| blob | 4bf14649d97459ac89e6738a9caf3267b2309fad |
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 From_Limited_With types until the
105 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 *);
246 /* The relevant constituents of a subprogram binding to a GCC builtin. Used
247 to pass around calls performing profile compatibility checks. */
256 \f
257 /* Given GNAT_ENTITY, a GNAT defining identifier node, which denotes some Ada
258 entity, return the equivalent GCC tree for that entity (a ..._DECL node)
259 and associate the ..._DECL node with the input GNAT defining identifier.
261 If GNAT_ENTITY is a variable or a constant declaration, GNU_EXPR gives its
262 initial value (in GCC tree form). This is optional for a variable. For
263 a renamed entity, GNU_EXPR gives the object being renamed.
265 DEFINITION is true if this call is intended for a definition. This is used
266 for separate compilation where it is necessary to know whether an external
267 declaration or a definition must be created if the GCC equivalent was not
268 created previously. */
270 tree
272 {
273 /* Contains the kind of the input GNAT node. */
275 /* True if this is a type. */
277 /* True if this is an artificial entity. */
279 /* True if debug info is requested for this entity. */
281 /* True if this entity is to be considered as imported. */
282 const bool imported_p
284 /* For a type, contains the equivalent GNAT node to be used in gigi. */
286 /* Temporary used to walk the GNAT tree. */
287 Entity_Id gnat_temp;
288 /* Contains the GCC DECL node which is equivalent to the input GNAT node.
289 This node will be associated with the GNAT node by calling at the end
290 of the `switch' statement. */
292 /* Contains the GCC type to be used for the GCC node. */
294 /* Contains the GCC size tree to be used for the GCC node. */
296 /* Contains the GCC name to be used for the GCC node. */
297 tree gnu_entity_name;
298 /* True if we have already saved gnu_decl as a GNAT association. */
300 /* True if we incremented defer_incomplete_level. */
302 /* True if we incremented force_global. */
304 /* True if we should check to see if elaborated during processing. */
306 /* True if we made GNU_DECL and its type here. */
308 /* Size and alignment of the GCC node, if meaningful. */
310 /* Contains the list of attributes directly attached to the entity. */
313 /* Since a use of an Itype is a definition, process it as such if it
314 is not in a with'ed unit. */
316 && is_type
320 {
321 /* Ensure that we are in a subprogram mentioned in the Scope chain of
322 this entity, our current scope is global, or we encountered a task
323 or entry (where we can't currently accurately check scoping). */
326 {
329 }
334 {
339 gnat_temp
351 && (current_function_decl
353 {
356 }
357 }
359 /* This abort means the Itype has an incorrect scope, i.e. that its
360 scope does not correspond to the subprogram it is declared in. */
362 }
364 /* If we've already processed this entity, return what we got last time.
365 If we are defining the node, we should not have already processed it.
366 In that case, we will abort below when we try to save a new GCC tree
367 for this object. We also need to handle the case of getting a dummy
368 type when a Full_View exists but be careful so as not to trigger its
369 premature elaboration. */
372 {
381 {
382 gnu_decl
386 }
389 }
391 /* If this is a numeric or enumeral type, or an access type, a nonzero Esize
392 must be specified unless it was specified by the programmer. Exceptions
393 are for access-to-protected-subprogram types and all access subtypes, as
394 another GNAT type is used to lay out the GCC type for them. */
406 /* The RM size must be specified for all discrete and fixed-point types. */
410 /* If we get here, it means we have not yet done anything with this entity.
411 If we are not defining it, it must be a type or an entity that is defined
412 elsewhere or externally, otherwise we should have defined it already. */
414 || type_annotate_only
415 || is_type
422 /* Get the name of the entity and set up the line number and filename of
423 the original definition for use in any decl we make. Make sure we do not
424 inherit another source location. */
430 /* For cases when we are not defining (i.e., we are referencing from
431 another compilation unit) public entities, show we are at global level
432 for the purpose of computing scopes. Don't do this for components or
433 discriminants since the relevant test is whether or not the record is
434 being defined. */
442 /* Handle any attributes directly attached to the entity. */
446 /* Do some common processing for types. */
448 {
449 /* Compute the equivalent type to be used in gigi. */
452 /* Machine_Attributes on types are expected to be propagated to
453 subtypes. The corresponding Gigi_Rep_Items are only attached
454 to the first subtype though, so we handle the propagation here. */
461 /* Compute a default value for the size of an elementary type. */
463 {
473 else
478 }
479 }
482 {
485 {
486 /* The GNAT record where the component was defined. */
489 /* If the entity is a discriminant of an extended tagged type used to
490 rename a discriminant of the parent type, return the latter. */
494 {
495 gnu_decl
500 }
502 /* If the entity is an inherited component (in the case of extended
503 tagged record types), just return the original entity, which must
504 be a FIELD_DECL. Likewise for discriminants. If the entity is a
505 non-girder discriminant (in the case of derived untagged record
506 types), return the stored discriminant it renames. */
509 {
510 gnu_decl
513 /* GNU_DECL contains a PLACEHOLDER_EXPR for discriminants. */
517 }
519 /* Otherwise, if we are not defining this and we have no GCC type
520 for the containing record, make one for it. Then we should
521 have made our own equivalent. */
523 {
524 /* ??? If this is in a record whose scope is a protected
525 type and we have an Original_Record_Component, use it.
526 This is a workaround for major problems in protected type
527 handling. */
531 {
532 gnu_decl
536 }
537 else
538 {
541 }
545 }
547 /* Here we have no GCC type and this is a reference rather than a
548 definition. This should never happen. Most likely the cause is
549 reference before declaration in the GNAT tree for gnat_entity. */
551 }
554 /* Ignore constant definitions already marked with the error node. See
555 the N_Object_Declaration case of gnat_to_gnu for the rationale. */
559 {
562 }
564 /* Ignore deferred constant definitions without address clause since
565 they are processed fully in the front-end. If No_Initialization
566 is set, this is not a deferred constant but a constant whose value
567 is built manually. And constants that are renamings are handled
568 like variables. */
570 && !gnu_expr
574 {
578 }
580 /* If this is a use of a deferred constant without address clause,
581 get its full definition. */
585 {
586 gnu_decl
590 }
592 /* If we have a constant that we are not defining, get the expression it
593 was defined to represent. This is necessary to avoid generating dumb
594 elaboration code in simple cases, but we may throw it away later if it
595 is not a constant. But do not retrieve it if it is an allocator since
596 the designated type might still be dummy at this point. */
602 /* The expression may contain N_Expression_With_Actions nodes and
603 thus object declarations from other units. Discard them. */
604 gnu_expr
607 /* ... fall through ... */
613 {
615 /* Always create a variable for volatile objects and variables seen
616 constant but with a Linker_Section pragma. */
617 bool const_flag
630 /* We implement RM 13.3(19) for exported and imported (non-constant)
631 objects by making them volatile. */
632 bool volatile_flag
639 tree gnu_object_size;
641 /* We need to translate the renamed object even though we are only
642 referencing the renaming. But it may contain a call for which
643 we'll generate a temporary to hold the return value and which
644 is part of the definition of the renaming, so discard it. */
646 {
650 else
652 }
654 /* Get the type after elaborating the renamed object. */
658 else
659 {
662 /* If this is a standard exception definition, use the standard
663 exception type. This is necessary to make sure that imported
664 and exported views of exceptions are merged in LTO mode. */
668 }
670 /* For a debug renaming declaration, build a debug-only entity. */
672 {
673 /* Force a non-null value to make sure the symbol is retained. */
677 integer_minus_one_node));
685 }
687 /* If this is a loop variable, its type should be the base type.
688 This is because the code for processing a loop determines whether
689 a normal loop end test can be done by comparing the bounds of the
690 loop against those of the base type, which is presumed to be the
691 size used for computation. But this is not correct when the size
692 of the subtype is smaller than the type. */
696 /* Reject non-renamed objects whose type is an unconstrained array or
697 any object whose type is a dummy type or void. */
702 {
705 force_global--;
707 }
709 /* If an alignment is specified, use it if valid. Note that exceptions
710 are objects but don't have an alignment. We must do this before we
711 validate the size, since the alignment can affect the size. */
713 {
719 /* No point in changing the type if there is an address clause
720 as the final type of the object will be a reference type. */
723 else
724 {
727 gnu_type
731 /* If a padding record was made, declare it now since it will
732 never be declared otherwise. This is necessary to ensure
733 that its subtrees are properly marked. */
737 }
738 }
740 /* If we are defining the object, see if it has a Size and validate it
741 if so. If we are not defining the object and a Size clause applies,
742 simply retrieve the value. We don't want to ignore the clause and
743 it is expected to have been validated already. Then get the new
744 type, if any. */
753 {
754 gnu_type
760 }
762 /* If this object has self-referential size, it must be a record with
763 a default discriminant. We are supposed to allocate an object of
764 the maximum size in this case, unless it is a constant with an
765 initializing expression, in which case we can get the size from
766 that. Note that the resulting size may still be a variable, so
767 this may end up with an indirect allocation. */
770 {
772 {
775 {
776 /* If the initializing expression is itself a constant,
777 despite having a nominal type with self-referential
778 size, we can get the size directly from it. */
780 && TYPE_IS_PADDING_P
784 || DECL_READONLY_ONCE_ELAB
787 else
788 gnu_size
790 }
791 else
793 }
794 /* We may have no GNU_EXPR because No_Initialization is
795 set even though there's an Expression. */
800 gnu_size
802 (Etype
804 else
805 {
808 }
810 /* If the size isn't constant and we are at global level, call
811 elaborate_expression_1 to make a variable for it rather than
812 calculating it each time. */
816 }
818 /* If the size is zero byte, make it one byte since some linkers have
819 troubles with zero-sized objects. If the object will have a
820 template, that will make it nonzero so don't bother. Also avoid
821 doing that for an object renaming or an object with an address
822 clause, as we would lose useful information on the view size
823 (e.g. for null array slices) and we are not allocating the object
824 here anyway. */
836 /* If this is an object with no specified size and alignment, and
837 if either it is atomic or we are not optimizing alignment for
838 space and it is composite and not an exception, an Out parameter
839 or a reference to another object, and the size of its type is a
840 constant, set the alignment to the smallest one which is not
841 smaller than the size, with an appropriate cap. */
850 && !imported_p
854 {
857 /* No point in promoting the alignment if this doesn't prevent
858 BLKmode access to the object, in particular block copy, as
859 this will for example disable the NRV optimization for it.
860 No point in jumping through all the hoops needed in order
861 to support BIGGEST_ALIGNMENT if we don't really have to.
862 So we cap to the smallest alignment that corresponds to
863 a known efficient memory access pattern of the target. */
865 {
868 }
869 else
870 {
873 }
880 else
883 /* But make sure not to under-align the object. */
887 /* And honor the minimum valid atomic alignment, if any. */
888 #ifdef MINIMUM_ATOMIC_ALIGNMENT
891 #endif
892 }
894 /* If the object is set to have atomic components, find the component
895 type and validate it.
897 ??? Note that we ignore Has_Volatile_Components on objects; it's
898 not at all clear what to do in that case. */
900 {
909 }
911 /* If this is an aliased object with an unconstrained array nominal
912 subtype, make a type that includes the template. We will either
913 allocate or create a variable of that type, see below. */
917 {
919 gnu_type
921 gnu_type,
924 debug_info_p);
925 }
927 /* ??? If this is an object of CW type initialized to a value, try to
928 ensure that the object is sufficient aligned for this value, but
929 without pessimizing the allocation. This is a kludge necessary
930 because we don't support dynamic alignment. */
937 #ifdef MINIMUM_ATOMIC_ALIGNMENT
938 /* If the size is a constant and no alignment is specified, force
939 the alignment to be the minimum valid atomic alignment. The
940 restriction on constant size avoids problems with variable-size
941 temporaries; if the size is variable, there's no issue with
942 atomic access. Also don't do this for a constant, since it isn't
943 necessary and can interfere with constant replacement. Finally,
944 do not do it for Out parameters since that creates an
945 size inconsistency with In parameters. */
955 #endif
957 /* Make a new type with the desired size and alignment, if needed.
958 But do not take into account alignment promotions to compute the
959 size of the object. */
962 {
968 /* If a padding record was made, declare it now since it will
969 never be declared otherwise. This is necessary to ensure
970 that its subtrees are properly marked. */
974 }
976 /* Now check if the type of the object allows atomic access. */
980 /* If this is a renaming, avoid as much as possible to create a new
981 object. However, in some cases, creating it is required because
982 renaming can be applied to objects that are not names in Ada.
983 This processing needs to be applied to the raw expression so as
984 to make it more likely to rename the underlying object. */
986 {
987 /* If the renamed object had padding, strip off the reference to
988 the inner object and reset our type. */
991 /* Strip useless conversions around the object. */
993 {
996 }
998 /* Or else, if the renamed object has an unconstrained type with
999 default discriminant, use the padded type. */
1003 /* Case 1: if this is a constant renaming stemming from a function
1004 call, treat it as a normal object whose initial value is what
1005 is being renamed. RM 3.3 says that the result of evaluating a
1006 function call is a constant object. Therefore, it can be the
1007 inner object of a constant renaming and the renaming must be
1008 fully instantiated, i.e. it cannot be a reference to (part of)
1009 an existing object. And treat other rvalues (addresses, null
1010 expressions, constructors and literals) the same way. */
1014 /* Expand_Dispatching_Call can prepend a comparison of the tags
1015 before the call to "=". */
1026 /* We need to detect the case where a temporary is created to
1027 hold the return value, since we cannot safely rename it at
1028 top level as it lives only in the elaboration routine. */
1031 /* We also need to detect the case where the front-end creates
1032 a dangling 'reference to a function call at top level and
1033 substitutes it in the renaming, for example:
1035 q__b : boolean renames r__f.e (1);
1037 can be rewritten into:
1039 q__R1s : constant q__A2s := r__f'reference;
1040 [...]
1041 q__b : boolean renames q__R1s.all.e (1);
1043 We cannot safely rename the rewritten expression since the
1044 underlying object lives only in the elaboration routine. */
1046 && (inner
1050 ;
1052 /* Case 2: if the renaming entity need not be materialized, use
1053 the elaborated renamed expression for the renaming. But this
1054 means that the caller is responsible for evaluating the address
1055 of the renaming in the correct place for the definition case to
1056 instantiate the SAVE_EXPRs. */
1058 {
1061 gnu_decl
1065 /* We cannot evaluate the first arm of a COMPOUND_EXPR in the
1066 correct place for this case. */
1069 /* No DECL_EXPR will be created so the expression needs to be
1070 marked manually because it will likely be shared. */
1074 /* This assertion will fail if the renamed object isn't aligned
1075 enough as to make it possible to honor the alignment set on
1076 the renaming. */
1078 {
1083 }
1085 /* The expression might not be a DECL so save it manually. */
1090 }
1092 /* Case 3: otherwise, make a constant pointer to the object we
1093 are renaming and attach the object to the pointer after it is
1094 elaborated. The object will be referenced directly instead
1095 of indirectly via the pointer to avoid aliasing problems with
1096 non-addressable entities. The pointer is called a "renaming"
1097 pointer in this case. Note that we also need to preserve the
1098 volatility of the renamed object through the indirection. */
1099 else
1100 {
1104 gnu_type
1113 renamed_obj
1117 /* The expression needs to be marked manually because it will
1118 likely be shared, even for a definition since the ADDR_EXPR
1119 built below can cause the first few nodes to be folded. */
1126 else
1127 {
1128 gnu_expr
1131 gnu_expr
1133 gnu_expr);
1134 }
1135 }
1136 }
1138 /* If we are defining an aliased object whose nominal subtype is
1139 unconstrained, the object is a record that contains both the
1140 template and the object. If there is an initializer, it will
1141 have already been converted to the right type, but we need to
1142 create the template if there is no initializer. */
1144 && !gnu_expr
1147 /* Beware that padding might have been introduced above. */
1150 == RECORD_TYPE
1151 && TYPE_CONTAINS_TEMPLATE_P
1153 {
1154 tree template_field
1162 NULL_TREE);
1165 }
1167 /* Convert the expression to the type of the object if need be. */
1171 /* If this is a pointer that doesn't have an initializing expression,
1172 initialize it to NULL, unless the object is declared imported as
1173 per RM B.1(24). */
1176 && !gnu_expr
1180 /* If we are defining the object and it has an Address clause, we must
1181 either get the address expression from the saved GCC tree for the
1182 object if it has a Freeze node, or elaborate the address expression
1183 here since the front-end has guaranteed that the elaboration has no
1184 effects in this case. */
1186 {
1189 tree gnu_address
1195 /* Convert the type of the object to a reference type that can
1196 alias everything as per RM 13.3(19). */
1199 gnu_type
1203 const_flag
1209 /* If this is an aliased object with an unconstrained array nominal
1210 subtype, then it can overlay only another aliased object with an
1211 unconstrained array nominal subtype and compatible template. */
1215 {
1219 /* This is the pattern built for a regular object. */
1223 /* This is the pattern built for an overaligned object. */
1226 == PLUS_EXPR
1229 gnu_address
1233 else
1234 {
1237 gnat_entity);
1240 }
1241 }
1243 /* If we don't have an initializing expression for the underlying
1244 variable, the initializing expression for the pointer is the
1245 specified address. Otherwise, we have to make a COMPOUND_EXPR
1246 to assign both the address and the initial value. */
1249 else
1250 gnu_expr
1254 NULL_TREE,
1255 gnu_address),
1256 gnu_expr),
1257 gnu_address);
1258 }
1260 /* If it has an address clause and we are not defining it, mark it
1261 as an indirect object. Likewise for Stdcall objects that are
1262 imported. */
1265 {
1266 /* Convert the type of the object to a reference type that can
1267 alias everything as per RM 13.3(19). */
1270 gnu_type
1277 /* No point in taking the address of an initializing expression
1278 that isn't going to be used. */
1281 /* If it has an address clause whose value is known at compile
1282 time, make the object a CONST_DECL. This will avoid a
1283 useless dereference. */
1285 {
1286 Node_Id gnat_address
1290 {
1293 }
1294 }
1295 }
1297 /* If we are at top level and this object is of variable size,
1298 make the actual type a hidden pointer to the real type and
1299 make the initializer be a memory allocation and initialization.
1300 Likewise for objects we aren't defining (presumed to be
1301 external references from other packages), but there we do
1302 not set up an initialization.
1304 If the object's size overflows, make an allocator too, so that
1305 Storage_Error gets raised. Note that we will never free
1306 such memory, so we presume it never will get allocated. */
1309 || !definition
1311 || (gnu_size
1313 size_binop
1315 bitsize_unit_node)),
1317 || !definition
1319 {
1328 /* In case this was a aliased object whose nominal subtype is
1329 unconstrained, the pointer above will be a thin pointer and
1330 build_allocator will automatically make the template.
1332 If we have a template initializer only (that we made above),
1333 pretend there is none and rely on what build_allocator creates
1334 again anyway. Otherwise (if we have a full initializer), get
1335 the data part and feed that to build_allocator.
1337 If we are elaborating a mutable object, tell build_allocator to
1338 ignore a possibly simpler size from the initializer, if any, as
1339 we must allocate the maximum possible size in this case. */
1341 {
1346 {
1347 gnu_alloc_type
1353 else
1354 gnu_expr
1355 = build_component_ref
1359 }
1364 gnat_entity);
1366 gnu_expr
1369 }
1370 else
1372 }
1374 /* If this object would go into the stack and has an alignment larger
1375 than the largest stack alignment the back-end can honor, resort to
1376 a variable of "aligning type". */
1379 && !imported_p
1380 && !static_flag
1382 {
1383 /* Create the new variable. No need for extra room before the
1384 aligned field as this is in automatic storage. */
1385 tree gnu_new_type
1389 tree gnu_new_var
1395 /* Initialize the aligned field if we have an initializer. */
1397 add_stmt_with_node
1399 build_component_ref
1402 gnu_expr),
1403 gnat_entity);
1405 /* And setup this entity as a reference to the aligned field. */
1407 gnu_expr
1408 = build_unary_op
1418 }
1420 /* If this is an aliased object with an unconstrained array nominal
1421 subtype, we make its type a thin reference, i.e. the reference
1422 counterpart of a thin pointer, so it points to the array part.
1423 This is aimed to make it easier for the debugger to decode the
1424 object. Note that we have to do it this late because of the
1425 couple of allocation adjustments that might be made above. */
1429 {
1430 /* In case the object with the template has already been allocated
1431 just above, we have nothing to do here. */
1433 {
1434 /* This variable is a GNAT encoding used by Workbench: let it
1435 go through the debugging information but mark it as
1436 artificial: users are not interested in it. */
1437 tree gnu_unc_var
1452 }
1455 gnu_type
1457 }
1459 /* Convert the expression to the type of the object if need be. */
1463 /* If this name is external or a name was specified, use it, but don't
1464 use the Interface_Name with an address clause (see cd30005). */
1470 /* If this is an aggregate constant initialized to a constant, force it
1471 to be statically allocated. This saves an initialization copy. */
1473 && const_flag
1482 /* Deal with a pragma Linker_Section on a constant or variable. */
1488 /* Now create the variable or the constant and set various flags. */
1489 gnu_decl
1499 /* If we are defining an Out parameter and optimization isn't enabled,
1500 create a fake PARM_DECL for debugging purposes and make it point to
1501 the VAR_DECL. Suppress debug info for the latter but make sure it
1502 will live in memory so that it can be accessed from within the
1503 debugger through the PARM_DECL. */
1505 && definition
1506 && debug_info_p
1507 && !optimize
1509 {
1516 }
1518 /* If this is a loop parameter, set the corresponding flag. */
1522 /* If this is a renaming pointer, attach the renamed object to it. */
1526 /* If this is a constant and we are defining it or it generates a real
1527 symbol at the object level and we are referencing it, we may want
1528 or need to have a true variable to represent it:
1529 - if optimization isn't enabled, for debugging purposes,
1530 - if the constant is public and not overlaid on something else,
1531 - if its address is taken,
1532 - if either itself or its type is aliased. */
1541 {
1542 tree gnu_corr_var
1550 }
1552 /* If this is a constant, even if we don't need a true variable, we
1553 may need to avoid returning the initializer in every case. That
1554 can happen for the address of a (constant) constructor because,
1555 upon dereferencing it, the constructor will be reinjected in the
1556 tree, which may not be valid in every case; see lvalue_required_p
1557 for more details. */
1561 /* If this object is declared in a block that contains a block with an
1562 exception handler, and we aren't using the GCC exception mechanism,
1563 we must force this variable in memory in order to avoid an invalid
1564 optimization. */
1569 /* If this is a local variable with non-BLKmode and aggregate type,
1570 and optimization isn't enabled, then force it in memory so that
1571 a register won't be allocated to it with possible subparts left
1572 uninitialized and reaching the register allocator. */
1582 /* If we are defining an object with variable size or an object with
1583 fixed size that will be dynamically allocated, and we are using the
1584 front-end setjmp/longjmp exception mechanism, update the setjmp
1585 buffer. */
1598 gnat_entity);
1600 /* Back-annotate Esize and Alignment of the object if not already
1601 known. Note that we pick the values of the type, not those of
1602 the object, to shield ourselves from low-level platform-dependent
1603 adjustments like alignment promotion. This is both consistent with
1604 all the treatment above, where alignment and size are set on the
1605 type of the object and not on the object directly, and makes it
1606 possible to support all confirming representation clauses. */
1608 used_by_ref);
1609 }
1613 /* Return a TYPE_DECL for "void" that we previously made. */
1618 /* A special case: for the types Character and Wide_Character in
1619 Standard, we do not list all the literals. So if the literals
1620 are not specified, make this an integer type. */
1622 {
1625 else
1629 /* Set TYPE_STRING_FLAG for Character and Wide_Character types.
1630 This is needed by the DWARF-2 back-end to distinguish between
1631 unsigned integer types and character types. */
1634 /* This flag is needed by the call just below. */
1638 }
1639 else
1640 {
1641 /* We have a list of enumeral constants in First_Literal. We make a
1642 CONST_DECL for each one and build into GNU_LITERAL_LIST the list
1643 to be placed into TYPE_FIELDS. Each node is itself a TREE_LIST
1644 whose TREE_VALUE is the literal name and whose TREE_PURPOSE is the
1645 value of the literal. But when we have a regular boolean type, we
1646 simplify this a little by using a BOOLEAN_TYPE. */
1651 Entity_Id gnat_literal;
1664 {
1665 tree gnu_value
1667 /* Do not generate debug info for individual enumerators. */
1668 tree gnu_literal
1674 gnu_list
1676 }
1681 /* Note that the bounds are updated at the end of this function
1682 to avoid an infinite recursion since they refer to the type. */
1684 }
1688 /* For integer types, just make a signed type the appropriate number
1689 of bits. */
1695 {
1696 /* Small_Value is the scale factor. */
1702 /* Try to decode the scale factor and to save it for the fixed-point
1703 types debug hook. */
1705 /* There are various ways to describe the scale factor, however there
1706 are cases where back-end internals cannot hold it. In such cases,
1707 we output invalid scale factor for such cases (i.e. the 0/0
1708 rational constant) but we expect GNAT to output GNAT encodings,
1709 then. Thus, keep this in sync with
1710 Exp_Dbug.Is_Handled_Scale_Factor. */
1712 /* When encoded as 1/2**N or 1/10**N, describe the scale factor as a
1713 binary or decimal scale: it is easier to read for humans. */
1717 {
1718 /* Given RM restrictions on 'Small values, we assume here that
1719 the denominator fits in an int. */
1722 const tree exponent
1725 scale_factor
1727 integer_one_node,
1730 }
1732 /* Default to arbitrary scale factors descriptions. */
1733 else
1734 {
1739 {
1740 const tree gnu_num
1743 const tree gnu_den
1748 }
1749 else
1750 /* If compiler internals cannot represent arbitrary scale
1751 factors, output an invalid scale factor so that debugger
1752 don't try to handle them but so that we still have a type
1753 in the output. Note that GNAT */
1755 }
1759 }
1763 {
1764 /* For modular types, make the unsigned type of the proper number
1765 of bits and then set up the modulus, if required. */
1768 /* Packed Array Impl. Types are supposed to be subtypes only. */
1773 /* Get the modulus in this type. If it overflows, assume it is because
1774 it is equal to 2**Esize. Note that there is no overflow checking
1775 done on unsigned type, so we detect the overflow by looking for
1776 a modulus of zero, which is otherwise invalid. */
1780 {
1785 }
1787 /* If the upper bound is not maximal, make an extra subtype. */
1790 {
1797 }
1798 }
1807 /* For integral subtypes, we make a new INTEGER_TYPE. Note that we do
1808 not want to call create_range_type since we would like each subtype
1809 node to be distinct. ??? Historically this was in preparation for
1810 when memory aliasing is implemented, but that's obsolete now given
1811 the call to relate_alias_sets below.
1813 The TREE_TYPE field of the INTEGER_TYPE points to the base type;
1814 this fact is used by the arithmetic conversion functions.
1816 We elaborate the Ancestor_Subtype if it is not in the current unit
1817 and one of our bounds is non-static. We do this to ensure consistent
1818 naming in the case where several subtypes share the same bounds, by
1819 elaborating the first such subtype first, thus using its name. */
1828 /* Set the precision to the Esize except for bit-packed arrays. */
1833 /* First subtypes of Character are treated as Character; otherwise
1834 this should be an unsigned type if the base type is unsigned or
1835 if the lower bound is constant and non-negative or if the type
1836 is biased. However, even if the lower bound is constant and
1837 non-negative, we use a signed type for a subtype with the same
1838 size as its signed base type, because this eliminates useless
1839 conversions to it and gives more leeway to the optimizer; but
1840 this means that we will need to explicitly test for this case
1841 when we change the representation based on the RM size. */
1853 else
1857 SET_TYPE_RM_MIN_VALUE
1860 debug_info_p));
1862 SET_TYPE_RM_MAX_VALUE
1865 debug_info_p));
1870 /* Do the same processing for Character subtypes as for types. */
1872 {
1877 }
1879 /* Inherit our alias set from what we're a subtype of. Subtypes
1880 are not different types and a pointer can designate any instance
1881 within a subtype hierarchy. */
1884 /* One of the above calls might have caused us to be elaborated,
1885 so don't blow up if so. */
1887 {
1890 }
1892 /* Attach the TYPE_STUB_DECL in case we have a parallel type. */
1896 /* For a packed array, make the original array type a parallel/debug
1897 type. */
1901 discrete_type:
1903 /* We have to handle clauses that under-align the type specially. */
1906 && Present
1909 {
1913 }
1915 /* If the type we are dealing with represents a bit-packed array,
1916 we need to have the bits left justified on big-endian targets
1917 and right justified on little-endian targets. We also need to
1918 ensure that when the value is read (e.g. for comparison of two
1919 such values), we only get the good bits, since the unused bits
1920 are uninitialized. Both goals are accomplished by wrapping up
1921 the modular type in an enclosing record type. */
1924 {
1927 /* Set the RM size before wrapping up the original type. */
1932 /* Strip the ___XP suffix for standard DWARF. */
1936 /* Create a stripped-down declaration, mainly for debugging. */
1938 gnat_entity);
1940 /* Now save it and build the enclosing record type. */
1950 /* Propagate the alignment of the modular type to the record type,
1951 unless there is an alignment clause that under-aligns the type.
1952 This means that bit-packed arrays are given "ceil" alignment for
1953 their size by default, which may seem counter-intuitive but makes
1954 it possible to overlay them on modular types easily. */
1958 /* Propagate the reverse storage order flag to the record type so
1959 that the required byte swapping is performed when retrieving the
1960 enclosed modular value. */
1966 /* Don't declare the field as addressable since we won't be taking
1967 its address and this would prevent create_field_decl from making
1968 a bitfield. */
1969 gnu_field
1973 /* We will output additional debug info manually below. */
1979 {
1980 /* Make the original array type a parallel/debug type. */
1983 /* Since GNU_TYPE is a padding type around the packed array
1984 implementation type, the padded type is its debug type. */
1987 }
1988 }
1990 /* If the type we are dealing with has got a smaller alignment than the
1991 natural one, we need to wrap it up in a record type and misalign the
1992 latter; we reuse the padding machinery for this purpose. */
1994 {
1997 /* Set the RM size before wrapping the type. */
2000 gnu_type
2006 }
2011 /* The type of the Low and High bounds can be our type if this is
2012 a type from Standard, so set them at the end of the function. */
2019 /* See the E_Signed_Integer_Subtype case for the rationale. */
2036 SET_TYPE_RM_MIN_VALUE
2039 debug_info_p));
2041 SET_TYPE_RM_MAX_VALUE
2044 debug_info_p));
2046 /* Inherit our alias set from what we're a subtype of, as for
2047 integer subtypes. */
2050 /* One of the above calls might have caused us to be elaborated,
2051 so don't blow up if so. */
2055 /* Array Types and Subtypes
2057 Unconstrained array types are represented by E_Array_Type and
2058 constrained array types are represented by E_Array_Subtype. There
2059 are no actual objects of an unconstrained array type; all we have
2060 are pointers to that type.
2062 The following fields are defined on array types and subtypes:
2064 Component_Type Component type of the array.
2065 Number_Dimensions Number of dimensions (an int).
2066 First_Index Type of first index. */
2069 {
2070 const bool convention_fortran_p
2073 tree gnu_template_type;
2074 tree gnu_ptr_template;
2081 tree comp_type;
2083 /* Create the type for the component now, as it simplifies breaking
2084 type reference loops. */
2085 comp_type
2088 {
2089 /* As a side effect, the type may have been translated. */
2092 }
2094 /* We complete an existing dummy fat pointer type in place. This both
2095 avoids further complex adjustments in update_pointer_to and yields
2096 better debugging information in DWARF by leveraging the support for
2097 incomplete declarations of "tagged" types in the DWARF back-end. */
2100 {
2103 /* Save the contents of the dummy type for update_pointer_to. */
2105 gnu_ptr_template =
2108 }
2109 else
2110 {
2114 }
2116 /* Make a node for the array. If we are not defining the array
2117 suppress expanding incomplete types. */
2121 {
2122 defer_incomplete_level++;
2124 }
2126 /* Build the fat pointer type. Use a "void *" object instead of
2127 a pointer to the array type since we don't have the array type
2128 yet (it will reference the fat pointer via the bounds). */
2129 tem
2137 {
2138 /* We are going to lay it out again so reset the alias set. */
2144 {
2147 }
2148 }
2149 else
2150 {
2153 }
2155 /* Build a reference to the template from a PLACEHOLDER_EXPR that
2156 is the fat pointer. This will be used to access the individual
2157 fields once we build them. */
2161 gnu_template_reference
2166 /* Now create the GCC type for each index and add the fields for that
2167 index to the template. */
2173 {
2176 tree gnu_index_base_type
2181 /* Make the FIELD_DECLs for the low and high bounds of this
2182 type and then make extractions of these fields from the
2183 template. */
2186 gnu_index_base_type,
2194 gnu_index_base_type,
2202 /* We can't use build_component_ref here since the template type
2203 isn't complete yet. */
2206 NULL_TREE);
2209 NULL_TREE);
2215 /* Compute the size of this dimension. See the E_Array_Subtype
2216 case below for the rationale. */
2217 gnu_high
2221 gnu_max,
2224 /* Make a range type with the new range in the Ada base type.
2225 Then make an index type with the size range in sizetype. */
2229 gnu_orig_min,
2230 gnu_orig_max),
2231 gnat_entity);
2233 /* Update the maximum size of the array in elements. */
2235 {
2236 tree gnu_min
2238 tree gnu_max
2240 tree gnu_this_max
2247 else
2248 gnu_max_size
2250 }
2254 }
2256 /* Install all the fields into the template. */
2261 gnu_template_fields
2264 debug_info_p);
2267 /* If Component_Size is not already specified, annotate it with the
2268 size of the component. */
2273 /* Compute the maximum size of the array in units and bits. */
2275 {
2281 }
2282 else
2285 /* Now build the array type. */
2288 {
2296 }
2298 /* If an alignment is specified, use it if valid. But ignore it
2299 for the original type of packed array types. If the alignment
2300 was requested with an explicit alignment clause, state so. */
2303 {
2306 gnat_entity,
2310 }
2312 /* Tag top-level ARRAY_TYPE nodes for packed arrays and their
2313 implementation types as such so that the debug information back-end
2314 can output the appropriate description for them. */
2322 /* Adjust the type of the pointer-to-array field of the fat pointer
2323 and record the aliasing relationships if necessary. */
2328 /* The result type is an UNCONSTRAINED_ARRAY_TYPE that indicates the
2329 corresponding fat pointer. */
2336 /* If the maximum size doesn't overflow, use it. */
2342 {
2347 }
2352 /* If told to generate GNAT encodings for them (GDB rely on them at the
2353 moment): give the fat pointer type a name. If this is a packed
2354 array, tell the debugger how to interpret the underlying bits. */
2357 else
2359 tree xup_name
2364 gnat_entity);
2366 /* Create the type to be designated by thin pointers: a record type for
2367 the array and its template. We used to shift the fields to have the
2368 template at a negative offset, but this was somewhat of a kludge; we
2369 now shift thin pointer values explicitly but only those which have a
2370 TYPE_UNCONSTRAINED_ARRAY attached to the designated RECORD_TYPE.
2371 Note that GDB can handle standard DWARF information for them, so we
2372 don't have to name them as a GNAT encoding, except if specifically
2373 asked to. */
2374 tree xut_name
2379 debug_info_p);
2383 }
2388 /* This is the actual data type for array variables. Multidimensional
2389 arrays are implemented as arrays of arrays. Note that arrays which
2390 have sparse enumeration subtypes as index components create sparse
2391 arrays, which is obviously space inefficient but so much easier to
2392 code for now.
2394 Also note that the subtype never refers to the unconstrained array
2395 type, which is somewhat at variance with Ada semantics.
2397 First check to see if this is simply a renaming of the array type.
2398 If so, the result is the array type. */
2402 ;
2403 else
2404 {
2406 const bool convention_fortran_p
2415 /* First create the GCC type for each index and find out whether
2416 special types are needed for debugging information. */
2419 gnat_base_index
2425 {
2427 tree gnu_index_base_type
2429 tree gnu_orig_min
2432 tree gnu_orig_max
2437 tree gnu_base_index_type
2439 tree gnu_base_index_base_type
2441 tree gnu_base_orig_min
2444 tree gnu_base_orig_max
2447 tree gnu_high;
2449 /* See if the base array type is already flat. If it is, we
2450 are probably compiling an ACATS test but it will cause the
2451 code below to malfunction if we don't handle it specially. */
2455 {
2459 }
2461 /* Similarly, if one of the values overflows in sizetype and the
2462 range is null, use 1..0 for the sizetype bounds. */
2467 {
2471 }
2473 /* If the minimum and maximum values both overflow in sizetype,
2474 but the difference in the original type does not overflow in
2475 sizetype, ignore the overflow indication. */
2479 && !TREE_OVERFLOW
2482 gnu_orig_max,
2483 gnu_orig_min))))
2484 {
2488 }
2490 /* Compute the size of this dimension in the general case. We
2491 need to provide GCC with an upper bound to use but have to
2492 deal with the "superflat" case. There are three ways to do
2493 this. If we can prove that the array can never be superflat,
2494 we can just use the high bound of the index type. */
2497 /* Bit-Packed Array Impl. Types are never superflat. */
2499 && Is_Bit_Packed_Array
2503 /* Otherwise, if the high bound is constant but the low bound is
2504 not, we use the expression (hb >= lb) ? lb : hb + 1 for the
2505 lower bound. Note that the comparison must be done in the
2506 original type to avoid any overflow during the conversion. */
2509 {
2511 gnu_min
2514 boolean_type_node,
2515 gnu_orig_max,
2516 gnu_orig_min),
2517 gnu_min,
2519 size_one_node));
2520 }
2522 /* Finally we use (hb >= lb) ? hb : lb - 1 for the upper bound
2523 in all the other cases. Note that, here as well as above,
2524 the condition used in the comparison must be equivalent to
2525 the condition (length != 0). This is relied upon in order
2526 to optimize array comparisons in compare_arrays. Moreover
2527 we use int_const_binop for the shift by 1 if the bound is
2528 constant to avoid any unwanted overflow. */
2529 else
2530 gnu_high
2533 boolean_type_node,
2534 gnu_orig_max,
2535 gnu_orig_min),
2536 gnu_max,
2539 size_one_node)
2541 size_one_node));
2543 /* Reuse the index type for the range type. Then make an index
2544 type with the size range in sizetype. */
2547 gnat_entity);
2549 /* Update the maximum size of the array in elements. Here we
2550 see if any constraint on the index type of the base type
2551 can be used in the case of self-referential bound on the
2552 index type of the subtype. We look for a non-"infinite"
2553 and non-self-referential bound from any type involved and
2554 handle each bound separately. */
2556 {
2559 tree gnu_base_base_min
2562 tree gnu_base_base_max
2583 else
2584 {
2585 tree gnu_this_max;
2587 /* Use int_const_binop if the bounds are constant to
2588 avoid any unwanted overflow. */
2591 gnu_this_max
2594 gnu_base_max,
2595 gnu_base_min));
2596 else
2597 gnu_this_max
2600 gnu_base_max,
2601 gnu_base_min));
2603 gnu_max_size
2605 }
2606 }
2608 /* We need special types for debugging information to point to
2609 the index types if they have variable bounds, are not integer
2610 types, are biased or are wider than sizetype. These are GNAT
2611 encodings, so we have to include them only when all encodings
2612 are requested. */
2622 }
2624 /* Then flatten: create the array of arrays. For an array type
2625 used to implement a packed array, get the component type from
2626 the original array type since the representation clauses that
2627 can affect it are on the latter. */
2630 {
2635 /* One of the above calls might have caused us to be elaborated,
2636 so don't blow up if so. */
2638 {
2641 }
2642 }
2643 else
2644 {
2646 debug_info_p);
2648 /* One of the above calls might have caused us to be elaborated,
2649 so don't blow up if so. */
2651 {
2654 }
2655 }
2657 /* Compute the maximum size of the array in units and bits. */
2659 {
2665 }
2666 else
2669 /* Now build the array type. */
2671 {
2680 }
2682 /* Strip the ___XP suffix for standard DWARF. */
2685 {
2686 Entity_Id gnat_original_array_type
2689 gnu_entity_name
2691 }
2693 /* Attach the TYPE_STUB_DECL in case we have a parallel type. */
2697 /* If this is a multi-dimensional array and we are at global level,
2698 we need to make a variable corresponding to the stride of the
2699 inner dimensions. */
2701 {
2702 tree gnu_arr_type;
2707 {
2717 /* ??? For now, store the size as a multiple of the
2718 alignment of the element type in bytes so that we
2719 can see the alignment from the tree. */
2727 /* ??? create_type_decl is not invoked on the inner types so
2728 the MULT_EXPR node built above will never be marked. */
2730 }
2731 }
2733 /* If we need to write out a record type giving the names of the
2734 bounds for debugging purposes, do it now and make the record
2735 type a parallel type. This is not needed for a packed array
2736 since the bounds are conveyed by the original array type. */
2738 && debug_info_p
2740 {
2743 tree gnu_field;
2749 {
2753 /* Make sure to reference the types themselves, and not just
2754 their names, as the debugger may fall back on them. */
2760 }
2764 }
2766 /* If this is a packed array type, make the original array type a
2767 parallel/debug type. Otherwise, if such GNAT encodings are
2768 required, do it for the base array type if it isn't artificial to
2769 make sure it is kept in the debug info. */
2771 {
2774 gnat_entity);
2775 else
2776 {
2777 tree gnu_base_decl
2784 }
2785 }
2791 /* Tag top-level ARRAY_TYPE nodes for packed arrays and their
2792 implementation types as such so that the debug information back-end
2793 can output the appropriate description for them. */
2798 /* If the size is self-referential and the maximum size doesn't
2799 overflow, use it. */
2801 && gnu_max_size
2806 {
2812 }
2814 /* Set our alias set to that of our base type. This gives all
2815 array subtypes the same alias set. */
2818 /* If this is a packed type, make this type the same as the packed
2819 array type, but do some adjusting in the type first. */
2821 {
2822 Entity_Id gnat_index;
2823 tree gnu_inner;
2825 /* First finish the type we had been making so that we output
2826 debugging information for it. */
2829 {
2830 const int quals
2831 = TYPE_QUAL_VOLATILE
2834 }
2835 /* Make it artificial only if the base type was artificial too.
2836 That's sort of "morally" true and will make it possible for
2837 the debugger to look it up by name in DWARF, which is needed
2838 in order to decode the packed array type. */
2839 gnu_decl
2843 gnat_entity);
2845 /* Save it as our equivalent in case the call below elaborates
2846 this type again. */
2849 gnu_decl
2864 /* We need to attach the index type to the type we just made so
2865 that the actual bounds can later be put into a template. */
2870 {
2872 {
2873 /* The TYPE_ACTUAL_BOUNDS field is overloaded with the
2874 TYPE_MODULUS for modular types so we make an extra
2875 subtype if necessary. */
2877 {
2878 tree gnu_subtype
2887 }
2891 /* Check for other cases of overloading. */
2893 }
2898 SET_TYPE_ACTUAL_BOUNDS
2905 SET_TYPE_ACTUAL_BOUNDS
2911 }
2912 }
2913 }
2917 /* Create the type for a string literal. */
2918 {
2919 Entity_Id gnat_full_type
2924 tree gnu_string_array_type
2926 tree gnu_string_index_type
2929 tree gnu_lower_bound
2932 tree gnu_length
2934 gnu_string_index_type);
2935 tree gnu_upper_bound
2937 gnu_lower_bound,
2940 integer_one_node)));
2941 tree gnu_index_type
2945 gnu_lower_bound,
2946 gnu_upper_bound),
2947 gnat_entity);
2949 gnu_type
2952 gnu_index_type);
2956 }
2959 /* Record Types and Subtypes
2961 The following fields are defined on record types:
2963 Has_Discriminants True if the record has discriminants
2964 First_Discriminant Points to head of list of discriminants
2965 First_Entity Points to head of list of fields
2966 Is_Tagged_Type True if the record is tagged
2968 Implementation of Ada records and discriminated records:
2970 A record type definition is transformed into the equivalent of a C
2971 struct definition. The fields that are the discriminants which are
2972 found in the Full_Type_Declaration node and the elements of the
2973 Component_List found in the Record_Type_Definition node. The
2974 Component_List can be a recursive structure since each Variant of
2975 the Variant_Part of the Component_List has a Component_List.
2977 Processing of a record type definition comprises starting the list of
2978 field declarations here from the discriminants and the calling the
2979 function components_to_record to add the rest of the fields from the
2980 component list and return the gnu type node. The function
2981 components_to_record will call itself recursively as it traverses
2982 the tree. */
2986 {
2987 gnu_type
2988 = build_complex_type
2989 (get_unpadded_type
2992 (Component_List
2993 (Type_Definition
2997 }
2999 {
3002 Node_Id gnat_constr;
3005 tree gnu_get_parent;
3006 /* Set PACKED in keeping with gnat_to_gnu_field. */
3007 const int packed
3016 const bool is_extension
3022 /* See if all fields have a rep clause. Stop when we find one
3023 that doesn't. */
3031 {
3034 }
3036 /* If this is a record extension, go a level further to find the
3037 record definition. Also, verify we have a Parent_Subtype. */
3039 {
3046 }
3048 /* Make a node for the record. If we are not defining the record,
3049 suppress expanding incomplete types. */
3058 {
3059 defer_incomplete_level++;
3061 }
3063 /* If both a size and rep clause were specified, put the size on
3064 the record type now so that it can get the proper layout. */
3069 /* Always set the alignment on the record type here so that it can
3070 get the proper layout. */
3075 else
3076 {
3079 /* If a type needs strict alignment, the minimum size will be the
3080 type size instead of the RM size (see validate_size). Cap the
3081 alignment lest it causes this type size to become too large. */
3083 {
3088 }
3089 }
3091 /* If we have a Parent_Subtype, make a field for the parent. If
3092 this record has rep clauses, force the position to zero. */
3094 {
3097 tree gnu_parent;
3100 /* A major complexity here is that the parent subtype will
3101 reference our discriminants in its Stored_Constraint list.
3102 But those must reference the parent component of this record
3103 which is precisely of the parent subtype we have not built yet!
3104 To break the circle we first build a dummy COMPONENT_REF which
3105 represents the "get to the parent" operation and initialize
3106 each of those discriminants to a COMPONENT_REF of the above
3107 dummy parent referencing the corresponding discriminant of the
3108 base type of the parent subtype. */
3113 gnu_dummy_parent_type),
3114 NULL_TREE);
3121 {
3122 tree gnu_field
3125 save_gnu_tree
3130 }
3132 /* Then we build the parent subtype. If it has discriminants but
3133 the type itself has unknown discriminants, this means that it
3134 doesn't contain information about how the discriminants are
3135 derived from those of the ancestor type, so it cannot be used
3136 directly. Instead it is built by cloning the parent subtype
3137 of the underlying record view of the type, for which the above
3138 derivation of discriminants has been made explicit. */
3141 {
3144 /* If we are defining the type, the underlying record
3145 view must already have been elaborated at this point.
3146 Otherwise do it now as its parent subtype cannot be
3147 technically elaborated on its own. */
3150 else
3155 /* Substitute the "get to the parent" of the type for that
3156 of its underlying record view in the cloned type. */
3161 {
3163 tree gnu_ref
3166 gnu_parent
3168 }
3169 }
3170 else
3173 /* The parent field needs strict alignment so, if it is to
3174 be created with a component clause below, then we need
3175 to apply the same adjustment as in gnat_to_gnu_field. */
3177 {
3178 /* ??? For historical reasons, we do it on strict-alignment
3179 platforms only, where it is really required. This means
3180 that a confirming representation clause will change the
3181 behavior of the compiler on the other platforms. */
3184 else
3185 parent_packed
3187 }
3189 /* Finally we fix up both kinds of twisted COMPONENT_REF we have
3190 initially built. The discriminants must reference the fields
3191 of the parent subtype and not those of its base type for the
3192 placeholder machinery to properly work. */
3194 {
3195 /* The actual parent subtype is the full view. */
3197 {
3200 else
3202 }
3208 {
3209 Entity_Id field;
3218 }
3219 }
3221 /* The "get to the parent" COMPONENT_REF must be given its
3222 proper type... */
3225 /* ...and reference the _Parent field of this record. */
3226 gnu_field
3229 has_rep
3231 has_rep
3237 }
3239 /* Make the fields for the discriminants and put them into the record
3240 unless it's an Unchecked_Union. */
3245 {
3246 /* If this is a record extension and this discriminant is the
3247 renaming of another discriminant, we've handled it above. */
3252 gnu_field
3254 debug_info_p);
3256 /* Make an expression using a PLACEHOLDER_EXPR from the
3257 FIELD_DECL node just created and link that with the
3258 corresponding GNAT defining identifier. */
3266 {
3269 }
3270 }
3272 /* If we have a derived untagged type that renames discriminants in
3273 the parent type, the (stored) discriminants are just a copy of the
3274 discriminants of the parent type. This means that any constraints
3275 added by the renaming in the derivation are disregarded as far as
3276 the layout of the derived type is concerned. To rescue them, we
3277 change the type of the (stored) discriminants to a subtype with
3278 the bounds of the type of the visible discriminants. */
3280 && !is_extension
3286 /* Ignore access discriminants. */
3289 {
3292 tree gnu_ref
3296 /* GNU_REF must be an expression using a PLACEHOLDER_EXPR built
3297 just above for one of the stored discriminants. */
3301 {
3303 tree gnu_subtype
3314 }
3315 }
3317 /* If this is a derived type with discriminants and these discriminants
3318 affect the initial shape it has inherited, factor them in. But for
3319 an Unchecked_Union (it must be an Itype), just process the type. */
3321 && !is_extension
3327 {
3328 tree gnu_parent_type
3337 /* Set the layout of the type to match that of the parent type,
3338 doing required substitutions. */
3342 }
3343 else
3344 {
3345 /* Add the fields into the record type and finish it up. */
3352 NULL);
3354 /* If there are entities in the chain corresponding to components
3355 that we did not elaborate, ensure we elaborate their types if
3356 they are Itypes. */
3365 }
3367 /* Fill in locations of fields. */
3370 /* If this is a record type associated with an exception definition,
3371 equate its fields to those of the standard exception type. This
3372 will make it possible to convert between them. */
3374 {
3375 tree gnu_std_field;
3378 gnu_field;
3383 }
3384 }
3388 /* If an equivalent type is present, that is what we should use.
3389 Otherwise, fall through to handle this like a record subtype
3390 since it may have constraints. */
3392 {
3396 }
3398 /* ... fall through ... */
3401 /* If Cloned_Subtype is Present it means this record subtype has
3402 identical layout to that type or subtype and we should use
3403 that GCC type for this one. The front end guarantees that
3404 the component list is shared. */
3406 {
3411 }
3413 /* Otherwise, first ensure the base type is elaborated. Then, if we are
3414 changing the type, make a new type with each field having the type of
3415 the field in the new subtype but the position computed by transforming
3416 every discriminant reference according to the constraints. We don't
3417 see any difference between private and non-private type here since
3418 derivations from types should have been deferred until the completion
3419 of the private type. */
3420 else
3421 {
3425 {
3426 defer_incomplete_level++;
3428 }
3430 tree gnu_base_type
3434 {
3437 }
3439 /* If this is a record subtype associated with a dispatch table,
3440 strip the suffix. This is necessary to make sure 2 different
3441 subtypes associated with the imported and exported views of a
3442 dispatch table are properly merged in LTO mode. */
3444 {
3451 }
3453 /* When the subtype has discriminants and these discriminants affect
3454 the initial shape it has inherited, factor them in. But for an
3455 Unchecked_Union (it must be an Itype), just return the type. */
3461 {
3464 tree gnu_unpad_base_type;
3475 /* Set the size, alignment and alias set of the type to match
3476 those of the base type, doing required substitutions. */
3478 gnu_subst_list);
3482 else
3485 /* Set the layout of the type to match that of the base type,
3486 doing required substitutions. We will output debug info
3487 manually below so pass false as last argument. */
3492 /* Fill in locations of fields. */
3495 /* If debugging information is being written for the type and if
3496 we are asked to output such encodings, write a record that
3497 shows what we are a subtype of and also make a variable that
3498 indicates our size, if still variable. */
3500 {
3502 tree gnu_unpad_base_name
3510 build_reference_type
3512 gnu_subtype_marker,
3529 }
3530 }
3532 /* Otherwise, go down all the components in the new type and make
3533 them equivalent to those in the base type. */
3534 else
3535 {
3545 gnat_to_gnu_field_decl
3548 }
3549 }
3554 /* Use the special descriptor type for dispatch tables if needed,
3555 that is to say for the Prim_Ptr of a-tags.ads and its clones.
3556 Note that we are only required to do so for static tables in
3557 order to be compatible with the C++ ABI, but Ada 2005 allows
3558 to extend library level tagged types at the local level so
3559 we do it in the non-static case as well. */
3562 {
3566 }
3568 /* ... fall through ... */
3575 {
3576 /* The designated type and its equivalent type for gigi. */
3579 /* Whether it comes from a limited with. */
3580 const bool is_from_limited_with
3583 /* The "full view" of the designated type. If this is an incomplete
3584 entity from a limited with, treat its non-limited view as the full
3585 view. Otherwise, if this is an incomplete or private type, use the
3586 full view. In the former case, we might point to a private type,
3587 in which case, we need its full view. Also, we want to look at the
3588 actual type used for the representation, so this takes a total of
3589 three steps. */
3590 Entity_Id gnat_desig_full_direct_first
3591 = (is_from_limited_with
3595 Entity_Id gnat_desig_full_direct
3596 = ((is_from_limited_with
3601 Entity_Id gnat_desig_full
3603 /* The type actually used to represent the designated type, either
3604 gnat_desig_full or gnat_desig_equiv. */
3605 Entity_Id gnat_desig_rep;
3606 /* We want to know if we'll be seeing the freeze node for any
3607 incomplete type we may be pointing to. */
3608 const bool in_main_unit
3612 /* True if we make a dummy type here. */
3614 /* The mode to be used for the pointer type. */
3616 /* The GCC type used for the designated type. */
3622 /* If either the designated type or its full view is an unconstrained
3623 array subtype, replace it with the type it's a subtype of. This
3624 avoids problems with multiple copies of unconstrained array types.
3625 Likewise, if the designated type is a subtype of an incomplete
3626 record type, use the parent type to avoid order of elaboration
3627 issues. This can lose some code efficiency, but there is no
3628 alternative. */
3639 /* Set the type that's the representation of the designated type. */
3640 gnat_desig_rep
3643 /* If we already know what the full type is, use it. */
3647 /* Get the type of the thing we are to point to and build a pointer to
3648 it. If it is a reference to an incomplete or private type with a
3649 full view that is a record or an array, make a dummy type node and
3650 get the actual type later when we have verified it is safe. */
3656 /* Likewise if this is a reference to a record, an array or a
3657 subprogram type and we are to defer elaborating incomplete
3658 types. We do this because this access type may be the full
3659 view of a private type. */
3666 /* If this is a reference from a limited_with type back to our
3667 main unit and there's a freeze node for it, either we have
3668 already processed the declaration and made the dummy type,
3669 in which case we just reuse the latter, or we have not yet,
3670 in which case we make the dummy type and it will be reused
3671 when the declaration is finally processed. In both cases,
3672 the pointer eventually created below will be automatically
3673 adjusted when the freeze node is processed. */
3674 || (in_main_unit
3675 && is_from_limited_with
3677 {
3680 }
3682 /* Otherwise handle the case of a pointer to itself. */
3684 {
3685 gnu_type
3689 }
3691 /* If expansion is disabled, the equivalent type of a concurrent type
3692 is absent, so we use the void pointer type. */
3696 /* If the ultimately designated type is an incomplete type with no full
3697 view, we use the void pointer type in LTO mode to avoid emitting a
3698 dummy type in the GIMPLE IR. We cannot do that in regular mode as
3699 the name of the dummy type in used by GDB for a global lookup. */
3705 /* Finally, handle the default case where we can just elaborate our
3706 designated type. */
3707 else
3710 /* It is possible that a call to gnat_to_gnu_type above resolved our
3711 type. If so, just return it. */
3713 {
3716 }
3718 /* Access-to-unconstrained-array types need a special treatment. */
3720 {
3721 /* If the processing above got something that has a pointer, then
3722 we are done. This could have happened either because the type
3723 was elaborated or because somebody else executed the code. */
3728 }
3730 /* If we haven't done it yet, build the pointer type the usual way. */
3732 {
3733 /* Modify the designated type if we are pointing only to constant
3734 objects, but don't do it for a dummy type. */
3737 gnu_desig_type
3740 gnu_type
3743 }
3745 /* If the designated type is not declared in the main unit and we made
3746 a dummy node for it, save our definition, elaborate the actual type
3747 and replace the dummy type we made with the actual one. But if we
3748 are to defer actually looking up the actual type, make an entry in
3749 the deferred list instead. If this is from a limited with, we may
3750 have to defer until the end of the current unit. */
3752 {
3754 gnu_type
3760 gnat_entity);
3767 {
3770 }
3771 else
3772 {
3775 = (is_from_limited_with
3782 }
3783 }
3784 }
3789 /* If we are just annotating types and have no equivalent record type,
3790 just use the void pointer type. */
3794 /* The run-time representation is the equivalent type. */
3795 else
3796 {
3799 }
3801 /* The designated subtype must be elaborated as well, if it does
3802 not have its own freeze node. */
3813 /* We treat this as identical to its base type; any constraint is
3814 meaningful only to the front-end. */
3817 /* The designated subtype must be elaborated as well, if it does
3818 not have its own freeze node. But designated subtypes created
3819 for constrained components of records with discriminants are
3820 not frozen by the front-end and not elaborated here, because
3821 their use may appear before the base type is frozen and it is
3822 not clear that they are needed in gigi. With the current model,
3823 there is no correct place where they could be elaborated. */
3828 {
3829 /* If we are to defer elaborating incomplete types, make a dummy
3830 type node and elaborate it later. */
3832 {
3835 p->old_type
3840 }
3843 Incomplete_Or_Private_Kind))
3846 }
3851 /* Subprogram Entities
3853 The following access functions are defined for subprograms:
3855 Etype Return type or Standard_Void_Type.
3856 First_Formal The first formal parameter.
3857 Is_Imported Indicates that the subprogram has appeared in
3858 an INTERFACE or IMPORT pragma. For now we
3859 assume that the external language is C.
3860 Is_Exported Likewise but for an EXPORT pragma.
3861 Is_Inlined True if the subprogram is to be inlined.
3863 Each parameter is first checked by calling must_pass_by_ref on its
3864 type to determine if it is passed by reference. For parameters which
3865 are copied in, if they are Ada In Out or Out parameters, their return
3866 value becomes part of a record which becomes the return type of the
3867 function (C function - note that this applies only to Ada procedures
3868 so there is no Ada return type). Additional code to store back the
3869 parameters will be generated on the caller side. This transformation
3870 is done here, not in the front-end.
3872 The intended result of the transformation can be seen from the
3873 equivalent source rewritings that follow:
3875 struct temp {int a,b};
3876 procedure P (A,B: In Out ...) is temp P (int A,B)
3877 begin {
3878 .. ..
3879 end P; return {A,B};
3880 }
3882 temp t;
3883 P(X,Y); t = P(X,Y);
3884 X = t.a , Y = t.b;
3886 For subprogram types we need to perform mainly the same conversions to
3887 GCC form that are needed for procedures and function declarations. The
3888 only difference is that at the end, we make a type declaration instead
3889 of a function declaration. */
3894 {
3895 tree gnu_ext_name
3897 enum inline_status_t inline_status
3899 ? is_suppressed
3901 ? is_required
3904 /* Subprograms marked both Intrinsic and Always_Inline need not
3905 have a body of their own. */
3906 bool extern_flag
3908 || imported_p
3911 tree gnu_param_list;
3913 /* A parameter may refer to this type, so defer completion of any
3914 incomplete types. */
3916 {
3917 defer_incomplete_level++;
3919 }
3921 /* If the subprogram has an alias, it is probably inherited, so
3922 we can use the original one. If the original "subprogram"
3923 is actually an enumeration literal, it may be the first use
3924 of its type, so we must elaborate that type now. */
3926 {
3933 gnu_decl
3936 /* Elaborate any Itypes in the parameters of this entity. */
3943 /* Materialize renamed subprograms in the debugging information
3944 when the renamed object is compile time known. We can consider
3945 such renamings as imported declarations.
3947 Because the parameters in generics instantiation are generally
3948 materialized as renamings, we ofter end up having both the
3949 renamed subprogram and the renaming in the same context and with
3950 the same name: in this case, renaming is both useless debug-wise
3951 and potentially harmful as name resolution in the debugger could
3952 return twice the same entity! So avoid this case. */
3961 && gnu_decl
3963 {
3968 }
3971 }
3973 /* Get the GCC tree for the (underlying) subprogram type. If the
3974 entity is an actual subprogram, also get the parameter list. */
3975 gnu_type
3979 {
3983 }
3985 /* Deal with platform-specific calling conventions. */
3987 prepend_one_attribute
3990 gnat_entity);
3992 prepend_one_attribute
3995 gnat_entity);
3997 /* If we should request stack realignment for a foreign convention
3998 subprogram, do so. Note that this applies to task entry points
3999 in particular. */
4002 prepend_one_attribute
4005 gnat_entity);
4007 /* Deal with a pragma Linker_Section on a subprogram. */
4013 /* If we are defining the subprogram and it has an Address clause
4014 we must get the address expression from the saved GCC tree for the
4015 subprogram if it has a Freeze_Node. Otherwise, we elaborate
4016 the address expression here since the front-end has guaranteed
4017 in that case that the elaboration has no effects. If there is
4018 an Address clause and we are not defining the object, just
4019 make it a constant. */
4021 {
4025 gnu_address
4032 /* Convert the type of the object to a reference type that can
4033 alias everything as per RM 13.3(19). */
4034 gnu_type
4039 gnu_decl
4045 }
4047 /* If this is a mere subprogram type, just create the declaration. */
4049 {
4052 gnu_decl
4055 }
4057 /* Otherwise create the subprogram declaration with the external name,
4058 the type and the parameter list. However, if this a reference to
4059 the allocation routines, reuse the canonical declaration nodes as
4060 they come with special properties. */
4061 else
4062 {
4067 else
4068 {
4069 gnu_decl
4078 }
4079 }
4080 }
4091 {
4092 const bool is_from_limited_with
4094 /* Get the "full view" of this entity. If this is an incomplete
4095 entity from a limited with, treat its non-limited view as the
4096 full view. Otherwise, use either the full view or the underlying
4097 full view, whichever is present. This is used in all the tests
4098 below. */
4099 const Entity_Id full_view
4100 = is_from_limited_with
4108 /* If this is an incomplete type with no full view, it must be a Taft
4109 Amendment type or an incomplete type coming from a limited context,
4110 in which cases we return a dummy type. Otherwise, we just get the
4111 type from its Etype. */
4113 {
4115 {
4118 }
4119 else
4120 {
4121 gnu_decl
4124 }
4125 }
4127 /* Or else, if we already made a type for the full view, reuse it. */
4131 /* Or else, if we are not defining the type or there is no freeze
4132 node on it, get the type for the full view. Likewise if this is
4133 a limited_with'ed type not declared in the main unit, which can
4134 happen for incomplete formal types instantiated on a type coming
4135 from a limited_with clause. */
4138 || (is_from_limited_with
4140 {
4143 }
4145 /* Otherwise, make a dummy type entry which will be replaced later.
4146 Save it as the full declaration's type so we can do any needed
4147 updates when we see it. */
4148 else
4149 {
4155 }
4156 }
4160 /* Class-wide types are always transformed into their root type. */
4169 /* If we are just annotating types and have no equivalent record type,
4170 just return void_type, except for root types that have discriminants
4171 because the discriminants will very likely be used in the declarative
4172 part of the associated body so they need to be translated. */
4174 {
4177 {
4179 Entity_Id gnat_field;
4181 /* This is a minimal version of the E_Record_Type handling. */
4188 {
4189 tree gnu_field
4201 }
4205 }
4206 else
4208 }
4210 /* Concurrent types are always transformed into their record type. */
4211 else
4222 /* Nothing at all to do here, so just return an ERROR_MARK and claim
4223 we've already saved it, so we don't try to. */
4229 /* This is a SPARK annotation that only reaches here when compiling in
4230 ASIS mode. */
4238 }
4240 /* If we had a case where we evaluated another type and it might have
4241 defined this one, handle it here. */
4243 {
4246 }
4248 /* If we are processing a type and there is either no decl for it or
4249 we just made one, do some common processing for the type, such as
4250 handling alignment and possible padding. */
4252 {
4255 /* Process the attributes, if not already done. Note that the type is
4256 already defined so we cannot pass true for IN_PLACE here. */
4259 /* Tell the middle-end that objects of tagged types are guaranteed to
4260 be properly aligned. This is necessary because conversions to the
4261 class-wide type are translated into conversions to the root type,
4262 which can be less aligned than some of its derived types. */
4267 /* Record whether the type is passed by reference. */
4271 /* ??? Don't set the size for a String_Literal since it is either
4272 confirming or we don't handle it properly (if the low bound is
4273 non-constant). */
4275 {
4278 gnu_size
4281 }
4283 /* If a size was specified, see if we can make a new type of that size
4284 by rearranging the type, for example from a fat to a thin pointer. */
4286 {
4287 gnu_type
4294 }
4296 /* If the alignment has not already been processed and this is not
4297 an unconstrained array type, see if an alignment is specified.
4298 If not, we pick a default alignment for atomic objects. */
4300 ;
4302 {
4306 /* Warn on suspiciously large alignments. This should catch
4307 errors about the (alignment,byte)/(size,bit) discrepancy. */
4309 {
4310 tree size;
4312 /* If a size was specified, take it into account. Otherwise
4313 use the RM size for records or unions as the type size has
4314 already been adjusted to the alignment. */
4320 else
4323 /* Consider an alignment as suspicious if the alignment/size
4324 ratio is greater or equal to the byte/bit ratio. */
4329 gnat_entity);
4330 }
4331 }
4342 /* See if we need to pad the type. If we did, and made a record,
4343 the name of the new type may be changed. So get it back for
4344 us when we make the new TYPE_DECL below. */
4352 /* Now set the RM size of the type. We cannot do it before padding
4353 because we need to accept arbitrary RM sizes on integral types. */
4356 /* If we are at global level, GCC will have applied variable_size to
4357 the type, but that won't have done anything. So, if it's not
4358 a constant or self-referential, call elaborate_expression_1 to
4359 make a variable for the size rather than calculating it each time.
4360 Handle both the RM size and the actual size. */
4365 {
4372 /* ??? For now, store the size as a multiple of the alignment in
4373 bytes so that we can see the alignment from the tree. */
4379 /* ??? gnu_type may come from an existing type so the MULT_EXPR node
4380 may not be marked by the call to create_type_decl below. */
4384 {
4389 {
4393 /* If the position of the variant part is constant, subtract
4394 it from the size of the type of the parent to get the new
4395 size. This manual CSE reduces the data size. */
4397 {
4405 }
4406 else
4407 {
4413 /* ??? For now, store the size as a multiple of the
4414 alignment in bytes so that we can see the alignment
4415 from the tree. */
4422 /* ??? For now, store the offset as a multiple of the
4423 alignment in bytes so that we can see the alignment
4424 from the tree. */
4428 DECL_OFFSET_ALIGN
4430 }
4434 }
4438 else
4439 ada_size
4443 }
4444 }
4446 /* Similarly, if this is a record type or subtype at global level, call
4447 elaborate_expression_2 on any field position. Skip any fields that
4448 we haven't made trees for to avoid problems with class-wide types. */
4453 {
4456 /* ??? For now, store the offset as a multiple of the alignment
4457 in bytes so that we can see the alignment from the tree. */
4460 {
4467 /* ??? The context of gnu_field is not necessarily gnu_type
4468 so the MULT_EXPR node built above may not be marked by
4469 the call to create_type_decl below. */
4471 }
4472 }
4477 /* If this is not an unconstrained array type, set some flags. */
4479 {
4486 /* If it is passed by reference, force BLKmode to ensure that
4487 objects of this type will always be put in memory. */
4492 }
4494 /* If this is a derived type, relate its alias set to that of its parent
4495 to avoid troubles when a call to an inherited primitive is inlined in
4496 a context where a derived object is accessed. The inlined code works
4497 on the parent view so the resulting code may access the same object
4498 using both the parent and the derived alias sets, which thus have to
4499 conflict. As the same issue arises with component references, the
4500 parent alias set also has to conflict with composite types enclosing
4501 derived components. For instance, if we have:
4503 type D is new T;
4504 type R is record
4505 Component : D;
4506 end record;
4508 we want T to conflict with both D and R, in addition to R being a
4509 superset of D by record/component construction.
4511 One way to achieve this is to perform an alias set copy from the
4512 parent to the derived type. This is not quite appropriate, though,
4513 as we don't want separate derived types to conflict with each other:
4515 type I1 is new Integer;
4516 type I2 is new Integer;
4518 We want I1 and I2 to both conflict with Integer but we do not want
4519 I1 to conflict with I2, and an alias set copy on derivation would
4520 have that effect.
4522 The option chosen is to make the alias set of the derived type a
4523 superset of that of its parent type. It trivially fulfills the
4524 simple requirement for the Integer derivation example above, and
4525 the component case as well by superset transitivity:
4527 superset superset
4528 R ----------> D ----------> T
4530 However, for composite types, conversions between derived types are
4531 translated into VIEW_CONVERT_EXPRs so a sequence like:
4533 type Comp1 is new Comp;
4534 type Comp2 is new Comp;
4535 procedure Proc (C : Comp1);
4537 C : Comp2;
4538 Proc (Comp1 (C));
4540 is translated into:
4542 C : Comp2;
4543 Proc ((Comp1 &) &VIEW_CONVERT_EXPR <Comp1> (C));
4545 and gimplified into:
4547 C : Comp2;
4548 Comp1 *C.0;
4549 C.0 = (Comp1 *) &C;
4550 Proc (C.0);
4552 i.e. generates code involving type punning. Therefore, Comp1 needs
4553 to conflict with Comp2 and an alias set copy is required.
4555 The language rules ensure the parent type is already frozen here. */
4559 {
4561 /* For constrained packed array subtypes, the implementation type is
4562 used instead of the nominal type. */
4570 }
4573 {
4574 const int quals
4575 = TYPE_QUAL_VOLATILE
4578 }
4583 gnat_entity);
4584 else
4585 {
4588 }
4589 }
4591 /* If we got a type that is not dummy, back-annotate the alignment of the
4592 type if not already in the tree. Likewise for the size, if any. */
4594 {
4598 {
4602 /* If the default alignment of "double" or larger scalar types is
4603 specifically capped and this is not an array with an alignment
4604 clause on the component type, return the cap. */
4606 is_capped_double
4609 is_capped_double
4611 else
4616 else
4620 }
4623 {
4626 /* If the size is self-referential, annotate the maximum value. */
4630 /* If we are just annotating types and the type is tagged, the tag
4631 and the parent components are not generated by the front-end so
4632 alignment and sizes must be adjusted if there is no rep clause. */
4639 {
4640 tree offset;
4643 {
4647 }
4648 else
4649 {
4650 unsigned int align
4654 }
4657 offset
4665 }
4667 /* If there is a rep clause, only adjust alignment and Esize. */
4669 {
4670 unsigned int align
4675 }
4677 /* Otherwise no adjustment is needed. */
4678 else
4680 }
4684 }
4686 /* If we haven't already, associate the ..._DECL node that we just made with
4687 the input GNAT entity node. */
4691 /* Now we are sure gnat_entity has a corresponding ..._DECL node,
4692 eliminate as many deferred computations as possible. */
4695 /* If this is an enumeration or floating-point type, we were not able to set
4696 the bounds since they refer to the type. These are always static. */
4699 {
4703 /* If this is a padded type, we need to use the underlying type. */
4707 /* If this is a floating point type and we haven't set a floating
4708 point type yet, use this in the evaluation of the bounds. */
4716 {
4717 /* Enumeration types have specific RM bounds. */
4720 }
4721 else
4722 {
4723 /* Floating-point types don't have specific RM bounds. */
4726 }
4727 }
4729 /* If we deferred processing of incomplete types, re-enable it. If there
4730 were no other disables and we have deferred types to process, do so. */
4734 {
4737 /* We are back to level 0 for the deferring of incomplete types.
4738 But processing these incomplete types below may itself require
4739 deferring, so preserve what we have and restart from scratch. */
4744 {
4751 }
4752 }
4754 /* If we are not defining this type, see if it's on one of the lists of
4755 incomplete types. If so, handle the list entry now. */
4757 {
4762 {
4766 }
4770 {
4776 }
4777 }
4780 force_global--;
4782 /* If this is a packed array type whose original array type is itself
4783 an Itype without freeze node, make sure the latter is processed. */
4791 }
4793 /* Similar, but if the returned value is a COMPONENT_REF, return the
4794 FIELD_DECL. */
4796 tree
4798 {
4805 }
4807 /* Similar, but GNAT_ENTITY is assumed to refer to a GNAT type. Return
4808 the GCC type corresponding to that entity. */
4810 tree
4812 {
4813 tree gnu_decl;
4815 /* The back end never attempts to annotate generic types. */
4823 }
4825 /* Similar, but GNAT_ENTITY is assumed to refer to a GNAT type. Return
4826 the unpadded version of the GCC type corresponding to that entity. */
4828 tree
4830 {
4837 }
4839 /* Return whether the E_Subprogram_Type/E_Function/E_Procedure GNAT_ENTITY is
4840 a C++ imported method or equivalent.
4842 We use the predicate on 32-bit x86/Windows to find out whether we need to
4843 use the "thiscall" calling convention for GNAT_ENTITY. This convention is
4844 used for C++ methods (functions with METHOD_TYPE) by the back-end. */
4846 bool
4848 {
4849 /* A constructor is a method on the C++ side. We deal with it now because
4850 it is declared without the 'this' parameter in the sources and, although
4851 the front-end will create a version with the 'this' parameter for code
4852 generation purposes, we want to return true for both versions. */
4856 /* Check that the subprogram has C++ convention. */
4860 /* And that the type of the first parameter (indirectly) has it too. */
4871 /* This is the main case: a C++ virtual method imported as a primitive
4872 operation of a tagged type. */
4876 /* This is set on the E_Subprogram_Type built for a dispatching call. */
4880 /* A thunk needs to be handled like its associated primitive operation. */
4884 /* Now on to the annoying case: a C++ non-virtual method, imported either
4885 as a non-primitive operation of a tagged type or as a primitive operation
4886 of an untagged type. We cannot reliably differentiate these cases from
4887 their static member or regular function equivalents in Ada, so we ask
4888 the C++ side through the mangled name of the function, as the implicit
4889 'this' parameter is not encoded in the mangled name of a method. */
4891 {
4898 DMGL_GNU_V3
4899 | DMGL_TYPES
4900 | DMGL_PARAMS
4906 /* We need to release MEM once we have a successful demangling. */
4913 {
4914 /* Make sure there is at least one parameter in C++ too. */
4916 {
4919 n_ada_args++;
4925 n_cpp_args++;
4931 }
4932 else
4934 }
4939 }
4942 }
4944 /* Finalize the processing of From_Limited_With incomplete types. */
4946 void
4948 {
4955 {
4959 {
4964 }
4967 }
4968 }
4970 /* Return the equivalent type to be used for GNAT_ENTITY, if it's a kind
4971 of type (such E_Task_Type) that has a different type which Gigi uses
4972 for its representation. If the type does not have a special type for
4973 its representation, return GNAT_ENTITY. */
4975 Entity_Id
4977 {
4984 {
5010 }
5013 }
5015 /* Return a GCC tree for a type corresponding to the component type of the
5016 array type or subtype GNAT_ARRAY. DEFINITION is true if this component
5017 is for an array being defined. DEBUG_INFO_P is true if we need to write
5018 debug information for other types that we may create in the process. */
5020 static tree
5023 {
5026 tree gnu_comp_size;
5029 /* If an alignment is specified, use it as a cap on the component type
5030 so that it can be honored for the whole type. But ignore it for the
5031 original type of packed array types. */
5035 else
5038 /* Try to get a smaller form of the component if needed. */
5051 /* Get and validate any specified Component_Size. */
5052 gnu_comp_size
5057 /* If the array has aliased components and the component size can be zero,
5058 force at least unit size to ensure that the components have distinct
5059 addresses. */
5065 gnu_comp_size
5068 /* If the component type is a RECORD_TYPE that has a self-referential size,
5069 then use the maximum size for the component size. */
5075 /* Honor the component size. This is not needed for bit-packed arrays. */
5077 {
5083 else
5089 /* If a padding record was made, declare it now since it will never be
5090 declared otherwise. This is necessary to ensure that its subtrees
5091 are properly marked. */
5094 gnat_array);
5095 }
5097 /* If the component type is a padded type made for a non-bit-packed array
5098 of scalars with reverse storage order, we need to propagate the reverse
5099 storage order to the padding type since it is the innermost enclosing
5100 aggregate type around the scalar. */
5108 {
5109 const int quals
5110 = TYPE_QUAL_VOLATILE
5113 }
5116 }
5118 /* Return a GCC tree for a parameter corresponding to GNAT_PARAM, to be placed
5119 in the parameter list of GNAT_SUBPROG. GNU_PARAM_TYPE is the GCC tree for
5120 the type of the parameter. FIRST is true if this is the first parameter in
5121 the list of GNAT_SUBPROG. Also set CICO to true if the parameter must use
5122 the copy-in copy-out implementation mechanism.
5124 The returned tree is a PARM_DECL, except for the cases where no parameter
5125 needs to be actually passed to the subprogram; the type of this "shadow"
5126 parameter is then returned instead. */
5128 static tree
5131 {
5137 /* The parameter can be indirectly modified if its address is taken. */
5143 tree gnu_param;
5145 /* Make sure to use the proper SLOC for vector ABI warnings. */
5149 /* Builtins are expanded inline and there is no real call sequence involved.
5150 So the type expected by the underlying expander is always the type of the
5151 argument "as is". */
5156 /* Handle the first parameter of a valued procedure specially: it's a copy
5157 mechanism for which the parameter is never allocated. */
5159 {
5163 }
5165 /* Or else, see if a Mechanism was supplied that forced this parameter
5166 to be passed one way or another. */
5168 ;
5170 /* Positive mechanism means by copy for sufficiently small parameters. */
5172 {
5177 else
5179 }
5181 /* Otherwise, it's an unsupported mechanism so error out. */
5182 else
5183 {
5186 }
5188 /* If this is either a foreign function or if the underlying type won't
5189 be passed by reference and is as aligned as the original type, strip
5190 off possible padding type. */
5192 {
5201 }
5203 /* If this is a read-only parameter, make a variant of the type that is
5204 read-only. ??? However, if this is a self-referential type, the type
5205 can be very complex, so skip it for now. */
5209 /* For foreign conventions, pass arrays as pointers to the element type.
5210 First check for unconstrained array and get the underlying array. */
5212 gnu_param_type
5215 /* Arrays are passed as pointers to element type for foreign conventions. */
5217 {
5218 /* Strip off any multi-dimensional entries, then strip
5219 off the last array to get the component type. */
5228 gnu_param_type
5232 }
5234 /* Fat pointers are passed as thin pointers for foreign conventions. */
5236 gnu_param_type
5239 /* If we were requested or muss pass by reference, do so.
5240 If we were requested to pass by copy, do so.
5241 Otherwise, for foreign conventions, pass In Out or Out parameters
5242 or aggregates by reference. For COBOL and Fortran, pass all
5243 integer and FP types that way too. For Convention Ada, use
5244 the standard Ada default. */
5248 && ((foreign
5250 || (foreign
5255 || (!foreign
5257 {
5258 /* We take advantage of 6.2(12) by considering that references built for
5259 parameters whose type isn't by-ref and for which the mechanism hasn't
5260 been forced to by-ref allow only a restricted form of aliasing. */
5261 restricted_aliasing_p
5265 }
5267 /* Pass In Out or Out parameters using copy-in copy-out mechanism. */
5276 /* If this is an Out parameter that isn't passed by reference and isn't
5277 a pointer or aggregate, we don't make a PARM_DECL for it. Instead,
5278 it will be a VAR_DECL created when we process the procedure, so just
5279 return its type. For the special parameter of a valued procedure,
5280 never pass it in.
5282 An exception is made to cover the RM-6.4.1 rule requiring "by copy"
5283 Out parameters with discriminants or implicit initial values to be
5284 handled like In Out parameters. These type are normally built as
5285 aggregates, hence passed by reference, except for some packed arrays
5286 which end up encoded in special integer types. Note that scalars can
5287 be given implicit initial values using the Default_Value aspect.
5289 The exception we need to make is then for packed arrays of records
5290 with discriminants or implicit initial values. We have no light/easy
5291 way to check for the latter case, so we merely check for packed arrays
5292 of records. This may lead to useless copy-in operations, but in very
5293 rare cases only, as these would be exceptions in a set of already
5294 exceptional situations. */
5296 && !by_ref
5297 && (by_return
5316 /* If no Mechanism was specified, indicate what we're using, then
5317 back-annotate it. */
5323 }
5325 /* Associate GNAT_SUBPROG with GNU_TYPE, which must be a dummy type, so that
5326 GNAT_SUBPROG is updated when GNU_TYPE is completed.
5328 Ada 2012 (AI05-019) says that freezing a subprogram does not always freeze
5329 the corresponding profile, which means that, by the time the freeze node
5330 of the subprogram is encountered, types involved in its profile may still
5331 be not yet frozen. That's why we need to update GNAT_SUBPROG when we see
5332 the freeze node of types involved in its profile, either types of formal
5333 parameters or the return type. */
5335 static void
5337 {
5345 {
5350 }
5352 /* Even if there is already a slot for GNU_TYPE, we need to set the flag
5353 because the vector might have been just emptied by update_profiles_with.
5354 This can happen when there are 2 freeze nodes associated with different
5355 views of the same type; the type will be really complete only after the
5356 second freeze node is encountered. */
5361 /* Make sure GNAT_SUBPROG is not associated twice with the same dummy type,
5362 since this would mean updating twice its profile. */
5364 {
5368 /* Entity_Id is a simple integer so we can implement a stable order on
5369 the vector with an ordered insertion scheme and binary search. */
5371 {
5378 else
5380 }
5382 /* l == u and therefore is the insertion point. */
5384 }
5385 else
5389 }
5391 /* Update the GCC tree previously built for the profile of GNAT_SUBPROG. */
5393 static void
5395 {
5396 tree gnu_param_list;
5401 {
5402 /* Builtins cannot have their address taken so we can reset them. */
5407 }
5413 /* If GNAT_SUBPROG is an actual subprogram, GNU_SUBPROG is a FUNCTION_DECL
5414 and needs to be adjusted too. */
5416 {
5418 tree gnu_ext_name
5423 }
5424 }
5426 /* Update the GCC trees previously built for the profiles involving GNU_TYPE,
5427 a dummy type which appears in profiles. */
5429 void
5431 {
5439 /* The flag needs to be reset before calling update_profile, in case
5440 associate_subprog_with_dummy_type is again invoked on GNU_TYPE. */
5449 }
5451 /* Return the GCC tree for GNAT_TYPE present in the profile of a subprogram.
5453 Ada 2012 (AI05-0151) says that incomplete types coming from a limited
5454 context may now appear as parameter and result types. As a consequence,
5455 we may need to defer their translation until after a freeze node is seen
5456 or to the end of the current unit. We also aim at handling temporarily
5457 incomplete types created by the usual delayed elaboration scheme. */
5459 static tree
5461 {
5462 /* This is the same logic as the E_Access_Type case of gnat_to_gnu_entity
5463 so the rationale is exposed in that place. These processings probably
5464 ought to be merged at some point. */
5466 const bool is_from_limited_with
5469 Entity_Id gnat_full_direct_first
5470 = (is_from_limited_with
5474 Entity_Id gnat_full_direct
5475 = ((is_from_limited_with
5483 tree gnu_type;
5489 && ((!in_main_unit
5496 {
5500 {
5507 }
5508 }
5513 else
5516 /* Access-to-unconstrained-array types need a special treatment. */
5518 {
5521 }
5524 }
5526 /* Return a GCC tree for a subprogram type corresponding to GNAT_SUBPROG.
5527 DEFINITION is true if this is for a subprogram being defined. DEBUG_INFO_P
5528 is true if we need to write debug information for other types that we may
5529 create in the process. Also set PARAM_LIST to the list of parameters.
5530 If GNAT_SUBPROG is bound to a GCC builtin, return the DECL for the builtin
5531 directly instead of its type. */
5533 static tree
5536 {
5539 Entity_Id gnat_param;
5542 tree gnu_return_type;
5545 /* Non-null for subprograms containing parameters passed by copy-in copy-out
5546 (In Out or Out parameters not passed by reference), in which case it is
5547 the list of nodes used to specify the values of the In Out/Out parameters
5548 that are returned as a record upon procedure return. The TREE_PURPOSE of
5549 an element of this list is a FIELD_DECL of the record and the TREE_VALUE
5550 is the PARM_DECL corresponding to that field. This list will be saved in
5551 the TYPE_CI_CO_LIST field of the FUNCTION_TYPE node we create. */
5554 /* Fields in return type of procedure with copy-in copy-out parameters. */
5556 /* The semantics of "pure" in Ada essentially matches that of "const"
5557 in the back-end. In particular, both properties are orthogonal to
5558 the "nothrow" property if the EH circuitry is explicit in the
5559 internal representation of the back-end. If we are to completely
5560 hide the EH circuitry from it, we need to declare that calls to pure
5561 Ada subprograms that can throw have side effects since they can
5562 trigger an "abnormal" transfer of control flow; thus they can be
5563 neither "const" nor "pure" in the back-end sense. */
5571 /* Look into the return type and get its associated GCC tree if it is not
5572 void, and then compute various flags for the subprogram type. But make
5573 sure not to do this processing multiple times. */
5580 {
5585 }
5587 else
5588 {
5589 /* For foreign convention subprograms, return System.Address as void *
5590 or equivalent. Note that this comprises GCC builtins. */
5594 else
5597 /* If this function returns by reference, make the actual return type
5598 the reference type and make a note of that. */
5600 {
5603 }
5605 /* If the return type is an unconstrained array type, the return value
5606 will be allocated on the secondary stack so the actual return type
5607 is the fat pointer type. */
5609 {
5612 }
5614 /* This is the same unconstrained array case, but for a dummy type. */
5617 {
5620 }
5622 /* Likewise, if the return type requires a transient scope, the return
5623 value will also be allocated on the secondary stack so the actual
5624 return type is the reference type. */
5626 {
5629 }
5631 /* If the Mechanism is By_Reference, ensure this function uses the
5632 target's by-invisible-reference mechanism, which may not be the
5633 same as above (e.g. it might be passing an extra parameter). */
5637 /* Likewise, if the return type is itself By_Reference. */
5641 /* If the type is a padded type and the underlying type would not be
5642 passed by reference or the function has a foreign convention, return
5643 the underlying type. */
5645 && (!default_pass_by_ref
5650 /* If the return type is unconstrained, it must have a maximum size.
5651 Use the padded type as the effective return type. And ensure the
5652 function uses the target's by-invisible-reference mechanism to
5653 avoid copying too much data when it returns. */
5655 {
5659 /* If the size overflows to 0, set it to an arbitrary positive
5660 value so that assignments in the type are preserved. Their
5661 actual size is independent of this positive value. */
5665 {
5668 }
5674 /* Declare it now since it will never be declared otherwise. This
5675 is necessary to ensure that its subtrees are properly marked. */
5682 }
5684 /* If the return type has a size that overflows, we usually cannot have
5685 a function that returns that type. This usage doesn't really make
5686 sense anyway, so issue an error here. */
5691 {
5696 }
5698 /* If the return type is incomplete, there are 2 cases: if the function
5699 returns by reference, then the return type is only linked indirectly
5700 in the profile, so the profile can be seen as complete since it need
5701 not be further modified, only the reference types need be adjusted;
5702 otherwise the profile is incomplete and need be adjusted too. */
5704 {
5707 }
5711 || return_by_direct_ref_p
5712 || return_by_invisi_ref_p
5714 }
5716 /* A procedure (something that doesn't return anything) shouldn't be
5717 considered const since there would be no reason for calling such a
5718 subprogram. Note that procedures with Out (or In Out) parameters
5719 have already been converted into a function with a return type.
5720 Similarly, if the function returns an unconstrained type, then the
5721 function will allocate the return value on the secondary stack and
5722 thus calls to it cannot be CSE'ed, lest the stack be reclaimed. */
5726 /* Loop over the parameters and get their associated GCC tree. While doing
5727 this, build a copy-in copy-out structure if we need one. */
5731 {
5732 const bool mech_is_by_ref
5739 /* Fetch an existing parameter with complete type and reuse it. But we
5740 didn't save the CICO property so we can only do it for In parameters
5741 or parameters passed by reference. */
5746 {
5749 }
5751 /* Otherwise translate the parameter type and act accordingly. */
5752 else
5753 {
5756 /* For foreign convention subprograms, pass System.Address as void *
5757 or equivalent. Note that this comprises GCC builtins. */
5761 else
5764 /* If the parameter type is incomplete, there are 2 cases: if it is
5765 passed by reference, then the type is only linked indirectly in
5766 the profile, so the profile can be seen as complete since it need
5767 not be further modified, only the reference type need be adjusted;
5768 otherwise the profile is incomplete and need be adjusted too. */
5770 {
5771 Node_Id gnat_decl;
5775 && TYPE_IS_FAT_POINTER_P
5778 {
5780 gnu_param
5790 }
5792 /* ??? This is a kludge to support null procedures in spec taking
5793 a parameter with an untagged incomplete type coming from a
5794 limited context. The front-end creates a body without knowing
5795 anything about the non-limited view, which is illegal Ada and
5796 cannot be supported. Create a parameter with a fake type. */
5804 else
5805 {
5806 /* Build a minimal PARM_DECL without DECL_ARG_TYPE so that
5807 Call_to_gnu will stop if it encounters the PARM_DECL. */
5808 gnu_param
5810 gnu_param_type);
5812 gnu_param_type);
5814 }
5815 }
5817 /* Otherwise build the parameter declaration normally. */
5818 else
5819 {
5820 gnu_param
5824 /* We are returned either a PARM_DECL or a type if no parameter
5825 needs to be passed; in either case, adjust the type. */
5828 else
5829 {
5832 }
5833 }
5834 }
5836 /* If we have a GCC tree for the parameter, register it. */
5839 {
5840 gnu_param_type_list
5845 /* If a parameter is a pointer, a function may modify memory through
5846 it and thus shouldn't be considered a const function. Also, the
5847 memory may be modified between two calls, so they can't be CSE'ed.
5848 The latter case also handles by-ref parameters. */
5852 }
5854 /* If the parameter uses the copy-in copy-out mechanism, allocate a field
5855 for it in the return type and register the association. */
5857 {
5859 {
5862 /* If this is a function, we also need a field for the
5863 return value to be placed. */
5865 {
5866 tree gnu_field
5868 gnu_return_type,
5874 gnu_cico_list
5876 }
5879 /* Set a default alignment to speed up accesses. But we should
5880 not increase the size of the structure too much, lest it does
5881 not fit in return registers anymore. */
5884 }
5886 tree gnu_field
5895 }
5896 }
5898 /* If the subprogram uses the copy-in copy-out mechanism, possibly adjust
5899 and finish up the return type. */
5901 {
5902 /* If we have a CICO list but it has only one entry, we convert
5903 this function into a function that returns this object. */
5907 /* Do not finalize the return type if the subprogram is stubbed
5908 since structures are incomplete for the back-end. */
5910 {
5914 /* Try to promote the mode of the return type if it is passed
5915 in registers, again to speed up accesses. */
5918 NULL_TREE))
5919 {
5920 unsigned int size
5923 machine_mode mode;
5929 {
5937 }
5938 }
5942 }
5945 }
5947 /* The lists have been built in reverse. */
5953 /* If the profile is incomplete, we only set the (temporary) return and
5954 parameter types; otherwise, we build the full type. In either case,
5955 we reuse an already existing GCC tree that we built previously here. */
5957 {
5959 ;
5960 else
5967 }
5968 else
5969 {
5971 {
5980 }
5981 else
5982 {
5983 gnu_type
5986 /* GNU_TYPE may be shared since GCC hashes types. Unshare it if it
5987 has a different TYPE_CI_CO_LIST or flags. */
5989 return_unconstrained_p,
5990 return_by_direct_ref_p,
5991 return_by_invisi_ref_p))
5992 {
5998 }
5999 }
6007 /* If this subprogram is expectedly bound to a GCC builtin, fetch the
6008 corresponding DECL node and check the parameter association. */
6011 {
6015 /* If we have a builtin DECL for that function, use it. Check if
6016 the profiles are compatible and warn if they are not. Note that
6017 the checker is expected to post diagnostics in this case. */
6019 {
6020 intrin_binding_t inb
6024 post_error
6026 gnat_subprog);
6029 }
6031 /* Inability to find the builtin DECL most often indicates a genuine
6032 mistake, but imports of unregistered intrinsics are sometimes used
6033 on purpose to allow hooking in alternate bodies; we post a warning
6034 conditioned on Wshadow in this case, to let developers be notified
6035 on demand without risking false positives with common default sets
6036 of options. */
6039 }
6040 }
6043 }
6045 /* Return the external name for GNAT_SUBPROG given its entity name. */
6047 static tree
6049 {
6052 /* If there was no specified Interface_Name and the external and
6053 internal names of the subprogram are the same, only use the
6054 internal name to allow disambiguation of nested subprograms. */
6059 }
6061 /* Like build_qualified_type, but TYPE_QUALS is added to the existing
6062 qualifiers on TYPE. */
6064 static tree
6066 {
6067 /* Qualifiers must be put on the associated array type. */
6072 }
6074 /* Set TYPE_NONALIASED_COMPONENT on an array type built by means of
6075 build_nonshared_array_type. */
6077 static void
6079 {
6082 }
6084 /* Set TYPE_REVERSE_STORAGE_ORDER on an array type built by means of
6085 build_nonshared_array_type. */
6087 static void
6089 {
6092 }
6094 /* Return true if DISCR1 and DISCR2 represent the same discriminant. */
6096 static bool
6098 {
6105 return
6107 }
6109 /* Return true if the array type GNU_TYPE, which represents a dimension of
6110 GNAT_TYPE, has a non-aliased component in the back-end sense. */
6112 static bool
6114 {
6115 /* If the array type is not the innermost dimension of the GNAT type,
6116 then it has a non-aliased component. */
6121 /* If the array type has an aliased component in the front-end sense,
6122 then it also has an aliased component in the back-end sense. */
6126 /* If this is a derived type, then it has a non-aliased component if
6127 and only if its parent type also has one. */
6129 {
6133 gnu_parent_type
6138 }
6140 /* Otherwise, rely exclusively on properties of the element type. */
6142 }
6144 /* Return true if GNAT_ADDRESS is a value known at compile-time. */
6146 static bool
6148 {
6149 /* Handle reference to a constant. */
6152 {
6156 }
6158 /* Catch System'To_Address. */
6163 }
6165 /* Return true if GNAT_RANGE, a N_Range node, cannot be superflat, i.e. if the
6166 inequality HB >= LB-1 is true. LB and HB are the low and high bounds. */
6168 static bool
6170 {
6172 Node_Id scalar_range;
6175 /* If the low bound is not constant, try to find an upper bound. */
6184 /* If the high bound is not constant, try to find a lower bound. */
6193 /* If we have failed to find constant bounds, punt. */
6198 /* We need at least a signed 64-bit type to catch most cases. */
6204 /* If the low bound is the smallest integer, nothing can be smaller. */
6210 }
6212 /* Return true if GNU_EXPR is (essentially) the address of a CONSTRUCTOR. */
6214 static bool
6216 {
6224 }
6226 /* Return true if the size in units represented by GNU_SIZE can be handled by
6227 an allocation. If STATIC_P is true, consider only what can be done with a
6228 static allocation. */
6230 static bool
6232 {
6233 /* We can allocate a fixed size if it is a valid for the middle-end. */
6237 /* We can allocate a variable size if this isn't a static allocation. */
6238 else
6240 }
6242 /* Return true if GNU_EXPR needs a conversion to GNU_TYPE when used as the
6243 initial value of an object of GNU_TYPE. */
6245 static bool
6247 {
6248 /* Do not convert if the object's type is unconstrained because this would
6249 generate useless evaluations of the CONSTRUCTOR to compute the size. */
6254 /* Do not convert if the object's type is a padding record whose field is of
6255 self-referential size because we want to copy only the actual data. */
6259 /* Do not convert a call to a function that returns with variable size since
6260 we want to use the return slot optimization in this case. */
6265 /* Do not convert to a record type with a variant part from a record type
6266 without one, to keep the object simpler. */
6273 /* In all the other cases, convert the expression to the object's type. */
6275 }
6276 \f
6277 /* Given GNAT_ENTITY, elaborate all expressions that are required to
6278 be elaborated at the point of its definition, but do nothing else. */
6280 void
6282 {
6284 {
6291 {
6295 /* ??? Tests to avoid Constraint_Error in static expressions
6296 are needed until after the front stops generating bogus
6297 conversions on bounds of real types. */
6305 }
6312 {
6313 Node_Id gnat_discriminant_expr;
6314 Entity_Id gnat_field;
6318 gnat_discriminant_expr
6323 /* Ignore access discriminants. */
6328 }
6331 }
6332 }
6333 \f
6334 /* Prepend to ATTR_LIST an entry for an attribute with provided TYPE,
6335 NAME, ARGS and ERROR_POINT. */
6337 static void
6340 tree attr_name,
6341 tree attr_args,
6342 Node_Id attr_error_point)
6343 {
6353 }
6355 /* Prepend to ATTR_LIST an entry for an attribute provided by GNAT_PRAGMA. */
6357 static void
6359 {
6364 /* Map the pragma at hand. Skip if this isn't one we know how to handle. */
6366 {
6397 }
6399 /* See what arguments we have and turn them into GCC trees for attribute
6400 handlers. These expect identifier for strings. We handle at most two
6401 arguments and static expressions only. */
6403 {
6409 {
6413 {
6417 }
6420 }
6424 {
6429 }
6430 }
6432 /* Prepend to the list. Make a list of the argument we might have, as GCC
6433 expects it. */
6435 gnu_arg1
6439 }
6441 /* Prepend to ATTR_LIST the list of attributes for GNAT_ENTITY, if any. */
6443 static void
6445 {
6446 Node_Id gnat_temp;
6448 /* Attributes are stored as Representation Item pragmas. */
6454 }
6455 \f
6456 /* Given a GNAT tree GNAT_EXPR, for an expression which is a value within a
6457 type definition (either a bound or a discriminant value) for GNAT_ENTITY,
6458 return the GCC tree to use for that expression. S is the suffix to use
6459 if a variable needs to be created and DEFINITION is true if this is done
6460 for a definition of GNAT_ENTITY. If NEED_VALUE is true, we need a result;
6461 otherwise, we are just elaborating the expression for side-effects. If
6462 NEED_DEBUG is true, we need a variable for debugging purposes even if it
6463 isn't needed for code generation. */
6465 static tree
6468 {
6469 tree gnu_expr;
6471 /* If we already elaborated this expression (e.g. it was involved
6472 in the definition of a private type), use the old value. */
6476 /* If we don't need a value and this is static or a discriminant,
6477 we don't need to do anything. */
6484 /* If it's a static expression, we don't need a variable for debugging. */
6488 /* Otherwise, convert this tree to its GCC equivalent and elaborate it. */
6492 /* Save the expression in case we try to elaborate this entity again. Since
6493 it's not a DECL, don't check it. Don't save if it's a discriminant. */
6498 }
6500 /* Similar, but take a GNU expression and always return a result. */
6502 static tree
6505 {
6510 /* If GNU_EXPR contains a placeholder, just return it. We rely on the fact
6511 that an expression cannot contain both a discriminant and a variable. */
6515 /* If GNU_EXPR is neither a constant nor based on a read-only variable, make
6516 a variable that is initialized to contain the expression when the package
6517 containing the definition is elaborated. If this entity is defined at top
6518 level, replace the expression by the variable; otherwise use a SAVE_EXPR
6519 if this is necessary. */
6522 else
6523 {
6524 /* Skip any conversions and simple constant arithmetics to see if the
6525 expression is based on a read-only variable. */
6533 expr_variable_p
6534 = !(inner
6537 }
6539 /* We only need to use the variable if we are in a global context since GCC
6540 can do the right thing in the local case. However, when not optimizing,
6541 use it for bounds of loop iteration scheme to avoid code duplication. */
6542 use_variable = expr_variable_p
6543 && (expr_global_p
6544 || (!optimize
6545 && definition
6550 /* Now create it, possibly only for debugging purposes. */
6552 {
6553 /* The following variable creation can happen when processing the body
6554 of subprograms that are defined out of the extended main unit and
6555 inlined. In this case, we are not at the global scope, and thus the
6556 new variable must not be tagged "external", as we used to do here as
6557 soon as DEFINITION was false. */
6558 tree gnu_decl
6565 /* Using this variable at debug time (if need_debug is true) requires a
6566 proper location. The back-end will compute a location for this
6567 variable only if the variable is used by the generated code.
6568 Returning the variable ensures the caller will use it in generated
6569 code. Note that there is no need for a location if the debug info
6570 contains an integer constant.
6571 TODO: when the encoding-based debug scheme is dropped, move this
6572 condition to the top-level IF block: we will not need to create a
6573 variable anymore in such cases, then. */
6576 }
6579 }
6581 /* Similar, but take an alignment factor and make it explicit in the tree. */
6583 static tree
6586 {
6588 return
6591 gnu_expr,
6592 unit_align),
6594 need_debug),
6595 unit_align);
6596 }
6598 /* Structure to hold internal data for elaborate_reference. */
6600 struct er_data
6601 {
6602 Entity_Id entity;
6605 };
6607 /* Wrapper function around elaborate_expression_1 for elaborate_reference. */
6609 static tree
6611 {
6615 /* This is what elaborate_expression_1 does if NEED_DEBUG is false. */
6619 /* If this is a COMPONENT_REF of a fat pointer, elaborate the entire fat
6620 pointer. This may be more efficient, but will also allow us to more
6621 easily find the match for the PLACEHOLDER_EXPR. */
6629 return
6631 }
6633 /* Elaborate the reference REF to be used as renamed object for GNAT_ENTITY.
6634 DEFINITION is true if this is done for a definition of GNAT_ENTITY and
6635 INIT is set to the first arm of a COMPOUND_EXPR present in REF, if any. */
6637 static tree
6640 {
6643 }
6644 \f
6645 /* Given a GNU tree and a GNAT list of choices, generate an expression to test
6646 the value passed against the list of choices. */
6648 static tree
6650 {
6651 Node_Id choice;
6652 Node_Id gnat_temp;
6657 {
6659 {
6664 this_test
6679 this_test
6690 /* This represents either a subtype range, an enumeration
6691 literal, or a constant Ekind says which. If an enumeration
6692 literal or constant, fall through to the next case. */
6695 {
6701 this_test
6709 }
6711 /* ... fall through ... */
6726 }
6730 else
6733 }
6736 }
6737 \f
6738 /* Adjust PACKED setting as passed to gnat_to_gnu_field for a field of
6739 type FIELD_TYPE to be placed in RECORD_TYPE. Return the result. */
6741 static int
6743 {
6744 /* If the field contains an item of variable size, we cannot pack it
6745 because we cannot create temporaries of non-fixed size in case
6746 we need to take the address of the field. See addressable_p and
6747 the notes on the addressability issues for further details. */
6751 /* In the other cases, we can honor the packing. */
6755 /* If the alignment of the record is specified and the field type
6756 is over-aligned, request Storage_Unit alignment for the field. */
6761 /* Likewise if the maximum alignment of the record is specified. */
6767 }
6769 /* Return a GCC tree for a field corresponding to GNAT_FIELD to be
6770 placed in GNU_RECORD_TYPE.
6772 PACKED is 1 if the enclosing record is packed or -1 if the enclosing
6773 record has Component_Alignment of Storage_Unit.
6775 DEFINITION is true if this field is for a record being defined.
6777 DEBUG_INFO_P is true if we need to write debug information for types
6778 that we may create in the process. */
6780 static tree
6783 {
6786 const bool is_atomic
6789 const bool is_independent
6791 const bool is_volatile
6794 /* We used to consider that volatile fields also require strict alignment,
6795 but that was an interpolation and would cause us to reject a pragma
6796 volatile on a packed record type containing boolean components, while
6797 there is no basis to do so in the RM. In such cases, the writes will
6798 involve load-modify-store sequences, but that's OK for volatile. The
6799 only constraint is the implementation advice whereby only the bits of
6800 the components should be accessed if they both start and end on byte
6801 boundaries, but that should be guaranteed by the GCC memory model. */
6802 const bool needs_strict_alignment
6808 /* If this field requires strict alignment, we cannot pack it because
6809 it would very likely be under-aligned in the record. */
6812 else
6815 /* If a size is specified, use it. Otherwise, if the record type is packed,
6816 use the official RM size. See "Handling of Type'Size Values" in Einfo
6817 for further details. */
6824 else
6827 /* If we have a specified size that is smaller than that of the field's type,
6828 or a position is specified, and the field's type is a record that doesn't
6829 require strict alignment, see if we can get either an integral mode form
6830 of the type or a smaller form. If we can, show a size was specified for
6831 the field if there wasn't one already, so we know to make this a bitfield
6832 and avoid making things wider.
6834 Changing to an integral mode form is useful when the record is packed as
6835 we can then place the field at a non-byte-aligned position and so achieve
6836 tighter packing. This is in addition required if the field shares a byte
6837 with another field and the front-end lets the back-end handle the access
6838 to the field, because GCC cannot handle non-byte-aligned BLKmode fields.
6840 Changing to a smaller form is required if the specified size is smaller
6841 than that of the field's type and the type contains sub-fields that are
6842 padded, in order to avoid generating accesses to these sub-fields that
6843 are wider than the field.
6845 We avoid the transformation if it is not required or potentially useful,
6846 as it might entail an increase of the field's alignment and have ripple
6847 effects on the outer record type. A typical case is a field known to be
6848 byte-aligned and not to share a byte with another field. */
6854 || (gnu_size
6860 {
6863 {
6867 }
6868 }
6874 {
6882 /* Ensure the position does not overlap with the parent subtype, if there
6883 is one. This test is omitted if the parent of the tagged type has a
6884 full rep clause since, in this case, component clauses are allowed to
6885 overlay the space allocated for the parent type and the front-end has
6886 checked that there are no overlapping components. */
6888 {
6893 post_error_ne_tree
6896 }
6898 /* If this field needs strict alignment, make sure that the record is
6899 sufficiently aligned and that the position and size are consistent
6900 with the type. But don't do it if we are just annotating types and
6901 the field's type is tagged, since tagged types aren't fully laid out
6902 in this mode. Also, note that atomic implies volatile so the inner
6903 test sequences ordering is significant here. */
6906 {
6912 /* If the position is not a multiple of the alignment of the type,
6913 then error out and reset the position. */
6916 {
6928 else
6932 type_align);
6934 }
6937 {
6941 /* If the size is lower than that of the type, or greater for
6942 atomic and aliased, then error out and reset the size. */
6944 {
6956 else
6960 gnu_type_size);
6962 }
6964 /* Likewise if the size is not a multiple of a byte, */
6966 bitsize_unit_node)))
6967 {
6976 else
6981 }
6982 }
6983 }
6984 }
6986 /* If the record has rep clauses and this is the tag field, make a rep
6987 clause for it as well. */
6990 {
6993 }
6995 else
6996 {
6999 /* If we are packing the record and the field is BLKmode, round the
7000 size up to a byte boundary. */
7003 }
7005 /* We need to make the size the maximum for the type if it is
7006 self-referential and an unconstrained type. In that case, we can't
7007 pack the field since we can't make a copy to align it. */
7009 && !gnu_size
7012 {
7015 }
7017 /* If a size is specified, adjust the field's type to it. */
7019 {
7020 tree orig_field_type;
7022 /* If the field's type is justified modular, we would need to remove
7023 the wrapper to (better) meet the layout requirements. However we
7024 can do so only if the field is not aliased to preserve the unique
7025 layout, if it has the same storage order as the enclosing record
7026 and if the prescribed size is not greater than that of the packed
7027 array to preserve the justification. */
7037 /* Similarly if the field's type is a misaligned integral type, but
7038 there is no restriction on the size as there is no justification. */
7044 gnu_field_type
7052 /* If a padding record was made, declare it now since it will never be
7053 declared otherwise. This is necessary to ensure that its subtrees
7054 are properly marked. */
7059 }
7061 /* Otherwise (or if there was an error), don't specify a position. */
7062 else
7065 /* If the field's type is a padded type made for a scalar field of a record
7066 type with reverse storage order, we need to propagate the reverse storage
7067 order to the padding type since it is the innermost enclosing aggregate
7068 type around the scalar. */
7077 /* Now create the decl for the field. */
7078 gnu_field
7086 {
7091 }
7094 }
7095 \f
7096 /* Return true if at least one member of COMPONENT_LIST needs strict
7097 alignment. */
7099 static bool
7101 {
7102 Node_Id component_decl;
7107 {
7115 }
7118 }
7120 /* Return true if TYPE is a type with variable size or a padding type with a
7121 field of variable size or a record that has a field with such a type. */
7123 static bool
7125 {
7126 tree field;
7143 }
7144 \f
7145 /* Return true if FIELD is an artificial field. */
7147 static bool
7149 {
7150 /* These fields are generated by the front-end proper. */
7154 /* These fields are generated by gigi. */
7159 }
7161 /* Return true if FIELD is a non-artificial field with self-referential
7162 size. */
7164 static bool
7166 {
7174 }
7176 /* Return true if FIELD is a non-artificial field with variable size. */
7178 static bool
7180 {
7188 }
7190 /* qsort comparer for the bit positions of two record components. */
7192 static int
7194 {
7197 const int ret
7201 }
7203 /* Reverse function from gnat_to_gnu_field: return the GNAT field present in
7204 either GNAT_COMPONENT_LIST or the discriminants of GNAT_RECORD_TYPE, and
7205 corresponding to the GNU tree GNU_FIELD. */
7207 static Entity_Id
7209 Entity_Id gnat_record_type)
7210 {
7218 {
7222 }
7232 }
7234 /* Issue a warning for the problematic placement of GNU_FIELD present in
7235 either GNAT_COMPONENT_LIST or the discriminants of GNAT_RECORD_TYPE.
7236 IN_VARIANT is true if GNAT_COMPONENT_LIST is the list of a variant.
7237 DO_REORDER is true if fields of GNAT_RECORD_TYPE are being reordered. */
7239 static void
7243 {
7245 = in_variant
7255 = do_reorder
7258 Entity_Id gnat_field
7266 }
7268 /* Structure holding information for a given variant. */
7270 {
7271 /* The record type of the variant. */
7272 tree type;
7274 /* The name of the variant. */
7275 tree name;
7277 /* The qualifier of the variant. */
7278 tree qual;
7280 /* Whether the variant has a rep clause. */
7283 /* Whether the variant is packed. */
7288 /* Translate and chain GNAT_COMPONENT_LIST present in GNAT_RECORD_TYPE to
7289 GNU_FIELD_LIST, set the result as the field list of GNU_RECORD_TYPE and
7290 finish it up. Return true if GNU_RECORD_TYPE has a rep clause that affects
7291 the layout (see below). When called from gnat_to_gnu_entity during the
7292 processing of a record definition, the GCC node for the parent, if any,
7293 will be the single field of GNU_RECORD_TYPE and the GCC nodes for the
7294 discriminants will be on GNU_FIELD_LIST. The other call to this function
7295 is a recursive call for the component list of a variant and, in this case,
7296 GNU_FIELD_LIST is empty.
7298 PACKED is 1 if this is for a packed record or -1 if this is for a record
7299 with Component_Alignment of Storage_Unit.
7301 DEFINITION is true if we are defining this record type.
7303 CANCEL_ALIGNMENT is true if the alignment should be zeroed before laying
7304 out the record. This means the alignment only serves to force fields to
7305 be bitfields, but not to require the record to be that aligned. This is
7306 used for variants.
7308 ALL_REP is true if a rep clause is present for all the fields.
7310 UNCHECKED_UNION is true if we are building this type for a record with a
7311 Pragma Unchecked_Union.
7313 ARTIFICIAL is true if this is a type that was generated by the compiler.
7315 DEBUG_INFO is true if we need to write debug information about the type.
7317 MAYBE_UNUSED is true if this type may be unused in the end; this doesn't
7318 mean that its contents may be unused as well, only the container itself.
7320 FIRST_FREE_POS, if nonzero, is the first (lowest) free field position in
7321 the outer record type down to this variant level. It is nonzero only if
7322 all the fields down to this level have a rep clause and ALL_REP is false.
7324 P_GNU_REP_LIST, if nonzero, is a pointer to a list to which each field
7325 with a rep clause is to be added; in this case, that is all that should
7326 be done with such fields and the return value will be false. */
7328 static bool
7335 {
7336 const bool needs_xv_encodings
7348 /* For each component referenced in a component declaration create a GCC
7349 field and add it to the list, skipping pragmas in the GNAT list. */
7356 {
7360 /* If present, the _Parent field must have been created as the single
7361 field of the record type. Put it before any other fields. */
7363 {
7366 }
7367 else
7368 {
7372 /* If this is the _Tag field, put it before any other fields. */
7376 /* If this is the _Controller field, put it before the other
7377 fields except for the _Tag or _Parent field. */
7379 {
7382 }
7384 /* If this is a regular field, put it after the other fields. */
7385 else
7386 {
7392 /* And record information for the final layout. */
7397 }
7398 }
7401 }
7403 /* At the end of the component list there may be a variant part. */
7406 /* We create a QUAL_UNION_TYPE for the variant part since the variants are
7407 mutually exclusive and should go in the same memory. To do this we need
7408 to treat each variant as a record whose elements are created from the
7409 component list for the variant. So here we create the records from the
7410 lists for the variants and put them all into the QUAL_UNION_TYPE.
7411 If this is an Unchecked_Union, we make a UNION_TYPE instead or
7412 use GNU_RECORD_TYPE if there are no fields so far. */
7414 {
7418 tree gnu_var_name
7429 gnu_union_name
7432 /* Reuse the enclosing union if this is an Unchecked_Union whose fields
7433 are all in the variant part, to match the layout of C unions. There
7434 is an associated check below. */
7437 else
7438 {
7439 gnu_union_type
7447 }
7449 /* If all the fields down to this level have a rep clause, find out
7450 whether all the fields at this level also have one. If so, then
7451 compute the new first free position to be passed downward. */
7454 {
7456 gnu_field;
7459 {
7462 this_first_free_pos
7464 }
7465 else
7466 {
7469 }
7470 }
7472 /* We build the variants in two passes. The bulk of the work is done in
7473 the first pass, that is to say translating the GNAT nodes, building
7474 the container types and computing the associated properties. However
7475 we cannot finish up the container types during this pass because we
7476 don't know where the variant part will be placed until the end. */
7480 {
7485 vinfo_t vinfo;
7493 /* Set the alignment of the inner type in case we need to make
7494 inner objects into bitfields, but then clear it out so the
7495 record actually gets only the alignment required. */
7501 /* Similarly, if the outer record has a size specified and all
7502 the fields have a rep clause, we can propagate the size. */
7504 {
7508 }
7510 /* Add the fields into the record type for the variant. Note that
7511 we aren't sure to really use it at this point, see below. */
7512 has_rep
7518 all_rep || this_first_free_pos
7521 /* Translate the qualifier and annotate the GNAT node. */
7525 /* Deal with packedness like in gnat_to_gnu_field. */
7527 {
7530 }
7531 else
7532 field_packed
7535 /* Push this variant onto the stack for the second pass. */
7543 /* Compute the global properties that will determine the placement of
7544 the variant part. */
7548 }
7550 /* Round up the first free position to the alignment of the variant part
7551 for the variants without rep clause. This will guarantee a consistent
7552 layout independently of the placement of the variant part. */
7556 /* In the second pass, the container types are adjusted if necessary and
7557 finished up, then the corresponding fields of the variant part are
7558 built with their qualifier, unless this is an unchecked union. */
7560 {
7564 /* If this is an Unchecked_Union whose fields are all in the variant
7565 part and we have a single field with no representation clause or
7566 placed at offset zero, use the field directly to match the layout
7567 of C unions. */
7569 && gnu_field_list
7573 {
7576 }
7577 else
7578 {
7579 /* Finalize the variant type now. We used to throw away empty
7580 record types but we no longer do that because we need them to
7581 generate complete debug info for the variant; otherwise, the
7582 union type definition will be lacking the fields associated
7583 with these empty variants. */
7585 {
7586 /* The variant part will be at offset 0 so we need to ensure
7587 that the fields are laid out starting from the first free
7588 position at this level. */
7590 tree gnu_rep_part;
7594 gnu_rep_part
7596 this_first_free_pos);
7601 }
7608 gnu_field
7610 gnu_union_type,
7611 all_rep_and_size
7620 }
7624 }
7626 /* Only make the QUAL_UNION_TYPE if there are non-empty variants. */
7628 {
7632 {
7636 }
7641 /* If GNU_UNION_TYPE is our record type, it means we must have an
7642 Unchecked_Union with no fields. Verify that and, if so, just
7643 return. */
7645 {
7647 && !gnu_field_list
7650 }
7655 /* Deal with packedness like in gnat_to_gnu_field. */
7658 else
7659 union_field_packed
7662 gnu_variant_part
7664 all_rep_and_size
7670 }
7671 }
7673 /* Scan GNU_FIELD_LIST and see if any fields have rep clauses. If they do,
7674 pull them out and put them onto the appropriate list. We have to do it
7675 in a separate pass since we want to handle the discriminants but can't
7676 play with them until we've used them in debugging data above.
7678 Similarly, pull out the fields with zero size and no rep clause, as they
7679 would otherwise modify the layout and thus very likely run afoul of the
7680 Ada semantics, which are different from those of C here.
7682 Finally, if there is an aliased field placed in the list after fields
7683 with self-referential size, pull out the latter in the same way.
7685 Optionally, if the reordering mechanism is enabled, pull out the fields
7686 with self-referential size, variable size and fixed size not a multiple
7687 of a byte, so that they don't cause the regular fields to be either at
7688 self-referential/variable offset or misaligned. Note, in the latter
7689 case, that this can only happen in packed record types so the alignment
7690 is effectively capped to the byte for the whole record.
7692 Optionally, if the layout warning is enabled, keep track of the above 4
7693 different kinds of fields and issue a warning if some of them would be
7694 (or are being) reordered by the reordering mechanism.
7696 Finally, pull out the fields whose size is not a multiple of a byte, so
7697 that they don't cause the regular fields to be misaligned. As this can
7698 only happen in packed record types, the alignment is capped to the byte.
7700 ??? If we reorder them, debugging information will be wrong but there is
7701 nothing that can be done about this at the moment. */
7703 const bool w_reorder
7704 = Warn_On_Questionable_Layout
7716 #define MOVE_FROM_FIELD_LIST_TO(LIST) \
7717 do { \
7718 if (gnu_last) \
7719 DECL_CHAIN (gnu_last) = gnu_next; \
7720 else \
7721 gnu_field_list = gnu_next; \
7722 \
7723 DECL_CHAIN (gnu_field) = (LIST); \
7724 (LIST) = gnu_field; \
7725 } while (0)
7729 {
7733 {
7736 }
7739 {
7749 }
7752 {
7755 }
7757 /* We don't need further processing in default mode. */
7759 {
7762 }
7765 {
7767 {
7771 do_reorder);
7772 else
7774 }
7777 {
7780 }
7781 }
7784 {
7786 {
7790 do_reorder);
7791 else
7793 }
7796 {
7799 }
7800 }
7802 else
7803 {
7804 /* If the field has no size, then it cannot be bit-packed. */
7805 const unsigned int bitp_size
7810 /* If the field is bit-packed, we move it to a temporary list that
7811 contains the contiguously preceding bit-packed fields, because
7812 we want to be able to put them back if the misalignment happens
7813 to cancel itself after several bit-packed fields. */
7815 {
7819 {
7822 }
7825 {
7828 }
7829 }
7831 /* No more bit-packed fields, move the existing ones to the end or
7832 put them back at their original location. */
7834 {
7838 {
7842 gnat_component_list,
7844 do_reorder);
7851 }
7852 else
7853 {
7854 /* Rechain the temporary list in front of GNU_FIELD. */
7857 {
7862 else
7866 }
7867 }
7868 }
7870 else
7872 }
7875 }
7877 #undef MOVE_FROM_FIELD_LIST_TO
7881 /* If permitted, we reorder the fields as follows:
7883 1) all (groups of) fields whose length is fixed and multiple of a byte,
7884 2) the remaining fields whose length is fixed and not multiple of a byte,
7885 3) the remaining fields whose length doesn't depend on discriminants,
7886 4) all fields whose length depends on discriminants,
7887 5) the variant part,
7889 within the record and within each variant recursively. */
7892 {
7893 /* If we have pending bit-packed fields, warn if they would be moved
7894 to after regular fields. */
7902 }
7905 {
7906 /* If we have pending bit-packed fields on the temporary list, we put
7907 them either on the bit-packed list or back on the regular list. */
7909 {
7912 else
7914 }
7916 gnu_field_list
7920 }
7922 /* Otherwise, if there is an aliased field placed after a field whose length
7923 depends on discriminants, we put all the fields of the latter sort, last.
7924 We need to do this in case an object of this record type is mutable. */
7928 /* If P_REP_LIST is nonzero, this means that we are asked to move the fields
7929 in our REP list to the previous level because this level needs them in
7930 order to do a correct layout, i.e. avoid having overlapping fields. */
7934 /* Deal with the annoying case of an extension of a record with variable size
7935 and partial rep clause, for which the _Parent field is forced at offset 0
7936 and has variable size, which we do not support below. Note that we cannot
7937 do it if the field has fixed size because we rely on the presence of the
7938 REP part built below to trigger the reordering of the fields in a derived
7939 record type when all the fields have a fixed position. */
7943 && !variants_have_rep
7944 && first_free_pos
7947 {
7951 }
7953 /* Otherwise, sort the fields by bit position and put them into their own
7954 record, before the others, if we also have fields without rep clause. */
7956 {
7961 /* If all the fields have a rep clause, we can do a flat layout. */
7962 layout_with_rep = !gnu_field_list
7964 gnu_rep_type
7968 gnu_field;
7974 /* Put the fields in the list in order of increasing position, which
7975 means we start from the end. */
7978 {
7982 }
7986 else
7987 {
7992 /* If FIRST_FREE_POS is nonzero, we need to ensure that the fields
7993 without rep clause are laid out starting from this position.
7994 Therefore, we force it as a minimal size on the REP part. */
7995 gnu_rep_part
7998 /* Chain the REP part at the beginning of the field list. */
8001 }
8002 }
8004 /* Chain the variant part at the end of the field list. */
8016 /* Chain the fields with zero size at the beginning of the field list. */
8022 }
8023 \f
8024 /* Given GNU_SIZE, a GCC tree representing a size, return a Uint to be
8025 placed into an Esize, Component_Bit_Offset, or Component_Size value
8026 in the GNAT tree. */
8028 static Uint
8030 {
8031 TCode tcode;
8036 /* See if we've already saved the value for this node. */
8038 {
8046 }
8047 else
8050 /* If we do not return inside this switch, TCODE will be set to the
8051 code to use for a Create_Node operand and LEN (set above) will be
8052 the number of recursive calls for us to make. */
8055 {
8057 /* For negative values, build NEGATE_EXPR of the opposite. Such values
8058 can appear for discriminants in expressions for variants. */
8060 {
8063 }
8068 /* The only case we handle here is a simple discriminant reference. */
8070 {
8073 /* Climb up the chain of successive extensions, if any. */
8080 return
8082 }
8089 /* Now just list the operations we handle. */
8120 /* For negative values in sizetype, build NEGATE_EXPR of the opposite.
8121 Such values appear in expressions with aligning patterns. Note that,
8122 since sizetype is unsigned, we have to jump through some hoops. */
8124 {
8128 {
8131 }
8132 }
8136 /* In regular mode, inline back only if symbolic annotation is requested
8137 in order to avoid memory explosion on big discriminated record types.
8138 But not in ASIS mode, as symbolic annotation is required for DDA. */
8140 {
8144 }
8145 else
8148 /* Fall through... */
8152 }
8154 /* Now get each of the operands that's relevant for this code. If any
8155 cannot be expressed as a repinfo node, say we can't. */
8160 {
8163 else
8167 }
8171 /* Save the result in the cache. */
8173 {
8175 /* We can't assume the hash table data hasn't moved since the initial
8176 look up, so we have to search again. Allocating and inserting an
8177 entry at that point would be an alternative, but then we'd better
8178 discard the entry if we decided not to cache it. */
8184 }
8187 }
8189 /* Given GNAT_ENTITY, an object (constant, variable, parameter, exception)
8190 and GNU_TYPE, its corresponding GCC type, set Esize and Alignment to the
8191 size and alignment used by Gigi. Prefer SIZE over TYPE_SIZE if non-null.
8192 BY_REF is true if the object is used by reference. */
8194 void
8196 {
8198 {
8201 else
8203 }
8206 {
8215 }
8220 }
8222 /* Return first element of field list whose TREE_PURPOSE is the same as ELEM.
8223 Return NULL_TREE if there is no such element in the list. */
8225 static tree
8227 {
8229 {
8234 }
8236 }
8238 /* Given GNAT_ENTITY, a record type, and GNU_TYPE, its corresponding GCC type,
8239 set Component_Bit_Offset and Esize of the components to the position and
8240 size used by Gigi. */
8242 static void
8244 {
8245 /* For an extension, the inherited components have not been translated because
8246 they are fetched from the _Parent component on the fly. */
8247 const bool is_extension
8250 /* We operate by first making a list of all fields and their position (we
8251 can get the size easily) and then update all the sizes in the tree. */
8252 tree gnu_list
8263 {
8265 gnu_list);
8267 {
8268 tree parent_offset;
8270 /* If we are just annotating types and the type is tagged, the tag
8271 and the parent components are not generated by the front-end so
8272 we need to add the appropriate offset to each component without
8273 representation clause. */
8277 {
8278 /* For a component appearing in the current extension, the
8279 offset is the size of the parent. */
8282 parent_offset
8284 bitsizetype);
8285 else
8289 parent_offset
8292 }
8293 else
8296 Set_Component_Bit_Offset
8298 annotate_value
8302 parent_offset)));
8306 }
8308 {
8309 /* If there is no entry, this is an inherited component whose
8310 position is the same as in the parent type. */
8313 /* If we are just annotating types, discriminants renaming those of
8314 the parent have no entry so deal with them specifically. */
8324 }
8325 }
8326 }
8327 \f
8328 /* Scan all fields in GNU_TYPE and return a TREE_LIST where TREE_PURPOSE is
8329 the FIELD_DECL and TREE_VALUE a TREE_VEC containing the byte position, the
8330 value to be placed into DECL_OFFSET_ALIGN and the bit position. The list
8331 of fields is flattened, except for variant parts if DO_NOT_FLATTEN_VARIANT
8332 is set to true. GNU_POS is to be added to the position, GNU_BITPOS to the
8333 bit position, OFFSET_ALIGN is the present offset alignment. GNU_LIST is a
8334 pre-existing list to be chained to the newly created entries. */
8336 static tree
8339 {
8340 tree gnu_field;
8343 gnu_field;
8345 {
8350 unsigned int our_offset_align
8359 /* Recurse on internal fields, flattening the nested fields except for
8360 those in the variant part, if requested. */
8362 {
8366 gnu_list
8370 else
8371 gnu_list
8375 }
8376 }
8379 }
8381 /* Return a list describing the substitutions needed to reflect the
8382 discriminant substitutions from GNAT_TYPE to GNAT_SUBTYPE. They can
8383 be in any order. The values in an element of the list are in the form
8384 of operands to SUBSTITUTE_IN_EXPR. DEFINITION is true if this is for
8385 a definition of GNAT_SUBTYPE. */
8389 {
8391 Entity_Id gnat_discrim;
8392 Node_Id gnat_constr;
8399 /* Ignore access discriminants. */
8401 {
8404 elaborate_expression
8410 }
8413 }
8415 /* Scan all fields in QUAL_UNION_TYPE and return a list describing the
8416 variants of QUAL_UNION_TYPE that are still relevant after applying
8417 the substitutions described in SUBST_LIST. GNU_LIST is a pre-existing
8418 list to be prepended to the newly created entries. */
8423 {
8424 tree gnu_field;
8427 gnu_field;
8429 {
8437 /* If the new qualifier is not unconditionally false, its variant may
8438 still be accessed. */
8440 {
8446 /* Recurse on the variant subpart of the variant, if any. */
8452 /* If the new qualifier is unconditionally true, the subsequent
8453 variants cannot be accessed. */
8456 }
8457 }
8460 }
8461 \f
8462 /* UINT_SIZE is a Uint giving the specified size for an object of GNU_TYPE
8463 corresponding to GNAT_OBJECT. If the size is valid, return an INTEGER_CST
8464 corresponding to its value. Otherwise, return NULL_TREE. KIND is set to
8465 VAR_DECL if we are specifying the size of an object, TYPE_DECL for the
8466 size of a type, and FIELD_DECL for the size of a field. COMPONENT_P is
8467 true if we are being called to process the Component_Size of GNAT_OBJECT;
8468 this is used only for error messages. ZERO_OK is true if a size of zero
8469 is permitted; if ZERO_OK is false, it means that a size of zero should be
8470 treated as an unspecified size. */
8472 static tree
8475 {
8476 Node_Id gnat_error_node;
8479 /* Return 0 if no size was specified. */
8483 /* Ignore a negative size since that corresponds to our back-annotation. */
8487 /* Find the node to use for error messages. */
8494 else
8497 /* Get the size as an INTEGER_CST. Issue an error if a size was specified
8498 but cannot be represented in bitsizetype. */
8501 {
8504 gnat_object);
8505 else
8507 gnat_object);
8509 }
8511 /* Ignore a zero size if it is not permitted. */
8515 /* The size of objects is always a multiple of a byte. */
8518 {
8522 else
8526 }
8528 /* If this is an integral type or a packed array type, the front-end has
8529 already verified the size, so we need not do it here (which would mean
8530 checking against the bounds). However, if this is an aliased object,
8531 it may not be smaller than the type of the object. */
8536 /* If the object is a record that contains a template, add the size of the
8537 template to the specified size. */
8543 /* If a type needs strict alignment, a component of this type in
8544 a packed record cannot be packed and thus uses the type size. */
8547 else
8550 /* Modify the size of a discriminated type to be the maximum size. */
8554 /* If this is an access type or a fat pointer, the minimum size is that given
8555 by the smallest integral mode that's valid for pointers. */
8557 {
8562 }
8564 /* Issue an error either if the default size of the object isn't a constant
8565 or if the new size is smaller than it. */
8569 {
8571 post_error_ne_tree
8574 else
8575 post_error_ne_tree
8579 }
8582 }
8583 \f
8584 /* Similarly, but both validate and process a value of RM size. This routine
8585 is only called for types. */
8587 static void
8589 {
8590 Node_Id gnat_attr_node;
8593 /* Do nothing if no size was specified. */
8597 /* Ignore a negative size since that corresponds to our back-annotation. */
8601 /* Only issue an error if a Value_Size clause was explicitly given.
8602 Otherwise, we'd be duplicating an error on the Size clause. */
8603 gnat_attr_node
8606 /* Get the size as an INTEGER_CST. Issue an error if a size was specified
8607 but cannot be represented in bitsizetype. */
8610 {
8613 gnat_entity);
8615 }
8617 /* Ignore a zero size unless a Value_Size clause exists, or a size clause
8618 exists, or this is an integer type, in which case the front-end will
8619 have always set it. */
8628 /* If the old size is self-referential, get the maximum size. */
8632 /* Issue an error either if the old size of the object isn't a constant or
8633 if the new size is smaller than it. The front-end has already verified
8634 this for scalar and packed array types. */
8642 && TYPE_PACKED_ARRAY_TYPE_P
8645 {
8647 post_error_ne_tree
8651 }
8653 /* Otherwise, set the RM size proper for integral types... */
8660 /* ...or the Ada size for record and union types. */
8664 }
8665 \f
8666 /* ALIGNMENT is a Uint giving the alignment specified for GNAT_ENTITY,
8667 a type or object whose present alignment is ALIGN. If this alignment is
8668 valid, return it. Otherwise, give an error and return ALIGN. */
8670 static unsigned int
8672 {
8675 Node_Id gnat_error_node;
8677 /* Don't worry about checking alignment if alignment was not specified
8678 by the source program and we already posted an error for this entity. */
8682 /* Post the error on the alignment clause if any. Note, for the implicit
8683 base type of an array type, the alignment clause is on the first
8684 subtype. */
8692 gnat_error_node =
8695 else
8698 /* Within GCC, an alignment is an integer, so we must make sure a value is
8699 specified that fits in that range. Also, there is an upper bound to
8700 alignments we can support/allow. */
8708 {
8712 /* If the default alignment of "double" or larger scalar types is
8713 specifically capped and the new alignment is above the cap, do
8714 not post an error and change the alignment only if there is an
8715 alignment clause; this makes it possible to have the associated
8716 GCC type overaligned by default for performance reasons. */
8718 {
8719 Entity_Id gnat_type
8721 is_capped_double
8723 }
8725 {
8726 Entity_Id gnat_type
8728 is_capped_double
8730 }
8731 else
8735 {
8738 }
8739 else
8740 {
8747 }
8748 }
8749 else
8750 {
8754 }
8757 }
8758 \f
8759 /* Verify that TYPE is something we can implement atomically. If not, issue
8760 an error for GNAT_ENTITY. COMPONENT_P is true if we are being called to
8761 process a component type. */
8763 static void
8765 {
8767 Node_Id gnat_node;
8768 machine_mode mode;
8771 tree size;
8773 /* If this is an anonymous base type, nothing to check, the error will be
8774 reported on the source type if need be. */
8783 /* Consider all aligned floating-point types atomic and any aligned types
8784 that are represented by integers no wider than a machine word. */
8791 /* For the moment, also allow anything that has an alignment equal to its
8792 size and which is smaller than a word. */
8803 {
8804 unsigned char pragma_id
8809 {
8812 }
8813 }
8821 else
8824 }
8825 \f
8827 /* Helper for the intrin compatibility checks family. Evaluate whether
8828 two types are definitely incompatible. */
8830 static bool
8832 {
8847 {
8854 /* Assume designated types are ok. We'd need to account for char * and
8855 void * variants to do better, which could rapidly get messy and isn't
8856 clearly worth the effort. */
8861 }
8864 }
8866 /* Helper for intrin_profiles_compatible_p, to perform compatibility checks
8867 on the Ada/builtin argument lists for the INB binding. */
8869 static bool
8871 {
8877 /* Sequence position of the last argument we checked. */
8881 {
8885 /* If we've exhausted both lists simultaneously, we're done. */
8889 /* If one list is shorter than the other, they fail to match. */
8893 /* If we're done with the Ada args and not with the internal builtin
8894 args, or the other way around, complain. */
8897 {
8900 }
8904 {
8908 }
8910 /* Otherwise, check that types match for the current argument. */
8911 argpos ++;
8913 {
8917 }
8922 }
8925 }
8927 /* Helper for intrin_profiles_compatible_p, to perform compatibility checks
8928 on the Ada/builtin return values for the INB binding. */
8930 static bool
8932 {
8936 /* Accept function imported as procedure, common and convenient. */
8941 /* Check return types compatibility otherwise. Note that this
8942 handles void/void as well. */
8944 {
8948 }
8951 }
8953 /* Check and return whether the Ada and gcc builtin profiles bound by INB are
8954 compatible. Issue relevant warnings when they are not.
8956 This is intended as a light check to diagnose the most obvious cases, not
8957 as a full fledged type compatibility predicate. It is the programmer's
8958 responsibility to ensure correctness of the Ada declarations in Imports,
8959 especially when binding straight to a compiler internal. */
8961 static bool
8963 {
8964 /* Check compatibility on return values and argument lists, each responsible
8965 for posting warnings as appropriate. Ensure use of the proper sloc for
8966 this purpose. */
8979 }
8980 \f
8981 /* Return a FIELD_DECL node modeled on OLD_FIELD. FIELD_TYPE is its type
8982 and RECORD_TYPE is the type of the parent. If SIZE is nonzero, it is the
8983 specified size for this field. POS_LIST is a position list describing
8984 the layout of OLD_FIELD and SUBST_LIST a substitution list to be applied
8985 to this layout. */
8987 static tree
8991 {
9003 /* If the position is now a constant, we can set it as the position of the
9004 field when we make it. Otherwise, we need to deal with it specially. */
9007 else
9010 new_field
9016 {
9018 /* Finalize the position. */
9027 }
9035 }
9037 /* Create the REP part of RECORD_TYPE with REP_TYPE. If MIN_SIZE is nonzero,
9038 it is the minimal size the REP_PART must have. */
9040 static tree
9042 {
9043 tree field;
9053 }
9055 /* Return the REP part of RECORD_TYPE, if any. Otherwise return NULL. */
9057 static tree
9059 {
9062 /* The REP part is the first field, internal, another record, and its name
9063 starts with an 'R'. */
9071 }
9073 /* Return the variant part of RECORD_TYPE, if any. Otherwise return NULL. */
9075 tree
9077 {
9078 tree field;
9080 /* The variant part is the only internal field that is a qualified union. */
9087 }
9089 /* Return a new variant part modeled on OLD_VARIANT_PART. VARIANT_LIST is
9090 the list of variants to be used and RECORD_TYPE is the type of the parent.
9091 POS_LIST is a position list describing the layout of fields present in
9092 OLD_VARIANT_PART and SUBST_LIST a substitution list to be applied to this
9093 layout. DEBUG_INFO_P is true if we need to write debug information. */
9095 static tree
9101 {
9109 /* First create the type of the variant part from that of the old one. */
9115 /* If the position of the variant part is constant, subtract it from the
9116 size of the type of the parent to get the new size. This manual CSE
9117 reduces the code size when not optimizing. */
9121 {
9131 first_bit));
9134 }
9135 else
9138 /* Now finish up the new variants and populate the union type. */
9140 {
9144 /* Skip variants that don't belong to this nesting level. */
9148 /* Retrieve the list of fields already added to the new variant. */
9152 /* If the old variant had a variant subpart, we need to create a new
9153 variant subpart and add it to the field list. */
9157 {
9158 tree new_variant_subpart
9161 debug_info_p);
9164 }
9166 /* Finish up the new variant and create the field. */
9172 new_field
9180 }
9182 /* Finish up the union type and create the variant part. Note that we don't
9183 reverse the field list because VARIANT_LIST has been traversed in reverse
9184 order. */
9190 new_variant_part
9196 /* With multiple discriminants it is possible for an inner variant to be
9197 statically selected while outer ones are not; in this case, the list
9198 of fields of the inner variant is not flattened and we end up with a
9199 qualified union with a single member. Drop the useless container. */
9201 {
9210 }
9213 }
9215 /* Copy the size (and alignment and alias set) from OLD_TYPE to NEW_TYPE,
9216 which are both RECORD_TYPE, after applying the substitutions described
9217 in SUBST_LIST. */
9219 static void
9222 {
9246 SET_TYPE_ADA_SIZE
9250 /* Finalize the size. */
9253 }
9255 /* Return true if DISC is a stored discriminant of RECORD_TYPE. */
9259 {
9264 else
9266 }
9268 /* Copy the layout from {GNAT,GNU}_OLD_TYPE to {GNAT,GNU}_NEW_TYPE, which are
9269 both record types, after applying the substitutions described in SUBST_LIST.
9270 DEBUG_INFO_P is true if we need to write debug information for NEW_TYPE. */
9272 static void
9274 Entity_Id gnat_old_type,
9275 tree gnu_new_type,
9276 tree gnu_old_type,
9279 {
9285 /* Look for REP and variant parts in the old type. */
9289 /* If there is a variant part, we must compute whether the constraints
9290 statically select a particular variant. If so, we simply drop the
9291 qualified union and flatten the list of fields. Otherwise we will
9292 build a new qualified union for the variants that are still relevant. */
9294 {
9301 /* If all the qualifiers are unconditionally true, the innermost variant
9302 is statically selected. */
9306 {
9309 }
9311 /* Otherwise, create the new variants. */
9314 {
9317 tree suffix
9326 gnu_subst_list);
9328 }
9329 }
9330 else
9331 {
9334 }
9336 /* Make a list of fields and their position in the old type. */
9337 tree gnu_pos_list
9343 /* Now go down every component in the new type and compute its size and
9344 position from those of the component in the old type and the stored
9345 constraints of the new type. */
9358 {
9367 /* If the type is the same, retrieve the GCC type from the
9368 old field to take into account possible adjustments. */
9371 else
9374 /* If there was a component clause, the field types must be the same
9375 for the old and new types, so copy the data from the old field to
9376 avoid recomputation here. Also if the field is justified modular
9377 and the optimization in gnat_to_gnu_field was applied. */
9383 {
9386 }
9388 /* If the old field was packed and of constant size, we have to get the
9389 old size here as it might differ from what the Etype conveys and the
9390 latter might overlap with the following field. Try to arrange the
9391 type for possible better packing along the way. */
9394 {
9400 }
9402 else
9405 /* If the context of the old field is the old type or its REP part,
9406 put the field directly in the new type; otherwise look up the
9407 context in the variant list and put the field either in the new
9408 type if there is a selected variant or in one new variant. */
9412 else
9413 {
9416 tree rep_part;
9426 else
9427 /* The front-end may pass us "ghost" components if it fails to
9428 recognize that a constrain statically selects a particular
9429 variant. Discard them. */
9431 }
9433 /* Now create the new field modeled on the old one. */
9434 gnu_field
9440 /* If the context is a variant, put it in the new variant directly. */
9442 {
9445 }
9447 /* To match the layout crafted in components_to_record, if this is
9448 the _Tag or _Parent field, put it before any other fields. */
9452 /* Similarly, if this is the _Controller field, put it before the
9453 other fields except for the _Tag or _Parent field. */
9455 {
9458 }
9460 /* Otherwise, put it after the other fields. */
9461 else
9462 {
9469 }
9471 /* For a stored discriminant in a derived type, replace the field. */
9473 {
9476 }
9477 else
9479 }
9481 /* If there is a variant list, a selected variant and the fields all have a
9482 constant position, put them in order of increasing position to match that
9483 of constant CONSTRUCTORs. Likewise if there is no variant list but a REP
9484 part, since the latter has been flattened in the process. */
9487 {
9498 {
9501 }
9502 }
9504 /* If there is a variant list and no selected variant, we need to create the
9505 nest of variant parts from the old nest. */
9507 {
9508 tree new_variant_part
9514 }
9521 /* If NEW_TYPE is a subtype, it inherits all the attributes from OLD_TYPE.
9522 Otherwise sizes and alignment must be computed independently. */
9524 {
9527 }
9528 else
9531 /* Now go through the entities again looking for Itypes that we have not yet
9532 elaborated (e.g. Etypes of fields that have Original_Components). */
9541 }
9543 /* Associate to GNU_TYPE, the translation of GNAT_ENTITY, which is
9544 the implementation type of a packed array type (Is_Packed_Array_Impl_Type),
9545 the original array type if it has been translated. This association is a
9546 parallel type for GNAT encodings or a debug type for standard DWARF. Note
9547 that for standard DWARF, we also want to get the original type name. */
9549 static void
9551 {
9552 Entity_Id gnat_original_array_type
9554 tree gnu_original_array_type;
9565 {
9573 }
9574 else
9576 }
9577 \f
9578 /* Given a type T, a FIELD_DECL F, and a replacement value R, return an
9579 equivalent type with adjusted size expressions where all occurrences
9580 of references to F in a PLACEHOLDER_EXPR have been replaced by R.
9582 The function doesn't update the layout of the type, i.e. it assumes
9583 that the substitution is purely formal. That's why the replacement
9584 value R must itself contain a PLACEHOLDER_EXPR. */
9586 tree
9588 {
9589 tree nt;
9594 {
9600 /* First the domain types of arrays. */
9603 {
9615 SET_TYPE_INDEX_TYPE
9619 }
9621 /* Then the subtypes. */
9624 {
9636 }
9648 /* These should never show up here. */
9652 {
9672 }
9677 {
9679 tree field;
9681 /* Start out with no fields, make new fields, and chain them
9682 in. If we haven't actually changed the type of any field,
9683 discard everything we've done and return the old type. */
9688 {
9693 {
9696 }
9700 {
9703 }
9705 /* Do the substitution inside the qualifier, if any. */
9707 {
9710 {
9713 }
9714 }
9721 }
9731 }
9735 }
9736 }
9737 \f
9738 /* Return the RM size of GNU_TYPE. This is the actual number of bits
9739 needed to represent the object. */
9741 tree
9743 {
9744 /* For integral types, we store the RM size explicitly. */
9748 /* Return the RM size of the actual data plus the size of the template. */
9751 return
9756 /* For record or union types, we store the size explicitly. */
9762 /* For other types, this is just the size. */
9764 }
9765 \f
9766 /* Return the name to be used for GNAT_ENTITY. If a type, create a
9767 fully-qualified name, possibly with type information encoding.
9768 Otherwise, return the name. */
9772 {
9775 }
9777 tree
9779 {
9782 }
9784 /* Return an identifier representing the external name to be used for
9785 GNAT_ENTITY. If SUFFIX is specified, the name is followed by "___"
9786 and the specified suffix. */
9788 tree
9790 {
9798 /* A variable using the Stdcall convention lives in a DLL. We adjust
9799 its name to use the jump table, the _imp__NAME contains the address
9800 for the NAME variable. */
9803 {
9809 }
9812 }
9814 /* Given GNU_NAME, an IDENTIFIER_NODE containing a name and SUFFIX, a
9815 string, return a new IDENTIFIER_NODE that is the concatenation of
9816 the name followed by "___" and the specified suffix. */
9818 tree
9820 {
9827 }
9829 /* Initialize data structures of the decl.c module. */
9831 void
9833 {
9834 /* Initialize the cache of annotated values. */
9837 /* Initialize the association of dummy types with subprograms. */
9839 }
9841 /* Destroy data structures of the decl.c module. */
9843 void
9845 {
9846 /* Destroy the cache of annotated values. */
9850 /* Destroy the association of dummy types with subprograms. */
9853 }