projects / gcc.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
history | raw | HEAD
re PR ada/26096 (Ada bootstrap fails in g-alleve.adb)
[gcc.git] / gcc / ada / decl.c
1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * D E C L *
6 * *
7 * C Implementation File *
8 * *
9 * Copyright (C) 1992-2006, 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 2, 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 distributed with GNAT; see file COPYING. If not, write *
19 * to the Free Software Foundation, 51 Franklin Street, Fifth Floor, *
20 * Boston, MA 02110-1301, USA. *
21 * *
22 * GNAT was originally developed by the GNAT team at New York University. *
23 * Extensive contributions were provided by Ada Core Technologies Inc. *
24 * *
25 ****************************************************************************/
26
27 #include "config.h"
28 #include "system.h"
29 #include "coretypes.h"
30 #include "tm.h"
31 #include "tree.h"
32 #include "flags.h"
33 #include "toplev.h"
34 #include "convert.h"
35 #include "ggc.h"
36 #include "obstack.h"
37 #include "target.h"
38 #include "expr.h"
39
40 #include "ada.h"
41 #include "types.h"
42 #include "atree.h"
43 #include "elists.h"
44 #include "namet.h"
45 #include "nlists.h"
46 #include "repinfo.h"
47 #include "snames.h"
48 #include "stringt.h"
49 #include "uintp.h"
50 #include "fe.h"
51 #include "sinfo.h"
52 #include "einfo.h"
53 #include "ada-tree.h"
54 #include "gigi.h"
55
56 /* Convention_Stdcall should be processed in a specific way on Windows targets
57 only. The macro below is a helper to avoid having to check for a Windows
58 specific attribute throughout this unit. */
59
60 #if TARGET_DLLIMPORT_DECL_ATTRIBUTES
61 #define Has_Stdcall_Convention(E) (Convention (E) == Convention_Stdcall)
62 #else
63 #define Has_Stdcall_Convention(E) (0)
64 #endif
65
66 /* These two variables are used to defer recursively expanding incomplete
67 types while we are processing a record or subprogram type. */
68
69 static int defer_incomplete_level = 0;
70 static struct incomplete
71 {
72 struct incomplete *next;
73 tree old_type;
74 Entity_Id full_type;
75 } *defer_incomplete_list = 0;
76
77 /* These two variables are used to defer emission of debug information for
78 nested incomplete record types */
79
80 static int defer_debug_level = 0;
81 static tree defer_debug_incomplete_list;
82
83 static void copy_alias_set (tree, tree);
84 static tree substitution_list (Entity_Id, Entity_Id, tree, bool);
85 static bool allocatable_size_p (tree, bool);
86 static void prepend_attributes (Entity_Id, struct attrib **);
87 static tree elaborate_expression (Node_Id, Entity_Id, tree, bool, bool, bool);
88 static bool is_variable_size (tree);
89 static tree elaborate_expression_1 (Node_Id, Entity_Id, tree, tree,
90 bool, bool);
91 static tree make_packable_type (tree);
92 static tree gnat_to_gnu_field (Entity_Id, tree, int, bool);
93 static void components_to_record (tree, Node_Id, tree, int, bool, tree *,
94 bool, bool, bool, bool);
95 static int compare_field_bitpos (const PTR, const PTR);
96 static Uint annotate_value (tree);
97 static void annotate_rep (Entity_Id, tree);
98 static tree compute_field_positions (tree, tree, tree, tree, unsigned int);
99 static tree validate_size (Uint, tree, Entity_Id, enum tree_code, bool, bool);
100 static void set_rm_size (Uint, tree, Entity_Id);
101 static tree make_type_from_size (tree, tree, bool);
102 static unsigned int validate_alignment (Uint, Entity_Id, unsigned int);
103 static void check_ok_for_atomic (tree, Entity_Id, bool);
104 static int compatible_signatures_p (tree ftype1, tree ftype2);
105
106 /* Given GNAT_ENTITY, an entity in the incoming GNAT tree, return a
107 GCC type corresponding to that entity. GNAT_ENTITY is assumed to
108 refer to an Ada type. */
109
110 tree
111 gnat_to_gnu_type (Entity_Id gnat_entity)
112 {
113 tree gnu_decl;
114
115 /* The back end never attempts to annotate generic types */
116 if (Is_Generic_Type (gnat_entity) && type_annotate_only)
117 return void_type_node;
118
119 /* Convert the ada entity type into a GCC TYPE_DECL node. */
120 gnu_decl = gnat_to_gnu_entity (gnat_entity, NULL_TREE, 0);
121 gcc_assert (TREE_CODE (gnu_decl) == TYPE_DECL);
122 return TREE_TYPE (gnu_decl);
123 }
124 \f
125 /* Given GNAT_ENTITY, a GNAT defining identifier node, which denotes some Ada
126 entity, this routine returns the equivalent GCC tree for that entity
127 (an ..._DECL node) and associates the ..._DECL node with the input GNAT
128 defining identifier.
129
130 If GNAT_ENTITY is a variable or a constant declaration, GNU_EXPR gives its
131 initial value (in GCC tree form). This is optional for variables.
132 For renamed entities, GNU_EXPR gives the object being renamed.
133
134 DEFINITION is nonzero if this call is intended for a definition. This is
135 used for separate compilation where it necessary to know whether an
136 external declaration or a definition should be created if the GCC equivalent
137 was not created previously. The value of 1 is normally used for a non-zero
138 DEFINITION, but a value of 2 is used in special circumstances, defined in
139 the code. */
140
141 tree
142 gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition)
143 {
144 tree gnu_entity_id;
145 tree gnu_type = NULL_TREE;
146 /* Contains the gnu XXXX_DECL tree node which is equivalent to the input
147 GNAT tree. This node will be associated with the GNAT node by calling
148 the save_gnu_tree routine at the end of the `switch' statement. */
149 tree gnu_decl = NULL_TREE;
150 /* true if we have already saved gnu_decl as a gnat association. */
151 bool saved = false;
152 /* Nonzero if we incremented defer_incomplete_level. */
153 bool this_deferred = false;
154 /* Nonzero if we incremented defer_debug_level. */
155 bool debug_deferred = false;
156 /* Nonzero if we incremented force_global. */
157 bool this_global = false;
158 /* Nonzero if we should check to see if elaborated during processing. */
159 bool maybe_present = false;
160 /* Nonzero if we made GNU_DECL and its type here. */
161 bool this_made_decl = false;
162 struct attrib *attr_list = NULL;
163 bool debug_info_p = (Needs_Debug_Info (gnat_entity)
164 || debug_info_level == DINFO_LEVEL_VERBOSE);
165 Entity_Kind kind = Ekind (gnat_entity);
166 Entity_Id gnat_temp;
167 unsigned int esize
168 = ((Known_Esize (gnat_entity)
169 && UI_Is_In_Int_Range (Esize (gnat_entity)))
170 ? MIN (UI_To_Int (Esize (gnat_entity)),
171 IN (kind, Float_Kind)
172 ? fp_prec_to_size (LONG_DOUBLE_TYPE_SIZE)
173 : IN (kind, Access_Kind) ? POINTER_SIZE * 2
174 : LONG_LONG_TYPE_SIZE)
175 : LONG_LONG_TYPE_SIZE);
176 tree gnu_size = 0;
177 bool imported_p
178 = ((Is_Imported (gnat_entity) && No (Address_Clause (gnat_entity)))
179 || From_With_Type (gnat_entity));
180 unsigned int align = 0;
181
182 /* Since a use of an Itype is a definition, process it as such if it
183 is not in a with'ed unit. */
184
185 if (!definition && Is_Itype (gnat_entity)
186 && !present_gnu_tree (gnat_entity)
187 && In_Extended_Main_Code_Unit (gnat_entity))
188 {
189 /* Ensure that we are in a subprogram mentioned in the Scope
190 chain of this entity, our current scope is global,
191 or that we encountered a task or entry (where we can't currently
192 accurately check scoping). */
193 if (!current_function_decl
194 || DECL_ELABORATION_PROC_P (current_function_decl))
195 {
196 process_type (gnat_entity);
197 return get_gnu_tree (gnat_entity);
198 }
199
200 for (gnat_temp = Scope (gnat_entity);
201 Present (gnat_temp); gnat_temp = Scope (gnat_temp))
202 {
203 if (Is_Type (gnat_temp))
204 gnat_temp = Underlying_Type (gnat_temp);
205
206 if (Ekind (gnat_temp) == E_Subprogram_Body)
207 gnat_temp
208 = Corresponding_Spec (Parent (Declaration_Node (gnat_temp)));
209
210 if (IN (Ekind (gnat_temp), Subprogram_Kind)
211 && Present (Protected_Body_Subprogram (gnat_temp)))
212 gnat_temp = Protected_Body_Subprogram (gnat_temp);
213
214 if (Ekind (gnat_temp) == E_Entry
215 || Ekind (gnat_temp) == E_Entry_Family
216 || Ekind (gnat_temp) == E_Task_Type
217 || (IN (Ekind (gnat_temp), Subprogram_Kind)
218 && present_gnu_tree (gnat_temp)
219 && (current_function_decl
220 == gnat_to_gnu_entity (gnat_temp, NULL_TREE, 0))))
221 {
222 process_type (gnat_entity);
223 return get_gnu_tree (gnat_entity);
224 }
225 }
226
227 /* This abort means the entity "gnat_entity" has an incorrect scope,
228 i.e. that its scope does not correspond to the subprogram in which
229 it is declared */
230 gcc_unreachable ();
231 }
232
233 /* If this is entity 0, something went badly wrong. */
234 gcc_assert (Present (gnat_entity));
235
236 /* If we've already processed this entity, return what we got last time.
237 If we are defining the node, we should not have already processed it.
238 In that case, we will abort below when we try to save a new GCC tree for
239 this object. We also need to handle the case of getting a dummy type
240 when a Full_View exists. */
241
242 if (present_gnu_tree (gnat_entity)
243 && (! definition
244 || (Is_Type (gnat_entity) && imported_p)))
245 {
246 gnu_decl = get_gnu_tree (gnat_entity);
247
248 if (TREE_CODE (gnu_decl) == TYPE_DECL
249 && TYPE_IS_DUMMY_P (TREE_TYPE (gnu_decl))
250 && IN (kind, Incomplete_Or_Private_Kind)
251 && Present (Full_View (gnat_entity)))
252 {
253 gnu_decl = gnat_to_gnu_entity (Full_View (gnat_entity),
254 NULL_TREE, 0);
255
256 save_gnu_tree (gnat_entity, NULL_TREE, false);
257 save_gnu_tree (gnat_entity, gnu_decl, false);
258 }
259
260 return gnu_decl;
261 }
262
263 /* If this is a numeric or enumeral type, or an access type, a nonzero
264 Esize must be specified unless it was specified by the programmer. */
265 gcc_assert (!Unknown_Esize (gnat_entity)
266 || Has_Size_Clause (gnat_entity)
267 || (!IN (kind, Numeric_Kind) && !IN (kind, Enumeration_Kind)
268 && (!IN (kind, Access_Kind)
269 || kind == E_Access_Protected_Subprogram_Type
270 || kind == E_Access_Subtype)));
271
272 /* Likewise, RM_Size must be specified for all discrete and fixed-point
273 types. */
274 gcc_assert (!IN (kind, Discrete_Or_Fixed_Point_Kind)
275 || !Unknown_RM_Size (gnat_entity));
276
277 /* Get the name of the entity and set up the line number and filename of
278 the original definition for use in any decl we make. */
279 gnu_entity_id = get_entity_name (gnat_entity);
280 Sloc_to_locus (Sloc (gnat_entity), &input_location);
281
282 /* If we get here, it means we have not yet done anything with this
283 entity. If we are not defining it here, it must be external,
284 otherwise we should have defined it already. */
285 gcc_assert (definition || Is_Public (gnat_entity) || type_annotate_only
286 || kind == E_Discriminant || kind == E_Component
287 || kind == E_Label
288 || (kind == E_Constant && Present (Full_View (gnat_entity)))
289 || IN (kind, Type_Kind));
290
291 /* For cases when we are not defining (i.e., we are referencing from
292 another compilation unit) Public entities, show we are at global level
293 for the purpose of computing scopes. Don't do this for components or
294 discriminants since the relevant test is whether or not the record is
295 being defined. But do this for Imported functions or procedures in
296 all cases. */
297 if ((!definition && Is_Public (gnat_entity)
298 && !Is_Statically_Allocated (gnat_entity)
299 && kind != E_Discriminant && kind != E_Component)
300 || (Is_Imported (gnat_entity)
301 && (kind == E_Function || kind == E_Procedure)))
302 force_global++, this_global = true;
303
304 /* Handle any attributes directly attached to the entity. */
305 if (Has_Gigi_Rep_Item (gnat_entity))
306 prepend_attributes (gnat_entity, &attr_list);
307
308 /* Machine_Attributes on types are expected to be propagated to subtypes.
309 The corresponding Gigi_Rep_Items are only attached to the first subtype
310 though, so we handle the propagation here. */
311 if (Is_Type (gnat_entity) && Base_Type (gnat_entity) != gnat_entity
312 && !Is_First_Subtype (gnat_entity)
313 && Has_Gigi_Rep_Item (First_Subtype (Base_Type (gnat_entity))))
314 prepend_attributes (First_Subtype (Base_Type (gnat_entity)), &attr_list);
315
316 switch (kind)
317 {
318 case E_Constant:
319 /* If this is a use of a deferred constant, get its full
320 declaration. */
321 if (!definition && Present (Full_View (gnat_entity)))
322 {
323 gnu_decl = gnat_to_gnu_entity (Full_View (gnat_entity),
324 gnu_expr, definition);
325 saved = true;
326 break;
327 }
328
329 /* If we have an external constant that we are not defining,
330 get the expression that is was defined to represent. We
331 may throw that expression away later if it is not a
332 constant.
333 Do not retrieve the expression if it is an aggregate, because
334 in complex instantiation contexts it may not be expanded */
335
336 if (!definition
337 && Present (Expression (Declaration_Node (gnat_entity)))
338 && !No_Initialization (Declaration_Node (gnat_entity))
339 && (Nkind (Expression (Declaration_Node (gnat_entity)))
340 != N_Aggregate))
341 gnu_expr = gnat_to_gnu (Expression (Declaration_Node (gnat_entity)));
342
343 /* Ignore deferred constant definitions; they are processed fully in the
344 front-end. For deferred constant references, get the full
345 definition. On the other hand, constants that are renamings are
346 handled like variable renamings. If No_Initialization is set, this is
347 not a deferred constant but a constant whose value is built
348 manually. */
349
350 if (definition && !gnu_expr
351 && !No_Initialization (Declaration_Node (gnat_entity))
352 && No (Renamed_Object (gnat_entity)))
353 {
354 gnu_decl = error_mark_node;
355 saved = true;
356 break;
357 }
358 else if (!definition && IN (kind, Incomplete_Or_Private_Kind)
359 && Present (Full_View (gnat_entity)))
360 {
361 gnu_decl = gnat_to_gnu_entity (Full_View (gnat_entity),
362 NULL_TREE, 0);
363 saved = true;
364 break;
365 }
366
367 goto object;
368
369 case E_Exception:
370 /* We used to special case VMS exceptions here to directly map them to
371 their associated condition code. Since this code had to be masked
372 dynamically to strip off the severity bits, this caused trouble in
373 the GCC/ZCX case because the "type" pointers we store in the tables
374 have to be static. We now don't special case here anymore, and let
375 the regular processing take place, which leaves us with a regular
376 exception data object for VMS exceptions too. The condition code
377 mapping is taken care of by the front end and the bitmasking by the
378 runtime library. */
379 goto object;
380
381 case E_Discriminant:
382 case E_Component:
383 {
384 /* The GNAT record where the component was defined. */
385 Entity_Id gnat_record = Underlying_Type (Scope (gnat_entity));
386
387 /* If the variable is an inherited record component (in the case of
388 extended record types), just return the inherited entity, which
389 must be a FIELD_DECL. Likewise for discriminants.
390 For discriminants of untagged records which have explicit
391 stored discriminants, return the entity for the corresponding
392 stored discriminant. Also use Original_Record_Component
393 if the record has a private extension. */
394
395 if (Present (Original_Record_Component (gnat_entity))
396 && Original_Record_Component (gnat_entity) != gnat_entity)
397 {
398 gnu_decl
399 = gnat_to_gnu_entity (Original_Record_Component (gnat_entity),
400 gnu_expr, definition);
401 saved = true;
402 break;
403 }
404
405 /* If the enclosing record has explicit stored discriminants,
406 then it is an untagged record. If the Corresponding_Discriminant
407 is not empty then this must be a renamed discriminant and its
408 Original_Record_Component must point to the corresponding explicit
409 stored discriminant (i.e., we should have taken the previous
410 branch). */
411
412 else if (Present (Corresponding_Discriminant (gnat_entity))
413 && Is_Tagged_Type (gnat_record))
414 {
415 /* A tagged record has no explicit stored discriminants. */
416
417 gcc_assert (First_Discriminant (gnat_record)
418 == First_Stored_Discriminant (gnat_record));
419 gnu_decl
420 = gnat_to_gnu_entity (Corresponding_Discriminant (gnat_entity),
421 gnu_expr, definition);
422 saved = true;
423 break;
424 }
425
426 /* If the enclosing record has explicit stored discriminants,
427 then it is an untagged record. If the Corresponding_Discriminant
428 is not empty then this must be a renamed discriminant and its
429 Original_Record_Component must point to the corresponding explicit
430 stored discriminant (i.e., we should have taken the first
431 branch). */
432
433 else if (Present (Corresponding_Discriminant (gnat_entity))
434 && (First_Discriminant (gnat_record)
435 != First_Stored_Discriminant (gnat_record)))
436 gcc_unreachable ();
437
438 /* Otherwise, if we are not defining this and we have no GCC type
439 for the containing record, make one for it. Then we should
440 have made our own equivalent. */
441 else if (!definition && !present_gnu_tree (gnat_record))
442 {
443 /* ??? If this is in a record whose scope is a protected
444 type and we have an Original_Record_Component, use it.
445 This is a workaround for major problems in protected type
446 handling. */
447
448 Entity_Id Scop = Scope (Scope (gnat_entity));
449 if ((Is_Protected_Type (Scop)
450 || (Is_Private_Type (Scop)
451 && Present (Full_View (Scop))
452 && Is_Protected_Type (Full_View (Scop))))
453 && Present (Original_Record_Component (gnat_entity)))
454 {
455 gnu_decl
456 = gnat_to_gnu_entity (Original_Record_Component
457 (gnat_entity),
458 gnu_expr, definition);
459 saved = true;
460 break;
461 }
462
463 gnat_to_gnu_entity (Scope (gnat_entity), NULL_TREE, 0);
464 gnu_decl = get_gnu_tree (gnat_entity);
465 saved = true;
466 break;
467 }
468
469 else
470 /* Here we have no GCC type and this is a reference rather than a
471 definition. This should never happen. Most likely the cause is a
472 reference before declaration in the gnat tree for gnat_entity. */
473 gcc_unreachable ();
474 }
475
476 case E_Loop_Parameter:
477 case E_Out_Parameter:
478 case E_Variable:
479
480 /* Simple variables, loop variables, OUT parameters, and exceptions. */
481 object:
482 {
483 bool used_by_ref = false;
484 bool const_flag
485 = ((kind == E_Constant || kind == E_Variable)
486 && !Is_Statically_Allocated (gnat_entity)
487 && Is_True_Constant (gnat_entity)
488 && (((Nkind (Declaration_Node (gnat_entity))
489 == N_Object_Declaration)
490 && Present (Expression (Declaration_Node (gnat_entity))))
491 || Present (Renamed_Object (gnat_entity))));
492 bool inner_const_flag = const_flag;
493 bool static_p = Is_Statically_Allocated (gnat_entity);
494 bool mutable_p = false;
495 tree gnu_ext_name = NULL_TREE;
496 tree renamed_obj = NULL_TREE;
497
498 if (Present (Renamed_Object (gnat_entity)) && !definition)
499 {
500 if (kind == E_Exception)
501 gnu_expr = gnat_to_gnu_entity (Renamed_Entity (gnat_entity),
502 NULL_TREE, 0);
503 else
504 gnu_expr = gnat_to_gnu (Renamed_Object (gnat_entity));
505 }
506
507 /* Get the type after elaborating the renamed object. */
508 gnu_type = gnat_to_gnu_type (Etype (gnat_entity));
509
510 /* If this is a loop variable, its type should be the base type.
511 This is because the code for processing a loop determines whether
512 a normal loop end test can be done by comparing the bounds of the
513 loop against those of the base type, which is presumed to be the
514 size used for computation. But this is not correct when the size
515 of the subtype is smaller than the type. */
516 if (kind == E_Loop_Parameter)
517 gnu_type = get_base_type (gnu_type);
518
519 /* Reject non-renamed objects whose types are unconstrained arrays or
520 any object whose type is a dummy type or VOID_TYPE. */
521
522 if ((TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE
523 && No (Renamed_Object (gnat_entity)))
524 || TYPE_IS_DUMMY_P (gnu_type)
525 || TREE_CODE (gnu_type) == VOID_TYPE)
526 {
527 gcc_assert (type_annotate_only);
528 if (this_global)
529 force_global--;
530 return error_mark_node;
531 }
532
533 /* If an alignment is specified, use it if valid. Note that
534 exceptions are objects but don't have alignments. We must do this
535 before we validate the size, since the alignment can affect the
536 size. */
537 if (kind != E_Exception && Known_Alignment (gnat_entity))
538 {
539 gcc_assert (Present (Alignment (gnat_entity)));
540 align = validate_alignment (Alignment (gnat_entity), gnat_entity,
541 TYPE_ALIGN (gnu_type));
542 gnu_type = maybe_pad_type (gnu_type, NULL_TREE, align,
543 gnat_entity, "PAD", 0, definition, 1);
544 }
545
546 /* If we are defining the object, see if it has a Size value and
547 validate it if so. If we are not defining the object and a Size
548 clause applies, simply retrieve the value. We don't want to ignore
549 the clause and it is expected to have been validated already. Then
550 get the new type, if any. */
551 if (definition)
552 gnu_size = validate_size (Esize (gnat_entity), gnu_type,
553 gnat_entity, VAR_DECL, false,
554 Has_Size_Clause (gnat_entity));
555 else if (Has_Size_Clause (gnat_entity))
556 gnu_size = UI_To_gnu (Esize (gnat_entity), bitsizetype);
557
558 if (gnu_size)
559 {
560 gnu_type
561 = make_type_from_size (gnu_type, gnu_size,
562 Has_Biased_Representation (gnat_entity));
563
564 if (operand_equal_p (TYPE_SIZE (gnu_type), gnu_size, 0))
565 gnu_size = NULL_TREE;
566 }
567
568 /* If this object has self-referential size, it must be a record with
569 a default value. We are supposed to allocate an object of the
570 maximum size in this case unless it is a constant with an
571 initializing expression, in which case we can get the size from
572 that. Note that the resulting size may still be a variable, so
573 this may end up with an indirect allocation. */
574
575 if (No (Renamed_Object (gnat_entity))
576 && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type)))
577 {
578 if (gnu_expr && kind == E_Constant)
579 gnu_size
580 = SUBSTITUTE_PLACEHOLDER_IN_EXPR
581 (TYPE_SIZE (TREE_TYPE (gnu_expr)), gnu_expr);
582
583 /* We may have no GNU_EXPR because No_Initialization is
584 set even though there's an Expression. */
585 else if (kind == E_Constant
586 && (Nkind (Declaration_Node (gnat_entity))
587 == N_Object_Declaration)
588 && Present (Expression (Declaration_Node (gnat_entity))))
589 gnu_size
590 = TYPE_SIZE (gnat_to_gnu_type
591 (Etype
592 (Expression (Declaration_Node (gnat_entity)))));
593 else
594 {
595 gnu_size = max_size (TYPE_SIZE (gnu_type), true);
596 mutable_p = true;
597 }
598 }
599
600 /* If the size is zero bytes, make it one byte since some linkers have
601 trouble with zero-sized objects. If the object will have a
602 template, that will make it nonzero so don't bother. Also avoid
603 doing that for an object renaming or an object with an address
604 clause, as we would lose useful information on the view size
605 (e.g. for null array slices) and we are not allocating the object
606 here anyway. */
607 if (((gnu_size && integer_zerop (gnu_size))
608 || (TYPE_SIZE (gnu_type) && integer_zerop (TYPE_SIZE (gnu_type))))
609 && (!Is_Constr_Subt_For_UN_Aliased (Etype (gnat_entity))
610 || !Is_Array_Type (Etype (gnat_entity)))
611 && !Present (Renamed_Object (gnat_entity))
612 && !Present (Address_Clause (gnat_entity)))
613 gnu_size = bitsize_unit_node;
614
615 /* If this is an atomic object with no specified size and alignment,
616 but where the size of the type is a constant, set the alignment to
617 the lowest power of two greater than the size, or to the
618 biggest meaningful alignment, whichever is smaller. */
619
620 if (Is_Atomic (gnat_entity) && !gnu_size && align == 0
621 && TREE_CODE (TYPE_SIZE (gnu_type)) == INTEGER_CST)
622 {
623 if (!host_integerp (TYPE_SIZE (gnu_type), 1)
624 || 0 <= compare_tree_int (TYPE_SIZE (gnu_type),
625 BIGGEST_ALIGNMENT))
626 align = BIGGEST_ALIGNMENT;
627 else
628 align = ((unsigned int) 1
629 << (floor_log2 (tree_low_cst
630 (TYPE_SIZE (gnu_type), 1) - 1)
631 + 1));
632 }
633
634 /* If the object is set to have atomic components, find the component
635 type and validate it.
636
637 ??? Note that we ignore Has_Volatile_Components on objects; it's
638 not at all clear what to do in that case. */
639
640 if (Has_Atomic_Components (gnat_entity))
641 {
642 tree gnu_inner = (TREE_CODE (gnu_type) == ARRAY_TYPE
643 ? TREE_TYPE (gnu_type) : gnu_type);
644
645 while (TREE_CODE (gnu_inner) == ARRAY_TYPE
646 && TYPE_MULTI_ARRAY_P (gnu_inner))
647 gnu_inner = TREE_TYPE (gnu_inner);
648
649 check_ok_for_atomic (gnu_inner, gnat_entity, true);
650 }
651
652 /* Now check if the type of the object allows atomic access. Note
653 that we must test the type, even if this object has size and
654 alignment to allow such access, because we will be going
655 inside the padded record to assign to the object. We could fix
656 this by always copying via an intermediate value, but it's not
657 clear it's worth the effort. */
658 if (Is_Atomic (gnat_entity))
659 check_ok_for_atomic (gnu_type, gnat_entity, false);
660
661 /* If this is an aliased object with an unconstrained nominal subtype,
662 make a type that includes the template. */
663 if (Is_Constr_Subt_For_UN_Aliased (Etype (gnat_entity))
664 && Is_Array_Type (Etype (gnat_entity))
665 && !type_annotate_only)
666 {
667 tree gnu_fat
668 = TREE_TYPE (gnat_to_gnu_type (Base_Type (Etype (gnat_entity))));
669
670 gnu_type
671 = build_unc_object_type_from_ptr (gnu_fat, gnu_type,
672 concat_id_with_name (gnu_entity_id,
673 "UNC"));
674 }
675
676 #ifdef MINIMUM_ATOMIC_ALIGNMENT
677 /* If the size is a constant and no alignment is specified, force
678 the alignment to be the minimum valid atomic alignment. The
679 restriction on constant size avoids problems with variable-size
680 temporaries; if the size is variable, there's no issue with
681 atomic access. Also don't do this for a constant, since it isn't
682 necessary and can interfere with constant replacement. Finally,
683 do not do it for Out parameters since that creates an
684 size inconsistency with In parameters. */
685 if (align == 0 && MINIMUM_ATOMIC_ALIGNMENT > TYPE_ALIGN (gnu_type)
686 && !FLOAT_TYPE_P (gnu_type)
687 && !const_flag && No (Renamed_Object (gnat_entity))
688 && !imported_p && No (Address_Clause (gnat_entity))
689 && kind != E_Out_Parameter
690 && (gnu_size ? TREE_CODE (gnu_size) == INTEGER_CST
691 : TREE_CODE (TYPE_SIZE (gnu_type)) == INTEGER_CST))
692 align = MINIMUM_ATOMIC_ALIGNMENT;
693 #endif
694
695 /* Make a new type with the desired size and alignment, if needed. */
696 gnu_type = maybe_pad_type (gnu_type, gnu_size, align, gnat_entity,
697 "PAD", false, definition, true);
698
699 /* Make a volatile version of this object's type if we are to
700 make the object volatile. Note that 13.3(19) says that we
701 should treat other types of objects as volatile as well. */
702 if ((Treat_As_Volatile (gnat_entity)
703 || Is_Exported (gnat_entity)
704 || Is_Imported (gnat_entity)
705 || Present (Address_Clause (gnat_entity)))
706 && !TYPE_VOLATILE (gnu_type))
707 gnu_type = build_qualified_type (gnu_type,
708 (TYPE_QUALS (gnu_type)
709 | TYPE_QUAL_VOLATILE));
710
711 /* Convert the expression to the type of the object except in the
712 case where the object's type is unconstrained or the object's type
713 is a padded record whose field is of self-referential size. In
714 the former case, converting will generate unnecessary evaluations
715 of the CONSTRUCTOR to compute the size and in the latter case, we
716 want to only copy the actual data. */
717 if (gnu_expr
718 && TREE_CODE (gnu_type) != UNCONSTRAINED_ARRAY_TYPE
719 && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type))
720 && !(TREE_CODE (gnu_type) == RECORD_TYPE
721 && TYPE_IS_PADDING_P (gnu_type)
722 && (CONTAINS_PLACEHOLDER_P
723 (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS (gnu_type)))))))
724 gnu_expr = convert (gnu_type, gnu_expr);
725
726 /* See if this is a renaming, and handle appropriately depending on
727 what is renamed and in which context. There are three major
728 cases:
729
730 1/ This is a constant renaming and we can just make an object
731 with what is renamed as its initial value,
732
733 2/ We can reuse a stabilized version of what is renamed in place
734 of the renaming,
735
736 3/ If neither 1 or 2 applies, we make the renaming entity a constant
737 pointer to what is being renamed. */
738
739 if (Present (Renamed_Object (gnat_entity)))
740 {
741 /* If the renamed object had padding, strip off the reference
742 to the inner object and reset our type. */
743 if (TREE_CODE (gnu_expr) == COMPONENT_REF
744 && (TREE_CODE (TREE_TYPE (TREE_OPERAND (gnu_expr, 0)))
745 == RECORD_TYPE)
746 && (TYPE_IS_PADDING_P
747 (TREE_TYPE (TREE_OPERAND (gnu_expr, 0)))))
748 {
749 gnu_expr = TREE_OPERAND (gnu_expr, 0);
750 gnu_type = TREE_TYPE (gnu_expr);
751 }
752
753 /* Case 1: If this is a constant renaming, treat it as a normal
754 object whose initial value is what is being renamed. We cannot
755 do this if the type is unconstrained or class-wide. */
756 if (const_flag
757 && !TREE_SIDE_EFFECTS (gnu_expr)
758 && TREE_CODE (gnu_type) != UNCONSTRAINED_ARRAY_TYPE
759 && TYPE_MODE (gnu_type) != BLKmode
760 && Ekind (Etype (gnat_entity)) != E_Class_Wide_Type
761 && !Is_Array_Type (Etype (gnat_entity)))
762 ;
763
764 /* Otherwise, see if we can proceed with a stabilized version of
765 the renamed entity or if we need to make a pointer. */
766 else
767 {
768 bool stabilized = false;
769 tree maybe_stable_expr = NULL_TREE;
770
771 /* Case 2: If the renaming entity need not be materialized and
772 the renamed expression is something we can stabilize, use
773 that for the renaming. At the global level, we can only do
774 this if we know no SAVE_EXPRs need be made, because the
775 expression we return might be used in arbitrary conditional
776 branches so we must force the SAVE_EXPRs evaluation
777 immediately and this requires a function context. */
778 if (!Materialize_Entity (gnat_entity)
779 && (!global_bindings_p ()
780 || (staticp (gnu_expr)
781 && !TREE_SIDE_EFFECTS (gnu_expr))))
782 {
783 maybe_stable_expr
784 = maybe_stabilize_reference (gnu_expr, true, false,
785 &stabilized);
786
787 if (stabilized)
788 {
789 gnu_decl = maybe_stable_expr;
790 save_gnu_tree (gnat_entity, gnu_decl, true);
791 saved = true;
792 break;
793 }
794
795 /* The stabilization failed. Keep maybe_stable_expr
796 untouched here to let the pointer case below know
797 about that failure. */
798 }
799
800 /* Case 3: Make this into a constant pointer to the object we
801 are to rename and attach the object to the pointer if it is
802 an lvalue that can be stabilized.
803
804 From the proper scope, attached objects will be referenced
805 directly instead of indirectly via the pointer to avoid
806 subtle aliasing problems with non addressable entities.
807 They have to be stable because we must not evaluate the
808 variables in the expression every time the renaming is used.
809 They also have to be lvalues because the context in which
810 they are reused sometimes requires so. We call pointers
811 with an attached object "renaming" pointers.
812
813 In the rare cases where we cannot stabilize the renamed
814 object, we just make a "bare" pointer, and the renamed
815 entity is always accessed indirectly through it. */
816 {
817 bool expr_has_side_effects = TREE_SIDE_EFFECTS (gnu_expr);
818
819 inner_const_flag = TREE_READONLY (gnu_expr);
820 const_flag = true;
821 gnu_type = build_reference_type (gnu_type);
822
823 /* If a previous attempt at unrestricted stabilization
824 failed, there is no point trying again and we can reuse
825 the result without attaching it to the pointer. */
826 if (maybe_stable_expr)
827 ;
828
829 /* Otherwise, try to stabilize now, restricting to
830 lvalues only, and attach the expression to the pointer
831 if the stabilization succeeds.
832
833 Note that this might introduce SAVE_EXPRs and we don't
834 check whether we're at the global level or not. This is
835 fine since we are building a pointer initializer and
836 neither the pointer nor the initializing expression can
837 be accessed before the pointer elaboration has taken
838 place in a correct program.
839
840 SAVE_EXPRs will be evaluated at the right spots by either
841 create_var_decl->expand_decl_init for the non-global case
842 or build_unit_elab for the global case, and will be
843 attached to the elaboration procedure by the RTL expander
844 in the latter case. We have no need to force an early
845 evaluation here. */
846 else
847 {
848 maybe_stable_expr
849 = maybe_stabilize_reference (gnu_expr, true, true,
850 &stabilized);
851
852 if (stabilized)
853 renamed_obj = maybe_stable_expr;
854 /* Attaching is actually performed downstream, as soon
855 as we have a DECL for the pointer we make. */
856 }
857
858 gnu_expr
859 = build_unary_op (ADDR_EXPR, gnu_type, maybe_stable_expr);
860
861 /* If the initial expression has side effects, we might
862 still have an unstabilized version at this point (for
863 instance if it involves a function call). Wrap the
864 result into a SAVE_EXPR now, in case it happens to be
865 referenced several times. */
866 if (expr_has_side_effects && ! stabilized)
867 gnu_expr = save_expr (gnu_expr);
868
869 gnu_size = NULL_TREE;
870 used_by_ref = true;
871 }
872 }
873 }
874
875 /* If this is an aliased object whose nominal subtype is unconstrained,
876 the object is a record that contains both the template and
877 the object. If there is an initializer, it will have already
878 been converted to the right type, but we need to create the
879 template if there is no initializer. */
880 else if (definition && TREE_CODE (gnu_type) == RECORD_TYPE
881 && (TYPE_CONTAINS_TEMPLATE_P (gnu_type)
882 /* Beware that padding might have been introduced
883 via maybe_pad_type above. */
884 || (TYPE_IS_PADDING_P (gnu_type)
885 && TREE_CODE (TREE_TYPE (TYPE_FIELDS (gnu_type)))
886 == RECORD_TYPE
887 && TYPE_CONTAINS_TEMPLATE_P
888 (TREE_TYPE (TYPE_FIELDS (gnu_type)))))
889 && !gnu_expr)
890 {
891 tree template_field
892 = TYPE_IS_PADDING_P (gnu_type)
893 ? TYPE_FIELDS (TREE_TYPE (TYPE_FIELDS (gnu_type)))
894 : TYPE_FIELDS (gnu_type);
895
896 gnu_expr
897 = gnat_build_constructor
898 (gnu_type,
899 tree_cons
900 (template_field,
901 build_template (TREE_TYPE (template_field),
902 TREE_TYPE (TREE_CHAIN (template_field)),
903 NULL_TREE),
904 NULL_TREE));
905 }
906
907 /* If this is a pointer and it does not have an initializing
908 expression, initialize it to NULL, unless the object is
909 imported. */
910 if (definition
911 && (POINTER_TYPE_P (gnu_type) || TYPE_FAT_POINTER_P (gnu_type))
912 && !Is_Imported (gnat_entity) && !gnu_expr)
913 gnu_expr = integer_zero_node;
914
915 /* If we are defining the object and it has an Address clause we must
916 get the address expression from the saved GCC tree for the
917 object if the object has a Freeze_Node. Otherwise, we elaborate
918 the address expression here since the front-end has guaranteed
919 in that case that the elaboration has no effects. Note that
920 only the latter mechanism is currently in use. */
921 if (definition && Present (Address_Clause (gnat_entity)))
922 {
923 tree gnu_address
924 = (present_gnu_tree (gnat_entity) ? get_gnu_tree (gnat_entity)
925 : gnat_to_gnu (Expression (Address_Clause (gnat_entity))));
926
927 save_gnu_tree (gnat_entity, NULL_TREE, false);
928
929 /* Ignore the size. It's either meaningless or was handled
930 above. */
931 gnu_size = NULL_TREE;
932 gnu_type = build_reference_type (gnu_type);
933 gnu_address = convert (gnu_type, gnu_address);
934 used_by_ref = true;
935 const_flag = !Is_Public (gnat_entity);
936
937 /* If we don't have an initializing expression for the underlying
938 variable, the initializing expression for the pointer is the
939 specified address. Otherwise, we have to make a COMPOUND_EXPR
940 to assign both the address and the initial value. */
941 if (!gnu_expr)
942 gnu_expr = gnu_address;
943 else
944 gnu_expr
945 = build2 (COMPOUND_EXPR, gnu_type,
946 build_binary_op
947 (MODIFY_EXPR, NULL_TREE,
948 build_unary_op (INDIRECT_REF, NULL_TREE,
949 gnu_address),
950 gnu_expr),
951 gnu_address);
952 }
953
954 /* If it has an address clause and we are not defining it, mark it
955 as an indirect object. Likewise for Stdcall objects that are
956 imported. */
957 if ((!definition && Present (Address_Clause (gnat_entity)))
958 || (Is_Imported (gnat_entity)
959 && Has_Stdcall_Convention (gnat_entity)))
960 {
961 gnu_type = build_reference_type (gnu_type);
962 gnu_size = NULL_TREE;
963
964 gnu_expr = NULL_TREE;
965 /* No point in taking the address of an initializing expression
966 that isn't going to be used. */
967
968 used_by_ref = true;
969 }
970
971 /* If we are at top level and this object is of variable size,
972 make the actual type a hidden pointer to the real type and
973 make the initializer be a memory allocation and initialization.
974 Likewise for objects we aren't defining (presumed to be
975 external references from other packages), but there we do
976 not set up an initialization.
977
978 If the object's size overflows, make an allocator too, so that
979 Storage_Error gets raised. Note that we will never free
980 such memory, so we presume it never will get allocated. */
981
982 if (!allocatable_size_p (TYPE_SIZE_UNIT (gnu_type),
983 global_bindings_p () || !definition
984 || static_p)
985 || (gnu_size
986 && ! allocatable_size_p (gnu_size,
987 global_bindings_p () || !definition
988 || static_p)))
989 {
990 gnu_type = build_reference_type (gnu_type);
991 gnu_size = NULL_TREE;
992 used_by_ref = true;
993 const_flag = true;
994
995 /* In case this was a aliased object whose nominal subtype is
996 unconstrained, the pointer above will be a thin pointer and
997 build_allocator will automatically make the template.
998
999 If we have a template initializer only (that we made above),
1000 pretend there is none and rely on what build_allocator creates
1001 again anyway. Otherwise (if we have a full initializer), get
1002 the data part and feed that to build_allocator.
1003
1004 If we are elaborating a mutable object, tell build_allocator to
1005 ignore a possibly simpler size from the initializer, if any, as
1006 we must allocate the maximum possible size in this case. */
1007
1008 if (definition)
1009 {
1010 tree gnu_alloc_type = TREE_TYPE (gnu_type);
1011
1012 if (TREE_CODE (gnu_alloc_type) == RECORD_TYPE
1013 && TYPE_CONTAINS_TEMPLATE_P (gnu_alloc_type))
1014 {
1015 gnu_alloc_type
1016 = TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (gnu_alloc_type)));
1017
1018 if (TREE_CODE (gnu_expr) == CONSTRUCTOR
1019 && 1 == VEC_length (constructor_elt,
1020 CONSTRUCTOR_ELTS (gnu_expr)))
1021 gnu_expr = 0;
1022 else
1023 gnu_expr
1024 = build_component_ref
1025 (gnu_expr, NULL_TREE,
1026 TREE_CHAIN (TYPE_FIELDS (TREE_TYPE (gnu_expr))),
1027 false);
1028 }
1029
1030 if (TREE_CODE (TYPE_SIZE_UNIT (gnu_alloc_type)) == INTEGER_CST
1031 && TREE_CONSTANT_OVERFLOW (TYPE_SIZE_UNIT (gnu_alloc_type))
1032 && !Is_Imported (gnat_entity))
1033 post_error ("Storage_Error will be raised at run-time?",
1034 gnat_entity);
1035
1036 gnu_expr = build_allocator (gnu_alloc_type, gnu_expr, gnu_type,
1037 0, 0, gnat_entity, mutable_p);
1038 }
1039 else
1040 {
1041 gnu_expr = NULL_TREE;
1042 const_flag = false;
1043 }
1044 }
1045
1046 /* If this object would go into the stack and has an alignment
1047 larger than the default largest alignment, make a variable
1048 to hold the "aligning type" with a modified initial value,
1049 if any, then point to it and make that the value of this
1050 variable, which is now indirect. */
1051 if (!global_bindings_p () && !static_p && definition
1052 && !imported_p && TYPE_ALIGN (gnu_type) > BIGGEST_ALIGNMENT)
1053 {
1054 tree gnu_new_type
1055 = make_aligning_type (gnu_type, TYPE_ALIGN (gnu_type),
1056 TYPE_SIZE_UNIT (gnu_type));
1057 tree gnu_new_var;
1058
1059 gnu_new_var
1060 = create_var_decl (create_concat_name (gnat_entity, "ALIGN"),
1061 NULL_TREE, gnu_new_type, NULL_TREE, false,
1062 false, false, false, NULL, gnat_entity);
1063
1064 if (gnu_expr)
1065 add_stmt_with_node
1066 (build_binary_op (MODIFY_EXPR, NULL_TREE,
1067 build_component_ref
1068 (gnu_new_var, NULL_TREE,
1069 TYPE_FIELDS (gnu_new_type), false),
1070 gnu_expr),
1071 gnat_entity);
1072
1073 gnu_type = build_reference_type (gnu_type);
1074 gnu_expr
1075 = build_unary_op
1076 (ADDR_EXPR, gnu_type,
1077 build_component_ref (gnu_new_var, NULL_TREE,
1078 TYPE_FIELDS (gnu_new_type), false));
1079
1080 gnu_size = NULL_TREE;
1081 used_by_ref = true;
1082 const_flag = true;
1083 }
1084
1085 if (const_flag)
1086 gnu_type = build_qualified_type (gnu_type, (TYPE_QUALS (gnu_type)
1087 | TYPE_QUAL_CONST));
1088
1089 /* Convert the expression to the type of the object except in the
1090 case where the object's type is unconstrained or the object's type
1091 is a padded record whose field is of self-referential size. In
1092 the former case, converting will generate unnecessary evaluations
1093 of the CONSTRUCTOR to compute the size and in the latter case, we
1094 want to only copy the actual data. */
1095 if (gnu_expr
1096 && TREE_CODE (gnu_type) != UNCONSTRAINED_ARRAY_TYPE
1097 && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type))
1098 && !(TREE_CODE (gnu_type) == RECORD_TYPE
1099 && TYPE_IS_PADDING_P (gnu_type)
1100 && (CONTAINS_PLACEHOLDER_P
1101 (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS (gnu_type)))))))
1102 gnu_expr = convert (gnu_type, gnu_expr);
1103
1104 /* If this name is external or there was a name specified, use it,
1105 unless this is a VMS exception object since this would conflict
1106 with the symbol we need to export in addition. Don't use the
1107 Interface_Name if there is an address clause (see CD30005). */
1108 if (!Is_VMS_Exception (gnat_entity)
1109 && ((Present (Interface_Name (gnat_entity))
1110 && No (Address_Clause (gnat_entity)))
1111 || (Is_Public (gnat_entity)
1112 && (!Is_Imported (gnat_entity)
1113 || Is_Exported (gnat_entity)))))
1114 gnu_ext_name = create_concat_name (gnat_entity, 0);
1115
1116 /* If this is constant initialized to a static constant and the
1117 object has an aggregate type, force it to be statically
1118 allocated. */
1119 if (const_flag && gnu_expr && TREE_CONSTANT (gnu_expr)
1120 && host_integerp (TYPE_SIZE_UNIT (gnu_type), 1)
1121 && (AGGREGATE_TYPE_P (gnu_type)
1122 && !(TREE_CODE (gnu_type) == RECORD_TYPE
1123 && TYPE_IS_PADDING_P (gnu_type))))
1124 static_p = true;
1125
1126 gnu_decl = create_var_decl (gnu_entity_id, gnu_ext_name, gnu_type,
1127 gnu_expr, const_flag,
1128 Is_Public (gnat_entity),
1129 imported_p || !definition,
1130 static_p, attr_list, gnat_entity);
1131 DECL_BY_REF_P (gnu_decl) = used_by_ref;
1132 DECL_POINTS_TO_READONLY_P (gnu_decl) = used_by_ref && inner_const_flag;
1133 if (TREE_CODE (gnu_decl) == VAR_DECL && renamed_obj)
1134 {
1135 SET_DECL_RENAMED_OBJECT (gnu_decl, renamed_obj);
1136 DECL_RENAMING_GLOBAL_P (gnu_decl) = global_bindings_p ();
1137 }
1138
1139 /* If we have an address clause and we've made this indirect, it's
1140 not enough to merely mark the type as volatile since volatile
1141 references only conflict with other volatile references while this
1142 reference must conflict with all other references. So ensure that
1143 the dereferenced value has alias set 0. */
1144 if (Present (Address_Clause (gnat_entity)) && used_by_ref)
1145 DECL_POINTER_ALIAS_SET (gnu_decl) = 0;
1146
1147 if (definition && DECL_SIZE (gnu_decl)
1148 && get_block_jmpbuf_decl ()
1149 && (TREE_CODE (DECL_SIZE (gnu_decl)) != INTEGER_CST
1150 || (flag_stack_check && !STACK_CHECK_BUILTIN
1151 && 0 < compare_tree_int (DECL_SIZE_UNIT (gnu_decl),
1152 STACK_CHECK_MAX_VAR_SIZE))))
1153 add_stmt_with_node (build_call_1_expr
1154 (update_setjmp_buf_decl,
1155 build_unary_op (ADDR_EXPR, NULL_TREE,
1156 get_block_jmpbuf_decl ())),
1157 gnat_entity);
1158
1159 /* If this is a public constant or we're not optimizing and we're not
1160 making a VAR_DECL for it, make one just for export or debugger
1161 use. Likewise if the address is taken or if the object or type is
1162 aliased. */
1163 if (definition && TREE_CODE (gnu_decl) == CONST_DECL
1164 && (Is_Public (gnat_entity)
1165 || optimize == 0
1166 || Address_Taken (gnat_entity)
1167 || Is_Aliased (gnat_entity)
1168 || Is_Aliased (Etype (gnat_entity))))
1169 {
1170 tree gnu_corr_var
1171 = create_var_decl (gnu_entity_id, gnu_ext_name, gnu_type,
1172 gnu_expr, false, Is_Public (gnat_entity),
1173 false, static_p, NULL, gnat_entity);
1174
1175 SET_DECL_CONST_CORRESPONDING_VAR (gnu_decl, gnu_corr_var);
1176 }
1177
1178 /* If this is declared in a block that contains a block with an
1179 exception handler, we must force this variable in memory to
1180 suppress an invalid optimization. */
1181 if (Has_Nested_Block_With_Handler (Scope (gnat_entity))
1182 && Exception_Mechanism != Back_End_Exceptions)
1183 TREE_ADDRESSABLE (gnu_decl) = 1;
1184
1185 /* Back-annotate the Alignment of the object if not already in the
1186 tree. Likewise for Esize if the object is of a constant size.
1187 But if the "object" is actually a pointer to an object, the
1188 alignment and size are the same as the type, so don't back-annotate
1189 the values for the pointer. */
1190 if (!used_by_ref && Unknown_Alignment (gnat_entity))
1191 Set_Alignment (gnat_entity,
1192 UI_From_Int (DECL_ALIGN (gnu_decl) / BITS_PER_UNIT));
1193
1194 if (!used_by_ref && Unknown_Esize (gnat_entity)
1195 && DECL_SIZE (gnu_decl))
1196 {
1197 tree gnu_back_size = DECL_SIZE (gnu_decl);
1198
1199 if (TREE_CODE (TREE_TYPE (gnu_decl)) == RECORD_TYPE
1200 && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (gnu_decl)))
1201 gnu_back_size
1202 = TYPE_SIZE (TREE_TYPE (TREE_CHAIN
1203 (TYPE_FIELDS (TREE_TYPE (gnu_decl)))));
1204
1205 Set_Esize (gnat_entity, annotate_value (gnu_back_size));
1206 }
1207 }
1208 break;
1209
1210 case E_Void:
1211 /* Return a TYPE_DECL for "void" that we previously made. */
1212 gnu_decl = void_type_decl_node;
1213 break;
1214
1215 case E_Enumeration_Type:
1216 /* A special case, for the types Character and Wide_Character in
1217 Standard, we do not list all the literals. So if the literals
1218 are not specified, make this an unsigned type. */
1219 if (No (First_Literal (gnat_entity)))
1220 {
1221 gnu_type = make_unsigned_type (esize);
1222 break;
1223 }
1224
1225 /* Normal case of non-character type, or non-Standard character type */
1226 {
1227 /* Here we have a list of enumeral constants in First_Literal.
1228 We make a CONST_DECL for each and build into GNU_LITERAL_LIST
1229 the list to be places into TYPE_FIELDS. Each node in the list
1230 is a TREE_LIST node whose TREE_VALUE is the literal name
1231 and whose TREE_PURPOSE is the value of the literal.
1232
1233 Esize contains the number of bits needed to represent the enumeral
1234 type, Type_Low_Bound also points to the first literal and
1235 Type_High_Bound points to the last literal. */
1236
1237 Entity_Id gnat_literal;
1238 tree gnu_literal_list = NULL_TREE;
1239
1240 if (Is_Unsigned_Type (gnat_entity))
1241 gnu_type = make_unsigned_type (esize);
1242 else
1243 gnu_type = make_signed_type (esize);
1244
1245 TREE_SET_CODE (gnu_type, ENUMERAL_TYPE);
1246
1247 for (gnat_literal = First_Literal (gnat_entity);
1248 Present (gnat_literal);
1249 gnat_literal = Next_Literal (gnat_literal))
1250 {
1251 tree gnu_value = UI_To_gnu (Enumeration_Rep (gnat_literal),
1252 gnu_type);
1253 tree gnu_literal
1254 = create_var_decl (get_entity_name (gnat_literal), NULL_TREE,
1255 gnu_type, gnu_value, true, false, false,
1256 false, NULL, gnat_literal);
1257
1258 save_gnu_tree (gnat_literal, gnu_literal, false);
1259 gnu_literal_list = tree_cons (DECL_NAME (gnu_literal),
1260 gnu_value, gnu_literal_list);
1261 }
1262
1263 TYPE_VALUES (gnu_type) = nreverse (gnu_literal_list);
1264
1265 /* Note that the bounds are updated at the end of this function
1266 because to avoid an infinite recursion when we get the bounds of
1267 this type, since those bounds are objects of this type. */
1268 }
1269 break;
1270
1271 case E_Signed_Integer_Type:
1272 case E_Ordinary_Fixed_Point_Type:
1273 case E_Decimal_Fixed_Point_Type:
1274 /* For integer types, just make a signed type the appropriate number
1275 of bits. */
1276 gnu_type = make_signed_type (esize);
1277 break;
1278
1279 case E_Modular_Integer_Type:
1280 /* For modular types, make the unsigned type of the proper number of
1281 bits and then set up the modulus, if required. */
1282 {
1283 enum machine_mode mode;
1284 tree gnu_modulus;
1285 tree gnu_high = 0;
1286
1287 if (Is_Packed_Array_Type (gnat_entity))
1288 esize = UI_To_Int (RM_Size (gnat_entity));
1289
1290 /* Find the smallest mode at least ESIZE bits wide and make a class
1291 using that mode. */
1292
1293 for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
1294 GET_MODE_BITSIZE (mode) < esize;
1295 mode = GET_MODE_WIDER_MODE (mode))
1296 ;
1297
1298 gnu_type = make_unsigned_type (GET_MODE_BITSIZE (mode));
1299 TYPE_PACKED_ARRAY_TYPE_P (gnu_type)
1300 = Is_Packed_Array_Type (gnat_entity);
1301
1302 /* Get the modulus in this type. If it overflows, assume it is because
1303 it is equal to 2**Esize. Note that there is no overflow checking
1304 done on unsigned type, so we detect the overflow by looking for
1305 a modulus of zero, which is otherwise invalid. */
1306 gnu_modulus = UI_To_gnu (Modulus (gnat_entity), gnu_type);
1307
1308 if (!integer_zerop (gnu_modulus))
1309 {
1310 TYPE_MODULAR_P (gnu_type) = 1;
1311 SET_TYPE_MODULUS (gnu_type, gnu_modulus);
1312 gnu_high = fold (build2 (MINUS_EXPR, gnu_type, gnu_modulus,
1313 convert (gnu_type, integer_one_node)));
1314 }
1315
1316 /* If we have to set TYPE_PRECISION different from its natural value,
1317 make a subtype to do do. Likewise if there is a modulus and
1318 it is not one greater than TYPE_MAX_VALUE. */
1319 if (TYPE_PRECISION (gnu_type) != esize
1320 || (TYPE_MODULAR_P (gnu_type)
1321 && !tree_int_cst_equal (TYPE_MAX_VALUE (gnu_type), gnu_high)))
1322 {
1323 tree gnu_subtype = make_node (INTEGER_TYPE);
1324
1325 TYPE_NAME (gnu_type) = create_concat_name (gnat_entity, "UMT");
1326 TREE_TYPE (gnu_subtype) = gnu_type;
1327 TYPE_MIN_VALUE (gnu_subtype) = TYPE_MIN_VALUE (gnu_type);
1328 TYPE_MAX_VALUE (gnu_subtype)
1329 = TYPE_MODULAR_P (gnu_type)
1330 ? gnu_high : TYPE_MAX_VALUE (gnu_type);
1331 TYPE_PRECISION (gnu_subtype) = esize;
1332 TYPE_UNSIGNED (gnu_subtype) = 1;
1333 TYPE_EXTRA_SUBTYPE_P (gnu_subtype) = 1;
1334 TYPE_PACKED_ARRAY_TYPE_P (gnu_subtype)
1335 = Is_Packed_Array_Type (gnat_entity);
1336 layout_type (gnu_subtype);
1337
1338 gnu_type = gnu_subtype;
1339 }
1340 }
1341 break;
1342
1343 case E_Signed_Integer_Subtype:
1344 case E_Enumeration_Subtype:
1345 case E_Modular_Integer_Subtype:
1346 case E_Ordinary_Fixed_Point_Subtype:
1347 case E_Decimal_Fixed_Point_Subtype:
1348
1349 /* For integral subtypes, we make a new INTEGER_TYPE. Note
1350 that we do not want to call build_range_type since we would
1351 like each subtype node to be distinct. This will be important
1352 when memory aliasing is implemented.
1353
1354 The TREE_TYPE field of the INTEGER_TYPE we make points to the
1355 parent type; this fact is used by the arithmetic conversion
1356 functions.
1357
1358 We elaborate the Ancestor_Subtype if it is not in the current
1359 unit and one of our bounds is non-static. We do this to ensure
1360 consistent naming in the case where several subtypes share the same
1361 bounds by always elaborating the first such subtype first, thus
1362 using its name. */
1363
1364 if (definition == 0
1365 && Present (Ancestor_Subtype (gnat_entity))
1366 && !In_Extended_Main_Code_Unit (Ancestor_Subtype (gnat_entity))
1367 && (!Compile_Time_Known_Value (Type_Low_Bound (gnat_entity))
1368 || !Compile_Time_Known_Value (Type_High_Bound (gnat_entity))))
1369 gnat_to_gnu_entity (Ancestor_Subtype (gnat_entity),
1370 gnu_expr, definition);
1371
1372 gnu_type = make_node (INTEGER_TYPE);
1373 if (Is_Packed_Array_Type (gnat_entity))
1374 {
1375 esize = UI_To_Int (RM_Size (gnat_entity));
1376 TYPE_PACKED_ARRAY_TYPE_P (gnu_type) = 1;
1377 }
1378
1379 TYPE_PRECISION (gnu_type) = esize;
1380 TREE_TYPE (gnu_type) = get_unpadded_type (Etype (gnat_entity));
1381
1382 TYPE_MIN_VALUE (gnu_type)
1383 = convert (TREE_TYPE (gnu_type),
1384 elaborate_expression (Type_Low_Bound (gnat_entity),
1385 gnat_entity,
1386 get_identifier ("L"), definition, 1,
1387 Needs_Debug_Info (gnat_entity)));
1388
1389 TYPE_MAX_VALUE (gnu_type)
1390 = convert (TREE_TYPE (gnu_type),
1391 elaborate_expression (Type_High_Bound (gnat_entity),
1392 gnat_entity,
1393 get_identifier ("U"), definition, 1,
1394 Needs_Debug_Info (gnat_entity)));
1395
1396 /* One of the above calls might have caused us to be elaborated,
1397 so don't blow up if so. */
1398 if (present_gnu_tree (gnat_entity))
1399 {
1400 maybe_present = true;
1401 break;
1402 }
1403
1404 TYPE_BIASED_REPRESENTATION_P (gnu_type)
1405 = Has_Biased_Representation (gnat_entity);
1406
1407 /* This should be an unsigned type if the lower bound is constant
1408 and non-negative or if the base type is unsigned; a signed type
1409 otherwise. */
1410 TYPE_UNSIGNED (gnu_type)
1411 = (TYPE_UNSIGNED (TREE_TYPE (gnu_type))
1412 || (TREE_CODE (TYPE_MIN_VALUE (gnu_type)) == INTEGER_CST
1413 && TREE_INT_CST_HIGH (TYPE_MIN_VALUE (gnu_type)) >= 0)
1414 || TYPE_BIASED_REPRESENTATION_P (gnu_type)
1415 || Is_Unsigned_Type (gnat_entity));
1416
1417 layout_type (gnu_type);
1418
1419 /* Inherit our alias set from what we're a subtype of. Subtypes
1420 are not different types and a pointer can designate any instance
1421 within a subtype hierarchy. */
1422 copy_alias_set (gnu_type, TREE_TYPE (gnu_type));
1423
1424 /* If the type we are dealing with is to represent a packed array,
1425 we need to have the bits left justified on big-endian targets
1426 and right justified on little-endian targets. We also need to
1427 ensure that when the value is read (e.g. for comparison of two
1428 such values), we only get the good bits, since the unused bits
1429 are uninitialized. Both goals are accomplished by wrapping the
1430 modular value in an enclosing struct. */
1431 if (Is_Packed_Array_Type (gnat_entity))
1432 {
1433 tree gnu_field_type = gnu_type;
1434 tree gnu_field;
1435
1436 TYPE_RM_SIZE_NUM (gnu_field_type)
1437 = UI_To_gnu (RM_Size (gnat_entity), bitsizetype);
1438 gnu_type = make_node (RECORD_TYPE);
1439 TYPE_NAME (gnu_type) = create_concat_name (gnat_entity, "JM");
1440 TYPE_ALIGN (gnu_type) = TYPE_ALIGN (gnu_field_type);
1441 TYPE_PACKED (gnu_type) = 1;
1442
1443 /* Create a stripped-down declaration of the original type, mainly
1444 for debugging. */
1445 create_type_decl (get_entity_name (gnat_entity), gnu_field_type,
1446 NULL, true, debug_info_p, gnat_entity);
1447
1448 /* Don't notify the field as "addressable", since we won't be taking
1449 it's address and it would prevent create_field_decl from making a
1450 bitfield. */
1451 gnu_field = create_field_decl (get_identifier ("OBJECT"),
1452 gnu_field_type, gnu_type, 1, 0, 0, 0);
1453
1454 finish_record_type (gnu_type, gnu_field, false, false);
1455 TYPE_JUSTIFIED_MODULAR_P (gnu_type) = 1;
1456 SET_TYPE_ADA_SIZE (gnu_type, bitsize_int (esize));
1457
1458 copy_alias_set (gnu_type, gnu_field_type);
1459 }
1460
1461 break;
1462
1463 case E_Floating_Point_Type:
1464 /* If this is a VAX floating-point type, use an integer of the proper
1465 size. All the operations will be handled with ASM statements. */
1466 if (Vax_Float (gnat_entity))
1467 {
1468 gnu_type = make_signed_type (esize);
1469 TYPE_VAX_FLOATING_POINT_P (gnu_type) = 1;
1470 SET_TYPE_DIGITS_VALUE (gnu_type,
1471 UI_To_gnu (Digits_Value (gnat_entity),
1472 sizetype));
1473 break;
1474 }
1475
1476 /* The type of the Low and High bounds can be our type if this is
1477 a type from Standard, so set them at the end of the function. */
1478 gnu_type = make_node (REAL_TYPE);
1479 TYPE_PRECISION (gnu_type) = fp_size_to_prec (esize);
1480 layout_type (gnu_type);
1481 break;
1482
1483 case E_Floating_Point_Subtype:
1484 if (Vax_Float (gnat_entity))
1485 {
1486 gnu_type = gnat_to_gnu_type (Etype (gnat_entity));
1487 break;
1488 }
1489
1490 {
1491 if (definition == 0
1492 && Present (Ancestor_Subtype (gnat_entity))
1493 && !In_Extended_Main_Code_Unit (Ancestor_Subtype (gnat_entity))
1494 && (!Compile_Time_Known_Value (Type_Low_Bound (gnat_entity))
1495 || !Compile_Time_Known_Value (Type_High_Bound (gnat_entity))))
1496 gnat_to_gnu_entity (Ancestor_Subtype (gnat_entity),
1497 gnu_expr, definition);
1498
1499 gnu_type = make_node (REAL_TYPE);
1500 TREE_TYPE (gnu_type) = get_unpadded_type (Etype (gnat_entity));
1501 TYPE_PRECISION (gnu_type) = fp_size_to_prec (esize);
1502
1503 TYPE_MIN_VALUE (gnu_type)
1504 = convert (TREE_TYPE (gnu_type),
1505 elaborate_expression (Type_Low_Bound (gnat_entity),
1506 gnat_entity, get_identifier ("L"),
1507 definition, 1,
1508 Needs_Debug_Info (gnat_entity)));
1509
1510 TYPE_MAX_VALUE (gnu_type)
1511 = convert (TREE_TYPE (gnu_type),
1512 elaborate_expression (Type_High_Bound (gnat_entity),
1513 gnat_entity, get_identifier ("U"),
1514 definition, 1,
1515 Needs_Debug_Info (gnat_entity)));
1516
1517 /* One of the above calls might have caused us to be elaborated,
1518 so don't blow up if so. */
1519 if (present_gnu_tree (gnat_entity))
1520 {
1521 maybe_present = true;
1522 break;
1523 }
1524
1525 layout_type (gnu_type);
1526
1527 /* Inherit our alias set from what we're a subtype of, as for
1528 integer subtypes. */
1529 copy_alias_set (gnu_type, TREE_TYPE (gnu_type));
1530 }
1531 break;
1532
1533 /* Array and String Types and Subtypes
1534
1535 Unconstrained array types are represented by E_Array_Type and
1536 constrained array types are represented by E_Array_Subtype. There
1537 are no actual objects of an unconstrained array type; all we have
1538 are pointers to that type.
1539
1540 The following fields are defined on array types and subtypes:
1541
1542 Component_Type Component type of the array.
1543 Number_Dimensions Number of dimensions (an int).
1544 First_Index Type of first index. */
1545
1546 case E_String_Type:
1547 case E_Array_Type:
1548 {
1549 tree gnu_template_fields = NULL_TREE;
1550 tree gnu_template_type = make_node (RECORD_TYPE);
1551 tree gnu_ptr_template = build_pointer_type (gnu_template_type);
1552 tree gnu_fat_type = make_node (RECORD_TYPE);
1553 int ndim = Number_Dimensions (gnat_entity);
1554 int firstdim
1555 = (Convention (gnat_entity) == Convention_Fortran) ? ndim - 1 : 0;
1556 int nextdim
1557 = (Convention (gnat_entity) == Convention_Fortran) ? - 1 : 1;
1558 tree *gnu_index_types = (tree *) alloca (ndim * sizeof (tree *));
1559 tree *gnu_temp_fields = (tree *) alloca (ndim * sizeof (tree *));
1560 tree gnu_comp_size = 0;
1561 tree gnu_max_size = size_one_node;
1562 tree gnu_max_size_unit;
1563 int index;
1564 Entity_Id gnat_ind_subtype;
1565 Entity_Id gnat_ind_base_subtype;
1566 tree gnu_template_reference;
1567 tree tem;
1568
1569 TYPE_NAME (gnu_template_type)
1570 = create_concat_name (gnat_entity, "XUB");
1571 TYPE_NAME (gnu_fat_type) = create_concat_name (gnat_entity, "XUP");
1572 TYPE_IS_FAT_POINTER_P (gnu_fat_type) = 1;
1573 TYPE_READONLY (gnu_template_type) = 1;
1574
1575 /* Make a node for the array. If we are not defining the array
1576 suppress expanding incomplete types. */
1577 gnu_type = make_node (UNCONSTRAINED_ARRAY_TYPE);
1578
1579 if (!definition)
1580 defer_incomplete_level++, this_deferred = true;
1581
1582 /* Build the fat pointer type. Use a "void *" object instead of
1583 a pointer to the array type since we don't have the array type
1584 yet (it will reference the fat pointer via the bounds). */
1585 tem = chainon (chainon (NULL_TREE,
1586 create_field_decl (get_identifier ("P_ARRAY"),
1587 ptr_void_type_node,
1588 gnu_fat_type, 0, 0, 0, 0)),
1589 create_field_decl (get_identifier ("P_BOUNDS"),
1590 gnu_ptr_template,
1591 gnu_fat_type, 0, 0, 0, 0));
1592
1593 /* Make sure we can put this into a register. */
1594 TYPE_ALIGN (gnu_fat_type) = MIN (BIGGEST_ALIGNMENT, 2 * POINTER_SIZE);
1595 finish_record_type (gnu_fat_type, tem, false, true);
1596
1597 /* Build a reference to the template from a PLACEHOLDER_EXPR that
1598 is the fat pointer. This will be used to access the individual
1599 fields once we build them. */
1600 tem = build3 (COMPONENT_REF, gnu_ptr_template,
1601 build0 (PLACEHOLDER_EXPR, gnu_fat_type),
1602 TREE_CHAIN (TYPE_FIELDS (gnu_fat_type)), NULL_TREE);
1603 gnu_template_reference
1604 = build_unary_op (INDIRECT_REF, gnu_template_type, tem);
1605 TREE_READONLY (gnu_template_reference) = 1;
1606
1607 /* Now create the GCC type for each index and add the fields for
1608 that index to the template. */
1609 for (index = firstdim, gnat_ind_subtype = First_Index (gnat_entity),
1610 gnat_ind_base_subtype
1611 = First_Index (Implementation_Base_Type (gnat_entity));
1612 index < ndim && index >= 0;
1613 index += nextdim,
1614 gnat_ind_subtype = Next_Index (gnat_ind_subtype),
1615 gnat_ind_base_subtype = Next_Index (gnat_ind_base_subtype))
1616 {
1617 char field_name[10];
1618 tree gnu_ind_subtype
1619 = get_unpadded_type (Base_Type (Etype (gnat_ind_subtype)));
1620 tree gnu_base_subtype
1621 = get_unpadded_type (Etype (gnat_ind_base_subtype));
1622 tree gnu_base_min
1623 = convert (sizetype, TYPE_MIN_VALUE (gnu_base_subtype));
1624 tree gnu_base_max
1625 = convert (sizetype, TYPE_MAX_VALUE (gnu_base_subtype));
1626 tree gnu_min_field, gnu_max_field, gnu_min, gnu_max;
1627
1628 /* Make the FIELD_DECLs for the minimum and maximum of this
1629 type and then make extractions of that field from the
1630 template. */
1631 sprintf (field_name, "LB%d", index);
1632 gnu_min_field = create_field_decl (get_identifier (field_name),
1633 gnu_ind_subtype,
1634 gnu_template_type, 0, 0, 0, 0);
1635 field_name[0] = 'U';
1636 gnu_max_field = create_field_decl (get_identifier (field_name),
1637 gnu_ind_subtype,
1638 gnu_template_type, 0, 0, 0, 0);
1639
1640 Sloc_to_locus (Sloc (gnat_entity),
1641 &DECL_SOURCE_LOCATION (gnu_min_field));
1642 Sloc_to_locus (Sloc (gnat_entity),
1643 &DECL_SOURCE_LOCATION (gnu_max_field));
1644 gnu_temp_fields[index] = chainon (gnu_min_field, gnu_max_field);
1645
1646 /* We can't use build_component_ref here since the template
1647 type isn't complete yet. */
1648 gnu_min = build3 (COMPONENT_REF, gnu_ind_subtype,
1649 gnu_template_reference, gnu_min_field,
1650 NULL_TREE);
1651 gnu_max = build3 (COMPONENT_REF, gnu_ind_subtype,
1652 gnu_template_reference, gnu_max_field,
1653 NULL_TREE);
1654 TREE_READONLY (gnu_min) = TREE_READONLY (gnu_max) = 1;
1655
1656 /* Make a range type with the new ranges, but using
1657 the Ada subtype. Then we convert to sizetype. */
1658 gnu_index_types[index]
1659 = create_index_type (convert (sizetype, gnu_min),
1660 convert (sizetype, gnu_max),
1661 build_range_type (gnu_ind_subtype,
1662 gnu_min, gnu_max));
1663 /* Update the maximum size of the array, in elements. */
1664 gnu_max_size
1665 = size_binop (MULT_EXPR, gnu_max_size,
1666 size_binop (PLUS_EXPR, size_one_node,
1667 size_binop (MINUS_EXPR, gnu_base_max,
1668 gnu_base_min)));
1669
1670 TYPE_NAME (gnu_index_types[index])
1671 = create_concat_name (gnat_entity, field_name);
1672 }
1673
1674 for (index = 0; index < ndim; index++)
1675 gnu_template_fields
1676 = chainon (gnu_template_fields, gnu_temp_fields[index]);
1677
1678 /* Install all the fields into the template. */
1679 finish_record_type (gnu_template_type, gnu_template_fields,
1680 false, false);
1681 TYPE_READONLY (gnu_template_type) = 1;
1682
1683 /* Now make the array of arrays and update the pointer to the array
1684 in the fat pointer. Note that it is the first field. */
1685
1686 tem = gnat_to_gnu_type (Component_Type (gnat_entity));
1687
1688 /* Get and validate any specified Component_Size, but if Packed,
1689 ignore it since the front end will have taken care of it. */
1690 gnu_comp_size
1691 = validate_size (Component_Size (gnat_entity), tem,
1692 gnat_entity,
1693 (Is_Bit_Packed_Array (gnat_entity)
1694 ? TYPE_DECL : VAR_DECL),
1695 true, Has_Component_Size_Clause (gnat_entity));
1696
1697 if (Has_Atomic_Components (gnat_entity))
1698 check_ok_for_atomic (tem, gnat_entity, true);
1699
1700 /* If the component type is a RECORD_TYPE that has a self-referential
1701 size, use the maxium size. */
1702 if (!gnu_comp_size && TREE_CODE (tem) == RECORD_TYPE
1703 && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (tem)))
1704 gnu_comp_size = max_size (TYPE_SIZE (tem), true);
1705
1706 if (!Is_Bit_Packed_Array (gnat_entity) && gnu_comp_size)
1707 {
1708 tem = make_type_from_size (tem, gnu_comp_size, false);
1709 tem = maybe_pad_type (tem, gnu_comp_size, 0, gnat_entity,
1710 "C_PAD", false, definition, true);
1711 }
1712
1713 if (Has_Volatile_Components (gnat_entity))
1714 tem = build_qualified_type (tem,
1715 TYPE_QUALS (tem) | TYPE_QUAL_VOLATILE);
1716
1717 /* If Component_Size is not already specified, annotate it with the
1718 size of the component. */
1719 if (Unknown_Component_Size (gnat_entity))
1720 Set_Component_Size (gnat_entity, annotate_value (TYPE_SIZE (tem)));
1721
1722 gnu_max_size_unit = size_binop (MAX_EXPR, size_zero_node,
1723 size_binop (MULT_EXPR, gnu_max_size,
1724 TYPE_SIZE_UNIT (tem)));
1725 gnu_max_size = size_binop (MAX_EXPR, bitsize_zero_node,
1726 size_binop (MULT_EXPR,
1727 convert (bitsizetype,
1728 gnu_max_size),
1729 TYPE_SIZE (tem)));
1730
1731 for (index = ndim - 1; index >= 0; index--)
1732 {
1733 tem = build_array_type (tem, gnu_index_types[index]);
1734 TYPE_MULTI_ARRAY_P (tem) = (index > 0);
1735
1736 /* If the type below this an multi-array type, then this
1737 does not not have aliased components.
1738
1739 ??? Otherwise, for now, we say that any component of aggregate
1740 type is addressable because the front end may take 'Reference
1741 of it. But we have to make it addressable if it must be passed
1742 by reference or it that is the default. */
1743 TYPE_NONALIASED_COMPONENT (tem)
1744 = ((TREE_CODE (TREE_TYPE (tem)) == ARRAY_TYPE
1745 && TYPE_MULTI_ARRAY_P (TREE_TYPE (tem))) ? 1
1746 : (!Has_Aliased_Components (gnat_entity)
1747 && !AGGREGATE_TYPE_P (TREE_TYPE (tem))));
1748 }
1749
1750 /* If an alignment is specified, use it if valid. But ignore it for
1751 types that represent the unpacked base type for packed arrays. */
1752 if (No (Packed_Array_Type (gnat_entity))
1753 && Known_Alignment (gnat_entity))
1754 {
1755 gcc_assert (Present (Alignment (gnat_entity)));
1756 TYPE_ALIGN (tem)
1757 = validate_alignment (Alignment (gnat_entity), gnat_entity,
1758 TYPE_ALIGN (tem));
1759 }
1760
1761 TYPE_CONVENTION_FORTRAN_P (tem)
1762 = (Convention (gnat_entity) == Convention_Fortran);
1763 TREE_TYPE (TYPE_FIELDS (gnu_fat_type)) = build_pointer_type (tem);
1764
1765 /* The result type is an UNCONSTRAINED_ARRAY_TYPE that indicates the
1766 corresponding fat pointer. */
1767 TREE_TYPE (gnu_type) = TYPE_POINTER_TO (gnu_type)
1768 = TYPE_REFERENCE_TO (gnu_type) = gnu_fat_type;
1769 TYPE_MODE (gnu_type) = BLKmode;
1770 TYPE_ALIGN (gnu_type) = TYPE_ALIGN (tem);
1771 SET_TYPE_UNCONSTRAINED_ARRAY (gnu_fat_type, gnu_type);
1772
1773 /* If the maximum size doesn't overflow, use it. */
1774 if (TREE_CODE (gnu_max_size) == INTEGER_CST
1775 && !TREE_OVERFLOW (gnu_max_size))
1776 TYPE_SIZE (tem)
1777 = size_binop (MIN_EXPR, gnu_max_size, TYPE_SIZE (tem));
1778 if (TREE_CODE (gnu_max_size_unit) == INTEGER_CST
1779 && !TREE_OVERFLOW (gnu_max_size_unit))
1780 TYPE_SIZE_UNIT (tem)
1781 = size_binop (MIN_EXPR, gnu_max_size_unit,
1782 TYPE_SIZE_UNIT (tem));
1783
1784 create_type_decl (create_concat_name (gnat_entity, "XUA"),
1785 tem, NULL, !Comes_From_Source (gnat_entity),
1786 debug_info_p, gnat_entity);
1787
1788 /* Create a record type for the object and its template and
1789 set the template at a negative offset. */
1790 tem = build_unc_object_type (gnu_template_type, tem,
1791 create_concat_name (gnat_entity, "XUT"));
1792 DECL_FIELD_OFFSET (TYPE_FIELDS (tem))
1793 = size_binop (MINUS_EXPR, size_zero_node,
1794 byte_position (TREE_CHAIN (TYPE_FIELDS (tem))));
1795 DECL_FIELD_OFFSET (TREE_CHAIN (TYPE_FIELDS (tem))) = size_zero_node;
1796 DECL_FIELD_BIT_OFFSET (TREE_CHAIN (TYPE_FIELDS (tem)))
1797 = bitsize_zero_node;
1798 SET_TYPE_UNCONSTRAINED_ARRAY (tem, gnu_type);
1799 TYPE_OBJECT_RECORD_TYPE (gnu_type) = tem;
1800
1801 /* Give the thin pointer type a name. */
1802 create_type_decl (create_concat_name (gnat_entity, "XUX"),
1803 build_pointer_type (tem), NULL,
1804 !Comes_From_Source (gnat_entity), debug_info_p,
1805 gnat_entity);
1806 }
1807 break;
1808
1809 case E_String_Subtype:
1810 case E_Array_Subtype:
1811
1812 /* This is the actual data type for array variables. Multidimensional
1813 arrays are implemented in the gnu tree as arrays of arrays. Note
1814 that for the moment arrays which have sparse enumeration subtypes as
1815 index components create sparse arrays, which is obviously space
1816 inefficient but so much easier to code for now.
1817
1818 Also note that the subtype never refers to the unconstrained
1819 array type, which is somewhat at variance with Ada semantics.
1820
1821 First check to see if this is simply a renaming of the array
1822 type. If so, the result is the array type. */
1823
1824 gnu_type = gnat_to_gnu_type (Etype (gnat_entity));
1825 if (!Is_Constrained (gnat_entity))
1826 break;
1827 else
1828 {
1829 int index;
1830 int array_dim = Number_Dimensions (gnat_entity);
1831 int first_dim
1832 = ((Convention (gnat_entity) == Convention_Fortran)
1833 ? array_dim - 1 : 0);
1834 int next_dim
1835 = (Convention (gnat_entity) == Convention_Fortran) ? -1 : 1;
1836 Entity_Id gnat_ind_subtype;
1837 Entity_Id gnat_ind_base_subtype;
1838 tree gnu_base_type = gnu_type;
1839 tree *gnu_index_type = (tree *) alloca (array_dim * sizeof (tree *));
1840 tree gnu_comp_size = NULL_TREE;
1841 tree gnu_max_size = size_one_node;
1842 tree gnu_max_size_unit;
1843 bool need_index_type_struct = false;
1844 bool max_overflow = false;
1845
1846 /* First create the gnu types for each index. Create types for
1847 debugging information to point to the index types if the
1848 are not integer types, have variable bounds, or are
1849 wider than sizetype. */
1850
1851 for (index = first_dim, gnat_ind_subtype = First_Index (gnat_entity),
1852 gnat_ind_base_subtype
1853 = First_Index (Implementation_Base_Type (gnat_entity));
1854 index < array_dim && index >= 0;
1855 index += next_dim,
1856 gnat_ind_subtype = Next_Index (gnat_ind_subtype),
1857 gnat_ind_base_subtype = Next_Index (gnat_ind_base_subtype))
1858 {
1859 tree gnu_index_subtype
1860 = get_unpadded_type (Etype (gnat_ind_subtype));
1861 tree gnu_min
1862 = convert (sizetype, TYPE_MIN_VALUE (gnu_index_subtype));
1863 tree gnu_max
1864 = convert (sizetype, TYPE_MAX_VALUE (gnu_index_subtype));
1865 tree gnu_base_subtype
1866 = get_unpadded_type (Etype (gnat_ind_base_subtype));
1867 tree gnu_base_min
1868 = convert (sizetype, TYPE_MIN_VALUE (gnu_base_subtype));
1869 tree gnu_base_max
1870 = convert (sizetype, TYPE_MAX_VALUE (gnu_base_subtype));
1871 tree gnu_base_type = get_base_type (gnu_base_subtype);
1872 tree gnu_base_base_min
1873 = convert (sizetype, TYPE_MIN_VALUE (gnu_base_type));
1874 tree gnu_base_base_max
1875 = convert (sizetype, TYPE_MAX_VALUE (gnu_base_type));
1876 tree gnu_high;
1877 tree gnu_this_max;
1878
1879 /* If the minimum and maximum values both overflow in
1880 SIZETYPE, but the difference in the original type
1881 does not overflow in SIZETYPE, ignore the overflow
1882 indications. */
1883 if ((TYPE_PRECISION (gnu_index_subtype)
1884 > TYPE_PRECISION (sizetype)
1885 || TYPE_UNSIGNED (gnu_index_subtype)
1886 != TYPE_UNSIGNED (sizetype))
1887 && TREE_CODE (gnu_min) == INTEGER_CST
1888 && TREE_CODE (gnu_max) == INTEGER_CST
1889 && TREE_OVERFLOW (gnu_min) && TREE_OVERFLOW (gnu_max)
1890 && (!TREE_OVERFLOW
1891 (fold (build2 (MINUS_EXPR, gnu_index_subtype,
1892 TYPE_MAX_VALUE (gnu_index_subtype),
1893 TYPE_MIN_VALUE (gnu_index_subtype))))))
1894 TREE_OVERFLOW (gnu_min) = TREE_OVERFLOW (gnu_max)
1895 = TREE_CONSTANT_OVERFLOW (gnu_min)
1896 = TREE_CONSTANT_OVERFLOW (gnu_max) = 0;
1897
1898 /* Similarly, if the range is null, use bounds of 1..0 for
1899 the sizetype bounds. */
1900 else if ((TYPE_PRECISION (gnu_index_subtype)
1901 > TYPE_PRECISION (sizetype)
1902 || TYPE_UNSIGNED (gnu_index_subtype)
1903 != TYPE_UNSIGNED (sizetype))
1904 && TREE_CODE (gnu_min) == INTEGER_CST
1905 && TREE_CODE (gnu_max) == INTEGER_CST
1906 && (TREE_OVERFLOW (gnu_min) || TREE_OVERFLOW (gnu_max))
1907 && tree_int_cst_lt (TYPE_MAX_VALUE (gnu_index_subtype),
1908 TYPE_MIN_VALUE (gnu_index_subtype)))
1909 gnu_min = size_one_node, gnu_max = size_zero_node;
1910
1911 /* Now compute the size of this bound. We need to provide
1912 GCC with an upper bound to use but have to deal with the
1913 "superflat" case. There are three ways to do this. If we
1914 can prove that the array can never be superflat, we can
1915 just use the high bound of the index subtype. If we can
1916 prove that the low bound minus one can't overflow, we
1917 can do this as MAX (hb, lb - 1). Otherwise, we have to use
1918 the expression hb >= lb ? hb : lb - 1. */
1919 gnu_high = size_binop (MINUS_EXPR, gnu_min, size_one_node);
1920
1921 /* See if the base array type is already flat. If it is, we
1922 are probably compiling an ACVC test, but it will cause the
1923 code below to malfunction if we don't handle it specially. */
1924 if (TREE_CODE (gnu_base_min) == INTEGER_CST
1925 && TREE_CODE (gnu_base_max) == INTEGER_CST
1926 && !TREE_CONSTANT_OVERFLOW (gnu_base_min)
1927 && !TREE_CONSTANT_OVERFLOW (gnu_base_max)
1928 && tree_int_cst_lt (gnu_base_max, gnu_base_min))
1929 gnu_high = size_zero_node, gnu_min = size_one_node;
1930
1931 /* If gnu_high is now an integer which overflowed, the array
1932 cannot be superflat. */
1933 else if (TREE_CODE (gnu_high) == INTEGER_CST
1934 && TREE_OVERFLOW (gnu_high))
1935 gnu_high = gnu_max;
1936 else if (TYPE_UNSIGNED (gnu_base_subtype)
1937 || TREE_CODE (gnu_high) == INTEGER_CST)
1938 gnu_high = size_binop (MAX_EXPR, gnu_max, gnu_high);
1939 else
1940 gnu_high
1941 = build_cond_expr
1942 (sizetype, build_binary_op (GE_EXPR, integer_type_node,
1943 gnu_max, gnu_min),
1944 gnu_max, gnu_high);
1945
1946 gnu_index_type[index]
1947 = create_index_type (gnu_min, gnu_high, gnu_index_subtype);
1948
1949 /* Also compute the maximum size of the array. Here we
1950 see if any constraint on the index type of the base type
1951 can be used in the case of self-referential bound on
1952 the index type of the subtype. We look for a non-"infinite"
1953 and non-self-referential bound from any type involved and
1954 handle each bound separately. */
1955
1956 if ((TREE_CODE (gnu_min) == INTEGER_CST
1957 && !TREE_OVERFLOW (gnu_min)
1958 && !operand_equal_p (gnu_min, gnu_base_base_min, 0))
1959 || !CONTAINS_PLACEHOLDER_P (gnu_min))
1960 gnu_base_min = gnu_min;
1961
1962 if ((TREE_CODE (gnu_max) == INTEGER_CST
1963 && !TREE_OVERFLOW (gnu_max)
1964 && !operand_equal_p (gnu_max, gnu_base_base_max, 0))
1965 || !CONTAINS_PLACEHOLDER_P (gnu_max))
1966 gnu_base_max = gnu_max;
1967
1968 if ((TREE_CODE (gnu_base_min) == INTEGER_CST
1969 && TREE_CONSTANT_OVERFLOW (gnu_base_min))
1970 || operand_equal_p (gnu_base_min, gnu_base_base_min, 0)
1971 || (TREE_CODE (gnu_base_max) == INTEGER_CST
1972 && TREE_CONSTANT_OVERFLOW (gnu_base_max))
1973 || operand_equal_p (gnu_base_max, gnu_base_base_max, 0))
1974 max_overflow = true;
1975
1976 gnu_base_min = size_binop (MAX_EXPR, gnu_base_min, gnu_min);
1977 gnu_base_max = size_binop (MIN_EXPR, gnu_base_max, gnu_max);
1978
1979 gnu_this_max
1980 = size_binop (MAX_EXPR,
1981 size_binop (PLUS_EXPR, size_one_node,
1982 size_binop (MINUS_EXPR, gnu_base_max,
1983 gnu_base_min)),
1984 size_zero_node);
1985
1986 if (TREE_CODE (gnu_this_max) == INTEGER_CST
1987 && TREE_CONSTANT_OVERFLOW (gnu_this_max))
1988 max_overflow = true;
1989
1990 gnu_max_size
1991 = size_binop (MULT_EXPR, gnu_max_size, gnu_this_max);
1992
1993 if (!integer_onep (TYPE_MIN_VALUE (gnu_index_subtype))
1994 || (TREE_CODE (TYPE_MAX_VALUE (gnu_index_subtype))
1995 != INTEGER_CST)
1996 || TREE_CODE (gnu_index_subtype) != INTEGER_TYPE
1997 || (TREE_TYPE (gnu_index_subtype)
1998 && (TREE_CODE (TREE_TYPE (gnu_index_subtype))
1999 != INTEGER_TYPE))
2000 || TYPE_BIASED_REPRESENTATION_P (gnu_index_subtype)
2001 || (TYPE_PRECISION (gnu_index_subtype)
2002 > TYPE_PRECISION (sizetype)))
2003 need_index_type_struct = true;
2004 }
2005
2006 /* Then flatten: create the array of arrays. */
2007
2008 gnu_type = gnat_to_gnu_type (Component_Type (gnat_entity));
2009
2010 /* One of the above calls might have caused us to be elaborated,
2011 so don't blow up if so. */
2012 if (present_gnu_tree (gnat_entity))
2013 {
2014 maybe_present = true;
2015 break;
2016 }
2017
2018 /* Get and validate any specified Component_Size, but if Packed,
2019 ignore it since the front end will have taken care of it. */
2020 gnu_comp_size
2021 = validate_size (Component_Size (gnat_entity), gnu_type,
2022 gnat_entity,
2023 (Is_Bit_Packed_Array (gnat_entity)
2024 ? TYPE_DECL : VAR_DECL),
2025 true, Has_Component_Size_Clause (gnat_entity));
2026
2027 /* If the component type is a RECORD_TYPE that has a self-referential
2028 size, use the maxium size. */
2029 if (!gnu_comp_size && TREE_CODE (gnu_type) == RECORD_TYPE
2030 && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type)))
2031 gnu_comp_size = max_size (TYPE_SIZE (gnu_type), true);
2032
2033 if (!Is_Bit_Packed_Array (gnat_entity) && gnu_comp_size)
2034 {
2035 gnu_type = make_type_from_size (gnu_type, gnu_comp_size, false);
2036 gnu_type = maybe_pad_type (gnu_type, gnu_comp_size, 0,
2037 gnat_entity, "C_PAD", false,
2038 definition, true);
2039 }
2040
2041 if (Has_Volatile_Components (Base_Type (gnat_entity)))
2042 gnu_type = build_qualified_type (gnu_type,
2043 (TYPE_QUALS (gnu_type)
2044 | TYPE_QUAL_VOLATILE));
2045
2046 gnu_max_size_unit = size_binop (MULT_EXPR, gnu_max_size,
2047 TYPE_SIZE_UNIT (gnu_type));
2048 gnu_max_size = size_binop (MULT_EXPR,
2049 convert (bitsizetype, gnu_max_size),
2050 TYPE_SIZE (gnu_type));
2051
2052 for (index = array_dim - 1; index >= 0; index --)
2053 {
2054 gnu_type = build_array_type (gnu_type, gnu_index_type[index]);
2055 TYPE_MULTI_ARRAY_P (gnu_type) = (index > 0);
2056 /* If the type below this an multi-array type, then this
2057 does not not have aliased components.
2058
2059 ??? Otherwise, for now, we say that any component of aggregate
2060 type is addressable because the front end may take 'Reference
2061 of it. But we have to make it addressable if it must be passed
2062 by reference or it that is the default. */
2063 TYPE_NONALIASED_COMPONENT (gnu_type)
2064 = ((TREE_CODE (TREE_TYPE (gnu_type)) == ARRAY_TYPE
2065 && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_type))) ? 1
2066 : (!Has_Aliased_Components (gnat_entity)
2067 && !AGGREGATE_TYPE_P (TREE_TYPE (gnu_type))));
2068 }
2069
2070 /* If we are at file level and this is a multi-dimensional array, we
2071 need to make a variable corresponding to the stride of the
2072 inner dimensions. */
2073 if (global_bindings_p () && array_dim > 1)
2074 {
2075 tree gnu_str_name = get_identifier ("ST");
2076 tree gnu_arr_type;
2077
2078 for (gnu_arr_type = TREE_TYPE (gnu_type);
2079 TREE_CODE (gnu_arr_type) == ARRAY_TYPE;
2080 gnu_arr_type = TREE_TYPE (gnu_arr_type),
2081 gnu_str_name = concat_id_with_name (gnu_str_name, "ST"))
2082 {
2083 tree eltype = TREE_TYPE (gnu_arr_type);
2084
2085 TYPE_SIZE (gnu_arr_type)
2086 = elaborate_expression_1 (gnat_entity, gnat_entity,
2087 TYPE_SIZE (gnu_arr_type),
2088 gnu_str_name, definition, 0);
2089
2090 /* ??? For now, store the size as a multiple of the
2091 alignment of the element type in bytes so that we
2092 can see the alignment from the tree. */
2093 TYPE_SIZE_UNIT (gnu_arr_type)
2094 = build_binary_op
2095 (MULT_EXPR, sizetype,
2096 elaborate_expression_1
2097 (gnat_entity, gnat_entity,
2098 build_binary_op (EXACT_DIV_EXPR, sizetype,
2099 TYPE_SIZE_UNIT (gnu_arr_type),
2100 size_int (TYPE_ALIGN (eltype)
2101 / BITS_PER_UNIT)),
2102 concat_id_with_name (gnu_str_name, "A_U"),
2103 definition, 0),
2104 size_int (TYPE_ALIGN (eltype) / BITS_PER_UNIT));
2105 }
2106 }
2107
2108 /* If we need to write out a record type giving the names of
2109 the bounds, do it now. */
2110 if (need_index_type_struct && debug_info_p)
2111 {
2112 tree gnu_bound_rec_type = make_node (RECORD_TYPE);
2113 tree gnu_field_list = NULL_TREE;
2114 tree gnu_field;
2115
2116 TYPE_NAME (gnu_bound_rec_type)
2117 = create_concat_name (gnat_entity, "XA");
2118
2119 for (index = array_dim - 1; index >= 0; index--)
2120 {
2121 tree gnu_type_name
2122 = TYPE_NAME (TYPE_INDEX_TYPE (gnu_index_type[index]));
2123
2124 if (TREE_CODE (gnu_type_name) == TYPE_DECL)
2125 gnu_type_name = DECL_NAME (gnu_type_name);
2126
2127 gnu_field = create_field_decl (gnu_type_name,
2128 integer_type_node,
2129 gnu_bound_rec_type,
2130 0, NULL_TREE, NULL_TREE, 0);
2131 TREE_CHAIN (gnu_field) = gnu_field_list;
2132 gnu_field_list = gnu_field;
2133 }
2134
2135 finish_record_type (gnu_bound_rec_type, gnu_field_list,
2136 false, false);
2137 }
2138
2139 TYPE_CONVENTION_FORTRAN_P (gnu_type)
2140 = (Convention (gnat_entity) == Convention_Fortran);
2141 TYPE_PACKED_ARRAY_TYPE_P (gnu_type)
2142 = Is_Packed_Array_Type (gnat_entity);
2143
2144 /* If our size depends on a placeholder and the maximum size doesn't
2145 overflow, use it. */
2146 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type))
2147 && !(TREE_CODE (gnu_max_size) == INTEGER_CST
2148 && TREE_OVERFLOW (gnu_max_size))
2149 && !(TREE_CODE (gnu_max_size_unit) == INTEGER_CST
2150 && TREE_OVERFLOW (gnu_max_size_unit))
2151 && !max_overflow)
2152 {
2153 TYPE_SIZE (gnu_type) = size_binop (MIN_EXPR, gnu_max_size,
2154 TYPE_SIZE (gnu_type));
2155 TYPE_SIZE_UNIT (gnu_type)
2156 = size_binop (MIN_EXPR, gnu_max_size_unit,
2157 TYPE_SIZE_UNIT (gnu_type));
2158 }
2159
2160 /* Set our alias set to that of our base type. This gives all
2161 array subtypes the same alias set. */
2162 copy_alias_set (gnu_type, gnu_base_type);
2163 }
2164
2165 /* If this is a packed type, make this type the same as the packed
2166 array type, but do some adjusting in the type first. */
2167
2168 if (Present (Packed_Array_Type (gnat_entity)))
2169 {
2170 Entity_Id gnat_index;
2171 tree gnu_inner_type;
2172
2173 /* First finish the type we had been making so that we output
2174 debugging information for it */
2175 gnu_type
2176 = build_qualified_type (gnu_type,
2177 (TYPE_QUALS (gnu_type)
2178 | (TYPE_QUAL_VOLATILE
2179 * Treat_As_Volatile (gnat_entity))));
2180 gnu_decl = create_type_decl (gnu_entity_id, gnu_type, attr_list,
2181 !Comes_From_Source (gnat_entity),
2182 debug_info_p, gnat_entity);
2183 if (!Comes_From_Source (gnat_entity))
2184 DECL_ARTIFICIAL (gnu_decl) = 1;
2185
2186 /* Save it as our equivalent in case the call below elaborates
2187 this type again. */
2188 save_gnu_tree (gnat_entity, gnu_decl, false);
2189
2190 gnu_decl = gnat_to_gnu_entity (Packed_Array_Type (gnat_entity),
2191 NULL_TREE, 0);
2192 this_made_decl = true;
2193 gnu_inner_type = gnu_type = TREE_TYPE (gnu_decl);
2194 save_gnu_tree (gnat_entity, NULL_TREE, false);
2195
2196 while (TREE_CODE (gnu_inner_type) == RECORD_TYPE
2197 && (TYPE_JUSTIFIED_MODULAR_P (gnu_inner_type)
2198 || TYPE_IS_PADDING_P (gnu_inner_type)))
2199 gnu_inner_type = TREE_TYPE (TYPE_FIELDS (gnu_inner_type));
2200
2201 /* We need to point the type we just made to our index type so
2202 the actual bounds can be put into a template. */
2203
2204 if ((TREE_CODE (gnu_inner_type) == ARRAY_TYPE
2205 && !TYPE_ACTUAL_BOUNDS (gnu_inner_type))
2206 || (TREE_CODE (gnu_inner_type) == INTEGER_TYPE
2207 && !TYPE_HAS_ACTUAL_BOUNDS_P (gnu_inner_type)))
2208 {
2209 if (TREE_CODE (gnu_inner_type) == INTEGER_TYPE)
2210 {
2211 /* The TYPE_ACTUAL_BOUNDS field is also used for the modulus.
2212 If it is, we need to make another type. */
2213 if (TYPE_MODULAR_P (gnu_inner_type))
2214 {
2215 tree gnu_subtype;
2216
2217 gnu_subtype = make_node (INTEGER_TYPE);
2218
2219 TREE_TYPE (gnu_subtype) = gnu_inner_type;
2220 TYPE_MIN_VALUE (gnu_subtype)
2221 = TYPE_MIN_VALUE (gnu_inner_type);
2222 TYPE_MAX_VALUE (gnu_subtype)
2223 = TYPE_MAX_VALUE (gnu_inner_type);
2224 TYPE_PRECISION (gnu_subtype)
2225 = TYPE_PRECISION (gnu_inner_type);
2226 TYPE_UNSIGNED (gnu_subtype)
2227 = TYPE_UNSIGNED (gnu_inner_type);
2228 TYPE_EXTRA_SUBTYPE_P (gnu_subtype) = 1;
2229 layout_type (gnu_subtype);
2230
2231 gnu_inner_type = gnu_subtype;
2232 }
2233
2234 TYPE_HAS_ACTUAL_BOUNDS_P (gnu_inner_type) = 1;
2235 }
2236
2237 SET_TYPE_ACTUAL_BOUNDS (gnu_inner_type, NULL_TREE);
2238
2239 for (gnat_index = First_Index (gnat_entity);
2240 Present (gnat_index); gnat_index = Next_Index (gnat_index))
2241 SET_TYPE_ACTUAL_BOUNDS
2242 (gnu_inner_type,
2243 tree_cons (NULL_TREE,
2244 get_unpadded_type (Etype (gnat_index)),
2245 TYPE_ACTUAL_BOUNDS (gnu_inner_type)));
2246
2247 if (Convention (gnat_entity) != Convention_Fortran)
2248 SET_TYPE_ACTUAL_BOUNDS
2249 (gnu_inner_type,
2250 nreverse (TYPE_ACTUAL_BOUNDS (gnu_inner_type)));
2251
2252 if (TREE_CODE (gnu_type) == RECORD_TYPE
2253 && TYPE_JUSTIFIED_MODULAR_P (gnu_type))
2254 TREE_TYPE (TYPE_FIELDS (gnu_type)) = gnu_inner_type;
2255 }
2256 }
2257
2258 /* Abort if packed array with no packed array type field set. */
2259 else
2260 gcc_assert (!Is_Packed (gnat_entity));
2261
2262 break;
2263
2264 case E_String_Literal_Subtype:
2265 /* Create the type for a string literal. */
2266 {
2267 Entity_Id gnat_full_type
2268 = (IN (Ekind (Etype (gnat_entity)), Private_Kind)
2269 && Present (Full_View (Etype (gnat_entity)))
2270 ? Full_View (Etype (gnat_entity)) : Etype (gnat_entity));
2271 tree gnu_string_type = get_unpadded_type (gnat_full_type);
2272 tree gnu_string_array_type
2273 = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_string_type))));
2274 tree gnu_string_index_type
2275 = get_base_type (TREE_TYPE (TYPE_INDEX_TYPE
2276 (TYPE_DOMAIN (gnu_string_array_type))));
2277 tree gnu_lower_bound
2278 = convert (gnu_string_index_type,
2279 gnat_to_gnu (String_Literal_Low_Bound (gnat_entity)));
2280 int length = UI_To_Int (String_Literal_Length (gnat_entity));
2281 tree gnu_length = ssize_int (length - 1);
2282 tree gnu_upper_bound
2283 = build_binary_op (PLUS_EXPR, gnu_string_index_type,
2284 gnu_lower_bound,
2285 convert (gnu_string_index_type, gnu_length));
2286 tree gnu_range_type
2287 = build_range_type (gnu_string_index_type,
2288 gnu_lower_bound, gnu_upper_bound);
2289 tree gnu_index_type
2290 = create_index_type (convert (sizetype,
2291 TYPE_MIN_VALUE (gnu_range_type)),
2292 convert (sizetype,
2293 TYPE_MAX_VALUE (gnu_range_type)),
2294 gnu_range_type);
2295
2296 gnu_type
2297 = build_array_type (gnat_to_gnu_type (Component_Type (gnat_entity)),
2298 gnu_index_type);
2299 copy_alias_set (gnu_type, gnu_string_type);
2300 }
2301 break;
2302
2303 /* Record Types and Subtypes
2304
2305 The following fields are defined on record types:
2306
2307 Has_Discriminants True if the record has discriminants
2308 First_Discriminant Points to head of list of discriminants
2309 First_Entity Points to head of list of fields
2310 Is_Tagged_Type True if the record is tagged
2311
2312 Implementation of Ada records and discriminated records:
2313
2314 A record type definition is transformed into the equivalent of a C
2315 struct definition. The fields that are the discriminants which are
2316 found in the Full_Type_Declaration node and the elements of the
2317 Component_List found in the Record_Type_Definition node. The
2318 Component_List can be a recursive structure since each Variant of
2319 the Variant_Part of the Component_List has a Component_List.
2320
2321 Processing of a record type definition comprises starting the list of
2322 field declarations here from the discriminants and the calling the
2323 function components_to_record to add the rest of the fields from the
2324 component list and return the gnu type node. The function
2325 components_to_record will call itself recursively as it traverses
2326 the tree. */
2327
2328 case E_Record_Type:
2329 if (Has_Complex_Representation (gnat_entity))
2330 {
2331 gnu_type
2332 = build_complex_type
2333 (get_unpadded_type
2334 (Etype (Defining_Entity
2335 (First (Component_Items
2336 (Component_List
2337 (Type_Definition
2338 (Declaration_Node (gnat_entity)))))))));
2339
2340 break;
2341 }
2342
2343 {
2344 Node_Id full_definition = Declaration_Node (gnat_entity);
2345 Node_Id record_definition = Type_Definition (full_definition);
2346 Entity_Id gnat_field;
2347 tree gnu_field;
2348 tree gnu_field_list = NULL_TREE;
2349 tree gnu_get_parent;
2350 int packed = (Is_Packed (gnat_entity) ? 1
2351 : (Component_Alignment (gnat_entity)
2352 == Calign_Storage_Unit) ? -1
2353 : 0);
2354 bool has_rep = Has_Specified_Layout (gnat_entity);
2355 bool all_rep = has_rep;
2356 bool is_extension
2357 = (Is_Tagged_Type (gnat_entity)
2358 && Nkind (record_definition) == N_Derived_Type_Definition);
2359
2360 /* See if all fields have a rep clause. Stop when we find one
2361 that doesn't. */
2362 for (gnat_field = First_Entity (gnat_entity);
2363 Present (gnat_field) && all_rep;
2364 gnat_field = Next_Entity (gnat_field))
2365 if ((Ekind (gnat_field) == E_Component
2366 || Ekind (gnat_field) == E_Discriminant)
2367 && No (Component_Clause (gnat_field)))
2368 all_rep = false;
2369
2370 /* If this is a record extension, go a level further to find the
2371 record definition. Also, verify we have a Parent_Subtype. */
2372 if (is_extension)
2373 {
2374 if (!type_annotate_only
2375 || Present (Record_Extension_Part (record_definition)))
2376 record_definition = Record_Extension_Part (record_definition);
2377
2378 gcc_assert (type_annotate_only
2379 || Present (Parent_Subtype (gnat_entity)));
2380 }
2381
2382 /* Make a node for the record. If we are not defining the record,
2383 suppress expanding incomplete types. We use the same RECORD_TYPE
2384 as for a dummy type and reset TYPE_DUMMY_P to show it's no longer
2385 a dummy.
2386
2387 It is very tempting to delay resetting this bit until we are done
2388 with completing the type, e.g. to let possible intermediate
2389 elaboration of access types designating the record know it is not
2390 complete and arrange for update_pointer_to to fix things up later.
2391
2392 It would be wrong, however, because dummy types are expected only
2393 to be created for Ada incomplete or private types, which is not
2394 what we have here. Doing so would make other parts of gigi think
2395 we are dealing with a really incomplete or private type, and have
2396 nasty side effects, typically on the generation of the associated
2397 debugging information. */
2398 gnu_type = make_dummy_type (gnat_entity);
2399 TYPE_DUMMY_P (gnu_type) = 0;
2400
2401 if (TREE_CODE (TYPE_NAME (gnu_type)) == TYPE_DECL && debug_info_p)
2402 DECL_IGNORED_P (TYPE_NAME (gnu_type)) = 0;
2403
2404 TYPE_ALIGN (gnu_type) = 0;
2405 TYPE_PACKED (gnu_type) = packed || has_rep;
2406
2407 if (!definition)
2408 defer_incomplete_level++, this_deferred = true;
2409
2410 /* If both a size and rep clause was specified, put the size in
2411 the record type now so that it can get the proper mode. */
2412 if (has_rep && Known_Esize (gnat_entity))
2413 TYPE_SIZE (gnu_type) = UI_To_gnu (Esize (gnat_entity), sizetype);
2414
2415 /* Always set the alignment here so that it can be used to
2416 set the mode, if it is making the alignment stricter. If
2417 it is invalid, it will be checked again below. If this is to
2418 be Atomic, choose a default alignment of a word unless we know
2419 the size and it's smaller. */
2420 if (Known_Alignment (gnat_entity))
2421 TYPE_ALIGN (gnu_type)
2422 = validate_alignment (Alignment (gnat_entity), gnat_entity, 0);
2423 else if (Is_Atomic (gnat_entity))
2424 TYPE_ALIGN (gnu_type)
2425 = (esize >= BITS_PER_WORD ? BITS_PER_WORD
2426 : 1 << (floor_log2 (esize - 1) + 1));
2427
2428 /* If we have a Parent_Subtype, make a field for the parent. If
2429 this record has rep clauses, force the position to zero. */
2430 if (Present (Parent_Subtype (gnat_entity)))
2431 {
2432 tree gnu_parent;
2433
2434 /* A major complexity here is that the parent subtype will
2435 reference our discriminants. But those must reference
2436 the parent component of this record. So here we will
2437 initialize each of those components to a COMPONENT_REF.
2438 The first operand of that COMPONENT_REF is another
2439 COMPONENT_REF which will be filled in below, once
2440 the parent type can be safely built. */
2441
2442 gnu_get_parent = build3 (COMPONENT_REF, void_type_node,
2443 build0 (PLACEHOLDER_EXPR, gnu_type),
2444 build_decl (FIELD_DECL, NULL_TREE,
2445 NULL_TREE),
2446 NULL_TREE);
2447
2448 if (Has_Discriminants (gnat_entity))
2449 for (gnat_field = First_Stored_Discriminant (gnat_entity);
2450 Present (gnat_field);
2451 gnat_field = Next_Stored_Discriminant (gnat_field))
2452 if (Present (Corresponding_Discriminant (gnat_field)))
2453 save_gnu_tree
2454 (gnat_field,
2455 build3 (COMPONENT_REF,
2456 get_unpadded_type (Etype (gnat_field)),
2457 gnu_get_parent,
2458 gnat_to_gnu_field_decl (Corresponding_Discriminant
2459 (gnat_field)),
2460 NULL_TREE),
2461 true);
2462
2463 gnu_parent = gnat_to_gnu_type (Parent_Subtype (gnat_entity));
2464
2465 gnu_field_list
2466 = create_field_decl (get_identifier
2467 (Get_Name_String (Name_uParent)),
2468 gnu_parent, gnu_type, 0,
2469 has_rep ? TYPE_SIZE (gnu_parent) : 0,
2470 has_rep ? bitsize_zero_node : 0, 1);
2471 DECL_INTERNAL_P (gnu_field_list) = 1;
2472
2473 TREE_TYPE (gnu_get_parent) = gnu_parent;
2474 TREE_OPERAND (gnu_get_parent, 1) = gnu_field_list;
2475 }
2476
2477 /* Make the fields for the discriminants and put them into the record
2478 unless it's an Unchecked_Union. */
2479 if (Has_Discriminants (gnat_entity))
2480 for (gnat_field = First_Stored_Discriminant (gnat_entity);
2481 Present (gnat_field);
2482 gnat_field = Next_Stored_Discriminant (gnat_field))
2483 {
2484 /* If this is a record extension and this discriminant
2485 is the renaming of another discriminant, we've already
2486 handled the discriminant above. */
2487 if (Present (Parent_Subtype (gnat_entity))
2488 && Present (Corresponding_Discriminant (gnat_field)))
2489 continue;
2490
2491 gnu_field
2492 = gnat_to_gnu_field (gnat_field, gnu_type, packed, definition);
2493
2494 /* Make an expression using a PLACEHOLDER_EXPR from the
2495 FIELD_DECL node just created and link that with the
2496 corresponding GNAT defining identifier. Then add to the
2497 list of fields. */
2498 save_gnu_tree (gnat_field,
2499 build3 (COMPONENT_REF, TREE_TYPE (gnu_field),
2500 build0 (PLACEHOLDER_EXPR,
2501 DECL_CONTEXT (gnu_field)),
2502 gnu_field, NULL_TREE),
2503 true);
2504
2505 if (!Is_Unchecked_Union (gnat_entity))
2506 {
2507 TREE_CHAIN (gnu_field) = gnu_field_list;
2508 gnu_field_list = gnu_field;
2509 }
2510 }
2511
2512 /* Put the discriminants into the record (backwards), so we can
2513 know the appropriate discriminant to use for the names of the
2514 variants. */
2515 TYPE_FIELDS (gnu_type) = gnu_field_list;
2516
2517 /* Add the listed fields into the record and finish up. */
2518 components_to_record (gnu_type, Component_List (record_definition),
2519 gnu_field_list, packed, definition, NULL,
2520 false, all_rep, this_deferred,
2521 Is_Unchecked_Union (gnat_entity));
2522
2523 if (this_deferred)
2524 {
2525 debug_deferred = true;
2526 defer_debug_level++;
2527
2528 defer_debug_incomplete_list
2529 = tree_cons (NULL_TREE, gnu_type,
2530 defer_debug_incomplete_list);
2531 }
2532
2533 /* We used to remove the associations of the discriminants and
2534 _Parent for validity checking, but we may need them if there's
2535 Freeze_Node for a subtype used in this record. */
2536
2537 TYPE_VOLATILE (gnu_type) = Treat_As_Volatile (gnat_entity);
2538 TYPE_BY_REFERENCE_P (gnu_type) = Is_By_Reference_Type (gnat_entity);
2539
2540 /* If it is a tagged record force the type to BLKmode to insure
2541 that these objects will always be placed in memory. Do the
2542 same thing for limited record types. */
2543 if (Is_Tagged_Type (gnat_entity) || Is_Limited_Record (gnat_entity))
2544 TYPE_MODE (gnu_type) = BLKmode;
2545
2546 /* If this is a derived type, we must make the alias set of this type
2547 the same as that of the type we are derived from. We assume here
2548 that the other type is already frozen. */
2549 if (Etype (gnat_entity) != gnat_entity
2550 && !(Is_Private_Type (Etype (gnat_entity))
2551 && Full_View (Etype (gnat_entity)) == gnat_entity))
2552 copy_alias_set (gnu_type, gnat_to_gnu_type (Etype (gnat_entity)));
2553
2554 /* Fill in locations of fields. */
2555 annotate_rep (gnat_entity, gnu_type);
2556
2557 /* If there are any entities in the chain corresponding to
2558 components that we did not elaborate, ensure we elaborate their
2559 types if they are Itypes. */
2560 for (gnat_temp = First_Entity (gnat_entity);
2561 Present (gnat_temp); gnat_temp = Next_Entity (gnat_temp))
2562 if ((Ekind (gnat_temp) == E_Component
2563 || Ekind (gnat_temp) == E_Discriminant)
2564 && Is_Itype (Etype (gnat_temp))
2565 && !present_gnu_tree (gnat_temp))
2566 gnat_to_gnu_entity (Etype (gnat_temp), NULL_TREE, 0);
2567 }
2568 break;
2569
2570 case E_Class_Wide_Subtype:
2571 /* If an equivalent type is present, that is what we should use.
2572 Otherwise, fall through to handle this like a record subtype
2573 since it may have constraints. */
2574
2575 if (Present (Equivalent_Type (gnat_entity)))
2576 {
2577 gnu_decl = gnat_to_gnu_entity (Equivalent_Type (gnat_entity),
2578 NULL_TREE, 0);
2579 maybe_present = true;
2580 break;
2581 }
2582
2583 /* ... fall through ... */
2584
2585 case E_Record_Subtype:
2586
2587 /* If Cloned_Subtype is Present it means this record subtype has
2588 identical layout to that type or subtype and we should use
2589 that GCC type for this one. The front end guarantees that
2590 the component list is shared. */
2591 if (Present (Cloned_Subtype (gnat_entity)))
2592 {
2593 gnu_decl = gnat_to_gnu_entity (Cloned_Subtype (gnat_entity),
2594 NULL_TREE, 0);
2595 maybe_present = true;
2596 }
2597
2598 /* Otherwise, first ensure the base type is elaborated. Then, if we are
2599 changing the type, make a new type with each field having the
2600 type of the field in the new subtype but having the position
2601 computed by transforming every discriminant reference according
2602 to the constraints. We don't see any difference between
2603 private and nonprivate type here since derivations from types should
2604 have been deferred until the completion of the private type. */
2605 else
2606 {
2607 Entity_Id gnat_base_type = Implementation_Base_Type (gnat_entity);
2608 tree gnu_base_type;
2609 tree gnu_orig_type;
2610
2611 if (!definition)
2612 defer_incomplete_level++, this_deferred = true;
2613
2614 /* Get the base type initially for its alignment and sizes. But
2615 if it is a padded type, we do all the other work with the
2616 unpadded type. */
2617 gnu_type = gnu_orig_type = gnu_base_type
2618 = gnat_to_gnu_type (gnat_base_type);
2619
2620 if (TREE_CODE (gnu_type) == RECORD_TYPE
2621 && TYPE_IS_PADDING_P (gnu_type))
2622 gnu_type = gnu_orig_type = TREE_TYPE (TYPE_FIELDS (gnu_type));
2623
2624 if (present_gnu_tree (gnat_entity))
2625 {
2626 maybe_present = true;
2627 break;
2628 }
2629
2630 /* When the type has discriminants, and these discriminants
2631 affect the shape of what it built, factor them in.
2632
2633 If we are making a subtype of an Unchecked_Union (must be an
2634 Itype), just return the type.
2635
2636 We can't just use Is_Constrained because private subtypes without
2637 discriminants of full types with discriminants with default
2638 expressions are Is_Constrained but aren't constrained! */
2639
2640 if (IN (Ekind (gnat_base_type), Record_Kind)
2641 && !Is_For_Access_Subtype (gnat_entity)
2642 && !Is_Unchecked_Union (gnat_base_type)
2643 && Is_Constrained (gnat_entity)
2644 && Stored_Constraint (gnat_entity) != No_Elist
2645 && Present (Discriminant_Constraint (gnat_entity)))
2646 {
2647 Entity_Id gnat_field;
2648 tree gnu_field_list = 0;
2649 tree gnu_pos_list
2650 = compute_field_positions (gnu_orig_type, NULL_TREE,
2651 size_zero_node, bitsize_zero_node,
2652 BIGGEST_ALIGNMENT);
2653 tree gnu_subst_list
2654 = substitution_list (gnat_entity, gnat_base_type, NULL_TREE,
2655 definition);
2656 tree gnu_temp;
2657
2658 gnu_type = make_node (RECORD_TYPE);
2659 TYPE_NAME (gnu_type) = gnu_entity_id;
2660 TYPE_STUB_DECL (gnu_type)
2661 = create_type_decl (NULL_TREE, gnu_type, NULL, false, false,
2662 gnat_entity);
2663 TYPE_ALIGN (gnu_type) = TYPE_ALIGN (gnu_base_type);
2664
2665 for (gnat_field = First_Entity (gnat_entity);
2666 Present (gnat_field); gnat_field = Next_Entity (gnat_field))
2667 if ((Ekind (gnat_field) == E_Component
2668 || Ekind (gnat_field) == E_Discriminant)
2669 && (Underlying_Type (Scope (Original_Record_Component
2670 (gnat_field)))
2671 == gnat_base_type)
2672 && (No (Corresponding_Discriminant (gnat_field))
2673 || !Is_Tagged_Type (gnat_base_type)))
2674 {
2675 tree gnu_old_field
2676 = gnat_to_gnu_field_decl (Original_Record_Component
2677 (gnat_field));
2678 tree gnu_offset
2679 = TREE_VALUE (purpose_member (gnu_old_field,
2680 gnu_pos_list));
2681 tree gnu_pos = TREE_PURPOSE (gnu_offset);
2682 tree gnu_bitpos = TREE_VALUE (TREE_VALUE (gnu_offset));
2683 tree gnu_field_type
2684 = gnat_to_gnu_type (Etype (gnat_field));
2685 tree gnu_size = TYPE_SIZE (gnu_field_type);
2686 tree gnu_new_pos = 0;
2687 unsigned int offset_align
2688 = tree_low_cst (TREE_PURPOSE (TREE_VALUE (gnu_offset)),
2689 1);
2690 tree gnu_field;
2691
2692 /* If there was a component clause, the field types must be
2693 the same for the type and subtype, so copy the data from
2694 the old field to avoid recomputation here. Also if the
2695 field is justified modular and the optimization in
2696 gnat_to_gnu_field was applied. */
2697 if (Present (Component_Clause
2698 (Original_Record_Component (gnat_field)))
2699 || (TREE_CODE (gnu_field_type) == RECORD_TYPE
2700 && TYPE_JUSTIFIED_MODULAR_P (gnu_field_type)
2701 && TREE_TYPE (TYPE_FIELDS (gnu_field_type))
2702 == TREE_TYPE (gnu_old_field)))
2703 {
2704 gnu_size = DECL_SIZE (gnu_old_field);
2705 gnu_field_type = TREE_TYPE (gnu_old_field);
2706 }
2707
2708 /* If this was a bitfield, get the size from the old field.
2709 Also ensure the type can be placed into a bitfield. */
2710 else if (DECL_BIT_FIELD (gnu_old_field))
2711 {
2712 gnu_size = DECL_SIZE (gnu_old_field);
2713 if (TYPE_MODE (gnu_field_type) == BLKmode
2714 && TREE_CODE (gnu_field_type) == RECORD_TYPE
2715 && host_integerp (TYPE_SIZE (gnu_field_type), 1))
2716 gnu_field_type = make_packable_type (gnu_field_type);
2717 }
2718
2719 if (CONTAINS_PLACEHOLDER_P (gnu_pos))
2720 for (gnu_temp = gnu_subst_list;
2721 gnu_temp; gnu_temp = TREE_CHAIN (gnu_temp))
2722 gnu_pos = substitute_in_expr (gnu_pos,
2723 TREE_PURPOSE (gnu_temp),
2724 TREE_VALUE (gnu_temp));
2725
2726 /* If the size is now a constant, we can set it as the
2727 size of the field when we make it. Otherwise, we need
2728 to deal with it specially. */
2729 if (TREE_CONSTANT (gnu_pos))
2730 gnu_new_pos = bit_from_pos (gnu_pos, gnu_bitpos);
2731
2732 gnu_field
2733 = create_field_decl
2734 (DECL_NAME (gnu_old_field), gnu_field_type, gnu_type,
2735 0, gnu_size, gnu_new_pos,
2736 !DECL_NONADDRESSABLE_P (gnu_old_field));
2737
2738 if (!TREE_CONSTANT (gnu_pos))
2739 {
2740 normalize_offset (&gnu_pos, &gnu_bitpos, offset_align);
2741 DECL_FIELD_OFFSET (gnu_field) = gnu_pos;
2742 DECL_FIELD_BIT_OFFSET (gnu_field) = gnu_bitpos;
2743 SET_DECL_OFFSET_ALIGN (gnu_field, offset_align);
2744 DECL_SIZE (gnu_field) = gnu_size;
2745 DECL_SIZE_UNIT (gnu_field)
2746 = convert (sizetype,
2747 size_binop (CEIL_DIV_EXPR, gnu_size,
2748 bitsize_unit_node));
2749 layout_decl (gnu_field, DECL_OFFSET_ALIGN (gnu_field));
2750 }
2751
2752 DECL_INTERNAL_P (gnu_field)
2753 = DECL_INTERNAL_P (gnu_old_field);
2754 SET_DECL_ORIGINAL_FIELD
2755 (gnu_field, (DECL_ORIGINAL_FIELD (gnu_old_field)
2756 ? DECL_ORIGINAL_FIELD (gnu_old_field)
2757 : gnu_old_field));
2758 DECL_DISCRIMINANT_NUMBER (gnu_field)
2759 = DECL_DISCRIMINANT_NUMBER (gnu_old_field);
2760 TREE_THIS_VOLATILE (gnu_field)
2761 = TREE_THIS_VOLATILE (gnu_old_field);
2762 TREE_CHAIN (gnu_field) = gnu_field_list;
2763 gnu_field_list = gnu_field;
2764 save_gnu_tree (gnat_field, gnu_field, false);
2765 }
2766
2767 /* Now go through the entities again looking for Itypes that
2768 we have not elaborated but should (e.g., Etypes of fields
2769 that have Original_Components). */
2770 for (gnat_field = First_Entity (gnat_entity);
2771 Present (gnat_field); gnat_field = Next_Entity (gnat_field))
2772 if ((Ekind (gnat_field) == E_Discriminant
2773 || Ekind (gnat_field) == E_Component)
2774 && !present_gnu_tree (Etype (gnat_field)))
2775 gnat_to_gnu_entity (Etype (gnat_field), NULL_TREE, 0);
2776
2777 finish_record_type (gnu_type, nreverse (gnu_field_list),
2778 true, false);
2779
2780 /* Now set the size, alignment and alias set of the new type to
2781 match that of the old one, doing any substitutions, as
2782 above. */
2783 TYPE_ALIGN (gnu_type) = TYPE_ALIGN (gnu_base_type);
2784 TYPE_SIZE (gnu_type) = TYPE_SIZE (gnu_base_type);
2785 TYPE_SIZE_UNIT (gnu_type) = TYPE_SIZE_UNIT (gnu_base_type);
2786 SET_TYPE_ADA_SIZE (gnu_type, TYPE_ADA_SIZE (gnu_base_type));
2787 copy_alias_set (gnu_type, gnu_base_type);
2788
2789 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type)))
2790 for (gnu_temp = gnu_subst_list;
2791 gnu_temp; gnu_temp = TREE_CHAIN (gnu_temp))
2792 TYPE_SIZE (gnu_type)
2793 = substitute_in_expr (TYPE_SIZE (gnu_type),
2794 TREE_PURPOSE (gnu_temp),
2795 TREE_VALUE (gnu_temp));
2796
2797 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE_UNIT (gnu_type)))
2798 for (gnu_temp = gnu_subst_list;
2799 gnu_temp; gnu_temp = TREE_CHAIN (gnu_temp))
2800 TYPE_SIZE_UNIT (gnu_type)
2801 = substitute_in_expr (TYPE_SIZE_UNIT (gnu_type),
2802 TREE_PURPOSE (gnu_temp),
2803 TREE_VALUE (gnu_temp));
2804
2805 if (CONTAINS_PLACEHOLDER_P (TYPE_ADA_SIZE (gnu_type)))
2806 for (gnu_temp = gnu_subst_list;
2807 gnu_temp; gnu_temp = TREE_CHAIN (gnu_temp))
2808 SET_TYPE_ADA_SIZE
2809 (gnu_type, substitute_in_expr (TYPE_ADA_SIZE (gnu_type),
2810 TREE_PURPOSE (gnu_temp),
2811 TREE_VALUE (gnu_temp)));
2812
2813 /* Recompute the mode of this record type now that we know its
2814 actual size. */
2815 compute_record_mode (gnu_type);
2816
2817 /* Fill in locations of fields. */
2818 annotate_rep (gnat_entity, gnu_type);
2819 }
2820
2821 /* If we've made a new type, record it and make an XVS type to show
2822 what this is a subtype of. Some debuggers require the XVS
2823 type to be output first, so do it in that order. */
2824 if (gnu_type != gnu_orig_type)
2825 {
2826 if (debug_info_p)
2827 {
2828 tree gnu_subtype_marker = make_node (RECORD_TYPE);
2829 tree gnu_orig_name = TYPE_NAME (gnu_orig_type);
2830
2831 if (TREE_CODE (gnu_orig_name) == TYPE_DECL)
2832 gnu_orig_name = DECL_NAME (gnu_orig_name);
2833
2834 TYPE_NAME (gnu_subtype_marker)
2835 = create_concat_name (gnat_entity, "XVS");
2836 finish_record_type (gnu_subtype_marker,
2837 create_field_decl (gnu_orig_name,
2838 integer_type_node,
2839 gnu_subtype_marker,
2840 0, NULL_TREE,
2841 NULL_TREE, 0),
2842 false, false);
2843 }
2844
2845 TYPE_VOLATILE (gnu_type) = Treat_As_Volatile (gnat_entity);
2846 TYPE_NAME (gnu_type) = gnu_entity_id;
2847 TYPE_STUB_DECL (gnu_type)
2848 = create_type_decl (TYPE_NAME (gnu_type), gnu_type,
2849 NULL, true, debug_info_p, gnat_entity);
2850 }
2851
2852 /* Otherwise, go down all the components in the new type and
2853 make them equivalent to those in the base type. */
2854 else
2855 for (gnat_temp = First_Entity (gnat_entity); Present (gnat_temp);
2856 gnat_temp = Next_Entity (gnat_temp))
2857 if ((Ekind (gnat_temp) == E_Discriminant
2858 && !Is_Unchecked_Union (gnat_base_type))
2859 || Ekind (gnat_temp) == E_Component)
2860 save_gnu_tree (gnat_temp,
2861 gnat_to_gnu_field_decl
2862 (Original_Record_Component (gnat_temp)), false);
2863 }
2864 break;
2865
2866 case E_Access_Subprogram_Type:
2867 case E_Anonymous_Access_Subprogram_Type:
2868 /* If we are not defining this entity, and we have incomplete
2869 entities being processed above us, make a dummy type and
2870 fill it in later. */
2871 if (!definition && defer_incomplete_level != 0)
2872 {
2873 struct incomplete *p
2874 = (struct incomplete *) xmalloc (sizeof (struct incomplete));
2875
2876 gnu_type
2877 = build_pointer_type
2878 (make_dummy_type (Directly_Designated_Type (gnat_entity)));
2879 gnu_decl = create_type_decl (gnu_entity_id, gnu_type, attr_list,
2880 !Comes_From_Source (gnat_entity),
2881 debug_info_p, gnat_entity);
2882 save_gnu_tree (gnat_entity, gnu_decl, false);
2883 this_made_decl = saved = true;
2884
2885 p->old_type = TREE_TYPE (gnu_type);
2886 p->full_type = Directly_Designated_Type (gnat_entity);
2887 p->next = defer_incomplete_list;
2888 defer_incomplete_list = p;
2889 break;
2890 }
2891
2892 /* ... fall through ... */
2893
2894 case E_Allocator_Type:
2895 case E_Access_Type:
2896 case E_Access_Attribute_Type:
2897 case E_Anonymous_Access_Type:
2898 case E_General_Access_Type:
2899 {
2900 Entity_Id gnat_desig_type = Directly_Designated_Type (gnat_entity);
2901 Entity_Id gnat_desig_full
2902 = ((IN (Ekind (Etype (gnat_desig_type)),
2903 Incomplete_Or_Private_Kind))
2904 ? Full_View (gnat_desig_type) : 0);
2905 /* We want to know if we'll be seeing the freeze node for any
2906 incomplete type we may be pointing to. */
2907 bool in_main_unit
2908 = (Present (gnat_desig_full)
2909 ? In_Extended_Main_Code_Unit (gnat_desig_full)
2910 : In_Extended_Main_Code_Unit (gnat_desig_type));
2911 bool got_fat_p = false;
2912 bool made_dummy = false;
2913 tree gnu_desig_type = NULL_TREE;
2914 enum machine_mode p_mode = mode_for_size (esize, MODE_INT, 0);
2915
2916 if (!targetm.valid_pointer_mode (p_mode))
2917 p_mode = ptr_mode;
2918
2919 if (No (gnat_desig_full)
2920 && (Ekind (gnat_desig_type) == E_Class_Wide_Type
2921 || (Ekind (gnat_desig_type) == E_Class_Wide_Subtype
2922 && Present (Equivalent_Type (gnat_desig_type)))))
2923 {
2924 if (Present (Equivalent_Type (gnat_desig_type)))
2925 {
2926 gnat_desig_full = Equivalent_Type (gnat_desig_type);
2927 if (IN (Ekind (gnat_desig_full), Incomplete_Or_Private_Kind))
2928 gnat_desig_full = Full_View (gnat_desig_full);
2929 }
2930 else if (IN (Ekind (Root_Type (gnat_desig_type)),
2931 Incomplete_Or_Private_Kind))
2932 gnat_desig_full = Full_View (Root_Type (gnat_desig_type));
2933 }
2934
2935 if (Present (gnat_desig_full) && Is_Concurrent_Type (gnat_desig_full))
2936 gnat_desig_full = Corresponding_Record_Type (gnat_desig_full);
2937
2938 /* If either the designated type or its full view is an
2939 unconstrained array subtype, replace it with the type it's a
2940 subtype of. This avoids problems with multiple copies of
2941 unconstrained array types. */
2942 if (Ekind (gnat_desig_type) == E_Array_Subtype
2943 && !Is_Constrained (gnat_desig_type))
2944 gnat_desig_type = Etype (gnat_desig_type);
2945 if (Present (gnat_desig_full)
2946 && Ekind (gnat_desig_full) == E_Array_Subtype
2947 && !Is_Constrained (gnat_desig_full))
2948 gnat_desig_full = Etype (gnat_desig_full);
2949
2950 /* If the designated type is a subtype of an incomplete record type,
2951 use the parent type to avoid order of elaboration issues. This
2952 can lose some code efficiency, but there is no alternative. */
2953 if (Present (gnat_desig_full)
2954 && Ekind (gnat_desig_full) == E_Record_Subtype
2955 && Ekind (Etype (gnat_desig_full)) == E_Record_Type)
2956 gnat_desig_full = Etype (gnat_desig_full);
2957
2958 /* If we are pointing to an incomplete type whose completion is an
2959 unconstrained array, make a fat pointer type instead of a pointer
2960 to VOID. The two types in our fields will be pointers to VOID and
2961 will be replaced in update_pointer_to. Similarly, if the type
2962 itself is a dummy type or an unconstrained array. Also make
2963 a dummy TYPE_OBJECT_RECORD_TYPE in case we have any thin
2964 pointers to it. */
2965
2966 if ((Present (gnat_desig_full)
2967 && Is_Array_Type (gnat_desig_full)
2968 && !Is_Constrained (gnat_desig_full))
2969 || (present_gnu_tree (gnat_desig_type)
2970 && TYPE_IS_DUMMY_P (TREE_TYPE
2971 (get_gnu_tree (gnat_desig_type)))
2972 && Is_Array_Type (gnat_desig_type)
2973 && !Is_Constrained (gnat_desig_type))
2974 || (present_gnu_tree (gnat_desig_type)
2975 && (TREE_CODE (TREE_TYPE (get_gnu_tree (gnat_desig_type)))
2976 == UNCONSTRAINED_ARRAY_TYPE)
2977 && !(TYPE_POINTER_TO (TREE_TYPE
2978 (get_gnu_tree (gnat_desig_type)))))
2979 || (No (gnat_desig_full) && !in_main_unit
2980 && defer_incomplete_level
2981 && !present_gnu_tree (gnat_desig_type)
2982 && Is_Array_Type (gnat_desig_type)
2983 && !Is_Constrained (gnat_desig_type)))
2984 {
2985 tree gnu_old
2986 = (present_gnu_tree (gnat_desig_type)
2987 ? gnat_to_gnu_type (gnat_desig_type)
2988 : make_dummy_type (gnat_desig_type));
2989 tree fields;
2990
2991 /* Show the dummy we get will be a fat pointer. */
2992 got_fat_p = made_dummy = true;
2993
2994 /* If the call above got something that has a pointer, that
2995 pointer is our type. This could have happened either
2996 because the type was elaborated or because somebody
2997 else executed the code below. */
2998 gnu_type = TYPE_POINTER_TO (gnu_old);
2999 if (!gnu_type)
3000 {
3001 gnu_type = make_node (RECORD_TYPE);
3002 SET_TYPE_UNCONSTRAINED_ARRAY (gnu_type, gnu_old);
3003 TYPE_POINTER_TO (gnu_old) = gnu_type;
3004
3005 Sloc_to_locus (Sloc (gnat_entity), &input_location);
3006 fields
3007 = chainon (chainon (NULL_TREE,
3008 create_field_decl
3009 (get_identifier ("P_ARRAY"),
3010 ptr_void_type_node, gnu_type,
3011 0, 0, 0, 0)),
3012 create_field_decl (get_identifier ("P_BOUNDS"),
3013 ptr_void_type_node,
3014 gnu_type, 0, 0, 0, 0));
3015
3016 /* Make sure we can place this into a register. */
3017 TYPE_ALIGN (gnu_type)
3018 = MIN (BIGGEST_ALIGNMENT, 2 * POINTER_SIZE);
3019 TYPE_IS_FAT_POINTER_P (gnu_type) = 1;
3020 finish_record_type (gnu_type, fields, false, true);
3021
3022 TYPE_OBJECT_RECORD_TYPE (gnu_old) = make_node (RECORD_TYPE);
3023 TYPE_NAME (TYPE_OBJECT_RECORD_TYPE (gnu_old))
3024 = concat_id_with_name (get_entity_name (gnat_desig_type),
3025 "XUT");
3026 TYPE_DUMMY_P (TYPE_OBJECT_RECORD_TYPE (gnu_old)) = 1;
3027 }
3028 }
3029
3030 /* If we already know what the full type is, use it. */
3031 else if (Present (gnat_desig_full)
3032 && present_gnu_tree (gnat_desig_full))
3033 gnu_desig_type = TREE_TYPE (get_gnu_tree (gnat_desig_full));
3034
3035 /* Get the type of the thing we are to point to and build a pointer
3036 to it. If it is a reference to an incomplete or private type with a
3037 full view that is a record, make a dummy type node and get the
3038 actual type later when we have verified it is safe. */
3039 else if (!in_main_unit
3040 && !present_gnu_tree (gnat_desig_type)
3041 && Present (gnat_desig_full)
3042 && !present_gnu_tree (gnat_desig_full)
3043 && Is_Record_Type (gnat_desig_full))
3044 {
3045 gnu_desig_type = make_dummy_type (gnat_desig_type);
3046 made_dummy = true;
3047 }
3048
3049 /* Likewise if we are pointing to a record or array and we are to defer
3050 elaborating incomplete types. We do this since this access type
3051 may be the full view of some private type. Note that the
3052 unconstrained array case is handled above. */
3053 else if ((!in_main_unit || imported_p) && defer_incomplete_level != 0
3054 && !present_gnu_tree (gnat_desig_type)
3055 && ((Is_Record_Type (gnat_desig_type)
3056 || Is_Array_Type (gnat_desig_type))
3057 || (Present (gnat_desig_full)
3058 && (Is_Record_Type (gnat_desig_full)
3059 || Is_Array_Type (gnat_desig_full)))))
3060 {
3061 gnu_desig_type = make_dummy_type (gnat_desig_type);
3062 made_dummy = true;
3063 }
3064 else if (gnat_desig_type == gnat_entity)
3065 {
3066 gnu_type
3067 = build_pointer_type_for_mode (make_node (VOID_TYPE),
3068 p_mode,
3069 No_Strict_Aliasing (gnat_entity));
3070 TREE_TYPE (gnu_type) = TYPE_POINTER_TO (gnu_type) = gnu_type;
3071 }
3072 else
3073 gnu_desig_type = gnat_to_gnu_type (gnat_desig_type);
3074
3075 /* It is possible that the above call to gnat_to_gnu_type resolved our
3076 type. If so, just return it. */
3077 if (present_gnu_tree (gnat_entity))
3078 {
3079 maybe_present = true;
3080 break;
3081 }
3082
3083 /* If we have a GCC type for the designated type, possibly modify it
3084 if we are pointing only to constant objects and then make a pointer
3085 to it. Don't do this for unconstrained arrays. */
3086 if (!gnu_type && gnu_desig_type)
3087 {
3088 if (Is_Access_Constant (gnat_entity)
3089 && TREE_CODE (gnu_desig_type) != UNCONSTRAINED_ARRAY_TYPE)
3090 {
3091 gnu_desig_type
3092 = build_qualified_type
3093 (gnu_desig_type,
3094 TYPE_QUALS (gnu_desig_type) | TYPE_QUAL_CONST);
3095
3096 /* Some extra processing is required if we are building a
3097 pointer to an incomplete type (in the GCC sense). We might
3098 have such a type if we just made a dummy, or directly out
3099 of the call to gnat_to_gnu_type above if we are processing
3100 an access type for a record component designating the
3101 record type itself. */
3102 if (TYPE_MODE (gnu_desig_type) == VOIDmode)
3103 {
3104 /* We must ensure that the pointer to variant we make will
3105 be processed by update_pointer_to when the initial type
3106 is completed. Pretend we made a dummy and let further
3107 processing act as usual. */
3108 made_dummy = true;
3109
3110 /* We must ensure that update_pointer_to will not retrieve
3111 the dummy variant when building a properly qualified
3112 version of the complete type. We take advantage of the
3113 fact that get_qualified_type is requiring TYPE_NAMEs to
3114 match to influence build_qualified_type and then also
3115 update_pointer_to here. */
3116 TYPE_NAME (gnu_desig_type)
3117 = create_concat_name (gnat_desig_type, "INCOMPLETE_CST");
3118 }
3119 }
3120
3121 gnu_type
3122 = build_pointer_type_for_mode (gnu_desig_type, p_mode,
3123 No_Strict_Aliasing (gnat_entity));
3124 }
3125
3126 /* If we are not defining this object and we made a dummy pointer,
3127 save our current definition, evaluate the actual type, and replace
3128 the tentative type we made with the actual one. If we are to defer
3129 actually looking up the actual type, make an entry in the
3130 deferred list. */
3131
3132 if (!in_main_unit && made_dummy)
3133 {
3134 tree gnu_old_type
3135 = TYPE_FAT_POINTER_P (gnu_type)
3136 ? TYPE_UNCONSTRAINED_ARRAY (gnu_type) : TREE_TYPE (gnu_type);
3137
3138 if (esize == POINTER_SIZE
3139 && (got_fat_p || TYPE_FAT_POINTER_P (gnu_type)))
3140 gnu_type
3141 = build_pointer_type
3142 (TYPE_OBJECT_RECORD_TYPE
3143 (TYPE_UNCONSTRAINED_ARRAY (gnu_type)));
3144
3145 gnu_decl = create_type_decl (gnu_entity_id, gnu_type, attr_list,
3146 !Comes_From_Source (gnat_entity),
3147 debug_info_p, gnat_entity);
3148 save_gnu_tree (gnat_entity, gnu_decl, false);
3149 this_made_decl = saved = true;
3150
3151 if (defer_incomplete_level == 0)
3152 /* Note that the call to gnat_to_gnu_type here might have
3153 updated gnu_old_type directly, in which case it is not a
3154 dummy type any more when we get into update_pointer_to.
3155
3156 This may happen for instance when the designated type is a
3157 record type, because their elaboration starts with an
3158 initial node from make_dummy_type, which may yield the same
3159 node as the one we got.
3160
3161 Besides, variants of this non-dummy type might have been
3162 created along the way. update_pointer_to is expected to
3163 properly take care of those situations. */
3164 update_pointer_to (TYPE_MAIN_VARIANT (gnu_old_type),
3165 gnat_to_gnu_type (gnat_desig_type));
3166 else
3167 {
3168 struct incomplete *p
3169 = (struct incomplete *) xmalloc (sizeof (struct incomplete));
3170
3171 p->old_type = gnu_old_type;
3172 p->full_type = gnat_desig_type;
3173 p->next = defer_incomplete_list;
3174 defer_incomplete_list = p;
3175 }
3176 }
3177 }
3178 break;
3179
3180 case E_Access_Protected_Subprogram_Type:
3181 case E_Anonymous_Access_Protected_Subprogram_Type:
3182 if (type_annotate_only && No (Equivalent_Type (gnat_entity)))
3183 gnu_type = build_pointer_type (void_type_node);
3184 else
3185 /* The runtime representation is the equivalent type. */
3186 gnu_type = gnat_to_gnu_type (Equivalent_Type (gnat_entity));
3187
3188 if (Is_Itype (Directly_Designated_Type (gnat_entity))
3189 && !present_gnu_tree (Directly_Designated_Type (gnat_entity))
3190 && No (Freeze_Node (Directly_Designated_Type (gnat_entity)))
3191 && !Is_Record_Type (Scope (Directly_Designated_Type (gnat_entity))))
3192 gnat_to_gnu_entity (Directly_Designated_Type (gnat_entity),
3193 NULL_TREE, 0);
3194
3195 break;
3196
3197 case E_Access_Subtype:
3198
3199 /* We treat this as identical to its base type; any constraint is
3200 meaningful only to the front end.
3201
3202 The designated type must be elaborated as well, if it does
3203 not have its own freeze node. Designated (sub)types created
3204 for constrained components of records with discriminants are
3205 not frozen by the front end and thus not elaborated by gigi,
3206 because their use may appear before the base type is frozen,
3207 and because it is not clear that they are needed anywhere in
3208 Gigi. With the current model, there is no correct place where
3209 they could be elaborated. */
3210
3211 gnu_type = gnat_to_gnu_type (Etype (gnat_entity));
3212 if (Is_Itype (Directly_Designated_Type (gnat_entity))
3213 && !present_gnu_tree (Directly_Designated_Type (gnat_entity))
3214 && Is_Frozen (Directly_Designated_Type (gnat_entity))
3215 && No (Freeze_Node (Directly_Designated_Type (gnat_entity))))
3216 {
3217 /* If we are not defining this entity, and we have incomplete
3218 entities being processed above us, make a dummy type and
3219 elaborate it later. */
3220 if (!definition && defer_incomplete_level != 0)
3221 {
3222 struct incomplete *p
3223 = (struct incomplete *) xmalloc (sizeof (struct incomplete));
3224 tree gnu_ptr_type
3225 = build_pointer_type
3226 (make_dummy_type (Directly_Designated_Type (gnat_entity)));
3227
3228 p->old_type = TREE_TYPE (gnu_ptr_type);
3229 p->full_type = Directly_Designated_Type (gnat_entity);
3230 p->next = defer_incomplete_list;
3231 defer_incomplete_list = p;
3232 }
3233 else if (IN (Ekind (Base_Type
3234 (Directly_Designated_Type (gnat_entity))),
3235 Incomplete_Or_Private_Kind))
3236 ;
3237 else
3238 gnat_to_gnu_entity (Directly_Designated_Type (gnat_entity),
3239 NULL_TREE, 0);
3240 }
3241
3242 maybe_present = true;
3243 break;
3244
3245 /* Subprogram Entities
3246
3247 The following access functions are defined for subprograms (functions
3248 or procedures):
3249
3250 First_Formal The first formal parameter.
3251 Is_Imported Indicates that the subprogram has appeared in
3252 an INTERFACE or IMPORT pragma. For now we
3253 assume that the external language is C.
3254 Is_Inlined True if the subprogram is to be inlined.
3255
3256 In addition for function subprograms we have:
3257
3258 Etype Return type of the function.
3259
3260 Each parameter is first checked by calling must_pass_by_ref on its
3261 type to determine if it is passed by reference. For parameters which
3262 are copied in, if they are Ada IN OUT or OUT parameters, their return
3263 value becomes part of a record which becomes the return type of the
3264 function (C function - note that this applies only to Ada procedures
3265 so there is no Ada return type). Additional code to store back the
3266 parameters will be generated on the caller side. This transformation
3267 is done here, not in the front-end.
3268
3269 The intended result of the transformation can be seen from the
3270 equivalent source rewritings that follow:
3271
3272 struct temp {int a,b};
3273 procedure P (A,B: IN OUT ...) is temp P (int A,B) {
3274 .. ..
3275 end P; return {A,B};
3276 }
3277 procedure call
3278
3279 {
3280 temp t;
3281 P(X,Y); t = P(X,Y);
3282 X = t.a , Y = t.b;
3283 }
3284
3285 For subprogram types we need to perform mainly the same conversions to
3286 GCC form that are needed for procedures and function declarations. The
3287 only difference is that at the end, we make a type declaration instead
3288 of a function declaration. */
3289
3290 case E_Subprogram_Type:
3291 case E_Function:
3292 case E_Procedure:
3293 {
3294 /* The first GCC parameter declaration (a PARM_DECL node). The
3295 PARM_DECL nodes are chained through the TREE_CHAIN field, so this
3296 actually is the head of this parameter list. */
3297 tree gnu_param_list = NULL_TREE;
3298 /* The type returned by a function. If the subprogram is a procedure
3299 this type should be void_type_node. */
3300 tree gnu_return_type = void_type_node;
3301 /* List of fields in return type of procedure with copy in copy out
3302 parameters. */
3303 tree gnu_field_list = NULL_TREE;
3304 /* Non-null for subprograms containing parameters passed by copy in
3305 copy out (Ada IN OUT or OUT parameters not passed by reference),
3306 in which case it is the list of nodes used to specify the values of
3307 the in out/out parameters that are returned as a record upon
3308 procedure return. The TREE_PURPOSE of an element of this list is
3309 a field of the record and the TREE_VALUE is the PARM_DECL
3310 corresponding to that field. This list will be saved in the
3311 TYPE_CI_CO_LIST field of the FUNCTION_TYPE node we create. */
3312 tree gnu_return_list = NULL_TREE;
3313 /* If an import pragma asks to map this subprogram to a GCC builtin,
3314 this is the builtin DECL node. */
3315 tree gnu_builtin_decl = NULL_TREE;
3316 Entity_Id gnat_param;
3317 bool inline_flag = Is_Inlined (gnat_entity);
3318 bool public_flag = Is_Public (gnat_entity);
3319 bool extern_flag
3320 = (Is_Public (gnat_entity) && !definition) || imported_p;
3321 bool pure_flag = Is_Pure (gnat_entity);
3322 bool volatile_flag = No_Return (gnat_entity);
3323 bool returns_by_ref = false;
3324 bool returns_unconstrained = false;
3325 bool returns_by_target_ptr = false;
3326 tree gnu_ext_name = create_concat_name (gnat_entity, 0);
3327 bool has_copy_in_out = false;
3328 int parmnum;
3329
3330 if (kind == E_Subprogram_Type && !definition)
3331 /* A parameter may refer to this type, so defer completion
3332 of any incomplete types. */
3333 defer_incomplete_level++, this_deferred = true;
3334
3335 /* If the subprogram has an alias, it is probably inherited, so
3336 we can use the original one. If the original "subprogram"
3337 is actually an enumeration literal, it may be the first use
3338 of its type, so we must elaborate that type now. */
3339 if (Present (Alias (gnat_entity)))
3340 {
3341 if (Ekind (Alias (gnat_entity)) == E_Enumeration_Literal)
3342 gnat_to_gnu_entity (Etype (Alias (gnat_entity)), NULL_TREE, 0);
3343
3344 gnu_decl = gnat_to_gnu_entity (Alias (gnat_entity),
3345 gnu_expr, 0);
3346
3347 /* Elaborate any Itypes in the parameters of this entity. */
3348 for (gnat_temp = First_Formal (gnat_entity);
3349 Present (gnat_temp);
3350 gnat_temp = Next_Formal_With_Extras (gnat_temp))
3351 if (Is_Itype (Etype (gnat_temp)))
3352 gnat_to_gnu_entity (Etype (gnat_temp), NULL_TREE, 0);
3353
3354 break;
3355 }
3356
3357 /* If this subprogram is expectedly bound to a GCC builtin, fetch the
3358 corresponding DECL node.
3359
3360 We still want the parameter associations to take place because the
3361 proper generation of calls depends on it (a GNAT parameter without
3362 a corresponding GCC tree has a very specific meaning), so we don't
3363 just break here. */
3364 if (Convention (gnat_entity) == Convention_Intrinsic)
3365 gnu_builtin_decl = builtin_decl_for (gnu_ext_name);
3366
3367 /* ??? What if we don't find the builtin node above ? warn ? err ?
3368 In the current state we neither warn nor err, and calls will just
3369 be handled as for regular subprograms. */
3370
3371 if (kind == E_Function || kind == E_Subprogram_Type)
3372 gnu_return_type = gnat_to_gnu_type (Etype (gnat_entity));
3373
3374 /* If this function returns by reference, make the actual
3375 return type of this function the pointer and mark the decl. */
3376 if (Returns_By_Ref (gnat_entity))
3377 {
3378 returns_by_ref = true;
3379 gnu_return_type = build_pointer_type (gnu_return_type);
3380 }
3381
3382 /* If the Mechanism is By_Reference, ensure the return type uses
3383 the machine's by-reference mechanism, which may not the same
3384 as above (e.g., it might be by passing a fake parameter). */
3385 else if (kind == E_Function
3386 && Mechanism (gnat_entity) == By_Reference)
3387 {
3388 gnu_return_type = copy_type (gnu_return_type);
3389 TREE_ADDRESSABLE (gnu_return_type) = 1;
3390 }
3391
3392 /* If we are supposed to return an unconstrained array,
3393 actually return a fat pointer and make a note of that. Return
3394 a pointer to an unconstrained record of variable size. */
3395 else if (TREE_CODE (gnu_return_type) == UNCONSTRAINED_ARRAY_TYPE)
3396 {
3397 gnu_return_type = TREE_TYPE (gnu_return_type);
3398 returns_unconstrained = true;
3399 }
3400
3401 /* If the type requires a transient scope, the result is allocated
3402 on the secondary stack, so the result type of the function is
3403 just a pointer. */
3404 else if (Requires_Transient_Scope (Etype (gnat_entity)))
3405 {
3406 gnu_return_type = build_pointer_type (gnu_return_type);
3407 returns_unconstrained = true;
3408 }
3409
3410 /* If the type is a padded type and the underlying type would not
3411 be passed by reference or this function has a foreign convention,
3412 return the underlying type. */
3413 else if (TREE_CODE (gnu_return_type) == RECORD_TYPE
3414 && TYPE_IS_PADDING_P (gnu_return_type)
3415 && (!default_pass_by_ref (TREE_TYPE
3416 (TYPE_FIELDS (gnu_return_type)))
3417 || Has_Foreign_Convention (gnat_entity)))
3418 gnu_return_type = TREE_TYPE (TYPE_FIELDS (gnu_return_type));
3419
3420 /* If the return type is unconstrained, that means it must have a
3421 maximum size. We convert the function into a procedure and its
3422 caller will pass a pointer to an object of that maximum size as the
3423 first parameter when we call the function. */
3424 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_return_type)))
3425 {
3426 returns_by_target_ptr = true;
3427 gnu_param_list
3428 = create_param_decl (get_identifier ("TARGET"),
3429 build_reference_type (gnu_return_type),
3430 true);
3431 gnu_return_type = void_type_node;
3432 }
3433
3434 /* If the return type has a size that overflows, we cannot have
3435 a function that returns that type. This usage doesn't make
3436 sense anyway, so give an error here. */
3437 if (TYPE_SIZE_UNIT (gnu_return_type)
3438 && TREE_OVERFLOW (TYPE_SIZE_UNIT (gnu_return_type)))
3439 {
3440 post_error ("cannot return type whose size overflows",
3441 gnat_entity);
3442 gnu_return_type = copy_node (gnu_return_type);
3443 TYPE_SIZE (gnu_return_type) = bitsize_zero_node;
3444 TYPE_SIZE_UNIT (gnu_return_type) = size_zero_node;
3445 TYPE_MAIN_VARIANT (gnu_return_type) = gnu_return_type;
3446 TYPE_NEXT_VARIANT (gnu_return_type) = NULL_TREE;
3447 }
3448
3449 /* Look at all our parameters and get the type of
3450 each. While doing this, build a copy-out structure if
3451 we need one. */
3452
3453 for (gnat_param = First_Formal (gnat_entity), parmnum = 0;
3454 Present (gnat_param);
3455 gnat_param = Next_Formal_With_Extras (gnat_param), parmnum++)
3456 {
3457 tree gnu_param_name = get_entity_name (gnat_param);
3458 tree gnu_param_type = gnat_to_gnu_type (Etype (gnat_param));
3459 tree gnu_param, gnu_field;
3460 bool by_ref_p = false;
3461 bool by_descr_p = false;
3462 bool by_component_ptr_p = false;
3463 bool copy_in_copy_out_flag = false;
3464 bool req_by_copy = false, req_by_ref = false;
3465
3466 /* Builtins are expanded inline and there is no real call sequence
3467 involved. so the type expected by the underlying expander is
3468 always the type of each argument "as is". */
3469 if (gnu_builtin_decl)
3470 req_by_copy = 1;
3471
3472 /* Otherwise, see if a Mechanism was supplied that forced this
3473 parameter to be passed one way or another. */
3474 else if (Is_Valued_Procedure (gnat_entity) && parmnum == 0)
3475 req_by_copy = true;
3476 else if (Mechanism (gnat_param) == Default)
3477 ;
3478 else if (Mechanism (gnat_param) == By_Copy)
3479 req_by_copy = true;
3480 else if (Mechanism (gnat_param) == By_Reference)
3481 req_by_ref = true;
3482 else if (Mechanism (gnat_param) <= By_Descriptor)
3483 by_descr_p = true;
3484 else if (Mechanism (gnat_param) > 0)
3485 {
3486 if (TREE_CODE (gnu_param_type) == UNCONSTRAINED_ARRAY_TYPE
3487 || TREE_CODE (TYPE_SIZE (gnu_param_type)) != INTEGER_CST
3488 || 0 < compare_tree_int (TYPE_SIZE (gnu_param_type),
3489 Mechanism (gnat_param)))
3490 req_by_ref = true;
3491 else
3492 req_by_copy = true;
3493 }
3494 else
3495 post_error ("unsupported mechanism for&", gnat_param);
3496
3497 /* If this is either a foreign function or if the
3498 underlying type won't be passed by reference, strip off
3499 possible padding type. */
3500 if (TREE_CODE (gnu_param_type) == RECORD_TYPE
3501 && TYPE_IS_PADDING_P (gnu_param_type)
3502 && (req_by_ref || Has_Foreign_Convention (gnat_entity)
3503 || (!must_pass_by_ref (TREE_TYPE (TYPE_FIELDS
3504 (gnu_param_type)))
3505 && (req_by_copy
3506 || !default_pass_by_ref (TREE_TYPE
3507 (TYPE_FIELDS
3508 (gnu_param_type)))))))
3509 gnu_param_type = TREE_TYPE (TYPE_FIELDS (gnu_param_type));
3510
3511 /* If this is an IN parameter it is read-only, so make a variant
3512 of the type that is read-only.
3513
3514 ??? However, if this is an unconstrained array, that type can
3515 be very complex. So skip it for now. Likewise for any other
3516 self-referential type. */
3517 if (Ekind (gnat_param) == E_In_Parameter
3518 && TREE_CODE (gnu_param_type) != UNCONSTRAINED_ARRAY_TYPE
3519 && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_param_type)))
3520 gnu_param_type
3521 = build_qualified_type (gnu_param_type,
3522 (TYPE_QUALS (gnu_param_type)
3523 | TYPE_QUAL_CONST));
3524
3525 /* For foreign conventions, pass arrays as a pointer to the
3526 underlying type. First check for unconstrained array and get
3527 the underlying array. Then get the component type and build
3528 a pointer to it. */
3529 if (Has_Foreign_Convention (gnat_entity)
3530 && TREE_CODE (gnu_param_type) == UNCONSTRAINED_ARRAY_TYPE)
3531 gnu_param_type
3532 = TREE_TYPE (TREE_TYPE (TYPE_FIELDS
3533 (TREE_TYPE (gnu_param_type))));
3534
3535 if (by_descr_p)
3536 gnu_param_type
3537 = build_pointer_type
3538 (build_vms_descriptor (gnu_param_type,
3539 Mechanism (gnat_param), gnat_entity));
3540
3541 else if (Has_Foreign_Convention (gnat_entity)
3542 && !req_by_copy
3543 && TREE_CODE (gnu_param_type) == ARRAY_TYPE)
3544 {
3545 /* Strip off any multi-dimensional entries, then strip
3546 off the last array to get the component type. */
3547 while (TREE_CODE (TREE_TYPE (gnu_param_type)) == ARRAY_TYPE
3548 && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_param_type)))
3549 gnu_param_type = TREE_TYPE (gnu_param_type);
3550
3551 by_component_ptr_p = true;
3552 gnu_param_type = TREE_TYPE (gnu_param_type);
3553
3554 if (Ekind (gnat_param) == E_In_Parameter)
3555 gnu_param_type
3556 = build_qualified_type (gnu_param_type,
3557 (TYPE_QUALS (gnu_param_type)
3558 | TYPE_QUAL_CONST));
3559
3560 gnu_param_type = build_pointer_type (gnu_param_type);
3561 }
3562
3563 /* Fat pointers are passed as thin pointers for foreign
3564 conventions. */
3565 else if (Has_Foreign_Convention (gnat_entity)
3566 && TYPE_FAT_POINTER_P (gnu_param_type))
3567 gnu_param_type
3568 = make_type_from_size (gnu_param_type,
3569 size_int (POINTER_SIZE), false);
3570
3571 /* If we must pass or were requested to pass by reference, do so.
3572 If we were requested to pass by copy, do so.
3573 Otherwise, for foreign conventions, pass all in out parameters
3574 or aggregates by reference. For COBOL and Fortran, pass
3575 all integer and FP types that way too. For Convention Ada,
3576 use the standard Ada default. */
3577 else if (must_pass_by_ref (gnu_param_type) || req_by_ref
3578 || (!req_by_copy
3579 && ((Has_Foreign_Convention (gnat_entity)
3580 && (Ekind (gnat_param) != E_In_Parameter
3581 || AGGREGATE_TYPE_P (gnu_param_type)))
3582 || (((Convention (gnat_entity)
3583 == Convention_Fortran)
3584 || (Convention (gnat_entity)
3585 == Convention_COBOL))
3586 && (INTEGRAL_TYPE_P (gnu_param_type)
3587 || FLOAT_TYPE_P (gnu_param_type)))
3588 /* For convention Ada, see if we pass by reference
3589 by default. */
3590 || (!Has_Foreign_Convention (gnat_entity)
3591 && default_pass_by_ref (gnu_param_type)))))
3592 {
3593 gnu_param_type = build_reference_type (gnu_param_type);
3594 by_ref_p = true;
3595 }
3596
3597 else if (Ekind (gnat_param) != E_In_Parameter)
3598 copy_in_copy_out_flag = true;
3599
3600 if (req_by_copy && (by_ref_p || by_component_ptr_p))
3601 post_error ("?cannot pass & by copy", gnat_param);
3602
3603 /* If this is an OUT parameter that isn't passed by reference
3604 and isn't a pointer or aggregate, we don't make a PARM_DECL
3605 for it. Instead, it will be a VAR_DECL created when we process
3606 the procedure. For the special parameter of Valued_Procedure,
3607 never pass it in.
3608
3609 An exception is made to cover the RM-6.4.1 rule requiring "by
3610 copy" out parameters with discriminants or implicit initial
3611 values to be handled like in out parameters. These type are
3612 normally built as aggregates, and hence passed by reference,
3613 except for some packed arrays which end up encoded in special
3614 integer types.
3615
3616 The exception we need to make is then for packed arrays of
3617 records with discriminants or implicit initial values. We have
3618 no light/easy way to check for the latter case, so we merely
3619 check for packed arrays of records. This may lead to useless
3620 copy-in operations, but in very rare cases only, as these would
3621 be exceptions in a set of already exceptional situations. */
3622 if (Ekind (gnat_param) == E_Out_Parameter && !by_ref_p
3623 && ((Is_Valued_Procedure (gnat_entity) && parmnum == 0)
3624 || (!by_descr_p
3625 && !POINTER_TYPE_P (gnu_param_type)
3626 && !AGGREGATE_TYPE_P (gnu_param_type)))
3627 && !(Is_Array_Type (Etype (gnat_param))
3628 && Is_Packed (Etype (gnat_param))
3629 && Is_Composite_Type (Component_Type
3630 (Etype (gnat_param)))))
3631 gnu_param = NULL_TREE;
3632 else
3633 {
3634 gnu_param
3635 = create_param_decl
3636 (gnu_param_name, gnu_param_type,
3637 by_ref_p || by_component_ptr_p
3638 || Ekind (gnat_param) == E_In_Parameter);
3639
3640 DECL_BY_REF_P (gnu_param) = by_ref_p;
3641 DECL_BY_COMPONENT_PTR_P (gnu_param) = by_component_ptr_p;
3642 DECL_BY_DESCRIPTOR_P (gnu_param) = by_descr_p;
3643 DECL_POINTS_TO_READONLY_P (gnu_param)
3644 = (Ekind (gnat_param) == E_In_Parameter
3645 && (by_ref_p || by_component_ptr_p));
3646 Sloc_to_locus (Sloc (gnat_param),
3647 &DECL_SOURCE_LOCATION (gnu_param));
3648 save_gnu_tree (gnat_param, gnu_param, false);
3649 gnu_param_list = chainon (gnu_param, gnu_param_list);
3650
3651 /* If a parameter is a pointer, this function may modify
3652 memory through it and thus shouldn't be considered
3653 a pure function. Also, the memory may be modified
3654 between two calls, so they can't be CSE'ed. The latter
3655 case also handles by-ref parameters. */
3656 if (POINTER_TYPE_P (gnu_param_type)
3657 || TYPE_FAT_POINTER_P (gnu_param_type))
3658 pure_flag = false;
3659 }
3660
3661 if (copy_in_copy_out_flag)
3662 {
3663 if (!has_copy_in_out)
3664 {
3665 gcc_assert (TREE_CODE (gnu_return_type) == VOID_TYPE);
3666 gnu_return_type = make_node (RECORD_TYPE);
3667 TYPE_NAME (gnu_return_type) = get_identifier ("RETURN");
3668 has_copy_in_out = true;
3669 }
3670
3671 gnu_field = create_field_decl (gnu_param_name, gnu_param_type,
3672 gnu_return_type, 0, 0, 0, 0);
3673 Sloc_to_locus (Sloc (gnat_param),
3674 &DECL_SOURCE_LOCATION (gnu_field));
3675 TREE_CHAIN (gnu_field) = gnu_field_list;
3676 gnu_field_list = gnu_field;
3677 gnu_return_list = tree_cons (gnu_field, gnu_param,
3678 gnu_return_list);
3679 }
3680 }
3681
3682 /* Do not compute record for out parameters if subprogram is
3683 stubbed since structures are incomplete for the back-end. */
3684 if (gnu_field_list
3685 && Convention (gnat_entity) != Convention_Stubbed)
3686 {
3687 /* If all types are not complete, defer emission of debug
3688 information for this record types. Otherwise, we risk emitting
3689 debug information for a dummy type contained in the fields
3690 for that record. */
3691 finish_record_type (gnu_return_type, nreverse (gnu_field_list),
3692 false, defer_incomplete_level);
3693
3694 if (defer_incomplete_level)
3695 {
3696 debug_deferred = true;
3697 defer_debug_level++;
3698
3699 defer_debug_incomplete_list
3700 = tree_cons (NULL_TREE, gnu_return_type,
3701 defer_debug_incomplete_list);
3702 }
3703 }
3704
3705 /* If we have a CICO list but it has only one entry, we convert
3706 this function into a function that simply returns that one
3707 object. */
3708 if (list_length (gnu_return_list) == 1)
3709 gnu_return_type = TREE_TYPE (TREE_PURPOSE (gnu_return_list));
3710
3711 if (Has_Stdcall_Convention (gnat_entity))
3712 {
3713 struct attrib *attr
3714 = (struct attrib *) xmalloc (sizeof (struct attrib));
3715
3716 attr->next = attr_list;
3717 attr->type = ATTR_MACHINE_ATTRIBUTE;
3718 attr->name = get_identifier ("stdcall");
3719 attr->args = NULL_TREE;
3720 attr->error_point = gnat_entity;
3721 attr_list = attr;
3722 }
3723
3724 /* Both lists ware built in reverse. */
3725 gnu_param_list = nreverse (gnu_param_list);
3726 gnu_return_list = nreverse (gnu_return_list);
3727
3728 gnu_type
3729 = create_subprog_type (gnu_return_type, gnu_param_list,
3730 gnu_return_list, returns_unconstrained,
3731 returns_by_ref,
3732 Function_Returns_With_DSP (gnat_entity),
3733 returns_by_target_ptr);
3734
3735 /* A subprogram (something that doesn't return anything) shouldn't
3736 be considered Pure since there would be no reason for such a
3737 subprogram. Note that procedures with Out (or In Out) parameters
3738 have already been converted into a function with a return type. */
3739 if (TREE_CODE (gnu_return_type) == VOID_TYPE)
3740 pure_flag = false;
3741
3742 gnu_type
3743 = build_qualified_type (gnu_type,
3744 (TYPE_QUALS (gnu_type)
3745 | (TYPE_QUAL_CONST * pure_flag)
3746 | (TYPE_QUAL_VOLATILE * volatile_flag)));
3747
3748 Sloc_to_locus (Sloc (gnat_entity), &input_location);
3749
3750 /* If we have a builtin decl for that function, check the signatures
3751 compatibilities. If the signatures are compatible, use the builtin
3752 decl. If they are not, we expect the checker predicate to have
3753 posted the appropriate errors, and just continue with what we have
3754 so far. */
3755 if (gnu_builtin_decl)
3756 {
3757 tree gnu_builtin_type = TREE_TYPE (gnu_builtin_decl);
3758
3759 if (compatible_signatures_p (gnu_type, gnu_builtin_type))
3760 {
3761 gnu_decl = gnu_builtin_decl;
3762 gnu_type = gnu_builtin_type;
3763 break;
3764 }
3765 }
3766
3767 /* If there was no specified Interface_Name and the external and
3768 internal names of the subprogram are the same, only use the
3769 internal name to allow disambiguation of nested subprograms. */
3770 if (No (Interface_Name (gnat_entity)) && gnu_ext_name == gnu_entity_id)
3771 gnu_ext_name = NULL_TREE;
3772
3773 /* If we are defining the subprogram and it has an Address clause
3774 we must get the address expression from the saved GCC tree for the
3775 subprogram if it has a Freeze_Node. Otherwise, we elaborate
3776 the address expression here since the front-end has guaranteed
3777 in that case that the elaboration has no effects. If there is
3778 an Address clause and we are not defining the object, just
3779 make it a constant. */
3780 if (Present (Address_Clause (gnat_entity)))
3781 {
3782 tree gnu_address = NULL_TREE;
3783
3784 if (definition)
3785 gnu_address
3786 = (present_gnu_tree (gnat_entity)
3787 ? get_gnu_tree (gnat_entity)
3788 : gnat_to_gnu (Expression (Address_Clause (gnat_entity))));
3789
3790 save_gnu_tree (gnat_entity, NULL_TREE, false);
3791
3792 gnu_type = build_reference_type (gnu_type);
3793 if (gnu_address)
3794 gnu_address = convert (gnu_type, gnu_address);
3795
3796 gnu_decl
3797 = create_var_decl (gnu_entity_id, gnu_ext_name, gnu_type,
3798 gnu_address, false, Is_Public (gnat_entity),
3799 extern_flag, false, NULL, gnat_entity);
3800 DECL_BY_REF_P (gnu_decl) = 1;
3801 }
3802
3803 else if (kind == E_Subprogram_Type)
3804 gnu_decl = create_type_decl (gnu_entity_id, gnu_type, attr_list,
3805 !Comes_From_Source (gnat_entity),
3806 debug_info_p && !defer_incomplete_level,
3807 gnat_entity);
3808 else
3809 {
3810 gnu_decl = create_subprog_decl (gnu_entity_id, gnu_ext_name,
3811 gnu_type, gnu_param_list,
3812 inline_flag, public_flag,
3813 extern_flag, attr_list,
3814 gnat_entity);
3815 DECL_STUBBED_P (gnu_decl)
3816 = Convention (gnat_entity) == Convention_Stubbed;
3817 }
3818 }
3819 break;
3820
3821 case E_Incomplete_Type:
3822 case E_Private_Type:
3823 case E_Limited_Private_Type:
3824 case E_Record_Type_With_Private:
3825 case E_Private_Subtype:
3826 case E_Limited_Private_Subtype:
3827 case E_Record_Subtype_With_Private:
3828
3829 /* If this type does not have a full view in the unit we are
3830 compiling, then just get the type from its Etype. */
3831 if (No (Full_View (gnat_entity)))
3832 {
3833 /* If this is an incomplete type with no full view, it must be
3834 either a limited view brought in by a limited_with clause, in
3835 which case we use the non-limited view, or a Taft Amendement
3836 type, in which case we just return a dummy type. */
3837 if (kind == E_Incomplete_Type)
3838 {
3839 if (From_With_Type (gnat_entity)
3840 && Present (Non_Limited_View (gnat_entity)))
3841 gnu_decl = gnat_to_gnu_entity (Non_Limited_View (gnat_entity),
3842 NULL_TREE, 0);
3843 else
3844 gnu_type = make_dummy_type (gnat_entity);
3845 }
3846
3847 else if (Present (Underlying_Full_View (gnat_entity)))
3848 gnu_decl = gnat_to_gnu_entity (Underlying_Full_View (gnat_entity),
3849 NULL_TREE, 0);
3850 else
3851 {
3852 gnu_decl = gnat_to_gnu_entity (Etype (gnat_entity),
3853 NULL_TREE, 0);
3854 maybe_present = true;
3855 }
3856
3857 break;
3858 }
3859
3860 /* Otherwise, if we are not defining the type now, get the
3861 type from the full view. But always get the type from the full
3862 view for define on use types, since otherwise we won't see them! */
3863
3864 else if (!definition
3865 || (Is_Itype (Full_View (gnat_entity))
3866 && No (Freeze_Node (gnat_entity)))
3867 || (Is_Itype (gnat_entity)
3868 && No (Freeze_Node (Full_View (gnat_entity)))))
3869 {
3870 gnu_decl = gnat_to_gnu_entity (Full_View (gnat_entity),
3871 NULL_TREE, 0);
3872 maybe_present = true;
3873 break;
3874 }
3875
3876 /* For incomplete types, make a dummy type entry which will be
3877 replaced later. */
3878 gnu_type = make_dummy_type (gnat_entity);
3879
3880 /* Save this type as the full declaration's type so we can do any needed
3881 updates when we see it. */
3882 gnu_decl = create_type_decl (gnu_entity_id, gnu_type, attr_list,
3883 !Comes_From_Source (gnat_entity),
3884 debug_info_p, gnat_entity);
3885 save_gnu_tree (Full_View (gnat_entity), gnu_decl, false);
3886 break;
3887
3888 /* Simple class_wide types are always viewed as their root_type
3889 by Gigi unless an Equivalent_Type is specified. */
3890 case E_Class_Wide_Type:
3891 if (Present (Equivalent_Type (gnat_entity)))
3892 gnu_type = gnat_to_gnu_type (Equivalent_Type (gnat_entity));
3893 else
3894 gnu_type = gnat_to_gnu_type (Root_Type (gnat_entity));
3895
3896 maybe_present = true;
3897 break;
3898
3899 case E_Task_Type:
3900 case E_Task_Subtype:
3901 case E_Protected_Type:
3902 case E_Protected_Subtype:
3903 if (type_annotate_only && No (Corresponding_Record_Type (gnat_entity)))
3904 gnu_type = void_type_node;
3905 else
3906 gnu_type = gnat_to_gnu_type (Corresponding_Record_Type (gnat_entity));
3907
3908 maybe_present = true;
3909 break;
3910
3911 case E_Label:
3912 gnu_decl = create_label_decl (gnu_entity_id);
3913 break;
3914
3915 case E_Block:
3916 case E_Loop:
3917 /* Nothing at all to do here, so just return an ERROR_MARK and claim
3918 we've already saved it, so we don't try to. */
3919 gnu_decl = error_mark_node;
3920 saved = true;
3921 break;
3922
3923 default:
3924 gcc_unreachable ();
3925 }
3926
3927 /* If we had a case where we evaluated another type and it might have
3928 defined this one, handle it here. */
3929 if (maybe_present && present_gnu_tree (gnat_entity))
3930 {
3931 gnu_decl = get_gnu_tree (gnat_entity);
3932 saved = true;
3933 }
3934
3935 /* If we are processing a type and there is either no decl for it or
3936 we just made one, do some common processing for the type, such as
3937 handling alignment and possible padding. */
3938
3939 if ((!gnu_decl || this_made_decl) && IN (kind, Type_Kind))
3940 {
3941 if (Is_Tagged_Type (gnat_entity)
3942 || Is_Class_Wide_Equivalent_Type (gnat_entity))
3943 TYPE_ALIGN_OK (gnu_type) = 1;
3944
3945 if (AGGREGATE_TYPE_P (gnu_type) && Is_By_Reference_Type (gnat_entity))
3946 TYPE_BY_REFERENCE_P (gnu_type) = 1;
3947
3948 /* ??? Don't set the size for a String_Literal since it is either
3949 confirming or we don't handle it properly (if the low bound is
3950 non-constant). */
3951 if (!gnu_size && kind != E_String_Literal_Subtype)
3952 gnu_size = validate_size (Esize (gnat_entity), gnu_type, gnat_entity,
3953 TYPE_DECL, false,
3954 Has_Size_Clause (gnat_entity));
3955
3956 /* If a size was specified, see if we can make a new type of that size
3957 by rearranging the type, for example from a fat to a thin pointer. */
3958 if (gnu_size)
3959 {
3960 gnu_type
3961 = make_type_from_size (gnu_type, gnu_size,
3962 Has_Biased_Representation (gnat_entity));
3963
3964 if (operand_equal_p (TYPE_SIZE (gnu_type), gnu_size, 0)
3965 && operand_equal_p (rm_size (gnu_type), gnu_size, 0))
3966 gnu_size = 0;
3967 }
3968
3969 /* If the alignment hasn't already been processed and this is
3970 not an unconstrained array, see if an alignment is specified.
3971 If not, we pick a default alignment for atomic objects. */
3972 if (align != 0 || TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE)
3973 ;
3974 else if (Known_Alignment (gnat_entity))
3975 align = validate_alignment (Alignment (gnat_entity), gnat_entity,
3976 TYPE_ALIGN (gnu_type));
3977 else if (Is_Atomic (gnat_entity) && !gnu_size
3978 && host_integerp (TYPE_SIZE (gnu_type), 1)
3979 && integer_pow2p (TYPE_SIZE (gnu_type)))
3980 align = MIN (BIGGEST_ALIGNMENT,
3981 tree_low_cst (TYPE_SIZE (gnu_type), 1));
3982 else if (Is_Atomic (gnat_entity) && gnu_size
3983 && host_integerp (gnu_size, 1)
3984 && integer_pow2p (gnu_size))
3985 align = MIN (BIGGEST_ALIGNMENT, tree_low_cst (gnu_size, 1));
3986
3987 /* See if we need to pad the type. If we did, and made a record,
3988 the name of the new type may be changed. So get it back for
3989 us when we make the new TYPE_DECL below. */
3990 gnu_type = maybe_pad_type (gnu_type, gnu_size, align, gnat_entity, "PAD",
3991 true, definition, false);
3992 if (TREE_CODE (gnu_type) == RECORD_TYPE
3993 && TYPE_IS_PADDING_P (gnu_type))
3994 {
3995 gnu_entity_id = TYPE_NAME (gnu_type);
3996 if (TREE_CODE (gnu_entity_id) == TYPE_DECL)
3997 gnu_entity_id = DECL_NAME (gnu_entity_id);
3998 }
3999
4000 set_rm_size (RM_Size (gnat_entity), gnu_type, gnat_entity);
4001
4002 /* If we are at global level, GCC will have applied variable_size to
4003 the type, but that won't have done anything. So, if it's not
4004 a constant or self-referential, call elaborate_expression_1 to
4005 make a variable for the size rather than calculating it each time.
4006 Handle both the RM size and the actual size. */
4007 if (global_bindings_p ()
4008 && TYPE_SIZE (gnu_type)
4009 && !TREE_CONSTANT (TYPE_SIZE (gnu_type))
4010 && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_type)))
4011 {
4012 if (TREE_CODE (gnu_type) == RECORD_TYPE
4013 && operand_equal_p (TYPE_ADA_SIZE (gnu_type),
4014 TYPE_SIZE (gnu_type), 0))
4015 {
4016 TYPE_SIZE (gnu_type)
4017 = elaborate_expression_1 (gnat_entity, gnat_entity,
4018 TYPE_SIZE (gnu_type),
4019 get_identifier ("SIZE"),
4020 definition, 0);
4021 SET_TYPE_ADA_SIZE (gnu_type, TYPE_SIZE (gnu_type));
4022 }
4023 else
4024 {
4025 TYPE_SIZE (gnu_type)
4026 = elaborate_expression_1 (gnat_entity, gnat_entity,
4027 TYPE_SIZE (gnu_type),
4028 get_identifier ("SIZE"),
4029 definition, 0);
4030
4031 /* ??? For now, store the size as a multiple of the alignment
4032 in bytes so that we can see the alignment from the tree. */
4033 TYPE_SIZE_UNIT (gnu_type)
4034 = build_binary_op
4035 (MULT_EXPR, sizetype,
4036 elaborate_expression_1
4037 (gnat_entity, gnat_entity,
4038 build_binary_op (EXACT_DIV_EXPR, sizetype,
4039 TYPE_SIZE_UNIT (gnu_type),
4040 size_int (TYPE_ALIGN (gnu_type)
4041 / BITS_PER_UNIT)),
4042 get_identifier ("SIZE_A_UNIT"),
4043 definition, 0),
4044 size_int (TYPE_ALIGN (gnu_type) / BITS_PER_UNIT));
4045
4046 if (TREE_CODE (gnu_type) == RECORD_TYPE)
4047 SET_TYPE_ADA_SIZE
4048 (gnu_type,
4049 elaborate_expression_1 (gnat_entity,
4050 gnat_entity,
4051 TYPE_ADA_SIZE (gnu_type),
4052 get_identifier ("RM_SIZE"),
4053 definition, 0));
4054 }
4055 }
4056
4057 /* If this is a record type or subtype, call elaborate_expression_1 on
4058 any field position. Do this for both global and local types.
4059 Skip any fields that we haven't made trees for to avoid problems with
4060 class wide types. */
4061 if (IN (kind, Record_Kind))
4062 for (gnat_temp = First_Entity (gnat_entity); Present (gnat_temp);
4063 gnat_temp = Next_Entity (gnat_temp))
4064 if (Ekind (gnat_temp) == E_Component && present_gnu_tree (gnat_temp))
4065 {
4066 tree gnu_field = get_gnu_tree (gnat_temp);
4067
4068 /* ??? Unfortunately, GCC needs to be able to prove the
4069 alignment of this offset and if it's a variable, it can't.
4070 In GCC 3.4, we'll use DECL_OFFSET_ALIGN in some way, but
4071 right now, we have to put in an explicit multiply and
4072 divide by that value. */
4073 if (!CONTAINS_PLACEHOLDER_P (DECL_FIELD_OFFSET (gnu_field)))
4074 DECL_FIELD_OFFSET (gnu_field)
4075 = build_binary_op
4076 (MULT_EXPR, sizetype,
4077 elaborate_expression_1
4078 (gnat_temp, gnat_temp,
4079 build_binary_op (EXACT_DIV_EXPR, sizetype,
4080 DECL_FIELD_OFFSET (gnu_field),
4081 size_int (DECL_OFFSET_ALIGN (gnu_field)
4082 / BITS_PER_UNIT)),
4083 get_identifier ("OFFSET"),
4084 definition, 0),
4085 size_int (DECL_OFFSET_ALIGN (gnu_field) / BITS_PER_UNIT));
4086 }
4087
4088 gnu_type = build_qualified_type (gnu_type,
4089 (TYPE_QUALS (gnu_type)
4090 | (TYPE_QUAL_VOLATILE
4091 * Treat_As_Volatile (gnat_entity))));
4092
4093 if (Is_Atomic (gnat_entity))
4094 check_ok_for_atomic (gnu_type, gnat_entity, false);
4095
4096 if (Known_Alignment (gnat_entity))
4097 TYPE_USER_ALIGN (gnu_type) = 1;
4098
4099 if (!gnu_decl)
4100 gnu_decl = create_type_decl (gnu_entity_id, gnu_type, attr_list,
4101 !Comes_From_Source (gnat_entity),
4102 debug_info_p, gnat_entity);
4103 else
4104 TREE_TYPE (gnu_decl) = gnu_type;
4105 }
4106
4107 if (IN (kind, Type_Kind) && !TYPE_IS_DUMMY_P (TREE_TYPE (gnu_decl)))
4108 {
4109 gnu_type = TREE_TYPE (gnu_decl);
4110
4111 /* Back-annotate the Alignment of the type if not already in the
4112 tree. Likewise for sizes. */
4113 if (Unknown_Alignment (gnat_entity))
4114 Set_Alignment (gnat_entity,
4115 UI_From_Int (TYPE_ALIGN (gnu_type) / BITS_PER_UNIT));
4116
4117 if (Unknown_Esize (gnat_entity) && TYPE_SIZE (gnu_type))
4118 {
4119 /* If the size is self-referential, we annotate the maximum
4120 value of that size. */
4121 tree gnu_size = TYPE_SIZE (gnu_type);
4122
4123 if (CONTAINS_PLACEHOLDER_P (gnu_size))
4124 gnu_size = max_size (gnu_size, true);
4125
4126 Set_Esize (gnat_entity, annotate_value (gnu_size));
4127
4128 if (type_annotate_only && Is_Tagged_Type (gnat_entity))
4129 {
4130 /* In this mode the tag and the parent components are not
4131 generated by the front-end, so the sizes must be adjusted
4132 explicitly now. */
4133
4134 int size_offset;
4135 int new_size;
4136
4137 if (Is_Derived_Type (gnat_entity))
4138 {
4139 size_offset
4140 = UI_To_Int (Esize (Etype (Base_Type (gnat_entity))));
4141 Set_Alignment (gnat_entity,
4142 Alignment (Etype (Base_Type (gnat_entity))));
4143 }
4144 else
4145 size_offset = POINTER_SIZE;
4146
4147 new_size = UI_To_Int (Esize (gnat_entity)) + size_offset;
4148 Set_Esize (gnat_entity,
4149 UI_From_Int (((new_size + (POINTER_SIZE - 1))
4150 / POINTER_SIZE) * POINTER_SIZE));
4151 Set_RM_Size (gnat_entity, Esize (gnat_entity));
4152 }
4153 }
4154
4155 if (Unknown_RM_Size (gnat_entity) && rm_size (gnu_type))
4156 Set_RM_Size (gnat_entity, annotate_value (rm_size (gnu_type)));
4157 }
4158
4159 if (!Comes_From_Source (gnat_entity) && DECL_P (gnu_decl))
4160 DECL_ARTIFICIAL (gnu_decl) = 1;
4161
4162 if (!debug_info_p && DECL_P (gnu_decl)
4163 && TREE_CODE (gnu_decl) != FUNCTION_DECL
4164 && No (Renamed_Object (gnat_entity)))
4165 DECL_IGNORED_P (gnu_decl) = 1;
4166
4167 /* If we haven't already, associate the ..._DECL node that we just made with
4168 the input GNAT entity node. */
4169 if (!saved)
4170 save_gnu_tree (gnat_entity, gnu_decl, false);
4171
4172 /* If this is an enumeral or floating-point type, we were not able to set
4173 the bounds since they refer to the type. These bounds are always static.
4174
4175 For enumeration types, also write debugging information and declare the
4176 enumeration literal table, if needed. */
4177
4178 if ((kind == E_Enumeration_Type && Present (First_Literal (gnat_entity)))
4179 || (kind == E_Floating_Point_Type && !Vax_Float (gnat_entity)))
4180 {
4181 tree gnu_scalar_type = gnu_type;
4182
4183 /* If this is a padded type, we need to use the underlying type. */
4184 if (TREE_CODE (gnu_scalar_type) == RECORD_TYPE
4185 && TYPE_IS_PADDING_P (gnu_scalar_type))
4186 gnu_scalar_type = TREE_TYPE (TYPE_FIELDS (gnu_scalar_type));
4187
4188 /* If this is a floating point type and we haven't set a floating
4189 point type yet, use this in the evaluation of the bounds. */
4190 if (!longest_float_type_node && kind == E_Floating_Point_Type)
4191 longest_float_type_node = gnu_type;
4192
4193 TYPE_MIN_VALUE (gnu_scalar_type)
4194 = gnat_to_gnu (Type_Low_Bound (gnat_entity));
4195 TYPE_MAX_VALUE (gnu_scalar_type)
4196 = gnat_to_gnu (Type_High_Bound (gnat_entity));
4197
4198 if (TREE_CODE (gnu_scalar_type) == ENUMERAL_TYPE)
4199 {
4200 TYPE_STUB_DECL (gnu_scalar_type) = gnu_decl;
4201
4202 /* Since this has both a typedef and a tag, avoid outputting
4203 the name twice. */
4204 DECL_ARTIFICIAL (gnu_decl) = 1;
4205 rest_of_type_compilation (gnu_scalar_type, global_bindings_p ());
4206 }
4207 }
4208
4209 /* If we deferred processing of incomplete types, re-enable it. If there
4210 were no other disables and we have some to process, do so. */
4211 if (this_deferred && --defer_incomplete_level == 0 && defer_incomplete_list)
4212 {
4213 struct incomplete *incp = defer_incomplete_list;
4214 struct incomplete *next;
4215
4216 defer_incomplete_list = NULL;
4217 for (; incp; incp = next)
4218 {
4219 next = incp->next;
4220
4221 if (incp->old_type)
4222 update_pointer_to (TYPE_MAIN_VARIANT (incp->old_type),
4223 gnat_to_gnu_type (incp->full_type));
4224 free (incp);
4225 }
4226 }
4227
4228 /* If we are not defining this type, see if it's in the incomplete list.
4229 If so, handle that list entry now. */
4230 else if (!definition)
4231 {
4232 struct incomplete *incp;
4233
4234 for (incp = defer_incomplete_list; incp; incp = incp->next)
4235 if (incp->old_type && incp->full_type == gnat_entity)
4236 {
4237 update_pointer_to (TYPE_MAIN_VARIANT (incp->old_type),
4238 TREE_TYPE (gnu_decl));
4239 incp->old_type = NULL_TREE;
4240 }
4241 }
4242
4243 /* If there are no incomplete types and we have deferred emission
4244 of debug information, check whether we have finished defining
4245 all nested records.
4246 If so, handle the list now. */
4247
4248 if (debug_deferred)
4249 defer_debug_level--;
4250
4251 if (defer_debug_incomplete_list
4252 && !defer_incomplete_level
4253 && !defer_debug_level)
4254 {
4255 tree c, n;
4256
4257 defer_debug_incomplete_list = nreverse (defer_debug_incomplete_list);
4258
4259 for (c = defer_debug_incomplete_list; c; c = n)
4260 {
4261 n = TREE_CHAIN (c);
4262 write_record_type_debug_info (TREE_VALUE (c));
4263 }
4264
4265 defer_debug_incomplete_list = 0;
4266 }
4267
4268 if (this_global)
4269 force_global--;
4270
4271 if (Is_Packed_Array_Type (gnat_entity)
4272 && Is_Itype (Associated_Node_For_Itype (gnat_entity))
4273 && No (Freeze_Node (Associated_Node_For_Itype (gnat_entity)))
4274 && !present_gnu_tree (Associated_Node_For_Itype (gnat_entity)))
4275 gnat_to_gnu_entity (Associated_Node_For_Itype (gnat_entity), NULL_TREE, 0);
4276
4277 return gnu_decl;
4278 }
4279
4280 /* Similar, but if the returned value is a COMPONENT_REF, return the
4281 FIELD_DECL. */
4282
4283 tree
4284 gnat_to_gnu_field_decl (Entity_Id gnat_entity)
4285 {
4286 tree gnu_field = gnat_to_gnu_entity (gnat_entity, NULL_TREE, 0);
4287
4288 if (TREE_CODE (gnu_field) == COMPONENT_REF)
4289 gnu_field = TREE_OPERAND (gnu_field, 1);
4290
4291 return gnu_field;
4292 }
4293 \f
4294 /* Given GNAT_ENTITY, elaborate all expressions that are required to
4295 be elaborated at the point of its definition, but do nothing else. */
4296
4297 void
4298 elaborate_entity (Entity_Id gnat_entity)
4299 {
4300 switch (Ekind (gnat_entity))
4301 {
4302 case E_Signed_Integer_Subtype:
4303 case E_Modular_Integer_Subtype:
4304 case E_Enumeration_Subtype:
4305 case E_Ordinary_Fixed_Point_Subtype:
4306 case E_Decimal_Fixed_Point_Subtype:
4307 case E_Floating_Point_Subtype:
4308 {
4309 Node_Id gnat_lb = Type_Low_Bound (gnat_entity);
4310 Node_Id gnat_hb = Type_High_Bound (gnat_entity);
4311
4312 /* ??? Tests for avoiding static constraint error expression
4313 is needed until the front stops generating bogus conversions
4314 on bounds of real types. */
4315
4316 if (!Raises_Constraint_Error (gnat_lb))
4317 elaborate_expression (gnat_lb, gnat_entity, get_identifier ("L"),
4318 1, 0, Needs_Debug_Info (gnat_entity));
4319 if (!Raises_Constraint_Error (gnat_hb))
4320 elaborate_expression (gnat_hb, gnat_entity, get_identifier ("U"),
4321 1, 0, Needs_Debug_Info (gnat_entity));
4322 break;
4323 }
4324
4325 case E_Record_Type:
4326 {
4327 Node_Id full_definition = Declaration_Node (gnat_entity);
4328 Node_Id record_definition = Type_Definition (full_definition);
4329
4330 /* If this is a record extension, go a level further to find the
4331 record definition. */
4332 if (Nkind (record_definition) == N_Derived_Type_Definition)
4333 record_definition = Record_Extension_Part (record_definition);
4334 }
4335 break;
4336
4337 case E_Record_Subtype:
4338 case E_Private_Subtype:
4339 case E_Limited_Private_Subtype:
4340 case E_Record_Subtype_With_Private:
4341 if (Is_Constrained (gnat_entity)
4342 && Has_Discriminants (Base_Type (gnat_entity))
4343 && Present (Discriminant_Constraint (gnat_entity)))
4344 {
4345 Node_Id gnat_discriminant_expr;
4346 Entity_Id gnat_field;
4347
4348 for (gnat_field = First_Discriminant (Base_Type (gnat_entity)),
4349 gnat_discriminant_expr
4350 = First_Elmt (Discriminant_Constraint (gnat_entity));
4351 Present (gnat_field);
4352 gnat_field = Next_Discriminant (gnat_field),
4353 gnat_discriminant_expr = Next_Elmt (gnat_discriminant_expr))
4354 /* ??? For now, ignore access discriminants. */
4355 if (!Is_Access_Type (Etype (Node (gnat_discriminant_expr))))
4356 elaborate_expression (Node (gnat_discriminant_expr),
4357 gnat_entity,
4358 get_entity_name (gnat_field), 1, 0, 0);
4359 }
4360 break;
4361
4362 }
4363 }
4364 \f
4365 /* Mark GNAT_ENTITY as going out of scope at this point. Recursively mark
4366 any entities on its entity chain similarly. */
4367
4368 void
4369 mark_out_of_scope (Entity_Id gnat_entity)
4370 {
4371 Entity_Id gnat_sub_entity;
4372 unsigned int kind = Ekind (gnat_entity);
4373
4374 /* If this has an entity list, process all in the list. */
4375 if (IN (kind, Class_Wide_Kind) || IN (kind, Concurrent_Kind)
4376 || IN (kind, Private_Kind)
4377 || kind == E_Block || kind == E_Entry || kind == E_Entry_Family
4378 || kind == E_Function || kind == E_Generic_Function
4379 || kind == E_Generic_Package || kind == E_Generic_Procedure
4380 || kind == E_Loop || kind == E_Operator || kind == E_Package
4381 || kind == E_Package_Body || kind == E_Procedure
4382 || kind == E_Record_Type || kind == E_Record_Subtype
4383 || kind == E_Subprogram_Body || kind == E_Subprogram_Type)
4384 for (gnat_sub_entity = First_Entity (gnat_entity);
4385 Present (gnat_sub_entity);
4386 gnat_sub_entity = Next_Entity (gnat_sub_entity))
4387 if (Scope (gnat_sub_entity) == gnat_entity
4388 && gnat_sub_entity != gnat_entity)
4389 mark_out_of_scope (gnat_sub_entity);
4390
4391 /* Now clear this if it has been defined, but only do so if it isn't
4392 a subprogram or parameter. We could refine this, but it isn't
4393 worth it. If this is statically allocated, it is supposed to
4394 hang around out of cope. */
4395 if (present_gnu_tree (gnat_entity) && !Is_Statically_Allocated (gnat_entity)
4396 && kind != E_Procedure && kind != E_Function && !IN (kind, Formal_Kind))
4397 {
4398 save_gnu_tree (gnat_entity, NULL_TREE, true);
4399 save_gnu_tree (gnat_entity, error_mark_node, true);
4400 }
4401 }
4402 \f
4403 /* Set the alias set of GNU_NEW_TYPE to be that of GNU_OLD_TYPE. If this
4404 is a multi-dimensional array type, do this recursively. */
4405
4406 static void
4407 copy_alias_set (tree gnu_new_type, tree gnu_old_type)
4408 {
4409 /* Remove any padding from GNU_OLD_TYPE. It doesn't matter in the case
4410 of a one-dimensional array, since the padding has the same alias set
4411 as the field type, but if it's a multi-dimensional array, we need to
4412 see the inner types. */
4413 while (TREE_CODE (gnu_old_type) == RECORD_TYPE
4414 && (TYPE_JUSTIFIED_MODULAR_P (gnu_old_type)
4415 || TYPE_IS_PADDING_P (gnu_old_type)))
4416 gnu_old_type = TREE_TYPE (TYPE_FIELDS (gnu_old_type));
4417
4418 /* We need to be careful here in case GNU_OLD_TYPE is an unconstrained
4419 array. In that case, it doesn't have the same shape as GNU_NEW_TYPE,
4420 so we need to go down to what does. */
4421 if (TREE_CODE (gnu_old_type) == UNCONSTRAINED_ARRAY_TYPE)
4422 gnu_old_type
4423 = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_old_type))));
4424
4425 if (TREE_CODE (gnu_new_type) == ARRAY_TYPE
4426 && TREE_CODE (TREE_TYPE (gnu_new_type)) == ARRAY_TYPE
4427 && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_new_type)))
4428 copy_alias_set (TREE_TYPE (gnu_new_type), TREE_TYPE (gnu_old_type));
4429
4430 TYPE_ALIAS_SET (gnu_new_type) = get_alias_set (gnu_old_type);
4431 record_component_aliases (gnu_new_type);
4432 }
4433 \f
4434 /* Return a TREE_LIST describing the substitutions needed to reflect
4435 discriminant substitutions from GNAT_SUBTYPE to GNAT_TYPE and add
4436 them to GNU_LIST. If GNAT_TYPE is not specified, use the base type
4437 of GNAT_SUBTYPE. The substitutions can be in any order. TREE_PURPOSE
4438 gives the tree for the discriminant and TREE_VALUES is the replacement
4439 value. They are in the form of operands to substitute_in_expr.
4440 DEFINITION is as in gnat_to_gnu_entity. */
4441
4442 static tree
4443 substitution_list (Entity_Id gnat_subtype, Entity_Id gnat_type,
4444 tree gnu_list, bool definition)
4445 {
4446 Entity_Id gnat_discrim;
4447 Node_Id gnat_value;
4448
4449 if (No (gnat_type))
4450 gnat_type = Implementation_Base_Type (gnat_subtype);
4451
4452 if (Has_Discriminants (gnat_type))
4453 for (gnat_discrim = First_Stored_Discriminant (gnat_type),
4454 gnat_value = First_Elmt (Stored_Constraint (gnat_subtype));
4455 Present (gnat_discrim);
4456 gnat_discrim = Next_Stored_Discriminant (gnat_discrim),
4457 gnat_value = Next_Elmt (gnat_value))
4458 /* Ignore access discriminants. */
4459 if (!Is_Access_Type (Etype (Node (gnat_value))))
4460 gnu_list = tree_cons (gnat_to_gnu_field_decl (gnat_discrim),
4461 elaborate_expression
4462 (Node (gnat_value), gnat_subtype,
4463 get_entity_name (gnat_discrim), definition,
4464 1, 0),
4465 gnu_list);
4466
4467 return gnu_list;
4468 }
4469 \f
4470 /* For the following two functions: for each GNAT entity, the GCC
4471 tree node used as a dummy for that entity, if any. */
4472
4473 static GTY((length ("max_gnat_nodes"))) tree * dummy_node_table;
4474
4475 /* Initialize the above table. */
4476
4477 void
4478 init_dummy_type (void)
4479 {
4480 Node_Id gnat_node;
4481
4482 dummy_node_table = (tree *) ggc_alloc (max_gnat_nodes * sizeof (tree));
4483
4484 for (gnat_node = 0; gnat_node < max_gnat_nodes; gnat_node++)
4485 dummy_node_table[gnat_node] = NULL_TREE;
4486
4487 dummy_node_table -= First_Node_Id;
4488 }
4489
4490 /* Make a dummy type corresponding to GNAT_TYPE. */
4491
4492 tree
4493 make_dummy_type (Entity_Id gnat_type)
4494 {
4495 Entity_Id gnat_underlying;
4496 tree gnu_type;
4497 enum tree_code code;
4498
4499 /* Find a full type for GNAT_TYPE, taking into account any class wide
4500 types. */
4501 if (Is_Class_Wide_Type (gnat_type) && Present (Equivalent_Type (gnat_type)))
4502 gnat_type = Equivalent_Type (gnat_type);
4503 else if (Ekind (gnat_type) == E_Class_Wide_Type)
4504 gnat_type = Root_Type (gnat_type);
4505
4506 for (gnat_underlying = gnat_type;
4507 (IN (Ekind (gnat_underlying), Incomplete_Or_Private_Kind)
4508 && Present (Full_View (gnat_underlying)));
4509 gnat_underlying = Full_View (gnat_underlying))
4510 ;
4511
4512 /* If it there already a dummy type, use that one. Else make one. */
4513 if (dummy_node_table[gnat_underlying])
4514 return dummy_node_table[gnat_underlying];
4515
4516 /* If this is a record, make this a RECORD_TYPE or UNION_TYPE; else make
4517 it an ENUMERAL_TYPE. */
4518 if (Is_Record_Type (gnat_underlying))
4519 {
4520 Node_Id component_list
4521 = Component_List (Type_Definition
4522 (Declaration_Node
4523 (Implementation_Base_Type (gnat_underlying))));
4524 Node_Id component;
4525
4526 /* Make this a UNION_TYPE unless it's either not an Unchecked_Union or
4527 we have a non-discriminant field outside a variant. In either case,
4528 it's a RECORD_TYPE. */
4529 code = UNION_TYPE;
4530 if (!Is_Unchecked_Union (gnat_underlying))
4531 code = RECORD_TYPE;
4532 else
4533 for (component = First_Non_Pragma (Component_Items (component_list));
4534 Present (component); component = Next_Non_Pragma (component))
4535 if (Ekind (Defining_Entity (component)) == E_Component)
4536 code = RECORD_TYPE;
4537 }
4538 else
4539 code = ENUMERAL_TYPE;
4540
4541 gnu_type = make_node (code);
4542 TYPE_NAME (gnu_type) = get_entity_name (gnat_type);
4543 TYPE_DUMMY_P (gnu_type) = 1;
4544 if (AGGREGATE_TYPE_P (gnu_type))
4545 TYPE_STUB_DECL (gnu_type) = build_decl (TYPE_DECL, NULL_TREE, gnu_type);
4546
4547 dummy_node_table[gnat_underlying] = gnu_type;
4548
4549 return gnu_type;
4550 }
4551 \f
4552 /* Return true if the size represented by GNU_SIZE can be handled by an
4553 allocation. If STATIC_P is true, consider only what can be done with a
4554 static allocation. */
4555
4556 static bool
4557 allocatable_size_p (tree gnu_size, bool static_p)
4558 {
4559 HOST_WIDE_INT our_size;
4560
4561 /* If this is not a static allocation, the only case we want to forbid
4562 is an overflowing size. That will be converted into a raise a
4563 Storage_Error. */
4564 if (!static_p)
4565 return !(TREE_CODE (gnu_size) == INTEGER_CST
4566 && TREE_CONSTANT_OVERFLOW (gnu_size));
4567
4568 /* Otherwise, we need to deal with both variable sizes and constant
4569 sizes that won't fit in a host int. We use int instead of HOST_WIDE_INT
4570 since assemblers may not like very large sizes. */
4571 if (!host_integerp (gnu_size, 1))
4572 return false;
4573
4574 our_size = tree_low_cst (gnu_size, 1);
4575 return (int) our_size == our_size;
4576 }
4577 \f
4578 /* Prepend to ATTR_LIST the list of attributes for GNAT_ENTITY, if any. */
4579
4580 static void
4581 prepend_attributes (Entity_Id gnat_entity, struct attrib ** attr_list)
4582 {
4583 Node_Id gnat_temp;
4584
4585 for (gnat_temp = First_Rep_Item (gnat_entity); Present (gnat_temp);
4586 gnat_temp = Next_Rep_Item (gnat_temp))
4587 if (Nkind (gnat_temp) == N_Pragma)
4588 {
4589 struct attrib *attr;
4590 tree gnu_arg0 = NULL_TREE, gnu_arg1 = NULL_TREE;
4591 Node_Id gnat_assoc = Pragma_Argument_Associations (gnat_temp);
4592 enum attr_type etype;
4593
4594 if (Present (gnat_assoc) && Present (First (gnat_assoc))
4595 && Present (Next (First (gnat_assoc)))
4596 && (Nkind (Expression (Next (First (gnat_assoc))))
4597 == N_String_Literal))
4598 {
4599 gnu_arg0 = get_identifier (TREE_STRING_POINTER
4600 (gnat_to_gnu
4601 (Expression (Next
4602 (First (gnat_assoc))))));
4603 if (Present (Next (Next (First (gnat_assoc))))
4604 && (Nkind (Expression (Next (Next (First (gnat_assoc)))))
4605 == N_String_Literal))
4606 gnu_arg1 = get_identifier (TREE_STRING_POINTER
4607 (gnat_to_gnu
4608 (Expression
4609 (Next (Next
4610 (First (gnat_assoc)))))));
4611 }
4612
4613 switch (Get_Pragma_Id (Chars (gnat_temp)))
4614 {
4615 case Pragma_Machine_Attribute:
4616 etype = ATTR_MACHINE_ATTRIBUTE;
4617 break;
4618
4619 case Pragma_Linker_Alias:
4620 etype = ATTR_LINK_ALIAS;
4621 break;
4622
4623 case Pragma_Linker_Section:
4624 etype = ATTR_LINK_SECTION;
4625 break;
4626
4627 case Pragma_Linker_Constructor:
4628 etype = ATTR_LINK_CONSTRUCTOR;
4629 break;
4630
4631 case Pragma_Linker_Destructor:
4632 etype = ATTR_LINK_DESTRUCTOR;
4633 break;
4634
4635 case Pragma_Weak_External:
4636 etype = ATTR_WEAK_EXTERNAL;
4637 break;
4638
4639 default:
4640 continue;
4641 }
4642
4643 attr = (struct attrib *) xmalloc (sizeof (struct attrib));
4644 attr->next = *attr_list;
4645 attr->type = etype;
4646 attr->name = gnu_arg0;
4647
4648 /* If we have an argument specified together with an attribute name,
4649 make it a single TREE_VALUE entry in a list of arguments, as GCC
4650 expects it. */
4651 if (gnu_arg1 != NULL_TREE)
4652 attr->args = build_tree_list (NULL_TREE, gnu_arg1);
4653 else
4654 attr->args = NULL_TREE;
4655
4656 attr->error_point
4657 = Present (Next (First (gnat_assoc)))
4658 ? Expression (Next (First (gnat_assoc))) : gnat_temp;
4659 *attr_list = attr;
4660 }
4661 }
4662 \f
4663 /* Get the unpadded version of a GNAT type. */
4664
4665 tree
4666 get_unpadded_type (Entity_Id gnat_entity)
4667 {
4668 tree type = gnat_to_gnu_type (gnat_entity);
4669
4670 if (TREE_CODE (type) == RECORD_TYPE && TYPE_IS_PADDING_P (type))
4671 type = TREE_TYPE (TYPE_FIELDS (type));
4672
4673 return type;
4674 }
4675 \f
4676 /* Called when we need to protect a variable object using a save_expr. */
4677
4678 tree
4679 maybe_variable (tree gnu_operand)
4680 {
4681 if (TREE_CONSTANT (gnu_operand) || TREE_READONLY (gnu_operand)
4682 || TREE_CODE (gnu_operand) == SAVE_EXPR
4683 || TREE_CODE (gnu_operand) == NULL_EXPR)
4684 return gnu_operand;
4685
4686 if (TREE_CODE (gnu_operand) == UNCONSTRAINED_ARRAY_REF)
4687 {
4688 tree gnu_result = build1 (UNCONSTRAINED_ARRAY_REF,
4689 TREE_TYPE (gnu_operand),
4690 variable_size (TREE_OPERAND (gnu_operand, 0)));
4691
4692 TREE_READONLY (gnu_result) = TREE_STATIC (gnu_result)
4693 = TYPE_READONLY (TREE_TYPE (TREE_TYPE (gnu_operand)));
4694 return gnu_result;
4695 }
4696 else
4697 return variable_size (gnu_operand);
4698 }
4699 \f
4700 /* Given a GNAT tree GNAT_EXPR, for an expression which is a value within a
4701 type definition (either a bound or a discriminant value) for GNAT_ENTITY,
4702 return the GCC tree to use for that expression. GNU_NAME is the
4703 qualification to use if an external name is appropriate and DEFINITION is
4704 nonzero if this is a definition of GNAT_ENTITY. If NEED_VALUE is nonzero,
4705 we need a result. Otherwise, we are just elaborating this for
4706 side-effects. If NEED_DEBUG is nonzero we need the symbol for debugging
4707 purposes even if it isn't needed for code generation. */
4708
4709 static tree
4710 elaborate_expression (Node_Id gnat_expr, Entity_Id gnat_entity,
4711 tree gnu_name, bool definition, bool need_value,
4712 bool need_debug)
4713 {
4714 tree gnu_expr;
4715
4716 /* If we already elaborated this expression (e.g., it was involved
4717 in the definition of a private type), use the old value. */
4718 if (present_gnu_tree (gnat_expr))
4719 return get_gnu_tree (gnat_expr);
4720
4721 /* If we don't need a value and this is static or a discriment, we
4722 don't need to do anything. */
4723 else if (!need_value
4724 && (Is_OK_Static_Expression (gnat_expr)
4725 || (Nkind (gnat_expr) == N_Identifier
4726 && Ekind (Entity (gnat_expr)) == E_Discriminant)))
4727 return 0;
4728
4729 /* Otherwise, convert this tree to its GCC equivalent. */
4730 gnu_expr
4731 = elaborate_expression_1 (gnat_expr, gnat_entity, gnat_to_gnu (gnat_expr),
4732 gnu_name, definition, need_debug);
4733
4734 /* Save the expression in case we try to elaborate this entity again. Since
4735 this is not a DECL, don't check it. Don't save if it's a discriminant. */
4736 if (!CONTAINS_PLACEHOLDER_P (gnu_expr))
4737 save_gnu_tree (gnat_expr, gnu_expr, true);
4738
4739 return need_value ? gnu_expr : error_mark_node;
4740 }
4741
4742 /* Similar, but take a GNU expression. */
4743
4744 static tree
4745 elaborate_expression_1 (Node_Id gnat_expr, Entity_Id gnat_entity,
4746 tree gnu_expr, tree gnu_name, bool definition,
4747 bool need_debug)
4748 {
4749 tree gnu_decl = NULL_TREE;
4750 /* Strip any conversions to see if the expression is a readonly variable.
4751 ??? This really should remain readonly, but we have to think about
4752 the typing of the tree here. */
4753 tree gnu_inner_expr = remove_conversions (gnu_expr, true);
4754 bool expr_global = Is_Public (gnat_entity) || global_bindings_p ();
4755 bool expr_variable;
4756
4757 /* In most cases, we won't see a naked FIELD_DECL here because a
4758 discriminant reference will have been replaced with a COMPONENT_REF
4759 when the type is being elaborated. However, there are some cases
4760 involving child types where we will. So convert it to a COMPONENT_REF
4761 here. We have to hope it will be at the highest level of the
4762 expression in these cases. */
4763 if (TREE_CODE (gnu_expr) == FIELD_DECL)
4764 gnu_expr = build3 (COMPONENT_REF, TREE_TYPE (gnu_expr),
4765 build0 (PLACEHOLDER_EXPR, DECL_CONTEXT (gnu_expr)),
4766 gnu_expr, NULL_TREE);
4767
4768 /* If GNU_EXPR is neither a placeholder nor a constant, nor a variable
4769 that is a constant, make a variable that is initialized to contain the
4770 bound when the package containing the definition is elaborated. If
4771 this entity is defined at top level and a bound or discriminant value
4772 isn't a constant or a reference to a discriminant, replace the bound
4773 by the variable; otherwise use a SAVE_EXPR if needed. Note that we
4774 rely here on the fact that an expression cannot contain both the
4775 discriminant and some other variable. */
4776
4777 expr_variable = (!CONSTANT_CLASS_P (gnu_expr)
4778 && !(TREE_CODE (gnu_inner_expr) == VAR_DECL
4779 && TREE_READONLY (gnu_inner_expr))
4780 && !CONTAINS_PLACEHOLDER_P (gnu_expr));
4781
4782 /* If this is a static expression or contains a discriminant, we don't
4783 need the variable for debugging (and can't elaborate anyway if a
4784 discriminant). */
4785 if (need_debug
4786 && (Is_OK_Static_Expression (gnat_expr)
4787 || CONTAINS_PLACEHOLDER_P (gnu_expr)))
4788 need_debug = false;
4789
4790 /* Now create the variable if we need it. */
4791 if (need_debug || (expr_variable && expr_global))
4792 gnu_decl
4793 = create_var_decl (create_concat_name (gnat_entity,
4794 IDENTIFIER_POINTER (gnu_name)),
4795 NULL_TREE, TREE_TYPE (gnu_expr), gnu_expr,
4796 !need_debug, Is_Public (gnat_entity),
4797 !definition, false, NULL, gnat_entity);
4798
4799 /* We only need to use this variable if we are in global context since GCC
4800 can do the right thing in the local case. */
4801 if (expr_global && expr_variable)
4802 return gnu_decl;
4803 else if (!expr_variable)
4804 return gnu_expr;
4805 else
4806 return maybe_variable (gnu_expr);
4807 }
4808 \f
4809 /* Create a record type that contains a field of TYPE with a starting bit
4810 position so that it is aligned to ALIGN bits and is SIZE bytes long. */
4811
4812 tree
4813 make_aligning_type (tree type, int align, tree size)
4814 {
4815 tree record_type = make_node (RECORD_TYPE);
4816 tree place = build0 (PLACEHOLDER_EXPR, record_type);
4817 tree size_addr_place = convert (sizetype,
4818 build_unary_op (ADDR_EXPR, NULL_TREE,
4819 place));
4820 tree name = TYPE_NAME (type);
4821 tree pos, field;
4822
4823 if (TREE_CODE (name) == TYPE_DECL)
4824 name = DECL_NAME (name);
4825
4826 TYPE_NAME (record_type) = concat_id_with_name (name, "_ALIGN");
4827
4828 /* The bit position is obtained by "and"ing the alignment minus 1
4829 with the two's complement of the address and multiplying
4830 by the number of bits per unit. Do all this in sizetype. */
4831 pos = size_binop (MULT_EXPR,
4832 convert (bitsizetype,
4833 size_binop (BIT_AND_EXPR,
4834 size_diffop (size_zero_node,
4835 size_addr_place),
4836 ssize_int ((align / BITS_PER_UNIT)
4837 - 1))),
4838 bitsize_unit_node);
4839
4840 /* Create the field, with -1 as the 'addressable' indication to avoid the
4841 creation of a bitfield. We don't need one, it would have damaging
4842 consequences on the alignment computation, and create_field_decl would
4843 make one without this special argument, for instance because of the
4844 complex position expression. */
4845 field = create_field_decl (get_identifier ("F"), type, record_type, 1, size,
4846 pos, -1);
4847
4848 finish_record_type (record_type, field, true, false);
4849 TYPE_ALIGN (record_type) = BIGGEST_ALIGNMENT;
4850 TYPE_SIZE (record_type)
4851 = size_binop (PLUS_EXPR,
4852 size_binop (MULT_EXPR, convert (bitsizetype, size),
4853 bitsize_unit_node),
4854 bitsize_int (align));
4855 TYPE_SIZE_UNIT (record_type)
4856 = size_binop (PLUS_EXPR, size, size_int (align / BITS_PER_UNIT));
4857 copy_alias_set (record_type, type);
4858 return record_type;
4859 }
4860 \f
4861 /* TYPE is a RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE, with BLKmode that's
4862 being used as the field type of a packed record. See if we can rewrite it
4863 as a record that has a non-BLKmode type, which we can pack tighter. If so,
4864 return the new type. If not, return the original type. */
4865
4866 static tree
4867 make_packable_type (tree type)
4868 {
4869 tree new_type = make_node (TREE_CODE (type));
4870 tree field_list = NULL_TREE;
4871 tree old_field;
4872
4873 /* Copy the name and flags from the old type to that of the new and set
4874 the alignment to try for an integral type. For QUAL_UNION_TYPE,
4875 also copy the size. */
4876 TYPE_NAME (new_type) = TYPE_NAME (type);
4877 TYPE_JUSTIFIED_MODULAR_P (new_type)
4878 = TYPE_JUSTIFIED_MODULAR_P (type);
4879 TYPE_CONTAINS_TEMPLATE_P (new_type) = TYPE_CONTAINS_TEMPLATE_P (type);
4880
4881 if (TREE_CODE (type) == RECORD_TYPE)
4882 TYPE_IS_PADDING_P (new_type) = TYPE_IS_PADDING_P (type);
4883 else if (TREE_CODE (type) == QUAL_UNION_TYPE)
4884 {
4885 TYPE_SIZE (new_type) = TYPE_SIZE (type);
4886 TYPE_SIZE_UNIT (new_type) = TYPE_SIZE_UNIT (type);
4887 }
4888
4889 TYPE_ALIGN (new_type)
4890 = ((HOST_WIDE_INT) 1
4891 << (floor_log2 (tree_low_cst (TYPE_SIZE (type), 1) - 1) + 1));
4892
4893 /* Now copy the fields, keeping the position and size. */
4894 for (old_field = TYPE_FIELDS (type); old_field;
4895 old_field = TREE_CHAIN (old_field))
4896 {
4897 tree new_field_type = TREE_TYPE (old_field);
4898 tree new_field;
4899
4900 if (TYPE_MODE (new_field_type) == BLKmode
4901 && (TREE_CODE (new_field_type) == RECORD_TYPE
4902 || TREE_CODE (new_field_type) == UNION_TYPE
4903 || TREE_CODE (new_field_type) == QUAL_UNION_TYPE)
4904 && host_integerp (TYPE_SIZE (new_field_type), 1))
4905 new_field_type = make_packable_type (new_field_type);
4906
4907 new_field = create_field_decl (DECL_NAME (old_field), new_field_type,
4908 new_type, TYPE_PACKED (type),
4909 DECL_SIZE (old_field),
4910 bit_position (old_field),
4911 !DECL_NONADDRESSABLE_P (old_field));
4912
4913 DECL_INTERNAL_P (new_field) = DECL_INTERNAL_P (old_field);
4914 SET_DECL_ORIGINAL_FIELD
4915 (new_field, (DECL_ORIGINAL_FIELD (old_field)
4916 ? DECL_ORIGINAL_FIELD (old_field) : old_field));
4917
4918 if (TREE_CODE (new_type) == QUAL_UNION_TYPE)
4919 DECL_QUALIFIER (new_field) = DECL_QUALIFIER (old_field);
4920
4921 TREE_CHAIN (new_field) = field_list;
4922 field_list = new_field;
4923 }
4924
4925 finish_record_type (new_type, nreverse (field_list), true, true);
4926 copy_alias_set (new_type, type);
4927 return TYPE_MODE (new_type) == BLKmode ? type : new_type;
4928 }
4929 \f
4930 /* Ensure that TYPE has SIZE and ALIGN. Make and return a new padded type
4931 if needed. We have already verified that SIZE and TYPE are large enough.
4932
4933 GNAT_ENTITY and NAME_TRAILER are used to name the resulting record and
4934 to issue a warning.
4935
4936 IS_USER_TYPE is true if we must be sure we complete the original type.
4937
4938 DEFINITION is true if this type is being defined.
4939
4940 SAME_RM_SIZE is true if the RM_Size of the resulting type is to be
4941 set to its TYPE_SIZE; otherwise, it's set to the RM_Size of the original
4942 type. */
4943
4944 tree
4945 maybe_pad_type (tree type, tree size, unsigned int align,
4946 Entity_Id gnat_entity, const char *name_trailer,
4947 bool is_user_type, bool definition, bool same_rm_size)
4948 {
4949 tree orig_size = TYPE_SIZE (type);
4950 tree record;
4951 tree field;
4952
4953 /* If TYPE is a padded type, see if it agrees with any size and alignment
4954 we were given. If so, return the original type. Otherwise, strip
4955 off the padding, since we will either be returning the inner type
4956 or repadding it. If no size or alignment is specified, use that of
4957 the original padded type. */
4958
4959 if (TREE_CODE (type) == RECORD_TYPE && TYPE_IS_PADDING_P (type))
4960 {
4961 if ((!size
4962 || operand_equal_p (round_up (size,
4963 MAX (align, TYPE_ALIGN (type))),
4964 round_up (TYPE_SIZE (type),
4965 MAX (align, TYPE_ALIGN (type))),
4966 0))
4967 && (align == 0 || align == TYPE_ALIGN (type)))
4968 return type;
4969
4970 if (!size)
4971 size = TYPE_SIZE (type);
4972 if (align == 0)
4973 align = TYPE_ALIGN (type);
4974
4975 type = TREE_TYPE (TYPE_FIELDS (type));
4976 orig_size = TYPE_SIZE (type);
4977 }
4978
4979 /* If the size is either not being changed or is being made smaller (which
4980 is not done here (and is only valid for bitfields anyway), show the size
4981 isn't changing. Likewise, clear the alignment if it isn't being
4982 changed. Then return if we aren't doing anything. */
4983
4984 if (size
4985 && (operand_equal_p (size, orig_size, 0)
4986 || (TREE_CODE (orig_size) == INTEGER_CST
4987 && tree_int_cst_lt (size, orig_size))))
4988 size = NULL_TREE;
4989
4990 if (align == TYPE_ALIGN (type))
4991 align = 0;
4992
4993 if (align == 0 && !size)
4994 return type;
4995
4996 /* We used to modify the record in place in some cases, but that could
4997 generate incorrect debugging information. So make a new record
4998 type and name. */
4999 record = make_node (RECORD_TYPE);
5000
5001 if (Present (gnat_entity))
5002 TYPE_NAME (record) = create_concat_name (gnat_entity, name_trailer);
5003
5004 /* If we were making a type, complete the original type and give it a
5005 name. */
5006 if (is_user_type)
5007 create_type_decl (get_entity_name (gnat_entity), type,
5008 NULL, !Comes_From_Source (gnat_entity),
5009 !(TYPE_NAME (type)
5010 && TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
5011 && DECL_IGNORED_P (TYPE_NAME (type))),
5012 gnat_entity);
5013
5014 /* If we are changing the alignment and the input type is a record with
5015 BLKmode and a small constant size, try to make a form that has an
5016 integral mode. That might allow this record to have an integral mode,
5017 which will be much more efficient. There is no point in doing this if a
5018 size is specified unless it is also smaller than the biggest alignment
5019 and it is incorrect to do this if the size of the original type is not a
5020 multiple of the alignment. */
5021 if (align != 0
5022 && TREE_CODE (type) == RECORD_TYPE
5023 && TYPE_MODE (type) == BLKmode
5024 && host_integerp (orig_size, 1)
5025 && compare_tree_int (orig_size, BIGGEST_ALIGNMENT) <= 0
5026 && (!size
5027 || (TREE_CODE (size) == INTEGER_CST
5028 && compare_tree_int (size, BIGGEST_ALIGNMENT) <= 0))
5029 && tree_low_cst (orig_size, 1) % align == 0)
5030 type = make_packable_type (type);
5031
5032 field = create_field_decl (get_identifier ("F"), type, record, 0,
5033 NULL_TREE, bitsize_zero_node, 1);
5034
5035 DECL_INTERNAL_P (field) = 1;
5036 TYPE_SIZE (record) = size ? size : orig_size;
5037 TYPE_SIZE_UNIT (record)
5038 = (size ? convert (sizetype,
5039 size_binop (CEIL_DIV_EXPR, size, bitsize_unit_node))
5040 : TYPE_SIZE_UNIT (type));
5041
5042 TYPE_ALIGN (record) = align;
5043 TYPE_IS_PADDING_P (record) = 1;
5044 TYPE_VOLATILE (record)
5045 = Present (gnat_entity) && Treat_As_Volatile (gnat_entity);
5046 finish_record_type (record, field, true, false);
5047
5048 /* Keep the RM_Size of the padded record as that of the old record
5049 if requested. */
5050 SET_TYPE_ADA_SIZE (record, same_rm_size ? size : rm_size (type));
5051
5052 /* Unless debugging information isn't being written for the input type,
5053 write a record that shows what we are a subtype of and also make a
5054 variable that indicates our size, if variable. */
5055 if (TYPE_NAME (record) && AGGREGATE_TYPE_P (type)
5056 && (TREE_CODE (TYPE_NAME (type)) != TYPE_DECL
5057 || !DECL_IGNORED_P (TYPE_NAME (type))))
5058 {
5059 tree marker = make_node (RECORD_TYPE);
5060 tree name = (TREE_CODE (TYPE_NAME (record)) == TYPE_DECL
5061 ? DECL_NAME (TYPE_NAME (record))
5062 : TYPE_NAME (record));
5063 tree orig_name = TYPE_NAME (type);
5064
5065 if (TREE_CODE (orig_name) == TYPE_DECL)
5066 orig_name = DECL_NAME (orig_name);
5067
5068 TYPE_NAME (marker) = concat_id_with_name (name, "XVS");
5069 finish_record_type (marker,
5070 create_field_decl (orig_name, integer_type_node,
5071 marker, 0, NULL_TREE, NULL_TREE,
5072 0),
5073 false, false);
5074
5075 if (size && TREE_CODE (size) != INTEGER_CST && definition)
5076 create_var_decl (concat_id_with_name (name, "XVZ"), NULL_TREE,
5077 bitsizetype, TYPE_SIZE (record), false, false, false,
5078 false, NULL, gnat_entity);
5079 }
5080
5081 type = record;
5082
5083 if (CONTAINS_PLACEHOLDER_P (orig_size))
5084 orig_size = max_size (orig_size, true);
5085
5086 /* If the size was widened explicitly, maybe give a warning. */
5087 if (size && Present (gnat_entity)
5088 && !operand_equal_p (size, orig_size, 0)
5089 && !(TREE_CODE (size) == INTEGER_CST
5090 && TREE_CODE (orig_size) == INTEGER_CST
5091 && tree_int_cst_lt (size, orig_size)))
5092 {
5093 Node_Id gnat_error_node = Empty;
5094
5095 if (Is_Packed_Array_Type (gnat_entity))
5096 gnat_entity = Associated_Node_For_Itype (gnat_entity);
5097
5098 if ((Ekind (gnat_entity) == E_Component
5099 || Ekind (gnat_entity) == E_Discriminant)
5100 && Present (Component_Clause (gnat_entity)))
5101 gnat_error_node = Last_Bit (Component_Clause (gnat_entity));
5102 else if (Present (Size_Clause (gnat_entity)))
5103 gnat_error_node = Expression (Size_Clause (gnat_entity));
5104
5105 /* Generate message only for entities that come from source, since
5106 if we have an entity created by expansion, the message will be
5107 generated for some other corresponding source entity. */
5108 if (Comes_From_Source (gnat_entity) && Present (gnat_error_node))
5109 post_error_ne_tree ("{^ }bits of & unused?", gnat_error_node,
5110 gnat_entity,
5111 size_diffop (size, orig_size));
5112
5113 else if (*name_trailer == 'C' && !Is_Internal (gnat_entity))
5114 post_error_ne_tree ("component of& padded{ by ^ bits}?",
5115 gnat_entity, gnat_entity,
5116 size_diffop (size, orig_size));
5117 }
5118
5119 return type;
5120 }
5121 \f
5122 /* Given a GNU tree and a GNAT list of choices, generate an expression to test
5123 the value passed against the list of choices. */
5124
5125 tree
5126 choices_to_gnu (tree operand, Node_Id choices)
5127 {
5128 Node_Id choice;
5129 Node_Id gnat_temp;
5130 tree result = integer_zero_node;
5131 tree this_test, low = 0, high = 0, single = 0;
5132
5133 for (choice = First (choices); Present (choice); choice = Next (choice))
5134 {
5135 switch (Nkind (choice))
5136 {
5137 case N_Range:
5138 low = gnat_to_gnu (Low_Bound (choice));
5139 high = gnat_to_gnu (High_Bound (choice));
5140
5141 /* There's no good type to use here, so we might as well use
5142 integer_type_node. */
5143 this_test
5144 = build_binary_op (TRUTH_ANDIF_EXPR, integer_type_node,
5145 build_binary_op (GE_EXPR, integer_type_node,
5146 operand, low),
5147 build_binary_op (LE_EXPR, integer_type_node,
5148 operand, high));
5149
5150 break;
5151
5152 case N_Subtype_Indication:
5153 gnat_temp = Range_Expression (Constraint (choice));
5154 low = gnat_to_gnu (Low_Bound (gnat_temp));
5155 high = gnat_to_gnu (High_Bound (gnat_temp));
5156
5157 this_test
5158 = build_binary_op (TRUTH_ANDIF_EXPR, integer_type_node,
5159 build_binary_op (GE_EXPR, integer_type_node,
5160 operand, low),
5161 build_binary_op (LE_EXPR, integer_type_node,
5162 operand, high));
5163 break;
5164
5165 case N_Identifier:
5166 case N_Expanded_Name:
5167 /* This represents either a subtype range, an enumeration
5168 literal, or a constant Ekind says which. If an enumeration
5169 literal or constant, fall through to the next case. */
5170 if (Ekind (Entity (choice)) != E_Enumeration_Literal
5171 && Ekind (Entity (choice)) != E_Constant)
5172 {
5173 tree type = gnat_to_gnu_type (Entity (choice));
5174
5175 low = TYPE_MIN_VALUE (type);
5176 high = TYPE_MAX_VALUE (type);
5177
5178 this_test
5179 = build_binary_op (TRUTH_ANDIF_EXPR, integer_type_node,
5180 build_binary_op (GE_EXPR, integer_type_node,
5181 operand, low),
5182 build_binary_op (LE_EXPR, integer_type_node,
5183 operand, high));
5184 break;
5185 }
5186 /* ... fall through ... */
5187 case N_Character_Literal:
5188 case N_Integer_Literal:
5189 single = gnat_to_gnu (choice);
5190 this_test = build_binary_op (EQ_EXPR, integer_type_node, operand,
5191 single);
5192 break;
5193
5194 case N_Others_Choice:
5195 this_test = integer_one_node;
5196 break;
5197
5198 default:
5199 gcc_unreachable ();
5200 }
5201
5202 result = build_binary_op (TRUTH_ORIF_EXPR, integer_type_node,
5203 result, this_test);
5204 }
5205
5206 return result;
5207 }
5208 \f
5209 /* Return a GCC tree for a field corresponding to GNAT_FIELD to be
5210 placed in GNU_RECORD_TYPE.
5211
5212 PACKED is 1 if the enclosing record is packed and -1 if the enclosing
5213 record has a Component_Alignment of Storage_Unit.
5214
5215 DEFINITION is true if this field is for a record being defined. */
5216
5217 static tree
5218 gnat_to_gnu_field (Entity_Id gnat_field, tree gnu_record_type, int packed,
5219 bool definition)
5220 {
5221 tree gnu_field_id = get_entity_name (gnat_field);
5222 tree gnu_field_type = gnat_to_gnu_type (Etype (gnat_field));
5223 tree gnu_pos = 0;
5224 tree gnu_size = 0;
5225 tree gnu_field;
5226 bool needs_strict_alignment
5227 = (Is_Aliased (gnat_field) || Strict_Alignment (Etype (gnat_field))
5228 || Treat_As_Volatile (gnat_field));
5229
5230 /* If this field requires strict alignment or contains an item of
5231 variable sized, pretend it isn't packed. */
5232 if (needs_strict_alignment || is_variable_size (gnu_field_type))
5233 packed = 0;
5234
5235 /* For packed records, this is one of the few occasions on which we use
5236 the official RM size for discrete or fixed-point components, instead
5237 of the normal GNAT size stored in Esize. See description in Einfo:
5238 "Handling of Type'Size Values" for further details. */
5239
5240 if (packed == 1)
5241 gnu_size = validate_size (RM_Size (Etype (gnat_field)), gnu_field_type,
5242 gnat_field, FIELD_DECL, false, true);
5243
5244 if (Known_Static_Esize (gnat_field))
5245 gnu_size = validate_size (Esize (gnat_field), gnu_field_type,
5246 gnat_field, FIELD_DECL, false, true);
5247
5248 /* If we have a specified size that's smaller than that of the field type,
5249 or a position is specified, and the field type is also a record that's
5250 BLKmode and with a small constant size, see if we can get an integral
5251 mode form of the type when appropriate. If we can, show a size was
5252 specified for the field if there wasn't one already, so we know to make
5253 this a bitfield and avoid making things wider.
5254
5255 Doing this is first useful if the record is packed because we can then
5256 place the field at a non-byte-aligned position and so achieve tigther
5257 packing.
5258
5259 This is in addition *required* if the field shares a byte with another
5260 field and the front-end lets the back-end handle the references, because
5261 GCC does not handle BLKmode bitfields properly.
5262
5263 We avoid the transformation if it is not required or potentially useful,
5264 as it might entail an increase of the field's alignment and have ripple
5265 effects on the outer record type. A typical case is a field known to be
5266 byte aligned and not to share a byte with another field.
5267
5268 Besides, we don't even look the possibility of a transformation in cases
5269 known to be in error already, for instance when an invalid size results
5270 from a component clause. */
5271
5272 if (TREE_CODE (gnu_field_type) == RECORD_TYPE
5273 && TYPE_MODE (gnu_field_type) == BLKmode
5274 && host_integerp (TYPE_SIZE (gnu_field_type), 1)
5275 && compare_tree_int (TYPE_SIZE (gnu_field_type), BIGGEST_ALIGNMENT) <= 0
5276 && (packed == 1
5277 || (gnu_size
5278 && tree_int_cst_lt (gnu_size, TYPE_SIZE (gnu_field_type)))
5279 || (Present (Component_Clause (gnat_field)) && gnu_size != 0)))
5280 {
5281 /* See what the alternate type and size would be. */
5282 tree gnu_packable_type = make_packable_type (gnu_field_type);
5283
5284 bool has_byte_aligned_clause
5285 = Present (Component_Clause (gnat_field))
5286 && (UI_To_Int (Component_Bit_Offset (gnat_field))
5287 % BITS_PER_UNIT == 0);
5288
5289 /* Compute whether we should avoid the substitution. */
5290 int reject =
5291 /* There is no point substituting if there is no change. */
5292 (gnu_packable_type == gnu_field_type
5293 ||
5294 /* ... nor when the field is known to be byte aligned and not to
5295 share a byte with another field. */
5296 (has_byte_aligned_clause
5297 && value_factor_p (gnu_size, BITS_PER_UNIT))
5298 ||
5299 /* The size of an aliased field must be an exact multiple of the
5300 type's alignment, which the substitution might increase. Reject
5301 substitutions that would so invalidate a component clause when the
5302 specified position is byte aligned, as the change would have no
5303 real benefit from the packing standpoint anyway. */
5304 (Is_Aliased (gnat_field)
5305 && has_byte_aligned_clause
5306 && ! value_factor_p (gnu_size, TYPE_ALIGN (gnu_packable_type)))
5307 );
5308
5309 /* Substitute unless told otherwise. */
5310 if (!reject)
5311 {
5312 gnu_field_type = gnu_packable_type;
5313
5314 if (gnu_size == 0)
5315 gnu_size = rm_size (gnu_field_type);
5316 }
5317 }
5318
5319 /* If we are packing the record and the field is BLKmode, round the
5320 size up to a byte boundary. */
5321 if (packed && TYPE_MODE (gnu_field_type) == BLKmode && gnu_size)
5322 gnu_size = round_up (gnu_size, BITS_PER_UNIT);
5323
5324 if (Present (Component_Clause (gnat_field)))
5325 {
5326 gnu_pos = UI_To_gnu (Component_Bit_Offset (gnat_field), bitsizetype);
5327 gnu_size = validate_size (Esize (gnat_field), gnu_field_type,
5328 gnat_field, FIELD_DECL, false, true);
5329
5330 /* Ensure the position does not overlap with the parent subtype,
5331 if there is one. */
5332 if (Present (Parent_Subtype (Underlying_Type (Scope (gnat_field)))))
5333 {
5334 tree gnu_parent
5335 = gnat_to_gnu_type (Parent_Subtype
5336 (Underlying_Type (Scope (gnat_field))));
5337
5338 if (TREE_CODE (TYPE_SIZE (gnu_parent)) == INTEGER_CST
5339 && tree_int_cst_lt (gnu_pos, TYPE_SIZE (gnu_parent)))
5340 {
5341 post_error_ne_tree
5342 ("offset of& must be beyond parent{, minimum allowed is ^}",
5343 First_Bit (Component_Clause (gnat_field)), gnat_field,
5344 TYPE_SIZE_UNIT (gnu_parent));
5345 }
5346 }
5347
5348 /* If this field needs strict alignment, ensure the record is
5349 sufficiently aligned and that that position and size are
5350 consistent with the alignment. */
5351 if (needs_strict_alignment)
5352 {
5353 tree gnu_rounded_size = round_up (rm_size (gnu_field_type),
5354 TYPE_ALIGN (gnu_field_type));
5355
5356 TYPE_ALIGN (gnu_record_type)
5357 = MAX (TYPE_ALIGN (gnu_record_type), TYPE_ALIGN (gnu_field_type));
5358
5359 /* If Atomic, the size must match exactly that of the field. */
5360 if ((Is_Atomic (gnat_field) || Is_Atomic (Etype (gnat_field)))
5361 && !operand_equal_p (gnu_size, TYPE_SIZE (gnu_field_type), 0))
5362 {
5363 post_error_ne_tree
5364 ("atomic field& must be natural size of type{ (^)}",
5365 Last_Bit (Component_Clause (gnat_field)), gnat_field,
5366 TYPE_SIZE (gnu_field_type));
5367
5368 gnu_size = NULL_TREE;
5369 }
5370
5371 /* If Aliased, the size must match exactly the rounded size. We
5372 used to be more accommodating here and accept greater sizes, but
5373 fully supporting this case on big-endian platforms would require
5374 switching to a more involved layout for the field. */
5375 else if (Is_Aliased (gnat_field)
5376 && gnu_size
5377 && ! operand_equal_p (gnu_size, gnu_rounded_size, 0))
5378 {
5379 post_error_ne_tree
5380 ("size of aliased field& must be ^ bits",
5381 Last_Bit (Component_Clause (gnat_field)), gnat_field,
5382 gnu_rounded_size);
5383 gnu_size = NULL_TREE;
5384 }
5385
5386 if (!integer_zerop (size_binop
5387 (TRUNC_MOD_EXPR, gnu_pos,
5388 bitsize_int (TYPE_ALIGN (gnu_field_type)))))
5389 {
5390 if (Is_Aliased (gnat_field))
5391 post_error_ne_num
5392 ("position of aliased field& must be multiple of ^ bits",
5393 First_Bit (Component_Clause (gnat_field)), gnat_field,
5394 TYPE_ALIGN (gnu_field_type));
5395
5396 else if (Treat_As_Volatile (gnat_field))
5397 post_error_ne_num
5398 ("position of volatile field& must be multiple of ^ bits",
5399 First_Bit (Component_Clause (gnat_field)), gnat_field,
5400 TYPE_ALIGN (gnu_field_type));
5401
5402 else if (Strict_Alignment (Etype (gnat_field)))
5403 post_error_ne_num
5404 ("position of & with aliased or tagged components not multiple of ^ bits",
5405 First_Bit (Component_Clause (gnat_field)), gnat_field,
5406 TYPE_ALIGN (gnu_field_type));
5407 else
5408 gcc_unreachable ();
5409
5410 gnu_pos = NULL_TREE;
5411 }
5412 }
5413
5414 if (Is_Atomic (gnat_field))
5415 check_ok_for_atomic (gnu_field_type, gnat_field, false);
5416 }
5417
5418 /* If the record has rep clauses and this is the tag field, make a rep
5419 clause for it as well. */
5420 else if (Has_Specified_Layout (Scope (gnat_field))
5421 && Chars (gnat_field) == Name_uTag)
5422 {
5423 gnu_pos = bitsize_zero_node;
5424 gnu_size = TYPE_SIZE (gnu_field_type);
5425 }
5426
5427 /* We need to make the size the maximum for the type if it is
5428 self-referential and an unconstrained type. In that case, we can't
5429 pack the field since we can't make a copy to align it. */
5430 if (TREE_CODE (gnu_field_type) == RECORD_TYPE
5431 && !gnu_size
5432 && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_field_type))
5433 && !Is_Constrained (Underlying_Type (Etype (gnat_field))))
5434 {
5435 gnu_size = max_size (TYPE_SIZE (gnu_field_type), true);
5436 packed = 0;
5437 }
5438
5439 /* If no size is specified (or if there was an error), don't specify a
5440 position. */
5441 if (!gnu_size)
5442 gnu_pos = NULL_TREE;
5443 else
5444 {
5445 /* If the field's type is justified modular, we would need to remove
5446 the wrapper to (better) meet the layout requirements. However we
5447 can do so only if the field is not aliased to preserve the unique
5448 layout and if the prescribed size is not greater than that of the
5449 packed array to preserve the justification. */
5450 if (!needs_strict_alignment
5451 && TREE_CODE (gnu_field_type) == RECORD_TYPE
5452 && TYPE_JUSTIFIED_MODULAR_P (gnu_field_type)
5453 && tree_int_cst_compare (gnu_size, TYPE_ADA_SIZE (gnu_field_type))
5454 <= 0)
5455 gnu_field_type = TREE_TYPE (TYPE_FIELDS (gnu_field_type));
5456
5457 gnu_field_type
5458 = make_type_from_size (gnu_field_type, gnu_size,
5459 Has_Biased_Representation (gnat_field));
5460 gnu_field_type = maybe_pad_type (gnu_field_type, gnu_size, 0, gnat_field,
5461 "PAD", false, definition, true);
5462 }
5463
5464 gcc_assert (TREE_CODE (gnu_field_type) != RECORD_TYPE
5465 || !TYPE_CONTAINS_TEMPLATE_P (gnu_field_type));
5466
5467 /* Now create the decl for the field. */
5468 gnu_field = create_field_decl (gnu_field_id, gnu_field_type, gnu_record_type,
5469 packed, gnu_size, gnu_pos,
5470 Is_Aliased (gnat_field));
5471 Sloc_to_locus (Sloc (gnat_field), &DECL_SOURCE_LOCATION (gnu_field));
5472 TREE_THIS_VOLATILE (gnu_field) = Treat_As_Volatile (gnat_field);
5473
5474 if (Ekind (gnat_field) == E_Discriminant)
5475 DECL_DISCRIMINANT_NUMBER (gnu_field)
5476 = UI_To_gnu (Discriminant_Number (gnat_field), sizetype);
5477
5478 return gnu_field;
5479 }
5480 \f
5481 /* Return true if TYPE is a type with variable size, a padding type with a
5482 field of variable size or is a record that has a field such a field. */
5483
5484 static bool
5485 is_variable_size (tree type)
5486 {
5487 tree field;
5488
5489 /* We need not be concerned about this at all if we don't have
5490 strict alignment. */
5491 if (!STRICT_ALIGNMENT)
5492 return false;
5493 else if (!TREE_CONSTANT (TYPE_SIZE (type)))
5494 return true;
5495 else if (TREE_CODE (type) == RECORD_TYPE && TYPE_IS_PADDING_P (type)
5496 && !TREE_CONSTANT (DECL_SIZE (TYPE_FIELDS (type))))
5497 return true;
5498 else if (TREE_CODE (type) != RECORD_TYPE
5499 && TREE_CODE (type) != UNION_TYPE
5500 && TREE_CODE (type) != QUAL_UNION_TYPE)
5501 return false;
5502
5503 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
5504 if (is_variable_size (TREE_TYPE (field)))
5505 return true;
5506
5507 return false;
5508 }
5509 \f
5510 /* Return a GCC tree for a record type given a GNAT Component_List and a chain
5511 of GCC trees for fields that are in the record and have already been
5512 processed. When called from gnat_to_gnu_entity during the processing of a
5513 record type definition, the GCC nodes for the discriminants will be on
5514 the chain. The other calls to this function are recursive calls from
5515 itself for the Component_List of a variant and the chain is empty.
5516
5517 PACKED is 1 if this is for a record with "pragma pack" and -1 is this is
5518 for a record type with "pragma component_alignment (storage_unit)".
5519
5520 DEFINITION is true if we are defining this record.
5521
5522 P_GNU_REP_LIST, if nonzero, is a pointer to a list to which each field
5523 with a rep clause is to be added. If it is nonzero, that is all that
5524 should be done with such fields.
5525
5526 CANCEL_ALIGNMENT, if true, means the alignment should be zeroed before
5527 laying out the record. This means the alignment only serves to force fields
5528 to be bitfields, but not require the record to be that aligned. This is
5529 used for variants.
5530
5531 ALL_REP, if true, means a rep clause was found for all the fields. This
5532 simplifies the logic since we know we're not in the mixed case.
5533
5534 DEFER_DEBUG, if true, means that the debugging routines should not be
5535 called when finishing constructing the record type.
5536
5537 UNCHECKED_UNION, if tree, means that we are building a type for a record
5538 with a Pragma Unchecked_Union.
5539
5540 The processing of the component list fills in the chain with all of the
5541 fields of the record and then the record type is finished. */
5542
5543 static void
5544 components_to_record (tree gnu_record_type, Node_Id component_list,
5545 tree gnu_field_list, int packed, bool definition,
5546 tree *p_gnu_rep_list, bool cancel_alignment,
5547 bool all_rep, bool defer_debug, bool unchecked_union)
5548 {
5549 Node_Id component_decl;
5550 Entity_Id gnat_field;
5551 Node_Id variant_part;
5552 tree gnu_our_rep_list = NULL_TREE;
5553 tree gnu_field, gnu_last;
5554 bool layout_with_rep = false;
5555 bool all_rep_and_size = all_rep && TYPE_SIZE (gnu_record_type);
5556
5557 /* For each variable within each component declaration create a GCC field
5558 and add it to the list, skipping any pragmas in the list. */
5559
5560 if (Present (Component_Items (component_list)))
5561 for (component_decl = First_Non_Pragma (Component_Items (component_list));
5562 Present (component_decl);
5563 component_decl = Next_Non_Pragma (component_decl))
5564 {
5565 gnat_field = Defining_Entity (component_decl);
5566
5567 if (Chars (gnat_field) == Name_uParent)
5568 gnu_field = tree_last (TYPE_FIELDS (gnu_record_type));
5569 else
5570 {
5571 gnu_field = gnat_to_gnu_field (gnat_field, gnu_record_type,
5572 packed, definition);
5573
5574 /* If this is the _Tag field, put it before any discriminants,
5575 instead of after them as is the case for all other fields.
5576 Ignore field of void type if only annotating. */
5577 if (Chars (gnat_field) == Name_uTag)
5578 gnu_field_list = chainon (gnu_field_list, gnu_field);
5579 else
5580 {
5581 TREE_CHAIN (gnu_field) = gnu_field_list;
5582 gnu_field_list = gnu_field;
5583 }
5584 }
5585
5586 save_gnu_tree (gnat_field, gnu_field, false);
5587 }
5588
5589 /* At the end of the component list there may be a variant part. */
5590 variant_part = Variant_Part (component_list);
5591
5592 /* We create a QUAL_UNION_TYPE for the variant part since the variants are
5593 mutually exclusive and should go in the same memory. To do this we need
5594 to treat each variant as a record whose elements are created from the
5595 component list for the variant. So here we create the records from the
5596 lists for the variants and put them all into the QUAL_UNION_TYPE.
5597 If this is an Unchecked_Union, we make a UNION_TYPE instead or
5598 use GNU_RECORD_TYPE if there are no fields so far. */
5599 if (Present (variant_part))
5600 {
5601 tree gnu_discriminant = gnat_to_gnu (Name (variant_part));
5602 Node_Id variant;
5603 tree gnu_name = TYPE_NAME (gnu_record_type);
5604 tree gnu_var_name
5605 = concat_id_with_name (get_identifier (Get_Name_String
5606 (Chars (Name (variant_part)))),
5607 "XVN");
5608 tree gnu_union_type;
5609 tree gnu_union_name;
5610 tree gnu_union_field;
5611 tree gnu_variant_list = NULL_TREE;
5612
5613 if (TREE_CODE (gnu_name) == TYPE_DECL)
5614 gnu_name = DECL_NAME (gnu_name);
5615
5616 gnu_union_name = concat_id_with_name (gnu_name,
5617 IDENTIFIER_POINTER (gnu_var_name));
5618
5619 if (!gnu_field_list && TREE_CODE (gnu_record_type) == UNION_TYPE)
5620 gnu_union_type = gnu_record_type;
5621 else
5622 {
5623
5624 gnu_union_type
5625 = make_node (unchecked_union ? UNION_TYPE : QUAL_UNION_TYPE);
5626
5627 TYPE_NAME (gnu_union_type) = gnu_union_name;
5628 TYPE_PACKED (gnu_union_type) = TYPE_PACKED (gnu_record_type);
5629 }
5630
5631 for (variant = First_Non_Pragma (Variants (variant_part));
5632 Present (variant);
5633 variant = Next_Non_Pragma (variant))
5634 {
5635 tree gnu_variant_type = make_node (RECORD_TYPE);
5636 tree gnu_inner_name;
5637 tree gnu_qual;
5638
5639 Get_Variant_Encoding (variant);
5640 gnu_inner_name = get_identifier (Name_Buffer);
5641 TYPE_NAME (gnu_variant_type)
5642 = concat_id_with_name (gnu_union_name,
5643 IDENTIFIER_POINTER (gnu_inner_name));
5644
5645 /* Set the alignment of the inner type in case we need to make
5646 inner objects into bitfields, but then clear it out
5647 so the record actually gets only the alignment required. */
5648 TYPE_ALIGN (gnu_variant_type) = TYPE_ALIGN (gnu_record_type);
5649 TYPE_PACKED (gnu_variant_type) = TYPE_PACKED (gnu_record_type);
5650
5651 /* Similarly, if the outer record has a size specified and all fields
5652 have record rep clauses, we can propagate the size into the
5653 variant part. */
5654 if (all_rep_and_size)
5655 {
5656 TYPE_SIZE (gnu_variant_type) = TYPE_SIZE (gnu_record_type);
5657 TYPE_SIZE_UNIT (gnu_variant_type)
5658 = TYPE_SIZE_UNIT (gnu_record_type);
5659 }
5660
5661 components_to_record (gnu_variant_type, Component_List (variant),
5662 NULL_TREE, packed, definition,
5663 &gnu_our_rep_list, !all_rep_and_size, all_rep,
5664 false, unchecked_union);
5665
5666 gnu_qual = choices_to_gnu (gnu_discriminant,
5667 Discrete_Choices (variant));
5668
5669 Set_Present_Expr (variant, annotate_value (gnu_qual));
5670
5671 /* If this is an Unchecked_Union and we have exactly one field,
5672 use that field here. */
5673 if (unchecked_union && TYPE_FIELDS (gnu_variant_type)
5674 && !TREE_CHAIN (TYPE_FIELDS (gnu_variant_type)))
5675 gnu_field = TYPE_FIELDS (gnu_variant_type);
5676 else
5677 {
5678 gnu_field = create_field_decl (gnu_inner_name, gnu_variant_type,
5679 gnu_union_type, 0,
5680 (all_rep_and_size
5681 ? TYPE_SIZE (gnu_record_type)
5682 : 0),
5683 (all_rep_and_size
5684 ? bitsize_zero_node : 0),
5685 0);
5686
5687 DECL_INTERNAL_P (gnu_field) = 1;
5688
5689 if (!unchecked_union)
5690 DECL_QUALIFIER (gnu_field) = gnu_qual;
5691 }
5692
5693 TREE_CHAIN (gnu_field) = gnu_variant_list;
5694 gnu_variant_list = gnu_field;
5695 }
5696
5697 /* We used to delete the empty variants from the end. However,
5698 we no longer do that because we need them to generate complete
5699 debugging information for the variant record. Otherwise,
5700 the union type definition will be missing the fields associated
5701 to these empty variants. */
5702
5703 /* Only make the QUAL_UNION_TYPE if there are any non-empty variants. */
5704 if (gnu_variant_list)
5705 {
5706 if (all_rep_and_size)
5707 {
5708 TYPE_SIZE (gnu_union_type) = TYPE_SIZE (gnu_record_type);
5709 TYPE_SIZE_UNIT (gnu_union_type)
5710 = TYPE_SIZE_UNIT (gnu_record_type);
5711 }
5712
5713 finish_record_type (gnu_union_type, nreverse (gnu_variant_list),
5714 all_rep_and_size, false);
5715
5716 /* If GNU_UNION_TYPE is our record type, it means we must have an
5717 Unchecked_Union with no fields. Verify that and, if so, just
5718 return. */
5719 if (gnu_union_type == gnu_record_type)
5720 {
5721 gcc_assert (!gnu_field_list && unchecked_union);
5722 return;
5723 }
5724
5725 gnu_union_field
5726 = create_field_decl (gnu_var_name, gnu_union_type, gnu_record_type,
5727 packed,
5728 all_rep ? TYPE_SIZE (gnu_union_type) : 0,
5729 all_rep ? bitsize_zero_node : 0, 0);
5730
5731 DECL_INTERNAL_P (gnu_union_field) = 1;
5732 TREE_CHAIN (gnu_union_field) = gnu_field_list;
5733 gnu_field_list = gnu_union_field;
5734 }
5735 }
5736
5737 /* Scan GNU_FIELD_LIST and see if any fields have rep clauses. If they
5738 do, pull them out and put them into GNU_OUR_REP_LIST. We have to do this
5739 in a separate pass since we want to handle the discriminants but can't
5740 play with them until we've used them in debugging data above.
5741
5742 ??? Note: if we then reorder them, debugging information will be wrong,
5743 but there's nothing that can be done about this at the moment. */
5744
5745 for (gnu_field = gnu_field_list, gnu_last = NULL_TREE; gnu_field; )
5746 {
5747 if (DECL_FIELD_OFFSET (gnu_field))
5748 {
5749 tree gnu_next = TREE_CHAIN (gnu_field);
5750
5751 if (!gnu_last)
5752 gnu_field_list = gnu_next;
5753 else
5754 TREE_CHAIN (gnu_last) = gnu_next;
5755
5756 TREE_CHAIN (gnu_field) = gnu_our_rep_list;
5757 gnu_our_rep_list = gnu_field;
5758 gnu_field = gnu_next;
5759 }
5760 else
5761 {
5762 gnu_last = gnu_field;
5763 gnu_field = TREE_CHAIN (gnu_field);
5764 }
5765 }
5766
5767 /* If we have any items in our rep'ed field list, it is not the case that all
5768 the fields in the record have rep clauses, and P_REP_LIST is nonzero,
5769 set it and ignore the items. */
5770 if (gnu_our_rep_list && p_gnu_rep_list && !all_rep)
5771 *p_gnu_rep_list = chainon (*p_gnu_rep_list, gnu_our_rep_list);
5772 else if (gnu_our_rep_list)
5773 {
5774 /* Otherwise, sort the fields by bit position and put them into their
5775 own record if we have any fields without rep clauses. */
5776 tree gnu_rep_type
5777 = (gnu_field_list ? make_node (RECORD_TYPE) : gnu_record_type);
5778 int len = list_length (gnu_our_rep_list);
5779 tree *gnu_arr = (tree *) alloca (sizeof (tree) * len);
5780 int i;
5781
5782 for (i = 0, gnu_field = gnu_our_rep_list; gnu_field;
5783 gnu_field = TREE_CHAIN (gnu_field), i++)
5784 gnu_arr[i] = gnu_field;
5785
5786 qsort (gnu_arr, len, sizeof (tree), compare_field_bitpos);
5787
5788 /* Put the fields in the list in order of increasing position, which
5789 means we start from the end. */
5790 gnu_our_rep_list = NULL_TREE;
5791 for (i = len - 1; i >= 0; i--)
5792 {
5793 TREE_CHAIN (gnu_arr[i]) = gnu_our_rep_list;
5794 gnu_our_rep_list = gnu_arr[i];
5795 DECL_CONTEXT (gnu_arr[i]) = gnu_rep_type;
5796 }
5797
5798 if (gnu_field_list)
5799 {
5800 finish_record_type (gnu_rep_type, gnu_our_rep_list, true, false);
5801 gnu_field = create_field_decl (get_identifier ("REP"), gnu_rep_type,
5802 gnu_record_type, 0, 0, 0, 1);
5803 DECL_INTERNAL_P (gnu_field) = 1;
5804 gnu_field_list = chainon (gnu_field_list, gnu_field);
5805 }
5806 else
5807 {
5808 layout_with_rep = true;
5809 gnu_field_list = nreverse (gnu_our_rep_list);
5810 }
5811 }
5812
5813 if (cancel_alignment)
5814 TYPE_ALIGN (gnu_record_type) = 0;
5815
5816 finish_record_type (gnu_record_type, nreverse (gnu_field_list),
5817 layout_with_rep, defer_debug);
5818 }
5819 \f
5820 /* Called via qsort from the above. Returns -1, 1, depending on the
5821 bit positions and ordinals of the two fields. Use DECL_UID to ensure
5822 a stable sort. */
5823
5824 static int
5825 compare_field_bitpos (const PTR rt1, const PTR rt2)
5826 {
5827 tree *t1 = (tree *) rt1;
5828 tree *t2 = (tree *) rt2;
5829
5830 if (tree_int_cst_equal (bit_position (*t1), bit_position (*t2)))
5831 return DECL_UID (*t1) < DECL_UID (*t2) ? -1 : 1;
5832 else if (tree_int_cst_lt (bit_position (*t1), bit_position (*t2)))
5833 return -1;
5834 else
5835 return 1;
5836 }
5837 \f
5838 /* Given GNU_SIZE, a GCC tree representing a size, return a Uint to be
5839 placed into an Esize, Component_Bit_Offset, or Component_Size value
5840 in the GNAT tree. */
5841
5842 static Uint
5843 annotate_value (tree gnu_size)
5844 {
5845 int len = TREE_CODE_LENGTH (TREE_CODE (gnu_size));
5846 TCode tcode;
5847 Node_Ref_Or_Val ops[3], ret;
5848 int i;
5849 int size;
5850
5851 /* See if we've already saved the value for this node. */
5852 if (EXPR_P (gnu_size) && TREE_COMPLEXITY (gnu_size))
5853 return (Node_Ref_Or_Val) TREE_COMPLEXITY (gnu_size);
5854
5855 /* If we do not return inside this switch, TCODE will be set to the
5856 code to use for a Create_Node operand and LEN (set above) will be
5857 the number of recursive calls for us to make. */
5858
5859 switch (TREE_CODE (gnu_size))
5860 {
5861 case INTEGER_CST:
5862 if (TREE_OVERFLOW (gnu_size))
5863 return No_Uint;
5864
5865 /* This may have come from a conversion from some smaller type,
5866 so ensure this is in bitsizetype. */
5867 gnu_size = convert (bitsizetype, gnu_size);
5868
5869 /* For negative values, use NEGATE_EXPR of the supplied value. */
5870 if (tree_int_cst_sgn (gnu_size) < 0)
5871 {
5872 /* The ridiculous code below is to handle the case of the largest
5873 negative integer. */
5874 tree negative_size = size_diffop (bitsize_zero_node, gnu_size);
5875 bool adjust = false;
5876 tree temp;
5877
5878 if (TREE_CONSTANT_OVERFLOW (negative_size))
5879 {
5880 negative_size
5881 = size_binop (MINUS_EXPR, bitsize_zero_node,
5882 size_binop (PLUS_EXPR, gnu_size,
5883 bitsize_one_node));
5884 adjust = true;
5885 }
5886
5887 temp = build1 (NEGATE_EXPR, bitsizetype, negative_size);
5888 if (adjust)
5889 temp = build2 (MINUS_EXPR, bitsizetype, temp, bitsize_one_node);
5890
5891 return annotate_value (temp);
5892 }
5893
5894 if (!host_integerp (gnu_size, 1))
5895 return No_Uint;
5896
5897 size = tree_low_cst (gnu_size, 1);
5898
5899 /* This peculiar test is to make sure that the size fits in an int
5900 on machines where HOST_WIDE_INT is not "int". */
5901 if (tree_low_cst (gnu_size, 1) == size)
5902 return UI_From_Int (size);
5903 else
5904 return No_Uint;
5905
5906 case COMPONENT_REF:
5907 /* The only case we handle here is a simple discriminant reference. */
5908 if (TREE_CODE (TREE_OPERAND (gnu_size, 0)) == PLACEHOLDER_EXPR
5909 && TREE_CODE (TREE_OPERAND (gnu_size, 1)) == FIELD_DECL
5910 && DECL_DISCRIMINANT_NUMBER (TREE_OPERAND (gnu_size, 1)))
5911 return Create_Node (Discrim_Val,
5912 annotate_value (DECL_DISCRIMINANT_NUMBER
5913 (TREE_OPERAND (gnu_size, 1))),
5914 No_Uint, No_Uint);
5915 else
5916 return No_Uint;
5917
5918 case NOP_EXPR: case CONVERT_EXPR: case NON_LVALUE_EXPR:
5919 return annotate_value (TREE_OPERAND (gnu_size, 0));
5920
5921 /* Now just list the operations we handle. */
5922 case COND_EXPR: tcode = Cond_Expr; break;
5923 case PLUS_EXPR: tcode = Plus_Expr; break;
5924 case MINUS_EXPR: tcode = Minus_Expr; break;
5925 case MULT_EXPR: tcode = Mult_Expr; break;
5926 case TRUNC_DIV_EXPR: tcode = Trunc_Div_Expr; break;
5927 case CEIL_DIV_EXPR: tcode = Ceil_Div_Expr; break;
5928 case FLOOR_DIV_EXPR: tcode = Floor_Div_Expr; break;
5929 case TRUNC_MOD_EXPR: tcode = Trunc_Mod_Expr; break;
5930 case CEIL_MOD_EXPR: tcode = Ceil_Mod_Expr; break;
5931 case FLOOR_MOD_EXPR: tcode = Floor_Mod_Expr; break;
5932 case EXACT_DIV_EXPR: tcode = Exact_Div_Expr; break;
5933 case NEGATE_EXPR: tcode = Negate_Expr; break;
5934 case MIN_EXPR: tcode = Min_Expr; break;
5935 case MAX_EXPR: tcode = Max_Expr; break;
5936 case ABS_EXPR: tcode = Abs_Expr; break;
5937 case TRUTH_ANDIF_EXPR: tcode = Truth_Andif_Expr; break;
5938 case TRUTH_ORIF_EXPR: tcode = Truth_Orif_Expr; break;
5939 case TRUTH_AND_EXPR: tcode = Truth_And_Expr; break;
5940 case TRUTH_OR_EXPR: tcode = Truth_Or_Expr; break;
5941 case TRUTH_XOR_EXPR: tcode = Truth_Xor_Expr; break;
5942 case TRUTH_NOT_EXPR: tcode = Truth_Not_Expr; break;
5943 case BIT_AND_EXPR: tcode = Bit_And_Expr; break;
5944 case LT_EXPR: tcode = Lt_Expr; break;
5945 case LE_EXPR: tcode = Le_Expr; break;
5946 case GT_EXPR: tcode = Gt_Expr; break;
5947 case GE_EXPR: tcode = Ge_Expr; break;
5948 case EQ_EXPR: tcode = Eq_Expr; break;
5949 case NE_EXPR: tcode = Ne_Expr; break;
5950
5951 default:
5952 return No_Uint;
5953 }
5954
5955 /* Now get each of the operands that's relevant for this code. If any
5956 cannot be expressed as a repinfo node, say we can't. */
5957 for (i = 0; i < 3; i++)
5958 ops[i] = No_Uint;
5959
5960 for (i = 0; i < len; i++)
5961 {
5962 ops[i] = annotate_value (TREE_OPERAND (gnu_size, i));
5963 if (ops[i] == No_Uint)
5964 return No_Uint;
5965 }
5966
5967 ret = Create_Node (tcode, ops[0], ops[1], ops[2]);
5968 TREE_COMPLEXITY (gnu_size) = ret;
5969 return ret;
5970 }
5971
5972 /* Given GNAT_ENTITY, a record type, and GNU_TYPE, its corresponding
5973 GCC type, set Component_Bit_Offset and Esize to the position and size
5974 used by Gigi. */
5975
5976 static void
5977 annotate_rep (Entity_Id gnat_entity, tree gnu_type)
5978 {
5979 tree gnu_list;
5980 tree gnu_entry;
5981 Entity_Id gnat_field;
5982
5983 /* We operate by first making a list of all fields and their positions
5984 (we can get the sizes easily at any time) by a recursive call
5985 and then update all the sizes into the tree. */
5986 gnu_list = compute_field_positions (gnu_type, NULL_TREE,
5987 size_zero_node, bitsize_zero_node,
5988 BIGGEST_ALIGNMENT);
5989
5990 for (gnat_field = First_Entity (gnat_entity); Present (gnat_field);
5991 gnat_field = Next_Entity (gnat_field))
5992 if ((Ekind (gnat_field) == E_Component
5993 || (Ekind (gnat_field) == E_Discriminant
5994 && !Is_Unchecked_Union (Scope (gnat_field)))))
5995 {
5996 tree parent_offset = bitsize_zero_node;
5997
5998 gnu_entry = purpose_member (gnat_to_gnu_field_decl (gnat_field),
5999 gnu_list);
6000
6001 if (gnu_entry)
6002 {
6003 if (type_annotate_only && Is_Tagged_Type (gnat_entity))
6004 {
6005 /* In this mode the tag and parent components have not been
6006 generated, so we add the appropriate offset to each
6007 component. For a component appearing in the current
6008 extension, the offset is the size of the parent. */
6009 if (Is_Derived_Type (gnat_entity)
6010 && Original_Record_Component (gnat_field) == gnat_field)
6011 parent_offset
6012 = UI_To_gnu (Esize (Etype (Base_Type (gnat_entity))),
6013 bitsizetype);
6014 else
6015 parent_offset = bitsize_int (POINTER_SIZE);
6016 }
6017
6018 Set_Component_Bit_Offset
6019 (gnat_field,
6020 annotate_value
6021 (size_binop (PLUS_EXPR,
6022 bit_from_pos (TREE_PURPOSE (TREE_VALUE (gnu_entry)),
6023 TREE_VALUE (TREE_VALUE
6024 (TREE_VALUE (gnu_entry)))),
6025 parent_offset)));
6026
6027 Set_Esize (gnat_field,
6028 annotate_value (DECL_SIZE (TREE_PURPOSE (gnu_entry))));
6029 }
6030 else if (Is_Tagged_Type (gnat_entity)
6031 && Is_Derived_Type (gnat_entity))
6032 {
6033 /* If there is no gnu_entry, this is an inherited component whose
6034 position is the same as in the parent type. */
6035 Set_Component_Bit_Offset
6036 (gnat_field,
6037 Component_Bit_Offset (Original_Record_Component (gnat_field)));
6038 Set_Esize (gnat_field,
6039 Esize (Original_Record_Component (gnat_field)));
6040 }
6041 }
6042 }
6043
6044 /* Scan all fields in GNU_TYPE and build entries where TREE_PURPOSE is the
6045 FIELD_DECL and TREE_VALUE a TREE_LIST with TREE_PURPOSE being the byte
6046 position and TREE_VALUE being a TREE_LIST with TREE_PURPOSE the value to be
6047 placed into DECL_OFFSET_ALIGN and TREE_VALUE the bit position. GNU_POS is
6048 to be added to the position, GNU_BITPOS to the bit position, OFFSET_ALIGN is
6049 the present value of DECL_OFFSET_ALIGN and GNU_LIST is a list of the entries
6050 so far. */
6051
6052 static tree
6053 compute_field_positions (tree gnu_type, tree gnu_list, tree gnu_pos,
6054 tree gnu_bitpos, unsigned int offset_align)
6055 {
6056 tree gnu_field;
6057 tree gnu_result = gnu_list;
6058
6059 for (gnu_field = TYPE_FIELDS (gnu_type); gnu_field;
6060 gnu_field = TREE_CHAIN (gnu_field))
6061 {
6062 tree gnu_our_bitpos = size_binop (PLUS_EXPR, gnu_bitpos,
6063 DECL_FIELD_BIT_OFFSET (gnu_field));
6064 tree gnu_our_offset = size_binop (PLUS_EXPR, gnu_pos,
6065 DECL_FIELD_OFFSET (gnu_field));
6066 unsigned int our_offset_align
6067 = MIN (offset_align, DECL_OFFSET_ALIGN (gnu_field));
6068
6069 gnu_result
6070 = tree_cons (gnu_field,
6071 tree_cons (gnu_our_offset,
6072 tree_cons (size_int (our_offset_align),
6073 gnu_our_bitpos, NULL_TREE),
6074 NULL_TREE),
6075 gnu_result);
6076
6077 if (DECL_INTERNAL_P (gnu_field))
6078 gnu_result
6079 = compute_field_positions (TREE_TYPE (gnu_field), gnu_result,
6080 gnu_our_offset, gnu_our_bitpos,
6081 our_offset_align);
6082 }
6083
6084 return gnu_result;
6085 }
6086 \f
6087 /* UINT_SIZE is a Uint giving the specified size for an object of GNU_TYPE
6088 corresponding to GNAT_OBJECT. If size is valid, return a tree corresponding
6089 to its value. Otherwise return 0. KIND is VAR_DECL is we are specifying
6090 the size for an object, TYPE_DECL for the size of a type, and FIELD_DECL
6091 for the size of a field. COMPONENT_P is true if we are being called
6092 to process the Component_Size of GNAT_OBJECT. This is used for error
6093 message handling and to indicate to use the object size of GNU_TYPE.
6094 ZERO_OK is true if a size of zero is permitted; if ZERO_OK is false,
6095 it means that a size of zero should be treated as an unspecified size. */
6096
6097 static tree
6098 validate_size (Uint uint_size, tree gnu_type, Entity_Id gnat_object,
6099 enum tree_code kind, bool component_p, bool zero_ok)
6100 {
6101 Node_Id gnat_error_node;
6102 tree type_size
6103 = kind == VAR_DECL ? TYPE_SIZE (gnu_type) : rm_size (gnu_type);
6104 tree size;
6105
6106 /* Find the node to use for errors. */
6107 if ((Ekind (gnat_object) == E_Component
6108 || Ekind (gnat_object) == E_Discriminant)
6109 && Present (Component_Clause (gnat_object)))
6110 gnat_error_node = Last_Bit (Component_Clause (gnat_object));
6111 else if (Present (Size_Clause (gnat_object)))
6112 gnat_error_node = Expression (Size_Clause (gnat_object));
6113 else
6114 gnat_error_node = gnat_object;
6115
6116 /* Return 0 if no size was specified, either because Esize was not Present or
6117 the specified size was zero. */
6118 if (No (uint_size) || uint_size == No_Uint)
6119 return NULL_TREE;
6120
6121 /* Get the size as a tree. Give an error if a size was specified, but cannot
6122 be represented as in sizetype. */
6123 size = UI_To_gnu (uint_size, bitsizetype);
6124 if (TREE_OVERFLOW (size))
6125 {
6126 post_error_ne (component_p ? "component size of & is too large"
6127 : "size of & is too large",
6128 gnat_error_node, gnat_object);
6129 return NULL_TREE;
6130 }
6131
6132 /* Ignore a negative size since that corresponds to our back-annotation.
6133 Also ignore a zero size unless a size clause exists. */
6134 else if (tree_int_cst_sgn (size) < 0 || (integer_zerop (size) && !zero_ok))
6135 return NULL_TREE;
6136
6137 /* The size of objects is always a multiple of a byte. */
6138 if (kind == VAR_DECL
6139 && !integer_zerop (size_binop (TRUNC_MOD_EXPR, size, bitsize_unit_node)))
6140 {
6141 if (component_p)
6142 post_error_ne ("component size for& is not a multiple of Storage_Unit",
6143 gnat_error_node, gnat_object);
6144 else
6145 post_error_ne ("size for& is not a multiple of Storage_Unit",
6146 gnat_error_node, gnat_object);
6147 return NULL_TREE;
6148 }
6149
6150 /* If this is an integral type or a packed array type, the front-end has
6151 verified the size, so we need not do it here (which would entail
6152 checking against the bounds). However, if this is an aliased object, it
6153 may not be smaller than the type of the object. */
6154 if ((INTEGRAL_TYPE_P (gnu_type) || TYPE_IS_PACKED_ARRAY_TYPE_P (gnu_type))
6155 && !(kind == VAR_DECL && Is_Aliased (gnat_object)))
6156 return size;
6157
6158 /* If the object is a record that contains a template, add the size of
6159 the template to the specified size. */
6160 if (TREE_CODE (gnu_type) == RECORD_TYPE
6161 && TYPE_CONTAINS_TEMPLATE_P (gnu_type))
6162 size = size_binop (PLUS_EXPR, DECL_SIZE (TYPE_FIELDS (gnu_type)), size);
6163
6164 /* Modify the size of the type to be that of the maximum size if it has a
6165 discriminant or the size of a thin pointer if this is a fat pointer. */
6166 if (type_size && CONTAINS_PLACEHOLDER_P (type_size))
6167 type_size = max_size (type_size, true);
6168 else if (TYPE_FAT_POINTER_P (gnu_type))
6169 type_size = bitsize_int (POINTER_SIZE);
6170
6171 /* If this is an access type, the minimum size is that given by the smallest
6172 integral mode that's valid for pointers. */
6173 if (TREE_CODE (gnu_type) == POINTER_TYPE)
6174 {
6175 enum machine_mode p_mode;
6176
6177 for (p_mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
6178 !targetm.valid_pointer_mode (p_mode);
6179 p_mode = GET_MODE_WIDER_MODE (p_mode))
6180 ;
6181
6182 type_size = bitsize_int (GET_MODE_BITSIZE (p_mode));
6183 }
6184
6185 /* If the size of the object is a constant, the new size must not be
6186 smaller. */
6187 if (TREE_CODE (type_size) != INTEGER_CST
6188 || TREE_OVERFLOW (type_size)
6189 || tree_int_cst_lt (size, type_size))
6190 {
6191 if (component_p)
6192 post_error_ne_tree
6193 ("component size for& too small{, minimum allowed is ^}",
6194 gnat_error_node, gnat_object, type_size);
6195 else
6196 post_error_ne_tree ("size for& too small{, minimum allowed is ^}",
6197 gnat_error_node, gnat_object, type_size);
6198
6199 if (kind == VAR_DECL && !component_p
6200 && TREE_CODE (rm_size (gnu_type)) == INTEGER_CST
6201 && !tree_int_cst_lt (size, rm_size (gnu_type)))
6202 post_error_ne_tree_2
6203 ("\\size of ^ is not a multiple of alignment (^ bits)",
6204 gnat_error_node, gnat_object, rm_size (gnu_type),
6205 TYPE_ALIGN (gnu_type));
6206
6207 else if (INTEGRAL_TYPE_P (gnu_type))
6208 post_error_ne ("\\size would be legal if & were not aliased!",
6209 gnat_error_node, gnat_object);
6210
6211 return NULL_TREE;
6212 }
6213
6214 return size;
6215 }
6216 \f
6217 /* Similarly, but both validate and process a value of RM_Size. This
6218 routine is only called for types. */
6219
6220 static void
6221 set_rm_size (Uint uint_size, tree gnu_type, Entity_Id gnat_entity)
6222 {
6223 /* Only give an error if a Value_Size clause was explicitly given.
6224 Otherwise, we'd be duplicating an error on the Size clause. */
6225 Node_Id gnat_attr_node
6226 = Get_Attribute_Definition_Clause (gnat_entity, Attr_Value_Size);
6227 tree old_size = rm_size (gnu_type);
6228 tree size;
6229
6230 /* Get the size as a tree. Do nothing if none was specified, either
6231 because RM_Size was not Present or if the specified size was zero.
6232 Give an error if a size was specified, but cannot be represented as
6233 in sizetype. */
6234 if (No (uint_size) || uint_size == No_Uint)
6235 return;
6236
6237 size = UI_To_gnu (uint_size, bitsizetype);
6238 if (TREE_OVERFLOW (size))
6239 {
6240 if (Present (gnat_attr_node))
6241 post_error_ne ("Value_Size of & is too large", gnat_attr_node,
6242 gnat_entity);
6243
6244 return;
6245 }
6246
6247 /* Ignore a negative size since that corresponds to our back-annotation.
6248 Also ignore a zero size unless a size clause exists, a Value_Size
6249 clause exists, or this is an integer type, in which case the
6250 front end will have always set it. */
6251 else if (tree_int_cst_sgn (size) < 0
6252 || (integer_zerop (size) && No (gnat_attr_node)
6253 && !Has_Size_Clause (gnat_entity)
6254 && !Is_Discrete_Or_Fixed_Point_Type (gnat_entity)))
6255 return;
6256
6257 /* If the old size is self-referential, get the maximum size. */
6258 if (CONTAINS_PLACEHOLDER_P (old_size))
6259 old_size = max_size (old_size, true);
6260
6261 /* If the size of the object is a constant, the new size must not be
6262 smaller (the front end checks this for scalar types). */
6263 if (TREE_CODE (old_size) != INTEGER_CST
6264 || TREE_OVERFLOW (old_size)
6265 || (AGGREGATE_TYPE_P (gnu_type)
6266 && tree_int_cst_lt (size, old_size)))
6267 {
6268 if (Present (gnat_attr_node))
6269 post_error_ne_tree
6270 ("Value_Size for& too small{, minimum allowed is ^}",
6271 gnat_attr_node, gnat_entity, old_size);
6272
6273 return;
6274 }
6275
6276 /* Otherwise, set the RM_Size. */
6277 if (TREE_CODE (gnu_type) == INTEGER_TYPE
6278 && Is_Discrete_Or_Fixed_Point_Type (gnat_entity))
6279 TYPE_RM_SIZE_NUM (gnu_type) = size;
6280 else if (TREE_CODE (gnu_type) == ENUMERAL_TYPE)
6281 TYPE_RM_SIZE_NUM (gnu_type) = size;
6282 else if ((TREE_CODE (gnu_type) == RECORD_TYPE
6283 || TREE_CODE (gnu_type) == UNION_TYPE
6284 || TREE_CODE (gnu_type) == QUAL_UNION_TYPE)
6285 && !TYPE_IS_FAT_POINTER_P (gnu_type))
6286 SET_TYPE_ADA_SIZE (gnu_type, size);
6287 }
6288 \f
6289 /* Given a type TYPE, return a new type whose size is appropriate for SIZE.
6290 If TYPE is the best type, return it. Otherwise, make a new type. We
6291 only support new integral and pointer types. BIASED_P is nonzero if
6292 we are making a biased type. */
6293
6294 static tree
6295 make_type_from_size (tree type, tree size_tree, bool biased_p)
6296 {
6297 tree new_type;
6298 unsigned HOST_WIDE_INT size;
6299 bool unsigned_p;
6300
6301 /* If size indicates an error, just return TYPE to avoid propagating the
6302 error. Likewise if it's too large to represent. */
6303 if (!size_tree || !host_integerp (size_tree, 1))
6304 return type;
6305
6306 size = tree_low_cst (size_tree, 1);
6307 switch (TREE_CODE (type))
6308 {
6309 case INTEGER_TYPE:
6310 case ENUMERAL_TYPE:
6311 /* Only do something if the type is not already the proper size and is
6312 not a packed array type. */
6313 if (TYPE_PACKED_ARRAY_TYPE_P (type)
6314 || (TYPE_PRECISION (type) == size
6315 && biased_p == (TREE_CODE (type) == INTEGER_CST
6316 && TYPE_BIASED_REPRESENTATION_P (type))))
6317 break;
6318
6319 biased_p |= (TREE_CODE (type) == INTEGER_TYPE
6320 && TYPE_BIASED_REPRESENTATION_P (type));
6321 unsigned_p = TYPE_UNSIGNED (type) || biased_p;
6322
6323 size = MIN (size, LONG_LONG_TYPE_SIZE);
6324 new_type
6325 = unsigned_p ? make_unsigned_type (size) : make_signed_type (size);
6326 TREE_TYPE (new_type) = TREE_TYPE (type) ? TREE_TYPE (type) : type;
6327 TYPE_MIN_VALUE (new_type)
6328 = convert (TREE_TYPE (new_type), TYPE_MIN_VALUE (type));
6329 TYPE_MAX_VALUE (new_type)
6330 = convert (TREE_TYPE (new_type), TYPE_MAX_VALUE (type));
6331 TYPE_BIASED_REPRESENTATION_P (new_type) = biased_p;
6332 TYPE_RM_SIZE_NUM (new_type) = bitsize_int (size);
6333 return new_type;
6334
6335 case RECORD_TYPE:
6336 /* Do something if this is a fat pointer, in which case we
6337 may need to return the thin pointer. */
6338 if (TYPE_IS_FAT_POINTER_P (type) && size < POINTER_SIZE * 2)
6339 return
6340 build_pointer_type
6341 (TYPE_OBJECT_RECORD_TYPE (TYPE_UNCONSTRAINED_ARRAY (type)));
6342 break;
6343
6344 case POINTER_TYPE:
6345 /* Only do something if this is a thin pointer, in which case we
6346 may need to return the fat pointer. */
6347 if (TYPE_THIN_POINTER_P (type) && size >= POINTER_SIZE * 2)
6348 return
6349 build_pointer_type (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type)));
6350
6351 break;
6352
6353 default:
6354 break;
6355 }
6356
6357 return type;
6358 }
6359 \f
6360 /* ALIGNMENT is a Uint giving the alignment specified for GNAT_ENTITY,
6361 a type or object whose present alignment is ALIGN. If this alignment is
6362 valid, return it. Otherwise, give an error and return ALIGN. */
6363
6364 static unsigned int
6365 validate_alignment (Uint alignment, Entity_Id gnat_entity, unsigned int align)
6366 {
6367 Node_Id gnat_error_node = gnat_entity;
6368 unsigned int new_align;
6369
6370 #ifndef MAX_OFILE_ALIGNMENT
6371 #define MAX_OFILE_ALIGNMENT BIGGEST_ALIGNMENT
6372 #endif
6373
6374 if (Present (Alignment_Clause (gnat_entity)))
6375 gnat_error_node = Expression (Alignment_Clause (gnat_entity));
6376
6377 /* Don't worry about checking alignment if alignment was not specified
6378 by the source program and we already posted an error for this entity. */
6379
6380 if (Error_Posted (gnat_entity) && !Has_Alignment_Clause (gnat_entity))
6381 return align;
6382
6383 /* Within GCC, an alignment is an integer, so we must make sure a
6384 value is specified that fits in that range. Also, alignments of
6385 more than MAX_OFILE_ALIGNMENT can't be supported. */
6386
6387 if (! UI_Is_In_Int_Range (alignment)
6388 || ((new_align = UI_To_Int (alignment))
6389 > MAX_OFILE_ALIGNMENT / BITS_PER_UNIT))
6390 post_error_ne_num ("largest supported alignment for& is ^",
6391 gnat_error_node, gnat_entity,
6392 MAX_OFILE_ALIGNMENT / BITS_PER_UNIT);
6393 else if (!(Present (Alignment_Clause (gnat_entity))
6394 && From_At_Mod (Alignment_Clause (gnat_entity)))
6395 && new_align * BITS_PER_UNIT < align)
6396 post_error_ne_num ("alignment for& must be at least ^",
6397 gnat_error_node, gnat_entity,
6398 align / BITS_PER_UNIT);
6399 else
6400 align = MAX (align, new_align == 0 ? 1 : new_align * BITS_PER_UNIT);
6401
6402 return align;
6403 }
6404 \f
6405 /* Verify that OBJECT, a type or decl, is something we can implement
6406 atomically. If not, give an error for GNAT_ENTITY. COMP_P is true
6407 if we require atomic components. */
6408
6409 static void
6410 check_ok_for_atomic (tree object, Entity_Id gnat_entity, bool comp_p)
6411 {
6412 Node_Id gnat_error_point = gnat_entity;
6413 Node_Id gnat_node;
6414 enum machine_mode mode;
6415 unsigned int align;
6416 tree size;
6417
6418 /* There are three case of what OBJECT can be. It can be a type, in which
6419 case we take the size, alignment and mode from the type. It can be a
6420 declaration that was indirect, in which case the relevant values are
6421 that of the type being pointed to, or it can be a normal declaration,
6422 in which case the values are of the decl. The code below assumes that
6423 OBJECT is either a type or a decl. */
6424 if (TYPE_P (object))
6425 {
6426 mode = TYPE_MODE (object);
6427 align = TYPE_ALIGN (object);
6428 size = TYPE_SIZE (object);
6429 }
6430 else if (DECL_BY_REF_P (object))
6431 {
6432 mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (object)));
6433 align = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (object)));
6434 size = TYPE_SIZE (TREE_TYPE (TREE_TYPE (object)));
6435 }
6436 else
6437 {
6438 mode = DECL_MODE (object);
6439 align = DECL_ALIGN (object);
6440 size = DECL_SIZE (object);
6441 }
6442
6443 /* Consider all floating-point types atomic and any types that that are
6444 represented by integers no wider than a machine word. */
6445 if (GET_MODE_CLASS (mode) == MODE_FLOAT
6446 || ((GET_MODE_CLASS (mode) == MODE_INT
6447 || GET_MODE_CLASS (mode) == MODE_PARTIAL_INT)
6448 && GET_MODE_BITSIZE (mode) <= BITS_PER_WORD))
6449 return;
6450
6451 /* For the moment, also allow anything that has an alignment equal
6452 to its size and which is smaller than a word. */
6453 if (size && TREE_CODE (size) == INTEGER_CST
6454 && compare_tree_int (size, align) == 0
6455 && align <= BITS_PER_WORD)
6456 return;
6457
6458 for (gnat_node = First_Rep_Item (gnat_entity); Present (gnat_node);
6459 gnat_node = Next_Rep_Item (gnat_node))
6460 {
6461 if (!comp_p && Nkind (gnat_node) == N_Pragma
6462 && Get_Pragma_Id (Chars (gnat_node)) == Pragma_Atomic)
6463 gnat_error_point = First (Pragma_Argument_Associations (gnat_node));
6464 else if (comp_p && Nkind (gnat_node) == N_Pragma
6465 && (Get_Pragma_Id (Chars (gnat_node))
6466 == Pragma_Atomic_Components))
6467 gnat_error_point = First (Pragma_Argument_Associations (gnat_node));
6468 }
6469
6470 if (comp_p)
6471 post_error_ne ("atomic access to component of & cannot be guaranteed",
6472 gnat_error_point, gnat_entity);
6473 else
6474 post_error_ne ("atomic access to & cannot be guaranteed",
6475 gnat_error_point, gnat_entity);
6476 }
6477 \f
6478 /* Check if FTYPE1 and FTYPE2, two potentially different function type nodes,
6479 have compatible signatures so that a call using one type may be safely
6480 issued if the actual target function type is the other. Return 1 if it is
6481 the case, 0 otherwise, and post errors on the incompatibilities.
6482
6483 This is used when an Ada subprogram is mapped onto a GCC builtin, to ensure
6484 that calls to the subprogram will have arguments suitable for the later
6485 underlying builtin expansion. */
6486
6487 static int
6488 compatible_signatures_p (tree ftype1, tree ftype2)
6489 {
6490 /* As of now, we only perform very trivial tests and consider it's the
6491 programmer's responsibility to ensure the type correctness in the Ada
6492 declaration, as in the regular Import cases.
6493
6494 Mismatches typically result in either error messages from the builtin
6495 expander, internal compiler errors, or in a real call sequence. This
6496 should be refined to issue diagnostics helping error detection and
6497 correction. */
6498
6499 /* Almost fake test, ensuring a use of each argument. */
6500 if (ftype1 == ftype2)
6501 return 1;
6502
6503 return 1;
6504 }
6505 \f
6506 /* Given a type T, a FIELD_DECL F, and a replacement value R, return a new type
6507 with all size expressions that contain F updated by replacing F with R.
6508 This is identical to GCC's substitute_in_type except that it knows about
6509 TYPE_INDEX_TYPE. If F is NULL_TREE, always make a new RECORD_TYPE, even if
6510 nothing has changed. */
6511
6512 tree
6513 gnat_substitute_in_type (tree t, tree f, tree r)
6514 {
6515 tree new = t;
6516 tree tem;
6517
6518 switch (TREE_CODE (t))
6519 {
6520 case INTEGER_TYPE:
6521 case ENUMERAL_TYPE:
6522 case BOOLEAN_TYPE:
6523 if (CONTAINS_PLACEHOLDER_P (TYPE_MIN_VALUE (t))
6524 || CONTAINS_PLACEHOLDER_P (TYPE_MAX_VALUE (t)))
6525 {
6526 tree low = SUBSTITUTE_IN_EXPR (TYPE_MIN_VALUE (t), f, r);
6527 tree high = SUBSTITUTE_IN_EXPR (TYPE_MAX_VALUE (t), f, r);
6528
6529 if (low == TYPE_MIN_VALUE (t) && high == TYPE_MAX_VALUE (t))
6530 return t;
6531
6532 new = build_range_type (TREE_TYPE (t), low, high);
6533 if (TYPE_INDEX_TYPE (t))
6534 SET_TYPE_INDEX_TYPE
6535 (new, gnat_substitute_in_type (TYPE_INDEX_TYPE (t), f, r));
6536 return new;
6537 }
6538
6539 return t;
6540
6541 case REAL_TYPE:
6542 if (CONTAINS_PLACEHOLDER_P (TYPE_MIN_VALUE (t))
6543 || CONTAINS_PLACEHOLDER_P (TYPE_MAX_VALUE (t)))
6544 {
6545 tree low = NULL_TREE, high = NULL_TREE;
6546
6547 if (TYPE_MIN_VALUE (t))
6548 low = SUBSTITUTE_IN_EXPR (TYPE_MIN_VALUE (t), f, r);
6549 if (TYPE_MAX_VALUE (t))
6550 high = SUBSTITUTE_IN_EXPR (TYPE_MAX_VALUE (t), f, r);
6551
6552 if (low == TYPE_MIN_VALUE (t) && high == TYPE_MAX_VALUE (t))
6553 return t;
6554
6555 t = copy_type (t);
6556 TYPE_MIN_VALUE (t) = low;
6557 TYPE_MAX_VALUE (t) = high;
6558 }
6559 return t;
6560
6561 case COMPLEX_TYPE:
6562 tem = gnat_substitute_in_type (TREE_TYPE (t), f, r);
6563 if (tem == TREE_TYPE (t))
6564 return t;
6565
6566 return build_complex_type (tem);
6567
6568 case OFFSET_TYPE:
6569 case METHOD_TYPE:
6570 case FUNCTION_TYPE:
6571 case LANG_TYPE:
6572 /* Don't know how to do these yet. */
6573 gcc_unreachable ();
6574
6575 case ARRAY_TYPE:
6576 {
6577 tree component = gnat_substitute_in_type (TREE_TYPE (t), f, r);
6578 tree domain = gnat_substitute_in_type (TYPE_DOMAIN (t), f, r);
6579
6580 if (component == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
6581 return t;
6582
6583 new = build_array_type (component, domain);
6584 TYPE_SIZE (new) = 0;
6585 TYPE_MULTI_ARRAY_P (new) = TYPE_MULTI_ARRAY_P (t);
6586 TYPE_CONVENTION_FORTRAN_P (new) = TYPE_CONVENTION_FORTRAN_P (t);
6587 layout_type (new);
6588 TYPE_ALIGN (new) = TYPE_ALIGN (t);
6589
6590 /* If we had bounded the sizes of T by a constant, bound the sizes of
6591 NEW by the same constant. */
6592 if (TREE_CODE (TYPE_SIZE (t)) == MIN_EXPR)
6593 TYPE_SIZE (new)
6594 = size_binop (MIN_EXPR, TREE_OPERAND (TYPE_SIZE (t), 1),
6595 TYPE_SIZE (new));
6596 if (TREE_CODE (TYPE_SIZE_UNIT (t)) == MIN_EXPR)
6597 TYPE_SIZE_UNIT (new)
6598 = size_binop (MIN_EXPR, TREE_OPERAND (TYPE_SIZE_UNIT (t), 1),
6599 TYPE_SIZE_UNIT (new));
6600 return new;
6601 }
6602
6603 case RECORD_TYPE:
6604 case UNION_TYPE:
6605 case QUAL_UNION_TYPE:
6606 {
6607 tree field;
6608 bool changed_field
6609 = (f == NULL_TREE && !TREE_CONSTANT (TYPE_SIZE (t)));
6610 bool field_has_rep = false;
6611 tree last_field = NULL_TREE;
6612
6613 tree new = copy_type (t);
6614
6615 /* Start out with no fields, make new fields, and chain them
6616 in. If we haven't actually changed the type of any field,
6617 discard everything we've done and return the old type. */
6618
6619 TYPE_FIELDS (new) = NULL_TREE;
6620 TYPE_SIZE (new) = NULL_TREE;
6621
6622 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
6623 {
6624 tree new_field = copy_node (field);
6625
6626 TREE_TYPE (new_field)
6627 = gnat_substitute_in_type (TREE_TYPE (new_field), f, r);
6628
6629 if (DECL_HAS_REP_P (field) && !DECL_INTERNAL_P (field))
6630 field_has_rep = true;
6631 else if (TREE_TYPE (new_field) != TREE_TYPE (field))
6632 changed_field = true;
6633
6634 /* If this is an internal field and the type of this field is
6635 a UNION_TYPE or RECORD_TYPE with no elements, ignore it. If
6636 the type just has one element, treat that as the field.
6637 But don't do this if we are processing a QUAL_UNION_TYPE. */
6638 if (TREE_CODE (t) != QUAL_UNION_TYPE
6639 && DECL_INTERNAL_P (new_field)
6640 && (TREE_CODE (TREE_TYPE (new_field)) == UNION_TYPE
6641 || TREE_CODE (TREE_TYPE (new_field)) == RECORD_TYPE))
6642 {
6643 if (!TYPE_FIELDS (TREE_TYPE (new_field)))
6644 continue;
6645
6646 if (!TREE_CHAIN (TYPE_FIELDS (TREE_TYPE (new_field))))
6647 {
6648 tree next_new_field
6649 = copy_node (TYPE_FIELDS (TREE_TYPE (new_field)));
6650
6651 /* Make sure omitting the union doesn't change
6652 the layout. */
6653 DECL_ALIGN (next_new_field) = DECL_ALIGN (new_field);
6654 new_field = next_new_field;
6655 }
6656 }
6657
6658 DECL_CONTEXT (new_field) = new;
6659 SET_DECL_ORIGINAL_FIELD (new_field,
6660 (DECL_ORIGINAL_FIELD (field)
6661 ? DECL_ORIGINAL_FIELD (field) : field));
6662
6663 /* If the size of the old field was set at a constant,
6664 propagate the size in case the type's size was variable.
6665 (This occurs in the case of a variant or discriminated
6666 record with a default size used as a field of another
6667 record.) */
6668 DECL_SIZE (new_field)
6669 = TREE_CODE (DECL_SIZE (field)) == INTEGER_CST
6670 ? DECL_SIZE (field) : NULL_TREE;
6671 DECL_SIZE_UNIT (new_field)
6672 = TREE_CODE (DECL_SIZE_UNIT (field)) == INTEGER_CST
6673 ? DECL_SIZE_UNIT (field) : NULL_TREE;
6674
6675 if (TREE_CODE (t) == QUAL_UNION_TYPE)
6676 {
6677 tree new_q = SUBSTITUTE_IN_EXPR (DECL_QUALIFIER (field), f, r);
6678
6679 if (new_q != DECL_QUALIFIER (new_field))
6680 changed_field = true;
6681
6682 /* Do the substitution inside the qualifier and if we find
6683 that this field will not be present, omit it. */
6684 DECL_QUALIFIER (new_field) = new_q;
6685
6686 if (integer_zerop (DECL_QUALIFIER (new_field)))
6687 continue;
6688 }
6689
6690 if (!last_field)
6691 TYPE_FIELDS (new) = new_field;
6692 else
6693 TREE_CHAIN (last_field) = new_field;
6694
6695 last_field = new_field;
6696
6697 /* If this is a qualified type and this field will always be
6698 present, we are done. */
6699 if (TREE_CODE (t) == QUAL_UNION_TYPE
6700 && integer_onep (DECL_QUALIFIER (new_field)))
6701 break;
6702 }
6703
6704 /* If this used to be a qualified union type, but we now know what
6705 field will be present, make this a normal union. */
6706 if (changed_field && TREE_CODE (new) == QUAL_UNION_TYPE
6707 && (!TYPE_FIELDS (new)
6708 || integer_onep (DECL_QUALIFIER (TYPE_FIELDS (new)))))
6709 TREE_SET_CODE (new, UNION_TYPE);
6710 else if (!changed_field)
6711 return t;
6712
6713 gcc_assert (!field_has_rep);
6714 layout_type (new);
6715
6716 /* If the size was originally a constant use it. */
6717 if (TYPE_SIZE (t) && TREE_CODE (TYPE_SIZE (t)) == INTEGER_CST
6718 && TREE_CODE (TYPE_SIZE (new)) != INTEGER_CST)
6719 {
6720 TYPE_SIZE (new) = TYPE_SIZE (t);
6721 TYPE_SIZE_UNIT (new) = TYPE_SIZE_UNIT (t);
6722 SET_TYPE_ADA_SIZE (new, TYPE_ADA_SIZE (t));
6723 }
6724
6725 return new;
6726 }
6727
6728 default:
6729 return t;
6730 }
6731 }
6732 \f
6733 /* Return the "RM size" of GNU_TYPE. This is the actual number of bits
6734 needed to represent the object. */
6735
6736 tree
6737 rm_size (tree gnu_type)
6738 {
6739 /* For integer types, this is the precision. For record types, we store
6740 the size explicitly. For other types, this is just the size. */
6741
6742 if (INTEGRAL_TYPE_P (gnu_type) && TYPE_RM_SIZE (gnu_type))
6743 return TYPE_RM_SIZE (gnu_type);
6744 else if (TREE_CODE (gnu_type) == RECORD_TYPE
6745 && TYPE_CONTAINS_TEMPLATE_P (gnu_type))
6746 /* Return the rm_size of the actual data plus the size of the template. */
6747 return
6748 size_binop (PLUS_EXPR,
6749 rm_size (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (gnu_type)))),
6750 DECL_SIZE (TYPE_FIELDS (gnu_type)));
6751 else if ((TREE_CODE (gnu_type) == RECORD_TYPE
6752 || TREE_CODE (gnu_type) == UNION_TYPE
6753 || TREE_CODE (gnu_type) == QUAL_UNION_TYPE)
6754 && !TYPE_IS_FAT_POINTER_P (gnu_type)
6755 && TYPE_ADA_SIZE (gnu_type))
6756 return TYPE_ADA_SIZE (gnu_type);
6757 else
6758 return TYPE_SIZE (gnu_type);
6759 }
6760 \f
6761 /* Return an identifier representing the external name to be used for
6762 GNAT_ENTITY. If SUFFIX is specified, the name is followed by "___"
6763 and the specified suffix. */
6764
6765 tree
6766 create_concat_name (Entity_Id gnat_entity, const char *suffix)
6767 {
6768 Entity_Kind kind = Ekind (gnat_entity);
6769
6770 const char *str = (!suffix ? "" : suffix);
6771 String_Template temp = {1, strlen (str)};
6772 Fat_Pointer fp = {str, &temp};
6773
6774 Get_External_Name_With_Suffix (gnat_entity, fp);
6775
6776 /* A variable using the Stdcall convention (meaning we are running
6777 on a Windows box) live in a DLL. Here we adjust its name to use
6778 the jump-table, the _imp__NAME contains the address for the NAME
6779 variable. */
6780 if ((kind == E_Variable || kind == E_Constant)
6781 && Has_Stdcall_Convention (gnat_entity))
6782 {
6783 const char *prefix = "_imp__";
6784 int k, plen = strlen (prefix);
6785
6786 for (k = 0; k <= Name_Len; k++)
6787 Name_Buffer [Name_Len - k + plen] = Name_Buffer [Name_Len - k];
6788 strncpy (Name_Buffer, prefix, plen);
6789 }
6790
6791 return get_identifier (Name_Buffer);
6792 }
6793
6794 /* Return the name to be used for GNAT_ENTITY. If a type, create a
6795 fully-qualified name, possibly with type information encoding.
6796 Otherwise, return the name. */
6797
6798 tree
6799 get_entity_name (Entity_Id gnat_entity)
6800 {
6801 Get_Encoded_Name (gnat_entity);
6802 return get_identifier (Name_Buffer);
6803 }
6804
6805 /* Given GNU_ID, an IDENTIFIER_NODE containing a name and SUFFIX, a
6806 string, return a new IDENTIFIER_NODE that is the concatenation of
6807 the name in GNU_ID and SUFFIX. */
6808
6809 tree
6810 concat_id_with_name (tree gnu_id, const char *suffix)
6811 {
6812 int len = IDENTIFIER_LENGTH (gnu_id);
6813
6814 strncpy (Name_Buffer, IDENTIFIER_POINTER (gnu_id),
6815 IDENTIFIER_LENGTH (gnu_id));
6816 strncpy (Name_Buffer + len, "___", 3);
6817 len += 3;
6818 strcpy (Name_Buffer + len, suffix);
6819 return get_identifier (Name_Buffer);
6820 }
6821
6822 #include "gt-ada-decl.h"