1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * D E C L *
6 * *
7 * C Implementation File *
8 * *
9 * Copyright (C) 1992-2018, Free Software Foundation, Inc. *
10 * *
11 * GNAT is free software; you can redistribute it and/or modify it under *
12 * terms of the GNU General Public License as published by the Free Soft- *
13 * ware Foundation; either version 3, or (at your option) any later ver- *
14 * sion. GNAT is distributed in the hope that it will be useful, but WITH- *
15 * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY *
16 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License *
17 * for more details. You should have received a copy of the GNU General *
18 * Public License along with GCC; see the file COPYING3. If not see *
19 * <http://www.gnu.org/licenses/>. *
20 * *
21 * GNAT was originally developed by the GNAT team at New York University. *
22 * Extensive contributions were provided by Ada Core Technologies Inc. *
23 * *
24 ****************************************************************************/
25
26 #include "config.h"
27 #include "system.h"
28 #include "coretypes.h"
29 #include "target.h"
30 #include "tree.h"
31 #include "stringpool.h"
32 #include "diagnostic-core.h"
33 #include "alias.h"
34 #include "fold-const.h"
35 #include "stor-layout.h"
36 #include "tree-inline.h"
37 #include "demangle.h"
38
39 #include "ada.h"
40 #include "types.h"
41 #include "atree.h"
42 #include "elists.h"
43 #include "namet.h"
44 #include "nlists.h"
45 #include "repinfo.h"
46 #include "snames.h"
47 #include "uintp.h"
48 #include "urealp.h"
49 #include "fe.h"
50 #include "sinfo.h"
51 #include "einfo.h"
52 #include "ada-tree.h"
53 #include "gigi.h"
54
55 /* "stdcall" and "thiscall" conventions should be processed in a specific way
56 on 32-bit x86/Windows only. The macros below are helpers to avoid having
57 to check for a Windows specific attribute throughout this unit. */
58
59 #if TARGET_DLLIMPORT_DECL_ATTRIBUTES
60 #ifdef TARGET_64BIT
61 #define Has_Stdcall_Convention(E) \
62 (!TARGET_64BIT && Convention (E) == Convention_Stdcall)
63 #define Has_Thiscall_Convention(E) \
64 (!TARGET_64BIT && is_cplusplus_method (E))
65 #else
66 #define Has_Stdcall_Convention(E) (Convention (E) == Convention_Stdcall)
67 #define Has_Thiscall_Convention(E) (is_cplusplus_method (E))
68 #endif
69 #else
70 #define Has_Stdcall_Convention(E) 0
71 #define Has_Thiscall_Convention(E) 0
72 #endif
73
74 #define STDCALL_PREFIX "_imp__"
75
76 /* Stack realignment is necessary for functions with foreign conventions when
77 the ABI doesn't mandate as much as what the compiler assumes - that is, up
78 to PREFERRED_STACK_BOUNDARY.
79
80 Such realignment can be requested with a dedicated function type attribute
81 on the targets that support it. We define FOREIGN_FORCE_REALIGN_STACK to
82 characterize the situations where the attribute should be set. We rely on
83 compiler configuration settings for 'main' to decide. */
84
85 #ifdef MAIN_STACK_BOUNDARY
86 #define FOREIGN_FORCE_REALIGN_STACK \
87 (MAIN_STACK_BOUNDARY < PREFERRED_STACK_BOUNDARY)
88 #else
89 #define FOREIGN_FORCE_REALIGN_STACK 0
90 #endif
91
92 struct incomplete
93 {
94 struct incomplete *next;
95 tree old_type;
96 Entity_Id full_type;
97 };
98
99 /* These variables are used to defer recursively expanding incomplete types
100 while we are processing a record, an array or a subprogram type. */
101 static int defer_incomplete_level = 0;
102 static struct incomplete *defer_incomplete_list;
103
104 /* This variable is used to delay expanding types coming from a limited with
105 clause and completed Taft Amendment types until the end of the spec. */
106 static struct incomplete *defer_limited_with_list;
107
108 typedef struct subst_pair_d {
109 tree discriminant;
110 tree replacement;
111 } subst_pair;
112
113
114 typedef struct variant_desc_d {
115 /* The type of the variant. */
116 tree type;
117
118 /* The associated field. */
119 tree field;
120
121 /* The value of the qualifier. */
122 tree qual;
123
124 /* The type of the variant after transformation. */
125 tree new_type;
126 } variant_desc;
127
128
129 /* A map used to cache the result of annotate_value. */
130 struct value_annotation_hasher : ggc_cache_ptr_hash<tree_int_map>
131 {
132 static inline hashval_t
hashvalue_annotation_hasher133 hash (tree_int_map *m)
134 {
135 return htab_hash_pointer (m->base.from);
136 }
137
138 static inline bool
equalvalue_annotation_hasher139 equal (tree_int_map *a, tree_int_map *b)
140 {
141 return a->base.from == b->base.from;
142 }
143
144 static int
keep_cache_entryvalue_annotation_hasher145 keep_cache_entry (tree_int_map *&m)
146 {
147 return ggc_marked_p (m->base.from);
148 }
149 };
150
151 static GTY ((cache)) hash_table<value_annotation_hasher> *annotate_value_cache;
152
153 /* A map used to associate a dummy type with a list of subprogram entities. */
154 struct GTY((for_user)) tree_entity_vec_map
155 {
156 struct tree_map_base base;
157 vec<Entity_Id, va_gc_atomic> *to;
158 };
159
160 void
gt_pch_nx(Entity_Id &)161 gt_pch_nx (Entity_Id &)
162 {
163 }
164
165 void
gt_pch_nx(Entity_Id * x,gt_pointer_operator op,void * cookie)166 gt_pch_nx (Entity_Id *x, gt_pointer_operator op, void *cookie)
167 {
168 op (x, cookie);
169 }
170
171 struct dummy_type_hasher : ggc_cache_ptr_hash<tree_entity_vec_map>
172 {
173 static inline hashval_t
hashdummy_type_hasher174 hash (tree_entity_vec_map *m)
175 {
176 return htab_hash_pointer (m->base.from);
177 }
178
179 static inline bool
equaldummy_type_hasher180 equal (tree_entity_vec_map *a, tree_entity_vec_map *b)
181 {
182 return a->base.from == b->base.from;
183 }
184
185 static int
keep_cache_entrydummy_type_hasher186 keep_cache_entry (tree_entity_vec_map *&m)
187 {
188 return ggc_marked_p (m->base.from);
189 }
190 };
191
192 static GTY ((cache)) hash_table<dummy_type_hasher> *dummy_to_subprog_map;
193
194 static void prepend_one_attribute (struct attrib **,
195 enum attrib_type, tree, tree, Node_Id);
196 static void prepend_one_attribute_pragma (struct attrib **, Node_Id);
197 static void prepend_attributes (struct attrib **, Entity_Id);
198 static tree elaborate_expression (Node_Id, Entity_Id, const char *, bool, bool,
199 bool);
200 static bool type_has_variable_size (tree);
201 static tree elaborate_expression_1 (tree, Entity_Id, const char *, bool, bool);
202 static tree elaborate_expression_2 (tree, Entity_Id, const char *, bool, bool,
203 unsigned int);
204 static tree elaborate_reference (tree, Entity_Id, bool, tree *);
205 static tree gnat_to_gnu_component_type (Entity_Id, bool, bool);
206 static tree gnat_to_gnu_subprog_type (Entity_Id, bool, bool, tree *);
207 static int adjust_packed (tree, tree, int);
208 static tree gnat_to_gnu_field (Entity_Id, tree, int, bool, bool);
209 static tree gnu_ext_name_for_subprog (Entity_Id, tree);
210 static void set_nonaliased_component_on_array_type (tree);
211 static void set_reverse_storage_order_on_array_type (tree);
212 static bool same_discriminant_p (Entity_Id, Entity_Id);
213 static bool array_type_has_nonaliased_component (tree, Entity_Id);
214 static bool compile_time_known_address_p (Node_Id);
215 static bool cannot_be_superflat (Node_Id);
216 static bool constructor_address_p (tree);
217 static bool allocatable_size_p (tree, bool);
218 static bool initial_value_needs_conversion (tree, tree);
219 static int compare_field_bitpos (const PTR, const PTR);
220 static bool components_to_record (Node_Id, Entity_Id, tree, tree, int, bool,
221 bool, bool, bool, bool, bool, bool, tree,
222 tree *);
223 static Uint annotate_value (tree);
224 static void annotate_rep (Entity_Id, tree);
225 static tree build_position_list (tree, bool, tree, tree, unsigned int, tree);
226 static vec<subst_pair> build_subst_list (Entity_Id, Entity_Id, bool);
227 static vec<variant_desc> build_variant_list (tree, vec<subst_pair>,
228 vec<variant_desc>);
229 static tree validate_size (Uint, tree, Entity_Id, enum tree_code, bool, bool);
230 static void set_rm_size (Uint, tree, Entity_Id);
231 static unsigned int validate_alignment (Uint, Entity_Id, unsigned int);
232 static unsigned int promote_object_alignment (tree, Entity_Id);
233 static void check_ok_for_atomic_type (tree, Entity_Id, bool);
234 static tree create_field_decl_from (tree, tree, tree, tree, tree,
235 vec<subst_pair>);
236 static tree create_rep_part (tree, tree, tree);
237 static tree get_rep_part (tree);
238 static tree create_variant_part_from (tree, vec<variant_desc>, tree,
239 tree, vec<subst_pair>, bool);
240 static void copy_and_substitute_in_size (tree, tree, vec<subst_pair>);
241 static void copy_and_substitute_in_layout (Entity_Id, Entity_Id, tree, tree,
242 vec<subst_pair>, bool);
243 static void associate_original_type_to_packed_array (tree, Entity_Id);
244 static const char *get_entity_char (Entity_Id);
245
246 /* The relevant constituents of a subprogram binding to a GCC builtin. Used
247 to pass around calls performing profile compatibility checks. */
248
249 typedef struct {
250 Entity_Id gnat_entity; /* The Ada subprogram entity. */
251 tree ada_fntype; /* The corresponding GCC type node. */
252 tree btin_fntype; /* The GCC builtin function type node. */
253 } intrin_binding_t;
254
255 static bool intrin_profiles_compatible_p (intrin_binding_t *);
256
257 /* Given GNAT_ENTITY, a GNAT defining identifier node, which denotes some Ada
258 entity, return the equivalent GCC tree for that entity (a ..._DECL node)
259 and associate the ..._DECL node with the input GNAT defining identifier.
260
261 If GNAT_ENTITY is a variable or a constant declaration, GNU_EXPR gives its
262 initial value (in GCC tree form). This is optional for a variable. For
263 a renamed entity, GNU_EXPR gives the object being renamed.
264
265 DEFINITION is true if this call is intended for a definition. This is used
266 for separate compilation where it is necessary to know whether an external
267 declaration or a definition must be created if the GCC equivalent was not
268 created previously. */
269
270 tree
gnat_to_gnu_entity(Entity_Id gnat_entity,tree gnu_expr,bool definition)271 gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
272 {
273 /* Contains the kind of the input GNAT node. */
274 const Entity_Kind kind = Ekind (gnat_entity);
275 /* True if this is a type. */
276 const bool is_type = IN (kind, Type_Kind);
277 /* True if this is an artificial entity. */
278 const bool artificial_p = !Comes_From_Source (gnat_entity);
279 /* True if debug info is requested for this entity. */
280 const bool debug_info_p = Needs_Debug_Info (gnat_entity);
281 /* True if this entity is to be considered as imported. */
282 const bool imported_p
283 = (Is_Imported (gnat_entity) && No (Address_Clause (gnat_entity)));
284 /* For a type, contains the equivalent GNAT node to be used in gigi. */
285 Entity_Id gnat_equiv_type = Empty;
286 /* Temporary used to walk the GNAT tree. */
287 Entity_Id gnat_temp;
288 /* Contains the GCC DECL node which is equivalent to the input GNAT node.
289 This node will be associated with the GNAT node by calling at the end
290 of the `switch' statement. */
291 tree gnu_decl = NULL_TREE;
292 /* Contains the GCC type to be used for the GCC node. */
293 tree gnu_type = NULL_TREE;
294 /* Contains the GCC size tree to be used for the GCC node. */
295 tree gnu_size = NULL_TREE;
296 /* Contains the GCC name to be used for the GCC node. */
297 tree gnu_entity_name;
298 /* True if we have already saved gnu_decl as a GNAT association. */
299 bool saved = false;
300 /* True if we incremented defer_incomplete_level. */
301 bool this_deferred = false;
302 /* True if we incremented force_global. */
303 bool this_global = false;
304 /* True if we should check to see if elaborated during processing. */
305 bool maybe_present = false;
306 /* True if we made GNU_DECL and its type here. */
307 bool this_made_decl = false;
308 /* Size and alignment of the GCC node, if meaningful. */
309 unsigned int esize = 0, align = 0;
310 /* Contains the list of attributes directly attached to the entity. */
311 struct attrib *attr_list = NULL;
312
313 /* Since a use of an Itype is a definition, process it as such if it is in
314 the main unit, except for E_Access_Subtype because it's actually a use
315 of its base type, and for E_Record_Subtype with cloned subtype because
316 it's actually a use of the cloned subtype, see below. */
317 if (!definition
318 && is_type
319 && Is_Itype (gnat_entity)
320 && !(kind == E_Access_Subtype
321 || (kind == E_Record_Subtype
322 && Present (Cloned_Subtype (gnat_entity))))
323 && !present_gnu_tree (gnat_entity)
324 && In_Extended_Main_Code_Unit (gnat_entity))
325 {
326 /* Ensure that we are in a subprogram mentioned in the Scope chain of
327 this entity, our current scope is global, or we encountered a task
328 or entry (where we can't currently accurately check scoping). */
329 if (!current_function_decl
330 || DECL_ELABORATION_PROC_P (current_function_decl))
331 {
332 process_type (gnat_entity);
333 return get_gnu_tree (gnat_entity);
334 }
335
336 for (gnat_temp = Scope (gnat_entity);
337 Present (gnat_temp);
338 gnat_temp = Scope (gnat_temp))
339 {
340 if (Is_Type (gnat_temp))
341 gnat_temp = Underlying_Type (gnat_temp);
342
343 if (Ekind (gnat_temp) == E_Subprogram_Body)
344 gnat_temp
345 = Corresponding_Spec (Parent (Declaration_Node (gnat_temp)));
346
347 if (Is_Subprogram (gnat_temp)
348 && Present (Protected_Body_Subprogram (gnat_temp)))
349 gnat_temp = Protected_Body_Subprogram (gnat_temp);
350
351 if (Ekind (gnat_temp) == E_Entry
352 || Ekind (gnat_temp) == E_Entry_Family
353 || Ekind (gnat_temp) == E_Task_Type
354 || (Is_Subprogram (gnat_temp)
355 && present_gnu_tree (gnat_temp)
356 && (current_function_decl
357 == gnat_to_gnu_entity (gnat_temp, NULL_TREE, false))))
358 {
359 process_type (gnat_entity);
360 return get_gnu_tree (gnat_entity);
361 }
362 }
363
364 /* This abort means the Itype has an incorrect scope, i.e. that its
365 scope does not correspond to the subprogram it is declared in. */
366 gcc_unreachable ();
367 }
368
369 /* If we've already processed this entity, return what we got last time.
370 If we are defining the node, we should not have already processed it.
371 In that case, we will abort below when we try to save a new GCC tree
372 for this object. We also need to handle the case of getting a dummy
373 type when a Full_View exists but be careful so as not to trigger its
374 premature elaboration. */
375 if ((!definition || (is_type && imported_p))
376 && present_gnu_tree (gnat_entity))
377 {
378 gnu_decl = get_gnu_tree (gnat_entity);
379
380 if (TREE_CODE (gnu_decl) == TYPE_DECL
381 && TYPE_IS_DUMMY_P (TREE_TYPE (gnu_decl))
382 && IN (kind, Incomplete_Or_Private_Kind)
383 && Present (Full_View (gnat_entity))
384 && (present_gnu_tree (Full_View (gnat_entity))
385 || No (Freeze_Node (Full_View (gnat_entity)))))
386 {
387 gnu_decl
388 = gnat_to_gnu_entity (Full_View (gnat_entity), NULL_TREE, false);
389 save_gnu_tree (gnat_entity, NULL_TREE, false);
390 save_gnu_tree (gnat_entity, gnu_decl, false);
391 }
392
393 return gnu_decl;
394 }
395
396 /* If this is a numeric or enumeral type, or an access type, a nonzero Esize
397 must be specified unless it was specified by the programmer. Exceptions
398 are for access-to-protected-subprogram types and all access subtypes, as
399 another GNAT type is used to lay out the GCC type for them. */
400 gcc_assert (!is_type
401 || Known_Esize (gnat_entity)
402 || Has_Size_Clause (gnat_entity)
403 || (!IN (kind, Numeric_Kind)
404 && !IN (kind, Enumeration_Kind)
405 && (!IN (kind, Access_Kind)
406 || kind == E_Access_Protected_Subprogram_Type
407 || kind == E_Anonymous_Access_Protected_Subprogram_Type
408 || kind == E_Access_Subtype
409 || type_annotate_only)));
410
411 /* The RM size must be specified for all discrete and fixed-point types. */
412 gcc_assert (!(IN (kind, Discrete_Or_Fixed_Point_Kind)
413 && Unknown_RM_Size (gnat_entity)));
414
415 /* If we get here, it means we have not yet done anything with this entity.
416 If we are not defining it, it must be a type or an entity that is defined
417 elsewhere or externally, otherwise we should have defined it already. */
418 gcc_assert (definition
419 || type_annotate_only
420 || is_type
421 || kind == E_Discriminant
422 || kind == E_Component
423 || kind == E_Label
424 || (kind == E_Constant && Present (Full_View (gnat_entity)))
425 || Is_Public (gnat_entity));
426
427 /* Get the name of the entity and set up the line number and filename of
428 the original definition for use in any decl we make. Make sure we do not
429 inherit another source location. */
430 gnu_entity_name = get_entity_name (gnat_entity);
431 if (Sloc (gnat_entity) != No_Location
432 && !renaming_from_instantiation_p (gnat_entity))
433 Sloc_to_locus (Sloc (gnat_entity), &input_location);
434
435 /* For cases when we are not defining (i.e., we are referencing from
436 another compilation unit) public entities, show we are at global level
437 for the purpose of computing scopes. Don't do this for components or
438 discriminants since the relevant test is whether or not the record is
439 being defined. */
440 if (!definition
441 && kind != E_Component
442 && kind != E_Discriminant
443 && Is_Public (gnat_entity)
444 && !Is_Statically_Allocated (gnat_entity))
445 force_global++, this_global = true;
446
447 /* Handle any attributes directly attached to the entity. */
448 if (Has_Gigi_Rep_Item (gnat_entity))
449 prepend_attributes (&attr_list, gnat_entity);
450
451 /* Do some common processing for types. */
452 if (is_type)
453 {
454 /* Compute the equivalent type to be used in gigi. */
455 gnat_equiv_type = Gigi_Equivalent_Type (gnat_entity);
456
457 /* Machine_Attributes on types are expected to be propagated to
458 subtypes. The corresponding Gigi_Rep_Items are only attached
459 to the first subtype though, so we handle the propagation here. */
460 if (Base_Type (gnat_entity) != gnat_entity
461 && !Is_First_Subtype (gnat_entity)
462 && Has_Gigi_Rep_Item (First_Subtype (Base_Type (gnat_entity))))
463 prepend_attributes (&attr_list,
464 First_Subtype (Base_Type (gnat_entity)));
465
466 /* Compute a default value for the size of an elementary type. */
467 if (Known_Esize (gnat_entity) && Is_Elementary_Type (gnat_entity))
468 {
469 unsigned int max_esize;
470
471 gcc_assert (UI_Is_In_Int_Range (Esize (gnat_entity)));
472 esize = UI_To_Int (Esize (gnat_entity));
473
474 if (IN (kind, Float_Kind))
475 max_esize = fp_prec_to_size (LONG_DOUBLE_TYPE_SIZE);
476 else if (IN (kind, Access_Kind))
477 max_esize = POINTER_SIZE * 2;
478 else
479 max_esize = LONG_LONG_TYPE_SIZE;
480
481 if (esize > max_esize)
482 esize = max_esize;
483 }
484 }
485
486 switch (kind)
487 {
488 case E_Component:
489 case E_Discriminant:
490 {
491 /* The GNAT record where the component was defined. */
492 Entity_Id gnat_record = Underlying_Type (Scope (gnat_entity));
493
494 /* If the entity is a discriminant of an extended tagged type used to
495 rename a discriminant of the parent type, return the latter. */
496 if (kind == E_Discriminant
497 && Present (Corresponding_Discriminant (gnat_entity))
498 && Is_Tagged_Type (gnat_record))
499 {
500 gnu_decl
501 = gnat_to_gnu_entity (Corresponding_Discriminant (gnat_entity),
502 gnu_expr, definition);
503 saved = true;
504 break;
505 }
506
507 /* If the entity is an inherited component (in the case of extended
508 tagged record types), just return the original entity, which must
509 be a FIELD_DECL. Likewise for discriminants. If the entity is a
510 non-girder discriminant (in the case of derived untagged record
511 types), return the stored discriminant it renames. */
512 if (Present (Original_Record_Component (gnat_entity))
513 && Original_Record_Component (gnat_entity) != gnat_entity)
514 {
515 gnu_decl
516 = gnat_to_gnu_entity (Original_Record_Component (gnat_entity),
517 gnu_expr, definition);
518 /* GNU_DECL contains a PLACEHOLDER_EXPR for discriminants. */
519 if (kind == E_Discriminant)
520 saved = true;
521 break;
522 }
523
524 /* Otherwise, if we are not defining this and we have no GCC type
525 for the containing record, make one for it. Then we should
526 have made our own equivalent. */
527 if (!definition && !present_gnu_tree (gnat_record))
528 {
529 /* ??? If this is in a record whose scope is a protected
530 type and we have an Original_Record_Component, use it.
531 This is a workaround for major problems in protected type
532 handling. */
533 Entity_Id Scop = Scope (Scope (gnat_entity));
534 if (Is_Protected_Type (Underlying_Type (Scop))
535 && Present (Original_Record_Component (gnat_entity)))
536 {
537 gnu_decl
538 = gnat_to_gnu_entity (Original_Record_Component
539 (gnat_entity),
540 gnu_expr, false);
541 }
542 else
543 {
544 gnat_to_gnu_entity (Scope (gnat_entity), NULL_TREE, false);
545 gnu_decl = get_gnu_tree (gnat_entity);
546 }
547
548 saved = true;
549 break;
550 }
551
552 /* Here we have no GCC type and this is a reference rather than a
553 definition. This should never happen. Most likely the cause is
554 reference before declaration in the GNAT tree for gnat_entity. */
555 gcc_unreachable ();
556 }
557
558 case E_Constant:
559 /* Ignore constant definitions already marked with the error node. See
560 the N_Object_Declaration case of gnat_to_gnu for the rationale. */
561 if (definition
562 && present_gnu_tree (gnat_entity)
563 && get_gnu_tree (gnat_entity) == error_mark_node)
564 {
565 maybe_present = true;
566 break;
567 }
568
569 /* Ignore deferred constant definitions without address clause since
570 they are processed fully in the front-end. If No_Initialization
571 is set, this is not a deferred constant but a constant whose value
572 is built manually. And constants that are renamings are handled
573 like variables. */
574 if (definition
575 && !gnu_expr
576 && No (Address_Clause (gnat_entity))
577 && !No_Initialization (Declaration_Node (gnat_entity))
578 && No (Renamed_Object (gnat_entity)))
579 {
580 gnu_decl = error_mark_node;
581 saved = true;
582 break;
583 }
584
585 /* If this is a use of a deferred constant without address clause,
586 get its full definition. */
587 if (!definition
588 && No (Address_Clause (gnat_entity))
589 && Present (Full_View (gnat_entity)))
590 {
591 gnu_decl
592 = gnat_to_gnu_entity (Full_View (gnat_entity), gnu_expr, false);
593 saved = true;
594 break;
595 }
596
597 /* If we have a constant that we are not defining, get the expression it
598 was defined to represent. This is necessary to avoid generating dumb
599 elaboration code in simple cases, but we may throw it away later if it
600 is not a constant. But do not do it for dispatch tables because they
601 are only referenced indirectly and we need to have a consistent view
602 of the exported and of the imported declarations of the tables from
603 external units for them to be properly merged in LTO mode. Moreover
604 simply do not retrieve the expression it if it is an allocator since
605 the designated type might still be dummy at this point. Note that we
606 invoke gnat_to_gnu_external and not gnat_to_gnu because the expression
607 may contain N_Expression_With_Actions nodes and thus declarations of
608 objects from other units that we need to discard. */
609 if (!definition
610 && !No_Initialization (Declaration_Node (gnat_entity))
611 && !Is_Dispatch_Table_Entity (gnat_entity)
612 && Present (gnat_temp = Expression (Declaration_Node (gnat_entity)))
613 && Nkind (gnat_temp) != N_Allocator
614 && (!type_annotate_only || Compile_Time_Known_Value (gnat_temp)))
615 gnu_expr = gnat_to_gnu_external (gnat_temp);
616
617 /* ... fall through ... */
618
619 case E_Exception:
620 case E_Loop_Parameter:
621 case E_Out_Parameter:
622 case E_Variable:
623 {
624 const Entity_Id gnat_type = Etype (gnat_entity);
625 /* Always create a variable for volatile objects and variables seen
626 constant but with a Linker_Section pragma. */
627 bool const_flag
628 = ((kind == E_Constant || kind == E_Variable)
629 && Is_True_Constant (gnat_entity)
630 && !(kind == E_Variable
631 && Present (Linker_Section_Pragma (gnat_entity)))
632 && !Treat_As_Volatile (gnat_entity)
633 && (((Nkind (Declaration_Node (gnat_entity))
634 == N_Object_Declaration)
635 && Present (Expression (Declaration_Node (gnat_entity))))
636 || Present (Renamed_Object (gnat_entity))
637 || imported_p));
638 bool inner_const_flag = const_flag;
639 bool static_flag = Is_Statically_Allocated (gnat_entity);
640 /* We implement RM 13.3(19) for exported and imported (non-constant)
641 objects by making them volatile. */
642 bool volatile_flag
643 = (Treat_As_Volatile (gnat_entity)
644 || (!const_flag && (Is_Exported (gnat_entity) || imported_p)));
645 bool mutable_p = false;
646 bool used_by_ref = false;
647 tree gnu_ext_name = NULL_TREE;
648 tree renamed_obj = NULL_TREE;
649 tree gnu_object_size;
650
651 /* We need to translate the renamed object even though we are only
652 referencing the renaming. But it may contain a call for which
653 we'll generate a temporary to hold the return value and which
654 is part of the definition of the renaming, so discard it. */
655 if (Present (Renamed_Object (gnat_entity)) && !definition)
656 {
657 if (kind == E_Exception)
658 gnu_expr = gnat_to_gnu_entity (Renamed_Entity (gnat_entity),
659 NULL_TREE, false);
660 else
661 gnu_expr = gnat_to_gnu_external (Renamed_Object (gnat_entity));
662 }
663
664 /* Get the type after elaborating the renamed object. */
665 if (Has_Foreign_Convention (gnat_entity)
666 && Is_Descendant_Of_Address (Underlying_Type (gnat_type)))
667 gnu_type = ptr_type_node;
668 else
669 {
670 gnu_type = gnat_to_gnu_type (gnat_type);
671
672 /* If this is a standard exception definition, use the standard
673 exception type. This is necessary to make sure that imported
674 and exported views of exceptions are merged in LTO mode. */
675 if (TREE_CODE (TYPE_NAME (gnu_type)) == TYPE_DECL
676 && DECL_NAME (TYPE_NAME (gnu_type)) == exception_data_name_id)
677 gnu_type = except_type_node;
678 }
679
680 /* For a debug renaming declaration, build a debug-only entity. */
681 if (Present (Debug_Renaming_Link (gnat_entity)))
682 {
683 /* Force a non-null value to make sure the symbol is retained. */
684 tree value = build1 (INDIRECT_REF, gnu_type,
685 build1 (NOP_EXPR,
686 build_pointer_type (gnu_type),
687 integer_minus_one_node));
688 gnu_decl = build_decl (input_location,
689 VAR_DECL, gnu_entity_name, gnu_type);
690 SET_DECL_VALUE_EXPR (gnu_decl, value);
691 DECL_HAS_VALUE_EXPR_P (gnu_decl) = 1;
692 TREE_STATIC (gnu_decl) = global_bindings_p ();
693 gnat_pushdecl (gnu_decl, gnat_entity);
694 break;
695 }
696
697 /* If this is a loop variable, its type should be the base type.
698 This is because the code for processing a loop determines whether
699 a normal loop end test can be done by comparing the bounds of the
700 loop against those of the base type, which is presumed to be the
701 size used for computation. But this is not correct when the size
702 of the subtype is smaller than the type. */
703 if (kind == E_Loop_Parameter)
704 gnu_type = get_base_type (gnu_type);
705
706 /* Reject non-renamed objects whose type is an unconstrained array or
707 any object whose type is a dummy type or void. */
708 if ((TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE
709 && No (Renamed_Object (gnat_entity)))
710 || TYPE_IS_DUMMY_P (gnu_type)
711 || TREE_CODE (gnu_type) == VOID_TYPE)
712 {
713 gcc_assert (type_annotate_only);
714 if (this_global)
715 force_global--;
716 return error_mark_node;
717 }
718
719 /* If an alignment is specified, use it if valid. Note that exceptions
720 are objects but don't have an alignment and there is also no point in
721 setting it for an address clause, since the final type of the object
722 will be a reference type. */
723 if (Known_Alignment (gnat_entity)
724 && kind != E_Exception
725 && No (Address_Clause (gnat_entity)))
726 align = validate_alignment (Alignment (gnat_entity), gnat_entity,
727 TYPE_ALIGN (gnu_type));
728
729 /* Likewise, if a size is specified, use it if valid. */
730 if (Known_Esize (gnat_entity))
731 gnu_size
732 = validate_size (Esize (gnat_entity), gnu_type, gnat_entity,
733 VAR_DECL, false, Has_Size_Clause (gnat_entity));
734 if (gnu_size)
735 {
736 gnu_type
737 = make_type_from_size (gnu_type, gnu_size,
738 Has_Biased_Representation (gnat_entity));
739
740 if (operand_equal_p (TYPE_SIZE (gnu_type), gnu_size, 0))
741 gnu_size = NULL_TREE;
742 }
743
744 /* If this object has self-referential size, it must be a record with
745 a default discriminant. We are supposed to allocate an object of
746 the maximum size in this case, unless it is a constant with an
747 initializing expression, in which case we can get the size from
748 that. Note that the resulting size may still be a variable, so
749 this may end up with an indirect allocation. */
750 if (No (Renamed_Object (gnat_entity))
751 && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type)))
752 {
753 if (gnu_expr && kind == E_Constant)
754 {
755 tree size = TYPE_SIZE (TREE_TYPE (gnu_expr));
756 if (CONTAINS_PLACEHOLDER_P (size))
757 {
758 /* If the initializing expression is itself a constant,
759 despite having a nominal type with self-referential
760 size, we can get the size directly from it. */
761 if (TREE_CODE (gnu_expr) == COMPONENT_REF
762 && TYPE_IS_PADDING_P
763 (TREE_TYPE (TREE_OPERAND (gnu_expr, 0)))
764 && TREE_CODE (TREE_OPERAND (gnu_expr, 0)) == VAR_DECL
765 && (TREE_READONLY (TREE_OPERAND (gnu_expr, 0))
766 || DECL_READONLY_ONCE_ELAB
767 (TREE_OPERAND (gnu_expr, 0))))
768 gnu_size = DECL_SIZE (TREE_OPERAND (gnu_expr, 0));
769 else
770 gnu_size
771 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, gnu_expr);
772 }
773 else
774 gnu_size = size;
775 }
776 /* We may have no GNU_EXPR because No_Initialization is
777 set even though there's an Expression. */
778 else if (kind == E_Constant
779 && (Nkind (Declaration_Node (gnat_entity))
780 == N_Object_Declaration)
781 && Present (Expression (Declaration_Node (gnat_entity))))
782 gnu_size
783 = TYPE_SIZE (gnat_to_gnu_type
784 (Etype
785 (Expression (Declaration_Node (gnat_entity)))));
786 else
787 {
788 gnu_size = max_size (TYPE_SIZE (gnu_type), true);
789 mutable_p = true;
790 }
791
792 /* If the size isn't constant and we are at global level, call
793 elaborate_expression_1 to make a variable for it rather than
794 calculating it each time. */
795 if (!TREE_CONSTANT (gnu_size) && global_bindings_p ())
796 gnu_size = elaborate_expression_1 (gnu_size, gnat_entity,
797 "SIZE", definition, false);
798 }
799
800 /* If the size is zero byte, make it one byte since some linkers have
801 troubles with zero-sized objects. If the object will have a
802 template, that will make it nonzero so don't bother. Also avoid
803 doing that for an object renaming or an object with an address
804 clause, as we would lose useful information on the view size
805 (e.g. for null array slices) and we are not allocating the object
806 here anyway. */
807 if (((gnu_size
808 && integer_zerop (gnu_size)
809 && !TREE_OVERFLOW (gnu_size))
810 || (TYPE_SIZE (gnu_type)
811 && integer_zerop (TYPE_SIZE (gnu_type))
812 && !TREE_OVERFLOW (TYPE_SIZE (gnu_type))))
813 && !Is_Constr_Subt_For_UN_Aliased (gnat_type)
814 && No (Renamed_Object (gnat_entity))
815 && No (Address_Clause (gnat_entity)))
816 gnu_size = bitsize_unit_node;
817
818 /* If this is an object with no specified size and alignment, and
819 if either it is atomic or we are not optimizing alignment for
820 space and it is composite and not an exception, an Out parameter
821 or a reference to another object, and the size of its type is a
822 constant, set the alignment to the smallest one which is not
823 smaller than the size, with an appropriate cap. */
824 if (!gnu_size && align == 0
825 && (Is_Atomic_Or_VFA (gnat_entity)
826 || (!Optimize_Alignment_Space (gnat_entity)
827 && kind != E_Exception
828 && kind != E_Out_Parameter
829 && Is_Composite_Type (gnat_type)
830 && !Is_Constr_Subt_For_UN_Aliased (gnat_type)
831 && !Is_Exported (gnat_entity)
832 && !imported_p
833 && No (Renamed_Object (gnat_entity))
834 && No (Address_Clause (gnat_entity))))
835 && TREE_CODE (TYPE_SIZE (gnu_type)) == INTEGER_CST)
836 align = promote_object_alignment (gnu_type, gnat_entity);
837
838 /* If the object is set to have atomic components, find the component
839 type and validate it.
840
841 ??? Note that we ignore Has_Volatile_Components on objects; it's
842 not at all clear what to do in that case. */
843 if (Has_Atomic_Components (gnat_entity))
844 {
845 tree gnu_inner = (TREE_CODE (gnu_type) == ARRAY_TYPE
846 ? TREE_TYPE (gnu_type) : gnu_type);
847
848 while (TREE_CODE (gnu_inner) == ARRAY_TYPE
849 && TYPE_MULTI_ARRAY_P (gnu_inner))
850 gnu_inner = TREE_TYPE (gnu_inner);
851
852 check_ok_for_atomic_type (gnu_inner, gnat_entity, true);
853 }
854
855 /* If this is an aliased object with an unconstrained array nominal
856 subtype, make a type that includes the template. We will either
857 allocate or create a variable of that type, see below. */
858 if (Is_Constr_Subt_For_UN_Aliased (gnat_type)
859 && Is_Array_Type (Underlying_Type (gnat_type))
860 && !type_annotate_only)
861 {
862 tree gnu_array = gnat_to_gnu_type (Base_Type (gnat_type));
863 gnu_type
864 = build_unc_object_type_from_ptr (TREE_TYPE (gnu_array),
865 gnu_type,
866 concat_name (gnu_entity_name,
867 "UNC"),
868 debug_info_p);
869 }
870
871 /* ??? If this is an object of CW type initialized to a value, try to
872 ensure that the object is sufficient aligned for this value, but
873 without pessimizing the allocation. This is a kludge necessary
874 because we don't support dynamic alignment. */
875 if (align == 0
876 && Ekind (gnat_type) == E_Class_Wide_Subtype
877 && No (Renamed_Object (gnat_entity))
878 && No (Address_Clause (gnat_entity)))
879 align = get_target_system_allocator_alignment () * BITS_PER_UNIT;
880
881 #ifdef MINIMUM_ATOMIC_ALIGNMENT
882 /* If the size is a constant and no alignment is specified, force
883 the alignment to be the minimum valid atomic alignment. The
884 restriction on constant size avoids problems with variable-size
885 temporaries; if the size is variable, there's no issue with
886 atomic access. Also don't do this for a constant, since it isn't
887 necessary and can interfere with constant replacement. Finally,
888 do not do it for Out parameters since that creates an
889 size inconsistency with In parameters. */
890 if (align == 0
891 && MINIMUM_ATOMIC_ALIGNMENT > TYPE_ALIGN (gnu_type)
892 && !FLOAT_TYPE_P (gnu_type)
893 && !const_flag && No (Renamed_Object (gnat_entity))
894 && !imported_p && No (Address_Clause (gnat_entity))
895 && kind != E_Out_Parameter
896 && (gnu_size ? TREE_CODE (gnu_size) == INTEGER_CST
897 : TREE_CODE (TYPE_SIZE (gnu_type)) == INTEGER_CST))
898 align = MINIMUM_ATOMIC_ALIGNMENT;
899 #endif
900
901 /* Make a new type with the desired size and alignment, if needed.
902 But do not take into account alignment promotions to compute the
903 size of the object. */
904 gnu_object_size = gnu_size ? gnu_size : TYPE_SIZE (gnu_type);
905 if (gnu_size || align > 0)
906 {
907 tree orig_type = gnu_type;
908
909 gnu_type = maybe_pad_type (gnu_type, gnu_size, align, gnat_entity,
910 false, false, definition, true);
911
912 /* If a padding record was made, declare it now since it will
913 never be declared otherwise. This is necessary to ensure
914 that its subtrees are properly marked. */
915 if (gnu_type != orig_type && !DECL_P (TYPE_NAME (gnu_type)))
916 create_type_decl (TYPE_NAME (gnu_type), gnu_type, true,
917 debug_info_p, gnat_entity);
918 }
919
920 /* Now check if the type of the object allows atomic access. */
921 if (Is_Atomic_Or_VFA (gnat_entity))
922 check_ok_for_atomic_type (gnu_type, gnat_entity, false);
923
924 /* If this is a renaming, avoid as much as possible to create a new
925 object. However, in some cases, creating it is required because
926 renaming can be applied to objects that are not names in Ada.
927 This processing needs to be applied to the raw expression so as
928 to make it more likely to rename the underlying object. */
929 if (Present (Renamed_Object (gnat_entity)))
930 {
931 /* If the renamed object had padding, strip off the reference to
932 the inner object and reset our type. */
933 if ((TREE_CODE (gnu_expr) == COMPONENT_REF
934 && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (gnu_expr, 0))))
935 /* Strip useless conversions around the object. */
936 || gnat_useless_type_conversion (gnu_expr))
937 {
938 gnu_expr = TREE_OPERAND (gnu_expr, 0);
939 gnu_type = TREE_TYPE (gnu_expr);
940 }
941
942 /* Or else, if the renamed object has an unconstrained type with
943 default discriminant, use the padded type. */
944 else if (type_is_padding_self_referential (TREE_TYPE (gnu_expr)))
945 gnu_type = TREE_TYPE (gnu_expr);
946
947 /* Case 1: if this is a constant renaming stemming from a function
948 call, treat it as a normal object whose initial value is what
949 is being renamed. RM 3.3 says that the result of evaluating a
950 function call is a constant object. Therefore, it can be the
951 inner object of a constant renaming and the renaming must be
952 fully instantiated, i.e. it cannot be a reference to (part of)
953 an existing object. And treat other rvalues the same way. */
954 tree inner = gnu_expr;
955 while (handled_component_p (inner) || CONVERT_EXPR_P (inner))
956 inner = TREE_OPERAND (inner, 0);
957 /* Expand_Dispatching_Call can prepend a comparison of the tags
958 before the call to "=". */
959 if (TREE_CODE (inner) == TRUTH_ANDIF_EXPR
960 || TREE_CODE (inner) == COMPOUND_EXPR)
961 inner = TREE_OPERAND (inner, 1);
962 if ((TREE_CODE (inner) == CALL_EXPR
963 && !call_is_atomic_load (inner))
964 || TREE_CODE (inner) == CONSTRUCTOR
965 || CONSTANT_CLASS_P (inner)
966 || COMPARISON_CLASS_P (inner)
967 || BINARY_CLASS_P (inner)
968 || EXPRESSION_CLASS_P (inner)
969 /* We need to detect the case where a temporary is created to
970 hold the return value, since we cannot safely rename it at
971 top level as it lives only in the elaboration routine. */
972 || (TREE_CODE (inner) == VAR_DECL
973 && DECL_RETURN_VALUE_P (inner))
974 /* We also need to detect the case where the front-end creates
975 a dangling 'reference to a function call at top level and
976 substitutes it in the renaming, for example:
977
978 q__b : boolean renames r__f.e (1);
979
980 can be rewritten into:
981
982 q__R1s : constant q__A2s := r__f'reference;
983 [...]
984 q__b : boolean renames q__R1s.all.e (1);
985
986 We cannot safely rename the rewritten expression since the
987 underlying object lives only in the elaboration routine. */
988 || (TREE_CODE (inner) == INDIRECT_REF
989 && (inner
990 = remove_conversions (TREE_OPERAND (inner, 0), true))
991 && TREE_CODE (inner) == VAR_DECL
992 && DECL_RETURN_VALUE_P (inner)))
993 ;
994
995 /* Case 2: if the renaming entity need not be materialized, use
996 the elaborated renamed expression for the renaming. But this
997 means that the caller is responsible for evaluating the address
998 of the renaming in the correct place for the definition case to
999 instantiate the SAVE_EXPRs. */
1000 else if (!Materialize_Entity (gnat_entity))
1001 {
1002 tree init = NULL_TREE;
1003
1004 gnu_decl
1005 = elaborate_reference (gnu_expr, gnat_entity, definition,
1006 &init);
1007
1008 /* We cannot evaluate the first arm of a COMPOUND_EXPR in the
1009 correct place for this case. */
1010 gcc_assert (!init);
1011
1012 /* No DECL_EXPR will be created so the expression needs to be
1013 marked manually because it will likely be shared. */
1014 if (global_bindings_p ())
1015 MARK_VISITED (gnu_decl);
1016
1017 /* This assertion will fail if the renamed object isn't aligned
1018 enough as to make it possible to honor the alignment set on
1019 the renaming. */
1020 if (align)
1021 {
1022 unsigned int ralign = DECL_P (gnu_decl)
1023 ? DECL_ALIGN (gnu_decl)
1024 : TYPE_ALIGN (TREE_TYPE (gnu_decl));
1025 gcc_assert (ralign >= align);
1026 }
1027
1028 /* The expression might not be a DECL so save it manually. */
1029 save_gnu_tree (gnat_entity, gnu_decl, true);
1030 saved = true;
1031 annotate_object (gnat_entity, gnu_type, NULL_TREE, false);
1032 break;
1033 }
1034
1035 /* Case 3: otherwise, make a constant pointer to the object we
1036 are renaming and attach the object to the pointer after it is
1037 elaborated. The object will be referenced directly instead
1038 of indirectly via the pointer to avoid aliasing problems with
1039 non-addressable entities. The pointer is called a "renaming"
1040 pointer in this case. Note that we also need to preserve the
1041 volatility of the renamed object through the indirection. */
1042 else
1043 {
1044 tree init = NULL_TREE;
1045
1046 if (TREE_THIS_VOLATILE (gnu_expr) && !TYPE_VOLATILE (gnu_type))
1047 gnu_type
1048 = change_qualified_type (gnu_type, TYPE_QUAL_VOLATILE);
1049 gnu_type = build_reference_type (gnu_type);
1050 used_by_ref = true;
1051 const_flag = true;
1052 volatile_flag = false;
1053 inner_const_flag = TREE_READONLY (gnu_expr);
1054 gnu_size = NULL_TREE;
1055
1056 renamed_obj
1057 = elaborate_reference (gnu_expr, gnat_entity, definition,
1058 &init);
1059
1060 /* The expression needs to be marked manually because it will
1061 likely be shared, even for a definition since the ADDR_EXPR
1062 built below can cause the first few nodes to be folded. */
1063 if (global_bindings_p ())
1064 MARK_VISITED (renamed_obj);
1065
1066 if (type_annotate_only
1067 && TREE_CODE (renamed_obj) == ERROR_MARK)
1068 gnu_expr = NULL_TREE;
1069 else
1070 {
1071 gnu_expr
1072 = build_unary_op (ADDR_EXPR, gnu_type, renamed_obj);
1073 if (init)
1074 gnu_expr
1075 = build_compound_expr (TREE_TYPE (gnu_expr), init,
1076 gnu_expr);
1077 }
1078 }
1079 }
1080
1081 /* If we are defining an aliased object whose nominal subtype is
1082 unconstrained, the object is a record that contains both the
1083 template and the object. If there is an initializer, it will
1084 have already been converted to the right type, but we need to
1085 create the template if there is no initializer. */
1086 if (definition
1087 && !gnu_expr
1088 && TREE_CODE (gnu_type) == RECORD_TYPE
1089 && (TYPE_CONTAINS_TEMPLATE_P (gnu_type)
1090 /* Beware that padding might have been introduced above. */
1091 || (TYPE_PADDING_P (gnu_type)
1092 && TREE_CODE (TREE_TYPE (TYPE_FIELDS (gnu_type)))
1093 == RECORD_TYPE
1094 && TYPE_CONTAINS_TEMPLATE_P
1095 (TREE_TYPE (TYPE_FIELDS (gnu_type))))))
1096 {
1097 tree template_field
1098 = TYPE_PADDING_P (gnu_type)
1099 ? TYPE_FIELDS (TREE_TYPE (TYPE_FIELDS (gnu_type)))
1100 : TYPE_FIELDS (gnu_type);
1101 vec<constructor_elt, va_gc> *v;
1102 vec_alloc (v, 1);
1103 tree t = build_template (TREE_TYPE (template_field),
1104 TREE_TYPE (DECL_CHAIN (template_field)),
1105 NULL_TREE);
1106 CONSTRUCTOR_APPEND_ELT (v, template_field, t);
1107 gnu_expr = gnat_build_constructor (gnu_type, v);
1108 }
1109
1110 /* Convert the expression to the type of the object if need be. */
1111 if (gnu_expr && initial_value_needs_conversion (gnu_type, gnu_expr))
1112 gnu_expr = convert (gnu_type, gnu_expr);
1113
1114 /* If this is a pointer that doesn't have an initializing expression,
1115 initialize it to NULL, unless the object is declared imported as
1116 per RM B.1(24). */
1117 if (definition
1118 && (POINTER_TYPE_P (gnu_type) || TYPE_IS_FAT_POINTER_P (gnu_type))
1119 && !gnu_expr
1120 && !Is_Imported (gnat_entity))
1121 gnu_expr = integer_zero_node;
1122
1123 /* If we are defining the object and it has an Address clause, we must
1124 either get the address expression from the saved GCC tree for the
1125 object if it has a Freeze node, or elaborate the address expression
1126 here since the front-end has guaranteed that the elaboration has no
1127 effects in this case. */
1128 if (definition && Present (Address_Clause (gnat_entity)))
1129 {
1130 const Node_Id gnat_clause = Address_Clause (gnat_entity);
1131 Node_Id gnat_address = Expression (gnat_clause);
1132 tree gnu_address
1133 = present_gnu_tree (gnat_entity)
1134 ? get_gnu_tree (gnat_entity) : gnat_to_gnu (gnat_address);
1135
1136 save_gnu_tree (gnat_entity, NULL_TREE, false);
1137
1138 /* Convert the type of the object to a reference type that can
1139 alias everything as per RM 13.3(19). */
1140 if (volatile_flag && !TYPE_VOLATILE (gnu_type))
1141 gnu_type = change_qualified_type (gnu_type, TYPE_QUAL_VOLATILE);
1142 gnu_type
1143 = build_reference_type_for_mode (gnu_type, ptr_mode, true);
1144 gnu_address = convert (gnu_type, gnu_address);
1145 used_by_ref = true;
1146 const_flag
1147 = (!Is_Public (gnat_entity)
1148 || compile_time_known_address_p (gnat_address));
1149 volatile_flag = false;
1150 gnu_size = NULL_TREE;
1151
1152 /* If this is an aliased object with an unconstrained array nominal
1153 subtype, then it can overlay only another aliased object with an
1154 unconstrained array nominal subtype and compatible template. */
1155 if (Is_Constr_Subt_For_UN_Aliased (gnat_type)
1156 && Is_Array_Type (Underlying_Type (gnat_type))
1157 && !type_annotate_only)
1158 {
1159 tree rec_type = TREE_TYPE (gnu_type);
1160 tree off = byte_position (DECL_CHAIN (TYPE_FIELDS (rec_type)));
1161
1162 /* This is the pattern built for a regular object. */
1163 if (TREE_CODE (gnu_address) == POINTER_PLUS_EXPR
1164 && TREE_OPERAND (gnu_address, 1) == off)
1165 gnu_address = TREE_OPERAND (gnu_address, 0);
1166 /* This is the pattern built for an overaligned object. */
1167 else if (TREE_CODE (gnu_address) == POINTER_PLUS_EXPR
1168 && TREE_CODE (TREE_OPERAND (gnu_address, 1))
1169 == PLUS_EXPR
1170 && TREE_OPERAND (TREE_OPERAND (gnu_address, 1), 1)
1171 == off)
1172 gnu_address
1173 = build2 (POINTER_PLUS_EXPR, gnu_type,
1174 TREE_OPERAND (gnu_address, 0),
1175 TREE_OPERAND (TREE_OPERAND (gnu_address, 1), 0));
1176 else
1177 {
1178 post_error_ne ("aliased object& with unconstrained array "
1179 "nominal subtype", gnat_clause,
1180 gnat_entity);
1181 post_error ("\\can overlay only aliased object with "
1182 "compatible subtype", gnat_clause);
1183 }
1184 }
1185
1186 /* If we don't have an initializing expression for the underlying
1187 variable, the initializing expression for the pointer is the
1188 specified address. Otherwise, we have to make a COMPOUND_EXPR
1189 to assign both the address and the initial value. */
1190 if (!gnu_expr)
1191 gnu_expr = gnu_address;
1192 else
1193 gnu_expr
1194 = build2 (COMPOUND_EXPR, gnu_type,
1195 build_binary_op (INIT_EXPR, NULL_TREE,
1196 build_unary_op (INDIRECT_REF,
1197 NULL_TREE,
1198 gnu_address),
1199 gnu_expr),
1200 gnu_address);
1201 }
1202
1203 /* If it has an address clause and we are not defining it, mark it
1204 as an indirect object. Likewise for Stdcall objects that are
1205 imported. */
1206 if ((!definition && Present (Address_Clause (gnat_entity)))
1207 || (imported_p && Has_Stdcall_Convention (gnat_entity)))
1208 {
1209 /* Convert the type of the object to a reference type that can
1210 alias everything as per RM 13.3(19). */
1211 if (volatile_flag && !TYPE_VOLATILE (gnu_type))
1212 gnu_type = change_qualified_type (gnu_type, TYPE_QUAL_VOLATILE);
1213 gnu_type
1214 = build_reference_type_for_mode (gnu_type, ptr_mode, true);
1215 used_by_ref = true;
1216 const_flag = false;
1217 volatile_flag = false;
1218 gnu_size = NULL_TREE;
1219
1220 /* No point in taking the address of an initializing expression
1221 that isn't going to be used. */
1222 gnu_expr = NULL_TREE;
1223
1224 /* If it has an address clause whose value is known at compile
1225 time, make the object a CONST_DECL. This will avoid a
1226 useless dereference. */
1227 if (Present (Address_Clause (gnat_entity)))
1228 {
1229 Node_Id gnat_address
1230 = Expression (Address_Clause (gnat_entity));
1231
1232 if (compile_time_known_address_p (gnat_address))
1233 {
1234 gnu_expr = gnat_to_gnu (gnat_address);
1235 const_flag = true;
1236 }
1237 }
1238 }
1239
1240 /* If we are at top level and this object is of variable size,
1241 make the actual type a hidden pointer to the real type and
1242 make the initializer be a memory allocation and initialization.
1243 Likewise for objects we aren't defining (presumed to be
1244 external references from other packages), but there we do
1245 not set up an initialization.
1246
1247 If the object's size overflows, make an allocator too, so that
1248 Storage_Error gets raised. Note that we will never free
1249 such memory, so we presume it never will get allocated. */
1250 if (!allocatable_size_p (TYPE_SIZE_UNIT (gnu_type),
1251 global_bindings_p ()
1252 || !definition
1253 || static_flag)
1254 || (gnu_size
1255 && !allocatable_size_p (convert (sizetype,
1256 size_binop
1257 (CEIL_DIV_EXPR, gnu_size,
1258 bitsize_unit_node)),
1259 global_bindings_p ()
1260 || !definition
1261 || static_flag)))
1262 {
1263 if (volatile_flag && !TYPE_VOLATILE (gnu_type))
1264 gnu_type = change_qualified_type (gnu_type, TYPE_QUAL_VOLATILE);
1265 gnu_type = build_reference_type (gnu_type);
1266 used_by_ref = true;
1267 const_flag = true;
1268 volatile_flag = false;
1269 gnu_size = NULL_TREE;
1270
1271 /* In case this was a aliased object whose nominal subtype is
1272 unconstrained, the pointer above will be a thin pointer and
1273 build_allocator will automatically make the template.
1274
1275 If we have a template initializer only (that we made above),
1276 pretend there is none and rely on what build_allocator creates
1277 again anyway. Otherwise (if we have a full initializer), get
1278 the data part and feed that to build_allocator.
1279
1280 If we are elaborating a mutable object, tell build_allocator to
1281 ignore a possibly simpler size from the initializer, if any, as
1282 we must allocate the maximum possible size in this case. */
1283 if (definition && !imported_p)
1284 {
1285 tree gnu_alloc_type = TREE_TYPE (gnu_type);
1286
1287 if (TREE_CODE (gnu_alloc_type) == RECORD_TYPE
1288 && TYPE_CONTAINS_TEMPLATE_P (gnu_alloc_type))
1289 {
1290 gnu_alloc_type
1291 = TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (gnu_alloc_type)));
1292
1293 if (TREE_CODE (gnu_expr) == CONSTRUCTOR
1294 && CONSTRUCTOR_NELTS (gnu_expr) == 1)
1295 gnu_expr = NULL_TREE;
1296 else
1297 gnu_expr
1298 = build_component_ref
1299 (gnu_expr,
1300 DECL_CHAIN (TYPE_FIELDS (TREE_TYPE (gnu_expr))),
1301 false);
1302 }
1303
1304 if (TREE_CODE (TYPE_SIZE_UNIT (gnu_alloc_type)) == INTEGER_CST
1305 && !valid_constant_size_p (TYPE_SIZE_UNIT (gnu_alloc_type)))
1306 post_error ("?`Storage_Error` will be raised at run time!",
1307 gnat_entity);
1308
1309 gnu_expr
1310 = build_allocator (gnu_alloc_type, gnu_expr, gnu_type,
1311 Empty, Empty, gnat_entity, mutable_p);
1312 }
1313 else
1314 gnu_expr = NULL_TREE;
1315 }
1316
1317 /* If this object would go into the stack and has an alignment larger
1318 than the largest stack alignment the back-end can honor, resort to
1319 a variable of "aligning type". */
1320 if (definition
1321 && TYPE_ALIGN (gnu_type) > BIGGEST_ALIGNMENT
1322 && !imported_p
1323 && !static_flag
1324 && !global_bindings_p ())
1325 {
1326 /* Create the new variable. No need for extra room before the
1327 aligned field as this is in automatic storage. */
1328 tree gnu_new_type
1329 = make_aligning_type (gnu_type, TYPE_ALIGN (gnu_type),
1330 TYPE_SIZE_UNIT (gnu_type),
1331 BIGGEST_ALIGNMENT, 0, gnat_entity);
1332 tree gnu_new_var
1333 = create_var_decl (create_concat_name (gnat_entity, "ALIGN"),
1334 NULL_TREE, gnu_new_type, NULL_TREE,
1335 false, false, false, false, false,
1336 true, debug_info_p && definition, NULL,
1337 gnat_entity);
1338
1339 /* Initialize the aligned field if we have an initializer. */
1340 if (gnu_expr)
1341 add_stmt_with_node
1342 (build_binary_op (INIT_EXPR, NULL_TREE,
1343 build_component_ref
1344 (gnu_new_var, TYPE_FIELDS (gnu_new_type),
1345 false),
1346 gnu_expr),
1347 gnat_entity);
1348
1349 /* And setup this entity as a reference to the aligned field. */
1350 gnu_type = build_reference_type (gnu_type);
1351 gnu_expr
1352 = build_unary_op
1353 (ADDR_EXPR, NULL_TREE,
1354 build_component_ref (gnu_new_var, TYPE_FIELDS (gnu_new_type),
1355 false));
1356 TREE_CONSTANT (gnu_expr) = 1;
1357
1358 used_by_ref = true;
1359 const_flag = true;
1360 volatile_flag = false;
1361 gnu_size = NULL_TREE;
1362 }
1363
1364 /* If this is an aggregate constant initialized to a constant, force it
1365 to be statically allocated. This saves an initialization copy. */
1366 if (!static_flag
1367 && const_flag
1368 && gnu_expr
1369 && TREE_CONSTANT (gnu_expr)
1370 && AGGREGATE_TYPE_P (gnu_type)
1371 && tree_fits_uhwi_p (TYPE_SIZE_UNIT (gnu_type))
1372 && !(TYPE_IS_PADDING_P (gnu_type)
1373 && !tree_fits_uhwi_p (TYPE_SIZE_UNIT
1374 (TREE_TYPE (TYPE_FIELDS (gnu_type))))))
1375 static_flag = true;
1376
1377 /* If this is an aliased object with an unconstrained array nominal
1378 subtype, we make its type a thin reference, i.e. the reference
1379 counterpart of a thin pointer, so it points to the array part.
1380 This is aimed to make it easier for the debugger to decode the
1381 object. Note that we have to do it this late because of the
1382 couple of allocation adjustments that might be made above. */
1383 if (Is_Constr_Subt_For_UN_Aliased (gnat_type)
1384 && Is_Array_Type (Underlying_Type (gnat_type))
1385 && !type_annotate_only)
1386 {
1387 /* In case the object with the template has already been allocated
1388 just above, we have nothing to do here. */
1389 if (!TYPE_IS_THIN_POINTER_P (gnu_type))
1390 {
1391 /* This variable is a GNAT encoding used by Workbench: let it
1392 go through the debugging information but mark it as
1393 artificial: users are not interested in it. */
1394 tree gnu_unc_var
1395 = create_var_decl (concat_name (gnu_entity_name, "UNC"),
1396 NULL_TREE, gnu_type, gnu_expr,
1397 const_flag, Is_Public (gnat_entity),
1398 imported_p || !definition, static_flag,
1399 volatile_flag, true,
1400 debug_info_p && definition,
1401 NULL, gnat_entity);
1402 gnu_expr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_unc_var);
1403 TREE_CONSTANT (gnu_expr) = 1;
1404
1405 used_by_ref = true;
1406 const_flag = true;
1407 volatile_flag = false;
1408 inner_const_flag = TREE_READONLY (gnu_unc_var);
1409 gnu_size = NULL_TREE;
1410 }
1411
1412 tree gnu_array = gnat_to_gnu_type (Base_Type (gnat_type));
1413 gnu_type
1414 = build_reference_type (TYPE_OBJECT_RECORD_TYPE (gnu_array));
1415 }
1416
1417 /* Convert the expression to the type of the object if need be. */
1418 if (gnu_expr && initial_value_needs_conversion (gnu_type, gnu_expr))
1419 gnu_expr = convert (gnu_type, gnu_expr);
1420
1421 /* If this name is external or a name was specified, use it, but don't
1422 use the Interface_Name with an address clause (see cd30005). */
1423 if ((Is_Public (gnat_entity) && !Is_Imported (gnat_entity))
1424 || (Present (Interface_Name (gnat_entity))
1425 && No (Address_Clause (gnat_entity))))
1426 gnu_ext_name = create_concat_name (gnat_entity, NULL);
1427
1428 /* Deal with a pragma Linker_Section on a constant or variable. */
1429 if ((kind == E_Constant || kind == E_Variable)
1430 && Present (Linker_Section_Pragma (gnat_entity)))
1431 prepend_one_attribute_pragma (&attr_list,
1432 Linker_Section_Pragma (gnat_entity));
1433
1434 /* Now create the variable or the constant and set various flags. */
1435 gnu_decl
1436 = create_var_decl (gnu_entity_name, gnu_ext_name, gnu_type,
1437 gnu_expr, const_flag, Is_Public (gnat_entity),
1438 imported_p || !definition, static_flag,
1439 volatile_flag, artificial_p,
1440 debug_info_p && definition, attr_list,
1441 gnat_entity, !renamed_obj);
1442 DECL_BY_REF_P (gnu_decl) = used_by_ref;
1443 DECL_POINTS_TO_READONLY_P (gnu_decl) = used_by_ref && inner_const_flag;
1444 DECL_CAN_NEVER_BE_NULL_P (gnu_decl) = Can_Never_Be_Null (gnat_entity);
1445
1446 /* If we are defining an Out parameter and optimization isn't enabled,
1447 create a fake PARM_DECL for debugging purposes and make it point to
1448 the VAR_DECL. Suppress debug info for the latter but make sure it
1449 will live in memory so that it can be accessed from within the
1450 debugger through the PARM_DECL. */
1451 if (kind == E_Out_Parameter
1452 && definition
1453 && debug_info_p
1454 && !optimize
1455 && !flag_generate_lto)
1456 {
1457 tree param = create_param_decl (gnu_entity_name, gnu_type);
1458 gnat_pushdecl (param, gnat_entity);
1459 SET_DECL_VALUE_EXPR (param, gnu_decl);
1460 DECL_HAS_VALUE_EXPR_P (param) = 1;
1461 DECL_IGNORED_P (gnu_decl) = 1;
1462 TREE_ADDRESSABLE (gnu_decl) = 1;
1463 }
1464
1465 /* If this is a loop parameter, set the corresponding flag. */
1466 else if (kind == E_Loop_Parameter)
1467 DECL_LOOP_PARM_P (gnu_decl) = 1;
1468
1469 /* If this is a renaming pointer, attach the renamed object to it. */
1470 if (renamed_obj)
1471 SET_DECL_RENAMED_OBJECT (gnu_decl, renamed_obj);
1472
1473 /* If this is a constant and we are defining it or it generates a real
1474 symbol at the object level and we are referencing it, we may want
1475 or need to have a true variable to represent it:
1476 - if optimization isn't enabled, for debugging purposes,
1477 - if the constant is public and not overlaid on something else,
1478 - if its address is taken,
1479 - if either itself or its type is aliased. */
1480 if (TREE_CODE (gnu_decl) == CONST_DECL
1481 && (definition || Sloc (gnat_entity) > Standard_Location)
1482 && ((!optimize && debug_info_p)
1483 || (Is_Public (gnat_entity)
1484 && No (Address_Clause (gnat_entity)))
1485 || Address_Taken (gnat_entity)
1486 || Is_Aliased (gnat_entity)
1487 || Is_Aliased (gnat_type)))
1488 {
1489 tree gnu_corr_var
1490 = create_var_decl (gnu_entity_name, gnu_ext_name, gnu_type,
1491 gnu_expr, true, Is_Public (gnat_entity),
1492 !definition, static_flag, volatile_flag,
1493 artificial_p, debug_info_p && definition,
1494 attr_list, gnat_entity, false);
1495
1496 SET_DECL_CONST_CORRESPONDING_VAR (gnu_decl, gnu_corr_var);
1497 }
1498
1499 /* If this is a constant, even if we don't need a true variable, we
1500 may need to avoid returning the initializer in every case. That
1501 can happen for the address of a (constant) constructor because,
1502 upon dereferencing it, the constructor will be reinjected in the
1503 tree, which may not be valid in every case; see lvalue_required_p
1504 for more details. */
1505 if (TREE_CODE (gnu_decl) == CONST_DECL)
1506 DECL_CONST_ADDRESS_P (gnu_decl) = constructor_address_p (gnu_expr);
1507
1508 /* If this object is declared in a block that contains a block with an
1509 exception handler, and we aren't using the GCC exception mechanism,
1510 we must force this variable in memory in order to avoid an invalid
1511 optimization. */
1512 if (Front_End_Exceptions ()
1513 && Has_Nested_Block_With_Handler (Scope (gnat_entity)))
1514 TREE_ADDRESSABLE (gnu_decl) = 1;
1515
1516 /* If this is a local variable with non-BLKmode and aggregate type,
1517 and optimization isn't enabled, then force it in memory so that
1518 a register won't be allocated to it with possible subparts left
1519 uninitialized and reaching the register allocator. */
1520 else if (TREE_CODE (gnu_decl) == VAR_DECL
1521 && !DECL_EXTERNAL (gnu_decl)
1522 && !TREE_STATIC (gnu_decl)
1523 && DECL_MODE (gnu_decl) != BLKmode
1524 && AGGREGATE_TYPE_P (TREE_TYPE (gnu_decl))
1525 && !TYPE_IS_FAT_POINTER_P (TREE_TYPE (gnu_decl))
1526 && !optimize)
1527 TREE_ADDRESSABLE (gnu_decl) = 1;
1528
1529 /* If we are defining an object with variable size or an object with
1530 fixed size that will be dynamically allocated, and we are using the
1531 front-end setjmp/longjmp exception mechanism, update the setjmp
1532 buffer. */
1533 if (definition
1534 && Exception_Mechanism == Front_End_SJLJ
1535 && get_block_jmpbuf_decl ()
1536 && DECL_SIZE_UNIT (gnu_decl)
1537 && (TREE_CODE (DECL_SIZE_UNIT (gnu_decl)) != INTEGER_CST
1538 || (flag_stack_check == GENERIC_STACK_CHECK
1539 && compare_tree_int (DECL_SIZE_UNIT (gnu_decl),
1540 STACK_CHECK_MAX_VAR_SIZE) > 0)))
1541 add_stmt_with_node (build_call_n_expr
1542 (update_setjmp_buf_decl, 1,
1543 build_unary_op (ADDR_EXPR, NULL_TREE,
1544 get_block_jmpbuf_decl ())),
1545 gnat_entity);
1546
1547 /* Back-annotate Esize and Alignment of the object if not already
1548 known. Note that we pick the values of the type, not those of
1549 the object, to shield ourselves from low-level platform-dependent
1550 adjustments like alignment promotion. This is both consistent with
1551 all the treatment above, where alignment and size are set on the
1552 type of the object and not on the object directly, and makes it
1553 possible to support all confirming representation clauses. */
1554 annotate_object (gnat_entity, TREE_TYPE (gnu_decl), gnu_object_size,
1555 used_by_ref);
1556 }
1557 break;
1558
1559 case E_Void:
1560 /* Return a TYPE_DECL for "void" that we previously made. */
1561 gnu_decl = TYPE_NAME (void_type_node);
1562 break;
1563
1564 case E_Enumeration_Type:
1565 /* A special case: for the types Character and Wide_Character in
1566 Standard, we do not list all the literals. So if the literals
1567 are not specified, make this an integer type. */
1568 if (No (First_Literal (gnat_entity)))
1569 {
1570 if (esize == CHAR_TYPE_SIZE && flag_signed_char)
1571 gnu_type = make_signed_type (CHAR_TYPE_SIZE);
1572 else
1573 gnu_type = make_unsigned_type (esize);
1574 TYPE_NAME (gnu_type) = gnu_entity_name;
1575
1576 /* Set TYPE_STRING_FLAG for Character and Wide_Character types.
1577 This is needed by the DWARF-2 back-end to distinguish between
1578 unsigned integer types and character types. */
1579 TYPE_STRING_FLAG (gnu_type) = 1;
1580
1581 /* This flag is needed by the call just below. */
1582 TYPE_ARTIFICIAL (gnu_type) = artificial_p;
1583
1584 finish_character_type (gnu_type);
1585 }
1586 else
1587 {
1588 /* We have a list of enumeral constants in First_Literal. We make a
1589 CONST_DECL for each one and build into GNU_LITERAL_LIST the list
1590 to be placed into TYPE_FIELDS. Each node is itself a TREE_LIST
1591 whose TREE_VALUE is the literal name and whose TREE_PURPOSE is the
1592 value of the literal. But when we have a regular boolean type, we
1593 simplify this a little by using a BOOLEAN_TYPE. */
1594 const bool is_boolean = Is_Boolean_Type (gnat_entity)
1595 && !Has_Non_Standard_Rep (gnat_entity);
1596 const bool is_unsigned = Is_Unsigned_Type (gnat_entity);
1597 tree gnu_list = NULL_TREE;
1598 Entity_Id gnat_literal;
1599
1600 gnu_type = make_node (is_boolean ? BOOLEAN_TYPE : ENUMERAL_TYPE);
1601 TYPE_PRECISION (gnu_type) = esize;
1602 TYPE_UNSIGNED (gnu_type) = is_unsigned;
1603 set_min_and_max_values_for_integral_type (gnu_type, esize,
1604 TYPE_SIGN (gnu_type));
1605 process_attributes (&gnu_type, &attr_list, true, gnat_entity);
1606 layout_type (gnu_type);
1607
1608 for (gnat_literal = First_Literal (gnat_entity);
1609 Present (gnat_literal);
1610 gnat_literal = Next_Literal (gnat_literal))
1611 {
1612 tree gnu_value
1613 = UI_To_gnu (Enumeration_Rep (gnat_literal), gnu_type);
1614 /* Do not generate debug info for individual enumerators. */
1615 tree gnu_literal
1616 = create_var_decl (get_entity_name (gnat_literal), NULL_TREE,
1617 gnu_type, gnu_value, true, false, false,
1618 false, false, artificial_p, false,
1619 NULL, gnat_literal);
1620 save_gnu_tree (gnat_literal, gnu_literal, false);
1621 gnu_list
1622 = tree_cons (DECL_NAME (gnu_literal), gnu_value, gnu_list);
1623 }
1624
1625 if (!is_boolean)
1626 TYPE_VALUES (gnu_type) = nreverse (gnu_list);
1627
1628 /* Note that the bounds are updated at the end of this function
1629 to avoid an infinite recursion since they refer to the type. */
1630 goto discrete_type;
1631 }
1632 break;
1633
1634 case E_Signed_Integer_Type:
1635 /* For integer types, just make a signed type the appropriate number
1636 of bits. */
1637 gnu_type = make_signed_type (esize);
1638 goto discrete_type;
1639
1640 case E_Ordinary_Fixed_Point_Type:
1641 case E_Decimal_Fixed_Point_Type:
1642 {
1643 /* Small_Value is the scale factor. */
1644 const Ureal gnat_small_value = Small_Value (gnat_entity);
1645 tree scale_factor = NULL_TREE;
1646
1647 gnu_type = make_signed_type (esize);
1648
1649 /* Try to decode the scale factor and to save it for the fixed-point
1650 types debug hook. */
1651
1652 /* There are various ways to describe the scale factor, however there
1653 are cases where back-end internals cannot hold it. In such cases,
1654 we output invalid scale factor for such cases (i.e. the 0/0
1655 rational constant) but we expect GNAT to output GNAT encodings,
1656 then. Thus, keep this in sync with
1657 Exp_Dbug.Is_Handled_Scale_Factor. */
1658
1659 /* When encoded as 1/2**N or 1/10**N, describe the scale factor as a
1660 binary or decimal scale: it is easier to read for humans. */
1661 if (UI_Eq (Numerator (gnat_small_value), Uint_1)
1662 && (Rbase (gnat_small_value) == 2
1663 || Rbase (gnat_small_value) == 10))
1664 {
1665 /* Given RM restrictions on 'Small values, we assume here that
1666 the denominator fits in an int. */
1667 const tree base = build_int_cst (integer_type_node,
1668 Rbase (gnat_small_value));
1669 const tree exponent
1670 = build_int_cst (integer_type_node,
1671 UI_To_Int (Denominator (gnat_small_value)));
1672 scale_factor
1673 = build2 (RDIV_EXPR, integer_type_node,
1674 integer_one_node,
1675 build2 (POWER_EXPR, integer_type_node,
1676 base, exponent));
1677 }
1678
1679 /* Default to arbitrary scale factors descriptions. */
1680 else
1681 {
1682 const Uint num = Norm_Num (gnat_small_value);
1683 const Uint den = Norm_Den (gnat_small_value);
1684
1685 if (UI_Is_In_Int_Range (num) && UI_Is_In_Int_Range (den))
1686 {
1687 const tree gnu_num
1688 = build_int_cst (integer_type_node,
1689 UI_To_Int (Norm_Num (gnat_small_value)));
1690 const tree gnu_den
1691 = build_int_cst (integer_type_node,
1692 UI_To_Int (Norm_Den (gnat_small_value)));
1693 scale_factor = build2 (RDIV_EXPR, integer_type_node,
1694 gnu_num, gnu_den);
1695 }
1696 else
1697 /* If compiler internals cannot represent arbitrary scale
1698 factors, output an invalid scale factor so that debugger
1699 don't try to handle them but so that we still have a type
1700 in the output. Note that GNAT */
1701 scale_factor = integer_zero_node;
1702 }
1703
1704 TYPE_FIXED_POINT_P (gnu_type) = 1;
1705 SET_TYPE_SCALE_FACTOR (gnu_type, scale_factor);
1706 }
1707 goto discrete_type;
1708
1709 case E_Modular_Integer_Type:
1710 {
1711 /* For modular types, make the unsigned type of the proper number
1712 of bits and then set up the modulus, if required. */
1713 tree gnu_modulus, gnu_high = NULL_TREE;
1714
1715 /* Packed Array Impl. Types are supposed to be subtypes only. */
1716 gcc_assert (!Is_Packed_Array_Impl_Type (gnat_entity));
1717
1718 gnu_type = make_unsigned_type (esize);
1719
1720 /* Get the modulus in this type. If it overflows, assume it is because
1721 it is equal to 2**Esize. Note that there is no overflow checking
1722 done on unsigned type, so we detect the overflow by looking for
1723 a modulus of zero, which is otherwise invalid. */
1724 gnu_modulus = UI_To_gnu (Modulus (gnat_entity), gnu_type);
1725
1726 if (!integer_zerop (gnu_modulus))
1727 {
1728 TYPE_MODULAR_P (gnu_type) = 1;
1729 SET_TYPE_MODULUS (gnu_type, gnu_modulus);
1730 gnu_high = fold_build2 (MINUS_EXPR, gnu_type, gnu_modulus,
1731 build_int_cst (gnu_type, 1));
1732 }
1733
1734 /* If the upper bound is not maximal, make an extra subtype. */
1735 if (gnu_high
1736 && !tree_int_cst_equal (gnu_high, TYPE_MAX_VALUE (gnu_type)))
1737 {
1738 tree gnu_subtype = make_unsigned_type (esize);
1739 SET_TYPE_RM_MAX_VALUE (gnu_subtype, gnu_high);
1740 TREE_TYPE (gnu_subtype) = gnu_type;
1741 TYPE_EXTRA_SUBTYPE_P (gnu_subtype) = 1;
1742 TYPE_NAME (gnu_type) = create_concat_name (gnat_entity, "UMT");
1743 gnu_type = gnu_subtype;
1744 }
1745 }
1746 goto discrete_type;
1747
1748 case E_Signed_Integer_Subtype:
1749 case E_Enumeration_Subtype:
1750 case E_Modular_Integer_Subtype:
1751 case E_Ordinary_Fixed_Point_Subtype:
1752 case E_Decimal_Fixed_Point_Subtype:
1753
1754 /* For integral subtypes, we make a new INTEGER_TYPE. Note that we do
1755 not want to call create_range_type since we would like each subtype
1756 node to be distinct. ??? Historically this was in preparation for
1757 when memory aliasing is implemented, but that's obsolete now given
1758 the call to relate_alias_sets below.
1759
1760 The TREE_TYPE field of the INTEGER_TYPE points to the base type;
1761 this fact is used by the arithmetic conversion functions.
1762
1763 We elaborate the Ancestor_Subtype if it is not in the current unit
1764 and one of our bounds is non-static. We do this to ensure consistent
1765 naming in the case where several subtypes share the same bounds, by
1766 elaborating the first such subtype first, thus using its name. */
1767
1768 if (!definition
1769 && Present (Ancestor_Subtype (gnat_entity))
1770 && !In_Extended_Main_Code_Unit (Ancestor_Subtype (gnat_entity))
1771 && (!Compile_Time_Known_Value (Type_Low_Bound (gnat_entity))
1772 || !Compile_Time_Known_Value (Type_High_Bound (gnat_entity))))
1773 gnat_to_gnu_entity (Ancestor_Subtype (gnat_entity), gnu_expr, false);
1774
1775 /* Set the precision to the Esize except for bit-packed arrays. */
1776 if (Is_Packed_Array_Impl_Type (gnat_entity)
1777 && Is_Bit_Packed_Array (Original_Array_Type (gnat_entity)))
1778 esize = UI_To_Int (RM_Size (gnat_entity));
1779
1780 /* First subtypes of Character are treated as Character; otherwise
1781 this should be an unsigned type if the base type is unsigned or
1782 if the lower bound is constant and non-negative or if the type
1783 is biased. However, even if the lower bound is constant and
1784 non-negative, we use a signed type for a subtype with the same
1785 size as its signed base type, because this eliminates useless
1786 conversions to it and gives more leeway to the optimizer; but
1787 this means that we will need to explicitly test for this case
1788 when we change the representation based on the RM size. */
1789 if (kind == E_Enumeration_Subtype
1790 && No (First_Literal (Etype (gnat_entity)))
1791 && Esize (gnat_entity) == RM_Size (gnat_entity)
1792 && esize == CHAR_TYPE_SIZE
1793 && flag_signed_char)
1794 gnu_type = make_signed_type (CHAR_TYPE_SIZE);
1795 else if (Is_Unsigned_Type (Underlying_Type (Etype (gnat_entity)))
1796 || (Esize (Etype (gnat_entity)) != Esize (gnat_entity)
1797 && Is_Unsigned_Type (gnat_entity))
1798 || Has_Biased_Representation (gnat_entity))
1799 gnu_type = make_unsigned_type (esize);
1800 else
1801 gnu_type = make_signed_type (esize);
1802 TREE_TYPE (gnu_type) = get_unpadded_type (Etype (gnat_entity));
1803
1804 SET_TYPE_RM_MIN_VALUE
1805 (gnu_type, elaborate_expression (Type_Low_Bound (gnat_entity),
1806 gnat_entity, "L", definition, true,
1807 debug_info_p));
1808
1809 SET_TYPE_RM_MAX_VALUE
1810 (gnu_type, elaborate_expression (Type_High_Bound (gnat_entity),
1811 gnat_entity, "U", definition, true,
1812 debug_info_p));
1813
1814 TYPE_BIASED_REPRESENTATION_P (gnu_type)
1815 = Has_Biased_Representation (gnat_entity);
1816
1817 /* Do the same processing for Character subtypes as for types. */
1818 if (TYPE_STRING_FLAG (TREE_TYPE (gnu_type)))
1819 {
1820 TYPE_NAME (gnu_type) = gnu_entity_name;
1821 TYPE_STRING_FLAG (gnu_type) = 1;
1822 TYPE_ARTIFICIAL (gnu_type) = artificial_p;
1823 finish_character_type (gnu_type);
1824 }
1825
1826 /* Inherit our alias set from what we're a subtype of. Subtypes
1827 are not different types and a pointer can designate any instance
1828 within a subtype hierarchy. */
1829 relate_alias_sets (gnu_type, TREE_TYPE (gnu_type), ALIAS_SET_COPY);
1830
1831 /* One of the above calls might have caused us to be elaborated,
1832 so don't blow up if so. */
1833 if (present_gnu_tree (gnat_entity))
1834 {
1835 maybe_present = true;
1836 break;
1837 }
1838
1839 /* Attach the TYPE_STUB_DECL in case we have a parallel type. */
1840 TYPE_STUB_DECL (gnu_type)
1841 = create_type_stub_decl (gnu_entity_name, gnu_type);
1842
1843 /* For a packed array, make the original array type a parallel/debug
1844 type. */
1845 if (debug_info_p && Is_Packed_Array_Impl_Type (gnat_entity))
1846 associate_original_type_to_packed_array (gnu_type, gnat_entity);
1847
1848 discrete_type:
1849
1850 /* We have to handle clauses that under-align the type specially. */
1851 if ((Present (Alignment_Clause (gnat_entity))
1852 || (Is_Packed_Array_Impl_Type (gnat_entity)
1853 && Present
1854 (Alignment_Clause (Original_Array_Type (gnat_entity)))))
1855 && UI_Is_In_Int_Range (Alignment (gnat_entity)))
1856 {
1857 align = UI_To_Int (Alignment (gnat_entity)) * BITS_PER_UNIT;
1858 if (align >= TYPE_ALIGN (gnu_type))
1859 align = 0;
1860 }
1861
1862 /* If the type we are dealing with represents a bit-packed array,
1863 we need to have the bits left justified on big-endian targets
1864 and right justified on little-endian targets. We also need to
1865 ensure that when the value is read (e.g. for comparison of two
1866 such values), we only get the good bits, since the unused bits
1867 are uninitialized. Both goals are accomplished by wrapping up
1868 the modular type in an enclosing record type. */
1869 if (Is_Packed_Array_Impl_Type (gnat_entity)
1870 && Is_Bit_Packed_Array (Original_Array_Type (gnat_entity)))
1871 {
1872 tree gnu_field_type, gnu_field;
1873
1874 /* Set the RM size before wrapping up the original type. */
1875 SET_TYPE_RM_SIZE (gnu_type,
1876 UI_To_gnu (RM_Size (gnat_entity), bitsizetype));
1877 TYPE_PACKED_ARRAY_TYPE_P (gnu_type) = 1;
1878
1879 /* Strip the ___XP suffix for standard DWARF. */
1880 if (gnat_encodings == DWARF_GNAT_ENCODINGS_MINIMAL)
1881 gnu_entity_name = TYPE_NAME (gnu_type);
1882
1883 /* Create a stripped-down declaration, mainly for debugging. */
1884 create_type_decl (gnu_entity_name, gnu_type, true, debug_info_p,
1885 gnat_entity);
1886
1887 /* Now save it and build the enclosing record type. */
1888 gnu_field_type = gnu_type;
1889
1890 gnu_type = make_node (RECORD_TYPE);
1891 TYPE_NAME (gnu_type) = create_concat_name (gnat_entity, "JM");
1892 TYPE_PACKED (gnu_type) = 1;
1893 TYPE_SIZE (gnu_type) = TYPE_SIZE (gnu_field_type);
1894 TYPE_SIZE_UNIT (gnu_type) = TYPE_SIZE_UNIT (gnu_field_type);
1895 SET_TYPE_ADA_SIZE (gnu_type, TYPE_RM_SIZE (gnu_field_type));
1896
1897 /* Propagate the alignment of the modular type to the record type,
1898 unless there is an alignment clause that under-aligns the type.
1899 This means that bit-packed arrays are given "ceil" alignment for
1900 their size by default, which may seem counter-intuitive but makes
1901 it possible to overlay them on modular types easily. */
1902 SET_TYPE_ALIGN (gnu_type,
1903 align > 0 ? align : TYPE_ALIGN (gnu_field_type));
1904
1905 /* Propagate the reverse storage order flag to the record type so
1906 that the required byte swapping is performed when retrieving the
1907 enclosed modular value. */
1908 TYPE_REVERSE_STORAGE_ORDER (gnu_type)
1909 = Reverse_Storage_Order (Original_Array_Type (gnat_entity));
1910
1911 relate_alias_sets (gnu_type, gnu_field_type, ALIAS_SET_COPY);
1912
1913 /* Don't declare the field as addressable since we won't be taking
1914 its address and this would prevent create_field_decl from making
1915 a bitfield. */
1916 gnu_field
1917 = create_field_decl (get_identifier ("OBJECT"), gnu_field_type,
1918 gnu_type, NULL_TREE, bitsize_zero_node, 1, 0);
1919
1920 /* We will output additional debug info manually below. */
1921 finish_record_type (gnu_type, gnu_field, 2, false);
1922 compute_record_mode (gnu_type);
1923 TYPE_JUSTIFIED_MODULAR_P (gnu_type) = 1;
1924
1925 if (debug_info_p)
1926 {
1927 /* Make the original array type a parallel/debug type. */
1928 associate_original_type_to_packed_array (gnu_type, gnat_entity);
1929
1930 /* Since GNU_TYPE is a padding type around the packed array
1931 implementation type, the padded type is its debug type. */
1932 if (gnat_encodings == DWARF_GNAT_ENCODINGS_MINIMAL)
1933 SET_TYPE_DEBUG_TYPE (gnu_type, gnu_field_type);
1934 }
1935 }
1936
1937 /* If the type we are dealing with has got a smaller alignment than the
1938 natural one, we need to wrap it up in a record type and misalign the
1939 latter; we reuse the padding machinery for this purpose. */
1940 else if (align > 0)
1941 {
1942 tree gnu_size = UI_To_gnu (RM_Size (gnat_entity), bitsizetype);
1943
1944 /* Set the RM size before wrapping the type. */
1945 SET_TYPE_RM_SIZE (gnu_type, gnu_size);
1946
1947 gnu_type
1948 = maybe_pad_type (gnu_type, TYPE_SIZE (gnu_type), align,
1949 gnat_entity, false, true, definition, false);
1950
1951 TYPE_PACKED (gnu_type) = 1;
1952 SET_TYPE_ADA_SIZE (gnu_type, gnu_size);
1953 }
1954
1955 break;
1956
1957 case E_Floating_Point_Type:
1958 /* The type of the Low and High bounds can be our type if this is
1959 a type from Standard, so set them at the end of the function. */
1960 gnu_type = make_node (REAL_TYPE);
1961 TYPE_PRECISION (gnu_type) = fp_size_to_prec (esize);
1962 layout_type (gnu_type);
1963 break;
1964
1965 case E_Floating_Point_Subtype:
1966 /* See the E_Signed_Integer_Subtype case for the rationale. */
1967 if (!definition
1968 && Present (Ancestor_Subtype (gnat_entity))
1969 && !In_Extended_Main_Code_Unit (Ancestor_Subtype (gnat_entity))
1970 && (!Compile_Time_Known_Value (Type_Low_Bound (gnat_entity))
1971 || !Compile_Time_Known_Value (Type_High_Bound (gnat_entity))))
1972 gnat_to_gnu_entity (Ancestor_Subtype (gnat_entity), gnu_expr, false);
1973
1974 gnu_type = make_node (REAL_TYPE);
1975 TREE_TYPE (gnu_type) = get_unpadded_type (Etype (gnat_entity));
1976 TYPE_PRECISION (gnu_type) = fp_size_to_prec (esize);
1977 TYPE_GCC_MIN_VALUE (gnu_type)
1978 = TYPE_GCC_MIN_VALUE (TREE_TYPE (gnu_type));
1979 TYPE_GCC_MAX_VALUE (gnu_type)
1980 = TYPE_GCC_MAX_VALUE (TREE_TYPE (gnu_type));
1981 layout_type (gnu_type);
1982
1983 SET_TYPE_RM_MIN_VALUE
1984 (gnu_type, elaborate_expression (Type_Low_Bound (gnat_entity),
1985 gnat_entity, "L", definition, true,
1986 debug_info_p));
1987
1988 SET_TYPE_RM_MAX_VALUE
1989 (gnu_type, elaborate_expression (Type_High_Bound (gnat_entity),
1990 gnat_entity, "U", definition, true,
1991 debug_info_p));
1992
1993 /* Inherit our alias set from what we're a subtype of, as for
1994 integer subtypes. */
1995 relate_alias_sets (gnu_type, TREE_TYPE (gnu_type), ALIAS_SET_COPY);
1996
1997 /* One of the above calls might have caused us to be elaborated,
1998 so don't blow up if so. */
1999 maybe_present = true;
2000 break;
2001
2002 /* Array Types and Subtypes
2003
2004 Unconstrained array types are represented by E_Array_Type and
2005 constrained array types are represented by E_Array_Subtype. There
2006 are no actual objects of an unconstrained array type; all we have
2007 are pointers to that type.
2008
2009 The following fields are defined on array types and subtypes:
2010
2011 Component_Type Component type of the array.
2012 Number_Dimensions Number of dimensions (an int).
2013 First_Index Type of first index. */
2014
2015 case E_Array_Type:
2016 {
2017 const bool convention_fortran_p
2018 = (Convention (gnat_entity) == Convention_Fortran);
2019 const int ndim = Number_Dimensions (gnat_entity);
2020 tree gnu_template_type;
2021 tree gnu_ptr_template;
2022 tree gnu_template_reference, gnu_template_fields, gnu_fat_type;
2023 tree *gnu_index_types = XALLOCAVEC (tree, ndim);
2024 tree *gnu_temp_fields = XALLOCAVEC (tree, ndim);
2025 tree gnu_max_size = size_one_node, gnu_max_size_unit, tem, t;
2026 Entity_Id gnat_index, gnat_name;
2027 int index;
2028 tree comp_type;
2029
2030 /* Create the type for the component now, as it simplifies breaking
2031 type reference loops. */
2032 comp_type
2033 = gnat_to_gnu_component_type (gnat_entity, definition, debug_info_p);
2034 if (present_gnu_tree (gnat_entity))
2035 {
2036 /* As a side effect, the type may have been translated. */
2037 maybe_present = true;
2038 break;
2039 }
2040
2041 /* We complete an existing dummy fat pointer type in place. This both
2042 avoids further complex adjustments in update_pointer_to and yields
2043 better debugging information in DWARF by leveraging the support for
2044 incomplete declarations of "tagged" types in the DWARF back-end. */
2045 gnu_type = get_dummy_type (gnat_entity);
2046 if (gnu_type && TYPE_POINTER_TO (gnu_type))
2047 {
2048 gnu_fat_type = TYPE_MAIN_VARIANT (TYPE_POINTER_TO (gnu_type));
2049 TYPE_NAME (gnu_fat_type) = NULL_TREE;
2050 gnu_ptr_template =
2051 TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (gnu_fat_type)));
2052 gnu_template_type = TREE_TYPE (gnu_ptr_template);
2053
2054 /* Save the contents of the dummy type for update_pointer_to. */
2055 TYPE_POINTER_TO (gnu_type) = copy_type (gnu_fat_type);
2056 TYPE_FIELDS (TYPE_POINTER_TO (gnu_type))
2057 = copy_node (TYPE_FIELDS (gnu_fat_type));
2058 DECL_CHAIN (TYPE_FIELDS (TYPE_POINTER_TO (gnu_type)))
2059 = copy_node (DECL_CHAIN (TYPE_FIELDS (gnu_fat_type)));
2060 }
2061 else
2062 {
2063 gnu_fat_type = make_node (RECORD_TYPE);
2064 gnu_template_type = make_node (RECORD_TYPE);
2065 gnu_ptr_template = build_pointer_type (gnu_template_type);
2066 }
2067
2068 /* Make a node for the array. If we are not defining the array
2069 suppress expanding incomplete types. */
2070 gnu_type = make_node (UNCONSTRAINED_ARRAY_TYPE);
2071
2072 if (!definition)
2073 {
2074 defer_incomplete_level++;
2075 this_deferred = true;
2076 }
2077
2078 /* Build the fat pointer type. Use a "void *" object instead of
2079 a pointer to the array type since we don't have the array type
2080 yet (it will reference the fat pointer via the bounds). Note
2081 that we reuse the existing fields of a dummy type because for:
2082
2083 type Arr is array (Positive range <>) of Element_Type;
2084 type Array_Ref is access Arr;
2085 Var : Array_Ref := Null;
2086
2087 in a declarative part, Arr will be frozen only after Var, which
2088 means that the fields used in the CONSTRUCTOR built for Null are
2089 those of the dummy type, which in turn means that COMPONENT_REFs
2090 of Var may be built with these fields. Now if COMPONENT_REFs of
2091 Var are also built later with the fields of the final type, the
2092 aliasing machinery may consider that the accesses are distinct
2093 if the FIELD_DECLs are distinct as objects. */
2094 if (COMPLETE_TYPE_P (gnu_fat_type))
2095 {
2096 tem = TYPE_FIELDS (gnu_fat_type);
2097 TREE_TYPE (tem) = ptr_type_node;
2098 TREE_TYPE (DECL_CHAIN (tem)) = gnu_ptr_template;
2099 TYPE_DECL_SUPPRESS_DEBUG (TYPE_STUB_DECL (gnu_fat_type)) = 0;
2100 for (t = gnu_fat_type; t; t = TYPE_NEXT_VARIANT (t))
2101 SET_TYPE_UNCONSTRAINED_ARRAY (t, gnu_type);
2102 }
2103 else
2104 {
2105 tem
2106 = create_field_decl (get_identifier ("P_ARRAY"),
2107 ptr_type_node, gnu_fat_type,
2108 NULL_TREE, NULL_TREE, 0, 0);
2109 DECL_CHAIN (tem)
2110 = create_field_decl (get_identifier ("P_BOUNDS"),
2111 gnu_ptr_template, gnu_fat_type,
2112 NULL_TREE, NULL_TREE, 0, 0);
2113 finish_fat_pointer_type (gnu_fat_type, tem);
2114 SET_TYPE_UNCONSTRAINED_ARRAY (gnu_fat_type, gnu_type);
2115 }
2116
2117 /* Build a reference to the template from a PLACEHOLDER_EXPR that
2118 is the fat pointer. This will be used to access the individual
2119 fields once we build them. */
2120 tem = build3 (COMPONENT_REF, gnu_ptr_template,
2121 build0 (PLACEHOLDER_EXPR, gnu_fat_type),
2122 DECL_CHAIN (TYPE_FIELDS (gnu_fat_type)), NULL_TREE);
2123 gnu_template_reference
2124 = build_unary_op (INDIRECT_REF, gnu_template_type, tem);
2125 TREE_READONLY (gnu_template_reference) = 1;
2126 TREE_THIS_NOTRAP (gnu_template_reference) = 1;
2127
2128 /* Now create the GCC type for each index and add the fields for that
2129 index to the template. */
2130 for (index = (convention_fortran_p ? ndim - 1 : 0),
2131 gnat_index = First_Index (gnat_entity);
2132 IN_RANGE (index, 0, ndim - 1);
2133 index += (convention_fortran_p ? - 1 : 1),
2134 gnat_index = Next_Index (gnat_index))
2135 {
2136 char field_name[16];
2137 tree gnu_index_type = get_unpadded_type (Etype (gnat_index));
2138 tree gnu_index_base_type
2139 = maybe_character_type (get_base_type (gnu_index_type));
2140 tree gnu_lb_field, gnu_hb_field, gnu_orig_min, gnu_orig_max;
2141 tree gnu_min, gnu_max, gnu_high;
2142
2143 /* Make the FIELD_DECLs for the low and high bounds of this
2144 type and then make extractions of these fields from the
2145 template. */
2146 sprintf (field_name, "LB%d", index);
2147 gnu_lb_field = create_field_decl (get_identifier (field_name),
2148 gnu_index_base_type,
2149 gnu_template_type, NULL_TREE,
2150 NULL_TREE, 0, 0);
2151 Sloc_to_locus (Sloc (gnat_entity),
2152 &DECL_SOURCE_LOCATION (gnu_lb_field));
2153
2154 field_name[0] = 'U';
2155 gnu_hb_field = create_field_decl (get_identifier (field_name),
2156 gnu_index_base_type,
2157 gnu_template_type, NULL_TREE,
2158 NULL_TREE, 0, 0);
2159 Sloc_to_locus (Sloc (gnat_entity),
2160 &DECL_SOURCE_LOCATION (gnu_hb_field));
2161
2162 gnu_temp_fields[index] = chainon (gnu_lb_field, gnu_hb_field);
2163
2164 /* We can't use build_component_ref here since the template type
2165 isn't complete yet. */
2166 gnu_orig_min = build3 (COMPONENT_REF, gnu_index_base_type,
2167 gnu_template_reference, gnu_lb_field,
2168 NULL_TREE);
2169 gnu_orig_max = build3 (COMPONENT_REF, gnu_index_base_type,
2170 gnu_template_reference, gnu_hb_field,
2171 NULL_TREE);
2172 TREE_READONLY (gnu_orig_min) = TREE_READONLY (gnu_orig_max) = 1;
2173
2174 gnu_min = convert (sizetype, gnu_orig_min);
2175 gnu_max = convert (sizetype, gnu_orig_max);
2176
2177 /* Compute the size of this dimension. See the E_Array_Subtype
2178 case below for the rationale. */
2179 gnu_high
2180 = build3 (COND_EXPR, sizetype,
2181 build2 (GE_EXPR, boolean_type_node,
2182 gnu_orig_max, gnu_orig_min),
2183 gnu_max,
2184 size_binop (MINUS_EXPR, gnu_min, size_one_node));
2185
2186 /* Make a range type with the new range in the Ada base type.
2187 Then make an index type with the size range in sizetype. */
2188 gnu_index_types[index]
2189 = create_index_type (gnu_min, gnu_high,
2190 create_range_type (gnu_index_base_type,
2191 gnu_orig_min,
2192 gnu_orig_max),
2193 gnat_entity);
2194
2195 /* Update the maximum size of the array in elements. */
2196 if (gnu_max_size)
2197 {
2198 tree gnu_min
2199 = convert (sizetype, TYPE_MIN_VALUE (gnu_index_type));
2200 tree gnu_max
2201 = convert (sizetype, TYPE_MAX_VALUE (gnu_index_type));
2202 tree gnu_this_max
2203 = size_binop (PLUS_EXPR, size_one_node,
2204 size_binop (MINUS_EXPR, gnu_max, gnu_min));
2205
2206 if (TREE_CODE (gnu_this_max) == INTEGER_CST
2207 && TREE_OVERFLOW (gnu_this_max))
2208 gnu_max_size = NULL_TREE;
2209 else
2210 gnu_max_size
2211 = size_binop (MULT_EXPR, gnu_max_size, gnu_this_max);
2212 }
2213
2214 TYPE_NAME (gnu_index_types[index])
2215 = create_concat_name (gnat_entity, field_name);
2216 }
2217
2218 /* Install all the fields into the template. */
2219 TYPE_NAME (gnu_template_type)
2220 = create_concat_name (gnat_entity, "XUB");
2221 gnu_template_fields = NULL_TREE;
2222 for (index = 0; index < ndim; index++)
2223 gnu_template_fields
2224 = chainon (gnu_template_fields, gnu_temp_fields[index]);
2225 finish_record_type (gnu_template_type, gnu_template_fields, 0,
2226 debug_info_p);
2227 TYPE_READONLY (gnu_template_type) = 1;
2228
2229 /* If Component_Size is not already specified, annotate it with the
2230 size of the component. */
2231 if (Unknown_Component_Size (gnat_entity))
2232 Set_Component_Size (gnat_entity,
2233 annotate_value (TYPE_SIZE (comp_type)));
2234
2235 /* Compute the maximum size of the array in units and bits. */
2236 if (gnu_max_size)
2237 {
2238 gnu_max_size_unit = size_binop (MULT_EXPR, gnu_max_size,
2239 TYPE_SIZE_UNIT (comp_type));
2240 gnu_max_size = size_binop (MULT_EXPR,
2241 convert (bitsizetype, gnu_max_size),
2242 TYPE_SIZE (comp_type));
2243 }
2244 else
2245 gnu_max_size_unit = NULL_TREE;
2246
2247 /* Now build the array type. */
2248 tem = comp_type;
2249 for (index = ndim - 1; index >= 0; index--)
2250 {
2251 tem = build_nonshared_array_type (tem, gnu_index_types[index]);
2252 TYPE_MULTI_ARRAY_P (tem) = (index > 0);
2253 TYPE_CONVENTION_FORTRAN_P (tem) = convention_fortran_p;
2254 if (index == ndim - 1 && Reverse_Storage_Order (gnat_entity))
2255 set_reverse_storage_order_on_array_type (tem);
2256 if (array_type_has_nonaliased_component (tem, gnat_entity))
2257 set_nonaliased_component_on_array_type (tem);
2258 }
2259
2260 /* If an alignment is specified, use it if valid. But ignore it
2261 for the original type of packed array types. If the alignment
2262 was requested with an explicit alignment clause, state so. */
2263 if (No (Packed_Array_Impl_Type (gnat_entity))
2264 && Known_Alignment (gnat_entity))
2265 {
2266 SET_TYPE_ALIGN (tem,
2267 validate_alignment (Alignment (gnat_entity),
2268 gnat_entity,
2269 TYPE_ALIGN (tem)));
2270 if (Present (Alignment_Clause (gnat_entity)))
2271 TYPE_USER_ALIGN (tem) = 1;
2272 }
2273
2274 /* Tag top-level ARRAY_TYPE nodes for packed arrays and their
2275 implementation types as such so that the debug information back-end
2276 can output the appropriate description for them. */
2277 TYPE_PACKED (tem)
2278 = (Is_Packed (gnat_entity)
2279 || Is_Packed_Array_Impl_Type (gnat_entity));
2280
2281 if (Treat_As_Volatile (gnat_entity))
2282 tem = change_qualified_type (tem, TYPE_QUAL_VOLATILE);
2283
2284 /* Adjust the type of the pointer-to-array field of the fat pointer
2285 and record the aliasing relationships if necessary. */
2286 TREE_TYPE (TYPE_FIELDS (gnu_fat_type)) = build_pointer_type (tem);
2287 if (TYPE_ALIAS_SET_KNOWN_P (gnu_fat_type))
2288 record_component_aliases (gnu_fat_type);
2289
2290 /* The result type is an UNCONSTRAINED_ARRAY_TYPE that indicates the
2291 corresponding fat pointer. */
2292 TREE_TYPE (gnu_type) = gnu_fat_type;
2293 TYPE_POINTER_TO (gnu_type) = gnu_fat_type;
2294 TYPE_REFERENCE_TO (gnu_type) = gnu_fat_type;
2295 SET_TYPE_MODE (gnu_type, BLKmode);
2296 SET_TYPE_ALIGN (gnu_type, TYPE_ALIGN (tem));
2297
2298 /* If the maximum size doesn't overflow, use it. */
2299 if (gnu_max_size
2300 && TREE_CODE (gnu_max_size) == INTEGER_CST
2301 && !TREE_OVERFLOW (gnu_max_size)
2302 && TREE_CODE (gnu_max_size_unit) == INTEGER_CST
2303 && !TREE_OVERFLOW (gnu_max_size_unit))
2304 {
2305 TYPE_SIZE (tem) = size_binop (MIN_EXPR, gnu_max_size,
2306 TYPE_SIZE (tem));
2307 TYPE_SIZE_UNIT (tem) = size_binop (MIN_EXPR, gnu_max_size_unit,
2308 TYPE_SIZE_UNIT (tem));
2309 }
2310
2311 create_type_decl (create_concat_name (gnat_entity, "XUA"), tem,
2312 artificial_p, debug_info_p, gnat_entity);
2313
2314 /* If told to generate GNAT encodings for them (GDB rely on them at the
2315 moment): give the fat pointer type a name. If this is a packed
2316 array, tell the debugger how to interpret the underlying bits. */
2317 if (Present (Packed_Array_Impl_Type (gnat_entity)))
2318 gnat_name = Packed_Array_Impl_Type (gnat_entity);
2319 else
2320 gnat_name = gnat_entity;
2321 tree xup_name
2322 = (gnat_encodings == DWARF_GNAT_ENCODINGS_MINIMAL)
2323 ? get_entity_name (gnat_name)
2324 : create_concat_name (gnat_name, "XUP");
2325 create_type_decl (xup_name, gnu_fat_type, artificial_p, debug_info_p,
2326 gnat_entity);
2327
2328 /* Create the type to be designated by thin pointers: a record type for
2329 the array and its template. We used to shift the fields to have the
2330 template at a negative offset, but this was somewhat of a kludge; we
2331 now shift thin pointer values explicitly but only those which have a
2332 TYPE_UNCONSTRAINED_ARRAY attached to the designated RECORD_TYPE.
2333 Note that GDB can handle standard DWARF information for them, so we
2334 don't have to name them as a GNAT encoding, except if specifically
2335 asked to. */
2336 tree xut_name
2337 = (gnat_encodings == DWARF_GNAT_ENCODINGS_MINIMAL)
2338 ? get_entity_name (gnat_name)
2339 : create_concat_name (gnat_name, "XUT");
2340 tem = build_unc_object_type (gnu_template_type, tem, xut_name,
2341 debug_info_p);
2342
2343 SET_TYPE_UNCONSTRAINED_ARRAY (tem, gnu_type);
2344 TYPE_OBJECT_RECORD_TYPE (gnu_type) = tem;
2345 }
2346 break;
2347
2348 case E_Array_Subtype:
2349
2350 /* This is the actual data type for array variables. Multidimensional
2351 arrays are implemented as arrays of arrays. Note that arrays which
2352 have sparse enumeration subtypes as index components create sparse
2353 arrays, which is obviously space inefficient but so much easier to
2354 code for now.
2355
2356 Also note that the subtype never refers to the unconstrained array
2357 type, which is somewhat at variance with Ada semantics.
2358
2359 First check to see if this is simply a renaming of the array type.
2360 If so, the result is the array type. */
2361
2362 gnu_type = TYPE_MAIN_VARIANT (gnat_to_gnu_type (Etype (gnat_entity)));
2363 if (!Is_Constrained (gnat_entity))
2364 ;
2365 else
2366 {
2367 Entity_Id gnat_index, gnat_base_index;
2368 const bool convention_fortran_p
2369 = (Convention (gnat_entity) == Convention_Fortran);
2370 const int ndim = Number_Dimensions (gnat_entity);
2371 tree gnu_base_type = gnu_type;
2372 tree *gnu_index_types = XALLOCAVEC (tree, ndim);
2373 tree gnu_max_size = size_one_node, gnu_max_size_unit;
2374 bool need_index_type_struct = false;
2375 int index;
2376
2377 /* First create the GCC type for each index and find out whether
2378 special types are needed for debugging information. */
2379 for (index = (convention_fortran_p ? ndim - 1 : 0),
2380 gnat_index = First_Index (gnat_entity),
2381 gnat_base_index
2382 = First_Index (Implementation_Base_Type (gnat_entity));
2383 IN_RANGE (index, 0, ndim - 1);
2384 index += (convention_fortran_p ? - 1 : 1),
2385 gnat_index = Next_Index (gnat_index),
2386 gnat_base_index = Next_Index (gnat_base_index))
2387 {
2388 tree gnu_index_type = get_unpadded_type (Etype (gnat_index));
2389 tree gnu_index_base_type
2390 = maybe_character_type (get_base_type (gnu_index_type));
2391 tree gnu_orig_min
2392 = convert (gnu_index_base_type,
2393 TYPE_MIN_VALUE (gnu_index_type));
2394 tree gnu_orig_max
2395 = convert (gnu_index_base_type,
2396 TYPE_MAX_VALUE (gnu_index_type));
2397 tree gnu_min = convert (sizetype, gnu_orig_min);
2398 tree gnu_max = convert (sizetype, gnu_orig_max);
2399 tree gnu_base_index_type
2400 = get_unpadded_type (Etype (gnat_base_index));
2401 tree gnu_base_index_base_type
2402 = maybe_character_type (get_base_type (gnu_base_index_type));
2403 tree gnu_base_orig_min
2404 = convert (gnu_base_index_base_type,
2405 TYPE_MIN_VALUE (gnu_base_index_type));
2406 tree gnu_base_orig_max
2407 = convert (gnu_base_index_base_type,
2408 TYPE_MAX_VALUE (gnu_base_index_type));
2409 tree gnu_high;
2410
2411 /* See if the base array type is already flat. If it is, we
2412 are probably compiling an ACATS test but it will cause the
2413 code below to malfunction if we don't handle it specially. */
2414 if (TREE_CODE (gnu_base_orig_min) == INTEGER_CST
2415 && TREE_CODE (gnu_base_orig_max) == INTEGER_CST
2416 && tree_int_cst_lt (gnu_base_orig_max, gnu_base_orig_min))
2417 {
2418 gnu_min = size_one_node;
2419 gnu_max = size_zero_node;
2420 gnu_high = gnu_max;
2421 }
2422
2423 /* Similarly, if one of the values overflows in sizetype and the
2424 range is null, use 1..0 for the sizetype bounds. */
2425 else if (TREE_CODE (gnu_min) == INTEGER_CST
2426 && TREE_CODE (gnu_max) == INTEGER_CST
2427 && (TREE_OVERFLOW (gnu_min) || TREE_OVERFLOW (gnu_max))
2428 && tree_int_cst_lt (gnu_orig_max, gnu_orig_min))
2429 {
2430 gnu_min = size_one_node;
2431 gnu_max = size_zero_node;
2432 gnu_high = gnu_max;
2433 }
2434
2435 /* If the minimum and maximum values both overflow in sizetype,
2436 but the difference in the original type does not overflow in
2437 sizetype, ignore the overflow indication. */
2438 else if (TREE_CODE (gnu_min) == INTEGER_CST
2439 && TREE_CODE (gnu_max) == INTEGER_CST
2440 && TREE_OVERFLOW (gnu_min) && TREE_OVERFLOW (gnu_max)
2441 && !TREE_OVERFLOW
2442 (convert (sizetype,
2443 fold_build2 (MINUS_EXPR, gnu_index_type,
2444 gnu_orig_max,
2445 gnu_orig_min))))
2446 {
2447 TREE_OVERFLOW (gnu_min) = 0;
2448 TREE_OVERFLOW (gnu_max) = 0;
2449 gnu_high = gnu_max;
2450 }
2451
2452 /* Compute the size of this dimension in the general case. We
2453 need to provide GCC with an upper bound to use but have to
2454 deal with the "superflat" case. There are three ways to do
2455 this. If we can prove that the array can never be superflat,
2456 we can just use the high bound of the index type. */
2457 else if ((Nkind (gnat_index) == N_Range
2458 && cannot_be_superflat (gnat_index))
2459 /* Bit-Packed Array Impl. Types are never superflat. */
2460 || (Is_Packed_Array_Impl_Type (gnat_entity)
2461 && Is_Bit_Packed_Array
2462 (Original_Array_Type (gnat_entity))))
2463 gnu_high = gnu_max;
2464
2465 /* Otherwise, if the high bound is constant but the low bound is
2466 not, we use the expression (hb >= lb) ? lb : hb + 1 for the
2467 lower bound. Note that the comparison must be done in the
2468 original type to avoid any overflow during the conversion. */
2469 else if (TREE_CODE (gnu_max) == INTEGER_CST
2470 && TREE_CODE (gnu_min) != INTEGER_CST)
2471 {
2472 gnu_high = gnu_max;
2473 gnu_min
2474 = build_cond_expr (sizetype,
2475 build_binary_op (GE_EXPR,
2476 boolean_type_node,
2477 gnu_orig_max,
2478 gnu_orig_min),
2479 gnu_min,
2480 int_const_binop (PLUS_EXPR, gnu_max,
2481 size_one_node));
2482 }
2483
2484 /* Finally we use (hb >= lb) ? hb : lb - 1 for the upper bound
2485 in all the other cases. Note that, here as well as above,
2486 the condition used in the comparison must be equivalent to
2487 the condition (length != 0). This is relied upon in order
2488 to optimize array comparisons in compare_arrays. Moreover
2489 we use int_const_binop for the shift by 1 if the bound is
2490 constant to avoid any unwanted overflow. */
2491 else
2492 gnu_high
2493 = build_cond_expr (sizetype,
2494 build_binary_op (GE_EXPR,
2495 boolean_type_node,
2496 gnu_orig_max,
2497 gnu_orig_min),
2498 gnu_max,
2499 TREE_CODE (gnu_min) == INTEGER_CST
2500 ? int_const_binop (MINUS_EXPR, gnu_min,
2501 size_one_node)
2502 : size_binop (MINUS_EXPR, gnu_min,
2503 size_one_node));
2504
2505 /* Reuse the index type for the range type. Then make an index
2506 type with the size range in sizetype. */
2507 gnu_index_types[index]
2508 = create_index_type (gnu_min, gnu_high, gnu_index_type,
2509 gnat_entity);
2510
2511 /* Update the maximum size of the array in elements. Here we
2512 see if any constraint on the index type of the base type
2513 can be used in the case of self-referential bound on the
2514 index type of the subtype. We look for a non-"infinite"
2515 and non-self-referential bound from any type involved and
2516 handle each bound separately. */
2517 if (gnu_max_size)
2518 {
2519 tree gnu_base_min = convert (sizetype, gnu_base_orig_min);
2520 tree gnu_base_max = convert (sizetype, gnu_base_orig_max);
2521 tree gnu_base_base_min
2522 = convert (sizetype,
2523 TYPE_MIN_VALUE (gnu_base_index_base_type));
2524 tree gnu_base_base_max
2525 = convert (sizetype,
2526 TYPE_MAX_VALUE (gnu_base_index_base_type));
2527
2528 if (!CONTAINS_PLACEHOLDER_P (gnu_min)
2529 || !(TREE_CODE (gnu_base_min) == INTEGER_CST
2530 && !TREE_OVERFLOW (gnu_base_min)))
2531 gnu_base_min = gnu_min;
2532
2533 if (!CONTAINS_PLACEHOLDER_P (gnu_max)
2534 || !(TREE_CODE (gnu_base_max) == INTEGER_CST
2535 && !TREE_OVERFLOW (gnu_base_max)))
2536 gnu_base_max = gnu_max;
2537
2538 if ((TREE_CODE (gnu_base_min) == INTEGER_CST
2539 && TREE_OVERFLOW (gnu_base_min))
2540 || operand_equal_p (gnu_base_min, gnu_base_base_min, 0)
2541 || (TREE_CODE (gnu_base_max) == INTEGER_CST
2542 && TREE_OVERFLOW (gnu_base_max))
2543 || operand_equal_p (gnu_base_max, gnu_base_base_max, 0))
2544 gnu_max_size = NULL_TREE;
2545 else
2546 {
2547 tree gnu_this_max;
2548
2549 /* Use int_const_binop if the bounds are constant to
2550 avoid any unwanted overflow. */
2551 if (TREE_CODE (gnu_base_min) == INTEGER_CST
2552 && TREE_CODE (gnu_base_max) == INTEGER_CST)
2553 gnu_this_max
2554 = int_const_binop (PLUS_EXPR, size_one_node,
2555 int_const_binop (MINUS_EXPR,
2556 gnu_base_max,
2557 gnu_base_min));
2558 else
2559 gnu_this_max
2560 = size_binop (PLUS_EXPR, size_one_node,
2561 size_binop (MINUS_EXPR,
2562 gnu_base_max,
2563 gnu_base_min));
2564
2565 gnu_max_size
2566 = size_binop (MULT_EXPR, gnu_max_size, gnu_this_max);
2567 }
2568 }
2569
2570 /* We need special types for debugging information to point to
2571 the index types if they have variable bounds, are not integer
2572 types, are biased or are wider than sizetype. These are GNAT
2573 encodings, so we have to include them only when all encodings
2574 are requested. */
2575 if ((TREE_CODE (gnu_orig_min) != INTEGER_CST
2576 || TREE_CODE (gnu_orig_max) != INTEGER_CST
2577 || TREE_CODE (gnu_index_type) != INTEGER_TYPE
2578 || (TREE_TYPE (gnu_index_type)
2579 && TREE_CODE (TREE_TYPE (gnu_index_type))
2580 != INTEGER_TYPE)
2581 || TYPE_BIASED_REPRESENTATION_P (gnu_index_type))
2582 && gnat_encodings != DWARF_GNAT_ENCODINGS_MINIMAL)
2583 need_index_type_struct = true;
2584 }
2585
2586 /* Then flatten: create the array of arrays. For an array type
2587 used to implement a packed array, get the component type from
2588 the original array type since the representation clauses that
2589 can affect it are on the latter. */
2590 if (Is_Packed_Array_Impl_Type (gnat_entity)
2591 && !Is_Bit_Packed_Array (Original_Array_Type (gnat_entity)))
2592 {
2593 gnu_type = gnat_to_gnu_type (Original_Array_Type (gnat_entity));
2594 for (index = ndim - 1; index >= 0; index--)
2595 gnu_type = TREE_TYPE (gnu_type);
2596
2597 /* One of the above calls might have caused us to be elaborated,
2598 so don't blow up if so. */
2599 if (present_gnu_tree (gnat_entity))
2600 {
2601 maybe_present = true;
2602 break;
2603 }
2604 }
2605 else
2606 {
2607 gnu_type = gnat_to_gnu_component_type (gnat_entity, definition,
2608 debug_info_p);
2609
2610 /* One of the above calls might have caused us to be elaborated,
2611 so don't blow up if so. */
2612 if (present_gnu_tree (gnat_entity))
2613 {
2614 maybe_present = true;
2615 break;
2616 }
2617 }
2618
2619 /* Compute the maximum size of the array in units and bits. */
2620 if (gnu_max_size)
2621 {
2622 gnu_max_size_unit = size_binop (MULT_EXPR, gnu_max_size,
2623 TYPE_SIZE_UNIT (gnu_type));
2624 gnu_max_size = size_binop (MULT_EXPR,
2625 convert (bitsizetype, gnu_max_size),
2626 TYPE_SIZE (gnu_type));
2627 }
2628 else
2629 gnu_max_size_unit = NULL_TREE;
2630
2631 /* Now build the array type. */
2632 for (index = ndim - 1; index >= 0; index --)
2633 {
2634 gnu_type = build_nonshared_array_type (gnu_type,
2635 gnu_index_types[index]);
2636 TYPE_MULTI_ARRAY_P (gnu_type) = (index > 0);
2637 TYPE_CONVENTION_FORTRAN_P (gnu_type) = convention_fortran_p;
2638 if (index == ndim - 1 && Reverse_Storage_Order (gnat_entity))
2639 set_reverse_storage_order_on_array_type (gnu_type);
2640 if (array_type_has_nonaliased_component (gnu_type, gnat_entity))
2641 set_nonaliased_component_on_array_type (gnu_type);
2642 }
2643
2644 /* Strip the ___XP suffix for standard DWARF. */
2645 if (Is_Packed_Array_Impl_Type (gnat_entity)
2646 && gnat_encodings == DWARF_GNAT_ENCODINGS_MINIMAL)
2647 {
2648 Entity_Id gnat_original_array_type
2649 = Underlying_Type (Original_Array_Type (gnat_entity));
2650
2651 gnu_entity_name
2652 = get_entity_name (gnat_original_array_type);
2653 }
2654
2655 /* Attach the TYPE_STUB_DECL in case we have a parallel type. */
2656 TYPE_STUB_DECL (gnu_type)
2657 = create_type_stub_decl (gnu_entity_name, gnu_type);
2658
2659 /* If this is a multi-dimensional array and we are at global level,
2660 we need to make a variable corresponding to the stride of the
2661 inner dimensions. */
2662 if (ndim > 1 && global_bindings_p ())
2663 {
2664 tree gnu_arr_type;
2665
2666 for (gnu_arr_type = TREE_TYPE (gnu_type), index = 1;
2667 TREE_CODE (gnu_arr_type) == ARRAY_TYPE;
2668 gnu_arr_type = TREE_TYPE (gnu_arr_type), index++)
2669 {
2670 tree eltype = TREE_TYPE (gnu_arr_type);
2671 char stride_name[32];
2672
2673 sprintf (stride_name, "ST%d", index);
2674 TYPE_SIZE (gnu_arr_type)
2675 = elaborate_expression_1 (TYPE_SIZE (gnu_arr_type),
2676 gnat_entity, stride_name,
2677 definition, false);
2678
2679 /* ??? For now, store the size as a multiple of the
2680 alignment of the element type in bytes so that we
2681 can see the alignment from the tree. */
2682 sprintf (stride_name, "ST%d_A_UNIT", index);
2683 TYPE_SIZE_UNIT (gnu_arr_type)
2684 = elaborate_expression_2 (TYPE_SIZE_UNIT (gnu_arr_type),
2685 gnat_entity, stride_name,
2686 definition, false,
2687 TYPE_ALIGN (eltype));
2688
2689 /* ??? create_type_decl is not invoked on the inner types so
2690 the MULT_EXPR node built above will never be marked. */
2691 MARK_VISITED (TYPE_SIZE_UNIT (gnu_arr_type));
2692 }
2693 }
2694
2695 /* If we need to write out a record type giving the names of the
2696 bounds for debugging purposes, do it now and make the record
2697 type a parallel type. This is not needed for a packed array
2698 since the bounds are conveyed by the original array type. */
2699 if (need_index_type_struct
2700 && debug_info_p
2701 && !Is_Packed_Array_Impl_Type (gnat_entity))
2702 {
2703 tree gnu_bound_rec = make_node (RECORD_TYPE);
2704 tree gnu_field_list = NULL_TREE;
2705 tree gnu_field;
2706
2707 TYPE_NAME (gnu_bound_rec)
2708 = create_concat_name (gnat_entity, "XA");
2709
2710 for (index = ndim - 1; index >= 0; index--)
2711 {
2712 tree gnu_index = TYPE_INDEX_TYPE (gnu_index_types[index]);
2713 tree gnu_index_name = TYPE_IDENTIFIER (gnu_index);
2714
2715 /* Make sure to reference the types themselves, and not just
2716 their names, as the debugger may fall back on them. */
2717 gnu_field = create_field_decl (gnu_index_name, gnu_index,
2718 gnu_bound_rec, NULL_TREE,
2719 NULL_TREE, 0, 0);
2720 DECL_CHAIN (gnu_field) = gnu_field_list;
2721 gnu_field_list = gnu_field;
2722 }
2723
2724 finish_record_type (gnu_bound_rec, gnu_field_list, 0, true);
2725 add_parallel_type (gnu_type, gnu_bound_rec);
2726 }
2727
2728 /* If this is a packed array type, make the original array type a
2729 parallel/debug type. Otherwise, if such GNAT encodings are
2730 required, do it for the base array type if it isn't artificial to
2731 make sure it is kept in the debug info. */
2732 if (debug_info_p)
2733 {
2734 if (Is_Packed_Array_Impl_Type (gnat_entity))
2735 associate_original_type_to_packed_array (gnu_type,
2736 gnat_entity);
2737 else
2738 {
2739 tree gnu_base_decl
2740 = gnat_to_gnu_entity (Etype (gnat_entity), NULL_TREE,
2741 false);
2742 if (!DECL_ARTIFICIAL (gnu_base_decl)
2743 && gnat_encodings != DWARF_GNAT_ENCODINGS_MINIMAL)
2744 add_parallel_type (gnu_type,
2745 TREE_TYPE (TREE_TYPE (gnu_base_decl)));
2746 }
2747 }
2748
2749 TYPE_PACKED_ARRAY_TYPE_P (gnu_type)
2750 = (Is_Packed_Array_Impl_Type (gnat_entity)
2751 && Is_Bit_Packed_Array (Original_Array_Type (gnat_entity)));
2752
2753 /* Tag top-level ARRAY_TYPE nodes for packed arrays and their
2754 implementation types as such so that the debug information back-end
2755 can output the appropriate description for them. */
2756 TYPE_PACKED (gnu_type)
2757 = (Is_Packed (gnat_entity)
2758 || Is_Packed_Array_Impl_Type (gnat_entity));
2759
2760 /* If the size is self-referential and the maximum size doesn't
2761 overflow, use it. */
2762 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type))
2763 && gnu_max_size
2764 && !(TREE_CODE (gnu_max_size) == INTEGER_CST
2765 && TREE_OVERFLOW (gnu_max_size))
2766 && !(TREE_CODE (gnu_max_size_unit) == INTEGER_CST
2767 && TREE_OVERFLOW (gnu_max_size_unit)))
2768 {
2769 TYPE_SIZE (gnu_type) = size_binop (MIN_EXPR, gnu_max_size,
2770 TYPE_SIZE (gnu_type));
2771 TYPE_SIZE_UNIT (gnu_type)
2772 = size_binop (MIN_EXPR, gnu_max_size_unit,
2773 TYPE_SIZE_UNIT (gnu_type));
2774 }
2775
2776 /* Set our alias set to that of our base type. This gives all
2777 array subtypes the same alias set. */
2778 relate_alias_sets (gnu_type, gnu_base_type, ALIAS_SET_COPY);
2779
2780 /* If this is a packed type, make this type the same as the packed
2781 array type, but do some adjusting in the type first. */
2782 if (Present (Packed_Array_Impl_Type (gnat_entity)))
2783 {
2784 Entity_Id gnat_index;
2785 tree gnu_inner;
2786
2787 /* First finish the type we had been making so that we output
2788 debugging information for it. */
2789 process_attributes (&gnu_type, &attr_list, false, gnat_entity);
2790 if (Treat_As_Volatile (gnat_entity))
2791 {
2792 const int quals
2793 = TYPE_QUAL_VOLATILE
2794 | (Is_Atomic_Or_VFA (gnat_entity) ? TYPE_QUAL_ATOMIC : 0);
2795 gnu_type = change_qualified_type (gnu_type, quals);
2796 }
2797 /* Make it artificial only if the base type was artificial too.
2798 That's sort of "morally" true and will make it possible for
2799 the debugger to look it up by name in DWARF, which is needed
2800 in order to decode the packed array type. */
2801 gnu_decl
2802 = create_type_decl (gnu_entity_name, gnu_type,
2803 !Comes_From_Source (Etype (gnat_entity))
2804 && artificial_p, debug_info_p,
2805 gnat_entity);
2806
2807 /* Save it as our equivalent in case the call below elaborates
2808 this type again. */
2809 save_gnu_tree (gnat_entity, gnu_decl, false);
2810
2811 gnu_decl
2812 = gnat_to_gnu_entity (Packed_Array_Impl_Type (gnat_entity),
2813 NULL_TREE, false);
2814 this_made_decl = true;
2815 gnu_type = TREE_TYPE (gnu_decl);
2816 save_gnu_tree (gnat_entity, NULL_TREE, false);
2817 save_gnu_tree (gnat_entity, gnu_decl, false);
2818 saved = true;
2819
2820 gnu_inner = gnu_type;
2821 while (TREE_CODE (gnu_inner) == RECORD_TYPE
2822 && (TYPE_JUSTIFIED_MODULAR_P (gnu_inner)
2823 || TYPE_PADDING_P (gnu_inner)))
2824 gnu_inner = TREE_TYPE (TYPE_FIELDS (gnu_inner));
2825
2826 /* We need to attach the index type to the type we just made so
2827 that the actual bounds can later be put into a template. */
2828 if ((TREE_CODE (gnu_inner) == ARRAY_TYPE
2829 && !TYPE_ACTUAL_BOUNDS (gnu_inner))
2830 || (TREE_CODE (gnu_inner) == INTEGER_TYPE
2831 && !TYPE_HAS_ACTUAL_BOUNDS_P (gnu_inner)))
2832 {
2833 if (TREE_CODE (gnu_inner) == INTEGER_TYPE)
2834 {
2835 /* The TYPE_ACTUAL_BOUNDS field is overloaded with the
2836 TYPE_MODULUS for modular types so we make an extra
2837 subtype if necessary. */
2838 if (TYPE_MODULAR_P (gnu_inner))
2839 {
2840 tree gnu_subtype
2841 = make_unsigned_type (TYPE_PRECISION (gnu_inner));
2842 TREE_TYPE (gnu_subtype) = gnu_inner;
2843 TYPE_EXTRA_SUBTYPE_P (gnu_subtype) = 1;
2844 SET_TYPE_RM_MIN_VALUE (gnu_subtype,
2845 TYPE_MIN_VALUE (gnu_inner));
2846 SET_TYPE_RM_MAX_VALUE (gnu_subtype,
2847 TYPE_MAX_VALUE (gnu_inner));
2848 gnu_inner = gnu_subtype;
2849 }
2850
2851 TYPE_HAS_ACTUAL_BOUNDS_P (gnu_inner) = 1;
2852
2853 /* Check for other cases of overloading. */
2854 gcc_checking_assert (!TYPE_ACTUAL_BOUNDS (gnu_inner));
2855 }
2856
2857 for (gnat_index = First_Index (gnat_entity);
2858 Present (gnat_index);
2859 gnat_index = Next_Index (gnat_index))
2860 SET_TYPE_ACTUAL_BOUNDS
2861 (gnu_inner,
2862 tree_cons (NULL_TREE,
2863 get_unpadded_type (Etype (gnat_index)),
2864 TYPE_ACTUAL_BOUNDS (gnu_inner)));
2865
2866 if (Convention (gnat_entity) != Convention_Fortran)
2867 SET_TYPE_ACTUAL_BOUNDS
2868 (gnu_inner, nreverse (TYPE_ACTUAL_BOUNDS (gnu_inner)));
2869
2870 if (TREE_CODE (gnu_type) == RECORD_TYPE
2871 && TYPE_JUSTIFIED_MODULAR_P (gnu_type))
2872 TREE_TYPE (TYPE_FIELDS (gnu_type)) = gnu_inner;
2873 }
2874 }
2875 }
2876 break;
2877
2878 case E_String_Literal_Subtype:
2879 /* Create the type for a string literal. */
2880 {
2881 Entity_Id gnat_full_type
2882 = (Is_Private_Type (Etype (gnat_entity))
2883 && Present (Full_View (Etype (gnat_entity)))
2884 ? Full_View (Etype (gnat_entity)) : Etype (gnat_entity));
2885 tree gnu_string_type = get_unpadded_type (gnat_full_type);
2886 tree gnu_string_array_type
2887 = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_string_type))));
2888 tree gnu_string_index_type
2889 = get_base_type (TREE_TYPE (TYPE_INDEX_TYPE
2890 (TYPE_DOMAIN (gnu_string_array_type))));
2891 tree gnu_lower_bound
2892 = convert (gnu_string_index_type,
2893 gnat_to_gnu (String_Literal_Low_Bound (gnat_entity)));
2894 tree gnu_length
2895 = UI_To_gnu (String_Literal_Length (gnat_entity),
2896 gnu_string_index_type);
2897 tree gnu_upper_bound
2898 = build_binary_op (PLUS_EXPR, gnu_string_index_type,
2899 gnu_lower_bound,
2900 int_const_binop (MINUS_EXPR, gnu_length,
2901 convert (gnu_string_index_type,
2902 integer_one_node)));
2903 tree gnu_index_type
2904 = create_index_type (convert (sizetype, gnu_lower_bound),
2905 convert (sizetype, gnu_upper_bound),
2906 create_range_type (gnu_string_index_type,
2907 gnu_lower_bound,
2908 gnu_upper_bound),
2909 gnat_entity);
2910
2911 gnu_type
2912 = build_nonshared_array_type (gnat_to_gnu_type
2913 (Component_Type (gnat_entity)),
2914 gnu_index_type);
2915 if (array_type_has_nonaliased_component (gnu_type, gnat_entity))
2916 set_nonaliased_component_on_array_type (gnu_type);
2917 relate_alias_sets (gnu_type, gnu_string_type, ALIAS_SET_COPY);
2918 }
2919 break;
2920
2921 /* Record Types and Subtypes
2922
2923 The following fields are defined on record types:
2924
2925 Has_Discriminants True if the record has discriminants
2926 First_Discriminant Points to head of list of discriminants
2927 First_Entity Points to head of list of fields
2928 Is_Tagged_Type True if the record is tagged
2929
2930 Implementation of Ada records and discriminated records:
2931
2932 A record type definition is transformed into the equivalent of a C
2933 struct definition. The fields that are the discriminants which are
2934 found in the Full_Type_Declaration node and the elements of the
2935 Component_List found in the Record_Type_Definition node. The
2936 Component_List can be a recursive structure since each Variant of
2937 the Variant_Part of the Component_List has a Component_List.
2938
2939 Processing of a record type definition comprises starting the list of
2940 field declarations here from the discriminants and the calling the
2941 function components_to_record to add the rest of the fields from the
2942 component list and return the gnu type node. The function
2943 components_to_record will call itself recursively as it traverses
2944 the tree. */
2945
2946 case E_Record_Type:
2947 if (Has_Complex_Representation (gnat_entity))
2948 {
2949 gnu_type
2950 = build_complex_type
2951 (get_unpadded_type
2952 (Etype (Defining_Entity
2953 (First (Component_Items
2954 (Component_List
2955 (Type_Definition
2956 (Declaration_Node (gnat_entity)))))))));
2957
2958 break;
2959 }
2960
2961 {
2962 Node_Id full_definition = Declaration_Node (gnat_entity);
2963 Node_Id record_definition = Type_Definition (full_definition);
2964 Node_Id gnat_constr;
2965 Entity_Id gnat_field, gnat_parent_type;
2966 tree gnu_field, gnu_field_list = NULL_TREE;
2967 tree gnu_get_parent;
2968 /* Set PACKED in keeping with gnat_to_gnu_field. */
2969 const int packed
2970 = Is_Packed (gnat_entity)
2971 ? 1
2972 : Component_Alignment (gnat_entity) == Calign_Storage_Unit
2973 ? -1
2974 : 0;
2975 const bool has_align = Known_Alignment (gnat_entity);
2976 const bool has_discr = Has_Discriminants (gnat_entity);
2977 const bool has_rep = Has_Specified_Layout (gnat_entity);
2978 const bool is_extension
2979 = (Is_Tagged_Type (gnat_entity)
2980 && Nkind (record_definition) == N_Derived_Type_Definition);
2981 const bool is_unchecked_union = Is_Unchecked_Union (gnat_entity);
2982 bool all_rep = has_rep;
2983
2984 /* See if all fields have a rep clause. Stop when we find one
2985 that doesn't. */
2986 if (all_rep)
2987 for (gnat_field = First_Entity (gnat_entity);
2988 Present (gnat_field);
2989 gnat_field = Next_Entity (gnat_field))
2990 if ((Ekind (gnat_field) == E_Component
2991 || Ekind (gnat_field) == E_Discriminant)
2992 && No (Component_Clause (gnat_field)))
2993 {
2994 all_rep = false;
2995 break;
2996 }
2997
2998 /* If this is a record extension, go a level further to find the
2999 record definition. Also, verify we have a Parent_Subtype. */
3000 if (is_extension)
3001 {
3002 if (!type_annotate_only
3003 || Present (Record_Extension_Part (record_definition)))
3004 record_definition = Record_Extension_Part (record_definition);
3005
3006 gcc_assert (type_annotate_only
3007 || Present (Parent_Subtype (gnat_entity)));
3008 }
3009
3010 /* Make a node for the record. If we are not defining the record,
3011 suppress expanding incomplete types. */
3012 gnu_type = make_node (tree_code_for_record_type (gnat_entity));
3013 TYPE_NAME (gnu_type) = gnu_entity_name;
3014 TYPE_PACKED (gnu_type) = (packed != 0) || has_align || has_rep;
3015 TYPE_REVERSE_STORAGE_ORDER (gnu_type)
3016 = Reverse_Storage_Order (gnat_entity);
3017 process_attributes (&gnu_type, &attr_list, true, gnat_entity);
3018
3019 if (!definition)
3020 {
3021 defer_incomplete_level++;
3022 this_deferred = true;
3023 }
3024
3025 /* If both a size and rep clause were specified, put the size on
3026 the record type now so that it can get the proper layout. */
3027 if (has_rep && Known_RM_Size (gnat_entity))
3028 TYPE_SIZE (gnu_type)
3029 = UI_To_gnu (RM_Size (gnat_entity), bitsizetype);
3030
3031 /* Always set the alignment on the record type here so that it can
3032 get the proper layout. */
3033 if (has_align)
3034 SET_TYPE_ALIGN (gnu_type,
3035 validate_alignment (Alignment (gnat_entity),
3036 gnat_entity, 0));
3037 else
3038 {
3039 SET_TYPE_ALIGN (gnu_type, 0);
3040
3041 /* If a type needs strict alignment, the minimum size will be the
3042 type size instead of the RM size (see validate_size). Cap the
3043 alignment lest it causes this type size to become too large. */
3044 if (Strict_Alignment (gnat_entity) && Known_RM_Size (gnat_entity))
3045 {
3046 unsigned int max_size = UI_To_Int (RM_Size (gnat_entity));
3047 unsigned int max_align = max_size & -max_size;
3048 if (max_align < BIGGEST_ALIGNMENT)
3049 TYPE_MAX_ALIGN (gnu_type) = max_align;
3050 }
3051 }
3052
3053 /* If we have a Parent_Subtype, make a field for the parent. If
3054 this record has rep clauses, force the position to zero. */
3055 if (Present (Parent_Subtype (gnat_entity)))
3056 {
3057 Entity_Id gnat_parent = Parent_Subtype (gnat_entity);
3058 tree gnu_dummy_parent_type = make_node (RECORD_TYPE);
3059 tree gnu_parent;
3060 int parent_packed = 0;
3061
3062 /* A major complexity here is that the parent subtype will
3063 reference our discriminants in its Stored_Constraint list.
3064 But those must reference the parent component of this record
3065 which is precisely of the parent subtype we have not built yet!
3066 To break the circle we first build a dummy COMPONENT_REF which
3067 represents the "get to the parent" operation and initialize
3068 each of those discriminants to a COMPONENT_REF of the above
3069 dummy parent referencing the corresponding discriminant of the
3070 base type of the parent subtype. */
3071 gnu_get_parent = build3 (COMPONENT_REF, gnu_dummy_parent_type,
3072 build0 (PLACEHOLDER_EXPR, gnu_type),
3073 build_decl (input_location,
3074 FIELD_DECL, NULL_TREE,
3075 gnu_dummy_parent_type),
3076 NULL_TREE);
3077
3078 if (has_discr)
3079 for (gnat_field = First_Stored_Discriminant (gnat_entity);
3080 Present (gnat_field);
3081 gnat_field = Next_Stored_Discriminant (gnat_field))
3082 if (Present (Corresponding_Discriminant (gnat_field)))
3083 {
3084 tree gnu_field
3085 = gnat_to_gnu_field_decl (Corresponding_Discriminant
3086 (gnat_field));
3087 save_gnu_tree
3088 (gnat_field,
3089 build3 (COMPONENT_REF, TREE_TYPE (gnu_field),
3090 gnu_get_parent, gnu_field, NULL_TREE),
3091 true);
3092 }
3093
3094 /* Then we build the parent subtype. If it has discriminants but
3095 the type itself has unknown discriminants, this means that it
3096 doesn't contain information about how the discriminants are
3097 derived from those of the ancestor type, so it cannot be used
3098 directly. Instead it is built by cloning the parent subtype
3099 of the underlying record view of the type, for which the above
3100 derivation of discriminants has been made explicit. */
3101 if (Has_Discriminants (gnat_parent)
3102 && Has_Unknown_Discriminants (gnat_entity))
3103 {
3104 Entity_Id gnat_uview = Underlying_Record_View (gnat_entity);
3105
3106 /* If we are defining the type, the underlying record
3107 view must already have been elaborated at this point.
3108 Otherwise do it now as its parent subtype cannot be
3109 technically elaborated on its own. */
3110 if (definition)
3111 gcc_assert (present_gnu_tree (gnat_uview));
3112 else
3113 gnat_to_gnu_entity (gnat_uview, NULL_TREE, false);
3114
3115 gnu_parent = gnat_to_gnu_type (Parent_Subtype (gnat_uview));
3116
3117 /* Substitute the "get to the parent" of the type for that
3118 of its underlying record view in the cloned type. */
3119 for (gnat_field = First_Stored_Discriminant (gnat_uview);
3120 Present (gnat_field);
3121 gnat_field = Next_Stored_Discriminant (gnat_field))
3122 if (Present (Corresponding_Discriminant (gnat_field)))
3123 {
3124 tree gnu_field = gnat_to_gnu_field_decl (gnat_field);
3125 tree gnu_ref
3126 = build3 (COMPONENT_REF, TREE_TYPE (gnu_field),
3127 gnu_get_parent, gnu_field, NULL_TREE);
3128 gnu_parent
3129 = substitute_in_type (gnu_parent, gnu_field, gnu_ref);
3130 }
3131 }
3132 else
3133 gnu_parent = gnat_to_gnu_type (gnat_parent);
3134
3135 /* The parent field needs strict alignment so, if it is to
3136 be created with a component clause below, then we need
3137 to apply the same adjustment as in gnat_to_gnu_field. */
3138 if (has_rep && TYPE_ALIGN (gnu_type) < TYPE_ALIGN (gnu_parent))
3139 {
3140 /* ??? For historical reasons, we do it on strict-alignment
3141 platforms only, where it is really required. This means
3142 that a confirming representation clause will change the
3143 behavior of the compiler on the other platforms. */
3144 if (STRICT_ALIGNMENT)
3145 SET_TYPE_ALIGN (gnu_type, TYPE_ALIGN (gnu_parent));
3146 else
3147 parent_packed
3148 = adjust_packed (gnu_parent, gnu_type, parent_packed);
3149 }
3150
3151 /* Finally we fix up both kinds of twisted COMPONENT_REF we have
3152 initially built. The discriminants must reference the fields
3153 of the parent subtype and not those of its base type for the
3154 placeholder machinery to properly work. */
3155 if (has_discr)
3156 {
3157 /* The actual parent subtype is the full view. */
3158 if (Is_Private_Type (gnat_parent))
3159 {
3160 if (Present (Full_View (gnat_parent)))
3161 gnat_parent = Full_View (gnat_parent);
3162 else
3163 gnat_parent = Underlying_Full_View (gnat_parent);
3164 }
3165
3166 for (gnat_field = First_Stored_Discriminant (gnat_entity);
3167 Present (gnat_field);
3168 gnat_field = Next_Stored_Discriminant (gnat_field))
3169 if (Present (Corresponding_Discriminant (gnat_field)))
3170 {
3171 Entity_Id field;
3172 for (field = First_Stored_Discriminant (gnat_parent);
3173 Present (field);
3174 field = Next_Stored_Discriminant (field))
3175 if (same_discriminant_p (gnat_field, field))
3176 break;
3177 gcc_assert (Present (field));
3178 TREE_OPERAND (get_gnu_tree (gnat_field), 1)
3179 = gnat_to_gnu_field_decl (field);
3180 }
3181 }
3182
3183 /* The "get to the parent" COMPONENT_REF must be given its
3184 proper type... */
3185 TREE_TYPE (gnu_get_parent) = gnu_parent;
3186
3187 /* ...and reference the _Parent field of this record. */
3188 gnu_field
3189 = create_field_decl (parent_name_id,
3190 gnu_parent, gnu_type,
3191 has_rep
3192 ? TYPE_SIZE (gnu_parent) : NULL_TREE,
3193 has_rep
3194 ? bitsize_zero_node : NULL_TREE,
3195 parent_packed, 1);
3196 DECL_INTERNAL_P (gnu_field) = 1;
3197 TREE_OPERAND (gnu_get_parent, 1) = gnu_field;
3198 TYPE_FIELDS (gnu_type) = gnu_field;
3199 }
3200
3201 /* Make the fields for the discriminants and put them into the record
3202 unless it's an Unchecked_Union. */
3203 if (has_discr)
3204 for (gnat_field = First_Stored_Discriminant (gnat_entity);
3205 Present (gnat_field);
3206 gnat_field = Next_Stored_Discriminant (gnat_field))
3207 {
3208 /* If this is a record extension and this discriminant is the
3209 renaming of another discriminant, we've handled it above. */
3210 if (is_extension
3211 && Present (Corresponding_Discriminant (gnat_field)))
3212 continue;
3213
3214 gnu_field
3215 = gnat_to_gnu_field (gnat_field, gnu_type, packed, definition,
3216 debug_info_p);
3217
3218 /* Make an expression using a PLACEHOLDER_EXPR from the
3219 FIELD_DECL node just created and link that with the
3220 corresponding GNAT defining identifier. */
3221 save_gnu_tree (gnat_field,
3222 build3 (COMPONENT_REF, TREE_TYPE (gnu_field),
3223 build0 (PLACEHOLDER_EXPR, gnu_type),
3224 gnu_field, NULL_TREE),
3225 true);
3226
3227 if (!is_unchecked_union)
3228 {
3229 DECL_CHAIN (gnu_field) = gnu_field_list;
3230 gnu_field_list = gnu_field;
3231 }
3232 }
3233
3234 /* If we have a derived untagged type that renames discriminants in
3235 the parent type, the (stored) discriminants are just a copy of the
3236 discriminants of the parent type. This means that any constraints
3237 added by the renaming in the derivation are disregarded as far as
3238 the layout of the derived type is concerned. To rescue them, we
3239 change the type of the (stored) discriminants to a subtype with
3240 the bounds of the type of the visible discriminants. */
3241 if (has_discr
3242 && !is_extension
3243 && Stored_Constraint (gnat_entity) != No_Elist)
3244 for (gnat_constr = First_Elmt (Stored_Constraint (gnat_entity));
3245 gnat_constr != No_Elmt;
3246 gnat_constr = Next_Elmt (gnat_constr))
3247 if (Nkind (Node (gnat_constr)) == N_Identifier
3248 /* Ignore access discriminants. */
3249 && !Is_Access_Type (Etype (Node (gnat_constr)))
3250 && Ekind (Entity (Node (gnat_constr))) == E_Discriminant)
3251 {
3252 Entity_Id gnat_discr = Entity (Node (gnat_constr));
3253 tree gnu_discr_type = gnat_to_gnu_type (Etype (gnat_discr));
3254 tree gnu_ref
3255 = gnat_to_gnu_entity (Original_Record_Component (gnat_discr),
3256 NULL_TREE, false);
3257
3258 /* GNU_REF must be an expression using a PLACEHOLDER_EXPR built
3259 just above for one of the stored discriminants. */
3260 gcc_assert (TREE_TYPE (TREE_OPERAND (gnu_ref, 0)) == gnu_type);
3261
3262 if (gnu_discr_type != TREE_TYPE (gnu_ref))
3263 {
3264 const unsigned prec = TYPE_PRECISION (TREE_TYPE (gnu_ref));
3265 tree gnu_subtype
3266 = TYPE_UNSIGNED (TREE_TYPE (gnu_ref))
3267 ? make_unsigned_type (prec) : make_signed_type (prec);
3268 TREE_TYPE (gnu_subtype) = TREE_TYPE (gnu_ref);
3269 TYPE_EXTRA_SUBTYPE_P (gnu_subtype) = 1;
3270 SET_TYPE_RM_MIN_VALUE (gnu_subtype,
3271 TYPE_MIN_VALUE (gnu_discr_type));
3272 SET_TYPE_RM_MAX_VALUE (gnu_subtype,
3273 TYPE_MAX_VALUE (gnu_discr_type));
3274 TREE_TYPE (gnu_ref)
3275 = TREE_TYPE (TREE_OPERAND (gnu_ref, 1)) = gnu_subtype;
3276 }
3277 }
3278
3279 /* If this is a derived type with discriminants and these discriminants
3280 affect the initial shape it has inherited, factor them in. */
3281 if (has_discr
3282 && !is_extension
3283 && !Has_Record_Rep_Clause (gnat_entity)
3284 && Stored_Constraint (gnat_entity) != No_Elist
3285 && (gnat_parent_type = Underlying_Type (Etype (gnat_entity)))
3286 && Is_Record_Type (gnat_parent_type)
3287 && Is_Unchecked_Union (gnat_entity)
3288 == Is_Unchecked_Union (gnat_parent_type)
3289 && No_Reordering (gnat_entity) == No_Reordering (gnat_parent_type))
3290 {
3291 tree gnu_parent_type
3292 = TYPE_MAIN_VARIANT (gnat_to_gnu_type (gnat_parent_type));
3293
3294 if (TYPE_IS_PADDING_P (gnu_parent_type))
3295 gnu_parent_type = TREE_TYPE (TYPE_FIELDS (gnu_parent_type));
3296
3297 vec<subst_pair> gnu_subst_list
3298 = build_subst_list (gnat_entity, gnat_parent_type, definition);
3299
3300 /* Set the layout of the type to match that of the parent type,
3301 doing required substitutions. If we are in minimal GNAT
3302 encodings mode, we don't need debug info for the inner record
3303 types, as they will be part of the embedding variant record's
3304 debug info. */
3305 copy_and_substitute_in_layout
3306 (gnat_entity, gnat_parent_type, gnu_type, gnu_parent_type,
3307 gnu_subst_list,
3308 debug_info_p && gnat_encodings != DWARF_GNAT_ENCODINGS_MINIMAL);
3309 }
3310 else
3311 {
3312 /* Add the fields into the record type and finish it up. */
3313 components_to_record (Component_List (record_definition),
3314 gnat_entity, gnu_field_list, gnu_type,
3315 packed, definition, false, all_rep,
3316 is_unchecked_union, artificial_p,
3317 debug_info_p, false,
3318 all_rep ? NULL_TREE : bitsize_zero_node,
3319 NULL);
3320
3321 /* If there are entities in the chain corresponding to components
3322 that we did not elaborate, ensure we elaborate their types if
3323 they are Itypes. */
3324 for (gnat_temp = First_Entity (gnat_entity);
3325 Present (gnat_temp);
3326 gnat_temp = Next_Entity (gnat_temp))
3327 if ((Ekind (gnat_temp) == E_Component
3328 || Ekind (gnat_temp) == E_Discriminant)
3329 && Is_Itype (Etype (gnat_temp))
3330 && !present_gnu_tree (gnat_temp))
3331 gnat_to_gnu_entity (Etype (gnat_temp), NULL_TREE, false);
3332 }
3333
3334 /* Fill in locations of fields. */
3335 annotate_rep (gnat_entity, gnu_type);
3336
3337 /* If this is a record type associated with an exception definition,
3338 equate its fields to those of the standard exception type. This
3339 will make it possible to convert between them. */
3340 if (gnu_entity_name == exception_data_name_id)
3341 {
3342 tree gnu_std_field;
3343 for (gnu_field = TYPE_FIELDS (gnu_type),
3344 gnu_std_field = TYPE_FIELDS (except_type_node);
3345 gnu_field;
3346 gnu_field = DECL_CHAIN (gnu_field),
3347 gnu_std_field = DECL_CHAIN (gnu_std_field))
3348 SET_DECL_ORIGINAL_FIELD_TO_FIELD (gnu_field, gnu_std_field);
3349 gcc_assert (!gnu_std_field);
3350 }
3351 }
3352 break;
3353
3354 case E_Class_Wide_Subtype:
3355 /* If an equivalent type is present, that is what we should use.
3356 Otherwise, fall through to handle this like a record subtype
3357 since it may have constraints. */
3358 if (gnat_equiv_type != gnat_entity)
3359 {
3360 gnu_decl = gnat_to_gnu_entity (gnat_equiv_type, NULL_TREE, false);
3361 maybe_present = true;
3362 break;
3363 }
3364
3365 /* ... fall through ... */
3366
3367 case E_Record_Subtype:
3368 /* If Cloned_Subtype is Present it means this record subtype has
3369 identical layout to that type or subtype and we should use
3370 that GCC type for this one. The front end guarantees that
3371 the component list is shared. */
3372 if (Present (Cloned_Subtype (gnat_entity)))
3373 {
3374 gnu_decl = gnat_to_gnu_entity (Cloned_Subtype (gnat_entity),
3375 NULL_TREE, false);
3376 saved = true;
3377 break;
3378 }
3379
3380 /* Otherwise, first ensure the base type is elaborated. Then, if we are
3381 changing the type, make a new type with each field having the type of
3382 the field in the new subtype but the position computed by transforming
3383 every discriminant reference according to the constraints. We don't
3384 see any difference between private and non-private type here since
3385 derivations from types should have been deferred until the completion
3386 of the private type. */
3387 else
3388 {
3389 Entity_Id gnat_base_type = Implementation_Base_Type (gnat_entity);
3390
3391 if (!definition)
3392 {
3393 defer_incomplete_level++;
3394 this_deferred = true;
3395 }
3396
3397 tree gnu_base_type
3398 = TYPE_MAIN_VARIANT (gnat_to_gnu_type (gnat_base_type));
3399
3400 if (present_gnu_tree (gnat_entity))
3401 {
3402 maybe_present = true;
3403 break;
3404 }
3405
3406 /* When the subtype has discriminants and these discriminants affect
3407 the initial shape it has inherited, factor them in. But for an
3408 Unchecked_Union (it must be an Itype), just return the type. */
3409 if (Has_Discriminants (gnat_entity)
3410 && Stored_Constraint (gnat_entity) != No_Elist
3411 && !Is_For_Access_Subtype (gnat_entity)
3412 && Is_Record_Type (gnat_base_type)
3413 && !Is_Unchecked_Union (gnat_base_type))
3414 {
3415 vec<subst_pair> gnu_subst_list
3416 = build_subst_list (gnat_entity, gnat_base_type, definition);
3417 tree gnu_unpad_base_type;
3418
3419 gnu_type = make_node (RECORD_TYPE);
3420 TYPE_NAME (gnu_type) = gnu_entity_name;
3421 if (gnat_encodings == DWARF_GNAT_ENCODINGS_MINIMAL)
3422 {
3423 /* Use the ultimate base record type as the debug type.
3424 Subtypes and derived types bring no useful
3425 information. */
3426 Entity_Id gnat_debug_type = gnat_entity;
3427 while (Etype (gnat_debug_type) != gnat_debug_type)
3428 gnat_debug_type = Etype (gnat_debug_type);
3429 tree gnu_debug_type
3430 = TYPE_MAIN_VARIANT (gnat_to_gnu_type (gnat_debug_type));
3431 SET_TYPE_DEBUG_TYPE (gnu_type, gnu_debug_type);
3432 }
3433 TYPE_PACKED (gnu_type) = TYPE_PACKED (gnu_base_type);
3434 TYPE_REVERSE_STORAGE_ORDER (gnu_type)
3435 = Reverse_Storage_Order (gnat_entity);
3436 process_attributes (&gnu_type, &attr_list, true, gnat_entity);
3437
3438 /* Set the size, alignment and alias set of the type to match
3439 those of the base type, doing required substitutions. */
3440 copy_and_substitute_in_size (gnu_type, gnu_base_type,
3441 gnu_subst_list);
3442
3443 if (TYPE_IS_PADDING_P (gnu_base_type))
3444 gnu_unpad_base_type = TREE_TYPE (TYPE_FIELDS (gnu_base_type));
3445 else
3446 gnu_unpad_base_type = gnu_base_type;
3447
3448 /* Set the layout of the type to match that of the base type,
3449 doing required substitutions. We will output debug info
3450 manually below so pass false as last argument. */
3451 copy_and_substitute_in_layout (gnat_entity, gnat_base_type,
3452 gnu_type, gnu_unpad_base_type,
3453 gnu_subst_list, false);
3454
3455 /* Fill in locations of fields. */
3456 annotate_rep (gnat_entity, gnu_type);
3457
3458 /* If debugging information is being written for the type and if
3459 we are asked to output such encodings, write a record that
3460 shows what we are a subtype of and also make a variable that
3461 indicates our size, if still variable. */
3462 if (gnat_encodings != DWARF_GNAT_ENCODINGS_MINIMAL)
3463 {
3464 tree gnu_subtype_marker = make_node (RECORD_TYPE);
3465 tree gnu_unpad_base_name
3466 = TYPE_IDENTIFIER (gnu_unpad_base_type);
3467 tree gnu_size_unit = TYPE_SIZE_UNIT (gnu_type);
3468
3469 TYPE_NAME (gnu_subtype_marker)
3470 = create_concat_name (gnat_entity, "XVS");
3471 finish_record_type (gnu_subtype_marker,
3472 create_field_decl (gnu_unpad_base_name,
3473 build_reference_type
3474 (gnu_unpad_base_type),
3475 gnu_subtype_marker,
3476 NULL_TREE, NULL_TREE,
3477 0, 0),
3478 0, true);
3479
3480 add_parallel_type (gnu_type, gnu_subtype_marker);
3481
3482 if (definition
3483 && TREE_CODE (gnu_size_unit) != INTEGER_CST
3484 && !CONTAINS_PLACEHOLDER_P (gnu_size_unit))
3485 TYPE_SIZE_UNIT (gnu_subtype_marker)
3486 = create_var_decl (create_concat_name (gnat_entity,
3487 "XVZ"),
3488 NULL_TREE, sizetype, gnu_size_unit,
3489 false, false, false, false, false,
3490 true, debug_info_p,
3491 NULL, gnat_entity);
3492 }
3493 }
3494
3495 /* Otherwise, go down all the components in the new type and make
3496 them equivalent to those in the base type. */
3497 else
3498 {
3499 gnu_type = gnu_base_type;
3500
3501 for (gnat_temp = First_Entity (gnat_entity);
3502 Present (gnat_temp);
3503 gnat_temp = Next_Entity (gnat_temp))
3504 if ((Ekind (gnat_temp) == E_Discriminant
3505 && !Is_Unchecked_Union (gnat_base_type))
3506 || Ekind (gnat_temp) == E_Component)
3507 save_gnu_tree (gnat_temp,
3508 gnat_to_gnu_field_decl
3509 (Original_Record_Component (gnat_temp)),
3510 false);
3511 }
3512 }
3513 break;
3514
3515 case E_Access_Subprogram_Type:
3516 case E_Anonymous_Access_Subprogram_Type:
3517 /* Use the special descriptor type for dispatch tables if needed,
3518 that is to say for the Prim_Ptr of a-tags.ads and its clones.
3519 Note that we are only required to do so for static tables in
3520 order to be compatible with the C++ ABI, but Ada 2005 allows
3521 to extend library level tagged types at the local level so
3522 we do it in the non-static case as well. */
3523 if (TARGET_VTABLE_USES_DESCRIPTORS
3524 && Is_Dispatch_Table_Entity (gnat_entity))
3525 {
3526 gnu_type = fdesc_type_node;
3527 gnu_size = TYPE_SIZE (gnu_type);
3528 break;
3529 }
3530
3531 /* ... fall through ... */
3532
3533 case E_Allocator_Type:
3534 case E_Access_Type:
3535 case E_Access_Attribute_Type:
3536 case E_Anonymous_Access_Type:
3537 case E_General_Access_Type:
3538 {
3539 /* The designated type and its equivalent type for gigi. */
3540 Entity_Id gnat_desig_type = Directly_Designated_Type (gnat_entity);
3541 Entity_Id gnat_desig_equiv = Gigi_Equivalent_Type (gnat_desig_type);
3542 /* Whether it comes from a limited with. */
3543 const bool is_from_limited_with
3544 = (Is_Incomplete_Type (gnat_desig_equiv)
3545 && From_Limited_With (gnat_desig_equiv));
3546 /* Whether it is a completed Taft Amendment type. Such a type is to
3547 be treated as coming from a limited with clause if it is not in
3548 the main unit, i.e. we break potential circularities here in case
3549 the body of an external unit is loaded for inter-unit inlining. */
3550 const bool is_completed_taft_type
3551 = (Is_Incomplete_Type (gnat_desig_equiv)
3552 && Has_Completion_In_Body (gnat_desig_equiv)
3553 && Present (Full_View (gnat_desig_equiv)));
3554 /* The "full view" of the designated type. If this is an incomplete
3555 entity from a limited with, treat its non-limited view as the full
3556 view. Otherwise, if this is an incomplete or private type, use the
3557 full view. In the former case, we might point to a private type,
3558 in which case, we need its full view. Also, we want to look at the
3559 actual type used for the representation, so this takes a total of
3560 three steps. */
3561 Entity_Id gnat_desig_full_direct_first
3562 = (is_from_limited_with
3563 ? Non_Limited_View (gnat_desig_equiv)
3564 : (Is_Incomplete_Or_Private_Type (gnat_desig_equiv)
3565 ? Full_View (gnat_desig_equiv) : Empty));
3566 Entity_Id gnat_desig_full_direct
3567 = ((is_from_limited_with
3568 && Present (gnat_desig_full_direct_first)
3569 && Is_Private_Type (gnat_desig_full_direct_first))
3570 ? Full_View (gnat_desig_full_direct_first)
3571 : gnat_desig_full_direct_first);
3572 Entity_Id gnat_desig_full
3573 = Gigi_Equivalent_Type (gnat_desig_full_direct);
3574 /* The type actually used to represent the designated type, either
3575 gnat_desig_full or gnat_desig_equiv. */
3576 Entity_Id gnat_desig_rep;
3577 /* We want to know if we'll be seeing the freeze node for any
3578 incomplete type we may be pointing to. */
3579 const bool in_main_unit
3580 = (Present (gnat_desig_full)
3581 ? In_Extended_Main_Code_Unit (gnat_desig_full)
3582 : In_Extended_Main_Code_Unit (gnat_desig_type));
3583 /* True if we make a dummy type here. */
3584 bool made_dummy = false;
3585 /* The mode to be used for the pointer type. */
3586 scalar_int_mode p_mode;
3587 /* The GCC type used for the designated type. */
3588 tree gnu_desig_type = NULL_TREE;
3589
3590 if (!int_mode_for_size (esize, 0).exists (&p_mode)
3591 || !targetm.valid_pointer_mode (p_mode))
3592 p_mode = ptr_mode;
3593
3594 /* If either the designated type or its full view is an unconstrained
3595 array subtype, replace it with the type it's a subtype of. This
3596 avoids problems with multiple copies of unconstrained array types.
3597 Likewise, if the designated type is a subtype of an incomplete
3598 record type, use the parent type to avoid order of elaboration
3599 issues. This can lose some code efficiency, but there is no
3600 alternative. */
3601 if (Ekind (gnat_desig_equiv) == E_Array_Subtype
3602 && !Is_Constrained (gnat_desig_equiv))
3603 gnat_desig_equiv = Etype (gnat_desig_equiv);
3604 if (Present (gnat_desig_full)
3605 && ((Ekind (gnat_desig_full) == E_Array_Subtype
3606 && !Is_Constrained (gnat_desig_full))
3607 || (Ekind (gnat_desig_full) == E_Record_Subtype
3608 && Ekind (Etype (gnat_desig_full)) == E_Record_Type)))
3609 gnat_desig_full = Etype (gnat_desig_full);
3610
3611 /* Set the type that's the representation of the designated type. */
3612 gnat_desig_rep
3613 = Present (gnat_desig_full) ? gnat_desig_full : gnat_desig_equiv;
3614
3615 /* If we already know what the full type is, use it. */
3616 if (Present (gnat_desig_full) && present_gnu_tree (gnat_desig_full))
3617 gnu_desig_type = TREE_TYPE (get_gnu_tree (gnat_desig_full));
3618
3619 /* Get the type of the thing we are to point to and build a pointer to
3620 it. If it is a reference to an incomplete or private type with a
3621 full view that is a record, an array or an access, make a dummy type
3622 and get the actual type later when we have verified it is safe. */
3623 else if ((!in_main_unit
3624 && !present_gnu_tree (gnat_desig_equiv)
3625 && Present (gnat_desig_full)
3626 && (Is_Record_Type (gnat_desig_full)
3627 || Is_Array_Type (gnat_desig_full)
3628 || Is_Access_Type (gnat_desig_full)))
3629 /* Likewise if this is a reference to a record, an array or a
3630 subprogram type and we are to defer elaborating incomplete
3631 types. We do this because this access type may be the full
3632 view of a private type. */
3633 || ((!in_main_unit || imported_p)
3634 && defer_incomplete_level != 0
3635 && !present_gnu_tree (gnat_desig_equiv)
3636 && (Is_Record_Type (gnat_desig_rep)
3637 || Is_Array_Type (gnat_desig_rep)
3638 || Ekind (gnat_desig_rep) == E_Subprogram_Type))
3639 /* If this is a reference from a limited_with type back to our
3640 main unit and there's a freeze node for it, either we have
3641 already processed the declaration and made the dummy type,
3642 in which case we just reuse the latter, or we have not yet,
3643 in which case we make the dummy type and it will be reused
3644 when the declaration is finally processed. In both cases,
3645 the pointer eventually created below will be automatically
3646 adjusted when the freeze node is processed. */
3647 || (in_main_unit
3648 && is_from_limited_with
3649 && Present (Freeze_Node (gnat_desig_rep))))
3650 {
3651 gnu_desig_type = make_dummy_type (gnat_desig_equiv);
3652 made_dummy = true;
3653 }
3654
3655 /* Otherwise handle the case of a pointer to itself. */
3656 else if (gnat_desig_equiv == gnat_entity)
3657 {
3658 gnu_type
3659 = build_pointer_type_for_mode (void_type_node, p_mode,
3660 No_Strict_Aliasing (gnat_entity));
3661 TREE_TYPE (gnu_type) = TYPE_POINTER_TO (gnu_type) = gnu_type;
3662 }
3663
3664 /* If expansion is disabled, the equivalent type of a concurrent type
3665 is absent, so we use the void pointer type. */
3666 else if (type_annotate_only && No (gnat_desig_equiv))
3667 gnu_type = ptr_type_node;
3668
3669 /* If the ultimately designated type is an incomplete type with no full
3670 view, we use the void pointer type in LTO mode to avoid emitting a
3671 dummy type in the GIMPLE IR. We cannot do that in regular mode as
3672 the name of the dummy type in used by GDB for a global lookup. */
3673 else if (Ekind (gnat_desig_rep) == E_Incomplete_Type
3674 && No (Full_View (gnat_desig_rep))
3675 && flag_generate_lto)
3676 gnu_type = ptr_type_node;
3677
3678 /* Finally, handle the default case where we can just elaborate our
3679 designated type. */
3680 else
3681 gnu_desig_type = gnat_to_gnu_type (gnat_desig_equiv);
3682
3683 /* It is possible that a call to gnat_to_gnu_type above resolved our
3684 type. If so, just return it. */
3685 if (present_gnu_tree (gnat_entity))
3686 {
3687 maybe_present = true;
3688 break;
3689 }
3690
3691 /* Access-to-unconstrained-array types need a special treatment. */
3692 if (Is_Array_Type (gnat_desig_rep) && !Is_Constrained (gnat_desig_rep))
3693 {
3694 /* If the processing above got something that has a pointer, then
3695 we are done. This could have happened either because the type
3696 was elaborated or because somebody else executed the code. */
3697 if (!TYPE_POINTER_TO (gnu_desig_type))
3698 build_dummy_unc_pointer_types (gnat_desig_equiv, gnu_desig_type);
3699
3700 gnu_type = TYPE_POINTER_TO (gnu_desig_type);
3701 }
3702
3703 /* If we haven't done it yet, build the pointer type the usual way. */
3704 else if (!gnu_type)
3705 {
3706 /* Modify the designated type if we are pointing only to constant
3707 objects, but don't do it for a dummy type. */
3708 if (Is_Access_Constant (gnat_entity)
3709 && !TYPE_IS_DUMMY_P (gnu_desig_type))
3710 gnu_desig_type
3711 = change_qualified_type (gnu_desig_type, TYPE_QUAL_CONST);
3712
3713 gnu_type
3714 = build_pointer_type_for_mode (gnu_desig_type, p_mode,
3715 No_Strict_Aliasing (gnat_entity));
3716 }
3717
3718 /* If the designated type is not declared in the main unit and we made
3719 a dummy node for it, save our definition, elaborate the actual type
3720 and replace the dummy type we made with the actual one. But if we
3721 are to defer actually looking up the actual type, make an entry in
3722 the deferred list instead. If this is from a limited with, we may
3723 have to defer until the end of the current unit. */
3724 if (!in_main_unit && made_dummy)
3725 {
3726 if (TYPE_IS_FAT_POINTER_P (gnu_type) && esize == POINTER_SIZE)
3727 gnu_type
3728 = build_pointer_type (TYPE_OBJECT_RECORD_TYPE (gnu_desig_type));
3729
3730 process_attributes (&gnu_type, &attr_list, false, gnat_entity);
3731 gnu_decl = create_type_decl (gnu_entity_name, gnu_type,
3732 artificial_p, debug_info_p,
3733 gnat_entity);
3734 this_made_decl = true;
3735 gnu_type = TREE_TYPE (gnu_decl);
3736 save_gnu_tree (gnat_entity, gnu_decl, false);
3737 saved = true;
3738
3739 if (defer_incomplete_level == 0
3740 && !is_from_limited_with
3741 && !is_completed_taft_type)
3742 {
3743 update_pointer_to (TYPE_MAIN_VARIANT (gnu_desig_type),
3744 gnat_to_gnu_type (gnat_desig_equiv));
3745 }
3746 else
3747 {
3748 struct incomplete *p = XNEW (struct incomplete);
3749 struct incomplete **head
3750 = (is_from_limited_with || is_completed_taft_type
3751 ? &defer_limited_with_list : &defer_incomplete_list);
3752
3753 p->old_type = gnu_desig_type;
3754 p->full_type = gnat_desig_equiv;
3755 p->next = *head;
3756 *head = p;
3757 }
3758 }
3759 }
3760 break;
3761
3762 case E_Access_Protected_Subprogram_Type:
3763 case E_Anonymous_Access_Protected_Subprogram_Type:
3764 /* If we are just annotating types and have no equivalent record type,
3765 just use the void pointer type. */
3766 if (type_annotate_only && gnat_equiv_type == gnat_entity)
3767 gnu_type = ptr_type_node;
3768
3769 /* The run-time representation is the equivalent type. */
3770 else
3771 {
3772 gnu_type = gnat_to_gnu_type (gnat_equiv_type);
3773 maybe_present = true;
3774 }
3775
3776 /* The designated subtype must be elaborated as well, if it does
3777 not have its own freeze node. */
3778 if (Is_Itype (Directly_Designated_Type (gnat_entity))
3779 && !present_gnu_tree (Directly_Designated_Type (gnat_entity))
3780 && No (Freeze_Node (Directly_Designated_Type (gnat_entity)))
3781 && !Is_Record_Type (Scope (Directly_Designated_Type (gnat_entity))))
3782 gnat_to_gnu_entity (Directly_Designated_Type (gnat_entity),
3783 NULL_TREE, false);
3784
3785 break;
3786
3787 case E_Access_Subtype:
3788 /* We treat this as identical to its base type; any constraint is
3789 meaningful only to the front-end. */
3790 gnu_decl = gnat_to_gnu_entity (Etype (gnat_entity), NULL_TREE, false);
3791 saved = true;
3792
3793 /* The designated subtype must be elaborated as well, if it does
3794 not have its own freeze node. But designated subtypes created
3795 for constrained components of records with discriminants are
3796 not frozen by the front-end and not elaborated here, because
3797 their use may appear before the base type is frozen and it is
3798 not clear that they are needed in gigi. With the current model,
3799 there is no correct place where they could be elaborated. */
3800 if (Is_Itype (Directly_Designated_Type (gnat_entity))
3801 && !present_gnu_tree (Directly_Designated_Type (gnat_entity))
3802 && Is_Frozen (Directly_Designated_Type (gnat_entity))
3803 && No (Freeze_Node (Directly_Designated_Type (gnat_entity))))
3804 {
3805 /* If we are to defer elaborating incomplete types, make a dummy
3806 type node and elaborate it later. */
3807 if (defer_incomplete_level != 0)
3808 {
3809 struct incomplete *p = XNEW (struct incomplete);
3810
3811 p->old_type
3812 = make_dummy_type (Directly_Designated_Type (gnat_entity));
3813 p->full_type = Directly_Designated_Type (gnat_entity);
3814 p->next = defer_incomplete_list;
3815 defer_incomplete_list = p;
3816 }
3817 else if (!Is_Incomplete_Or_Private_Type
3818 (Base_Type (Directly_Designated_Type (gnat_entity))))
3819 gnat_to_gnu_entity (Directly_Designated_Type (gnat_entity),
3820 NULL_TREE, false);
3821 }
3822 break;
3823
3824 /* Subprogram Entities
3825
3826 The following access functions are defined for subprograms:
3827
3828 Etype Return type or Standard_Void_Type.
3829 First_Formal The first formal parameter.
3830 Is_Imported Indicates that the subprogram has appeared in
3831 an INTERFACE or IMPORT pragma. For now we
3832 assume that the external language is C.
3833 Is_Exported Likewise but for an EXPORT pragma.
3834 Is_Inlined True if the subprogram is to be inlined.
3835
3836 Each parameter is first checked by calling must_pass_by_ref on its
3837 type to determine if it is passed by reference. For parameters which
3838 are copied in, if they are Ada In Out or Out parameters, their return
3839 value becomes part of a record which becomes the return type of the
3840 function (C function - note that this applies only to Ada procedures
3841 so there is no Ada return type). Additional code to store back the
3842 parameters will be generated on the caller side. This transformation
3843 is done here, not in the front-end.
3844
3845 The intended result of the transformation can be seen from the
3846 equivalent source rewritings that follow:
3847
3848 struct temp {int a,b};
3849 procedure P (A,B: In Out ...) is temp P (int A,B)
3850 begin {
3851 .. ..
3852 end P; return {A,B};
3853 }
3854
3855 temp t;
3856 P(X,Y); t = P(X,Y);
3857 X = t.a , Y = t.b;
3858
3859 For subprogram types we need to perform mainly the same conversions to
3860 GCC form that are needed for procedures and function declarations. The
3861 only difference is that at the end, we make a type declaration instead
3862 of a function declaration. */
3863
3864 case E_Subprogram_Type:
3865 case E_Function:
3866 case E_Procedure:
3867 {
3868 tree gnu_ext_name
3869 = gnu_ext_name_for_subprog (gnat_entity, gnu_entity_name);
3870 enum inline_status_t inline_status
3871 = Has_Pragma_No_Inline (gnat_entity)
3872 ? is_suppressed
3873 : Has_Pragma_Inline_Always (gnat_entity)
3874 ? is_required
3875 : (Is_Inlined (gnat_entity) ? is_enabled : is_disabled);
3876 bool public_flag = Is_Public (gnat_entity) || imported_p;
3877 /* Subprograms marked both Intrinsic and Always_Inline need not
3878 have a body of their own. */
3879 bool extern_flag
3880 = ((Is_Public (gnat_entity) && !definition)
3881 || imported_p
3882 || (Convention (gnat_entity) == Convention_Intrinsic
3883 && Has_Pragma_Inline_Always (gnat_entity)));
3884 tree gnu_param_list;
3885
3886 /* A parameter may refer to this type, so defer completion of any
3887 incomplete types. */
3888 if (kind == E_Subprogram_Type && !definition)
3889 {
3890 defer_incomplete_level++;
3891 this_deferred = true;
3892 }
3893
3894 /* If the subprogram has an alias, it is probably inherited, so
3895 we can use the original one. If the original "subprogram"
3896 is actually an enumeration literal, it may be the first use
3897 of its type, so we must elaborate that type now. */
3898 if (Present (Alias (gnat_entity)))
3899 {
3900 const Entity_Id gnat_renamed = Renamed_Object (gnat_entity);
3901
3902 if (Ekind (Alias (gnat_entity)) == E_Enumeration_Literal)
3903 gnat_to_gnu_entity (Etype (Alias (gnat_entity)), NULL_TREE,
3904 false);
3905
3906 gnu_decl
3907 = gnat_to_gnu_entity (Alias (gnat_entity), gnu_expr, false);
3908
3909 /* Elaborate any Itypes in the parameters of this entity. */
3910 for (gnat_temp = First_Formal_With_Extras (gnat_entity);
3911 Present (gnat_temp);
3912 gnat_temp = Next_Formal_With_Extras (gnat_temp))
3913 if (Is_Itype (Etype (gnat_temp)))
3914 gnat_to_gnu_entity (Etype (gnat_temp), NULL_TREE, false);
3915
3916 /* Materialize renamed subprograms in the debugging information
3917 when the renamed object is compile time known. We can consider
3918 such renamings as imported declarations.
3919
3920 Because the parameters in generics instantiation are generally
3921 materialized as renamings, we ofter end up having both the
3922 renamed subprogram and the renaming in the same context and with
3923 the same name: in this case, renaming is both useless debug-wise
3924 and potentially harmful as name resolution in the debugger could
3925 return twice the same entity! So avoid this case. */
3926 if (debug_info_p && !artificial_p
3927 && !(get_debug_scope (gnat_entity, NULL)
3928 == get_debug_scope (gnat_renamed, NULL)
3929 && Name_Equals (Chars (gnat_entity),
3930 Chars (gnat_renamed)))
3931 && Present (gnat_renamed)
3932 && (Ekind (gnat_renamed) == E_Function
3933 || Ekind (gnat_renamed) == E_Procedure)
3934 && gnu_decl
3935 && TREE_CODE (gnu_decl) == FUNCTION_DECL)
3936 {
3937 tree decl = build_decl (input_location, IMPORTED_DECL,
3938 gnu_entity_name, void_type_node);
3939 IMPORTED_DECL_ASSOCIATED_DECL (decl) = gnu_decl;
3940 gnat_pushdecl (decl, gnat_entity);
3941 }
3942
3943 break;
3944 }
3945
3946 /* Get the GCC tree for the (underlying) subprogram type. If the
3947 entity is an actual subprogram, also get the parameter list. */
3948 gnu_type
3949 = gnat_to_gnu_subprog_type (gnat_entity, definition, debug_info_p,
3950 &gnu_param_list);
3951 if (DECL_P (gnu_type))
3952 {
3953 gnu_decl = gnu_type;
3954 gnu_type = TREE_TYPE (gnu_decl);
3955 break;
3956 }
3957
3958 /* Deal with platform-specific calling conventions. */
3959 if (Has_Stdcall_Convention (gnat_entity))
3960 prepend_one_attribute
3961 (&attr_list, ATTR_MACHINE_ATTRIBUTE,
3962 get_identifier ("stdcall"), NULL_TREE,
3963 gnat_entity);
3964 else if (Has_Thiscall_Convention (gnat_entity))
3965 prepend_one_attribute
3966 (&attr_list, ATTR_MACHINE_ATTRIBUTE,
3967 get_identifier ("thiscall"), NULL_TREE,
3968 gnat_entity);
3969
3970 /* If we should request stack realignment for a foreign convention
3971 subprogram, do so. Note that this applies to task entry points
3972 in particular. */
3973 if (FOREIGN_FORCE_REALIGN_STACK
3974 && Has_Foreign_Convention (gnat_entity))
3975 prepend_one_attribute
3976 (&attr_list, ATTR_MACHINE_ATTRIBUTE,
3977 get_identifier ("force_align_arg_pointer"), NULL_TREE,
3978 gnat_entity);
3979
3980 /* Deal with a pragma Linker_Section on a subprogram. */
3981 if ((kind == E_Function || kind == E_Procedure)
3982 && Present (Linker_Section_Pragma (gnat_entity)))
3983 prepend_one_attribute_pragma (&attr_list,
3984 Linker_Section_Pragma (gnat_entity));
3985
3986 /* If we are defining the subprogram and it has an Address clause
3987 we must get the address expression from the saved GCC tree for the
3988 subprogram if it has a Freeze_Node. Otherwise, we elaborate
3989 the address expression here since the front-end has guaranteed
3990 in that case that the elaboration has no effects. If there is
3991 an Address clause and we are not defining the object, just
3992 make it a constant. */
3993 if (Present (Address_Clause (gnat_entity)))
3994 {
3995 tree gnu_address = NULL_TREE;
3996
3997 if (definition)
3998 gnu_address
3999 = (present_gnu_tree (gnat_entity)
4000 ? get_gnu_tree (gnat_entity)
4001 : gnat_to_gnu (Expression (Address_Clause (gnat_entity))));
4002
4003 save_gnu_tree (gnat_entity, NULL_TREE, false);
4004
4005 /* Convert the type of the object to a reference type that can
4006 alias everything as per RM 13.3(19). */
4007 gnu_type
4008 = build_reference_type_for_mode (gnu_type, ptr_mode, true);
4009 if (gnu_address)
4010 gnu_address = convert (gnu_type, gnu_address);
4011
4012 gnu_decl
4013 = create_var_decl (gnu_entity_name, gnu_ext_name, gnu_type,
4014 gnu_address, false, Is_Public (gnat_entity),
4015 extern_flag, false, false, artificial_p,
4016 debug_info_p, NULL, gnat_entity);
4017 DECL_BY_REF_P (gnu_decl) = 1;
4018 }
4019
4020 /* If this is a mere subprogram type, just create the declaration. */
4021 else if (kind == E_Subprogram_Type)
4022 {
4023 process_attributes (&gnu_type, &attr_list, false, gnat_entity);
4024
4025 gnu_decl
4026 = create_type_decl (gnu_entity_name, gnu_type, artificial_p,
4027 debug_info_p, gnat_entity);
4028 }
4029
4030 /* Otherwise create the subprogram declaration with the external name,
4031 the type and the parameter list. However, if this a reference to
4032 the allocation routines, reuse the canonical declaration nodes as
4033 they come with special properties. */
4034 else
4035 {
4036 if (extern_flag && gnu_ext_name == DECL_NAME (malloc_decl))
4037 gnu_decl = malloc_decl;
4038 else if (extern_flag && gnu_ext_name == DECL_NAME (realloc_decl))
4039 gnu_decl = realloc_decl;
4040 else
4041 {
4042 gnu_decl
4043 = create_subprog_decl (gnu_entity_name, gnu_ext_name,
4044 gnu_type, gnu_param_list,
4045 inline_status, public_flag,
4046 extern_flag, artificial_p,
4047 debug_info_p,
4048 definition && imported_p, attr_list,
4049 gnat_entity);
4050
4051 DECL_STUBBED_P (gnu_decl)
4052 = (Convention (gnat_entity) == Convention_Stubbed);
4053 }
4054 }
4055 }
4056 break;
4057
4058 case E_Incomplete_Type:
4059 case E_Incomplete_Subtype:
4060 case E_Private_Type:
4061 case E_Private_Subtype:
4062 case E_Limited_Private_Type:
4063 case E_Limited_Private_Subtype:
4064 case E_Record_Type_With_Private:
4065 case E_Record_Subtype_With_Private:
4066 {
4067 const bool is_from_limited_with
4068 = (IN (kind, Incomplete_Kind) && From_Limited_With (gnat_entity));
4069 /* Get the "full view" of this entity. If this is an incomplete
4070 entity from a limited with, treat its non-limited view as the
4071 full view. Otherwise, use either the full view or the underlying
4072 full view, whichever is present. This is used in all the tests
4073 below. */
4074 const Entity_Id full_view
4075 = is_from_limited_with
4076 ? Non_Limited_View (gnat_entity)
4077 : Present (Full_View (gnat_entity))
4078 ? Full_View (gnat_entity)
4079 : IN (kind, Private_Kind)
4080 ? Underlying_Full_View (gnat_entity)
4081 : Empty;
4082
4083 /* If this is an incomplete type with no full view, it must be a Taft
4084 Amendment type or an incomplete type coming from a limited context,
4085 in which cases we return a dummy type. Otherwise, we just get the
4086 type from its Etype. */
4087 if (No (full_view))
4088 {
4089 if (kind == E_Incomplete_Type)
4090 {
4091 gnu_type = make_dummy_type (gnat_entity);
4092 gnu_decl = TYPE_STUB_DECL (gnu_type);
4093 }
4094 else
4095 {
4096 gnu_decl
4097 = gnat_to_gnu_entity (Etype (gnat_entity), NULL_TREE, false);
4098 maybe_present = true;
4099 }
4100 }
4101
4102 /* Or else, if we already made a type for the full view, reuse it. */
4103 else if (present_gnu_tree (full_view))
4104 gnu_decl = get_gnu_tree (full_view);
4105
4106 /* Or else, if we are not defining the type or there is no freeze
4107 node on it, get the type for the full view. Likewise if this is
4108 a limited_with'ed type not declared in the main unit, which can
4109 happen for incomplete formal types instantiated on a type coming
4110 from a limited_with clause. */
4111 else if (!definition
4112 || No (Freeze_Node (full_view))
4113 || (is_from_limited_with
4114 && !In_Extended_Main_Code_Unit (full_view)))
4115 {
4116 gnu_decl = gnat_to_gnu_entity (full_view, NULL_TREE, false);
4117 maybe_present = true;
4118 }
4119
4120 /* Otherwise, make a dummy type entry which will be replaced later.
4121 Save it as the full declaration's type so we can do any needed
4122 updates when we see it. */
4123 else
4124 {
4125 gnu_type = make_dummy_type (gnat_entity);
4126 gnu_decl = TYPE_STUB_DECL (gnu_type);
4127 if (Has_Completion_In_Body (gnat_entity))
4128 DECL_TAFT_TYPE_P (gnu_decl) = 1;
4129 save_gnu_tree (full_view, gnu_decl, false);
4130 }
4131 }
4132 break;
4133
4134 case E_Class_Wide_Type:
4135 /* Class-wide types are always transformed into their root type. */
4136 gnu_decl = gnat_to_gnu_entity (gnat_equiv_type, NULL_TREE, false);
4137 maybe_present = true;
4138 break;
4139
4140 case E_Protected_Type:
4141 case E_Protected_Subtype:
4142 case E_Task_Type:
4143 case E_Task_Subtype:
4144 /* If we are just annotating types and have no equivalent record type,
4145 just return void_type, except for root types that have discriminants
4146 because the discriminants will very likely be used in the declarative
4147 part of the associated body so they need to be translated. */
4148 if (type_annotate_only && gnat_equiv_type == gnat_entity)
4149 {
4150 if (Has_Discriminants (gnat_entity)
4151 && Root_Type (gnat_entity) == gnat_entity)
4152 {
4153 tree gnu_field_list = NULL_TREE;
4154 Entity_Id gnat_field;
4155
4156 /* This is a minimal version of the E_Record_Type handling. */
4157 gnu_type = make_node (RECORD_TYPE);
4158 TYPE_NAME (gnu_type) = gnu_entity_name;
4159
4160 for (gnat_field = First_Stored_Discriminant (gnat_entity);
4161 Present (gnat_field);
4162 gnat_field = Next_Stored_Discriminant (gnat_field))
4163 {
4164 tree gnu_field
4165 = gnat_to_gnu_field (gnat_field, gnu_type, false,
4166 definition, debug_info_p);
4167
4168 save_gnu_tree (gnat_field,
4169 build3 (COMPONENT_REF, TREE_TYPE (gnu_field),
4170 build0 (PLACEHOLDER_EXPR, gnu_type),
4171 gnu_field, NULL_TREE),
4172 true);
4173
4174 DECL_CHAIN (gnu_field) = gnu_field_list;
4175 gnu_field_list = gnu_field;
4176 }
4177
4178 finish_record_type (gnu_type, nreverse (gnu_field_list), 0,
4179 false);
4180 }
4181 else
4182 gnu_type = void_type_node;
4183 }
4184
4185 /* Concurrent types are always transformed into their record type. */
4186 else
4187 gnu_decl = gnat_to_gnu_entity (gnat_equiv_type, NULL_TREE, false);
4188 maybe_present = true;
4189 break;
4190
4191 case E_Label:
4192 gnu_decl = create_label_decl (gnu_entity_name, gnat_entity);
4193 break;
4194
4195 case E_Block:
4196 case E_Loop:
4197 /* Nothing at all to do here, so just return an ERROR_MARK and claim
4198 we've already saved it, so we don't try to. */
4199 gnu_decl = error_mark_node;
4200 saved = true;
4201 break;
4202
4203 case E_Abstract_State:
4204 /* This is a SPARK annotation that only reaches here when compiling in
4205 ASIS mode. */
4206 gcc_assert (type_annotate_only);
4207 gnu_decl = error_mark_node;
4208 saved = true;
4209 break;
4210
4211 default:
4212 gcc_unreachable ();
4213 }
4214
4215 /* If we had a case where we evaluated another type and it might have
4216 defined this one, handle it here. */
4217 if (maybe_present && present_gnu_tree (gnat_entity))
4218 {
4219 gnu_decl = get_gnu_tree (gnat_entity);
4220 saved = true;
4221 }
4222
4223 /* If we are processing a type and there is either no decl for it or
4224 we just made one, do some common processing for the type, such as
4225 handling alignment and possible padding. */
4226 if (is_type && (!gnu_decl || this_made_decl))
4227 {
4228 gcc_assert (!TYPE_IS_DUMMY_P (gnu_type));
4229
4230 /* Process the attributes, if not already done. Note that the type is
4231 already defined so we cannot pass true for IN_PLACE here. */
4232 process_attributes (&gnu_type, &attr_list, false, gnat_entity);
4233
4234 /* ??? Don't set the size for a String_Literal since it is either
4235 confirming or we don't handle it properly (if the low bound is
4236 non-constant). */
4237 if (!gnu_size && kind != E_String_Literal_Subtype)
4238 {
4239 Uint gnat_size = Known_Esize (gnat_entity)
4240 ? Esize (gnat_entity) : RM_Size (gnat_entity);
4241 gnu_size
4242 = validate_size (gnat_size, gnu_type, gnat_entity, TYPE_DECL,
4243 false, Has_Size_Clause (gnat_entity));
4244 }
4245
4246 /* If a size was specified, see if we can make a new type of that size
4247 by rearranging the type, for example from a fat to a thin pointer. */
4248 if (gnu_size)
4249 {
4250 gnu_type
4251 = make_type_from_size (gnu_type, gnu_size,
4252 Has_Biased_Representation (gnat_entity));
4253
4254 if (operand_equal_p (TYPE_SIZE (gnu_type), gnu_size, 0)
4255 && operand_equal_p (rm_size (gnu_type), gnu_size, 0))
4256 gnu_size = NULL_TREE;
4257 }
4258
4259 /* If the alignment has not already been processed and this is not
4260 an unconstrained array type, see if an alignment is specified.
4261 If not, we pick a default alignment for atomic objects. */
4262 if (align != 0 || TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE)
4263 ;
4264 else if (Known_Alignment (gnat_entity))
4265 {
4266 align = validate_alignment (Alignment (gnat_entity), gnat_entity,
4267 TYPE_ALIGN (gnu_type));
4268
4269 /* Warn on suspiciously large alignments. This should catch
4270 errors about the (alignment,byte)/(size,bit) discrepancy. */
4271 if (align > BIGGEST_ALIGNMENT && Has_Alignment_Clause (gnat_entity))
4272 {
4273 tree size;
4274
4275 /* If a size was specified, take it into account. Otherwise
4276 use the RM size for records or unions as the type size has
4277 already been adjusted to the alignment. */
4278 if (gnu_size)
4279 size = gnu_size;
4280 else if (RECORD_OR_UNION_TYPE_P (gnu_type)
4281 && !TYPE_FAT_POINTER_P (gnu_type))
4282 size = rm_size (gnu_type);
4283 else
4284 size = TYPE_SIZE (gnu_type);
4285
4286 /* Consider an alignment as suspicious if the alignment/size
4287 ratio is greater or equal to the byte/bit ratio. */
4288 if (tree_fits_uhwi_p (size)
4289 && align >= tree_to_uhwi (size) * BITS_PER_UNIT)
4290 post_error_ne ("?suspiciously large alignment specified for&",
4291 Expression (Alignment_Clause (gnat_entity)),
4292 gnat_entity);
4293 }
4294 }
4295 else if (Is_Atomic_Or_VFA (gnat_entity) && !gnu_size
4296 && tree_fits_uhwi_p (TYPE_SIZE (gnu_type))
4297 && integer_pow2p (TYPE_SIZE (gnu_type)))
4298 align = MIN (BIGGEST_ALIGNMENT,
4299 tree_to_uhwi (TYPE_SIZE (gnu_type)));
4300 else if (Is_Atomic_Or_VFA (gnat_entity) && gnu_size
4301 && tree_fits_uhwi_p (gnu_size)
4302 && integer_pow2p (gnu_size))
4303 align = MIN (BIGGEST_ALIGNMENT, tree_to_uhwi (gnu_size));
4304
4305 /* See if we need to pad the type. If we did, and made a record,
4306 the name of the new type may be changed. So get it back for
4307 us when we make the new TYPE_DECL below. */
4308 if (gnu_size || align > 0)
4309 gnu_type = maybe_pad_type (gnu_type, gnu_size, align, gnat_entity,
4310 false, !gnu_decl, definition, false);
4311
4312 if (TYPE_IS_PADDING_P (gnu_type))
4313 gnu_entity_name = TYPE_IDENTIFIER (gnu_type);
4314
4315 /* Now set the RM size of the type. We cannot do it before padding
4316 because we need to accept arbitrary RM sizes on integral types. */
4317 set_rm_size (RM_Size (gnat_entity), gnu_type, gnat_entity);
4318
4319 /* If we are at global level, GCC will have applied variable_size to
4320 the type, but that won't have done anything. So, if it's not
4321 a constant or self-referential, call elaborate_expression_1 to
4322 make a variable for the size rather than calculating it each time.
4323 Handle both the RM size and the actual size. */
4324 if (TYPE_SIZE (gnu_type)
4325 && !TREE_CONSTANT (TYPE_SIZE (gnu_type))
4326 && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type))
4327 && global_bindings_p ())
4328 {
4329 tree size = TYPE_SIZE (gnu_type);
4330
4331 TYPE_SIZE (gnu_type)
4332 = elaborate_expression_1 (size, gnat_entity, "SIZE", definition,
4333 false);
4334
4335 /* ??? For now, store the size as a multiple of the alignment in
4336 bytes so that we can see the alignment from the tree. */
4337 TYPE_SIZE_UNIT (gnu_type)
4338 = elaborate_expression_2 (TYPE_SIZE_UNIT (gnu_type), gnat_entity,
4339 "SIZE_A_UNIT", definition, false,
4340 TYPE_ALIGN (gnu_type));
4341
4342 /* ??? gnu_type may come from an existing type so the MULT_EXPR node
4343 may not be marked by the call to create_type_decl below. */
4344 MARK_VISITED (TYPE_SIZE_UNIT (gnu_type));
4345
4346 if (TREE_CODE (gnu_type) == RECORD_TYPE)
4347 {
4348 tree variant_part = get_variant_part (gnu_type);
4349 tree ada_size = TYPE_ADA_SIZE (gnu_type);
4350
4351 if (variant_part)
4352 {
4353 tree union_type = TREE_TYPE (variant_part);
4354 tree offset = DECL_FIELD_OFFSET (variant_part);
4355
4356 /* If the position of the variant part is constant, subtract
4357 it from the size of the type of the parent to get the new
4358 size. This manual CSE reduces the data size. */
4359 if (TREE_CODE (offset) == INTEGER_CST)
4360 {
4361 tree bitpos = DECL_FIELD_BIT_OFFSET (variant_part);
4362 TYPE_SIZE (union_type)
4363 = size_binop (MINUS_EXPR, TYPE_SIZE (gnu_type),
4364 bit_from_pos (offset, bitpos));
4365 TYPE_SIZE_UNIT (union_type)
4366 = size_binop (MINUS_EXPR, TYPE_SIZE_UNIT (gnu_type),
4367 byte_from_pos (offset, bitpos));
4368 }
4369 else
4370 {
4371 TYPE_SIZE (union_type)
4372 = elaborate_expression_1 (TYPE_SIZE (union_type),
4373 gnat_entity, "VSIZE",
4374 definition, false);
4375
4376 /* ??? For now, store the size as a multiple of the
4377 alignment in bytes so that we can see the alignment
4378 from the tree. */
4379 TYPE_SIZE_UNIT (union_type)
4380 = elaborate_expression_2 (TYPE_SIZE_UNIT (union_type),
4381 gnat_entity, "VSIZE_A_UNIT",
4382 definition, false,
4383 TYPE_ALIGN (union_type));
4384
4385 /* ??? For now, store the offset as a multiple of the
4386 alignment in bytes so that we can see the alignment
4387 from the tree. */
4388 DECL_FIELD_OFFSET (variant_part)
4389 = elaborate_expression_2 (offset, gnat_entity,
4390 "VOFFSET", definition, false,
4391 DECL_OFFSET_ALIGN
4392 (variant_part));
4393 }
4394
4395 DECL_SIZE (variant_part) = TYPE_SIZE (union_type);
4396 DECL_SIZE_UNIT (variant_part) = TYPE_SIZE_UNIT (union_type);
4397 }
4398
4399 if (operand_equal_p (ada_size, size, 0))
4400 ada_size = TYPE_SIZE (gnu_type);
4401 else
4402 ada_size
4403 = elaborate_expression_1 (ada_size, gnat_entity, "RM_SIZE",
4404 definition, false);
4405 SET_TYPE_ADA_SIZE (gnu_type, ada_size);
4406 }
4407 }
4408
4409 /* Similarly, if this is a record type or subtype at global level, call
4410 elaborate_expression_2 on any field position. Skip any fields that
4411 we haven't made trees for to avoid problems with class-wide types. */
4412 if (IN (kind, Record_Kind) && global_bindings_p ())
4413 for (gnat_temp = First_Entity (gnat_entity); Present (gnat_temp);
4414 gnat_temp = Next_Entity (gnat_temp))
4415 if (Ekind (gnat_temp) == E_Component && present_gnu_tree (gnat_temp))
4416 {
4417 tree gnu_field = get_gnu_tree (gnat_temp);
4418
4419 /* ??? For now, store the offset as a multiple of the alignment
4420 in bytes so that we can see the alignment from the tree. */
4421 if (!TREE_CONSTANT (DECL_FIELD_OFFSET (gnu_field))
4422 && !CONTAINS_PLACEHOLDER_P (DECL_FIELD_OFFSET (gnu_field)))
4423 {
4424 DECL_FIELD_OFFSET (gnu_field)
4425 = elaborate_expression_2 (DECL_FIELD_OFFSET (gnu_field),
4426 gnat_temp, "OFFSET", definition,
4427 false,
4428 DECL_OFFSET_ALIGN (gnu_field));
4429
4430 /* ??? The context of gnu_field is not necessarily gnu_type
4431 so the MULT_EXPR node built above may not be marked by
4432 the call to create_type_decl below. */
4433 MARK_VISITED (DECL_FIELD_OFFSET (gnu_field));
4434 }
4435 }
4436
4437 if (Is_Atomic_Or_VFA (gnat_entity))
4438 check_ok_for_atomic_type (gnu_type, gnat_entity, false);
4439
4440 /* If this is not an unconstrained array type, set some flags. */
4441 if (TREE_CODE (gnu_type) != UNCONSTRAINED_ARRAY_TYPE)
4442 {
4443 /* Record the property that objects of tagged types are guaranteed to
4444 be properly aligned. This is necessary because conversions to the
4445 class-wide type are translated into conversions to the root type,
4446 which can be less aligned than some of its derived types. */
4447 if (Is_Tagged_Type (gnat_entity)
4448 || Is_Class_Wide_Equivalent_Type (gnat_entity))
4449 TYPE_ALIGN_OK (gnu_type) = 1;
4450
4451 /* Record whether the type is passed by reference. */
4452 if (Is_By_Reference_Type (gnat_entity) && !VOID_TYPE_P (gnu_type))
4453 TYPE_BY_REFERENCE_P (gnu_type) = 1;
4454
4455 /* Record whether an alignment clause was specified. */
4456 if (Present (Alignment_Clause (gnat_entity)))
4457 TYPE_USER_ALIGN (gnu_type) = 1;
4458
4459 /* Record whether a pragma Universal_Aliasing was specified. */
4460 if (Universal_Aliasing (gnat_entity) && !TYPE_IS_DUMMY_P (gnu_type))
4461 TYPE_UNIVERSAL_ALIASING_P (gnu_type) = 1;
4462
4463 /* If it is passed by reference, force BLKmode to ensure that
4464 objects of this type will always be put in memory. */
4465 if (AGGREGATE_TYPE_P (gnu_type) && TYPE_BY_REFERENCE_P (gnu_type))
4466 SET_TYPE_MODE (gnu_type, BLKmode);
4467 }
4468
4469 /* If this is a derived type, relate its alias set to that of its parent
4470 to avoid troubles when a call to an inherited primitive is inlined in
4471 a context where a derived object is accessed. The inlined code works
4472 on the parent view so the resulting code may access the same object
4473 using both the parent and the derived alias sets, which thus have to
4474 conflict. As the same issue arises with component references, the
4475 parent alias set also has to conflict with composite types enclosing
4476 derived components. For instance, if we have:
4477
4478 type D is new T;
4479 type R is record
4480 Component : D;
4481 end record;
4482
4483 we want T to conflict with both D and R, in addition to R being a
4484 superset of D by record/component construction.
4485
4486 One way to achieve this is to perform an alias set copy from the
4487 parent to the derived type. This is not quite appropriate, though,
4488 as we don't want separate derived types to conflict with each other:
4489
4490 type I1 is new Integer;
4491 type I2 is new Integer;
4492
4493 We want I1 and I2 to both conflict with Integer but we do not want
4494 I1 to conflict with I2, and an alias set copy on derivation would
4495 have that effect.
4496
4497 The option chosen is to make the alias set of the derived type a
4498 superset of that of its parent type. It trivially fulfills the
4499 simple requirement for the Integer derivation example above, and
4500 the component case as well by superset transitivity:
4501
4502 superset superset
4503 R ----------> D ----------> T
4504
4505 However, for composite types, conversions between derived types are
4506 translated into VIEW_CONVERT_EXPRs so a sequence like:
4507
4508 type Comp1 is new Comp;
4509 type Comp2 is new Comp;
4510 procedure Proc (C : Comp1);
4511
4512 C : Comp2;
4513 Proc (Comp1 (C));
4514
4515 is translated into:
4516
4517 C : Comp2;
4518 Proc ((Comp1 &) &VIEW_CONVERT_EXPR <Comp1> (C));
4519
4520 and gimplified into:
4521
4522 C : Comp2;
4523 Comp1 *C.0;
4524 C.0 = (Comp1 *) &C;
4525 Proc (C.0);
4526
4527 i.e. generates code involving type punning. Therefore, Comp1 needs
4528 to conflict with Comp2 and an alias set copy is required.
4529
4530 The language rules ensure the parent type is already frozen here. */
4531 if (kind != E_Subprogram_Type
4532 && Is_Derived_Type (gnat_entity)
4533 && !type_annotate_only)
4534 {
4535 Entity_Id gnat_parent_type = Underlying_Type (Etype (gnat_entity));
4536 /* For constrained packed array subtypes, the implementation type is
4537 used instead of the nominal type. */
4538 if (kind == E_Array_Subtype
4539 && Is_Constrained (gnat_entity)
4540 && Present (Packed_Array_Impl_Type (gnat_parent_type)))
4541 gnat_parent_type = Packed_Array_Impl_Type (gnat_parent_type);
4542 relate_alias_sets (gnu_type, gnat_to_gnu_type (gnat_parent_type),
4543 Is_Composite_Type (gnat_entity)
4544 ? ALIAS_SET_COPY : ALIAS_SET_SUPERSET);
4545 }
4546
4547 /* Finally get to the appropriate variant, except for the implementation
4548 type of a packed array because the GNU type might be further adjusted
4549 when the original array type is itself processed. */
4550 if (Treat_As_Volatile (gnat_entity)
4551 && !Is_Packed_Array_Impl_Type (gnat_entity))
4552 {
4553 const int quals
4554 = TYPE_QUAL_VOLATILE
4555 | (Is_Atomic_Or_VFA (gnat_entity) ? TYPE_QUAL_ATOMIC : 0);
4556 gnu_type = change_qualified_type (gnu_type, quals);
4557 }
4558
4559 /* If we already made a decl, just set the type, otherwise create it. */
4560 if (gnu_decl)
4561 {
4562 TREE_TYPE (gnu_decl) = gnu_type;
4563 TYPE_STUB_DECL (gnu_type) = gnu_decl;
4564 }
4565 else
4566 gnu_decl = create_type_decl (gnu_entity_name, gnu_type, artificial_p,
4567 debug_info_p, gnat_entity);
4568 }
4569
4570 /* If we got a type that is not dummy, back-annotate the alignment of the
4571 type if not already in the tree. Likewise for the size, if any. */
4572 if (is_type && !TYPE_IS_DUMMY_P (TREE_TYPE (gnu_decl)))
4573 {
4574 gnu_type = TREE_TYPE (gnu_decl);
4575
4576 if (Unknown_Alignment (gnat_entity))
4577 {
4578 unsigned int double_align, align;
4579 bool is_capped_double, align_clause;
4580
4581 /* If the default alignment of "double" or larger scalar types is
4582 specifically capped and this is not an array with an alignment
4583 clause on the component type, return the cap. */
4584 if ((double_align = double_float_alignment) > 0)
4585 is_capped_double
4586 = is_double_float_or_array (gnat_entity, &align_clause);
4587 else if ((double_align = double_scalar_alignment) > 0)
4588 is_capped_double
4589 = is_double_scalar_or_array (gnat_entity, &align_clause);
4590 else
4591 is_capped_double = align_clause = false;
4592
4593 if (is_capped_double && !align_clause)
4594 align = double_align;
4595 else
4596 align = TYPE_ALIGN (gnu_type) / BITS_PER_UNIT;
4597
4598 Set_Alignment (gnat_entity, UI_From_Int (align));
4599 }
4600
4601 if (Unknown_Esize (gnat_entity) && TYPE_SIZE (gnu_type))
4602 {
4603 tree gnu_size = TYPE_SIZE (gnu_type);
4604
4605 /* If the size is self-referential, annotate the maximum value. */
4606 if (CONTAINS_PLACEHOLDER_P (gnu_size))
4607 gnu_size = max_size (gnu_size, true);
4608
4609 /* If we are just annotating types and the type is tagged, the tag
4610 and the parent components are not generated by the front-end so
4611 alignment and sizes must be adjusted if there is no rep clause. */
4612 if (type_annotate_only
4613 && Is_Tagged_Type (gnat_entity)
4614 && Unknown_RM_Size (gnat_entity)
4615 && !VOID_TYPE_P (gnu_type)
4616 && (!TYPE_FIELDS (gnu_type)
4617 || integer_zerop (bit_position (TYPE_FIELDS (gnu_type)))))
4618 {
4619 tree offset;
4620
4621 if (Is_Derived_Type (gnat_entity))
4622 {
4623 Entity_Id gnat_parent = Etype (Base_Type (gnat_entity));
4624 offset = UI_To_gnu (Esize (gnat_parent), bitsizetype);
4625 Set_Alignment (gnat_entity, Alignment (gnat_parent));
4626 }
4627 else
4628 {
4629 unsigned int align
4630 = MAX (TYPE_ALIGN (gnu_type), POINTER_SIZE) / BITS_PER_UNIT;
4631 offset = bitsize_int (POINTER_SIZE);
4632 Set_Alignment (gnat_entity, UI_From_Int (align));
4633 }
4634
4635 if (TYPE_FIELDS (gnu_type))
4636 offset
4637 = round_up (offset, DECL_ALIGN (TYPE_FIELDS (gnu_type)));
4638
4639 gnu_size = size_binop (PLUS_EXPR, gnu_size, offset);
4640 gnu_size = round_up (gnu_size, POINTER_SIZE);
4641 Uint uint_size = annotate_value (gnu_size);
4642 Set_RM_Size (gnat_entity, uint_size);
4643 Set_Esize (gnat_entity, uint_size);
4644 }
4645
4646 /* If there is a rep clause, only adjust alignment and Esize. */
4647 else if (type_annotate_only && Is_Tagged_Type (gnat_entity))
4648 {
4649 unsigned int align
4650 = MAX (TYPE_ALIGN (gnu_type), POINTER_SIZE) / BITS_PER_UNIT;
4651 Set_Alignment (gnat_entity, UI_From_Int (align));
4652 gnu_size = round_up (gnu_size, POINTER_SIZE);
4653 Set_Esize (gnat_entity, annotate_value (gnu_size));
4654 }
4655
4656 /* Otherwise no adjustment is needed. */
4657 else
4658 Set_Esize (gnat_entity, annotate_value (gnu_size));
4659 }
4660
4661 if (Unknown_RM_Size (gnat_entity) && TYPE_SIZE (gnu_type))
4662 Set_RM_Size (gnat_entity, annotate_value (rm_size (gnu_type)));
4663 }
4664
4665 /* If we haven't already, associate the ..._DECL node that we just made with
4666 the input GNAT entity node. */
4667 if (!saved)
4668 save_gnu_tree (gnat_entity, gnu_decl, false);
4669
4670 /* Now we are sure gnat_entity has a corresponding ..._DECL node,
4671 eliminate as many deferred computations as possible. */
4672 process_deferred_decl_context (false);
4673
4674 /* If this is an enumeration or floating-point type, we were not able to set
4675 the bounds since they refer to the type. These are always static. */
4676 if ((kind == E_Enumeration_Type && Present (First_Literal (gnat_entity)))
4677 || (kind == E_Floating_Point_Type))
4678 {
4679 tree gnu_scalar_type = gnu_type;
4680 tree gnu_low_bound, gnu_high_bound;
4681
4682 /* If this is a padded type, we need to use the underlying type. */
4683 if (TYPE_IS_PADDING_P (gnu_scalar_type))
4684 gnu_scalar_type = TREE_TYPE (TYPE_FIELDS (gnu_scalar_type));
4685
4686 /* If this is a floating point type and we haven't set a floating
4687 point type yet, use this in the evaluation of the bounds. */
4688 if (!longest_float_type_node && kind == E_Floating_Point_Type)
4689 longest_float_type_node = gnu_scalar_type;
4690
4691 gnu_low_bound = gnat_to_gnu (Type_Low_Bound (gnat_entity));
4692 gnu_high_bound = gnat_to_gnu (Type_High_Bound (gnat_entity));
4693
4694 if (kind == E_Enumeration_Type)
4695 {
4696 /* Enumeration types have specific RM bounds. */
4697 SET_TYPE_RM_MIN_VALUE (gnu_scalar_type, gnu_low_bound);
4698 SET_TYPE_RM_MAX_VALUE (gnu_scalar_type, gnu_high_bound);
4699 }
4700 else
4701 {
4702 /* Floating-point types don't have specific RM bounds. */
4703 TYPE_GCC_MIN_VALUE (gnu_scalar_type) = gnu_low_bound;
4704 TYPE_GCC_MAX_VALUE (gnu_scalar_type) = gnu_high_bound;
4705 }
4706 }
4707
4708 /* If we deferred processing of incomplete types, re-enable it. If there
4709 were no other disables and we have deferred types to process, do so. */
4710 if (this_deferred
4711 && --defer_incomplete_level == 0
4712 && defer_incomplete_list)
4713 {
4714 struct incomplete *p, *next;
4715
4716 /* We are back to level 0 for the deferring of incomplete types.
4717 But processing these incomplete types below may itself require
4718 deferring, so preserve what we have and restart from scratch. */
4719 p = defer_incomplete_list;
4720 defer_incomplete_list = NULL;
4721
4722 for (; p; p = next)
4723 {
4724 next = p->next;
4725
4726 if (p->old_type)
4727 update_pointer_to (TYPE_MAIN_VARIANT (p->old_type),
4728 gnat_to_gnu_type (p->full_type));
4729 free (p);
4730 }
4731 }
4732
4733 /* If we are not defining this type, see if it's on one of the lists of
4734 incomplete types. If so, handle the list entry now. */
4735 if (is_type && !definition)
4736 {
4737 struct incomplete *p;
4738
4739 for (p = defer_incomplete_list; p; p = p->next)
4740 if (p->old_type && p->full_type == gnat_entity)
4741 {
4742 update_pointer_to (TYPE_MAIN_VARIANT (p->old_type),
4743 TREE_TYPE (gnu_decl));
4744 p->old_type = NULL_TREE;
4745 }
4746
4747 for (p = defer_limited_with_list; p; p = p->next)
4748 if (p->old_type
4749 && (Non_Limited_View (p->full_type) == gnat_entity
4750 || Full_View (p->full_type) == gnat_entity))
4751 {
4752 update_pointer_to (TYPE_MAIN_VARIANT (p->old_type),
4753 TREE_TYPE (gnu_decl));
4754 if (TYPE_DUMMY_IN_PROFILE_P (p->old_type))
4755 update_profiles_with (p->old_type);
4756 p->old_type = NULL_TREE;
4757 }
4758 }
4759
4760 if (this_global)
4761 force_global--;
4762
4763 /* If this is a packed array type whose original array type is itself
4764 an Itype without freeze node, make sure the latter is processed. */
4765 if (Is_Packed_Array_Impl_Type (gnat_entity)
4766 && Is_Itype (Original_Array_Type (gnat_entity))
4767 && No (Freeze_Node (Original_Array_Type (gnat_entity)))
4768 && !present_gnu_tree (Original_Array_Type (gnat_entity)))
4769 gnat_to_gnu_entity (Original_Array_Type (gnat_entity), NULL_TREE, false);
4770
4771 return gnu_decl;
4772 }
4773
4774 /* Similar, but if the returned value is a COMPONENT_REF, return the
4775 FIELD_DECL. */
4776
4777 tree
gnat_to_gnu_field_decl(Entity_Id gnat_entity)4778 gnat_to_gnu_field_decl (Entity_Id gnat_entity)
4779 {
4780 tree gnu_field = gnat_to_gnu_entity (gnat_entity, NULL_TREE, false);
4781
4782 if (TREE_CODE (gnu_field) == COMPONENT_REF)
4783 gnu_field = TREE_OPERAND (gnu_field, 1);
4784
4785 return gnu_field;
4786 }
4787
4788 /* Similar, but GNAT_ENTITY is assumed to refer to a GNAT type. Return
4789 the GCC type corresponding to that entity. */
4790
4791 tree
gnat_to_gnu_type(Entity_Id gnat_entity)4792 gnat_to_gnu_type (Entity_Id gnat_entity)
4793 {
4794 tree gnu_decl;
4795
4796 /* The back end never attempts to annotate generic types. */
4797 if (Is_Generic_Type (gnat_entity) && type_annotate_only)
4798 return void_type_node;
4799
4800 gnu_decl = gnat_to_gnu_entity (gnat_entity, NULL_TREE, false);
4801 gcc_assert (TREE_CODE (gnu_decl) == TYPE_DECL);
4802
4803 return TREE_TYPE (gnu_decl);
4804 }
4805
4806 /* Similar, but GNAT_ENTITY is assumed to refer to a GNAT type. Return
4807 the unpadded version of the GCC type corresponding to that entity. */
4808
4809 tree
get_unpadded_type(Entity_Id gnat_entity)4810 get_unpadded_type (Entity_Id gnat_entity)
4811 {
4812 tree type = gnat_to_gnu_type (gnat_entity);
4813
4814 if (TYPE_IS_PADDING_P (type))
4815 type = TREE_TYPE (TYPE_FIELDS (type));
4816
4817 return type;
4818 }
4819
4820 /* Return whether the E_Subprogram_Type/E_Function/E_Procedure GNAT_ENTITY is
4821 a C++ imported method or equivalent.
4822
4823 We use the predicate on 32-bit x86/Windows to find out whether we need to
4824 use the "thiscall" calling convention for GNAT_ENTITY. This convention is
4825 used for C++ methods (functions with METHOD_TYPE) by the back-end. */
4826
4827 bool
is_cplusplus_method(Entity_Id gnat_entity)4828 is_cplusplus_method (Entity_Id gnat_entity)
4829 {
4830 /* A constructor is a method on the C++ side. We deal with it now because
4831 it is declared without the 'this' parameter in the sources and, although
4832 the front-end will create a version with the 'this' parameter for code
4833 generation purposes, we want to return true for both versions. */
4834 if (Is_Constructor (gnat_entity))
4835 return true;
4836
4837 /* Check that the subprogram has C++ convention. */
4838 if (Convention (gnat_entity) != Convention_CPP)
4839 return false;
4840
4841 /* And that the type of the first parameter (indirectly) has it too. */
4842 Entity_Id gnat_first = First_Formal (gnat_entity);
4843 if (No (gnat_first))
4844 return false;
4845
4846 Entity_Id gnat_type = Etype (gnat_first);
4847 if (Is_Access_Type (gnat_type))
4848 gnat_type = Directly_Designated_Type (gnat_type);
4849 if (Convention (gnat_type) != Convention_CPP)
4850 return false;
4851
4852 /* This is the main case: a C++ virtual method imported as a primitive
4853 operation of a tagged type. */
4854 if (Is_Dispatching_Operation (gnat_entity))
4855 return true;
4856
4857 /* This is set on the E_Subprogram_Type built for a dispatching call. */
4858 if (Is_Dispatch_Table_Entity (gnat_entity))
4859 return true;
4860
4861 /* A thunk needs to be handled like its associated primitive operation. */
4862 if (Is_Subprogram (gnat_entity) && Is_Thunk (gnat_entity))
4863 return true;
4864
4865 /* Now on to the annoying case: a C++ non-virtual method, imported either
4866 as a non-primitive operation of a tagged type or as a primitive operation
4867 of an untagged type. We cannot reliably differentiate these cases from
4868 their static member or regular function equivalents in Ada, so we ask
4869 the C++ side through the mangled name of the function, as the implicit
4870 'this' parameter is not encoded in the mangled name of a method. */
4871 if (Is_Subprogram (gnat_entity) && Present (Interface_Name (gnat_entity)))
4872 {
4873 String_Pointer sp = { NULL, NULL };
4874 Get_External_Name (gnat_entity, false, sp);
4875
4876 void *mem;
4877 struct demangle_component *cmp
4878 = cplus_demangle_v3_components (Name_Buffer,
4879 DMGL_GNU_V3
4880 | DMGL_TYPES
4881 | DMGL_PARAMS
4882 | DMGL_RET_DROP,
4883 &mem);
4884 if (!cmp)
4885 return false;
4886
4887 /* We need to release MEM once we have a successful demangling. */
4888 bool ret = false;
4889
4890 if (cmp->type == DEMANGLE_COMPONENT_TYPED_NAME
4891 && cmp->u.s_binary.right->type == DEMANGLE_COMPONENT_FUNCTION_TYPE
4892 && (cmp = cmp->u.s_binary.right->u.s_binary.right) != NULL
4893 && cmp->type == DEMANGLE_COMPONENT_ARGLIST)
4894 {
4895 /* Make sure there is at least one parameter in C++ too. */
4896 if (cmp->u.s_binary.left)
4897 {
4898 unsigned int n_ada_args = 0;
4899 do {
4900 n_ada_args++;
4901 gnat_first = Next_Formal (gnat_first);
4902 } while (Present (gnat_first));
4903
4904 unsigned int n_cpp_args = 0;
4905 do {
4906 n_cpp_args++;
4907 cmp = cmp->u.s_binary.right;
4908 } while (cmp);
4909
4910 if (n_cpp_args < n_ada_args)
4911 ret = true;
4912 }
4913 else
4914 ret = true;
4915 }
4916
4917 free (mem);
4918
4919 return ret;
4920 }
4921
4922 return false;
4923 }
4924
4925 /* Finalize the processing of From_Limited_With incomplete types. */
4926
4927 void
finalize_from_limited_with(void)4928 finalize_from_limited_with (void)
4929 {
4930 struct incomplete *p, *next;
4931
4932 p = defer_limited_with_list;
4933 defer_limited_with_list = NULL;
4934
4935 for (; p; p = next)
4936 {
4937 next = p->next;
4938
4939 if (p->old_type)
4940 {
4941 update_pointer_to (TYPE_MAIN_VARIANT (p->old_type),
4942 gnat_to_gnu_type (p->full_type));
4943 if (TYPE_DUMMY_IN_PROFILE_P (p->old_type))
4944 update_profiles_with (p->old_type);
4945 }
4946
4947 free (p);
4948 }
4949 }
4950
4951 /* Return the equivalent type to be used for GNAT_ENTITY, if it's a kind
4952 of type (such E_Task_Type) that has a different type which Gigi uses
4953 for its representation. If the type does not have a special type for
4954 its representation, return GNAT_ENTITY. */
4955
4956 Entity_Id
Gigi_Equivalent_Type(Entity_Id gnat_entity)4957 Gigi_Equivalent_Type (Entity_Id gnat_entity)
4958 {
4959 Entity_Id gnat_equiv = gnat_entity;
4960
4961 if (No (gnat_entity))
4962 return gnat_entity;
4963
4964 switch (Ekind (gnat_entity))
4965 {
4966 case E_Class_Wide_Subtype:
4967 if (Present (Equivalent_Type (gnat_entity)))
4968 gnat_equiv = Equivalent_Type (gnat_entity);
4969 break;
4970
4971 case E_Access_Protected_Subprogram_Type:
4972 case E_Anonymous_Access_Protected_Subprogram_Type:
4973 if (Present (Equivalent_Type (gnat_entity)))
4974 gnat_equiv = Equivalent_Type (gnat_entity);
4975 break;
4976
4977 case E_Class_Wide_Type:
4978 gnat_equiv = Root_Type (gnat_entity);
4979 break;
4980
4981 case E_Protected_Type:
4982 case E_Protected_Subtype:
4983 case E_Task_Type:
4984 case E_Task_Subtype:
4985 if (Present (Corresponding_Record_Type (gnat_entity)))
4986 gnat_equiv = Corresponding_Record_Type (gnat_entity);
4987 break;
4988
4989 default:
4990 break;
4991 }
4992
4993 return gnat_equiv;
4994 }
4995
4996 /* Return a GCC tree for a type corresponding to the component type of the
4997 array type or subtype GNAT_ARRAY. DEFINITION is true if this component
4998 is for an array being defined. DEBUG_INFO_P is true if we need to write
4999 debug information for other types that we may create in the process. */
5000
5001 static tree
gnat_to_gnu_component_type(Entity_Id gnat_array,bool definition,bool debug_info_p)5002 gnat_to_gnu_component_type (Entity_Id gnat_array, bool definition,
5003 bool debug_info_p)
5004 {
5005 const Entity_Id gnat_type = Component_Type (gnat_array);
5006 tree gnu_type = gnat_to_gnu_type (gnat_type);
5007 tree gnu_comp_size;
5008 unsigned int max_align;
5009
5010 /* If an alignment is specified, use it as a cap on the component type
5011 so that it can be honored for the whole type. But ignore it for the
5012 original type of packed array types. */
5013 if (No (Packed_Array_Impl_Type (gnat_array))
5014 && Known_Alignment (gnat_array))
5015 max_align = validate_alignment (Alignment (gnat_array), gnat_array, 0);
5016 else
5017 max_align = 0;
5018
5019 /* Try to get a smaller form of the component if needed. */
5020 if ((Is_Packed (gnat_array) || Has_Component_Size_Clause (gnat_array))
5021 && !Is_Bit_Packed_Array (gnat_array)
5022 && !Has_Aliased_Components (gnat_array)
5023 && !Strict_Alignment (gnat_type)
5024 && RECORD_OR_UNION_TYPE_P (gnu_type)
5025 && !TYPE_FAT_POINTER_P (gnu_type)
5026 && tree_fits_uhwi_p (TYPE_SIZE (gnu_type)))
5027 gnu_type = make_packable_type (gnu_type, false, max_align);
5028
5029 /* Get and validate any specified Component_Size. */
5030 gnu_comp_size
5031 = validate_size (Component_Size (gnat_array), gnu_type, gnat_array,
5032 Is_Bit_Packed_Array (gnat_array) ? TYPE_DECL : VAR_DECL,
5033 true, Has_Component_Size_Clause (gnat_array));
5034
5035 /* If the component type is a RECORD_TYPE that has a self-referential size,
5036 then use the maximum size for the component size. */
5037 if (!gnu_comp_size
5038 && TREE_CODE (gnu_type) == RECORD_TYPE
5039 && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type)))
5040 gnu_comp_size = max_size (TYPE_SIZE (gnu_type), true);
5041
5042 /* If the array has aliased components and the component size is zero, force
5043 the unit size to ensure that the components have distinct addresses. */
5044 if (!gnu_comp_size
5045 && Has_Aliased_Components (gnat_array)
5046 && integer_zerop (TYPE_SIZE (gnu_type)))
5047 gnu_comp_size = bitsize_unit_node;
5048
5049 /* Honor the component size. This is not needed for bit-packed arrays. */
5050 if (gnu_comp_size && !Is_Bit_Packed_Array (gnat_array))
5051 {
5052 tree orig_type = gnu_type;
5053
5054 gnu_type = make_type_from_size (gnu_type, gnu_comp_size, false);
5055 if (max_align > 0 && TYPE_ALIGN (gnu_type) > max_align)
5056 gnu_type = orig_type;
5057 else
5058 orig_type = gnu_type;
5059
5060 gnu_type = maybe_pad_type (gnu_type, gnu_comp_size, 0, gnat_array,
5061 true, false, definition, true);
5062
5063 /* If a padding record was made, declare it now since it will never be
5064 declared otherwise. This is necessary to ensure that its subtrees
5065 are properly marked. */
5066 if (gnu_type != orig_type && !DECL_P (TYPE_NAME (gnu_type)))
5067 create_type_decl (TYPE_NAME (gnu_type), gnu_type, true, debug_info_p,
5068 gnat_array);
5069 }
5070
5071 /* This is a very special case where the array has aliased components and the
5072 component size might be zero at run time. As explained above, we force at
5073 least the unit size but we don't want to build a distinct padding type for
5074 each invocation (they are not canonicalized if they have variable size) so
5075 we cache this special padding type as TYPE_PADDING_FOR_COMPONENT. */
5076 else if (Has_Aliased_Components (gnat_array)
5077 && TREE_CODE (gnu_type) == ARRAY_TYPE
5078 && !TREE_CONSTANT (TYPE_SIZE (gnu_type)))
5079 {
5080 if (TYPE_PADDING_FOR_COMPONENT (gnu_type))
5081 gnu_type = TYPE_PADDING_FOR_COMPONENT (gnu_type);
5082 else
5083 {
5084 gnu_comp_size
5085 = size_binop (MAX_EXPR, TYPE_SIZE (gnu_type), bitsize_unit_node);
5086 TYPE_PADDING_FOR_COMPONENT (gnu_type)
5087 = maybe_pad_type (gnu_type, gnu_comp_size, 0, gnat_array,
5088 true, false, definition, true);
5089 gnu_type = TYPE_PADDING_FOR_COMPONENT (gnu_type);
5090 create_type_decl (TYPE_NAME (gnu_type), gnu_type, true, debug_info_p,
5091 gnat_array);
5092 }
5093 }
5094
5095 if (Has_Atomic_Components (gnat_array) || Is_Atomic_Or_VFA (gnat_type))
5096 check_ok_for_atomic_type (gnu_type, gnat_array, true);
5097
5098 /* If the component type is a padded type made for a non-bit-packed array
5099 of scalars with reverse storage order, we need to propagate the reverse
5100 storage order to the padding type since it is the innermost enclosing
5101 aggregate type around the scalar. */
5102 if (TYPE_IS_PADDING_P (gnu_type)
5103 && Reverse_Storage_Order (gnat_array)
5104 && !Is_Bit_Packed_Array (gnat_array)
5105 && Is_Scalar_Type (gnat_type))
5106 gnu_type = set_reverse_storage_order_on_pad_type (gnu_type);
5107
5108 if (Has_Volatile_Components (gnat_array))
5109 {
5110 const int quals
5111 = TYPE_QUAL_VOLATILE
5112 | (Has_Atomic_Components (gnat_array) ? TYPE_QUAL_ATOMIC : 0);
5113 gnu_type = change_qualified_type (gnu_type, quals);
5114 }
5115
5116 return gnu_type;
5117 }
5118
5119 /* Return a GCC tree for a parameter corresponding to GNAT_PARAM, to be placed
5120 in the parameter list of GNAT_SUBPROG. GNU_PARAM_TYPE is the GCC tree for
5121 the type of the parameter. FIRST is true if this is the first parameter in
5122 the list of GNAT_SUBPROG. Also set CICO to true if the parameter must use
5123 the copy-in copy-out implementation mechanism.
5124
5125 The returned tree is a PARM_DECL, except for the cases where no parameter
5126 needs to be actually passed to the subprogram; the type of this "shadow"
5127 parameter is then returned instead. */
5128
5129 static tree
gnat_to_gnu_param(Entity_Id gnat_param,tree gnu_param_type,bool first,Entity_Id gnat_subprog,bool * cico)5130 gnat_to_gnu_param (Entity_Id gnat_param, tree gnu_param_type, bool first,
5131 Entity_Id gnat_subprog, bool *cico)
5132 {
5133 Entity_Id gnat_param_type = Etype (gnat_param);
5134 Mechanism_Type mech = Mechanism (gnat_param);
5135 tree gnu_param_name = get_entity_name (gnat_param);
5136 bool foreign = Has_Foreign_Convention (gnat_subprog);
5137 bool in_param = (Ekind (gnat_param) == E_In_Parameter);
5138 /* The parameter can be indirectly modified if its address is taken. */
5139 bool ro_param = in_param && !Address_Taken (gnat_param);
5140 bool by_return = false, by_component_ptr = false;
5141 bool by_ref = false;
5142 bool restricted_aliasing_p = false;
5143 location_t saved_location = input_location;
5144 tree gnu_param;
5145
5146 /* Make sure to use the proper SLOC for vector ABI warnings. */
5147 if (VECTOR_TYPE_P (gnu_param_type))
5148 Sloc_to_locus (Sloc (gnat_subprog), &input_location);
5149
5150 /* Builtins are expanded inline and there is no real call sequence involved.
5151 So the type expected by the underlying expander is always the type of the
5152 argument "as is". */
5153 if (Convention (gnat_subprog) == Convention_Intrinsic
5154 && Present (Interface_Name (gnat_subprog)))
5155 mech = By_Copy;
5156
5157 /* Handle the first parameter of a valued procedure specially: it's a copy
5158 mechanism for which the parameter is never allocated. */
5159 else if (first && Is_Valued_Procedure (gnat_subprog))
5160 {
5161 gcc_assert (Ekind (gnat_param) == E_Out_Parameter);
5162 mech = By_Copy;
5163 by_return = true;
5164 }
5165
5166 /* Or else, see if a Mechanism was supplied that forced this parameter
5167 to be passed one way or another. */
5168 else if (mech == Default || mech == By_Copy || mech == By_Reference)
5169 ;
5170
5171 /* Positive mechanism means by copy for sufficiently small parameters. */
5172 else if (mech > 0)
5173 {
5174 if (TREE_CODE (gnu_param_type) == UNCONSTRAINED_ARRAY_TYPE
5175 || TREE_CODE (TYPE_SIZE (gnu_param_type)) != INTEGER_CST
5176 || compare_tree_int (TYPE_SIZE (gnu_param_type), mech) > 0)
5177 mech = By_Reference;
5178 else
5179 mech = By_Copy;
5180 }
5181
5182 /* Otherwise, it's an unsupported mechanism so error out. */
5183 else
5184 {
5185 post_error ("unsupported mechanism for&", gnat_param);
5186 mech = Default;
5187 }
5188
5189 /* If this is either a foreign function or if the underlying type won't
5190 be passed by reference and is as aligned as the original type, strip
5191 off possible padding type. */
5192 if (TYPE_IS_PADDING_P (gnu_param_type))
5193 {
5194 tree unpadded_type = TREE_TYPE (TYPE_FIELDS (gnu_param_type));
5195
5196 if (foreign
5197 || (!must_pass_by_ref (unpadded_type)
5198 && mech != By_Reference
5199 && (mech == By_Copy || !default_pass_by_ref (unpadded_type))
5200 && TYPE_ALIGN (unpadded_type) >= TYPE_ALIGN (gnu_param_type)))
5201 gnu_param_type = unpadded_type;
5202 }
5203
5204 /* If this is a read-only parameter, make a variant of the type that is
5205 read-only. ??? However, if this is a self-referential type, the type
5206 can be very complex, so skip it for now. */
5207 if (ro_param && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_param_type)))
5208 gnu_param_type = change_qualified_type (gnu_param_type, TYPE_QUAL_CONST);
5209
5210 /* For foreign conventions, pass arrays as pointers to the element type.
5211 First check for unconstrained array and get the underlying array. */
5212 if (foreign && TREE_CODE (gnu_param_type) == UNCONSTRAINED_ARRAY_TYPE)
5213 gnu_param_type
5214 = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_param_type))));
5215
5216 /* Arrays are passed as pointers to element type for foreign conventions. */
5217 if (foreign && mech != By_Copy && TREE_CODE (gnu_param_type) == ARRAY_TYPE)
5218 {
5219 /* Strip off any multi-dimensional entries, then strip
5220 off the last array to get the component type. */
5221 while (TREE_CODE (TREE_TYPE (gnu_param_type)) == ARRAY_TYPE
5222 && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_param_type)))
5223 gnu_param_type = TREE_TYPE (gnu_param_type);
5224
5225 by_component_ptr = true;
5226 gnu_param_type = TREE_TYPE (gnu_param_type);
5227
5228 if (ro_param)
5229 gnu_param_type
5230 = change_qualified_type (gnu_param_type, TYPE_QUAL_CONST);
5231
5232 gnu_param_type = build_pointer_type (gnu_param_type);
5233 }
5234
5235 /* Fat pointers are passed as thin pointers for foreign conventions. */
5236 else if (foreign && TYPE_IS_FAT_POINTER_P (gnu_param_type))
5237 gnu_param_type
5238 = make_type_from_size (gnu_param_type, size_int (POINTER_SIZE), 0);
5239
5240 /* If we were requested or muss pass by reference, do so.
5241 If we were requested to pass by copy, do so.
5242 Otherwise, for foreign conventions, pass In Out or Out parameters
5243 or aggregates by reference. For COBOL and Fortran, pass all
5244 integer and FP types that way too. For Convention Ada, use
5245 the standard Ada default. */
5246 else if (mech == By_Reference
5247 || must_pass_by_ref (gnu_param_type)
5248 || (mech != By_Copy
5249 && ((foreign
5250 && (!in_param || AGGREGATE_TYPE_P (gnu_param_type)))
5251 || (foreign
5252 && (Convention (gnat_subprog) == Convention_Fortran
5253 || Convention (gnat_subprog) == Convention_COBOL)
5254 && (INTEGRAL_TYPE_P (gnu_param_type)
5255 || FLOAT_TYPE_P (gnu_param_type)))
5256 || (!foreign
5257 && default_pass_by_ref (gnu_param_type)))))
5258 {
5259 /* We take advantage of 6.2(12) by considering that references built for
5260 parameters whose type isn't by-ref and for which the mechanism hasn't
5261 been forced to by-ref allow only a restricted form of aliasing. */
5262 restricted_aliasing_p
5263 = !TYPE_IS_BY_REFERENCE_P (gnu_param_type) && mech != By_Reference;
5264 gnu_param_type = build_reference_type (gnu_param_type);
5265 by_ref = true;
5266 }
5267
5268 /* Pass In Out or Out parameters using copy-in copy-out mechanism. */
5269 else if (!in_param)
5270 *cico = true;
5271
5272 input_location = saved_location;
5273
5274 if (mech == By_Copy && (by_ref || by_component_ptr))
5275 post_error ("?cannot pass & by copy", gnat_param);
5276
5277 /* If this is an Out parameter that isn't passed by reference and isn't
5278 a pointer or aggregate, we don't make a PARM_DECL for it. Instead,
5279 it will be a VAR_DECL created when we process the procedure, so just
5280 return its type. For the special parameter of a valued procedure,
5281 never pass it in.
5282
5283 An exception is made to cover the RM-6.4.1 rule requiring "by copy"
5284 Out parameters with discriminants or implicit initial values to be
5285 handled like In Out parameters. These type are normally built as
5286 aggregates, hence passed by reference, except for some packed arrays
5287 which end up encoded in special integer types. Note that scalars can
5288 be given implicit initial values using the Default_Value aspect.
5289
5290 The exception we need to make is then for packed arrays of records
5291 with discriminants or implicit initial values. We have no light/easy
5292 way to check for the latter case, so we merely check for packed arrays
5293 of records. This may lead to useless copy-in operations, but in very
5294 rare cases only, as these would be exceptions in a set of already
5295 exceptional situations. */
5296 if (Ekind (gnat_param) == E_Out_Parameter
5297 && !by_ref
5298 && (by_return
5299 || (!POINTER_TYPE_P (gnu_param_type)
5300 && !AGGREGATE_TYPE_P (gnu_param_type)
5301 && !Has_Default_Aspect (gnat_param_type)))
5302 && !(Is_Array_Type (gnat_param_type)
5303 && Is_Packed (gnat_param_type)
5304 && Is_Composite_Type (Component_Type (gnat_param_type))))
5305 return gnu_param_type;
5306
5307 gnu_param = create_param_decl (gnu_param_name, gnu_param_type);
5308 TREE_READONLY (gnu_param) = ro_param || by_ref || by_component_ptr;
5309 DECL_BY_REF_P (gnu_param) = by_ref;
5310 DECL_BY_COMPONENT_PTR_P (gnu_param) = by_component_ptr;
5311 DECL_POINTS_TO_READONLY_P (gnu_param)
5312 = (ro_param && (by_ref || by_component_ptr));
5313 DECL_CAN_NEVER_BE_NULL_P (gnu_param) = Can_Never_Be_Null (gnat_param);
5314 DECL_RESTRICTED_ALIASING_P (gnu_param) = restricted_aliasing_p;
5315 Sloc_to_locus (Sloc (gnat_param), &DECL_SOURCE_LOCATION (gnu_param));
5316
5317 /* If no Mechanism was specified, indicate what we're using, then
5318 back-annotate it. */
5319 if (mech == Default)
5320 mech = (by_ref || by_component_ptr) ? By_Reference : By_Copy;
5321
5322 Set_Mechanism (gnat_param, mech);
5323 return gnu_param;
5324 }
5325
5326 /* Associate GNAT_SUBPROG with GNU_TYPE, which must be a dummy type, so that
5327 GNAT_SUBPROG is updated when GNU_TYPE is completed.
5328
5329 Ada 2012 (AI05-019) says that freezing a subprogram does not always freeze
5330 the corresponding profile, which means that, by the time the freeze node
5331 of the subprogram is encountered, types involved in its profile may still
5332 be not yet frozen. That's why we need to update GNAT_SUBPROG when we see
5333 the freeze node of types involved in its profile, either types of formal
5334 parameters or the return type. */
5335
5336 static void
associate_subprog_with_dummy_type(Entity_Id gnat_subprog,tree gnu_type)5337 associate_subprog_with_dummy_type (Entity_Id gnat_subprog, tree gnu_type)
5338 {
5339 gcc_assert (TYPE_IS_DUMMY_P (gnu_type));
5340
5341 struct tree_entity_vec_map in;
5342 in.base.from = gnu_type;
5343 struct tree_entity_vec_map **slot
5344 = dummy_to_subprog_map->find_slot (&in, INSERT);
5345 if (!*slot)
5346 {
5347 tree_entity_vec_map *e = ggc_alloc<tree_entity_vec_map> ();
5348 e->base.from = gnu_type;
5349 e->to = NULL;
5350 *slot = e;
5351 }
5352
5353 /* Even if there is already a slot for GNU_TYPE, we need to set the flag
5354 because the vector might have been just emptied by update_profiles_with.
5355 This can happen when there are 2 freeze nodes associated with different
5356 views of the same type; the type will be really complete only after the
5357 second freeze node is encountered. */
5358 TYPE_DUMMY_IN_PROFILE_P (gnu_type) = 1;
5359
5360 vec<Entity_Id, va_gc_atomic> *v = (*slot)->to;
5361
5362 /* Make sure GNAT_SUBPROG is not associated twice with the same dummy type,
5363 since this would mean updating twice its profile. */
5364 if (v)
5365 {
5366 const unsigned len = v->length ();
5367 unsigned int l = 0, u = len;
5368
5369 /* Entity_Id is a simple integer so we can implement a stable order on
5370 the vector with an ordered insertion scheme and binary search. */
5371 while (l < u)
5372 {
5373 unsigned int m = (l + u) / 2;
5374 int diff = (int) (*v)[m] - (int) gnat_subprog;
5375 if (diff > 0)
5376 u = m;
5377 else if (diff < 0)
5378 l = m + 1;
5379 else
5380 return;
5381 }
5382
5383 /* l == u and therefore is the insertion point. */
5384 vec_safe_insert (v, l, gnat_subprog);
5385 }
5386 else
5387 vec_safe_push (v, gnat_subprog);
5388
5389 (*slot)->to = v;
5390 }
5391
5392 /* Update the GCC tree previously built for the profile of GNAT_SUBPROG. */
5393
5394 static void
update_profile(Entity_Id gnat_subprog)5395 update_profile (Entity_Id gnat_subprog)
5396 {
5397 tree gnu_param_list;
5398 tree gnu_type = gnat_to_gnu_subprog_type (gnat_subprog, true,
5399 Needs_Debug_Info (gnat_subprog),
5400 &gnu_param_list);
5401 if (DECL_P (gnu_type))
5402 {
5403 /* Builtins cannot have their address taken so we can reset them. */
5404 gcc_assert (DECL_BUILT_IN (gnu_type));
5405 save_gnu_tree (gnat_subprog, NULL_TREE, false);
5406 save_gnu_tree (gnat_subprog, gnu_type, false);
5407 return;
5408 }
5409
5410 tree gnu_subprog = get_gnu_tree (gnat_subprog);
5411
5412 TREE_TYPE (gnu_subprog) = gnu_type;
5413
5414 /* If GNAT_SUBPROG is an actual subprogram, GNU_SUBPROG is a FUNCTION_DECL
5415 and needs to be adjusted too. */
5416 if (Ekind (gnat_subprog) != E_Subprogram_Type)
5417 {
5418 tree gnu_entity_name = get_entity_name (gnat_subprog);
5419 tree gnu_ext_name
5420 = gnu_ext_name_for_subprog (gnat_subprog, gnu_entity_name);
5421
5422 DECL_ARGUMENTS (gnu_subprog) = gnu_param_list;
5423 finish_subprog_decl (gnu_subprog, gnu_ext_name, gnu_type);
5424 }
5425 }
5426
5427 /* Update the GCC trees previously built for the profiles involving GNU_TYPE,
5428 a dummy type which appears in profiles. */
5429
5430 void
update_profiles_with(tree gnu_type)5431 update_profiles_with (tree gnu_type)
5432 {
5433 struct tree_entity_vec_map in;
5434 in.base.from = gnu_type;
5435 struct tree_entity_vec_map *e = dummy_to_subprog_map->find (&in);
5436 gcc_assert (e);
5437 vec<Entity_Id, va_gc_atomic> *v = e->to;
5438 e->to = NULL;
5439
5440 /* The flag needs to be reset before calling update_profile, in case
5441 associate_subprog_with_dummy_type is again invoked on GNU_TYPE. */
5442 TYPE_DUMMY_IN_PROFILE_P (gnu_type) = 0;
5443
5444 unsigned int i;
5445 Entity_Id *iter;
5446 FOR_EACH_VEC_ELT (*v, i, iter)
5447 update_profile (*iter);
5448
5449 vec_free (v);
5450 }
5451
5452 /* Return the GCC tree for GNAT_TYPE present in the profile of a subprogram.
5453
5454 Ada 2012 (AI05-0151) says that incomplete types coming from a limited
5455 context may now appear as parameter and result types. As a consequence,
5456 we may need to defer their translation until after a freeze node is seen
5457 or to the end of the current unit. We also aim at handling temporarily
5458 incomplete types created by the usual delayed elaboration scheme. */
5459
5460 static tree
gnat_to_gnu_profile_type(Entity_Id gnat_type)5461 gnat_to_gnu_profile_type (Entity_Id gnat_type)
5462 {
5463 /* This is the same logic as the E_Access_Type case of gnat_to_gnu_entity
5464 so the rationale is exposed in that place. These processings probably
5465 ought to be merged at some point. */
5466 Entity_Id gnat_equiv = Gigi_Equivalent_Type (gnat_type);
5467 const bool is_from_limited_with
5468 = (Is_Incomplete_Type (gnat_equiv)
5469 && From_Limited_With (gnat_equiv));
5470 Entity_Id gnat_full_direct_first
5471 = (is_from_limited_with
5472 ? Non_Limited_View (gnat_equiv)
5473 : (Is_Incomplete_Or_Private_Type (gnat_equiv)
5474 ? Full_View (gnat_equiv) : Empty));
5475 Entity_Id gnat_full_direct
5476 = ((is_from_limited_with
5477 && Present (gnat_full_direct_first)
5478 && Is_Private_Type (gnat_full_direct_first))
5479 ? Full_View (gnat_full_direct_first)
5480 : gnat_full_direct_first);
5481 Entity_Id gnat_full = Gigi_Equivalent_Type (gnat_full_direct);
5482 Entity_Id gnat_rep = Present (gnat_full) ? gnat_full : gnat_equiv;
5483 const bool in_main_unit = In_Extended_Main_Code_Unit (gnat_rep);
5484 tree gnu_type;
5485
5486 if (Present (gnat_full) && present_gnu_tree (gnat_full))
5487 gnu_type = TREE_TYPE (get_gnu_tree (gnat_full));
5488
5489 else if (is_from_limited_with
5490 && ((!in_main_unit
5491 && !present_gnu_tree (gnat_equiv)
5492 && Present (gnat_full)
5493 && (Is_Record_Type (gnat_full)
5494 || Is_Array_Type (gnat_full)
5495 || Is_Access_Type (gnat_full)))
5496 || (in_main_unit && Present (Freeze_Node (gnat_rep)))))
5497 {
5498 gnu_type = make_dummy_type (gnat_equiv);
5499
5500 if (!in_main_unit)
5501 {
5502 struct incomplete *p = XNEW (struct incomplete);
5503
5504 p->old_type = gnu_type;
5505 p->full_type = gnat_equiv;
5506 p->next = defer_limited_with_list;
5507 defer_limited_with_list = p;
5508 }
5509 }
5510
5511 else if (type_annotate_only && No (gnat_equiv))
5512 gnu_type = void_type_node;
5513
5514 else
5515 gnu_type = gnat_to_gnu_type (gnat_equiv);
5516
5517 /* Access-to-unconstrained-array types need a special treatment. */
5518 if (Is_Array_Type (gnat_rep) && !Is_Constrained (gnat_rep))
5519 {
5520 if (!TYPE_POINTER_TO (gnu_type))
5521 build_dummy_unc_pointer_types (gnat_equiv, gnu_type);
5522 }
5523
5524 return gnu_type;
5525 }
5526
5527 /* Return a GCC tree for a subprogram type corresponding to GNAT_SUBPROG.
5528 DEFINITION is true if this is for a subprogram being defined. DEBUG_INFO_P
5529 is true if we need to write debug information for other types that we may
5530 create in the process. Also set PARAM_LIST to the list of parameters.
5531 If GNAT_SUBPROG is bound to a GCC builtin, return the DECL for the builtin
5532 directly instead of its type. */
5533
5534 static tree
gnat_to_gnu_subprog_type(Entity_Id gnat_subprog,bool definition,bool debug_info_p,tree * param_list)5535 gnat_to_gnu_subprog_type (Entity_Id gnat_subprog, bool definition,
5536 bool debug_info_p, tree *param_list)
5537 {
5538 const Entity_Kind kind = Ekind (gnat_subprog);
5539 Entity_Id gnat_return_type = Etype (gnat_subprog);
5540 Entity_Id gnat_param;
5541 tree gnu_type = present_gnu_tree (gnat_subprog)
5542 ? TREE_TYPE (get_gnu_tree (gnat_subprog)) : NULL_TREE;
5543 tree gnu_return_type;
5544 tree gnu_param_type_list = NULL_TREE;
5545 tree gnu_param_list = NULL_TREE;
5546 /* Non-null for subprograms containing parameters passed by copy-in copy-out
5547 (In Out or Out parameters not passed by reference), in which case it is
5548 the list of nodes used to specify the values of the In Out/Out parameters
5549 that are returned as a record upon procedure return. The TREE_PURPOSE of
5550 an element of this list is a FIELD_DECL of the record and the TREE_VALUE
5551 is the PARM_DECL corresponding to that field. This list will be saved in
5552 the TYPE_CI_CO_LIST field of the FUNCTION_TYPE node we create. */
5553 tree gnu_cico_list = NULL_TREE;
5554 tree gnu_cico_return_type = NULL_TREE;
5555 /* Fields in return type of procedure with copy-in copy-out parameters. */
5556 tree gnu_field_list = NULL_TREE;
5557 /* The semantics of "pure" in Ada essentially matches that of "const"
5558 in the back-end. In particular, both properties are orthogonal to
5559 the "nothrow" property if the EH circuitry is explicit in the
5560 internal representation of the back-end. If we are to completely
5561 hide the EH circuitry from it, we need to declare that calls to pure
5562 Ada subprograms that can throw have side effects since they can
5563 trigger an "abnormal" transfer of control flow; thus they can be
5564 neither "const" nor "pure" in the back-end sense. */
5565 bool const_flag = (Back_End_Exceptions () && Is_Pure (gnat_subprog));
5566 bool return_by_direct_ref_p = false;
5567 bool return_by_invisi_ref_p = false;
5568 bool return_unconstrained_p = false;
5569 bool incomplete_profile_p = false;
5570 unsigned int num;
5571
5572 /* Look into the return type and get its associated GCC tree if it is not
5573 void, and then compute various flags for the subprogram type. But make
5574 sure not to do this processing multiple times. */
5575 if (Ekind (gnat_return_type) == E_Void)
5576 gnu_return_type = void_type_node;
5577
5578 else if (gnu_type
5579 && TREE_CODE (gnu_type) == FUNCTION_TYPE
5580 && !TYPE_IS_DUMMY_P (TREE_TYPE (gnu_type)))
5581 {
5582 gnu_return_type = TREE_TYPE (gnu_type);
5583 return_unconstrained_p = TYPE_RETURN_UNCONSTRAINED_P (gnu_type);
5584 return_by_direct_ref_p = TYPE_RETURN_BY_DIRECT_REF_P (gnu_type);
5585 return_by_invisi_ref_p = TREE_ADDRESSABLE (gnu_type);
5586 }
5587
5588 else
5589 {
5590 /* For foreign convention subprograms, return System.Address as void *
5591 or equivalent. Note that this comprises GCC builtins. */
5592 if (Has_Foreign_Convention (gnat_subprog)
5593 && Is_Descendant_Of_Address (Underlying_Type (gnat_return_type)))
5594 gnu_return_type = ptr_type_node;
5595 else
5596 gnu_return_type = gnat_to_gnu_profile_type (gnat_return_type);
5597
5598 /* If this function returns by reference, make the actual return type
5599 the reference type and make a note of that. */
5600 if (Returns_By_Ref (gnat_subprog))
5601 {
5602 gnu_return_type = build_reference_type (gnu_return_type);
5603 return_by_direct_ref_p = true;
5604 }
5605
5606 /* If the return type is an unconstrained array type, the return value
5607 will be allocated on the secondary stack so the actual return type
5608 is the fat pointer type. */
5609 else if (TREE_CODE (gnu_return_type) == UNCONSTRAINED_ARRAY_TYPE)
5610 {
5611 gnu_return_type = TYPE_REFERENCE_TO (gnu_return_type);
5612 return_unconstrained_p = true;
5613 }
5614
5615 /* This is the same unconstrained array case, but for a dummy type. */
5616 else if (TYPE_REFERENCE_TO (gnu_return_type)
5617 && TYPE_IS_FAT_POINTER_P (TYPE_REFERENCE_TO (gnu_return_type)))
5618 {
5619 gnu_return_type = TYPE_REFERENCE_TO (gnu_return_type);
5620 return_unconstrained_p = true;
5621 }
5622
5623 /* Likewise, if the return type requires a transient scope, the return
5624 value will also be allocated on the secondary stack so the actual
5625 return type is the reference type. */
5626 else if (Requires_Transient_Scope (gnat_return_type))
5627 {
5628 gnu_return_type = build_reference_type (gnu_return_type);
5629 return_unconstrained_p = true;
5630 }
5631
5632 /* If the Mechanism is By_Reference, ensure this function uses the
5633 target's by-invisible-reference mechanism, which may not be the
5634 same as above (e.g. it might be passing an extra parameter). */
5635 else if (kind == E_Function && Mechanism (gnat_subprog) == By_Reference)
5636 return_by_invisi_ref_p = true;
5637
5638 /* Likewise, if the return type is itself By_Reference. */
5639 else if (TYPE_IS_BY_REFERENCE_P (gnu_return_type))
5640 return_by_invisi_ref_p = true;
5641
5642 /* If the type is a padded type and the underlying type would not be
5643 passed by reference or the function has a foreign convention, return
5644 the underlying type. */
5645 else if (TYPE_IS_PADDING_P (gnu_return_type)
5646 && (!default_pass_by_ref
5647 (TREE_TYPE (TYPE_FIELDS (gnu_return_type)))
5648 || Has_Foreign_Convention (gnat_subprog)))
5649 gnu_return_type = TREE_TYPE (TYPE_FIELDS (gnu_return_type));
5650
5651 /* If the return type is unconstrained, it must have a maximum size.
5652 Use the padded type as the effective return type. And ensure the
5653 function uses the target's by-invisible-reference mechanism to
5654 avoid copying too much data when it returns. */
5655 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_return_type)))
5656 {
5657 tree orig_type = gnu_return_type;
5658 tree max_return_size = max_size (TYPE_SIZE (gnu_return_type), true);
5659
5660 /* If the size overflows to 0, set it to an arbitrary positive
5661 value so that assignments in the type are preserved. Their
5662 actual size is independent of this positive value. */
5663 if (TREE_CODE (max_return_size) == INTEGER_CST
5664 && TREE_OVERFLOW (max_return_size)
5665 && integer_zerop (max_return_size))
5666 {
5667 max_return_size = copy_node (bitsize_unit_node);
5668 TREE_OVERFLOW (max_return_size) = 1;
5669 }
5670
5671 gnu_return_type = maybe_pad_type (gnu_return_type, max_return_size,
5672 0, gnat_subprog, false, false,
5673 definition, true);
5674
5675 /* Declare it now since it will never be declared otherwise. This
5676 is necessary to ensure that its subtrees are properly marked. */
5677 if (gnu_return_type != orig_type
5678 && !DECL_P (TYPE_NAME (gnu_return_type)))
5679 create_type_decl (TYPE_NAME (gnu_return_type), gnu_return_type,
5680 true, debug_info_p, gnat_subprog);
5681
5682 return_by_invisi_ref_p = true;
5683 }
5684
5685 /* If the return type has a size that overflows, we usually cannot have
5686 a function that returns that type. This usage doesn't really make
5687 sense anyway, so issue an error here. */
5688 if (!return_by_invisi_ref_p
5689 && TYPE_SIZE_UNIT (gnu_return_type)
5690 && TREE_CODE (TYPE_SIZE_UNIT (gnu_return_type)) == INTEGER_CST
5691 && !valid_constant_size_p (TYPE_SIZE_UNIT (gnu_return_type)))
5692 {
5693 post_error ("cannot return type whose size overflows", gnat_subprog);
5694 gnu_return_type = copy_type (gnu_return_type);
5695 TYPE_SIZE (gnu_return_type) = bitsize_zero_node;
5696 TYPE_SIZE_UNIT (gnu_return_type) = size_zero_node;
5697 }
5698
5699 /* If the return type is incomplete, there are 2 cases: if the function
5700 returns by reference, then the return type is only linked indirectly
5701 in the profile, so the profile can be seen as complete since it need
5702 not be further modified, only the reference types need be adjusted;
5703 otherwise the profile is incomplete and need be adjusted too. */
5704 if (TYPE_IS_DUMMY_P (gnu_return_type))
5705 {
5706 associate_subprog_with_dummy_type (gnat_subprog, gnu_return_type);
5707 incomplete_profile_p = true;
5708 }
5709
5710 if (kind == E_Function)
5711 Set_Mechanism (gnat_subprog, return_unconstrained_p
5712 || return_by_direct_ref_p
5713 || return_by_invisi_ref_p
5714 ? By_Reference : By_Copy);
5715 }
5716
5717 /* A procedure (something that doesn't return anything) shouldn't be
5718 considered const since there would be no reason for calling such a
5719 subprogram. Note that procedures with Out (or In Out) parameters
5720 have already been converted into a function with a return type.
5721 Similarly, if the function returns an unconstrained type, then the
5722 function will allocate the return value on the secondary stack and
5723 thus calls to it cannot be CSE'ed, lest the stack be reclaimed. */
5724 if (TREE_CODE (gnu_return_type) == VOID_TYPE || return_unconstrained_p)
5725 const_flag = false;
5726
5727 /* Loop over the parameters and get their associated GCC tree. While doing
5728 this, build a copy-in copy-out structure if we need one. */
5729 for (gnat_param = First_Formal_With_Extras (gnat_subprog), num = 0;
5730 Present (gnat_param);
5731 gnat_param = Next_Formal_With_Extras (gnat_param), num++)
5732 {
5733 const bool mech_is_by_ref
5734 = Mechanism (gnat_param) == By_Reference
5735 && !(num == 0 && Is_Valued_Procedure (gnat_subprog));
5736 tree gnu_param_name = get_entity_name (gnat_param);
5737 tree gnu_param, gnu_param_type;
5738 bool cico = false;
5739
5740 /* Fetch an existing parameter with complete type and reuse it. But we
5741 didn't save the CICO property so we can only do it for In parameters
5742 or parameters passed by reference. */
5743 if ((Ekind (gnat_param) == E_In_Parameter || mech_is_by_ref)
5744 && present_gnu_tree (gnat_param)
5745 && (gnu_param = get_gnu_tree (gnat_param))
5746 && !TYPE_IS_DUMMY_P (TREE_TYPE (gnu_param)))
5747 {
5748 DECL_CHAIN (gnu_param) = NULL_TREE;
5749 gnu_param_type = TREE_TYPE (gnu_param);
5750 }
5751
5752 /* Otherwise translate the parameter type and act accordingly. */
5753 else
5754 {
5755 Entity_Id gnat_param_type = Etype (gnat_param);
5756
5757 /* For foreign convention subprograms, pass System.Address as void *
5758 or equivalent. Note that this comprises GCC builtins. */
5759 if (Has_Foreign_Convention (gnat_subprog)
5760 && Is_Descendant_Of_Address (Underlying_Type (gnat_param_type)))
5761 gnu_param_type = ptr_type_node;
5762 else
5763 gnu_param_type = gnat_to_gnu_profile_type (gnat_param_type);
5764
5765 /* If the parameter type is incomplete, there are 2 cases: if it is
5766 passed by reference, then the type is only linked indirectly in
5767 the profile, so the profile can be seen as complete since it need
5768 not be further modified, only the reference type need be adjusted;
5769 otherwise the profile is incomplete and need be adjusted too. */
5770 if (TYPE_IS_DUMMY_P (gnu_param_type))
5771 {
5772 Node_Id gnat_decl;
5773
5774 if (mech_is_by_ref
5775 || (TYPE_REFERENCE_TO (gnu_param_type)
5776 && TYPE_IS_FAT_POINTER_P
5777 (TYPE_REFERENCE_TO (gnu_param_type)))
5778 || TYPE_IS_BY_REFERENCE_P (gnu_param_type))
5779 {
5780 gnu_param_type = build_reference_type (gnu_param_type);
5781 gnu_param
5782 = create_param_decl (gnu_param_name, gnu_param_type);
5783 TREE_READONLY (gnu_param) = 1;
5784 DECL_BY_REF_P (gnu_param) = 1;
5785 DECL_POINTS_TO_READONLY_P (gnu_param)
5786 = (Ekind (gnat_param) == E_In_Parameter
5787 && !Address_Taken (gnat_param));
5788 Set_Mechanism (gnat_param, By_Reference);
5789 Sloc_to_locus (Sloc (gnat_param),
5790 &DECL_SOURCE_LOCATION (gnu_param));
5791 }
5792
5793 /* ??? This is a kludge to support null procedures in spec taking
5794 a parameter with an untagged incomplete type coming from a
5795 limited context. The front-end creates a body without knowing
5796 anything about the non-limited view, which is illegal Ada and
5797 cannot be supported. Create a parameter with a fake type. */
5798 else if (kind == E_Procedure
5799 && (gnat_decl = Parent (gnat_subprog))
5800 && Nkind (gnat_decl) == N_Procedure_Specification
5801 && Null_Present (gnat_decl)
5802 && Is_Incomplete_Type (gnat_param_type))
5803 gnu_param = create_param_decl (gnu_param_name, ptr_type_node);
5804
5805 else
5806 {
5807 /* Build a minimal PARM_DECL without DECL_ARG_TYPE so that
5808 Call_to_gnu will stop if it encounters the PARM_DECL. */
5809 gnu_param
5810 = build_decl (input_location, PARM_DECL, gnu_param_name,
5811 gnu_param_type);
5812 associate_subprog_with_dummy_type (gnat_subprog,
5813 gnu_param_type);
5814 incomplete_profile_p = true;
5815 }
5816 }
5817
5818 /* Otherwise build the parameter declaration normally. */
5819 else
5820 {
5821 gnu_param
5822 = gnat_to_gnu_param (gnat_param, gnu_param_type, num == 0,
5823 gnat_subprog, &cico);
5824
5825 /* We are returned either a PARM_DECL or a type if no parameter
5826 needs to be passed; in either case, adjust the type. */
5827 if (DECL_P (gnu_param))
5828 gnu_param_type = TREE_TYPE (gnu_param);
5829 else
5830 {
5831 gnu_param_type = gnu_param;
5832 gnu_param = NULL_TREE;
5833 }
5834 }
5835 }
5836
5837 /* If we have a GCC tree for the parameter, register it. */
5838 save_gnu_tree (gnat_param, NULL_TREE, false);
5839 if (gnu_param)
5840 {
5841 gnu_param_type_list
5842 = tree_cons (NULL_TREE, gnu_param_type, gnu_param_type_list);
5843 gnu_param_list = chainon (gnu_param, gnu_param_list);
5844 save_gnu_tree (gnat_param, gnu_param, false);
5845
5846 /* If a parameter is a pointer, a function may modify memory through
5847 it and thus shouldn't be considered a const function. Also, the
5848 memory may be modified between two calls, so they can't be CSE'ed.
5849 The latter case also handles by-ref parameters. */
5850 if (POINTER_TYPE_P (gnu_param_type)
5851 || TYPE_IS_FAT_POINTER_P (gnu_param_type))
5852 const_flag = false;
5853 }
5854
5855 /* If the parameter uses the copy-in copy-out mechanism, allocate a field
5856 for it in the return type and register the association. */
5857 if (cico && !incomplete_profile_p)
5858 {
5859 if (!gnu_cico_list)
5860 {
5861 gnu_cico_return_type = make_node (RECORD_TYPE);
5862
5863 /* If this is a function, we also need a field for the
5864 return value to be placed. */
5865 if (!VOID_TYPE_P (gnu_return_type))
5866 {
5867 tree gnu_field
5868 = create_field_decl (get_identifier ("RETVAL"),
5869 gnu_return_type,
5870 gnu_cico_return_type, NULL_TREE,
5871 NULL_TREE, 0, 0);
5872 Sloc_to_locus (Sloc (gnat_subprog),
5873 &DECL_SOURCE_LOCATION (gnu_field));
5874 gnu_field_list = gnu_field;
5875 gnu_cico_list
5876 = tree_cons (gnu_field, void_type_node, NULL_TREE);
5877 }
5878
5879 TYPE_NAME (gnu_cico_return_type) = get_identifier ("RETURN");
5880 /* Set a default alignment to speed up accesses. But we should
5881 not increase the size of the structure too much, lest it does
5882 not fit in return registers anymore. */
5883 SET_TYPE_ALIGN (gnu_cico_return_type,
5884 get_mode_alignment (ptr_mode));
5885 }
5886
5887 tree gnu_field
5888 = create_field_decl (gnu_param_name, gnu_param_type,
5889 gnu_cico_return_type, NULL_TREE, NULL_TREE,
5890 0, 0);
5891 Sloc_to_locus (Sloc (gnat_param),
5892 &DECL_SOURCE_LOCATION (gnu_field));
5893 DECL_CHAIN (gnu_field) = gnu_field_list;
5894 gnu_field_list = gnu_field;
5895 gnu_cico_list = tree_cons (gnu_field, gnu_param, gnu_cico_list);
5896 }
5897 }
5898
5899 /* If the subprogram uses the copy-in copy-out mechanism, possibly adjust
5900 and finish up the return type. */
5901 if (gnu_cico_list && !incomplete_profile_p)
5902 {
5903 /* If we have a CICO list but it has only one entry, we convert
5904 this function into a function that returns this object. */
5905 if (list_length (gnu_cico_list) == 1)
5906 gnu_cico_return_type = TREE_TYPE (TREE_PURPOSE (gnu_cico_list));
5907
5908 /* Do not finalize the return type if the subprogram is stubbed
5909 since structures are incomplete for the back-end. */
5910 else if (Convention (gnat_subprog) != Convention_Stubbed)
5911 {
5912 finish_record_type (gnu_cico_return_type, nreverse (gnu_field_list),
5913 0, false);
5914
5915 /* Try to promote the mode of the return type if it is passed
5916 in registers, again to speed up accesses. */
5917 if (TYPE_MODE (gnu_cico_return_type) == BLKmode
5918 && !targetm.calls.return_in_memory (gnu_cico_return_type,
5919 NULL_TREE))
5920 {
5921 unsigned int size
5922 = TREE_INT_CST_LOW (TYPE_SIZE (gnu_cico_return_type));
5923 unsigned int i = BITS_PER_UNIT;
5924 scalar_int_mode mode;
5925
5926 while (i < size)
5927 i <<= 1;
5928 if (int_mode_for_size (i, 0).exists (&mode))
5929 {
5930 SET_TYPE_MODE (gnu_cico_return_type, mode);
5931 SET_TYPE_ALIGN (gnu_cico_return_type,
5932 GET_MODE_ALIGNMENT (mode));
5933 TYPE_SIZE (gnu_cico_return_type)
5934 = bitsize_int (GET_MODE_BITSIZE (mode));
5935 TYPE_SIZE_UNIT (gnu_cico_return_type)
5936 = size_int (GET_MODE_SIZE (mode));
5937 }
5938 }
5939
5940 if (debug_info_p)
5941 rest_of_record_type_compilation (gnu_cico_return_type);
5942 }
5943
5944 gnu_return_type = gnu_cico_return_type;
5945 }
5946
5947 /* The lists have been built in reverse. */
5948 gnu_param_type_list = nreverse (gnu_param_type_list);
5949 gnu_param_type_list = chainon (gnu_param_type_list, void_list_node);
5950 *param_list = nreverse (gnu_param_list);
5951 gnu_cico_list = nreverse (gnu_cico_list);
5952
5953 /* If the profile is incomplete, we only set the (temporary) return and
5954 parameter types; otherwise, we build the full type. In either case,
5955 we reuse an already existing GCC tree that we built previously here. */
5956 if (incomplete_profile_p)
5957 {
5958 if (gnu_type && TREE_CODE (gnu_type) == FUNCTION_TYPE)
5959 ;
5960 else
5961 gnu_type = make_node (FUNCTION_TYPE);
5962 TREE_TYPE (gnu_type) = gnu_return_type;
5963 TYPE_ARG_TYPES (gnu_type) = gnu_param_type_list;
5964 TYPE_RETURN_UNCONSTRAINED_P (gnu_type) = return_unconstrained_p;
5965 TYPE_RETURN_BY_DIRECT_REF_P (gnu_type) = return_by_direct_ref_p;
5966 TREE_ADDRESSABLE (gnu_type) = return_by_invisi_ref_p;
5967 }
5968 else
5969 {
5970 if (gnu_type && TREE_CODE (gnu_type) == FUNCTION_TYPE)
5971 {
5972 TREE_TYPE (gnu_type) = gnu_return_type;
5973 TYPE_ARG_TYPES (gnu_type) = gnu_param_type_list;
5974 TYPE_CI_CO_LIST (gnu_type) = gnu_cico_list;
5975 TYPE_RETURN_UNCONSTRAINED_P (gnu_type) = return_unconstrained_p;
5976 TYPE_RETURN_BY_DIRECT_REF_P (gnu_type) = return_by_direct_ref_p;
5977 TREE_ADDRESSABLE (gnu_type) = return_by_invisi_ref_p;
5978 TYPE_CANONICAL (gnu_type) = gnu_type;
5979 layout_type (gnu_type);
5980 }
5981 else
5982 {
5983 gnu_type
5984 = build_function_type (gnu_return_type, gnu_param_type_list);
5985
5986 /* GNU_TYPE may be shared since GCC hashes types. Unshare it if it
5987 has a different TYPE_CI_CO_LIST or flags. */
5988 if (!fntype_same_flags_p (gnu_type, gnu_cico_list,
5989 return_unconstrained_p,
5990 return_by_direct_ref_p,
5991 return_by_invisi_ref_p))
5992 {
5993 gnu_type = copy_type (gnu_type);
5994 TYPE_CI_CO_LIST (gnu_type) = gnu_cico_list;
5995 TYPE_RETURN_UNCONSTRAINED_P (gnu_type) = return_unconstrained_p;
5996 TYPE_RETURN_BY_DIRECT_REF_P (gnu_type) = return_by_direct_ref_p;
5997 TREE_ADDRESSABLE (gnu_type) = return_by_invisi_ref_p;
5998 }
5999 }
6000
6001 if (const_flag)
6002 gnu_type = change_qualified_type (gnu_type, TYPE_QUAL_CONST);
6003
6004 if (No_Return (gnat_subprog))
6005 gnu_type = change_qualified_type (gnu_type, TYPE_QUAL_VOLATILE);
6006
6007 /* If this subprogram is expectedly bound to a GCC builtin, fetch the
6008 corresponding DECL node and check the parameter association. */
6009 if (Convention (gnat_subprog) == Convention_Intrinsic
6010 && Present (Interface_Name (gnat_subprog)))
6011 {
6012 tree gnu_ext_name = create_concat_name (gnat_subprog, NULL);
6013 tree gnu_builtin_decl = builtin_decl_for (gnu_ext_name);
6014
6015 /* If we have a builtin DECL for that function, use it. Check if
6016 the profiles are compatible and warn if they are not. Note that
6017 the checker is expected to post diagnostics in this case. */
6018 if (gnu_builtin_decl)
6019 {
6020 intrin_binding_t inb
6021 = { gnat_subprog, gnu_type, TREE_TYPE (gnu_builtin_decl) };
6022
6023 if (!intrin_profiles_compatible_p (&inb))
6024 post_error
6025 ("?profile of& doesn''t match the builtin it binds!",
6026 gnat_subprog);
6027
6028 return gnu_builtin_decl;
6029 }
6030
6031 /* Inability to find the builtin DECL most often indicates a genuine
6032 mistake, but imports of unregistered intrinsics are sometimes used
6033 on purpose to allow hooking in alternate bodies; we post a warning
6034 conditioned on Wshadow in this case, to let developers be notified
6035 on demand without risking false positives with common default sets
6036 of options. */
6037 if (warn_shadow)
6038 post_error ("?gcc intrinsic not found for&!", gnat_subprog);
6039 }
6040 }
6041
6042 return gnu_type;
6043 }
6044
6045 /* Return the external name for GNAT_SUBPROG given its entity name. */
6046
6047 static tree
gnu_ext_name_for_subprog(Entity_Id gnat_subprog,tree gnu_entity_name)6048 gnu_ext_name_for_subprog (Entity_Id gnat_subprog, tree gnu_entity_name)
6049 {
6050 tree gnu_ext_name = create_concat_name (gnat_subprog, NULL);
6051
6052 /* If there was no specified Interface_Name and the external and
6053 internal names of the subprogram are the same, only use the
6054 internal name to allow disambiguation of nested subprograms. */
6055 if (No (Interface_Name (gnat_subprog)) && gnu_ext_name == gnu_entity_name)
6056 gnu_ext_name = NULL_TREE;
6057
6058 return gnu_ext_name;
6059 }
6060
6061 /* Set TYPE_NONALIASED_COMPONENT on an array type built by means of
6062 build_nonshared_array_type. */
6063
6064 static void
set_nonaliased_component_on_array_type(tree type)6065 set_nonaliased_component_on_array_type (tree type)
6066 {
6067 TYPE_NONALIASED_COMPONENT (type) = 1;
6068 TYPE_NONALIASED_COMPONENT (TYPE_CANONICAL (type)) = 1;
6069 }
6070
6071 /* Set TYPE_REVERSE_STORAGE_ORDER on an array type built by means of
6072 build_nonshared_array_type. */
6073
6074 static void
set_reverse_storage_order_on_array_type(tree type)6075 set_reverse_storage_order_on_array_type (tree type)
6076 {
6077 TYPE_REVERSE_STORAGE_ORDER (type) = 1;
6078 TYPE_REVERSE_STORAGE_ORDER (TYPE_CANONICAL (type)) = 1;
6079 }
6080
6081 /* Return true if DISCR1 and DISCR2 represent the same discriminant. */
6082
6083 static bool
same_discriminant_p(Entity_Id discr1,Entity_Id discr2)6084 same_discriminant_p (Entity_Id discr1, Entity_Id discr2)
6085 {
6086 while (Present (Corresponding_Discriminant (discr1)))
6087 discr1 = Corresponding_Discriminant (discr1);
6088
6089 while (Present (Corresponding_Discriminant (discr2)))
6090 discr2 = Corresponding_Discriminant (discr2);
6091
6092 return
6093 Original_Record_Component (discr1) == Original_Record_Component (discr2);
6094 }
6095
6096 /* Return true if the array type GNU_TYPE, which represents a dimension of
6097 GNAT_TYPE, has a non-aliased component in the back-end sense. */
6098
6099 static bool
array_type_has_nonaliased_component(tree gnu_type,Entity_Id gnat_type)6100 array_type_has_nonaliased_component (tree gnu_type, Entity_Id gnat_type)
6101 {
6102 /* If the array type has an aliased component in the front-end sense,
6103 then it also has an aliased component in the back-end sense. */
6104 if (Has_Aliased_Components (gnat_type))
6105 return false;
6106
6107 /* If this is a derived type, then it has a non-aliased component if
6108 and only if its parent type also has one. */
6109 if (Is_Derived_Type (gnat_type))
6110 {
6111 tree gnu_parent_type = gnat_to_gnu_type (Etype (gnat_type));
6112 if (TREE_CODE (gnu_parent_type) == UNCONSTRAINED_ARRAY_TYPE)
6113 gnu_parent_type
6114 = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_parent_type))));
6115 return TYPE_NONALIASED_COMPONENT (gnu_parent_type);
6116 }
6117
6118 /* For a multi-dimensional array type, find the component type. */
6119 while (TREE_CODE (TREE_TYPE (gnu_type)) == ARRAY_TYPE
6120 && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_type)))
6121 gnu_type = TREE_TYPE (gnu_type);
6122
6123 /* Consider that an array of pointers has an aliased component, which is
6124 sort of logical and helps with Taft Amendment types in LTO mode. */
6125 if (POINTER_TYPE_P (TREE_TYPE (gnu_type)))
6126 return false;
6127
6128 /* Otherwise, rely exclusively on properties of the element type. */
6129 return type_for_nonaliased_component_p (TREE_TYPE (gnu_type));
6130 }
6131
6132 /* Return true if GNAT_ADDRESS is a value known at compile-time. */
6133
6134 static bool
compile_time_known_address_p(Node_Id gnat_address)6135 compile_time_known_address_p (Node_Id gnat_address)
6136 {
6137 /* Handle reference to a constant. */
6138 if (Is_Entity_Name (gnat_address)
6139 && Ekind (Entity (gnat_address)) == E_Constant)
6140 {
6141 gnat_address = Constant_Value (Entity (gnat_address));
6142 if (No (gnat_address))
6143 return false;
6144 }
6145
6146 /* Catch System'To_Address. */
6147 if (Nkind (gnat_address) == N_Unchecked_Type_Conversion)
6148 gnat_address = Expression (gnat_address);
6149
6150 return Compile_Time_Known_Value (gnat_address);
6151 }
6152
6153 /* Return true if GNAT_RANGE, a N_Range node, cannot be superflat, i.e. if the
6154 inequality HB >= LB-1 is true. LB and HB are the low and high bounds. */
6155
6156 static bool
cannot_be_superflat(Node_Id gnat_range)6157 cannot_be_superflat (Node_Id gnat_range)
6158 {
6159 Node_Id gnat_lb = Low_Bound (gnat_range), gnat_hb = High_Bound (gnat_range);
6160 Node_Id scalar_range;
6161 tree gnu_lb, gnu_hb, gnu_lb_minus_one;
6162
6163 /* If the low bound is not constant, try to find an upper bound. */
6164 while (Nkind (gnat_lb) != N_Integer_Literal
6165 && (Ekind (Etype (gnat_lb)) == E_Signed_Integer_Subtype
6166 || Ekind (Etype (gnat_lb)) == E_Modular_Integer_Subtype)
6167 && (scalar_range = Scalar_Range (Etype (gnat_lb)))
6168 && (Nkind (scalar_range) == N_Signed_Integer_Type_Definition
6169 || Nkind (scalar_range) == N_Range))
6170 gnat_lb = High_Bound (scalar_range);
6171
6172 /* If the high bound is not constant, try to find a lower bound. */
6173 while (Nkind (gnat_hb) != N_Integer_Literal
6174 && (Ekind (Etype (gnat_hb)) == E_Signed_Integer_Subtype
6175 || Ekind (Etype (gnat_hb)) == E_Modular_Integer_Subtype)
6176 && (scalar_range = Scalar_Range (Etype (gnat_hb)))
6177 && (Nkind (scalar_range) == N_Signed_Integer_Type_Definition
6178 || Nkind (scalar_range) == N_Range))
6179 gnat_hb = Low_Bound (scalar_range);
6180
6181 /* If we have failed to find constant bounds, punt. */
6182 if (Nkind (gnat_lb) != N_Integer_Literal
6183 || Nkind (gnat_hb) != N_Integer_Literal)
6184 return false;
6185
6186 /* We need at least a signed 64-bit type to catch most cases. */
6187 gnu_lb = UI_To_gnu (Intval (gnat_lb), sbitsizetype);
6188 gnu_hb = UI_To_gnu (Intval (gnat_hb), sbitsizetype);
6189 if (TREE_OVERFLOW (gnu_lb) || TREE_OVERFLOW (gnu_hb))
6190 return false;
6191
6192 /* If the low bound is the smallest integer, nothing can be smaller. */
6193 gnu_lb_minus_one = size_binop (MINUS_EXPR, gnu_lb, sbitsize_one_node);
6194 if (TREE_OVERFLOW (gnu_lb_minus_one))
6195 return true;
6196
6197 return !tree_int_cst_lt (gnu_hb, gnu_lb_minus_one);
6198 }
6199
6200 /* Return true if GNU_EXPR is (essentially) the address of a CONSTRUCTOR. */
6201
6202 static bool
constructor_address_p(tree gnu_expr)6203 constructor_address_p (tree gnu_expr)
6204 {
6205 while (TREE_CODE (gnu_expr) == NOP_EXPR
6206 || TREE_CODE (gnu_expr) == CONVERT_EXPR
6207 || TREE_CODE (gnu_expr) == NON_LVALUE_EXPR)
6208 gnu_expr = TREE_OPERAND (gnu_expr, 0);
6209
6210 return (TREE_CODE (gnu_expr) == ADDR_EXPR
6211 && TREE_CODE (TREE_OPERAND (gnu_expr, 0)) == CONSTRUCTOR);
6212 }
6213
6214 /* Return true if the size in units represented by GNU_SIZE can be handled by
6215 an allocation. If STATIC_P is true, consider only what can be done with a
6216 static allocation. */
6217
6218 static bool
allocatable_size_p(tree gnu_size,bool static_p)6219 allocatable_size_p (tree gnu_size, bool static_p)
6220 {
6221 /* We can allocate a fixed size if it is a valid for the middle-end. */
6222 if (TREE_CODE (gnu_size) == INTEGER_CST)
6223 return valid_constant_size_p (gnu_size);
6224
6225 /* We can allocate a variable size if this isn't a static allocation. */
6226 else
6227 return !static_p;
6228 }
6229
6230 /* Return true if GNU_EXPR needs a conversion to GNU_TYPE when used as the
6231 initial value of an object of GNU_TYPE. */
6232
6233 static bool
initial_value_needs_conversion(tree gnu_type,tree gnu_expr)6234 initial_value_needs_conversion (tree gnu_type, tree gnu_expr)
6235 {
6236 /* Do not convert if the object's type is unconstrained because this would
6237 generate useless evaluations of the CONSTRUCTOR to compute the size. */
6238 if (TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE
6239 || CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type)))
6240 return false;
6241
6242 /* Do not convert if the object's type is a padding record whose field is of
6243 self-referential size because we want to copy only the actual data. */
6244 if (type_is_padding_self_referential (gnu_type))
6245 return false;
6246
6247 /* Do not convert a call to a function that returns with variable size since
6248 we want to use the return slot optimization in this case. */
6249 if (TREE_CODE (gnu_expr) == CALL_EXPR
6250 && return_type_with_variable_size_p (TREE_TYPE (gnu_expr)))
6251 return false;
6252
6253 /* Do not convert to a record type with a variant part from a record type
6254 without one, to keep the object simpler. */
6255 if (TREE_CODE (gnu_type) == RECORD_TYPE
6256 && TREE_CODE (TREE_TYPE (gnu_expr)) == RECORD_TYPE
6257 && get_variant_part (gnu_type)
6258 && !get_variant_part (TREE_TYPE (gnu_expr)))
6259 return false;
6260
6261 /* In all the other cases, convert the expression to the object's type. */
6262 return true;
6263 }
6264
6265 /* Given GNAT_ENTITY, elaborate all expressions that are required to
6266 be elaborated at the point of its definition, but do nothing else. */
6267
6268 void
elaborate_entity(Entity_Id gnat_entity)6269 elaborate_entity (Entity_Id gnat_entity)
6270 {
6271 switch (Ekind (gnat_entity))
6272 {
6273 case E_Signed_Integer_Subtype:
6274 case E_Modular_Integer_Subtype:
6275 case E_Enumeration_Subtype:
6276 case E_Ordinary_Fixed_Point_Subtype:
6277 case E_Decimal_Fixed_Point_Subtype:
6278 case E_Floating_Point_Subtype:
6279 {
6280 Node_Id gnat_lb = Type_Low_Bound (gnat_entity);
6281 Node_Id gnat_hb = Type_High_Bound (gnat_entity);
6282
6283 /* ??? Tests to avoid Constraint_Error in static expressions
6284 are needed until after the front stops generating bogus
6285 conversions on bounds of real types. */
6286 if (!Raises_Constraint_Error (gnat_lb))
6287 elaborate_expression (gnat_lb, gnat_entity, "L", true, false,
6288 Needs_Debug_Info (gnat_entity));
6289 if (!Raises_Constraint_Error (gnat_hb))
6290 elaborate_expression (gnat_hb, gnat_entity, "U", true, false,
6291 Needs_Debug_Info (gnat_entity));
6292 break;
6293 }
6294
6295 case E_Record_Subtype:
6296 case E_Private_Subtype:
6297 case E_Limited_Private_Subtype:
6298 case E_Record_Subtype_With_Private:
6299 if (Has_Discriminants (gnat_entity) && Is_Constrained (gnat_entity))
6300 {
6301 Node_Id gnat_discriminant_expr;
6302 Entity_Id gnat_field;
6303
6304 for (gnat_field
6305 = First_Discriminant (Implementation_Base_Type (gnat_entity)),
6306 gnat_discriminant_expr
6307 = First_Elmt (Discriminant_Constraint (gnat_entity));
6308 Present (gnat_field);
6309 gnat_field = Next_Discriminant (gnat_field),
6310 gnat_discriminant_expr = Next_Elmt (gnat_discriminant_expr))
6311 /* Ignore access discriminants. */
6312 if (!Is_Access_Type (Etype (Node (gnat_discriminant_expr))))
6313 elaborate_expression (Node (gnat_discriminant_expr),
6314 gnat_entity, get_entity_char (gnat_field),
6315 true, false, false);
6316 }
6317 break;
6318
6319 }
6320 }
6321
6322 /* Prepend to ATTR_LIST an entry for an attribute with provided TYPE,
6323 NAME, ARGS and ERROR_POINT. */
6324
6325 static void
prepend_one_attribute(struct attrib ** attr_list,enum attrib_type attrib_type,tree attr_name,tree attr_args,Node_Id attr_error_point)6326 prepend_one_attribute (struct attrib **attr_list,
6327 enum attrib_type attrib_type,
6328 tree attr_name,
6329 tree attr_args,
6330 Node_Id attr_error_point)
6331 {
6332 struct attrib * attr = (struct attrib *) xmalloc (sizeof (struct attrib));
6333
6334 attr->type = attrib_type;
6335 attr->name = attr_name;
6336 attr->args = attr_args;
6337 attr->error_point = attr_error_point;
6338
6339 attr->next = *attr_list;
6340 *attr_list = attr;
6341 }
6342
6343 /* Prepend to ATTR_LIST an entry for an attribute provided by GNAT_PRAGMA. */
6344
6345 static void
prepend_one_attribute_pragma(struct attrib ** attr_list,Node_Id gnat_pragma)6346 prepend_one_attribute_pragma (struct attrib **attr_list, Node_Id gnat_pragma)
6347 {
6348 const Node_Id gnat_arg = Pragma_Argument_Associations (gnat_pragma);
6349 tree gnu_arg0 = NULL_TREE, gnu_arg1 = NULL_TREE;
6350 enum attrib_type etype;
6351
6352 /* Map the pragma at hand. Skip if this isn't one we know how to handle. */
6353 switch (Get_Pragma_Id (Chars (Pragma_Identifier (gnat_pragma))))
6354 {
6355 case Pragma_Machine_Attribute:
6356 etype = ATTR_MACHINE_ATTRIBUTE;
6357 break;
6358
6359 case Pragma_Linker_Alias:
6360 etype = ATTR_LINK_ALIAS;
6361 break;
6362
6363 case Pragma_Linker_Section:
6364 etype = ATTR_LINK_SECTION;
6365 break;
6366
6367 case Pragma_Linker_Constructor:
6368 etype = ATTR_LINK_CONSTRUCTOR;
6369 break;
6370
6371 case Pragma_Linker_Destructor:
6372 etype = ATTR_LINK_DESTRUCTOR;
6373 break;
6374
6375 case Pragma_Weak_External:
6376 etype = ATTR_WEAK_EXTERNAL;
6377 break;
6378
6379 case Pragma_Thread_Local_Storage:
6380 etype = ATTR_THREAD_LOCAL_STORAGE;
6381 break;
6382
6383 default:
6384 return;
6385 }
6386
6387 /* See what arguments we have and turn them into GCC trees for attribute
6388 handlers. These expect identifier for strings. We handle at most two
6389 arguments and static expressions only. */
6390 if (Present (gnat_arg) && Present (First (gnat_arg)))
6391 {
6392 Node_Id gnat_arg0 = Next (First (gnat_arg));
6393 Node_Id gnat_arg1 = Empty;
6394
6395 if (Present (gnat_arg0)
6396 && Is_OK_Static_Expression (Expression (gnat_arg0)))
6397 {
6398 gnu_arg0 = gnat_to_gnu (Expression (gnat_arg0));
6399
6400 if (TREE_CODE (gnu_arg0) == STRING_CST)
6401 {
6402 gnu_arg0 = get_identifier (TREE_STRING_POINTER (gnu_arg0));
6403 if (IDENTIFIER_LENGTH (gnu_arg0) == 0)
6404 return;
6405 }
6406
6407 gnat_arg1 = Next (gnat_arg0);
6408 }
6409
6410 if (Present (gnat_arg1)
6411 && Is_OK_Static_Expression (Expression (gnat_arg1)))
6412 {
6413 gnu_arg1 = gnat_to_gnu (Expression (gnat_arg1));
6414
6415 if (TREE_CODE (gnu_arg1) == STRING_CST)
6416 gnu_arg1 = get_identifier (TREE_STRING_POINTER (gnu_arg1));
6417 }
6418 }
6419
6420 /* Prepend to the list. Make a list of the argument we might have, as GCC
6421 expects it. */
6422 prepend_one_attribute (attr_list, etype, gnu_arg0,
6423 gnu_arg1
6424 ? build_tree_list (NULL_TREE, gnu_arg1) : NULL_TREE,
6425 Present (Next (First (gnat_arg)))
6426 ? Expression (Next (First (gnat_arg))) : gnat_pragma);
6427 }
6428
6429 /* Prepend to ATTR_LIST the list of attributes for GNAT_ENTITY, if any. */
6430
6431 static void
prepend_attributes(struct attrib ** attr_list,Entity_Id gnat_entity)6432 prepend_attributes (struct attrib **attr_list, Entity_Id gnat_entity)
6433 {
6434 Node_Id gnat_temp;
6435
6436 /* Attributes are stored as Representation Item pragmas. */
6437 for (gnat_temp = First_Rep_Item (gnat_entity);
6438 Present (gnat_temp);
6439 gnat_temp = Next_Rep_Item (gnat_temp))
6440 if (Nkind (gnat_temp) == N_Pragma)
6441 prepend_one_attribute_pragma (attr_list, gnat_temp);
6442 }
6443
6444 /* Given a GNAT tree GNAT_EXPR, for an expression which is a value within a
6445 type definition (either a bound or a discriminant value) for GNAT_ENTITY,
6446 return the GCC tree to use for that expression. S is the suffix to use
6447 if a variable needs to be created and DEFINITION is true if this is done
6448 for a definition of GNAT_ENTITY. If NEED_VALUE is true, we need a result;
6449 otherwise, we are just elaborating the expression for side-effects. If
6450 NEED_DEBUG is true, we need a variable for debugging purposes even if it
6451 isn't needed for code generation. */
6452
6453 static tree
elaborate_expression(Node_Id gnat_expr,Entity_Id gnat_entity,const char * s,bool definition,bool need_value,bool need_debug)6454 elaborate_expression (Node_Id gnat_expr, Entity_Id gnat_entity, const char *s,
6455 bool definition, bool need_value, bool need_debug)
6456 {
6457 tree gnu_expr;
6458
6459 /* If we already elaborated this expression (e.g. it was involved
6460 in the definition of a private type), use the old value. */
6461 if (present_gnu_tree (gnat_expr))
6462 return get_gnu_tree (gnat_expr);
6463
6464 /* If we don't need a value and this is static or a discriminant,
6465 we don't need to do anything. */
6466 if (!need_value
6467 && (Is_OK_Static_Expression (gnat_expr)
6468 || (Nkind (gnat_expr) == N_Identifier
6469 && Ekind (Entity (gnat_expr)) == E_Discriminant)))
6470 return NULL_TREE;
6471
6472 /* If it's a static expression, we don't need a variable for debugging. */
6473 if (need_debug && Is_OK_Static_Expression (gnat_expr))
6474 need_debug = false;
6475
6476 /* Otherwise, convert this tree to its GCC equivalent and elaborate it. */
6477 gnu_expr = elaborate_expression_1 (gnat_to_gnu (gnat_expr), gnat_entity, s,
6478 definition, need_debug);
6479
6480 /* Save the expression in case we try to elaborate this entity again. Since
6481 it's not a DECL, don't check it. Don't save if it's a discriminant. */
6482 if (!CONTAINS_PLACEHOLDER_P (gnu_expr))
6483 save_gnu_tree (gnat_expr, gnu_expr, true);
6484
6485 return need_value ? gnu_expr : error_mark_node;
6486 }
6487
6488 /* Similar, but take a GNU expression and always return a result. */
6489
6490 static tree
elaborate_expression_1(tree gnu_expr,Entity_Id gnat_entity,const char * s,bool definition,bool need_debug)6491 elaborate_expression_1 (tree gnu_expr, Entity_Id gnat_entity, const char *s,
6492 bool definition, bool need_debug)
6493 {
6494 const bool expr_public_p = Is_Public (gnat_entity);
6495 const bool expr_global_p = expr_public_p || global_bindings_p ();
6496 bool expr_variable_p, use_variable;
6497
6498 /* If GNU_EXPR contains a placeholder, just return it. We rely on the fact
6499 that an expression cannot contain both a discriminant and a variable. */
6500 if (CONTAINS_PLACEHOLDER_P (gnu_expr))
6501 return gnu_expr;
6502
6503 /* If GNU_EXPR is neither a constant nor based on a read-only variable, make
6504 a variable that is initialized to contain the expression when the package
6505 containing the definition is elaborated. If this entity is defined at top
6506 level, replace the expression by the variable; otherwise use a SAVE_EXPR
6507 if this is necessary. */
6508 if (TREE_CONSTANT (gnu_expr))
6509 expr_variable_p = false;
6510 else
6511 {
6512 /* Skip any conversions and simple constant arithmetics to see if the
6513 expression is based on a read-only variable. */
6514 tree inner = remove_conversions (gnu_expr, true);
6515
6516 inner = skip_simple_constant_arithmetic (inner);
6517
6518 if (handled_component_p (inner))
6519 inner = get_inner_constant_reference (inner);
6520
6521 expr_variable_p
6522 = !(inner
6523 && TREE_CODE (inner) == VAR_DECL
6524 && (TREE_READONLY (inner) || DECL_READONLY_ONCE_ELAB (inner)));
6525 }
6526
6527 /* We only need to use the variable if we are in a global context since GCC
6528 can do the right thing in the local case. However, when not optimizing,
6529 use it for bounds of loop iteration scheme to avoid code duplication. */
6530 use_variable = expr_variable_p
6531 && (expr_global_p
6532 || (!optimize
6533 && definition
6534 && Is_Itype (gnat_entity)
6535 && Nkind (Associated_Node_For_Itype (gnat_entity))
6536 == N_Loop_Parameter_Specification));
6537
6538 /* Now create it, possibly only for debugging purposes. */
6539 if (use_variable || need_debug)
6540 {
6541 /* The following variable creation can happen when processing the body
6542 of subprograms that are defined out of the extended main unit and
6543 inlined. In this case, we are not at the global scope, and thus the
6544 new variable must not be tagged "external", as we used to do here as
6545 soon as DEFINITION was false. */
6546 tree gnu_decl
6547 = create_var_decl (create_concat_name (gnat_entity, s), NULL_TREE,
6548 TREE_TYPE (gnu_expr), gnu_expr, true,
6549 expr_public_p, !definition && expr_global_p,
6550 expr_global_p, false, true, need_debug,
6551 NULL, gnat_entity);
6552
6553 /* Using this variable at debug time (if need_debug is true) requires a
6554 proper location. The back-end will compute a location for this
6555 variable only if the variable is used by the generated code.
6556 Returning the variable ensures the caller will use it in generated
6557 code. Note that there is no need for a location if the debug info
6558 contains an integer constant.
6559 TODO: when the encoding-based debug scheme is dropped, move this
6560 condition to the top-level IF block: we will not need to create a
6561 variable anymore in such cases, then. */
6562 if (use_variable || (need_debug && !TREE_CONSTANT (gnu_expr)))
6563 return gnu_decl;
6564 }
6565
6566 return expr_variable_p ? gnat_save_expr (gnu_expr) : gnu_expr;
6567 }
6568
6569 /* Similar, but take an alignment factor and make it explicit in the tree. */
6570
6571 static tree
elaborate_expression_2(tree gnu_expr,Entity_Id gnat_entity,const char * s,bool definition,bool need_debug,unsigned int align)6572 elaborate_expression_2 (tree gnu_expr, Entity_Id gnat_entity, const char *s,
6573 bool definition, bool need_debug, unsigned int align)
6574 {
6575 tree unit_align = size_int (align / BITS_PER_UNIT);
6576 return
6577 size_binop (MULT_EXPR,
6578 elaborate_expression_1 (size_binop (EXACT_DIV_EXPR,
6579 gnu_expr,
6580 unit_align),
6581 gnat_entity, s, definition,
6582 need_debug),
6583 unit_align);
6584 }
6585
6586 /* Structure to hold internal data for elaborate_reference. */
6587
6588 struct er_data
6589 {
6590 Entity_Id entity;
6591 bool definition;
6592 unsigned int n;
6593 };
6594
6595 /* Wrapper function around elaborate_expression_1 for elaborate_reference. */
6596
6597 static tree
elaborate_reference_1(tree ref,void * data)6598 elaborate_reference_1 (tree ref, void *data)
6599 {
6600 struct er_data *er = (struct er_data *)data;
6601 char suffix[16];
6602
6603 /* This is what elaborate_expression_1 does if NEED_DEBUG is false. */
6604 if (TREE_CONSTANT (ref))
6605 return ref;
6606
6607 /* If this is a COMPONENT_REF of a fat pointer, elaborate the entire fat
6608 pointer. This may be more efficient, but will also allow us to more
6609 easily find the match for the PLACEHOLDER_EXPR. */
6610 if (TREE_CODE (ref) == COMPONENT_REF
6611 && TYPE_IS_FAT_POINTER_P (TREE_TYPE (TREE_OPERAND (ref, 0))))
6612 return build3 (COMPONENT_REF, TREE_TYPE (ref),
6613 elaborate_reference_1 (TREE_OPERAND (ref, 0), data),
6614 TREE_OPERAND (ref, 1), NULL_TREE);
6615
6616 sprintf (suffix, "EXP%d", ++er->n);
6617 return
6618 elaborate_expression_1 (ref, er->entity, suffix, er->definition, false);
6619 }
6620
6621 /* Elaborate the reference REF to be used as renamed object for GNAT_ENTITY.
6622 DEFINITION is true if this is done for a definition of GNAT_ENTITY and
6623 INIT is set to the first arm of a COMPOUND_EXPR present in REF, if any. */
6624
6625 static tree
elaborate_reference(tree ref,Entity_Id gnat_entity,bool definition,tree * init)6626 elaborate_reference (tree ref, Entity_Id gnat_entity, bool definition,
6627 tree *init)
6628 {
6629 struct er_data er = { gnat_entity, definition, 0 };
6630 return gnat_rewrite_reference (ref, elaborate_reference_1, &er, init);
6631 }
6632
6633 /* Given a GNU tree and a GNAT list of choices, generate an expression to test
6634 the value passed against the list of choices. */
6635
6636 static tree
choices_to_gnu(tree gnu_operand,Node_Id gnat_choices)6637 choices_to_gnu (tree gnu_operand, Node_Id gnat_choices)
6638 {
6639 tree gnu_result = boolean_false_node, gnu_type;
6640
6641 gnu_operand = maybe_character_value (gnu_operand);
6642 gnu_type = TREE_TYPE (gnu_operand);
6643
6644 for (Node_Id gnat_choice = First (gnat_choices);
6645 Present (gnat_choice);
6646 gnat_choice = Next (gnat_choice))
6647 {
6648 tree gnu_low = NULL_TREE, gnu_high = NULL_TREE;
6649 tree gnu_test;
6650
6651 switch (Nkind (gnat_choice))
6652 {
6653 case N_Range:
6654 gnu_low = gnat_to_gnu (Low_Bound (gnat_choice));
6655 gnu_high = gnat_to_gnu (High_Bound (gnat_choice));
6656 break;
6657
6658 case N_Subtype_Indication:
6659 gnu_low = gnat_to_gnu (Low_Bound (Range_Expression
6660 (Constraint (gnat_choice))));
6661 gnu_high = gnat_to_gnu (High_Bound (Range_Expression
6662 (Constraint (gnat_choice))));
6663 break;
6664
6665 case N_Identifier:
6666 case N_Expanded_Name:
6667 /* This represents either a subtype range or a static value of
6668 some kind; Ekind says which. */
6669 if (Is_Type (Entity (gnat_choice)))
6670 {
6671 tree gnu_type = get_unpadded_type (Entity (gnat_choice));
6672
6673 gnu_low = TYPE_MIN_VALUE (gnu_type);
6674 gnu_high = TYPE_MAX_VALUE (gnu_type);
6675 break;
6676 }
6677
6678 /* ... fall through ... */
6679
6680 case N_Character_Literal:
6681 case N_Integer_Literal:
6682 gnu_low = gnat_to_gnu (gnat_choice);
6683 break;
6684
6685 case N_Others_Choice:
6686 break;
6687
6688 default:
6689 gcc_unreachable ();
6690 }
6691
6692 /* Everything should be folded into constants at this point. */
6693 gcc_assert (!gnu_low || TREE_CODE (gnu_low) == INTEGER_CST);
6694 gcc_assert (!gnu_high || TREE_CODE (gnu_high) == INTEGER_CST);
6695
6696 if (gnu_low && TREE_TYPE (gnu_low) != gnu_type)
6697 gnu_low = convert (gnu_type, gnu_low);
6698 if (gnu_high && TREE_TYPE (gnu_high) != gnu_type)
6699 gnu_high = convert (gnu_type, gnu_high);
6700
6701 if (gnu_low && gnu_high)
6702 gnu_test
6703 = build_binary_op (TRUTH_ANDIF_EXPR, boolean_type_node,
6704 build_binary_op (GE_EXPR, boolean_type_node,
6705 gnu_operand, gnu_low, true),
6706 build_binary_op (LE_EXPR, boolean_type_node,
6707 gnu_operand, gnu_high, true),
6708 true);
6709 else if (gnu_low)
6710 gnu_test
6711 = build_binary_op (EQ_EXPR, boolean_type_node, gnu_operand, gnu_low,
6712 true);
6713 else
6714 gnu_test = boolean_true_node;
6715
6716 if (gnu_result == boolean_false_node)
6717 gnu_result = gnu_test;
6718 else
6719 gnu_result
6720 = build_binary_op (TRUTH_ORIF_EXPR, boolean_type_node, gnu_result,
6721 gnu_test, true);
6722 }
6723
6724 return gnu_result;
6725 }
6726
6727 /* Adjust PACKED setting as passed to gnat_to_gnu_field for a field of
6728 type FIELD_TYPE to be placed in RECORD_TYPE. Return the result. */
6729
6730 static int
adjust_packed(tree field_type,tree record_type,int packed)6731 adjust_packed (tree field_type, tree record_type, int packed)
6732 {
6733 /* If the field contains an item of variable size, we cannot pack it
6734 because we cannot create temporaries of non-fixed size in case
6735 we need to take the address of the field. See addressable_p and
6736 the notes on the addressability issues for further details. */
6737 if (type_has_variable_size (field_type))
6738 return 0;
6739
6740 /* In the other cases, we can honor the packing. */
6741 if (packed)
6742 return packed;
6743
6744 /* If the alignment of the record is specified and the field type
6745 is over-aligned, request Storage_Unit alignment for the field. */
6746 if (TYPE_ALIGN (record_type)
6747 && TYPE_ALIGN (field_type) > TYPE_ALIGN (record_type))
6748 return -1;
6749
6750 /* Likewise if the maximum alignment of the record is specified. */
6751 if (TYPE_MAX_ALIGN (record_type)
6752 && TYPE_ALIGN (field_type) > TYPE_MAX_ALIGN (record_type))
6753 return -1;
6754
6755 return 0;
6756 }
6757
6758 /* Return a GCC tree for a field corresponding to GNAT_FIELD to be
6759 placed in GNU_RECORD_TYPE.
6760
6761 PACKED is 1 if the enclosing record is packed or -1 if the enclosing
6762 record has Component_Alignment of Storage_Unit.
6763
6764 DEFINITION is true if this field is for a record being defined.
6765
6766 DEBUG_INFO_P is true if we need to write debug information for types
6767 that we may create in the process. */
6768
6769 static tree
gnat_to_gnu_field(Entity_Id gnat_field,tree gnu_record_type,int packed,bool definition,bool debug_info_p)6770 gnat_to_gnu_field (Entity_Id gnat_field, tree gnu_record_type, int packed,
6771 bool definition, bool debug_info_p)
6772 {
6773 const Entity_Id gnat_record_type = Underlying_Type (Scope (gnat_field));
6774 const Entity_Id gnat_field_type = Etype (gnat_field);
6775 const bool is_atomic
6776 = (Is_Atomic_Or_VFA (gnat_field) || Is_Atomic_Or_VFA (gnat_field_type));
6777 const bool is_aliased = Is_Aliased (gnat_field);
6778 const bool is_independent
6779 = (Is_Independent (gnat_field) || Is_Independent (gnat_field_type));
6780 const bool is_volatile
6781 = (Treat_As_Volatile (gnat_field) || Treat_As_Volatile (gnat_field_type));
6782 const bool is_strict_alignment = Strict_Alignment (gnat_field_type);
6783 /* We used to consider that volatile fields also require strict alignment,
6784 but that was an interpolation and would cause us to reject a pragma
6785 volatile on a packed record type containing boolean components, while
6786 there is no basis to do so in the RM. In such cases, the writes will
6787 involve load-modify-store sequences, but that's OK for volatile. The
6788 only constraint is the implementation advice whereby only the bits of
6789 the components should be accessed if they both start and end on byte
6790 boundaries, but that should be guaranteed by the GCC memory model. */
6791 const bool needs_strict_alignment
6792 = (is_atomic || is_aliased || is_independent || is_strict_alignment);
6793 tree gnu_field_type = gnat_to_gnu_type (gnat_field_type);
6794 tree gnu_field_id = get_entity_name (gnat_field);
6795 tree gnu_field, gnu_size, gnu_pos;
6796
6797 /* If this field requires strict alignment, we cannot pack it because
6798 it would very likely be under-aligned in the record. */
6799 if (needs_strict_alignment)
6800 packed = 0;
6801 else
6802 packed = adjust_packed (gnu_field_type, gnu_record_type, packed);
6803
6804 /* If a size is specified, use it. Otherwise, if the record type is packed,
6805 use the official RM size. See "Handling of Type'Size Values" in Einfo
6806 for further details. */
6807 if (Known_Esize (gnat_field))
6808 gnu_size = validate_size (Esize (gnat_field), gnu_field_type,
6809 gnat_field, FIELD_DECL, false, true);
6810 else if (packed == 1)
6811 gnu_size = validate_size (RM_Size (gnat_field_type), gnu_field_type,
6812 gnat_field, FIELD_DECL, false, true);
6813 else
6814 gnu_size = NULL_TREE;
6815
6816 /* If we have a specified size that is smaller than that of the field's type,
6817 or a position is specified, and the field's type is a record that doesn't
6818 require strict alignment, see if we can get either an integral mode form
6819 of the type or a smaller form. If we can, show a size was specified for
6820 the field if there wasn't one already, so we know to make this a bitfield
6821 and avoid making things wider.
6822
6823 Changing to an integral mode form is useful when the record is packed as
6824 we can then place the field at a non-byte-aligned position and so achieve
6825 tighter packing. This is in addition required if the field shares a byte
6826 with another field and the front-end lets the back-end handle the access
6827 to the field, because GCC cannot handle non-byte-aligned BLKmode fields.
6828
6829 Changing to a smaller form is required if the specified size is smaller
6830 than that of the field's type and the type contains sub-fields that are
6831 padded, in order to avoid generating accesses to these sub-fields that
6832 are wider than the field.
6833
6834 We avoid the transformation if it is not required or potentially useful,
6835 as it might entail an increase of the field's alignment and have ripple
6836 effects on the outer record type. A typical case is a field known to be
6837 byte-aligned and not to share a byte with another field. */
6838 if (!needs_strict_alignment
6839 && RECORD_OR_UNION_TYPE_P (gnu_field_type)
6840 && !TYPE_FAT_POINTER_P (gnu_field_type)
6841 && tree_fits_uhwi_p (TYPE_SIZE (gnu_field_type))
6842 && (packed == 1
6843 || (gnu_size
6844 && (tree_int_cst_lt (gnu_size, TYPE_SIZE (gnu_field_type))
6845 || (Present (Component_Clause (gnat_field))
6846 && !(UI_To_Int (Component_Bit_Offset (gnat_field))
6847 % BITS_PER_UNIT == 0
6848 && value_factor_p (gnu_size, BITS_PER_UNIT)))))))
6849 {
6850 tree gnu_packable_type = make_packable_type (gnu_field_type, true);
6851 if (gnu_packable_type != gnu_field_type)
6852 {
6853 gnu_field_type = gnu_packable_type;
6854 if (!gnu_size)
6855 gnu_size = rm_size (gnu_field_type);
6856 }
6857 }
6858
6859 if (Is_Atomic_Or_VFA (gnat_field))
6860 {
6861 const unsigned int align
6862 = promote_object_alignment (gnu_field_type, gnat_field);
6863 if (align > 0)
6864 gnu_field_type
6865 = maybe_pad_type (gnu_field_type, NULL_TREE, align, gnat_field,
6866 false, false, definition, true);
6867 check_ok_for_atomic_type (gnu_field_type, gnat_field, false);
6868 }
6869
6870 if (Present (Component_Clause (gnat_field)))
6871 {
6872 Node_Id gnat_clause = Component_Clause (gnat_field);
6873 Entity_Id gnat_parent = Parent_Subtype (gnat_record_type);
6874
6875 gnu_pos = UI_To_gnu (Component_Bit_Offset (gnat_field), bitsizetype);
6876 gnu_size = validate_size (Esize (gnat_field), gnu_field_type,
6877 gnat_field, FIELD_DECL, false, true);
6878
6879 /* Ensure the position does not overlap with the parent subtype, if there
6880 is one. This test is omitted if the parent of the tagged type has a
6881 full rep clause since, in this case, component clauses are allowed to
6882 overlay the space allocated for the parent type and the front-end has
6883 checked that there are no overlapping components. */
6884 if (Present (gnat_parent) && !Is_Fully_Repped_Tagged_Type (gnat_parent))
6885 {
6886 tree gnu_parent = gnat_to_gnu_type (gnat_parent);
6887
6888 if (TREE_CODE (TYPE_SIZE (gnu_parent)) == INTEGER_CST
6889 && tree_int_cst_lt (gnu_pos, TYPE_SIZE (gnu_parent)))
6890 post_error_ne_tree
6891 ("offset of& must be beyond parent{, minimum allowed is ^}",
6892 Position (gnat_clause), gnat_field, TYPE_SIZE_UNIT (gnu_parent));
6893 }
6894
6895 /* If this field needs strict alignment, make sure that the record is
6896 sufficiently aligned and that the position and size are consistent
6897 with the type. But don't do it if we are just annotating types and
6898 the field's type is tagged, since tagged types aren't fully laid out
6899 in this mode. Also, note that atomic implies volatile so the inner
6900 test sequences ordering is significant here. */
6901 if (needs_strict_alignment
6902 && !(type_annotate_only && Is_Tagged_Type (gnat_field_type)))
6903 {
6904 const unsigned int type_align = TYPE_ALIGN (gnu_field_type);
6905
6906 if (TYPE_ALIGN (gnu_record_type)
6907 && TYPE_ALIGN (gnu_record_type) < type_align)
6908 SET_TYPE_ALIGN (gnu_record_type, type_align);
6909
6910 /* If the position is not a multiple of the alignment of the type,
6911 then error out and reset the position. */
6912 if (!integer_zerop (size_binop (TRUNC_MOD_EXPR, gnu_pos,
6913 bitsize_int (type_align))))
6914 {
6915 const char *s;
6916
6917 if (is_atomic)
6918 s = "position of atomic field& must be multiple of ^ bits";
6919 else if (is_aliased)
6920 s = "position of aliased field& must be multiple of ^ bits";
6921 else if (is_independent)
6922 s = "position of independent field& must be multiple of ^ bits";
6923 else if (is_strict_alignment)
6924 s = "position of & with aliased or tagged part must be"
6925 " multiple of ^ bits";
6926 else
6927 gcc_unreachable ();
6928
6929 post_error_ne_num (s, First_Bit (gnat_clause), gnat_field,
6930 type_align);
6931 gnu_pos = NULL_TREE;
6932 }
6933
6934 if (gnu_size)
6935 {
6936 tree gnu_type_size = TYPE_SIZE (gnu_field_type);
6937 const int cmp = tree_int_cst_compare (gnu_size, gnu_type_size);
6938
6939 /* If the size is lower than that of the type, or greater for
6940 atomic and aliased, then error out and reset the size. */
6941 if (cmp < 0 || (cmp > 0 && (is_atomic || is_aliased)))
6942 {
6943 const char *s;
6944
6945 if (is_atomic)
6946 s = "size of atomic field& must be ^ bits";
6947 else if (is_aliased)
6948 s = "size of aliased field& must be ^ bits";
6949 else if (is_independent)
6950 s = "size of independent field& must be at least ^ bits";
6951 else if (is_strict_alignment)
6952 s = "size of & with aliased or tagged part must be"
6953 " at least ^ bits";
6954 else
6955 gcc_unreachable ();
6956
6957 post_error_ne_tree (s, Last_Bit (gnat_clause), gnat_field,
6958 gnu_type_size);
6959 gnu_size = NULL_TREE;
6960 }
6961
6962 /* Likewise if the size is not a multiple of a byte, */
6963 else if (!integer_zerop (size_binop (TRUNC_MOD_EXPR, gnu_size,
6964 bitsize_unit_node)))
6965 {
6966 const char *s;
6967
6968 if (is_independent)
6969 s = "size of independent field& must be multiple of"
6970 " Storage_Unit";
6971 else if (is_strict_alignment)
6972 s = "size of & with aliased or tagged part must be"
6973 " multiple of Storage_Unit";
6974 else
6975 gcc_unreachable ();
6976
6977 post_error_ne (s, Last_Bit (gnat_clause), gnat_field);
6978 gnu_size = NULL_TREE;
6979 }
6980 }
6981 }
6982 }
6983
6984 /* If the record has rep clauses and this is the tag field, make a rep
6985 clause for it as well. */
6986 else if (Has_Specified_Layout (gnat_record_type)
6987 && Chars (gnat_field) == Name_uTag)
6988 {
6989 gnu_pos = bitsize_zero_node;
6990 gnu_size = TYPE_SIZE (gnu_field_type);
6991 }
6992
6993 else
6994 {
6995 gnu_pos = NULL_TREE;
6996
6997 /* If we are packing the record and the field is BLKmode, round the
6998 size up to a byte boundary. */
6999 if (packed && TYPE_MODE (gnu_field_type) == BLKmode && gnu_size)
7000 gnu_size = round_up (gnu_size, BITS_PER_UNIT);
7001 }
7002
7003 /* We need to make the size the maximum for the type if it is
7004 self-referential and an unconstrained type. In that case, we can't
7005 pack the field since we can't make a copy to align it. */
7006 if (TREE_CODE (gnu_field_type) == RECORD_TYPE
7007 && !gnu_size
7008 && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_field_type))
7009 && !Is_Constrained (Underlying_Type (gnat_field_type)))
7010 {
7011 gnu_size = max_size (TYPE_SIZE (gnu_field_type), true);
7012 packed = 0;
7013 }
7014
7015 /* If a size is specified, adjust the field's type to it. */
7016 if (gnu_size)
7017 {
7018 tree orig_field_type;
7019
7020 /* If the field's type is justified modular, we would need to remove
7021 the wrapper to (better) meet the layout requirements. However we
7022 can do so only if the field is not aliased to preserve the unique
7023 layout, if it has the same storage order as the enclosing record
7024 and if the prescribed size is not greater than that of the packed
7025 array to preserve the justification. */
7026 if (!needs_strict_alignment
7027 && TREE_CODE (gnu_field_type) == RECORD_TYPE
7028 && TYPE_JUSTIFIED_MODULAR_P (gnu_field_type)
7029 && TYPE_REVERSE_STORAGE_ORDER (gnu_field_type)
7030 == Reverse_Storage_Order (gnat_record_type)
7031 && tree_int_cst_compare (gnu_size, TYPE_ADA_SIZE (gnu_field_type))
7032 <= 0)
7033 gnu_field_type = TREE_TYPE (TYPE_FIELDS (gnu_field_type));
7034
7035 /* Similarly if the field's type is a misaligned integral type, but
7036 there is no restriction on the size as there is no justification. */
7037 if (!needs_strict_alignment
7038 && TYPE_IS_PADDING_P (gnu_field_type)
7039 && INTEGRAL_TYPE_P (TREE_TYPE (TYPE_FIELDS (gnu_field_type))))
7040 gnu_field_type = TREE_TYPE (TYPE_FIELDS (gnu_field_type));
7041
7042 gnu_field_type
7043 = make_type_from_size (gnu_field_type, gnu_size,
7044 Has_Biased_Representation (gnat_field));
7045
7046 orig_field_type = gnu_field_type;
7047 gnu_field_type = maybe_pad_type (gnu_field_type, gnu_size, 0, gnat_field,
7048 false, false, definition, true);
7049
7050 /* If a padding record was made, declare it now since it will never be
7051 declared otherwise. This is necessary to ensure that its subtrees
7052 are properly marked. */
7053 if (gnu_field_type != orig_field_type
7054 && !DECL_P (TYPE_NAME (gnu_field_type)))
7055 create_type_decl (TYPE_NAME (gnu_field_type), gnu_field_type, true,
7056 debug_info_p, gnat_field);
7057 }
7058
7059 /* Otherwise (or if there was an error), don't specify a position. */
7060 else
7061 gnu_pos = NULL_TREE;
7062
7063 /* If the field's type is a padded type made for a scalar field of a record
7064 type with reverse storage order, we need to propagate the reverse storage
7065 order to the padding type since it is the innermost enclosing aggregate
7066 type around the scalar. */
7067 if (TYPE_IS_PADDING_P (gnu_field_type)
7068 && TYPE_REVERSE_STORAGE_ORDER (gnu_record_type)
7069 && Is_Scalar_Type (gnat_field_type))
7070 gnu_field_type = set_reverse_storage_order_on_pad_type (gnu_field_type);
7071
7072 gcc_assert (TREE_CODE (gnu_field_type) != RECORD_TYPE
7073 || !TYPE_CONTAINS_TEMPLATE_P (gnu_field_type));
7074
7075 /* Now create the decl for the field. */
7076 gnu_field
7077 = create_field_decl (gnu_field_id, gnu_field_type, gnu_record_type,
7078 gnu_size, gnu_pos, packed, is_aliased);
7079 Sloc_to_locus (Sloc (gnat_field), &DECL_SOURCE_LOCATION (gnu_field));
7080 DECL_ALIASED_P (gnu_field) = is_aliased;
7081 TREE_SIDE_EFFECTS (gnu_field) = TREE_THIS_VOLATILE (gnu_field) = is_volatile;
7082
7083 if (Ekind (gnat_field) == E_Discriminant)
7084 {
7085 DECL_INVARIANT_P (gnu_field)
7086 = No (Discriminant_Default_Value (gnat_field));
7087 DECL_DISCRIMINANT_NUMBER (gnu_field)
7088 = UI_To_gnu (Discriminant_Number (gnat_field), sizetype);
7089 }
7090
7091 return gnu_field;
7092 }
7093
7094 /* Return true if at least one member of COMPONENT_LIST needs strict
7095 alignment. */
7096
7097 static bool
components_need_strict_alignment(Node_Id component_list)7098 components_need_strict_alignment (Node_Id component_list)
7099 {
7100 Node_Id component_decl;
7101
7102 for (component_decl = First_Non_Pragma (Component_Items (component_list));
7103 Present (component_decl);
7104 component_decl = Next_Non_Pragma (component_decl))
7105 {
7106 Entity_Id gnat_field = Defining_Entity (component_decl);
7107
7108 if (Is_Aliased (gnat_field))
7109 return true;
7110
7111 if (Strict_Alignment (Etype (gnat_field)))
7112 return true;
7113 }
7114
7115 return false;
7116 }
7117
7118 /* Return true if TYPE is a type with variable size or a padding type with a
7119 field of variable size or a record that has a field with such a type. */
7120
7121 static bool
type_has_variable_size(tree type)7122 type_has_variable_size (tree type)
7123 {
7124 tree field;
7125
7126 if (!TREE_CONSTANT (TYPE_SIZE (type)))
7127 return true;
7128
7129 if (TYPE_IS_PADDING_P (type)
7130 && !TREE_CONSTANT (DECL_SIZE (TYPE_FIELDS (type))))
7131 return true;
7132
7133 if (!RECORD_OR_UNION_TYPE_P (type))
7134 return false;
7135
7136 for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
7137 if (type_has_variable_size (TREE_TYPE (field)))
7138 return true;
7139
7140 return false;
7141 }
7142
7143 /* Return true if FIELD is an artificial field. */
7144
7145 static bool
field_is_artificial(tree field)7146 field_is_artificial (tree field)
7147 {
7148 /* These fields are generated by the front-end proper. */
7149 if (IDENTIFIER_POINTER (DECL_NAME (field)) [0] == '_')
7150 return true;
7151
7152 /* These fields are generated by gigi. */
7153 if (DECL_INTERNAL_P (field))
7154 return true;
7155
7156 return false;
7157 }
7158
7159 /* Return true if FIELD is a non-artificial field with self-referential
7160 size. */
7161
7162 static bool
field_has_self_size(tree field)7163 field_has_self_size (tree field)
7164 {
7165 if (field_is_artificial (field))
7166 return false;
7167
7168 if (DECL_SIZE (field) && TREE_CODE (DECL_SIZE (field)) == INTEGER_CST)
7169 return false;
7170
7171 return CONTAINS_PLACEHOLDER_P (TYPE_SIZE (TREE_TYPE (field)));
7172 }
7173
7174 /* Return true if FIELD is a non-artificial field with variable size. */
7175
7176 static bool
field_has_variable_size(tree field)7177 field_has_variable_size (tree field)
7178 {
7179 if (field_is_artificial (field))
7180 return false;
7181
7182 if (DECL_SIZE (field) && TREE_CODE (DECL_SIZE (field)) == INTEGER_CST)
7183 return false;
7184
7185 return TREE_CODE (TYPE_SIZE (TREE_TYPE (field))) != INTEGER_CST;
7186 }
7187
7188 /* qsort comparer for the bit positions of two record components. */
7189
7190 static int
compare_field_bitpos(const PTR rt1,const PTR rt2)7191 compare_field_bitpos (const PTR rt1, const PTR rt2)
7192 {
7193 const_tree const field1 = * (const_tree const *) rt1;
7194 const_tree const field2 = * (const_tree const *) rt2;
7195 const int ret
7196 = tree_int_cst_compare (bit_position (field1), bit_position (field2));
7197
7198 return ret ? ret : (int) (DECL_UID (field1) - DECL_UID (field2));
7199 }
7200
7201 /* Reverse function from gnat_to_gnu_field: return the GNAT field present in
7202 either GNAT_COMPONENT_LIST or the discriminants of GNAT_RECORD_TYPE, and
7203 corresponding to the GNU tree GNU_FIELD. */
7204
7205 static Entity_Id
gnu_field_to_gnat(tree gnu_field,Node_Id gnat_component_list,Entity_Id gnat_record_type)7206 gnu_field_to_gnat (tree gnu_field, Node_Id gnat_component_list,
7207 Entity_Id gnat_record_type)
7208 {
7209 Entity_Id gnat_component_decl, gnat_field;
7210
7211 if (Present (Component_Items (gnat_component_list)))
7212 for (gnat_component_decl
7213 = First_Non_Pragma (Component_Items (gnat_component_list));
7214 Present (gnat_component_decl);
7215 gnat_component_decl = Next_Non_Pragma (gnat_component_decl))
7216 {
7217 gnat_field = Defining_Entity (gnat_component_decl);
7218 if (gnat_to_gnu_field_decl (gnat_field) == gnu_field)
7219 return gnat_field;
7220 }
7221
7222 if (Has_Discriminants (gnat_record_type))
7223 for (gnat_field = First_Stored_Discriminant (gnat_record_type);
7224 Present (gnat_field);
7225 gnat_field = Next_Stored_Discriminant (gnat_field))
7226 if (gnat_to_gnu_field_decl (gnat_field) == gnu_field)
7227 return gnat_field;
7228
7229 return Empty;
7230 }
7231
7232 /* Issue a warning for the problematic placement of GNU_FIELD present in
7233 either GNAT_COMPONENT_LIST or the discriminants of GNAT_RECORD_TYPE.
7234 IN_VARIANT is true if GNAT_COMPONENT_LIST is the list of a variant.
7235 DO_REORDER is true if fields of GNAT_RECORD_TYPE are being reordered. */
7236
7237 static void
warn_on_field_placement(tree gnu_field,Node_Id gnat_component_list,Entity_Id gnat_record_type,bool in_variant,bool do_reorder)7238 warn_on_field_placement (tree gnu_field, Node_Id gnat_component_list,
7239 Entity_Id gnat_record_type, bool in_variant,
7240 bool do_reorder)
7241 {
7242 if (!Comes_From_Source (gnat_record_type))
7243 return;
7244
7245 Entity_Id gnat_field
7246 = gnu_field_to_gnat (gnu_field, gnat_component_list, gnat_record_type);
7247 gcc_assert (Present (gnat_field));
7248
7249 const char *msg1
7250 = in_variant
7251 ? "?variant layout may cause performance issues"
7252 : "?record layout may cause performance issues";
7253 const char *msg2
7254 = Ekind (gnat_field) == E_Discriminant
7255 ? "?discriminant & whose length is not multiple of a byte"
7256 : field_has_self_size (gnu_field)
7257 ? "?component & whose length depends on a discriminant"
7258 : field_has_variable_size (gnu_field)
7259 ? "?component & whose length is not fixed"
7260 : "?component & whose length is not multiple of a byte";
7261 const char *msg3
7262 = do_reorder
7263 ? "?comes too early and was moved down"
7264 : "?comes too early and ought to be moved down";
7265
7266 post_error (msg1, gnat_field);
7267 post_error_ne (msg2, gnat_field, gnat_field);
7268 post_error (msg3, gnat_field);
7269 }
7270
7271 /* Likewise but for every field present on GNU_FIELD_LIST. */
7272
7273 static void
warn_on_list_placement(tree gnu_field_list,Node_Id gnat_component_list,Entity_Id gnat_record_type,bool in_variant,bool do_reorder)7274 warn_on_list_placement (tree gnu_field_list, Node_Id gnat_component_list,
7275 Entity_Id gnat_record_type, bool in_variant,
7276 bool do_reorder)
7277 {
7278 for (tree gnu_tmp = gnu_field_list; gnu_tmp; gnu_tmp = DECL_CHAIN (gnu_tmp))
7279 warn_on_field_placement (gnu_tmp, gnat_component_list, gnat_record_type,
7280 in_variant, do_reorder);
7281 }
7282
7283 /* Structure holding information for a given variant. */
7284 typedef struct vinfo
7285 {
7286 /* The record type of the variant. */
7287 tree type;
7288
7289 /* The name of the variant. */
7290 tree name;
7291
7292 /* The qualifier of the variant. */
7293 tree qual;
7294
7295 /* Whether the variant has a rep clause. */
7296 bool has_rep;
7297
7298 /* Whether the variant is packed. */
7299 bool packed;
7300
7301 } vinfo_t;
7302
7303 /* Translate and chain GNAT_COMPONENT_LIST present in GNAT_RECORD_TYPE to
7304 GNU_FIELD_LIST, set the result as the field list of GNU_RECORD_TYPE and
7305 finish it up. Return true if GNU_RECORD_TYPE has a rep clause that affects
7306 the layout (see below). When called from gnat_to_gnu_entity during the
7307 processing of a record definition, the GCC node for the parent, if any,
7308 will be the single field of GNU_RECORD_TYPE and the GCC nodes for the
7309 discriminants will be on GNU_FIELD_LIST. The other call to this function
7310 is a recursive call for the component list of a variant and, in this case,
7311 GNU_FIELD_LIST is empty.
7312
7313 PACKED is 1 if this is for a packed record or -1 if this is for a record
7314 with Component_Alignment of Storage_Unit.
7315
7316 DEFINITION is true if we are defining this record type.
7317
7318 CANCEL_ALIGNMENT is true if the alignment should be zeroed before laying
7319 out the record. This means the alignment only serves to force fields to
7320 be bitfields, but not to require the record to be that aligned. This is
7321 used for variants.
7322
7323 ALL_REP is true if a rep clause is present for all the fields.
7324
7325 UNCHECKED_UNION is true if we are building this type for a record with a
7326 Pragma Unchecked_Union.
7327
7328 ARTIFICIAL is true if this is a type that was generated by the compiler.
7329
7330 DEBUG_INFO is true if we need to write debug information about the type.
7331
7332 MAYBE_UNUSED is true if this type may be unused in the end; this doesn't
7333 mean that its contents may be unused as well, only the container itself.
7334
7335 FIRST_FREE_POS, if nonzero, is the first (lowest) free field position in
7336 the outer record type down to this variant level. It is nonzero only if
7337 all the fields down to this level have a rep clause and ALL_REP is false.
7338
7339 P_GNU_REP_LIST, if nonzero, is a pointer to a list to which each field
7340 with a rep clause is to be added; in this case, that is all that should
7341 be done with such fields and the return value will be false. */
7342
7343 static bool
components_to_record(Node_Id gnat_component_list,Entity_Id gnat_record_type,tree gnu_field_list,tree gnu_record_type,int packed,bool definition,bool cancel_alignment,bool all_rep,bool unchecked_union,bool artificial,bool debug_info,bool maybe_unused,tree first_free_pos,tree * p_gnu_rep_list)7344 components_to_record (Node_Id gnat_component_list, Entity_Id gnat_record_type,
7345 tree gnu_field_list, tree gnu_record_type, int packed,
7346 bool definition, bool cancel_alignment, bool all_rep,
7347 bool unchecked_union, bool artificial, bool debug_info,
7348 bool maybe_unused, tree first_free_pos,
7349 tree *p_gnu_rep_list)
7350 {
7351 const bool needs_xv_encodings
7352 = debug_info && gnat_encodings != DWARF_GNAT_ENCODINGS_MINIMAL;
7353 bool all_rep_and_size = all_rep && TYPE_SIZE (gnu_record_type);
7354 bool variants_have_rep = all_rep;
7355 bool layout_with_rep = false;
7356 bool has_self_field = false;
7357 bool has_aliased_after_self_field = false;
7358 Entity_Id gnat_component_decl, gnat_variant_part;
7359 tree gnu_field, gnu_next, gnu_last;
7360 tree gnu_variant_part = NULL_TREE;
7361 tree gnu_rep_list = NULL_TREE;
7362
7363 /* For each component referenced in a component declaration create a GCC
7364 field and add it to the list, skipping pragmas in the GNAT list. */
7365 gnu_last = tree_last (gnu_field_list);
7366 if (Present (Component_Items (gnat_component_list)))
7367 for (gnat_component_decl
7368 = First_Non_Pragma (Component_Items (gnat_component_list));
7369 Present (gnat_component_decl);
7370 gnat_component_decl = Next_Non_Pragma (gnat_component_decl))
7371 {
7372 Entity_Id gnat_field = Defining_Entity (gnat_component_decl);
7373 Name_Id gnat_name = Chars (gnat_field);
7374
7375 /* If present, the _Parent field must have been created as the single
7376 field of the record type. Put it before any other fields. */
7377 if (gnat_name == Name_uParent)
7378 {
7379 gnu_field = TYPE_FIELDS (gnu_record_type);
7380 gnu_field_list = chainon (gnu_field_list, gnu_field);
7381 }
7382 else
7383 {
7384 gnu_field = gnat_to_gnu_field (gnat_field, gnu_record_type, packed,
7385 definition, debug_info);
7386
7387 /* If this is the _Tag field, put it before any other fields. */
7388 if (gnat_name == Name_uTag)
7389 gnu_field_list = chainon (gnu_field_list, gnu_field);
7390
7391 /* If this is the _Controller field, put it before the other
7392 fields except for the _Tag or _Parent field. */
7393 else if (gnat_name == Name_uController && gnu_last)
7394 {
7395 DECL_CHAIN (gnu_field) = DECL_CHAIN (gnu_last);
7396 DECL_CHAIN (gnu_last) = gnu_field;
7397 }
7398
7399 /* If this is a regular field, put it after the other fields. */
7400 else
7401 {
7402 DECL_CHAIN (gnu_field) = gnu_field_list;
7403 gnu_field_list = gnu_field;
7404 if (!gnu_last)
7405 gnu_last = gnu_field;
7406
7407 /* And record information for the final layout. */
7408 if (field_has_self_size (gnu_field))
7409 has_self_field = true;
7410 else if (has_self_field && DECL_ALIASED_P (gnu_field))
7411 has_aliased_after_self_field = true;
7412 }
7413 }
7414
7415 save_gnu_tree (gnat_field, gnu_field, false);
7416 }
7417
7418 /* At the end of the component list there may be a variant part. */
7419 gnat_variant_part = Variant_Part (gnat_component_list);
7420
7421 /* We create a QUAL_UNION_TYPE for the variant part since the variants are
7422 mutually exclusive and should go in the same memory. To do this we need
7423 to treat each variant as a record whose elements are created from the
7424 component list for the variant. So here we create the records from the
7425 lists for the variants and put them all into the QUAL_UNION_TYPE.
7426 If this is an Unchecked_Union, we make a UNION_TYPE instead or
7427 use GNU_RECORD_TYPE if there are no fields so far. */
7428 if (Present (gnat_variant_part))
7429 {
7430 Node_Id gnat_discr = Name (gnat_variant_part), variant;
7431 tree gnu_discr = gnat_to_gnu (gnat_discr);
7432 tree gnu_name = TYPE_IDENTIFIER (gnu_record_type);
7433 tree gnu_var_name
7434 = concat_name (get_identifier (Get_Name_String (Chars (gnat_discr))),
7435 "XVN");
7436 tree gnu_union_type, gnu_union_name;
7437 tree this_first_free_pos, gnu_variant_list = NULL_TREE;
7438 bool union_field_needs_strict_alignment = false;
7439 auto_vec <vinfo_t, 16> variant_types;
7440 vinfo_t *gnu_variant;
7441 unsigned int variants_align = 0;
7442 unsigned int i;
7443
7444 gnu_union_name
7445 = concat_name (gnu_name, IDENTIFIER_POINTER (gnu_var_name));
7446
7447 /* Reuse the enclosing union if this is an Unchecked_Union whose fields
7448 are all in the variant part, to match the layout of C unions. There
7449 is an associated check below. */
7450 if (TREE_CODE (gnu_record_type) == UNION_TYPE)
7451 gnu_union_type = gnu_record_type;
7452 else
7453 {
7454 gnu_union_type
7455 = make_node (unchecked_union ? UNION_TYPE : QUAL_UNION_TYPE);
7456
7457 TYPE_NAME (gnu_union_type) = gnu_union_name;
7458 SET_TYPE_ALIGN (gnu_union_type, 0);
7459 TYPE_PACKED (gnu_union_type) = TYPE_PACKED (gnu_record_type);
7460 TYPE_REVERSE_STORAGE_ORDER (gnu_union_type)
7461 = TYPE_REVERSE_STORAGE_ORDER (gnu_record_type);
7462 }
7463
7464 /* If all the fields down to this level have a rep clause, find out
7465 whether all the fields at this level also have one. If so, then
7466 compute the new first free position to be passed downward. */
7467 this_first_free_pos = first_free_pos;
7468 if (this_first_free_pos)
7469 {
7470 for (gnu_field = gnu_field_list;
7471 gnu_field;
7472 gnu_field = DECL_CHAIN (gnu_field))
7473 if (DECL_FIELD_OFFSET (gnu_field))
7474 {
7475 tree pos = bit_position (gnu_field);
7476 if (!tree_int_cst_lt (pos, this_first_free_pos))
7477 this_first_free_pos
7478 = size_binop (PLUS_EXPR, pos, DECL_SIZE (gnu_field));
7479 }
7480 else
7481 {
7482 this_first_free_pos = NULL_TREE;
7483 break;
7484 }
7485 }
7486
7487 /* We build the variants in two passes. The bulk of the work is done in
7488 the first pass, that is to say translating the GNAT nodes, building
7489 the container types and computing the associated properties. However
7490 we cannot finish up the container types during this pass because we
7491 don't know where the variant part will be placed until the end. */
7492 for (variant = First_Non_Pragma (Variants (gnat_variant_part));
7493 Present (variant);
7494 variant = Next_Non_Pragma (variant))
7495 {
7496 tree gnu_variant_type = make_node (RECORD_TYPE);
7497 tree gnu_inner_name, gnu_qual;
7498 bool has_rep;
7499 int field_packed;
7500 vinfo_t vinfo;
7501
7502 Get_Variant_Encoding (variant);
7503 gnu_inner_name = get_identifier_with_length (Name_Buffer, Name_Len);
7504 TYPE_NAME (gnu_variant_type)
7505 = concat_name (gnu_union_name,
7506 IDENTIFIER_POINTER (gnu_inner_name));
7507
7508 /* Set the alignment of the inner type in case we need to make
7509 inner objects into bitfields, but then clear it out so the
7510 record actually gets only the alignment required. */
7511 SET_TYPE_ALIGN (gnu_variant_type, TYPE_ALIGN (gnu_record_type));
7512 TYPE_PACKED (gnu_variant_type) = TYPE_PACKED (gnu_record_type);
7513 TYPE_REVERSE_STORAGE_ORDER (gnu_variant_type)
7514 = TYPE_REVERSE_STORAGE_ORDER (gnu_record_type);
7515
7516 /* Similarly, if the outer record has a size specified and all
7517 the fields have a rep clause, we can propagate the size. */
7518 if (all_rep_and_size)
7519 {
7520 TYPE_SIZE (gnu_variant_type) = TYPE_SIZE (gnu_record_type);
7521 TYPE_SIZE_UNIT (gnu_variant_type)
7522 = TYPE_SIZE_UNIT (gnu_record_type);
7523 }
7524
7525 /* Add the fields into the record type for the variant. Note that
7526 we aren't sure to really use it at this point, see below. */
7527 has_rep
7528 = components_to_record (Component_List (variant), gnat_record_type,
7529 NULL_TREE, gnu_variant_type, packed,
7530 definition, !all_rep_and_size, all_rep,
7531 unchecked_union, true, needs_xv_encodings,
7532 true, this_first_free_pos,
7533 all_rep || this_first_free_pos
7534 ? NULL : &gnu_rep_list);
7535
7536 /* Translate the qualifier and annotate the GNAT node. */
7537 gnu_qual = choices_to_gnu (gnu_discr, Discrete_Choices (variant));
7538 Set_Present_Expr (variant, annotate_value (gnu_qual));
7539
7540 /* Deal with packedness like in gnat_to_gnu_field. */
7541 if (components_need_strict_alignment (Component_List (variant)))
7542 {
7543 field_packed = 0;
7544 union_field_needs_strict_alignment = true;
7545 }
7546 else
7547 field_packed
7548 = adjust_packed (gnu_variant_type, gnu_record_type, packed);
7549
7550 /* Push this variant onto the stack for the second pass. */
7551 vinfo.type = gnu_variant_type;
7552 vinfo.name = gnu_inner_name;
7553 vinfo.qual = gnu_qual;
7554 vinfo.has_rep = has_rep;
7555 vinfo.packed = field_packed;
7556 variant_types.safe_push (vinfo);
7557
7558 /* Compute the global properties that will determine the placement of
7559 the variant part. */
7560 variants_have_rep |= has_rep;
7561 if (!field_packed && TYPE_ALIGN (gnu_variant_type) > variants_align)
7562 variants_align = TYPE_ALIGN (gnu_variant_type);
7563 }
7564
7565 /* Round up the first free position to the alignment of the variant part
7566 for the variants without rep clause. This will guarantee a consistent
7567 layout independently of the placement of the variant part. */
7568 if (variants_have_rep && variants_align > 0 && this_first_free_pos)
7569 this_first_free_pos = round_up (this_first_free_pos, variants_align);
7570
7571 /* In the second pass, the container types are adjusted if necessary and
7572 finished up, then the corresponding fields of the variant part are
7573 built with their qualifier, unless this is an unchecked union. */
7574 FOR_EACH_VEC_ELT (variant_types, i, gnu_variant)
7575 {
7576 tree gnu_variant_type = gnu_variant->type;
7577 tree gnu_field_list = TYPE_FIELDS (gnu_variant_type);
7578
7579 /* If this is an Unchecked_Union whose fields are all in the variant
7580 part and we have a single field with no representation clause or
7581 placed at offset zero, use the field directly to match the layout
7582 of C unions. */
7583 if (TREE_CODE (gnu_record_type) == UNION_TYPE
7584 && gnu_field_list
7585 && !DECL_CHAIN (gnu_field_list)
7586 && (!DECL_FIELD_OFFSET (gnu_field_list)
7587 || integer_zerop (bit_position (gnu_field_list))))
7588 {
7589 gnu_field = gnu_field_list;
7590 DECL_CONTEXT (gnu_field) = gnu_record_type;
7591 }
7592 else
7593 {
7594 /* Finalize the variant type now. We used to throw away empty
7595 record types but we no longer do that because we need them to
7596 generate complete debug info for the variant; otherwise, the
7597 union type definition will be lacking the fields associated
7598 with these empty variants. */
7599 if (gnu_field_list && variants_have_rep && !gnu_variant->has_rep)
7600 {
7601 /* The variant part will be at offset 0 so we need to ensure
7602 that the fields are laid out starting from the first free
7603 position at this level. */
7604 tree gnu_rep_type = make_node (RECORD_TYPE);
7605 tree gnu_rep_part;
7606 TYPE_REVERSE_STORAGE_ORDER (gnu_rep_type)
7607 = TYPE_REVERSE_STORAGE_ORDER (gnu_variant_type);
7608 finish_record_type (gnu_rep_type, NULL_TREE, 0, debug_info);
7609 gnu_rep_part
7610 = create_rep_part (gnu_rep_type, gnu_variant_type,
7611 this_first_free_pos);
7612 DECL_CHAIN (gnu_rep_part) = gnu_field_list;
7613 gnu_field_list = gnu_rep_part;
7614 finish_record_type (gnu_variant_type, gnu_field_list, 0,
7615 false);
7616 }
7617
7618 if (debug_info)
7619 rest_of_record_type_compilation (gnu_variant_type);
7620 create_type_decl (TYPE_NAME (gnu_variant_type), gnu_variant_type,
7621 true, needs_xv_encodings, gnat_component_list);
7622
7623 gnu_field
7624 = create_field_decl (gnu_variant->name, gnu_variant_type,
7625 gnu_union_type,
7626 all_rep_and_size
7627 ? TYPE_SIZE (gnu_variant_type) : 0,
7628 variants_have_rep ? bitsize_zero_node : 0,
7629 gnu_variant->packed, 0);
7630
7631 DECL_INTERNAL_P (gnu_field) = 1;
7632
7633 if (!unchecked_union)
7634 DECL_QUALIFIER (gnu_field) = gnu_variant->qual;
7635 }
7636
7637 DECL_CHAIN (gnu_field) = gnu_variant_list;
7638 gnu_variant_list = gnu_field;
7639 }
7640
7641 /* Only make the QUAL_UNION_TYPE if there are non-empty variants. */
7642 if (gnu_variant_list)
7643 {
7644 int union_field_packed;
7645
7646 if (all_rep_and_size)
7647 {
7648 TYPE_SIZE (gnu_union_type) = TYPE_SIZE (gnu_record_type);
7649 TYPE_SIZE_UNIT (gnu_union_type)
7650 = TYPE_SIZE_UNIT (gnu_record_type);
7651 }
7652
7653 finish_record_type (gnu_union_type, nreverse (gnu_variant_list),
7654 all_rep_and_size ? 1 : 0, needs_xv_encodings);
7655
7656 /* If GNU_UNION_TYPE is our record type, it means we must have an
7657 Unchecked_Union with no fields. Verify that and, if so, just
7658 return. */
7659 if (gnu_union_type == gnu_record_type)
7660 {
7661 gcc_assert (unchecked_union
7662 && !gnu_field_list
7663 && !gnu_rep_list);
7664 return variants_have_rep;
7665 }
7666
7667 create_type_decl (TYPE_NAME (gnu_union_type), gnu_union_type, true,
7668 needs_xv_encodings, gnat_component_list);
7669
7670 /* Deal with packedness like in gnat_to_gnu_field. */
7671 if (union_field_needs_strict_alignment)
7672 union_field_packed = 0;
7673 else
7674 union_field_packed
7675 = adjust_packed (gnu_union_type, gnu_record_type, packed);
7676
7677 gnu_variant_part
7678 = create_field_decl (gnu_var_name, gnu_union_type, gnu_record_type,
7679 all_rep_and_size
7680 ? TYPE_SIZE (gnu_union_type) : 0,
7681 variants_have_rep ? bitsize_zero_node : 0,
7682 union_field_packed, 0);
7683
7684 DECL_INTERNAL_P (gnu_variant_part) = 1;
7685 }
7686 }
7687
7688 /* Scan GNU_FIELD_LIST and see if any fields have rep clauses. If they do,
7689 pull them out and put them onto the appropriate list.
7690
7691 Similarly, pull out the fields with zero size and no rep clause, as they
7692 would otherwise modify the layout and thus very likely run afoul of the
7693 Ada semantics, which are different from those of C here.
7694
7695 Finally, if there is an aliased field placed in the list after fields
7696 with self-referential size, pull out the latter in the same way.
7697
7698 Optionally, if the reordering mechanism is enabled, pull out the fields
7699 with self-referential size, variable size and fixed size not a multiple
7700 of a byte, so that they don't cause the regular fields to be either at
7701 self-referential/variable offset or misaligned. Note, in the latter
7702 case, that this can only happen in packed record types so the alignment
7703 is effectively capped to the byte for the whole record. But we don't
7704 do it for non-packed record types if pragma Optimize_Alignment (Space)
7705 is specified because this can prevent alignment gaps from being filled.
7706
7707 Optionally, if the layout warning is enabled, keep track of the above 4
7708 different kinds of fields and issue a warning if some of them would be
7709 (or are being) reordered by the reordering mechanism.
7710
7711 ??? If we reorder fields, the debugging information will be affected and
7712 the debugger print fields in a different order from the source code. */
7713 const bool do_reorder
7714 = (Convention (gnat_record_type) == Convention_Ada
7715 && !No_Reordering (gnat_record_type)
7716 && (!Optimize_Alignment_Space (gnat_record_type)
7717 || Is_Packed (gnat_record_type))
7718 && !debug__debug_flag_dot_r);
7719 const bool w_reorder
7720 = (Convention (gnat_record_type) == Convention_Ada
7721 && Warn_On_Questionable_Layout
7722 && !(No_Reordering (gnat_record_type) && GNAT_Mode));
7723 const bool in_variant = (p_gnu_rep_list != NULL);
7724 tree gnu_zero_list = NULL_TREE;
7725 tree gnu_self_list = NULL_TREE;
7726 tree gnu_var_list = NULL_TREE;
7727 tree gnu_bitp_list = NULL_TREE;
7728 tree gnu_tmp_bitp_list = NULL_TREE;
7729 unsigned int tmp_bitp_size = 0;
7730 unsigned int last_reorder_field_type = -1;
7731 unsigned int tmp_last_reorder_field_type = -1;
7732
7733 #define MOVE_FROM_FIELD_LIST_TO(LIST) \
7734 do { \
7735 if (gnu_last) \
7736 DECL_CHAIN (gnu_last) = gnu_next; \
7737 else \
7738 gnu_field_list = gnu_next; \
7739 \
7740 DECL_CHAIN (gnu_field) = (LIST); \
7741 (LIST) = gnu_field; \
7742 } while (0)
7743
7744 gnu_last = NULL_TREE;
7745 for (gnu_field = gnu_field_list; gnu_field; gnu_field = gnu_next)
7746 {
7747 gnu_next = DECL_CHAIN (gnu_field);
7748
7749 if (DECL_FIELD_OFFSET (gnu_field))
7750 {
7751 MOVE_FROM_FIELD_LIST_TO (gnu_rep_list);
7752 continue;
7753 }
7754
7755 if (DECL_SIZE (gnu_field) && integer_zerop (DECL_SIZE (gnu_field)))
7756 {
7757 DECL_FIELD_OFFSET (gnu_field) = size_zero_node;
7758 SET_DECL_OFFSET_ALIGN (gnu_field, BIGGEST_ALIGNMENT);
7759 DECL_FIELD_BIT_OFFSET (gnu_field) = bitsize_zero_node;
7760 if (DECL_ALIASED_P (gnu_field))
7761 SET_TYPE_ALIGN (gnu_record_type,
7762 MAX (TYPE_ALIGN (gnu_record_type),
7763 TYPE_ALIGN (TREE_TYPE (gnu_field))));
7764 MOVE_FROM_FIELD_LIST_TO (gnu_zero_list);
7765 continue;
7766 }
7767
7768 if (has_aliased_after_self_field && field_has_self_size (gnu_field))
7769 {
7770 MOVE_FROM_FIELD_LIST_TO (gnu_self_list);
7771 continue;
7772 }
7773
7774 /* We don't need further processing in default mode. */
7775 if (!w_reorder && !do_reorder)
7776 {
7777 gnu_last = gnu_field;
7778 continue;
7779 }
7780
7781 if (field_has_self_size (gnu_field))
7782 {
7783 if (w_reorder)
7784 {
7785 if (last_reorder_field_type < 4)
7786 warn_on_field_placement (gnu_field, gnat_component_list,
7787 gnat_record_type, in_variant,
7788 do_reorder);
7789 else
7790 last_reorder_field_type = 4;
7791 }
7792
7793 if (do_reorder)
7794 {
7795 MOVE_FROM_FIELD_LIST_TO (gnu_self_list);
7796 continue;
7797 }
7798 }
7799
7800 else if (field_has_variable_size (gnu_field))
7801 {
7802 if (w_reorder)
7803 {
7804 if (last_reorder_field_type < 3)
7805 warn_on_field_placement (gnu_field, gnat_component_list,
7806 gnat_record_type, in_variant,
7807 do_reorder);
7808 else
7809 last_reorder_field_type = 3;
7810 }
7811
7812 if (do_reorder)
7813 {
7814 MOVE_FROM_FIELD_LIST_TO (gnu_var_list);
7815 continue;
7816 }
7817 }
7818
7819 else
7820 {
7821 /* If the field has no size, then it cannot be bit-packed. */
7822 const unsigned int bitp_size
7823 = DECL_SIZE (gnu_field)
7824 ? TREE_INT_CST_LOW (DECL_SIZE (gnu_field)) % BITS_PER_UNIT
7825 : 0;
7826
7827 /* If the field is bit-packed, we move it to a temporary list that
7828 contains the contiguously preceding bit-packed fields, because
7829 we want to be able to put them back if the misalignment happens
7830 to cancel itself after several bit-packed fields. */
7831 if (bitp_size != 0)
7832 {
7833 tmp_bitp_size = (tmp_bitp_size + bitp_size) % BITS_PER_UNIT;
7834
7835 if (last_reorder_field_type != 2)
7836 {
7837 tmp_last_reorder_field_type = last_reorder_field_type;
7838 last_reorder_field_type = 2;
7839 }
7840
7841 if (do_reorder)
7842 {
7843 MOVE_FROM_FIELD_LIST_TO (gnu_tmp_bitp_list);
7844 continue;
7845 }
7846 }
7847
7848 /* No more bit-packed fields, move the existing ones to the end or
7849 put them back at their original location. */
7850 else if (last_reorder_field_type == 2 || gnu_tmp_bitp_list)
7851 {
7852 last_reorder_field_type = 1;
7853
7854 if (tmp_bitp_size != 0)
7855 {
7856 if (w_reorder && tmp_last_reorder_field_type < 2)
7857 {
7858 if (gnu_tmp_bitp_list)
7859 warn_on_list_placement (gnu_tmp_bitp_list,
7860 gnat_component_list,
7861 gnat_record_type, in_variant,
7862 do_reorder);
7863 else
7864 warn_on_field_placement (gnu_last,
7865 gnat_component_list,
7866 gnat_record_type, in_variant,
7867 do_reorder);
7868 }
7869
7870 if (do_reorder)
7871 gnu_bitp_list = chainon (gnu_tmp_bitp_list, gnu_bitp_list);
7872
7873 gnu_tmp_bitp_list = NULL_TREE;
7874 tmp_bitp_size = 0;
7875 }
7876 else
7877 {
7878 /* Rechain the temporary list in front of GNU_FIELD. */
7879 tree gnu_bitp_field = gnu_field;
7880 while (gnu_tmp_bitp_list)
7881 {
7882 tree gnu_bitp_next = DECL_CHAIN (gnu_tmp_bitp_list);
7883 DECL_CHAIN (gnu_tmp_bitp_list) = gnu_bitp_field;
7884 if (gnu_last)
7885 DECL_CHAIN (gnu_last) = gnu_tmp_bitp_list;
7886 else
7887 gnu_field_list = gnu_tmp_bitp_list;
7888 gnu_bitp_field = gnu_tmp_bitp_list;
7889 gnu_tmp_bitp_list = gnu_bitp_next;
7890 }
7891 }
7892 }
7893
7894 else
7895 last_reorder_field_type = 1;
7896 }
7897
7898 gnu_last = gnu_field;
7899 }
7900
7901 #undef MOVE_FROM_FIELD_LIST_TO
7902
7903 gnu_field_list = nreverse (gnu_field_list);
7904
7905 /* If permitted, we reorder the fields as follows:
7906
7907 1) all (groups of) fields whose length is fixed and multiple of a byte,
7908 2) the remaining fields whose length is fixed and not multiple of a byte,
7909 3) the remaining fields whose length doesn't depend on discriminants,
7910 4) all fields whose length depends on discriminants,
7911 5) the variant part,
7912
7913 within the record and within each variant recursively. */
7914
7915 if (w_reorder)
7916 {
7917 /* If we have pending bit-packed fields, warn if they would be moved
7918 to after regular fields. */
7919 if (last_reorder_field_type == 2
7920 && tmp_bitp_size != 0
7921 && tmp_last_reorder_field_type < 2)
7922 {
7923 if (gnu_tmp_bitp_list)
7924 warn_on_list_placement (gnu_tmp_bitp_list,
7925 gnat_component_list, gnat_record_type,
7926 in_variant, do_reorder);
7927 else
7928 warn_on_field_placement (gnu_field_list,
7929 gnat_component_list, gnat_record_type,
7930 in_variant, do_reorder);
7931 }
7932 }
7933
7934 if (do_reorder)
7935 {
7936 /* If we have pending bit-packed fields on the temporary list, we put
7937 them either on the bit-packed list or back on the regular list. */
7938 if (gnu_tmp_bitp_list)
7939 {
7940 if (tmp_bitp_size != 0)
7941 gnu_bitp_list = chainon (gnu_tmp_bitp_list, gnu_bitp_list);
7942 else
7943 gnu_field_list = chainon (gnu_tmp_bitp_list, gnu_field_list);
7944 }
7945
7946 gnu_field_list
7947 = chainon (gnu_field_list,
7948 chainon (gnu_bitp_list,
7949 chainon (gnu_var_list, gnu_self_list)));
7950 }
7951
7952 /* Otherwise, if there is an aliased field placed after a field whose length
7953 depends on discriminants, we put all the fields of the latter sort, last.
7954 We need to do this in case an object of this record type is mutable. */
7955 else if (has_aliased_after_self_field)
7956 gnu_field_list = chainon (gnu_field_list, gnu_self_list);
7957
7958 /* If P_REP_LIST is nonzero, this means that we are asked to move the fields
7959 in our REP list to the previous level because this level needs them in
7960 order to do a correct layout, i.e. avoid having overlapping fields. */
7961 if (p_gnu_rep_list && gnu_rep_list)
7962 *p_gnu_rep_list = chainon (*p_gnu_rep_list, gnu_rep_list);
7963
7964 /* Deal with the annoying case of an extension of a record with variable size
7965 and partial rep clause, for which the _Parent field is forced at offset 0
7966 and has variable size, which we do not support below. Note that we cannot
7967 do it if the field has fixed size because we rely on the presence of the
7968 REP part built below to trigger the reordering of the fields in a derived
7969 record type when all the fields have a fixed position. */
7970 else if (gnu_rep_list
7971 && !DECL_CHAIN (gnu_rep_list)
7972 && TREE_CODE (DECL_SIZE (gnu_rep_list)) != INTEGER_CST
7973 && !variants_have_rep
7974 && first_free_pos
7975 && integer_zerop (first_free_pos)
7976 && integer_zerop (bit_position (gnu_rep_list)))
7977 {
7978 DECL_CHAIN (gnu_rep_list) = gnu_field_list;
7979 gnu_field_list = gnu_rep_list;
7980 gnu_rep_list = NULL_TREE;
7981 }
7982
7983 /* Otherwise, sort the fields by bit position and put them into their own
7984 record, before the others, if we also have fields without rep clause. */
7985 else if (gnu_rep_list)
7986 {
7987 tree gnu_rep_type, gnu_rep_part;
7988 int i, len = list_length (gnu_rep_list);
7989 tree *gnu_arr = XALLOCAVEC (tree, len);
7990
7991 /* If all the fields have a rep clause, we can do a flat layout. */
7992 layout_with_rep = !gnu_field_list
7993 && (!gnu_variant_part || variants_have_rep);
7994 gnu_rep_type
7995 = layout_with_rep ? gnu_record_type : make_node (RECORD_TYPE);
7996
7997 for (gnu_field = gnu_rep_list, i = 0;
7998 gnu_field;
7999 gnu_field = DECL_CHAIN (gnu_field), i++)
8000 gnu_arr[i] = gnu_field;
8001
8002 qsort (gnu_arr, len, sizeof (tree), compare_field_bitpos);
8003
8004 /* Put the fields in the list in order of increasing position, which
8005 means we start from the end. */
8006 gnu_rep_list = NULL_TREE;
8007 for (i = len - 1; i >= 0; i--)
8008 {
8009 DECL_CHAIN (gnu_arr[i]) = gnu_rep_list;
8010 gnu_rep_list = gnu_arr[i];
8011 DECL_CONTEXT (gnu_arr[i]) = gnu_rep_type;
8012 }
8013
8014 if (layout_with_rep)
8015 gnu_field_list = gnu_rep_list;
8016 else
8017 {
8018 TYPE_REVERSE_STORAGE_ORDER (gnu_rep_type)
8019 = TYPE_REVERSE_STORAGE_ORDER (gnu_record_type);
8020 finish_record_type (gnu_rep_type, gnu_rep_list, 1, debug_info);
8021
8022 /* If FIRST_FREE_POS is nonzero, we need to ensure that the fields
8023 without rep clause are laid out starting from this position.
8024 Therefore, we force it as a minimal size on the REP part. */
8025 gnu_rep_part
8026 = create_rep_part (gnu_rep_type, gnu_record_type, first_free_pos);
8027
8028 /* Chain the REP part at the beginning of the field list. */
8029 DECL_CHAIN (gnu_rep_part) = gnu_field_list;
8030 gnu_field_list = gnu_rep_part;
8031 }
8032 }
8033
8034 /* Chain the variant part at the end of the field list. */
8035 if (gnu_variant_part)
8036 gnu_field_list = chainon (gnu_field_list, gnu_variant_part);
8037
8038 if (cancel_alignment)
8039 SET_TYPE_ALIGN (gnu_record_type, 0);
8040
8041 TYPE_ARTIFICIAL (gnu_record_type) = artificial;
8042
8043 finish_record_type (gnu_record_type, gnu_field_list, layout_with_rep ? 1 : 0,
8044 debug_info && !maybe_unused);
8045
8046 /* Chain the fields with zero size at the beginning of the field list. */
8047 if (gnu_zero_list)
8048 TYPE_FIELDS (gnu_record_type)
8049 = chainon (gnu_zero_list, TYPE_FIELDS (gnu_record_type));
8050
8051 return (gnu_rep_list && !p_gnu_rep_list) || variants_have_rep;
8052 }
8053
8054 /* Given GNU_SIZE, a GCC tree representing a size, return a Uint to be
8055 placed into an Esize, Component_Bit_Offset, or Component_Size value
8056 in the GNAT tree. */
8057
8058 static Uint
annotate_value(tree gnu_size)8059 annotate_value (tree gnu_size)
8060 {
8061 static int var_count = 0;
8062 TCode tcode;
8063 Node_Ref_Or_Val ops[3] = { No_Uint, No_Uint, No_Uint };
8064 struct tree_int_map in;
8065
8066 /* See if we've already saved the value for this node. */
8067 if (EXPR_P (gnu_size) || DECL_P (gnu_size))
8068 {
8069 struct tree_int_map *e;
8070
8071 in.base.from = gnu_size;
8072 e = annotate_value_cache->find (&in);
8073
8074 if (e)
8075 return (Node_Ref_Or_Val) e->to;
8076 }
8077 else
8078 in.base.from = NULL_TREE;
8079
8080 /* If we do not return inside this switch, TCODE will be set to the
8081 code to be used in a call to Create_Node. */
8082 switch (TREE_CODE (gnu_size))
8083 {
8084 case INTEGER_CST:
8085 /* For negative values, build NEGATE_EXPR of the opposite. Such values
8086 can appear for discriminants in expressions for variants. Note that,
8087 sizetype being unsigned, we don't directly use tree_int_cst_sgn. */
8088 if (tree_int_cst_sign_bit (gnu_size))
8089 {
8090 tree t = wide_int_to_tree (sizetype, -wi::to_wide (gnu_size));
8091 tcode = Negate_Expr;
8092 ops[0] = UI_From_gnu (t);
8093 }
8094 else
8095 return TREE_OVERFLOW (gnu_size) ? No_Uint : UI_From_gnu (gnu_size);
8096 break;
8097
8098 case COMPONENT_REF:
8099 /* The only case we handle here is a simple discriminant reference. */
8100 if (DECL_DISCRIMINANT_NUMBER (TREE_OPERAND (gnu_size, 1)))
8101 {
8102 tree ref = gnu_size;
8103 gnu_size = TREE_OPERAND (ref, 1);
8104
8105 /* Climb up the chain of successive extensions, if any. */
8106 while (TREE_CODE (TREE_OPERAND (ref, 0)) == COMPONENT_REF
8107 && DECL_NAME (TREE_OPERAND (TREE_OPERAND (ref, 0), 1))
8108 == parent_name_id)
8109 ref = TREE_OPERAND (ref, 0);
8110
8111 if (TREE_CODE (TREE_OPERAND (ref, 0)) == PLACEHOLDER_EXPR)
8112 {
8113 /* Fall through to common processing as a FIELD_DECL. */
8114 tcode = Discrim_Val;
8115 ops[0] = UI_From_gnu (DECL_DISCRIMINANT_NUMBER (gnu_size));
8116 }
8117 else
8118 return No_Uint;
8119 }
8120 else
8121 return No_Uint;
8122 break;
8123
8124 case VAR_DECL:
8125 tcode = Dynamic_Val;
8126 ops[0] = UI_From_Int (++var_count);
8127 break;
8128
8129 CASE_CONVERT:
8130 case NON_LVALUE_EXPR:
8131 return annotate_value (TREE_OPERAND (gnu_size, 0));
8132
8133 /* Now just list the operations we handle. */
8134 case COND_EXPR: tcode = Cond_Expr; break;
8135 case MINUS_EXPR: tcode = Minus_Expr; break;
8136 case TRUNC_DIV_EXPR: tcode = Trunc_Div_Expr; break;
8137 case CEIL_DIV_EXPR: tcode = Ceil_Div_Expr; break;
8138 case FLOOR_DIV_EXPR: tcode = Floor_Div_Expr; break;
8139 case TRUNC_MOD_EXPR: tcode = Trunc_Mod_Expr; break;
8140 case CEIL_MOD_EXPR: tcode = Ceil_Mod_Expr; break;
8141 case FLOOR_MOD_EXPR: tcode = Floor_Mod_Expr; break;
8142 case EXACT_DIV_EXPR: tcode = Exact_Div_Expr; break;
8143 case NEGATE_EXPR: tcode = Negate_Expr; break;
8144 case MIN_EXPR: tcode = Min_Expr; break;
8145 case MAX_EXPR: tcode = Max_Expr; break;
8146 case ABS_EXPR: tcode = Abs_Expr; break;
8147 case TRUTH_ANDIF_EXPR: tcode = Truth_Andif_Expr; break;
8148 case TRUTH_ORIF_EXPR: tcode = Truth_Orif_Expr; break;
8149 case TRUTH_AND_EXPR: tcode = Truth_And_Expr; break;
8150 case TRUTH_OR_EXPR: tcode = Truth_Or_Expr; break;
8151 case TRUTH_XOR_EXPR: tcode = Truth_Xor_Expr; break;
8152 case TRUTH_NOT_EXPR: tcode = Truth_Not_Expr; break;
8153 case LT_EXPR: tcode = Lt_Expr; break;
8154 case LE_EXPR: tcode = Le_Expr; break;
8155 case GT_EXPR: tcode = Gt_Expr; break;
8156 case GE_EXPR: tcode = Ge_Expr; break;
8157 case EQ_EXPR: tcode = Eq_Expr; break;
8158 case NE_EXPR: tcode = Ne_Expr; break;
8159
8160 case PLUS_EXPR:
8161 /* Turn addition of negative constant into subtraction. */
8162 if (TREE_CODE (TREE_OPERAND (gnu_size, 1)) == INTEGER_CST
8163 && tree_int_cst_sign_bit (TREE_OPERAND (gnu_size, 1)))
8164 {
8165 tcode = Minus_Expr;
8166 ops[0] = annotate_value (TREE_OPERAND (gnu_size, 0));
8167 wide_int op1 = -wi::to_wide (TREE_OPERAND (gnu_size, 1));
8168 ops[1] = annotate_value (wide_int_to_tree (sizetype, op1));
8169 break;
8170 }
8171
8172 /* ... fall through ... */
8173
8174 case MULT_EXPR:
8175 tcode = (TREE_CODE (gnu_size) == MULT_EXPR ? Mult_Expr : Plus_Expr);
8176 /* Fold conversions from bytes to bits into inner operations. */
8177 if (TREE_CODE (TREE_OPERAND (gnu_size, 1)) == INTEGER_CST
8178 && CONVERT_EXPR_P (TREE_OPERAND (gnu_size, 0)))
8179 {
8180 tree inner_op = TREE_OPERAND (TREE_OPERAND (gnu_size, 0), 0);
8181 if (TREE_CODE (inner_op) == TREE_CODE (gnu_size)
8182 && TREE_CODE (TREE_OPERAND (inner_op, 1)) == INTEGER_CST)
8183 {
8184 ops[0] = annotate_value (TREE_OPERAND (inner_op, 0));
8185 tree inner_op_op1 = TREE_OPERAND (inner_op, 1);
8186 tree gnu_size_op1 = TREE_OPERAND (gnu_size, 1);
8187 widest_int op1;
8188 if (TREE_CODE (gnu_size) == MULT_EXPR)
8189 op1 = (wi::to_widest (inner_op_op1)
8190 * wi::to_widest (gnu_size_op1));
8191 else
8192 {
8193 op1 = (wi::to_widest (inner_op_op1)
8194 + wi::to_widest (gnu_size_op1));
8195 if (wi::zext (op1, TYPE_PRECISION (sizetype)) == 0)
8196 return ops[0];
8197 }
8198 ops[1] = annotate_value (wide_int_to_tree (sizetype, op1));
8199 }
8200 }
8201 break;
8202
8203 case BIT_AND_EXPR:
8204 tcode = Bit_And_Expr;
8205 /* For negative values in sizetype, build NEGATE_EXPR of the opposite.
8206 Such values can appear in expressions with aligning patterns. */
8207 if (TREE_CODE (TREE_OPERAND (gnu_size, 1)) == INTEGER_CST)
8208 {
8209 wide_int op1 = wi::sext (wi::to_wide (TREE_OPERAND (gnu_size, 1)),
8210 TYPE_PRECISION (sizetype));
8211 ops[1] = annotate_value (wide_int_to_tree (sizetype, op1));
8212 }
8213 break;
8214
8215 case CALL_EXPR:
8216 /* In regular mode, inline back only if symbolic annotation is requested
8217 in order to avoid memory explosion on big discriminated record types.
8218 But not in ASIS mode, as symbolic annotation is required for DDA. */
8219 if (List_Representation_Info == 3 || type_annotate_only)
8220 {
8221 tree t = maybe_inline_call_in_expr (gnu_size);
8222 return t ? annotate_value (t) : No_Uint;
8223 }
8224 else
8225 return Uint_Minus_1;
8226
8227 default:
8228 return No_Uint;
8229 }
8230
8231 /* Now get each of the operands that's relevant for this code. If any
8232 cannot be expressed as a repinfo node, say we can't. */
8233 for (int i = 0; i < TREE_CODE_LENGTH (TREE_CODE (gnu_size)); i++)
8234 if (ops[i] == No_Uint)
8235 {
8236 ops[i] = annotate_value (TREE_OPERAND (gnu_size, i));
8237 if (ops[i] == No_Uint)
8238 return No_Uint;
8239 }
8240
8241 Node_Ref_Or_Val ret = Create_Node (tcode, ops[0], ops[1], ops[2]);
8242
8243 /* Save the result in the cache. */
8244 if (in.base.from)
8245 {
8246 struct tree_int_map **h;
8247 /* We can't assume the hash table data hasn't moved since the initial
8248 look up, so we have to search again. Allocating and inserting an
8249 entry at that point would be an alternative, but then we'd better
8250 discard the entry if we decided not to cache it. */
8251 h = annotate_value_cache->find_slot (&in, INSERT);
8252 gcc_assert (!*h);
8253 *h = ggc_alloc<tree_int_map> ();
8254 (*h)->base.from = in.base.from;
8255 (*h)->to = ret;
8256 }
8257
8258 return ret;
8259 }
8260
8261 /* Given GNAT_ENTITY, an object (constant, variable, parameter, exception)
8262 and GNU_TYPE, its corresponding GCC type, set Esize and Alignment to the
8263 size and alignment used by Gigi. Prefer SIZE over TYPE_SIZE if non-null.
8264 BY_REF is true if the object is used by reference. */
8265
8266 void
annotate_object(Entity_Id gnat_entity,tree gnu_type,tree size,bool by_ref)8267 annotate_object (Entity_Id gnat_entity, tree gnu_type, tree size, bool by_ref)
8268 {
8269 if (by_ref)
8270 {
8271 if (TYPE_IS_FAT_POINTER_P (gnu_type))
8272 gnu_type = TYPE_UNCONSTRAINED_ARRAY (gnu_type);
8273 else
8274 gnu_type = TREE_TYPE (gnu_type);
8275 }
8276
8277 if (Unknown_Esize (gnat_entity))
8278 {
8279 if (TREE_CODE (gnu_type) == RECORD_TYPE
8280 && TYPE_CONTAINS_TEMPLATE_P (gnu_type))
8281 size = TYPE_SIZE (TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (gnu_type))));
8282 else if (!size)
8283 size = TYPE_SIZE (gnu_type);
8284
8285 if (size)
8286 Set_Esize (gnat_entity, annotate_value (size));
8287 }
8288
8289 if (Unknown_Alignment (gnat_entity))
8290 Set_Alignment (gnat_entity,
8291 UI_From_Int (TYPE_ALIGN (gnu_type) / BITS_PER_UNIT));
8292 }
8293
8294 /* Return first element of field list whose TREE_PURPOSE is the same as ELEM.
8295 Return NULL_TREE if there is no such element in the list. */
8296
8297 static tree
purpose_member_field(const_tree elem,tree list)8298 purpose_member_field (const_tree elem, tree list)
8299 {
8300 while (list)
8301 {
8302 tree field = TREE_PURPOSE (list);
8303 if (SAME_FIELD_P (field, elem))
8304 return list;
8305 list = TREE_CHAIN (list);
8306 }
8307 return NULL_TREE;
8308 }
8309
8310 /* Given GNAT_ENTITY, a record type, and GNU_TYPE, its corresponding GCC type,
8311 set Component_Bit_Offset and Esize of the components to the position and
8312 size used by Gigi. */
8313
8314 static void
annotate_rep(Entity_Id gnat_entity,tree gnu_type)8315 annotate_rep (Entity_Id gnat_entity, tree gnu_type)
8316 {
8317 /* For an extension, the inherited components have not been translated because
8318 they are fetched from the _Parent component on the fly. */
8319 const bool is_extension
8320 = Is_Tagged_Type (gnat_entity) && Is_Derived_Type (gnat_entity);
8321
8322 /* We operate by first making a list of all fields and their position (we
8323 can get the size easily) and then update all the sizes in the tree. */
8324 tree gnu_list
8325 = build_position_list (gnu_type, false, size_zero_node, bitsize_zero_node,
8326 BIGGEST_ALIGNMENT, NULL_TREE);
8327
8328 for (Entity_Id gnat_field = First_Entity (gnat_entity);
8329 Present (gnat_field);
8330 gnat_field = Next_Entity (gnat_field))
8331 if ((Ekind (gnat_field) == E_Component
8332 && (is_extension || present_gnu_tree (gnat_field)))
8333 || (Ekind (gnat_field) == E_Discriminant
8334 && !Is_Unchecked_Union (Scope (gnat_field))))
8335 {
8336 tree t = purpose_member_field (gnat_to_gnu_field_decl (gnat_field),
8337 gnu_list);
8338 if (t)
8339 {
8340 tree parent_offset;
8341
8342 /* If we are just annotating types and the type is tagged, the tag
8343 and the parent components are not generated by the front-end so
8344 we need to add the appropriate offset to each component without
8345 representation clause. */
8346 if (type_annotate_only
8347 && Is_Tagged_Type (gnat_entity)
8348 && No (Component_Clause (gnat_field)))
8349 {
8350 /* For a component appearing in the current extension, the
8351 offset is the size of the parent. */
8352 if (Is_Derived_Type (gnat_entity)
8353 && Original_Record_Component (gnat_field) == gnat_field)
8354 parent_offset
8355 = UI_To_gnu (Esize (Etype (Base_Type (gnat_entity))),
8356 bitsizetype);
8357 else
8358 parent_offset = bitsize_int (POINTER_SIZE);
8359
8360 if (TYPE_FIELDS (gnu_type))
8361 parent_offset
8362 = round_up (parent_offset,
8363 DECL_ALIGN (TYPE_FIELDS (gnu_type)));
8364 }
8365 else
8366 parent_offset = bitsize_zero_node;
8367
8368 Set_Component_Bit_Offset
8369 (gnat_field,
8370 annotate_value
8371 (size_binop (PLUS_EXPR,
8372 bit_from_pos (TREE_VEC_ELT (TREE_VALUE (t), 0),
8373 TREE_VEC_ELT (TREE_VALUE (t), 2)),
8374 parent_offset)));
8375
8376 Set_Esize (gnat_field,
8377 annotate_value (DECL_SIZE (TREE_PURPOSE (t))));
8378 }
8379 else if (is_extension)
8380 {
8381 /* If there is no entry, this is an inherited component whose
8382 position is the same as in the parent type. */
8383 Entity_Id gnat_orig_field = Original_Record_Component (gnat_field);
8384
8385 /* If we are just annotating types, discriminants renaming those of
8386 the parent have no entry so deal with them specifically. */
8387 if (type_annotate_only
8388 && gnat_orig_field == gnat_field
8389 && Ekind (gnat_field) == E_Discriminant)
8390 gnat_orig_field = Corresponding_Discriminant (gnat_field);
8391
8392 Set_Component_Bit_Offset (gnat_field,
8393 Component_Bit_Offset (gnat_orig_field));
8394
8395 Set_Esize (gnat_field, Esize (gnat_orig_field));
8396 }
8397 }
8398 }
8399
8400 /* Scan all fields in GNU_TYPE and return a TREE_LIST where TREE_PURPOSE is
8401 the FIELD_DECL and TREE_VALUE a TREE_VEC containing the byte position, the
8402 value to be placed into DECL_OFFSET_ALIGN and the bit position. The list
8403 of fields is flattened, except for variant parts if DO_NOT_FLATTEN_VARIANT
8404 is set to true. GNU_POS is to be added to the position, GNU_BITPOS to the
8405 bit position, OFFSET_ALIGN is the present offset alignment. GNU_LIST is a
8406 pre-existing list to be chained to the newly created entries. */
8407
8408 static tree
build_position_list(tree gnu_type,bool do_not_flatten_variant,tree gnu_pos,tree gnu_bitpos,unsigned int offset_align,tree gnu_list)8409 build_position_list (tree gnu_type, bool do_not_flatten_variant, tree gnu_pos,
8410 tree gnu_bitpos, unsigned int offset_align, tree gnu_list)
8411 {
8412 tree gnu_field;
8413
8414 for (gnu_field = TYPE_FIELDS (gnu_type);
8415 gnu_field;
8416 gnu_field = DECL_CHAIN (gnu_field))
8417 {
8418 tree gnu_our_bitpos = size_binop (PLUS_EXPR, gnu_bitpos,
8419 DECL_FIELD_BIT_OFFSET (gnu_field));
8420 tree gnu_our_offset = size_binop (PLUS_EXPR, gnu_pos,
8421 DECL_FIELD_OFFSET (gnu_field));
8422 unsigned int our_offset_align
8423 = MIN (offset_align, DECL_OFFSET_ALIGN (gnu_field));
8424 tree v = make_tree_vec (3);
8425
8426 TREE_VEC_ELT (v, 0) = gnu_our_offset;
8427 TREE_VEC_ELT (v, 1) = size_int (our_offset_align);
8428 TREE_VEC_ELT (v, 2) = gnu_our_bitpos;
8429 gnu_list = tree_cons (gnu_field, v, gnu_list);
8430
8431 /* Recurse on internal fields, flattening the nested fields except for
8432 those in the variant part, if requested. */
8433 if (DECL_INTERNAL_P (gnu_field))
8434 {
8435 tree gnu_field_type = TREE_TYPE (gnu_field);
8436 if (do_not_flatten_variant
8437 && TREE_CODE (gnu_field_type) == QUAL_UNION_TYPE)
8438 gnu_list
8439 = build_position_list (gnu_field_type, do_not_flatten_variant,
8440 size_zero_node, bitsize_zero_node,
8441 BIGGEST_ALIGNMENT, gnu_list);
8442 else
8443 gnu_list
8444 = build_position_list (gnu_field_type, do_not_flatten_variant,
8445 gnu_our_offset, gnu_our_bitpos,
8446 our_offset_align, gnu_list);
8447 }
8448 }
8449
8450 return gnu_list;
8451 }
8452
8453 /* Return a list describing the substitutions needed to reflect the
8454 discriminant substitutions from GNAT_TYPE to GNAT_SUBTYPE. They can
8455 be in any order. The values in an element of the list are in the form
8456 of operands to SUBSTITUTE_IN_EXPR. DEFINITION is true if this is for
8457 a definition of GNAT_SUBTYPE. */
8458
8459 static vec<subst_pair>
build_subst_list(Entity_Id gnat_subtype,Entity_Id gnat_type,bool definition)8460 build_subst_list (Entity_Id gnat_subtype, Entity_Id gnat_type, bool definition)
8461 {
8462 vec<subst_pair> gnu_list = vNULL;
8463 Entity_Id gnat_discrim;
8464 Node_Id gnat_constr;
8465
8466 for (gnat_discrim = First_Stored_Discriminant (gnat_type),
8467 gnat_constr = First_Elmt (Stored_Constraint (gnat_subtype));
8468 Present (gnat_discrim);
8469 gnat_discrim = Next_Stored_Discriminant (gnat_discrim),
8470 gnat_constr = Next_Elmt (gnat_constr))
8471 /* Ignore access discriminants. */
8472 if (!Is_Access_Type (Etype (Node (gnat_constr))))
8473 {
8474 tree gnu_field = gnat_to_gnu_field_decl (gnat_discrim);
8475 tree replacement = convert (TREE_TYPE (gnu_field),
8476 elaborate_expression
8477 (Node (gnat_constr), gnat_subtype,
8478 get_entity_char (gnat_discrim),
8479 definition, true, false));
8480 subst_pair s = { gnu_field, replacement };
8481 gnu_list.safe_push (s);
8482 }
8483
8484 return gnu_list;
8485 }
8486
8487 /* Scan all fields in QUAL_UNION_TYPE and return a list describing the
8488 variants of QUAL_UNION_TYPE that are still relevant after applying
8489 the substitutions described in SUBST_LIST. GNU_LIST is a pre-existing
8490 list to be prepended to the newly created entries. */
8491
8492 static vec<variant_desc>
build_variant_list(tree qual_union_type,vec<subst_pair> subst_list,vec<variant_desc> gnu_list)8493 build_variant_list (tree qual_union_type, vec<subst_pair> subst_list,
8494 vec<variant_desc> gnu_list)
8495 {
8496 tree gnu_field;
8497
8498 for (gnu_field = TYPE_FIELDS (qual_union_type);
8499 gnu_field;
8500 gnu_field = DECL_CHAIN (gnu_field))
8501 {
8502 tree qual = DECL_QUALIFIER (gnu_field);
8503 unsigned int i;
8504 subst_pair *s;
8505
8506 FOR_EACH_VEC_ELT (subst_list, i, s)
8507 qual = SUBSTITUTE_IN_EXPR (qual, s->discriminant, s->replacement);
8508
8509 /* If the new qualifier is not unconditionally false, its variant may
8510 still be accessed. */
8511 if (!integer_zerop (qual))
8512 {
8513 tree variant_type = TREE_TYPE (gnu_field), variant_subpart;
8514 variant_desc v = { variant_type, gnu_field, qual, NULL_TREE };
8515
8516 gnu_list.safe_push (v);
8517
8518 /* Recurse on the variant subpart of the variant, if any. */
8519 variant_subpart = get_variant_part (variant_type);
8520 if (variant_subpart)
8521 gnu_list = build_variant_list (TREE_TYPE (variant_subpart),
8522 subst_list, gnu_list);
8523
8524 /* If the new qualifier is unconditionally true, the subsequent
8525 variants cannot be accessed. */
8526 if (integer_onep (qual))
8527 break;
8528 }
8529 }
8530
8531 return gnu_list;
8532 }
8533
8534 /* UINT_SIZE is a Uint giving the specified size for an object of GNU_TYPE
8535 corresponding to GNAT_OBJECT. If the size is valid, return an INTEGER_CST
8536 corresponding to its value. Otherwise, return NULL_TREE. KIND is set to
8537 VAR_DECL if we are specifying the size of an object, TYPE_DECL for the
8538 size of a type, and FIELD_DECL for the size of a field. COMPONENT_P is
8539 true if we are being called to process the Component_Size of GNAT_OBJECT;
8540 this is used only for error messages. ZERO_OK is true if a size of zero
8541 is permitted; if ZERO_OK is false, it means that a size of zero should be
8542 treated as an unspecified size. */
8543
8544 static tree
validate_size(Uint uint_size,tree gnu_type,Entity_Id gnat_object,enum tree_code kind,bool component_p,bool zero_ok)8545 validate_size (Uint uint_size, tree gnu_type, Entity_Id gnat_object,
8546 enum tree_code kind, bool component_p, bool zero_ok)
8547 {
8548 Node_Id gnat_error_node;
8549 tree type_size, size;
8550
8551 /* Return 0 if no size was specified. */
8552 if (uint_size == No_Uint)
8553 return NULL_TREE;
8554
8555 /* Ignore a negative size since that corresponds to our back-annotation. */
8556 if (UI_Lt (uint_size, Uint_0))
8557 return NULL_TREE;
8558
8559 /* Find the node to use for error messages. */
8560 if ((Ekind (gnat_object) == E_Component
8561 || Ekind (gnat_object) == E_Discriminant)
8562 && Present (Component_Clause (gnat_object)))
8563 gnat_error_node = Last_Bit (Component_Clause (gnat_object));
8564 else if (Present (Size_Clause (gnat_object)))
8565 gnat_error_node = Expression (Size_Clause (gnat_object));
8566 else
8567 gnat_error_node = gnat_object;
8568
8569 /* Get the size as an INTEGER_CST. Issue an error if a size was specified
8570 but cannot be represented in bitsizetype. */
8571 size = UI_To_gnu (uint_size, bitsizetype);
8572 if (TREE_OVERFLOW (size))
8573 {
8574 if (component_p)
8575 post_error_ne ("component size for& is too large", gnat_error_node,
8576 gnat_object);
8577 else
8578 post_error_ne ("size for& is too large", gnat_error_node,
8579 gnat_object);
8580 return NULL_TREE;
8581 }
8582
8583 /* Ignore a zero size if it is not permitted. */
8584 if (!zero_ok && integer_zerop (size))
8585 return NULL_TREE;
8586
8587 /* The size of objects is always a multiple of a byte. */
8588 if (kind == VAR_DECL
8589 && !integer_zerop (size_binop (TRUNC_MOD_EXPR, size, bitsize_unit_node)))
8590 {
8591 if (component_p)
8592 post_error_ne ("component size for& is not a multiple of Storage_Unit",
8593 gnat_error_node, gnat_object);
8594 else
8595 post_error_ne ("size for& is not a multiple of Storage_Unit",
8596 gnat_error_node, gnat_object);
8597 return NULL_TREE;
8598 }
8599
8600 /* If this is an integral type or a packed array type, the front-end has
8601 already verified the size, so we need not do it here (which would mean
8602 checking against the bounds). However, if this is an aliased object,
8603 it may not be smaller than the type of the object. */
8604 if ((INTEGRAL_TYPE_P (gnu_type) || TYPE_IS_PACKED_ARRAY_TYPE_P (gnu_type))
8605 && !(kind == VAR_DECL && Is_Aliased (gnat_object)))
8606 return size;
8607
8608 /* If the object is a record that contains a template, add the size of the
8609 template to the specified size. */
8610 if (TREE_CODE (gnu_type) == RECORD_TYPE
8611 && TYPE_CONTAINS_TEMPLATE_P (gnu_type))
8612 size = size_binop (PLUS_EXPR, DECL_SIZE (TYPE_FIELDS (gnu_type)), size);
8613
8614 if (kind == VAR_DECL
8615 /* If a type needs strict alignment, a component of this type in
8616 a packed record cannot be packed and thus uses the type size. */
8617 || (kind == TYPE_DECL && Strict_Alignment (gnat_object)))
8618 type_size = TYPE_SIZE (gnu_type);
8619 else
8620 type_size = rm_size (gnu_type);
8621
8622 /* Modify the size of a discriminated type to be the maximum size. */
8623 if (type_size && CONTAINS_PLACEHOLDER_P (type_size))
8624 type_size = max_size (type_size, true);
8625
8626 /* If this is an access type or a fat pointer, the minimum size is that given
8627 by the smallest integral mode that's valid for pointers. */
8628 if (TREE_CODE (gnu_type) == POINTER_TYPE || TYPE_IS_FAT_POINTER_P (gnu_type))
8629 {
8630 scalar_int_mode p_mode = NARROWEST_INT_MODE;
8631 while (!targetm.valid_pointer_mode (p_mode))
8632 p_mode = GET_MODE_WIDER_MODE (p_mode).require ();
8633 type_size = bitsize_int (GET_MODE_BITSIZE (p_mode));
8634 }
8635
8636 /* Issue an error either if the default size of the object isn't a constant
8637 or if the new size is smaller than it. */
8638 if (TREE_CODE (type_size) != INTEGER_CST
8639 || TREE_OVERFLOW (type_size)
8640 || tree_int_cst_lt (size, type_size))
8641 {
8642 if (component_p)
8643 post_error_ne_tree
8644 ("component size for& too small{, minimum allowed is ^}",
8645 gnat_error_node, gnat_object, type_size);
8646 else
8647 post_error_ne_tree
8648 ("size for& too small{, minimum allowed is ^}",
8649 gnat_error_node, gnat_object, type_size);
8650 return NULL_TREE;
8651 }
8652
8653 return size;
8654 }
8655
8656 /* Similarly, but both validate and process a value of RM size. This routine
8657 is only called for types. */
8658
8659 static void
set_rm_size(Uint uint_size,tree gnu_type,Entity_Id gnat_entity)8660 set_rm_size (Uint uint_size, tree gnu_type, Entity_Id gnat_entity)
8661 {
8662 Node_Id gnat_attr_node;
8663 tree old_size, size;
8664
8665 /* Do nothing if no size was specified. */
8666 if (uint_size == No_Uint)
8667 return;
8668
8669 /* Ignore a negative size since that corresponds to our back-annotation. */
8670 if (UI_Lt (uint_size, Uint_0))
8671 return;
8672
8673 /* Only issue an error if a Value_Size clause was explicitly given.
8674 Otherwise, we'd be duplicating an error on the Size clause. */
8675 gnat_attr_node
8676 = Get_Attribute_Definition_Clause (gnat_entity, Attr_Value_Size);
8677
8678 /* Get the size as an INTEGER_CST. Issue an error if a size was specified
8679 but cannot be represented in bitsizetype. */
8680 size = UI_To_gnu (uint_size, bitsizetype);
8681 if (TREE_OVERFLOW (size))
8682 {
8683 if (Present (gnat_attr_node))
8684 post_error_ne ("Value_Size for& is too large", gnat_attr_node,
8685 gnat_entity);
8686 return;
8687 }
8688
8689 /* Ignore a zero size unless a Value_Size clause exists, or a size clause
8690 exists, or this is an integer type, in which case the front-end will
8691 have always set it. */
8692 if (No (gnat_attr_node)
8693 && integer_zerop (size)
8694 && !Has_Size_Clause (gnat_entity)
8695 && !Is_Discrete_Or_Fixed_Point_Type (gnat_entity))
8696 return;
8697
8698 old_size = rm_size (gnu_type);
8699
8700 /* If the old size is self-referential, get the maximum size. */
8701 if (CONTAINS_PLACEHOLDER_P (old_size))
8702 old_size = max_size (old_size, true);
8703
8704 /* Issue an error either if the old size of the object isn't a constant or
8705 if the new size is smaller than it. The front-end has already verified
8706 this for scalar and packed array types. */
8707 if (TREE_CODE (old_size) != INTEGER_CST
8708 || TREE_OVERFLOW (old_size)
8709 || (AGGREGATE_TYPE_P (gnu_type)
8710 && !(TREE_CODE (gnu_type) == ARRAY_TYPE
8711 && TYPE_PACKED_ARRAY_TYPE_P (gnu_type))
8712 && !(TYPE_IS_PADDING_P (gnu_type)
8713 && TREE_CODE (TREE_TYPE (TYPE_FIELDS (gnu_type))) == ARRAY_TYPE
8714 && TYPE_PACKED_ARRAY_TYPE_P
8715 (TREE_TYPE (TYPE_FIELDS (gnu_type))))
8716 && tree_int_cst_lt (size, old_size)))
8717 {
8718 if (Present (gnat_attr_node))
8719 post_error_ne_tree
8720 ("Value_Size for& too small{, minimum allowed is ^}",
8721 gnat_attr_node, gnat_entity, old_size);
8722 return;
8723 }
8724
8725 /* Otherwise, set the RM size proper for integral types... */
8726 if ((TREE_CODE (gnu_type) == INTEGER_TYPE
8727 && Is_Discrete_Or_Fixed_Point_Type (gnat_entity))
8728 || (TREE_CODE (gnu_type) == ENUMERAL_TYPE
8729 || TREE_CODE (gnu_type) == BOOLEAN_TYPE))
8730 SET_TYPE_RM_SIZE (gnu_type, size);
8731
8732 /* ...or the Ada size for record and union types. */
8733 else if (RECORD_OR_UNION_TYPE_P (gnu_type)
8734 && !TYPE_FAT_POINTER_P (gnu_type))
8735 SET_TYPE_ADA_SIZE (gnu_type, size);
8736 }
8737
8738 /* ALIGNMENT is a Uint giving the alignment specified for GNAT_ENTITY,
8739 a type or object whose present alignment is ALIGN. If this alignment is
8740 valid, return it. Otherwise, give an error and return ALIGN. */
8741
8742 static unsigned int
validate_alignment(Uint alignment,Entity_Id gnat_entity,unsigned int align)8743 validate_alignment (Uint alignment, Entity_Id gnat_entity, unsigned int align)
8744 {
8745 unsigned int max_allowed_alignment = get_target_maximum_allowed_alignment ();
8746 unsigned int new_align;
8747 Node_Id gnat_error_node;
8748
8749 /* Don't worry about checking alignment if alignment was not specified
8750 by the source program and we already posted an error for this entity. */
8751 if (Error_Posted (gnat_entity) && !Has_Alignment_Clause (gnat_entity))
8752 return align;
8753
8754 /* Post the error on the alignment clause if any. Note, for the implicit
8755 base type of an array type, the alignment clause is on the first
8756 subtype. */
8757 if (Present (Alignment_Clause (gnat_entity)))
8758 gnat_error_node = Expression (Alignment_Clause (gnat_entity));
8759
8760 else if (Is_Itype (gnat_entity)
8761 && Is_Array_Type (gnat_entity)
8762 && Etype (gnat_entity) == gnat_entity
8763 && Present (Alignment_Clause (First_Subtype (gnat_entity))))
8764 gnat_error_node =
8765 Expression (Alignment_Clause (First_Subtype (gnat_entity)));
8766
8767 else
8768 gnat_error_node = gnat_entity;
8769
8770 /* Within GCC, an alignment is an integer, so we must make sure a value is
8771 specified that fits in that range. Also, there is an upper bound to
8772 alignments we can support/allow. */
8773 if (!UI_Is_In_Int_Range (alignment)
8774 || ((new_align = UI_To_Int (alignment)) > max_allowed_alignment))
8775 post_error_ne_num ("largest supported alignment for& is ^",
8776 gnat_error_node, gnat_entity, max_allowed_alignment);
8777 else if (!(Present (Alignment_Clause (gnat_entity))
8778 && From_At_Mod (Alignment_Clause (gnat_entity)))
8779 && new_align * BITS_PER_UNIT < align)
8780 {
8781 unsigned int double_align;
8782 bool is_capped_double, align_clause;
8783
8784 /* If the default alignment of "double" or larger scalar types is
8785 specifically capped and the new alignment is above the cap, do
8786 not post an error and change the alignment only if there is an
8787 alignment clause; this makes it possible to have the associated
8788 GCC type overaligned by default for performance reasons. */
8789 if ((double_align = double_float_alignment) > 0)
8790 {
8791 Entity_Id gnat_type
8792 = Is_Type (gnat_entity) ? gnat_entity : Etype (gnat_entity);
8793 is_capped_double
8794 = is_double_float_or_array (gnat_type, &align_clause);
8795 }
8796 else if ((double_align = double_scalar_alignment) > 0)
8797 {
8798 Entity_Id gnat_type
8799 = Is_Type (gnat_entity) ? gnat_entity : Etype (gnat_entity);
8800 is_capped_double
8801 = is_double_scalar_or_array (gnat_type, &align_clause);
8802 }
8803 else
8804 is_capped_double = align_clause = false;
8805
8806 if (is_capped_double && new_align >= double_align)
8807 {
8808 if (align_clause)
8809 align = new_align * BITS_PER_UNIT;
8810 }
8811 else
8812 {
8813 if (is_capped_double)
8814 align = double_align * BITS_PER_UNIT;
8815
8816 post_error_ne_num ("alignment for& must be at least ^",
8817 gnat_error_node, gnat_entity,
8818 align / BITS_PER_UNIT);
8819 }
8820 }
8821 else
8822 {
8823 new_align = (new_align > 0 ? new_align * BITS_PER_UNIT : 1);
8824 if (new_align > align)
8825 align = new_align;
8826 }
8827
8828 return align;
8829 }
8830
8831 /* Promote the alignment of GNU_TYPE corresponding to GNAT_ENTITY. Return
8832 a positive value on success or zero on failure. */
8833
8834 static unsigned int
promote_object_alignment(tree gnu_type,Entity_Id gnat_entity)8835 promote_object_alignment (tree gnu_type, Entity_Id gnat_entity)
8836 {
8837 unsigned int align, size_cap, align_cap;
8838
8839 /* No point in promoting the alignment if this doesn't prevent BLKmode access
8840 to the object, in particular block copy, as this will for example disable
8841 the NRV optimization for it. No point in jumping through all the hoops
8842 needed in order to support BIGGEST_ALIGNMENT if we don't really have to.
8843 So we cap to the smallest alignment that corresponds to a known efficient
8844 memory access pattern, except for Atomic and Volatile_Full_Access. */
8845 if (Is_Atomic_Or_VFA (gnat_entity))
8846 {
8847 size_cap = UINT_MAX;
8848 align_cap = BIGGEST_ALIGNMENT;
8849 }
8850 else
8851 {
8852 size_cap = MAX_FIXED_MODE_SIZE;
8853 align_cap = get_mode_alignment (ptr_mode);
8854 }
8855
8856 /* Do the promotion within the above limits. */
8857 if (!tree_fits_uhwi_p (TYPE_SIZE (gnu_type))
8858 || compare_tree_int (TYPE_SIZE (gnu_type), size_cap) > 0)
8859 align = 0;
8860 else if (compare_tree_int (TYPE_SIZE (gnu_type), align_cap) > 0)
8861 align = align_cap;
8862 else
8863 align = ceil_pow2 (tree_to_uhwi (TYPE_SIZE (gnu_type)));
8864
8865 /* But make sure not to under-align the object. */
8866 if (align <= TYPE_ALIGN (gnu_type))
8867 align = 0;
8868
8869 /* And honor the minimum valid atomic alignment, if any. */
8870 #ifdef MINIMUM_ATOMIC_ALIGNMENT
8871 else if (align < MINIMUM_ATOMIC_ALIGNMENT)
8872 align = MINIMUM_ATOMIC_ALIGNMENT;
8873 #endif
8874
8875 return align;
8876 }
8877
8878 /* Verify that TYPE is something we can implement atomically. If not, issue
8879 an error for GNAT_ENTITY. COMPONENT_P is true if we are being called to
8880 process a component type. */
8881
8882 static void
check_ok_for_atomic_type(tree type,Entity_Id gnat_entity,bool component_p)8883 check_ok_for_atomic_type (tree type, Entity_Id gnat_entity, bool component_p)
8884 {
8885 Node_Id gnat_error_point = gnat_entity;
8886 Node_Id gnat_node;
8887 machine_mode mode;
8888 enum mode_class mclass;
8889 unsigned int align;
8890 tree size;
8891
8892 /* If this is an anonymous base type, nothing to check, the error will be
8893 reported on the source type if need be. */
8894 if (!Comes_From_Source (gnat_entity))
8895 return;
8896
8897 mode = TYPE_MODE (type);
8898 mclass = GET_MODE_CLASS (mode);
8899 align = TYPE_ALIGN (type);
8900 size = TYPE_SIZE (type);
8901
8902 /* Consider all aligned floating-point types atomic and any aligned types
8903 that are represented by integers no wider than a machine word. */
8904 scalar_int_mode int_mode;
8905 if ((mclass == MODE_FLOAT
8906 || (is_a <scalar_int_mode> (mode, &int_mode)
8907 && GET_MODE_BITSIZE (int_mode) <= BITS_PER_WORD))
8908 && align >= GET_MODE_ALIGNMENT (mode))
8909 return;
8910
8911 /* For the moment, also allow anything that has an alignment equal to its
8912 size and which is smaller than a word. */
8913 if (size
8914 && TREE_CODE (size) == INTEGER_CST
8915 && compare_tree_int (size, align) == 0
8916 && align <= BITS_PER_WORD)
8917 return;
8918
8919 for (gnat_node = First_Rep_Item (gnat_entity);
8920 Present (gnat_node);
8921 gnat_node = Next_Rep_Item (gnat_node))
8922 if (Nkind (gnat_node) == N_Pragma)
8923 {
8924 unsigned char pragma_id
8925 = Get_Pragma_Id (Chars (Pragma_Identifier (gnat_node)));
8926
8927 if ((pragma_id == Pragma_Atomic && !component_p)
8928 || (pragma_id == Pragma_Atomic_Components && component_p))
8929 {
8930 gnat_error_point = First (Pragma_Argument_Associations (gnat_node));
8931 break;
8932 }
8933 }
8934
8935 if (component_p)
8936 post_error_ne ("atomic access to component of & cannot be guaranteed",
8937 gnat_error_point, gnat_entity);
8938 else if (Is_Volatile_Full_Access (gnat_entity))
8939 post_error_ne ("volatile full access to & cannot be guaranteed",
8940 gnat_error_point, gnat_entity);
8941 else
8942 post_error_ne ("atomic access to & cannot be guaranteed",
8943 gnat_error_point, gnat_entity);
8944 }
8945
8946
8947 /* Helper for the intrin compatibility checks family. Evaluate whether
8948 two types are definitely incompatible. */
8949
8950 static bool
intrin_types_incompatible_p(tree t1,tree t2)8951 intrin_types_incompatible_p (tree t1, tree t2)
8952 {
8953 enum tree_code code;
8954
8955 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
8956 return false;
8957
8958 if (TYPE_MODE (t1) != TYPE_MODE (t2))
8959 return true;
8960
8961 if (TREE_CODE (t1) != TREE_CODE (t2))
8962 return true;
8963
8964 code = TREE_CODE (t1);
8965
8966 switch (code)
8967 {
8968 case INTEGER_TYPE:
8969 case REAL_TYPE:
8970 return TYPE_PRECISION (t1) != TYPE_PRECISION (t2);
8971
8972 case POINTER_TYPE:
8973 case REFERENCE_TYPE:
8974 /* Assume designated types are ok. We'd need to account for char * and
8975 void * variants to do better, which could rapidly get messy and isn't
8976 clearly worth the effort. */
8977 return false;
8978
8979 default:
8980 break;
8981 }
8982
8983 return false;
8984 }
8985
8986 /* Helper for intrin_profiles_compatible_p, to perform compatibility checks
8987 on the Ada/builtin argument lists for the INB binding. */
8988
8989 static bool
intrin_arglists_compatible_p(intrin_binding_t * inb)8990 intrin_arglists_compatible_p (intrin_binding_t * inb)
8991 {
8992 function_args_iterator ada_iter, btin_iter;
8993
8994 function_args_iter_init (&ada_iter, inb->ada_fntype);
8995 function_args_iter_init (&btin_iter, inb->btin_fntype);
8996
8997 /* Sequence position of the last argument we checked. */
8998 int argpos = 0;
8999
9000 while (true)
9001 {
9002 tree ada_type = function_args_iter_cond (&ada_iter);
9003 tree btin_type = function_args_iter_cond (&btin_iter);
9004
9005 /* If we've exhausted both lists simultaneously, we're done. */
9006 if (!ada_type && !btin_type)
9007 break;
9008
9009 /* If one list is shorter than the other, they fail to match. */
9010 if (!ada_type || !btin_type)
9011 return false;
9012
9013 /* If we're done with the Ada args and not with the internal builtin
9014 args, or the other way around, complain. */
9015 if (ada_type == void_type_node
9016 && btin_type != void_type_node)
9017 {
9018 post_error ("?Ada arguments list too short!", inb->gnat_entity);
9019 return false;
9020 }
9021
9022 if (btin_type == void_type_node
9023 && ada_type != void_type_node)
9024 {
9025 post_error_ne_num ("?Ada arguments list too long ('> ^)!",
9026 inb->gnat_entity, inb->gnat_entity, argpos);
9027 return false;
9028 }
9029
9030 /* Otherwise, check that types match for the current argument. */
9031 argpos ++;
9032 if (intrin_types_incompatible_p (ada_type, btin_type))
9033 {
9034 post_error_ne_num ("?intrinsic binding type mismatch on argument ^!",
9035 inb->gnat_entity, inb->gnat_entity, argpos);
9036 return false;
9037 }
9038
9039
9040 function_args_iter_next (&ada_iter);
9041 function_args_iter_next (&btin_iter);
9042 }
9043
9044 return true;
9045 }
9046
9047 /* Helper for intrin_profiles_compatible_p, to perform compatibility checks
9048 on the Ada/builtin return values for the INB binding. */
9049
9050 static bool
intrin_return_compatible_p(intrin_binding_t * inb)9051 intrin_return_compatible_p (intrin_binding_t * inb)
9052 {
9053 tree ada_return_type = TREE_TYPE (inb->ada_fntype);
9054 tree btin_return_type = TREE_TYPE (inb->btin_fntype);
9055
9056 /* Accept function imported as procedure, common and convenient. */
9057 if (VOID_TYPE_P (ada_return_type)
9058 && !VOID_TYPE_P (btin_return_type))
9059 return true;
9060
9061 /* Check return types compatibility otherwise. Note that this
9062 handles void/void as well. */
9063 if (intrin_types_incompatible_p (btin_return_type, ada_return_type))
9064 {
9065 post_error ("?intrinsic binding type mismatch on return value!",
9066 inb->gnat_entity);
9067 return false;
9068 }
9069
9070 return true;
9071 }
9072
9073 /* Check and return whether the Ada and gcc builtin profiles bound by INB are
9074 compatible. Issue relevant warnings when they are not.
9075
9076 This is intended as a light check to diagnose the most obvious cases, not
9077 as a full fledged type compatibility predicate. It is the programmer's
9078 responsibility to ensure correctness of the Ada declarations in Imports,
9079 especially when binding straight to a compiler internal. */
9080
9081 static bool
intrin_profiles_compatible_p(intrin_binding_t * inb)9082 intrin_profiles_compatible_p (intrin_binding_t * inb)
9083 {
9084 /* Check compatibility on return values and argument lists, each responsible
9085 for posting warnings as appropriate. Ensure use of the proper sloc for
9086 this purpose. */
9087
9088 bool arglists_compatible_p, return_compatible_p;
9089 location_t saved_location = input_location;
9090
9091 Sloc_to_locus (Sloc (inb->gnat_entity), &input_location);
9092
9093 return_compatible_p = intrin_return_compatible_p (inb);
9094 arglists_compatible_p = intrin_arglists_compatible_p (inb);
9095
9096 input_location = saved_location;
9097
9098 return return_compatible_p && arglists_compatible_p;
9099 }
9100
9101 /* Return a FIELD_DECL node modeled on OLD_FIELD. FIELD_TYPE is its type
9102 and RECORD_TYPE is the type of the parent. If SIZE is nonzero, it is the
9103 specified size for this field. POS_LIST is a position list describing
9104 the layout of OLD_FIELD and SUBST_LIST a substitution list to be applied
9105 to this layout. */
9106
9107 static tree
create_field_decl_from(tree old_field,tree field_type,tree record_type,tree size,tree pos_list,vec<subst_pair> subst_list)9108 create_field_decl_from (tree old_field, tree field_type, tree record_type,
9109 tree size, tree pos_list,
9110 vec<subst_pair> subst_list)
9111 {
9112 tree t = TREE_VALUE (purpose_member (old_field, pos_list));
9113 tree pos = TREE_VEC_ELT (t, 0), bitpos = TREE_VEC_ELT (t, 2);
9114 unsigned int offset_align = tree_to_uhwi (TREE_VEC_ELT (t, 1));
9115 tree new_pos, new_field;
9116 unsigned int i;
9117 subst_pair *s;
9118
9119 if (CONTAINS_PLACEHOLDER_P (pos))
9120 FOR_EACH_VEC_ELT (subst_list, i, s)
9121 pos = SUBSTITUTE_IN_EXPR (pos, s->discriminant, s->replacement);
9122
9123 /* If the position is now a constant, we can set it as the position of the
9124 field when we make it. Otherwise, we need to deal with it specially. */
9125 if (TREE_CONSTANT (pos))
9126 new_pos = bit_from_pos (pos, bitpos);
9127 else
9128 new_pos = NULL_TREE;
9129
9130 new_field
9131 = create_field_decl (DECL_NAME (old_field), field_type, record_type,
9132 size, new_pos, DECL_PACKED (old_field),
9133 !DECL_NONADDRESSABLE_P (old_field));
9134
9135 if (!new_pos)
9136 {
9137 normalize_offset (&pos, &bitpos, offset_align);
9138 /* Finalize the position. */
9139 DECL_FIELD_OFFSET (new_field) = variable_size (pos);
9140 DECL_FIELD_BIT_OFFSET (new_field) = bitpos;
9141 SET_DECL_OFFSET_ALIGN (new_field, offset_align);
9142 DECL_SIZE (new_field) = size;
9143 DECL_SIZE_UNIT (new_field)
9144 = convert (sizetype,
9145 size_binop (CEIL_DIV_EXPR, size, bitsize_unit_node));
9146 layout_decl (new_field, DECL_OFFSET_ALIGN (new_field));
9147 }
9148
9149 DECL_INTERNAL_P (new_field) = DECL_INTERNAL_P (old_field);
9150 SET_DECL_ORIGINAL_FIELD_TO_FIELD (new_field, old_field);
9151 DECL_DISCRIMINANT_NUMBER (new_field) = DECL_DISCRIMINANT_NUMBER (old_field);
9152 TREE_THIS_VOLATILE (new_field) = TREE_THIS_VOLATILE (old_field);
9153
9154 return new_field;
9155 }
9156
9157 /* Create the REP part of RECORD_TYPE with REP_TYPE. If MIN_SIZE is nonzero,
9158 it is the minimal size the REP_PART must have. */
9159
9160 static tree
create_rep_part(tree rep_type,tree record_type,tree min_size)9161 create_rep_part (tree rep_type, tree record_type, tree min_size)
9162 {
9163 tree field;
9164
9165 if (min_size && !tree_int_cst_lt (TYPE_SIZE (rep_type), min_size))
9166 min_size = NULL_TREE;
9167
9168 field = create_field_decl (get_identifier ("REP"), rep_type, record_type,
9169 min_size, NULL_TREE, 0, 1);
9170 DECL_INTERNAL_P (field) = 1;
9171
9172 return field;
9173 }
9174
9175 /* Return the REP part of RECORD_TYPE, if any. Otherwise return NULL. */
9176
9177 static tree
get_rep_part(tree record_type)9178 get_rep_part (tree record_type)
9179 {
9180 tree field = TYPE_FIELDS (record_type);
9181
9182 /* The REP part is the first field, internal, another record, and its name
9183 starts with an 'R'. */
9184 if (field
9185 && DECL_INTERNAL_P (field)
9186 && TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE
9187 && IDENTIFIER_POINTER (DECL_NAME (field)) [0] == 'R')
9188 return field;
9189
9190 return NULL_TREE;
9191 }
9192
9193 /* Return the variant part of RECORD_TYPE, if any. Otherwise return NULL. */
9194
9195 tree
get_variant_part(tree record_type)9196 get_variant_part (tree record_type)
9197 {
9198 tree field;
9199
9200 /* The variant part is the only internal field that is a qualified union. */
9201 for (field = TYPE_FIELDS (record_type); field; field = DECL_CHAIN (field))
9202 if (DECL_INTERNAL_P (field)
9203 && TREE_CODE (TREE_TYPE (field)) == QUAL_UNION_TYPE)
9204 return field;
9205
9206 return NULL_TREE;
9207 }
9208
9209 /* Return a new variant part modeled on OLD_VARIANT_PART. VARIANT_LIST is
9210 the list of variants to be used and RECORD_TYPE is the type of the parent.
9211 POS_LIST is a position list describing the layout of fields present in
9212 OLD_VARIANT_PART and SUBST_LIST a substitution list to be applied to this
9213 layout. DEBUG_INFO_P is true if we need to write debug information. */
9214
9215 static tree
create_variant_part_from(tree old_variant_part,vec<variant_desc> variant_list,tree record_type,tree pos_list,vec<subst_pair> subst_list,bool debug_info_p)9216 create_variant_part_from (tree old_variant_part,
9217 vec<variant_desc> variant_list,
9218 tree record_type, tree pos_list,
9219 vec<subst_pair> subst_list,
9220 bool debug_info_p)
9221 {
9222 tree offset = DECL_FIELD_OFFSET (old_variant_part);
9223 tree old_union_type = TREE_TYPE (old_variant_part);
9224 tree new_union_type, new_variant_part;
9225 tree union_field_list = NULL_TREE;
9226 variant_desc *v;
9227 unsigned int i;
9228
9229 /* First create the type of the variant part from that of the old one. */
9230 new_union_type = make_node (QUAL_UNION_TYPE);
9231 TYPE_NAME (new_union_type)
9232 = concat_name (TYPE_NAME (record_type),
9233 IDENTIFIER_POINTER (DECL_NAME (old_variant_part)));
9234
9235 /* If the position of the variant part is constant, subtract it from the
9236 size of the type of the parent to get the new size. This manual CSE
9237 reduces the code size when not optimizing. */
9238 if (TREE_CODE (offset) == INTEGER_CST
9239 && TYPE_SIZE (record_type)
9240 && TYPE_SIZE_UNIT (record_type))
9241 {
9242 tree bitpos = DECL_FIELD_BIT_OFFSET (old_variant_part);
9243 tree first_bit = bit_from_pos (offset, bitpos);
9244 TYPE_SIZE (new_union_type)
9245 = size_binop (MINUS_EXPR, TYPE_SIZE (record_type), first_bit);
9246 TYPE_SIZE_UNIT (new_union_type)
9247 = size_binop (MINUS_EXPR, TYPE_SIZE_UNIT (record_type),
9248 byte_from_pos (offset, bitpos));
9249 SET_TYPE_ADA_SIZE (new_union_type,
9250 size_binop (MINUS_EXPR, TYPE_ADA_SIZE (record_type),
9251 first_bit));
9252 SET_TYPE_ALIGN (new_union_type, TYPE_ALIGN (old_union_type));
9253 relate_alias_sets (new_union_type, old_union_type, ALIAS_SET_COPY);
9254 }
9255 else
9256 copy_and_substitute_in_size (new_union_type, old_union_type, subst_list);
9257
9258 /* Now finish up the new variants and populate the union type. */
9259 FOR_EACH_VEC_ELT_REVERSE (variant_list, i, v)
9260 {
9261 tree old_field = v->field, new_field;
9262 tree old_variant, old_variant_subpart, new_variant, field_list;
9263
9264 /* Skip variants that don't belong to this nesting level. */
9265 if (DECL_CONTEXT (old_field) != old_union_type)
9266 continue;
9267
9268 /* Retrieve the list of fields already added to the new variant. */
9269 new_variant = v->new_type;
9270 field_list = TYPE_FIELDS (new_variant);
9271
9272 /* If the old variant had a variant subpart, we need to create a new
9273 variant subpart and add it to the field list. */
9274 old_variant = v->type;
9275 old_variant_subpart = get_variant_part (old_variant);
9276 if (old_variant_subpart)
9277 {
9278 tree new_variant_subpart
9279 = create_variant_part_from (old_variant_subpart, variant_list,
9280 new_variant, pos_list, subst_list,
9281 debug_info_p);
9282 DECL_CHAIN (new_variant_subpart) = field_list;
9283 field_list = new_variant_subpart;
9284 }
9285
9286 /* Finish up the new variant and create the field. */
9287 finish_record_type (new_variant, nreverse (field_list), 2, debug_info_p);
9288 compute_record_mode (new_variant);
9289 create_type_decl (TYPE_NAME (new_variant), new_variant, true,
9290 debug_info_p, Empty);
9291
9292 new_field
9293 = create_field_decl_from (old_field, new_variant, new_union_type,
9294 TYPE_SIZE (new_variant),
9295 pos_list, subst_list);
9296 DECL_QUALIFIER (new_field) = v->qual;
9297 DECL_INTERNAL_P (new_field) = 1;
9298 DECL_CHAIN (new_field) = union_field_list;
9299 union_field_list = new_field;
9300 }
9301
9302 /* Finish up the union type and create the variant part. Note that we don't
9303 reverse the field list because VARIANT_LIST has been traversed in reverse
9304 order. */
9305 finish_record_type (new_union_type, union_field_list, 2, debug_info_p);
9306 compute_record_mode (new_union_type);
9307 create_type_decl (TYPE_NAME (new_union_type), new_union_type, true,
9308 debug_info_p, Empty);
9309
9310 new_variant_part
9311 = create_field_decl_from (old_variant_part, new_union_type, record_type,
9312 TYPE_SIZE (new_union_type),
9313 pos_list, subst_list);
9314 DECL_INTERNAL_P (new_variant_part) = 1;
9315
9316 /* With multiple discriminants it is possible for an inner variant to be
9317 statically selected while outer ones are not; in this case, the list
9318 of fields of the inner variant is not flattened and we end up with a
9319 qualified union with a single member. Drop the useless container. */
9320 if (!DECL_CHAIN (union_field_list))
9321 {
9322 DECL_CONTEXT (union_field_list) = record_type;
9323 DECL_FIELD_OFFSET (union_field_list)
9324 = DECL_FIELD_OFFSET (new_variant_part);
9325 DECL_FIELD_BIT_OFFSET (union_field_list)
9326 = DECL_FIELD_BIT_OFFSET (new_variant_part);
9327 SET_DECL_OFFSET_ALIGN (union_field_list,
9328 DECL_OFFSET_ALIGN (new_variant_part));
9329 new_variant_part = union_field_list;
9330 }
9331
9332 return new_variant_part;
9333 }
9334
9335 /* Copy the size (and alignment and alias set) from OLD_TYPE to NEW_TYPE,
9336 which are both RECORD_TYPE, after applying the substitutions described
9337 in SUBST_LIST. */
9338
9339 static void
copy_and_substitute_in_size(tree new_type,tree old_type,vec<subst_pair> subst_list)9340 copy_and_substitute_in_size (tree new_type, tree old_type,
9341 vec<subst_pair> subst_list)
9342 {
9343 unsigned int i;
9344 subst_pair *s;
9345
9346 TYPE_SIZE (new_type) = TYPE_SIZE (old_type);
9347 TYPE_SIZE_UNIT (new_type) = TYPE_SIZE_UNIT (old_type);
9348 SET_TYPE_ADA_SIZE (new_type, TYPE_ADA_SIZE (old_type));
9349 SET_TYPE_ALIGN (new_type, TYPE_ALIGN (old_type));
9350 relate_alias_sets (new_type, old_type, ALIAS_SET_COPY);
9351
9352 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (new_type)))
9353 FOR_EACH_VEC_ELT (subst_list, i, s)
9354 TYPE_SIZE (new_type)
9355 = SUBSTITUTE_IN_EXPR (TYPE_SIZE (new_type),
9356 s->discriminant, s->replacement);
9357
9358 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE_UNIT (new_type)))
9359 FOR_EACH_VEC_ELT (subst_list, i, s)
9360 TYPE_SIZE_UNIT (new_type)
9361 = SUBSTITUTE_IN_EXPR (TYPE_SIZE_UNIT (new_type),
9362 s->discriminant, s->replacement);
9363
9364 if (CONTAINS_PLACEHOLDER_P (TYPE_ADA_SIZE (new_type)))
9365 FOR_EACH_VEC_ELT (subst_list, i, s)
9366 SET_TYPE_ADA_SIZE
9367 (new_type, SUBSTITUTE_IN_EXPR (TYPE_ADA_SIZE (new_type),
9368 s->discriminant, s->replacement));
9369
9370 /* Finalize the size. */
9371 TYPE_SIZE (new_type) = variable_size (TYPE_SIZE (new_type));
9372 TYPE_SIZE_UNIT (new_type) = variable_size (TYPE_SIZE_UNIT (new_type));
9373 }
9374
9375 /* Return true if DISC is a stored discriminant of RECORD_TYPE. */
9376
9377 static inline bool
is_stored_discriminant(Entity_Id discr,Entity_Id record_type)9378 is_stored_discriminant (Entity_Id discr, Entity_Id record_type)
9379 {
9380 if (Is_Unchecked_Union (record_type))
9381 return false;
9382 else if (Is_Tagged_Type (record_type))
9383 return No (Corresponding_Discriminant (discr));
9384 else if (Ekind (record_type) == E_Record_Type)
9385 return Original_Record_Component (discr) == discr;
9386 else
9387 return true;
9388 }
9389
9390 /* Copy the layout from {GNAT,GNU}_OLD_TYPE to {GNAT,GNU}_NEW_TYPE, which are
9391 both record types, after applying the substitutions described in SUBST_LIST.
9392 DEBUG_INFO_P is true if we need to write debug information for NEW_TYPE. */
9393
9394 static void
copy_and_substitute_in_layout(Entity_Id gnat_new_type,Entity_Id gnat_old_type,tree gnu_new_type,tree gnu_old_type,vec<subst_pair> gnu_subst_list,bool debug_info_p)9395 copy_and_substitute_in_layout (Entity_Id gnat_new_type,
9396 Entity_Id gnat_old_type,
9397 tree gnu_new_type,
9398 tree gnu_old_type,
9399 vec<subst_pair> gnu_subst_list,
9400 bool debug_info_p)
9401 {
9402 const bool is_subtype = (Ekind (gnat_new_type) == E_Record_Subtype);
9403 tree gnu_field_list = NULL_TREE;
9404 bool selected_variant, all_constant_pos = true;
9405 vec<variant_desc> gnu_variant_list;
9406
9407 /* Look for REP and variant parts in the old type. */
9408 tree gnu_rep_part = get_rep_part (gnu_old_type);
9409 tree gnu_variant_part = get_variant_part (gnu_old_type);
9410
9411 /* If there is a variant part, we must compute whether the constraints
9412 statically select a particular variant. If so, we simply drop the
9413 qualified union and flatten the list of fields. Otherwise we will
9414 build a new qualified union for the variants that are still relevant. */
9415 if (gnu_variant_part)
9416 {
9417 variant_desc *v;
9418 unsigned int i;
9419
9420 gnu_variant_list = build_variant_list (TREE_TYPE (gnu_variant_part),
9421 gnu_subst_list, vNULL);
9422
9423 /* If all the qualifiers are unconditionally true, the innermost variant
9424 is statically selected. */
9425 selected_variant = true;
9426 FOR_EACH_VEC_ELT (gnu_variant_list, i, v)
9427 if (!integer_onep (v->qual))
9428 {
9429 selected_variant = false;
9430 break;
9431 }
9432
9433 /* Otherwise, create the new variants. */
9434 if (!selected_variant)
9435 FOR_EACH_VEC_ELT (gnu_variant_list, i, v)
9436 {
9437 tree old_variant = v->type;
9438 tree new_variant = make_node (RECORD_TYPE);
9439 tree suffix
9440 = concat_name (DECL_NAME (gnu_variant_part),
9441 IDENTIFIER_POINTER (DECL_NAME (v->field)));
9442 TYPE_NAME (new_variant)
9443 = concat_name (TYPE_NAME (gnu_new_type),
9444 IDENTIFIER_POINTER (suffix));
9445 TYPE_REVERSE_STORAGE_ORDER (new_variant)
9446 = TYPE_REVERSE_STORAGE_ORDER (gnu_new_type);
9447 copy_and_substitute_in_size (new_variant, old_variant,
9448 gnu_subst_list);
9449 v->new_type = new_variant;
9450 }
9451 }
9452 else
9453 {
9454 gnu_variant_list.create (0);
9455 selected_variant = false;
9456 }
9457
9458 /* Make a list of fields and their position in the old type. */
9459 tree gnu_pos_list
9460 = build_position_list (gnu_old_type,
9461 gnu_variant_list.exists () && !selected_variant,
9462 size_zero_node, bitsize_zero_node,
9463 BIGGEST_ALIGNMENT, NULL_TREE);
9464
9465 /* Now go down every component in the new type and compute its size and
9466 position from those of the component in the old type and the stored
9467 constraints of the new type. */
9468 Entity_Id gnat_field, gnat_old_field;
9469 for (gnat_field = First_Entity (gnat_new_type);
9470 Present (gnat_field);
9471 gnat_field = Next_Entity (gnat_field))
9472 if ((Ekind (gnat_field) == E_Component
9473 || (Ekind (gnat_field) == E_Discriminant
9474 && is_stored_discriminant (gnat_field, gnat_new_type)))
9475 && (gnat_old_field = is_subtype
9476 ? Original_Record_Component (gnat_field)
9477 : Corresponding_Record_Component (gnat_field))
9478 && Underlying_Type (Scope (gnat_old_field)) == gnat_old_type
9479 && present_gnu_tree (gnat_old_field))
9480 {
9481 Name_Id gnat_name = Chars (gnat_field);
9482 tree gnu_old_field = get_gnu_tree (gnat_old_field);
9483 if (TREE_CODE (gnu_old_field) == COMPONENT_REF)
9484 gnu_old_field = TREE_OPERAND (gnu_old_field, 1);
9485 tree gnu_context = DECL_CONTEXT (gnu_old_field);
9486 tree gnu_field, gnu_field_type, gnu_size, gnu_pos;
9487 tree gnu_cont_type, gnu_last = NULL_TREE;
9488
9489 /* If the type is the same, retrieve the GCC type from the
9490 old field to take into account possible adjustments. */
9491 if (Etype (gnat_field) == Etype (gnat_old_field))
9492 gnu_field_type = TREE_TYPE (gnu_old_field);
9493 else
9494 gnu_field_type = gnat_to_gnu_type (Etype (gnat_field));
9495
9496 /* If there was a component clause, the field types must be the same
9497 for the old and new types, so copy the data from the old field to
9498 avoid recomputation here. Also if the field is justified modular
9499 and the optimization in gnat_to_gnu_field was applied. */
9500 if (Present (Component_Clause (gnat_old_field))
9501 || (TREE_CODE (gnu_field_type) == RECORD_TYPE
9502 && TYPE_JUSTIFIED_MODULAR_P (gnu_field_type)
9503 && TREE_TYPE (TYPE_FIELDS (gnu_field_type))
9504 == TREE_TYPE (gnu_old_field)))
9505 {
9506 gnu_size = DECL_SIZE (gnu_old_field);
9507 gnu_field_type = TREE_TYPE (gnu_old_field);
9508 }
9509
9510 /* If the old field was packed and of constant size, we have to get the
9511 old size here as it might differ from what the Etype conveys and the
9512 latter might overlap with the following field. Try to arrange the
9513 type for possible better packing along the way. */
9514 else if (DECL_PACKED (gnu_old_field)
9515 && TREE_CODE (DECL_SIZE (gnu_old_field)) == INTEGER_CST)
9516 {
9517 gnu_size = DECL_SIZE (gnu_old_field);
9518 if (RECORD_OR_UNION_TYPE_P (gnu_field_type)
9519 && !TYPE_FAT_POINTER_P (gnu_field_type)
9520 && tree_fits_uhwi_p (TYPE_SIZE (gnu_field_type)))
9521 gnu_field_type = make_packable_type (gnu_field_type, true);
9522 }
9523
9524 else
9525 gnu_size = TYPE_SIZE (gnu_field_type);
9526
9527 /* If the context of the old field is the old type or its REP part,
9528 put the field directly in the new type; otherwise look up the
9529 context in the variant list and put the field either in the new
9530 type if there is a selected variant or in one new variant. */
9531 if (gnu_context == gnu_old_type
9532 || (gnu_rep_part && gnu_context == TREE_TYPE (gnu_rep_part)))
9533 gnu_cont_type = gnu_new_type;
9534 else
9535 {
9536 variant_desc *v;
9537 unsigned int i;
9538 tree rep_part;
9539
9540 FOR_EACH_VEC_ELT (gnu_variant_list, i, v)
9541 if (gnu_context == v->type
9542 || ((rep_part = get_rep_part (v->type))
9543 && gnu_context == TREE_TYPE (rep_part)))
9544 break;
9545
9546 if (v)
9547 gnu_cont_type = selected_variant ? gnu_new_type : v->new_type;
9548 else
9549 /* The front-end may pass us "ghost" components if it fails to
9550 recognize that a constrain statically selects a particular
9551 variant. Discard them. */
9552 continue;
9553 }
9554
9555 /* Now create the new field modeled on the old one. */
9556 gnu_field
9557 = create_field_decl_from (gnu_old_field, gnu_field_type,
9558 gnu_cont_type, gnu_size,
9559 gnu_pos_list, gnu_subst_list);
9560 gnu_pos = DECL_FIELD_OFFSET (gnu_field);
9561
9562 /* If the context is a variant, put it in the new variant directly. */
9563 if (gnu_cont_type != gnu_new_type)
9564 {
9565 DECL_CHAIN (gnu_field) = TYPE_FIELDS (gnu_cont_type);
9566 TYPE_FIELDS (gnu_cont_type) = gnu_field;
9567 }
9568
9569 /* To match the layout crafted in components_to_record, if this is
9570 the _Tag or _Parent field, put it before any other fields. */
9571 else if (gnat_name == Name_uTag || gnat_name == Name_uParent)
9572 gnu_field_list = chainon (gnu_field_list, gnu_field);
9573
9574 /* Similarly, if this is the _Controller field, put it before the
9575 other fields except for the _Tag or _Parent field. */
9576 else if (gnat_name == Name_uController && gnu_last)
9577 {
9578 DECL_CHAIN (gnu_field) = DECL_CHAIN (gnu_last);
9579 DECL_CHAIN (gnu_last) = gnu_field;
9580 }
9581
9582 /* Otherwise, put it after the other fields. */
9583 else
9584 {
9585 DECL_CHAIN (gnu_field) = gnu_field_list;
9586 gnu_field_list = gnu_field;
9587 if (!gnu_last)
9588 gnu_last = gnu_field;
9589 if (TREE_CODE (gnu_pos) != INTEGER_CST)
9590 all_constant_pos = false;
9591 }
9592
9593 /* For a stored discriminant in a derived type, replace the field. */
9594 if (!is_subtype && Ekind (gnat_field) == E_Discriminant)
9595 {
9596 tree gnu_ref = get_gnu_tree (gnat_field);
9597 TREE_OPERAND (gnu_ref, 1) = gnu_field;
9598 }
9599 else
9600 save_gnu_tree (gnat_field, gnu_field, false);
9601 }
9602
9603 /* If there is no variant list or a selected variant and the fields all have
9604 constant position, put them in order of increasing position to match that
9605 of constant CONSTRUCTORs. */
9606 if ((!gnu_variant_list.exists () || selected_variant) && all_constant_pos)
9607 {
9608 const int len = list_length (gnu_field_list);
9609 tree *field_arr = XALLOCAVEC (tree, len), t = gnu_field_list;
9610
9611 for (int i = 0; t; t = DECL_CHAIN (t), i++)
9612 field_arr[i] = t;
9613
9614 qsort (field_arr, len, sizeof (tree), compare_field_bitpos);
9615
9616 gnu_field_list = NULL_TREE;
9617 for (int i = 0; i < len; i++)
9618 {
9619 DECL_CHAIN (field_arr[i]) = gnu_field_list;
9620 gnu_field_list = field_arr[i];
9621 }
9622 }
9623
9624 /* If there is a variant list and no selected variant, we need to create the
9625 nest of variant parts from the old nest. */
9626 else if (gnu_variant_list.exists () && !selected_variant)
9627 {
9628 tree new_variant_part
9629 = create_variant_part_from (gnu_variant_part, gnu_variant_list,
9630 gnu_new_type, gnu_pos_list,
9631 gnu_subst_list, debug_info_p);
9632 DECL_CHAIN (new_variant_part) = gnu_field_list;
9633 gnu_field_list = new_variant_part;
9634 }
9635
9636 gnu_variant_list.release ();
9637 gnu_subst_list.release ();
9638
9639 gnu_field_list = nreverse (gnu_field_list);
9640
9641 /* If NEW_TYPE is a subtype, it inherits all the attributes from OLD_TYPE.
9642 Otherwise sizes and alignment must be computed independently. */
9643 if (is_subtype)
9644 {
9645 finish_record_type (gnu_new_type, gnu_field_list, 2, debug_info_p);
9646 compute_record_mode (gnu_new_type);
9647 }
9648 else
9649 finish_record_type (gnu_new_type, gnu_field_list, 1, debug_info_p);
9650
9651 /* Now go through the entities again looking for Itypes that we have not yet
9652 elaborated (e.g. Etypes of fields that have Original_Components). */
9653 for (Entity_Id gnat_field = First_Entity (gnat_new_type);
9654 Present (gnat_field);
9655 gnat_field = Next_Entity (gnat_field))
9656 if ((Ekind (gnat_field) == E_Component
9657 || Ekind (gnat_field) == E_Discriminant)
9658 && Is_Itype (Etype (gnat_field))
9659 && !present_gnu_tree (Etype (gnat_field)))
9660 gnat_to_gnu_entity (Etype (gnat_field), NULL_TREE, false);
9661 }
9662
9663 /* Associate to GNU_TYPE, the translation of GNAT_ENTITY, which is
9664 the implementation type of a packed array type (Is_Packed_Array_Impl_Type),
9665 the original array type if it has been translated. This association is a
9666 parallel type for GNAT encodings or a debug type for standard DWARF. Note
9667 that for standard DWARF, we also want to get the original type name. */
9668
9669 static void
associate_original_type_to_packed_array(tree gnu_type,Entity_Id gnat_entity)9670 associate_original_type_to_packed_array (tree gnu_type, Entity_Id gnat_entity)
9671 {
9672 Entity_Id gnat_original_array_type
9673 = Underlying_Type (Original_Array_Type (gnat_entity));
9674 tree gnu_original_array_type;
9675
9676 if (!present_gnu_tree (gnat_original_array_type))
9677 return;
9678
9679 gnu_original_array_type = gnat_to_gnu_type (gnat_original_array_type);
9680
9681 if (TYPE_IS_DUMMY_P (gnu_original_array_type))
9682 return;
9683
9684 if (gnat_encodings == DWARF_GNAT_ENCODINGS_MINIMAL)
9685 {
9686 tree original_name = TYPE_NAME (gnu_original_array_type);
9687
9688 if (TREE_CODE (original_name) == TYPE_DECL)
9689 original_name = DECL_NAME (original_name);
9690
9691 SET_TYPE_ORIGINAL_PACKED_ARRAY (gnu_type, gnu_original_array_type);
9692 TYPE_NAME (gnu_type) = original_name;
9693 }
9694 else
9695 add_parallel_type (gnu_type, gnu_original_array_type);
9696 }
9697
9698 /* Given a type T, a FIELD_DECL F, and a replacement value R, return an
9699 equivalent type with adjusted size expressions where all occurrences
9700 of references to F in a PLACEHOLDER_EXPR have been replaced by R.
9701
9702 The function doesn't update the layout of the type, i.e. it assumes
9703 that the substitution is purely formal. That's why the replacement
9704 value R must itself contain a PLACEHOLDER_EXPR. */
9705
9706 tree
substitute_in_type(tree t,tree f,tree r)9707 substitute_in_type (tree t, tree f, tree r)
9708 {
9709 tree nt;
9710
9711 gcc_assert (CONTAINS_PLACEHOLDER_P (r));
9712
9713 switch (TREE_CODE (t))
9714 {
9715 case INTEGER_TYPE:
9716 case ENUMERAL_TYPE:
9717 case BOOLEAN_TYPE:
9718 case REAL_TYPE:
9719
9720 /* First the domain types of arrays. */
9721 if (CONTAINS_PLACEHOLDER_P (TYPE_GCC_MIN_VALUE (t))
9722 || CONTAINS_PLACEHOLDER_P (TYPE_GCC_MAX_VALUE (t)))
9723 {
9724 tree low = SUBSTITUTE_IN_EXPR (TYPE_GCC_MIN_VALUE (t), f, r);
9725 tree high = SUBSTITUTE_IN_EXPR (TYPE_GCC_MAX_VALUE (t), f, r);
9726
9727 if (low == TYPE_GCC_MIN_VALUE (t) && high == TYPE_GCC_MAX_VALUE (t))
9728 return t;
9729
9730 nt = copy_type (t);
9731 TYPE_GCC_MIN_VALUE (nt) = low;
9732 TYPE_GCC_MAX_VALUE (nt) = high;
9733
9734 if (TREE_CODE (t) == INTEGER_TYPE && TYPE_INDEX_TYPE (t))
9735 SET_TYPE_INDEX_TYPE
9736 (nt, substitute_in_type (TYPE_INDEX_TYPE (t), f, r));
9737
9738 return nt;
9739 }
9740
9741 /* Then the subtypes. */
9742 if (CONTAINS_PLACEHOLDER_P (TYPE_RM_MIN_VALUE (t))
9743 || CONTAINS_PLACEHOLDER_P (TYPE_RM_MAX_VALUE (t)))
9744 {
9745 tree low = SUBSTITUTE_IN_EXPR (TYPE_RM_MIN_VALUE (t), f, r);
9746 tree high = SUBSTITUTE_IN_EXPR (TYPE_RM_MAX_VALUE (t), f, r);
9747
9748 if (low == TYPE_RM_MIN_VALUE (t) && high == TYPE_RM_MAX_VALUE (t))
9749 return t;
9750
9751 nt = copy_type (t);
9752 SET_TYPE_RM_MIN_VALUE (nt, low);
9753 SET_TYPE_RM_MAX_VALUE (nt, high);
9754
9755 return nt;
9756 }
9757
9758 return t;
9759
9760 case COMPLEX_TYPE:
9761 nt = substitute_in_type (TREE_TYPE (t), f, r);
9762 if (nt == TREE_TYPE (t))
9763 return t;
9764
9765 return build_complex_type (nt);
9766
9767 case FUNCTION_TYPE:
9768 /* These should never show up here. */
9769 gcc_unreachable ();
9770
9771 case ARRAY_TYPE:
9772 {
9773 tree component = substitute_in_type (TREE_TYPE (t), f, r);
9774 tree domain = substitute_in_type (TYPE_DOMAIN (t), f, r);
9775
9776 if (component == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
9777 return t;
9778
9779 nt = build_nonshared_array_type (component, domain);
9780 SET_TYPE_ALIGN (nt, TYPE_ALIGN (t));
9781 TYPE_USER_ALIGN (nt) = TYPE_USER_ALIGN (t);
9782 SET_TYPE_MODE (nt, TYPE_MODE (t));
9783 TYPE_SIZE (nt) = SUBSTITUTE_IN_EXPR (TYPE_SIZE (t), f, r);
9784 TYPE_SIZE_UNIT (nt) = SUBSTITUTE_IN_EXPR (TYPE_SIZE_UNIT (t), f, r);
9785 TYPE_MULTI_ARRAY_P (nt) = TYPE_MULTI_ARRAY_P (t);
9786 TYPE_CONVENTION_FORTRAN_P (nt) = TYPE_CONVENTION_FORTRAN_P (t);
9787 if (TYPE_REVERSE_STORAGE_ORDER (t))
9788 set_reverse_storage_order_on_array_type (nt);
9789 if (TYPE_NONALIASED_COMPONENT (t))
9790 set_nonaliased_component_on_array_type (nt);
9791 return nt;
9792 }
9793
9794 case RECORD_TYPE:
9795 case UNION_TYPE:
9796 case QUAL_UNION_TYPE:
9797 {
9798 bool changed_field = false;
9799 tree field;
9800
9801 /* Start out with no fields, make new fields, and chain them
9802 in. If we haven't actually changed the type of any field,
9803 discard everything we've done and return the old type. */
9804 nt = copy_type (t);
9805 TYPE_FIELDS (nt) = NULL_TREE;
9806
9807 for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field))
9808 {
9809 tree new_field = copy_node (field), new_n;
9810
9811 new_n = substitute_in_type (TREE_TYPE (field), f, r);
9812 if (new_n != TREE_TYPE (field))
9813 {
9814 TREE_TYPE (new_field) = new_n;
9815 changed_field = true;
9816 }
9817
9818 new_n = SUBSTITUTE_IN_EXPR (DECL_FIELD_OFFSET (field), f, r);
9819 if (new_n != DECL_FIELD_OFFSET (field))
9820 {
9821 DECL_FIELD_OFFSET (new_field) = new_n;
9822 changed_field = true;
9823 }
9824
9825 /* Do the substitution inside the qualifier, if any. */
9826 if (TREE_CODE (t) == QUAL_UNION_TYPE)
9827 {
9828 new_n = SUBSTITUTE_IN_EXPR (DECL_QUALIFIER (field), f, r);
9829 if (new_n != DECL_QUALIFIER (field))
9830 {
9831 DECL_QUALIFIER (new_field) = new_n;
9832 changed_field = true;
9833 }
9834 }
9835
9836 DECL_CONTEXT (new_field) = nt;
9837 SET_DECL_ORIGINAL_FIELD_TO_FIELD (new_field, field);
9838
9839 DECL_CHAIN (new_field) = TYPE_FIELDS (nt);
9840 TYPE_FIELDS (nt) = new_field;
9841 }
9842
9843 if (!changed_field)
9844 return t;
9845
9846 TYPE_FIELDS (nt) = nreverse (TYPE_FIELDS (nt));
9847 TYPE_SIZE (nt) = SUBSTITUTE_IN_EXPR (TYPE_SIZE (t), f, r);
9848 TYPE_SIZE_UNIT (nt) = SUBSTITUTE_IN_EXPR (TYPE_SIZE_UNIT (t), f, r);
9849 SET_TYPE_ADA_SIZE (nt, SUBSTITUTE_IN_EXPR (TYPE_ADA_SIZE (t), f, r));
9850 return nt;
9851 }
9852
9853 default:
9854 return t;
9855 }
9856 }
9857
9858 /* Return the RM size of GNU_TYPE. This is the actual number of bits
9859 needed to represent the object. */
9860
9861 tree
rm_size(tree gnu_type)9862 rm_size (tree gnu_type)
9863 {
9864 /* For integral types, we store the RM size explicitly. */
9865 if (INTEGRAL_TYPE_P (gnu_type) && TYPE_RM_SIZE (gnu_type))
9866 return TYPE_RM_SIZE (gnu_type);
9867
9868 /* Return the RM size of the actual data plus the size of the template. */
9869 if (TREE_CODE (gnu_type) == RECORD_TYPE
9870 && TYPE_CONTAINS_TEMPLATE_P (gnu_type))
9871 return
9872 size_binop (PLUS_EXPR,
9873 rm_size (TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (gnu_type)))),
9874 DECL_SIZE (TYPE_FIELDS (gnu_type)));
9875
9876 /* For record or union types, we store the size explicitly. */
9877 if (RECORD_OR_UNION_TYPE_P (gnu_type)
9878 && !TYPE_FAT_POINTER_P (gnu_type)
9879 && TYPE_ADA_SIZE (gnu_type))
9880 return TYPE_ADA_SIZE (gnu_type);
9881
9882 /* For other types, this is just the size. */
9883 return TYPE_SIZE (gnu_type);
9884 }
9885
9886 /* Return the name to be used for GNAT_ENTITY. If a type, create a
9887 fully-qualified name, possibly with type information encoding.
9888 Otherwise, return the name. */
9889
9890 static const char *
get_entity_char(Entity_Id gnat_entity)9891 get_entity_char (Entity_Id gnat_entity)
9892 {
9893 Get_Encoded_Name (gnat_entity);
9894 return ggc_strdup (Name_Buffer);
9895 }
9896
9897 tree
get_entity_name(Entity_Id gnat_entity)9898 get_entity_name (Entity_Id gnat_entity)
9899 {
9900 Get_Encoded_Name (gnat_entity);
9901 return get_identifier_with_length (Name_Buffer, Name_Len);
9902 }
9903
9904 /* Return an identifier representing the external name to be used for
9905 GNAT_ENTITY. If SUFFIX is specified, the name is followed by "___"
9906 and the specified suffix. */
9907
9908 tree
create_concat_name(Entity_Id gnat_entity,const char * suffix)9909 create_concat_name (Entity_Id gnat_entity, const char *suffix)
9910 {
9911 const Entity_Kind kind = Ekind (gnat_entity);
9912 const bool has_suffix = (suffix != NULL);
9913 String_Template temp = {1, has_suffix ? strlen (suffix) : 0};
9914 String_Pointer sp = {suffix, &temp};
9915
9916 Get_External_Name (gnat_entity, has_suffix, sp);
9917
9918 /* A variable using the Stdcall convention lives in a DLL. We adjust
9919 its name to use the jump table, the _imp__NAME contains the address
9920 for the NAME variable. */
9921 if ((kind == E_Variable || kind == E_Constant)
9922 && Has_Stdcall_Convention (gnat_entity))
9923 {
9924 const int len = strlen (STDCALL_PREFIX) + Name_Len;
9925 char *new_name = (char *) alloca (len + 1);
9926 strcpy (new_name, STDCALL_PREFIX);
9927 strcat (new_name, Name_Buffer);
9928 return get_identifier_with_length (new_name, len);
9929 }
9930
9931 return get_identifier_with_length (Name_Buffer, Name_Len);
9932 }
9933
9934 /* Given GNU_NAME, an IDENTIFIER_NODE containing a name and SUFFIX, a
9935 string, return a new IDENTIFIER_NODE that is the concatenation of
9936 the name followed by "___" and the specified suffix. */
9937
9938 tree
concat_name(tree gnu_name,const char * suffix)9939 concat_name (tree gnu_name, const char *suffix)
9940 {
9941 const int len = IDENTIFIER_LENGTH (gnu_name) + 3 + strlen (suffix);
9942 char *new_name = (char *) alloca (len + 1);
9943 strcpy (new_name, IDENTIFIER_POINTER (gnu_name));
9944 strcat (new_name, "___");
9945 strcat (new_name, suffix);
9946 return get_identifier_with_length (new_name, len);
9947 }
9948
9949 /* Initialize data structures of the decl.c module. */
9950
9951 void
init_gnat_decl(void)9952 init_gnat_decl (void)
9953 {
9954 /* Initialize the cache of annotated values. */
9955 annotate_value_cache = hash_table<value_annotation_hasher>::create_ggc (512);
9956
9957 /* Initialize the association of dummy types with subprograms. */
9958 dummy_to_subprog_map = hash_table<dummy_type_hasher>::create_ggc (512);
9959 }
9960
9961 /* Destroy data structures of the decl.c module. */
9962
9963 void
destroy_gnat_decl(void)9964 destroy_gnat_decl (void)
9965 {
9966 /* Destroy the cache of annotated values. */
9967 annotate_value_cache->empty ();
9968 annotate_value_cache = NULL;
9969
9970 /* Destroy the association of dummy types with subprograms. */
9971 dummy_to_subprog_map->empty ();
9972 dummy_to_subprog_map = NULL;
9973 }
9974
9975 #include "gt-ada-decl.h"
9976