1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * D E C L *
6 * *
7 * C Implementation File *
8 * *
9 * Copyright (C) 1992-2013, 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 "tm.h"
30 #include "tree.h"
31 #include "flags.h"
32 #include "toplev.h"
33 #include "ggc.h"
34 #include "target.h"
35 #include "tree-inline.h"
36 #include "diagnostic-core.h"
37
38 #include "ada.h"
39 #include "types.h"
40 #include "atree.h"
41 #include "elists.h"
42 #include "namet.h"
43 #include "nlists.h"
44 #include "repinfo.h"
45 #include "snames.h"
46 #include "stringt.h"
47 #include "uintp.h"
48 #include "fe.h"
49 #include "sinfo.h"
50 #include "einfo.h"
51 #include "ada-tree.h"
52 #include "gigi.h"
53
54 /* "stdcall" and "thiscall" conventions should be processed in a specific way
55 on 32-bit x86/Windows only. The macros below are helpers to avoid having
56 to check for a Windows specific attribute throughout this unit. */
57
58 #if TARGET_DLLIMPORT_DECL_ATTRIBUTES
59 #ifdef TARGET_64BIT
60 #define Has_Stdcall_Convention(E) \
61 (!TARGET_64BIT && Convention (E) == Convention_Stdcall)
62 #define Has_Thiscall_Convention(E) \
63 (!TARGET_64BIT && is_cplusplus_method (E))
64 #else
65 #define Has_Stdcall_Convention(E) (Convention (E) == Convention_Stdcall)
66 #define Has_Thiscall_Convention(E) (is_cplusplus_method (E))
67 #endif
68 #else
69 #define Has_Stdcall_Convention(E) 0
70 #define Has_Thiscall_Convention(E) 0
71 #endif
72
73 /* Stack realignment is necessary for functions with foreign conventions when
74 the ABI doesn't mandate as much as what the compiler assumes - that is, up
75 to PREFERRED_STACK_BOUNDARY.
76
77 Such realignment can be requested with a dedicated function type attribute
78 on the targets that support it. We define FOREIGN_FORCE_REALIGN_STACK to
79 characterize the situations where the attribute should be set. We rely on
80 compiler configuration settings for 'main' to decide. */
81
82 #ifdef MAIN_STACK_BOUNDARY
83 #define FOREIGN_FORCE_REALIGN_STACK \
84 (MAIN_STACK_BOUNDARY < PREFERRED_STACK_BOUNDARY)
85 #else
86 #define FOREIGN_FORCE_REALIGN_STACK 0
87 #endif
88
89 struct incomplete
90 {
91 struct incomplete *next;
92 tree old_type;
93 Entity_Id full_type;
94 };
95
96 /* These variables are used to defer recursively expanding incomplete types
97 while we are processing an array, a record or a subprogram type. */
98 static int defer_incomplete_level = 0;
99 static struct incomplete *defer_incomplete_list;
100
101 /* This variable is used to delay expanding From_With_Type types until the
102 end of the spec. */
103 static struct incomplete *defer_limited_with;
104
105 typedef struct subst_pair_d {
106 tree discriminant;
107 tree replacement;
108 } subst_pair;
109
110
111 typedef struct variant_desc_d {
112 /* The type of the variant. */
113 tree type;
114
115 /* The associated field. */
116 tree field;
117
118 /* The value of the qualifier. */
119 tree qual;
120
121 /* The type of the variant after transformation. */
122 tree new_type;
123 } variant_desc;
124
125
126 /* A hash table used to cache the result of annotate_value. */
127 static GTY ((if_marked ("tree_int_map_marked_p"),
128 param_is (struct tree_int_map))) htab_t annotate_value_cache;
129
130 static bool allocatable_size_p (tree, bool);
131 static void prepend_one_attribute_to (struct attrib **,
132 enum attr_type, tree, tree, Node_Id);
133 static void prepend_attributes (Entity_Id, struct attrib **);
134 static tree elaborate_expression (Node_Id, Entity_Id, tree, bool, bool, bool);
135 static bool type_has_variable_size (tree);
136 static tree elaborate_expression_1 (tree, Entity_Id, tree, bool, bool);
137 static tree elaborate_expression_2 (tree, Entity_Id, tree, bool, bool,
138 unsigned int);
139 static tree gnat_to_gnu_component_type (Entity_Id, bool, bool);
140 static tree gnat_to_gnu_param (Entity_Id, Mechanism_Type, Entity_Id, bool,
141 bool *);
142 static tree gnat_to_gnu_field (Entity_Id, tree, int, bool, bool);
143 static bool same_discriminant_p (Entity_Id, Entity_Id);
144 static bool array_type_has_nonaliased_component (tree, Entity_Id);
145 static bool compile_time_known_address_p (Node_Id);
146 static bool cannot_be_superflat_p (Node_Id);
147 static bool constructor_address_p (tree);
148 static void components_to_record (tree, Node_Id, tree, int, bool, bool, bool,
149 bool, bool, bool, bool, bool, tree, tree *);
150 static Uint annotate_value (tree);
151 static void annotate_rep (Entity_Id, tree);
152 static tree build_position_list (tree, bool, tree, tree, unsigned int, tree);
153 static vec<subst_pair> build_subst_list (Entity_Id, Entity_Id, bool);
154 static vec<variant_desc> build_variant_list (tree,
155 vec<subst_pair> ,
156 vec<variant_desc> );
157 static tree validate_size (Uint, tree, Entity_Id, enum tree_code, bool, bool);
158 static void set_rm_size (Uint, tree, Entity_Id);
159 static unsigned int validate_alignment (Uint, Entity_Id, unsigned int);
160 static void check_ok_for_atomic (tree, Entity_Id, bool);
161 static tree create_field_decl_from (tree, tree, tree, tree, tree,
162 vec<subst_pair> );
163 static tree create_rep_part (tree, tree, tree);
164 static tree get_rep_part (tree);
165 static tree create_variant_part_from (tree, vec<variant_desc> , tree,
166 tree, vec<subst_pair> );
167 static void copy_and_substitute_in_size (tree, tree, vec<subst_pair> );
168
169 /* The relevant constituents of a subprogram binding to a GCC builtin. Used
170 to pass around calls performing profile compatibility checks. */
171
172 typedef struct {
173 Entity_Id gnat_entity; /* The Ada subprogram entity. */
174 tree ada_fntype; /* The corresponding GCC type node. */
175 tree btin_fntype; /* The GCC builtin function type node. */
176 } intrin_binding_t;
177
178 static bool intrin_profiles_compatible_p (intrin_binding_t *);
179
180 /* Given GNAT_ENTITY, a GNAT defining identifier node, which denotes some Ada
181 entity, return the equivalent GCC tree for that entity (a ..._DECL node)
182 and associate the ..._DECL node with the input GNAT defining identifier.
183
184 If GNAT_ENTITY is a variable or a constant declaration, GNU_EXPR gives its
185 initial value (in GCC tree form). This is optional for a variable. For
186 a renamed entity, GNU_EXPR gives the object being renamed.
187
188 DEFINITION is nonzero if this call is intended for a definition. This is
189 used for separate compilation where it is necessary to know whether an
190 external declaration or a definition must be created if the GCC equivalent
191 was not created previously. The value of 1 is normally used for a nonzero
192 DEFINITION, but a value of 2 is used in special circumstances, defined in
193 the code. */
194
195 tree
gnat_to_gnu_entity(Entity_Id gnat_entity,tree gnu_expr,int definition)196 gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition)
197 {
198 /* Contains the kind of the input GNAT node. */
199 const Entity_Kind kind = Ekind (gnat_entity);
200 /* True if this is a type. */
201 const bool is_type = IN (kind, Type_Kind);
202 /* True if debug info is requested for this entity. */
203 const bool debug_info_p = Needs_Debug_Info (gnat_entity);
204 /* True if this entity is to be considered as imported. */
205 const bool imported_p
206 = (Is_Imported (gnat_entity) && No (Address_Clause (gnat_entity)));
207 /* For a type, contains the equivalent GNAT node to be used in gigi. */
208 Entity_Id gnat_equiv_type = Empty;
209 /* Temporary used to walk the GNAT tree. */
210 Entity_Id gnat_temp;
211 /* Contains the GCC DECL node which is equivalent to the input GNAT node.
212 This node will be associated with the GNAT node by calling at the end
213 of the `switch' statement. */
214 tree gnu_decl = NULL_TREE;
215 /* Contains the GCC type to be used for the GCC node. */
216 tree gnu_type = NULL_TREE;
217 /* Contains the GCC size tree to be used for the GCC node. */
218 tree gnu_size = NULL_TREE;
219 /* Contains the GCC name to be used for the GCC node. */
220 tree gnu_entity_name;
221 /* True if we have already saved gnu_decl as a GNAT association. */
222 bool saved = false;
223 /* True if we incremented defer_incomplete_level. */
224 bool this_deferred = false;
225 /* True if we incremented force_global. */
226 bool this_global = false;
227 /* True if we should check to see if elaborated during processing. */
228 bool maybe_present = false;
229 /* True if we made GNU_DECL and its type here. */
230 bool this_made_decl = false;
231 /* Size and alignment of the GCC node, if meaningful. */
232 unsigned int esize = 0, align = 0;
233 /* Contains the list of attributes directly attached to the entity. */
234 struct attrib *attr_list = NULL;
235
236 /* Since a use of an Itype is a definition, process it as such if it
237 is not in a with'ed unit. */
238 if (!definition
239 && is_type
240 && Is_Itype (gnat_entity)
241 && !present_gnu_tree (gnat_entity)
242 && In_Extended_Main_Code_Unit (gnat_entity))
243 {
244 /* Ensure that we are in a subprogram mentioned in the Scope chain of
245 this entity, our current scope is global, or we encountered a task
246 or entry (where we can't currently accurately check scoping). */
247 if (!current_function_decl
248 || DECL_ELABORATION_PROC_P (current_function_decl))
249 {
250 process_type (gnat_entity);
251 return get_gnu_tree (gnat_entity);
252 }
253
254 for (gnat_temp = Scope (gnat_entity);
255 Present (gnat_temp);
256 gnat_temp = Scope (gnat_temp))
257 {
258 if (Is_Type (gnat_temp))
259 gnat_temp = Underlying_Type (gnat_temp);
260
261 if (Ekind (gnat_temp) == E_Subprogram_Body)
262 gnat_temp
263 = Corresponding_Spec (Parent (Declaration_Node (gnat_temp)));
264
265 if (IN (Ekind (gnat_temp), Subprogram_Kind)
266 && Present (Protected_Body_Subprogram (gnat_temp)))
267 gnat_temp = Protected_Body_Subprogram (gnat_temp);
268
269 if (Ekind (gnat_temp) == E_Entry
270 || Ekind (gnat_temp) == E_Entry_Family
271 || Ekind (gnat_temp) == E_Task_Type
272 || (IN (Ekind (gnat_temp), Subprogram_Kind)
273 && present_gnu_tree (gnat_temp)
274 && (current_function_decl
275 == gnat_to_gnu_entity (gnat_temp, NULL_TREE, 0))))
276 {
277 process_type (gnat_entity);
278 return get_gnu_tree (gnat_entity);
279 }
280 }
281
282 /* This abort means the Itype has an incorrect scope, i.e. that its
283 scope does not correspond to the subprogram it is declared in. */
284 gcc_unreachable ();
285 }
286
287 /* If we've already processed this entity, return what we got last time.
288 If we are defining the node, we should not have already processed it.
289 In that case, we will abort below when we try to save a new GCC tree
290 for this object. We also need to handle the case of getting a dummy
291 type when a Full_View exists. */
292 if ((!definition || (is_type && imported_p))
293 && present_gnu_tree (gnat_entity))
294 {
295 gnu_decl = get_gnu_tree (gnat_entity);
296
297 if (TREE_CODE (gnu_decl) == TYPE_DECL
298 && TYPE_IS_DUMMY_P (TREE_TYPE (gnu_decl))
299 && IN (kind, Incomplete_Or_Private_Kind)
300 && Present (Full_View (gnat_entity)))
301 {
302 gnu_decl
303 = gnat_to_gnu_entity (Full_View (gnat_entity), NULL_TREE, 0);
304 save_gnu_tree (gnat_entity, NULL_TREE, false);
305 save_gnu_tree (gnat_entity, gnu_decl, false);
306 }
307
308 return gnu_decl;
309 }
310
311 /* If this is a numeric or enumeral type, or an access type, a nonzero
312 Esize must be specified unless it was specified by the programmer. */
313 gcc_assert (!Unknown_Esize (gnat_entity)
314 || Has_Size_Clause (gnat_entity)
315 || (!IN (kind, Numeric_Kind)
316 && !IN (kind, Enumeration_Kind)
317 && (!IN (kind, Access_Kind)
318 || kind == E_Access_Protected_Subprogram_Type
319 || kind == E_Anonymous_Access_Protected_Subprogram_Type
320 || kind == E_Access_Subtype)));
321
322 /* The RM size must be specified for all discrete and fixed-point types. */
323 gcc_assert (!(IN (kind, Discrete_Or_Fixed_Point_Kind)
324 && Unknown_RM_Size (gnat_entity)));
325
326 /* If we get here, it means we have not yet done anything with this entity.
327 If we are not defining it, it must be a type or an entity that is defined
328 elsewhere or externally, otherwise we should have defined it already. */
329 gcc_assert (definition
330 || type_annotate_only
331 || is_type
332 || kind == E_Discriminant
333 || kind == E_Component
334 || kind == E_Label
335 || (kind == E_Constant && Present (Full_View (gnat_entity)))
336 || Is_Public (gnat_entity));
337
338 /* Get the name of the entity and set up the line number and filename of
339 the original definition for use in any decl we make. */
340 gnu_entity_name = get_entity_name (gnat_entity);
341 Sloc_to_locus (Sloc (gnat_entity), &input_location);
342
343 /* For cases when we are not defining (i.e., we are referencing from
344 another compilation unit) public entities, show we are at global level
345 for the purpose of computing scopes. Don't do this for components or
346 discriminants since the relevant test is whether or not the record is
347 being defined. */
348 if (!definition
349 && kind != E_Component
350 && kind != E_Discriminant
351 && Is_Public (gnat_entity)
352 && !Is_Statically_Allocated (gnat_entity))
353 force_global++, this_global = true;
354
355 /* Handle any attributes directly attached to the entity. */
356 if (Has_Gigi_Rep_Item (gnat_entity))
357 prepend_attributes (gnat_entity, &attr_list);
358
359 /* Do some common processing for types. */
360 if (is_type)
361 {
362 /* Compute the equivalent type to be used in gigi. */
363 gnat_equiv_type = Gigi_Equivalent_Type (gnat_entity);
364
365 /* Machine_Attributes on types are expected to be propagated to
366 subtypes. The corresponding Gigi_Rep_Items are only attached
367 to the first subtype though, so we handle the propagation here. */
368 if (Base_Type (gnat_entity) != gnat_entity
369 && !Is_First_Subtype (gnat_entity)
370 && Has_Gigi_Rep_Item (First_Subtype (Base_Type (gnat_entity))))
371 prepend_attributes (First_Subtype (Base_Type (gnat_entity)),
372 &attr_list);
373
374 /* Compute a default value for the size of an elementary type. */
375 if (Known_Esize (gnat_entity) && Is_Elementary_Type (gnat_entity))
376 {
377 unsigned int max_esize;
378
379 gcc_assert (UI_Is_In_Int_Range (Esize (gnat_entity)));
380 esize = UI_To_Int (Esize (gnat_entity));
381
382 if (IN (kind, Float_Kind))
383 max_esize = fp_prec_to_size (LONG_DOUBLE_TYPE_SIZE);
384 else if (IN (kind, Access_Kind))
385 max_esize = POINTER_SIZE * 2;
386 else
387 max_esize = LONG_LONG_TYPE_SIZE;
388
389 if (esize > max_esize)
390 esize = max_esize;
391 }
392 }
393
394 switch (kind)
395 {
396 case E_Constant:
397 /* If this is a use of a deferred constant without address clause,
398 get its full definition. */
399 if (!definition
400 && No (Address_Clause (gnat_entity))
401 && Present (Full_View (gnat_entity)))
402 {
403 gnu_decl
404 = gnat_to_gnu_entity (Full_View (gnat_entity), gnu_expr, 0);
405 saved = true;
406 break;
407 }
408
409 /* If we have an external constant that we are not defining, get the
410 expression that is was defined to represent. We may throw it away
411 later if it is not a constant. But do not retrieve the expression
412 if it is an allocator because the designated type might be dummy
413 at this point. */
414 if (!definition
415 && !No_Initialization (Declaration_Node (gnat_entity))
416 && Present (Expression (Declaration_Node (gnat_entity)))
417 && Nkind (Expression (Declaration_Node (gnat_entity)))
418 != N_Allocator)
419 {
420 bool went_into_elab_proc = false;
421 int save_force_global = force_global;
422
423 /* The expression may contain N_Expression_With_Actions nodes and
424 thus object declarations from other units. In this case, even
425 though the expression will eventually be discarded since not a
426 constant, the declarations would be stuck either in the global
427 varpool or in the current scope. Therefore we force the local
428 context and create a fake scope that we'll zap at the end. */
429 if (!current_function_decl)
430 {
431 current_function_decl = get_elaboration_procedure ();
432 went_into_elab_proc = true;
433 }
434 force_global = 0;
435 gnat_pushlevel ();
436
437 gnu_expr = gnat_to_gnu (Expression (Declaration_Node (gnat_entity)));
438
439 gnat_zaplevel ();
440 force_global = save_force_global;
441 if (went_into_elab_proc)
442 current_function_decl = NULL_TREE;
443 }
444
445 /* Ignore deferred constant definitions without address clause since
446 they are processed fully in the front-end. If No_Initialization
447 is set, this is not a deferred constant but a constant whose value
448 is built manually. And constants that are renamings are handled
449 like variables. */
450 if (definition
451 && !gnu_expr
452 && No (Address_Clause (gnat_entity))
453 && !No_Initialization (Declaration_Node (gnat_entity))
454 && No (Renamed_Object (gnat_entity)))
455 {
456 gnu_decl = error_mark_node;
457 saved = true;
458 break;
459 }
460
461 /* Ignore constant definitions already marked with the error node. See
462 the N_Object_Declaration case of gnat_to_gnu for the rationale. */
463 if (definition
464 && gnu_expr
465 && present_gnu_tree (gnat_entity)
466 && get_gnu_tree (gnat_entity) == error_mark_node)
467 {
468 maybe_present = true;
469 break;
470 }
471
472 goto object;
473
474 case E_Exception:
475 /* We used to special case VMS exceptions here to directly map them to
476 their associated condition code. Since this code had to be masked
477 dynamically to strip off the severity bits, this caused trouble in
478 the GCC/ZCX case because the "type" pointers we store in the tables
479 have to be static. We now don't special case here anymore, and let
480 the regular processing take place, which leaves us with a regular
481 exception data object for VMS exceptions too. The condition code
482 mapping is taken care of by the front end and the bitmasking by the
483 run-time library. */
484 goto object;
485
486 case E_Discriminant:
487 case E_Component:
488 {
489 /* The GNAT record where the component was defined. */
490 Entity_Id gnat_record = Underlying_Type (Scope (gnat_entity));
491
492 /* If the variable is an inherited record component (in the case of
493 extended record types), just return the inherited entity, which
494 must be a FIELD_DECL. Likewise for discriminants.
495 For discriminants of untagged records which have explicit
496 stored discriminants, return the entity for the corresponding
497 stored discriminant. Also use Original_Record_Component
498 if the record has a private extension. */
499 if (Present (Original_Record_Component (gnat_entity))
500 && Original_Record_Component (gnat_entity) != gnat_entity)
501 {
502 gnu_decl
503 = gnat_to_gnu_entity (Original_Record_Component (gnat_entity),
504 gnu_expr, definition);
505 saved = true;
506 break;
507 }
508
509 /* If the enclosing record has explicit stored discriminants,
510 then it is an untagged record. If the Corresponding_Discriminant
511 is not empty then this must be a renamed discriminant and its
512 Original_Record_Component must point to the corresponding explicit
513 stored discriminant (i.e. we should have taken the previous
514 branch). */
515 else if (Present (Corresponding_Discriminant (gnat_entity))
516 && Is_Tagged_Type (gnat_record))
517 {
518 /* A tagged record has no explicit stored discriminants. */
519 gcc_assert (First_Discriminant (gnat_record)
520 == First_Stored_Discriminant (gnat_record));
521 gnu_decl
522 = gnat_to_gnu_entity (Corresponding_Discriminant (gnat_entity),
523 gnu_expr, definition);
524 saved = true;
525 break;
526 }
527
528 else if (Present (CR_Discriminant (gnat_entity))
529 && type_annotate_only)
530 {
531 gnu_decl = gnat_to_gnu_entity (CR_Discriminant (gnat_entity),
532 gnu_expr, definition);
533 saved = true;
534 break;
535 }
536
537 /* If the enclosing record has explicit stored discriminants, then
538 it is an untagged record. If the Corresponding_Discriminant
539 is not empty then this must be a renamed discriminant and its
540 Original_Record_Component must point to the corresponding explicit
541 stored discriminant (i.e. we should have taken the first
542 branch). */
543 else if (Present (Corresponding_Discriminant (gnat_entity))
544 && (First_Discriminant (gnat_record)
545 != First_Stored_Discriminant (gnat_record)))
546 gcc_unreachable ();
547
548 /* Otherwise, if we are not defining this and we have no GCC type
549 for the containing record, make one for it. Then we should
550 have made our own equivalent. */
551 else if (!definition && !present_gnu_tree (gnat_record))
552 {
553 /* ??? If this is in a record whose scope is a protected
554 type and we have an Original_Record_Component, use it.
555 This is a workaround for major problems in protected type
556 handling. */
557 Entity_Id Scop = Scope (Scope (gnat_entity));
558 if ((Is_Protected_Type (Scop)
559 || (Is_Private_Type (Scop)
560 && Present (Full_View (Scop))
561 && Is_Protected_Type (Full_View (Scop))))
562 && Present (Original_Record_Component (gnat_entity)))
563 {
564 gnu_decl
565 = gnat_to_gnu_entity (Original_Record_Component
566 (gnat_entity),
567 gnu_expr, 0);
568 saved = true;
569 break;
570 }
571
572 gnat_to_gnu_entity (Scope (gnat_entity), NULL_TREE, 0);
573 gnu_decl = get_gnu_tree (gnat_entity);
574 saved = true;
575 break;
576 }
577
578 else
579 /* Here we have no GCC type and this is a reference rather than a
580 definition. This should never happen. Most likely the cause is
581 reference before declaration in the gnat tree for gnat_entity. */
582 gcc_unreachable ();
583 }
584
585 case E_Loop_Parameter:
586 case E_Out_Parameter:
587 case E_Variable:
588
589 /* Simple variables, loop variables, Out parameters and exceptions. */
590 object:
591 {
592 bool const_flag
593 = ((kind == E_Constant || kind == E_Variable)
594 && Is_True_Constant (gnat_entity)
595 && !Treat_As_Volatile (gnat_entity)
596 && (((Nkind (Declaration_Node (gnat_entity))
597 == N_Object_Declaration)
598 && Present (Expression (Declaration_Node (gnat_entity))))
599 || Present (Renamed_Object (gnat_entity))
600 || imported_p));
601 bool inner_const_flag = const_flag;
602 bool static_p = Is_Statically_Allocated (gnat_entity);
603 bool mutable_p = false;
604 bool used_by_ref = false;
605 tree gnu_ext_name = NULL_TREE;
606 tree renamed_obj = NULL_TREE;
607 tree gnu_object_size;
608
609 if (Present (Renamed_Object (gnat_entity)) && !definition)
610 {
611 if (kind == E_Exception)
612 gnu_expr = gnat_to_gnu_entity (Renamed_Entity (gnat_entity),
613 NULL_TREE, 0);
614 else
615 gnu_expr = gnat_to_gnu (Renamed_Object (gnat_entity));
616 }
617
618 /* Get the type after elaborating the renamed object. */
619 gnu_type = gnat_to_gnu_type (Etype (gnat_entity));
620
621 /* If this is a standard exception definition, then use the standard
622 exception type. This is necessary to make sure that imported and
623 exported views of exceptions are properly merged in LTO mode. */
624 if (TREE_CODE (TYPE_NAME (gnu_type)) == TYPE_DECL
625 && DECL_NAME (TYPE_NAME (gnu_type)) == exception_data_name_id)
626 gnu_type = except_type_node;
627
628 /* For a debug renaming declaration, build a debug-only entity. */
629 if (Present (Debug_Renaming_Link (gnat_entity)))
630 {
631 /* Force a non-null value to make sure the symbol is retained. */
632 tree value = build1 (INDIRECT_REF, gnu_type,
633 build1 (NOP_EXPR,
634 build_pointer_type (gnu_type),
635 integer_minus_one_node));
636 gnu_decl = build_decl (input_location,
637 VAR_DECL, gnu_entity_name, gnu_type);
638 SET_DECL_VALUE_EXPR (gnu_decl, value);
639 DECL_HAS_VALUE_EXPR_P (gnu_decl) = 1;
640 gnat_pushdecl (gnu_decl, gnat_entity);
641 break;
642 }
643
644 /* If this is a loop variable, its type should be the base type.
645 This is because the code for processing a loop determines whether
646 a normal loop end test can be done by comparing the bounds of the
647 loop against those of the base type, which is presumed to be the
648 size used for computation. But this is not correct when the size
649 of the subtype is smaller than the type. */
650 if (kind == E_Loop_Parameter)
651 gnu_type = get_base_type (gnu_type);
652
653 /* Reject non-renamed objects whose type is an unconstrained array or
654 any object whose type is a dummy type or void. */
655 if ((TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE
656 && No (Renamed_Object (gnat_entity)))
657 || TYPE_IS_DUMMY_P (gnu_type)
658 || TREE_CODE (gnu_type) == VOID_TYPE)
659 {
660 gcc_assert (type_annotate_only);
661 if (this_global)
662 force_global--;
663 return error_mark_node;
664 }
665
666 /* If an alignment is specified, use it if valid. Note that exceptions
667 are objects but don't have an alignment. We must do this before we
668 validate the size, since the alignment can affect the size. */
669 if (kind != E_Exception && Known_Alignment (gnat_entity))
670 {
671 gcc_assert (Present (Alignment (gnat_entity)));
672
673 align = validate_alignment (Alignment (gnat_entity), gnat_entity,
674 TYPE_ALIGN (gnu_type));
675
676 /* No point in changing the type if there is an address clause
677 as the final type of the object will be a reference type. */
678 if (Present (Address_Clause (gnat_entity)))
679 align = 0;
680 else
681 {
682 tree orig_type = gnu_type;
683
684 gnu_type
685 = maybe_pad_type (gnu_type, NULL_TREE, align, gnat_entity,
686 false, false, definition, true);
687
688 /* If a padding record was made, declare it now since it will
689 never be declared otherwise. This is necessary to ensure
690 that its subtrees are properly marked. */
691 if (gnu_type != orig_type && !DECL_P (TYPE_NAME (gnu_type)))
692 create_type_decl (TYPE_NAME (gnu_type), gnu_type, NULL, true,
693 debug_info_p, gnat_entity);
694 }
695 }
696
697 /* If we are defining the object, see if it has a Size and validate it
698 if so. If we are not defining the object and a Size clause applies,
699 simply retrieve the value. We don't want to ignore the clause and
700 it is expected to have been validated already. Then get the new
701 type, if any. */
702 if (definition)
703 gnu_size = validate_size (Esize (gnat_entity), gnu_type,
704 gnat_entity, VAR_DECL, false,
705 Has_Size_Clause (gnat_entity));
706 else if (Has_Size_Clause (gnat_entity))
707 gnu_size = UI_To_gnu (Esize (gnat_entity), bitsizetype);
708
709 if (gnu_size)
710 {
711 gnu_type
712 = make_type_from_size (gnu_type, gnu_size,
713 Has_Biased_Representation (gnat_entity));
714
715 if (operand_equal_p (TYPE_SIZE (gnu_type), gnu_size, 0))
716 gnu_size = NULL_TREE;
717 }
718
719 /* If this object has self-referential size, it must be a record with
720 a default discriminant. We are supposed to allocate an object of
721 the maximum size in this case, unless it is a constant with an
722 initializing expression, in which case we can get the size from
723 that. Note that the resulting size may still be a variable, so
724 this may end up with an indirect allocation. */
725 if (No (Renamed_Object (gnat_entity))
726 && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type)))
727 {
728 if (gnu_expr && kind == E_Constant)
729 {
730 tree size = TYPE_SIZE (TREE_TYPE (gnu_expr));
731 if (CONTAINS_PLACEHOLDER_P (size))
732 {
733 /* If the initializing expression is itself a constant,
734 despite having a nominal type with self-referential
735 size, we can get the size directly from it. */
736 if (TREE_CODE (gnu_expr) == COMPONENT_REF
737 && TYPE_IS_PADDING_P
738 (TREE_TYPE (TREE_OPERAND (gnu_expr, 0)))
739 && TREE_CODE (TREE_OPERAND (gnu_expr, 0)) == VAR_DECL
740 && (TREE_READONLY (TREE_OPERAND (gnu_expr, 0))
741 || DECL_READONLY_ONCE_ELAB
742 (TREE_OPERAND (gnu_expr, 0))))
743 gnu_size = DECL_SIZE (TREE_OPERAND (gnu_expr, 0));
744 else
745 gnu_size
746 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, gnu_expr);
747 }
748 else
749 gnu_size = size;
750 }
751 /* We may have no GNU_EXPR because No_Initialization is
752 set even though there's an Expression. */
753 else if (kind == E_Constant
754 && (Nkind (Declaration_Node (gnat_entity))
755 == N_Object_Declaration)
756 && Present (Expression (Declaration_Node (gnat_entity))))
757 gnu_size
758 = TYPE_SIZE (gnat_to_gnu_type
759 (Etype
760 (Expression (Declaration_Node (gnat_entity)))));
761 else
762 {
763 gnu_size = max_size (TYPE_SIZE (gnu_type), true);
764 mutable_p = true;
765 }
766
767 /* If we are at global level and the size isn't constant, call
768 elaborate_expression_1 to make a variable for it rather than
769 calculating it each time. */
770 if (global_bindings_p () && !TREE_CONSTANT (gnu_size))
771 gnu_size = elaborate_expression_1 (gnu_size, gnat_entity,
772 get_identifier ("SIZE"),
773 definition, false);
774 }
775
776 /* If the size is zero byte, make it one byte since some linkers have
777 troubles with zero-sized objects. If the object will have a
778 template, that will make it nonzero so don't bother. Also avoid
779 doing that for an object renaming or an object with an address
780 clause, as we would lose useful information on the view size
781 (e.g. for null array slices) and we are not allocating the object
782 here anyway. */
783 if (((gnu_size
784 && integer_zerop (gnu_size)
785 && !TREE_OVERFLOW (gnu_size))
786 || (TYPE_SIZE (gnu_type)
787 && integer_zerop (TYPE_SIZE (gnu_type))
788 && !TREE_OVERFLOW (TYPE_SIZE (gnu_type))))
789 && (!Is_Constr_Subt_For_UN_Aliased (Etype (gnat_entity))
790 || !Is_Array_Type (Etype (gnat_entity)))
791 && No (Renamed_Object (gnat_entity))
792 && No (Address_Clause (gnat_entity)))
793 gnu_size = bitsize_unit_node;
794
795 /* If this is an object with no specified size and alignment, and
796 if either it is atomic or we are not optimizing alignment for
797 space and it is composite and not an exception, an Out parameter
798 or a reference to another object, and the size of its type is a
799 constant, set the alignment to the smallest one which is not
800 smaller than the size, with an appropriate cap. */
801 if (!gnu_size && align == 0
802 && (Is_Atomic (gnat_entity)
803 || (!Optimize_Alignment_Space (gnat_entity)
804 && kind != E_Exception
805 && kind != E_Out_Parameter
806 && Is_Composite_Type (Etype (gnat_entity))
807 && !Is_Constr_Subt_For_UN_Aliased (Etype (gnat_entity))
808 && !Is_Exported (gnat_entity)
809 && !imported_p
810 && No (Renamed_Object (gnat_entity))
811 && No (Address_Clause (gnat_entity))))
812 && TREE_CODE (TYPE_SIZE (gnu_type)) == INTEGER_CST)
813 {
814 unsigned int size_cap, align_cap;
815
816 /* No point in promoting the alignment if this doesn't prevent
817 BLKmode access to the object, in particular block copy, as
818 this will for example disable the NRV optimization for it.
819 No point in jumping through all the hoops needed in order
820 to support BIGGEST_ALIGNMENT if we don't really have to.
821 So we cap to the smallest alignment that corresponds to
822 a known efficient memory access pattern of the target. */
823 if (Is_Atomic (gnat_entity))
824 {
825 size_cap = UINT_MAX;
826 align_cap = BIGGEST_ALIGNMENT;
827 }
828 else
829 {
830 size_cap = MAX_FIXED_MODE_SIZE;
831 align_cap = get_mode_alignment (ptr_mode);
832 }
833
834 if (!host_integerp (TYPE_SIZE (gnu_type), 1)
835 || compare_tree_int (TYPE_SIZE (gnu_type), size_cap) > 0)
836 align = 0;
837 else if (compare_tree_int (TYPE_SIZE (gnu_type), align_cap) > 0)
838 align = align_cap;
839 else
840 align = ceil_pow2 (tree_low_cst (TYPE_SIZE (gnu_type), 1));
841
842 /* But make sure not to under-align the object. */
843 if (align <= TYPE_ALIGN (gnu_type))
844 align = 0;
845
846 /* And honor the minimum valid atomic alignment, if any. */
847 #ifdef MINIMUM_ATOMIC_ALIGNMENT
848 else if (align < MINIMUM_ATOMIC_ALIGNMENT)
849 align = MINIMUM_ATOMIC_ALIGNMENT;
850 #endif
851 }
852
853 /* If the object is set to have atomic components, find the component
854 type and validate it.
855
856 ??? Note that we ignore Has_Volatile_Components on objects; it's
857 not at all clear what to do in that case. */
858 if (Has_Atomic_Components (gnat_entity))
859 {
860 tree gnu_inner = (TREE_CODE (gnu_type) == ARRAY_TYPE
861 ? TREE_TYPE (gnu_type) : gnu_type);
862
863 while (TREE_CODE (gnu_inner) == ARRAY_TYPE
864 && TYPE_MULTI_ARRAY_P (gnu_inner))
865 gnu_inner = TREE_TYPE (gnu_inner);
866
867 check_ok_for_atomic (gnu_inner, gnat_entity, true);
868 }
869
870 /* Now check if the type of the object allows atomic access. Note
871 that we must test the type, even if this object has size and
872 alignment to allow such access, because we will be going inside
873 the padded record to assign to the object. We could fix this by
874 always copying via an intermediate value, but it's not clear it's
875 worth the effort. */
876 if (Is_Atomic (gnat_entity))
877 check_ok_for_atomic (gnu_type, gnat_entity, false);
878
879 /* If this is an aliased object with an unconstrained nominal subtype,
880 make a type that includes the template. */
881 if (Is_Constr_Subt_For_UN_Aliased (Etype (gnat_entity))
882 && Is_Array_Type (Etype (gnat_entity))
883 && !type_annotate_only)
884 {
885 tree gnu_array
886 = gnat_to_gnu_type (Base_Type (Etype (gnat_entity)));
887 gnu_type
888 = build_unc_object_type_from_ptr (TREE_TYPE (gnu_array),
889 gnu_type,
890 concat_name (gnu_entity_name,
891 "UNC"),
892 debug_info_p);
893 }
894
895 /* ??? If this is an object of CW type initialized to a value, try to
896 ensure that the object is sufficient aligned for this value, but
897 without pessimizing the allocation. This is a kludge necessary
898 because we don't support dynamic alignment. */
899 if (align == 0
900 && Ekind (Etype (gnat_entity)) == E_Class_Wide_Subtype
901 && No (Renamed_Object (gnat_entity))
902 && No (Address_Clause (gnat_entity)))
903 align = get_target_system_allocator_alignment () * BITS_PER_UNIT;
904
905 #ifdef MINIMUM_ATOMIC_ALIGNMENT
906 /* If the size is a constant and no alignment is specified, force
907 the alignment to be the minimum valid atomic alignment. The
908 restriction on constant size avoids problems with variable-size
909 temporaries; if the size is variable, there's no issue with
910 atomic access. Also don't do this for a constant, since it isn't
911 necessary and can interfere with constant replacement. Finally,
912 do not do it for Out parameters since that creates an
913 size inconsistency with In parameters. */
914 if (align == 0
915 && MINIMUM_ATOMIC_ALIGNMENT > TYPE_ALIGN (gnu_type)
916 && !FLOAT_TYPE_P (gnu_type)
917 && !const_flag && No (Renamed_Object (gnat_entity))
918 && !imported_p && No (Address_Clause (gnat_entity))
919 && kind != E_Out_Parameter
920 && (gnu_size ? TREE_CODE (gnu_size) == INTEGER_CST
921 : TREE_CODE (TYPE_SIZE (gnu_type)) == INTEGER_CST))
922 align = MINIMUM_ATOMIC_ALIGNMENT;
923 #endif
924
925 /* Make a new type with the desired size and alignment, if needed.
926 But do not take into account alignment promotions to compute the
927 size of the object. */
928 gnu_object_size = gnu_size ? gnu_size : TYPE_SIZE (gnu_type);
929 if (gnu_size || align > 0)
930 {
931 tree orig_type = gnu_type;
932
933 gnu_type = maybe_pad_type (gnu_type, gnu_size, align, gnat_entity,
934 false, false, definition, true);
935
936 /* If a padding record was made, declare it now since it will
937 never be declared otherwise. This is necessary to ensure
938 that its subtrees are properly marked. */
939 if (gnu_type != orig_type && !DECL_P (TYPE_NAME (gnu_type)))
940 create_type_decl (TYPE_NAME (gnu_type), gnu_type, NULL, true,
941 debug_info_p, gnat_entity);
942 }
943
944 /* If this is a renaming, avoid as much as possible to create a new
945 object. However, in several cases, creating it is required.
946 This processing needs to be applied to the raw expression so
947 as to make it more likely to rename the underlying object. */
948 if (Present (Renamed_Object (gnat_entity)))
949 {
950 bool create_normal_object = false;
951
952 /* If the renamed object had padding, strip off the reference
953 to the inner object and reset our type. */
954 if ((TREE_CODE (gnu_expr) == COMPONENT_REF
955 && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (gnu_expr, 0))))
956 /* Strip useless conversions around the object. */
957 || gnat_useless_type_conversion (gnu_expr))
958 {
959 gnu_expr = TREE_OPERAND (gnu_expr, 0);
960 gnu_type = TREE_TYPE (gnu_expr);
961 }
962
963 /* Or else, if the renamed object has an unconstrained type with
964 default discriminant, use the padded type. */
965 else if (TYPE_IS_PADDING_P (TREE_TYPE (gnu_expr))
966 && TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_expr)))
967 == gnu_type
968 && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type)))
969 gnu_type = TREE_TYPE (gnu_expr);
970
971 /* Case 1: If this is a constant renaming stemming from a function
972 call, treat it as a normal object whose initial value is what
973 is being renamed. RM 3.3 says that the result of evaluating a
974 function call is a constant object. As a consequence, it can
975 be the inner object of a constant renaming. In this case, the
976 renaming must be fully instantiated, i.e. it cannot be a mere
977 reference to (part of) an existing object. */
978 if (const_flag)
979 {
980 tree inner_object = gnu_expr;
981 while (handled_component_p (inner_object))
982 inner_object = TREE_OPERAND (inner_object, 0);
983 if (TREE_CODE (inner_object) == CALL_EXPR)
984 create_normal_object = true;
985 }
986
987 /* Otherwise, see if we can proceed with a stabilized version of
988 the renamed entity or if we need to make a new object. */
989 if (!create_normal_object)
990 {
991 tree maybe_stable_expr = NULL_TREE;
992 bool stable = false;
993
994 /* Case 2: If the renaming entity need not be materialized and
995 the renamed expression is something we can stabilize, use
996 that for the renaming. At the global level, we can only do
997 this if we know no SAVE_EXPRs need be made, because the
998 expression we return might be used in arbitrary conditional
999 branches so we must force the evaluation of the SAVE_EXPRs
1000 immediately and this requires a proper function context.
1001 Note that an external constant is at the global level. */
1002 if (!Materialize_Entity (gnat_entity)
1003 && (!((!definition && kind == E_Constant)
1004 || global_bindings_p ())
1005 || (staticp (gnu_expr)
1006 && !TREE_SIDE_EFFECTS (gnu_expr))))
1007 {
1008 maybe_stable_expr
1009 = gnat_stabilize_reference (gnu_expr, true, &stable);
1010
1011 if (stable)
1012 {
1013 /* ??? No DECL_EXPR is created so we need to mark
1014 the expression manually lest it is shared. */
1015 if ((!definition && kind == E_Constant)
1016 || global_bindings_p ())
1017 MARK_VISITED (maybe_stable_expr);
1018 gnu_decl = maybe_stable_expr;
1019 save_gnu_tree (gnat_entity, gnu_decl, true);
1020 saved = true;
1021 annotate_object (gnat_entity, gnu_type, NULL_TREE,
1022 false, false);
1023 /* This assertion will fail if the renamed object
1024 isn't aligned enough as to make it possible to
1025 honor the alignment set on the renaming. */
1026 if (align)
1027 {
1028 unsigned int renamed_align
1029 = DECL_P (gnu_decl)
1030 ? DECL_ALIGN (gnu_decl)
1031 : TYPE_ALIGN (TREE_TYPE (gnu_decl));
1032 gcc_assert (renamed_align >= align);
1033 }
1034 break;
1035 }
1036
1037 /* The stabilization failed. Keep maybe_stable_expr
1038 untouched here to let the pointer case below know
1039 about that failure. */
1040 }
1041
1042 /* Case 3: If this is a constant renaming and creating a
1043 new object is allowed and cheap, treat it as a normal
1044 object whose initial value is what is being renamed. */
1045 if (const_flag
1046 && !Is_Composite_Type
1047 (Underlying_Type (Etype (gnat_entity))))
1048 ;
1049
1050 /* Case 4: Make this into a constant pointer to the object we
1051 are to rename and attach the object to the pointer if it is
1052 something we can stabilize.
1053
1054 From the proper scope, attached objects will be referenced
1055 directly instead of indirectly via the pointer to avoid
1056 subtle aliasing problems with non-addressable entities.
1057 They have to be stable because we must not evaluate the
1058 variables in the expression every time the renaming is used.
1059 The pointer is called a "renaming" pointer in this case.
1060
1061 In the rare cases where we cannot stabilize the renamed
1062 object, we just make a "bare" pointer, and the renamed
1063 entity is always accessed indirectly through it. */
1064 else
1065 {
1066 /* We need to preserve the volatileness of the renamed
1067 object through the indirection. */
1068 if (TREE_THIS_VOLATILE (gnu_expr)
1069 && !TYPE_VOLATILE (gnu_type))
1070 gnu_type
1071 = build_qualified_type (gnu_type,
1072 (TYPE_QUALS (gnu_type)
1073 | TYPE_QUAL_VOLATILE));
1074 gnu_type = build_reference_type (gnu_type);
1075 inner_const_flag = TREE_READONLY (gnu_expr);
1076 const_flag = true;
1077
1078 /* If the previous attempt at stabilizing failed, there
1079 is no point in trying again and we reuse the result
1080 without attaching it to the pointer. In this case it
1081 will only be used as the initializing expression of
1082 the pointer and thus needs no special treatment with
1083 regard to multiple evaluations. */
1084 if (maybe_stable_expr)
1085 ;
1086
1087 /* Otherwise, try to stabilize and attach the expression
1088 to the pointer if the stabilization succeeds.
1089
1090 Note that this might introduce SAVE_EXPRs and we don't
1091 check whether we're at the global level or not. This
1092 is fine since we are building a pointer initializer and
1093 neither the pointer nor the initializing expression can
1094 be accessed before the pointer elaboration has taken
1095 place in a correct program.
1096
1097 These SAVE_EXPRs will be evaluated at the right place
1098 by either the evaluation of the initializer for the
1099 non-global case or the elaboration code for the global
1100 case, and will be attached to the elaboration procedure
1101 in the latter case. */
1102 else
1103 {
1104 maybe_stable_expr
1105 = gnat_stabilize_reference (gnu_expr, true, &stable);
1106
1107 if (stable)
1108 renamed_obj = maybe_stable_expr;
1109
1110 /* Attaching is actually performed downstream, as soon
1111 as we have a VAR_DECL for the pointer we make. */
1112 }
1113
1114 gnu_expr = build_unary_op (ADDR_EXPR, gnu_type,
1115 maybe_stable_expr);
1116
1117 gnu_size = NULL_TREE;
1118 used_by_ref = true;
1119 }
1120 }
1121 }
1122
1123 /* Make a volatile version of this object's type if we are to make
1124 the object volatile. We also interpret 13.3(19) conservatively
1125 and disallow any optimizations for such a non-constant object. */
1126 if ((Treat_As_Volatile (gnat_entity)
1127 || (!const_flag
1128 && gnu_type != except_type_node
1129 && (Is_Exported (gnat_entity)
1130 || imported_p
1131 || Present (Address_Clause (gnat_entity)))))
1132 && !TYPE_VOLATILE (gnu_type))
1133 gnu_type = build_qualified_type (gnu_type,
1134 (TYPE_QUALS (gnu_type)
1135 | TYPE_QUAL_VOLATILE));
1136
1137 /* If we are defining an aliased object whose nominal subtype is
1138 unconstrained, the object is a record that contains both the
1139 template and the object. If there is an initializer, it will
1140 have already been converted to the right type, but we need to
1141 create the template if there is no initializer. */
1142 if (definition
1143 && !gnu_expr
1144 && TREE_CODE (gnu_type) == RECORD_TYPE
1145 && (TYPE_CONTAINS_TEMPLATE_P (gnu_type)
1146 /* Beware that padding might have been introduced above. */
1147 || (TYPE_PADDING_P (gnu_type)
1148 && TREE_CODE (TREE_TYPE (TYPE_FIELDS (gnu_type)))
1149 == RECORD_TYPE
1150 && TYPE_CONTAINS_TEMPLATE_P
1151 (TREE_TYPE (TYPE_FIELDS (gnu_type))))))
1152 {
1153 tree template_field
1154 = TYPE_PADDING_P (gnu_type)
1155 ? TYPE_FIELDS (TREE_TYPE (TYPE_FIELDS (gnu_type)))
1156 : TYPE_FIELDS (gnu_type);
1157 vec<constructor_elt, va_gc> *v;
1158 vec_alloc (v, 1);
1159 tree t = build_template (TREE_TYPE (template_field),
1160 TREE_TYPE (DECL_CHAIN (template_field)),
1161 NULL_TREE);
1162 CONSTRUCTOR_APPEND_ELT (v, template_field, t);
1163 gnu_expr = gnat_build_constructor (gnu_type, v);
1164 }
1165
1166 /* Convert the expression to the type of the object except in the
1167 case where the object's type is unconstrained or the object's type
1168 is a padded record whose field is of self-referential size. In
1169 the former case, converting will generate unnecessary evaluations
1170 of the CONSTRUCTOR to compute the size and in the latter case, we
1171 want to only copy the actual data. Also don't convert to a record
1172 type with a variant part from a record type without one, to keep
1173 the object simpler. */
1174 if (gnu_expr
1175 && TREE_CODE (gnu_type) != UNCONSTRAINED_ARRAY_TYPE
1176 && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type))
1177 && !(TYPE_IS_PADDING_P (gnu_type)
1178 && CONTAINS_PLACEHOLDER_P
1179 (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS (gnu_type)))))
1180 && !(TREE_CODE (gnu_type) == RECORD_TYPE
1181 && TREE_CODE (TREE_TYPE (gnu_expr)) == RECORD_TYPE
1182 && get_variant_part (gnu_type) != NULL_TREE
1183 && get_variant_part (TREE_TYPE (gnu_expr)) == NULL_TREE))
1184 gnu_expr = convert (gnu_type, gnu_expr);
1185
1186 /* If this is a pointer that doesn't have an initializing expression,
1187 initialize it to NULL, unless the object is imported. */
1188 if (definition
1189 && (POINTER_TYPE_P (gnu_type) || TYPE_IS_FAT_POINTER_P (gnu_type))
1190 && !gnu_expr
1191 && !Is_Imported (gnat_entity))
1192 gnu_expr = integer_zero_node;
1193
1194 /* If we are defining the object and it has an Address clause, we must
1195 either get the address expression from the saved GCC tree for the
1196 object if it has a Freeze node, or elaborate the address expression
1197 here since the front-end has guaranteed that the elaboration has no
1198 effects in this case. */
1199 if (definition && Present (Address_Clause (gnat_entity)))
1200 {
1201 Node_Id gnat_expr = Expression (Address_Clause (gnat_entity));
1202 tree gnu_address
1203 = present_gnu_tree (gnat_entity)
1204 ? get_gnu_tree (gnat_entity) : gnat_to_gnu (gnat_expr);
1205
1206 save_gnu_tree (gnat_entity, NULL_TREE, false);
1207
1208 /* Ignore the size. It's either meaningless or was handled
1209 above. */
1210 gnu_size = NULL_TREE;
1211 /* Convert the type of the object to a reference type that can
1212 alias everything as per 13.3(19). */
1213 gnu_type
1214 = build_reference_type_for_mode (gnu_type, ptr_mode, true);
1215 gnu_address = convert (gnu_type, gnu_address);
1216 used_by_ref = true;
1217 const_flag
1218 = !Is_Public (gnat_entity)
1219 || compile_time_known_address_p (gnat_expr);
1220
1221 /* If this is a deferred constant, the initializer is attached to
1222 the full view. */
1223 if (kind == E_Constant && Present (Full_View (gnat_entity)))
1224 gnu_expr
1225 = gnat_to_gnu
1226 (Expression (Declaration_Node (Full_View (gnat_entity))));
1227
1228 /* If we don't have an initializing expression for the underlying
1229 variable, the initializing expression for the pointer is the
1230 specified address. Otherwise, we have to make a COMPOUND_EXPR
1231 to assign both the address and the initial value. */
1232 if (!gnu_expr)
1233 gnu_expr = gnu_address;
1234 else
1235 gnu_expr
1236 = build2 (COMPOUND_EXPR, gnu_type,
1237 build_binary_op
1238 (MODIFY_EXPR, NULL_TREE,
1239 build_unary_op (INDIRECT_REF, NULL_TREE,
1240 gnu_address),
1241 gnu_expr),
1242 gnu_address);
1243 }
1244
1245 /* If it has an address clause and we are not defining it, mark it
1246 as an indirect object. Likewise for Stdcall objects that are
1247 imported. */
1248 if ((!definition && Present (Address_Clause (gnat_entity)))
1249 || (Is_Imported (gnat_entity)
1250 && Has_Stdcall_Convention (gnat_entity)))
1251 {
1252 /* Convert the type of the object to a reference type that can
1253 alias everything as per 13.3(19). */
1254 gnu_type
1255 = build_reference_type_for_mode (gnu_type, ptr_mode, true);
1256 gnu_size = NULL_TREE;
1257
1258 /* No point in taking the address of an initializing expression
1259 that isn't going to be used. */
1260 gnu_expr = NULL_TREE;
1261
1262 /* If it has an address clause whose value is known at compile
1263 time, make the object a CONST_DECL. This will avoid a
1264 useless dereference. */
1265 if (Present (Address_Clause (gnat_entity)))
1266 {
1267 Node_Id gnat_address
1268 = Expression (Address_Clause (gnat_entity));
1269
1270 if (compile_time_known_address_p (gnat_address))
1271 {
1272 gnu_expr = gnat_to_gnu (gnat_address);
1273 const_flag = true;
1274 }
1275 }
1276
1277 used_by_ref = true;
1278 }
1279
1280 /* If we are at top level and this object is of variable size,
1281 make the actual type a hidden pointer to the real type and
1282 make the initializer be a memory allocation and initialization.
1283 Likewise for objects we aren't defining (presumed to be
1284 external references from other packages), but there we do
1285 not set up an initialization.
1286
1287 If the object's size overflows, make an allocator too, so that
1288 Storage_Error gets raised. Note that we will never free
1289 such memory, so we presume it never will get allocated. */
1290 if (!allocatable_size_p (TYPE_SIZE_UNIT (gnu_type),
1291 global_bindings_p ()
1292 || !definition
1293 || static_p)
1294 || (gnu_size
1295 && !allocatable_size_p (convert (sizetype,
1296 size_binop
1297 (CEIL_DIV_EXPR, gnu_size,
1298 bitsize_unit_node)),
1299 global_bindings_p ()
1300 || !definition
1301 || static_p)))
1302 {
1303 gnu_type = build_reference_type (gnu_type);
1304 gnu_size = NULL_TREE;
1305 used_by_ref = true;
1306
1307 /* In case this was a aliased object whose nominal subtype is
1308 unconstrained, the pointer above will be a thin pointer and
1309 build_allocator will automatically make the template.
1310
1311 If we have a template initializer only (that we made above),
1312 pretend there is none and rely on what build_allocator creates
1313 again anyway. Otherwise (if we have a full initializer), get
1314 the data part and feed that to build_allocator.
1315
1316 If we are elaborating a mutable object, tell build_allocator to
1317 ignore a possibly simpler size from the initializer, if any, as
1318 we must allocate the maximum possible size in this case. */
1319 if (definition && !imported_p)
1320 {
1321 tree gnu_alloc_type = TREE_TYPE (gnu_type);
1322
1323 if (TREE_CODE (gnu_alloc_type) == RECORD_TYPE
1324 && TYPE_CONTAINS_TEMPLATE_P (gnu_alloc_type))
1325 {
1326 gnu_alloc_type
1327 = TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (gnu_alloc_type)));
1328
1329 if (TREE_CODE (gnu_expr) == CONSTRUCTOR
1330 && 1 == vec_safe_length (CONSTRUCTOR_ELTS (gnu_expr)))
1331 gnu_expr = 0;
1332 else
1333 gnu_expr
1334 = build_component_ref
1335 (gnu_expr, NULL_TREE,
1336 DECL_CHAIN (TYPE_FIELDS (TREE_TYPE (gnu_expr))),
1337 false);
1338 }
1339
1340 if (TREE_CODE (TYPE_SIZE_UNIT (gnu_alloc_type)) == INTEGER_CST
1341 && !valid_constant_size_p (TYPE_SIZE_UNIT (gnu_alloc_type)))
1342 post_error ("?`Storage_Error` will be raised at run time!",
1343 gnat_entity);
1344
1345 gnu_expr
1346 = build_allocator (gnu_alloc_type, gnu_expr, gnu_type,
1347 Empty, Empty, gnat_entity, mutable_p);
1348 const_flag = true;
1349 }
1350 else
1351 {
1352 gnu_expr = NULL_TREE;
1353 const_flag = false;
1354 }
1355 }
1356
1357 /* If this object would go into the stack and has an alignment larger
1358 than the largest stack alignment the back-end can honor, resort to
1359 a variable of "aligning type". */
1360 if (!global_bindings_p () && !static_p && definition
1361 && !imported_p && TYPE_ALIGN (gnu_type) > BIGGEST_ALIGNMENT)
1362 {
1363 /* Create the new variable. No need for extra room before the
1364 aligned field as this is in automatic storage. */
1365 tree gnu_new_type
1366 = make_aligning_type (gnu_type, TYPE_ALIGN (gnu_type),
1367 TYPE_SIZE_UNIT (gnu_type),
1368 BIGGEST_ALIGNMENT, 0);
1369 tree gnu_new_var
1370 = create_var_decl (create_concat_name (gnat_entity, "ALIGN"),
1371 NULL_TREE, gnu_new_type, NULL_TREE, false,
1372 false, false, false, NULL, gnat_entity);
1373
1374 /* Initialize the aligned field if we have an initializer. */
1375 if (gnu_expr)
1376 add_stmt_with_node
1377 (build_binary_op (MODIFY_EXPR, NULL_TREE,
1378 build_component_ref
1379 (gnu_new_var, NULL_TREE,
1380 TYPE_FIELDS (gnu_new_type), false),
1381 gnu_expr),
1382 gnat_entity);
1383
1384 /* And setup this entity as a reference to the aligned field. */
1385 gnu_type = build_reference_type (gnu_type);
1386 gnu_expr
1387 = build_unary_op
1388 (ADDR_EXPR, gnu_type,
1389 build_component_ref (gnu_new_var, NULL_TREE,
1390 TYPE_FIELDS (gnu_new_type), false));
1391
1392 gnu_size = NULL_TREE;
1393 used_by_ref = true;
1394 const_flag = true;
1395 }
1396
1397 /* If this is an aliased object with an unconstrained nominal subtype,
1398 we make its type a thin reference, i.e. the reference counterpart
1399 of a thin pointer, so that it points to the array part. This is
1400 aimed at making it easier for the debugger to decode the object.
1401 Note that we have to do that this late because of the couple of
1402 allocation adjustments that might be made just above. */
1403 if (Is_Constr_Subt_For_UN_Aliased (Etype (gnat_entity))
1404 && Is_Array_Type (Etype (gnat_entity))
1405 && !type_annotate_only)
1406 {
1407 tree gnu_array
1408 = gnat_to_gnu_type (Base_Type (Etype (gnat_entity)));
1409
1410 /* In case the object with the template has already been allocated
1411 just above, we have nothing to do here. */
1412 if (!TYPE_IS_THIN_POINTER_P (gnu_type))
1413 {
1414 gnu_size = NULL_TREE;
1415 used_by_ref = true;
1416
1417 if (definition && !imported_p)
1418 {
1419 tree gnu_unc_var
1420 = create_var_decl (concat_name (gnu_entity_name, "UNC"),
1421 NULL_TREE, gnu_type, gnu_expr,
1422 const_flag, Is_Public (gnat_entity),
1423 false, static_p, NULL, gnat_entity);
1424 gnu_expr
1425 = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_unc_var);
1426 TREE_CONSTANT (gnu_expr) = 1;
1427 const_flag = true;
1428 }
1429 else
1430 {
1431 gnu_expr = NULL_TREE;
1432 const_flag = false;
1433 }
1434 }
1435
1436 gnu_type
1437 = build_reference_type (TYPE_OBJECT_RECORD_TYPE (gnu_array));
1438 }
1439
1440 if (const_flag)
1441 gnu_type = build_qualified_type (gnu_type, (TYPE_QUALS (gnu_type)
1442 | TYPE_QUAL_CONST));
1443
1444 /* Convert the expression to the type of the object except in the
1445 case where the object's type is unconstrained or the object's type
1446 is a padded record whose field is of self-referential size. In
1447 the former case, converting will generate unnecessary evaluations
1448 of the CONSTRUCTOR to compute the size and in the latter case, we
1449 want to only copy the actual data. Also don't convert to a record
1450 type with a variant part from a record type without one, to keep
1451 the object simpler. */
1452 if (gnu_expr
1453 && TREE_CODE (gnu_type) != UNCONSTRAINED_ARRAY_TYPE
1454 && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type))
1455 && !(TYPE_IS_PADDING_P (gnu_type)
1456 && CONTAINS_PLACEHOLDER_P
1457 (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS (gnu_type)))))
1458 && !(TREE_CODE (gnu_type) == RECORD_TYPE
1459 && TREE_CODE (TREE_TYPE (gnu_expr)) == RECORD_TYPE
1460 && get_variant_part (gnu_type) != NULL_TREE
1461 && get_variant_part (TREE_TYPE (gnu_expr)) == NULL_TREE))
1462 gnu_expr = convert (gnu_type, gnu_expr);
1463
1464 /* If this name is external or there was a name specified, use it,
1465 unless this is a VMS exception object since this would conflict
1466 with the symbol we need to export in addition. Don't use the
1467 Interface_Name if there is an address clause (see CD30005). */
1468 if (!Is_VMS_Exception (gnat_entity)
1469 && ((Present (Interface_Name (gnat_entity))
1470 && No (Address_Clause (gnat_entity)))
1471 || (Is_Public (gnat_entity)
1472 && (!Is_Imported (gnat_entity)
1473 || Is_Exported (gnat_entity)))))
1474 gnu_ext_name = create_concat_name (gnat_entity, NULL);
1475
1476 /* If this is an aggregate constant initialized to a constant, force it
1477 to be statically allocated. This saves an initialization copy. */
1478 if (!static_p
1479 && const_flag
1480 && gnu_expr && TREE_CONSTANT (gnu_expr)
1481 && AGGREGATE_TYPE_P (gnu_type)
1482 && host_integerp (TYPE_SIZE_UNIT (gnu_type), 1)
1483 && !(TYPE_IS_PADDING_P (gnu_type)
1484 && !host_integerp (TYPE_SIZE_UNIT
1485 (TREE_TYPE (TYPE_FIELDS (gnu_type))), 1)))
1486 static_p = true;
1487
1488 /* Now create the variable or the constant and set various flags. */
1489 gnu_decl
1490 = create_var_decl (gnu_entity_name, gnu_ext_name, gnu_type,
1491 gnu_expr, const_flag, Is_Public (gnat_entity),
1492 imported_p || !definition, static_p, attr_list,
1493 gnat_entity);
1494 DECL_BY_REF_P (gnu_decl) = used_by_ref;
1495 DECL_POINTS_TO_READONLY_P (gnu_decl) = used_by_ref && inner_const_flag;
1496 DECL_CAN_NEVER_BE_NULL_P (gnu_decl) = Can_Never_Be_Null (gnat_entity);
1497
1498 /* If we are defining an Out parameter and optimization isn't enabled,
1499 create a fake PARM_DECL for debugging purposes and make it point to
1500 the VAR_DECL. Suppress debug info for the latter but make sure it
1501 will live on the stack so that it can be accessed from within the
1502 debugger through the PARM_DECL. */
1503 if (kind == E_Out_Parameter
1504 && definition
1505 && debug_info_p
1506 && !optimize
1507 && !flag_generate_lto)
1508 {
1509 tree param = create_param_decl (gnu_entity_name, gnu_type, false);
1510 gnat_pushdecl (param, gnat_entity);
1511 SET_DECL_VALUE_EXPR (param, gnu_decl);
1512 DECL_HAS_VALUE_EXPR_P (param) = 1;
1513 DECL_IGNORED_P (gnu_decl) = 1;
1514 TREE_ADDRESSABLE (gnu_decl) = 1;
1515 }
1516
1517 /* If this is a loop parameter, set the corresponding flag. */
1518 else if (kind == E_Loop_Parameter)
1519 DECL_LOOP_PARM_P (gnu_decl) = 1;
1520
1521 /* If this is a renaming pointer, attach the renamed object to it and
1522 register it if we are at the global level. Note that an external
1523 constant is at the global level. */
1524 else if (TREE_CODE (gnu_decl) == VAR_DECL && renamed_obj)
1525 {
1526 SET_DECL_RENAMED_OBJECT (gnu_decl, renamed_obj);
1527 if ((!definition && kind == E_Constant) || global_bindings_p ())
1528 {
1529 DECL_RENAMING_GLOBAL_P (gnu_decl) = 1;
1530 record_global_renaming_pointer (gnu_decl);
1531 }
1532 }
1533
1534 /* If this is a constant and we are defining it or it generates a real
1535 symbol at the object level and we are referencing it, we may want
1536 or need to have a true variable to represent it:
1537 - if optimization isn't enabled, for debugging purposes,
1538 - if the constant is public and not overlaid on something else,
1539 - if its address is taken,
1540 - if either itself or its type is aliased. */
1541 if (TREE_CODE (gnu_decl) == CONST_DECL
1542 && (definition || Sloc (gnat_entity) > Standard_Location)
1543 && ((!optimize && debug_info_p)
1544 || (Is_Public (gnat_entity)
1545 && No (Address_Clause (gnat_entity)))
1546 || Address_Taken (gnat_entity)
1547 || Is_Aliased (gnat_entity)
1548 || Is_Aliased (Etype (gnat_entity))))
1549 {
1550 tree gnu_corr_var
1551 = create_true_var_decl (gnu_entity_name, gnu_ext_name, gnu_type,
1552 gnu_expr, true, Is_Public (gnat_entity),
1553 !definition, static_p, attr_list,
1554 gnat_entity);
1555
1556 SET_DECL_CONST_CORRESPONDING_VAR (gnu_decl, gnu_corr_var);
1557
1558 /* As debugging information will be generated for the variable,
1559 do not generate debugging information for the constant. */
1560 if (debug_info_p)
1561 DECL_IGNORED_P (gnu_decl) = 1;
1562 else
1563 DECL_IGNORED_P (gnu_corr_var) = 1;
1564 }
1565
1566 /* If this is a constant, even if we don't need a true variable, we
1567 may need to avoid returning the initializer in every case. That
1568 can happen for the address of a (constant) constructor because,
1569 upon dereferencing it, the constructor will be reinjected in the
1570 tree, which may not be valid in every case; see lvalue_required_p
1571 for more details. */
1572 if (TREE_CODE (gnu_decl) == CONST_DECL)
1573 DECL_CONST_ADDRESS_P (gnu_decl) = constructor_address_p (gnu_expr);
1574
1575 /* If this object is declared in a block that contains a block with an
1576 exception handler, and we aren't using the GCC exception mechanism,
1577 we must force this variable in memory in order to avoid an invalid
1578 optimization. */
1579 if (Exception_Mechanism != Back_End_Exceptions
1580 && Has_Nested_Block_With_Handler (Scope (gnat_entity)))
1581 TREE_ADDRESSABLE (gnu_decl) = 1;
1582
1583 /* If we are defining an object with variable size or an object with
1584 fixed size that will be dynamically allocated, and we are using the
1585 setjmp/longjmp exception mechanism, update the setjmp buffer. */
1586 if (definition
1587 && Exception_Mechanism == Setjmp_Longjmp
1588 && get_block_jmpbuf_decl ()
1589 && DECL_SIZE_UNIT (gnu_decl)
1590 && (TREE_CODE (DECL_SIZE_UNIT (gnu_decl)) != INTEGER_CST
1591 || (flag_stack_check == GENERIC_STACK_CHECK
1592 && compare_tree_int (DECL_SIZE_UNIT (gnu_decl),
1593 STACK_CHECK_MAX_VAR_SIZE) > 0)))
1594 add_stmt_with_node (build_call_n_expr
1595 (update_setjmp_buf_decl, 1,
1596 build_unary_op (ADDR_EXPR, NULL_TREE,
1597 get_block_jmpbuf_decl ())),
1598 gnat_entity);
1599
1600 /* Back-annotate Esize and Alignment of the object if not already
1601 known. Note that we pick the values of the type, not those of
1602 the object, to shield ourselves from low-level platform-dependent
1603 adjustments like alignment promotion. This is both consistent with
1604 all the treatment above, where alignment and size are set on the
1605 type of the object and not on the object directly, and makes it
1606 possible to support all confirming representation clauses. */
1607 annotate_object (gnat_entity, TREE_TYPE (gnu_decl), gnu_object_size,
1608 used_by_ref, false);
1609 }
1610 break;
1611
1612 case E_Void:
1613 /* Return a TYPE_DECL for "void" that we previously made. */
1614 gnu_decl = TYPE_NAME (void_type_node);
1615 break;
1616
1617 case E_Enumeration_Type:
1618 /* A special case: for the types Character and Wide_Character in
1619 Standard, we do not list all the literals. So if the literals
1620 are not specified, make this an unsigned type. */
1621 if (No (First_Literal (gnat_entity)))
1622 {
1623 gnu_type = make_unsigned_type (esize);
1624 TYPE_NAME (gnu_type) = gnu_entity_name;
1625
1626 /* Set TYPE_STRING_FLAG for Character and Wide_Character types.
1627 This is needed by the DWARF-2 back-end to distinguish between
1628 unsigned integer types and character types. */
1629 TYPE_STRING_FLAG (gnu_type) = 1;
1630 break;
1631 }
1632
1633 {
1634 /* We have a list of enumeral constants in First_Literal. We make a
1635 CONST_DECL for each one and build into GNU_LITERAL_LIST the list to
1636 be placed into TYPE_FIELDS. Each node in the list is a TREE_LIST
1637 whose TREE_VALUE is the literal name and whose TREE_PURPOSE is the
1638 value of the literal. But when we have a regular boolean type, we
1639 simplify this a little by using a BOOLEAN_TYPE. */
1640 bool is_boolean = Is_Boolean_Type (gnat_entity)
1641 && !Has_Non_Standard_Rep (gnat_entity);
1642 tree gnu_literal_list = NULL_TREE;
1643 Entity_Id gnat_literal;
1644
1645 if (Is_Unsigned_Type (gnat_entity))
1646 gnu_type = make_unsigned_type (esize);
1647 else
1648 gnu_type = make_signed_type (esize);
1649
1650 TREE_SET_CODE (gnu_type, is_boolean ? BOOLEAN_TYPE : ENUMERAL_TYPE);
1651
1652 for (gnat_literal = First_Literal (gnat_entity);
1653 Present (gnat_literal);
1654 gnat_literal = Next_Literal (gnat_literal))
1655 {
1656 tree gnu_value
1657 = UI_To_gnu (Enumeration_Rep (gnat_literal), gnu_type);
1658 tree gnu_literal
1659 = create_var_decl (get_entity_name (gnat_literal), NULL_TREE,
1660 gnu_type, gnu_value, true, false, false,
1661 false, NULL, gnat_literal);
1662 /* Do not generate debug info for individual enumerators. */
1663 DECL_IGNORED_P (gnu_literal) = 1;
1664 save_gnu_tree (gnat_literal, gnu_literal, false);
1665 gnu_literal_list = tree_cons (DECL_NAME (gnu_literal),
1666 gnu_value, gnu_literal_list);
1667 }
1668
1669 if (!is_boolean)
1670 TYPE_VALUES (gnu_type) = nreverse (gnu_literal_list);
1671
1672 /* Note that the bounds are updated at the end of this function
1673 to avoid an infinite recursion since they refer to the type. */
1674 }
1675 goto discrete_type;
1676
1677 case E_Signed_Integer_Type:
1678 case E_Ordinary_Fixed_Point_Type:
1679 case E_Decimal_Fixed_Point_Type:
1680 /* For integer types, just make a signed type the appropriate number
1681 of bits. */
1682 gnu_type = make_signed_type (esize);
1683 goto discrete_type;
1684
1685 case E_Modular_Integer_Type:
1686 {
1687 /* For modular types, make the unsigned type of the proper number
1688 of bits and then set up the modulus, if required. */
1689 tree gnu_modulus, gnu_high = NULL_TREE;
1690
1691 /* Packed array types are supposed to be subtypes only. */
1692 gcc_assert (!Is_Packed_Array_Type (gnat_entity));
1693
1694 gnu_type = make_unsigned_type (esize);
1695
1696 /* Get the modulus in this type. If it overflows, assume it is because
1697 it is equal to 2**Esize. Note that there is no overflow checking
1698 done on unsigned type, so we detect the overflow by looking for
1699 a modulus of zero, which is otherwise invalid. */
1700 gnu_modulus = UI_To_gnu (Modulus (gnat_entity), gnu_type);
1701
1702 if (!integer_zerop (gnu_modulus))
1703 {
1704 TYPE_MODULAR_P (gnu_type) = 1;
1705 SET_TYPE_MODULUS (gnu_type, gnu_modulus);
1706 gnu_high = fold_build2 (MINUS_EXPR, gnu_type, gnu_modulus,
1707 convert (gnu_type, integer_one_node));
1708 }
1709
1710 /* If the upper bound is not maximal, make an extra subtype. */
1711 if (gnu_high
1712 && !tree_int_cst_equal (gnu_high, TYPE_MAX_VALUE (gnu_type)))
1713 {
1714 tree gnu_subtype = make_unsigned_type (esize);
1715 SET_TYPE_RM_MAX_VALUE (gnu_subtype, gnu_high);
1716 TREE_TYPE (gnu_subtype) = gnu_type;
1717 TYPE_EXTRA_SUBTYPE_P (gnu_subtype) = 1;
1718 TYPE_NAME (gnu_type) = create_concat_name (gnat_entity, "UMT");
1719 gnu_type = gnu_subtype;
1720 }
1721 }
1722 goto discrete_type;
1723
1724 case E_Signed_Integer_Subtype:
1725 case E_Enumeration_Subtype:
1726 case E_Modular_Integer_Subtype:
1727 case E_Ordinary_Fixed_Point_Subtype:
1728 case E_Decimal_Fixed_Point_Subtype:
1729
1730 /* For integral subtypes, we make a new INTEGER_TYPE. Note that we do
1731 not want to call create_range_type since we would like each subtype
1732 node to be distinct. ??? Historically this was in preparation for
1733 when memory aliasing is implemented, but that's obsolete now given
1734 the call to relate_alias_sets below.
1735
1736 The TREE_TYPE field of the INTEGER_TYPE points to the base type;
1737 this fact is used by the arithmetic conversion functions.
1738
1739 We elaborate the Ancestor_Subtype if it is not in the current unit
1740 and one of our bounds is non-static. We do this to ensure consistent
1741 naming in the case where several subtypes share the same bounds, by
1742 elaborating the first such subtype first, thus using its name. */
1743
1744 if (!definition
1745 && Present (Ancestor_Subtype (gnat_entity))
1746 && !In_Extended_Main_Code_Unit (Ancestor_Subtype (gnat_entity))
1747 && (!Compile_Time_Known_Value (Type_Low_Bound (gnat_entity))
1748 || !Compile_Time_Known_Value (Type_High_Bound (gnat_entity))))
1749 gnat_to_gnu_entity (Ancestor_Subtype (gnat_entity), gnu_expr, 0);
1750
1751 /* Set the precision to the Esize except for bit-packed arrays. */
1752 if (Is_Packed_Array_Type (gnat_entity)
1753 && Is_Bit_Packed_Array (Original_Array_Type (gnat_entity)))
1754 esize = UI_To_Int (RM_Size (gnat_entity));
1755
1756 /* This should be an unsigned type if the base type is unsigned or
1757 if the lower bound is constant and non-negative or if the type
1758 is biased. */
1759 if (Is_Unsigned_Type (Etype (gnat_entity))
1760 || Is_Unsigned_Type (gnat_entity)
1761 || Has_Biased_Representation (gnat_entity))
1762 gnu_type = make_unsigned_type (esize);
1763 else
1764 gnu_type = make_signed_type (esize);
1765 TREE_TYPE (gnu_type) = get_unpadded_type (Etype (gnat_entity));
1766
1767 SET_TYPE_RM_MIN_VALUE
1768 (gnu_type,
1769 convert (TREE_TYPE (gnu_type),
1770 elaborate_expression (Type_Low_Bound (gnat_entity),
1771 gnat_entity, get_identifier ("L"),
1772 definition, true,
1773 Needs_Debug_Info (gnat_entity))));
1774
1775 SET_TYPE_RM_MAX_VALUE
1776 (gnu_type,
1777 convert (TREE_TYPE (gnu_type),
1778 elaborate_expression (Type_High_Bound (gnat_entity),
1779 gnat_entity, get_identifier ("U"),
1780 definition, true,
1781 Needs_Debug_Info (gnat_entity))));
1782
1783 /* One of the above calls might have caused us to be elaborated,
1784 so don't blow up if so. */
1785 if (present_gnu_tree (gnat_entity))
1786 {
1787 maybe_present = true;
1788 break;
1789 }
1790
1791 TYPE_BIASED_REPRESENTATION_P (gnu_type)
1792 = Has_Biased_Representation (gnat_entity);
1793
1794 /* Attach the TYPE_STUB_DECL in case we have a parallel type. */
1795 TYPE_STUB_DECL (gnu_type)
1796 = create_type_stub_decl (gnu_entity_name, gnu_type);
1797
1798 /* Inherit our alias set from what we're a subtype of. Subtypes
1799 are not different types and a pointer can designate any instance
1800 within a subtype hierarchy. */
1801 relate_alias_sets (gnu_type, TREE_TYPE (gnu_type), ALIAS_SET_COPY);
1802
1803 /* For a packed array, make the original array type a parallel type. */
1804 if (debug_info_p
1805 && Is_Packed_Array_Type (gnat_entity)
1806 && present_gnu_tree (Original_Array_Type (gnat_entity)))
1807 add_parallel_type (gnu_type,
1808 gnat_to_gnu_type
1809 (Original_Array_Type (gnat_entity)));
1810
1811 discrete_type:
1812
1813 /* We have to handle clauses that under-align the type specially. */
1814 if ((Present (Alignment_Clause (gnat_entity))
1815 || (Is_Packed_Array_Type (gnat_entity)
1816 && Present
1817 (Alignment_Clause (Original_Array_Type (gnat_entity)))))
1818 && UI_Is_In_Int_Range (Alignment (gnat_entity)))
1819 {
1820 align = UI_To_Int (Alignment (gnat_entity)) * BITS_PER_UNIT;
1821 if (align >= TYPE_ALIGN (gnu_type))
1822 align = 0;
1823 }
1824
1825 /* If the type we are dealing with represents a bit-packed array,
1826 we need to have the bits left justified on big-endian targets
1827 and right justified on little-endian targets. We also need to
1828 ensure that when the value is read (e.g. for comparison of two
1829 such values), we only get the good bits, since the unused bits
1830 are uninitialized. Both goals are accomplished by wrapping up
1831 the modular type in an enclosing record type. */
1832 if (Is_Packed_Array_Type (gnat_entity)
1833 && Is_Bit_Packed_Array (Original_Array_Type (gnat_entity)))
1834 {
1835 tree gnu_field_type, gnu_field;
1836
1837 /* Set the RM size before wrapping up the original type. */
1838 SET_TYPE_RM_SIZE (gnu_type,
1839 UI_To_gnu (RM_Size (gnat_entity), bitsizetype));
1840 TYPE_PACKED_ARRAY_TYPE_P (gnu_type) = 1;
1841
1842 /* Create a stripped-down declaration, mainly for debugging. */
1843 create_type_decl (gnu_entity_name, gnu_type, NULL, true,
1844 debug_info_p, gnat_entity);
1845
1846 /* Now save it and build the enclosing record type. */
1847 gnu_field_type = gnu_type;
1848
1849 gnu_type = make_node (RECORD_TYPE);
1850 TYPE_NAME (gnu_type) = create_concat_name (gnat_entity, "JM");
1851 TYPE_PACKED (gnu_type) = 1;
1852 TYPE_SIZE (gnu_type) = TYPE_SIZE (gnu_field_type);
1853 TYPE_SIZE_UNIT (gnu_type) = TYPE_SIZE_UNIT (gnu_field_type);
1854 SET_TYPE_ADA_SIZE (gnu_type, TYPE_RM_SIZE (gnu_field_type));
1855
1856 /* Propagate the alignment of the modular type to the record type,
1857 unless there is an alignment clause that under-aligns the type.
1858 This means that bit-packed arrays are given "ceil" alignment for
1859 their size by default, which may seem counter-intuitive but makes
1860 it possible to overlay them on modular types easily. */
1861 TYPE_ALIGN (gnu_type)
1862 = align > 0 ? align : TYPE_ALIGN (gnu_field_type);
1863
1864 relate_alias_sets (gnu_type, gnu_field_type, ALIAS_SET_COPY);
1865
1866 /* Don't declare the field as addressable since we won't be taking
1867 its address and this would prevent create_field_decl from making
1868 a bitfield. */
1869 gnu_field
1870 = create_field_decl (get_identifier ("OBJECT"), gnu_field_type,
1871 gnu_type, NULL_TREE, bitsize_zero_node, 1, 0);
1872
1873 /* Do not emit debug info until after the parallel type is added. */
1874 finish_record_type (gnu_type, gnu_field, 2, false);
1875 compute_record_mode (gnu_type);
1876 TYPE_JUSTIFIED_MODULAR_P (gnu_type) = 1;
1877
1878 if (debug_info_p)
1879 {
1880 /* Make the original array type a parallel type. */
1881 if (present_gnu_tree (Original_Array_Type (gnat_entity)))
1882 add_parallel_type (gnu_type,
1883 gnat_to_gnu_type
1884 (Original_Array_Type (gnat_entity)));
1885
1886 rest_of_record_type_compilation (gnu_type);
1887 }
1888 }
1889
1890 /* If the type we are dealing with has got a smaller alignment than the
1891 natural one, we need to wrap it up in a record type and misalign the
1892 latter; we reuse the padding machinery for this purpose. Note that,
1893 even if the record type is marked as packed because of misalignment,
1894 we don't pack the field so as to give it the size of the type. */
1895 else if (align > 0)
1896 {
1897 tree gnu_field_type, gnu_field;
1898
1899 /* Set the RM size before wrapping up the type. */
1900 SET_TYPE_RM_SIZE (gnu_type,
1901 UI_To_gnu (RM_Size (gnat_entity), bitsizetype));
1902
1903 /* Create a stripped-down declaration, mainly for debugging. */
1904 create_type_decl (gnu_entity_name, gnu_type, NULL, true,
1905 debug_info_p, gnat_entity);
1906
1907 /* Now save it and build the enclosing record type. */
1908 gnu_field_type = gnu_type;
1909
1910 gnu_type = make_node (RECORD_TYPE);
1911 TYPE_NAME (gnu_type) = create_concat_name (gnat_entity, "PAD");
1912 TYPE_PACKED (gnu_type) = 1;
1913 TYPE_SIZE (gnu_type) = TYPE_SIZE (gnu_field_type);
1914 TYPE_SIZE_UNIT (gnu_type) = TYPE_SIZE_UNIT (gnu_field_type);
1915 SET_TYPE_ADA_SIZE (gnu_type, TYPE_RM_SIZE (gnu_field_type));
1916 TYPE_ALIGN (gnu_type) = align;
1917 relate_alias_sets (gnu_type, gnu_field_type, ALIAS_SET_COPY);
1918
1919 /* Don't declare the field as addressable since we won't be taking
1920 its address and this would prevent create_field_decl from making
1921 a bitfield. */
1922 gnu_field
1923 = create_field_decl (get_identifier ("F"), gnu_field_type,
1924 gnu_type, TYPE_SIZE (gnu_field_type),
1925 bitsize_zero_node, 0, 0);
1926
1927 finish_record_type (gnu_type, gnu_field, 2, debug_info_p);
1928 compute_record_mode (gnu_type);
1929 TYPE_PADDING_P (gnu_type) = 1;
1930 }
1931
1932 break;
1933
1934 case E_Floating_Point_Type:
1935 /* If this is a VAX floating-point type, use an integer of the proper
1936 size. All the operations will be handled with ASM statements. */
1937 if (Vax_Float (gnat_entity))
1938 {
1939 gnu_type = make_signed_type (esize);
1940 TYPE_VAX_FLOATING_POINT_P (gnu_type) = 1;
1941 SET_TYPE_DIGITS_VALUE (gnu_type,
1942 UI_To_gnu (Digits_Value (gnat_entity),
1943 sizetype));
1944 break;
1945 }
1946
1947 /* The type of the Low and High bounds can be our type if this is
1948 a type from Standard, so set them at the end of the function. */
1949 gnu_type = make_node (REAL_TYPE);
1950 TYPE_PRECISION (gnu_type) = fp_size_to_prec (esize);
1951 layout_type (gnu_type);
1952 break;
1953
1954 case E_Floating_Point_Subtype:
1955 if (Vax_Float (gnat_entity))
1956 {
1957 gnu_type = gnat_to_gnu_type (Etype (gnat_entity));
1958 break;
1959 }
1960
1961 {
1962 if (!definition
1963 && Present (Ancestor_Subtype (gnat_entity))
1964 && !In_Extended_Main_Code_Unit (Ancestor_Subtype (gnat_entity))
1965 && (!Compile_Time_Known_Value (Type_Low_Bound (gnat_entity))
1966 || !Compile_Time_Known_Value (Type_High_Bound (gnat_entity))))
1967 gnat_to_gnu_entity (Ancestor_Subtype (gnat_entity),
1968 gnu_expr, 0);
1969
1970 gnu_type = make_node (REAL_TYPE);
1971 TREE_TYPE (gnu_type) = get_unpadded_type (Etype (gnat_entity));
1972 TYPE_PRECISION (gnu_type) = fp_size_to_prec (esize);
1973 TYPE_GCC_MIN_VALUE (gnu_type)
1974 = TYPE_GCC_MIN_VALUE (TREE_TYPE (gnu_type));
1975 TYPE_GCC_MAX_VALUE (gnu_type)
1976 = TYPE_GCC_MAX_VALUE (TREE_TYPE (gnu_type));
1977 layout_type (gnu_type);
1978
1979 SET_TYPE_RM_MIN_VALUE
1980 (gnu_type,
1981 convert (TREE_TYPE (gnu_type),
1982 elaborate_expression (Type_Low_Bound (gnat_entity),
1983 gnat_entity, get_identifier ("L"),
1984 definition, true,
1985 Needs_Debug_Info (gnat_entity))));
1986
1987 SET_TYPE_RM_MAX_VALUE
1988 (gnu_type,
1989 convert (TREE_TYPE (gnu_type),
1990 elaborate_expression (Type_High_Bound (gnat_entity),
1991 gnat_entity, get_identifier ("U"),
1992 definition, true,
1993 Needs_Debug_Info (gnat_entity))));
1994
1995 /* One of the above calls might have caused us to be elaborated,
1996 so don't blow up if so. */
1997 if (present_gnu_tree (gnat_entity))
1998 {
1999 maybe_present = true;
2000 break;
2001 }
2002
2003 /* Inherit our alias set from what we're a subtype of, as for
2004 integer subtypes. */
2005 relate_alias_sets (gnu_type, TREE_TYPE (gnu_type), ALIAS_SET_COPY);
2006 }
2007 break;
2008
2009 /* Array and String Types and Subtypes
2010
2011 Unconstrained array types are represented by E_Array_Type and
2012 constrained array types are represented by E_Array_Subtype. There
2013 are no actual objects of an unconstrained array type; all we have
2014 are pointers to that type.
2015
2016 The following fields are defined on array types and subtypes:
2017
2018 Component_Type Component type of the array.
2019 Number_Dimensions Number of dimensions (an int).
2020 First_Index Type of first index. */
2021
2022 case E_String_Type:
2023 case E_Array_Type:
2024 {
2025 const bool convention_fortran_p
2026 = (Convention (gnat_entity) == Convention_Fortran);
2027 const int ndim = Number_Dimensions (gnat_entity);
2028 tree gnu_template_type;
2029 tree gnu_ptr_template;
2030 tree gnu_template_reference, gnu_template_fields, gnu_fat_type;
2031 tree *gnu_index_types = XALLOCAVEC (tree, ndim);
2032 tree *gnu_temp_fields = XALLOCAVEC (tree, ndim);
2033 tree gnu_max_size = size_one_node, gnu_max_size_unit, tem, t;
2034 Entity_Id gnat_index, gnat_name;
2035 int index;
2036 tree comp_type;
2037
2038 /* Create the type for the component now, as it simplifies breaking
2039 type reference loops. */
2040 comp_type
2041 = gnat_to_gnu_component_type (gnat_entity, definition, debug_info_p);
2042 if (present_gnu_tree (gnat_entity))
2043 {
2044 /* As a side effect, the type may have been translated. */
2045 maybe_present = true;
2046 break;
2047 }
2048
2049 /* We complete an existing dummy fat pointer type in place. This both
2050 avoids further complex adjustments in update_pointer_to and yields
2051 better debugging information in DWARF by leveraging the support for
2052 incomplete declarations of "tagged" types in the DWARF back-end. */
2053 gnu_type = get_dummy_type (gnat_entity);
2054 if (gnu_type && TYPE_POINTER_TO (gnu_type))
2055 {
2056 gnu_fat_type = TYPE_MAIN_VARIANT (TYPE_POINTER_TO (gnu_type));
2057 TYPE_NAME (gnu_fat_type) = NULL_TREE;
2058 /* Save the contents of the dummy type for update_pointer_to. */
2059 TYPE_POINTER_TO (gnu_type) = copy_type (gnu_fat_type);
2060 gnu_ptr_template =
2061 TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (gnu_fat_type)));
2062 gnu_template_type = TREE_TYPE (gnu_ptr_template);
2063 }
2064 else
2065 {
2066 gnu_fat_type = make_node (RECORD_TYPE);
2067 gnu_template_type = make_node (RECORD_TYPE);
2068 gnu_ptr_template = build_pointer_type (gnu_template_type);
2069 }
2070
2071 /* Make a node for the array. If we are not defining the array
2072 suppress expanding incomplete types. */
2073 gnu_type = make_node (UNCONSTRAINED_ARRAY_TYPE);
2074
2075 if (!definition)
2076 {
2077 defer_incomplete_level++;
2078 this_deferred = true;
2079 }
2080
2081 /* Build the fat pointer type. Use a "void *" object instead of
2082 a pointer to the array type since we don't have the array type
2083 yet (it will reference the fat pointer via the bounds). */
2084 tem
2085 = create_field_decl (get_identifier ("P_ARRAY"), ptr_void_type_node,
2086 gnu_fat_type, NULL_TREE, NULL_TREE, 0, 0);
2087 DECL_CHAIN (tem)
2088 = create_field_decl (get_identifier ("P_BOUNDS"), gnu_ptr_template,
2089 gnu_fat_type, NULL_TREE, NULL_TREE, 0, 0);
2090
2091 if (COMPLETE_TYPE_P (gnu_fat_type))
2092 {
2093 /* We are going to lay it out again so reset the alias set. */
2094 alias_set_type alias_set = TYPE_ALIAS_SET (gnu_fat_type);
2095 TYPE_ALIAS_SET (gnu_fat_type) = -1;
2096 finish_fat_pointer_type (gnu_fat_type, tem);
2097 TYPE_ALIAS_SET (gnu_fat_type) = alias_set;
2098 for (t = gnu_fat_type; t; t = TYPE_NEXT_VARIANT (t))
2099 {
2100 TYPE_FIELDS (t) = tem;
2101 SET_TYPE_UNCONSTRAINED_ARRAY (t, gnu_type);
2102 }
2103 }
2104 else
2105 {
2106 finish_fat_pointer_type (gnu_fat_type, tem);
2107 SET_TYPE_UNCONSTRAINED_ARRAY (gnu_fat_type, gnu_type);
2108 }
2109
2110 /* Build a reference to the template from a PLACEHOLDER_EXPR that
2111 is the fat pointer. This will be used to access the individual
2112 fields once we build them. */
2113 tem = build3 (COMPONENT_REF, gnu_ptr_template,
2114 build0 (PLACEHOLDER_EXPR, gnu_fat_type),
2115 DECL_CHAIN (TYPE_FIELDS (gnu_fat_type)), NULL_TREE);
2116 gnu_template_reference
2117 = build_unary_op (INDIRECT_REF, gnu_template_type, tem);
2118 TREE_READONLY (gnu_template_reference) = 1;
2119 TREE_THIS_NOTRAP (gnu_template_reference) = 1;
2120
2121 /* Now create the GCC type for each index and add the fields for that
2122 index to the template. */
2123 for (index = (convention_fortran_p ? ndim - 1 : 0),
2124 gnat_index = First_Index (gnat_entity);
2125 0 <= index && index < ndim;
2126 index += (convention_fortran_p ? - 1 : 1),
2127 gnat_index = Next_Index (gnat_index))
2128 {
2129 char field_name[16];
2130 tree gnu_index_base_type
2131 = get_unpadded_type (Base_Type (Etype (gnat_index)));
2132 tree gnu_lb_field, gnu_hb_field, gnu_orig_min, gnu_orig_max;
2133 tree gnu_min, gnu_max, gnu_high;
2134
2135 /* Make the FIELD_DECLs for the low and high bounds of this
2136 type and then make extractions of these fields from the
2137 template. */
2138 sprintf (field_name, "LB%d", index);
2139 gnu_lb_field = create_field_decl (get_identifier (field_name),
2140 gnu_index_base_type,
2141 gnu_template_type, NULL_TREE,
2142 NULL_TREE, 0, 0);
2143 Sloc_to_locus (Sloc (gnat_entity),
2144 &DECL_SOURCE_LOCATION (gnu_lb_field));
2145
2146 field_name[0] = 'U';
2147 gnu_hb_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_hb_field));
2153
2154 gnu_temp_fields[index] = chainon (gnu_lb_field, gnu_hb_field);
2155
2156 /* We can't use build_component_ref here since the template type
2157 isn't complete yet. */
2158 gnu_orig_min = build3 (COMPONENT_REF, gnu_index_base_type,
2159 gnu_template_reference, gnu_lb_field,
2160 NULL_TREE);
2161 gnu_orig_max = build3 (COMPONENT_REF, gnu_index_base_type,
2162 gnu_template_reference, gnu_hb_field,
2163 NULL_TREE);
2164 TREE_READONLY (gnu_orig_min) = TREE_READONLY (gnu_orig_max) = 1;
2165
2166 gnu_min = convert (sizetype, gnu_orig_min);
2167 gnu_max = convert (sizetype, gnu_orig_max);
2168
2169 /* Compute the size of this dimension. See the E_Array_Subtype
2170 case below for the rationale. */
2171 gnu_high
2172 = build3 (COND_EXPR, sizetype,
2173 build2 (GE_EXPR, boolean_type_node,
2174 gnu_orig_max, gnu_orig_min),
2175 gnu_max,
2176 size_binop (MINUS_EXPR, gnu_min, size_one_node));
2177
2178 /* Make a range type with the new range in the Ada base type.
2179 Then make an index type with the size range in sizetype. */
2180 gnu_index_types[index]
2181 = create_index_type (gnu_min, gnu_high,
2182 create_range_type (gnu_index_base_type,
2183 gnu_orig_min,
2184 gnu_orig_max),
2185 gnat_entity);
2186
2187 /* Update the maximum size of the array in elements. */
2188 if (gnu_max_size)
2189 {
2190 tree gnu_index_type = get_unpadded_type (Etype (gnat_index));
2191 tree gnu_min
2192 = convert (sizetype, TYPE_MIN_VALUE (gnu_index_type));
2193 tree gnu_max
2194 = convert (sizetype, TYPE_MAX_VALUE (gnu_index_type));
2195 tree gnu_this_max
2196 = size_binop (MAX_EXPR,
2197 size_binop (PLUS_EXPR, size_one_node,
2198 size_binop (MINUS_EXPR,
2199 gnu_max, gnu_min)),
2200 size_zero_node);
2201
2202 if (TREE_CODE (gnu_this_max) == INTEGER_CST
2203 && TREE_OVERFLOW (gnu_this_max))
2204 gnu_max_size = NULL_TREE;
2205 else
2206 gnu_max_size
2207 = size_binop (MULT_EXPR, gnu_max_size, gnu_this_max);
2208 }
2209
2210 TYPE_NAME (gnu_index_types[index])
2211 = create_concat_name (gnat_entity, field_name);
2212 }
2213
2214 /* Install all the fields into the template. */
2215 TYPE_NAME (gnu_template_type)
2216 = create_concat_name (gnat_entity, "XUB");
2217 gnu_template_fields = NULL_TREE;
2218 for (index = 0; index < ndim; index++)
2219 gnu_template_fields
2220 = chainon (gnu_template_fields, gnu_temp_fields[index]);
2221 finish_record_type (gnu_template_type, gnu_template_fields, 0,
2222 debug_info_p);
2223 TYPE_READONLY (gnu_template_type) = 1;
2224
2225 /* If Component_Size is not already specified, annotate it with the
2226 size of the component. */
2227 if (Unknown_Component_Size (gnat_entity))
2228 Set_Component_Size (gnat_entity,
2229 annotate_value (TYPE_SIZE (comp_type)));
2230
2231 /* Compute the maximum size of the array in units and bits. */
2232 if (gnu_max_size)
2233 {
2234 gnu_max_size_unit = size_binop (MULT_EXPR, gnu_max_size,
2235 TYPE_SIZE_UNIT (comp_type));
2236 gnu_max_size = size_binop (MULT_EXPR,
2237 convert (bitsizetype, gnu_max_size),
2238 TYPE_SIZE (comp_type));
2239 }
2240 else
2241 gnu_max_size_unit = NULL_TREE;
2242
2243 /* Now build the array type. */
2244 tem = comp_type;
2245 for (index = ndim - 1; index >= 0; index--)
2246 {
2247 tem = build_nonshared_array_type (tem, gnu_index_types[index]);
2248 if (Reverse_Storage_Order (gnat_entity))
2249 sorry ("non-default Scalar_Storage_Order");
2250 TYPE_MULTI_ARRAY_P (tem) = (index > 0);
2251 if (array_type_has_nonaliased_component (tem, gnat_entity))
2252 TYPE_NONALIASED_COMPONENT (tem) = 1;
2253
2254 /* If it is passed by reference, force BLKmode to ensure that
2255 objects of this type will always be put in memory. */
2256 if (TYPE_MODE (tem) != BLKmode
2257 && Is_By_Reference_Type (gnat_entity))
2258 SET_TYPE_MODE (tem, BLKmode);
2259 }
2260
2261 /* If an alignment is specified, use it if valid. But ignore it
2262 for the original type of packed array types. If the alignment
2263 was requested with an explicit alignment clause, state so. */
2264 if (No (Packed_Array_Type (gnat_entity))
2265 && Known_Alignment (gnat_entity))
2266 {
2267 TYPE_ALIGN (tem)
2268 = validate_alignment (Alignment (gnat_entity), gnat_entity,
2269 TYPE_ALIGN (tem));
2270 if (Present (Alignment_Clause (gnat_entity)))
2271 TYPE_USER_ALIGN (tem) = 1;
2272 }
2273
2274 TYPE_CONVENTION_FORTRAN_P (tem) = convention_fortran_p;
2275
2276 /* Adjust the type of the pointer-to-array field of the fat pointer
2277 and record the aliasing relationships if necessary. */
2278 TREE_TYPE (TYPE_FIELDS (gnu_fat_type)) = build_pointer_type (tem);
2279 if (TYPE_ALIAS_SET_KNOWN_P (gnu_fat_type))
2280 record_component_aliases (gnu_fat_type);
2281
2282 /* The result type is an UNCONSTRAINED_ARRAY_TYPE that indicates the
2283 corresponding fat pointer. */
2284 TREE_TYPE (gnu_type) = gnu_fat_type;
2285 TYPE_POINTER_TO (gnu_type) = gnu_fat_type;
2286 TYPE_REFERENCE_TO (gnu_type) = gnu_fat_type;
2287 SET_TYPE_MODE (gnu_type, BLKmode);
2288 TYPE_ALIGN (gnu_type) = TYPE_ALIGN (tem);
2289
2290 /* If the maximum size doesn't overflow, use it. */
2291 if (gnu_max_size
2292 && TREE_CODE (gnu_max_size) == INTEGER_CST
2293 && !TREE_OVERFLOW (gnu_max_size)
2294 && TREE_CODE (gnu_max_size_unit) == INTEGER_CST
2295 && !TREE_OVERFLOW (gnu_max_size_unit))
2296 {
2297 TYPE_SIZE (tem) = size_binop (MIN_EXPR, gnu_max_size,
2298 TYPE_SIZE (tem));
2299 TYPE_SIZE_UNIT (tem) = size_binop (MIN_EXPR, gnu_max_size_unit,
2300 TYPE_SIZE_UNIT (tem));
2301 }
2302
2303 create_type_decl (create_concat_name (gnat_entity, "XUA"),
2304 tem, NULL, !Comes_From_Source (gnat_entity),
2305 debug_info_p, gnat_entity);
2306
2307 /* Give the fat pointer type a name. If this is a packed type, tell
2308 the debugger how to interpret the underlying bits. */
2309 if (Present (Packed_Array_Type (gnat_entity)))
2310 gnat_name = Packed_Array_Type (gnat_entity);
2311 else
2312 gnat_name = gnat_entity;
2313 create_type_decl (create_concat_name (gnat_name, "XUP"),
2314 gnu_fat_type, NULL, !Comes_From_Source (gnat_entity),
2315 debug_info_p, gnat_entity);
2316
2317 /* Create the type to be designated by thin pointers: a record type for
2318 the array and its template. We used to shift the fields to have the
2319 template at a negative offset, but this was somewhat of a kludge; we
2320 now shift thin pointer values explicitly but only those which have a
2321 TYPE_UNCONSTRAINED_ARRAY attached to the designated RECORD_TYPE. */
2322 tem = build_unc_object_type (gnu_template_type, tem,
2323 create_concat_name (gnat_name, "XUT"),
2324 debug_info_p);
2325
2326 SET_TYPE_UNCONSTRAINED_ARRAY (tem, gnu_type);
2327 TYPE_OBJECT_RECORD_TYPE (gnu_type) = tem;
2328 }
2329 break;
2330
2331 case E_String_Subtype:
2332 case E_Array_Subtype:
2333
2334 /* This is the actual data type for array variables. Multidimensional
2335 arrays are implemented as arrays of arrays. Note that arrays which
2336 have sparse enumeration subtypes as index components create sparse
2337 arrays, which is obviously space inefficient but so much easier to
2338 code for now.
2339
2340 Also note that the subtype never refers to the unconstrained array
2341 type, which is somewhat at variance with Ada semantics.
2342
2343 First check to see if this is simply a renaming of the array type.
2344 If so, the result is the array type. */
2345
2346 gnu_type = gnat_to_gnu_type (Etype (gnat_entity));
2347 if (!Is_Constrained (gnat_entity))
2348 ;
2349 else
2350 {
2351 Entity_Id gnat_index, gnat_base_index;
2352 const bool convention_fortran_p
2353 = (Convention (gnat_entity) == Convention_Fortran);
2354 const int ndim = Number_Dimensions (gnat_entity);
2355 tree gnu_base_type = gnu_type;
2356 tree *gnu_index_types = XALLOCAVEC (tree, ndim);
2357 tree gnu_max_size = size_one_node, gnu_max_size_unit;
2358 bool need_index_type_struct = false;
2359 int index;
2360
2361 /* First create the GCC type for each index and find out whether
2362 special types are needed for debugging information. */
2363 for (index = (convention_fortran_p ? ndim - 1 : 0),
2364 gnat_index = First_Index (gnat_entity),
2365 gnat_base_index
2366 = First_Index (Implementation_Base_Type (gnat_entity));
2367 0 <= index && index < ndim;
2368 index += (convention_fortran_p ? - 1 : 1),
2369 gnat_index = Next_Index (gnat_index),
2370 gnat_base_index = Next_Index (gnat_base_index))
2371 {
2372 tree gnu_index_type = get_unpadded_type (Etype (gnat_index));
2373 tree gnu_orig_min = TYPE_MIN_VALUE (gnu_index_type);
2374 tree gnu_orig_max = TYPE_MAX_VALUE (gnu_index_type);
2375 tree gnu_min = convert (sizetype, gnu_orig_min);
2376 tree gnu_max = convert (sizetype, gnu_orig_max);
2377 tree gnu_base_index_type
2378 = get_unpadded_type (Etype (gnat_base_index));
2379 tree gnu_base_orig_min = TYPE_MIN_VALUE (gnu_base_index_type);
2380 tree gnu_base_orig_max = TYPE_MAX_VALUE (gnu_base_index_type);
2381 tree gnu_high;
2382
2383 /* See if the base array type is already flat. If it is, we
2384 are probably compiling an ACATS test but it will cause the
2385 code below to malfunction if we don't handle it specially. */
2386 if (TREE_CODE (gnu_base_orig_min) == INTEGER_CST
2387 && TREE_CODE (gnu_base_orig_max) == INTEGER_CST
2388 && tree_int_cst_lt (gnu_base_orig_max, gnu_base_orig_min))
2389 {
2390 gnu_min = size_one_node;
2391 gnu_max = size_zero_node;
2392 gnu_high = gnu_max;
2393 }
2394
2395 /* Similarly, if one of the values overflows in sizetype and the
2396 range is null, use 1..0 for the sizetype bounds. */
2397 else if (TREE_CODE (gnu_min) == INTEGER_CST
2398 && TREE_CODE (gnu_max) == INTEGER_CST
2399 && (TREE_OVERFLOW (gnu_min) || TREE_OVERFLOW (gnu_max))
2400 && tree_int_cst_lt (gnu_orig_max, gnu_orig_min))
2401 {
2402 gnu_min = size_one_node;
2403 gnu_max = size_zero_node;
2404 gnu_high = gnu_max;
2405 }
2406
2407 /* If the minimum and maximum values both overflow in sizetype,
2408 but the difference in the original type does not overflow in
2409 sizetype, ignore the overflow indication. */
2410 else if (TREE_CODE (gnu_min) == INTEGER_CST
2411 && TREE_CODE (gnu_max) == INTEGER_CST
2412 && TREE_OVERFLOW (gnu_min) && TREE_OVERFLOW (gnu_max)
2413 && !TREE_OVERFLOW
2414 (convert (sizetype,
2415 fold_build2 (MINUS_EXPR, gnu_index_type,
2416 gnu_orig_max,
2417 gnu_orig_min))))
2418 {
2419 TREE_OVERFLOW (gnu_min) = 0;
2420 TREE_OVERFLOW (gnu_max) = 0;
2421 gnu_high = gnu_max;
2422 }
2423
2424 /* Compute the size of this dimension in the general case. We
2425 need to provide GCC with an upper bound to use but have to
2426 deal with the "superflat" case. There are three ways to do
2427 this. If we can prove that the array can never be superflat,
2428 we can just use the high bound of the index type. */
2429 else if ((Nkind (gnat_index) == N_Range
2430 && cannot_be_superflat_p (gnat_index))
2431 /* Packed Array Types are never superflat. */
2432 || Is_Packed_Array_Type (gnat_entity))
2433 gnu_high = gnu_max;
2434
2435 /* Otherwise, if the high bound is constant but the low bound is
2436 not, we use the expression (hb >= lb) ? lb : hb + 1 for the
2437 lower bound. Note that the comparison must be done in the
2438 original type to avoid any overflow during the conversion. */
2439 else if (TREE_CODE (gnu_max) == INTEGER_CST
2440 && TREE_CODE (gnu_min) != INTEGER_CST)
2441 {
2442 gnu_high = gnu_max;
2443 gnu_min
2444 = build_cond_expr (sizetype,
2445 build_binary_op (GE_EXPR,
2446 boolean_type_node,
2447 gnu_orig_max,
2448 gnu_orig_min),
2449 gnu_min,
2450 int_const_binop (PLUS_EXPR, gnu_max,
2451 size_one_node));
2452 }
2453
2454 /* Finally we use (hb >= lb) ? hb : lb - 1 for the upper bound
2455 in all the other cases. Note that, here as well as above,
2456 the condition used in the comparison must be equivalent to
2457 the condition (length != 0). This is relied upon in order
2458 to optimize array comparisons in compare_arrays. Moreover
2459 we use int_const_binop for the shift by 1 if the bound is
2460 constant to avoid any unwanted overflow. */
2461 else
2462 gnu_high
2463 = build_cond_expr (sizetype,
2464 build_binary_op (GE_EXPR,
2465 boolean_type_node,
2466 gnu_orig_max,
2467 gnu_orig_min),
2468 gnu_max,
2469 TREE_CODE (gnu_min) == INTEGER_CST
2470 ? int_const_binop (MINUS_EXPR, gnu_min,
2471 size_one_node)
2472 : size_binop (MINUS_EXPR, gnu_min,
2473 size_one_node));
2474
2475 /* Reuse the index type for the range type. Then make an index
2476 type with the size range in sizetype. */
2477 gnu_index_types[index]
2478 = create_index_type (gnu_min, gnu_high, gnu_index_type,
2479 gnat_entity);
2480
2481 /* Update the maximum size of the array in elements. Here we
2482 see if any constraint on the index type of the base type
2483 can be used in the case of self-referential bound on the
2484 index type of the subtype. We look for a non-"infinite"
2485 and non-self-referential bound from any type involved and
2486 handle each bound separately. */
2487 if (gnu_max_size)
2488 {
2489 tree gnu_base_min = convert (sizetype, gnu_base_orig_min);
2490 tree gnu_base_max = convert (sizetype, gnu_base_orig_max);
2491 tree gnu_base_index_base_type
2492 = get_base_type (gnu_base_index_type);
2493 tree gnu_base_base_min
2494 = convert (sizetype,
2495 TYPE_MIN_VALUE (gnu_base_index_base_type));
2496 tree gnu_base_base_max
2497 = convert (sizetype,
2498 TYPE_MAX_VALUE (gnu_base_index_base_type));
2499
2500 if (!CONTAINS_PLACEHOLDER_P (gnu_min)
2501 || !(TREE_CODE (gnu_base_min) == INTEGER_CST
2502 && !TREE_OVERFLOW (gnu_base_min)))
2503 gnu_base_min = gnu_min;
2504
2505 if (!CONTAINS_PLACEHOLDER_P (gnu_max)
2506 || !(TREE_CODE (gnu_base_max) == INTEGER_CST
2507 && !TREE_OVERFLOW (gnu_base_max)))
2508 gnu_base_max = gnu_max;
2509
2510 if ((TREE_CODE (gnu_base_min) == INTEGER_CST
2511 && TREE_OVERFLOW (gnu_base_min))
2512 || operand_equal_p (gnu_base_min, gnu_base_base_min, 0)
2513 || (TREE_CODE (gnu_base_max) == INTEGER_CST
2514 && TREE_OVERFLOW (gnu_base_max))
2515 || operand_equal_p (gnu_base_max, gnu_base_base_max, 0))
2516 gnu_max_size = NULL_TREE;
2517 else
2518 {
2519 tree gnu_this_max
2520 = size_binop (MAX_EXPR,
2521 size_binop (PLUS_EXPR, size_one_node,
2522 size_binop (MINUS_EXPR,
2523 gnu_base_max,
2524 gnu_base_min)),
2525 size_zero_node);
2526
2527 if (TREE_CODE (gnu_this_max) == INTEGER_CST
2528 && TREE_OVERFLOW (gnu_this_max))
2529 gnu_max_size = NULL_TREE;
2530 else
2531 gnu_max_size
2532 = size_binop (MULT_EXPR, gnu_max_size, gnu_this_max);
2533 }
2534 }
2535
2536 /* We need special types for debugging information to point to
2537 the index types if they have variable bounds, are not integer
2538 types, are biased or are wider than sizetype. */
2539 if (!integer_onep (gnu_orig_min)
2540 || TREE_CODE (gnu_orig_max) != INTEGER_CST
2541 || TREE_CODE (gnu_index_type) != INTEGER_TYPE
2542 || (TREE_TYPE (gnu_index_type)
2543 && TREE_CODE (TREE_TYPE (gnu_index_type))
2544 != INTEGER_TYPE)
2545 || TYPE_BIASED_REPRESENTATION_P (gnu_index_type)
2546 || compare_tree_int (rm_size (gnu_index_type),
2547 TYPE_PRECISION (sizetype)) > 0)
2548 need_index_type_struct = true;
2549 }
2550
2551 /* Then flatten: create the array of arrays. For an array type
2552 used to implement a packed array, get the component type from
2553 the original array type since the representation clauses that
2554 can affect it are on the latter. */
2555 if (Is_Packed_Array_Type (gnat_entity)
2556 && !Is_Bit_Packed_Array (Original_Array_Type (gnat_entity)))
2557 {
2558 gnu_type = gnat_to_gnu_type (Original_Array_Type (gnat_entity));
2559 for (index = ndim - 1; index >= 0; index--)
2560 gnu_type = TREE_TYPE (gnu_type);
2561
2562 /* One of the above calls might have caused us to be elaborated,
2563 so don't blow up if so. */
2564 if (present_gnu_tree (gnat_entity))
2565 {
2566 maybe_present = true;
2567 break;
2568 }
2569 }
2570 else
2571 {
2572 gnu_type = gnat_to_gnu_component_type (gnat_entity, definition,
2573 debug_info_p);
2574
2575 /* One of the above calls might have caused us to be elaborated,
2576 so don't blow up if so. */
2577 if (present_gnu_tree (gnat_entity))
2578 {
2579 maybe_present = true;
2580 break;
2581 }
2582 }
2583
2584 /* Compute the maximum size of the array in units and bits. */
2585 if (gnu_max_size)
2586 {
2587 gnu_max_size_unit = size_binop (MULT_EXPR, gnu_max_size,
2588 TYPE_SIZE_UNIT (gnu_type));
2589 gnu_max_size = size_binop (MULT_EXPR,
2590 convert (bitsizetype, gnu_max_size),
2591 TYPE_SIZE (gnu_type));
2592 }
2593 else
2594 gnu_max_size_unit = NULL_TREE;
2595
2596 /* Now build the array type. */
2597 for (index = ndim - 1; index >= 0; index --)
2598 {
2599 gnu_type = build_nonshared_array_type (gnu_type,
2600 gnu_index_types[index]);
2601 TYPE_MULTI_ARRAY_P (gnu_type) = (index > 0);
2602 if (array_type_has_nonaliased_component (gnu_type, gnat_entity))
2603 TYPE_NONALIASED_COMPONENT (gnu_type) = 1;
2604
2605 /* See the E_Array_Type case for the rationale. */
2606 if (TYPE_MODE (gnu_type) != BLKmode
2607 && Is_By_Reference_Type (gnat_entity))
2608 SET_TYPE_MODE (gnu_type, BLKmode);
2609 }
2610
2611 /* Attach the TYPE_STUB_DECL in case we have a parallel type. */
2612 TYPE_STUB_DECL (gnu_type)
2613 = create_type_stub_decl (gnu_entity_name, gnu_type);
2614
2615 /* If we are at file level and this is a multi-dimensional array,
2616 we need to make a variable corresponding to the stride of the
2617 inner dimensions. */
2618 if (global_bindings_p () && ndim > 1)
2619 {
2620 tree gnu_st_name = get_identifier ("ST");
2621 tree gnu_arr_type;
2622
2623 for (gnu_arr_type = TREE_TYPE (gnu_type);
2624 TREE_CODE (gnu_arr_type) == ARRAY_TYPE;
2625 gnu_arr_type = TREE_TYPE (gnu_arr_type),
2626 gnu_st_name = concat_name (gnu_st_name, "ST"))
2627 {
2628 tree eltype = TREE_TYPE (gnu_arr_type);
2629
2630 TYPE_SIZE (gnu_arr_type)
2631 = elaborate_expression_1 (TYPE_SIZE (gnu_arr_type),
2632 gnat_entity, gnu_st_name,
2633 definition, false);
2634
2635 /* ??? For now, store the size as a multiple of the
2636 alignment of the element type in bytes so that we
2637 can see the alignment from the tree. */
2638 TYPE_SIZE_UNIT (gnu_arr_type)
2639 = elaborate_expression_2 (TYPE_SIZE_UNIT (gnu_arr_type),
2640 gnat_entity,
2641 concat_name (gnu_st_name, "A_U"),
2642 definition, false,
2643 TYPE_ALIGN (eltype));
2644
2645 /* ??? create_type_decl is not invoked on the inner types so
2646 the MULT_EXPR node built above will never be marked. */
2647 MARK_VISITED (TYPE_SIZE_UNIT (gnu_arr_type));
2648 }
2649 }
2650
2651 /* If we need to write out a record type giving the names of the
2652 bounds for debugging purposes, do it now and make the record
2653 type a parallel type. This is not needed for a packed array
2654 since the bounds are conveyed by the original array type. */
2655 if (need_index_type_struct
2656 && debug_info_p
2657 && !Is_Packed_Array_Type (gnat_entity))
2658 {
2659 tree gnu_bound_rec = make_node (RECORD_TYPE);
2660 tree gnu_field_list = NULL_TREE;
2661 tree gnu_field;
2662
2663 TYPE_NAME (gnu_bound_rec)
2664 = create_concat_name (gnat_entity, "XA");
2665
2666 for (index = ndim - 1; index >= 0; index--)
2667 {
2668 tree gnu_index = TYPE_INDEX_TYPE (gnu_index_types[index]);
2669 tree gnu_index_name = TYPE_NAME (gnu_index);
2670
2671 if (TREE_CODE (gnu_index_name) == TYPE_DECL)
2672 gnu_index_name = DECL_NAME (gnu_index_name);
2673
2674 /* Make sure to reference the types themselves, and not just
2675 their names, as the debugger may fall back on them. */
2676 gnu_field = create_field_decl (gnu_index_name, gnu_index,
2677 gnu_bound_rec, NULL_TREE,
2678 NULL_TREE, 0, 0);
2679 DECL_CHAIN (gnu_field) = gnu_field_list;
2680 gnu_field_list = gnu_field;
2681 }
2682
2683 finish_record_type (gnu_bound_rec, gnu_field_list, 0, true);
2684 add_parallel_type (gnu_type, gnu_bound_rec);
2685 }
2686
2687 /* If this is a packed array type, make the original array type a
2688 parallel type. Otherwise, do it for the base array type if it
2689 isn't artificial to make sure it is kept in the debug info. */
2690 if (debug_info_p)
2691 {
2692 if (Is_Packed_Array_Type (gnat_entity)
2693 && present_gnu_tree (Original_Array_Type (gnat_entity)))
2694 add_parallel_type (gnu_type,
2695 gnat_to_gnu_type
2696 (Original_Array_Type (gnat_entity)));
2697 else
2698 {
2699 tree gnu_base_decl
2700 = gnat_to_gnu_entity (Etype (gnat_entity), NULL_TREE, 0);
2701 if (!DECL_ARTIFICIAL (gnu_base_decl))
2702 add_parallel_type (gnu_type,
2703 TREE_TYPE (TREE_TYPE (gnu_base_decl)));
2704 }
2705 }
2706
2707 TYPE_CONVENTION_FORTRAN_P (gnu_type) = convention_fortran_p;
2708 TYPE_PACKED_ARRAY_TYPE_P (gnu_type)
2709 = (Is_Packed_Array_Type (gnat_entity)
2710 && Is_Bit_Packed_Array (Original_Array_Type (gnat_entity)));
2711
2712 /* If the size is self-referential and the maximum size doesn't
2713 overflow, use it. */
2714 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type))
2715 && gnu_max_size
2716 && !(TREE_CODE (gnu_max_size) == INTEGER_CST
2717 && TREE_OVERFLOW (gnu_max_size))
2718 && !(TREE_CODE (gnu_max_size_unit) == INTEGER_CST
2719 && TREE_OVERFLOW (gnu_max_size_unit)))
2720 {
2721 TYPE_SIZE (gnu_type) = size_binop (MIN_EXPR, gnu_max_size,
2722 TYPE_SIZE (gnu_type));
2723 TYPE_SIZE_UNIT (gnu_type)
2724 = size_binop (MIN_EXPR, gnu_max_size_unit,
2725 TYPE_SIZE_UNIT (gnu_type));
2726 }
2727
2728 /* Set our alias set to that of our base type. This gives all
2729 array subtypes the same alias set. */
2730 relate_alias_sets (gnu_type, gnu_base_type, ALIAS_SET_COPY);
2731
2732 /* If this is a packed type, make this type the same as the packed
2733 array type, but do some adjusting in the type first. */
2734 if (Present (Packed_Array_Type (gnat_entity)))
2735 {
2736 Entity_Id gnat_index;
2737 tree gnu_inner;
2738
2739 /* First finish the type we had been making so that we output
2740 debugging information for it. */
2741 if (Treat_As_Volatile (gnat_entity))
2742 gnu_type
2743 = build_qualified_type (gnu_type,
2744 TYPE_QUALS (gnu_type)
2745 | TYPE_QUAL_VOLATILE);
2746
2747 /* Make it artificial only if the base type was artificial too.
2748 That's sort of "morally" true and will make it possible for
2749 the debugger to look it up by name in DWARF, which is needed
2750 in order to decode the packed array type. */
2751 gnu_decl
2752 = create_type_decl (gnu_entity_name, gnu_type, attr_list,
2753 !Comes_From_Source (Etype (gnat_entity))
2754 && !Comes_From_Source (gnat_entity),
2755 debug_info_p, gnat_entity);
2756
2757 /* Save it as our equivalent in case the call below elaborates
2758 this type again. */
2759 save_gnu_tree (gnat_entity, gnu_decl, false);
2760
2761 gnu_decl = gnat_to_gnu_entity (Packed_Array_Type (gnat_entity),
2762 NULL_TREE, 0);
2763 this_made_decl = true;
2764 gnu_type = TREE_TYPE (gnu_decl);
2765 save_gnu_tree (gnat_entity, NULL_TREE, false);
2766
2767 gnu_inner = gnu_type;
2768 while (TREE_CODE (gnu_inner) == RECORD_TYPE
2769 && (TYPE_JUSTIFIED_MODULAR_P (gnu_inner)
2770 || TYPE_PADDING_P (gnu_inner)))
2771 gnu_inner = TREE_TYPE (TYPE_FIELDS (gnu_inner));
2772
2773 /* We need to attach the index type to the type we just made so
2774 that the actual bounds can later be put into a template. */
2775 if ((TREE_CODE (gnu_inner) == ARRAY_TYPE
2776 && !TYPE_ACTUAL_BOUNDS (gnu_inner))
2777 || (TREE_CODE (gnu_inner) == INTEGER_TYPE
2778 && !TYPE_HAS_ACTUAL_BOUNDS_P (gnu_inner)))
2779 {
2780 if (TREE_CODE (gnu_inner) == INTEGER_TYPE)
2781 {
2782 /* The TYPE_ACTUAL_BOUNDS field is overloaded with the
2783 TYPE_MODULUS for modular types so we make an extra
2784 subtype if necessary. */
2785 if (TYPE_MODULAR_P (gnu_inner))
2786 {
2787 tree gnu_subtype
2788 = make_unsigned_type (TYPE_PRECISION (gnu_inner));
2789 TREE_TYPE (gnu_subtype) = gnu_inner;
2790 TYPE_EXTRA_SUBTYPE_P (gnu_subtype) = 1;
2791 SET_TYPE_RM_MIN_VALUE (gnu_subtype,
2792 TYPE_MIN_VALUE (gnu_inner));
2793 SET_TYPE_RM_MAX_VALUE (gnu_subtype,
2794 TYPE_MAX_VALUE (gnu_inner));
2795 gnu_inner = gnu_subtype;
2796 }
2797
2798 TYPE_HAS_ACTUAL_BOUNDS_P (gnu_inner) = 1;
2799
2800 #ifdef ENABLE_CHECKING
2801 /* Check for other cases of overloading. */
2802 gcc_assert (!TYPE_ACTUAL_BOUNDS (gnu_inner));
2803 #endif
2804 }
2805
2806 for (gnat_index = First_Index (gnat_entity);
2807 Present (gnat_index);
2808 gnat_index = Next_Index (gnat_index))
2809 SET_TYPE_ACTUAL_BOUNDS
2810 (gnu_inner,
2811 tree_cons (NULL_TREE,
2812 get_unpadded_type (Etype (gnat_index)),
2813 TYPE_ACTUAL_BOUNDS (gnu_inner)));
2814
2815 if (Convention (gnat_entity) != Convention_Fortran)
2816 SET_TYPE_ACTUAL_BOUNDS
2817 (gnu_inner, nreverse (TYPE_ACTUAL_BOUNDS (gnu_inner)));
2818
2819 if (TREE_CODE (gnu_type) == RECORD_TYPE
2820 && TYPE_JUSTIFIED_MODULAR_P (gnu_type))
2821 TREE_TYPE (TYPE_FIELDS (gnu_type)) = gnu_inner;
2822 }
2823 }
2824
2825 else
2826 /* Abort if packed array with no Packed_Array_Type field set. */
2827 gcc_assert (!Is_Packed (gnat_entity));
2828 }
2829 break;
2830
2831 case E_String_Literal_Subtype:
2832 /* Create the type for a string literal. */
2833 {
2834 Entity_Id gnat_full_type
2835 = (IN (Ekind (Etype (gnat_entity)), Private_Kind)
2836 && Present (Full_View (Etype (gnat_entity)))
2837 ? Full_View (Etype (gnat_entity)) : Etype (gnat_entity));
2838 tree gnu_string_type = get_unpadded_type (gnat_full_type);
2839 tree gnu_string_array_type
2840 = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_string_type))));
2841 tree gnu_string_index_type
2842 = get_base_type (TREE_TYPE (TYPE_INDEX_TYPE
2843 (TYPE_DOMAIN (gnu_string_array_type))));
2844 tree gnu_lower_bound
2845 = convert (gnu_string_index_type,
2846 gnat_to_gnu (String_Literal_Low_Bound (gnat_entity)));
2847 tree gnu_length
2848 = UI_To_gnu (String_Literal_Length (gnat_entity),
2849 gnu_string_index_type);
2850 tree gnu_upper_bound
2851 = build_binary_op (PLUS_EXPR, gnu_string_index_type,
2852 gnu_lower_bound,
2853 int_const_binop (MINUS_EXPR, gnu_length,
2854 integer_one_node));
2855 tree gnu_index_type
2856 = create_index_type (convert (sizetype, gnu_lower_bound),
2857 convert (sizetype, gnu_upper_bound),
2858 create_range_type (gnu_string_index_type,
2859 gnu_lower_bound,
2860 gnu_upper_bound),
2861 gnat_entity);
2862
2863 gnu_type
2864 = build_nonshared_array_type (gnat_to_gnu_type
2865 (Component_Type (gnat_entity)),
2866 gnu_index_type);
2867 if (array_type_has_nonaliased_component (gnu_type, gnat_entity))
2868 TYPE_NONALIASED_COMPONENT (gnu_type) = 1;
2869 relate_alias_sets (gnu_type, gnu_string_type, ALIAS_SET_COPY);
2870 }
2871 break;
2872
2873 /* Record Types and Subtypes
2874
2875 The following fields are defined on record types:
2876
2877 Has_Discriminants True if the record has discriminants
2878 First_Discriminant Points to head of list of discriminants
2879 First_Entity Points to head of list of fields
2880 Is_Tagged_Type True if the record is tagged
2881
2882 Implementation of Ada records and discriminated records:
2883
2884 A record type definition is transformed into the equivalent of a C
2885 struct definition. The fields that are the discriminants which are
2886 found in the Full_Type_Declaration node and the elements of the
2887 Component_List found in the Record_Type_Definition node. The
2888 Component_List can be a recursive structure since each Variant of
2889 the Variant_Part of the Component_List has a Component_List.
2890
2891 Processing of a record type definition comprises starting the list of
2892 field declarations here from the discriminants and the calling the
2893 function components_to_record to add the rest of the fields from the
2894 component list and return the gnu type node. The function
2895 components_to_record will call itself recursively as it traverses
2896 the tree. */
2897
2898 case E_Record_Type:
2899 if (Has_Complex_Representation (gnat_entity))
2900 {
2901 gnu_type
2902 = build_complex_type
2903 (get_unpadded_type
2904 (Etype (Defining_Entity
2905 (First (Component_Items
2906 (Component_List
2907 (Type_Definition
2908 (Declaration_Node (gnat_entity)))))))));
2909
2910 break;
2911 }
2912
2913 {
2914 Node_Id full_definition = Declaration_Node (gnat_entity);
2915 Node_Id record_definition = Type_Definition (full_definition);
2916 Entity_Id gnat_field;
2917 tree gnu_field, gnu_field_list = NULL_TREE, gnu_get_parent;
2918 /* Set PACKED in keeping with gnat_to_gnu_field. */
2919 int packed
2920 = Is_Packed (gnat_entity)
2921 ? 1
2922 : Component_Alignment (gnat_entity) == Calign_Storage_Unit
2923 ? -1
2924 : (Known_Alignment (gnat_entity)
2925 || (Strict_Alignment (gnat_entity)
2926 && Known_RM_Size (gnat_entity)))
2927 ? -2
2928 : 0;
2929 bool has_discr = Has_Discriminants (gnat_entity);
2930 bool has_rep = Has_Specified_Layout (gnat_entity);
2931 bool all_rep = has_rep;
2932 bool is_extension
2933 = (Is_Tagged_Type (gnat_entity)
2934 && Nkind (record_definition) == N_Derived_Type_Definition);
2935 bool is_unchecked_union = Is_Unchecked_Union (gnat_entity);
2936
2937 /* See if all fields have a rep clause. Stop when we find one
2938 that doesn't. */
2939 if (all_rep)
2940 for (gnat_field = First_Entity (gnat_entity);
2941 Present (gnat_field);
2942 gnat_field = Next_Entity (gnat_field))
2943 if ((Ekind (gnat_field) == E_Component
2944 || Ekind (gnat_field) == E_Discriminant)
2945 && No (Component_Clause (gnat_field)))
2946 {
2947 all_rep = false;
2948 break;
2949 }
2950
2951 /* If this is a record extension, go a level further to find the
2952 record definition. Also, verify we have a Parent_Subtype. */
2953 if (is_extension)
2954 {
2955 if (!type_annotate_only
2956 || Present (Record_Extension_Part (record_definition)))
2957 record_definition = Record_Extension_Part (record_definition);
2958
2959 gcc_assert (type_annotate_only
2960 || Present (Parent_Subtype (gnat_entity)));
2961 }
2962
2963 /* Make a node for the record. If we are not defining the record,
2964 suppress expanding incomplete types. */
2965 gnu_type = make_node (tree_code_for_record_type (gnat_entity));
2966 TYPE_NAME (gnu_type) = gnu_entity_name;
2967 TYPE_PACKED (gnu_type) = (packed != 0) || has_rep;
2968 if (Reverse_Storage_Order (gnat_entity))
2969 sorry ("non-default Scalar_Storage_Order");
2970
2971 if (!definition)
2972 {
2973 defer_incomplete_level++;
2974 this_deferred = true;
2975 }
2976
2977 /* If both a size and rep clause was specified, put the size in
2978 the record type now so that it can get the proper mode. */
2979 if (has_rep && Known_RM_Size (gnat_entity))
2980 TYPE_SIZE (gnu_type)
2981 = UI_To_gnu (RM_Size (gnat_entity), bitsizetype);
2982
2983 /* Always set the alignment here so that it can be used to
2984 set the mode, if it is making the alignment stricter. If
2985 it is invalid, it will be checked again below. If this is to
2986 be Atomic, choose a default alignment of a word unless we know
2987 the size and it's smaller. */
2988 if (Known_Alignment (gnat_entity))
2989 TYPE_ALIGN (gnu_type)
2990 = validate_alignment (Alignment (gnat_entity), gnat_entity, 0);
2991 else if (Is_Atomic (gnat_entity) && Known_Esize (gnat_entity))
2992 {
2993 unsigned int size = UI_To_Int (Esize (gnat_entity));
2994 TYPE_ALIGN (gnu_type)
2995 = size >= BITS_PER_WORD ? BITS_PER_WORD : ceil_pow2 (size);
2996 }
2997 /* If a type needs strict alignment, the minimum size will be the
2998 type size instead of the RM size (see validate_size). Cap the
2999 alignment, lest it causes this type size to become too large. */
3000 else if (Strict_Alignment (gnat_entity) && Known_RM_Size (gnat_entity))
3001 {
3002 unsigned int raw_size = UI_To_Int (RM_Size (gnat_entity));
3003 unsigned int raw_align = raw_size & -raw_size;
3004 if (raw_align < BIGGEST_ALIGNMENT)
3005 TYPE_ALIGN (gnu_type) = raw_align;
3006 }
3007 else
3008 TYPE_ALIGN (gnu_type) = 0;
3009
3010 /* If we have a Parent_Subtype, make a field for the parent. If
3011 this record has rep clauses, force the position to zero. */
3012 if (Present (Parent_Subtype (gnat_entity)))
3013 {
3014 Entity_Id gnat_parent = Parent_Subtype (gnat_entity);
3015 tree gnu_dummy_parent_type = make_node (RECORD_TYPE);
3016 tree gnu_parent;
3017
3018 /* A major complexity here is that the parent subtype will
3019 reference our discriminants in its Stored_Constraint list.
3020 But those must reference the parent component of this record
3021 which is precisely of the parent subtype we have not built yet!
3022 To break the circle we first build a dummy COMPONENT_REF which
3023 represents the "get to the parent" operation and initialize
3024 each of those discriminants to a COMPONENT_REF of the above
3025 dummy parent referencing the corresponding discriminant of the
3026 base type of the parent subtype. */
3027 gnu_get_parent = build3 (COMPONENT_REF, gnu_dummy_parent_type,
3028 build0 (PLACEHOLDER_EXPR, gnu_type),
3029 build_decl (input_location,
3030 FIELD_DECL, NULL_TREE,
3031 gnu_dummy_parent_type),
3032 NULL_TREE);
3033
3034 if (has_discr)
3035 for (gnat_field = First_Stored_Discriminant (gnat_entity);
3036 Present (gnat_field);
3037 gnat_field = Next_Stored_Discriminant (gnat_field))
3038 if (Present (Corresponding_Discriminant (gnat_field)))
3039 {
3040 tree gnu_field
3041 = gnat_to_gnu_field_decl (Corresponding_Discriminant
3042 (gnat_field));
3043 save_gnu_tree
3044 (gnat_field,
3045 build3 (COMPONENT_REF, TREE_TYPE (gnu_field),
3046 gnu_get_parent, gnu_field, NULL_TREE),
3047 true);
3048 }
3049
3050 /* Then we build the parent subtype. If it has discriminants but
3051 the type itself has unknown discriminants, this means that it
3052 doesn't contain information about how the discriminants are
3053 derived from those of the ancestor type, so it cannot be used
3054 directly. Instead it is built by cloning the parent subtype
3055 of the underlying record view of the type, for which the above
3056 derivation of discriminants has been made explicit. */
3057 if (Has_Discriminants (gnat_parent)
3058 && Has_Unknown_Discriminants (gnat_entity))
3059 {
3060 Entity_Id gnat_uview = Underlying_Record_View (gnat_entity);
3061
3062 /* If we are defining the type, the underlying record
3063 view must already have been elaborated at this point.
3064 Otherwise do it now as its parent subtype cannot be
3065 technically elaborated on its own. */
3066 if (definition)
3067 gcc_assert (present_gnu_tree (gnat_uview));
3068 else
3069 gnat_to_gnu_entity (gnat_uview, NULL_TREE, 0);
3070
3071 gnu_parent = gnat_to_gnu_type (Parent_Subtype (gnat_uview));
3072
3073 /* Substitute the "get to the parent" of the type for that
3074 of its underlying record view in the cloned type. */
3075 for (gnat_field = First_Stored_Discriminant (gnat_uview);
3076 Present (gnat_field);
3077 gnat_field = Next_Stored_Discriminant (gnat_field))
3078 if (Present (Corresponding_Discriminant (gnat_field)))
3079 {
3080 tree gnu_field = gnat_to_gnu_field_decl (gnat_field);
3081 tree gnu_ref
3082 = build3 (COMPONENT_REF, TREE_TYPE (gnu_field),
3083 gnu_get_parent, gnu_field, NULL_TREE);
3084 gnu_parent
3085 = substitute_in_type (gnu_parent, gnu_field, gnu_ref);
3086 }
3087 }
3088 else
3089 gnu_parent = gnat_to_gnu_type (gnat_parent);
3090
3091 /* Finally we fix up both kinds of twisted COMPONENT_REF we have
3092 initially built. The discriminants must reference the fields
3093 of the parent subtype and not those of its base type for the
3094 placeholder machinery to properly work. */
3095 if (has_discr)
3096 {
3097 /* The actual parent subtype is the full view. */
3098 if (IN (Ekind (gnat_parent), Private_Kind))
3099 {
3100 if (Present (Full_View (gnat_parent)))
3101 gnat_parent = Full_View (gnat_parent);
3102 else
3103 gnat_parent = Underlying_Full_View (gnat_parent);
3104 }
3105
3106 for (gnat_field = First_Stored_Discriminant (gnat_entity);
3107 Present (gnat_field);
3108 gnat_field = Next_Stored_Discriminant (gnat_field))
3109 if (Present (Corresponding_Discriminant (gnat_field)))
3110 {
3111 Entity_Id field = Empty;
3112 for (field = First_Stored_Discriminant (gnat_parent);
3113 Present (field);
3114 field = Next_Stored_Discriminant (field))
3115 if (same_discriminant_p (gnat_field, field))
3116 break;
3117 gcc_assert (Present (field));
3118 TREE_OPERAND (get_gnu_tree (gnat_field), 1)
3119 = gnat_to_gnu_field_decl (field);
3120 }
3121 }
3122
3123 /* The "get to the parent" COMPONENT_REF must be given its
3124 proper type... */
3125 TREE_TYPE (gnu_get_parent) = gnu_parent;
3126
3127 /* ...and reference the _Parent field of this record. */
3128 gnu_field
3129 = create_field_decl (parent_name_id,
3130 gnu_parent, gnu_type,
3131 has_rep
3132 ? TYPE_SIZE (gnu_parent) : NULL_TREE,
3133 has_rep
3134 ? bitsize_zero_node : NULL_TREE,
3135 0, 1);
3136 DECL_INTERNAL_P (gnu_field) = 1;
3137 TREE_OPERAND (gnu_get_parent, 1) = gnu_field;
3138 TYPE_FIELDS (gnu_type) = gnu_field;
3139 }
3140
3141 /* Make the fields for the discriminants and put them into the record
3142 unless it's an Unchecked_Union. */
3143 if (has_discr)
3144 for (gnat_field = First_Stored_Discriminant (gnat_entity);
3145 Present (gnat_field);
3146 gnat_field = Next_Stored_Discriminant (gnat_field))
3147 {
3148 /* If this is a record extension and this discriminant is the
3149 renaming of another discriminant, we've handled it above. */
3150 if (Present (Parent_Subtype (gnat_entity))
3151 && Present (Corresponding_Discriminant (gnat_field)))
3152 continue;
3153
3154 gnu_field
3155 = gnat_to_gnu_field (gnat_field, gnu_type, packed, definition,
3156 debug_info_p);
3157
3158 /* Make an expression using a PLACEHOLDER_EXPR from the
3159 FIELD_DECL node just created and link that with the
3160 corresponding GNAT defining identifier. */
3161 save_gnu_tree (gnat_field,
3162 build3 (COMPONENT_REF, TREE_TYPE (gnu_field),
3163 build0 (PLACEHOLDER_EXPR, gnu_type),
3164 gnu_field, NULL_TREE),
3165 true);
3166
3167 if (!is_unchecked_union)
3168 {
3169 DECL_CHAIN (gnu_field) = gnu_field_list;
3170 gnu_field_list = gnu_field;
3171 }
3172 }
3173
3174 /* Add the fields into the record type and finish it up. */
3175 components_to_record (gnu_type, Component_List (record_definition),
3176 gnu_field_list, packed, definition, false,
3177 all_rep, is_unchecked_union,
3178 !Comes_From_Source (gnat_entity), debug_info_p,
3179 false, OK_To_Reorder_Components (gnat_entity),
3180 all_rep ? NULL_TREE : bitsize_zero_node, NULL);
3181
3182 /* If it is passed by reference, force BLKmode to ensure that objects
3183 of this type will always be put in memory. */
3184 if (TYPE_MODE (gnu_type) != BLKmode
3185 && Is_By_Reference_Type (gnat_entity))
3186 SET_TYPE_MODE (gnu_type, BLKmode);
3187
3188 /* We used to remove the associations of the discriminants and _Parent
3189 for validity checking but we may need them if there's a Freeze_Node
3190 for a subtype used in this record. */
3191 TYPE_VOLATILE (gnu_type) = Treat_As_Volatile (gnat_entity);
3192
3193 /* Fill in locations of fields. */
3194 annotate_rep (gnat_entity, gnu_type);
3195
3196 /* If there are any entities in the chain corresponding to components
3197 that we did not elaborate, ensure we elaborate their types if they
3198 are Itypes. */
3199 for (gnat_temp = First_Entity (gnat_entity);
3200 Present (gnat_temp);
3201 gnat_temp = Next_Entity (gnat_temp))
3202 if ((Ekind (gnat_temp) == E_Component
3203 || Ekind (gnat_temp) == E_Discriminant)
3204 && Is_Itype (Etype (gnat_temp))
3205 && !present_gnu_tree (gnat_temp))
3206 gnat_to_gnu_entity (Etype (gnat_temp), NULL_TREE, 0);
3207
3208 /* If this is a record type associated with an exception definition,
3209 equate its fields to those of the standard exception type. This
3210 will make it possible to convert between them. */
3211 if (gnu_entity_name == exception_data_name_id)
3212 {
3213 tree gnu_std_field;
3214 for (gnu_field = TYPE_FIELDS (gnu_type),
3215 gnu_std_field = TYPE_FIELDS (except_type_node);
3216 gnu_field;
3217 gnu_field = DECL_CHAIN (gnu_field),
3218 gnu_std_field = DECL_CHAIN (gnu_std_field))
3219 SET_DECL_ORIGINAL_FIELD_TO_FIELD (gnu_field, gnu_std_field);
3220 gcc_assert (!gnu_std_field);
3221 }
3222 }
3223 break;
3224
3225 case E_Class_Wide_Subtype:
3226 /* If an equivalent type is present, that is what we should use.
3227 Otherwise, fall through to handle this like a record subtype
3228 since it may have constraints. */
3229 if (gnat_equiv_type != gnat_entity)
3230 {
3231 gnu_decl = gnat_to_gnu_entity (gnat_equiv_type, NULL_TREE, 0);
3232 maybe_present = true;
3233 break;
3234 }
3235
3236 /* ... fall through ... */
3237
3238 case E_Record_Subtype:
3239 /* If Cloned_Subtype is Present it means this record subtype has
3240 identical layout to that type or subtype and we should use
3241 that GCC type for this one. The front end guarantees that
3242 the component list is shared. */
3243 if (Present (Cloned_Subtype (gnat_entity)))
3244 {
3245 gnu_decl = gnat_to_gnu_entity (Cloned_Subtype (gnat_entity),
3246 NULL_TREE, 0);
3247 maybe_present = true;
3248 break;
3249 }
3250
3251 /* Otherwise, first ensure the base type is elaborated. Then, if we are
3252 changing the type, make a new type with each field having the type of
3253 the field in the new subtype but the position computed by transforming
3254 every discriminant reference according to the constraints. We don't
3255 see any difference between private and non-private type here since
3256 derivations from types should have been deferred until the completion
3257 of the private type. */
3258 else
3259 {
3260 Entity_Id gnat_base_type = Implementation_Base_Type (gnat_entity);
3261 tree gnu_base_type;
3262
3263 if (!definition)
3264 {
3265 defer_incomplete_level++;
3266 this_deferred = true;
3267 }
3268
3269 gnu_base_type = gnat_to_gnu_type (gnat_base_type);
3270
3271 if (present_gnu_tree (gnat_entity))
3272 {
3273 maybe_present = true;
3274 break;
3275 }
3276
3277 /* If this is a record subtype associated with a dispatch table,
3278 strip the suffix. This is necessary to make sure 2 different
3279 subtypes associated with the imported and exported views of a
3280 dispatch table are properly merged in LTO mode. */
3281 if (Is_Dispatch_Table_Entity (gnat_entity))
3282 {
3283 char *p;
3284 Get_Encoded_Name (gnat_entity);
3285 p = strchr (Name_Buffer, '_');
3286 gcc_assert (p);
3287 strcpy (p+2, "dtS");
3288 gnu_entity_name = get_identifier (Name_Buffer);
3289 }
3290
3291 /* When the subtype has discriminants and these discriminants affect
3292 the initial shape it has inherited, factor them in. But for an
3293 Unchecked_Union (it must be an Itype), just return the type.
3294 We can't just test Is_Constrained because private subtypes without
3295 discriminants of types with discriminants with default expressions
3296 are Is_Constrained but aren't constrained! */
3297 if (IN (Ekind (gnat_base_type), Record_Kind)
3298 && !Is_Unchecked_Union (gnat_base_type)
3299 && !Is_For_Access_Subtype (gnat_entity)
3300 && Has_Discriminants (gnat_entity)
3301 && Is_Constrained (gnat_entity)
3302 && Stored_Constraint (gnat_entity) != No_Elist)
3303 {
3304 vec<subst_pair> gnu_subst_list
3305 = build_subst_list (gnat_entity, gnat_base_type, definition);
3306 tree gnu_unpad_base_type, gnu_rep_part, gnu_variant_part, t;
3307 tree gnu_pos_list, gnu_field_list = NULL_TREE;
3308 bool selected_variant = false;
3309 Entity_Id gnat_field;
3310 vec<variant_desc> gnu_variant_list;
3311
3312 gnu_type = make_node (RECORD_TYPE);
3313 TYPE_NAME (gnu_type) = gnu_entity_name;
3314 TYPE_PACKED (gnu_type) = TYPE_PACKED (gnu_base_type);
3315
3316 /* Set the size, alignment and alias set of the new type to
3317 match that of the old one, doing required substitutions. */
3318 copy_and_substitute_in_size (gnu_type, gnu_base_type,
3319 gnu_subst_list);
3320
3321 if (TYPE_IS_PADDING_P (gnu_base_type))
3322 gnu_unpad_base_type = TREE_TYPE (TYPE_FIELDS (gnu_base_type));
3323 else
3324 gnu_unpad_base_type = gnu_base_type;
3325
3326 /* Look for a variant part in the base type. */
3327 gnu_variant_part = get_variant_part (gnu_unpad_base_type);
3328
3329 /* If there is a variant part, we must compute whether the
3330 constraints statically select a particular variant. If
3331 so, we simply drop the qualified union and flatten the
3332 list of fields. Otherwise we'll build a new qualified
3333 union for the variants that are still relevant. */
3334 if (gnu_variant_part)
3335 {
3336 variant_desc *v;
3337 unsigned int i;
3338
3339 gnu_variant_list
3340 = build_variant_list (TREE_TYPE (gnu_variant_part),
3341 gnu_subst_list,
3342 vNULL);
3343
3344 /* If all the qualifiers are unconditionally true, the
3345 innermost variant is statically selected. */
3346 selected_variant = true;
3347 FOR_EACH_VEC_ELT (gnu_variant_list, i, v)
3348 if (!integer_onep (v->qual))
3349 {
3350 selected_variant = false;
3351 break;
3352 }
3353
3354 /* Otherwise, create the new variants. */
3355 if (!selected_variant)
3356 FOR_EACH_VEC_ELT (gnu_variant_list, i, v)
3357 {
3358 tree old_variant = v->type;
3359 tree new_variant = make_node (RECORD_TYPE);
3360 tree suffix
3361 = concat_name (DECL_NAME (gnu_variant_part),
3362 IDENTIFIER_POINTER
3363 (DECL_NAME (v->field)));
3364 TYPE_NAME (new_variant)
3365 = concat_name (TYPE_NAME (gnu_type),
3366 IDENTIFIER_POINTER (suffix));
3367 copy_and_substitute_in_size (new_variant, old_variant,
3368 gnu_subst_list);
3369 v->new_type = new_variant;
3370 }
3371 }
3372 else
3373 {
3374 gnu_variant_list.create (0);
3375 selected_variant = false;
3376 }
3377
3378 gnu_pos_list
3379 = build_position_list (gnu_unpad_base_type,
3380 gnu_variant_list.exists ()
3381 && !selected_variant,
3382 size_zero_node, bitsize_zero_node,
3383 BIGGEST_ALIGNMENT, NULL_TREE);
3384
3385 for (gnat_field = First_Entity (gnat_entity);
3386 Present (gnat_field);
3387 gnat_field = Next_Entity (gnat_field))
3388 if ((Ekind (gnat_field) == E_Component
3389 || Ekind (gnat_field) == E_Discriminant)
3390 && !(Present (Corresponding_Discriminant (gnat_field))
3391 && Is_Tagged_Type (gnat_base_type))
3392 && Underlying_Type (Scope (Original_Record_Component
3393 (gnat_field)))
3394 == gnat_base_type)
3395 {
3396 Name_Id gnat_name = Chars (gnat_field);
3397 Entity_Id gnat_old_field
3398 = Original_Record_Component (gnat_field);
3399 tree gnu_old_field
3400 = gnat_to_gnu_field_decl (gnat_old_field);
3401 tree gnu_context = DECL_CONTEXT (gnu_old_field);
3402 tree gnu_field, gnu_field_type, gnu_size;
3403 tree gnu_cont_type, gnu_last = NULL_TREE;
3404
3405 /* If the type is the same, retrieve the GCC type from the
3406 old field to take into account possible adjustments. */
3407 if (Etype (gnat_field) == Etype (gnat_old_field))
3408 gnu_field_type = TREE_TYPE (gnu_old_field);
3409 else
3410 gnu_field_type = gnat_to_gnu_type (Etype (gnat_field));
3411
3412 /* If there was a component clause, the field types must be
3413 the same for the type and subtype, so copy the data from
3414 the old field to avoid recomputation here. Also if the
3415 field is justified modular and the optimization in
3416 gnat_to_gnu_field was applied. */
3417 if (Present (Component_Clause (gnat_old_field))
3418 || (TREE_CODE (gnu_field_type) == RECORD_TYPE
3419 && TYPE_JUSTIFIED_MODULAR_P (gnu_field_type)
3420 && TREE_TYPE (TYPE_FIELDS (gnu_field_type))
3421 == TREE_TYPE (gnu_old_field)))
3422 {
3423 gnu_size = DECL_SIZE (gnu_old_field);
3424 gnu_field_type = TREE_TYPE (gnu_old_field);
3425 }
3426
3427 /* If the old field was packed and of constant size, we
3428 have to get the old size here, as it might differ from
3429 what the Etype conveys and the latter might overlap
3430 onto the following field. Try to arrange the type for
3431 possible better packing along the way. */
3432 else if (DECL_PACKED (gnu_old_field)
3433 && TREE_CODE (DECL_SIZE (gnu_old_field))
3434 == INTEGER_CST)
3435 {
3436 gnu_size = DECL_SIZE (gnu_old_field);
3437 if (RECORD_OR_UNION_TYPE_P (gnu_field_type)
3438 && !TYPE_FAT_POINTER_P (gnu_field_type)
3439 && host_integerp (TYPE_SIZE (gnu_field_type), 1))
3440 gnu_field_type
3441 = make_packable_type (gnu_field_type, true);
3442 }
3443
3444 else
3445 gnu_size = TYPE_SIZE (gnu_field_type);
3446
3447 /* If the context of the old field is the base type or its
3448 REP part (if any), put the field directly in the new
3449 type; otherwise look up the context in the variant list
3450 and put the field either in the new type if there is a
3451 selected variant or in one of the new variants. */
3452 if (gnu_context == gnu_unpad_base_type
3453 || ((gnu_rep_part = get_rep_part (gnu_unpad_base_type))
3454 && gnu_context == TREE_TYPE (gnu_rep_part)))
3455 gnu_cont_type = gnu_type;
3456 else
3457 {
3458 variant_desc *v;
3459 unsigned int i;
3460
3461 t = NULL_TREE;
3462 FOR_EACH_VEC_ELT (gnu_variant_list, i, v)
3463 if (gnu_context == v->type
3464 || ((gnu_rep_part = get_rep_part (v->type))
3465 && gnu_context == TREE_TYPE (gnu_rep_part)))
3466 {
3467 t = v->type;
3468 break;
3469 }
3470 if (t)
3471 {
3472 if (selected_variant)
3473 gnu_cont_type = gnu_type;
3474 else
3475 gnu_cont_type = v->new_type;
3476 }
3477 else
3478 /* The front-end may pass us "ghost" components if
3479 it fails to recognize that a constrained subtype
3480 is statically constrained. Discard them. */
3481 continue;
3482 }
3483
3484 /* Now create the new field modeled on the old one. */
3485 gnu_field
3486 = create_field_decl_from (gnu_old_field, gnu_field_type,
3487 gnu_cont_type, gnu_size,
3488 gnu_pos_list, gnu_subst_list);
3489
3490 /* Put it in one of the new variants directly. */
3491 if (gnu_cont_type != gnu_type)
3492 {
3493 DECL_CHAIN (gnu_field) = TYPE_FIELDS (gnu_cont_type);
3494 TYPE_FIELDS (gnu_cont_type) = gnu_field;
3495 }
3496
3497 /* To match the layout crafted in components_to_record,
3498 if this is the _Tag or _Parent field, put it before
3499 any other fields. */
3500 else if (gnat_name == Name_uTag
3501 || gnat_name == Name_uParent)
3502 gnu_field_list = chainon (gnu_field_list, gnu_field);
3503
3504 /* Similarly, if this is the _Controller field, put
3505 it before the other fields except for the _Tag or
3506 _Parent field. */
3507 else if (gnat_name == Name_uController && gnu_last)
3508 {
3509 DECL_CHAIN (gnu_field) = DECL_CHAIN (gnu_last);
3510 DECL_CHAIN (gnu_last) = gnu_field;
3511 }
3512
3513 /* Otherwise, if this is a regular field, put it after
3514 the other fields. */
3515 else
3516 {
3517 DECL_CHAIN (gnu_field) = gnu_field_list;
3518 gnu_field_list = gnu_field;
3519 if (!gnu_last)
3520 gnu_last = gnu_field;
3521 }
3522
3523 save_gnu_tree (gnat_field, gnu_field, false);
3524 }
3525
3526 /* If there is a variant list and no selected variant, we need
3527 to create the nest of variant parts from the old nest. */
3528 if (gnu_variant_list.exists () && !selected_variant)
3529 {
3530 tree new_variant_part
3531 = create_variant_part_from (gnu_variant_part,
3532 gnu_variant_list, gnu_type,
3533 gnu_pos_list, gnu_subst_list);
3534 DECL_CHAIN (new_variant_part) = gnu_field_list;
3535 gnu_field_list = new_variant_part;
3536 }
3537
3538 /* Now go through the entities again looking for Itypes that
3539 we have not elaborated but should (e.g., Etypes of fields
3540 that have Original_Components). */
3541 for (gnat_field = First_Entity (gnat_entity);
3542 Present (gnat_field); gnat_field = Next_Entity (gnat_field))
3543 if ((Ekind (gnat_field) == E_Discriminant
3544 || Ekind (gnat_field) == E_Component)
3545 && !present_gnu_tree (Etype (gnat_field)))
3546 gnat_to_gnu_entity (Etype (gnat_field), NULL_TREE, 0);
3547
3548 /* Do not emit debug info for the type yet since we're going to
3549 modify it below. */
3550 finish_record_type (gnu_type, nreverse (gnu_field_list), 2,
3551 false);
3552 compute_record_mode (gnu_type);
3553
3554 /* See the E_Record_Type case for the rationale. */
3555 if (TYPE_MODE (gnu_type) != BLKmode
3556 && Is_By_Reference_Type (gnat_entity))
3557 SET_TYPE_MODE (gnu_type, BLKmode);
3558
3559 TYPE_VOLATILE (gnu_type) = Treat_As_Volatile (gnat_entity);
3560
3561 /* Fill in locations of fields. */
3562 annotate_rep (gnat_entity, gnu_type);
3563
3564 /* If debugging information is being written for the type, write
3565 a record that shows what we are a subtype of and also make a
3566 variable that indicates our size, if still variable. */
3567 if (debug_info_p)
3568 {
3569 tree gnu_subtype_marker = make_node (RECORD_TYPE);
3570 tree gnu_unpad_base_name = TYPE_NAME (gnu_unpad_base_type);
3571 tree gnu_size_unit = TYPE_SIZE_UNIT (gnu_type);
3572
3573 if (TREE_CODE (gnu_unpad_base_name) == TYPE_DECL)
3574 gnu_unpad_base_name = DECL_NAME (gnu_unpad_base_name);
3575
3576 TYPE_NAME (gnu_subtype_marker)
3577 = create_concat_name (gnat_entity, "XVS");
3578 finish_record_type (gnu_subtype_marker,
3579 create_field_decl (gnu_unpad_base_name,
3580 build_reference_type
3581 (gnu_unpad_base_type),
3582 gnu_subtype_marker,
3583 NULL_TREE, NULL_TREE,
3584 0, 0),
3585 0, true);
3586
3587 add_parallel_type (gnu_type, gnu_subtype_marker);
3588
3589 if (definition
3590 && TREE_CODE (gnu_size_unit) != INTEGER_CST
3591 && !CONTAINS_PLACEHOLDER_P (gnu_size_unit))
3592 TYPE_SIZE_UNIT (gnu_subtype_marker)
3593 = create_var_decl (create_concat_name (gnat_entity,
3594 "XVZ"),
3595 NULL_TREE, sizetype, gnu_size_unit,
3596 false, false, false, false, NULL,
3597 gnat_entity);
3598 }
3599
3600 gnu_variant_list.release ();
3601 gnu_subst_list.release ();
3602
3603 /* Now we can finalize it. */
3604 rest_of_record_type_compilation (gnu_type);
3605 }
3606
3607 /* Otherwise, go down all the components in the new type and make
3608 them equivalent to those in the base type. */
3609 else
3610 {
3611 gnu_type = gnu_base_type;
3612
3613 for (gnat_temp = First_Entity (gnat_entity);
3614 Present (gnat_temp);
3615 gnat_temp = Next_Entity (gnat_temp))
3616 if ((Ekind (gnat_temp) == E_Discriminant
3617 && !Is_Unchecked_Union (gnat_base_type))
3618 || Ekind (gnat_temp) == E_Component)
3619 save_gnu_tree (gnat_temp,
3620 gnat_to_gnu_field_decl
3621 (Original_Record_Component (gnat_temp)),
3622 false);
3623 }
3624 }
3625 break;
3626
3627 case E_Access_Subprogram_Type:
3628 /* Use the special descriptor type for dispatch tables if needed,
3629 that is to say for the Prim_Ptr of a-tags.ads and its clones.
3630 Note that we are only required to do so for static tables in
3631 order to be compatible with the C++ ABI, but Ada 2005 allows
3632 to extend library level tagged types at the local level so
3633 we do it in the non-static case as well. */
3634 if (TARGET_VTABLE_USES_DESCRIPTORS
3635 && Is_Dispatch_Table_Entity (gnat_entity))
3636 {
3637 gnu_type = fdesc_type_node;
3638 gnu_size = TYPE_SIZE (gnu_type);
3639 break;
3640 }
3641
3642 /* ... fall through ... */
3643
3644 case E_Anonymous_Access_Subprogram_Type:
3645 /* If we are not defining this entity, and we have incomplete
3646 entities being processed above us, make a dummy type and
3647 fill it in later. */
3648 if (!definition && defer_incomplete_level != 0)
3649 {
3650 struct incomplete *p = XNEW (struct incomplete);
3651
3652 gnu_type
3653 = build_pointer_type
3654 (make_dummy_type (Directly_Designated_Type (gnat_entity)));
3655 gnu_decl = create_type_decl (gnu_entity_name, gnu_type, attr_list,
3656 !Comes_From_Source (gnat_entity),
3657 debug_info_p, gnat_entity);
3658 this_made_decl = true;
3659 gnu_type = TREE_TYPE (gnu_decl);
3660 save_gnu_tree (gnat_entity, gnu_decl, false);
3661 saved = true;
3662
3663 p->old_type = TREE_TYPE (gnu_type);
3664 p->full_type = Directly_Designated_Type (gnat_entity);
3665 p->next = defer_incomplete_list;
3666 defer_incomplete_list = p;
3667 break;
3668 }
3669
3670 /* ... fall through ... */
3671
3672 case E_Allocator_Type:
3673 case E_Access_Type:
3674 case E_Access_Attribute_Type:
3675 case E_Anonymous_Access_Type:
3676 case E_General_Access_Type:
3677 {
3678 /* The designated type and its equivalent type for gigi. */
3679 Entity_Id gnat_desig_type = Directly_Designated_Type (gnat_entity);
3680 Entity_Id gnat_desig_equiv = Gigi_Equivalent_Type (gnat_desig_type);
3681 /* Whether it comes from a limited with. */
3682 bool is_from_limited_with
3683 = (IN (Ekind (gnat_desig_equiv), Incomplete_Kind)
3684 && From_With_Type (gnat_desig_equiv));
3685 /* The "full view" of the designated type. If this is an incomplete
3686 entity from a limited with, treat its non-limited view as the full
3687 view. Otherwise, if this is an incomplete or private type, use the
3688 full view. In the former case, we might point to a private type,
3689 in which case, we need its full view. Also, we want to look at the
3690 actual type used for the representation, so this takes a total of
3691 three steps. */
3692 Entity_Id gnat_desig_full_direct_first
3693 = (is_from_limited_with
3694 ? Non_Limited_View (gnat_desig_equiv)
3695 : (IN (Ekind (gnat_desig_equiv), Incomplete_Or_Private_Kind)
3696 ? Full_View (gnat_desig_equiv) : Empty));
3697 Entity_Id gnat_desig_full_direct
3698 = ((is_from_limited_with
3699 && Present (gnat_desig_full_direct_first)
3700 && IN (Ekind (gnat_desig_full_direct_first), Private_Kind))
3701 ? Full_View (gnat_desig_full_direct_first)
3702 : gnat_desig_full_direct_first);
3703 Entity_Id gnat_desig_full
3704 = Gigi_Equivalent_Type (gnat_desig_full_direct);
3705 /* The type actually used to represent the designated type, either
3706 gnat_desig_full or gnat_desig_equiv. */
3707 Entity_Id gnat_desig_rep;
3708 /* True if this is a pointer to an unconstrained array. */
3709 bool is_unconstrained_array;
3710 /* We want to know if we'll be seeing the freeze node for any
3711 incomplete type we may be pointing to. */
3712 bool in_main_unit
3713 = (Present (gnat_desig_full)
3714 ? In_Extended_Main_Code_Unit (gnat_desig_full)
3715 : In_Extended_Main_Code_Unit (gnat_desig_type));
3716 /* True if we make a dummy type here. */
3717 bool made_dummy = false;
3718 /* The mode to be used for the pointer type. */
3719 enum machine_mode p_mode = mode_for_size (esize, MODE_INT, 0);
3720 /* The GCC type used for the designated type. */
3721 tree gnu_desig_type = NULL_TREE;
3722
3723 if (!targetm.valid_pointer_mode (p_mode))
3724 p_mode = ptr_mode;
3725
3726 /* If either the designated type or its full view is an unconstrained
3727 array subtype, replace it with the type it's a subtype of. This
3728 avoids problems with multiple copies of unconstrained array types.
3729 Likewise, if the designated type is a subtype of an incomplete
3730 record type, use the parent type to avoid order of elaboration
3731 issues. This can lose some code efficiency, but there is no
3732 alternative. */
3733 if (Ekind (gnat_desig_equiv) == E_Array_Subtype
3734 && !Is_Constrained (gnat_desig_equiv))
3735 gnat_desig_equiv = Etype (gnat_desig_equiv);
3736 if (Present (gnat_desig_full)
3737 && ((Ekind (gnat_desig_full) == E_Array_Subtype
3738 && !Is_Constrained (gnat_desig_full))
3739 || (Ekind (gnat_desig_full) == E_Record_Subtype
3740 && Ekind (Etype (gnat_desig_full)) == E_Record_Type)))
3741 gnat_desig_full = Etype (gnat_desig_full);
3742
3743 /* Set the type that's actually the representation of the designated
3744 type and also flag whether we have a unconstrained array. */
3745 gnat_desig_rep
3746 = Present (gnat_desig_full) ? gnat_desig_full : gnat_desig_equiv;
3747 is_unconstrained_array
3748 = Is_Array_Type (gnat_desig_rep) && !Is_Constrained (gnat_desig_rep);
3749
3750 /* If we are pointing to an incomplete type whose completion is an
3751 unconstrained array, make dummy fat and thin pointer types to it.
3752 Likewise if the type itself is dummy or an unconstrained array. */
3753 if (is_unconstrained_array
3754 && (Present (gnat_desig_full)
3755 || (present_gnu_tree (gnat_desig_equiv)
3756 && TYPE_IS_DUMMY_P
3757 (TREE_TYPE (get_gnu_tree (gnat_desig_equiv))))
3758 || (!in_main_unit
3759 && defer_incomplete_level != 0
3760 && !present_gnu_tree (gnat_desig_equiv))
3761 || (in_main_unit
3762 && is_from_limited_with
3763 && Present (Freeze_Node (gnat_desig_equiv)))))
3764 {
3765 if (present_gnu_tree (gnat_desig_rep))
3766 gnu_desig_type = TREE_TYPE (get_gnu_tree (gnat_desig_rep));
3767 else
3768 {
3769 gnu_desig_type = make_dummy_type (gnat_desig_rep);
3770 made_dummy = true;
3771 }
3772
3773 /* If the call above got something that has a pointer, the pointer
3774 is our type. This could have happened either because the type
3775 was elaborated or because somebody else executed the code. */
3776 if (!TYPE_POINTER_TO (gnu_desig_type))
3777 build_dummy_unc_pointer_types (gnat_desig_equiv, gnu_desig_type);
3778 gnu_type = TYPE_POINTER_TO (gnu_desig_type);
3779 }
3780
3781 /* If we already know what the full type is, use it. */
3782 else if (Present (gnat_desig_full)
3783 && present_gnu_tree (gnat_desig_full))
3784 gnu_desig_type = TREE_TYPE (get_gnu_tree (gnat_desig_full));
3785
3786 /* Get the type of the thing we are to point to and build a pointer to
3787 it. If it is a reference to an incomplete or private type with a
3788 full view that is a record, make a dummy type node and get the
3789 actual type later when we have verified it is safe. */
3790 else if ((!in_main_unit
3791 && !present_gnu_tree (gnat_desig_equiv)
3792 && Present (gnat_desig_full)
3793 && !present_gnu_tree (gnat_desig_full)
3794 && Is_Record_Type (gnat_desig_full))
3795 /* Likewise if we are pointing to a record or array and we are
3796 to defer elaborating incomplete types. We do this as this
3797 access type may be the full view of a private type. Note
3798 that the unconstrained array case is handled above. */
3799 || ((!in_main_unit || imported_p)
3800 && defer_incomplete_level != 0
3801 && !present_gnu_tree (gnat_desig_equiv)
3802 && (Is_Record_Type (gnat_desig_rep)
3803 || Is_Array_Type (gnat_desig_rep)))
3804 /* If this is a reference from a limited_with type back to our
3805 main unit and there's a freeze node for it, either we have
3806 already processed the declaration and made the dummy type,
3807 in which case we just reuse the latter, or we have not yet,
3808 in which case we make the dummy type and it will be reused
3809 when the declaration is finally processed. In both cases,
3810 the pointer eventually created below will be automatically
3811 adjusted when the freeze node is processed. Note that the
3812 unconstrained array case is handled above. */
3813 || (in_main_unit
3814 && is_from_limited_with
3815 && Present (Freeze_Node (gnat_desig_rep))))
3816 {
3817 gnu_desig_type = make_dummy_type (gnat_desig_equiv);
3818 made_dummy = true;
3819 }
3820
3821 /* Otherwise handle the case of a pointer to itself. */
3822 else if (gnat_desig_equiv == gnat_entity)
3823 {
3824 gnu_type
3825 = build_pointer_type_for_mode (void_type_node, p_mode,
3826 No_Strict_Aliasing (gnat_entity));
3827 TREE_TYPE (gnu_type) = TYPE_POINTER_TO (gnu_type) = gnu_type;
3828 }
3829
3830 /* If expansion is disabled, the equivalent type of a concurrent type
3831 is absent, so build a dummy pointer type. */
3832 else if (type_annotate_only && No (gnat_desig_equiv))
3833 gnu_type = ptr_void_type_node;
3834
3835 /* Finally, handle the default case where we can just elaborate our
3836 designated type. */
3837 else
3838 gnu_desig_type = gnat_to_gnu_type (gnat_desig_equiv);
3839
3840 /* It is possible that a call to gnat_to_gnu_type above resolved our
3841 type. If so, just return it. */
3842 if (present_gnu_tree (gnat_entity))
3843 {
3844 maybe_present = true;
3845 break;
3846 }
3847
3848 /* If we haven't done it yet, build the pointer type the usual way. */
3849 if (!gnu_type)
3850 {
3851 /* Modify the designated type if we are pointing only to constant
3852 objects, but don't do it for unconstrained arrays. */
3853 if (Is_Access_Constant (gnat_entity)
3854 && TREE_CODE (gnu_desig_type) != UNCONSTRAINED_ARRAY_TYPE)
3855 {
3856 gnu_desig_type
3857 = build_qualified_type
3858 (gnu_desig_type,
3859 TYPE_QUALS (gnu_desig_type) | TYPE_QUAL_CONST);
3860
3861 /* Some extra processing is required if we are building a
3862 pointer to an incomplete type (in the GCC sense). We might
3863 have such a type if we just made a dummy, or directly out
3864 of the call to gnat_to_gnu_type above if we are processing
3865 an access type for a record component designating the
3866 record type itself. */
3867 if (TYPE_MODE (gnu_desig_type) == VOIDmode)
3868 {
3869 /* We must ensure that the pointer to variant we make will
3870 be processed by update_pointer_to when the initial type
3871 is completed. Pretend we made a dummy and let further
3872 processing act as usual. */
3873 made_dummy = true;
3874
3875 /* We must ensure that update_pointer_to will not retrieve
3876 the dummy variant when building a properly qualified
3877 version of the complete type. We take advantage of the
3878 fact that get_qualified_type is requiring TYPE_NAMEs to
3879 match to influence build_qualified_type and then also
3880 update_pointer_to here. */
3881 TYPE_NAME (gnu_desig_type)
3882 = create_concat_name (gnat_desig_type, "INCOMPLETE_CST");
3883 }
3884 }
3885
3886 gnu_type
3887 = build_pointer_type_for_mode (gnu_desig_type, p_mode,
3888 No_Strict_Aliasing (gnat_entity));
3889 }
3890
3891 /* If we are not defining this object and we have made a dummy pointer,
3892 save our current definition, evaluate the actual type, and replace
3893 the tentative type we made with the actual one. If we are to defer
3894 actually looking up the actual type, make an entry in the deferred
3895 list. If this is from a limited with, we may have to defer to the
3896 end of the current unit. */
3897 if ((!in_main_unit || is_from_limited_with) && made_dummy)
3898 {
3899 tree gnu_old_desig_type;
3900
3901 if (TYPE_IS_FAT_POINTER_P (gnu_type))
3902 {
3903 gnu_old_desig_type = TYPE_UNCONSTRAINED_ARRAY (gnu_type);
3904 if (esize == POINTER_SIZE)
3905 gnu_type = build_pointer_type
3906 (TYPE_OBJECT_RECORD_TYPE (gnu_old_desig_type));
3907 }
3908 else
3909 gnu_old_desig_type = TREE_TYPE (gnu_type);
3910
3911 gnu_decl = create_type_decl (gnu_entity_name, gnu_type, attr_list,
3912 !Comes_From_Source (gnat_entity),
3913 debug_info_p, gnat_entity);
3914 this_made_decl = true;
3915 gnu_type = TREE_TYPE (gnu_decl);
3916 save_gnu_tree (gnat_entity, gnu_decl, false);
3917 saved = true;
3918
3919 /* Note that the call to gnat_to_gnu_type on gnat_desig_equiv might
3920 update gnu_old_desig_type directly, in which case it will not be
3921 a dummy type any more when we get into update_pointer_to.
3922
3923 This can happen e.g. when the designated type is a record type,
3924 because their elaboration starts with an initial node from
3925 make_dummy_type, which may be the same node as the one we got.
3926
3927 Besides, variants of this non-dummy type might have been created
3928 along the way. update_pointer_to is expected to properly take
3929 care of those situations. */
3930 if (defer_incomplete_level == 0 && !is_from_limited_with)
3931 {
3932 update_pointer_to (TYPE_MAIN_VARIANT (gnu_old_desig_type),
3933 gnat_to_gnu_type (gnat_desig_equiv));
3934 }
3935 else
3936 {
3937 struct incomplete *p = XNEW (struct incomplete);
3938 struct incomplete **head
3939 = (is_from_limited_with
3940 ? &defer_limited_with : &defer_incomplete_list);
3941 p->old_type = gnu_old_desig_type;
3942 p->full_type = gnat_desig_equiv;
3943 p->next = *head;
3944 *head = p;
3945 }
3946 }
3947 }
3948 break;
3949
3950 case E_Access_Protected_Subprogram_Type:
3951 case E_Anonymous_Access_Protected_Subprogram_Type:
3952 if (type_annotate_only && No (gnat_equiv_type))
3953 gnu_type = ptr_void_type_node;
3954 else
3955 {
3956 /* The run-time representation is the equivalent type. */
3957 gnu_type = gnat_to_gnu_type (gnat_equiv_type);
3958 maybe_present = true;
3959 }
3960
3961 if (Is_Itype (Directly_Designated_Type (gnat_entity))
3962 && !present_gnu_tree (Directly_Designated_Type (gnat_entity))
3963 && No (Freeze_Node (Directly_Designated_Type (gnat_entity)))
3964 && !Is_Record_Type (Scope (Directly_Designated_Type (gnat_entity))))
3965 gnat_to_gnu_entity (Directly_Designated_Type (gnat_entity),
3966 NULL_TREE, 0);
3967
3968 break;
3969
3970 case E_Access_Subtype:
3971
3972 /* We treat this as identical to its base type; any constraint is
3973 meaningful only to the front-end.
3974
3975 The designated type must be elaborated as well, if it does
3976 not have its own freeze node. Designated (sub)types created
3977 for constrained components of records with discriminants are
3978 not frozen by the front-end and thus not elaborated by gigi,
3979 because their use may appear before the base type is frozen,
3980 and because it is not clear that they are needed anywhere in
3981 gigi. With the current model, there is no correct place where
3982 they could be elaborated. */
3983
3984 gnu_type = gnat_to_gnu_type (Etype (gnat_entity));
3985 if (Is_Itype (Directly_Designated_Type (gnat_entity))
3986 && !present_gnu_tree (Directly_Designated_Type (gnat_entity))
3987 && Is_Frozen (Directly_Designated_Type (gnat_entity))
3988 && No (Freeze_Node (Directly_Designated_Type (gnat_entity))))
3989 {
3990 /* If we are not defining this entity, and we have incomplete
3991 entities being processed above us, make a dummy type and
3992 elaborate it later. */
3993 if (!definition && defer_incomplete_level != 0)
3994 {
3995 struct incomplete *p = XNEW (struct incomplete);
3996
3997 p->old_type
3998 = make_dummy_type (Directly_Designated_Type (gnat_entity));
3999 p->full_type = Directly_Designated_Type (gnat_entity);
4000 p->next = defer_incomplete_list;
4001 defer_incomplete_list = p;
4002 }
4003 else if (!IN (Ekind (Base_Type
4004 (Directly_Designated_Type (gnat_entity))),
4005 Incomplete_Or_Private_Kind))
4006 gnat_to_gnu_entity (Directly_Designated_Type (gnat_entity),
4007 NULL_TREE, 0);
4008 }
4009
4010 maybe_present = true;
4011 break;
4012
4013 /* Subprogram Entities
4014
4015 The following access functions are defined for subprograms:
4016
4017 Etype Return type or Standard_Void_Type.
4018 First_Formal The first formal parameter.
4019 Is_Imported Indicates that the subprogram has appeared in
4020 an INTERFACE or IMPORT pragma. For now we
4021 assume that the external language is C.
4022 Is_Exported Likewise but for an EXPORT pragma.
4023 Is_Inlined True if the subprogram is to be inlined.
4024
4025 Each parameter is first checked by calling must_pass_by_ref on its
4026 type to determine if it is passed by reference. For parameters which
4027 are copied in, if they are Ada In Out or Out parameters, their return
4028 value becomes part of a record which becomes the return type of the
4029 function (C function - note that this applies only to Ada procedures
4030 so there is no Ada return type). Additional code to store back the
4031 parameters will be generated on the caller side. This transformation
4032 is done here, not in the front-end.
4033
4034 The intended result of the transformation can be seen from the
4035 equivalent source rewritings that follow:
4036
4037 struct temp {int a,b};
4038 procedure P (A,B: In Out ...) is temp P (int A,B)
4039 begin {
4040 .. ..
4041 end P; return {A,B};
4042 }
4043
4044 temp t;
4045 P(X,Y); t = P(X,Y);
4046 X = t.a , Y = t.b;
4047
4048 For subprogram types we need to perform mainly the same conversions to
4049 GCC form that are needed for procedures and function declarations. The
4050 only difference is that at the end, we make a type declaration instead
4051 of a function declaration. */
4052
4053 case E_Subprogram_Type:
4054 case E_Function:
4055 case E_Procedure:
4056 {
4057 /* The type returned by a function or else Standard_Void_Type for a
4058 procedure. */
4059 Entity_Id gnat_return_type = Etype (gnat_entity);
4060 tree gnu_return_type;
4061 /* The first GCC parameter declaration (a PARM_DECL node). The
4062 PARM_DECL nodes are chained through the DECL_CHAIN field, so this
4063 actually is the head of this parameter list. */
4064 tree gnu_param_list = NULL_TREE;
4065 /* Likewise for the stub associated with an exported procedure. */
4066 tree gnu_stub_param_list = NULL_TREE;
4067 /* Non-null for subprograms containing parameters passed by copy-in
4068 copy-out (Ada In Out or Out parameters not passed by reference),
4069 in which case it is the list of nodes used to specify the values
4070 of the In Out/Out parameters that are returned as a record upon
4071 procedure return. The TREE_PURPOSE of an element of this list is
4072 a field of the record and the TREE_VALUE is the PARM_DECL
4073 corresponding to that field. This list will be saved in the
4074 TYPE_CI_CO_LIST field of the FUNCTION_TYPE node we create. */
4075 tree gnu_cico_list = NULL_TREE;
4076 /* List of fields in return type of procedure with copy-in copy-out
4077 parameters. */
4078 tree gnu_field_list = NULL_TREE;
4079 /* If an import pragma asks to map this subprogram to a GCC builtin,
4080 this is the builtin DECL node. */
4081 tree gnu_builtin_decl = NULL_TREE;
4082 /* For the stub associated with an exported procedure. */
4083 tree gnu_stub_type = NULL_TREE, gnu_stub_name = NULL_TREE;
4084 tree gnu_ext_name = create_concat_name (gnat_entity, NULL);
4085 Entity_Id gnat_param;
4086 bool inline_flag = Is_Inlined (gnat_entity);
4087 bool public_flag = Is_Public (gnat_entity) || imported_p;
4088 bool extern_flag
4089 = (Is_Public (gnat_entity) && !definition) || imported_p;
4090 bool artificial_flag = !Comes_From_Source (gnat_entity);
4091 /* The semantics of "pure" in Ada essentially matches that of "const"
4092 in the back-end. In particular, both properties are orthogonal to
4093 the "nothrow" property if the EH circuitry is explicit in the
4094 internal representation of the back-end. If we are to completely
4095 hide the EH circuitry from it, we need to declare that calls to pure
4096 Ada subprograms that can throw have side effects since they can
4097 trigger an "abnormal" transfer of control flow; thus they can be
4098 neither "const" nor "pure" in the back-end sense. */
4099 bool const_flag
4100 = (Exception_Mechanism == Back_End_Exceptions
4101 && Is_Pure (gnat_entity));
4102 bool volatile_flag = No_Return (gnat_entity);
4103 bool return_by_direct_ref_p = false;
4104 bool return_by_invisi_ref_p = false;
4105 bool return_unconstrained_p = false;
4106 bool has_stub = false;
4107 int parmnum;
4108
4109 /* A parameter may refer to this type, so defer completion of any
4110 incomplete types. */
4111 if (kind == E_Subprogram_Type && !definition)
4112 {
4113 defer_incomplete_level++;
4114 this_deferred = true;
4115 }
4116
4117 /* If the subprogram has an alias, it is probably inherited, so
4118 we can use the original one. If the original "subprogram"
4119 is actually an enumeration literal, it may be the first use
4120 of its type, so we must elaborate that type now. */
4121 if (Present (Alias (gnat_entity)))
4122 {
4123 if (Ekind (Alias (gnat_entity)) == E_Enumeration_Literal)
4124 gnat_to_gnu_entity (Etype (Alias (gnat_entity)), NULL_TREE, 0);
4125
4126 gnu_decl = gnat_to_gnu_entity (Alias (gnat_entity), gnu_expr, 0);
4127
4128 /* Elaborate any Itypes in the parameters of this entity. */
4129 for (gnat_temp = First_Formal_With_Extras (gnat_entity);
4130 Present (gnat_temp);
4131 gnat_temp = Next_Formal_With_Extras (gnat_temp))
4132 if (Is_Itype (Etype (gnat_temp)))
4133 gnat_to_gnu_entity (Etype (gnat_temp), NULL_TREE, 0);
4134
4135 break;
4136 }
4137
4138 /* If this subprogram is expectedly bound to a GCC builtin, fetch the
4139 corresponding DECL node. Proper generation of calls later on need
4140 proper parameter associations so we don't "break;" here. */
4141 if (Convention (gnat_entity) == Convention_Intrinsic
4142 && Present (Interface_Name (gnat_entity)))
4143 {
4144 gnu_builtin_decl = builtin_decl_for (gnu_ext_name);
4145
4146 /* Inability to find the builtin decl most often indicates a
4147 genuine mistake, but imports of unregistered intrinsics are
4148 sometimes issued on purpose to allow hooking in alternate
4149 bodies. We post a warning conditioned on Wshadow in this case,
4150 to let developers be notified on demand without risking false
4151 positives with common default sets of options. */
4152
4153 if (gnu_builtin_decl == NULL_TREE && warn_shadow)
4154 post_error ("?gcc intrinsic not found for&!", gnat_entity);
4155 }
4156
4157 /* ??? What if we don't find the builtin node above ? warn ? err ?
4158 In the current state we neither warn nor err, and calls will just
4159 be handled as for regular subprograms. */
4160
4161 /* Look into the return type and get its associated GCC tree. If it
4162 is not void, compute various flags for the subprogram type. */
4163 if (Ekind (gnat_return_type) == E_Void)
4164 gnu_return_type = void_type_node;
4165 else
4166 {
4167 /* Ada 2012 (AI05-0151): Incomplete types coming from a limited
4168 context may now appear in parameter and result profiles. If
4169 we are only annotating types, break circularities here. */
4170 if (type_annotate_only
4171 && IN (Ekind (gnat_return_type), Incomplete_Kind)
4172 && From_With_Type (gnat_return_type)
4173 && In_Extended_Main_Code_Unit
4174 (Non_Limited_View (gnat_return_type))
4175 && !present_gnu_tree (Non_Limited_View (gnat_return_type)))
4176 gnu_return_type = ptr_void_type_node;
4177 else
4178 gnu_return_type = gnat_to_gnu_type (gnat_return_type);
4179
4180 /* If this function returns by reference, make the actual return
4181 type the pointer type and make a note of that. */
4182 if (Returns_By_Ref (gnat_entity))
4183 {
4184 gnu_return_type = build_pointer_type (gnu_return_type);
4185 return_by_direct_ref_p = true;
4186 }
4187
4188 /* If we are supposed to return an unconstrained array type, make
4189 the actual return type the fat pointer type. */
4190 else if (TREE_CODE (gnu_return_type) == UNCONSTRAINED_ARRAY_TYPE)
4191 {
4192 gnu_return_type = TREE_TYPE (gnu_return_type);
4193 return_unconstrained_p = true;
4194 }
4195
4196 /* Likewise, if the return type requires a transient scope, the
4197 return value will be allocated on the secondary stack so the
4198 actual return type is the pointer type. */
4199 else if (Requires_Transient_Scope (gnat_return_type))
4200 {
4201 gnu_return_type = build_pointer_type (gnu_return_type);
4202 return_unconstrained_p = true;
4203 }
4204
4205 /* If the Mechanism is By_Reference, ensure this function uses the
4206 target's by-invisible-reference mechanism, which may not be the
4207 same as above (e.g. it might be passing an extra parameter). */
4208 else if (kind == E_Function
4209 && Mechanism (gnat_entity) == By_Reference)
4210 return_by_invisi_ref_p = true;
4211
4212 /* Likewise, if the return type is itself By_Reference. */
4213 else if (TYPE_IS_BY_REFERENCE_P (gnu_return_type))
4214 return_by_invisi_ref_p = true;
4215
4216 /* If the type is a padded type and the underlying type would not
4217 be passed by reference or the function has a foreign convention,
4218 return the underlying type. */
4219 else if (TYPE_IS_PADDING_P (gnu_return_type)
4220 && (!default_pass_by_ref
4221 (TREE_TYPE (TYPE_FIELDS (gnu_return_type)))
4222 || Has_Foreign_Convention (gnat_entity)))
4223 gnu_return_type = TREE_TYPE (TYPE_FIELDS (gnu_return_type));
4224
4225 /* If the return type is unconstrained, that means it must have a
4226 maximum size. Use the padded type as the effective return type.
4227 And ensure the function uses the target's by-invisible-reference
4228 mechanism to avoid copying too much data when it returns. */
4229 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_return_type)))
4230 {
4231 tree orig_type = gnu_return_type;
4232
4233 gnu_return_type
4234 = maybe_pad_type (gnu_return_type,
4235 max_size (TYPE_SIZE (gnu_return_type),
4236 true),
4237 0, gnat_entity, false, false, false, true);
4238
4239 /* Declare it now since it will never be declared otherwise.
4240 This is necessary to ensure that its subtrees are properly
4241 marked. */
4242 if (gnu_return_type != orig_type
4243 && !DECL_P (TYPE_NAME (gnu_return_type)))
4244 create_type_decl (TYPE_NAME (gnu_return_type),
4245 gnu_return_type, NULL, true,
4246 debug_info_p, gnat_entity);
4247
4248 return_by_invisi_ref_p = true;
4249 }
4250
4251 /* If the return type has a size that overflows, we cannot have
4252 a function that returns that type. This usage doesn't make
4253 sense anyway, so give an error here. */
4254 if (TYPE_SIZE_UNIT (gnu_return_type)
4255 && TREE_CODE (TYPE_SIZE_UNIT (gnu_return_type)) == INTEGER_CST
4256 && !valid_constant_size_p (TYPE_SIZE_UNIT (gnu_return_type)))
4257 {
4258 post_error ("cannot return type whose size overflows",
4259 gnat_entity);
4260 gnu_return_type = copy_node (gnu_return_type);
4261 TYPE_SIZE (gnu_return_type) = bitsize_zero_node;
4262 TYPE_SIZE_UNIT (gnu_return_type) = size_zero_node;
4263 TYPE_MAIN_VARIANT (gnu_return_type) = gnu_return_type;
4264 TYPE_NEXT_VARIANT (gnu_return_type) = NULL_TREE;
4265 }
4266 }
4267
4268 /* Loop over the parameters and get their associated GCC tree. While
4269 doing this, build a copy-in copy-out structure if we need one. */
4270 for (gnat_param = First_Formal_With_Extras (gnat_entity), parmnum = 0;
4271 Present (gnat_param);
4272 gnat_param = Next_Formal_With_Extras (gnat_param), parmnum++)
4273 {
4274 Entity_Id gnat_param_type = Etype (gnat_param);
4275 tree gnu_param_name = get_entity_name (gnat_param);
4276 tree gnu_param_type, gnu_param, gnu_field;
4277 Mechanism_Type mech = Mechanism (gnat_param);
4278 bool copy_in_copy_out = false, fake_param_type;
4279
4280 /* Ada 2012 (AI05-0151): Incomplete types coming from a limited
4281 context may now appear in parameter and result profiles. If
4282 we are only annotating types, break circularities here. */
4283 if (type_annotate_only
4284 && IN (Ekind (gnat_param_type), Incomplete_Kind)
4285 && From_With_Type (Etype (gnat_param_type))
4286 && In_Extended_Main_Code_Unit
4287 (Non_Limited_View (gnat_param_type))
4288 && !present_gnu_tree (Non_Limited_View (gnat_param_type)))
4289 {
4290 gnu_param_type = ptr_void_type_node;
4291 fake_param_type = true;
4292 }
4293 else
4294 {
4295 gnu_param_type = gnat_to_gnu_type (gnat_param_type);
4296 fake_param_type = false;
4297 }
4298
4299 /* Builtins are expanded inline and there is no real call sequence
4300 involved. So the type expected by the underlying expander is
4301 always the type of each argument "as is". */
4302 if (gnu_builtin_decl)
4303 mech = By_Copy;
4304 /* Handle the first parameter of a valued procedure specially. */
4305 else if (Is_Valued_Procedure (gnat_entity) && parmnum == 0)
4306 mech = By_Copy_Return;
4307 /* Otherwise, see if a Mechanism was supplied that forced this
4308 parameter to be passed one way or another. */
4309 else if (mech == Default
4310 || mech == By_Copy || mech == By_Reference)
4311 ;
4312 else if (By_Descriptor_Last <= mech && mech <= By_Descriptor)
4313 mech = By_Descriptor;
4314
4315 else if (By_Short_Descriptor_Last <= mech &&
4316 mech <= By_Short_Descriptor)
4317 mech = By_Short_Descriptor;
4318
4319 else if (mech > 0)
4320 {
4321 if (TREE_CODE (gnu_param_type) == UNCONSTRAINED_ARRAY_TYPE
4322 || TREE_CODE (TYPE_SIZE (gnu_param_type)) != INTEGER_CST
4323 || 0 < compare_tree_int (TYPE_SIZE (gnu_param_type),
4324 mech))
4325 mech = By_Reference;
4326 else
4327 mech = By_Copy;
4328 }
4329 else
4330 {
4331 post_error ("unsupported mechanism for&", gnat_param);
4332 mech = Default;
4333 }
4334
4335 /* Do not call gnat_to_gnu_param for a fake parameter type since
4336 it will try to use the real type again. */
4337 if (fake_param_type)
4338 {
4339 if (Ekind (gnat_param) == E_Out_Parameter)
4340 gnu_param = NULL_TREE;
4341 else
4342 {
4343 gnu_param
4344 = create_param_decl (gnu_param_name, gnu_param_type,
4345 false);
4346 Set_Mechanism (gnat_param,
4347 mech == Default ? By_Copy : mech);
4348 if (Ekind (gnat_param) == E_In_Out_Parameter)
4349 copy_in_copy_out = true;
4350 }
4351 }
4352 else
4353 gnu_param
4354 = gnat_to_gnu_param (gnat_param, mech, gnat_entity,
4355 Has_Foreign_Convention (gnat_entity),
4356 ©_in_copy_out);
4357
4358 /* We are returned either a PARM_DECL or a type if no parameter
4359 needs to be passed; in either case, adjust the type. */
4360 if (DECL_P (gnu_param))
4361 gnu_param_type = TREE_TYPE (gnu_param);
4362 else
4363 {
4364 gnu_param_type = gnu_param;
4365 gnu_param = NULL_TREE;
4366 }
4367
4368 /* The failure of this assertion will very likely come from an
4369 order of elaboration issue for the type of the parameter. */
4370 gcc_assert (kind == E_Subprogram_Type
4371 || !TYPE_IS_DUMMY_P (gnu_param_type)
4372 || type_annotate_only);
4373
4374 if (gnu_param)
4375 {
4376 /* If it's an exported subprogram, we build a parameter list
4377 in parallel, in case we need to emit a stub for it. */
4378 if (Is_Exported (gnat_entity))
4379 {
4380 gnu_stub_param_list
4381 = chainon (gnu_param, gnu_stub_param_list);
4382 /* Change By_Descriptor parameter to By_Reference for
4383 the internal version of an exported subprogram. */
4384 if (mech == By_Descriptor || mech == By_Short_Descriptor)
4385 {
4386 gnu_param
4387 = gnat_to_gnu_param (gnat_param, By_Reference,
4388 gnat_entity, false,
4389 ©_in_copy_out);
4390 has_stub = true;
4391 }
4392 else
4393 gnu_param = copy_node (gnu_param);
4394 }
4395
4396 gnu_param_list = chainon (gnu_param, gnu_param_list);
4397 Sloc_to_locus (Sloc (gnat_param),
4398 &DECL_SOURCE_LOCATION (gnu_param));
4399 save_gnu_tree (gnat_param, gnu_param, false);
4400
4401 /* If a parameter is a pointer, this function may modify
4402 memory through it and thus shouldn't be considered
4403 a const function. Also, the memory may be modified
4404 between two calls, so they can't be CSE'ed. The latter
4405 case also handles by-ref parameters. */
4406 if (POINTER_TYPE_P (gnu_param_type)
4407 || TYPE_IS_FAT_POINTER_P (gnu_param_type))
4408 const_flag = false;
4409 }
4410
4411 if (copy_in_copy_out)
4412 {
4413 if (!gnu_cico_list)
4414 {
4415 tree gnu_new_ret_type = make_node (RECORD_TYPE);
4416
4417 /* If this is a function, we also need a field for the
4418 return value to be placed. */
4419 if (TREE_CODE (gnu_return_type) != VOID_TYPE)
4420 {
4421 gnu_field
4422 = create_field_decl (get_identifier ("RETVAL"),
4423 gnu_return_type,
4424 gnu_new_ret_type, NULL_TREE,
4425 NULL_TREE, 0, 0);
4426 Sloc_to_locus (Sloc (gnat_entity),
4427 &DECL_SOURCE_LOCATION (gnu_field));
4428 gnu_field_list = gnu_field;
4429 gnu_cico_list
4430 = tree_cons (gnu_field, void_type_node, NULL_TREE);
4431 }
4432
4433 gnu_return_type = gnu_new_ret_type;
4434 TYPE_NAME (gnu_return_type) = get_identifier ("RETURN");
4435 /* Set a default alignment to speed up accesses. But we
4436 shouldn't increase the size of the structure too much,
4437 lest it doesn't fit in return registers anymore. */
4438 TYPE_ALIGN (gnu_return_type)
4439 = get_mode_alignment (ptr_mode);
4440 }
4441
4442 gnu_field
4443 = create_field_decl (gnu_param_name, gnu_param_type,
4444 gnu_return_type, NULL_TREE, NULL_TREE,
4445 0, 0);
4446 Sloc_to_locus (Sloc (gnat_param),
4447 &DECL_SOURCE_LOCATION (gnu_field));
4448 DECL_CHAIN (gnu_field) = gnu_field_list;
4449 gnu_field_list = gnu_field;
4450 gnu_cico_list
4451 = tree_cons (gnu_field, gnu_param, gnu_cico_list);
4452 }
4453 }
4454
4455 if (gnu_cico_list)
4456 {
4457 /* If we have a CICO list but it has only one entry, we convert
4458 this function into a function that returns this object. */
4459 if (list_length (gnu_cico_list) == 1)
4460 gnu_return_type = TREE_TYPE (TREE_PURPOSE (gnu_cico_list));
4461
4462 /* Do not finalize the return type if the subprogram is stubbed
4463 since structures are incomplete for the back-end. */
4464 else if (Convention (gnat_entity) != Convention_Stubbed)
4465 {
4466 finish_record_type (gnu_return_type, nreverse (gnu_field_list),
4467 0, false);
4468
4469 /* Try to promote the mode of the return type if it is passed
4470 in registers, again to speed up accesses. */
4471 if (TYPE_MODE (gnu_return_type) == BLKmode
4472 && !targetm.calls.return_in_memory (gnu_return_type,
4473 NULL_TREE))
4474 {
4475 unsigned int size
4476 = TREE_INT_CST_LOW (TYPE_SIZE (gnu_return_type));
4477 unsigned int i = BITS_PER_UNIT;
4478 enum machine_mode mode;
4479
4480 while (i < size)
4481 i <<= 1;
4482 mode = mode_for_size (i, MODE_INT, 0);
4483 if (mode != BLKmode)
4484 {
4485 SET_TYPE_MODE (gnu_return_type, mode);
4486 TYPE_ALIGN (gnu_return_type)
4487 = GET_MODE_ALIGNMENT (mode);
4488 TYPE_SIZE (gnu_return_type)
4489 = bitsize_int (GET_MODE_BITSIZE (mode));
4490 TYPE_SIZE_UNIT (gnu_return_type)
4491 = size_int (GET_MODE_SIZE (mode));
4492 }
4493 }
4494
4495 if (debug_info_p)
4496 rest_of_record_type_compilation (gnu_return_type);
4497 }
4498 }
4499
4500 if (Has_Stdcall_Convention (gnat_entity))
4501 prepend_one_attribute_to
4502 (&attr_list, ATTR_MACHINE_ATTRIBUTE,
4503 get_identifier ("stdcall"), NULL_TREE,
4504 gnat_entity);
4505 else if (Has_Thiscall_Convention (gnat_entity))
4506 prepend_one_attribute_to
4507 (&attr_list, ATTR_MACHINE_ATTRIBUTE,
4508 get_identifier ("thiscall"), NULL_TREE,
4509 gnat_entity);
4510
4511 /* If we should request stack realignment for a foreign convention
4512 subprogram, do so. Note that this applies to task entry points in
4513 particular. */
4514 if (FOREIGN_FORCE_REALIGN_STACK
4515 && Has_Foreign_Convention (gnat_entity))
4516 prepend_one_attribute_to
4517 (&attr_list, ATTR_MACHINE_ATTRIBUTE,
4518 get_identifier ("force_align_arg_pointer"), NULL_TREE,
4519 gnat_entity);
4520
4521 /* The lists have been built in reverse. */
4522 gnu_param_list = nreverse (gnu_param_list);
4523 if (has_stub)
4524 gnu_stub_param_list = nreverse (gnu_stub_param_list);
4525 gnu_cico_list = nreverse (gnu_cico_list);
4526
4527 if (kind == E_Function)
4528 Set_Mechanism (gnat_entity, return_unconstrained_p
4529 || return_by_direct_ref_p
4530 || return_by_invisi_ref_p
4531 ? By_Reference : By_Copy);
4532 gnu_type
4533 = create_subprog_type (gnu_return_type, gnu_param_list,
4534 gnu_cico_list, return_unconstrained_p,
4535 return_by_direct_ref_p,
4536 return_by_invisi_ref_p);
4537
4538 if (has_stub)
4539 gnu_stub_type
4540 = create_subprog_type (gnu_return_type, gnu_stub_param_list,
4541 gnu_cico_list, return_unconstrained_p,
4542 return_by_direct_ref_p,
4543 return_by_invisi_ref_p);
4544
4545 /* A subprogram (something that doesn't return anything) shouldn't
4546 be considered const since there would be no reason for such a
4547 subprogram. Note that procedures with Out (or In Out) parameters
4548 have already been converted into a function with a return type. */
4549 if (TREE_CODE (gnu_return_type) == VOID_TYPE)
4550 const_flag = false;
4551
4552 gnu_type
4553 = build_qualified_type (gnu_type,
4554 TYPE_QUALS (gnu_type)
4555 | (TYPE_QUAL_CONST * const_flag)
4556 | (TYPE_QUAL_VOLATILE * volatile_flag));
4557
4558 if (has_stub)
4559 gnu_stub_type
4560 = build_qualified_type (gnu_stub_type,
4561 TYPE_QUALS (gnu_stub_type)
4562 | (TYPE_QUAL_CONST * const_flag)
4563 | (TYPE_QUAL_VOLATILE * volatile_flag));
4564
4565 /* If we have a builtin decl for that function, use it. Check if the
4566 profiles are compatible and warn if they are not. The checker is
4567 expected to post extra diagnostics in this case. */
4568 if (gnu_builtin_decl)
4569 {
4570 intrin_binding_t inb;
4571
4572 inb.gnat_entity = gnat_entity;
4573 inb.ada_fntype = gnu_type;
4574 inb.btin_fntype = TREE_TYPE (gnu_builtin_decl);
4575
4576 if (!intrin_profiles_compatible_p (&inb))
4577 post_error
4578 ("?profile of& doesn''t match the builtin it binds!",
4579 gnat_entity);
4580
4581 gnu_decl = gnu_builtin_decl;
4582 gnu_type = TREE_TYPE (gnu_builtin_decl);
4583 break;
4584 }
4585
4586 /* If there was no specified Interface_Name and the external and
4587 internal names of the subprogram are the same, only use the
4588 internal name to allow disambiguation of nested subprograms. */
4589 if (No (Interface_Name (gnat_entity))
4590 && gnu_ext_name == gnu_entity_name)
4591 gnu_ext_name = NULL_TREE;
4592
4593 /* If we are defining the subprogram and it has an Address clause
4594 we must get the address expression from the saved GCC tree for the
4595 subprogram if it has a Freeze_Node. Otherwise, we elaborate
4596 the address expression here since the front-end has guaranteed
4597 in that case that the elaboration has no effects. If there is
4598 an Address clause and we are not defining the object, just
4599 make it a constant. */
4600 if (Present (Address_Clause (gnat_entity)))
4601 {
4602 tree gnu_address = NULL_TREE;
4603
4604 if (definition)
4605 gnu_address
4606 = (present_gnu_tree (gnat_entity)
4607 ? get_gnu_tree (gnat_entity)
4608 : gnat_to_gnu (Expression (Address_Clause (gnat_entity))));
4609
4610 save_gnu_tree (gnat_entity, NULL_TREE, false);
4611
4612 /* Convert the type of the object to a reference type that can
4613 alias everything as per 13.3(19). */
4614 gnu_type
4615 = build_reference_type_for_mode (gnu_type, ptr_mode, true);
4616 if (gnu_address)
4617 gnu_address = convert (gnu_type, gnu_address);
4618
4619 gnu_decl
4620 = create_var_decl (gnu_entity_name, gnu_ext_name, gnu_type,
4621 gnu_address, false, Is_Public (gnat_entity),
4622 extern_flag, false, NULL, gnat_entity);
4623 DECL_BY_REF_P (gnu_decl) = 1;
4624 }
4625
4626 else if (kind == E_Subprogram_Type)
4627 gnu_decl
4628 = create_type_decl (gnu_entity_name, gnu_type, attr_list,
4629 artificial_flag, debug_info_p, gnat_entity);
4630 else
4631 {
4632 if (has_stub)
4633 {
4634 gnu_stub_name = gnu_ext_name;
4635 gnu_ext_name = create_concat_name (gnat_entity, "internal");
4636 public_flag = false;
4637 artificial_flag = true;
4638 }
4639
4640 gnu_decl
4641 = create_subprog_decl (gnu_entity_name, gnu_ext_name, gnu_type,
4642 gnu_param_list, inline_flag, public_flag,
4643 extern_flag, artificial_flag, attr_list,
4644 gnat_entity);
4645 if (has_stub)
4646 {
4647 tree gnu_stub_decl
4648 = create_subprog_decl (gnu_entity_name, gnu_stub_name,
4649 gnu_stub_type, gnu_stub_param_list,
4650 inline_flag, true, extern_flag,
4651 false, attr_list, gnat_entity);
4652 SET_DECL_FUNCTION_STUB (gnu_decl, gnu_stub_decl);
4653 }
4654
4655 /* This is unrelated to the stub built right above. */
4656 DECL_STUBBED_P (gnu_decl)
4657 = Convention (gnat_entity) == Convention_Stubbed;
4658 }
4659 }
4660 break;
4661
4662 case E_Incomplete_Type:
4663 case E_Incomplete_Subtype:
4664 case E_Private_Type:
4665 case E_Private_Subtype:
4666 case E_Limited_Private_Type:
4667 case E_Limited_Private_Subtype:
4668 case E_Record_Type_With_Private:
4669 case E_Record_Subtype_With_Private:
4670 {
4671 /* Get the "full view" of this entity. If this is an incomplete
4672 entity from a limited with, treat its non-limited view as the
4673 full view. Otherwise, use either the full view or the underlying
4674 full view, whichever is present. This is used in all the tests
4675 below. */
4676 Entity_Id full_view
4677 = (IN (kind, Incomplete_Kind) && From_With_Type (gnat_entity))
4678 ? Non_Limited_View (gnat_entity)
4679 : Present (Full_View (gnat_entity))
4680 ? Full_View (gnat_entity)
4681 : Underlying_Full_View (gnat_entity);
4682
4683 /* If this is an incomplete type with no full view, it must be a Taft
4684 Amendment type, in which case we return a dummy type. Otherwise,
4685 just get the type from its Etype. */
4686 if (No (full_view))
4687 {
4688 if (kind == E_Incomplete_Type)
4689 {
4690 gnu_type = make_dummy_type (gnat_entity);
4691 gnu_decl = TYPE_STUB_DECL (gnu_type);
4692 }
4693 else
4694 {
4695 gnu_decl = gnat_to_gnu_entity (Etype (gnat_entity),
4696 NULL_TREE, 0);
4697 maybe_present = true;
4698 }
4699 break;
4700 }
4701
4702 /* If we already made a type for the full view, reuse it. */
4703 else if (present_gnu_tree (full_view))
4704 {
4705 gnu_decl = get_gnu_tree (full_view);
4706 break;
4707 }
4708
4709 /* Otherwise, if we are not defining the type now, get the type
4710 from the full view. But always get the type from the full view
4711 for define on use types, since otherwise we won't see them! */
4712 else if (!definition
4713 || (Is_Itype (full_view)
4714 && No (Freeze_Node (gnat_entity)))
4715 || (Is_Itype (gnat_entity)
4716 && No (Freeze_Node (full_view))))
4717 {
4718 gnu_decl = gnat_to_gnu_entity (full_view, NULL_TREE, 0);
4719 maybe_present = true;
4720 break;
4721 }
4722
4723 /* For incomplete types, make a dummy type entry which will be
4724 replaced later. Save it as the full declaration's type so
4725 we can do any needed updates when we see it. */
4726 gnu_type = make_dummy_type (gnat_entity);
4727 gnu_decl = TYPE_STUB_DECL (gnu_type);
4728 if (Has_Completion_In_Body (gnat_entity))
4729 DECL_TAFT_TYPE_P (gnu_decl) = 1;
4730 save_gnu_tree (full_view, gnu_decl, 0);
4731 break;
4732 }
4733
4734 case E_Class_Wide_Type:
4735 /* Class-wide types are always transformed into their root type. */
4736 gnu_decl = gnat_to_gnu_entity (gnat_equiv_type, NULL_TREE, 0);
4737 maybe_present = true;
4738 break;
4739
4740 case E_Task_Type:
4741 case E_Task_Subtype:
4742 case E_Protected_Type:
4743 case E_Protected_Subtype:
4744 /* Concurrent types are always transformed into their record type. */
4745 if (type_annotate_only && No (gnat_equiv_type))
4746 gnu_type = void_type_node;
4747 else
4748 gnu_decl = gnat_to_gnu_entity (gnat_equiv_type, NULL_TREE, 0);
4749 maybe_present = true;
4750 break;
4751
4752 case E_Label:
4753 gnu_decl = create_label_decl (gnu_entity_name, gnat_entity);
4754 break;
4755
4756 case E_Block:
4757 case E_Loop:
4758 /* Nothing at all to do here, so just return an ERROR_MARK and claim
4759 we've already saved it, so we don't try to. */
4760 gnu_decl = error_mark_node;
4761 saved = true;
4762 break;
4763
4764 default:
4765 gcc_unreachable ();
4766 }
4767
4768 /* If we had a case where we evaluated another type and it might have
4769 defined this one, handle it here. */
4770 if (maybe_present && present_gnu_tree (gnat_entity))
4771 {
4772 gnu_decl = get_gnu_tree (gnat_entity);
4773 saved = true;
4774 }
4775
4776 /* If we are processing a type and there is either no decl for it or
4777 we just made one, do some common processing for the type, such as
4778 handling alignment and possible padding. */
4779 if (is_type && (!gnu_decl || this_made_decl))
4780 {
4781 /* Tell the middle-end that objects of tagged types are guaranteed to
4782 be properly aligned. This is necessary because conversions to the
4783 class-wide type are translated into conversions to the root type,
4784 which can be less aligned than some of its derived types. */
4785 if (Is_Tagged_Type (gnat_entity)
4786 || Is_Class_Wide_Equivalent_Type (gnat_entity))
4787 TYPE_ALIGN_OK (gnu_type) = 1;
4788
4789 /* Record whether the type is passed by reference. */
4790 if (!VOID_TYPE_P (gnu_type) && Is_By_Reference_Type (gnat_entity))
4791 TYPE_BY_REFERENCE_P (gnu_type) = 1;
4792
4793 /* ??? Don't set the size for a String_Literal since it is either
4794 confirming or we don't handle it properly (if the low bound is
4795 non-constant). */
4796 if (!gnu_size && kind != E_String_Literal_Subtype)
4797 {
4798 Uint gnat_size = Known_Esize (gnat_entity)
4799 ? Esize (gnat_entity) : RM_Size (gnat_entity);
4800 gnu_size
4801 = validate_size (gnat_size, gnu_type, gnat_entity, TYPE_DECL,
4802 false, Has_Size_Clause (gnat_entity));
4803 }
4804
4805 /* If a size was specified, see if we can make a new type of that size
4806 by rearranging the type, for example from a fat to a thin pointer. */
4807 if (gnu_size)
4808 {
4809 gnu_type
4810 = make_type_from_size (gnu_type, gnu_size,
4811 Has_Biased_Representation (gnat_entity));
4812
4813 if (operand_equal_p (TYPE_SIZE (gnu_type), gnu_size, 0)
4814 && operand_equal_p (rm_size (gnu_type), gnu_size, 0))
4815 gnu_size = NULL_TREE;
4816 }
4817
4818 /* If the alignment hasn't already been processed and this is
4819 not an unconstrained array, see if an alignment is specified.
4820 If not, we pick a default alignment for atomic objects. */
4821 if (align != 0 || TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE)
4822 ;
4823 else if (Known_Alignment (gnat_entity))
4824 {
4825 align = validate_alignment (Alignment (gnat_entity), gnat_entity,
4826 TYPE_ALIGN (gnu_type));
4827
4828 /* Warn on suspiciously large alignments. This should catch
4829 errors about the (alignment,byte)/(size,bit) discrepancy. */
4830 if (align > BIGGEST_ALIGNMENT && Has_Alignment_Clause (gnat_entity))
4831 {
4832 tree size;
4833
4834 /* If a size was specified, take it into account. Otherwise
4835 use the RM size for records or unions as the type size has
4836 already been adjusted to the alignment. */
4837 if (gnu_size)
4838 size = gnu_size;
4839 else if (RECORD_OR_UNION_TYPE_P (gnu_type)
4840 && !TYPE_FAT_POINTER_P (gnu_type))
4841 size = rm_size (gnu_type);
4842 else
4843 size = TYPE_SIZE (gnu_type);
4844
4845 /* Consider an alignment as suspicious if the alignment/size
4846 ratio is greater or equal to the byte/bit ratio. */
4847 if (host_integerp (size, 1)
4848 && align >= TREE_INT_CST_LOW (size) * BITS_PER_UNIT)
4849 post_error_ne ("?suspiciously large alignment specified for&",
4850 Expression (Alignment_Clause (gnat_entity)),
4851 gnat_entity);
4852 }
4853 }
4854 else if (Is_Atomic (gnat_entity) && !gnu_size
4855 && host_integerp (TYPE_SIZE (gnu_type), 1)
4856 && integer_pow2p (TYPE_SIZE (gnu_type)))
4857 align = MIN (BIGGEST_ALIGNMENT,
4858 tree_low_cst (TYPE_SIZE (gnu_type), 1));
4859 else if (Is_Atomic (gnat_entity) && gnu_size
4860 && host_integerp (gnu_size, 1)
4861 && integer_pow2p (gnu_size))
4862 align = MIN (BIGGEST_ALIGNMENT, tree_low_cst (gnu_size, 1));
4863
4864 /* See if we need to pad the type. If we did, and made a record,
4865 the name of the new type may be changed. So get it back for
4866 us when we make the new TYPE_DECL below. */
4867 if (gnu_size || align > 0)
4868 gnu_type = maybe_pad_type (gnu_type, gnu_size, align, gnat_entity,
4869 false, !gnu_decl, definition, false);
4870
4871 if (TYPE_IS_PADDING_P (gnu_type))
4872 {
4873 gnu_entity_name = TYPE_NAME (gnu_type);
4874 if (TREE_CODE (gnu_entity_name) == TYPE_DECL)
4875 gnu_entity_name = DECL_NAME (gnu_entity_name);
4876 }
4877
4878 /* Now set the RM size of the type. We cannot do it before padding
4879 because we need to accept arbitrary RM sizes on integral types. */
4880 set_rm_size (RM_Size (gnat_entity), gnu_type, gnat_entity);
4881
4882 /* If we are at global level, GCC will have applied variable_size to
4883 the type, but that won't have done anything. So, if it's not
4884 a constant or self-referential, call elaborate_expression_1 to
4885 make a variable for the size rather than calculating it each time.
4886 Handle both the RM size and the actual size. */
4887 if (global_bindings_p ()
4888 && TYPE_SIZE (gnu_type)
4889 && !TREE_CONSTANT (TYPE_SIZE (gnu_type))
4890 && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type)))
4891 {
4892 tree size = TYPE_SIZE (gnu_type);
4893
4894 TYPE_SIZE (gnu_type)
4895 = elaborate_expression_1 (size, gnat_entity,
4896 get_identifier ("SIZE"),
4897 definition, false);
4898
4899 /* ??? For now, store the size as a multiple of the alignment in
4900 bytes so that we can see the alignment from the tree. */
4901 TYPE_SIZE_UNIT (gnu_type)
4902 = elaborate_expression_2 (TYPE_SIZE_UNIT (gnu_type), gnat_entity,
4903 get_identifier ("SIZE_A_UNIT"),
4904 definition, false,
4905 TYPE_ALIGN (gnu_type));
4906
4907 /* ??? gnu_type may come from an existing type so the MULT_EXPR node
4908 may not be marked by the call to create_type_decl below. */
4909 MARK_VISITED (TYPE_SIZE_UNIT (gnu_type));
4910
4911 if (TREE_CODE (gnu_type) == RECORD_TYPE)
4912 {
4913 tree variant_part = get_variant_part (gnu_type);
4914 tree ada_size = TYPE_ADA_SIZE (gnu_type);
4915
4916 if (variant_part)
4917 {
4918 tree union_type = TREE_TYPE (variant_part);
4919 tree offset = DECL_FIELD_OFFSET (variant_part);
4920
4921 /* If the position of the variant part is constant, subtract
4922 it from the size of the type of the parent to get the new
4923 size. This manual CSE reduces the data size. */
4924 if (TREE_CODE (offset) == INTEGER_CST)
4925 {
4926 tree bitpos = DECL_FIELD_BIT_OFFSET (variant_part);
4927 TYPE_SIZE (union_type)
4928 = size_binop (MINUS_EXPR, TYPE_SIZE (gnu_type),
4929 bit_from_pos (offset, bitpos));
4930 TYPE_SIZE_UNIT (union_type)
4931 = size_binop (MINUS_EXPR, TYPE_SIZE_UNIT (gnu_type),
4932 byte_from_pos (offset, bitpos));
4933 }
4934 else
4935 {
4936 TYPE_SIZE (union_type)
4937 = elaborate_expression_1 (TYPE_SIZE (union_type),
4938 gnat_entity,
4939 get_identifier ("VSIZE"),
4940 definition, false);
4941
4942 /* ??? For now, store the size as a multiple of the
4943 alignment in bytes so that we can see the alignment
4944 from the tree. */
4945 TYPE_SIZE_UNIT (union_type)
4946 = elaborate_expression_2 (TYPE_SIZE_UNIT (union_type),
4947 gnat_entity,
4948 get_identifier
4949 ("VSIZE_A_UNIT"),
4950 definition, false,
4951 TYPE_ALIGN (union_type));
4952
4953 /* ??? For now, store the offset as a multiple of the
4954 alignment in bytes so that we can see the alignment
4955 from the tree. */
4956 DECL_FIELD_OFFSET (variant_part)
4957 = elaborate_expression_2 (offset,
4958 gnat_entity,
4959 get_identifier ("VOFFSET"),
4960 definition, false,
4961 DECL_OFFSET_ALIGN
4962 (variant_part));
4963 }
4964
4965 DECL_SIZE (variant_part) = TYPE_SIZE (union_type);
4966 DECL_SIZE_UNIT (variant_part) = TYPE_SIZE_UNIT (union_type);
4967 }
4968
4969 if (operand_equal_p (ada_size, size, 0))
4970 ada_size = TYPE_SIZE (gnu_type);
4971 else
4972 ada_size
4973 = elaborate_expression_1 (ada_size, gnat_entity,
4974 get_identifier ("RM_SIZE"),
4975 definition, false);
4976 SET_TYPE_ADA_SIZE (gnu_type, ada_size);
4977 }
4978 }
4979
4980 /* If this is a record type or subtype, call elaborate_expression_2 on
4981 any field position. Do this for both global and local types.
4982 Skip any fields that we haven't made trees for to avoid problems with
4983 class wide types. */
4984 if (IN (kind, Record_Kind))
4985 for (gnat_temp = First_Entity (gnat_entity); Present (gnat_temp);
4986 gnat_temp = Next_Entity (gnat_temp))
4987 if (Ekind (gnat_temp) == E_Component && present_gnu_tree (gnat_temp))
4988 {
4989 tree gnu_field = get_gnu_tree (gnat_temp);
4990
4991 /* ??? For now, store the offset as a multiple of the alignment
4992 in bytes so that we can see the alignment from the tree. */
4993 if (!CONTAINS_PLACEHOLDER_P (DECL_FIELD_OFFSET (gnu_field)))
4994 {
4995 DECL_FIELD_OFFSET (gnu_field)
4996 = elaborate_expression_2 (DECL_FIELD_OFFSET (gnu_field),
4997 gnat_temp,
4998 get_identifier ("OFFSET"),
4999 definition, false,
5000 DECL_OFFSET_ALIGN (gnu_field));
5001
5002 /* ??? The context of gnu_field is not necessarily gnu_type
5003 so the MULT_EXPR node built above may not be marked by
5004 the call to create_type_decl below. */
5005 if (global_bindings_p ())
5006 MARK_VISITED (DECL_FIELD_OFFSET (gnu_field));
5007 }
5008 }
5009
5010 if (Treat_As_Volatile (gnat_entity))
5011 gnu_type
5012 = build_qualified_type (gnu_type,
5013 TYPE_QUALS (gnu_type) | TYPE_QUAL_VOLATILE);
5014
5015 if (Is_Atomic (gnat_entity))
5016 check_ok_for_atomic (gnu_type, gnat_entity, false);
5017
5018 if (Present (Alignment_Clause (gnat_entity)))
5019 TYPE_USER_ALIGN (gnu_type) = 1;
5020
5021 if (Universal_Aliasing (gnat_entity))
5022 TYPE_UNIVERSAL_ALIASING_P (TYPE_MAIN_VARIANT (gnu_type)) = 1;
5023
5024 if (!gnu_decl)
5025 gnu_decl = create_type_decl (gnu_entity_name, gnu_type, attr_list,
5026 !Comes_From_Source (gnat_entity),
5027 debug_info_p, gnat_entity);
5028 else
5029 {
5030 TREE_TYPE (gnu_decl) = gnu_type;
5031 TYPE_STUB_DECL (gnu_type) = gnu_decl;
5032 }
5033 }
5034
5035 if (is_type && !TYPE_IS_DUMMY_P (TREE_TYPE (gnu_decl)))
5036 {
5037 gnu_type = TREE_TYPE (gnu_decl);
5038
5039 /* If this is a derived type, relate its alias set to that of its parent
5040 to avoid troubles when a call to an inherited primitive is inlined in
5041 a context where a derived object is accessed. The inlined code works
5042 on the parent view so the resulting code may access the same object
5043 using both the parent and the derived alias sets, which thus have to
5044 conflict. As the same issue arises with component references, the
5045 parent alias set also has to conflict with composite types enclosing
5046 derived components. For instance, if we have:
5047
5048 type D is new T;
5049 type R is record
5050 Component : D;
5051 end record;
5052
5053 we want T to conflict with both D and R, in addition to R being a
5054 superset of D by record/component construction.
5055
5056 One way to achieve this is to perform an alias set copy from the
5057 parent to the derived type. This is not quite appropriate, though,
5058 as we don't want separate derived types to conflict with each other:
5059
5060 type I1 is new Integer;
5061 type I2 is new Integer;
5062
5063 We want I1 and I2 to both conflict with Integer but we do not want
5064 I1 to conflict with I2, and an alias set copy on derivation would
5065 have that effect.
5066
5067 The option chosen is to make the alias set of the derived type a
5068 superset of that of its parent type. It trivially fulfills the
5069 simple requirement for the Integer derivation example above, and
5070 the component case as well by superset transitivity:
5071
5072 superset superset
5073 R ----------> D ----------> T
5074
5075 However, for composite types, conversions between derived types are
5076 translated into VIEW_CONVERT_EXPRs so a sequence like:
5077
5078 type Comp1 is new Comp;
5079 type Comp2 is new Comp;
5080 procedure Proc (C : Comp1);
5081
5082 C : Comp2;
5083 Proc (Comp1 (C));
5084
5085 is translated into:
5086
5087 C : Comp2;
5088 Proc ((Comp1 &) &VIEW_CONVERT_EXPR <Comp1> (C));
5089
5090 and gimplified into:
5091
5092 C : Comp2;
5093 Comp1 *C.0;
5094 C.0 = (Comp1 *) &C;
5095 Proc (C.0);
5096
5097 i.e. generates code involving type punning. Therefore, Comp1 needs
5098 to conflict with Comp2 and an alias set copy is required.
5099
5100 The language rules ensure the parent type is already frozen here. */
5101 if (Is_Derived_Type (gnat_entity))
5102 {
5103 tree gnu_parent_type = gnat_to_gnu_type (Etype (gnat_entity));
5104 relate_alias_sets (gnu_type, gnu_parent_type,
5105 Is_Composite_Type (gnat_entity)
5106 ? ALIAS_SET_COPY : ALIAS_SET_SUPERSET);
5107 }
5108
5109 /* Back-annotate the Alignment of the type if not already in the
5110 tree. Likewise for sizes. */
5111 if (Unknown_Alignment (gnat_entity))
5112 {
5113 unsigned int double_align, align;
5114 bool is_capped_double, align_clause;
5115
5116 /* If the default alignment of "double" or larger scalar types is
5117 specifically capped and this is not an array with an alignment
5118 clause on the component type, return the cap. */
5119 if ((double_align = double_float_alignment) > 0)
5120 is_capped_double
5121 = is_double_float_or_array (gnat_entity, &align_clause);
5122 else if ((double_align = double_scalar_alignment) > 0)
5123 is_capped_double
5124 = is_double_scalar_or_array (gnat_entity, &align_clause);
5125 else
5126 is_capped_double = align_clause = false;
5127
5128 if (is_capped_double && !align_clause)
5129 align = double_align;
5130 else
5131 align = TYPE_ALIGN (gnu_type) / BITS_PER_UNIT;
5132
5133 Set_Alignment (gnat_entity, UI_From_Int (align));
5134 }
5135
5136 if (Unknown_Esize (gnat_entity) && TYPE_SIZE (gnu_type))
5137 {
5138 tree gnu_size = TYPE_SIZE (gnu_type);
5139
5140 /* If the size is self-referential, annotate the maximum value. */
5141 if (CONTAINS_PLACEHOLDER_P (gnu_size))
5142 gnu_size = max_size (gnu_size, true);
5143
5144 /* If we are just annotating types and the type is tagged, the tag
5145 and the parent components are not generated by the front-end so
5146 sizes must be adjusted if there is no representation clause. */
5147 if (type_annotate_only
5148 && Is_Tagged_Type (gnat_entity)
5149 && !VOID_TYPE_P (gnu_type)
5150 && (!TYPE_FIELDS (gnu_type)
5151 || integer_zerop (bit_position (TYPE_FIELDS (gnu_type)))))
5152 {
5153 tree pointer_size = bitsize_int (POINTER_SIZE), offset;
5154 Uint uint_size;
5155
5156 if (Is_Derived_Type (gnat_entity))
5157 {
5158 Entity_Id gnat_parent = Etype (Base_Type (gnat_entity));
5159 offset = UI_To_gnu (Esize (gnat_parent), bitsizetype);
5160 Set_Alignment (gnat_entity, Alignment (gnat_parent));
5161 }
5162 else
5163 offset = pointer_size;
5164
5165 if (TYPE_FIELDS (gnu_type))
5166 offset
5167 = round_up (offset, DECL_ALIGN (TYPE_FIELDS (gnu_type)));
5168
5169 gnu_size = size_binop (PLUS_EXPR, gnu_size, offset);
5170 gnu_size = round_up (gnu_size, POINTER_SIZE);
5171 uint_size = annotate_value (gnu_size);
5172 Set_Esize (gnat_entity, uint_size);
5173 Set_RM_Size (gnat_entity, uint_size);
5174 }
5175 else
5176 Set_Esize (gnat_entity, annotate_value (gnu_size));
5177 }
5178
5179 if (Unknown_RM_Size (gnat_entity) && rm_size (gnu_type))
5180 Set_RM_Size (gnat_entity, annotate_value (rm_size (gnu_type)));
5181 }
5182
5183 /* If we really have a ..._DECL node, set a couple of flags on it. But we
5184 cannot do so if we are reusing the ..._DECL node made for an equivalent
5185 type or an alias or a renamed object as the predicates don't apply to it
5186 but to GNAT_ENTITY. */
5187 if (DECL_P (gnu_decl)
5188 && !(is_type && gnat_equiv_type != gnat_entity)
5189 && !Present (Alias (gnat_entity))
5190 && !(Present (Renamed_Object (gnat_entity)) && saved))
5191 {
5192 if (!Comes_From_Source (gnat_entity))
5193 DECL_ARTIFICIAL (gnu_decl) = 1;
5194
5195 if (!debug_info_p)
5196 DECL_IGNORED_P (gnu_decl) = 1;
5197 }
5198
5199 /* If we haven't already, associate the ..._DECL node that we just made with
5200 the input GNAT entity node. */
5201 if (!saved)
5202 save_gnu_tree (gnat_entity, gnu_decl, false);
5203
5204 /* If this is an enumeration or floating-point type, we were not able to set
5205 the bounds since they refer to the type. These are always static. */
5206 if ((kind == E_Enumeration_Type && Present (First_Literal (gnat_entity)))
5207 || (kind == E_Floating_Point_Type && !Vax_Float (gnat_entity)))
5208 {
5209 tree gnu_scalar_type = gnu_type;
5210 tree gnu_low_bound, gnu_high_bound;
5211
5212 /* If this is a padded type, we need to use the underlying type. */
5213 if (TYPE_IS_PADDING_P (gnu_scalar_type))
5214 gnu_scalar_type = TREE_TYPE (TYPE_FIELDS (gnu_scalar_type));
5215
5216 /* If this is a floating point type and we haven't set a floating
5217 point type yet, use this in the evaluation of the bounds. */
5218 if (!longest_float_type_node && kind == E_Floating_Point_Type)
5219 longest_float_type_node = gnu_scalar_type;
5220
5221 gnu_low_bound = gnat_to_gnu (Type_Low_Bound (gnat_entity));
5222 gnu_high_bound = gnat_to_gnu (Type_High_Bound (gnat_entity));
5223
5224 if (kind == E_Enumeration_Type)
5225 {
5226 /* Enumeration types have specific RM bounds. */
5227 SET_TYPE_RM_MIN_VALUE (gnu_scalar_type, gnu_low_bound);
5228 SET_TYPE_RM_MAX_VALUE (gnu_scalar_type, gnu_high_bound);
5229 }
5230 else
5231 {
5232 /* Floating-point types don't have specific RM bounds. */
5233 TYPE_GCC_MIN_VALUE (gnu_scalar_type) = gnu_low_bound;
5234 TYPE_GCC_MAX_VALUE (gnu_scalar_type) = gnu_high_bound;
5235 }
5236 }
5237
5238 /* If we deferred processing of incomplete types, re-enable it. If there
5239 were no other disables and we have deferred types to process, do so. */
5240 if (this_deferred
5241 && --defer_incomplete_level == 0
5242 && defer_incomplete_list)
5243 {
5244 struct incomplete *p, *next;
5245
5246 /* We are back to level 0 for the deferring of incomplete types.
5247 But processing these incomplete types below may itself require
5248 deferring, so preserve what we have and restart from scratch. */
5249 p = defer_incomplete_list;
5250 defer_incomplete_list = NULL;
5251
5252 for (; p; p = next)
5253 {
5254 next = p->next;
5255
5256 if (p->old_type)
5257 update_pointer_to (TYPE_MAIN_VARIANT (p->old_type),
5258 gnat_to_gnu_type (p->full_type));
5259 free (p);
5260 }
5261 }
5262
5263 /* If we are not defining this type, see if it's on one of the lists of
5264 incomplete types. If so, handle the list entry now. */
5265 if (is_type && !definition)
5266 {
5267 struct incomplete *p;
5268
5269 for (p = defer_incomplete_list; p; p = p->next)
5270 if (p->old_type && p->full_type == gnat_entity)
5271 {
5272 update_pointer_to (TYPE_MAIN_VARIANT (p->old_type),
5273 TREE_TYPE (gnu_decl));
5274 p->old_type = NULL_TREE;
5275 }
5276
5277 for (p = defer_limited_with; p; p = p->next)
5278 if (p->old_type && Non_Limited_View (p->full_type) == gnat_entity)
5279 {
5280 update_pointer_to (TYPE_MAIN_VARIANT (p->old_type),
5281 TREE_TYPE (gnu_decl));
5282 p->old_type = NULL_TREE;
5283 }
5284 }
5285
5286 if (this_global)
5287 force_global--;
5288
5289 /* If this is a packed array type whose original array type is itself
5290 an Itype without freeze node, make sure the latter is processed. */
5291 if (Is_Packed_Array_Type (gnat_entity)
5292 && Is_Itype (Original_Array_Type (gnat_entity))
5293 && No (Freeze_Node (Original_Array_Type (gnat_entity)))
5294 && !present_gnu_tree (Original_Array_Type (gnat_entity)))
5295 gnat_to_gnu_entity (Original_Array_Type (gnat_entity), NULL_TREE, 0);
5296
5297 return gnu_decl;
5298 }
5299
5300 /* Similar, but if the returned value is a COMPONENT_REF, return the
5301 FIELD_DECL. */
5302
5303 tree
gnat_to_gnu_field_decl(Entity_Id gnat_entity)5304 gnat_to_gnu_field_decl (Entity_Id gnat_entity)
5305 {
5306 tree gnu_field = gnat_to_gnu_entity (gnat_entity, NULL_TREE, 0);
5307
5308 if (TREE_CODE (gnu_field) == COMPONENT_REF)
5309 gnu_field = TREE_OPERAND (gnu_field, 1);
5310
5311 return gnu_field;
5312 }
5313
5314 /* Similar, but GNAT_ENTITY is assumed to refer to a GNAT type. Return
5315 the GCC type corresponding to that entity. */
5316
5317 tree
gnat_to_gnu_type(Entity_Id gnat_entity)5318 gnat_to_gnu_type (Entity_Id gnat_entity)
5319 {
5320 tree gnu_decl;
5321
5322 /* The back end never attempts to annotate generic types. */
5323 if (Is_Generic_Type (gnat_entity) && type_annotate_only)
5324 return void_type_node;
5325
5326 gnu_decl = gnat_to_gnu_entity (gnat_entity, NULL_TREE, 0);
5327 gcc_assert (TREE_CODE (gnu_decl) == TYPE_DECL);
5328
5329 return TREE_TYPE (gnu_decl);
5330 }
5331
5332 /* Similar, but GNAT_ENTITY is assumed to refer to a GNAT type. Return
5333 the unpadded version of the GCC type corresponding to that entity. */
5334
5335 tree
get_unpadded_type(Entity_Id gnat_entity)5336 get_unpadded_type (Entity_Id gnat_entity)
5337 {
5338 tree type = gnat_to_gnu_type (gnat_entity);
5339
5340 if (TYPE_IS_PADDING_P (type))
5341 type = TREE_TYPE (TYPE_FIELDS (type));
5342
5343 return type;
5344 }
5345
5346 /* Return the DECL associated with the public subprogram GNAT_ENTITY but whose
5347 type has been changed to that of the parameterless procedure, except if an
5348 alias is already present, in which case it is returned instead. */
5349
5350 tree
get_minimal_subprog_decl(Entity_Id gnat_entity)5351 get_minimal_subprog_decl (Entity_Id gnat_entity)
5352 {
5353 tree gnu_entity_name, gnu_ext_name;
5354 struct attrib *attr_list = NULL;
5355
5356 /* See the E_Function/E_Procedure case of gnat_to_gnu_entity for the model
5357 of the handling applied here. */
5358
5359 while (Present (Alias (gnat_entity)))
5360 {
5361 gnat_entity = Alias (gnat_entity);
5362 if (present_gnu_tree (gnat_entity))
5363 return get_gnu_tree (gnat_entity);
5364 }
5365
5366 gnu_entity_name = get_entity_name (gnat_entity);
5367 gnu_ext_name = create_concat_name (gnat_entity, NULL);
5368
5369 if (Has_Stdcall_Convention (gnat_entity))
5370 prepend_one_attribute_to (&attr_list, ATTR_MACHINE_ATTRIBUTE,
5371 get_identifier ("stdcall"), NULL_TREE,
5372 gnat_entity);
5373 else if (Has_Thiscall_Convention (gnat_entity))
5374 prepend_one_attribute_to (&attr_list, ATTR_MACHINE_ATTRIBUTE,
5375 get_identifier ("thiscall"), NULL_TREE,
5376 gnat_entity);
5377
5378 if (No (Interface_Name (gnat_entity)) && gnu_ext_name == gnu_entity_name)
5379 gnu_ext_name = NULL_TREE;
5380
5381 return
5382 create_subprog_decl (gnu_entity_name, gnu_ext_name, void_ftype, NULL_TREE,
5383 false, true, true, true, attr_list, gnat_entity);
5384 }
5385
5386 /* Return whether the E_Subprogram_Type/E_Function/E_Procedure GNAT_ENTITY is
5387 a C++ imported method or equivalent.
5388
5389 We use the predicate on 32-bit x86/Windows to find out whether we need to
5390 use the "thiscall" calling convention for GNAT_ENTITY. This convention is
5391 used for C++ methods (functions with METHOD_TYPE) by the back-end. */
5392
5393 bool
is_cplusplus_method(Entity_Id gnat_entity)5394 is_cplusplus_method (Entity_Id gnat_entity)
5395 {
5396 if (Convention (gnat_entity) != Convention_CPP)
5397 return False;
5398
5399 /* This is the main case: C++ method imported as a primitive operation. */
5400 if (Is_Dispatching_Operation (gnat_entity))
5401 return True;
5402
5403 /* A thunk needs to be handled like its associated primitive operation. */
5404 if (Is_Subprogram (gnat_entity) && Is_Thunk (gnat_entity))
5405 return True;
5406
5407 /* C++ classes with no virtual functions can be imported as limited
5408 record types, but we need to return true for the constructors. */
5409 if (Is_Constructor (gnat_entity))
5410 return True;
5411
5412 /* This is set on the E_Subprogram_Type built for a dispatching call. */
5413 if (Is_Dispatch_Table_Entity (gnat_entity))
5414 return True;
5415
5416 return False;
5417 }
5418
5419 /* Finalize the processing of From_With_Type incomplete types. */
5420
5421 void
finalize_from_with_types(void)5422 finalize_from_with_types (void)
5423 {
5424 struct incomplete *p, *next;
5425
5426 p = defer_limited_with;
5427 defer_limited_with = NULL;
5428
5429 for (; p; p = next)
5430 {
5431 next = p->next;
5432
5433 if (p->old_type)
5434 update_pointer_to (TYPE_MAIN_VARIANT (p->old_type),
5435 gnat_to_gnu_type (p->full_type));
5436 free (p);
5437 }
5438 }
5439
5440 /* Return the equivalent type to be used for GNAT_ENTITY, if it's a
5441 kind of type (such E_Task_Type) that has a different type which Gigi
5442 uses for its representation. If the type does not have a special type
5443 for its representation, return GNAT_ENTITY. If a type is supposed to
5444 exist, but does not, abort unless annotating types, in which case
5445 return Empty. If GNAT_ENTITY is Empty, return Empty. */
5446
5447 Entity_Id
Gigi_Equivalent_Type(Entity_Id gnat_entity)5448 Gigi_Equivalent_Type (Entity_Id gnat_entity)
5449 {
5450 Entity_Id gnat_equiv = gnat_entity;
5451
5452 if (No (gnat_entity))
5453 return gnat_entity;
5454
5455 switch (Ekind (gnat_entity))
5456 {
5457 case E_Class_Wide_Subtype:
5458 if (Present (Equivalent_Type (gnat_entity)))
5459 gnat_equiv = Equivalent_Type (gnat_entity);
5460 break;
5461
5462 case E_Access_Protected_Subprogram_Type:
5463 case E_Anonymous_Access_Protected_Subprogram_Type:
5464 gnat_equiv = Equivalent_Type (gnat_entity);
5465 break;
5466
5467 case E_Class_Wide_Type:
5468 gnat_equiv = Root_Type (gnat_entity);
5469 break;
5470
5471 case E_Task_Type:
5472 case E_Task_Subtype:
5473 case E_Protected_Type:
5474 case E_Protected_Subtype:
5475 gnat_equiv = Corresponding_Record_Type (gnat_entity);
5476 break;
5477
5478 default:
5479 break;
5480 }
5481
5482 gcc_assert (Present (gnat_equiv) || type_annotate_only);
5483
5484 return gnat_equiv;
5485 }
5486
5487 /* Return a GCC tree for a type corresponding to the component type of the
5488 array type or subtype GNAT_ARRAY. DEFINITION is true if this component
5489 is for an array being defined. DEBUG_INFO_P is true if we need to write
5490 debug information for other types that we may create in the process. */
5491
5492 static tree
gnat_to_gnu_component_type(Entity_Id gnat_array,bool definition,bool debug_info_p)5493 gnat_to_gnu_component_type (Entity_Id gnat_array, bool definition,
5494 bool debug_info_p)
5495 {
5496 const Entity_Id gnat_type = Component_Type (gnat_array);
5497 tree gnu_type = gnat_to_gnu_type (gnat_type);
5498 tree gnu_comp_size;
5499
5500 /* Try to get a smaller form of the component if needed. */
5501 if ((Is_Packed (gnat_array)
5502 || Has_Component_Size_Clause (gnat_array))
5503 && !Is_Bit_Packed_Array (gnat_array)
5504 && !Has_Aliased_Components (gnat_array)
5505 && !Strict_Alignment (gnat_type)
5506 && RECORD_OR_UNION_TYPE_P (gnu_type)
5507 && !TYPE_FAT_POINTER_P (gnu_type)
5508 && host_integerp (TYPE_SIZE (gnu_type), 1))
5509 gnu_type = make_packable_type (gnu_type, false);
5510
5511 if (Has_Atomic_Components (gnat_array))
5512 check_ok_for_atomic (gnu_type, gnat_array, true);
5513
5514 /* Get and validate any specified Component_Size. */
5515 gnu_comp_size
5516 = validate_size (Component_Size (gnat_array), gnu_type, gnat_array,
5517 Is_Bit_Packed_Array (gnat_array) ? TYPE_DECL : VAR_DECL,
5518 true, Has_Component_Size_Clause (gnat_array));
5519
5520 /* If the array has aliased components and the component size can be zero,
5521 force at least unit size to ensure that the components have distinct
5522 addresses. */
5523 if (!gnu_comp_size
5524 && Has_Aliased_Components (gnat_array)
5525 && (integer_zerop (TYPE_SIZE (gnu_type))
5526 || (TREE_CODE (gnu_type) == ARRAY_TYPE
5527 && !TREE_CONSTANT (TYPE_SIZE (gnu_type)))))
5528 gnu_comp_size
5529 = size_binop (MAX_EXPR, TYPE_SIZE (gnu_type), bitsize_unit_node);
5530
5531 /* If the component type is a RECORD_TYPE that has a self-referential size,
5532 then use the maximum size for the component size. */
5533 if (!gnu_comp_size
5534 && TREE_CODE (gnu_type) == RECORD_TYPE
5535 && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type)))
5536 gnu_comp_size = max_size (TYPE_SIZE (gnu_type), true);
5537
5538 /* Honor the component size. This is not needed for bit-packed arrays. */
5539 if (gnu_comp_size && !Is_Bit_Packed_Array (gnat_array))
5540 {
5541 tree orig_type = gnu_type;
5542 unsigned int max_align;
5543
5544 /* If an alignment is specified, use it as a cap on the component type
5545 so that it can be honored for the whole type. But ignore it for the
5546 original type of packed array types. */
5547 if (No (Packed_Array_Type (gnat_array)) && Known_Alignment (gnat_array))
5548 max_align = validate_alignment (Alignment (gnat_array), gnat_array, 0);
5549 else
5550 max_align = 0;
5551
5552 gnu_type = make_type_from_size (gnu_type, gnu_comp_size, false);
5553 if (max_align > 0 && TYPE_ALIGN (gnu_type) > max_align)
5554 gnu_type = orig_type;
5555 else
5556 orig_type = gnu_type;
5557
5558 gnu_type = maybe_pad_type (gnu_type, gnu_comp_size, 0, gnat_array,
5559 true, false, definition, true);
5560
5561 /* If a padding record was made, declare it now since it will never be
5562 declared otherwise. This is necessary to ensure that its subtrees
5563 are properly marked. */
5564 if (gnu_type != orig_type && !DECL_P (TYPE_NAME (gnu_type)))
5565 create_type_decl (TYPE_NAME (gnu_type), gnu_type, NULL, true,
5566 debug_info_p, gnat_array);
5567 }
5568
5569 if (Has_Volatile_Components (gnat_array))
5570 gnu_type
5571 = build_qualified_type (gnu_type,
5572 TYPE_QUALS (gnu_type) | TYPE_QUAL_VOLATILE);
5573
5574 return gnu_type;
5575 }
5576
5577 /* Return a GCC tree for a parameter corresponding to GNAT_PARAM and
5578 using MECH as its passing mechanism, to be placed in the parameter
5579 list built for GNAT_SUBPROG. Assume a foreign convention for the
5580 latter if FOREIGN is true. Also set CICO to true if the parameter
5581 must use the copy-in copy-out implementation mechanism.
5582
5583 The returned tree is a PARM_DECL, except for those cases where no
5584 parameter needs to be actually passed to the subprogram; the type
5585 of this "shadow" parameter is then returned instead. */
5586
5587 static tree
gnat_to_gnu_param(Entity_Id gnat_param,Mechanism_Type mech,Entity_Id gnat_subprog,bool foreign,bool * cico)5588 gnat_to_gnu_param (Entity_Id gnat_param, Mechanism_Type mech,
5589 Entity_Id gnat_subprog, bool foreign, bool *cico)
5590 {
5591 tree gnu_param_name = get_entity_name (gnat_param);
5592 tree gnu_param_type = gnat_to_gnu_type (Etype (gnat_param));
5593 tree gnu_param_type_alt = NULL_TREE;
5594 bool in_param = (Ekind (gnat_param) == E_In_Parameter);
5595 /* The parameter can be indirectly modified if its address is taken. */
5596 bool ro_param = in_param && !Address_Taken (gnat_param);
5597 bool by_return = false, by_component_ptr = false;
5598 bool by_ref = false, by_double_ref = false;
5599 tree gnu_param;
5600
5601 /* Copy-return is used only for the first parameter of a valued procedure.
5602 It's a copy mechanism for which a parameter is never allocated. */
5603 if (mech == By_Copy_Return)
5604 {
5605 gcc_assert (Ekind (gnat_param) == E_Out_Parameter);
5606 mech = By_Copy;
5607 by_return = true;
5608 }
5609
5610 /* If this is either a foreign function or if the underlying type won't
5611 be passed by reference, strip off possible padding type. */
5612 if (TYPE_IS_PADDING_P (gnu_param_type))
5613 {
5614 tree unpadded_type = TREE_TYPE (TYPE_FIELDS (gnu_param_type));
5615
5616 if (mech == By_Reference
5617 || foreign
5618 || (!must_pass_by_ref (unpadded_type)
5619 && (mech == By_Copy || !default_pass_by_ref (unpadded_type))))
5620 gnu_param_type = unpadded_type;
5621 }
5622
5623 /* If this is a read-only parameter, make a variant of the type that is
5624 read-only. ??? However, if this is an unconstrained array, that type
5625 can be very complex, so skip it for now. Likewise for any other
5626 self-referential type. */
5627 if (ro_param
5628 && TREE_CODE (gnu_param_type) != UNCONSTRAINED_ARRAY_TYPE
5629 && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_param_type)))
5630 gnu_param_type = build_qualified_type (gnu_param_type,
5631 (TYPE_QUALS (gnu_param_type)
5632 | TYPE_QUAL_CONST));
5633
5634 /* For foreign conventions, pass arrays as pointers to the element type.
5635 First check for unconstrained array and get the underlying array. */
5636 if (foreign && TREE_CODE (gnu_param_type) == UNCONSTRAINED_ARRAY_TYPE)
5637 gnu_param_type
5638 = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_param_type))));
5639
5640 /* For GCC builtins, pass Address integer types as (void *) */
5641 if (Convention (gnat_subprog) == Convention_Intrinsic
5642 && Present (Interface_Name (gnat_subprog))
5643 && Is_Descendent_Of_Address (Etype (gnat_param)))
5644 gnu_param_type = ptr_void_type_node;
5645
5646 /* VMS descriptors are themselves passed by reference. */
5647 if (mech == By_Short_Descriptor ||
5648 (mech == By_Descriptor && TARGET_ABI_OPEN_VMS && !flag_vms_malloc64))
5649 gnu_param_type
5650 = build_pointer_type (build_vms_descriptor32 (gnu_param_type,
5651 Mechanism (gnat_param),
5652 gnat_subprog));
5653 else if (mech == By_Descriptor)
5654 {
5655 /* Build both a 32-bit and 64-bit descriptor, one of which will be
5656 chosen in fill_vms_descriptor. */
5657 gnu_param_type_alt
5658 = build_pointer_type (build_vms_descriptor32 (gnu_param_type,
5659 Mechanism (gnat_param),
5660 gnat_subprog));
5661 gnu_param_type
5662 = build_pointer_type (build_vms_descriptor (gnu_param_type,
5663 Mechanism (gnat_param),
5664 gnat_subprog));
5665 }
5666
5667 /* Arrays are passed as pointers to element type for foreign conventions. */
5668 else if (foreign
5669 && mech != By_Copy
5670 && TREE_CODE (gnu_param_type) == ARRAY_TYPE)
5671 {
5672 /* Strip off any multi-dimensional entries, then strip
5673 off the last array to get the component type. */
5674 while (TREE_CODE (TREE_TYPE (gnu_param_type)) == ARRAY_TYPE
5675 && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_param_type)))
5676 gnu_param_type = TREE_TYPE (gnu_param_type);
5677
5678 by_component_ptr = true;
5679 gnu_param_type = TREE_TYPE (gnu_param_type);
5680
5681 if (ro_param)
5682 gnu_param_type = build_qualified_type (gnu_param_type,
5683 (TYPE_QUALS (gnu_param_type)
5684 | TYPE_QUAL_CONST));
5685
5686 gnu_param_type = build_pointer_type (gnu_param_type);
5687 }
5688
5689 /* Fat pointers are passed as thin pointers for foreign conventions. */
5690 else if (foreign && TYPE_IS_FAT_POINTER_P (gnu_param_type))
5691 gnu_param_type
5692 = make_type_from_size (gnu_param_type, size_int (POINTER_SIZE), 0);
5693
5694 /* If we must pass or were requested to pass by reference, do so.
5695 If we were requested to pass by copy, do so.
5696 Otherwise, for foreign conventions, pass In Out or Out parameters
5697 or aggregates by reference. For COBOL and Fortran, pass all
5698 integer and FP types that way too. For Convention Ada, use
5699 the standard Ada default. */
5700 else if (must_pass_by_ref (gnu_param_type)
5701 || mech == By_Reference
5702 || (mech != By_Copy
5703 && ((foreign
5704 && (!in_param || AGGREGATE_TYPE_P (gnu_param_type)))
5705 || (foreign
5706 && (Convention (gnat_subprog) == Convention_Fortran
5707 || Convention (gnat_subprog) == Convention_COBOL)
5708 && (INTEGRAL_TYPE_P (gnu_param_type)
5709 || FLOAT_TYPE_P (gnu_param_type)))
5710 || (!foreign
5711 && default_pass_by_ref (gnu_param_type)))))
5712 {
5713 /* We take advantage of 6.2(12) by considering that references built for
5714 parameters whose type isn't by-ref and for which the mechanism hasn't
5715 been forced to by-ref are restrict-qualified in the C sense. */
5716 bool restrict_p
5717 = !TYPE_IS_BY_REFERENCE_P (gnu_param_type) && mech != By_Reference;
5718 gnu_param_type = build_reference_type (gnu_param_type);
5719 if (restrict_p)
5720 gnu_param_type
5721 = build_qualified_type (gnu_param_type, TYPE_QUAL_RESTRICT);
5722 by_ref = true;
5723
5724 /* In some ABIs, e.g. SPARC 32-bit, fat pointer types are themselves
5725 passed by reference. Pass them by explicit reference, this will
5726 generate more debuggable code at -O0. */
5727 if (TYPE_IS_FAT_POINTER_P (gnu_param_type)
5728 && targetm.calls.pass_by_reference (pack_cumulative_args (NULL),
5729 TYPE_MODE (gnu_param_type),
5730 gnu_param_type,
5731 true))
5732 {
5733 gnu_param_type = build_reference_type (gnu_param_type);
5734 by_double_ref = true;
5735 }
5736 }
5737
5738 /* Pass In Out or Out parameters using copy-in copy-out mechanism. */
5739 else if (!in_param)
5740 *cico = true;
5741
5742 if (mech == By_Copy && (by_ref || by_component_ptr))
5743 post_error ("?cannot pass & by copy", gnat_param);
5744
5745 /* If this is an Out parameter that isn't passed by reference and isn't
5746 a pointer or aggregate, we don't make a PARM_DECL for it. Instead,
5747 it will be a VAR_DECL created when we process the procedure, so just
5748 return its type. For the special parameter of a valued procedure,
5749 never pass it in.
5750
5751 An exception is made to cover the RM-6.4.1 rule requiring "by copy"
5752 Out parameters with discriminants or implicit initial values to be
5753 handled like In Out parameters. These type are normally built as
5754 aggregates, hence passed by reference, except for some packed arrays
5755 which end up encoded in special integer types.
5756
5757 The exception we need to make is then for packed arrays of records
5758 with discriminants or implicit initial values. We have no light/easy
5759 way to check for the latter case, so we merely check for packed arrays
5760 of records. This may lead to useless copy-in operations, but in very
5761 rare cases only, as these would be exceptions in a set of already
5762 exceptional situations. */
5763 if (Ekind (gnat_param) == E_Out_Parameter
5764 && !by_ref
5765 && (by_return
5766 || (mech != By_Descriptor
5767 && mech != By_Short_Descriptor
5768 && !POINTER_TYPE_P (gnu_param_type)
5769 && !AGGREGATE_TYPE_P (gnu_param_type)))
5770 && !(Is_Array_Type (Etype (gnat_param))
5771 && Is_Packed (Etype (gnat_param))
5772 && Is_Composite_Type (Component_Type (Etype (gnat_param)))))
5773 return gnu_param_type;
5774
5775 gnu_param = create_param_decl (gnu_param_name, gnu_param_type,
5776 ro_param || by_ref || by_component_ptr);
5777 DECL_BY_REF_P (gnu_param) = by_ref;
5778 DECL_BY_DOUBLE_REF_P (gnu_param) = by_double_ref;
5779 DECL_BY_COMPONENT_PTR_P (gnu_param) = by_component_ptr;
5780 DECL_BY_DESCRIPTOR_P (gnu_param) = (mech == By_Descriptor ||
5781 mech == By_Short_Descriptor);
5782 /* Note that, in case of a parameter passed by double reference, the
5783 DECL_POINTS_TO_READONLY_P flag is meant for the second reference.
5784 The first reference always points to read-only, as it points to
5785 the second reference, i.e. the reference to the actual parameter. */
5786 DECL_POINTS_TO_READONLY_P (gnu_param)
5787 = (ro_param && (by_ref || by_component_ptr));
5788 DECL_CAN_NEVER_BE_NULL_P (gnu_param) = Can_Never_Be_Null (gnat_param);
5789
5790 /* Save the alternate descriptor type, if any. */
5791 if (gnu_param_type_alt)
5792 SET_DECL_PARM_ALT_TYPE (gnu_param, gnu_param_type_alt);
5793
5794 /* If no Mechanism was specified, indicate what we're using, then
5795 back-annotate it. */
5796 if (mech == Default)
5797 mech = (by_ref || by_component_ptr) ? By_Reference : By_Copy;
5798
5799 Set_Mechanism (gnat_param, mech);
5800 return gnu_param;
5801 }
5802
5803 /* Return true if DISCR1 and DISCR2 represent the same discriminant. */
5804
5805 static bool
same_discriminant_p(Entity_Id discr1,Entity_Id discr2)5806 same_discriminant_p (Entity_Id discr1, Entity_Id discr2)
5807 {
5808 while (Present (Corresponding_Discriminant (discr1)))
5809 discr1 = Corresponding_Discriminant (discr1);
5810
5811 while (Present (Corresponding_Discriminant (discr2)))
5812 discr2 = Corresponding_Discriminant (discr2);
5813
5814 return
5815 Original_Record_Component (discr1) == Original_Record_Component (discr2);
5816 }
5817
5818 /* Return true if the array type GNU_TYPE, which represents a dimension of
5819 GNAT_TYPE, has a non-aliased component in the back-end sense. */
5820
5821 static bool
array_type_has_nonaliased_component(tree gnu_type,Entity_Id gnat_type)5822 array_type_has_nonaliased_component (tree gnu_type, Entity_Id gnat_type)
5823 {
5824 /* If the array type is not the innermost dimension of the GNAT type,
5825 then it has a non-aliased component. */
5826 if (TREE_CODE (TREE_TYPE (gnu_type)) == ARRAY_TYPE
5827 && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_type)))
5828 return true;
5829
5830 /* If the array type has an aliased component in the front-end sense,
5831 then it also has an aliased component in the back-end sense. */
5832 if (Has_Aliased_Components (gnat_type))
5833 return false;
5834
5835 /* If this is a derived type, then it has a non-aliased component if
5836 and only if its parent type also has one. */
5837 if (Is_Derived_Type (gnat_type))
5838 {
5839 tree gnu_parent_type = gnat_to_gnu_type (Etype (gnat_type));
5840 int index;
5841 if (TREE_CODE (gnu_parent_type) == UNCONSTRAINED_ARRAY_TYPE)
5842 gnu_parent_type
5843 = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_parent_type))));
5844 for (index = Number_Dimensions (gnat_type) - 1; index > 0; index--)
5845 gnu_parent_type = TREE_TYPE (gnu_parent_type);
5846 return TYPE_NONALIASED_COMPONENT (gnu_parent_type);
5847 }
5848
5849 /* Otherwise, rely exclusively on properties of the element type. */
5850 return type_for_nonaliased_component_p (TREE_TYPE (gnu_type));
5851 }
5852
5853 /* Return true if GNAT_ADDRESS is a value known at compile-time. */
5854
5855 static bool
compile_time_known_address_p(Node_Id gnat_address)5856 compile_time_known_address_p (Node_Id gnat_address)
5857 {
5858 /* Catch System'To_Address. */
5859 if (Nkind (gnat_address) == N_Unchecked_Type_Conversion)
5860 gnat_address = Expression (gnat_address);
5861
5862 return Compile_Time_Known_Value (gnat_address);
5863 }
5864
5865 /* Return true if GNAT_RANGE, a N_Range node, cannot be superflat, i.e. if the
5866 inequality HB >= LB-1 is true. LB and HB are the low and high bounds. */
5867
5868 static bool
cannot_be_superflat_p(Node_Id gnat_range)5869 cannot_be_superflat_p (Node_Id gnat_range)
5870 {
5871 Node_Id gnat_lb = Low_Bound (gnat_range), gnat_hb = High_Bound (gnat_range);
5872 Node_Id scalar_range;
5873 tree gnu_lb, gnu_hb, gnu_lb_minus_one;
5874
5875 /* If the low bound is not constant, try to find an upper bound. */
5876 while (Nkind (gnat_lb) != N_Integer_Literal
5877 && (Ekind (Etype (gnat_lb)) == E_Signed_Integer_Subtype
5878 || Ekind (Etype (gnat_lb)) == E_Modular_Integer_Subtype)
5879 && (scalar_range = Scalar_Range (Etype (gnat_lb)))
5880 && (Nkind (scalar_range) == N_Signed_Integer_Type_Definition
5881 || Nkind (scalar_range) == N_Range))
5882 gnat_lb = High_Bound (scalar_range);
5883
5884 /* If the high bound is not constant, try to find a lower bound. */
5885 while (Nkind (gnat_hb) != N_Integer_Literal
5886 && (Ekind (Etype (gnat_hb)) == E_Signed_Integer_Subtype
5887 || Ekind (Etype (gnat_hb)) == E_Modular_Integer_Subtype)
5888 && (scalar_range = Scalar_Range (Etype (gnat_hb)))
5889 && (Nkind (scalar_range) == N_Signed_Integer_Type_Definition
5890 || Nkind (scalar_range) == N_Range))
5891 gnat_hb = Low_Bound (scalar_range);
5892
5893 /* If we have failed to find constant bounds, punt. */
5894 if (Nkind (gnat_lb) != N_Integer_Literal
5895 || Nkind (gnat_hb) != N_Integer_Literal)
5896 return false;
5897
5898 /* We need at least a signed 64-bit type to catch most cases. */
5899 gnu_lb = UI_To_gnu (Intval (gnat_lb), sbitsizetype);
5900 gnu_hb = UI_To_gnu (Intval (gnat_hb), sbitsizetype);
5901 if (TREE_OVERFLOW (gnu_lb) || TREE_OVERFLOW (gnu_hb))
5902 return false;
5903
5904 /* If the low bound is the smallest integer, nothing can be smaller. */
5905 gnu_lb_minus_one = size_binop (MINUS_EXPR, gnu_lb, sbitsize_one_node);
5906 if (TREE_OVERFLOW (gnu_lb_minus_one))
5907 return true;
5908
5909 return !tree_int_cst_lt (gnu_hb, gnu_lb_minus_one);
5910 }
5911
5912 /* Return true if GNU_EXPR is (essentially) the address of a CONSTRUCTOR. */
5913
5914 static bool
constructor_address_p(tree gnu_expr)5915 constructor_address_p (tree gnu_expr)
5916 {
5917 while (TREE_CODE (gnu_expr) == NOP_EXPR
5918 || TREE_CODE (gnu_expr) == CONVERT_EXPR
5919 || TREE_CODE (gnu_expr) == NON_LVALUE_EXPR)
5920 gnu_expr = TREE_OPERAND (gnu_expr, 0);
5921
5922 return (TREE_CODE (gnu_expr) == ADDR_EXPR
5923 && TREE_CODE (TREE_OPERAND (gnu_expr, 0)) == CONSTRUCTOR);
5924 }
5925
5926 /* Given GNAT_ENTITY, elaborate all expressions that are required to
5927 be elaborated at the point of its definition, but do nothing else. */
5928
5929 void
elaborate_entity(Entity_Id gnat_entity)5930 elaborate_entity (Entity_Id gnat_entity)
5931 {
5932 switch (Ekind (gnat_entity))
5933 {
5934 case E_Signed_Integer_Subtype:
5935 case E_Modular_Integer_Subtype:
5936 case E_Enumeration_Subtype:
5937 case E_Ordinary_Fixed_Point_Subtype:
5938 case E_Decimal_Fixed_Point_Subtype:
5939 case E_Floating_Point_Subtype:
5940 {
5941 Node_Id gnat_lb = Type_Low_Bound (gnat_entity);
5942 Node_Id gnat_hb = Type_High_Bound (gnat_entity);
5943
5944 /* ??? Tests to avoid Constraint_Error in static expressions
5945 are needed until after the front stops generating bogus
5946 conversions on bounds of real types. */
5947 if (!Raises_Constraint_Error (gnat_lb))
5948 elaborate_expression (gnat_lb, gnat_entity, get_identifier ("L"),
5949 true, false, Needs_Debug_Info (gnat_entity));
5950 if (!Raises_Constraint_Error (gnat_hb))
5951 elaborate_expression (gnat_hb, gnat_entity, get_identifier ("U"),
5952 true, false, Needs_Debug_Info (gnat_entity));
5953 break;
5954 }
5955
5956 case E_Record_Subtype:
5957 case E_Private_Subtype:
5958 case E_Limited_Private_Subtype:
5959 case E_Record_Subtype_With_Private:
5960 if (Has_Discriminants (gnat_entity) && Is_Constrained (gnat_entity))
5961 {
5962 Node_Id gnat_discriminant_expr;
5963 Entity_Id gnat_field;
5964
5965 for (gnat_field
5966 = First_Discriminant (Implementation_Base_Type (gnat_entity)),
5967 gnat_discriminant_expr
5968 = First_Elmt (Discriminant_Constraint (gnat_entity));
5969 Present (gnat_field);
5970 gnat_field = Next_Discriminant (gnat_field),
5971 gnat_discriminant_expr = Next_Elmt (gnat_discriminant_expr))
5972 /* ??? For now, ignore access discriminants. */
5973 if (!Is_Access_Type (Etype (Node (gnat_discriminant_expr))))
5974 elaborate_expression (Node (gnat_discriminant_expr),
5975 gnat_entity, get_entity_name (gnat_field),
5976 true, false, false);
5977 }
5978 break;
5979
5980 }
5981 }
5982
5983 /* Return true if the size in units represented by GNU_SIZE can be handled by
5984 an allocation. If STATIC_P is true, consider only what can be done with a
5985 static allocation. */
5986
5987 static bool
allocatable_size_p(tree gnu_size,bool static_p)5988 allocatable_size_p (tree gnu_size, bool static_p)
5989 {
5990 /* We can allocate a fixed size if it is a valid for the middle-end. */
5991 if (TREE_CODE (gnu_size) == INTEGER_CST)
5992 return valid_constant_size_p (gnu_size);
5993
5994 /* We can allocate a variable size if this isn't a static allocation. */
5995 else
5996 return !static_p;
5997 }
5998
5999 /* Prepend to ATTR_LIST an entry for an attribute with provided TYPE,
6000 NAME, ARGS and ERROR_POINT. */
6001
6002 static void
prepend_one_attribute_to(struct attrib ** attr_list,enum attr_type attr_type,tree attr_name,tree attr_args,Node_Id attr_error_point)6003 prepend_one_attribute_to (struct attrib ** attr_list,
6004 enum attr_type attr_type,
6005 tree attr_name,
6006 tree attr_args,
6007 Node_Id attr_error_point)
6008 {
6009 struct attrib * attr = (struct attrib *) xmalloc (sizeof (struct attrib));
6010
6011 attr->type = attr_type;
6012 attr->name = attr_name;
6013 attr->args = attr_args;
6014 attr->error_point = attr_error_point;
6015
6016 attr->next = *attr_list;
6017 *attr_list = attr;
6018 }
6019
6020 /* Prepend to ATTR_LIST the list of attributes for GNAT_ENTITY, if any. */
6021
6022 static void
prepend_attributes(Entity_Id gnat_entity,struct attrib ** attr_list)6023 prepend_attributes (Entity_Id gnat_entity, struct attrib ** attr_list)
6024 {
6025 Node_Id gnat_temp;
6026
6027 /* Attributes are stored as Representation Item pragmas. */
6028
6029 for (gnat_temp = First_Rep_Item (gnat_entity); Present (gnat_temp);
6030 gnat_temp = Next_Rep_Item (gnat_temp))
6031 if (Nkind (gnat_temp) == N_Pragma)
6032 {
6033 tree gnu_arg0 = NULL_TREE, gnu_arg1 = NULL_TREE;
6034 Node_Id gnat_assoc = Pragma_Argument_Associations (gnat_temp);
6035 enum attr_type etype;
6036
6037 /* Map the kind of pragma at hand. Skip if this is not one
6038 we know how to handle. */
6039
6040 switch (Get_Pragma_Id (Chars (Pragma_Identifier (gnat_temp))))
6041 {
6042 case Pragma_Machine_Attribute:
6043 etype = ATTR_MACHINE_ATTRIBUTE;
6044 break;
6045
6046 case Pragma_Linker_Alias:
6047 etype = ATTR_LINK_ALIAS;
6048 break;
6049
6050 case Pragma_Linker_Section:
6051 etype = ATTR_LINK_SECTION;
6052 break;
6053
6054 case Pragma_Linker_Constructor:
6055 etype = ATTR_LINK_CONSTRUCTOR;
6056 break;
6057
6058 case Pragma_Linker_Destructor:
6059 etype = ATTR_LINK_DESTRUCTOR;
6060 break;
6061
6062 case Pragma_Weak_External:
6063 etype = ATTR_WEAK_EXTERNAL;
6064 break;
6065
6066 case Pragma_Thread_Local_Storage:
6067 etype = ATTR_THREAD_LOCAL_STORAGE;
6068 break;
6069
6070 default:
6071 continue;
6072 }
6073
6074 /* See what arguments we have and turn them into GCC trees for
6075 attribute handlers. These expect identifier for strings. We
6076 handle at most two arguments, static expressions only. */
6077
6078 if (Present (gnat_assoc) && Present (First (gnat_assoc)))
6079 {
6080 Node_Id gnat_arg0 = Next (First (gnat_assoc));
6081 Node_Id gnat_arg1 = Empty;
6082
6083 if (Present (gnat_arg0)
6084 && Is_Static_Expression (Expression (gnat_arg0)))
6085 {
6086 gnu_arg0 = gnat_to_gnu (Expression (gnat_arg0));
6087
6088 if (TREE_CODE (gnu_arg0) == STRING_CST)
6089 gnu_arg0 = get_identifier (TREE_STRING_POINTER (gnu_arg0));
6090
6091 gnat_arg1 = Next (gnat_arg0);
6092 }
6093
6094 if (Present (gnat_arg1)
6095 && Is_Static_Expression (Expression (gnat_arg1)))
6096 {
6097 gnu_arg1 = gnat_to_gnu (Expression (gnat_arg1));
6098
6099 if (TREE_CODE (gnu_arg1) == STRING_CST)
6100 gnu_arg1 = get_identifier (TREE_STRING_POINTER (gnu_arg1));
6101 }
6102 }
6103
6104 /* Prepend to the list now. Make a list of the argument we might
6105 have, as GCC expects it. */
6106 prepend_one_attribute_to
6107 (attr_list,
6108 etype, gnu_arg0,
6109 (gnu_arg1 != NULL_TREE)
6110 ? build_tree_list (NULL_TREE, gnu_arg1) : NULL_TREE,
6111 Present (Next (First (gnat_assoc)))
6112 ? Expression (Next (First (gnat_assoc))) : gnat_temp);
6113 }
6114 }
6115
6116 /* Given a GNAT tree GNAT_EXPR, for an expression which is a value within a
6117 type definition (either a bound or a discriminant value) for GNAT_ENTITY,
6118 return the GCC tree to use for that expression. GNU_NAME is the suffix
6119 to use if a variable needs to be created and DEFINITION is true if this
6120 is a definition of GNAT_ENTITY. If NEED_VALUE is true, we need a result;
6121 otherwise, we are just elaborating the expression for side-effects. If
6122 NEED_DEBUG is true, we need a variable for debugging purposes even if it
6123 isn't needed for code generation. */
6124
6125 static tree
elaborate_expression(Node_Id gnat_expr,Entity_Id gnat_entity,tree gnu_name,bool definition,bool need_value,bool need_debug)6126 elaborate_expression (Node_Id gnat_expr, Entity_Id gnat_entity, tree gnu_name,
6127 bool definition, bool need_value, bool need_debug)
6128 {
6129 tree gnu_expr;
6130
6131 /* If we already elaborated this expression (e.g. it was involved
6132 in the definition of a private type), use the old value. */
6133 if (present_gnu_tree (gnat_expr))
6134 return get_gnu_tree (gnat_expr);
6135
6136 /* If we don't need a value and this is static or a discriminant,
6137 we don't need to do anything. */
6138 if (!need_value
6139 && (Is_OK_Static_Expression (gnat_expr)
6140 || (Nkind (gnat_expr) == N_Identifier
6141 && Ekind (Entity (gnat_expr)) == E_Discriminant)))
6142 return NULL_TREE;
6143
6144 /* If it's a static expression, we don't need a variable for debugging. */
6145 if (need_debug && Is_OK_Static_Expression (gnat_expr))
6146 need_debug = false;
6147
6148 /* Otherwise, convert this tree to its GCC equivalent and elaborate it. */
6149 gnu_expr = elaborate_expression_1 (gnat_to_gnu (gnat_expr), gnat_entity,
6150 gnu_name, definition, need_debug);
6151
6152 /* Save the expression in case we try to elaborate this entity again. Since
6153 it's not a DECL, don't check it. Don't save if it's a discriminant. */
6154 if (!CONTAINS_PLACEHOLDER_P (gnu_expr))
6155 save_gnu_tree (gnat_expr, gnu_expr, true);
6156
6157 return need_value ? gnu_expr : error_mark_node;
6158 }
6159
6160 /* Similar, but take a GNU expression and always return a result. */
6161
6162 static tree
elaborate_expression_1(tree gnu_expr,Entity_Id gnat_entity,tree gnu_name,bool definition,bool need_debug)6163 elaborate_expression_1 (tree gnu_expr, Entity_Id gnat_entity, tree gnu_name,
6164 bool definition, bool need_debug)
6165 {
6166 const bool expr_public_p = Is_Public (gnat_entity);
6167 const bool expr_global_p = expr_public_p || global_bindings_p ();
6168 bool expr_variable_p, use_variable;
6169
6170 /* In most cases, we won't see a naked FIELD_DECL because a discriminant
6171 reference will have been replaced with a COMPONENT_REF when the type
6172 is being elaborated. However, there are some cases involving child
6173 types where we will. So convert it to a COMPONENT_REF. We hope it
6174 will be at the highest level of the expression in these cases. */
6175 if (TREE_CODE (gnu_expr) == FIELD_DECL)
6176 gnu_expr = build3 (COMPONENT_REF, TREE_TYPE (gnu_expr),
6177 build0 (PLACEHOLDER_EXPR, DECL_CONTEXT (gnu_expr)),
6178 gnu_expr, NULL_TREE);
6179
6180 /* If GNU_EXPR contains a placeholder, just return it. We rely on the fact
6181 that an expression cannot contain both a discriminant and a variable. */
6182 if (CONTAINS_PLACEHOLDER_P (gnu_expr))
6183 return gnu_expr;
6184
6185 /* If GNU_EXPR is neither a constant nor based on a read-only variable, make
6186 a variable that is initialized to contain the expression when the package
6187 containing the definition is elaborated. If this entity is defined at top
6188 level, replace the expression by the variable; otherwise use a SAVE_EXPR
6189 if this is necessary. */
6190 if (CONSTANT_CLASS_P (gnu_expr))
6191 expr_variable_p = false;
6192 else
6193 {
6194 /* Skip any conversions and simple arithmetics to see if the expression
6195 is based on a read-only variable.
6196 ??? This really should remain read-only, but we have to think about
6197 the typing of the tree here. */
6198 tree inner
6199 = skip_simple_arithmetic (remove_conversions (gnu_expr, true));
6200
6201 if (handled_component_p (inner))
6202 {
6203 HOST_WIDE_INT bitsize, bitpos;
6204 tree offset;
6205 enum machine_mode mode;
6206 int unsignedp, volatilep;
6207
6208 inner = get_inner_reference (inner, &bitsize, &bitpos, &offset,
6209 &mode, &unsignedp, &volatilep, false);
6210 /* If the offset is variable, err on the side of caution. */
6211 if (offset)
6212 inner = NULL_TREE;
6213 }
6214
6215 expr_variable_p
6216 = !(inner
6217 && TREE_CODE (inner) == VAR_DECL
6218 && (TREE_READONLY (inner) || DECL_READONLY_ONCE_ELAB (inner)));
6219 }
6220
6221 /* We only need to use the variable if we are in a global context since GCC
6222 can do the right thing in the local case. However, when not optimizing,
6223 use it for bounds of loop iteration scheme to avoid code duplication. */
6224 use_variable = expr_variable_p
6225 && (expr_global_p
6226 || (!optimize
6227 && definition
6228 && Is_Itype (gnat_entity)
6229 && Nkind (Associated_Node_For_Itype (gnat_entity))
6230 == N_Loop_Parameter_Specification));
6231
6232 /* Now create it, possibly only for debugging purposes. */
6233 if (use_variable || need_debug)
6234 {
6235 tree gnu_decl
6236 = create_var_decl_1
6237 (create_concat_name (gnat_entity, IDENTIFIER_POINTER (gnu_name)),
6238 NULL_TREE, TREE_TYPE (gnu_expr), gnu_expr, true, expr_public_p,
6239 !definition, expr_global_p, !need_debug, NULL, gnat_entity);
6240
6241 if (use_variable)
6242 return gnu_decl;
6243 }
6244
6245 return expr_variable_p ? gnat_save_expr (gnu_expr) : gnu_expr;
6246 }
6247
6248 /* Similar, but take an alignment factor and make it explicit in the tree. */
6249
6250 static tree
elaborate_expression_2(tree gnu_expr,Entity_Id gnat_entity,tree gnu_name,bool definition,bool need_debug,unsigned int align)6251 elaborate_expression_2 (tree gnu_expr, Entity_Id gnat_entity, tree gnu_name,
6252 bool definition, bool need_debug, unsigned int align)
6253 {
6254 tree unit_align = size_int (align / BITS_PER_UNIT);
6255 return
6256 size_binop (MULT_EXPR,
6257 elaborate_expression_1 (size_binop (EXACT_DIV_EXPR,
6258 gnu_expr,
6259 unit_align),
6260 gnat_entity, gnu_name, definition,
6261 need_debug),
6262 unit_align);
6263 }
6264
6265 /* Given a GNU tree and a GNAT list of choices, generate an expression to test
6266 the value passed against the list of choices. */
6267
6268 tree
choices_to_gnu(tree operand,Node_Id choices)6269 choices_to_gnu (tree operand, Node_Id choices)
6270 {
6271 Node_Id choice;
6272 Node_Id gnat_temp;
6273 tree result = boolean_false_node;
6274 tree this_test, low = 0, high = 0, single = 0;
6275
6276 for (choice = First (choices); Present (choice); choice = Next (choice))
6277 {
6278 switch (Nkind (choice))
6279 {
6280 case N_Range:
6281 low = gnat_to_gnu (Low_Bound (choice));
6282 high = gnat_to_gnu (High_Bound (choice));
6283
6284 this_test
6285 = build_binary_op (TRUTH_ANDIF_EXPR, boolean_type_node,
6286 build_binary_op (GE_EXPR, boolean_type_node,
6287 operand, low),
6288 build_binary_op (LE_EXPR, boolean_type_node,
6289 operand, high));
6290
6291 break;
6292
6293 case N_Subtype_Indication:
6294 gnat_temp = Range_Expression (Constraint (choice));
6295 low = gnat_to_gnu (Low_Bound (gnat_temp));
6296 high = gnat_to_gnu (High_Bound (gnat_temp));
6297
6298 this_test
6299 = build_binary_op (TRUTH_ANDIF_EXPR, boolean_type_node,
6300 build_binary_op (GE_EXPR, boolean_type_node,
6301 operand, low),
6302 build_binary_op (LE_EXPR, boolean_type_node,
6303 operand, high));
6304 break;
6305
6306 case N_Identifier:
6307 case N_Expanded_Name:
6308 /* This represents either a subtype range, an enumeration
6309 literal, or a constant Ekind says which. If an enumeration
6310 literal or constant, fall through to the next case. */
6311 if (Ekind (Entity (choice)) != E_Enumeration_Literal
6312 && Ekind (Entity (choice)) != E_Constant)
6313 {
6314 tree type = gnat_to_gnu_type (Entity (choice));
6315
6316 low = TYPE_MIN_VALUE (type);
6317 high = TYPE_MAX_VALUE (type);
6318
6319 this_test
6320 = build_binary_op (TRUTH_ANDIF_EXPR, boolean_type_node,
6321 build_binary_op (GE_EXPR, boolean_type_node,
6322 operand, low),
6323 build_binary_op (LE_EXPR, boolean_type_node,
6324 operand, high));
6325 break;
6326 }
6327
6328 /* ... fall through ... */
6329
6330 case N_Character_Literal:
6331 case N_Integer_Literal:
6332 single = gnat_to_gnu (choice);
6333 this_test = build_binary_op (EQ_EXPR, boolean_type_node, operand,
6334 single);
6335 break;
6336
6337 case N_Others_Choice:
6338 this_test = boolean_true_node;
6339 break;
6340
6341 default:
6342 gcc_unreachable ();
6343 }
6344
6345 result = build_binary_op (TRUTH_ORIF_EXPR, boolean_type_node, result,
6346 this_test);
6347 }
6348
6349 return result;
6350 }
6351
6352 /* Adjust PACKED setting as passed to gnat_to_gnu_field for a field of
6353 type FIELD_TYPE to be placed in RECORD_TYPE. Return the result. */
6354
6355 static int
adjust_packed(tree field_type,tree record_type,int packed)6356 adjust_packed (tree field_type, tree record_type, int packed)
6357 {
6358 /* If the field contains an item of variable size, we cannot pack it
6359 because we cannot create temporaries of non-fixed size in case
6360 we need to take the address of the field. See addressable_p and
6361 the notes on the addressability issues for further details. */
6362 if (type_has_variable_size (field_type))
6363 return 0;
6364
6365 /* If the alignment of the record is specified and the field type
6366 is over-aligned, request Storage_Unit alignment for the field. */
6367 if (packed == -2)
6368 {
6369 if (TYPE_ALIGN (field_type) > TYPE_ALIGN (record_type))
6370 return -1;
6371 else
6372 return 0;
6373 }
6374
6375 return packed;
6376 }
6377
6378 /* Return a GCC tree for a field corresponding to GNAT_FIELD to be
6379 placed in GNU_RECORD_TYPE.
6380
6381 PACKED is 1 if the enclosing record is packed, -1 if the enclosing
6382 record has Component_Alignment of Storage_Unit, -2 if the enclosing
6383 record has a specified alignment.
6384
6385 DEFINITION is true if this field is for a record being defined.
6386
6387 DEBUG_INFO_P is true if we need to write debug information for types
6388 that we may create in the process. */
6389
6390 static tree
gnat_to_gnu_field(Entity_Id gnat_field,tree gnu_record_type,int packed,bool definition,bool debug_info_p)6391 gnat_to_gnu_field (Entity_Id gnat_field, tree gnu_record_type, int packed,
6392 bool definition, bool debug_info_p)
6393 {
6394 const Entity_Id gnat_field_type = Etype (gnat_field);
6395 tree gnu_field_type = gnat_to_gnu_type (gnat_field_type);
6396 tree gnu_field_id = get_entity_name (gnat_field);
6397 tree gnu_field, gnu_size, gnu_pos;
6398 bool is_volatile
6399 = (Treat_As_Volatile (gnat_field) || Treat_As_Volatile (gnat_field_type));
6400 bool needs_strict_alignment
6401 = (is_volatile
6402 || Is_Aliased (gnat_field)
6403 || Strict_Alignment (gnat_field_type));
6404
6405 /* If this field requires strict alignment, we cannot pack it because
6406 it would very likely be under-aligned in the record. */
6407 if (needs_strict_alignment)
6408 packed = 0;
6409 else
6410 packed = adjust_packed (gnu_field_type, gnu_record_type, packed);
6411
6412 /* If a size is specified, use it. Otherwise, if the record type is packed,
6413 use the official RM size. See "Handling of Type'Size Values" in Einfo
6414 for further details. */
6415 if (Known_Esize (gnat_field))
6416 gnu_size = validate_size (Esize (gnat_field), gnu_field_type,
6417 gnat_field, FIELD_DECL, false, true);
6418 else if (packed == 1)
6419 gnu_size = validate_size (RM_Size (gnat_field_type), gnu_field_type,
6420 gnat_field, FIELD_DECL, false, true);
6421 else
6422 gnu_size = NULL_TREE;
6423
6424 /* If we have a specified size that is smaller than that of the field's type,
6425 or a position is specified, and the field's type is a record that doesn't
6426 require strict alignment, see if we can get either an integral mode form
6427 of the type or a smaller form. If we can, show a size was specified for
6428 the field if there wasn't one already, so we know to make this a bitfield
6429 and avoid making things wider.
6430
6431 Changing to an integral mode form is useful when the record is packed as
6432 we can then place the field at a non-byte-aligned position and so achieve
6433 tighter packing. This is in addition required if the field shares a byte
6434 with another field and the front-end lets the back-end handle the access
6435 to the field, because GCC cannot handle non-byte-aligned BLKmode fields.
6436
6437 Changing to a smaller form is required if the specified size is smaller
6438 than that of the field's type and the type contains sub-fields that are
6439 padded, in order to avoid generating accesses to these sub-fields that
6440 are wider than the field.
6441
6442 We avoid the transformation if it is not required or potentially useful,
6443 as it might entail an increase of the field's alignment and have ripple
6444 effects on the outer record type. A typical case is a field known to be
6445 byte-aligned and not to share a byte with another field. */
6446 if (!needs_strict_alignment
6447 && RECORD_OR_UNION_TYPE_P (gnu_field_type)
6448 && !TYPE_FAT_POINTER_P (gnu_field_type)
6449 && host_integerp (TYPE_SIZE (gnu_field_type), 1)
6450 && (packed == 1
6451 || (gnu_size
6452 && (tree_int_cst_lt (gnu_size, TYPE_SIZE (gnu_field_type))
6453 || (Present (Component_Clause (gnat_field))
6454 && !(UI_To_Int (Component_Bit_Offset (gnat_field))
6455 % BITS_PER_UNIT == 0
6456 && value_factor_p (gnu_size, BITS_PER_UNIT)))))))
6457 {
6458 tree gnu_packable_type = make_packable_type (gnu_field_type, true);
6459 if (gnu_packable_type != gnu_field_type)
6460 {
6461 gnu_field_type = gnu_packable_type;
6462 if (!gnu_size)
6463 gnu_size = rm_size (gnu_field_type);
6464 }
6465 }
6466
6467 if (Is_Atomic (gnat_field))
6468 check_ok_for_atomic (gnu_field_type, gnat_field, false);
6469
6470 if (Present (Component_Clause (gnat_field)))
6471 {
6472 Entity_Id gnat_parent
6473 = Parent_Subtype (Underlying_Type (Scope (gnat_field)));
6474
6475 gnu_pos = UI_To_gnu (Component_Bit_Offset (gnat_field), bitsizetype);
6476 gnu_size = validate_size (Esize (gnat_field), gnu_field_type,
6477 gnat_field, FIELD_DECL, false, true);
6478
6479 /* Ensure the position does not overlap with the parent subtype, if there
6480 is one. This test is omitted if the parent of the tagged type has a
6481 full rep clause since, in this case, component clauses are allowed to
6482 overlay the space allocated for the parent type and the front-end has
6483 checked that there are no overlapping components. */
6484 if (Present (gnat_parent) && !Is_Fully_Repped_Tagged_Type (gnat_parent))
6485 {
6486 tree gnu_parent = gnat_to_gnu_type (gnat_parent);
6487
6488 if (TREE_CODE (TYPE_SIZE (gnu_parent)) == INTEGER_CST
6489 && tree_int_cst_lt (gnu_pos, TYPE_SIZE (gnu_parent)))
6490 {
6491 post_error_ne_tree
6492 ("offset of& must be beyond parent{, minimum allowed is ^}",
6493 First_Bit (Component_Clause (gnat_field)), gnat_field,
6494 TYPE_SIZE_UNIT (gnu_parent));
6495 }
6496 }
6497
6498 /* If this field needs strict alignment, check that the record is
6499 sufficiently aligned and that position and size are consistent with
6500 the alignment. But don't do it if we are just annotating types and
6501 the field's type is tagged, since tagged types aren't fully laid out
6502 in this mode. Also, note that atomic implies volatile so the inner
6503 test sequences ordering is significant here. */
6504 if (needs_strict_alignment
6505 && !(type_annotate_only && Is_Tagged_Type (gnat_field_type)))
6506 {
6507 TYPE_ALIGN (gnu_record_type)
6508 = MAX (TYPE_ALIGN (gnu_record_type), TYPE_ALIGN (gnu_field_type));
6509
6510 if (gnu_size
6511 && !operand_equal_p (gnu_size, TYPE_SIZE (gnu_field_type), 0))
6512 {
6513 if (Is_Atomic (gnat_field) || Is_Atomic (gnat_field_type))
6514 post_error_ne_tree
6515 ("atomic field& must be natural size of type{ (^)}",
6516 Last_Bit (Component_Clause (gnat_field)), gnat_field,
6517 TYPE_SIZE (gnu_field_type));
6518
6519 else if (is_volatile)
6520 post_error_ne_tree
6521 ("volatile field& must be natural size of type{ (^)}",
6522 Last_Bit (Component_Clause (gnat_field)), gnat_field,
6523 TYPE_SIZE (gnu_field_type));
6524
6525 else if (Is_Aliased (gnat_field))
6526 post_error_ne_tree
6527 ("size of aliased field& must be ^ bits",
6528 Last_Bit (Component_Clause (gnat_field)), gnat_field,
6529 TYPE_SIZE (gnu_field_type));
6530
6531 else if (Strict_Alignment (gnat_field_type))
6532 post_error_ne_tree
6533 ("size of & with aliased or tagged components not ^ bits",
6534 Last_Bit (Component_Clause (gnat_field)), gnat_field,
6535 TYPE_SIZE (gnu_field_type));
6536
6537 else
6538 gcc_unreachable ();
6539
6540 gnu_size = NULL_TREE;
6541 }
6542
6543 if (!integer_zerop (size_binop
6544 (TRUNC_MOD_EXPR, gnu_pos,
6545 bitsize_int (TYPE_ALIGN (gnu_field_type)))))
6546 {
6547 if (Is_Atomic (gnat_field) || Is_Atomic (gnat_field_type))
6548 post_error_ne_num
6549 ("position of atomic field& must be multiple of ^ bits",
6550 First_Bit (Component_Clause (gnat_field)), gnat_field,
6551 TYPE_ALIGN (gnu_field_type));
6552
6553 else if (is_volatile)
6554 post_error_ne_num
6555 ("position of volatile field& must be multiple of ^ bits",
6556 First_Bit (Component_Clause (gnat_field)), gnat_field,
6557 TYPE_ALIGN (gnu_field_type));
6558
6559 else if (Is_Aliased (gnat_field))
6560 post_error_ne_num
6561 ("position of aliased field& must be multiple of ^ bits",
6562 First_Bit (Component_Clause (gnat_field)), gnat_field,
6563 TYPE_ALIGN (gnu_field_type));
6564
6565 else if (Strict_Alignment (gnat_field_type))
6566 post_error_ne
6567 ("position of & is not compatible with alignment required "
6568 "by its components",
6569 First_Bit (Component_Clause (gnat_field)), gnat_field);
6570
6571 else
6572 gcc_unreachable ();
6573
6574 gnu_pos = NULL_TREE;
6575 }
6576 }
6577 }
6578
6579 /* If the record has rep clauses and this is the tag field, make a rep
6580 clause for it as well. */
6581 else if (Has_Specified_Layout (Scope (gnat_field))
6582 && Chars (gnat_field) == Name_uTag)
6583 {
6584 gnu_pos = bitsize_zero_node;
6585 gnu_size = TYPE_SIZE (gnu_field_type);
6586 }
6587
6588 else
6589 {
6590 gnu_pos = NULL_TREE;
6591
6592 /* If we are packing the record and the field is BLKmode, round the
6593 size up to a byte boundary. */
6594 if (packed && TYPE_MODE (gnu_field_type) == BLKmode && gnu_size)
6595 gnu_size = round_up (gnu_size, BITS_PER_UNIT);
6596 }
6597
6598 /* We need to make the size the maximum for the type if it is
6599 self-referential and an unconstrained type. In that case, we can't
6600 pack the field since we can't make a copy to align it. */
6601 if (TREE_CODE (gnu_field_type) == RECORD_TYPE
6602 && !gnu_size
6603 && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_field_type))
6604 && !Is_Constrained (Underlying_Type (gnat_field_type)))
6605 {
6606 gnu_size = max_size (TYPE_SIZE (gnu_field_type), true);
6607 packed = 0;
6608 }
6609
6610 /* If a size is specified, adjust the field's type to it. */
6611 if (gnu_size)
6612 {
6613 tree orig_field_type;
6614
6615 /* If the field's type is justified modular, we would need to remove
6616 the wrapper to (better) meet the layout requirements. However we
6617 can do so only if the field is not aliased to preserve the unique
6618 layout and if the prescribed size is not greater than that of the
6619 packed array to preserve the justification. */
6620 if (!needs_strict_alignment
6621 && TREE_CODE (gnu_field_type) == RECORD_TYPE
6622 && TYPE_JUSTIFIED_MODULAR_P (gnu_field_type)
6623 && tree_int_cst_compare (gnu_size, TYPE_ADA_SIZE (gnu_field_type))
6624 <= 0)
6625 gnu_field_type = TREE_TYPE (TYPE_FIELDS (gnu_field_type));
6626
6627 /* Similarly if the field's type is a misaligned integral type, but
6628 there is no restriction on the size as there is no justification. */
6629 if (!needs_strict_alignment
6630 && TYPE_IS_PADDING_P (gnu_field_type)
6631 && INTEGRAL_TYPE_P (TREE_TYPE (TYPE_FIELDS (gnu_field_type))))
6632 gnu_field_type = TREE_TYPE (TYPE_FIELDS (gnu_field_type));
6633
6634 gnu_field_type
6635 = make_type_from_size (gnu_field_type, gnu_size,
6636 Has_Biased_Representation (gnat_field));
6637
6638 orig_field_type = gnu_field_type;
6639 gnu_field_type = maybe_pad_type (gnu_field_type, gnu_size, 0, gnat_field,
6640 false, false, definition, true);
6641
6642 /* If a padding record was made, declare it now since it will never be
6643 declared otherwise. This is necessary to ensure that its subtrees
6644 are properly marked. */
6645 if (gnu_field_type != orig_field_type
6646 && !DECL_P (TYPE_NAME (gnu_field_type)))
6647 create_type_decl (TYPE_NAME (gnu_field_type), gnu_field_type, NULL,
6648 true, debug_info_p, gnat_field);
6649 }
6650
6651 /* Otherwise (or if there was an error), don't specify a position. */
6652 else
6653 gnu_pos = NULL_TREE;
6654
6655 gcc_assert (TREE_CODE (gnu_field_type) != RECORD_TYPE
6656 || !TYPE_CONTAINS_TEMPLATE_P (gnu_field_type));
6657
6658 /* Now create the decl for the field. */
6659 gnu_field
6660 = create_field_decl (gnu_field_id, gnu_field_type, gnu_record_type,
6661 gnu_size, gnu_pos, packed, Is_Aliased (gnat_field));
6662 Sloc_to_locus (Sloc (gnat_field), &DECL_SOURCE_LOCATION (gnu_field));
6663 DECL_ALIASED_P (gnu_field) = Is_Aliased (gnat_field);
6664 TREE_THIS_VOLATILE (gnu_field) = TREE_SIDE_EFFECTS (gnu_field) = is_volatile;
6665
6666 if (Ekind (gnat_field) == E_Discriminant)
6667 DECL_DISCRIMINANT_NUMBER (gnu_field)
6668 = UI_To_gnu (Discriminant_Number (gnat_field), sizetype);
6669
6670 return gnu_field;
6671 }
6672
6673 /* Return true if at least one member of COMPONENT_LIST needs strict
6674 alignment. */
6675
6676 static bool
components_need_strict_alignment(Node_Id component_list)6677 components_need_strict_alignment (Node_Id component_list)
6678 {
6679 Node_Id component_decl;
6680
6681 for (component_decl = First_Non_Pragma (Component_Items (component_list));
6682 Present (component_decl);
6683 component_decl = Next_Non_Pragma (component_decl))
6684 {
6685 Entity_Id gnat_field = Defining_Entity (component_decl);
6686
6687 if (Is_Aliased (gnat_field))
6688 return True;
6689
6690 if (Strict_Alignment (Etype (gnat_field)))
6691 return True;
6692 }
6693
6694 return False;
6695 }
6696
6697 /* Return true if TYPE is a type with variable size or a padding type with a
6698 field of variable size or a record that has a field with such a type. */
6699
6700 static bool
type_has_variable_size(tree type)6701 type_has_variable_size (tree type)
6702 {
6703 tree field;
6704
6705 if (!TREE_CONSTANT (TYPE_SIZE (type)))
6706 return true;
6707
6708 if (TYPE_IS_PADDING_P (type)
6709 && !TREE_CONSTANT (DECL_SIZE (TYPE_FIELDS (type))))
6710 return true;
6711
6712 if (!RECORD_OR_UNION_TYPE_P (type))
6713 return false;
6714
6715 for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
6716 if (type_has_variable_size (TREE_TYPE (field)))
6717 return true;
6718
6719 return false;
6720 }
6721
6722 /* Return true if FIELD is an artificial field. */
6723
6724 static bool
field_is_artificial(tree field)6725 field_is_artificial (tree field)
6726 {
6727 /* These fields are generated by the front-end proper. */
6728 if (IDENTIFIER_POINTER (DECL_NAME (field)) [0] == '_')
6729 return true;
6730
6731 /* These fields are generated by gigi. */
6732 if (DECL_INTERNAL_P (field))
6733 return true;
6734
6735 return false;
6736 }
6737
6738 /* Return true if FIELD is a non-artificial aliased field. */
6739
6740 static bool
field_is_aliased(tree field)6741 field_is_aliased (tree field)
6742 {
6743 if (field_is_artificial (field))
6744 return false;
6745
6746 return DECL_ALIASED_P (field);
6747 }
6748
6749 /* Return true if FIELD is a non-artificial field with self-referential
6750 size. */
6751
6752 static bool
field_has_self_size(tree field)6753 field_has_self_size (tree field)
6754 {
6755 if (field_is_artificial (field))
6756 return false;
6757
6758 if (DECL_SIZE (field) && TREE_CODE (DECL_SIZE (field)) == INTEGER_CST)
6759 return false;
6760
6761 return CONTAINS_PLACEHOLDER_P (TYPE_SIZE (TREE_TYPE (field)));
6762 }
6763
6764 /* Return true if FIELD is a non-artificial field with variable size. */
6765
6766 static bool
field_has_variable_size(tree field)6767 field_has_variable_size (tree field)
6768 {
6769 if (field_is_artificial (field))
6770 return false;
6771
6772 if (DECL_SIZE (field) && TREE_CODE (DECL_SIZE (field)) == INTEGER_CST)
6773 return false;
6774
6775 return TREE_CODE (TYPE_SIZE (TREE_TYPE (field))) != INTEGER_CST;
6776 }
6777
6778 /* qsort comparer for the bit positions of two record components. */
6779
6780 static int
compare_field_bitpos(const PTR rt1,const PTR rt2)6781 compare_field_bitpos (const PTR rt1, const PTR rt2)
6782 {
6783 const_tree const field1 = * (const_tree const *) rt1;
6784 const_tree const field2 = * (const_tree const *) rt2;
6785 const int ret
6786 = tree_int_cst_compare (bit_position (field1), bit_position (field2));
6787
6788 return ret ? ret : (int) (DECL_UID (field1) - DECL_UID (field2));
6789 }
6790
6791 /* Translate and chain the GNAT_COMPONENT_LIST to the GNU_FIELD_LIST, set
6792 the result as the field list of GNU_RECORD_TYPE and finish it up. When
6793 called from gnat_to_gnu_entity during the processing of a record type
6794 definition, the GCC node for the parent, if any, will be the single field
6795 of GNU_RECORD_TYPE and the GCC nodes for the discriminants will be on the
6796 GNU_FIELD_LIST. The other calls to this function are recursive calls for
6797 the component list of a variant and, in this case, GNU_FIELD_LIST is empty.
6798
6799 PACKED is 1 if this is for a packed record, -1 if this is for a record
6800 with Component_Alignment of Storage_Unit, -2 if this is for a record
6801 with a specified alignment.
6802
6803 DEFINITION is true if we are defining this record type.
6804
6805 CANCEL_ALIGNMENT is true if the alignment should be zeroed before laying
6806 out the record. This means the alignment only serves to force fields to
6807 be bitfields, but not to require the record to be that aligned. This is
6808 used for variants.
6809
6810 ALL_REP is true if a rep clause is present for all the fields.
6811
6812 UNCHECKED_UNION is true if we are building this type for a record with a
6813 Pragma Unchecked_Union.
6814
6815 ARTIFICIAL is true if this is a type that was generated by the compiler.
6816
6817 DEBUG_INFO is true if we need to write debug information about the type.
6818
6819 MAYBE_UNUSED is true if this type may be unused in the end; this doesn't
6820 mean that its contents may be unused as well, only the container itself.
6821
6822 REORDER is true if we are permitted to reorder components of this type.
6823
6824 FIRST_FREE_POS, if nonzero, is the first (lowest) free field position in
6825 the outer record type down to this variant level. It is nonzero only if
6826 all the fields down to this level have a rep clause and ALL_REP is false.
6827
6828 P_GNU_REP_LIST, if nonzero, is a pointer to a list to which each field
6829 with a rep clause is to be added; in this case, that is all that should
6830 be done with such fields. */
6831
6832 static void
components_to_record(tree gnu_record_type,Node_Id gnat_component_list,tree gnu_field_list,int packed,bool definition,bool cancel_alignment,bool all_rep,bool unchecked_union,bool artificial,bool debug_info,bool maybe_unused,bool reorder,tree first_free_pos,tree * p_gnu_rep_list)6833 components_to_record (tree gnu_record_type, Node_Id gnat_component_list,
6834 tree gnu_field_list, int packed, bool definition,
6835 bool cancel_alignment, bool all_rep,
6836 bool unchecked_union, bool artificial,
6837 bool debug_info, bool maybe_unused, bool reorder,
6838 tree first_free_pos, tree *p_gnu_rep_list)
6839 {
6840 bool all_rep_and_size = all_rep && TYPE_SIZE (gnu_record_type);
6841 bool layout_with_rep = false;
6842 bool has_self_field = false;
6843 bool has_aliased_after_self_field = false;
6844 Node_Id component_decl, variant_part;
6845 tree gnu_field, gnu_next, gnu_last;
6846 tree gnu_rep_part = NULL_TREE;
6847 tree gnu_variant_part = NULL_TREE;
6848 tree gnu_rep_list = NULL_TREE;
6849 tree gnu_var_list = NULL_TREE;
6850 tree gnu_self_list = NULL_TREE;
6851
6852 /* For each component referenced in a component declaration create a GCC
6853 field and add it to the list, skipping pragmas in the GNAT list. */
6854 gnu_last = tree_last (gnu_field_list);
6855 if (Present (Component_Items (gnat_component_list)))
6856 for (component_decl
6857 = First_Non_Pragma (Component_Items (gnat_component_list));
6858 Present (component_decl);
6859 component_decl = Next_Non_Pragma (component_decl))
6860 {
6861 Entity_Id gnat_field = Defining_Entity (component_decl);
6862 Name_Id gnat_name = Chars (gnat_field);
6863
6864 /* If present, the _Parent field must have been created as the single
6865 field of the record type. Put it before any other fields. */
6866 if (gnat_name == Name_uParent)
6867 {
6868 gnu_field = TYPE_FIELDS (gnu_record_type);
6869 gnu_field_list = chainon (gnu_field_list, gnu_field);
6870 }
6871 else
6872 {
6873 gnu_field = gnat_to_gnu_field (gnat_field, gnu_record_type, packed,
6874 definition, debug_info);
6875
6876 /* If this is the _Tag field, put it before any other fields. */
6877 if (gnat_name == Name_uTag)
6878 gnu_field_list = chainon (gnu_field_list, gnu_field);
6879
6880 /* If this is the _Controller field, put it before the other
6881 fields except for the _Tag or _Parent field. */
6882 else if (gnat_name == Name_uController && gnu_last)
6883 {
6884 DECL_CHAIN (gnu_field) = DECL_CHAIN (gnu_last);
6885 DECL_CHAIN (gnu_last) = gnu_field;
6886 }
6887
6888 /* If this is a regular field, put it after the other fields. */
6889 else
6890 {
6891 DECL_CHAIN (gnu_field) = gnu_field_list;
6892 gnu_field_list = gnu_field;
6893 if (!gnu_last)
6894 gnu_last = gnu_field;
6895
6896 /* And record information for the final layout. */
6897 if (field_has_self_size (gnu_field))
6898 has_self_field = true;
6899 else if (has_self_field && field_is_aliased (gnu_field))
6900 has_aliased_after_self_field = true;
6901 }
6902 }
6903
6904 save_gnu_tree (gnat_field, gnu_field, false);
6905 }
6906
6907 /* At the end of the component list there may be a variant part. */
6908 variant_part = Variant_Part (gnat_component_list);
6909
6910 /* We create a QUAL_UNION_TYPE for the variant part since the variants are
6911 mutually exclusive and should go in the same memory. To do this we need
6912 to treat each variant as a record whose elements are created from the
6913 component list for the variant. So here we create the records from the
6914 lists for the variants and put them all into the QUAL_UNION_TYPE.
6915 If this is an Unchecked_Union, we make a UNION_TYPE instead or
6916 use GNU_RECORD_TYPE if there are no fields so far. */
6917 if (Present (variant_part))
6918 {
6919 Node_Id gnat_discr = Name (variant_part), variant;
6920 tree gnu_discr = gnat_to_gnu (gnat_discr);
6921 tree gnu_name = TYPE_NAME (gnu_record_type);
6922 tree gnu_var_name
6923 = concat_name (get_identifier (Get_Name_String (Chars (gnat_discr))),
6924 "XVN");
6925 tree gnu_union_type, gnu_union_name;
6926 tree this_first_free_pos, gnu_variant_list = NULL_TREE;
6927 bool union_field_needs_strict_alignment = false;
6928
6929 if (TREE_CODE (gnu_name) == TYPE_DECL)
6930 gnu_name = DECL_NAME (gnu_name);
6931
6932 gnu_union_name
6933 = concat_name (gnu_name, IDENTIFIER_POINTER (gnu_var_name));
6934
6935 /* Reuse the enclosing union if this is an Unchecked_Union whose fields
6936 are all in the variant part, to match the layout of C unions. There
6937 is an associated check below. */
6938 if (TREE_CODE (gnu_record_type) == UNION_TYPE)
6939 gnu_union_type = gnu_record_type;
6940 else
6941 {
6942 gnu_union_type
6943 = make_node (unchecked_union ? UNION_TYPE : QUAL_UNION_TYPE);
6944
6945 TYPE_NAME (gnu_union_type) = gnu_union_name;
6946 TYPE_ALIGN (gnu_union_type) = 0;
6947 TYPE_PACKED (gnu_union_type) = TYPE_PACKED (gnu_record_type);
6948 }
6949
6950 /* If all the fields down to this level have a rep clause, find out
6951 whether all the fields at this level also have one. If so, then
6952 compute the new first free position to be passed downward. */
6953 this_first_free_pos = first_free_pos;
6954 if (this_first_free_pos)
6955 {
6956 for (gnu_field = gnu_field_list;
6957 gnu_field;
6958 gnu_field = DECL_CHAIN (gnu_field))
6959 if (DECL_FIELD_OFFSET (gnu_field))
6960 {
6961 tree pos = bit_position (gnu_field);
6962 if (!tree_int_cst_lt (pos, this_first_free_pos))
6963 this_first_free_pos
6964 = size_binop (PLUS_EXPR, pos, DECL_SIZE (gnu_field));
6965 }
6966 else
6967 {
6968 this_first_free_pos = NULL_TREE;
6969 break;
6970 }
6971 }
6972
6973 for (variant = First_Non_Pragma (Variants (variant_part));
6974 Present (variant);
6975 variant = Next_Non_Pragma (variant))
6976 {
6977 tree gnu_variant_type = make_node (RECORD_TYPE);
6978 tree gnu_inner_name;
6979 tree gnu_qual;
6980
6981 Get_Variant_Encoding (variant);
6982 gnu_inner_name = get_identifier_with_length (Name_Buffer, Name_Len);
6983 TYPE_NAME (gnu_variant_type)
6984 = concat_name (gnu_union_name,
6985 IDENTIFIER_POINTER (gnu_inner_name));
6986
6987 /* Set the alignment of the inner type in case we need to make
6988 inner objects into bitfields, but then clear it out so the
6989 record actually gets only the alignment required. */
6990 TYPE_ALIGN (gnu_variant_type) = TYPE_ALIGN (gnu_record_type);
6991 TYPE_PACKED (gnu_variant_type) = TYPE_PACKED (gnu_record_type);
6992
6993 /* Similarly, if the outer record has a size specified and all
6994 the fields have a rep clause, we can propagate the size. */
6995 if (all_rep_and_size)
6996 {
6997 TYPE_SIZE (gnu_variant_type) = TYPE_SIZE (gnu_record_type);
6998 TYPE_SIZE_UNIT (gnu_variant_type)
6999 = TYPE_SIZE_UNIT (gnu_record_type);
7000 }
7001
7002 /* Add the fields into the record type for the variant. Note that
7003 we aren't sure to really use it at this point, see below. */
7004 components_to_record (gnu_variant_type, Component_List (variant),
7005 NULL_TREE, packed, definition,
7006 !all_rep_and_size, all_rep, unchecked_union,
7007 true, debug_info, true, reorder,
7008 this_first_free_pos,
7009 all_rep || this_first_free_pos
7010 ? NULL : &gnu_rep_list);
7011
7012 gnu_qual = choices_to_gnu (gnu_discr, Discrete_Choices (variant));
7013 Set_Present_Expr (variant, annotate_value (gnu_qual));
7014
7015 /* If this is an Unchecked_Union whose fields are all in the variant
7016 part and we have a single field with no representation clause or
7017 placed at offset zero, use the field directly to match the layout
7018 of C unions. */
7019 if (TREE_CODE (gnu_record_type) == UNION_TYPE
7020 && (gnu_field = TYPE_FIELDS (gnu_variant_type)) != NULL_TREE
7021 && !DECL_CHAIN (gnu_field)
7022 && (!DECL_FIELD_OFFSET (gnu_field)
7023 || integer_zerop (bit_position (gnu_field))))
7024 DECL_CONTEXT (gnu_field) = gnu_union_type;
7025 else
7026 {
7027 /* Deal with packedness like in gnat_to_gnu_field. */
7028 bool field_needs_strict_alignment
7029 = components_need_strict_alignment (Component_List (variant));
7030 int field_packed;
7031
7032 if (field_needs_strict_alignment)
7033 {
7034 field_packed = 0;
7035 union_field_needs_strict_alignment = true;
7036 }
7037 else
7038 field_packed
7039 = adjust_packed (gnu_variant_type, gnu_record_type, packed);
7040
7041 /* Finalize the record type now. We used to throw away
7042 empty records but we no longer do that because we need
7043 them to generate complete debug info for the variant;
7044 otherwise, the union type definition will be lacking
7045 the fields associated with these empty variants. */
7046 rest_of_record_type_compilation (gnu_variant_type);
7047 create_type_decl (TYPE_NAME (gnu_variant_type), gnu_variant_type,
7048 NULL, true, debug_info, gnat_component_list);
7049
7050 gnu_field
7051 = create_field_decl (gnu_inner_name, gnu_variant_type,
7052 gnu_union_type,
7053 all_rep_and_size
7054 ? TYPE_SIZE (gnu_variant_type) : 0,
7055 all_rep ? bitsize_zero_node : 0,
7056 field_packed, 0);
7057
7058 DECL_INTERNAL_P (gnu_field) = 1;
7059
7060 if (!unchecked_union)
7061 DECL_QUALIFIER (gnu_field) = gnu_qual;
7062 }
7063
7064 DECL_CHAIN (gnu_field) = gnu_variant_list;
7065 gnu_variant_list = gnu_field;
7066 }
7067
7068 /* Only make the QUAL_UNION_TYPE if there are non-empty variants. */
7069 if (gnu_variant_list)
7070 {
7071 int union_field_packed;
7072
7073 if (all_rep_and_size)
7074 {
7075 TYPE_SIZE (gnu_union_type) = TYPE_SIZE (gnu_record_type);
7076 TYPE_SIZE_UNIT (gnu_union_type)
7077 = TYPE_SIZE_UNIT (gnu_record_type);
7078 }
7079
7080 finish_record_type (gnu_union_type, nreverse (gnu_variant_list),
7081 all_rep_and_size ? 1 : 0, debug_info);
7082
7083 /* If GNU_UNION_TYPE is our record type, it means we must have an
7084 Unchecked_Union with no fields. Verify that and, if so, just
7085 return. */
7086 if (gnu_union_type == gnu_record_type)
7087 {
7088 gcc_assert (unchecked_union
7089 && !gnu_field_list
7090 && !gnu_rep_list);
7091 return;
7092 }
7093
7094 create_type_decl (TYPE_NAME (gnu_union_type), gnu_union_type,
7095 NULL, true, debug_info, gnat_component_list);
7096
7097 /* Deal with packedness like in gnat_to_gnu_field. */
7098 if (union_field_needs_strict_alignment)
7099 union_field_packed = 0;
7100 else
7101 union_field_packed
7102 = adjust_packed (gnu_union_type, gnu_record_type, packed);
7103
7104 gnu_variant_part
7105 = create_field_decl (gnu_var_name, gnu_union_type, gnu_record_type,
7106 all_rep_and_size
7107 ? TYPE_SIZE (gnu_union_type) : 0,
7108 all_rep || this_first_free_pos
7109 ? bitsize_zero_node : 0,
7110 union_field_packed, 0);
7111
7112 DECL_INTERNAL_P (gnu_variant_part) = 1;
7113 }
7114 }
7115
7116 /* From now on, a zero FIRST_FREE_POS is totally useless. */
7117 if (first_free_pos && integer_zerop (first_free_pos))
7118 first_free_pos = NULL_TREE;
7119
7120 /* Scan GNU_FIELD_LIST and see if any fields have rep clauses and, if we are
7121 permitted to reorder components, self-referential sizes or variable sizes.
7122 If they do, pull them out and put them onto the appropriate list. We have
7123 to do this in a separate pass since we want to handle the discriminants
7124 but can't play with them until we've used them in debugging data above.
7125
7126 ??? If we reorder them, debugging information will be wrong but there is
7127 nothing that can be done about this at the moment. */
7128 gnu_last = NULL_TREE;
7129
7130 #define MOVE_FROM_FIELD_LIST_TO(LIST) \
7131 do { \
7132 if (gnu_last) \
7133 DECL_CHAIN (gnu_last) = gnu_next; \
7134 else \
7135 gnu_field_list = gnu_next; \
7136 \
7137 DECL_CHAIN (gnu_field) = (LIST); \
7138 (LIST) = gnu_field; \
7139 } while (0)
7140
7141 for (gnu_field = gnu_field_list; gnu_field; gnu_field = gnu_next)
7142 {
7143 gnu_next = DECL_CHAIN (gnu_field);
7144
7145 if (DECL_FIELD_OFFSET (gnu_field))
7146 {
7147 MOVE_FROM_FIELD_LIST_TO (gnu_rep_list);
7148 continue;
7149 }
7150
7151 if ((reorder || has_aliased_after_self_field)
7152 && field_has_self_size (gnu_field))
7153 {
7154 MOVE_FROM_FIELD_LIST_TO (gnu_self_list);
7155 continue;
7156 }
7157
7158 if (reorder && field_has_variable_size (gnu_field))
7159 {
7160 MOVE_FROM_FIELD_LIST_TO (gnu_var_list);
7161 continue;
7162 }
7163
7164 gnu_last = gnu_field;
7165 }
7166
7167 #undef MOVE_FROM_FIELD_LIST_TO
7168
7169 /* If permitted, we reorder the fields as follows:
7170
7171 1) all fixed length fields,
7172 2) all fields whose length doesn't depend on discriminants,
7173 3) all fields whose length depends on discriminants,
7174 4) the variant part,
7175
7176 within the record and within each variant recursively. */
7177 if (reorder)
7178 gnu_field_list
7179 = chainon (nreverse (gnu_self_list),
7180 chainon (nreverse (gnu_var_list), gnu_field_list));
7181
7182 /* Otherwise, if there is an aliased field placed after a field whose length
7183 depends on discriminants, we put all the fields of the latter sort, last.
7184 We need to do this in case an object of this record type is mutable. */
7185 else if (has_aliased_after_self_field)
7186 gnu_field_list = chainon (nreverse (gnu_self_list), gnu_field_list);
7187
7188 /* If P_REP_LIST is nonzero, this means that we are asked to move the fields
7189 in our REP list to the previous level because this level needs them in
7190 order to do a correct layout, i.e. avoid having overlapping fields. */
7191 if (p_gnu_rep_list && gnu_rep_list)
7192 *p_gnu_rep_list = chainon (*p_gnu_rep_list, gnu_rep_list);
7193
7194 /* Otherwise, sort the fields by bit position and put them into their own
7195 record, before the others, if we also have fields without rep clause. */
7196 else if (gnu_rep_list)
7197 {
7198 tree gnu_rep_type
7199 = (gnu_field_list ? make_node (RECORD_TYPE) : gnu_record_type);
7200 int i, len = list_length (gnu_rep_list);
7201 tree *gnu_arr = XALLOCAVEC (tree, len);
7202
7203 for (gnu_field = gnu_rep_list, i = 0;
7204 gnu_field;
7205 gnu_field = DECL_CHAIN (gnu_field), i++)
7206 gnu_arr[i] = gnu_field;
7207
7208 qsort (gnu_arr, len, sizeof (tree), compare_field_bitpos);
7209
7210 /* Put the fields in the list in order of increasing position, which
7211 means we start from the end. */
7212 gnu_rep_list = NULL_TREE;
7213 for (i = len - 1; i >= 0; i--)
7214 {
7215 DECL_CHAIN (gnu_arr[i]) = gnu_rep_list;
7216 gnu_rep_list = gnu_arr[i];
7217 DECL_CONTEXT (gnu_arr[i]) = gnu_rep_type;
7218 }
7219
7220 if (gnu_field_list)
7221 {
7222 finish_record_type (gnu_rep_type, gnu_rep_list, 1, debug_info);
7223
7224 /* If FIRST_FREE_POS is nonzero, we need to ensure that the fields
7225 without rep clause are laid out starting from this position.
7226 Therefore, we force it as a minimal size on the REP part. */
7227 gnu_rep_part
7228 = create_rep_part (gnu_rep_type, gnu_record_type, first_free_pos);
7229 }
7230 else
7231 {
7232 layout_with_rep = true;
7233 gnu_field_list = nreverse (gnu_rep_list);
7234 }
7235 }
7236
7237 /* If FIRST_FREE_POS is nonzero, we need to ensure that the fields without
7238 rep clause are laid out starting from this position. Therefore, if we
7239 have not already done so, we create a fake REP part with this size. */
7240 if (first_free_pos && !layout_with_rep && !gnu_rep_part)
7241 {
7242 tree gnu_rep_type = make_node (RECORD_TYPE);
7243 finish_record_type (gnu_rep_type, NULL_TREE, 0, debug_info);
7244 gnu_rep_part
7245 = create_rep_part (gnu_rep_type, gnu_record_type, first_free_pos);
7246 }
7247
7248 /* Now chain the REP part at the end of the reversed field list. */
7249 if (gnu_rep_part)
7250 gnu_field_list = chainon (gnu_field_list, gnu_rep_part);
7251
7252 /* And the variant part at the beginning. */
7253 if (gnu_variant_part)
7254 {
7255 DECL_CHAIN (gnu_variant_part) = gnu_field_list;
7256 gnu_field_list = gnu_variant_part;
7257 }
7258
7259 if (cancel_alignment)
7260 TYPE_ALIGN (gnu_record_type) = 0;
7261
7262 finish_record_type (gnu_record_type, nreverse (gnu_field_list),
7263 layout_with_rep ? 1 : 0, false);
7264 TYPE_ARTIFICIAL (gnu_record_type) = artificial;
7265 if (debug_info && !maybe_unused)
7266 rest_of_record_type_compilation (gnu_record_type);
7267 }
7268
7269 /* Given GNU_SIZE, a GCC tree representing a size, return a Uint to be
7270 placed into an Esize, Component_Bit_Offset, or Component_Size value
7271 in the GNAT tree. */
7272
7273 static Uint
annotate_value(tree gnu_size)7274 annotate_value (tree gnu_size)
7275 {
7276 TCode tcode;
7277 Node_Ref_Or_Val ops[3], ret, pre_op1 = No_Uint;
7278 struct tree_int_map in;
7279 int i;
7280
7281 /* See if we've already saved the value for this node. */
7282 if (EXPR_P (gnu_size))
7283 {
7284 struct tree_int_map *e;
7285
7286 if (!annotate_value_cache)
7287 annotate_value_cache = htab_create_ggc (512, tree_int_map_hash,
7288 tree_int_map_eq, 0);
7289 in.base.from = gnu_size;
7290 e = (struct tree_int_map *)
7291 htab_find (annotate_value_cache, &in);
7292
7293 if (e)
7294 return (Node_Ref_Or_Val) e->to;
7295 }
7296 else
7297 in.base.from = NULL_TREE;
7298
7299 /* If we do not return inside this switch, TCODE will be set to the
7300 code to use for a Create_Node operand and LEN (set above) will be
7301 the number of recursive calls for us to make. */
7302
7303 switch (TREE_CODE (gnu_size))
7304 {
7305 case INTEGER_CST:
7306 return TREE_OVERFLOW (gnu_size) ? No_Uint : UI_From_gnu (gnu_size);
7307
7308 case COMPONENT_REF:
7309 /* The only case we handle here is a simple discriminant reference. */
7310 if (DECL_DISCRIMINANT_NUMBER (TREE_OPERAND (gnu_size, 1)))
7311 {
7312 tree n = DECL_DISCRIMINANT_NUMBER (TREE_OPERAND (gnu_size, 1));
7313
7314 /* Climb up the chain of successive extensions, if any. */
7315 while (TREE_CODE (TREE_OPERAND (gnu_size, 0)) == COMPONENT_REF
7316 && DECL_NAME (TREE_OPERAND (TREE_OPERAND (gnu_size, 0), 1))
7317 == parent_name_id)
7318 gnu_size = TREE_OPERAND (gnu_size, 0);
7319
7320 if (TREE_CODE (TREE_OPERAND (gnu_size, 0)) == PLACEHOLDER_EXPR)
7321 return
7322 Create_Node (Discrim_Val, annotate_value (n), No_Uint, No_Uint);
7323 }
7324
7325 return No_Uint;
7326
7327 CASE_CONVERT: case NON_LVALUE_EXPR:
7328 return annotate_value (TREE_OPERAND (gnu_size, 0));
7329
7330 /* Now just list the operations we handle. */
7331 case COND_EXPR: tcode = Cond_Expr; break;
7332 case PLUS_EXPR: tcode = Plus_Expr; break;
7333 case MINUS_EXPR: tcode = Minus_Expr; break;
7334 case MULT_EXPR: tcode = Mult_Expr; break;
7335 case TRUNC_DIV_EXPR: tcode = Trunc_Div_Expr; break;
7336 case CEIL_DIV_EXPR: tcode = Ceil_Div_Expr; break;
7337 case FLOOR_DIV_EXPR: tcode = Floor_Div_Expr; break;
7338 case TRUNC_MOD_EXPR: tcode = Trunc_Mod_Expr; break;
7339 case CEIL_MOD_EXPR: tcode = Ceil_Mod_Expr; break;
7340 case FLOOR_MOD_EXPR: tcode = Floor_Mod_Expr; break;
7341 case EXACT_DIV_EXPR: tcode = Exact_Div_Expr; break;
7342 case NEGATE_EXPR: tcode = Negate_Expr; break;
7343 case MIN_EXPR: tcode = Min_Expr; break;
7344 case MAX_EXPR: tcode = Max_Expr; break;
7345 case ABS_EXPR: tcode = Abs_Expr; break;
7346 case TRUTH_ANDIF_EXPR: tcode = Truth_Andif_Expr; break;
7347 case TRUTH_ORIF_EXPR: tcode = Truth_Orif_Expr; break;
7348 case TRUTH_AND_EXPR: tcode = Truth_And_Expr; break;
7349 case TRUTH_OR_EXPR: tcode = Truth_Or_Expr; break;
7350 case TRUTH_XOR_EXPR: tcode = Truth_Xor_Expr; break;
7351 case TRUTH_NOT_EXPR: tcode = Truth_Not_Expr; break;
7352 case LT_EXPR: tcode = Lt_Expr; break;
7353 case LE_EXPR: tcode = Le_Expr; break;
7354 case GT_EXPR: tcode = Gt_Expr; break;
7355 case GE_EXPR: tcode = Ge_Expr; break;
7356 case EQ_EXPR: tcode = Eq_Expr; break;
7357 case NE_EXPR: tcode = Ne_Expr; break;
7358
7359 case BIT_AND_EXPR:
7360 tcode = Bit_And_Expr;
7361 /* For negative values, build NEGATE_EXPR of the opposite. Such values
7362 appear in expressions containing aligning patterns. Note that, since
7363 sizetype is unsigned, we have to jump through some hoops. */
7364 if (TREE_CODE (TREE_OPERAND (gnu_size, 1)) == INTEGER_CST)
7365 {
7366 tree op1 = TREE_OPERAND (gnu_size, 1);
7367 double_int signed_op1
7368 = tree_to_double_int (op1).sext (TYPE_PRECISION (sizetype));
7369 if (signed_op1.is_negative ())
7370 {
7371 op1 = double_int_to_tree (sizetype, -signed_op1);
7372 pre_op1 = annotate_value (build1 (NEGATE_EXPR, sizetype, op1));
7373 }
7374 }
7375 break;
7376
7377 case CALL_EXPR:
7378 {
7379 tree t = maybe_inline_call_in_expr (gnu_size);
7380 if (t)
7381 return annotate_value (t);
7382 }
7383
7384 /* Fall through... */
7385
7386 default:
7387 return No_Uint;
7388 }
7389
7390 /* Now get each of the operands that's relevant for this code. If any
7391 cannot be expressed as a repinfo node, say we can't. */
7392 for (i = 0; i < 3; i++)
7393 ops[i] = No_Uint;
7394
7395 for (i = 0; i < TREE_CODE_LENGTH (TREE_CODE (gnu_size)); i++)
7396 {
7397 if (i == 1 && pre_op1 != No_Uint)
7398 ops[i] = pre_op1;
7399 else
7400 ops[i] = annotate_value (TREE_OPERAND (gnu_size, i));
7401 if (ops[i] == No_Uint)
7402 return No_Uint;
7403 }
7404
7405 ret = Create_Node (tcode, ops[0], ops[1], ops[2]);
7406
7407 /* Save the result in the cache. */
7408 if (in.base.from)
7409 {
7410 struct tree_int_map **h;
7411 /* We can't assume the hash table data hasn't moved since the
7412 initial look up, so we have to search again. Allocating and
7413 inserting an entry at that point would be an alternative, but
7414 then we'd better discard the entry if we decided not to cache
7415 it. */
7416 h = (struct tree_int_map **)
7417 htab_find_slot (annotate_value_cache, &in, INSERT);
7418 gcc_assert (!*h);
7419 *h = ggc_alloc_tree_int_map ();
7420 (*h)->base.from = gnu_size;
7421 (*h)->to = ret;
7422 }
7423
7424 return ret;
7425 }
7426
7427 /* Given GNAT_ENTITY, an object (constant, variable, parameter, exception)
7428 and GNU_TYPE, its corresponding GCC type, set Esize and Alignment to the
7429 size and alignment used by Gigi. Prefer SIZE over TYPE_SIZE if non-null.
7430 BY_REF is true if the object is used by reference and BY_DOUBLE_REF is
7431 true if the object is used by double reference. */
7432
7433 void
annotate_object(Entity_Id gnat_entity,tree gnu_type,tree size,bool by_ref,bool by_double_ref)7434 annotate_object (Entity_Id gnat_entity, tree gnu_type, tree size, bool by_ref,
7435 bool by_double_ref)
7436 {
7437 if (by_ref)
7438 {
7439 if (by_double_ref)
7440 gnu_type = TREE_TYPE (gnu_type);
7441
7442 if (TYPE_IS_FAT_POINTER_P (gnu_type))
7443 gnu_type = TYPE_UNCONSTRAINED_ARRAY (gnu_type);
7444 else
7445 gnu_type = TREE_TYPE (gnu_type);
7446 }
7447
7448 if (Unknown_Esize (gnat_entity))
7449 {
7450 if (TREE_CODE (gnu_type) == RECORD_TYPE
7451 && TYPE_CONTAINS_TEMPLATE_P (gnu_type))
7452 size = TYPE_SIZE (TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (gnu_type))));
7453 else if (!size)
7454 size = TYPE_SIZE (gnu_type);
7455
7456 if (size)
7457 Set_Esize (gnat_entity, annotate_value (size));
7458 }
7459
7460 if (Unknown_Alignment (gnat_entity))
7461 Set_Alignment (gnat_entity,
7462 UI_From_Int (TYPE_ALIGN (gnu_type) / BITS_PER_UNIT));
7463 }
7464
7465 /* Return first element of field list whose TREE_PURPOSE is the same as ELEM.
7466 Return NULL_TREE if there is no such element in the list. */
7467
7468 static tree
purpose_member_field(const_tree elem,tree list)7469 purpose_member_field (const_tree elem, tree list)
7470 {
7471 while (list)
7472 {
7473 tree field = TREE_PURPOSE (list);
7474 if (SAME_FIELD_P (field, elem))
7475 return list;
7476 list = TREE_CHAIN (list);
7477 }
7478 return NULL_TREE;
7479 }
7480
7481 /* Given GNAT_ENTITY, a record type, and GNU_TYPE, its corresponding GCC type,
7482 set Component_Bit_Offset and Esize of the components to the position and
7483 size used by Gigi. */
7484
7485 static void
annotate_rep(Entity_Id gnat_entity,tree gnu_type)7486 annotate_rep (Entity_Id gnat_entity, tree gnu_type)
7487 {
7488 Entity_Id gnat_field;
7489 tree gnu_list;
7490
7491 /* We operate by first making a list of all fields and their position (we
7492 can get the size easily) and then update all the sizes in the tree. */
7493 gnu_list
7494 = build_position_list (gnu_type, false, size_zero_node, bitsize_zero_node,
7495 BIGGEST_ALIGNMENT, NULL_TREE);
7496
7497 for (gnat_field = First_Entity (gnat_entity);
7498 Present (gnat_field);
7499 gnat_field = Next_Entity (gnat_field))
7500 if (Ekind (gnat_field) == E_Component
7501 || (Ekind (gnat_field) == E_Discriminant
7502 && !Is_Unchecked_Union (Scope (gnat_field))))
7503 {
7504 tree t = purpose_member_field (gnat_to_gnu_field_decl (gnat_field),
7505 gnu_list);
7506 if (t)
7507 {
7508 tree parent_offset;
7509
7510 /* If we are just annotating types and the type is tagged, the tag
7511 and the parent components are not generated by the front-end so
7512 we need to add the appropriate offset to each component without
7513 representation clause. */
7514 if (type_annotate_only
7515 && Is_Tagged_Type (gnat_entity)
7516 && No (Component_Clause (gnat_field)))
7517 {
7518 /* For a component appearing in the current extension, the
7519 offset is the size of the parent. */
7520 if (Is_Derived_Type (gnat_entity)
7521 && Original_Record_Component (gnat_field) == gnat_field)
7522 parent_offset
7523 = UI_To_gnu (Esize (Etype (Base_Type (gnat_entity))),
7524 bitsizetype);
7525 else
7526 parent_offset = bitsize_int (POINTER_SIZE);
7527
7528 if (TYPE_FIELDS (gnu_type))
7529 parent_offset
7530 = round_up (parent_offset,
7531 DECL_ALIGN (TYPE_FIELDS (gnu_type)));
7532 }
7533 else
7534 parent_offset = bitsize_zero_node;
7535
7536 Set_Component_Bit_Offset
7537 (gnat_field,
7538 annotate_value
7539 (size_binop (PLUS_EXPR,
7540 bit_from_pos (TREE_VEC_ELT (TREE_VALUE (t), 0),
7541 TREE_VEC_ELT (TREE_VALUE (t), 2)),
7542 parent_offset)));
7543
7544 Set_Esize (gnat_field,
7545 annotate_value (DECL_SIZE (TREE_PURPOSE (t))));
7546 }
7547 else if (Is_Tagged_Type (gnat_entity) && Is_Derived_Type (gnat_entity))
7548 {
7549 /* If there is no entry, this is an inherited component whose
7550 position is the same as in the parent type. */
7551 Set_Component_Bit_Offset
7552 (gnat_field,
7553 Component_Bit_Offset (Original_Record_Component (gnat_field)));
7554
7555 Set_Esize (gnat_field,
7556 Esize (Original_Record_Component (gnat_field)));
7557 }
7558 }
7559 }
7560
7561 /* Scan all fields in GNU_TYPE and return a TREE_LIST where TREE_PURPOSE is
7562 the FIELD_DECL and TREE_VALUE a TREE_VEC containing the byte position, the
7563 value to be placed into DECL_OFFSET_ALIGN and the bit position. The list
7564 of fields is flattened, except for variant parts if DO_NOT_FLATTEN_VARIANT
7565 is set to true. GNU_POS is to be added to the position, GNU_BITPOS to the
7566 bit position, OFFSET_ALIGN is the present offset alignment. GNU_LIST is a
7567 pre-existing list to be chained to the newly created entries. */
7568
7569 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)7570 build_position_list (tree gnu_type, bool do_not_flatten_variant, tree gnu_pos,
7571 tree gnu_bitpos, unsigned int offset_align, tree gnu_list)
7572 {
7573 tree gnu_field;
7574
7575 for (gnu_field = TYPE_FIELDS (gnu_type);
7576 gnu_field;
7577 gnu_field = DECL_CHAIN (gnu_field))
7578 {
7579 tree gnu_our_bitpos = size_binop (PLUS_EXPR, gnu_bitpos,
7580 DECL_FIELD_BIT_OFFSET (gnu_field));
7581 tree gnu_our_offset = size_binop (PLUS_EXPR, gnu_pos,
7582 DECL_FIELD_OFFSET (gnu_field));
7583 unsigned int our_offset_align
7584 = MIN (offset_align, DECL_OFFSET_ALIGN (gnu_field));
7585 tree v = make_tree_vec (3);
7586
7587 TREE_VEC_ELT (v, 0) = gnu_our_offset;
7588 TREE_VEC_ELT (v, 1) = size_int (our_offset_align);
7589 TREE_VEC_ELT (v, 2) = gnu_our_bitpos;
7590 gnu_list = tree_cons (gnu_field, v, gnu_list);
7591
7592 /* Recurse on internal fields, flattening the nested fields except for
7593 those in the variant part, if requested. */
7594 if (DECL_INTERNAL_P (gnu_field))
7595 {
7596 tree gnu_field_type = TREE_TYPE (gnu_field);
7597 if (do_not_flatten_variant
7598 && TREE_CODE (gnu_field_type) == QUAL_UNION_TYPE)
7599 gnu_list
7600 = build_position_list (gnu_field_type, do_not_flatten_variant,
7601 size_zero_node, bitsize_zero_node,
7602 BIGGEST_ALIGNMENT, gnu_list);
7603 else
7604 gnu_list
7605 = build_position_list (gnu_field_type, do_not_flatten_variant,
7606 gnu_our_offset, gnu_our_bitpos,
7607 our_offset_align, gnu_list);
7608 }
7609 }
7610
7611 return gnu_list;
7612 }
7613
7614 /* Return a list describing the substitutions needed to reflect the
7615 discriminant substitutions from GNAT_TYPE to GNAT_SUBTYPE. They can
7616 be in any order. The values in an element of the list are in the form
7617 of operands to SUBSTITUTE_IN_EXPR. DEFINITION is true if this is for
7618 a definition of GNAT_SUBTYPE. */
7619
7620 static vec<subst_pair>
build_subst_list(Entity_Id gnat_subtype,Entity_Id gnat_type,bool definition)7621 build_subst_list (Entity_Id gnat_subtype, Entity_Id gnat_type, bool definition)
7622 {
7623 vec<subst_pair> gnu_list = vNULL;
7624 Entity_Id gnat_discrim;
7625 Node_Id gnat_value;
7626
7627 for (gnat_discrim = First_Stored_Discriminant (gnat_type),
7628 gnat_value = First_Elmt (Stored_Constraint (gnat_subtype));
7629 Present (gnat_discrim);
7630 gnat_discrim = Next_Stored_Discriminant (gnat_discrim),
7631 gnat_value = Next_Elmt (gnat_value))
7632 /* Ignore access discriminants. */
7633 if (!Is_Access_Type (Etype (Node (gnat_value))))
7634 {
7635 tree gnu_field = gnat_to_gnu_field_decl (gnat_discrim);
7636 tree replacement = convert (TREE_TYPE (gnu_field),
7637 elaborate_expression
7638 (Node (gnat_value), gnat_subtype,
7639 get_entity_name (gnat_discrim),
7640 definition, true, false));
7641 subst_pair s = {gnu_field, replacement};
7642 gnu_list.safe_push (s);
7643 }
7644
7645 return gnu_list;
7646 }
7647
7648 /* Scan all fields in QUAL_UNION_TYPE and return a list describing the
7649 variants of QUAL_UNION_TYPE that are still relevant after applying
7650 the substitutions described in SUBST_LIST. GNU_LIST is a pre-existing
7651 list to be prepended to the newly created entries. */
7652
7653 static vec<variant_desc>
build_variant_list(tree qual_union_type,vec<subst_pair> subst_list,vec<variant_desc> gnu_list)7654 build_variant_list (tree qual_union_type, vec<subst_pair> subst_list,
7655 vec<variant_desc> gnu_list)
7656 {
7657 tree gnu_field;
7658
7659 for (gnu_field = TYPE_FIELDS (qual_union_type);
7660 gnu_field;
7661 gnu_field = DECL_CHAIN (gnu_field))
7662 {
7663 tree qual = DECL_QUALIFIER (gnu_field);
7664 unsigned int i;
7665 subst_pair *s;
7666
7667 FOR_EACH_VEC_ELT (subst_list, i, s)
7668 qual = SUBSTITUTE_IN_EXPR (qual, s->discriminant, s->replacement);
7669
7670 /* If the new qualifier is not unconditionally false, its variant may
7671 still be accessed. */
7672 if (!integer_zerop (qual))
7673 {
7674 tree variant_type = TREE_TYPE (gnu_field), variant_subpart;
7675 variant_desc v = {variant_type, gnu_field, qual, NULL_TREE};
7676
7677 gnu_list.safe_push (v);
7678
7679 /* Recurse on the variant subpart of the variant, if any. */
7680 variant_subpart = get_variant_part (variant_type);
7681 if (variant_subpart)
7682 gnu_list = build_variant_list (TREE_TYPE (variant_subpart),
7683 subst_list, gnu_list);
7684
7685 /* If the new qualifier is unconditionally true, the subsequent
7686 variants cannot be accessed. */
7687 if (integer_onep (qual))
7688 break;
7689 }
7690 }
7691
7692 return gnu_list;
7693 }
7694
7695 /* UINT_SIZE is a Uint giving the specified size for an object of GNU_TYPE
7696 corresponding to GNAT_OBJECT. If the size is valid, return an INTEGER_CST
7697 corresponding to its value. Otherwise, return NULL_TREE. KIND is set to
7698 VAR_DECL if we are specifying the size of an object, TYPE_DECL for the
7699 size of a type, and FIELD_DECL for the size of a field. COMPONENT_P is
7700 true if we are being called to process the Component_Size of GNAT_OBJECT;
7701 this is used only for error messages. ZERO_OK is true if a size of zero
7702 is permitted; if ZERO_OK is false, it means that a size of zero should be
7703 treated as an unspecified size. */
7704
7705 static tree
validate_size(Uint uint_size,tree gnu_type,Entity_Id gnat_object,enum tree_code kind,bool component_p,bool zero_ok)7706 validate_size (Uint uint_size, tree gnu_type, Entity_Id gnat_object,
7707 enum tree_code kind, bool component_p, bool zero_ok)
7708 {
7709 Node_Id gnat_error_node;
7710 tree type_size, size;
7711
7712 /* Return 0 if no size was specified. */
7713 if (uint_size == No_Uint)
7714 return NULL_TREE;
7715
7716 /* Ignore a negative size since that corresponds to our back-annotation. */
7717 if (UI_Lt (uint_size, Uint_0))
7718 return NULL_TREE;
7719
7720 /* Find the node to use for error messages. */
7721 if ((Ekind (gnat_object) == E_Component
7722 || Ekind (gnat_object) == E_Discriminant)
7723 && Present (Component_Clause (gnat_object)))
7724 gnat_error_node = Last_Bit (Component_Clause (gnat_object));
7725 else if (Present (Size_Clause (gnat_object)))
7726 gnat_error_node = Expression (Size_Clause (gnat_object));
7727 else
7728 gnat_error_node = gnat_object;
7729
7730 /* Get the size as an INTEGER_CST. Issue an error if a size was specified
7731 but cannot be represented in bitsizetype. */
7732 size = UI_To_gnu (uint_size, bitsizetype);
7733 if (TREE_OVERFLOW (size))
7734 {
7735 if (component_p)
7736 post_error_ne ("component size for& is too large", gnat_error_node,
7737 gnat_object);
7738 else
7739 post_error_ne ("size for& is too large", gnat_error_node,
7740 gnat_object);
7741 return NULL_TREE;
7742 }
7743
7744 /* Ignore a zero size if it is not permitted. */
7745 if (!zero_ok && integer_zerop (size))
7746 return NULL_TREE;
7747
7748 /* The size of objects is always a multiple of a byte. */
7749 if (kind == VAR_DECL
7750 && !integer_zerop (size_binop (TRUNC_MOD_EXPR, size, bitsize_unit_node)))
7751 {
7752 if (component_p)
7753 post_error_ne ("component size for& is not a multiple of Storage_Unit",
7754 gnat_error_node, gnat_object);
7755 else
7756 post_error_ne ("size for& is not a multiple of Storage_Unit",
7757 gnat_error_node, gnat_object);
7758 return NULL_TREE;
7759 }
7760
7761 /* If this is an integral type or a packed array type, the front-end has
7762 already verified the size, so we need not do it here (which would mean
7763 checking against the bounds). However, if this is an aliased object,
7764 it may not be smaller than the type of the object. */
7765 if ((INTEGRAL_TYPE_P (gnu_type) || TYPE_IS_PACKED_ARRAY_TYPE_P (gnu_type))
7766 && !(kind == VAR_DECL && Is_Aliased (gnat_object)))
7767 return size;
7768
7769 /* If the object is a record that contains a template, add the size of the
7770 template to the specified size. */
7771 if (TREE_CODE (gnu_type) == RECORD_TYPE
7772 && TYPE_CONTAINS_TEMPLATE_P (gnu_type))
7773 size = size_binop (PLUS_EXPR, DECL_SIZE (TYPE_FIELDS (gnu_type)), size);
7774
7775 if (kind == VAR_DECL
7776 /* If a type needs strict alignment, a component of this type in
7777 a packed record cannot be packed and thus uses the type size. */
7778 || (kind == TYPE_DECL && Strict_Alignment (gnat_object)))
7779 type_size = TYPE_SIZE (gnu_type);
7780 else
7781 type_size = rm_size (gnu_type);
7782
7783 /* Modify the size of a discriminated type to be the maximum size. */
7784 if (type_size && CONTAINS_PLACEHOLDER_P (type_size))
7785 type_size = max_size (type_size, true);
7786
7787 /* If this is an access type or a fat pointer, the minimum size is that given
7788 by the smallest integral mode that's valid for pointers. */
7789 if (TREE_CODE (gnu_type) == POINTER_TYPE || TYPE_IS_FAT_POINTER_P (gnu_type))
7790 {
7791 enum machine_mode p_mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
7792 while (!targetm.valid_pointer_mode (p_mode))
7793 p_mode = GET_MODE_WIDER_MODE (p_mode);
7794 type_size = bitsize_int (GET_MODE_BITSIZE (p_mode));
7795 }
7796
7797 /* Issue an error either if the default size of the object isn't a constant
7798 or if the new size is smaller than it. */
7799 if (TREE_CODE (type_size) != INTEGER_CST
7800 || TREE_OVERFLOW (type_size)
7801 || tree_int_cst_lt (size, type_size))
7802 {
7803 if (component_p)
7804 post_error_ne_tree
7805 ("component size for& too small{, minimum allowed is ^}",
7806 gnat_error_node, gnat_object, type_size);
7807 else
7808 post_error_ne_tree
7809 ("size for& too small{, minimum allowed is ^}",
7810 gnat_error_node, gnat_object, type_size);
7811 return NULL_TREE;
7812 }
7813
7814 return size;
7815 }
7816
7817 /* Similarly, but both validate and process a value of RM size. This routine
7818 is only called for types. */
7819
7820 static void
set_rm_size(Uint uint_size,tree gnu_type,Entity_Id gnat_entity)7821 set_rm_size (Uint uint_size, tree gnu_type, Entity_Id gnat_entity)
7822 {
7823 Node_Id gnat_attr_node;
7824 tree old_size, size;
7825
7826 /* Do nothing if no size was specified. */
7827 if (uint_size == No_Uint)
7828 return;
7829
7830 /* Ignore a negative size since that corresponds to our back-annotation. */
7831 if (UI_Lt (uint_size, Uint_0))
7832 return;
7833
7834 /* Only issue an error if a Value_Size clause was explicitly given.
7835 Otherwise, we'd be duplicating an error on the Size clause. */
7836 gnat_attr_node
7837 = Get_Attribute_Definition_Clause (gnat_entity, Attr_Value_Size);
7838
7839 /* Get the size as an INTEGER_CST. Issue an error if a size was specified
7840 but cannot be represented in bitsizetype. */
7841 size = UI_To_gnu (uint_size, bitsizetype);
7842 if (TREE_OVERFLOW (size))
7843 {
7844 if (Present (gnat_attr_node))
7845 post_error_ne ("Value_Size for& is too large", gnat_attr_node,
7846 gnat_entity);
7847 return;
7848 }
7849
7850 /* Ignore a zero size unless a Value_Size clause exists, or a size clause
7851 exists, or this is an integer type, in which case the front-end will
7852 have always set it. */
7853 if (No (gnat_attr_node)
7854 && integer_zerop (size)
7855 && !Has_Size_Clause (gnat_entity)
7856 && !Is_Discrete_Or_Fixed_Point_Type (gnat_entity))
7857 return;
7858
7859 old_size = rm_size (gnu_type);
7860
7861 /* If the old size is self-referential, get the maximum size. */
7862 if (CONTAINS_PLACEHOLDER_P (old_size))
7863 old_size = max_size (old_size, true);
7864
7865 /* Issue an error either if the old size of the object isn't a constant or
7866 if the new size is smaller than it. The front-end has already verified
7867 this for scalar and packed array types. */
7868 if (TREE_CODE (old_size) != INTEGER_CST
7869 || TREE_OVERFLOW (old_size)
7870 || (AGGREGATE_TYPE_P (gnu_type)
7871 && !(TREE_CODE (gnu_type) == ARRAY_TYPE
7872 && TYPE_PACKED_ARRAY_TYPE_P (gnu_type))
7873 && !(TYPE_IS_PADDING_P (gnu_type)
7874 && TREE_CODE (TREE_TYPE (TYPE_FIELDS (gnu_type))) == ARRAY_TYPE
7875 && TYPE_PACKED_ARRAY_TYPE_P
7876 (TREE_TYPE (TYPE_FIELDS (gnu_type))))
7877 && tree_int_cst_lt (size, old_size)))
7878 {
7879 if (Present (gnat_attr_node))
7880 post_error_ne_tree
7881 ("Value_Size for& too small{, minimum allowed is ^}",
7882 gnat_attr_node, gnat_entity, old_size);
7883 return;
7884 }
7885
7886 /* Otherwise, set the RM size proper for integral types... */
7887 if ((TREE_CODE (gnu_type) == INTEGER_TYPE
7888 && Is_Discrete_Or_Fixed_Point_Type (gnat_entity))
7889 || (TREE_CODE (gnu_type) == ENUMERAL_TYPE
7890 || TREE_CODE (gnu_type) == BOOLEAN_TYPE))
7891 SET_TYPE_RM_SIZE (gnu_type, size);
7892
7893 /* ...or the Ada size for record and union types. */
7894 else if (RECORD_OR_UNION_TYPE_P (gnu_type)
7895 && !TYPE_FAT_POINTER_P (gnu_type))
7896 SET_TYPE_ADA_SIZE (gnu_type, size);
7897 }
7898
7899 /* ALIGNMENT is a Uint giving the alignment specified for GNAT_ENTITY,
7900 a type or object whose present alignment is ALIGN. If this alignment is
7901 valid, return it. Otherwise, give an error and return ALIGN. */
7902
7903 static unsigned int
validate_alignment(Uint alignment,Entity_Id gnat_entity,unsigned int align)7904 validate_alignment (Uint alignment, Entity_Id gnat_entity, unsigned int align)
7905 {
7906 unsigned int max_allowed_alignment = get_target_maximum_allowed_alignment ();
7907 unsigned int new_align;
7908 Node_Id gnat_error_node;
7909
7910 /* Don't worry about checking alignment if alignment was not specified
7911 by the source program and we already posted an error for this entity. */
7912 if (Error_Posted (gnat_entity) && !Has_Alignment_Clause (gnat_entity))
7913 return align;
7914
7915 /* Post the error on the alignment clause if any. Note, for the implicit
7916 base type of an array type, the alignment clause is on the first
7917 subtype. */
7918 if (Present (Alignment_Clause (gnat_entity)))
7919 gnat_error_node = Expression (Alignment_Clause (gnat_entity));
7920
7921 else if (Is_Itype (gnat_entity)
7922 && Is_Array_Type (gnat_entity)
7923 && Etype (gnat_entity) == gnat_entity
7924 && Present (Alignment_Clause (First_Subtype (gnat_entity))))
7925 gnat_error_node =
7926 Expression (Alignment_Clause (First_Subtype (gnat_entity)));
7927
7928 else
7929 gnat_error_node = gnat_entity;
7930
7931 /* Within GCC, an alignment is an integer, so we must make sure a value is
7932 specified that fits in that range. Also, there is an upper bound to
7933 alignments we can support/allow. */
7934 if (!UI_Is_In_Int_Range (alignment)
7935 || ((new_align = UI_To_Int (alignment)) > max_allowed_alignment))
7936 post_error_ne_num ("largest supported alignment for& is ^",
7937 gnat_error_node, gnat_entity, max_allowed_alignment);
7938 else if (!(Present (Alignment_Clause (gnat_entity))
7939 && From_At_Mod (Alignment_Clause (gnat_entity)))
7940 && new_align * BITS_PER_UNIT < align)
7941 {
7942 unsigned int double_align;
7943 bool is_capped_double, align_clause;
7944
7945 /* If the default alignment of "double" or larger scalar types is
7946 specifically capped and the new alignment is above the cap, do
7947 not post an error and change the alignment only if there is an
7948 alignment clause; this makes it possible to have the associated
7949 GCC type overaligned by default for performance reasons. */
7950 if ((double_align = double_float_alignment) > 0)
7951 {
7952 Entity_Id gnat_type
7953 = Is_Type (gnat_entity) ? gnat_entity : Etype (gnat_entity);
7954 is_capped_double
7955 = is_double_float_or_array (gnat_type, &align_clause);
7956 }
7957 else if ((double_align = double_scalar_alignment) > 0)
7958 {
7959 Entity_Id gnat_type
7960 = Is_Type (gnat_entity) ? gnat_entity : Etype (gnat_entity);
7961 is_capped_double
7962 = is_double_scalar_or_array (gnat_type, &align_clause);
7963 }
7964 else
7965 is_capped_double = align_clause = false;
7966
7967 if (is_capped_double && new_align >= double_align)
7968 {
7969 if (align_clause)
7970 align = new_align * BITS_PER_UNIT;
7971 }
7972 else
7973 {
7974 if (is_capped_double)
7975 align = double_align * BITS_PER_UNIT;
7976
7977 post_error_ne_num ("alignment for& must be at least ^",
7978 gnat_error_node, gnat_entity,
7979 align / BITS_PER_UNIT);
7980 }
7981 }
7982 else
7983 {
7984 new_align = (new_align > 0 ? new_align * BITS_PER_UNIT : 1);
7985 if (new_align > align)
7986 align = new_align;
7987 }
7988
7989 return align;
7990 }
7991
7992 /* Verify that OBJECT, a type or decl, is something we can implement
7993 atomically. If not, give an error for GNAT_ENTITY. COMP_P is true
7994 if we require atomic components. */
7995
7996 static void
check_ok_for_atomic(tree object,Entity_Id gnat_entity,bool comp_p)7997 check_ok_for_atomic (tree object, Entity_Id gnat_entity, bool comp_p)
7998 {
7999 Node_Id gnat_error_point = gnat_entity;
8000 Node_Id gnat_node;
8001 enum machine_mode mode;
8002 unsigned int align;
8003 tree size;
8004
8005 /* There are three case of what OBJECT can be. It can be a type, in which
8006 case we take the size, alignment and mode from the type. It can be a
8007 declaration that was indirect, in which case the relevant values are
8008 that of the type being pointed to, or it can be a normal declaration,
8009 in which case the values are of the decl. The code below assumes that
8010 OBJECT is either a type or a decl. */
8011 if (TYPE_P (object))
8012 {
8013 /* If this is an anonymous base type, nothing to check. Error will be
8014 reported on the source type. */
8015 if (!Comes_From_Source (gnat_entity))
8016 return;
8017
8018 mode = TYPE_MODE (object);
8019 align = TYPE_ALIGN (object);
8020 size = TYPE_SIZE (object);
8021 }
8022 else if (DECL_BY_REF_P (object))
8023 {
8024 mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (object)));
8025 align = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (object)));
8026 size = TYPE_SIZE (TREE_TYPE (TREE_TYPE (object)));
8027 }
8028 else
8029 {
8030 mode = DECL_MODE (object);
8031 align = DECL_ALIGN (object);
8032 size = DECL_SIZE (object);
8033 }
8034
8035 /* Consider all floating-point types atomic and any types that that are
8036 represented by integers no wider than a machine word. */
8037 if (GET_MODE_CLASS (mode) == MODE_FLOAT
8038 || ((GET_MODE_CLASS (mode) == MODE_INT
8039 || GET_MODE_CLASS (mode) == MODE_PARTIAL_INT)
8040 && GET_MODE_BITSIZE (mode) <= BITS_PER_WORD))
8041 return;
8042
8043 /* For the moment, also allow anything that has an alignment equal
8044 to its size and which is smaller than a word. */
8045 if (size && TREE_CODE (size) == INTEGER_CST
8046 && compare_tree_int (size, align) == 0
8047 && align <= BITS_PER_WORD)
8048 return;
8049
8050 for (gnat_node = First_Rep_Item (gnat_entity); Present (gnat_node);
8051 gnat_node = Next_Rep_Item (gnat_node))
8052 {
8053 if (!comp_p && Nkind (gnat_node) == N_Pragma
8054 && (Get_Pragma_Id (Chars (Pragma_Identifier (gnat_node)))
8055 == Pragma_Atomic))
8056 gnat_error_point = First (Pragma_Argument_Associations (gnat_node));
8057 else if (comp_p && Nkind (gnat_node) == N_Pragma
8058 && (Get_Pragma_Id (Chars (Pragma_Identifier (gnat_node)))
8059 == Pragma_Atomic_Components))
8060 gnat_error_point = First (Pragma_Argument_Associations (gnat_node));
8061 }
8062
8063 if (comp_p)
8064 post_error_ne ("atomic access to component of & cannot be guaranteed",
8065 gnat_error_point, gnat_entity);
8066 else
8067 post_error_ne ("atomic access to & cannot be guaranteed",
8068 gnat_error_point, gnat_entity);
8069 }
8070
8071
8072 /* Helper for the intrin compatibility checks family. Evaluate whether
8073 two types are definitely incompatible. */
8074
8075 static bool
intrin_types_incompatible_p(tree t1,tree t2)8076 intrin_types_incompatible_p (tree t1, tree t2)
8077 {
8078 enum tree_code code;
8079
8080 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
8081 return false;
8082
8083 if (TYPE_MODE (t1) != TYPE_MODE (t2))
8084 return true;
8085
8086 if (TREE_CODE (t1) != TREE_CODE (t2))
8087 return true;
8088
8089 code = TREE_CODE (t1);
8090
8091 switch (code)
8092 {
8093 case INTEGER_TYPE:
8094 case REAL_TYPE:
8095 return TYPE_PRECISION (t1) != TYPE_PRECISION (t2);
8096
8097 case POINTER_TYPE:
8098 case REFERENCE_TYPE:
8099 /* Assume designated types are ok. We'd need to account for char * and
8100 void * variants to do better, which could rapidly get messy and isn't
8101 clearly worth the effort. */
8102 return false;
8103
8104 default:
8105 break;
8106 }
8107
8108 return false;
8109 }
8110
8111 /* Helper for intrin_profiles_compatible_p, to perform compatibility checks
8112 on the Ada/builtin argument lists for the INB binding. */
8113
8114 static bool
intrin_arglists_compatible_p(intrin_binding_t * inb)8115 intrin_arglists_compatible_p (intrin_binding_t * inb)
8116 {
8117 function_args_iterator ada_iter, btin_iter;
8118
8119 function_args_iter_init (&ada_iter, inb->ada_fntype);
8120 function_args_iter_init (&btin_iter, inb->btin_fntype);
8121
8122 /* Sequence position of the last argument we checked. */
8123 int argpos = 0;
8124
8125 while (1)
8126 {
8127 tree ada_type = function_args_iter_cond (&ada_iter);
8128 tree btin_type = function_args_iter_cond (&btin_iter);
8129
8130 /* If we've exhausted both lists simultaneously, we're done. */
8131 if (ada_type == NULL_TREE && btin_type == NULL_TREE)
8132 break;
8133
8134 /* If one list is shorter than the other, they fail to match. */
8135 if (ada_type == NULL_TREE || btin_type == NULL_TREE)
8136 return false;
8137
8138 /* If we're done with the Ada args and not with the internal builtin
8139 args, or the other way around, complain. */
8140 if (ada_type == void_type_node
8141 && btin_type != void_type_node)
8142 {
8143 post_error ("?Ada arguments list too short!", inb->gnat_entity);
8144 return false;
8145 }
8146
8147 if (btin_type == void_type_node
8148 && ada_type != void_type_node)
8149 {
8150 post_error_ne_num ("?Ada arguments list too long ('> ^)!",
8151 inb->gnat_entity, inb->gnat_entity, argpos);
8152 return false;
8153 }
8154
8155 /* Otherwise, check that types match for the current argument. */
8156 argpos ++;
8157 if (intrin_types_incompatible_p (ada_type, btin_type))
8158 {
8159 post_error_ne_num ("?intrinsic binding type mismatch on argument ^!",
8160 inb->gnat_entity, inb->gnat_entity, argpos);
8161 return false;
8162 }
8163
8164
8165 function_args_iter_next (&ada_iter);
8166 function_args_iter_next (&btin_iter);
8167 }
8168
8169 return true;
8170 }
8171
8172 /* Helper for intrin_profiles_compatible_p, to perform compatibility checks
8173 on the Ada/builtin return values for the INB binding. */
8174
8175 static bool
intrin_return_compatible_p(intrin_binding_t * inb)8176 intrin_return_compatible_p (intrin_binding_t * inb)
8177 {
8178 tree ada_return_type = TREE_TYPE (inb->ada_fntype);
8179 tree btin_return_type = TREE_TYPE (inb->btin_fntype);
8180
8181 /* Accept function imported as procedure, common and convenient. */
8182 if (VOID_TYPE_P (ada_return_type)
8183 && !VOID_TYPE_P (btin_return_type))
8184 return true;
8185
8186 /* If return type is Address (integer type), map it to void *. */
8187 if (Is_Descendent_Of_Address (Etype (inb->gnat_entity)))
8188 ada_return_type = ptr_void_type_node;
8189
8190 /* Check return types compatibility otherwise. Note that this
8191 handles void/void as well. */
8192 if (intrin_types_incompatible_p (btin_return_type, ada_return_type))
8193 {
8194 post_error ("?intrinsic binding type mismatch on return value!",
8195 inb->gnat_entity);
8196 return false;
8197 }
8198
8199 return true;
8200 }
8201
8202 /* Check and return whether the Ada and gcc builtin profiles bound by INB are
8203 compatible. Issue relevant warnings when they are not.
8204
8205 This is intended as a light check to diagnose the most obvious cases, not
8206 as a full fledged type compatibility predicate. It is the programmer's
8207 responsibility to ensure correctness of the Ada declarations in Imports,
8208 especially when binding straight to a compiler internal. */
8209
8210 static bool
intrin_profiles_compatible_p(intrin_binding_t * inb)8211 intrin_profiles_compatible_p (intrin_binding_t * inb)
8212 {
8213 /* Check compatibility on return values and argument lists, each responsible
8214 for posting warnings as appropriate. Ensure use of the proper sloc for
8215 this purpose. */
8216
8217 bool arglists_compatible_p, return_compatible_p;
8218 location_t saved_location = input_location;
8219
8220 Sloc_to_locus (Sloc (inb->gnat_entity), &input_location);
8221
8222 return_compatible_p = intrin_return_compatible_p (inb);
8223 arglists_compatible_p = intrin_arglists_compatible_p (inb);
8224
8225 input_location = saved_location;
8226
8227 return return_compatible_p && arglists_compatible_p;
8228 }
8229
8230 /* Return a FIELD_DECL node modeled on OLD_FIELD. FIELD_TYPE is its type
8231 and RECORD_TYPE is the type of the parent. If SIZE is nonzero, it is the
8232 specified size for this field. POS_LIST is a position list describing
8233 the layout of OLD_FIELD and SUBST_LIST a substitution list to be applied
8234 to this layout. */
8235
8236 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)8237 create_field_decl_from (tree old_field, tree field_type, tree record_type,
8238 tree size, tree pos_list,
8239 vec<subst_pair> subst_list)
8240 {
8241 tree t = TREE_VALUE (purpose_member (old_field, pos_list));
8242 tree pos = TREE_VEC_ELT (t, 0), bitpos = TREE_VEC_ELT (t, 2);
8243 unsigned int offset_align = tree_low_cst (TREE_VEC_ELT (t, 1), 1);
8244 tree new_pos, new_field;
8245 unsigned int i;
8246 subst_pair *s;
8247
8248 if (CONTAINS_PLACEHOLDER_P (pos))
8249 FOR_EACH_VEC_ELT (subst_list, i, s)
8250 pos = SUBSTITUTE_IN_EXPR (pos, s->discriminant, s->replacement);
8251
8252 /* If the position is now a constant, we can set it as the position of the
8253 field when we make it. Otherwise, we need to deal with it specially. */
8254 if (TREE_CONSTANT (pos))
8255 new_pos = bit_from_pos (pos, bitpos);
8256 else
8257 new_pos = NULL_TREE;
8258
8259 new_field
8260 = create_field_decl (DECL_NAME (old_field), field_type, record_type,
8261 size, new_pos, DECL_PACKED (old_field),
8262 !DECL_NONADDRESSABLE_P (old_field));
8263
8264 if (!new_pos)
8265 {
8266 normalize_offset (&pos, &bitpos, offset_align);
8267 DECL_FIELD_OFFSET (new_field) = pos;
8268 DECL_FIELD_BIT_OFFSET (new_field) = bitpos;
8269 SET_DECL_OFFSET_ALIGN (new_field, offset_align);
8270 DECL_SIZE (new_field) = size;
8271 DECL_SIZE_UNIT (new_field)
8272 = convert (sizetype,
8273 size_binop (CEIL_DIV_EXPR, size, bitsize_unit_node));
8274 layout_decl (new_field, DECL_OFFSET_ALIGN (new_field));
8275 }
8276
8277 DECL_INTERNAL_P (new_field) = DECL_INTERNAL_P (old_field);
8278 SET_DECL_ORIGINAL_FIELD_TO_FIELD (new_field, old_field);
8279 DECL_DISCRIMINANT_NUMBER (new_field) = DECL_DISCRIMINANT_NUMBER (old_field);
8280 TREE_THIS_VOLATILE (new_field) = TREE_THIS_VOLATILE (old_field);
8281
8282 return new_field;
8283 }
8284
8285 /* Create the REP part of RECORD_TYPE with REP_TYPE. If MIN_SIZE is nonzero,
8286 it is the minimal size the REP_PART must have. */
8287
8288 static tree
create_rep_part(tree rep_type,tree record_type,tree min_size)8289 create_rep_part (tree rep_type, tree record_type, tree min_size)
8290 {
8291 tree field;
8292
8293 if (min_size && !tree_int_cst_lt (TYPE_SIZE (rep_type), min_size))
8294 min_size = NULL_TREE;
8295
8296 field = create_field_decl (get_identifier ("REP"), rep_type, record_type,
8297 min_size, bitsize_zero_node, 0, 1);
8298 DECL_INTERNAL_P (field) = 1;
8299
8300 return field;
8301 }
8302
8303 /* Return the REP part of RECORD_TYPE, if any. Otherwise return NULL. */
8304
8305 static tree
get_rep_part(tree record_type)8306 get_rep_part (tree record_type)
8307 {
8308 tree field = TYPE_FIELDS (record_type);
8309
8310 /* The REP part is the first field, internal, another record, and its name
8311 starts with an 'R'. */
8312 if (field
8313 && DECL_INTERNAL_P (field)
8314 && TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE
8315 && IDENTIFIER_POINTER (DECL_NAME (field)) [0] == 'R')
8316 return field;
8317
8318 return NULL_TREE;
8319 }
8320
8321 /* Return the variant part of RECORD_TYPE, if any. Otherwise return NULL. */
8322
8323 tree
get_variant_part(tree record_type)8324 get_variant_part (tree record_type)
8325 {
8326 tree field;
8327
8328 /* The variant part is the only internal field that is a qualified union. */
8329 for (field = TYPE_FIELDS (record_type); field; field = DECL_CHAIN (field))
8330 if (DECL_INTERNAL_P (field)
8331 && TREE_CODE (TREE_TYPE (field)) == QUAL_UNION_TYPE)
8332 return field;
8333
8334 return NULL_TREE;
8335 }
8336
8337 /* Return a new variant part modeled on OLD_VARIANT_PART. VARIANT_LIST is
8338 the list of variants to be used and RECORD_TYPE is the type of the parent.
8339 POS_LIST is a position list describing the layout of fields present in
8340 OLD_VARIANT_PART and SUBST_LIST a substitution list to be applied to this
8341 layout. */
8342
8343 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)8344 create_variant_part_from (tree old_variant_part,
8345 vec<variant_desc> variant_list,
8346 tree record_type, tree pos_list,
8347 vec<subst_pair> subst_list)
8348 {
8349 tree offset = DECL_FIELD_OFFSET (old_variant_part);
8350 tree old_union_type = TREE_TYPE (old_variant_part);
8351 tree new_union_type, new_variant_part;
8352 tree union_field_list = NULL_TREE;
8353 variant_desc *v;
8354 unsigned int i;
8355
8356 /* First create the type of the variant part from that of the old one. */
8357 new_union_type = make_node (QUAL_UNION_TYPE);
8358 TYPE_NAME (new_union_type)
8359 = concat_name (TYPE_NAME (record_type),
8360 IDENTIFIER_POINTER (DECL_NAME (old_variant_part)));
8361
8362 /* If the position of the variant part is constant, subtract it from the
8363 size of the type of the parent to get the new size. This manual CSE
8364 reduces the code size when not optimizing. */
8365 if (TREE_CODE (offset) == INTEGER_CST)
8366 {
8367 tree bitpos = DECL_FIELD_BIT_OFFSET (old_variant_part);
8368 tree first_bit = bit_from_pos (offset, bitpos);
8369 TYPE_SIZE (new_union_type)
8370 = size_binop (MINUS_EXPR, TYPE_SIZE (record_type), first_bit);
8371 TYPE_SIZE_UNIT (new_union_type)
8372 = size_binop (MINUS_EXPR, TYPE_SIZE_UNIT (record_type),
8373 byte_from_pos (offset, bitpos));
8374 SET_TYPE_ADA_SIZE (new_union_type,
8375 size_binop (MINUS_EXPR, TYPE_ADA_SIZE (record_type),
8376 first_bit));
8377 TYPE_ALIGN (new_union_type) = TYPE_ALIGN (old_union_type);
8378 relate_alias_sets (new_union_type, old_union_type, ALIAS_SET_COPY);
8379 }
8380 else
8381 copy_and_substitute_in_size (new_union_type, old_union_type, subst_list);
8382
8383 /* Now finish up the new variants and populate the union type. */
8384 FOR_EACH_VEC_ELT_REVERSE (variant_list, i, v)
8385 {
8386 tree old_field = v->field, new_field;
8387 tree old_variant, old_variant_subpart, new_variant, field_list;
8388
8389 /* Skip variants that don't belong to this nesting level. */
8390 if (DECL_CONTEXT (old_field) != old_union_type)
8391 continue;
8392
8393 /* Retrieve the list of fields already added to the new variant. */
8394 new_variant = v->new_type;
8395 field_list = TYPE_FIELDS (new_variant);
8396
8397 /* If the old variant had a variant subpart, we need to create a new
8398 variant subpart and add it to the field list. */
8399 old_variant = v->type;
8400 old_variant_subpart = get_variant_part (old_variant);
8401 if (old_variant_subpart)
8402 {
8403 tree new_variant_subpart
8404 = create_variant_part_from (old_variant_subpart, variant_list,
8405 new_variant, pos_list, subst_list);
8406 DECL_CHAIN (new_variant_subpart) = field_list;
8407 field_list = new_variant_subpart;
8408 }
8409
8410 /* Finish up the new variant and create the field. No need for debug
8411 info thanks to the XVS type. */
8412 finish_record_type (new_variant, nreverse (field_list), 2, false);
8413 compute_record_mode (new_variant);
8414 create_type_decl (TYPE_NAME (new_variant), new_variant, NULL,
8415 true, false, Empty);
8416
8417 new_field
8418 = create_field_decl_from (old_field, new_variant, new_union_type,
8419 TYPE_SIZE (new_variant),
8420 pos_list, subst_list);
8421 DECL_QUALIFIER (new_field) = v->qual;
8422 DECL_INTERNAL_P (new_field) = 1;
8423 DECL_CHAIN (new_field) = union_field_list;
8424 union_field_list = new_field;
8425 }
8426
8427 /* Finish up the union type and create the variant part. No need for debug
8428 info thanks to the XVS type. Note that we don't reverse the field list
8429 because VARIANT_LIST has been traversed in reverse order. */
8430 finish_record_type (new_union_type, union_field_list, 2, false);
8431 compute_record_mode (new_union_type);
8432 create_type_decl (TYPE_NAME (new_union_type), new_union_type, NULL,
8433 true, false, Empty);
8434
8435 new_variant_part
8436 = create_field_decl_from (old_variant_part, new_union_type, record_type,
8437 TYPE_SIZE (new_union_type),
8438 pos_list, subst_list);
8439 DECL_INTERNAL_P (new_variant_part) = 1;
8440
8441 /* With multiple discriminants it is possible for an inner variant to be
8442 statically selected while outer ones are not; in this case, the list
8443 of fields of the inner variant is not flattened and we end up with a
8444 qualified union with a single member. Drop the useless container. */
8445 if (!DECL_CHAIN (union_field_list))
8446 {
8447 DECL_CONTEXT (union_field_list) = record_type;
8448 DECL_FIELD_OFFSET (union_field_list)
8449 = DECL_FIELD_OFFSET (new_variant_part);
8450 DECL_FIELD_BIT_OFFSET (union_field_list)
8451 = DECL_FIELD_BIT_OFFSET (new_variant_part);
8452 SET_DECL_OFFSET_ALIGN (union_field_list,
8453 DECL_OFFSET_ALIGN (new_variant_part));
8454 new_variant_part = union_field_list;
8455 }
8456
8457 return new_variant_part;
8458 }
8459
8460 /* Copy the size (and alignment and alias set) from OLD_TYPE to NEW_TYPE,
8461 which are both RECORD_TYPE, after applying the substitutions described
8462 in SUBST_LIST. */
8463
8464 static void
copy_and_substitute_in_size(tree new_type,tree old_type,vec<subst_pair> subst_list)8465 copy_and_substitute_in_size (tree new_type, tree old_type,
8466 vec<subst_pair> subst_list)
8467 {
8468 unsigned int i;
8469 subst_pair *s;
8470
8471 TYPE_SIZE (new_type) = TYPE_SIZE (old_type);
8472 TYPE_SIZE_UNIT (new_type) = TYPE_SIZE_UNIT (old_type);
8473 SET_TYPE_ADA_SIZE (new_type, TYPE_ADA_SIZE (old_type));
8474 TYPE_ALIGN (new_type) = TYPE_ALIGN (old_type);
8475 relate_alias_sets (new_type, old_type, ALIAS_SET_COPY);
8476
8477 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (new_type)))
8478 FOR_EACH_VEC_ELT (subst_list, i, s)
8479 TYPE_SIZE (new_type)
8480 = SUBSTITUTE_IN_EXPR (TYPE_SIZE (new_type),
8481 s->discriminant, s->replacement);
8482
8483 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE_UNIT (new_type)))
8484 FOR_EACH_VEC_ELT (subst_list, i, s)
8485 TYPE_SIZE_UNIT (new_type)
8486 = SUBSTITUTE_IN_EXPR (TYPE_SIZE_UNIT (new_type),
8487 s->discriminant, s->replacement);
8488
8489 if (CONTAINS_PLACEHOLDER_P (TYPE_ADA_SIZE (new_type)))
8490 FOR_EACH_VEC_ELT (subst_list, i, s)
8491 SET_TYPE_ADA_SIZE
8492 (new_type, SUBSTITUTE_IN_EXPR (TYPE_ADA_SIZE (new_type),
8493 s->discriminant, s->replacement));
8494
8495 /* Finalize the size. */
8496 TYPE_SIZE (new_type) = variable_size (TYPE_SIZE (new_type));
8497 TYPE_SIZE_UNIT (new_type) = variable_size (TYPE_SIZE_UNIT (new_type));
8498 }
8499
8500 /* Given a type T, a FIELD_DECL F, and a replacement value R, return a
8501 type with all size expressions that contain F in a PLACEHOLDER_EXPR
8502 updated by replacing F with R.
8503
8504 The function doesn't update the layout of the type, i.e. it assumes
8505 that the substitution is purely formal. That's why the replacement
8506 value R must itself contain a PLACEHOLDER_EXPR. */
8507
8508 tree
substitute_in_type(tree t,tree f,tree r)8509 substitute_in_type (tree t, tree f, tree r)
8510 {
8511 tree nt;
8512
8513 gcc_assert (CONTAINS_PLACEHOLDER_P (r));
8514
8515 switch (TREE_CODE (t))
8516 {
8517 case INTEGER_TYPE:
8518 case ENUMERAL_TYPE:
8519 case BOOLEAN_TYPE:
8520 case REAL_TYPE:
8521
8522 /* First the domain types of arrays. */
8523 if (CONTAINS_PLACEHOLDER_P (TYPE_GCC_MIN_VALUE (t))
8524 || CONTAINS_PLACEHOLDER_P (TYPE_GCC_MAX_VALUE (t)))
8525 {
8526 tree low = SUBSTITUTE_IN_EXPR (TYPE_GCC_MIN_VALUE (t), f, r);
8527 tree high = SUBSTITUTE_IN_EXPR (TYPE_GCC_MAX_VALUE (t), f, r);
8528
8529 if (low == TYPE_GCC_MIN_VALUE (t) && high == TYPE_GCC_MAX_VALUE (t))
8530 return t;
8531
8532 nt = copy_type (t);
8533 TYPE_GCC_MIN_VALUE (nt) = low;
8534 TYPE_GCC_MAX_VALUE (nt) = high;
8535
8536 if (TREE_CODE (t) == INTEGER_TYPE && TYPE_INDEX_TYPE (t))
8537 SET_TYPE_INDEX_TYPE
8538 (nt, substitute_in_type (TYPE_INDEX_TYPE (t), f, r));
8539
8540 return nt;
8541 }
8542
8543 /* Then the subtypes. */
8544 if (CONTAINS_PLACEHOLDER_P (TYPE_RM_MIN_VALUE (t))
8545 || CONTAINS_PLACEHOLDER_P (TYPE_RM_MAX_VALUE (t)))
8546 {
8547 tree low = SUBSTITUTE_IN_EXPR (TYPE_RM_MIN_VALUE (t), f, r);
8548 tree high = SUBSTITUTE_IN_EXPR (TYPE_RM_MAX_VALUE (t), f, r);
8549
8550 if (low == TYPE_RM_MIN_VALUE (t) && high == TYPE_RM_MAX_VALUE (t))
8551 return t;
8552
8553 nt = copy_type (t);
8554 SET_TYPE_RM_MIN_VALUE (nt, low);
8555 SET_TYPE_RM_MAX_VALUE (nt, high);
8556
8557 return nt;
8558 }
8559
8560 return t;
8561
8562 case COMPLEX_TYPE:
8563 nt = substitute_in_type (TREE_TYPE (t), f, r);
8564 if (nt == TREE_TYPE (t))
8565 return t;
8566
8567 return build_complex_type (nt);
8568
8569 case FUNCTION_TYPE:
8570 /* These should never show up here. */
8571 gcc_unreachable ();
8572
8573 case ARRAY_TYPE:
8574 {
8575 tree component = substitute_in_type (TREE_TYPE (t), f, r);
8576 tree domain = substitute_in_type (TYPE_DOMAIN (t), f, r);
8577
8578 if (component == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
8579 return t;
8580
8581 nt = build_nonshared_array_type (component, domain);
8582 TYPE_ALIGN (nt) = TYPE_ALIGN (t);
8583 TYPE_USER_ALIGN (nt) = TYPE_USER_ALIGN (t);
8584 SET_TYPE_MODE (nt, TYPE_MODE (t));
8585 TYPE_SIZE (nt) = SUBSTITUTE_IN_EXPR (TYPE_SIZE (t), f, r);
8586 TYPE_SIZE_UNIT (nt) = SUBSTITUTE_IN_EXPR (TYPE_SIZE_UNIT (t), f, r);
8587 TYPE_NONALIASED_COMPONENT (nt) = TYPE_NONALIASED_COMPONENT (t);
8588 TYPE_MULTI_ARRAY_P (nt) = TYPE_MULTI_ARRAY_P (t);
8589 TYPE_CONVENTION_FORTRAN_P (nt) = TYPE_CONVENTION_FORTRAN_P (t);
8590 return nt;
8591 }
8592
8593 case RECORD_TYPE:
8594 case UNION_TYPE:
8595 case QUAL_UNION_TYPE:
8596 {
8597 bool changed_field = false;
8598 tree field;
8599
8600 /* Start out with no fields, make new fields, and chain them
8601 in. If we haven't actually changed the type of any field,
8602 discard everything we've done and return the old type. */
8603 nt = copy_type (t);
8604 TYPE_FIELDS (nt) = NULL_TREE;
8605
8606 for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field))
8607 {
8608 tree new_field = copy_node (field), new_n;
8609
8610 new_n = substitute_in_type (TREE_TYPE (field), f, r);
8611 if (new_n != TREE_TYPE (field))
8612 {
8613 TREE_TYPE (new_field) = new_n;
8614 changed_field = true;
8615 }
8616
8617 new_n = SUBSTITUTE_IN_EXPR (DECL_FIELD_OFFSET (field), f, r);
8618 if (new_n != DECL_FIELD_OFFSET (field))
8619 {
8620 DECL_FIELD_OFFSET (new_field) = new_n;
8621 changed_field = true;
8622 }
8623
8624 /* Do the substitution inside the qualifier, if any. */
8625 if (TREE_CODE (t) == QUAL_UNION_TYPE)
8626 {
8627 new_n = SUBSTITUTE_IN_EXPR (DECL_QUALIFIER (field), f, r);
8628 if (new_n != DECL_QUALIFIER (field))
8629 {
8630 DECL_QUALIFIER (new_field) = new_n;
8631 changed_field = true;
8632 }
8633 }
8634
8635 DECL_CONTEXT (new_field) = nt;
8636 SET_DECL_ORIGINAL_FIELD_TO_FIELD (new_field, field);
8637
8638 DECL_CHAIN (new_field) = TYPE_FIELDS (nt);
8639 TYPE_FIELDS (nt) = new_field;
8640 }
8641
8642 if (!changed_field)
8643 return t;
8644
8645 TYPE_FIELDS (nt) = nreverse (TYPE_FIELDS (nt));
8646 TYPE_SIZE (nt) = SUBSTITUTE_IN_EXPR (TYPE_SIZE (t), f, r);
8647 TYPE_SIZE_UNIT (nt) = SUBSTITUTE_IN_EXPR (TYPE_SIZE_UNIT (t), f, r);
8648 SET_TYPE_ADA_SIZE (nt, SUBSTITUTE_IN_EXPR (TYPE_ADA_SIZE (t), f, r));
8649 return nt;
8650 }
8651
8652 default:
8653 return t;
8654 }
8655 }
8656
8657 /* Return the RM size of GNU_TYPE. This is the actual number of bits
8658 needed to represent the object. */
8659
8660 tree
rm_size(tree gnu_type)8661 rm_size (tree gnu_type)
8662 {
8663 /* For integral types, we store the RM size explicitly. */
8664 if (INTEGRAL_TYPE_P (gnu_type) && TYPE_RM_SIZE (gnu_type))
8665 return TYPE_RM_SIZE (gnu_type);
8666
8667 /* Return the RM size of the actual data plus the size of the template. */
8668 if (TREE_CODE (gnu_type) == RECORD_TYPE
8669 && TYPE_CONTAINS_TEMPLATE_P (gnu_type))
8670 return
8671 size_binop (PLUS_EXPR,
8672 rm_size (TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (gnu_type)))),
8673 DECL_SIZE (TYPE_FIELDS (gnu_type)));
8674
8675 /* For record or union types, we store the size explicitly. */
8676 if (RECORD_OR_UNION_TYPE_P (gnu_type)
8677 && !TYPE_FAT_POINTER_P (gnu_type)
8678 && TYPE_ADA_SIZE (gnu_type))
8679 return TYPE_ADA_SIZE (gnu_type);
8680
8681 /* For other types, this is just the size. */
8682 return TYPE_SIZE (gnu_type);
8683 }
8684
8685 /* Return the name to be used for GNAT_ENTITY. If a type, create a
8686 fully-qualified name, possibly with type information encoding.
8687 Otherwise, return the name. */
8688
8689 tree
get_entity_name(Entity_Id gnat_entity)8690 get_entity_name (Entity_Id gnat_entity)
8691 {
8692 Get_Encoded_Name (gnat_entity);
8693 return get_identifier_with_length (Name_Buffer, Name_Len);
8694 }
8695
8696 /* Return an identifier representing the external name to be used for
8697 GNAT_ENTITY. If SUFFIX is specified, the name is followed by "___"
8698 and the specified suffix. */
8699
8700 tree
create_concat_name(Entity_Id gnat_entity,const char * suffix)8701 create_concat_name (Entity_Id gnat_entity, const char *suffix)
8702 {
8703 Entity_Kind kind = Ekind (gnat_entity);
8704
8705 if (suffix)
8706 {
8707 String_Template temp = {1, (int) strlen (suffix)};
8708 Fat_Pointer fp = {suffix, &temp};
8709 Get_External_Name_With_Suffix (gnat_entity, fp);
8710 }
8711 else
8712 Get_External_Name (gnat_entity, 0);
8713
8714 /* A variable using the Stdcall convention lives in a DLL. We adjust
8715 its name to use the jump table, the _imp__NAME contains the address
8716 for the NAME variable. */
8717 if ((kind == E_Variable || kind == E_Constant)
8718 && Has_Stdcall_Convention (gnat_entity))
8719 {
8720 const int len = 6 + Name_Len;
8721 char *new_name = (char *) alloca (len + 1);
8722 strcpy (new_name, "_imp__");
8723 strcat (new_name, Name_Buffer);
8724 return get_identifier_with_length (new_name, len);
8725 }
8726
8727 return get_identifier_with_length (Name_Buffer, Name_Len);
8728 }
8729
8730 /* Given GNU_NAME, an IDENTIFIER_NODE containing a name and SUFFIX, a
8731 string, return a new IDENTIFIER_NODE that is the concatenation of
8732 the name followed by "___" and the specified suffix. */
8733
8734 tree
concat_name(tree gnu_name,const char * suffix)8735 concat_name (tree gnu_name, const char *suffix)
8736 {
8737 const int len = IDENTIFIER_LENGTH (gnu_name) + 3 + strlen (suffix);
8738 char *new_name = (char *) alloca (len + 1);
8739 strcpy (new_name, IDENTIFIER_POINTER (gnu_name));
8740 strcat (new_name, "___");
8741 strcat (new_name, suffix);
8742 return get_identifier_with_length (new_name, len);
8743 }
8744
8745 #include "gt-ada-decl.h"
8746