPE_P (gnu_in_base_type)) + return convert (gnu_type, gnu_expr); + + /* If the mode of the input base type is larger, then converting to it below + may pessimize the final conversion step, for example generate a libcall + instead of a simple instruction, so use a narrower type in this case. */ + if (TYPE_MODE (gnu_in_base_type) != TYPE_MODE (gnu_in_type) + && !(TREE_CODE (gnu_in_type) == INTEGER_TYPE + && TYPE_BIASED_REPRESENTATION_P (gnu_in_type))) + gnu_in_base_type = gnat_type_for_mode (TYPE_MODE (gnu_in_type), + TYPE_UNSIGNED (gnu_in_type)); + + /* First convert the expression to the base type. This will never generate + code, but makes the tests below simpler. But don't do this if converting + from an integer type to an unconstrained array type since then we need to + get the bounds from the original (unpacked) type. */ + if (TREE_CODE (gnu_type) != UNCONSTRAINED_ARRAY_TYPE) + gnu_result = convert (gnu_in_base_type, gnu_result); + + /* If overflow checks are requested, we need to be sure the result will fit + in the output base type. But don't do this if the input is integer and + the output floating-point. */ + if (overflow_p + && !(FLOAT_TYPE_P (gnu_base_type) && INTEGRAL_TYPE_P (gnu_in_base_type))) + { + /* Ensure GNU_EXPR only gets evaluated once. */ + tree gnu_input = gnat_protect_expr (gnu_result); + tree gnu_cond = boolean_false_node; + tree gnu_in_lb = TYPE_MIN_VALUE (gnu_in_base_type); + tree gnu_in_ub = TYPE_MAX_VALUE (gnu_in_base_type); + tree gnu_out_lb = TYPE_MIN_VALUE (gnu_base_type); + tree gnu_out_ub + = (TREE_CODE (gnu_base_type) == INTEGER_TYPE + && TYPE_MODULAR_P (gnu_base_type)) + ? fold_build2 (MINUS_EXPR, gnu_base_type, + TYPE_MODULUS (gnu_base_type), + build_int_cst (gnu_base_type, 1)) + : TYPE_MAX_VALUE (gnu_base_type); + + /* Convert the lower bounds to signed types, so we're sure we're + comparing them properly. Likewise, convert the upper bounds + to unsigned types. */ + if (INTEGRAL_TYPE_P (gnu_in_base_type) + && TYPE_UNSIGNED (gnu_in_base_type)) + gnu_in_lb + = convert (gnat_signed_type_for (gnu_in_base_type), gnu_in_lb); + + if (INTEGRAL_TYPE_P (gnu_in_base_type) + && !TYPE_UNSIGNED (gnu_in_base_type)) + gnu_in_ub + = convert (gnat_unsigned_type_for (gnu_in_base_type), gnu_in_ub); + + if (INTEGRAL_TYPE_P (gnu_base_type) && TYPE_UNSIGNED (gnu_base_type)) + gnu_out_lb + = convert (gnat_signed_type_for (gnu_base_type), gnu_out_lb); + + if (INTEGRAL_TYPE_P (gnu_base_type) && !TYPE_UNSIGNED (gnu_base_type)) + gnu_out_ub + = convert (gnat_unsigned_type_for (gnu_base_type), gnu_out_ub); + + /* Check each bound separately and only if the result bound + is tighter than the bound on the input type. Note that all the + types are base types, so the bounds must be constant. Also, + the comparison is done in the base type of the input, which + always has the proper signedness. First check for input + integer (which means output integer), output float (which means + both float), or mixed, in which case we always compare. + Note that we have to do the comparison which would *fail* in the + case of an error since if it's an FP comparison and one of the + values is a NaN or Inf, the comparison will fail. */ + if (INTEGRAL_TYPE_P (gnu_in_base_type) + ? tree_int_cst_lt (gnu_in_lb, gnu_out_lb) + : (FLOAT_TYPE_P (gnu_base_type) + ? real_less (&TREE_REAL_CST (gnu_in_lb), + &TREE_REAL_CST (gnu_out_lb)) + : 1)) + gnu_cond + = invert_truthvalue + (build_binary_op (GE_EXPR, boolean_type_node, + gnu_input, convert (gnu_in_base_type, + gnu_out_lb))); + + if (INTEGRAL_TYPE_P (gnu_in_base_type) + ? tree_int_cst_lt (gnu_out_ub, gnu_in_ub) + : (FLOAT_TYPE_P (gnu_base_type) + ? real_less (&TREE_REAL_CST (gnu_out_ub), + &TREE_REAL_CST (gnu_in_ub)) + : 1)) + gnu_cond + = build_binary_op (TRUTH_ORIF_EXPR, boolean_type_node, gnu_cond, + invert_truthvalue + (build_binary_op (LE_EXPR, boolean_type_node, + gnu_input, + convert (gnu_in_base_type, + gnu_out_ub)))); + + if (!integer_zerop (gnu_cond)) + gnu_result = emit_check (gnu_cond, gnu_input, + CE_Overflow_Check_Failed, gnat_node); + } + + /* Now convert to the result base type. If this is a non-truncating + float-to-integer conversion, round. */ + if (INTEGRAL_TYPE_P (gnu_base_type) + && FLOAT_TYPE_P (gnu_in_base_type) + && !truncate_p) + { + REAL_VALUE_TYPE half_minus_pred_half, pred_half; + tree gnu_conv, gnu_zero, gnu_comp, calc_type; + tree gnu_pred_half, gnu_add_pred_half, gnu_subtract_pred_half; + const struct real_format *fmt; + + /* The following calculations depend on proper rounding to even + of each arithmetic operation. In order to prevent excess + precision from spoiling this property, use the widest hardware + floating-point type if FP_ARITH_MAY_WIDEN is true. */ + calc_type + = fp_arith_may_widen ? longest_float_type_node : gnu_in_base_type; + + /* Compute the exact value calc_type'Pred (0.5) at compile time. */ + fmt = REAL_MODE_FORMAT (TYPE_MODE (calc_type)); + real_2expN (&half_minus_pred_half, -(fmt->p) - 1, TYPE_MODE (calc_type)); + real_arithmetic (&pred_half, MINUS_EXPR, &dconsthalf, + &half_minus_pred_half); + gnu_pred_half = build_real (calc_type, pred_half); + + /* If the input is strictly negative, subtract this value + and otherwise add it from the input. For 0.5, the result + is exactly between 1.0 and the machine number preceding 1.0 + (for calc_type). Since the last bit of 1.0 is even, this 0.5 + will round to 1.0, while all other number with an absolute + value less than 0.5 round to 0.0. For larger numbers exactly + halfway between integers, rounding will always be correct as + the true mathematical result will be closer to the higher + integer compared to the lower one. So, this constant works + for all floating-point numbers. + + The reason to use the same constant with subtract/add instead + of a positive and negative constant is to allow the comparison + to be scheduled in parallel with retrieval of the constant and + conversion of the input to the calc_type (if necessary). */ + + gnu_zero = build_real (gnu_in_base_type, dconst0); + gnu_result = gnat_protect_expr (gnu_result); + gnu_conv = convert (calc_type, gnu_result); + gnu_comp + = fold_build2 (GE_EXPR, boolean_type_node, gnu_result, gnu_zero); + gnu_add_pred_half + = fold_build2 (PLUS_EXPR, calc_type, gnu_conv, gnu_pred_half); + gnu_subtract_pred_half + = fold_build2 (MINUS_EXPR, calc_type, gnu_conv, gnu_pred_half); + gnu_result = fold_build3 (COND_EXPR, calc_type, gnu_comp, + gnu_add_pred_half, gnu_subtract_pred_half); + } + + if (TREE_CODE (gnu_base_type) == INTEGER_TYPE + && TYPE_HAS_ACTUAL_BOUNDS_P (gnu_base_type) + && TREE_CODE (gnu_result) == UNCONSTRAINED_ARRAY_REF) + gnu_result = unchecked_convert (gnu_base_type, gnu_result, false); + else + gnu_result = convert (gnu_base_type, gnu_result); + + return convert (gnu_type, gnu_result); +} + +/* Return true if GNU_EXPR can be directly addressed. This is the case + unless it is an expression involving computation or if it involves a + reference to a bitfield or to an object not sufficiently aligned for + its type. If GNU_TYPE is non-null, return true only if GNU_EXPR can + be directly addressed as an object of this type. + + *** Notes on addressability issues in the Ada compiler *** + + This predicate is necessary in order to bridge the gap between Gigi + and the middle-end about addressability of GENERIC trees. A tree + is said to be addressable if it can be directly addressed, i.e. if + its address can be taken, is a multiple of the type's alignment on + strict-alignment architectures and returns the first storage unit + assigned to the object represented by the tree. + + In the C family of languages, everything is in practice addressable + at the language level, except for bit-fields. This means that these + compilers will take the address of any tree that doesn't represent + a bit-field reference and expect the result to be the first storage + unit assigned to the object. Even in cases where this will result + in unaligned accesses at run time, nothing is supposed to be done + and the program is considered as erroneous instead (see PR c/18287). + + The implicit assumptions made in the middle-end are in keeping with + the C viewpoint described above: + - the address of a bit-field reference is supposed to be never + taken; the compiler (generally) will stop on such a construct, + - any other tree is addressable if it is formally addressable, + i.e. if it is formally allowed to be the operand of ADDR_EXPR. + + In Ada, the viewpoint is the opposite one: nothing is addressable + at the language level unless explicitly declared so. This means + that the compiler will both make sure that the trees representing + references to addressable ("aliased" in Ada parlance) objects are + addressable and make no real attempts at ensuring that the trees + representing references to non-addressable objects are addressable. + + In the first case, Ada is effectively equivalent to C and handing + down the direct result of applying ADDR_EXPR to these trees to the + middle-end works flawlessly. In the second case, Ada cannot afford + to consider the program as erroneous if the address of trees that + are not addressable is requested for technical reasons, unlike C; + as a consequence, the Ada compiler must arrange for either making + sure that this address is not requested in the middle-end or for + compensating by inserting temporaries if it is requested in Gigi. + + The first goal can be achieved because the middle-end should not + request the address of non-addressable trees on its own; the only + exception is for the invocation of low-level block operations like + memcpy, for which the addressability requirements are lower since + the type's alignment can be disregarded. In practice, this means + that Gigi must make sure that such operations cannot be applied to + non-BLKmode bit-fields. + + The second goal is achieved by means of the addressable_p predicate, + which computes whether a temporary must be inserted by Gigi when the + address of a tree is requested; if so, the address of the temporary + will be used in lieu of that of the original tree and some glue code + generated to connect everything together. */ + +static bool +addressable_p (tree gnu_expr, tree gnu_type) +{ + /* For an integral type, the size of the actual type of the object may not + be greater than that of the expected type, otherwise an indirect access + in the latter type wouldn't correctly set all the bits of the object. */ + if (gnu_type + && INTEGRAL_TYPE_P (gnu_type) + && smaller_form_type_p (gnu_type, TREE_TYPE (gnu_expr))) + return false; + + /* The size of the actual type of the object may not be smaller than that + of the expected type, otherwise an indirect access in the latter type + would be larger than the object. But only record types need to be + considered in practice for this case. */ + if (gnu_type + && TREE_CODE (gnu_type) == RECORD_TYPE + && smaller_form_type_p (TREE_TYPE (gnu_expr), gnu_type)) + return false; + + switch (TREE_CODE (gnu_expr)) + { + case VAR_DECL: + case PARM_DECL: + case FUNCTION_DECL: + case RESULT_DECL: + /* All DECLs are addressable: if they are in a register, we can force + them to memory. */ + return true; + + case UNCONSTRAINED_ARRAY_REF: + case INDIRECT_REF: + /* Taking the address of a dereference yields the original pointer. */ + return true; + + case STRING_CST: + case INTEGER_CST: + case REAL_CST: + /* Taking the address yields a pointer to the constant pool. */ + return true; + + case CONSTRUCTOR: + /* Taking the address of a static constructor yields a pointer to the + tree constant pool. */ + return TREE_STATIC (gnu_expr) ? true : false; + + case NULL_EXPR: + case ADDR_EXPR: + case SAVE_EXPR: + case CALL_EXPR: + case PLUS_EXPR: + case MINUS_EXPR: + case BIT_IOR_EXPR: + case BIT_XOR_EXPR: + case BIT_AND_EXPR: + case BIT_NOT_EXPR: + /* All rvalues are deemed addressable since taking their address will + force a temporary to be created by the middle-end. */ + return true; + + case COMPOUND_EXPR: + /* The address of a compound expression is that of its 2nd operand. */ + return addressable_p (TREE_OPERAND (gnu_expr, 1), gnu_type); + + case COND_EXPR: + /* We accept &COND_EXPR as soon as both operands are addressable and + expect the outcome to be the address of the selected operand. */ + return (addressable_p (TREE_OPERAND (gnu_expr, 1), NULL_TREE) + && addressable_p (TREE_OPERAND (gnu_expr, 2), NULL_TREE)); + + case COMPONENT_REF: + return (((!DECL_BIT_FIELD (TREE_OPERAND (gnu_expr, 1)) + /* Even with DECL_BIT_FIELD cleared, we have to ensure that + the field is sufficiently aligned, in case it is subject + to a pragma Component_Alignment. But we don't need to + check the alignment of the containing record, as it is + guaranteed to be not smaller than that of its most + aligned field that is not a bit-field. */ + && (!STRICT_ALIGNMENT + || DECL_ALIGN (TREE_OPERAND (gnu_expr, 1)) + >= TYPE_ALIGN (TREE_TYPE (gnu_expr)))) + /* The field of a padding record is always addressable. */ + || TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (gnu_expr, 0)))) + && addressable_p (TREE_OPERAND (gnu_expr, 0), NULL_TREE)); + + case ARRAY_REF: case ARRAY_RANGE_REF: + case REALPART_EXPR: case IMAGPART_EXPR: + case NOP_EXPR: + return addressable_p (TREE_OPERAND (gnu_expr, 0), NULL_TREE); + + case CONVERT_EXPR: + return (AGGREGATE_TYPE_P (TREE_TYPE (gnu_expr)) + && addressable_p (TREE_OPERAND (gnu_expr, 0), NULL_TREE)); + + case VIEW_CONVERT_EXPR: + { + /* This is addressable if we can avoid a copy. */ + tree type = TREE_TYPE (gnu_expr); + tree inner_type = TREE_TYPE (TREE_OPERAND (gnu_expr, 0)); + return (((TYPE_MODE (type) == TYPE_MODE (inner_type) + && (!STRICT_ALIGNMENT + || TYPE_ALIGN (type) <= TYPE_ALIGN (inner_type) + || TYPE_ALIGN (inner_type) >= BIGGEST_ALIGNMENT)) + || ((TYPE_MODE (type) == BLKmode + || TYPE_MODE (inner_type) == BLKmode) + && (!STRICT_ALIGNMENT + || TYPE_ALIGN (type) <= TYPE_ALIGN (inner_type) + || TYPE_ALIGN (inner_type) >= BIGGEST_ALIGNMENT + || TYPE_ALIGN_OK (type) + || TYPE_ALIGN_OK (inner_type)))) + && addressable_p (TREE_OPERAND (gnu_expr, 0), NULL_TREE)); + } + + default: + return false; + } +} + +/* Do the processing for the declaration of a GNAT_ENTITY, a type or subtype. + If a Freeze node exists for the entity, delay the bulk of the processing. + Otherwise make a GCC type for GNAT_ENTITY and set up the correspondence. */ + +void +process_type (Entity_Id gnat_entity) +{ + tree gnu_old + = present_gnu_tree (gnat_entity) ? get_gnu_tree (gnat_entity) : NULL_TREE; + + /* If we are to delay elaboration of this type, just do any elaboration + needed for expressions within the declaration and make a dummy node + for it and its Full_View (if any), in case something points to it. + Do not do this if it has already been done (the only way that can + happen is if the private completion is also delayed). */ + if (Present (Freeze_Node (gnat_entity))) + { + elaborate_entity (gnat_entity); + + if (!gnu_old) + { + tree gnu_decl = TYPE_STUB_DECL (make_dummy_type (gnat_entity)); + save_gnu_tree (gnat_entity, gnu_decl, false); + if (Is_Incomplete_Or_Private_Type (gnat_entity) + && Present (Full_View (gnat_entity))) + { + if (Has_Completion_In_Body (gnat_entity)) + DECL_TAFT_TYPE_P (gnu_decl) = 1; + save_gnu_tree (Full_View (gnat_entity), gnu_decl, false); + } + } + + return; + } + + /* If we saved away a dummy type for this node, it means that this made the + type that corresponds to the full type of an incomplete type. Clear that + type for now and then update the type in the pointers below. But, if the + saved type is not dummy, it very likely means that we have a use before + declaration for the type in the tree, what we really cannot handle. */ + if (gnu_old) + { + gcc_assert (TREE_CODE (gnu_old) == TYPE_DECL + && TYPE_IS_DUMMY_P (TREE_TYPE (gnu_old))); + + save_gnu_tree (gnat_entity, NULL_TREE, false); + } + + /* Now fully elaborate the type. */ + tree gnu_new = gnat_to_gnu_entity (gnat_entity, NULL_TREE, true); + gcc_assert (TREE_CODE (gnu_new) == TYPE_DECL); + + /* If we have an old type and we've made pointers to this type, update those + pointers. If this is a Taft amendment type in the main unit, we need to + mark the type as used since other units referencing it don't see the full + declaration and, therefore, cannot mark it as used themselves. */ + if (gnu_old) + { + update_pointer_to (TYPE_MAIN_VARIANT (TREE_TYPE (gnu_old)), + TREE_TYPE (gnu_new)); + if (DECL_TAFT_TYPE_P (gnu_old)) + used_types_insert (TREE_TYPE (gnu_new)); + } + + /* If this is a record type corresponding to a task or protected type + that is a completion of an incomplete type, perform a similar update + on the type. ??? Including protected types here is a guess. */ + if (Is_Record_Type (gnat_entity) + && Is_Concurrent_Record_Type (gnat_entity) + && present_gnu_tree (Corresponding_Concurrent_Type (gnat_entity))) + { + tree gnu_task_old + = get_gnu_tree (Corresponding_Concurrent_Type (gnat_entity)); + + save_gnu_tree (Corresponding_Concurrent_Type (gnat_entity), + NULL_TREE, false); + save_gnu_tree (Corresponding_Concurrent_Type (gnat_entity), + gnu_new, false); + + update_pointer_to (TYPE_MAIN_VARIANT (TREE_TYPE (gnu_task_old)), + TREE_TYPE (gnu_new)); + } +} + +/* Subroutine of assoc_to_constructor: VALUES is a list of field associations, + some of which are from RECORD_TYPE. Return a CONSTRUCTOR consisting of the + associations that are from RECORD_TYPE. If we see an internal record, make + a recursive call to fill it in as well. */ + +static tree +extract_values (tree values, tree record_type) +{ + vec<constructor_elt, va_gc> *v = NULL; + tree field; + + for (field = TYPE_FIELDS (record_type); field; field = DECL_CHAIN (field)) + { + tree tem, value = NULL_TREE; + + /* _Parent is an internal field, but may have values in the aggregate, + so check for values first. */ + if ((tem = purpose_member (field, values))) + { + value = TREE_VALUE (tem); + TREE_ADDRESSABLE (tem) = 1; + } + + else if (DECL_INTERNAL_P (field)) + { + value = extract_values (values, TREE_TYPE (field)); + if (TREE_CODE (value) == CONSTRUCTOR + && vec_safe_is_empty (CONSTRUCTOR_ELTS (value))) + value = NULL_TREE; + } + else + /* If we have a record subtype, the names will match, but not the + actual FIELD_DECLs. */ + for (tem = values; tem; tem = TREE_CHAIN (tem)) + if (DECL_NAME (TREE_PURPOSE (tem)) == DECL_NAME (field)) + { + value = convert (TREE_TYPE (field), TREE_VALUE (tem)); + TREE_ADDRESSABLE (tem) = 1; + } + + if (!value) + continue; + + CONSTRUCTOR_APPEND_ELT (v, field, value); + } + + return gnat_build_constructor (record_type, v); +} + +/* GNAT_ENTITY is the type of the resulting constructor, GNAT_ASSOC is the + front of the Component_Associations of an N_Aggregate and GNU_TYPE is the + GCC type of the corresponding record type. Return the CONSTRUCTOR. */ + +static tree +assoc_to_constructor (Entity_Id gnat_entity, Node_Id gnat_assoc, tree gnu_type) +{ + tree gnu_list = NULL_TREE, gnu_result; + + /* We test for GNU_FIELD being empty in the case where a variant + was the last thing since we don't take things off GNAT_ASSOC in + that case. We check GNAT_ASSOC in case we have a variant, but it + has no fields. */ + + for (; Present (gnat_assoc); gnat_assoc = Next (gnat_assoc)) + { + const Node_Id gnat_field = First (Choices (gnat_assoc)); + const Node_Id gnat_expr = Expression (gnat_assoc); + tree gnu_field = gnat_to_gnu_field_decl (Entity (gnat_field)); + tree gnu_expr = gnat_to_gnu (Expression (gnat_assoc)); + + /* The expander is supposed to put a single component selector name + in every record component association. */ + gcc_assert (No (Next (gnat_field))); + + /* Ignore discriminants that have Corresponding_Discriminants in tagged + types since we'll be setting those fields in the parent subtype. */ + if (Ekind (Entity (gnat_field)) == E_Discriminant + && Present (Corresponding_Discriminant (Entity (gnat_field))) + && Is_Tagged_Type (Scope (Entity (gnat_field)))) + continue; + + /* Also ignore discriminants of Unchecked_Unions. */ + if (Ekind (Entity (gnat_field)) == E_Discriminant + && Is_Unchecked_Union (gnat_entity)) + continue; + + gigi_checking_assert (!Do_Range_Check (gnat_expr)); + + /* Convert to the type of the field. */ + gnu_expr = convert (TREE_TYPE (gnu_field), gnu_expr); + + /* Add the field and expression to the list. */ + gnu_list = tree_cons (gnu_field, gnu_expr, gnu_list); + } + + gnu_result = extract_values (gnu_list, gnu_type); + + if (flag_checking) + { + /* Verify that every entry in GNU_LIST was used. */ + for (; gnu_list; gnu_list = TREE_CHAIN (gnu_list)) + gcc_assert (TREE_ADDRESSABLE (gnu_list)); + } + + return gnu_result; +} + +/* Build a possibly nested constructor for array aggregates. GNAT_EXPR is + the first element of an array aggregate. It may itself be an aggregate. + GNU_ARRAY_TYPE is the GCC type corresponding to the array aggregate. */ + +static tree +pos_to_constructor (Node_Id gnat_expr, tree gnu_array_type) +{ + tree gnu_index = TYPE_MIN_VALUE (TYPE_DOMAIN (gnu_array_type)); + vec<constructor_elt, va_gc> *gnu_expr_vec = NULL; + + for (; Present (gnat_expr); gnat_expr = Next (gnat_expr)) + { + tree gnu_expr; + + /* If the expression is itself an array aggregate then first build the + innermost constructor if it is part of our array (multi-dimensional + case). */ + if (Nkind (gnat_expr) == N_Aggregate + && TREE_CODE (TREE_TYPE (gnu_array_type)) == ARRAY_TYPE + && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_array_type))) + gnu_expr = pos_to_constructor (First (Expressions (gnat_expr)), + TREE_TYPE (gnu_array_type)); + else + { + /* If the expression is a conversion to an unconstrained array type, + skip it to avoid spilling to memory. */ + if (Nkind (gnat_expr) == N_Type_Conversion + && Is_Array_Type (Etype (gnat_expr)) + && !Is_Constrained (Etype (gnat_expr))) + gnu_expr = gnat_to_gnu (Expression (gnat_expr)); + else + gnu_expr = gnat_to_gnu (gnat_expr); + + gigi_checking_assert (!Do_Range_Check (gnat_expr)); + } + + CONSTRUCTOR_APPEND_ELT (gnu_expr_vec, gnu_index, + convert (TREE_TYPE (gnu_array_type), gnu_expr)); + + gnu_index = int_const_binop (PLUS_EXPR, gnu_index, + convert (TREE_TYPE (gnu_index), + integer_one_node)); + } + + return gnat_build_constructor (gnu_array_type, gnu_expr_vec); +} + +/* Process a N_Validate_Unchecked_Conversion node. */ + +static void +validate_unchecked_conversion (Node_Id gnat_node) +{ + tree gnu_source_type = gnat_to_gnu_type (Source_Type (gnat_node)); + tree gnu_target_type = gnat_to_gnu_type (Target_Type (gnat_node)); + + /* If the target is a pointer type, see if we are either converting from a + non-pointer or from a pointer to a type with a different alias set and + warn if so, unless the pointer has been marked to alias everything. */ + if (POINTER_TYPE_P (gnu_target_type) + && !TYPE_REF_CAN_ALIAS_ALL (gnu_target_type)) + { + tree gnu_source_desig_type = POINTER_TYPE_P (gnu_source_type) + ? TREE_TYPE (gnu_source_type) + : NULL_TREE; + tree gnu_target_desig_type = TREE_TYPE (gnu_target_type); + alias_set_type target_alias_set = get_alias_set (gnu_target_desig_type); + + if (target_alias_set != 0 + && (!POINTER_TYPE_P (gnu_source_type) + || !alias_sets_conflict_p (get_alias_set (gnu_source_desig_type), + target_alias_set))) + { + post_error_ne ("??possible aliasing problem for type&", + gnat_node, Target_Type (gnat_node)); + post_error ("\\?use -fno-strict-aliasing switch for references", + gnat_node); + post_error_ne ("\\?or use `pragma No_Strict_Aliasing (&);`", + gnat_node, Target_Type (gnat_node)); + } + } + + /* Likewise if the target is a fat pointer type, but we have no mechanism to + mitigate the problem in this case, so we unconditionally warn. */ + else if (TYPE_IS_FAT_POINTER_P (gnu_target_type)) + { + tree gnu_source_desig_type + = TYPE_IS_FAT_POINTER_P (gnu_source_type) + ? TREE_TYPE (TREE_TYPE (TYPE_FIELDS (gnu_source_type))) + : NULL_TREE; + tree gnu_target_desig_type + = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (gnu_target_type))); + alias_set_type target_alias_set = get_alias_set (gnu_target_desig_type); + + if (target_alias_set != 0 + && (!TYPE_IS_FAT_POINTER_P (gnu_source_type) + || !alias_sets_conflict_p (get_alias_set (gnu_source_desig_type), + target_alias_set))) + { + post_error_ne ("??possible aliasing problem for type&", + gnat_node, Target_Type (gnat_node)); + post_error ("\\?use -fno-strict-aliasing switch for references", + gnat_node); + } + } +} + +/* Convert SLOC into LOCUS. Return true if SLOC corresponds to a + source code location and false if it doesn't. If CLEAR_COLUMN is + true, set the column information to 0. If DECL is given and SLOC + refers to a File with an instance, map DECL to that instance. */ + +bool +Sloc_to_locus (Source_Ptr Sloc, location_t *locus, bool clear_column, + const_tree decl) +{ + if (Sloc == No_Location) + return false; + + if (Sloc <= Standard_Location) + { + *locus = BUILTINS_LOCATION; + return false; + } + + Source_File_Index file = Get_Source_File_Index (Sloc); + Line_Number_Type line = Get_Logical_Line_Number (Sloc); + Column_Number_Type column = (clear_column ? 0 : Get_Column_Number (Sloc)); + line_map_ordinary *map = LINEMAPS_ORDINARY_MAP_AT (line_table, file - 1); + + /* We can have zero if pragma Source_Reference is in effect. */ + if (line < 1) + line = 1; + + /* Translate the location. */ + *locus + = linemap_position_for_line_and_column (line_table, map, line, column); + + if (file_map && file_map[file - 1].Instance) + decl_to_instance_map->put (decl, file_map[file - 1].Instance); + + return true; +} + +/* Return whether GNAT_NODE is a defining identifier for a renaming that comes + from the parameter association for the instantiation of a generic. We do + not want to emit source location for them: the code generated for their + initialization is likely to disturb debugging. */ + +bool +renaming_from_instantiation_p (Node_Id gnat_node) +{ + if (Nkind (gnat_node) != N_Defining_Identifier + || !Is_Object (gnat_node) + || Comes_From_Source (gnat_node) + || !Present (Renamed_Object (gnat_node))) + return false; + + /* Get the object declaration of the renamed object, if any and if the + renamed object is a mere identifier. */ + gnat_node = Renamed_Object (gnat_node); + if (Nkind (gnat_node) != N_Identifier) + return false; + + gnat_node = Parent (Entity (gnat_node)); + return (Present (gnat_node) + && Nkind (gnat_node) == N_Object_Declaration + && Present (Corresponding_Generic_Association (gnat_node))); +} + +/* Similar to set_expr_location, but start with the Sloc of GNAT_NODE and + don't do anything if it doesn't correspond to a source location. And, + if CLEAR_COLUMN is true, set the column information to 0. */ + +static void +set_expr_location_from_node (tree node, Node_Id gnat_node, bool clear_column) +{ + location_t locus; + + /* Do not set a location for constructs likely to disturb debugging. */ + if (Nkind (gnat_node) == N_Defining_Identifier) + { + if (Is_Type (gnat_node) && Is_Actual_Subtype (gnat_node)) + return; + + if (renaming_from_instantiation_p (gnat_node)) + return; + } + + if (!Sloc_to_locus (Sloc (gnat_node), &locus, clear_column)) + return; + + SET_EXPR_LOCATION (node, locus); +} + +/* More elaborate version of set_expr_location_from_node to be used in more + general contexts, for example the result of the translation of a generic + GNAT node. */ + +static void +set_gnu_expr_location_from_node (tree node, Node_Id gnat_node) +{ + /* Set the location information on the node if it is a real expression. + References can be reused for multiple GNAT nodes and they would get + the location information of their last use. Also make sure not to + overwrite an existing location as it is probably more precise. */ + + switch (TREE_CODE (node)) + { + CASE_CONVERT: + case NON_LVALUE_EXPR: + case SAVE_EXPR: + break; + + case COMPOUND_EXPR: + if (EXPR_P (TREE_OPERAND (node, 1))) + set_gnu_expr_location_from_node (TREE_OPERAND (node, 1), gnat_node); + + /* ... fall through ... */ + + default: + if (!REFERENCE_CLASS_P (node) && !EXPR_HAS_LOCATION (node)) + { + set_expr_location_from_node (node, gnat_node); + set_end_locus_from_node (node, gnat_node); + } + break; + } +} + +/* Set the end_locus information for GNU_NODE, if any, from an explicit end + location associated with GNAT_NODE or GNAT_NODE itself, whichever makes + most sense. Return true if a sensible assignment was performed. */ + +static bool +set_end_locus_from_node (tree gnu_node, Node_Id gnat_node) +{ + Node_Id gnat_end_label; + location_t end_locus; + + /* Pick the GNAT node of which we'll take the sloc to assign to the GCC node + end_locus when there is one. We consider only GNAT nodes with a possible + End_Label attached. If the End_Label actually was unassigned, fallback + on the original node. We'd better assign an explicit sloc associated with + the outer construct in any case. */ + + switch (Nkind (gnat_node)) + { + case N_Package_Body: + case N_Subprogram_Body: + case N_Block_Statement: + if (Present (Handled_Statement_Sequence (gnat_node))) + gnat_end_label = End_Label (Handled_Statement_Sequence (gnat_node)); + else + gnat_end_label = Empty; + + break; + + case N_Package_Declaration: + gcc_checking_assert (Present (Specification (gnat_node))); + gnat_end_label = End_Label (Specification (gnat_node)); + break; + + default: + return false; + } + + if (Present (gnat_end_label)) + gnat_node = gnat_end_label; + + /* Some expanded subprograms have neither an End_Label nor a Sloc + attached. Notify that to callers. For a block statement with no + End_Label, clear column information, so that the tree for a + transient block does not receive the sloc of a source condition. */ + if (!Sloc_to_locus (Sloc (gnat_node), &end_locus, + No (gnat_end_label) + && (Nkind (gnat_node) == N_Block_Statement))) + return false; + + switch (TREE_CODE (gnu_node)) + { + case BIND_EXPR: + BLOCK_SOURCE_END_LOCATION (BIND_EXPR_BLOCK (gnu_node)) = end_locus; + return true; + + case FUNCTION_DECL: + DECL_STRUCT_FUNCTION (gnu_node)->function_end_locus = end_locus; + return true; + + default: + return false; + } +} + +/* Post an error message. MSG is the error message, properly annotated. + NODE is the node at which to post the error and the node to use for the + '&' substitution. */ + +void +post_error (const char *msg, Node_Id node) +{ + String_Template temp; + String_Pointer sp; + + if (No (node)) + return; + + temp.Low_Bound = 1; + temp.High_Bound = strlen (msg); + sp.Bounds = &temp; + sp.Array = msg; + Error_Msg_N (sp, node); +} + +/* Similar to post_error, but NODE is the node at which to post the error and + ENT is the node to use for the '&' substitution. */ + +void +post_error_ne (const char *msg, Node_Id node, Entity_Id ent) +{ + String_Template temp; + String_Pointer sp; + + if (No (node)) + return; + + temp.Low_Bound = 1; + temp.High_Bound = strlen (msg); + sp.Bounds = &temp; + sp.Array = msg; + Error_Msg_NE (sp, node, ent); +} + +/* Similar to post_error_ne, but NUM is the number to use for the '^'. */ + +void +post_error_ne_num (const char *msg, Node_Id node, Entity_Id ent, int num) +{ + Error_Msg_Uint_1 = UI_From_Int (num); + post_error_ne (msg, node, ent); +} + +/* Similar to post_error_ne, but T is a GCC tree representing the number to + write. If T represents a constant, the text inside curly brackets in + MSG will be output (presumably including a '^'). Otherwise it will not + be output and the text inside square brackets will be output instead. */ + +void +post_error_ne_tree (const char *msg, Node_Id node, Entity_Id ent, tree t) +{ + char *new_msg = XALLOCAVEC (char, strlen (msg) + 1); + char start_yes, end_yes, start_no, end_no; + const char *p; + char *q; + + if (TREE_CODE (t) == INTEGER_CST) + { + Error_Msg_Uint_1 = UI_From_gnu (t); + start_yes = '{', end_yes = '}', start_no = '[', end_no = ']'; + } + else + start_yes = '[', end_yes = ']', start_no = '{', end_no = '}'; + + for (p = msg, q = new_msg; *p; p++) + { + if (*p == start_yes) + for (p++; *p != end_yes; p++) + *q++ = *p; + else if (*p == start_no) + for (p++; *p != end_no; p++) + ; + else + *q++ = *p; + } + + *q = 0; + + post_error_ne (new_msg, node, ent); +} + +/* Similar to post_error_ne_tree, but NUM is a second integer to write. */ + +void +post_error_ne_tree_2 (const char *msg, Node_Id node, Entity_Id ent, tree t, + int num) +{ + Error_Msg_Uint_2 = UI_From_Int (num); + post_error_ne_tree (msg, node, ent, t); +} + +/* Return a label to branch to for the exception type in KIND or Empty + if none. */ + +Entity_Id +get_exception_label (char kind) +{ + switch (kind) + { + case N_Raise_Constraint_Error: + return gnu_constraint_error_label_stack.last (); + + case N_Raise_Storage_Error: + return gnu_storage_error_label_stack.last (); + + case N_Raise_Program_Error: + return gnu_program_error_label_stack.last (); + + default: + return Empty; + } + + gcc_unreachable (); +} + +/* Return the decl for the current elaboration procedure. */ + +static tree +get_elaboration_procedure (void) +{ + return gnu_elab_proc_stack->last (); +} + +/* Return the controlling type of a dispatching subprogram. */ + +static Entity_Id +get_controlling_type (Entity_Id subprog) +{ + /* This is modeled on Expand_Interface_Thunk. */ + Entity_Id controlling_type = Etype (First_Formal (subprog)); + if (Is_Access_Type (controlling_type)) + controlling_type = Directly_Designated_Type (controlling_type); + controlling_type = Underlying_Type (controlling_type); + if (Is_Concurrent_Type (controlling_type)) + controlling_type = Corresponding_Record_Type (controlling_type); + controlling_type = Base_Type (controlling_type); + return controlling_type; +} + +/* Return whether we should use an alias for the TARGET of a thunk + in order to make the call generated in the thunk local. */ + +static bool +use_alias_for_thunk_p (tree target) +{ + /* We cannot generate a local call in this case. */ + if (DECL_EXTERNAL (target)) + return false; + + /* The call is already local in this case. */ + if (TREE_CODE (DECL_CONTEXT (target)) == FUNCTION_DECL) + return false; + + return TARGET_USE_LOCAL_THUNK_ALIAS_P (target); +} + +static GTY(()) unsigned long thunk_labelno = 0; + +/* Create an alias for TARGET to be used as the target of a thunk. */ + +static tree +make_alias_for_thunk (tree target) +{ + char buf[64]; + targetm.asm_out.generate_internal_label (buf, "LTHUNK", thunk_labelno++); + + tree alias = build_decl (DECL_SOURCE_LOCATION (target), TREE_CODE (target), + get_identifier (buf), TREE_TYPE (target)); + + DECL_LANG_SPECIFIC (alias) = DECL_LANG_SPECIFIC (target); + DECL_CONTEXT (alias) = DECL_CONTEXT (target); + TREE_READONLY (alias) = TREE_READONLY (target); + TREE_THIS_VOLATILE (alias) = TREE_THIS_VOLATILE (target); + DECL_ARTIFICIAL (alias) = 1; + DECL_INITIAL (alias) = error_mark_node; + DECL_ARGUMENTS (alias) = copy_list (DECL_ARGUMENTS (target)); + TREE_ADDRESSABLE (alias) = 1; + SET_DECL_ASSEMBLER_NAME (alias, DECL_NAME (alias)); + + cgraph_node *n = cgraph_node::create_same_body_alias (alias, target); + gcc_assert (n); + + return alias; +} + +/* Create the local covariant part of {GNAT,GNU}_THUNK. */ + +static tree +make_covariant_thunk (Entity_Id gnat_thunk, tree gnu_thunk) +{ + tree gnu_name = create_concat_name (gnat_thunk, "CV"); + tree gnu_cv_thunk + = build_decl (DECL_SOURCE_LOCATION (gnu_thunk), TREE_CODE (gnu_thunk), + gnu_name, TREE_TYPE (gnu_thunk)); + + DECL_ARGUMENTS (gnu_cv_thunk) = copy_list (DECL_ARGUMENTS (gnu_thunk)); + for (tree param_decl = DECL_ARGUMENTS (gnu_cv_thunk); + param_decl; + param_decl = DECL_CHAIN (param_decl)) + DECL_CONTEXT (param_decl) = gnu_cv_thunk; + + DECL_RESULT (gnu_cv_thunk) = copy_node (DECL_RESULT (gnu_thunk)); + DECL_CONTEXT (DECL_RESULT (gnu_cv_thunk)) = gnu_cv_thunk; + + DECL_LANG_SPECIFIC (gnu_cv_thunk) = DECL_LANG_SPECIFIC (gnu_thunk); + DECL_CONTEXT (gnu_cv_thunk) = DECL_CONTEXT (gnu_thunk); + TREE_READONLY (gnu_cv_thunk) = TREE_READONLY (gnu_thunk); + TREE_THIS_VOLATILE (gnu_cv_thunk) = TREE_THIS_VOLATILE (gnu_thunk); + DECL_ARTIFICIAL (gnu_cv_thunk) = 1; + + return gnu_cv_thunk; +} + +/* Try to create a GNU thunk for {GNAT,GNU}_THUNK and return true on success. + + GNU thunks are more efficient than GNAT thunks because they don't call into + the runtime to retrieve the offset used in the displacement operation, but + they are tailored to C++ and thus too limited to support the full range of + thunks generated in Ada. Here's the complete list of limitations: + + 1. Multi-controlling thunks, i.e thunks with more than one controlling + parameter, are simply not supported. + + 2. Covariant thunks, i.e. thunks for which the result is also controlling, + are split into a pair of (this, covariant-only) thunks. + + 3. Variable-offset thunks, i.e. thunks for which the offset depends on the + object and not only on its type, are supported as 2nd class citizens. + + 4. External thunks, i.e. thunks for which the target is not declared in + the same unit as the thunk, are supported as 2nd class citizens. + + 5. Local thunks, i.e. thunks generated for a local type, are supported as + 2nd class citizens. */ + +static bool +maybe_make_gnu_thunk (Entity_Id gnat_thunk, tree gnu_thunk) +{ + const Entity_Id gnat_target = Thunk_Entity (gnat_thunk); + + /* Check that the first formal of the target is the only controlling one. */ + Entity_Id gnat_formal = First_Formal (gnat_target); + if (!Is_Controlling_Formal (gnat_formal)) + return false; + for (gnat_formal = Next_Formal (gnat_formal); + Present (gnat_formal); + gnat_formal = Next_Formal (gnat_formal)) + if (Is_Controlling_Formal (gnat_formal)) + return false; + + /* Look for the types that control the target and the thunk. */ + const Entity_Id gnat_controlling_type = get_controlling_type (gnat_target); + const Entity_Id gnat_interface_type = get_controlling_type (gnat_thunk); + + /* We must have an interface type at this point. */ + gcc_assert (Is_Interface (gnat_interface_type)); + + /* Now compute whether the former covers the latter. */ + const Entity_Id gnat_interface_tag + = Find_Interface_Tag (gnat_controlling_type, gnat_interface_type); + tree gnu_interface_tag + = Present (gnat_interface_tag) + ? gnat_to_gnu_field_decl (gnat_interface_tag) + : NULL_TREE; + tree gnu_interface_offset + = gnu_interface_tag ? byte_position (gnu_interface_tag) : NULL_TREE; + + /* There are three ways to retrieve the offset between the interface view + and the base object. Either the controlling type covers the interface + type and the offset of the corresponding tag is fixed, in which case it + can be statically encoded in the thunk (see FIXED_OFFSET below). Or the + controlling type doesn't cover the interface type but is of fixed size, + in which case the offset is stored in the dispatch table, two pointers + above the dispatch table address (see VIRTUAL_VALUE below). Otherwise, + the offset is variable and is stored right after the tag in every object + (see INDIRECT_OFFSET below). See also a-tags.ads for more details. */ + HOST_WIDE_INT fixed_offset, virtual_value, indirect_offset; + tree virtual_offset; + + if (gnu_interface_offset && TREE_CODE (gnu_interface_offset) == INTEGER_CST) + { + fixed_offset = - tree_to_shwi (gnu_interface_offset); + virtual_value = 0; + virtual_offset = NULL_TREE; + indirect_offset = 0; + } + else if (!gnu_interface_offset + && !Is_Variable_Size_Record (gnat_controlling_type)) + { + fixed_offset = 0; + virtual_value = - 2 * (HOST_WIDE_INT) (POINTER_SIZE / BITS_PER_UNIT); + virtual_offset = build_int_cst (integer_type_node, virtual_value); + indirect_offset = 0; + } + else + { + /* Covariant thunks with variable offset are not supported. */ + if (Has_Controlling_Result (gnat_target)) + return false; + + fixed_offset = 0; + virtual_value = 0; + virtual_offset = NULL_TREE; + indirect_offset = (HOST_WIDE_INT) (POINTER_SIZE / BITS_PER_UNIT); + } + + tree gnu_target = gnat_to_gnu_entity (gnat_target, NULL_TREE, false); + + /* If the target is local, then thunk and target must have the same context + because cgraph_node::expand_thunk can only forward the static chain. */ + if (DECL_STATIC_CHAIN (gnu_target) + && DECL_CONTEXT (gnu_thunk) != DECL_CONTEXT (gnu_target)) + return false; + + /* If the target returns by invisible reference and is external, apply the + same transformation as Subprogram_Body_to_gnu here. */ + if (TREE_ADDRESSABLE (TREE_TYPE (gnu_target)) + && DECL_EXTERNAL (gnu_target) + && !POINTER_TYPE_P (TREE_TYPE (DECL_RESULT (gnu_target)))) + { + TREE_TYPE (DECL_RESULT (gnu_target)) + = build_reference_type (TREE_TYPE (DECL_RESULT (gnu_target))); + relayout_decl (DECL_RESULT (gnu_target)); + } + + /* The thunk expander requires the return types of thunk and target to be + compatible, which is not fully the case with the CICO mechanism. */ + if (TYPE_CI_CO_LIST (TREE_TYPE (gnu_thunk))) + { + tree gnu_target_type = TREE_TYPE (gnu_target); + gcc_assert (TYPE_CI_CO_LIST (gnu_target_type)); + TYPE_CANONICAL (TREE_TYPE (TREE_TYPE (gnu_thunk))) + = TYPE_CANONICAL (TREE_TYPE (gnu_target_type)); + } + + cgraph_node *target_node = cgraph_node::get_create (gnu_target); + + /* We may also need to create an alias for the target in order to make + the call local, depending on the linkage of the target. */ + tree gnu_alias = use_alias_for_thunk_p (gnu_target) + ? make_alias_for_thunk (gnu_target) + : gnu_target; + + /* If the return type of the target is a controlling type, then we need + both an usual this thunk and a covariant thunk in this order: + + this thunk --> covariant thunk --> target + + For covariant thunks, we can only handle a fixed offset. */ + if (Has_Controlling_Result (gnat_target)) + { + gcc_assert (fixed_offset < 0); + tree gnu_cv_thunk = make_covariant_thunk (gnat_thunk, gnu_thunk); + target_node->create_thunk (gnu_cv_thunk, gnu_target, false, + - fixed_offset, 0, 0, + NULL_TREE, gnu_alias); + + gnu_alias = gnu_target = gnu_cv_thunk; + } + + target_node->create_thunk (gnu_thunk, gnu_target, true, + fixed_offset, virtual_value, indirect_offset, + virtual_offset, gnu_alias); + + return true; +} + +/* Initialize the table that maps GNAT codes to GCC codes for simple + binary and unary operations. */ + +static void +init_code_table (void) +{ + gnu_codes[N_Op_And] = TRUTH_AND_EXPR; + gnu_codes[N_Op_Or] = TRUTH_OR_EXPR; + gnu_codes[N_Op_Xor] = TRUTH_XOR_EXPR; + gnu_codes[N_Op_Eq] = EQ_EXPR; + gnu_codes[N_Op_Ne] = NE_EXPR; + gnu_codes[N_Op_Lt] = LT_EXPR; + gnu_codes[N_Op_Le] = LE_EXPR; + gnu_codes[N_Op_Gt] = GT_EXPR; + gnu_codes[N_Op_Ge] = GE_EXPR; + gnu_codes[N_Op_Add] = PLUS_EXPR; + gnu_codes[N_Op_Subtract] = MINUS_EXPR; + gnu_codes[N_Op_Multiply] = MULT_EXPR; + gnu_codes[N_Op_Mod] = FLOOR_MOD_EXPR; + gnu_codes[N_Op_Rem] = TRUNC_MOD_EXPR; + gnu_codes[N_Op_Minus] = NEGATE_EXPR; + gnu_codes[N_Op_Abs] = ABS_EXPR; + gnu_codes[N_Op_Not] = TRUTH_NOT_EXPR; + gnu_codes[N_Op_Rotate_Left] = LROTATE_EXPR; + gnu_codes[N_Op_Rotate_Right] = RROTATE_EXPR; + gnu_codes[N_Op_Shift_Left] = LSHIFT_EXPR; + gnu_codes[N_Op_Shift_Right] = RSHIFT_EXPR; + gnu_codes[N_Op_Shift_Right_Arithmetic] = RSHIFT_EXPR; + gnu_codes[N_And_Then] = TRUTH_ANDIF_EXPR; + gnu_codes[N_Or_Else] = TRUTH_ORIF_EXPR; +} + +#include "gt-ada-trans.h" |