| blob | f2da070ab0fba652411a3edeaad60fb84718a0ce |
1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * D E C L *
6 * *
7 * C Implementation File *
8 * *
9 * Copyright (C) 1992-2017, Free Software Foundation, Inc. *
10 * *
11 * GNAT is free software; you can redistribute it and/or modify it under *
12 * terms of the GNU General Public License as published by the Free Soft- *
13 * ware Foundation; either version 3, or (at your option) any later ver- *
14 * sion. GNAT is distributed in the hope that it will be useful, but WITH- *
15 * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY *
16 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License *
17 * for more details. You should have received a copy of the GNU General *
18 * Public License along with GCC; see the file COPYING3. If not see *
19 * <http://www.gnu.org/licenses/>. *
20 * *
21 * GNAT was originally developed by the GNAT team at New York University. *
22 * Extensive contributions were provided by Ada Core Technologies Inc. *
23 * *
24 ****************************************************************************/
55 /* "stdcall" and "thiscall" conventions should be processed in a specific way
56 on 32-bit x86/Windows only. The macros below are helpers to avoid having
57 to check for a Windows specific attribute throughout this unit. */
59 #if TARGET_DLLIMPORT_DECL_ATTRIBUTES
60 #ifdef TARGET_64BIT
61 #define Has_Stdcall_Convention(E) \
62 (!TARGET_64BIT && Convention (E) == Convention_Stdcall)
63 #define Has_Thiscall_Convention(E) \
64 (!TARGET_64BIT && is_cplusplus_method (E))
65 #else
66 #define Has_Stdcall_Convention(E) (Convention (E) == Convention_Stdcall)
67 #define Has_Thiscall_Convention(E) (is_cplusplus_method (E))
68 #endif
69 #else
70 #define Has_Stdcall_Convention(E) 0
71 #define Has_Thiscall_Convention(E) 0
72 #endif
76 /* Stack realignment is necessary for functions with foreign conventions when
77 the ABI doesn't mandate as much as what the compiler assumes - that is, up
78 to PREFERRED_STACK_BOUNDARY.
80 Such realignment can be requested with a dedicated function type attribute
81 on the targets that support it. We define FOREIGN_FORCE_REALIGN_STACK to
82 characterize the situations where the attribute should be set. We rely on
83 compiler configuration settings for 'main' to decide. */
85 #ifdef MAIN_STACK_BOUNDARY
86 #define FOREIGN_FORCE_REALIGN_STACK \
87 (MAIN_STACK_BOUNDARY < PREFERRED_STACK_BOUNDARY)
88 #else
89 #define FOREIGN_FORCE_REALIGN_STACK 0
90 #endif
92 struct incomplete
93 {
95 tree old_type;
96 Entity_Id full_type;
97 };
99 /* These variables are used to defer recursively expanding incomplete types
100 while we are processing a record, an array or a subprogram type. */
104 /* This variable is used to delay expanding types coming from a limited with
105 clause and completed Taft Amendment types until the end of the spec. */
109 tree discriminant;
110 tree replacement;
115 /* The type of the variant. */
116 tree type;
118 /* The associated field. */
119 tree field;
121 /* The value of the qualifier. */
122 tree qual;
124 /* The type of the variant after transformation. */
125 tree new_type;
129 /* A map used to cache the result of annotate_value. */
131 {
134 {
136 }
140 {
142 }
144 static int
146 {
148 }
149 };
153 /* A map used to associate a dummy type with a list of subprogram entities. */
155 {
158 };
160 void
162 {
163 }
165 void
167 {
169 }
172 {
175 {
177 }
181 {
183 }
185 static int
187 {
189 }
190 };
223 tree *);
247 /* The relevant constituents of a subprogram binding to a GCC builtin. Used
248 to pass around calls performing profile compatibility checks. */
257 \f
258 /* Given GNAT_ENTITY, a GNAT defining identifier node, which denotes some Ada
259 entity, return the equivalent GCC tree for that entity (a ..._DECL node)
260 and associate the ..._DECL node with the input GNAT defining identifier.
262 If GNAT_ENTITY is a variable or a constant declaration, GNU_EXPR gives its
263 initial value (in GCC tree form). This is optional for a variable. For
264 a renamed entity, GNU_EXPR gives the object being renamed.
266 DEFINITION is true if this call is intended for a definition. This is used
267 for separate compilation where it is necessary to know whether an external
268 declaration or a definition must be created if the GCC equivalent was not
269 created previously. */
271 tree
273 {
274 /* Contains the kind of the input GNAT node. */
276 /* True if this is a type. */
278 /* True if this is an artificial entity. */
280 /* True if debug info is requested for this entity. */
282 /* True if this entity is to be considered as imported. */
283 const bool imported_p
285 /* For a type, contains the equivalent GNAT node to be used in gigi. */
287 /* Temporary used to walk the GNAT tree. */
288 Entity_Id gnat_temp;
289 /* Contains the GCC DECL node which is equivalent to the input GNAT node.
290 This node will be associated with the GNAT node by calling at the end
291 of the `switch' statement. */
293 /* Contains the GCC type to be used for the GCC node. */
295 /* Contains the GCC size tree to be used for the GCC node. */
297 /* Contains the GCC name to be used for the GCC node. */
298 tree gnu_entity_name;
299 /* True if we have already saved gnu_decl as a GNAT association. */
301 /* True if we incremented defer_incomplete_level. */
303 /* True if we incremented force_global. */
305 /* True if we should check to see if elaborated during processing. */
307 /* True if we made GNU_DECL and its type here. */
309 /* Size and alignment of the GCC node, if meaningful. */
311 /* Contains the list of attributes directly attached to the entity. */
314 /* Since a use of an Itype is a definition, process it as such if it is in
315 the main unit, except for E_Access_Subtype because it's actually a use
316 of its base type, and for E_Record_Subtype with cloned subtype because
317 it's actually a use of the cloned subtype, see below. */
319 && is_type
326 {
327 /* Ensure that we are in a subprogram mentioned in the Scope chain of
328 this entity, our current scope is global, or we encountered a task
329 or entry (where we can't currently accurately check scoping). */
332 {
335 }
340 {
345 gnat_temp
357 && (current_function_decl
359 {
362 }
363 }
365 /* This abort means the Itype has an incorrect scope, i.e. that its
366 scope does not correspond to the subprogram it is declared in. */
368 }
370 /* If we've already processed this entity, return what we got last time.
371 If we are defining the node, we should not have already processed it.
372 In that case, we will abort below when we try to save a new GCC tree
373 for this object. We also need to handle the case of getting a dummy
374 type when a Full_View exists but be careful so as not to trigger its
375 premature elaboration. */
378 {
387 {
388 gnu_decl
392 }
395 }
397 /* If this is a numeric or enumeral type, or an access type, a nonzero Esize
398 must be specified unless it was specified by the programmer. Exceptions
399 are for access-to-protected-subprogram types and all access subtypes, as
400 another GNAT type is used to lay out the GCC type for them. */
412 /* The RM size must be specified for all discrete and fixed-point types. */
416 /* If we get here, it means we have not yet done anything with this entity.
417 If we are not defining it, it must be a type or an entity that is defined
418 elsewhere or externally, otherwise we should have defined it already. */
420 || type_annotate_only
421 || is_type
428 /* Get the name of the entity and set up the line number and filename of
429 the original definition for use in any decl we make. Make sure we do not
430 inherit another source location. */
436 /* For cases when we are not defining (i.e., we are referencing from
437 another compilation unit) public entities, show we are at global level
438 for the purpose of computing scopes. Don't do this for components or
439 discriminants since the relevant test is whether or not the record is
440 being defined. */
448 /* Handle any attributes directly attached to the entity. */
452 /* Do some common processing for types. */
454 {
455 /* Compute the equivalent type to be used in gigi. */
458 /* Machine_Attributes on types are expected to be propagated to
459 subtypes. The corresponding Gigi_Rep_Items are only attached
460 to the first subtype though, so we handle the propagation here. */
467 /* Compute a default value for the size of an elementary type. */
469 {
479 else
484 }
485 }
488 {
491 {
492 /* The GNAT record where the component was defined. */
495 /* If the entity is a discriminant of an extended tagged type used to
496 rename a discriminant of the parent type, return the latter. */
500 {
501 gnu_decl
506 }
508 /* If the entity is an inherited component (in the case of extended
509 tagged record types), just return the original entity, which must
510 be a FIELD_DECL. Likewise for discriminants. If the entity is a
511 non-girder discriminant (in the case of derived untagged record
512 types), return the stored discriminant it renames. */
515 {
516 gnu_decl
519 /* GNU_DECL contains a PLACEHOLDER_EXPR for discriminants. */
523 }
525 /* Otherwise, if we are not defining this and we have no GCC type
526 for the containing record, make one for it. Then we should
527 have made our own equivalent. */
529 {
530 /* ??? If this is in a record whose scope is a protected
531 type and we have an Original_Record_Component, use it.
532 This is a workaround for major problems in protected type
533 handling. */
537 {
538 gnu_decl
542 }
543 else
544 {
547 }
551 }
553 /* Here we have no GCC type and this is a reference rather than a
554 definition. This should never happen. Most likely the cause is
555 reference before declaration in the GNAT tree for gnat_entity. */
557 }
560 /* Ignore constant definitions already marked with the error node. See
561 the N_Object_Declaration case of gnat_to_gnu for the rationale. */
565 {
568 }
570 /* Ignore deferred constant definitions without address clause since
571 they are processed fully in the front-end. If No_Initialization
572 is set, this is not a deferred constant but a constant whose value
573 is built manually. And constants that are renamings are handled
574 like variables. */
576 && !gnu_expr
580 {
584 }
586 /* If this is a use of a deferred constant without address clause,
587 get its full definition. */
591 {
592 gnu_decl
596 }
598 /* If we have a constant that we are not defining, get the expression it
599 was defined to represent. This is necessary to avoid generating dumb
600 elaboration code in simple cases, but we may throw it away later if it
601 is not a constant. But do not retrieve it if it is an allocator since
602 the designated type might still be dummy at this point. */
608 /* The expression may contain N_Expression_With_Actions nodes and
609 thus object declarations from other units. Discard them. */
610 gnu_expr
613 /* ... fall through ... */
619 {
621 /* Always create a variable for volatile objects and variables seen
622 constant but with a Linker_Section pragma. */
623 bool const_flag
636 /* We implement RM 13.3(19) for exported and imported (non-constant)
637 objects by making them volatile. */
638 bool volatile_flag
645 tree gnu_object_size;
647 /* We need to translate the renamed object even though we are only
648 referencing the renaming. But it may contain a call for which
649 we'll generate a temporary to hold the return value and which
650 is part of the definition of the renaming, so discard it. */
652 {
656 else
658 }
660 /* Get the type after elaborating the renamed object. */
664 else
665 {
668 /* If this is a standard exception definition, use the standard
669 exception type. This is necessary to make sure that imported
670 and exported views of exceptions are merged in LTO mode. */
674 }
676 /* For a debug renaming declaration, build a debug-only entity. */
678 {
679 /* Force a non-null value to make sure the symbol is retained. */
683 integer_minus_one_node));
691 }
693 /* If this is a loop variable, its type should be the base type.
694 This is because the code for processing a loop determines whether
695 a normal loop end test can be done by comparing the bounds of the
696 loop against those of the base type, which is presumed to be the
697 size used for computation. But this is not correct when the size
698 of the subtype is smaller than the type. */
702 /* Reject non-renamed objects whose type is an unconstrained array or
703 any object whose type is a dummy type or void. */
708 {
711 force_global--;
713 }
715 /* If an alignment is specified, use it if valid. Note that exceptions
716 are objects but don't have an alignment and there is also no point in
717 setting it for an address clause, since the final type of the object
718 will be a reference type. */
725 /* Likewise, if a size is specified, use it if valid. */
727 gnu_size
731 {
732 gnu_type
738 }
740 /* If this object has self-referential size, it must be a record with
741 a default discriminant. We are supposed to allocate an object of
742 the maximum size in this case, unless it is a constant with an
743 initializing expression, in which case we can get the size from
744 that. Note that the resulting size may still be a variable, so
745 this may end up with an indirect allocation. */
748 {
750 {
753 {
754 /* If the initializing expression is itself a constant,
755 despite having a nominal type with self-referential
756 size, we can get the size directly from it. */
758 && TYPE_IS_PADDING_P
762 || DECL_READONLY_ONCE_ELAB
765 else
766 gnu_size
768 }
769 else
771 }
772 /* We may have no GNU_EXPR because No_Initialization is
773 set even though there's an Expression. */
778 gnu_size
780 (Etype
782 else
783 {
786 }
788 /* If the size isn't constant and we are at global level, call
789 elaborate_expression_1 to make a variable for it rather than
790 calculating it each time. */
794 }
796 /* If the size is zero byte, make it one byte since some linkers have
797 troubles with zero-sized objects. If the object will have a
798 template, that will make it nonzero so don't bother. Also avoid
799 doing that for an object renaming or an object with an address
800 clause, as we would lose useful information on the view size
801 (e.g. for null array slices) and we are not allocating the object
802 here anyway. */
814 /* If this is an object with no specified size and alignment, and
815 if either it is atomic or we are not optimizing alignment for
816 space and it is composite and not an exception, an Out parameter
817 or a reference to another object, and the size of its type is a
818 constant, set the alignment to the smallest one which is not
819 smaller than the size, with an appropriate cap. */
828 && !imported_p
834 /* If the object is set to have atomic components, find the component
835 type and validate it.
837 ??? Note that we ignore Has_Volatile_Components on objects; it's
838 not at all clear what to do in that case. */
840 {
849 }
851 /* If this is an aliased object with an unconstrained array nominal
852 subtype, make a type that includes the template. We will either
853 allocate or create a variable of that type, see below. */
857 {
859 gnu_type
861 gnu_type,
864 debug_info_p);
865 }
867 /* ??? If this is an object of CW type initialized to a value, try to
868 ensure that the object is sufficient aligned for this value, but
869 without pessimizing the allocation. This is a kludge necessary
870 because we don't support dynamic alignment. */
877 #ifdef MINIMUM_ATOMIC_ALIGNMENT
878 /* If the size is a constant and no alignment is specified, force
879 the alignment to be the minimum valid atomic alignment. The
880 restriction on constant size avoids problems with variable-size
881 temporaries; if the size is variable, there's no issue with
882 atomic access. Also don't do this for a constant, since it isn't
883 necessary and can interfere with constant replacement. Finally,
884 do not do it for Out parameters since that creates an
885 size inconsistency with In parameters. */
895 #endif
897 /* Make a new type with the desired size and alignment, if needed.
898 But do not take into account alignment promotions to compute the
899 size of the object. */
902 {
908 /* If a padding record was made, declare it now since it will
909 never be declared otherwise. This is necessary to ensure
910 that its subtrees are properly marked. */
914 }
916 /* Now check if the type of the object allows atomic access. */
920 /* If this is a renaming, avoid as much as possible to create a new
921 object. However, in some cases, creating it is required because
922 renaming can be applied to objects that are not names in Ada.
923 This processing needs to be applied to the raw expression so as
924 to make it more likely to rename the underlying object. */
926 {
927 /* If the renamed object had padding, strip off the reference to
928 the inner object and reset our type. */
931 /* Strip useless conversions around the object. */
933 {
936 }
938 /* Or else, if the renamed object has an unconstrained type with
939 default discriminant, use the padded type. */
943 /* Case 1: if this is a constant renaming stemming from a function
944 call, treat it as a normal object whose initial value is what
945 is being renamed. RM 3.3 says that the result of evaluating a
946 function call is a constant object. Therefore, it can be the
947 inner object of a constant renaming and the renaming must be
948 fully instantiated, i.e. it cannot be a reference to (part of)
949 an existing object. And treat other rvalues (addresses, null
950 expressions, constructors and literals) the same way. */
954 /* Expand_Dispatching_Call can prepend a comparison of the tags
955 before the call to "=". */
966 /* We need to detect the case where a temporary is created to
967 hold the return value, since we cannot safely rename it at
968 top level as it lives only in the elaboration routine. */
971 /* We also need to detect the case where the front-end creates
972 a dangling 'reference to a function call at top level and
973 substitutes it in the renaming, for example:
975 q__b : boolean renames r__f.e (1);
977 can be rewritten into:
979 q__R1s : constant q__A2s := r__f'reference;
980 [...]
981 q__b : boolean renames q__R1s.all.e (1);
983 We cannot safely rename the rewritten expression since the
984 underlying object lives only in the elaboration routine. */
986 && (inner
990 ;
992 /* Case 2: if the renaming entity need not be materialized, use
993 the elaborated renamed expression for the renaming. But this
994 means that the caller is responsible for evaluating the address
995 of the renaming in the correct place for the definition case to
996 instantiate the SAVE_EXPRs. */
998 {
1001 gnu_decl
1005 /* We cannot evaluate the first arm of a COMPOUND_EXPR in the
1006 correct place for this case. */
1009 /* No DECL_EXPR will be created so the expression needs to be
1010 marked manually because it will likely be shared. */
1014 /* This assertion will fail if the renamed object isn't aligned
1015 enough as to make it possible to honor the alignment set on
1016 the renaming. */
1018 {
1023 }
1025 /* The expression might not be a DECL so save it manually. */
1030 }
1032 /* Case 3: otherwise, make a constant pointer to the object we
1033 are renaming and attach the object to the pointer after it is
1034 elaborated. The object will be referenced directly instead
1035 of indirectly via the pointer to avoid aliasing problems with
1036 non-addressable entities. The pointer is called a "renaming"
1037 pointer in this case. Note that we also need to preserve the
1038 volatility of the renamed object through the indirection. */
1039 else
1040 {
1044 gnu_type
1053 renamed_obj
1057 /* The expression needs to be marked manually because it will
1058 likely be shared, even for a definition since the ADDR_EXPR
1059 built below can cause the first few nodes to be folded. */
1066 else
1067 {
1068 gnu_expr
1071 gnu_expr
1073 gnu_expr);
1074 }
1075 }
1076 }
1078 /* If we are defining an aliased object whose nominal subtype is
1079 unconstrained, the object is a record that contains both the
1080 template and the object. If there is an initializer, it will
1081 have already been converted to the right type, but we need to
1082 create the template if there is no initializer. */
1084 && !gnu_expr
1087 /* Beware that padding might have been introduced above. */
1090 == RECORD_TYPE
1091 && TYPE_CONTAINS_TEMPLATE_P
1093 {
1094 tree template_field
1102 NULL_TREE);
1105 }
1107 /* Convert the expression to the type of the object if need be. */
1111 /* If this is a pointer that doesn't have an initializing expression,
1112 initialize it to NULL, unless the object is declared imported as
1113 per RM B.1(24). */
1116 && !gnu_expr
1120 /* If we are defining the object and it has an Address clause, we must
1121 either get the address expression from the saved GCC tree for the
1122 object if it has a Freeze node, or elaborate the address expression
1123 here since the front-end has guaranteed that the elaboration has no
1124 effects in this case. */
1126 {
1129 tree gnu_address
1135 /* Convert the type of the object to a reference type that can
1136 alias everything as per RM 13.3(19). */
1139 gnu_type
1143 const_flag
1149 /* If this is an aliased object with an unconstrained array nominal
1150 subtype, then it can overlay only another aliased object with an
1151 unconstrained array nominal subtype and compatible template. */
1155 {
1159 /* This is the pattern built for a regular object. */
1163 /* This is the pattern built for an overaligned object. */
1166 == PLUS_EXPR
1169 gnu_address
1173 else
1174 {
1177 gnat_entity);
1180 }
1181 }
1183 /* If we don't have an initializing expression for the underlying
1184 variable, the initializing expression for the pointer is the
1185 specified address. Otherwise, we have to make a COMPOUND_EXPR
1186 to assign both the address and the initial value. */
1189 else
1190 gnu_expr
1194 NULL_TREE,
1195 gnu_address),
1196 gnu_expr),
1197 gnu_address);
1198 }
1200 /* If it has an address clause and we are not defining it, mark it
1201 as an indirect object. Likewise for Stdcall objects that are
1202 imported. */
1205 {
1206 /* Convert the type of the object to a reference type that can
1207 alias everything as per RM 13.3(19). */
1210 gnu_type
1217 /* No point in taking the address of an initializing expression
1218 that isn't going to be used. */
1221 /* If it has an address clause whose value is known at compile
1222 time, make the object a CONST_DECL. This will avoid a
1223 useless dereference. */
1225 {
1226 Node_Id gnat_address
1230 {
1233 }
1234 }
1235 }
1237 /* If we are at top level and this object is of variable size,
1238 make the actual type a hidden pointer to the real type and
1239 make the initializer be a memory allocation and initialization.
1240 Likewise for objects we aren't defining (presumed to be
1241 external references from other packages), but there we do
1242 not set up an initialization.
1244 If the object's size overflows, make an allocator too, so that
1245 Storage_Error gets raised. Note that we will never free
1246 such memory, so we presume it never will get allocated. */
1249 || !definition
1251 || (gnu_size
1253 size_binop
1255 bitsize_unit_node)),
1257 || !definition
1259 {
1268 /* In case this was a aliased object whose nominal subtype is
1269 unconstrained, the pointer above will be a thin pointer and
1270 build_allocator will automatically make the template.
1272 If we have a template initializer only (that we made above),
1273 pretend there is none and rely on what build_allocator creates
1274 again anyway. Otherwise (if we have a full initializer), get
1275 the data part and feed that to build_allocator.
1277 If we are elaborating a mutable object, tell build_allocator to
1278 ignore a possibly simpler size from the initializer, if any, as
1279 we must allocate the maximum possible size in this case. */
1281 {
1286 {
1287 gnu_alloc_type
1293 else
1294 gnu_expr
1295 = build_component_ref
1299 }
1304 gnat_entity);
1306 gnu_expr
1309 }
1310 else
1312 }
1314 /* If this object would go into the stack and has an alignment larger
1315 than the largest stack alignment the back-end can honor, resort to
1316 a variable of "aligning type". */
1319 && !imported_p
1320 && !static_flag
1322 {
1323 /* Create the new variable. No need for extra room before the
1324 aligned field as this is in automatic storage. */
1325 tree gnu_new_type
1329 tree gnu_new_var
1334 gnat_entity);
1336 /* Initialize the aligned field if we have an initializer. */
1338 add_stmt_with_node
1340 build_component_ref
1343 gnu_expr),
1344 gnat_entity);
1346 /* And setup this entity as a reference to the aligned field. */
1348 gnu_expr
1349 = build_unary_op
1359 }
1361 /* If this is an aggregate constant initialized to a constant, force it
1362 to be statically allocated. This saves an initialization copy. */
1364 && const_flag
1365 && gnu_expr
1374 /* If this is an aliased object with an unconstrained array nominal
1375 subtype, we make its type a thin reference, i.e. the reference
1376 counterpart of a thin pointer, so it points to the array part.
1377 This is aimed to make it easier for the debugger to decode the
1378 object. Note that we have to do it this late because of the
1379 couple of allocation adjustments that might be made above. */
1383 {
1384 /* In case the object with the template has already been allocated
1385 just above, we have nothing to do here. */
1387 {
1388 /* This variable is a GNAT encoding used by Workbench: let it
1389 go through the debugging information but mark it as
1390 artificial: users are not interested in it. */
1391 tree gnu_unc_var
1407 }
1410 gnu_type
1412 }
1414 /* Convert the expression to the type of the object if need be. */
1418 /* If this name is external or a name was specified, use it, but don't
1419 use the Interface_Name with an address clause (see cd30005). */
1425 /* Deal with a pragma Linker_Section on a constant or variable. */
1431 /* Now create the variable or the constant and set various flags. */
1432 gnu_decl
1443 /* If we are defining an Out parameter and optimization isn't enabled,
1444 create a fake PARM_DECL for debugging purposes and make it point to
1445 the VAR_DECL. Suppress debug info for the latter but make sure it
1446 will live in memory so that it can be accessed from within the
1447 debugger through the PARM_DECL. */
1449 && definition
1450 && debug_info_p
1451 && !optimize
1453 {
1460 }
1462 /* If this is a loop parameter, set the corresponding flag. */
1466 /* If this is a renaming pointer, attach the renamed object to it. */
1470 /* If this is a constant and we are defining it or it generates a real
1471 symbol at the object level and we are referencing it, we may want
1472 or need to have a true variable to represent it:
1473 - if optimization isn't enabled, for debugging purposes,
1474 - if the constant is public and not overlaid on something else,
1475 - if its address is taken,
1476 - if either itself or its type is aliased. */
1485 {
1486 tree gnu_corr_var
1494 }
1496 /* If this is a constant, even if we don't need a true variable, we
1497 may need to avoid returning the initializer in every case. That
1498 can happen for the address of a (constant) constructor because,
1499 upon dereferencing it, the constructor will be reinjected in the
1500 tree, which may not be valid in every case; see lvalue_required_p
1501 for more details. */
1505 /* If this object is declared in a block that contains a block with an
1506 exception handler, and we aren't using the GCC exception mechanism,
1507 we must force this variable in memory in order to avoid an invalid
1508 optimization. */
1513 /* If this is a local variable with non-BLKmode and aggregate type,
1514 and optimization isn't enabled, then force it in memory so that
1515 a register won't be allocated to it with possible subparts left
1516 uninitialized and reaching the register allocator. */
1526 /* If we are defining an object with variable size or an object with
1527 fixed size that will be dynamically allocated, and we are using the
1528 front-end setjmp/longjmp exception mechanism, update the setjmp
1529 buffer. */
1542 gnat_entity);
1544 /* Back-annotate Esize and Alignment of the object if not already
1545 known. Note that we pick the values of the type, not those of
1546 the object, to shield ourselves from low-level platform-dependent
1547 adjustments like alignment promotion. This is both consistent with
1548 all the treatment above, where alignment and size are set on the
1549 type of the object and not on the object directly, and makes it
1550 possible to support all confirming representation clauses. */
1552 used_by_ref);
1553 }
1557 /* Return a TYPE_DECL for "void" that we previously made. */
1562 /* A special case: for the types Character and Wide_Character in
1563 Standard, we do not list all the literals. So if the literals
1564 are not specified, make this an integer type. */
1566 {
1569 else
1573 /* Set TYPE_STRING_FLAG for Character and Wide_Character types.
1574 This is needed by the DWARF-2 back-end to distinguish between
1575 unsigned integer types and character types. */
1578 /* This flag is needed by the call just below. */
1582 }
1583 else
1584 {
1585 /* We have a list of enumeral constants in First_Literal. We make a
1586 CONST_DECL for each one and build into GNU_LITERAL_LIST the list
1587 to be placed into TYPE_FIELDS. Each node is itself a TREE_LIST
1588 whose TREE_VALUE is the literal name and whose TREE_PURPOSE is the
1589 value of the literal. But when we have a regular boolean type, we
1590 simplify this a little by using a BOOLEAN_TYPE. */
1595 Entity_Id gnat_literal;
1608 {
1609 tree gnu_value
1611 /* Do not generate debug info for individual enumerators. */
1612 tree gnu_literal
1618 gnu_list
1620 }
1625 /* Note that the bounds are updated at the end of this function
1626 to avoid an infinite recursion since they refer to the type. */
1628 }
1632 /* For integer types, just make a signed type the appropriate number
1633 of bits. */
1639 {
1640 /* Small_Value is the scale factor. */
1646 /* Try to decode the scale factor and to save it for the fixed-point
1647 types debug hook. */
1649 /* There are various ways to describe the scale factor, however there
1650 are cases where back-end internals cannot hold it. In such cases,
1651 we output invalid scale factor for such cases (i.e. the 0/0
1652 rational constant) but we expect GNAT to output GNAT encodings,
1653 then. Thus, keep this in sync with
1654 Exp_Dbug.Is_Handled_Scale_Factor. */
1656 /* When encoded as 1/2**N or 1/10**N, describe the scale factor as a
1657 binary or decimal scale: it is easier to read for humans. */
1661 {
1662 /* Given RM restrictions on 'Small values, we assume here that
1663 the denominator fits in an int. */
1666 const tree exponent
1669 scale_factor
1671 integer_one_node,
1674 }
1676 /* Default to arbitrary scale factors descriptions. */
1677 else
1678 {
1683 {
1684 const tree gnu_num
1687 const tree gnu_den
1692 }
1693 else
1694 /* If compiler internals cannot represent arbitrary scale
1695 factors, output an invalid scale factor so that debugger
1696 don't try to handle them but so that we still have a type
1697 in the output. Note that GNAT */
1699 }
1703 }
1707 {
1708 /* For modular types, make the unsigned type of the proper number
1709 of bits and then set up the modulus, if required. */
1712 /* Packed Array Impl. Types are supposed to be subtypes only. */
1717 /* Get the modulus in this type. If it overflows, assume it is because
1718 it is equal to 2**Esize. Note that there is no overflow checking
1719 done on unsigned type, so we detect the overflow by looking for
1720 a modulus of zero, which is otherwise invalid. */
1724 {
1729 }
1731 /* If the upper bound is not maximal, make an extra subtype. */
1734 {
1741 }
1742 }
1751 /* For integral subtypes, we make a new INTEGER_TYPE. Note that we do
1752 not want to call create_range_type since we would like each subtype
1753 node to be distinct. ??? Historically this was in preparation for
1754 when memory aliasing is implemented, but that's obsolete now given
1755 the call to relate_alias_sets below.
1757 The TREE_TYPE field of the INTEGER_TYPE points to the base type;
1758 this fact is used by the arithmetic conversion functions.
1760 We elaborate the Ancestor_Subtype if it is not in the current unit
1761 and one of our bounds is non-static. We do this to ensure consistent
1762 naming in the case where several subtypes share the same bounds, by
1763 elaborating the first such subtype first, thus using its name. */
1772 /* Set the precision to the Esize except for bit-packed arrays. */
1777 /* First subtypes of Character are treated as Character; otherwise
1778 this should be an unsigned type if the base type is unsigned or
1779 if the lower bound is constant and non-negative or if the type
1780 is biased. However, even if the lower bound is constant and
1781 non-negative, we use a signed type for a subtype with the same
1782 size as its signed base type, because this eliminates useless
1783 conversions to it and gives more leeway to the optimizer; but
1784 this means that we will need to explicitly test for this case
1785 when we change the representation based on the RM size. */
1797 else
1801 SET_TYPE_RM_MIN_VALUE
1804 debug_info_p));
1806 SET_TYPE_RM_MAX_VALUE
1809 debug_info_p));
1814 /* Do the same processing for Character subtypes as for types. */
1816 {
1821 }
1823 /* Inherit our alias set from what we're a subtype of. Subtypes
1824 are not different types and a pointer can designate any instance
1825 within a subtype hierarchy. */
1828 /* One of the above calls might have caused us to be elaborated,
1829 so don't blow up if so. */
1831 {
1834 }
1836 /* Attach the TYPE_STUB_DECL in case we have a parallel type. */
1840 /* For a packed array, make the original array type a parallel/debug
1841 type. */
1845 discrete_type:
1847 /* We have to handle clauses that under-align the type specially. */
1850 && Present
1853 {
1857 }
1859 /* If the type we are dealing with represents a bit-packed array,
1860 we need to have the bits left justified on big-endian targets
1861 and right justified on little-endian targets. We also need to
1862 ensure that when the value is read (e.g. for comparison of two
1863 such values), we only get the good bits, since the unused bits
1864 are uninitialized. Both goals are accomplished by wrapping up
1865 the modular type in an enclosing record type. */
1868 {
1871 /* Set the RM size before wrapping up the original type. */
1876 /* Strip the ___XP suffix for standard DWARF. */
1880 /* Create a stripped-down declaration, mainly for debugging. */
1882 gnat_entity);
1884 /* Now save it and build the enclosing record type. */
1894 /* Propagate the alignment of the modular type to the record type,
1895 unless there is an alignment clause that under-aligns the type.
1896 This means that bit-packed arrays are given "ceil" alignment for
1897 their size by default, which may seem counter-intuitive but makes
1898 it possible to overlay them on modular types easily. */
1902 /* Propagate the reverse storage order flag to the record type so
1903 that the required byte swapping is performed when retrieving the
1904 enclosed modular value. */
1910 /* Don't declare the field as addressable since we won't be taking
1911 its address and this would prevent create_field_decl from making
1912 a bitfield. */
1913 gnu_field
1917 /* We will output additional debug info manually below. */
1923 {
1924 /* Make the original array type a parallel/debug type. */
1927 /* Since GNU_TYPE is a padding type around the packed array
1928 implementation type, the padded type is its debug type. */
1931 }
1932 }
1934 /* If the type we are dealing with has got a smaller alignment than the
1935 natural one, we need to wrap it up in a record type and misalign the
1936 latter; we reuse the padding machinery for this purpose. */
1938 {
1941 /* Set the RM size before wrapping the type. */
1944 gnu_type
1950 }
1955 /* The type of the Low and High bounds can be our type if this is
1956 a type from Standard, so set them at the end of the function. */
1963 /* See the E_Signed_Integer_Subtype case for the rationale. */
1980 SET_TYPE_RM_MIN_VALUE
1983 debug_info_p));
1985 SET_TYPE_RM_MAX_VALUE
1988 debug_info_p));
1990 /* Inherit our alias set from what we're a subtype of, as for
1991 integer subtypes. */
1994 /* One of the above calls might have caused us to be elaborated,
1995 so don't blow up if so. */
1999 /* Array Types and Subtypes
2001 Unconstrained array types are represented by E_Array_Type and
2002 constrained array types are represented by E_Array_Subtype. There
2003 are no actual objects of an unconstrained array type; all we have
2004 are pointers to that type.
2006 The following fields are defined on array types and subtypes:
2008 Component_Type Component type of the array.
2009 Number_Dimensions Number of dimensions (an int).
2010 First_Index Type of first index. */
2013 {
2014 const bool convention_fortran_p
2017 tree gnu_template_type;
2018 tree gnu_ptr_template;
2025 tree comp_type;
2027 /* Create the type for the component now, as it simplifies breaking
2028 type reference loops. */
2029 comp_type
2032 {
2033 /* As a side effect, the type may have been translated. */
2036 }
2038 /* We complete an existing dummy fat pointer type in place. This both
2039 avoids further complex adjustments in update_pointer_to and yields
2040 better debugging information in DWARF by leveraging the support for
2041 incomplete declarations of "tagged" types in the DWARF back-end. */
2044 {
2047 /* Save the contents of the dummy type for update_pointer_to. */
2049 gnu_ptr_template =
2052 }
2053 else
2054 {
2058 }
2060 /* Make a node for the array. If we are not defining the array
2061 suppress expanding incomplete types. */
2065 {
2066 defer_incomplete_level++;
2068 }
2070 /* Build the fat pointer type. Use a "void *" object instead of
2071 a pointer to the array type since we don't have the array type
2072 yet (it will reference the fat pointer via the bounds). */
2073 tem
2081 {
2082 /* We are going to lay it out again so reset the alias set. */
2088 {
2091 }
2092 }
2093 else
2094 {
2097 }
2099 /* Build a reference to the template from a PLACEHOLDER_EXPR that
2100 is the fat pointer. This will be used to access the individual
2101 fields once we build them. */
2105 gnu_template_reference
2110 /* Now create the GCC type for each index and add the fields for that
2111 index to the template. */
2117 {
2120 tree gnu_index_base_type
2125 /* Make the FIELD_DECLs for the low and high bounds of this
2126 type and then make extractions of these fields from the
2127 template. */
2130 gnu_index_base_type,
2138 gnu_index_base_type,
2146 /* We can't use build_component_ref here since the template type
2147 isn't complete yet. */
2150 NULL_TREE);
2153 NULL_TREE);
2159 /* Compute the size of this dimension. See the E_Array_Subtype
2160 case below for the rationale. */
2161 gnu_high
2165 gnu_max,
2168 /* Make a range type with the new range in the Ada base type.
2169 Then make an index type with the size range in sizetype. */
2173 gnu_orig_min,
2174 gnu_orig_max),
2175 gnat_entity);
2177 /* Update the maximum size of the array in elements. */
2179 {
2180 tree gnu_min
2182 tree gnu_max
2184 tree gnu_this_max
2191 else
2192 gnu_max_size
2194 }
2198 }
2200 /* Install all the fields into the template. */
2205 gnu_template_fields
2208 debug_info_p);
2211 /* If Component_Size is not already specified, annotate it with the
2212 size of the component. */
2217 /* Compute the maximum size of the array in units and bits. */
2219 {
2225 }
2226 else
2229 /* Now build the array type. */
2232 {
2240 }
2242 /* If an alignment is specified, use it if valid. But ignore it
2243 for the original type of packed array types. If the alignment
2244 was requested with an explicit alignment clause, state so. */
2247 {
2250 gnat_entity,
2254 }
2256 /* Tag top-level ARRAY_TYPE nodes for packed arrays and their
2257 implementation types as such so that the debug information back-end
2258 can output the appropriate description for them. */
2266 /* Adjust the type of the pointer-to-array field of the fat pointer
2267 and record the aliasing relationships if necessary. */
2272 /* The result type is an UNCONSTRAINED_ARRAY_TYPE that indicates the
2273 corresponding fat pointer. */
2280 /* If the maximum size doesn't overflow, use it. */
2286 {
2291 }
2296 /* If told to generate GNAT encodings for them (GDB rely on them at the
2297 moment): give the fat pointer type a name. If this is a packed
2298 array, tell the debugger how to interpret the underlying bits. */
2301 else
2303 tree xup_name
2308 gnat_entity);
2310 /* Create the type to be designated by thin pointers: a record type for
2311 the array and its template. We used to shift the fields to have the
2312 template at a negative offset, but this was somewhat of a kludge; we
2313 now shift thin pointer values explicitly but only those which have a
2314 TYPE_UNCONSTRAINED_ARRAY attached to the designated RECORD_TYPE.
2315 Note that GDB can handle standard DWARF information for them, so we
2316 don't have to name them as a GNAT encoding, except if specifically
2317 asked to. */
2318 tree xut_name
2323 debug_info_p);
2327 }
2332 /* This is the actual data type for array variables. Multidimensional
2333 arrays are implemented as arrays of arrays. Note that arrays which
2334 have sparse enumeration subtypes as index components create sparse
2335 arrays, which is obviously space inefficient but so much easier to
2336 code for now.
2338 Also note that the subtype never refers to the unconstrained array
2339 type, which is somewhat at variance with Ada semantics.
2341 First check to see if this is simply a renaming of the array type.
2342 If so, the result is the array type. */
2346 ;
2347 else
2348 {
2350 const bool convention_fortran_p
2359 /* First create the GCC type for each index and find out whether
2360 special types are needed for debugging information. */
2363 gnat_base_index
2369 {
2371 tree gnu_index_base_type
2373 tree gnu_orig_min
2376 tree gnu_orig_max
2381 tree gnu_base_index_type
2383 tree gnu_base_index_base_type
2385 tree gnu_base_orig_min
2388 tree gnu_base_orig_max
2391 tree gnu_high;
2393 /* See if the base array type is already flat. If it is, we
2394 are probably compiling an ACATS test but it will cause the
2395 code below to malfunction if we don't handle it specially. */
2399 {
2403 }
2405 /* Similarly, if one of the values overflows in sizetype and the
2406 range is null, use 1..0 for the sizetype bounds. */
2411 {
2415 }
2417 /* If the minimum and maximum values both overflow in sizetype,
2418 but the difference in the original type does not overflow in
2419 sizetype, ignore the overflow indication. */
2423 && !TREE_OVERFLOW
2426 gnu_orig_max,
2427 gnu_orig_min))))
2428 {
2432 }
2434 /* Compute the size of this dimension in the general case. We
2435 need to provide GCC with an upper bound to use but have to
2436 deal with the "superflat" case. There are three ways to do
2437 this. If we can prove that the array can never be superflat,
2438 we can just use the high bound of the index type. */
2441 /* Bit-Packed Array Impl. Types are never superflat. */
2443 && Is_Bit_Packed_Array
2447 /* Otherwise, if the high bound is constant but the low bound is
2448 not, we use the expression (hb >= lb) ? lb : hb + 1 for the
2449 lower bound. Note that the comparison must be done in the
2450 original type to avoid any overflow during the conversion. */
2453 {
2455 gnu_min
2458 boolean_type_node,
2459 gnu_orig_max,
2460 gnu_orig_min),
2461 gnu_min,
2463 size_one_node));
2464 }
2466 /* Finally we use (hb >= lb) ? hb : lb - 1 for the upper bound
2467 in all the other cases. Note that, here as well as above,
2468 the condition used in the comparison must be equivalent to
2469 the condition (length != 0). This is relied upon in order
2470 to optimize array comparisons in compare_arrays. Moreover
2471 we use int_const_binop for the shift by 1 if the bound is
2472 constant to avoid any unwanted overflow. */
2473 else
2474 gnu_high
2477 boolean_type_node,
2478 gnu_orig_max,
2479 gnu_orig_min),
2480 gnu_max,
2483 size_one_node)
2485 size_one_node));
2487 /* Reuse the index type for the range type. Then make an index
2488 type with the size range in sizetype. */
2491 gnat_entity);
2493 /* Update the maximum size of the array in elements. Here we
2494 see if any constraint on the index type of the base type
2495 can be used in the case of self-referential bound on the
2496 index type of the subtype. We look for a non-"infinite"
2497 and non-self-referential bound from any type involved and
2498 handle each bound separately. */
2500 {
2503 tree gnu_base_base_min
2506 tree gnu_base_base_max
2527 else
2528 {
2529 tree gnu_this_max;
2531 /* Use int_const_binop if the bounds are constant to
2532 avoid any unwanted overflow. */
2535 gnu_this_max
2538 gnu_base_max,
2539 gnu_base_min));
2540 else
2541 gnu_this_max
2544 gnu_base_max,
2545 gnu_base_min));
2547 gnu_max_size
2549 }
2550 }
2552 /* We need special types for debugging information to point to
2553 the index types if they have variable bounds, are not integer
2554 types, are biased or are wider than sizetype. These are GNAT
2555 encodings, so we have to include them only when all encodings
2556 are requested. */
2566 }
2568 /* Then flatten: create the array of arrays. For an array type
2569 used to implement a packed array, get the component type from
2570 the original array type since the representation clauses that
2571 can affect it are on the latter. */
2574 {
2579 /* One of the above calls might have caused us to be elaborated,
2580 so don't blow up if so. */
2582 {
2585 }
2586 }
2587 else
2588 {
2590 debug_info_p);
2592 /* One of the above calls might have caused us to be elaborated,
2593 so don't blow up if so. */
2595 {
2598 }
2599 }
2601 /* Compute the maximum size of the array in units and bits. */
2603 {
2609 }
2610 else
2613 /* Now build the array type. */
2615 {
2624 }
2626 /* Strip the ___XP suffix for standard DWARF. */
2629 {
2630 Entity_Id gnat_original_array_type
2633 gnu_entity_name
2635 }
2637 /* Attach the TYPE_STUB_DECL in case we have a parallel type. */
2641 /* If this is a multi-dimensional array and we are at global level,
2642 we need to make a variable corresponding to the stride of the
2643 inner dimensions. */
2645 {
2646 tree gnu_arr_type;
2651 {
2661 /* ??? For now, store the size as a multiple of the
2662 alignment of the element type in bytes so that we
2663 can see the alignment from the tree. */
2671 /* ??? create_type_decl is not invoked on the inner types so
2672 the MULT_EXPR node built above will never be marked. */
2674 }
2675 }
2677 /* If we need to write out a record type giving the names of the
2678 bounds for debugging purposes, do it now and make the record
2679 type a parallel type. This is not needed for a packed array
2680 since the bounds are conveyed by the original array type. */
2682 && debug_info_p
2684 {
2687 tree gnu_field;
2693 {
2697 /* Make sure to reference the types themselves, and not just
2698 their names, as the debugger may fall back on them. */
2704 }
2708 }
2710 /* If this is a packed array type, make the original array type a
2711 parallel/debug type. Otherwise, if such GNAT encodings are
2712 required, do it for the base array type if it isn't artificial to
2713 make sure it is kept in the debug info. */
2715 {
2718 gnat_entity);
2719 else
2720 {
2721 tree gnu_base_decl
2728 }
2729 }
2735 /* Tag top-level ARRAY_TYPE nodes for packed arrays and their
2736 implementation types as such so that the debug information back-end
2737 can output the appropriate description for them. */
2742 /* If the size is self-referential and the maximum size doesn't
2743 overflow, use it. */
2745 && gnu_max_size
2750 {
2756 }
2758 /* Set our alias set to that of our base type. This gives all
2759 array subtypes the same alias set. */
2762 /* If this is a packed type, make this type the same as the packed
2763 array type, but do some adjusting in the type first. */
2765 {
2766 Entity_Id gnat_index;
2767 tree gnu_inner;
2769 /* First finish the type we had been making so that we output
2770 debugging information for it. */
2773 {
2774 const int quals
2775 = TYPE_QUAL_VOLATILE
2778 }
2779 /* Make it artificial only if the base type was artificial too.
2780 That's sort of "morally" true and will make it possible for
2781 the debugger to look it up by name in DWARF, which is needed
2782 in order to decode the packed array type. */
2783 gnu_decl
2787 gnat_entity);
2789 /* Save it as our equivalent in case the call below elaborates
2790 this type again. */
2793 gnu_decl
2808 /* We need to attach the index type to the type we just made so
2809 that the actual bounds can later be put into a template. */
2814 {
2816 {
2817 /* The TYPE_ACTUAL_BOUNDS field is overloaded with the
2818 TYPE_MODULUS for modular types so we make an extra
2819 subtype if necessary. */
2821 {
2822 tree gnu_subtype
2831 }
2835 /* Check for other cases of overloading. */
2837 }
2842 SET_TYPE_ACTUAL_BOUNDS
2849 SET_TYPE_ACTUAL_BOUNDS
2855 }
2856 }
2857 }
2861 /* Create the type for a string literal. */
2862 {
2863 Entity_Id gnat_full_type
2868 tree gnu_string_array_type
2870 tree gnu_string_index_type
2873 tree gnu_lower_bound
2876 tree gnu_length
2878 gnu_string_index_type);
2879 tree gnu_upper_bound
2881 gnu_lower_bound,
2884 integer_one_node)));
2885 tree gnu_index_type
2889 gnu_lower_bound,
2890 gnu_upper_bound),
2891 gnat_entity);
2893 gnu_type
2896 gnu_index_type);
2900 }
2903 /* Record Types and Subtypes
2905 The following fields are defined on record types:
2907 Has_Discriminants True if the record has discriminants
2908 First_Discriminant Points to head of list of discriminants
2909 First_Entity Points to head of list of fields
2910 Is_Tagged_Type True if the record is tagged
2912 Implementation of Ada records and discriminated records:
2914 A record type definition is transformed into the equivalent of a C
2915 struct definition. The fields that are the discriminants which are
2916 found in the Full_Type_Declaration node and the elements of the
2917 Component_List found in the Record_Type_Definition node. The
2918 Component_List can be a recursive structure since each Variant of
2919 the Variant_Part of the Component_List has a Component_List.
2921 Processing of a record type definition comprises starting the list of
2922 field declarations here from the discriminants and the calling the
2923 function components_to_record to add the rest of the fields from the
2924 component list and return the gnu type node. The function
2925 components_to_record will call itself recursively as it traverses
2926 the tree. */
2930 {
2931 gnu_type
2932 = build_complex_type
2933 (get_unpadded_type
2936 (Component_List
2937 (Type_Definition
2941 }
2943 {
2946 Node_Id gnat_constr;
2949 tree gnu_get_parent;
2950 /* Set PACKED in keeping with gnat_to_gnu_field. */
2951 const int packed
2960 const bool is_extension
2966 /* See if all fields have a rep clause. Stop when we find one
2967 that doesn't. */
2975 {
2978 }
2980 /* If this is a record extension, go a level further to find the
2981 record definition. Also, verify we have a Parent_Subtype. */
2983 {
2990 }
2992 /* Make a node for the record. If we are not defining the record,
2993 suppress expanding incomplete types. */
3002 {
3003 defer_incomplete_level++;
3005 }
3007 /* If both a size and rep clause were specified, put the size on
3008 the record type now so that it can get the proper layout. */
3013 /* Always set the alignment on the record type here so that it can
3014 get the proper layout. */
3019 else
3020 {
3023 /* If a type needs strict alignment, the minimum size will be the
3024 type size instead of the RM size (see validate_size). Cap the
3025 alignment lest it causes this type size to become too large. */
3027 {
3032 }
3033 }
3035 /* If we have a Parent_Subtype, make a field for the parent. If
3036 this record has rep clauses, force the position to zero. */
3038 {
3041 tree gnu_parent;
3044 /* A major complexity here is that the parent subtype will
3045 reference our discriminants in its Stored_Constraint list.
3046 But those must reference the parent component of this record
3047 which is precisely of the parent subtype we have not built yet!
3048 To break the circle we first build a dummy COMPONENT_REF which
3049 represents the "get to the parent" operation and initialize
3050 each of those discriminants to a COMPONENT_REF of the above
3051 dummy parent referencing the corresponding discriminant of the
3052 base type of the parent subtype. */
3057 gnu_dummy_parent_type),
3058 NULL_TREE);
3065 {
3066 tree gnu_field
3069 save_gnu_tree
3074 }
3076 /* Then we build the parent subtype. If it has discriminants but
3077 the type itself has unknown discriminants, this means that it
3078 doesn't contain information about how the discriminants are
3079 derived from those of the ancestor type, so it cannot be used
3080 directly. Instead it is built by cloning the parent subtype
3081 of the underlying record view of the type, for which the above
3082 derivation of discriminants has been made explicit. */
3085 {
3088 /* If we are defining the type, the underlying record
3089 view must already have been elaborated at this point.
3090 Otherwise do it now as its parent subtype cannot be
3091 technically elaborated on its own. */
3094 else
3099 /* Substitute the "get to the parent" of the type for that
3100 of its underlying record view in the cloned type. */
3105 {
3107 tree gnu_ref
3110 gnu_parent
3112 }
3113 }
3114 else
3117 /* The parent field needs strict alignment so, if it is to
3118 be created with a component clause below, then we need
3119 to apply the same adjustment as in gnat_to_gnu_field. */
3121 {
3122 /* ??? For historical reasons, we do it on strict-alignment
3123 platforms only, where it is really required. This means
3124 that a confirming representation clause will change the
3125 behavior of the compiler on the other platforms. */
3128 else
3129 parent_packed
3131 }
3133 /* Finally we fix up both kinds of twisted COMPONENT_REF we have
3134 initially built. The discriminants must reference the fields
3135 of the parent subtype and not those of its base type for the
3136 placeholder machinery to properly work. */
3138 {
3139 /* The actual parent subtype is the full view. */
3141 {
3144 else
3146 }
3152 {
3153 Entity_Id field;
3162 }
3163 }
3165 /* The "get to the parent" COMPONENT_REF must be given its
3166 proper type... */
3169 /* ...and reference the _Parent field of this record. */
3170 gnu_field
3173 has_rep
3175 has_rep
3181 }
3183 /* Make the fields for the discriminants and put them into the record
3184 unless it's an Unchecked_Union. */
3189 {
3190 /* If this is a record extension and this discriminant is the
3191 renaming of another discriminant, we've handled it above. */
3196 gnu_field
3198 debug_info_p);
3200 /* Make an expression using a PLACEHOLDER_EXPR from the
3201 FIELD_DECL node just created and link that with the
3202 corresponding GNAT defining identifier. */
3210 {
3213 }
3214 }
3216 /* If we have a derived untagged type that renames discriminants in
3217 the parent type, the (stored) discriminants are just a copy of the
3218 discriminants of the parent type. This means that any constraints
3219 added by the renaming in the derivation are disregarded as far as
3220 the layout of the derived type is concerned. To rescue them, we
3221 change the type of the (stored) discriminants to a subtype with
3222 the bounds of the type of the visible discriminants. */
3224 && !is_extension
3230 /* Ignore access discriminants. */
3233 {
3236 tree gnu_ref
3240 /* GNU_REF must be an expression using a PLACEHOLDER_EXPR built
3241 just above for one of the stored discriminants. */
3245 {
3247 tree gnu_subtype
3258 }
3259 }
3261 /* If this is a derived type with discriminants and these discriminants
3262 affect the initial shape it has inherited, factor them in. */
3264 && !is_extension
3272 {
3273 tree gnu_parent_type
3282 /* Set the layout of the type to match that of the parent type,
3283 doing required substitutions. If we are in minimal GNAT
3284 encodings mode, we don't need debug info for the inner record
3285 types, as they will be part of the embedding variant record's
3286 debug info. */
3287 copy_and_substitute_in_layout
3289 gnu_subst_list,
3291 }
3292 else
3293 {
3294 /* Add the fields into the record type and finish it up. */
3301 NULL);
3303 /* If there are entities in the chain corresponding to components
3304 that we did not elaborate, ensure we elaborate their types if
3305 they are Itypes. */
3314 }
3316 /* Fill in locations of fields. */
3319 /* If this is a record type associated with an exception definition,
3320 equate its fields to those of the standard exception type. This
3321 will make it possible to convert between them. */
3323 {
3324 tree gnu_std_field;
3327 gnu_field;
3332 }
3333 }
3337 /* If an equivalent type is present, that is what we should use.
3338 Otherwise, fall through to handle this like a record subtype
3339 since it may have constraints. */
3341 {
3345 }
3347 /* ... fall through ... */
3350 /* If Cloned_Subtype is Present it means this record subtype has
3351 identical layout to that type or subtype and we should use
3352 that GCC type for this one. The front end guarantees that
3353 the component list is shared. */
3355 {
3360 }
3362 /* Otherwise, first ensure the base type is elaborated. Then, if we are
3363 changing the type, make a new type with each field having the type of
3364 the field in the new subtype but the position computed by transforming
3365 every discriminant reference according to the constraints. We don't
3366 see any difference between private and non-private type here since
3367 derivations from types should have been deferred until the completion
3368 of the private type. */
3369 else
3370 {
3374 {
3375 defer_incomplete_level++;
3377 }
3379 tree gnu_base_type
3383 {
3386 }
3388 /* If this is a record subtype associated with a dispatch table,
3389 strip the suffix. This is necessary to make sure 2 different
3390 subtypes associated with the imported and exported views of a
3391 dispatch table are properly merged in LTO mode. */
3393 {
3400 }
3402 /* When the subtype has discriminants and these discriminants affect
3403 the initial shape it has inherited, factor them in. But for an
3404 Unchecked_Union (it must be an Itype), just return the type. */
3410 {
3413 tree gnu_unpad_base_type;
3418 {
3419 /* Use the ultimate base record type as the debug type.
3420 Subtypes and derived types bring no useful
3421 information. */
3425 tree gnu_debug_type
3428 }
3434 /* Set the size, alignment and alias set of the type to match
3435 those of the base type, doing required substitutions. */
3437 gnu_subst_list);
3441 else
3444 /* Set the layout of the type to match that of the base type,
3445 doing required substitutions. We will output debug info
3446 manually below so pass false as last argument. */
3451 /* Fill in locations of fields. */
3454 /* If debugging information is being written for the type and if
3455 we are asked to output such encodings, write a record that
3456 shows what we are a subtype of and also make a variable that
3457 indicates our size, if still variable. */
3459 {
3461 tree gnu_unpad_base_name
3469 build_reference_type
3471 gnu_subtype_marker,
3488 }
3489 }
3491 /* Otherwise, go down all the components in the new type and make
3492 them equivalent to those in the base type. */
3493 else
3494 {
3504 gnat_to_gnu_field_decl
3507 }
3508 }
3513 /* Use the special descriptor type for dispatch tables if needed,
3514 that is to say for the Prim_Ptr of a-tags.ads and its clones.
3515 Note that we are only required to do so for static tables in
3516 order to be compatible with the C++ ABI, but Ada 2005 allows
3517 to extend library level tagged types at the local level so
3518 we do it in the non-static case as well. */
3521 {
3525 }
3527 /* ... fall through ... */
3534 {
3535 /* The designated type and its equivalent type for gigi. */
3538 /* Whether it comes from a limited with. */
3539 const bool is_from_limited_with
3542 /* Whether it is a completed Taft Amendment type. Such a type is to
3543 be treated as coming from a limited with clause if it is not in
3544 the main unit, i.e. we break potential circularities here in case
3545 the body of an external unit is loaded for inter-unit inlining. */
3546 const bool is_completed_taft_type
3550 /* The "full view" of the designated type. If this is an incomplete
3551 entity from a limited with, treat its non-limited view as the full
3552 view. Otherwise, if this is an incomplete or private type, use the
3553 full view. In the former case, we might point to a private type,
3554 in which case, we need its full view. Also, we want to look at the
3555 actual type used for the representation, so this takes a total of
3556 three steps. */
3557 Entity_Id gnat_desig_full_direct_first
3558 = (is_from_limited_with
3562 Entity_Id gnat_desig_full_direct
3563 = ((is_from_limited_with
3568 Entity_Id gnat_desig_full
3570 /* The type actually used to represent the designated type, either
3571 gnat_desig_full or gnat_desig_equiv. */
3572 Entity_Id gnat_desig_rep;
3573 /* We want to know if we'll be seeing the freeze node for any
3574 incomplete type we may be pointing to. */
3575 const bool in_main_unit
3579 /* True if we make a dummy type here. */
3581 /* The mode to be used for the pointer type. */
3582 scalar_int_mode p_mode;
3583 /* The GCC type used for the designated type. */
3590 /* If either the designated type or its full view is an unconstrained
3591 array subtype, replace it with the type it's a subtype of. This
3592 avoids problems with multiple copies of unconstrained array types.
3593 Likewise, if the designated type is a subtype of an incomplete
3594 record type, use the parent type to avoid order of elaboration
3595 issues. This can lose some code efficiency, but there is no
3596 alternative. */
3607 /* Set the type that's the representation of the designated type. */
3608 gnat_desig_rep
3611 /* If we already know what the full type is, use it. */
3615 /* Get the type of the thing we are to point to and build a pointer to
3616 it. If it is a reference to an incomplete or private type with a
3617 full view that is a record, an array or an access, make a dummy type
3618 and get the actual type later when we have verified it is safe. */
3625 /* Likewise if this is a reference to a record, an array or a
3626 subprogram type and we are to defer elaborating incomplete
3627 types. We do this because this access type may be the full
3628 view of a private type. */
3635 /* If this is a reference from a limited_with type back to our
3636 main unit and there's a freeze node for it, either we have
3637 already processed the declaration and made the dummy type,
3638 in which case we just reuse the latter, or we have not yet,
3639 in which case we make the dummy type and it will be reused
3640 when the declaration is finally processed. In both cases,
3641 the pointer eventually created below will be automatically
3642 adjusted when the freeze node is processed. */
3643 || (in_main_unit
3644 && is_from_limited_with
3646 {
3649 }
3651 /* Otherwise handle the case of a pointer to itself. */
3653 {
3654 gnu_type
3658 }
3660 /* If expansion is disabled, the equivalent type of a concurrent type
3661 is absent, so we use the void pointer type. */
3665 /* If the ultimately designated type is an incomplete type with no full
3666 view, we use the void pointer type in LTO mode to avoid emitting a
3667 dummy type in the GIMPLE IR. We cannot do that in regular mode as
3668 the name of the dummy type in used by GDB for a global lookup. */
3674 /* Finally, handle the default case where we can just elaborate our
3675 designated type. */
3676 else
3679 /* It is possible that a call to gnat_to_gnu_type above resolved our
3680 type. If so, just return it. */
3682 {
3685 }
3687 /* Access-to-unconstrained-array types need a special treatment. */
3689 {
3690 /* If the processing above got something that has a pointer, then
3691 we are done. This could have happened either because the type
3692 was elaborated or because somebody else executed the code. */
3697 }
3699 /* If we haven't done it yet, build the pointer type the usual way. */
3701 {
3702 /* Modify the designated type if we are pointing only to constant
3703 objects, but don't do it for a dummy type. */
3706 gnu_desig_type
3709 gnu_type
3712 }
3714 /* If the designated type is not declared in the main unit and we made
3715 a dummy node for it, save our definition, elaborate the actual type
3716 and replace the dummy type we made with the actual one. But if we
3717 are to defer actually looking up the actual type, make an entry in
3718 the deferred list instead. If this is from a limited with, we may
3719 have to defer until the end of the current unit. */
3721 {
3723 gnu_type
3729 gnat_entity);
3736 && !is_from_limited_with
3738 {
3741 }
3742 else
3743 {
3753 }
3754 }
3755 }
3760 /* If we are just annotating types and have no equivalent record type,
3761 just use the void pointer type. */
3765 /* The run-time representation is the equivalent type. */
3766 else
3767 {
3770 }
3772 /* The designated subtype must be elaborated as well, if it does
3773 not have its own freeze node. */
3784 /* We treat this as identical to its base type; any constraint is
3785 meaningful only to the front-end. */
3789 /* The designated subtype must be elaborated as well, if it does
3790 not have its own freeze node. But designated subtypes created
3791 for constrained components of records with discriminants are
3792 not frozen by the front-end and not elaborated here, because
3793 their use may appear before the base type is frozen and it is
3794 not clear that they are needed in gigi. With the current model,
3795 there is no correct place where they could be elaborated. */
3800 {
3801 /* If we are to defer elaborating incomplete types, make a dummy
3802 type node and elaborate it later. */
3804 {
3807 p->old_type
3812 }
3817 }
3820 /* Subprogram Entities
3822 The following access functions are defined for subprograms:
3824 Etype Return type or Standard_Void_Type.
3825 First_Formal The first formal parameter.
3826 Is_Imported Indicates that the subprogram has appeared in
3827 an INTERFACE or IMPORT pragma. For now we
3828 assume that the external language is C.
3829 Is_Exported Likewise but for an EXPORT pragma.
3830 Is_Inlined True if the subprogram is to be inlined.
3832 Each parameter is first checked by calling must_pass_by_ref on its
3833 type to determine if it is passed by reference. For parameters which
3834 are copied in, if they are Ada In Out or Out parameters, their return
3835 value becomes part of a record which becomes the return type of the
3836 function (C function - note that this applies only to Ada procedures
3837 so there is no Ada return type). Additional code to store back the
3838 parameters will be generated on the caller side. This transformation
3839 is done here, not in the front-end.
3841 The intended result of the transformation can be seen from the
3842 equivalent source rewritings that follow:
3844 struct temp {int a,b};
3845 procedure P (A,B: In Out ...) is temp P (int A,B)
3846 begin {
3847 .. ..
3848 end P; return {A,B};
3849 }
3851 temp t;
3852 P(X,Y); t = P(X,Y);
3853 X = t.a , Y = t.b;
3855 For subprogram types we need to perform mainly the same conversions to
3856 GCC form that are needed for procedures and function declarations. The
3857 only difference is that at the end, we make a type declaration instead
3858 of a function declaration. */
3863 {
3864 tree gnu_ext_name
3866 enum inline_status_t inline_status
3868 ? is_suppressed
3870 ? is_required
3873 /* Subprograms marked both Intrinsic and Always_Inline need not
3874 have a body of their own. */
3875 bool extern_flag
3877 || imported_p
3880 tree gnu_param_list;
3882 /* A parameter may refer to this type, so defer completion of any
3883 incomplete types. */
3885 {
3886 defer_incomplete_level++;
3888 }
3890 /* If the subprogram has an alias, it is probably inherited, so
3891 we can use the original one. If the original "subprogram"
3892 is actually an enumeration literal, it may be the first use
3893 of its type, so we must elaborate that type now. */
3895 {
3902 gnu_decl
3905 /* Elaborate any Itypes in the parameters of this entity. */
3912 /* Materialize renamed subprograms in the debugging information
3913 when the renamed object is compile time known. We can consider
3914 such renamings as imported declarations.
3916 Because the parameters in generics instantiation are generally
3917 materialized as renamings, we ofter end up having both the
3918 renamed subprogram and the renaming in the same context and with
3919 the same name: in this case, renaming is both useless debug-wise
3920 and potentially harmful as name resolution in the debugger could
3921 return twice the same entity! So avoid this case. */
3930 && gnu_decl
3932 {
3937 }
3940 }
3942 /* Get the GCC tree for the (underlying) subprogram type. If the
3943 entity is an actual subprogram, also get the parameter list. */
3944 gnu_type
3948 {
3952 }
3954 /* Deal with platform-specific calling conventions. */
3956 prepend_one_attribute
3959 gnat_entity);
3961 prepend_one_attribute
3964 gnat_entity);
3966 /* If we should request stack realignment for a foreign convention
3967 subprogram, do so. Note that this applies to task entry points
3968 in particular. */
3971 prepend_one_attribute
3974 gnat_entity);
3976 /* Deal with a pragma Linker_Section on a subprogram. */
3982 /* If we are defining the subprogram and it has an Address clause
3983 we must get the address expression from the saved GCC tree for the
3984 subprogram if it has a Freeze_Node. Otherwise, we elaborate
3985 the address expression here since the front-end has guaranteed
3986 in that case that the elaboration has no effects. If there is
3987 an Address clause and we are not defining the object, just
3988 make it a constant. */
3990 {
3994 gnu_address
4001 /* Convert the type of the object to a reference type that can
4002 alias everything as per RM 13.3(19). */
4003 gnu_type
4008 gnu_decl
4014 }
4016 /* If this is a mere subprogram type, just create the declaration. */
4018 {
4021 gnu_decl
4024 }
4026 /* Otherwise create the subprogram declaration with the external name,
4027 the type and the parameter list. However, if this a reference to
4028 the allocation routines, reuse the canonical declaration nodes as
4029 they come with special properties. */
4030 else
4031 {
4036 else
4037 {
4038 gnu_decl
4043 debug_info_p,
4045 gnat_entity);
4049 }
4050 }
4051 }
4062 {
4063 const bool is_from_limited_with
4065 /* Get the "full view" of this entity. If this is an incomplete
4066 entity from a limited with, treat its non-limited view as the
4067 full view. Otherwise, use either the full view or the underlying
4068 full view, whichever is present. This is used in all the tests
4069 below. */
4070 const Entity_Id full_view
4071 = is_from_limited_with
4079 /* If this is an incomplete type with no full view, it must be a Taft
4080 Amendment type or an incomplete type coming from a limited context,
4081 in which cases we return a dummy type. Otherwise, we just get the
4082 type from its Etype. */
4084 {
4086 {
4089 }
4090 else
4091 {
4092 gnu_decl
4095 }
4096 }
4098 /* Or else, if we already made a type for the full view, reuse it. */
4102 /* Or else, if we are not defining the type or there is no freeze
4103 node on it, get the type for the full view. Likewise if this is
4104 a limited_with'ed type not declared in the main unit, which can
4105 happen for incomplete formal types instantiated on a type coming
4106 from a limited_with clause. */
4109 || (is_from_limited_with
4111 {
4114 }
4116 /* Otherwise, make a dummy type entry which will be replaced later.
4117 Save it as the full declaration's type so we can do any needed
4118 updates when we see it. */
4119 else
4120 {
4126 }
4127 }
4131 /* Class-wide types are always transformed into their root type. */
4140 /* If we are just annotating types and have no equivalent record type,
4141 just return void_type, except for root types that have discriminants
4142 because the discriminants will very likely be used in the declarative
4143 part of the associated body so they need to be translated. */
4145 {
4148 {
4150 Entity_Id gnat_field;
4152 /* This is a minimal version of the E_Record_Type handling. */
4159 {
4160 tree gnu_field
4172 }
4176 }
4177 else
4179 }
4181 /* Concurrent types are always transformed into their record type. */
4182 else
4193 /* Nothing at all to do here, so just return an ERROR_MARK and claim
4194 we've already saved it, so we don't try to. */
4200 /* This is a SPARK annotation that only reaches here when compiling in
4201 ASIS mode. */
4209 }
4211 /* If we had a case where we evaluated another type and it might have
4212 defined this one, handle it here. */
4214 {
4217 }
4219 /* If we are processing a type and there is either no decl for it or
4220 we just made one, do some common processing for the type, such as
4221 handling alignment and possible padding. */
4223 {
4226 /* Process the attributes, if not already done. Note that the type is
4227 already defined so we cannot pass true for IN_PLACE here. */
4230 /* ??? Don't set the size for a String_Literal since it is either
4231 confirming or we don't handle it properly (if the low bound is
4232 non-constant). */
4234 {
4237 gnu_size
4240 }
4242 /* If a size was specified, see if we can make a new type of that size
4243 by rearranging the type, for example from a fat to a thin pointer. */
4245 {
4246 gnu_type
4253 }
4255 /* If the alignment has not already been processed and this is not
4256 an unconstrained array type, see if an alignment is specified.
4257 If not, we pick a default alignment for atomic objects. */
4259 ;
4261 {
4265 /* Warn on suspiciously large alignments. This should catch
4266 errors about the (alignment,byte)/(size,bit) discrepancy. */
4268 {
4269 tree size;
4271 /* If a size was specified, take it into account. Otherwise
4272 use the RM size for records or unions as the type size has
4273 already been adjusted to the alignment. */
4279 else
4282 /* Consider an alignment as suspicious if the alignment/size
4283 ratio is greater or equal to the byte/bit ratio. */
4288 gnat_entity);
4289 }
4290 }
4301 /* See if we need to pad the type. If we did, and made a record,
4302 the name of the new type may be changed. So get it back for
4303 us when we make the new TYPE_DECL below. */
4311 /* Now set the RM size of the type. We cannot do it before padding
4312 because we need to accept arbitrary RM sizes on integral types. */
4315 /* If we are at global level, GCC will have applied variable_size to
4316 the type, but that won't have done anything. So, if it's not
4317 a constant or self-referential, call elaborate_expression_1 to
4318 make a variable for the size rather than calculating it each time.
4319 Handle both the RM size and the actual size. */
4324 {
4331 /* ??? For now, store the size as a multiple of the alignment in
4332 bytes so that we can see the alignment from the tree. */
4338 /* ??? gnu_type may come from an existing type so the MULT_EXPR node
4339 may not be marked by the call to create_type_decl below. */
4343 {
4348 {
4352 /* If the position of the variant part is constant, subtract
4353 it from the size of the type of the parent to get the new
4354 size. This manual CSE reduces the data size. */
4356 {
4364 }
4365 else
4366 {
4372 /* ??? For now, store the size as a multiple of the
4373 alignment in bytes so that we can see the alignment
4374 from the tree. */
4381 /* ??? For now, store the offset as a multiple of the
4382 alignment in bytes so that we can see the alignment
4383 from the tree. */
4387 DECL_OFFSET_ALIGN
4389 }
4393 }
4397 else
4398 ada_size
4402 }
4403 }
4405 /* Similarly, if this is a record type or subtype at global level, call
4406 elaborate_expression_2 on any field position. Skip any fields that
4407 we haven't made trees for to avoid problems with class-wide types. */
4412 {
4415 /* ??? For now, store the offset as a multiple of the alignment
4416 in bytes so that we can see the alignment from the tree. */
4419 {
4426 /* ??? The context of gnu_field is not necessarily gnu_type
4427 so the MULT_EXPR node built above may not be marked by
4428 the call to create_type_decl below. */
4430 }
4431 }
4436 /* If this is not an unconstrained array type, set some flags. */
4438 {
4439 /* Tell the middle-end that objects of tagged types are guaranteed to
4440 be properly aligned. This is necessary because conversions to the
4441 class-wide type are translated into conversions to the root type,
4442 which can be less aligned than some of its derived types. */
4447 /* Record whether the type is passed by reference. */
4451 /* Record whether an alignment clause was specified. */
4455 /* Record whether a pragma Universal_Aliasing was specified. */
4459 /* If it is passed by reference, force BLKmode to ensure that
4460 objects of this type will always be put in memory. */
4463 }
4465 /* If this is a derived type, relate its alias set to that of its parent
4466 to avoid troubles when a call to an inherited primitive is inlined in
4467 a context where a derived object is accessed. The inlined code works
4468 on the parent view so the resulting code may access the same object
4469 using both the parent and the derived alias sets, which thus have to
4470 conflict. As the same issue arises with component references, the
4471 parent alias set also has to conflict with composite types enclosing
4472 derived components. For instance, if we have:
4474 type D is new T;
4475 type R is record
4476 Component : D;
4477 end record;
4479 we want T to conflict with both D and R, in addition to R being a
4480 superset of D by record/component construction.
4482 One way to achieve this is to perform an alias set copy from the
4483 parent to the derived type. This is not quite appropriate, though,
4484 as we don't want separate derived types to conflict with each other:
4486 type I1 is new Integer;
4487 type I2 is new Integer;
4489 We want I1 and I2 to both conflict with Integer but we do not want
4490 I1 to conflict with I2, and an alias set copy on derivation would
4491 have that effect.
4493 The option chosen is to make the alias set of the derived type a
4494 superset of that of its parent type. It trivially fulfills the
4495 simple requirement for the Integer derivation example above, and
4496 the component case as well by superset transitivity:
4498 superset superset
4499 R ----------> D ----------> T
4501 However, for composite types, conversions between derived types are
4502 translated into VIEW_CONVERT_EXPRs so a sequence like:
4504 type Comp1 is new Comp;
4505 type Comp2 is new Comp;
4506 procedure Proc (C : Comp1);
4508 C : Comp2;
4509 Proc (Comp1 (C));
4511 is translated into:
4513 C : Comp2;
4514 Proc ((Comp1 &) &VIEW_CONVERT_EXPR <Comp1> (C));
4516 and gimplified into:
4518 C : Comp2;
4519 Comp1 *C.0;
4520 C.0 = (Comp1 *) &C;
4521 Proc (C.0);
4523 i.e. generates code involving type punning. Therefore, Comp1 needs
4524 to conflict with Comp2 and an alias set copy is required.
4526 The language rules ensure the parent type is already frozen here. */
4530 {
4532 /* For constrained packed array subtypes, the implementation type is
4533 used instead of the nominal type. */
4541 }
4543 /* Finally get to the appropriate variant, except for the implementation
4544 type of a packed array because the GNU type might be further adjusted
4545 when the original array type is itself processed. */
4548 {
4549 const int quals
4550 = TYPE_QUAL_VOLATILE
4553 }
4555 /* If we already made a decl, just set the type, otherwise create it. */
4557 {
4560 }
4561 else
4564 }
4566 /* If we got a type that is not dummy, back-annotate the alignment of the
4567 type if not already in the tree. Likewise for the size, if any. */
4569 {
4573 {
4577 /* If the default alignment of "double" or larger scalar types is
4578 specifically capped and this is not an array with an alignment
4579 clause on the component type, return the cap. */
4581 is_capped_double
4584 is_capped_double
4586 else
4591 else
4595 }
4598 {
4601 /* If the size is self-referential, annotate the maximum value. */
4605 /* If we are just annotating types and the type is tagged, the tag
4606 and the parent components are not generated by the front-end so
4607 alignment and sizes must be adjusted if there is no rep clause. */
4614 {
4615 tree offset;
4618 {
4622 }
4623 else
4624 {
4625 unsigned int align
4629 }
4632 offset
4640 }
4642 /* If there is a rep clause, only adjust alignment and Esize. */
4644 {
4645 unsigned int align
4650 }
4652 /* Otherwise no adjustment is needed. */
4653 else
4655 }
4659 }
4661 /* If we haven't already, associate the ..._DECL node that we just made with
4662 the input GNAT entity node. */
4666 /* Now we are sure gnat_entity has a corresponding ..._DECL node,
4667 eliminate as many deferred computations as possible. */
4670 /* If this is an enumeration or floating-point type, we were not able to set
4671 the bounds since they refer to the type. These are always static. */
4674 {
4678 /* If this is a padded type, we need to use the underlying type. */
4682 /* If this is a floating point type and we haven't set a floating
4683 point type yet, use this in the evaluation of the bounds. */
4691 {
4692 /* Enumeration types have specific RM bounds. */
4695 }
4696 else
4697 {
4698 /* Floating-point types don't have specific RM bounds. */
4701 }
4702 }
4704 /* If we deferred processing of incomplete types, re-enable it. If there
4705 were no other disables and we have deferred types to process, do so. */
4709 {
4712 /* We are back to level 0 for the deferring of incomplete types.
4713 But processing these incomplete types below may itself require
4714 deferring, so preserve what we have and restart from scratch. */
4719 {
4726 }
4727 }
4729 /* If we are not defining this type, see if it's on one of the lists of
4730 incomplete types. If so, handle the list entry now. */
4732 {
4737 {
4741 }
4747 {
4753 }
4754 }
4757 force_global--;
4759 /* If this is a packed array type whose original array type is itself
4760 an Itype without freeze node, make sure the latter is processed. */
4768 }
4770 /* Similar, but if the returned value is a COMPONENT_REF, return the
4771 FIELD_DECL. */
4773 tree
4775 {
4782 }
4784 /* Similar, but GNAT_ENTITY is assumed to refer to a GNAT type. Return
4785 the GCC type corresponding to that entity. */
4787 tree
4789 {
4790 tree gnu_decl;
4792 /* The back end never attempts to annotate generic types. */
4800 }
4802 /* Similar, but GNAT_ENTITY is assumed to refer to a GNAT type. Return
4803 the unpadded version of the GCC type corresponding to that entity. */
4805 tree
4807 {
4814 }
4816 /* Return whether the E_Subprogram_Type/E_Function/E_Procedure GNAT_ENTITY is
4817 a C++ imported method or equivalent.
4819 We use the predicate on 32-bit x86/Windows to find out whether we need to
4820 use the "thiscall" calling convention for GNAT_ENTITY. This convention is
4821 used for C++ methods (functions with METHOD_TYPE) by the back-end. */
4823 bool
4825 {
4826 /* A constructor is a method on the C++ side. We deal with it now because
4827 it is declared without the 'this' parameter in the sources and, although
4828 the front-end will create a version with the 'this' parameter for code
4829 generation purposes, we want to return true for both versions. */
4833 /* Check that the subprogram has C++ convention. */
4837 /* And that the type of the first parameter (indirectly) has it too. */
4848 /* This is the main case: a C++ virtual method imported as a primitive
4849 operation of a tagged type. */
4853 /* This is set on the E_Subprogram_Type built for a dispatching call. */
4857 /* A thunk needs to be handled like its associated primitive operation. */
4861 /* Now on to the annoying case: a C++ non-virtual method, imported either
4862 as a non-primitive operation of a tagged type or as a primitive operation
4863 of an untagged type. We cannot reliably differentiate these cases from
4864 their static member or regular function equivalents in Ada, so we ask
4865 the C++ side through the mangled name of the function, as the implicit
4866 'this' parameter is not encoded in the mangled name of a method. */
4868 {
4875 DMGL_GNU_V3
4876 | DMGL_TYPES
4877 | DMGL_PARAMS
4883 /* We need to release MEM once we have a successful demangling. */
4890 {
4891 /* Make sure there is at least one parameter in C++ too. */
4893 {
4896 n_ada_args++;
4902 n_cpp_args++;
4908 }
4909 else
4911 }
4916 }
4919 }
4921 /* Finalize the processing of From_Limited_With incomplete types. */
4923 void
4925 {
4932 {
4936 {
4941 }
4944 }
4945 }
4947 /* Return the equivalent type to be used for GNAT_ENTITY, if it's a kind
4948 of type (such E_Task_Type) that has a different type which Gigi uses
4949 for its representation. If the type does not have a special type for
4950 its representation, return GNAT_ENTITY. */
4952 Entity_Id
4954 {
4961 {
4987 }
4990 }
4992 /* Return a GCC tree for a type corresponding to the component type of the
4993 array type or subtype GNAT_ARRAY. DEFINITION is true if this component
4994 is for an array being defined. DEBUG_INFO_P is true if we need to write
4995 debug information for other types that we may create in the process. */
4997 static tree
5000 {
5003 tree gnu_comp_size;
5006 /* If an alignment is specified, use it as a cap on the component type
5007 so that it can be honored for the whole type. But ignore it for the
5008 original type of packed array types. */
5012 else
5015 /* Try to get a smaller form of the component if needed. */
5028 /* Get and validate any specified Component_Size. */
5029 gnu_comp_size
5034 /* If the array has aliased components and the component size can be zero,
5035 force at least unit size to ensure that the components have distinct
5036 addresses. */
5042 gnu_comp_size
5045 /* If the component type is a RECORD_TYPE that has a self-referential size,
5046 then use the maximum size for the component size. */
5052 /* Honor the component size. This is not needed for bit-packed arrays. */
5054 {
5060 else
5066 /* If a padding record was made, declare it now since it will never be
5067 declared otherwise. This is necessary to ensure that its subtrees
5068 are properly marked. */
5071 gnat_array);
5072 }
5074 /* If the component type is a padded type made for a non-bit-packed array
5075 of scalars with reverse storage order, we need to propagate the reverse
5076 storage order to the padding type since it is the innermost enclosing
5077 aggregate type around the scalar. */
5085 {
5086 const int quals
5087 = TYPE_QUAL_VOLATILE
5090 }
5093 }
5095 /* Return a GCC tree for a parameter corresponding to GNAT_PARAM, to be placed
5096 in the parameter list of GNAT_SUBPROG. GNU_PARAM_TYPE is the GCC tree for
5097 the type of the parameter. FIRST is true if this is the first parameter in
5098 the list of GNAT_SUBPROG. Also set CICO to true if the parameter must use
5099 the copy-in copy-out implementation mechanism.
5101 The returned tree is a PARM_DECL, except for the cases where no parameter
5102 needs to be actually passed to the subprogram; the type of this "shadow"
5103 parameter is then returned instead. */
5105 static tree
5108 {
5114 /* The parameter can be indirectly modified if its address is taken. */
5120 tree gnu_param;
5122 /* Make sure to use the proper SLOC for vector ABI warnings. */
5126 /* Builtins are expanded inline and there is no real call sequence involved.
5127 So the type expected by the underlying expander is always the type of the
5128 argument "as is". */
5133 /* Handle the first parameter of a valued procedure specially: it's a copy
5134 mechanism for which the parameter is never allocated. */
5136 {
5140 }
5142 /* Or else, see if a Mechanism was supplied that forced this parameter
5143 to be passed one way or another. */
5145 ;
5147 /* Positive mechanism means by copy for sufficiently small parameters. */
5149 {
5154 else
5156 }
5158 /* Otherwise, it's an unsupported mechanism so error out. */
5159 else
5160 {
5163 }
5165 /* If this is either a foreign function or if the underlying type won't
5166 be passed by reference and is as aligned as the original type, strip
5167 off possible padding type. */
5169 {
5178 }
5180 /* If this is a read-only parameter, make a variant of the type that is
5181 read-only. ??? However, if this is a self-referential type, the type
5182 can be very complex, so skip it for now. */
5186 /* For foreign conventions, pass arrays as pointers to the element type.
5187 First check for unconstrained array and get the underlying array. */
5189 gnu_param_type
5192 /* Arrays are passed as pointers to element type for foreign conventions. */
5194 {
5195 /* Strip off any multi-dimensional entries, then strip
5196 off the last array to get the component type. */
5205 gnu_param_type
5209 }
5211 /* Fat pointers are passed as thin pointers for foreign conventions. */
5213 gnu_param_type
5216 /* If we were requested or muss pass by reference, do so.
5217 If we were requested to pass by copy, do so.
5218 Otherwise, for foreign conventions, pass In Out or Out parameters
5219 or aggregates by reference. For COBOL and Fortran, pass all
5220 integer and FP types that way too. For Convention Ada, use
5221 the standard Ada default. */
5225 && ((foreign
5227 || (foreign
5232 || (!foreign
5234 {
5235 /* We take advantage of 6.2(12) by considering that references built for
5236 parameters whose type isn't by-ref and for which the mechanism hasn't
5237 been forced to by-ref allow only a restricted form of aliasing. */
5238 restricted_aliasing_p
5242 }
5244 /* Pass In Out or Out parameters using copy-in copy-out mechanism. */
5253 /* If this is an Out parameter that isn't passed by reference and isn't
5254 a pointer or aggregate, we don't make a PARM_DECL for it. Instead,
5255 it will be a VAR_DECL created when we process the procedure, so just
5256 return its type. For the special parameter of a valued procedure,
5257 never pass it in.
5259 An exception is made to cover the RM-6.4.1 rule requiring "by copy"
5260 Out parameters with discriminants or implicit initial values to be
5261 handled like In Out parameters. These type are normally built as
5262 aggregates, hence passed by reference, except for some packed arrays
5263 which end up encoded in special integer types. Note that scalars can
5264 be given implicit initial values using the Default_Value aspect.
5266 The exception we need to make is then for packed arrays of records
5267 with discriminants or implicit initial values. We have no light/easy
5268 way to check for the latter case, so we merely check for packed arrays
5269 of records. This may lead to useless copy-in operations, but in very
5270 rare cases only, as these would be exceptions in a set of already
5271 exceptional situations. */
5273 && !by_ref
5274 && (by_return
5293 /* If no Mechanism was specified, indicate what we're using, then
5294 back-annotate it. */
5300 }
5302 /* Associate GNAT_SUBPROG with GNU_TYPE, which must be a dummy type, so that
5303 GNAT_SUBPROG is updated when GNU_TYPE is completed.
5305 Ada 2012 (AI05-019) says that freezing a subprogram does not always freeze
5306 the corresponding profile, which means that, by the time the freeze node
5307 of the subprogram is encountered, types involved in its profile may still
5308 be not yet frozen. That's why we need to update GNAT_SUBPROG when we see
5309 the freeze node of types involved in its profile, either types of formal
5310 parameters or the return type. */
5312 static void
5314 {
5322 {
5327 }
5329 /* Even if there is already a slot for GNU_TYPE, we need to set the flag
5330 because the vector might have been just emptied by update_profiles_with.
5331 This can happen when there are 2 freeze nodes associated with different
5332 views of the same type; the type will be really complete only after the
5333 second freeze node is encountered. */
5338 /* Make sure GNAT_SUBPROG is not associated twice with the same dummy type,
5339 since this would mean updating twice its profile. */
5341 {
5345 /* Entity_Id is a simple integer so we can implement a stable order on
5346 the vector with an ordered insertion scheme and binary search. */
5348 {
5355 else
5357 }
5359 /* l == u and therefore is the insertion point. */
5361 }
5362 else
5366 }
5368 /* Update the GCC tree previously built for the profile of GNAT_SUBPROG. */
5370 static void
5372 {
5373 tree gnu_param_list;
5378 {
5379 /* Builtins cannot have their address taken so we can reset them. */
5384 }
5390 /* If GNAT_SUBPROG is an actual subprogram, GNU_SUBPROG is a FUNCTION_DECL
5391 and needs to be adjusted too. */
5393 {
5395 tree gnu_ext_name
5400 }
5401 }
5403 /* Update the GCC trees previously built for the profiles involving GNU_TYPE,
5404 a dummy type which appears in profiles. */
5406 void
5408 {
5416 /* The flag needs to be reset before calling update_profile, in case
5417 associate_subprog_with_dummy_type is again invoked on GNU_TYPE. */
5426 }
5428 /* Return the GCC tree for GNAT_TYPE present in the profile of a subprogram.
5430 Ada 2012 (AI05-0151) says that incomplete types coming from a limited
5431 context may now appear as parameter and result types. As a consequence,
5432 we may need to defer their translation until after a freeze node is seen
5433 or to the end of the current unit. We also aim at handling temporarily
5434 incomplete types created by the usual delayed elaboration scheme. */
5436 static tree
5438 {
5439 /* This is the same logic as the E_Access_Type case of gnat_to_gnu_entity
5440 so the rationale is exposed in that place. These processings probably
5441 ought to be merged at some point. */
5443 const bool is_from_limited_with
5446 Entity_Id gnat_full_direct_first
5447 = (is_from_limited_with
5451 Entity_Id gnat_full_direct
5452 = ((is_from_limited_with
5460 tree gnu_type;
5466 && ((!in_main_unit
5473 {
5477 {
5484 }
5485 }
5490 else
5493 /* Access-to-unconstrained-array types need a special treatment. */
5495 {
5498 }
5501 }
5503 /* Return a GCC tree for a subprogram type corresponding to GNAT_SUBPROG.
5504 DEFINITION is true if this is for a subprogram being defined. DEBUG_INFO_P
5505 is true if we need to write debug information for other types that we may
5506 create in the process. Also set PARAM_LIST to the list of parameters.
5507 If GNAT_SUBPROG is bound to a GCC builtin, return the DECL for the builtin
5508 directly instead of its type. */
5510 static tree
5513 {
5516 Entity_Id gnat_param;
5519 tree gnu_return_type;
5522 /* Non-null for subprograms containing parameters passed by copy-in copy-out
5523 (In Out or Out parameters not passed by reference), in which case it is
5524 the list of nodes used to specify the values of the In Out/Out parameters
5525 that are returned as a record upon procedure return. The TREE_PURPOSE of
5526 an element of this list is a FIELD_DECL of the record and the TREE_VALUE
5527 is the PARM_DECL corresponding to that field. This list will be saved in
5528 the TYPE_CI_CO_LIST field of the FUNCTION_TYPE node we create. */
5531 /* Fields in return type of procedure with copy-in copy-out parameters. */
5533 /* The semantics of "pure" in Ada essentially matches that of "const"
5534 in the back-end. In particular, both properties are orthogonal to
5535 the "nothrow" property if the EH circuitry is explicit in the
5536 internal representation of the back-end. If we are to completely
5537 hide the EH circuitry from it, we need to declare that calls to pure
5538 Ada subprograms that can throw have side effects since they can
5539 trigger an "abnormal" transfer of control flow; thus they can be
5540 neither "const" nor "pure" in the back-end sense. */
5548 /* Look into the return type and get its associated GCC tree if it is not
5549 void, and then compute various flags for the subprogram type. But make
5550 sure not to do this processing multiple times. */
5557 {
5562 }
5564 else
5565 {
5566 /* For foreign convention subprograms, return System.Address as void *
5567 or equivalent. Note that this comprises GCC builtins. */
5571 else
5574 /* If this function returns by reference, make the actual return type
5575 the reference type and make a note of that. */
5577 {
5580 }
5582 /* If the return type is an unconstrained array type, the return value
5583 will be allocated on the secondary stack so the actual return type
5584 is the fat pointer type. */
5586 {
5589 }
5591 /* This is the same unconstrained array case, but for a dummy type. */
5594 {
5597 }
5599 /* Likewise, if the return type requires a transient scope, the return
5600 value will also be allocated on the secondary stack so the actual
5601 return type is the reference type. */
5603 {
5606 }
5608 /* If the Mechanism is By_Reference, ensure this function uses the
5609 target's by-invisible-reference mechanism, which may not be the
5610 same as above (e.g. it might be passing an extra parameter). */
5614 /* Likewise, if the return type is itself By_Reference. */
5618 /* If the type is a padded type and the underlying type would not be
5619 passed by reference or the function has a foreign convention, return
5620 the underlying type. */
5622 && (!default_pass_by_ref
5627 /* If the return type is unconstrained, it must have a maximum size.
5628 Use the padded type as the effective return type. And ensure the
5629 function uses the target's by-invisible-reference mechanism to
5630 avoid copying too much data when it returns. */
5632 {
5636 /* If the size overflows to 0, set it to an arbitrary positive
5637 value so that assignments in the type are preserved. Their
5638 actual size is independent of this positive value. */
5642 {
5645 }
5651 /* Declare it now since it will never be declared otherwise. This
5652 is necessary to ensure that its subtrees are properly marked. */
5659 }
5661 /* If the return type has a size that overflows, we usually cannot have
5662 a function that returns that type. This usage doesn't really make
5663 sense anyway, so issue an error here. */
5668 {
5673 }
5675 /* If the return type is incomplete, there are 2 cases: if the function
5676 returns by reference, then the return type is only linked indirectly
5677 in the profile, so the profile can be seen as complete since it need
5678 not be further modified, only the reference types need be adjusted;
5679 otherwise the profile is incomplete and need be adjusted too. */
5681 {
5684 }
5688 || return_by_direct_ref_p
5689 || return_by_invisi_ref_p
5691 }
5693 /* A procedure (something that doesn't return anything) shouldn't be
5694 considered const since there would be no reason for calling such a
5695 subprogram. Note that procedures with Out (or In Out) parameters
5696 have already been converted into a function with a return type.
5697 Similarly, if the function returns an unconstrained type, then the
5698 function will allocate the return value on the secondary stack and
5699 thus calls to it cannot be CSE'ed, lest the stack be reclaimed. */
5703 /* Loop over the parameters and get their associated GCC tree. While doing
5704 this, build a copy-in copy-out structure if we need one. */
5708 {
5709 const bool mech_is_by_ref
5716 /* Fetch an existing parameter with complete type and reuse it. But we
5717 didn't save the CICO property so we can only do it for In parameters
5718 or parameters passed by reference. */
5723 {
5726 }
5728 /* Otherwise translate the parameter type and act accordingly. */
5729 else
5730 {
5733 /* For foreign convention subprograms, pass System.Address as void *
5734 or equivalent. Note that this comprises GCC builtins. */
5738 else
5741 /* If the parameter type is incomplete, there are 2 cases: if it is
5742 passed by reference, then the type is only linked indirectly in
5743 the profile, so the profile can be seen as complete since it need
5744 not be further modified, only the reference type need be adjusted;
5745 otherwise the profile is incomplete and need be adjusted too. */
5747 {
5748 Node_Id gnat_decl;
5752 && TYPE_IS_FAT_POINTER_P
5755 {
5757 gnu_param
5767 }
5769 /* ??? This is a kludge to support null procedures in spec taking
5770 a parameter with an untagged incomplete type coming from a
5771 limited context. The front-end creates a body without knowing
5772 anything about the non-limited view, which is illegal Ada and
5773 cannot be supported. Create a parameter with a fake type. */
5781 else
5782 {
5783 /* Build a minimal PARM_DECL without DECL_ARG_TYPE so that
5784 Call_to_gnu will stop if it encounters the PARM_DECL. */
5785 gnu_param
5787 gnu_param_type);
5789 gnu_param_type);
5791 }
5792 }
5794 /* Otherwise build the parameter declaration normally. */
5795 else
5796 {
5797 gnu_param
5801 /* We are returned either a PARM_DECL or a type if no parameter
5802 needs to be passed; in either case, adjust the type. */
5805 else
5806 {
5809 }
5810 }
5811 }
5813 /* If we have a GCC tree for the parameter, register it. */
5816 {
5817 gnu_param_type_list
5822 /* If a parameter is a pointer, a function may modify memory through
5823 it and thus shouldn't be considered a const function. Also, the
5824 memory may be modified between two calls, so they can't be CSE'ed.
5825 The latter case also handles by-ref parameters. */
5829 }
5831 /* If the parameter uses the copy-in copy-out mechanism, allocate a field
5832 for it in the return type and register the association. */
5834 {
5836 {
5839 /* If this is a function, we also need a field for the
5840 return value to be placed. */
5842 {
5843 tree gnu_field
5845 gnu_return_type,
5851 gnu_cico_list
5853 }
5856 /* Set a default alignment to speed up accesses. But we should
5857 not increase the size of the structure too much, lest it does
5858 not fit in return registers anymore. */
5861 }
5863 tree gnu_field
5872 }
5873 }
5875 /* If the subprogram uses the copy-in copy-out mechanism, possibly adjust
5876 and finish up the return type. */
5878 {
5879 /* If we have a CICO list but it has only one entry, we convert
5880 this function into a function that returns this object. */
5884 /* Do not finalize the return type if the subprogram is stubbed
5885 since structures are incomplete for the back-end. */
5887 {
5891 /* Try to promote the mode of the return type if it is passed
5892 in registers, again to speed up accesses. */
5895 NULL_TREE))
5896 {
5897 unsigned int size
5900 scalar_int_mode mode;
5905 {
5913 }
5914 }
5918 }
5921 }
5923 /* The lists have been built in reverse. */
5929 /* If the profile is incomplete, we only set the (temporary) return and
5930 parameter types; otherwise, we build the full type. In either case,
5931 we reuse an already existing GCC tree that we built previously here. */
5933 {
5935 ;
5936 else
5943 }
5944 else
5945 {
5947 {
5956 }
5957 else
5958 {
5959 gnu_type
5962 /* GNU_TYPE may be shared since GCC hashes types. Unshare it if it
5963 has a different TYPE_CI_CO_LIST or flags. */
5965 return_unconstrained_p,
5966 return_by_direct_ref_p,
5967 return_by_invisi_ref_p))
5968 {
5974 }
5975 }
5983 /* If this subprogram is expectedly bound to a GCC builtin, fetch the
5984 corresponding DECL node and check the parameter association. */
5987 {
5991 /* If we have a builtin DECL for that function, use it. Check if
5992 the profiles are compatible and warn if they are not. Note that
5993 the checker is expected to post diagnostics in this case. */
5995 {
5996 intrin_binding_t inb
6000 post_error
6002 gnat_subprog);
6005 }
6007 /* Inability to find the builtin DECL most often indicates a genuine
6008 mistake, but imports of unregistered intrinsics are sometimes used
6009 on purpose to allow hooking in alternate bodies; we post a warning
6010 conditioned on Wshadow in this case, to let developers be notified
6011 on demand without risking false positives with common default sets
6012 of options. */
6015 }
6016 }
6019 }
6021 /* Return the external name for GNAT_SUBPROG given its entity name. */
6023 static tree
6025 {
6028 /* If there was no specified Interface_Name and the external and
6029 internal names of the subprogram are the same, only use the
6030 internal name to allow disambiguation of nested subprograms. */
6035 }
6037 /* Like build_qualified_type, but TYPE_QUALS is added to the existing
6038 qualifiers on TYPE. */
6040 static tree
6042 {
6043 /* Qualifiers must be put on the associated array type. */
6048 }
6050 /* Set TYPE_NONALIASED_COMPONENT on an array type built by means of
6051 build_nonshared_array_type. */
6053 static void
6055 {
6058 }
6060 /* Set TYPE_REVERSE_STORAGE_ORDER on an array type built by means of
6061 build_nonshared_array_type. */
6063 static void
6065 {
6068 }
6070 /* Return true if DISCR1 and DISCR2 represent the same discriminant. */
6072 static bool
6074 {
6081 return
6083 }
6085 /* Return true if the array type GNU_TYPE, which represents a dimension of
6086 GNAT_TYPE, has a non-aliased component in the back-end sense. */
6088 static bool
6090 {
6091 /* If the array type is not the innermost dimension of the GNAT type,
6092 then it has a non-aliased component. */
6097 /* If the array type has an aliased component in the front-end sense,
6098 then it also has an aliased component in the back-end sense. */
6102 /* If this is a derived type, then it has a non-aliased component if
6103 and only if its parent type also has one. */
6105 {
6109 gnu_parent_type
6114 }
6116 /* Otherwise, rely exclusively on properties of the element type. */
6118 }
6120 /* Return true if GNAT_ADDRESS is a value known at compile-time. */
6122 static bool
6124 {
6125 /* Handle reference to a constant. */
6128 {
6132 }
6134 /* Catch System'To_Address. */
6139 }
6141 /* Return true if GNAT_RANGE, a N_Range node, cannot be superflat, i.e. if the
6142 inequality HB >= LB-1 is true. LB and HB are the low and high bounds. */
6144 static bool
6146 {
6148 Node_Id scalar_range;
6151 /* If the low bound is not constant, try to find an upper bound. */
6160 /* If the high bound is not constant, try to find a lower bound. */
6169 /* If we have failed to find constant bounds, punt. */
6174 /* We need at least a signed 64-bit type to catch most cases. */
6180 /* If the low bound is the smallest integer, nothing can be smaller. */
6186 }
6188 /* Return true if GNU_EXPR is (essentially) the address of a CONSTRUCTOR. */
6190 static bool
6192 {
6200 }
6202 /* Return true if the size in units represented by GNU_SIZE can be handled by
6203 an allocation. If STATIC_P is true, consider only what can be done with a
6204 static allocation. */
6206 static bool
6208 {
6209 /* We can allocate a fixed size if it is a valid for the middle-end. */
6213 /* We can allocate a variable size if this isn't a static allocation. */
6214 else
6216 }
6218 /* Return true if GNU_EXPR needs a conversion to GNU_TYPE when used as the
6219 initial value of an object of GNU_TYPE. */
6221 static bool
6223 {
6224 /* Do not convert if the object's type is unconstrained because this would
6225 generate useless evaluations of the CONSTRUCTOR to compute the size. */
6230 /* Do not convert if the object's type is a padding record whose field is of
6231 self-referential size because we want to copy only the actual data. */
6235 /* Do not convert a call to a function that returns with variable size since
6236 we want to use the return slot optimization in this case. */
6241 /* Do not convert to a record type with a variant part from a record type
6242 without one, to keep the object simpler. */
6249 /* In all the other cases, convert the expression to the object's type. */
6251 }
6252 \f
6253 /* Given GNAT_ENTITY, elaborate all expressions that are required to
6254 be elaborated at the point of its definition, but do nothing else. */
6256 void
6258 {
6260 {
6267 {
6271 /* ??? Tests to avoid Constraint_Error in static expressions
6272 are needed until after the front stops generating bogus
6273 conversions on bounds of real types. */
6281 }
6288 {
6289 Node_Id gnat_discriminant_expr;
6290 Entity_Id gnat_field;
6294 gnat_discriminant_expr
6299 /* Ignore access discriminants. */
6304 }
6307 }
6308 }
6309 \f
6310 /* Prepend to ATTR_LIST an entry for an attribute with provided TYPE,
6311 NAME, ARGS and ERROR_POINT. */
6313 static void
6316 tree attr_name,
6317 tree attr_args,
6318 Node_Id attr_error_point)
6319 {
6329 }
6331 /* Prepend to ATTR_LIST an entry for an attribute provided by GNAT_PRAGMA. */
6333 static void
6335 {
6340 /* Map the pragma at hand. Skip if this isn't one we know how to handle. */
6342 {
6373 }
6375 /* See what arguments we have and turn them into GCC trees for attribute
6376 handlers. These expect identifier for strings. We handle at most two
6377 arguments and static expressions only. */
6379 {
6385 {
6389 {
6393 }
6396 }
6400 {
6405 }
6406 }
6408 /* Prepend to the list. Make a list of the argument we might have, as GCC
6409 expects it. */
6411 gnu_arg1
6415 }
6417 /* Prepend to ATTR_LIST the list of attributes for GNAT_ENTITY, if any. */
6419 static void
6421 {
6422 Node_Id gnat_temp;
6424 /* Attributes are stored as Representation Item pragmas. */
6430 }
6431 \f
6432 /* Given a GNAT tree GNAT_EXPR, for an expression which is a value within a
6433 type definition (either a bound or a discriminant value) for GNAT_ENTITY,
6434 return the GCC tree to use for that expression. S is the suffix to use
6435 if a variable needs to be created and DEFINITION is true if this is done
6436 for a definition of GNAT_ENTITY. If NEED_VALUE is true, we need a result;
6437 otherwise, we are just elaborating the expression for side-effects. If
6438 NEED_DEBUG is true, we need a variable for debugging purposes even if it
6439 isn't needed for code generation. */
6441 static tree
6444 {
6445 tree gnu_expr;
6447 /* If we already elaborated this expression (e.g. it was involved
6448 in the definition of a private type), use the old value. */
6452 /* If we don't need a value and this is static or a discriminant,
6453 we don't need to do anything. */
6460 /* If it's a static expression, we don't need a variable for debugging. */
6464 /* Otherwise, convert this tree to its GCC equivalent and elaborate it. */
6468 /* Save the expression in case we try to elaborate this entity again. Since
6469 it's not a DECL, don't check it. Don't save if it's a discriminant. */
6474 }
6476 /* Similar, but take a GNU expression and always return a result. */
6478 static tree
6481 {
6486 /* If GNU_EXPR contains a placeholder, just return it. We rely on the fact
6487 that an expression cannot contain both a discriminant and a variable. */
6491 /* If GNU_EXPR is neither a constant nor based on a read-only variable, make
6492 a variable that is initialized to contain the expression when the package
6493 containing the definition is elaborated. If this entity is defined at top
6494 level, replace the expression by the variable; otherwise use a SAVE_EXPR
6495 if this is necessary. */
6498 else
6499 {
6500 /* Skip any conversions and simple constant arithmetics to see if the
6501 expression is based on a read-only variable. */
6509 expr_variable_p
6510 = !(inner
6513 }
6515 /* We only need to use the variable if we are in a global context since GCC
6516 can do the right thing in the local case. However, when not optimizing,
6517 use it for bounds of loop iteration scheme to avoid code duplication. */
6518 use_variable = expr_variable_p
6519 && (expr_global_p
6520 || (!optimize
6521 && definition
6526 /* Now create it, possibly only for debugging purposes. */
6528 {
6529 /* The following variable creation can happen when processing the body
6530 of subprograms that are defined out of the extended main unit and
6531 inlined. In this case, we are not at the global scope, and thus the
6532 new variable must not be tagged "external", as we used to do here as
6533 soon as DEFINITION was false. */
6534 tree gnu_decl
6541 /* Using this variable at debug time (if need_debug is true) requires a
6542 proper location. The back-end will compute a location for this
6543 variable only if the variable is used by the generated code.
6544 Returning the variable ensures the caller will use it in generated
6545 code. Note that there is no need for a location if the debug info
6546 contains an integer constant.
6547 TODO: when the encoding-based debug scheme is dropped, move this
6548 condition to the top-level IF block: we will not need to create a
6549 variable anymore in such cases, then. */
6552 }
6555 }
6557 /* Similar, but take an alignment factor and make it explicit in the tree. */
6559 static tree
6562 {
6564 return
6567 gnu_expr,
6568 unit_align),
6570 need_debug),
6571 unit_align);
6572 }
6574 /* Structure to hold internal data for elaborate_reference. */
6576 struct er_data
6577 {
6578 Entity_Id entity;
6581 };
6583 /* Wrapper function around elaborate_expression_1 for elaborate_reference. */
6585 static tree
6587 {
6591 /* This is what elaborate_expression_1 does if NEED_DEBUG is false. */
6595 /* If this is a COMPONENT_REF of a fat pointer, elaborate the entire fat
6596 pointer. This may be more efficient, but will also allow us to more
6597 easily find the match for the PLACEHOLDER_EXPR. */
6605 return
6607 }
6609 /* Elaborate the reference REF to be used as renamed object for GNAT_ENTITY.
6610 DEFINITION is true if this is done for a definition of GNAT_ENTITY and
6611 INIT is set to the first arm of a COMPOUND_EXPR present in REF, if any. */
6613 static tree
6616 {
6619 }
6620 \f
6621 /* Given a GNU tree and a GNAT list of choices, generate an expression to test
6622 the value passed against the list of choices. */
6624 static tree
6626 {
6627 Node_Id choice;
6628 Node_Id gnat_temp;
6633 {
6635 {
6640 this_test
6655 this_test
6666 /* This represents either a subtype range, an enumeration
6667 literal, or a constant Ekind says which. If an enumeration
6668 literal or constant, fall through to the next case. */
6671 {
6677 this_test
6685 }
6687 /* ... fall through ... */
6702 }
6706 else
6709 }
6712 }
6713 \f
6714 /* Adjust PACKED setting as passed to gnat_to_gnu_field for a field of
6715 type FIELD_TYPE to be placed in RECORD_TYPE. Return the result. */
6717 static int
6719 {
6720 /* If the field contains an item of variable size, we cannot pack it
6721 because we cannot create temporaries of non-fixed size in case
6722 we need to take the address of the field. See addressable_p and
6723 the notes on the addressability issues for further details. */
6727 /* In the other cases, we can honor the packing. */
6731 /* If the alignment of the record is specified and the field type
6732 is over-aligned, request Storage_Unit alignment for the field. */
6737 /* Likewise if the maximum alignment of the record is specified. */
6743 }
6745 /* Return a GCC tree for a field corresponding to GNAT_FIELD to be
6746 placed in GNU_RECORD_TYPE.
6748 PACKED is 1 if the enclosing record is packed or -1 if the enclosing
6749 record has Component_Alignment of Storage_Unit.
6751 DEFINITION is true if this field is for a record being defined.
6753 DEBUG_INFO_P is true if we need to write debug information for types
6754 that we may create in the process. */
6756 static tree
6759 {
6762 const bool is_atomic
6765 const bool is_independent
6767 const bool is_volatile
6770 /* We used to consider that volatile fields also require strict alignment,
6771 but that was an interpolation and would cause us to reject a pragma
6772 volatile on a packed record type containing boolean components, while
6773 there is no basis to do so in the RM. In such cases, the writes will
6774 involve load-modify-store sequences, but that's OK for volatile. The
6775 only constraint is the implementation advice whereby only the bits of
6776 the components should be accessed if they both start and end on byte
6777 boundaries, but that should be guaranteed by the GCC memory model. */
6778 const bool needs_strict_alignment
6784 /* If this field requires strict alignment, we cannot pack it because
6785 it would very likely be under-aligned in the record. */
6788 else
6791 /* If a size is specified, use it. Otherwise, if the record type is packed,
6792 use the official RM size. See "Handling of Type'Size Values" in Einfo
6793 for further details. */
6800 else
6803 /* If we have a specified size that is smaller than that of the field's type,
6804 or a position is specified, and the field's type is a record that doesn't
6805 require strict alignment, see if we can get either an integral mode form
6806 of the type or a smaller form. If we can, show a size was specified for
6807 the field if there wasn't one already, so we know to make this a bitfield
6808 and avoid making things wider.
6810 Changing to an integral mode form is useful when the record is packed as
6811 we can then place the field at a non-byte-aligned position and so achieve
6812 tighter packing. This is in addition required if the field shares a byte
6813 with another field and the front-end lets the back-end handle the access
6814 to the field, because GCC cannot handle non-byte-aligned BLKmode fields.
6816 Changing to a smaller form is required if the specified size is smaller
6817 than that of the field's type and the type contains sub-fields that are
6818 padded, in order to avoid generating accesses to these sub-fields that
6819 are wider than the field.
6821 We avoid the transformation if it is not required or potentially useful,
6822 as it might entail an increase of the field's alignment and have ripple
6823 effects on the outer record type. A typical case is a field known to be
6824 byte-aligned and not to share a byte with another field. */
6830 || (gnu_size
6836 {
6839 {
6843 }
6844 }
6847 {
6848 const unsigned int align
6851 gnu_field_type
6855 }
6858 {
6866 /* Ensure the position does not overlap with the parent subtype, if there
6867 is one. This test is omitted if the parent of the tagged type has a
6868 full rep clause since, in this case, component clauses are allowed to
6869 overlay the space allocated for the parent type and the front-end has
6870 checked that there are no overlapping components. */
6872 {
6877 post_error_ne_tree
6880 }
6882 /* If this field needs strict alignment, make sure that the record is
6883 sufficiently aligned and that the position and size are consistent
6884 with the type. But don't do it if we are just annotating types and
6885 the field's type is tagged, since tagged types aren't fully laid out
6886 in this mode. Also, note that atomic implies volatile so the inner
6887 test sequences ordering is significant here. */
6890 {
6896 /* If the position is not a multiple of the alignment of the type,
6897 then error out and reset the position. */
6900 {
6912 else
6916 type_align);
6918 }
6921 {
6925 /* If the size is lower than that of the type, or greater for
6926 atomic and aliased, then error out and reset the size. */
6928 {
6940 else
6944 gnu_type_size);
6946 }
6948 /* Likewise if the size is not a multiple of a byte, */
6950 bitsize_unit_node)))
6951 {
6960 else
6965 }
6966 }
6967 }
6968 }
6970 /* If the record has rep clauses and this is the tag field, make a rep
6971 clause for it as well. */
6974 {
6977 }
6979 else
6980 {
6983 /* If we are packing the record and the field is BLKmode, round the
6984 size up to a byte boundary. */
6987 }
6989 /* We need to make the size the maximum for the type if it is
6990 self-referential and an unconstrained type. In that case, we can't
6991 pack the field since we can't make a copy to align it. */
6993 && !gnu_size
6996 {
6999 }
7001 /* If a size is specified, adjust the field's type to it. */
7003 {
7004 tree orig_field_type;
7006 /* If the field's type is justified modular, we would need to remove
7007 the wrapper to (better) meet the layout requirements. However we
7008 can do so only if the field is not aliased to preserve the unique
7009 layout, if it has the same storage order as the enclosing record
7010 and if the prescribed size is not greater than that of the packed
7011 array to preserve the justification. */
7021 /* Similarly if the field's type is a misaligned integral type, but
7022 there is no restriction on the size as there is no justification. */
7028 gnu_field_type
7036 /* If a padding record was made, declare it now since it will never be
7037 declared otherwise. This is necessary to ensure that its subtrees
7038 are properly marked. */
7043 }
7045 /* Otherwise (or if there was an error), don't specify a position. */
7046 else
7049 /* If the field's type is a padded type made for a scalar field of a record
7050 type with reverse storage order, we need to propagate the reverse storage
7051 order to the padding type since it is the innermost enclosing aggregate
7052 type around the scalar. */
7061 /* Now create the decl for the field. */
7062 gnu_field
7070 {
7075 }
7078 }
7079 \f
7080 /* Return true if at least one member of COMPONENT_LIST needs strict
7081 alignment. */
7083 static bool
7085 {
7086 Node_Id component_decl;
7091 {
7099 }
7102 }
7104 /* Return true if TYPE is a type with variable size or a padding type with a
7105 field of variable size or a record that has a field with such a type. */
7107 static bool
7109 {
7110 tree field;
7127 }
7128 \f
7129 /* Return true if FIELD is an artificial field. */
7131 static bool
7133 {
7134 /* These fields are generated by the front-end proper. */
7138 /* These fields are generated by gigi. */
7143 }
7145 /* Return true if FIELD is a non-artificial field with self-referential
7146 size. */
7148 static bool
7150 {
7158 }
7160 /* Return true if FIELD is a non-artificial field with variable size. */
7162 static bool
7164 {
7172 }
7174 /* qsort comparer for the bit positions of two record components. */
7176 static int
7178 {
7181 const int ret
7185 }
7187 /* Reverse function from gnat_to_gnu_field: return the GNAT field present in
7188 either GNAT_COMPONENT_LIST or the discriminants of GNAT_RECORD_TYPE, and
7189 corresponding to the GNU tree GNU_FIELD. */
7191 static Entity_Id
7193 Entity_Id gnat_record_type)
7194 {
7202 {
7206 }
7216 }
7218 /* Issue a warning for the problematic placement of GNU_FIELD present in
7219 either GNAT_COMPONENT_LIST or the discriminants of GNAT_RECORD_TYPE.
7220 IN_VARIANT is true if GNAT_COMPONENT_LIST is the list of a variant.
7221 DO_REORDER is true if fields of GNAT_RECORD_TYPE are being reordered. */
7223 static void
7227 {
7232 = in_variant
7242 = do_reorder
7246 Entity_Id gnat_field
7254 }
7256 /* Structure holding information for a given variant. */
7258 {
7259 /* The record type of the variant. */
7260 tree type;
7262 /* The name of the variant. */
7263 tree name;
7265 /* The qualifier of the variant. */
7266 tree qual;
7268 /* Whether the variant has a rep clause. */
7271 /* Whether the variant is packed. */
7276 /* Translate and chain GNAT_COMPONENT_LIST present in GNAT_RECORD_TYPE to
7277 GNU_FIELD_LIST, set the result as the field list of GNU_RECORD_TYPE and
7278 finish it up. Return true if GNU_RECORD_TYPE has a rep clause that affects
7279 the layout (see below). When called from gnat_to_gnu_entity during the
7280 processing of a record definition, the GCC node for the parent, if any,
7281 will be the single field of GNU_RECORD_TYPE and the GCC nodes for the
7282 discriminants will be on GNU_FIELD_LIST. The other call to this function
7283 is a recursive call for the component list of a variant and, in this case,
7284 GNU_FIELD_LIST is empty.
7286 PACKED is 1 if this is for a packed record or -1 if this is for a record
7287 with Component_Alignment of Storage_Unit.
7289 DEFINITION is true if we are defining this record type.
7291 CANCEL_ALIGNMENT is true if the alignment should be zeroed before laying
7292 out the record. This means the alignment only serves to force fields to
7293 be bitfields, but not to require the record to be that aligned. This is
7294 used for variants.
7296 ALL_REP is true if a rep clause is present for all the fields.
7298 UNCHECKED_UNION is true if we are building this type for a record with a
7299 Pragma Unchecked_Union.
7301 ARTIFICIAL is true if this is a type that was generated by the compiler.
7303 DEBUG_INFO is true if we need to write debug information about the type.
7305 MAYBE_UNUSED is true if this type may be unused in the end; this doesn't
7306 mean that its contents may be unused as well, only the container itself.
7308 FIRST_FREE_POS, if nonzero, is the first (lowest) free field position in
7309 the outer record type down to this variant level. It is nonzero only if
7310 all the fields down to this level have a rep clause and ALL_REP is false.
7312 P_GNU_REP_LIST, if nonzero, is a pointer to a list to which each field
7313 with a rep clause is to be added; in this case, that is all that should
7314 be done with such fields and the return value will be false. */
7316 static bool
7323 {
7324 const bool needs_xv_encodings
7336 /* For each component referenced in a component declaration create a GCC
7337 field and add it to the list, skipping pragmas in the GNAT list. */
7344 {
7348 /* If present, the _Parent field must have been created as the single
7349 field of the record type. Put it before any other fields. */
7351 {
7354 }
7355 else
7356 {
7360 /* If this is the _Tag field, put it before any other fields. */
7364 /* If this is the _Controller field, put it before the other
7365 fields except for the _Tag or _Parent field. */
7367 {
7370 }
7372 /* If this is a regular field, put it after the other fields. */
7373 else
7374 {
7380 /* And record information for the final layout. */
7385 }
7386 }
7389 }
7391 /* At the end of the component list there may be a variant part. */
7394 /* We create a QUAL_UNION_TYPE for the variant part since the variants are
7395 mutually exclusive and should go in the same memory. To do this we need
7396 to treat each variant as a record whose elements are created from the
7397 component list for the variant. So here we create the records from the
7398 lists for the variants and put them all into the QUAL_UNION_TYPE.
7399 If this is an Unchecked_Union, we make a UNION_TYPE instead or
7400 use GNU_RECORD_TYPE if there are no fields so far. */
7402 {
7406 tree gnu_var_name
7417 gnu_union_name
7420 /* Reuse the enclosing union if this is an Unchecked_Union whose fields
7421 are all in the variant part, to match the layout of C unions. There
7422 is an associated check below. */
7425 else
7426 {
7427 gnu_union_type
7435 }
7437 /* If all the fields down to this level have a rep clause, find out
7438 whether all the fields at this level also have one. If so, then
7439 compute the new first free position to be passed downward. */
7442 {
7444 gnu_field;
7447 {
7450 this_first_free_pos
7452 }
7453 else
7454 {
7457 }
7458 }
7460 /* We build the variants in two passes. The bulk of the work is done in
7461 the first pass, that is to say translating the GNAT nodes, building
7462 the container types and computing the associated properties. However
7463 we cannot finish up the container types during this pass because we
7464 don't know where the variant part will be placed until the end. */
7468 {
7473 vinfo_t vinfo;
7481 /* Set the alignment of the inner type in case we need to make
7482 inner objects into bitfields, but then clear it out so the
7483 record actually gets only the alignment required. */
7489 /* Similarly, if the outer record has a size specified and all
7490 the fields have a rep clause, we can propagate the size. */
7492 {
7496 }
7498 /* Add the fields into the record type for the variant. Note that
7499 we aren't sure to really use it at this point, see below. */
7500 has_rep
7506 all_rep || this_first_free_pos
7509 /* Translate the qualifier and annotate the GNAT node. */
7513 /* Deal with packedness like in gnat_to_gnu_field. */
7515 {
7518 }
7519 else
7520 field_packed
7523 /* Push this variant onto the stack for the second pass. */
7531 /* Compute the global properties that will determine the placement of
7532 the variant part. */
7536 }
7538 /* Round up the first free position to the alignment of the variant part
7539 for the variants without rep clause. This will guarantee a consistent
7540 layout independently of the placement of the variant part. */
7544 /* In the second pass, the container types are adjusted if necessary and
7545 finished up, then the corresponding fields of the variant part are
7546 built with their qualifier, unless this is an unchecked union. */
7548 {
7552 /* If this is an Unchecked_Union whose fields are all in the variant
7553 part and we have a single field with no representation clause or
7554 placed at offset zero, use the field directly to match the layout
7555 of C unions. */
7557 && gnu_field_list
7561 {
7564 }
7565 else
7566 {
7567 /* Finalize the variant type now. We used to throw away empty
7568 record types but we no longer do that because we need them to
7569 generate complete debug info for the variant; otherwise, the
7570 union type definition will be lacking the fields associated
7571 with these empty variants. */
7573 {
7574 /* The variant part will be at offset 0 so we need to ensure
7575 that the fields are laid out starting from the first free
7576 position at this level. */
7578 tree gnu_rep_part;
7582 gnu_rep_part
7584 this_first_free_pos);
7589 }
7596 gnu_field
7598 gnu_union_type,
7599 all_rep_and_size
7608 }
7612 }
7614 /* Only make the QUAL_UNION_TYPE if there are non-empty variants. */
7616 {
7620 {
7624 }
7629 /* If GNU_UNION_TYPE is our record type, it means we must have an
7630 Unchecked_Union with no fields. Verify that and, if so, just
7631 return. */
7633 {
7635 && !gnu_field_list
7638 }
7643 /* Deal with packedness like in gnat_to_gnu_field. */
7646 else
7647 union_field_packed
7650 gnu_variant_part
7652 all_rep_and_size
7658 }
7659 }
7661 /* Scan GNU_FIELD_LIST and see if any fields have rep clauses. If they do,
7662 pull them out and put them onto the appropriate list.
7664 Similarly, pull out the fields with zero size and no rep clause, as they
7665 would otherwise modify the layout and thus very likely run afoul of the
7666 Ada semantics, which are different from those of C here.
7668 Finally, if there is an aliased field placed in the list after fields
7669 with self-referential size, pull out the latter in the same way.
7671 Optionally, if the reordering mechanism is enabled, pull out the fields
7672 with self-referential size, variable size and fixed size not a multiple
7673 of a byte, so that they don't cause the regular fields to be either at
7674 self-referential/variable offset or misaligned. Note, in the latter
7675 case, that this can only happen in packed record types so the alignment
7676 is effectively capped to the byte for the whole record. But we don't
7677 do it for non-packed record types if pragma Optimize_Alignment (Space)
7678 is specified because this can prevent alignment gaps from being filled.
7680 Optionally, if the layout warning is enabled, keep track of the above 4
7681 different kinds of fields and issue a warning if some of them would be
7682 (or are being) reordered by the reordering mechanism.
7684 ??? If we reorder fields, the debugging information will be affected and
7685 the debugger print fields in a different order from the source code. */
7686 const bool do_reorder
7692 const bool w_reorder
7694 && Warn_On_Questionable_Layout
7706 #define MOVE_FROM_FIELD_LIST_TO(LIST) \
7707 do { \
7708 if (gnu_last) \
7709 DECL_CHAIN (gnu_last) = gnu_next; \
7710 else \
7711 gnu_field_list = gnu_next; \
7712 \
7713 DECL_CHAIN (gnu_field) = (LIST); \
7714 (LIST) = gnu_field; \
7715 } while (0)
7719 {
7723 {
7726 }
7729 {
7739 }
7742 {
7745 }
7747 /* We don't need further processing in default mode. */
7749 {
7752 }
7755 {
7757 {
7761 do_reorder);
7762 else
7764 }
7767 {
7770 }
7771 }
7774 {
7776 {
7780 do_reorder);
7781 else
7783 }
7786 {
7789 }
7790 }
7792 else
7793 {
7794 /* If the field has no size, then it cannot be bit-packed. */
7795 const unsigned int bitp_size
7800 /* If the field is bit-packed, we move it to a temporary list that
7801 contains the contiguously preceding bit-packed fields, because
7802 we want to be able to put them back if the misalignment happens
7803 to cancel itself after several bit-packed fields. */
7805 {
7809 {
7812 }
7815 {
7818 }
7819 }
7821 /* No more bit-packed fields, move the existing ones to the end or
7822 put them back at their original location. */
7824 {
7828 {
7832 gnat_component_list,
7834 do_reorder);
7841 }
7842 else
7843 {
7844 /* Rechain the temporary list in front of GNU_FIELD. */
7847 {
7852 else
7856 }
7857 }
7858 }
7860 else
7862 }
7865 }
7867 #undef MOVE_FROM_FIELD_LIST_TO
7871 /* If permitted, we reorder the fields as follows:
7873 1) all (groups of) fields whose length is fixed and multiple of a byte,
7874 2) the remaining fields whose length is fixed and not multiple of a byte,
7875 3) the remaining fields whose length doesn't depend on discriminants,
7876 4) all fields whose length depends on discriminants,
7877 5) the variant part,
7879 within the record and within each variant recursively. */
7882 {
7883 /* If we have pending bit-packed fields, warn if they would be moved
7884 to after regular fields. */
7892 }
7895 {
7896 /* If we have pending bit-packed fields on the temporary list, we put
7897 them either on the bit-packed list or back on the regular list. */
7899 {
7902 else
7904 }
7906 gnu_field_list
7910 }
7912 /* Otherwise, if there is an aliased field placed after a field whose length
7913 depends on discriminants, we put all the fields of the latter sort, last.
7914 We need to do this in case an object of this record type is mutable. */
7918 /* If P_REP_LIST is nonzero, this means that we are asked to move the fields
7919 in our REP list to the previous level because this level needs them in
7920 order to do a correct layout, i.e. avoid having overlapping fields. */
7924 /* Deal with the annoying case of an extension of a record with variable size
7925 and partial rep clause, for which the _Parent field is forced at offset 0
7926 and has variable size, which we do not support below. Note that we cannot
7927 do it if the field has fixed size because we rely on the presence of the
7928 REP part built below to trigger the reordering of the fields in a derived
7929 record type when all the fields have a fixed position. */
7933 && !variants_have_rep
7934 && first_free_pos
7937 {
7941 }
7943 /* Otherwise, sort the fields by bit position and put them into their own
7944 record, before the others, if we also have fields without rep clause. */
7946 {
7951 /* If all the fields have a rep clause, we can do a flat layout. */
7952 layout_with_rep = !gnu_field_list
7954 gnu_rep_type
7958 gnu_field;
7964 /* Put the fields in the list in order of increasing position, which
7965 means we start from the end. */
7968 {
7972 }
7976 else
7977 {
7982 /* If FIRST_FREE_POS is nonzero, we need to ensure that the fields
7983 without rep clause are laid out starting from this position.
7984 Therefore, we force it as a minimal size on the REP part. */
7985 gnu_rep_part
7988 /* Chain the REP part at the beginning of the field list. */
7991 }
7992 }
7994 /* Chain the variant part at the end of the field list. */
8006 /* Chain the fields with zero size at the beginning of the field list. */
8012 }
8013 \f
8014 /* Given GNU_SIZE, a GCC tree representing a size, return a Uint to be
8015 placed into an Esize, Component_Bit_Offset, or Component_Size value
8016 in the GNAT tree. */
8018 static Uint
8020 {
8022 TCode tcode;
8026 /* See if we've already saved the value for this node. */
8028 {
8036 }
8037 else
8040 /* If we do not return inside this switch, TCODE will be set to the
8041 code to be used in a call to Create_Node. */
8043 {
8045 /* For negative values, build NEGATE_EXPR of the opposite. Such values
8046 can appear for discriminants in expressions for variants. */
8048 {
8052 }
8053 else
8058 /* The only case we handle here is a simple discriminant reference. */
8060 {
8064 /* Climb up the chain of successive extensions, if any. */
8071 {
8072 /* Fall through to common processing as a FIELD_DECL. */
8075 }
8076 else
8078 }
8079 else
8088 CASE_CONVERT:
8092 /* Now just list the operations we handle. */
8122 /* Fold conversions from bytes to bits into inner operations. */
8125 {
8129 {
8132 widest_int op1;
8136 else
8141 }
8142 }
8147 /* For negative values in sizetype, build NEGATE_EXPR of the opposite.
8148 Such values appear in expressions with aligning patterns. Note that,
8149 since sizetype is unsigned, we have to jump through some hoops. */
8151 {
8156 {
8159 }
8160 }
8164 /* In regular mode, inline back only if symbolic annotation is requested
8165 in order to avoid memory explosion on big discriminated record types.
8166 But not in ASIS mode, as symbolic annotation is required for DDA. */
8168 {
8171 }
8172 else
8177 }
8179 /* Now get each of the operands that's relevant for this code. If any
8180 cannot be expressed as a repinfo node, say we can't. */
8183 {
8187 }
8191 /* Save the result in the cache. */
8193 {
8195 /* We can't assume the hash table data hasn't moved since the initial
8196 look up, so we have to search again. Allocating and inserting an
8197 entry at that point would be an alternative, but then we'd better
8198 discard the entry if we decided not to cache it. */
8204 }
8207 }
8209 /* Given GNAT_ENTITY, an object (constant, variable, parameter, exception)
8210 and GNU_TYPE, its corresponding GCC type, set Esize and Alignment to the
8211 size and alignment used by Gigi. Prefer SIZE over TYPE_SIZE if non-null.
8212 BY_REF is true if the object is used by reference. */
8214 void
8216 {
8218 {
8221 else
8223 }
8226 {
8235 }
8240 }
8242 /* Return first element of field list whose TREE_PURPOSE is the same as ELEM.
8243 Return NULL_TREE if there is no such element in the list. */
8245 static tree
8247 {
8249 {
8254 }
8256 }
8258 /* Given GNAT_ENTITY, a record type, and GNU_TYPE, its corresponding GCC type,
8259 set Component_Bit_Offset and Esize of the components to the position and
8260 size used by Gigi. */
8262 static void
8264 {
8265 /* For an extension, the inherited components have not been translated because
8266 they are fetched from the _Parent component on the fly. */
8267 const bool is_extension
8270 /* We operate by first making a list of all fields and their position (we
8271 can get the size easily) and then update all the sizes in the tree. */
8272 tree gnu_list
8283 {
8285 gnu_list);
8287 {
8288 tree parent_offset;
8290 /* If we are just annotating types and the type is tagged, the tag
8291 and the parent components are not generated by the front-end so
8292 we need to add the appropriate offset to each component without
8293 representation clause. */
8297 {
8298 /* For a component appearing in the current extension, the
8299 offset is the size of the parent. */
8302 parent_offset
8304 bitsizetype);
8305 else
8309 parent_offset
8312 }
8313 else
8316 Set_Component_Bit_Offset
8318 annotate_value
8322 parent_offset)));
8326 }
8328 {
8329 /* If there is no entry, this is an inherited component whose
8330 position is the same as in the parent type. */
8333 /* If we are just annotating types, discriminants renaming those of
8334 the parent have no entry so deal with them specifically. */
8344 }
8345 }
8346 }
8347 \f
8348 /* Scan all fields in GNU_TYPE and return a TREE_LIST where TREE_PURPOSE is
8349 the FIELD_DECL and TREE_VALUE a TREE_VEC containing the byte position, the
8350 value to be placed into DECL_OFFSET_ALIGN and the bit position. The list
8351 of fields is flattened, except for variant parts if DO_NOT_FLATTEN_VARIANT
8352 is set to true. GNU_POS is to be added to the position, GNU_BITPOS to the
8353 bit position, OFFSET_ALIGN is the present offset alignment. GNU_LIST is a
8354 pre-existing list to be chained to the newly created entries. */
8356 static tree
8359 {
8360 tree gnu_field;
8363 gnu_field;
8365 {
8370 unsigned int our_offset_align
8379 /* Recurse on internal fields, flattening the nested fields except for
8380 those in the variant part, if requested. */
8382 {
8386 gnu_list
8390 else
8391 gnu_list
8395 }
8396 }
8399 }
8401 /* Return a list describing the substitutions needed to reflect the
8402 discriminant substitutions from GNAT_TYPE to GNAT_SUBTYPE. They can
8403 be in any order. The values in an element of the list are in the form
8404 of operands to SUBSTITUTE_IN_EXPR. DEFINITION is true if this is for
8405 a definition of GNAT_SUBTYPE. */
8409 {
8411 Entity_Id gnat_discrim;
8412 Node_Id gnat_constr;
8419 /* Ignore access discriminants. */
8421 {
8424 elaborate_expression
8430 }
8433 }
8435 /* Scan all fields in QUAL_UNION_TYPE and return a list describing the
8436 variants of QUAL_UNION_TYPE that are still relevant after applying
8437 the substitutions described in SUBST_LIST. GNU_LIST is a pre-existing
8438 list to be prepended to the newly created entries. */
8443 {
8444 tree gnu_field;
8447 gnu_field;
8449 {
8457 /* If the new qualifier is not unconditionally false, its variant may
8458 still be accessed. */
8460 {
8466 /* Recurse on the variant subpart of the variant, if any. */
8472 /* If the new qualifier is unconditionally true, the subsequent
8473 variants cannot be accessed. */
8476 }
8477 }
8480 }
8481 \f
8482 /* UINT_SIZE is a Uint giving the specified size for an object of GNU_TYPE
8483 corresponding to GNAT_OBJECT. If the size is valid, return an INTEGER_CST
8484 corresponding to its value. Otherwise, return NULL_TREE. KIND is set to
8485 VAR_DECL if we are specifying the size of an object, TYPE_DECL for the
8486 size of a type, and FIELD_DECL for the size of a field. COMPONENT_P is
8487 true if we are being called to process the Component_Size of GNAT_OBJECT;
8488 this is used only for error messages. ZERO_OK is true if a size of zero
8489 is permitted; if ZERO_OK is false, it means that a size of zero should be
8490 treated as an unspecified size. */
8492 static tree
8495 {
8496 Node_Id gnat_error_node;
8499 /* Return 0 if no size was specified. */
8503 /* Ignore a negative size since that corresponds to our back-annotation. */
8507 /* Find the node to use for error messages. */
8514 else
8517 /* Get the size as an INTEGER_CST. Issue an error if a size was specified
8518 but cannot be represented in bitsizetype. */
8521 {
8524 gnat_object);
8525 else
8527 gnat_object);
8529 }
8531 /* Ignore a zero size if it is not permitted. */
8535 /* The size of objects is always a multiple of a byte. */
8538 {
8542 else
8546 }
8548 /* If this is an integral type or a packed array type, the front-end has
8549 already verified the size, so we need not do it here (which would mean
8550 checking against the bounds). However, if this is an aliased object,
8551 it may not be smaller than the type of the object. */
8556 /* If the object is a record that contains a template, add the size of the
8557 template to the specified size. */
8563 /* If a type needs strict alignment, a component of this type in
8564 a packed record cannot be packed and thus uses the type size. */
8567 else
8570 /* Modify the size of a discriminated type to be the maximum size. */
8574 /* If this is an access type or a fat pointer, the minimum size is that given
8575 by the smallest integral mode that's valid for pointers. */
8577 {
8582 }
8584 /* Issue an error either if the default size of the object isn't a constant
8585 or if the new size is smaller than it. */
8589 {
8591 post_error_ne_tree
8594 else
8595 post_error_ne_tree
8599 }
8602 }
8603 \f
8604 /* Similarly, but both validate and process a value of RM size. This routine
8605 is only called for types. */
8607 static void
8609 {
8610 Node_Id gnat_attr_node;
8613 /* Do nothing if no size was specified. */
8617 /* Ignore a negative size since that corresponds to our back-annotation. */
8621 /* Only issue an error if a Value_Size clause was explicitly given.
8622 Otherwise, we'd be duplicating an error on the Size clause. */
8623 gnat_attr_node
8626 /* Get the size as an INTEGER_CST. Issue an error if a size was specified
8627 but cannot be represented in bitsizetype. */
8630 {
8633 gnat_entity);
8635 }
8637 /* Ignore a zero size unless a Value_Size clause exists, or a size clause
8638 exists, or this is an integer type, in which case the front-end will
8639 have always set it. */
8648 /* If the old size is self-referential, get the maximum size. */
8652 /* Issue an error either if the old size of the object isn't a constant or
8653 if the new size is smaller than it. The front-end has already verified
8654 this for scalar and packed array types. */
8662 && TYPE_PACKED_ARRAY_TYPE_P
8665 {
8667 post_error_ne_tree
8671 }
8673 /* Otherwise, set the RM size proper for integral types... */
8680 /* ...or the Ada size for record and union types. */
8684 }
8685 \f
8686 /* ALIGNMENT is a Uint giving the alignment specified for GNAT_ENTITY,
8687 a type or object whose present alignment is ALIGN. If this alignment is
8688 valid, return it. Otherwise, give an error and return ALIGN. */
8690 static unsigned int
8692 {
8695 Node_Id gnat_error_node;
8697 /* Don't worry about checking alignment if alignment was not specified
8698 by the source program and we already posted an error for this entity. */
8702 /* Post the error on the alignment clause if any. Note, for the implicit
8703 base type of an array type, the alignment clause is on the first
8704 subtype. */
8712 gnat_error_node =
8715 else
8718 /* Within GCC, an alignment is an integer, so we must make sure a value is
8719 specified that fits in that range. Also, there is an upper bound to
8720 alignments we can support/allow. */
8728 {
8732 /* If the default alignment of "double" or larger scalar types is
8733 specifically capped and the new alignment is above the cap, do
8734 not post an error and change the alignment only if there is an
8735 alignment clause; this makes it possible to have the associated
8736 GCC type overaligned by default for performance reasons. */
8738 {
8739 Entity_Id gnat_type
8741 is_capped_double
8743 }
8745 {
8746 Entity_Id gnat_type
8748 is_capped_double
8750 }
8751 else
8755 {
8758 }
8759 else
8760 {
8767 }
8768 }
8769 else
8770 {
8774 }
8777 }
8778 \f
8779 /* Promote the alignment of GNU_TYPE corresponding to GNAT_ENTITY. Return
8780 a positive value on success or zero on failure. */
8782 static unsigned int
8784 {
8787 /* No point in promoting the alignment if this doesn't prevent BLKmode access
8788 to the object, in particular block copy, as this will for example disable
8789 the NRV optimization for it. No point in jumping through all the hoops
8790 needed in order to support BIGGEST_ALIGNMENT if we don't really have to.
8791 So we cap to the smallest alignment that corresponds to a known efficient
8792 memory access pattern, except for Atomic and Volatile_Full_Access. */
8794 {
8797 }
8798 else
8799 {
8802 }
8804 /* Do the promotion within the above limits. */
8810 else
8813 /* But make sure not to under-align the object. */
8817 /* And honor the minimum valid atomic alignment, if any. */
8818 #ifdef MINIMUM_ATOMIC_ALIGNMENT
8821 #endif
8824 }
8825 \f
8826 /* Verify that TYPE is something we can implement atomically. If not, issue
8827 an error for GNAT_ENTITY. COMPONENT_P is true if we are being called to
8828 process a component type. */
8830 static void
8832 {
8834 Node_Id gnat_node;
8835 machine_mode mode;
8838 tree size;
8840 /* If this is an anonymous base type, nothing to check, the error will be
8841 reported on the source type if need be. */
8850 /* Consider all aligned floating-point types atomic and any aligned types
8851 that are represented by integers no wider than a machine word. */
8852 scalar_int_mode int_mode;
8859 /* For the moment, also allow anything that has an alignment equal to its
8860 size and which is smaller than a word. */
8871 {
8872 unsigned char pragma_id
8877 {
8880 }
8881 }
8889 else
8892 }
8893 \f
8895 /* Helper for the intrin compatibility checks family. Evaluate whether
8896 two types are definitely incompatible. */
8898 static bool
8900 {
8915 {
8922 /* Assume designated types are ok. We'd need to account for char * and
8923 void * variants to do better, which could rapidly get messy and isn't
8924 clearly worth the effort. */
8929 }
8932 }
8934 /* Helper for intrin_profiles_compatible_p, to perform compatibility checks
8935 on the Ada/builtin argument lists for the INB binding. */
8937 static bool
8939 {
8945 /* Sequence position of the last argument we checked. */
8949 {
8953 /* If we've exhausted both lists simultaneously, we're done. */
8957 /* If one list is shorter than the other, they fail to match. */
8961 /* If we're done with the Ada args and not with the internal builtin
8962 args, or the other way around, complain. */
8965 {
8968 }
8972 {
8976 }
8978 /* Otherwise, check that types match for the current argument. */
8979 argpos ++;
8981 {
8985 }
8990 }
8993 }
8995 /* Helper for intrin_profiles_compatible_p, to perform compatibility checks
8996 on the Ada/builtin return values for the INB binding. */
8998 static bool
9000 {
9004 /* Accept function imported as procedure, common and convenient. */
9009 /* Check return types compatibility otherwise. Note that this
9010 handles void/void as well. */
9012 {
9016 }
9019 }
9021 /* Check and return whether the Ada and gcc builtin profiles bound by INB are
9022 compatible. Issue relevant warnings when they are not.
9024 This is intended as a light check to diagnose the most obvious cases, not
9025 as a full fledged type compatibility predicate. It is the programmer's
9026 responsibility to ensure correctness of the Ada declarations in Imports,
9027 especially when binding straight to a compiler internal. */
9029 static bool
9031 {
9032 /* Check compatibility on return values and argument lists, each responsible
9033 for posting warnings as appropriate. Ensure use of the proper sloc for
9034 this purpose. */
9047 }
9048 \f
9049 /* Return a FIELD_DECL node modeled on OLD_FIELD. FIELD_TYPE is its type
9050 and RECORD_TYPE is the type of the parent. If SIZE is nonzero, it is the
9051 specified size for this field. POS_LIST is a position list describing
9052 the layout of OLD_FIELD and SUBST_LIST a substitution list to be applied
9053 to this layout. */
9055 static tree
9059 {
9071 /* If the position is now a constant, we can set it as the position of the
9072 field when we make it. Otherwise, we need to deal with it specially. */
9075 else
9078 new_field
9084 {
9086 /* Finalize the position. */
9095 }
9103 }
9105 /* Create the REP part of RECORD_TYPE with REP_TYPE. If MIN_SIZE is nonzero,
9106 it is the minimal size the REP_PART must have. */
9108 static tree
9110 {
9111 tree field;
9121 }
9123 /* Return the REP part of RECORD_TYPE, if any. Otherwise return NULL. */
9125 static tree
9127 {
9130 /* The REP part is the first field, internal, another record, and its name
9131 starts with an 'R'. */
9139 }
9141 /* Return the variant part of RECORD_TYPE, if any. Otherwise return NULL. */
9143 tree
9145 {
9146 tree field;
9148 /* The variant part is the only internal field that is a qualified union. */
9155 }
9157 /* Return a new variant part modeled on OLD_VARIANT_PART. VARIANT_LIST is
9158 the list of variants to be used and RECORD_TYPE is the type of the parent.
9159 POS_LIST is a position list describing the layout of fields present in
9160 OLD_VARIANT_PART and SUBST_LIST a substitution list to be applied to this
9161 layout. DEBUG_INFO_P is true if we need to write debug information. */
9163 static tree
9169 {
9177 /* First create the type of the variant part from that of the old one. */
9183 /* If the position of the variant part is constant, subtract it from the
9184 size of the type of the parent to get the new size. This manual CSE
9185 reduces the code size when not optimizing. */
9189 {
9199 first_bit));
9202 }
9203 else
9206 /* Now finish up the new variants and populate the union type. */
9208 {
9212 /* Skip variants that don't belong to this nesting level. */
9216 /* Retrieve the list of fields already added to the new variant. */
9220 /* If the old variant had a variant subpart, we need to create a new
9221 variant subpart and add it to the field list. */
9225 {
9226 tree new_variant_subpart
9229 debug_info_p);
9232 }
9234 /* Finish up the new variant and create the field. */
9240 new_field
9248 }
9250 /* Finish up the union type and create the variant part. Note that we don't
9251 reverse the field list because VARIANT_LIST has been traversed in reverse
9252 order. */
9258 new_variant_part
9264 /* With multiple discriminants it is possible for an inner variant to be
9265 statically selected while outer ones are not; in this case, the list
9266 of fields of the inner variant is not flattened and we end up with a
9267 qualified union with a single member. Drop the useless container. */
9269 {
9278 }
9281 }
9283 /* Copy the size (and alignment and alias set) from OLD_TYPE to NEW_TYPE,
9284 which are both RECORD_TYPE, after applying the substitutions described
9285 in SUBST_LIST. */
9287 static void
9290 {
9314 SET_TYPE_ADA_SIZE
9318 /* Finalize the size. */
9321 }
9323 /* Return true if DISC is a stored discriminant of RECORD_TYPE. */
9327 {
9334 else
9336 }
9338 /* Copy the layout from {GNAT,GNU}_OLD_TYPE to {GNAT,GNU}_NEW_TYPE, which are
9339 both record types, after applying the substitutions described in SUBST_LIST.
9340 DEBUG_INFO_P is true if we need to write debug information for NEW_TYPE. */
9342 static void
9344 Entity_Id gnat_old_type,
9345 tree gnu_new_type,
9346 tree gnu_old_type,
9349 {
9355 /* Look for REP and variant parts in the old type. */
9359 /* If there is a variant part, we must compute whether the constraints
9360 statically select a particular variant. If so, we simply drop the
9361 qualified union and flatten the list of fields. Otherwise we will
9362 build a new qualified union for the variants that are still relevant. */
9364 {
9371 /* If all the qualifiers are unconditionally true, the innermost variant
9372 is statically selected. */
9376 {
9379 }
9381 /* Otherwise, create the new variants. */
9384 {
9387 tree suffix
9396 gnu_subst_list);
9398 }
9399 }
9400 else
9401 {
9404 }
9406 /* Make a list of fields and their position in the old type. */
9407 tree gnu_pos_list
9413 /* Now go down every component in the new type and compute its size and
9414 position from those of the component in the old type and the stored
9415 constraints of the new type. */
9428 {
9437 /* If the type is the same, retrieve the GCC type from the
9438 old field to take into account possible adjustments. */
9441 else
9444 /* If there was a component clause, the field types must be the same
9445 for the old and new types, so copy the data from the old field to
9446 avoid recomputation here. Also if the field is justified modular
9447 and the optimization in gnat_to_gnu_field was applied. */
9453 {
9456 }
9458 /* If the old field was packed and of constant size, we have to get the
9459 old size here as it might differ from what the Etype conveys and the
9460 latter might overlap with the following field. Try to arrange the
9461 type for possible better packing along the way. */
9464 {
9470 }
9472 else
9475 /* If the context of the old field is the old type or its REP part,
9476 put the field directly in the new type; otherwise look up the
9477 context in the variant list and put the field either in the new
9478 type if there is a selected variant or in one new variant. */
9482 else
9483 {
9486 tree rep_part;
9496 else
9497 /* The front-end may pass us "ghost" components if it fails to
9498 recognize that a constrain statically selects a particular
9499 variant. Discard them. */
9501 }
9503 /* Now create the new field modeled on the old one. */
9504 gnu_field
9510 /* If the context is a variant, put it in the new variant directly. */
9512 {
9515 }
9517 /* To match the layout crafted in components_to_record, if this is
9518 the _Tag or _Parent field, put it before any other fields. */
9522 /* Similarly, if this is the _Controller field, put it before the
9523 other fields except for the _Tag or _Parent field. */
9525 {
9528 }
9530 /* Otherwise, put it after the other fields. */
9531 else
9532 {
9539 }
9541 /* For a stored discriminant in a derived type, replace the field. */
9543 {
9546 }
9547 else
9549 }
9551 /* If there is no variant list or a selected variant and the fields all have
9552 constant position, put them in order of increasing position to match that
9553 of constant CONSTRUCTORs. */
9555 {
9566 {
9569 }
9570 }
9572 /* If there is a variant list and no selected variant, we need to create the
9573 nest of variant parts from the old nest. */
9575 {
9576 tree new_variant_part
9582 }
9589 /* If NEW_TYPE is a subtype, it inherits all the attributes from OLD_TYPE.
9590 Otherwise sizes and alignment must be computed independently. */
9592 {
9595 }
9596 else
9599 /* Now go through the entities again looking for Itypes that we have not yet
9600 elaborated (e.g. Etypes of fields that have Original_Components). */
9609 }
9611 /* Associate to GNU_TYPE, the translation of GNAT_ENTITY, which is
9612 the implementation type of a packed array type (Is_Packed_Array_Impl_Type),
9613 the original array type if it has been translated. This association is a
9614 parallel type for GNAT encodings or a debug type for standard DWARF. Note
9615 that for standard DWARF, we also want to get the original type name. */
9617 static void
9619 {
9620 Entity_Id gnat_original_array_type
9622 tree gnu_original_array_type;
9633 {
9641 }
9642 else
9644 }
9645 \f
9646 /* Given a type T, a FIELD_DECL F, and a replacement value R, return an
9647 equivalent type with adjusted size expressions where all occurrences
9648 of references to F in a PLACEHOLDER_EXPR have been replaced by R.
9650 The function doesn't update the layout of the type, i.e. it assumes
9651 that the substitution is purely formal. That's why the replacement
9652 value R must itself contain a PLACEHOLDER_EXPR. */
9654 tree
9656 {
9657 tree nt;
9662 {
9668 /* First the domain types of arrays. */
9671 {
9683 SET_TYPE_INDEX_TYPE
9687 }
9689 /* Then the subtypes. */
9692 {
9704 }
9716 /* These should never show up here. */
9720 {
9740 }
9745 {
9747 tree field;
9749 /* Start out with no fields, make new fields, and chain them
9750 in. If we haven't actually changed the type of any field,
9751 discard everything we've done and return the old type. */
9756 {
9761 {
9764 }
9768 {
9771 }
9773 /* Do the substitution inside the qualifier, if any. */
9775 {
9778 {
9781 }
9782 }
9789 }
9799 }
9803 }
9804 }
9805 \f
9806 /* Return the RM size of GNU_TYPE. This is the actual number of bits
9807 needed to represent the object. */
9809 tree
9811 {
9812 /* For integral types, we store the RM size explicitly. */
9816 /* Return the RM size of the actual data plus the size of the template. */
9819 return
9824 /* For record or union types, we store the size explicitly. */
9830 /* For other types, this is just the size. */
9832 }
9833 \f
9834 /* Return the name to be used for GNAT_ENTITY. If a type, create a
9835 fully-qualified name, possibly with type information encoding.
9836 Otherwise, return the name. */
9840 {
9843 }
9845 tree
9847 {
9850 }
9852 /* Return an identifier representing the external name to be used for
9853 GNAT_ENTITY. If SUFFIX is specified, the name is followed by "___"
9854 and the specified suffix. */
9856 tree
9858 {
9866 /* A variable using the Stdcall convention lives in a DLL. We adjust
9867 its name to use the jump table, the _imp__NAME contains the address
9868 for the NAME variable. */
9871 {
9877 }
9880 }
9882 /* Given GNU_NAME, an IDENTIFIER_NODE containing a name and SUFFIX, a
9883 string, return a new IDENTIFIER_NODE that is the concatenation of
9884 the name followed by "___" and the specified suffix. */
9886 tree
9888 {
9895 }
9897 /* Initialize data structures of the decl.c module. */
9899 void
9901 {
9902 /* Initialize the cache of annotated values. */
9905 /* Initialize the association of dummy types with subprograms. */
9907 }
9909 /* Destroy data structures of the decl.c module. */
9911 void
9913 {
9914 /* Destroy the cache of annotated values. */
9918 /* Destroy the association of dummy types with subprograms. */
9921 }