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1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * D E C L *
6 * *
7 * C Implementation File *
8 * *
9 * Copyright (C) 1992-2017, Free Software Foundation, Inc. *
10 * *
11 * GNAT is free software; you can redistribute it and/or modify it under *
12 * terms of the GNU General Public License as published by the Free Soft- *
13 * ware Foundation; either version 3, or (at your option) any later ver- *
14 * sion. GNAT is distributed in the hope that it will be useful, but WITH- *
15 * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY *
16 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License *
17 * for more details. You should have received a copy of the GNU General *
18 * Public License along with GCC; see the file COPYING3. If not see *
19 * <http://www.gnu.org/licenses/>. *
20 * *
21 * GNAT was originally developed by the GNAT team at New York University. *
22 * Extensive contributions were provided by Ada Core Technologies Inc. *
23 * *
24 ****************************************************************************/
55 /* "stdcall" and "thiscall" conventions should be processed in a specific way
56 on 32-bit x86/Windows only. The macros below are helpers to avoid having
57 to check for a Windows specific attribute throughout this unit. */
59 #if TARGET_DLLIMPORT_DECL_ATTRIBUTES
60 #ifdef TARGET_64BIT
61 #define Has_Stdcall_Convention(E) \
62 (!TARGET_64BIT && Convention (E) == Convention_Stdcall)
63 #define Has_Thiscall_Convention(E) \
64 (!TARGET_64BIT && is_cplusplus_method (E))
65 #else
66 #define Has_Stdcall_Convention(E) (Convention (E) == Convention_Stdcall)
67 #define Has_Thiscall_Convention(E) (is_cplusplus_method (E))
68 #endif
69 #else
70 #define Has_Stdcall_Convention(E) 0
71 #define Has_Thiscall_Convention(E) 0
72 #endif
76 /* Stack realignment is necessary for functions with foreign conventions when
77 the ABI doesn't mandate as much as what the compiler assumes - that is, up
78 to PREFERRED_STACK_BOUNDARY.
80 Such realignment can be requested with a dedicated function type attribute
81 on the targets that support it. We define FOREIGN_FORCE_REALIGN_STACK to
82 characterize the situations where the attribute should be set. We rely on
83 compiler configuration settings for 'main' to decide. */
85 #ifdef MAIN_STACK_BOUNDARY
86 #define FOREIGN_FORCE_REALIGN_STACK \
87 (MAIN_STACK_BOUNDARY < PREFERRED_STACK_BOUNDARY)
88 #else
89 #define FOREIGN_FORCE_REALIGN_STACK 0
90 #endif
92 struct incomplete
93 {
95 tree old_type;
96 Entity_Id full_type;
97 };
99 /* These variables are used to defer recursively expanding incomplete types
100 while we are processing a record, an array or a subprogram type. */
104 /* This variable is used to delay expanding types coming from a limited with
105 clause and completed Taft Amendment types until the end of the spec. */
109 tree discriminant;
110 tree replacement;
115 /* The type of the variant. */
116 tree type;
118 /* The associated field. */
119 tree field;
121 /* The value of the qualifier. */
122 tree qual;
124 /* The type of the variant after transformation. */
125 tree new_type;
129 /* A map used to cache the result of annotate_value. */
131 {
134 {
136 }
140 {
142 }
144 static int
146 {
148 }
149 };
153 /* A map used to associate a dummy type with a list of subprogram entities. */
155 {
158 };
160 void
162 {
163 }
165 void
167 {
169 }
172 {
175 {
177 }
181 {
183 }
185 static int
187 {
189 }
190 };
223 tree *);
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 is in
314 the main unit, except for E_Access_Subtype because it's actually a use
315 of its base type, see below. */
317 && is_type
322 {
323 /* Ensure that we are in a subprogram mentioned in the Scope chain of
324 this entity, our current scope is global, or we encountered a task
325 or entry (where we can't currently accurately check scoping). */
328 {
331 }
336 {
341 gnat_temp
353 && (current_function_decl
355 {
358 }
359 }
361 /* This abort means the Itype has an incorrect scope, i.e. that its
362 scope does not correspond to the subprogram it is declared in. */
364 }
366 /* If we've already processed this entity, return what we got last time.
367 If we are defining the node, we should not have already processed it.
368 In that case, we will abort below when we try to save a new GCC tree
369 for this object. We also need to handle the case of getting a dummy
370 type when a Full_View exists but be careful so as not to trigger its
371 premature elaboration. */
374 {
383 {
384 gnu_decl
388 }
391 }
393 /* If this is a numeric or enumeral type, or an access type, a nonzero Esize
394 must be specified unless it was specified by the programmer. Exceptions
395 are for access-to-protected-subprogram types and all access subtypes, as
396 another GNAT type is used to lay out the GCC type for them. */
408 /* The RM size must be specified for all discrete and fixed-point types. */
412 /* If we get here, it means we have not yet done anything with this entity.
413 If we are not defining it, it must be a type or an entity that is defined
414 elsewhere or externally, otherwise we should have defined it already. */
416 || type_annotate_only
417 || is_type
424 /* Get the name of the entity and set up the line number and filename of
425 the original definition for use in any decl we make. Make sure we do not
426 inherit another source location. */
432 /* For cases when we are not defining (i.e., we are referencing from
433 another compilation unit) public entities, show we are at global level
434 for the purpose of computing scopes. Don't do this for components or
435 discriminants since the relevant test is whether or not the record is
436 being defined. */
444 /* Handle any attributes directly attached to the entity. */
448 /* Do some common processing for types. */
450 {
451 /* Compute the equivalent type to be used in gigi. */
454 /* Machine_Attributes on types are expected to be propagated to
455 subtypes. The corresponding Gigi_Rep_Items are only attached
456 to the first subtype though, so we handle the propagation here. */
463 /* Compute a default value for the size of an elementary type. */
465 {
475 else
480 }
481 }
484 {
487 {
488 /* The GNAT record where the component was defined. */
491 /* If the entity is a discriminant of an extended tagged type used to
492 rename a discriminant of the parent type, return the latter. */
496 {
497 gnu_decl
502 }
504 /* If the entity is an inherited component (in the case of extended
505 tagged record types), just return the original entity, which must
506 be a FIELD_DECL. Likewise for discriminants. If the entity is a
507 non-girder discriminant (in the case of derived untagged record
508 types), return the stored discriminant it renames. */
511 {
512 gnu_decl
515 /* GNU_DECL contains a PLACEHOLDER_EXPR for discriminants. */
519 }
521 /* Otherwise, if we are not defining this and we have no GCC type
522 for the containing record, make one for it. Then we should
523 have made our own equivalent. */
525 {
526 /* ??? If this is in a record whose scope is a protected
527 type and we have an Original_Record_Component, use it.
528 This is a workaround for major problems in protected type
529 handling. */
533 {
534 gnu_decl
538 }
539 else
540 {
543 }
547 }
549 /* Here we have no GCC type and this is a reference rather than a
550 definition. This should never happen. Most likely the cause is
551 reference before declaration in the GNAT tree for gnat_entity. */
553 }
556 /* Ignore constant definitions already marked with the error node. See
557 the N_Object_Declaration case of gnat_to_gnu for the rationale. */
561 {
564 }
566 /* Ignore deferred constant definitions without address clause since
567 they are processed fully in the front-end. If No_Initialization
568 is set, this is not a deferred constant but a constant whose value
569 is built manually. And constants that are renamings are handled
570 like variables. */
572 && !gnu_expr
576 {
580 }
582 /* If this is a use of a deferred constant without address clause,
583 get its full definition. */
587 {
588 gnu_decl
592 }
594 /* If we have a constant that we are not defining, get the expression it
595 was defined to represent. This is necessary to avoid generating dumb
596 elaboration code in simple cases, but we may throw it away later if it
597 is not a constant. But do not retrieve it if it is an allocator since
598 the designated type might still be dummy at this point. */
604 /* The expression may contain N_Expression_With_Actions nodes and
605 thus object declarations from other units. Discard them. */
606 gnu_expr
609 /* ... fall through ... */
615 {
617 /* Always create a variable for volatile objects and variables seen
618 constant but with a Linker_Section pragma. */
619 bool const_flag
632 /* We implement RM 13.3(19) for exported and imported (non-constant)
633 objects by making them volatile. */
634 bool volatile_flag
641 tree gnu_object_size;
643 /* We need to translate the renamed object even though we are only
644 referencing the renaming. But it may contain a call for which
645 we'll generate a temporary to hold the return value and which
646 is part of the definition of the renaming, so discard it. */
648 {
652 else
654 }
656 /* Get the type after elaborating the renamed object. */
660 else
661 {
664 /* If this is a standard exception definition, use the standard
665 exception type. This is necessary to make sure that imported
666 and exported views of exceptions are merged in LTO mode. */
670 }
672 /* For a debug renaming declaration, build a debug-only entity. */
674 {
675 /* Force a non-null value to make sure the symbol is retained. */
679 integer_minus_one_node));
687 }
689 /* If this is a loop variable, its type should be the base type.
690 This is because the code for processing a loop determines whether
691 a normal loop end test can be done by comparing the bounds of the
692 loop against those of the base type, which is presumed to be the
693 size used for computation. But this is not correct when the size
694 of the subtype is smaller than the type. */
698 /* Reject non-renamed objects whose type is an unconstrained array or
699 any object whose type is a dummy type or void. */
704 {
707 force_global--;
709 }
711 /* If an alignment is specified, use it if valid. Note that exceptions
712 are objects but don't have an alignment. We must do this before we
713 validate the size, since the alignment can affect the size. */
715 {
721 /* No point in changing the type if there is an address clause
722 as the final type of the object will be a reference type. */
725 else
726 {
729 gnu_type
733 /* If a padding record was made, declare it now since it will
734 never be declared otherwise. This is necessary to ensure
735 that its subtrees are properly marked. */
739 }
740 }
742 /* If we are defining the object, see if it has a Size and validate it
743 if so. If we are not defining the object and a Size clause applies,
744 simply retrieve the value. We don't want to ignore the clause and
745 it is expected to have been validated already. Then get the new
746 type, if any. */
755 {
756 gnu_type
762 }
764 /* If this object has self-referential size, it must be a record with
765 a default discriminant. We are supposed to allocate an object of
766 the maximum size in this case, unless it is a constant with an
767 initializing expression, in which case we can get the size from
768 that. Note that the resulting size may still be a variable, so
769 this may end up with an indirect allocation. */
772 {
774 {
777 {
778 /* If the initializing expression is itself a constant,
779 despite having a nominal type with self-referential
780 size, we can get the size directly from it. */
782 && TYPE_IS_PADDING_P
786 || DECL_READONLY_ONCE_ELAB
789 else
790 gnu_size
792 }
793 else
795 }
796 /* We may have no GNU_EXPR because No_Initialization is
797 set even though there's an Expression. */
802 gnu_size
804 (Etype
806 else
807 {
810 }
812 /* If the size isn't constant and we are at global level, call
813 elaborate_expression_1 to make a variable for it rather than
814 calculating it each time. */
818 }
820 /* If the size is zero byte, make it one byte since some linkers have
821 troubles with zero-sized objects. If the object will have a
822 template, that will make it nonzero so don't bother. Also avoid
823 doing that for an object renaming or an object with an address
824 clause, as we would lose useful information on the view size
825 (e.g. for null array slices) and we are not allocating the object
826 here anyway. */
838 /* If this is an object with no specified size and alignment, and
839 if either it is atomic or we are not optimizing alignment for
840 space and it is composite and not an exception, an Out parameter
841 or a reference to another object, and the size of its type is a
842 constant, set the alignment to the smallest one which is not
843 smaller than the size, with an appropriate cap. */
852 && !imported_p
856 {
859 /* No point in promoting the alignment if this doesn't prevent
860 BLKmode access to the object, in particular block copy, as
861 this will for example disable the NRV optimization for it.
862 No point in jumping through all the hoops needed in order
863 to support BIGGEST_ALIGNMENT if we don't really have to.
864 So we cap to the smallest alignment that corresponds to
865 a known efficient memory access pattern of the target. */
867 {
870 }
871 else
872 {
875 }
882 else
885 /* But make sure not to under-align the object. */
889 /* And honor the minimum valid atomic alignment, if any. */
890 #ifdef MINIMUM_ATOMIC_ALIGNMENT
893 #endif
894 }
896 /* If the object is set to have atomic components, find the component
897 type and validate it.
899 ??? Note that we ignore Has_Volatile_Components on objects; it's
900 not at all clear what to do in that case. */
902 {
911 }
913 /* If this is an aliased object with an unconstrained array nominal
914 subtype, make a type that includes the template. We will either
915 allocate or create a variable of that type, see below. */
919 {
921 gnu_type
923 gnu_type,
926 debug_info_p);
927 }
929 /* ??? If this is an object of CW type initialized to a value, try to
930 ensure that the object is sufficient aligned for this value, but
931 without pessimizing the allocation. This is a kludge necessary
932 because we don't support dynamic alignment. */
939 #ifdef MINIMUM_ATOMIC_ALIGNMENT
940 /* If the size is a constant and no alignment is specified, force
941 the alignment to be the minimum valid atomic alignment. The
942 restriction on constant size avoids problems with variable-size
943 temporaries; if the size is variable, there's no issue with
944 atomic access. Also don't do this for a constant, since it isn't
945 necessary and can interfere with constant replacement. Finally,
946 do not do it for Out parameters since that creates an
947 size inconsistency with In parameters. */
957 #endif
959 /* Make a new type with the desired size and alignment, if needed.
960 But do not take into account alignment promotions to compute the
961 size of the object. */
964 {
970 /* If a padding record was made, declare it now since it will
971 never be declared otherwise. This is necessary to ensure
972 that its subtrees are properly marked. */
976 }
978 /* Now check if the type of the object allows atomic access. */
982 /* If this is a renaming, avoid as much as possible to create a new
983 object. However, in some cases, creating it is required because
984 renaming can be applied to objects that are not names in Ada.
985 This processing needs to be applied to the raw expression so as
986 to make it more likely to rename the underlying object. */
988 {
989 /* If the renamed object had padding, strip off the reference to
990 the inner object and reset our type. */
993 /* Strip useless conversions around the object. */
995 {
998 }
1000 /* Or else, if the renamed object has an unconstrained type with
1001 default discriminant, use the padded type. */
1005 /* Case 1: if this is a constant renaming stemming from a function
1006 call, treat it as a normal object whose initial value is what
1007 is being renamed. RM 3.3 says that the result of evaluating a
1008 function call is a constant object. Therefore, it can be the
1009 inner object of a constant renaming and the renaming must be
1010 fully instantiated, i.e. it cannot be a reference to (part of)
1011 an existing object. And treat other rvalues (addresses, null
1012 expressions, constructors and literals) the same way. */
1016 /* Expand_Dispatching_Call can prepend a comparison of the tags
1017 before the call to "=". */
1028 /* We need to detect the case where a temporary is created to
1029 hold the return value, since we cannot safely rename it at
1030 top level as it lives only in the elaboration routine. */
1033 /* We also need to detect the case where the front-end creates
1034 a dangling 'reference to a function call at top level and
1035 substitutes it in the renaming, for example:
1037 q__b : boolean renames r__f.e (1);
1039 can be rewritten into:
1041 q__R1s : constant q__A2s := r__f'reference;
1042 [...]
1043 q__b : boolean renames q__R1s.all.e (1);
1045 We cannot safely rename the rewritten expression since the
1046 underlying object lives only in the elaboration routine. */
1048 && (inner
1052 ;
1054 /* Case 2: if the renaming entity need not be materialized, use
1055 the elaborated renamed expression for the renaming. But this
1056 means that the caller is responsible for evaluating the address
1057 of the renaming in the correct place for the definition case to
1058 instantiate the SAVE_EXPRs. */
1060 {
1063 gnu_decl
1067 /* We cannot evaluate the first arm of a COMPOUND_EXPR in the
1068 correct place for this case. */
1071 /* No DECL_EXPR will be created so the expression needs to be
1072 marked manually because it will likely be shared. */
1076 /* This assertion will fail if the renamed object isn't aligned
1077 enough as to make it possible to honor the alignment set on
1078 the renaming. */
1080 {
1085 }
1087 /* The expression might not be a DECL so save it manually. */
1092 }
1094 /* Case 3: otherwise, make a constant pointer to the object we
1095 are renaming and attach the object to the pointer after it is
1096 elaborated. The object will be referenced directly instead
1097 of indirectly via the pointer to avoid aliasing problems with
1098 non-addressable entities. The pointer is called a "renaming"
1099 pointer in this case. Note that we also need to preserve the
1100 volatility of the renamed object through the indirection. */
1101 else
1102 {
1106 gnu_type
1115 renamed_obj
1119 /* The expression needs to be marked manually because it will
1120 likely be shared, even for a definition since the ADDR_EXPR
1121 built below can cause the first few nodes to be folded. */
1128 else
1129 {
1130 gnu_expr
1133 gnu_expr
1135 gnu_expr);
1136 }
1137 }
1138 }
1140 /* If we are defining an aliased object whose nominal subtype is
1141 unconstrained, the object is a record that contains both the
1142 template and the object. If there is an initializer, it will
1143 have already been converted to the right type, but we need to
1144 create the template if there is no initializer. */
1146 && !gnu_expr
1149 /* Beware that padding might have been introduced above. */
1152 == RECORD_TYPE
1153 && TYPE_CONTAINS_TEMPLATE_P
1155 {
1156 tree template_field
1164 NULL_TREE);
1167 }
1169 /* Convert the expression to the type of the object if need be. */
1173 /* If this is a pointer that doesn't have an initializing expression,
1174 initialize it to NULL, unless the object is declared imported as
1175 per RM B.1(24). */
1178 && !gnu_expr
1182 /* If we are defining the object and it has an Address clause, we must
1183 either get the address expression from the saved GCC tree for the
1184 object if it has a Freeze node, or elaborate the address expression
1185 here since the front-end has guaranteed that the elaboration has no
1186 effects in this case. */
1188 {
1191 tree gnu_address
1197 /* Convert the type of the object to a reference type that can
1198 alias everything as per RM 13.3(19). */
1201 gnu_type
1205 const_flag
1211 /* If this is an aliased object with an unconstrained array nominal
1212 subtype, then it can overlay only another aliased object with an
1213 unconstrained array nominal subtype and compatible template. */
1217 {
1221 /* This is the pattern built for a regular object. */
1225 /* This is the pattern built for an overaligned object. */
1228 == PLUS_EXPR
1231 gnu_address
1235 else
1236 {
1239 gnat_entity);
1242 }
1243 }
1245 /* If we don't have an initializing expression for the underlying
1246 variable, the initializing expression for the pointer is the
1247 specified address. Otherwise, we have to make a COMPOUND_EXPR
1248 to assign both the address and the initial value. */
1251 else
1252 gnu_expr
1256 NULL_TREE,
1257 gnu_address),
1258 gnu_expr),
1259 gnu_address);
1260 }
1262 /* If it has an address clause and we are not defining it, mark it
1263 as an indirect object. Likewise for Stdcall objects that are
1264 imported. */
1267 {
1268 /* Convert the type of the object to a reference type that can
1269 alias everything as per RM 13.3(19). */
1272 gnu_type
1279 /* No point in taking the address of an initializing expression
1280 that isn't going to be used. */
1283 /* If it has an address clause whose value is known at compile
1284 time, make the object a CONST_DECL. This will avoid a
1285 useless dereference. */
1287 {
1288 Node_Id gnat_address
1292 {
1295 }
1296 }
1297 }
1299 /* If we are at top level and this object is of variable size,
1300 make the actual type a hidden pointer to the real type and
1301 make the initializer be a memory allocation and initialization.
1302 Likewise for objects we aren't defining (presumed to be
1303 external references from other packages), but there we do
1304 not set up an initialization.
1306 If the object's size overflows, make an allocator too, so that
1307 Storage_Error gets raised. Note that we will never free
1308 such memory, so we presume it never will get allocated. */
1311 || !definition
1313 || (gnu_size
1315 size_binop
1317 bitsize_unit_node)),
1319 || !definition
1321 {
1330 /* In case this was a aliased object whose nominal subtype is
1331 unconstrained, the pointer above will be a thin pointer and
1332 build_allocator will automatically make the template.
1334 If we have a template initializer only (that we made above),
1335 pretend there is none and rely on what build_allocator creates
1336 again anyway. Otherwise (if we have a full initializer), get
1337 the data part and feed that to build_allocator.
1339 If we are elaborating a mutable object, tell build_allocator to
1340 ignore a possibly simpler size from the initializer, if any, as
1341 we must allocate the maximum possible size in this case. */
1343 {
1348 {
1349 gnu_alloc_type
1355 else
1356 gnu_expr
1357 = build_component_ref
1361 }
1366 gnat_entity);
1368 gnu_expr
1371 }
1372 else
1374 }
1376 /* If this object would go into the stack and has an alignment larger
1377 than the largest stack alignment the back-end can honor, resort to
1378 a variable of "aligning type". */
1381 && !imported_p
1382 && !static_flag
1384 {
1385 /* Create the new variable. No need for extra room before the
1386 aligned field as this is in automatic storage. */
1387 tree gnu_new_type
1391 tree gnu_new_var
1396 gnat_entity);
1398 /* Initialize the aligned field if we have an initializer. */
1400 add_stmt_with_node
1402 build_component_ref
1405 gnu_expr),
1406 gnat_entity);
1408 /* And setup this entity as a reference to the aligned field. */
1410 gnu_expr
1411 = build_unary_op
1421 }
1423 /* If this is an aliased object with an unconstrained array nominal
1424 subtype, we make its type a thin reference, i.e. the reference
1425 counterpart of a thin pointer, so it points to the array part.
1426 This is aimed to make it easier for the debugger to decode the
1427 object. Note that we have to do it this late because of the
1428 couple of allocation adjustments that might be made above. */
1432 {
1433 /* In case the object with the template has already been allocated
1434 just above, we have nothing to do here. */
1436 {
1437 /* This variable is a GNAT encoding used by Workbench: let it
1438 go through the debugging information but mark it as
1439 artificial: users are not interested in it. */
1440 tree gnu_unc_var
1456 }
1459 gnu_type
1461 }
1463 /* Convert the expression to the type of the object if need be. */
1467 /* If this name is external or a name was specified, use it, but don't
1468 use the Interface_Name with an address clause (see cd30005). */
1474 /* If this is an aggregate constant initialized to a constant, force it
1475 to be statically allocated. This saves an initialization copy. */
1477 && const_flag
1486 /* Deal with a pragma Linker_Section on a constant or variable. */
1492 /* Now create the variable or the constant and set various flags. */
1493 gnu_decl
1504 /* If we are defining an Out parameter and optimization isn't enabled,
1505 create a fake PARM_DECL for debugging purposes and make it point to
1506 the VAR_DECL. Suppress debug info for the latter but make sure it
1507 will live in memory so that it can be accessed from within the
1508 debugger through the PARM_DECL. */
1510 && definition
1511 && debug_info_p
1512 && !optimize
1514 {
1521 }
1523 /* If this is a loop parameter, set the corresponding flag. */
1527 /* If this is a renaming pointer, attach the renamed object to it. */
1531 /* If this is a constant and we are defining it or it generates a real
1532 symbol at the object level and we are referencing it, we may want
1533 or need to have a true variable to represent it:
1534 - if optimization isn't enabled, for debugging purposes,
1535 - if the constant is public and not overlaid on something else,
1536 - if its address is taken,
1537 - if either itself or its type is aliased. */
1546 {
1547 tree gnu_corr_var
1555 }
1557 /* If this is a constant, even if we don't need a true variable, we
1558 may need to avoid returning the initializer in every case. That
1559 can happen for the address of a (constant) constructor because,
1560 upon dereferencing it, the constructor will be reinjected in the
1561 tree, which may not be valid in every case; see lvalue_required_p
1562 for more details. */
1566 /* If this object is declared in a block that contains a block with an
1567 exception handler, and we aren't using the GCC exception mechanism,
1568 we must force this variable in memory in order to avoid an invalid
1569 optimization. */
1574 /* If this is a local variable with non-BLKmode and aggregate type,
1575 and optimization isn't enabled, then force it in memory so that
1576 a register won't be allocated to it with possible subparts left
1577 uninitialized and reaching the register allocator. */
1587 /* If we are defining an object with variable size or an object with
1588 fixed size that will be dynamically allocated, and we are using the
1589 front-end setjmp/longjmp exception mechanism, update the setjmp
1590 buffer. */
1603 gnat_entity);
1605 /* Back-annotate Esize and Alignment of the object if not already
1606 known. Note that we pick the values of the type, not those of
1607 the object, to shield ourselves from low-level platform-dependent
1608 adjustments like alignment promotion. This is both consistent with
1609 all the treatment above, where alignment and size are set on the
1610 type of the object and not on the object directly, and makes it
1611 possible to support all confirming representation clauses. */
1613 used_by_ref);
1614 }
1618 /* Return a TYPE_DECL for "void" that we previously made. */
1623 /* A special case: for the types Character and Wide_Character in
1624 Standard, we do not list all the literals. So if the literals
1625 are not specified, make this an integer type. */
1627 {
1630 else
1634 /* Set TYPE_STRING_FLAG for Character and Wide_Character types.
1635 This is needed by the DWARF-2 back-end to distinguish between
1636 unsigned integer types and character types. */
1639 /* This flag is needed by the call just below. */
1643 }
1644 else
1645 {
1646 /* We have a list of enumeral constants in First_Literal. We make a
1647 CONST_DECL for each one and build into GNU_LITERAL_LIST the list
1648 to be placed into TYPE_FIELDS. Each node is itself a TREE_LIST
1649 whose TREE_VALUE is the literal name and whose TREE_PURPOSE is the
1650 value of the literal. But when we have a regular boolean type, we
1651 simplify this a little by using a BOOLEAN_TYPE. */
1656 Entity_Id gnat_literal;
1669 {
1670 tree gnu_value
1672 /* Do not generate debug info for individual enumerators. */
1673 tree gnu_literal
1679 gnu_list
1681 }
1686 /* Note that the bounds are updated at the end of this function
1687 to avoid an infinite recursion since they refer to the type. */
1689 }
1693 /* For integer types, just make a signed type the appropriate number
1694 of bits. */
1700 {
1701 /* Small_Value is the scale factor. */
1707 /* Try to decode the scale factor and to save it for the fixed-point
1708 types debug hook. */
1710 /* There are various ways to describe the scale factor, however there
1711 are cases where back-end internals cannot hold it. In such cases,
1712 we output invalid scale factor for such cases (i.e. the 0/0
1713 rational constant) but we expect GNAT to output GNAT encodings,
1714 then. Thus, keep this in sync with
1715 Exp_Dbug.Is_Handled_Scale_Factor. */
1717 /* When encoded as 1/2**N or 1/10**N, describe the scale factor as a
1718 binary or decimal scale: it is easier to read for humans. */
1722 {
1723 /* Given RM restrictions on 'Small values, we assume here that
1724 the denominator fits in an int. */
1727 const tree exponent
1730 scale_factor
1732 integer_one_node,
1735 }
1737 /* Default to arbitrary scale factors descriptions. */
1738 else
1739 {
1744 {
1745 const tree gnu_num
1748 const tree gnu_den
1753 }
1754 else
1755 /* If compiler internals cannot represent arbitrary scale
1756 factors, output an invalid scale factor so that debugger
1757 don't try to handle them but so that we still have a type
1758 in the output. Note that GNAT */
1760 }
1764 }
1768 {
1769 /* For modular types, make the unsigned type of the proper number
1770 of bits and then set up the modulus, if required. */
1773 /* Packed Array Impl. Types are supposed to be subtypes only. */
1778 /* Get the modulus in this type. If it overflows, assume it is because
1779 it is equal to 2**Esize. Note that there is no overflow checking
1780 done on unsigned type, so we detect the overflow by looking for
1781 a modulus of zero, which is otherwise invalid. */
1785 {
1790 }
1792 /* If the upper bound is not maximal, make an extra subtype. */
1795 {
1802 }
1803 }
1812 /* For integral subtypes, we make a new INTEGER_TYPE. Note that we do
1813 not want to call create_range_type since we would like each subtype
1814 node to be distinct. ??? Historically this was in preparation for
1815 when memory aliasing is implemented, but that's obsolete now given
1816 the call to relate_alias_sets below.
1818 The TREE_TYPE field of the INTEGER_TYPE points to the base type;
1819 this fact is used by the arithmetic conversion functions.
1821 We elaborate the Ancestor_Subtype if it is not in the current unit
1822 and one of our bounds is non-static. We do this to ensure consistent
1823 naming in the case where several subtypes share the same bounds, by
1824 elaborating the first such subtype first, thus using its name. */
1833 /* Set the precision to the Esize except for bit-packed arrays. */
1838 /* First subtypes of Character are treated as Character; otherwise
1839 this should be an unsigned type if the base type is unsigned or
1840 if the lower bound is constant and non-negative or if the type
1841 is biased. However, even if the lower bound is constant and
1842 non-negative, we use a signed type for a subtype with the same
1843 size as its signed base type, because this eliminates useless
1844 conversions to it and gives more leeway to the optimizer; but
1845 this means that we will need to explicitly test for this case
1846 when we change the representation based on the RM size. */
1858 else
1862 SET_TYPE_RM_MIN_VALUE
1865 debug_info_p));
1867 SET_TYPE_RM_MAX_VALUE
1870 debug_info_p));
1875 /* Do the same processing for Character subtypes as for types. */
1877 {
1882 }
1884 /* Inherit our alias set from what we're a subtype of. Subtypes
1885 are not different types and a pointer can designate any instance
1886 within a subtype hierarchy. */
1889 /* One of the above calls might have caused us to be elaborated,
1890 so don't blow up if so. */
1892 {
1895 }
1897 /* Attach the TYPE_STUB_DECL in case we have a parallel type. */
1901 /* For a packed array, make the original array type a parallel/debug
1902 type. */
1906 discrete_type:
1908 /* We have to handle clauses that under-align the type specially. */
1911 && Present
1914 {
1918 }
1920 /* If the type we are dealing with represents a bit-packed array,
1921 we need to have the bits left justified on big-endian targets
1922 and right justified on little-endian targets. We also need to
1923 ensure that when the value is read (e.g. for comparison of two
1924 such values), we only get the good bits, since the unused bits
1925 are uninitialized. Both goals are accomplished by wrapping up
1926 the modular type in an enclosing record type. */
1929 {
1932 /* Set the RM size before wrapping up the original type. */
1937 /* Strip the ___XP suffix for standard DWARF. */
1941 /* Create a stripped-down declaration, mainly for debugging. */
1943 gnat_entity);
1945 /* Now save it and build the enclosing record type. */
1955 /* Propagate the alignment of the modular type to the record type,
1956 unless there is an alignment clause that under-aligns the type.
1957 This means that bit-packed arrays are given "ceil" alignment for
1958 their size by default, which may seem counter-intuitive but makes
1959 it possible to overlay them on modular types easily. */
1963 /* Propagate the reverse storage order flag to the record type so
1964 that the required byte swapping is performed when retrieving the
1965 enclosed modular value. */
1971 /* Don't declare the field as addressable since we won't be taking
1972 its address and this would prevent create_field_decl from making
1973 a bitfield. */
1974 gnu_field
1978 /* We will output additional debug info manually below. */
1984 {
1985 /* Make the original array type a parallel/debug type. */
1988 /* Since GNU_TYPE is a padding type around the packed array
1989 implementation type, the padded type is its debug type. */
1992 }
1993 }
1995 /* If the type we are dealing with has got a smaller alignment than the
1996 natural one, we need to wrap it up in a record type and misalign the
1997 latter; we reuse the padding machinery for this purpose. */
1999 {
2002 /* Set the RM size before wrapping the type. */
2005 gnu_type
2011 }
2016 /* The type of the Low and High bounds can be our type if this is
2017 a type from Standard, so set them at the end of the function. */
2024 /* See the E_Signed_Integer_Subtype case for the rationale. */
2041 SET_TYPE_RM_MIN_VALUE
2044 debug_info_p));
2046 SET_TYPE_RM_MAX_VALUE
2049 debug_info_p));
2051 /* Inherit our alias set from what we're a subtype of, as for
2052 integer subtypes. */
2055 /* One of the above calls might have caused us to be elaborated,
2056 so don't blow up if so. */
2060 /* Array Types and Subtypes
2062 Unconstrained array types are represented by E_Array_Type and
2063 constrained array types are represented by E_Array_Subtype. There
2064 are no actual objects of an unconstrained array type; all we have
2065 are pointers to that type.
2067 The following fields are defined on array types and subtypes:
2069 Component_Type Component type of the array.
2070 Number_Dimensions Number of dimensions (an int).
2071 First_Index Type of first index. */
2074 {
2075 const bool convention_fortran_p
2078 tree gnu_template_type;
2079 tree gnu_ptr_template;
2086 tree comp_type;
2088 /* Create the type for the component now, as it simplifies breaking
2089 type reference loops. */
2090 comp_type
2093 {
2094 /* As a side effect, the type may have been translated. */
2097 }
2099 /* We complete an existing dummy fat pointer type in place. This both
2100 avoids further complex adjustments in update_pointer_to and yields
2101 better debugging information in DWARF by leveraging the support for
2102 incomplete declarations of "tagged" types in the DWARF back-end. */
2105 {
2108 /* Save the contents of the dummy type for update_pointer_to. */
2110 gnu_ptr_template =
2113 }
2114 else
2115 {
2119 }
2121 /* Make a node for the array. If we are not defining the array
2122 suppress expanding incomplete types. */
2126 {
2127 defer_incomplete_level++;
2129 }
2131 /* Build the fat pointer type. Use a "void *" object instead of
2132 a pointer to the array type since we don't have the array type
2133 yet (it will reference the fat pointer via the bounds). */
2134 tem
2142 {
2143 /* We are going to lay it out again so reset the alias set. */
2149 {
2152 }
2153 }
2154 else
2155 {
2158 }
2160 /* Build a reference to the template from a PLACEHOLDER_EXPR that
2161 is the fat pointer. This will be used to access the individual
2162 fields once we build them. */
2166 gnu_template_reference
2171 /* Now create the GCC type for each index and add the fields for that
2172 index to the template. */
2178 {
2181 tree gnu_index_base_type
2186 /* Make the FIELD_DECLs for the low and high bounds of this
2187 type and then make extractions of these fields from the
2188 template. */
2191 gnu_index_base_type,
2199 gnu_index_base_type,
2207 /* We can't use build_component_ref here since the template type
2208 isn't complete yet. */
2211 NULL_TREE);
2214 NULL_TREE);
2220 /* Compute the size of this dimension. See the E_Array_Subtype
2221 case below for the rationale. */
2222 gnu_high
2226 gnu_max,
2229 /* Make a range type with the new range in the Ada base type.
2230 Then make an index type with the size range in sizetype. */
2234 gnu_orig_min,
2235 gnu_orig_max),
2236 gnat_entity);
2238 /* Update the maximum size of the array in elements. */
2240 {
2241 tree gnu_min
2243 tree gnu_max
2245 tree gnu_this_max
2252 else
2253 gnu_max_size
2255 }
2259 }
2261 /* Install all the fields into the template. */
2266 gnu_template_fields
2269 debug_info_p);
2272 /* If Component_Size is not already specified, annotate it with the
2273 size of the component. */
2278 /* Compute the maximum size of the array in units and bits. */
2280 {
2286 }
2287 else
2290 /* Now build the array type. */
2293 {
2301 }
2303 /* If an alignment is specified, use it if valid. But ignore it
2304 for the original type of packed array types. If the alignment
2305 was requested with an explicit alignment clause, state so. */
2308 {
2311 gnat_entity,
2315 }
2317 /* Tag top-level ARRAY_TYPE nodes for packed arrays and their
2318 implementation types as such so that the debug information back-end
2319 can output the appropriate description for them. */
2327 /* Adjust the type of the pointer-to-array field of the fat pointer
2328 and record the aliasing relationships if necessary. */
2333 /* The result type is an UNCONSTRAINED_ARRAY_TYPE that indicates the
2334 corresponding fat pointer. */
2341 /* If the maximum size doesn't overflow, use it. */
2347 {
2352 }
2357 /* If told to generate GNAT encodings for them (GDB rely on them at the
2358 moment): give the fat pointer type a name. If this is a packed
2359 array, tell the debugger how to interpret the underlying bits. */
2362 else
2364 tree xup_name
2369 gnat_entity);
2371 /* Create the type to be designated by thin pointers: a record type for
2372 the array and its template. We used to shift the fields to have the
2373 template at a negative offset, but this was somewhat of a kludge; we
2374 now shift thin pointer values explicitly but only those which have a
2375 TYPE_UNCONSTRAINED_ARRAY attached to the designated RECORD_TYPE.
2376 Note that GDB can handle standard DWARF information for them, so we
2377 don't have to name them as a GNAT encoding, except if specifically
2378 asked to. */
2379 tree xut_name
2384 debug_info_p);
2388 }
2393 /* This is the actual data type for array variables. Multidimensional
2394 arrays are implemented as arrays of arrays. Note that arrays which
2395 have sparse enumeration subtypes as index components create sparse
2396 arrays, which is obviously space inefficient but so much easier to
2397 code for now.
2399 Also note that the subtype never refers to the unconstrained array
2400 type, which is somewhat at variance with Ada semantics.
2402 First check to see if this is simply a renaming of the array type.
2403 If so, the result is the array type. */
2407 ;
2408 else
2409 {
2411 const bool convention_fortran_p
2420 /* First create the GCC type for each index and find out whether
2421 special types are needed for debugging information. */
2424 gnat_base_index
2430 {
2432 tree gnu_index_base_type
2434 tree gnu_orig_min
2437 tree gnu_orig_max
2442 tree gnu_base_index_type
2444 tree gnu_base_index_base_type
2446 tree gnu_base_orig_min
2449 tree gnu_base_orig_max
2452 tree gnu_high;
2454 /* See if the base array type is already flat. If it is, we
2455 are probably compiling an ACATS test but it will cause the
2456 code below to malfunction if we don't handle it specially. */
2460 {
2464 }
2466 /* Similarly, if one of the values overflows in sizetype and the
2467 range is null, use 1..0 for the sizetype bounds. */
2472 {
2476 }
2478 /* If the minimum and maximum values both overflow in sizetype,
2479 but the difference in the original type does not overflow in
2480 sizetype, ignore the overflow indication. */
2484 && !TREE_OVERFLOW
2487 gnu_orig_max,
2488 gnu_orig_min))))
2489 {
2493 }
2495 /* Compute the size of this dimension in the general case. We
2496 need to provide GCC with an upper bound to use but have to
2497 deal with the "superflat" case. There are three ways to do
2498 this. If we can prove that the array can never be superflat,
2499 we can just use the high bound of the index type. */
2502 /* Bit-Packed Array Impl. Types are never superflat. */
2504 && Is_Bit_Packed_Array
2508 /* Otherwise, if the high bound is constant but the low bound is
2509 not, we use the expression (hb >= lb) ? lb : hb + 1 for the
2510 lower bound. Note that the comparison must be done in the
2511 original type to avoid any overflow during the conversion. */
2514 {
2516 gnu_min
2519 boolean_type_node,
2520 gnu_orig_max,
2521 gnu_orig_min),
2522 gnu_min,
2524 size_one_node));
2525 }
2527 /* Finally we use (hb >= lb) ? hb : lb - 1 for the upper bound
2528 in all the other cases. Note that, here as well as above,
2529 the condition used in the comparison must be equivalent to
2530 the condition (length != 0). This is relied upon in order
2531 to optimize array comparisons in compare_arrays. Moreover
2532 we use int_const_binop for the shift by 1 if the bound is
2533 constant to avoid any unwanted overflow. */
2534 else
2535 gnu_high
2538 boolean_type_node,
2539 gnu_orig_max,
2540 gnu_orig_min),
2541 gnu_max,
2544 size_one_node)
2546 size_one_node));
2548 /* Reuse the index type for the range type. Then make an index
2549 type with the size range in sizetype. */
2552 gnat_entity);
2554 /* Update the maximum size of the array in elements. Here we
2555 see if any constraint on the index type of the base type
2556 can be used in the case of self-referential bound on the
2557 index type of the subtype. We look for a non-"infinite"
2558 and non-self-referential bound from any type involved and
2559 handle each bound separately. */
2561 {
2564 tree gnu_base_base_min
2567 tree gnu_base_base_max
2588 else
2589 {
2590 tree gnu_this_max;
2592 /* Use int_const_binop if the bounds are constant to
2593 avoid any unwanted overflow. */
2596 gnu_this_max
2599 gnu_base_max,
2600 gnu_base_min));
2601 else
2602 gnu_this_max
2605 gnu_base_max,
2606 gnu_base_min));
2608 gnu_max_size
2610 }
2611 }
2613 /* We need special types for debugging information to point to
2614 the index types if they have variable bounds, are not integer
2615 types, are biased or are wider than sizetype. These are GNAT
2616 encodings, so we have to include them only when all encodings
2617 are requested. */
2627 }
2629 /* Then flatten: create the array of arrays. For an array type
2630 used to implement a packed array, get the component type from
2631 the original array type since the representation clauses that
2632 can affect it are on the latter. */
2635 {
2640 /* One of the above calls might have caused us to be elaborated,
2641 so don't blow up if so. */
2643 {
2646 }
2647 }
2648 else
2649 {
2651 debug_info_p);
2653 /* One of the above calls might have caused us to be elaborated,
2654 so don't blow up if so. */
2656 {
2659 }
2660 }
2662 /* Compute the maximum size of the array in units and bits. */
2664 {
2670 }
2671 else
2674 /* Now build the array type. */
2676 {
2685 }
2687 /* Strip the ___XP suffix for standard DWARF. */
2690 {
2691 Entity_Id gnat_original_array_type
2694 gnu_entity_name
2696 }
2698 /* Attach the TYPE_STUB_DECL in case we have a parallel type. */
2702 /* If this is a multi-dimensional array and we are at global level,
2703 we need to make a variable corresponding to the stride of the
2704 inner dimensions. */
2706 {
2707 tree gnu_arr_type;
2712 {
2722 /* ??? For now, store the size as a multiple of the
2723 alignment of the element type in bytes so that we
2724 can see the alignment from the tree. */
2732 /* ??? create_type_decl is not invoked on the inner types so
2733 the MULT_EXPR node built above will never be marked. */
2735 }
2736 }
2738 /* If we need to write out a record type giving the names of the
2739 bounds for debugging purposes, do it now and make the record
2740 type a parallel type. This is not needed for a packed array
2741 since the bounds are conveyed by the original array type. */
2743 && debug_info_p
2745 {
2748 tree gnu_field;
2754 {
2758 /* Make sure to reference the types themselves, and not just
2759 their names, as the debugger may fall back on them. */
2765 }
2769 }
2771 /* If this is a packed array type, make the original array type a
2772 parallel/debug type. Otherwise, if such GNAT encodings are
2773 required, do it for the base array type if it isn't artificial to
2774 make sure it is kept in the debug info. */
2776 {
2779 gnat_entity);
2780 else
2781 {
2782 tree gnu_base_decl
2789 }
2790 }
2796 /* Tag top-level ARRAY_TYPE nodes for packed arrays and their
2797 implementation types as such so that the debug information back-end
2798 can output the appropriate description for them. */
2803 /* If the size is self-referential and the maximum size doesn't
2804 overflow, use it. */
2806 && gnu_max_size
2811 {
2817 }
2819 /* Set our alias set to that of our base type. This gives all
2820 array subtypes the same alias set. */
2823 /* If this is a packed type, make this type the same as the packed
2824 array type, but do some adjusting in the type first. */
2826 {
2827 Entity_Id gnat_index;
2828 tree gnu_inner;
2830 /* First finish the type we had been making so that we output
2831 debugging information for it. */
2834 {
2835 const int quals
2836 = TYPE_QUAL_VOLATILE
2839 }
2840 /* Make it artificial only if the base type was artificial too.
2841 That's sort of "morally" true and will make it possible for
2842 the debugger to look it up by name in DWARF, which is needed
2843 in order to decode the packed array type. */
2844 gnu_decl
2848 gnat_entity);
2850 /* Save it as our equivalent in case the call below elaborates
2851 this type again. */
2854 gnu_decl
2869 /* We need to attach the index type to the type we just made so
2870 that the actual bounds can later be put into a template. */
2875 {
2877 {
2878 /* The TYPE_ACTUAL_BOUNDS field is overloaded with the
2879 TYPE_MODULUS for modular types so we make an extra
2880 subtype if necessary. */
2882 {
2883 tree gnu_subtype
2892 }
2896 /* Check for other cases of overloading. */
2898 }
2903 SET_TYPE_ACTUAL_BOUNDS
2910 SET_TYPE_ACTUAL_BOUNDS
2916 }
2917 }
2918 }
2922 /* Create the type for a string literal. */
2923 {
2924 Entity_Id gnat_full_type
2929 tree gnu_string_array_type
2931 tree gnu_string_index_type
2934 tree gnu_lower_bound
2937 tree gnu_length
2939 gnu_string_index_type);
2940 tree gnu_upper_bound
2942 gnu_lower_bound,
2945 integer_one_node)));
2946 tree gnu_index_type
2950 gnu_lower_bound,
2951 gnu_upper_bound),
2952 gnat_entity);
2954 gnu_type
2957 gnu_index_type);
2961 }
2964 /* Record Types and Subtypes
2966 The following fields are defined on record types:
2968 Has_Discriminants True if the record has discriminants
2969 First_Discriminant Points to head of list of discriminants
2970 First_Entity Points to head of list of fields
2971 Is_Tagged_Type True if the record is tagged
2973 Implementation of Ada records and discriminated records:
2975 A record type definition is transformed into the equivalent of a C
2976 struct definition. The fields that are the discriminants which are
2977 found in the Full_Type_Declaration node and the elements of the
2978 Component_List found in the Record_Type_Definition node. The
2979 Component_List can be a recursive structure since each Variant of
2980 the Variant_Part of the Component_List has a Component_List.
2982 Processing of a record type definition comprises starting the list of
2983 field declarations here from the discriminants and the calling the
2984 function components_to_record to add the rest of the fields from the
2985 component list and return the gnu type node. The function
2986 components_to_record will call itself recursively as it traverses
2987 the tree. */
2991 {
2992 gnu_type
2993 = build_complex_type
2994 (get_unpadded_type
2997 (Component_List
2998 (Type_Definition
3002 }
3004 {
3007 Node_Id gnat_constr;
3010 tree gnu_get_parent;
3011 /* Set PACKED in keeping with gnat_to_gnu_field. */
3012 const int packed
3021 const bool is_extension
3027 /* See if all fields have a rep clause. Stop when we find one
3028 that doesn't. */
3036 {
3039 }
3041 /* If this is a record extension, go a level further to find the
3042 record definition. Also, verify we have a Parent_Subtype. */
3044 {
3051 }
3053 /* Make a node for the record. If we are not defining the record,
3054 suppress expanding incomplete types. */
3063 {
3064 defer_incomplete_level++;
3066 }
3068 /* If both a size and rep clause were specified, put the size on
3069 the record type now so that it can get the proper layout. */
3074 /* Always set the alignment on the record type here so that it can
3075 get the proper layout. */
3080 else
3081 {
3084 /* If a type needs strict alignment, the minimum size will be the
3085 type size instead of the RM size (see validate_size). Cap the
3086 alignment lest it causes this type size to become too large. */
3088 {
3093 }
3094 }
3096 /* If we have a Parent_Subtype, make a field for the parent. If
3097 this record has rep clauses, force the position to zero. */
3099 {
3102 tree gnu_parent;
3105 /* A major complexity here is that the parent subtype will
3106 reference our discriminants in its Stored_Constraint list.
3107 But those must reference the parent component of this record
3108 which is precisely of the parent subtype we have not built yet!
3109 To break the circle we first build a dummy COMPONENT_REF which
3110 represents the "get to the parent" operation and initialize
3111 each of those discriminants to a COMPONENT_REF of the above
3112 dummy parent referencing the corresponding discriminant of the
3113 base type of the parent subtype. */
3118 gnu_dummy_parent_type),
3119 NULL_TREE);
3126 {
3127 tree gnu_field
3130 save_gnu_tree
3135 }
3137 /* Then we build the parent subtype. If it has discriminants but
3138 the type itself has unknown discriminants, this means that it
3139 doesn't contain information about how the discriminants are
3140 derived from those of the ancestor type, so it cannot be used
3141 directly. Instead it is built by cloning the parent subtype
3142 of the underlying record view of the type, for which the above
3143 derivation of discriminants has been made explicit. */
3146 {
3149 /* If we are defining the type, the underlying record
3150 view must already have been elaborated at this point.
3151 Otherwise do it now as its parent subtype cannot be
3152 technically elaborated on its own. */
3155 else
3160 /* Substitute the "get to the parent" of the type for that
3161 of its underlying record view in the cloned type. */
3166 {
3168 tree gnu_ref
3171 gnu_parent
3173 }
3174 }
3175 else
3178 /* The parent field needs strict alignment so, if it is to
3179 be created with a component clause below, then we need
3180 to apply the same adjustment as in gnat_to_gnu_field. */
3182 {
3183 /* ??? For historical reasons, we do it on strict-alignment
3184 platforms only, where it is really required. This means
3185 that a confirming representation clause will change the
3186 behavior of the compiler on the other platforms. */
3189 else
3190 parent_packed
3192 }
3194 /* Finally we fix up both kinds of twisted COMPONENT_REF we have
3195 initially built. The discriminants must reference the fields
3196 of the parent subtype and not those of its base type for the
3197 placeholder machinery to properly work. */
3199 {
3200 /* The actual parent subtype is the full view. */
3202 {
3205 else
3207 }
3213 {
3214 Entity_Id field;
3223 }
3224 }
3226 /* The "get to the parent" COMPONENT_REF must be given its
3227 proper type... */
3230 /* ...and reference the _Parent field of this record. */
3231 gnu_field
3234 has_rep
3236 has_rep
3242 }
3244 /* Make the fields for the discriminants and put them into the record
3245 unless it's an Unchecked_Union. */
3250 {
3251 /* If this is a record extension and this discriminant is the
3252 renaming of another discriminant, we've handled it above. */
3257 gnu_field
3259 debug_info_p);
3261 /* Make an expression using a PLACEHOLDER_EXPR from the
3262 FIELD_DECL node just created and link that with the
3263 corresponding GNAT defining identifier. */
3271 {
3274 }
3275 }
3277 /* If we have a derived untagged type that renames discriminants in
3278 the parent type, the (stored) discriminants are just a copy of the
3279 discriminants of the parent type. This means that any constraints
3280 added by the renaming in the derivation are disregarded as far as
3281 the layout of the derived type is concerned. To rescue them, we
3282 change the type of the (stored) discriminants to a subtype with
3283 the bounds of the type of the visible discriminants. */
3285 && !is_extension
3291 /* Ignore access discriminants. */
3294 {
3297 tree gnu_ref
3301 /* GNU_REF must be an expression using a PLACEHOLDER_EXPR built
3302 just above for one of the stored discriminants. */
3306 {
3308 tree gnu_subtype
3319 }
3320 }
3322 /* If this is a derived type with discriminants and these discriminants
3323 affect the initial shape it has inherited, factor them in. But for
3324 an Unchecked_Union (it must be an Itype), just process the type. */
3326 && !is_extension
3332 {
3333 tree gnu_parent_type
3342 /* Set the layout of the type to match that of the parent type,
3343 doing required substitutions. */
3347 }
3348 else
3349 {
3350 /* Add the fields into the record type and finish it up. */
3357 NULL);
3359 /* If there are entities in the chain corresponding to components
3360 that we did not elaborate, ensure we elaborate their types if
3361 they are Itypes. */
3370 }
3372 /* Fill in locations of fields. */
3375 /* If this is a record type associated with an exception definition,
3376 equate its fields to those of the standard exception type. This
3377 will make it possible to convert between them. */
3379 {
3380 tree gnu_std_field;
3383 gnu_field;
3388 }
3389 }
3393 /* If an equivalent type is present, that is what we should use.
3394 Otherwise, fall through to handle this like a record subtype
3395 since it may have constraints. */
3397 {
3401 }
3403 /* ... fall through ... */
3406 /* If Cloned_Subtype is Present it means this record subtype has
3407 identical layout to that type or subtype and we should use
3408 that GCC type for this one. The front end guarantees that
3409 the component list is shared. */
3411 {
3416 }
3418 /* Otherwise, first ensure the base type is elaborated. Then, if we are
3419 changing the type, make a new type with each field having the type of
3420 the field in the new subtype but the position computed by transforming
3421 every discriminant reference according to the constraints. We don't
3422 see any difference between private and non-private type here since
3423 derivations from types should have been deferred until the completion
3424 of the private type. */
3425 else
3426 {
3430 {
3431 defer_incomplete_level++;
3433 }
3435 tree gnu_base_type
3439 {
3442 }
3444 /* If this is a record subtype associated with a dispatch table,
3445 strip the suffix. This is necessary to make sure 2 different
3446 subtypes associated with the imported and exported views of a
3447 dispatch table are properly merged in LTO mode. */
3449 {
3456 }
3458 /* When the subtype has discriminants and these discriminants affect
3459 the initial shape it has inherited, factor them in. But for an
3460 Unchecked_Union (it must be an Itype), just return the type. */
3466 {
3469 tree gnu_unpad_base_type;
3480 /* Set the size, alignment and alias set of the type to match
3481 those of the base type, doing required substitutions. */
3483 gnu_subst_list);
3487 else
3490 /* Set the layout of the type to match that of the base type,
3491 doing required substitutions. We will output debug info
3492 manually below so pass false as last argument. */
3497 /* Fill in locations of fields. */
3500 /* If debugging information is being written for the type and if
3501 we are asked to output such encodings, write a record that
3502 shows what we are a subtype of and also make a variable that
3503 indicates our size, if still variable. */
3505 {
3507 tree gnu_unpad_base_name
3515 build_reference_type
3517 gnu_subtype_marker,
3534 }
3535 }
3537 /* Otherwise, go down all the components in the new type and make
3538 them equivalent to those in the base type. */
3539 else
3540 {
3550 gnat_to_gnu_field_decl
3553 }
3554 }
3559 /* Use the special descriptor type for dispatch tables if needed,
3560 that is to say for the Prim_Ptr of a-tags.ads and its clones.
3561 Note that we are only required to do so for static tables in
3562 order to be compatible with the C++ ABI, but Ada 2005 allows
3563 to extend library level tagged types at the local level so
3564 we do it in the non-static case as well. */
3567 {
3571 }
3573 /* ... fall through ... */
3580 {
3581 /* The designated type and its equivalent type for gigi. */
3584 /* Whether it comes from a limited with. */
3585 const bool is_from_limited_with
3588 /* Whether it is a completed Taft Amendment type. Such a type is to
3589 be treated as coming from a limited with clause if it is not in
3590 the main unit, i.e. we break potential circularities here in case
3591 the body of an external unit is loaded for inter-unit inlining. */
3592 const bool is_completed_taft_type
3596 /* The "full view" of the designated type. If this is an incomplete
3597 entity from a limited with, treat its non-limited view as the full
3598 view. Otherwise, if this is an incomplete or private type, use the
3599 full view. In the former case, we might point to a private type,
3600 in which case, we need its full view. Also, we want to look at the
3601 actual type used for the representation, so this takes a total of
3602 three steps. */
3603 Entity_Id gnat_desig_full_direct_first
3604 = (is_from_limited_with
3608 Entity_Id gnat_desig_full_direct
3609 = ((is_from_limited_with
3614 Entity_Id gnat_desig_full
3616 /* The type actually used to represent the designated type, either
3617 gnat_desig_full or gnat_desig_equiv. */
3618 Entity_Id gnat_desig_rep;
3619 /* We want to know if we'll be seeing the freeze node for any
3620 incomplete type we may be pointing to. */
3621 const bool in_main_unit
3625 /* True if we make a dummy type here. */
3627 /* The mode to be used for the pointer type. */
3628 scalar_int_mode p_mode;
3629 /* The GCC type used for the designated type. */
3636 /* If either the designated type or its full view is an unconstrained
3637 array subtype, replace it with the type it's a subtype of. This
3638 avoids problems with multiple copies of unconstrained array types.
3639 Likewise, if the designated type is a subtype of an incomplete
3640 record type, use the parent type to avoid order of elaboration
3641 issues. This can lose some code efficiency, but there is no
3642 alternative. */
3653 /* Set the type that's the representation of the designated type. */
3654 gnat_desig_rep
3657 /* If we already know what the full type is, use it. */
3661 /* Get the type of the thing we are to point to and build a pointer to
3662 it. If it is a reference to an incomplete or private type with a
3663 full view that is a record, an array or an access, make a dummy type
3664 and get the actual type later when we have verified it is safe. */
3671 /* Likewise if this is a reference to a record, an array or a
3672 subprogram type and we are to defer elaborating incomplete
3673 types. We do this because this access type may be the full
3674 view of a private type. */
3681 /* If this is a reference from a limited_with type back to our
3682 main unit and there's a freeze node for it, either we have
3683 already processed the declaration and made the dummy type,
3684 in which case we just reuse the latter, or we have not yet,
3685 in which case we make the dummy type and it will be reused
3686 when the declaration is finally processed. In both cases,
3687 the pointer eventually created below will be automatically
3688 adjusted when the freeze node is processed. */
3689 || (in_main_unit
3690 && is_from_limited_with
3692 {
3695 }
3697 /* Otherwise handle the case of a pointer to itself. */
3699 {
3700 gnu_type
3704 }
3706 /* If expansion is disabled, the equivalent type of a concurrent type
3707 is absent, so we use the void pointer type. */
3711 /* If the ultimately designated type is an incomplete type with no full
3712 view, we use the void pointer type in LTO mode to avoid emitting a
3713 dummy type in the GIMPLE IR. We cannot do that in regular mode as
3714 the name of the dummy type in used by GDB for a global lookup. */
3720 /* Finally, handle the default case where we can just elaborate our
3721 designated type. */
3722 else
3725 /* It is possible that a call to gnat_to_gnu_type above resolved our
3726 type. If so, just return it. */
3728 {
3731 }
3733 /* Access-to-unconstrained-array types need a special treatment. */
3735 {
3736 /* If the processing above got something that has a pointer, then
3737 we are done. This could have happened either because the type
3738 was elaborated or because somebody else executed the code. */
3743 }
3745 /* If we haven't done it yet, build the pointer type the usual way. */
3747 {
3748 /* Modify the designated type if we are pointing only to constant
3749 objects, but don't do it for a dummy type. */
3752 gnu_desig_type
3755 gnu_type
3758 }
3760 /* If the designated type is not declared in the main unit and we made
3761 a dummy node for it, save our definition, elaborate the actual type
3762 and replace the dummy type we made with the actual one. But if we
3763 are to defer actually looking up the actual type, make an entry in
3764 the deferred list instead. If this is from a limited with, we may
3765 have to defer until the end of the current unit. */
3767 {
3769 gnu_type
3775 gnat_entity);
3782 && !is_from_limited_with
3784 {
3787 }
3788 else
3789 {
3799 }
3800 }
3801 }
3806 /* If we are just annotating types and have no equivalent record type,
3807 just use the void pointer type. */
3811 /* The run-time representation is the equivalent type. */
3812 else
3813 {
3816 }
3818 /* The designated subtype must be elaborated as well, if it does
3819 not have its own freeze node. */
3830 /* We treat this as identical to its base type; any constraint is
3831 meaningful only to the front-end. */
3835 /* The designated subtype must be elaborated as well, if it does
3836 not have its own freeze node. But designated subtypes created
3837 for constrained components of records with discriminants are
3838 not frozen by the front-end and not elaborated here, because
3839 their use may appear before the base type is frozen and it is
3840 not clear that they are needed in gigi. With the current model,
3841 there is no correct place where they could be elaborated. */
3846 {
3847 /* If we are to defer elaborating incomplete types, make a dummy
3848 type node and elaborate it later. */
3850 {
3853 p->old_type
3858 }
3861 Incomplete_Or_Private_Kind))
3864 }
3867 /* Subprogram Entities
3869 The following access functions are defined for subprograms:
3871 Etype Return type or Standard_Void_Type.
3872 First_Formal The first formal parameter.
3873 Is_Imported Indicates that the subprogram has appeared in
3874 an INTERFACE or IMPORT pragma. For now we
3875 assume that the external language is C.
3876 Is_Exported Likewise but for an EXPORT pragma.
3877 Is_Inlined True if the subprogram is to be inlined.
3879 Each parameter is first checked by calling must_pass_by_ref on its
3880 type to determine if it is passed by reference. For parameters which
3881 are copied in, if they are Ada In Out or Out parameters, their return
3882 value becomes part of a record which becomes the return type of the
3883 function (C function - note that this applies only to Ada procedures
3884 so there is no Ada return type). Additional code to store back the
3885 parameters will be generated on the caller side. This transformation
3886 is done here, not in the front-end.
3888 The intended result of the transformation can be seen from the
3889 equivalent source rewritings that follow:
3891 struct temp {int a,b};
3892 procedure P (A,B: In Out ...) is temp P (int A,B)
3893 begin {
3894 .. ..
3895 end P; return {A,B};
3896 }
3898 temp t;
3899 P(X,Y); t = P(X,Y);
3900 X = t.a , Y = t.b;
3902 For subprogram types we need to perform mainly the same conversions to
3903 GCC form that are needed for procedures and function declarations. The
3904 only difference is that at the end, we make a type declaration instead
3905 of a function declaration. */
3910 {
3911 tree gnu_ext_name
3913 enum inline_status_t inline_status
3915 ? is_suppressed
3917 ? is_required
3920 /* Subprograms marked both Intrinsic and Always_Inline need not
3921 have a body of their own. */
3922 bool extern_flag
3924 || imported_p
3927 tree gnu_param_list;
3929 /* A parameter may refer to this type, so defer completion of any
3930 incomplete types. */
3932 {
3933 defer_incomplete_level++;
3935 }
3937 /* If the subprogram has an alias, it is probably inherited, so
3938 we can use the original one. If the original "subprogram"
3939 is actually an enumeration literal, it may be the first use
3940 of its type, so we must elaborate that type now. */
3942 {
3949 gnu_decl
3952 /* Elaborate any Itypes in the parameters of this entity. */
3959 /* Materialize renamed subprograms in the debugging information
3960 when the renamed object is compile time known. We can consider
3961 such renamings as imported declarations.
3963 Because the parameters in generics instantiation are generally
3964 materialized as renamings, we ofter end up having both the
3965 renamed subprogram and the renaming in the same context and with
3966 the same name: in this case, renaming is both useless debug-wise
3967 and potentially harmful as name resolution in the debugger could
3968 return twice the same entity! So avoid this case. */
3977 && gnu_decl
3979 {
3984 }
3987 }
3989 /* Get the GCC tree for the (underlying) subprogram type. If the
3990 entity is an actual subprogram, also get the parameter list. */
3991 gnu_type
3995 {
3999 }
4001 /* Deal with platform-specific calling conventions. */
4003 prepend_one_attribute
4006 gnat_entity);
4008 prepend_one_attribute
4011 gnat_entity);
4013 /* If we should request stack realignment for a foreign convention
4014 subprogram, do so. Note that this applies to task entry points
4015 in particular. */
4018 prepend_one_attribute
4021 gnat_entity);
4023 /* Deal with a pragma Linker_Section on a subprogram. */
4029 /* If we are defining the subprogram and it has an Address clause
4030 we must get the address expression from the saved GCC tree for the
4031 subprogram if it has a Freeze_Node. Otherwise, we elaborate
4032 the address expression here since the front-end has guaranteed
4033 in that case that the elaboration has no effects. If there is
4034 an Address clause and we are not defining the object, just
4035 make it a constant. */
4037 {
4041 gnu_address
4048 /* Convert the type of the object to a reference type that can
4049 alias everything as per RM 13.3(19). */
4050 gnu_type
4055 gnu_decl
4061 }
4063 /* If this is a mere subprogram type, just create the declaration. */
4065 {
4068 gnu_decl
4071 }
4073 /* Otherwise create the subprogram declaration with the external name,
4074 the type and the parameter list. However, if this a reference to
4075 the allocation routines, reuse the canonical declaration nodes as
4076 they come with special properties. */
4077 else
4078 {
4083 else
4084 {
4085 gnu_decl
4090 debug_info_p,
4092 gnat_entity);
4096 }
4097 }
4098 }
4109 {
4110 const bool is_from_limited_with
4112 /* Get the "full view" of this entity. If this is an incomplete
4113 entity from a limited with, treat its non-limited view as the
4114 full view. Otherwise, use either the full view or the underlying
4115 full view, whichever is present. This is used in all the tests
4116 below. */
4117 const Entity_Id full_view
4118 = is_from_limited_with
4126 /* If this is an incomplete type with no full view, it must be a Taft
4127 Amendment type or an incomplete type coming from a limited context,
4128 in which cases we return a dummy type. Otherwise, we just get the
4129 type from its Etype. */
4131 {
4133 {
4136 }
4137 else
4138 {
4139 gnu_decl
4142 }
4143 }
4145 /* Or else, if we already made a type for the full view, reuse it. */
4149 /* Or else, if we are not defining the type or there is no freeze
4150 node on it, get the type for the full view. Likewise if this is
4151 a limited_with'ed type not declared in the main unit, which can
4152 happen for incomplete formal types instantiated on a type coming
4153 from a limited_with clause. */
4156 || (is_from_limited_with
4158 {
4161 }
4163 /* Otherwise, make a dummy type entry which will be replaced later.
4164 Save it as the full declaration's type so we can do any needed
4165 updates when we see it. */
4166 else
4167 {
4173 }
4174 }
4178 /* Class-wide types are always transformed into their root type. */
4187 /* If we are just annotating types and have no equivalent record type,
4188 just return void_type, except for root types that have discriminants
4189 because the discriminants will very likely be used in the declarative
4190 part of the associated body so they need to be translated. */
4192 {
4195 {
4197 Entity_Id gnat_field;
4199 /* This is a minimal version of the E_Record_Type handling. */
4206 {
4207 tree gnu_field
4219 }
4223 }
4224 else
4226 }
4228 /* Concurrent types are always transformed into their record type. */
4229 else
4240 /* Nothing at all to do here, so just return an ERROR_MARK and claim
4241 we've already saved it, so we don't try to. */
4247 /* This is a SPARK annotation that only reaches here when compiling in
4248 ASIS mode. */
4256 }
4258 /* If we had a case where we evaluated another type and it might have
4259 defined this one, handle it here. */
4261 {
4264 }
4266 /* If we are processing a type and there is either no decl for it or
4267 we just made one, do some common processing for the type, such as
4268 handling alignment and possible padding. */
4270 {
4273 /* Process the attributes, if not already done. Note that the type is
4274 already defined so we cannot pass true for IN_PLACE here. */
4277 /* Tell the middle-end that objects of tagged types are guaranteed to
4278 be properly aligned. This is necessary because conversions to the
4279 class-wide type are translated into conversions to the root type,
4280 which can be less aligned than some of its derived types. */
4285 /* Record whether the type is passed by reference. */
4289 /* ??? Don't set the size for a String_Literal since it is either
4290 confirming or we don't handle it properly (if the low bound is
4291 non-constant). */
4293 {
4296 gnu_size
4299 }
4301 /* If a size was specified, see if we can make a new type of that size
4302 by rearranging the type, for example from a fat to a thin pointer. */
4304 {
4305 gnu_type
4312 }
4314 /* If the alignment has not already been processed and this is not
4315 an unconstrained array type, see if an alignment is specified.
4316 If not, we pick a default alignment for atomic objects. */
4318 ;
4320 {
4324 /* Warn on suspiciously large alignments. This should catch
4325 errors about the (alignment,byte)/(size,bit) discrepancy. */
4327 {
4328 tree size;
4330 /* If a size was specified, take it into account. Otherwise
4331 use the RM size for records or unions as the type size has
4332 already been adjusted to the alignment. */
4338 else
4341 /* Consider an alignment as suspicious if the alignment/size
4342 ratio is greater or equal to the byte/bit ratio. */
4347 gnat_entity);
4348 }
4349 }
4360 /* See if we need to pad the type. If we did, and made a record,
4361 the name of the new type may be changed. So get it back for
4362 us when we make the new TYPE_DECL below. */
4370 /* Now set the RM size of the type. We cannot do it before padding
4371 because we need to accept arbitrary RM sizes on integral types. */
4374 /* If we are at global level, GCC will have applied variable_size to
4375 the type, but that won't have done anything. So, if it's not
4376 a constant or self-referential, call elaborate_expression_1 to
4377 make a variable for the size rather than calculating it each time.
4378 Handle both the RM size and the actual size. */
4383 {
4390 /* ??? For now, store the size as a multiple of the alignment in
4391 bytes so that we can see the alignment from the tree. */
4397 /* ??? gnu_type may come from an existing type so the MULT_EXPR node
4398 may not be marked by the call to create_type_decl below. */
4402 {
4407 {
4411 /* If the position of the variant part is constant, subtract
4412 it from the size of the type of the parent to get the new
4413 size. This manual CSE reduces the data size. */
4415 {
4423 }
4424 else
4425 {
4431 /* ??? For now, store the size as a multiple of the
4432 alignment in bytes so that we can see the alignment
4433 from the tree. */
4440 /* ??? For now, store the offset as a multiple of the
4441 alignment in bytes so that we can see the alignment
4442 from the tree. */
4446 DECL_OFFSET_ALIGN
4448 }
4452 }
4456 else
4457 ada_size
4461 }
4462 }
4464 /* Similarly, if this is a record type or subtype at global level, call
4465 elaborate_expression_2 on any field position. Skip any fields that
4466 we haven't made trees for to avoid problems with class-wide types. */
4471 {
4474 /* ??? For now, store the offset as a multiple of the alignment
4475 in bytes so that we can see the alignment from the tree. */
4478 {
4485 /* ??? The context of gnu_field is not necessarily gnu_type
4486 so the MULT_EXPR node built above may not be marked by
4487 the call to create_type_decl below. */
4489 }
4490 }
4495 /* If this is not an unconstrained array type, set some flags. */
4497 {
4504 /* If it is passed by reference, force BLKmode to ensure that
4505 objects of this type will always be put in memory. */
4510 }
4512 /* If this is a derived type, relate its alias set to that of its parent
4513 to avoid troubles when a call to an inherited primitive is inlined in
4514 a context where a derived object is accessed. The inlined code works
4515 on the parent view so the resulting code may access the same object
4516 using both the parent and the derived alias sets, which thus have to
4517 conflict. As the same issue arises with component references, the
4518 parent alias set also has to conflict with composite types enclosing
4519 derived components. For instance, if we have:
4521 type D is new T;
4522 type R is record
4523 Component : D;
4524 end record;
4526 we want T to conflict with both D and R, in addition to R being a
4527 superset of D by record/component construction.
4529 One way to achieve this is to perform an alias set copy from the
4530 parent to the derived type. This is not quite appropriate, though,
4531 as we don't want separate derived types to conflict with each other:
4533 type I1 is new Integer;
4534 type I2 is new Integer;
4536 We want I1 and I2 to both conflict with Integer but we do not want
4537 I1 to conflict with I2, and an alias set copy on derivation would
4538 have that effect.
4540 The option chosen is to make the alias set of the derived type a
4541 superset of that of its parent type. It trivially fulfills the
4542 simple requirement for the Integer derivation example above, and
4543 the component case as well by superset transitivity:
4545 superset superset
4546 R ----------> D ----------> T
4548 However, for composite types, conversions between derived types are
4549 translated into VIEW_CONVERT_EXPRs so a sequence like:
4551 type Comp1 is new Comp;
4552 type Comp2 is new Comp;
4553 procedure Proc (C : Comp1);
4555 C : Comp2;
4556 Proc (Comp1 (C));
4558 is translated into:
4560 C : Comp2;
4561 Proc ((Comp1 &) &VIEW_CONVERT_EXPR <Comp1> (C));
4563 and gimplified into:
4565 C : Comp2;
4566 Comp1 *C.0;
4567 C.0 = (Comp1 *) &C;
4568 Proc (C.0);
4570 i.e. generates code involving type punning. Therefore, Comp1 needs
4571 to conflict with Comp2 and an alias set copy is required.
4573 The language rules ensure the parent type is already frozen here. */
4577 {
4579 /* For constrained packed array subtypes, the implementation type is
4580 used instead of the nominal type. */
4588 }
4591 {
4592 const int quals
4593 = TYPE_QUAL_VOLATILE
4596 }
4601 gnat_entity);
4602 else
4603 {
4606 }
4607 }
4609 /* If we got a type that is not dummy, back-annotate the alignment of the
4610 type if not already in the tree. Likewise for the size, if any. */
4612 {
4616 {
4620 /* If the default alignment of "double" or larger scalar types is
4621 specifically capped and this is not an array with an alignment
4622 clause on the component type, return the cap. */
4624 is_capped_double
4627 is_capped_double
4629 else
4634 else
4638 }
4641 {
4644 /* If the size is self-referential, annotate the maximum value. */
4648 /* If we are just annotating types and the type is tagged, the tag
4649 and the parent components are not generated by the front-end so
4650 alignment and sizes must be adjusted if there is no rep clause. */
4657 {
4658 tree offset;
4661 {
4665 }
4666 else
4667 {
4668 unsigned int align
4672 }
4675 offset
4683 }
4685 /* If there is a rep clause, only adjust alignment and Esize. */
4687 {
4688 unsigned int align
4693 }
4695 /* Otherwise no adjustment is needed. */
4696 else
4698 }
4702 }
4704 /* If we haven't already, associate the ..._DECL node that we just made with
4705 the input GNAT entity node. */
4709 /* Now we are sure gnat_entity has a corresponding ..._DECL node,
4710 eliminate as many deferred computations as possible. */
4713 /* If this is an enumeration or floating-point type, we were not able to set
4714 the bounds since they refer to the type. These are always static. */
4717 {
4721 /* If this is a padded type, we need to use the underlying type. */
4725 /* If this is a floating point type and we haven't set a floating
4726 point type yet, use this in the evaluation of the bounds. */
4734 {
4735 /* Enumeration types have specific RM bounds. */
4738 }
4739 else
4740 {
4741 /* Floating-point types don't have specific RM bounds. */
4744 }
4745 }
4747 /* If we deferred processing of incomplete types, re-enable it. If there
4748 were no other disables and we have deferred types to process, do so. */
4752 {
4755 /* We are back to level 0 for the deferring of incomplete types.
4756 But processing these incomplete types below may itself require
4757 deferring, so preserve what we have and restart from scratch. */
4762 {
4769 }
4770 }
4772 /* If we are not defining this type, see if it's on one of the lists of
4773 incomplete types. If so, handle the list entry now. */
4775 {
4780 {
4784 }
4790 {
4796 }
4797 }
4800 force_global--;
4802 /* If this is a packed array type whose original array type is itself
4803 an Itype without freeze node, make sure the latter is processed. */
4811 }
4813 /* Similar, but if the returned value is a COMPONENT_REF, return the
4814 FIELD_DECL. */
4816 tree
4818 {
4825 }
4827 /* Similar, but GNAT_ENTITY is assumed to refer to a GNAT type. Return
4828 the GCC type corresponding to that entity. */
4830 tree
4832 {
4833 tree gnu_decl;
4835 /* The back end never attempts to annotate generic types. */
4843 }
4845 /* Similar, but GNAT_ENTITY is assumed to refer to a GNAT type. Return
4846 the unpadded version of the GCC type corresponding to that entity. */
4848 tree
4850 {
4857 }
4859 /* Return whether the E_Subprogram_Type/E_Function/E_Procedure GNAT_ENTITY is
4860 a C++ imported method or equivalent.
4862 We use the predicate on 32-bit x86/Windows to find out whether we need to
4863 use the "thiscall" calling convention for GNAT_ENTITY. This convention is
4864 used for C++ methods (functions with METHOD_TYPE) by the back-end. */
4866 bool
4868 {
4869 /* A constructor is a method on the C++ side. We deal with it now because
4870 it is declared without the 'this' parameter in the sources and, although
4871 the front-end will create a version with the 'this' parameter for code
4872 generation purposes, we want to return true for both versions. */
4876 /* Check that the subprogram has C++ convention. */
4880 /* And that the type of the first parameter (indirectly) has it too. */
4891 /* This is the main case: a C++ virtual method imported as a primitive
4892 operation of a tagged type. */
4896 /* This is set on the E_Subprogram_Type built for a dispatching call. */
4900 /* A thunk needs to be handled like its associated primitive operation. */
4904 /* Now on to the annoying case: a C++ non-virtual method, imported either
4905 as a non-primitive operation of a tagged type or as a primitive operation
4906 of an untagged type. We cannot reliably differentiate these cases from
4907 their static member or regular function equivalents in Ada, so we ask
4908 the C++ side through the mangled name of the function, as the implicit
4909 'this' parameter is not encoded in the mangled name of a method. */
4911 {
4918 DMGL_GNU_V3
4919 | DMGL_TYPES
4920 | DMGL_PARAMS
4926 /* We need to release MEM once we have a successful demangling. */
4933 {
4934 /* Make sure there is at least one parameter in C++ too. */
4936 {
4939 n_ada_args++;
4945 n_cpp_args++;
4951 }
4952 else
4954 }
4959 }
4962 }
4964 /* Finalize the processing of From_Limited_With incomplete types. */
4966 void
4968 {
4975 {
4979 {
4984 }
4987 }
4988 }
4990 /* Return the equivalent type to be used for GNAT_ENTITY, if it's a kind
4991 of type (such E_Task_Type) that has a different type which Gigi uses
4992 for its representation. If the type does not have a special type for
4993 its representation, return GNAT_ENTITY. */
4995 Entity_Id
4997 {
5004 {
5030 }
5033 }
5035 /* Return a GCC tree for a type corresponding to the component type of the
5036 array type or subtype GNAT_ARRAY. DEFINITION is true if this component
5037 is for an array being defined. DEBUG_INFO_P is true if we need to write
5038 debug information for other types that we may create in the process. */
5040 static tree
5043 {
5046 tree gnu_comp_size;
5049 /* If an alignment is specified, use it as a cap on the component type
5050 so that it can be honored for the whole type. But ignore it for the
5051 original type of packed array types. */
5055 else
5058 /* Try to get a smaller form of the component if needed. */
5071 /* Get and validate any specified Component_Size. */
5072 gnu_comp_size
5077 /* If the array has aliased components and the component size can be zero,
5078 force at least unit size to ensure that the components have distinct
5079 addresses. */
5085 gnu_comp_size
5088 /* If the component type is a RECORD_TYPE that has a self-referential size,
5089 then use the maximum size for the component size. */
5095 /* Honor the component size. This is not needed for bit-packed arrays. */
5097 {
5103 else
5109 /* If a padding record was made, declare it now since it will never be
5110 declared otherwise. This is necessary to ensure that its subtrees
5111 are properly marked. */
5114 gnat_array);
5115 }
5117 /* If the component type is a padded type made for a non-bit-packed array
5118 of scalars with reverse storage order, we need to propagate the reverse
5119 storage order to the padding type since it is the innermost enclosing
5120 aggregate type around the scalar. */
5128 {
5129 const int quals
5130 = TYPE_QUAL_VOLATILE
5133 }
5136 }
5138 /* Return a GCC tree for a parameter corresponding to GNAT_PARAM, to be placed
5139 in the parameter list of GNAT_SUBPROG. GNU_PARAM_TYPE is the GCC tree for
5140 the type of the parameter. FIRST is true if this is the first parameter in
5141 the list of GNAT_SUBPROG. Also set CICO to true if the parameter must use
5142 the copy-in copy-out implementation mechanism.
5144 The returned tree is a PARM_DECL, except for the cases where no parameter
5145 needs to be actually passed to the subprogram; the type of this "shadow"
5146 parameter is then returned instead. */
5148 static tree
5151 {
5157 /* The parameter can be indirectly modified if its address is taken. */
5163 tree gnu_param;
5165 /* Make sure to use the proper SLOC for vector ABI warnings. */
5169 /* Builtins are expanded inline and there is no real call sequence involved.
5170 So the type expected by the underlying expander is always the type of the
5171 argument "as is". */
5176 /* Handle the first parameter of a valued procedure specially: it's a copy
5177 mechanism for which the parameter is never allocated. */
5179 {
5183 }
5185 /* Or else, see if a Mechanism was supplied that forced this parameter
5186 to be passed one way or another. */
5188 ;
5190 /* Positive mechanism means by copy for sufficiently small parameters. */
5192 {
5197 else
5199 }
5201 /* Otherwise, it's an unsupported mechanism so error out. */
5202 else
5203 {
5206 }
5208 /* If this is either a foreign function or if the underlying type won't
5209 be passed by reference and is as aligned as the original type, strip
5210 off possible padding type. */
5212 {
5221 }
5223 /* If this is a read-only parameter, make a variant of the type that is
5224 read-only. ??? However, if this is a self-referential type, the type
5225 can be very complex, so skip it for now. */
5229 /* For foreign conventions, pass arrays as pointers to the element type.
5230 First check for unconstrained array and get the underlying array. */
5232 gnu_param_type
5235 /* Arrays are passed as pointers to element type for foreign conventions. */
5237 {
5238 /* Strip off any multi-dimensional entries, then strip
5239 off the last array to get the component type. */
5248 gnu_param_type
5252 }
5254 /* Fat pointers are passed as thin pointers for foreign conventions. */
5256 gnu_param_type
5259 /* If we were requested or muss pass by reference, do so.
5260 If we were requested to pass by copy, do so.
5261 Otherwise, for foreign conventions, pass In Out or Out parameters
5262 or aggregates by reference. For COBOL and Fortran, pass all
5263 integer and FP types that way too. For Convention Ada, use
5264 the standard Ada default. */
5268 && ((foreign
5270 || (foreign
5275 || (!foreign
5277 {
5278 /* We take advantage of 6.2(12) by considering that references built for
5279 parameters whose type isn't by-ref and for which the mechanism hasn't
5280 been forced to by-ref allow only a restricted form of aliasing. */
5281 restricted_aliasing_p
5285 }
5287 /* Pass In Out or Out parameters using copy-in copy-out mechanism. */
5296 /* If this is an Out parameter that isn't passed by reference and isn't
5297 a pointer or aggregate, we don't make a PARM_DECL for it. Instead,
5298 it will be a VAR_DECL created when we process the procedure, so just
5299 return its type. For the special parameter of a valued procedure,
5300 never pass it in.
5302 An exception is made to cover the RM-6.4.1 rule requiring "by copy"
5303 Out parameters with discriminants or implicit initial values to be
5304 handled like In Out parameters. These type are normally built as
5305 aggregates, hence passed by reference, except for some packed arrays
5306 which end up encoded in special integer types. Note that scalars can
5307 be given implicit initial values using the Default_Value aspect.
5309 The exception we need to make is then for packed arrays of records
5310 with discriminants or implicit initial values. We have no light/easy
5311 way to check for the latter case, so we merely check for packed arrays
5312 of records. This may lead to useless copy-in operations, but in very
5313 rare cases only, as these would be exceptions in a set of already
5314 exceptional situations. */
5316 && !by_ref
5317 && (by_return
5336 /* If no Mechanism was specified, indicate what we're using, then
5337 back-annotate it. */
5343 }
5345 /* Associate GNAT_SUBPROG with GNU_TYPE, which must be a dummy type, so that
5346 GNAT_SUBPROG is updated when GNU_TYPE is completed.
5348 Ada 2012 (AI05-019) says that freezing a subprogram does not always freeze
5349 the corresponding profile, which means that, by the time the freeze node
5350 of the subprogram is encountered, types involved in its profile may still
5351 be not yet frozen. That's why we need to update GNAT_SUBPROG when we see
5352 the freeze node of types involved in its profile, either types of formal
5353 parameters or the return type. */
5355 static void
5357 {
5365 {
5370 }
5372 /* Even if there is already a slot for GNU_TYPE, we need to set the flag
5373 because the vector might have been just emptied by update_profiles_with.
5374 This can happen when there are 2 freeze nodes associated with different
5375 views of the same type; the type will be really complete only after the
5376 second freeze node is encountered. */
5381 /* Make sure GNAT_SUBPROG is not associated twice with the same dummy type,
5382 since this would mean updating twice its profile. */
5384 {
5388 /* Entity_Id is a simple integer so we can implement a stable order on
5389 the vector with an ordered insertion scheme and binary search. */
5391 {
5398 else
5400 }
5402 /* l == u and therefore is the insertion point. */
5404 }
5405 else
5409 }
5411 /* Update the GCC tree previously built for the profile of GNAT_SUBPROG. */
5413 static void
5415 {
5416 tree gnu_param_list;
5421 {
5422 /* Builtins cannot have their address taken so we can reset them. */
5427 }
5433 /* If GNAT_SUBPROG is an actual subprogram, GNU_SUBPROG is a FUNCTION_DECL
5434 and needs to be adjusted too. */
5436 {
5438 tree gnu_ext_name
5443 }
5444 }
5446 /* Update the GCC trees previously built for the profiles involving GNU_TYPE,
5447 a dummy type which appears in profiles. */
5449 void
5451 {
5459 /* The flag needs to be reset before calling update_profile, in case
5460 associate_subprog_with_dummy_type is again invoked on GNU_TYPE. */
5469 }
5471 /* Return the GCC tree for GNAT_TYPE present in the profile of a subprogram.
5473 Ada 2012 (AI05-0151) says that incomplete types coming from a limited
5474 context may now appear as parameter and result types. As a consequence,
5475 we may need to defer their translation until after a freeze node is seen
5476 or to the end of the current unit. We also aim at handling temporarily
5477 incomplete types created by the usual delayed elaboration scheme. */
5479 static tree
5481 {
5482 /* This is the same logic as the E_Access_Type case of gnat_to_gnu_entity
5483 so the rationale is exposed in that place. These processings probably
5484 ought to be merged at some point. */
5486 const bool is_from_limited_with
5489 Entity_Id gnat_full_direct_first
5490 = (is_from_limited_with
5494 Entity_Id gnat_full_direct
5495 = ((is_from_limited_with
5503 tree gnu_type;
5509 && ((!in_main_unit
5516 {
5520 {
5527 }
5528 }
5533 else
5536 /* Access-to-unconstrained-array types need a special treatment. */
5538 {
5541 }
5544 }
5546 /* Return a GCC tree for a subprogram type corresponding to GNAT_SUBPROG.
5547 DEFINITION is true if this is for a subprogram being defined. DEBUG_INFO_P
5548 is true if we need to write debug information for other types that we may
5549 create in the process. Also set PARAM_LIST to the list of parameters.
5550 If GNAT_SUBPROG is bound to a GCC builtin, return the DECL for the builtin
5551 directly instead of its type. */
5553 static tree
5556 {
5559 Entity_Id gnat_param;
5562 tree gnu_return_type;
5565 /* Non-null for subprograms containing parameters passed by copy-in copy-out
5566 (In Out or Out parameters not passed by reference), in which case it is
5567 the list of nodes used to specify the values of the In Out/Out parameters
5568 that are returned as a record upon procedure return. The TREE_PURPOSE of
5569 an element of this list is a FIELD_DECL of the record and the TREE_VALUE
5570 is the PARM_DECL corresponding to that field. This list will be saved in
5571 the TYPE_CI_CO_LIST field of the FUNCTION_TYPE node we create. */
5574 /* Fields in return type of procedure with copy-in copy-out parameters. */
5576 /* The semantics of "pure" in Ada essentially matches that of "const"
5577 in the back-end. In particular, both properties are orthogonal to
5578 the "nothrow" property if the EH circuitry is explicit in the
5579 internal representation of the back-end. If we are to completely
5580 hide the EH circuitry from it, we need to declare that calls to pure
5581 Ada subprograms that can throw have side effects since they can
5582 trigger an "abnormal" transfer of control flow; thus they can be
5583 neither "const" nor "pure" in the back-end sense. */
5591 /* Look into the return type and get its associated GCC tree if it is not
5592 void, and then compute various flags for the subprogram type. But make
5593 sure not to do this processing multiple times. */
5600 {
5605 }
5607 else
5608 {
5609 /* For foreign convention subprograms, return System.Address as void *
5610 or equivalent. Note that this comprises GCC builtins. */
5614 else
5617 /* If this function returns by reference, make the actual return type
5618 the reference type and make a note of that. */
5620 {
5623 }
5625 /* If the return type is an unconstrained array type, the return value
5626 will be allocated on the secondary stack so the actual return type
5627 is the fat pointer type. */
5629 {
5632 }
5634 /* This is the same unconstrained array case, but for a dummy type. */
5637 {
5640 }
5642 /* Likewise, if the return type requires a transient scope, the return
5643 value will also be allocated on the secondary stack so the actual
5644 return type is the reference type. */
5646 {
5649 }
5651 /* If the Mechanism is By_Reference, ensure this function uses the
5652 target's by-invisible-reference mechanism, which may not be the
5653 same as above (e.g. it might be passing an extra parameter). */
5657 /* Likewise, if the return type is itself By_Reference. */
5661 /* If the type is a padded type and the underlying type would not be
5662 passed by reference or the function has a foreign convention, return
5663 the underlying type. */
5665 && (!default_pass_by_ref
5670 /* If the return type is unconstrained, it must have a maximum size.
5671 Use the padded type as the effective return type. And ensure the
5672 function uses the target's by-invisible-reference mechanism to
5673 avoid copying too much data when it returns. */
5675 {
5679 /* If the size overflows to 0, set it to an arbitrary positive
5680 value so that assignments in the type are preserved. Their
5681 actual size is independent of this positive value. */
5685 {
5688 }
5694 /* Declare it now since it will never be declared otherwise. This
5695 is necessary to ensure that its subtrees are properly marked. */
5702 }
5704 /* If the return type has a size that overflows, we usually cannot have
5705 a function that returns that type. This usage doesn't really make
5706 sense anyway, so issue an error here. */
5711 {
5716 }
5718 /* If the return type is incomplete, there are 2 cases: if the function
5719 returns by reference, then the return type is only linked indirectly
5720 in the profile, so the profile can be seen as complete since it need
5721 not be further modified, only the reference types need be adjusted;
5722 otherwise the profile is incomplete and need be adjusted too. */
5724 {
5727 }
5731 || return_by_direct_ref_p
5732 || return_by_invisi_ref_p
5734 }
5736 /* A procedure (something that doesn't return anything) shouldn't be
5737 considered const since there would be no reason for calling such a
5738 subprogram. Note that procedures with Out (or In Out) parameters
5739 have already been converted into a function with a return type.
5740 Similarly, if the function returns an unconstrained type, then the
5741 function will allocate the return value on the secondary stack and
5742 thus calls to it cannot be CSE'ed, lest the stack be reclaimed. */
5746 /* Loop over the parameters and get their associated GCC tree. While doing
5747 this, build a copy-in copy-out structure if we need one. */
5751 {
5752 const bool mech_is_by_ref
5759 /* Fetch an existing parameter with complete type and reuse it. But we
5760 didn't save the CICO property so we can only do it for In parameters
5761 or parameters passed by reference. */
5766 {
5769 }
5771 /* Otherwise translate the parameter type and act accordingly. */
5772 else
5773 {
5776 /* For foreign convention subprograms, pass System.Address as void *
5777 or equivalent. Note that this comprises GCC builtins. */
5781 else
5784 /* If the parameter type is incomplete, there are 2 cases: if it is
5785 passed by reference, then the type is only linked indirectly in
5786 the profile, so the profile can be seen as complete since it need
5787 not be further modified, only the reference type need be adjusted;
5788 otherwise the profile is incomplete and need be adjusted too. */
5790 {
5791 Node_Id gnat_decl;
5795 && TYPE_IS_FAT_POINTER_P
5798 {
5800 gnu_param
5810 }
5812 /* ??? This is a kludge to support null procedures in spec taking
5813 a parameter with an untagged incomplete type coming from a
5814 limited context. The front-end creates a body without knowing
5815 anything about the non-limited view, which is illegal Ada and
5816 cannot be supported. Create a parameter with a fake type. */
5824 else
5825 {
5826 /* Build a minimal PARM_DECL without DECL_ARG_TYPE so that
5827 Call_to_gnu will stop if it encounters the PARM_DECL. */
5828 gnu_param
5830 gnu_param_type);
5832 gnu_param_type);
5834 }
5835 }
5837 /* Otherwise build the parameter declaration normally. */
5838 else
5839 {
5840 gnu_param
5844 /* We are returned either a PARM_DECL or a type if no parameter
5845 needs to be passed; in either case, adjust the type. */
5848 else
5849 {
5852 }
5853 }
5854 }
5856 /* If we have a GCC tree for the parameter, register it. */
5859 {
5860 gnu_param_type_list
5865 /* If a parameter is a pointer, a function may modify memory through
5866 it and thus shouldn't be considered a const function. Also, the
5867 memory may be modified between two calls, so they can't be CSE'ed.
5868 The latter case also handles by-ref parameters. */
5872 }
5874 /* If the parameter uses the copy-in copy-out mechanism, allocate a field
5875 for it in the return type and register the association. */
5877 {
5879 {
5882 /* If this is a function, we also need a field for the
5883 return value to be placed. */
5885 {
5886 tree gnu_field
5888 gnu_return_type,
5894 gnu_cico_list
5896 }
5899 /* Set a default alignment to speed up accesses. But we should
5900 not increase the size of the structure too much, lest it does
5901 not fit in return registers anymore. */
5904 }
5906 tree gnu_field
5915 }
5916 }
5918 /* If the subprogram uses the copy-in copy-out mechanism, possibly adjust
5919 and finish up the return type. */
5921 {
5922 /* If we have a CICO list but it has only one entry, we convert
5923 this function into a function that returns this object. */
5927 /* Do not finalize the return type if the subprogram is stubbed
5928 since structures are incomplete for the back-end. */
5930 {
5934 /* Try to promote the mode of the return type if it is passed
5935 in registers, again to speed up accesses. */
5938 NULL_TREE))
5939 {
5940 unsigned int size
5943 scalar_int_mode mode;
5948 {
5956 }
5957 }
5961 }
5964 }
5966 /* The lists have been built in reverse. */
5972 /* If the profile is incomplete, we only set the (temporary) return and
5973 parameter types; otherwise, we build the full type. In either case,
5974 we reuse an already existing GCC tree that we built previously here. */
5976 {
5978 ;
5979 else
5986 }
5987 else
5988 {
5990 {
5999 }
6000 else
6001 {
6002 gnu_type
6005 /* GNU_TYPE may be shared since GCC hashes types. Unshare it if it
6006 has a different TYPE_CI_CO_LIST or flags. */
6008 return_unconstrained_p,
6009 return_by_direct_ref_p,
6010 return_by_invisi_ref_p))
6011 {
6017 }
6018 }
6026 /* If this subprogram is expectedly bound to a GCC builtin, fetch the
6027 corresponding DECL node and check the parameter association. */
6030 {
6034 /* If we have a builtin DECL for that function, use it. Check if
6035 the profiles are compatible and warn if they are not. Note that
6036 the checker is expected to post diagnostics in this case. */
6038 {
6039 intrin_binding_t inb
6043 post_error
6045 gnat_subprog);
6048 }
6050 /* Inability to find the builtin DECL most often indicates a genuine
6051 mistake, but imports of unregistered intrinsics are sometimes used
6052 on purpose to allow hooking in alternate bodies; we post a warning
6053 conditioned on Wshadow in this case, to let developers be notified
6054 on demand without risking false positives with common default sets
6055 of options. */
6058 }
6059 }
6062 }
6064 /* Return the external name for GNAT_SUBPROG given its entity name. */
6066 static tree
6068 {
6071 /* If there was no specified Interface_Name and the external and
6072 internal names of the subprogram are the same, only use the
6073 internal name to allow disambiguation of nested subprograms. */
6078 }
6080 /* Like build_qualified_type, but TYPE_QUALS is added to the existing
6081 qualifiers on TYPE. */
6083 static tree
6085 {
6086 /* Qualifiers must be put on the associated array type. */
6091 }
6093 /* Set TYPE_NONALIASED_COMPONENT on an array type built by means of
6094 build_nonshared_array_type. */
6096 static void
6098 {
6101 }
6103 /* Set TYPE_REVERSE_STORAGE_ORDER on an array type built by means of
6104 build_nonshared_array_type. */
6106 static void
6108 {
6111 }
6113 /* Return true if DISCR1 and DISCR2 represent the same discriminant. */
6115 static bool
6117 {
6124 return
6126 }
6128 /* Return true if the array type GNU_TYPE, which represents a dimension of
6129 GNAT_TYPE, has a non-aliased component in the back-end sense. */
6131 static bool
6133 {
6134 /* If the array type is not the innermost dimension of the GNAT type,
6135 then it has a non-aliased component. */
6140 /* If the array type has an aliased component in the front-end sense,
6141 then it also has an aliased component in the back-end sense. */
6145 /* If this is a derived type, then it has a non-aliased component if
6146 and only if its parent type also has one. */
6148 {
6152 gnu_parent_type
6157 }
6159 /* Otherwise, rely exclusively on properties of the element type. */
6161 }
6163 /* Return true if GNAT_ADDRESS is a value known at compile-time. */
6165 static bool
6167 {
6168 /* Handle reference to a constant. */
6171 {
6175 }
6177 /* Catch System'To_Address. */
6182 }
6184 /* Return true if GNAT_RANGE, a N_Range node, cannot be superflat, i.e. if the
6185 inequality HB >= LB-1 is true. LB and HB are the low and high bounds. */
6187 static bool
6189 {
6191 Node_Id scalar_range;
6194 /* If the low bound is not constant, try to find an upper bound. */
6203 /* If the high bound is not constant, try to find a lower bound. */
6212 /* If we have failed to find constant bounds, punt. */
6217 /* We need at least a signed 64-bit type to catch most cases. */
6223 /* If the low bound is the smallest integer, nothing can be smaller. */
6229 }
6231 /* Return true if GNU_EXPR is (essentially) the address of a CONSTRUCTOR. */
6233 static bool
6235 {
6243 }
6245 /* Return true if the size in units represented by GNU_SIZE can be handled by
6246 an allocation. If STATIC_P is true, consider only what can be done with a
6247 static allocation. */
6249 static bool
6251 {
6252 /* We can allocate a fixed size if it is a valid for the middle-end. */
6256 /* We can allocate a variable size if this isn't a static allocation. */
6257 else
6259 }
6261 /* Return true if GNU_EXPR needs a conversion to GNU_TYPE when used as the
6262 initial value of an object of GNU_TYPE. */
6264 static bool
6266 {
6267 /* Do not convert if the object's type is unconstrained because this would
6268 generate useless evaluations of the CONSTRUCTOR to compute the size. */
6273 /* Do not convert if the object's type is a padding record whose field is of
6274 self-referential size because we want to copy only the actual data. */
6278 /* Do not convert a call to a function that returns with variable size since
6279 we want to use the return slot optimization in this case. */
6284 /* Do not convert to a record type with a variant part from a record type
6285 without one, to keep the object simpler. */
6292 /* In all the other cases, convert the expression to the object's type. */
6294 }
6295 \f
6296 /* Given GNAT_ENTITY, elaborate all expressions that are required to
6297 be elaborated at the point of its definition, but do nothing else. */
6299 void
6301 {
6303 {
6310 {
6314 /* ??? Tests to avoid Constraint_Error in static expressions
6315 are needed until after the front stops generating bogus
6316 conversions on bounds of real types. */
6324 }
6331 {
6332 Node_Id gnat_discriminant_expr;
6333 Entity_Id gnat_field;
6337 gnat_discriminant_expr
6342 /* Ignore access discriminants. */
6347 }
6350 }
6351 }
6352 \f
6353 /* Prepend to ATTR_LIST an entry for an attribute with provided TYPE,
6354 NAME, ARGS and ERROR_POINT. */
6356 static void
6359 tree attr_name,
6360 tree attr_args,
6361 Node_Id attr_error_point)
6362 {
6372 }
6374 /* Prepend to ATTR_LIST an entry for an attribute provided by GNAT_PRAGMA. */
6376 static void
6378 {
6383 /* Map the pragma at hand. Skip if this isn't one we know how to handle. */
6385 {
6416 }
6418 /* See what arguments we have and turn them into GCC trees for attribute
6419 handlers. These expect identifier for strings. We handle at most two
6420 arguments and static expressions only. */
6422 {
6428 {
6432 {
6436 }
6439 }
6443 {
6448 }
6449 }
6451 /* Prepend to the list. Make a list of the argument we might have, as GCC
6452 expects it. */
6454 gnu_arg1
6458 }
6460 /* Prepend to ATTR_LIST the list of attributes for GNAT_ENTITY, if any. */
6462 static void
6464 {
6465 Node_Id gnat_temp;
6467 /* Attributes are stored as Representation Item pragmas. */
6473 }
6474 \f
6475 /* Given a GNAT tree GNAT_EXPR, for an expression which is a value within a
6476 type definition (either a bound or a discriminant value) for GNAT_ENTITY,
6477 return the GCC tree to use for that expression. S is the suffix to use
6478 if a variable needs to be created and DEFINITION is true if this is done
6479 for a definition of GNAT_ENTITY. If NEED_VALUE is true, we need a result;
6480 otherwise, we are just elaborating the expression for side-effects. If
6481 NEED_DEBUG is true, we need a variable for debugging purposes even if it
6482 isn't needed for code generation. */
6484 static tree
6487 {
6488 tree gnu_expr;
6490 /* If we already elaborated this expression (e.g. it was involved
6491 in the definition of a private type), use the old value. */
6495 /* If we don't need a value and this is static or a discriminant,
6496 we don't need to do anything. */
6503 /* If it's a static expression, we don't need a variable for debugging. */
6507 /* Otherwise, convert this tree to its GCC equivalent and elaborate it. */
6511 /* Save the expression in case we try to elaborate this entity again. Since
6512 it's not a DECL, don't check it. Don't save if it's a discriminant. */
6517 }
6519 /* Similar, but take a GNU expression and always return a result. */
6521 static tree
6524 {
6529 /* If GNU_EXPR contains a placeholder, just return it. We rely on the fact
6530 that an expression cannot contain both a discriminant and a variable. */
6534 /* If GNU_EXPR is neither a constant nor based on a read-only variable, make
6535 a variable that is initialized to contain the expression when the package
6536 containing the definition is elaborated. If this entity is defined at top
6537 level, replace the expression by the variable; otherwise use a SAVE_EXPR
6538 if this is necessary. */
6541 else
6542 {
6543 /* Skip any conversions and simple constant arithmetics to see if the
6544 expression is based on a read-only variable. */
6552 expr_variable_p
6553 = !(inner
6556 }
6558 /* We only need to use the variable if we are in a global context since GCC
6559 can do the right thing in the local case. However, when not optimizing,
6560 use it for bounds of loop iteration scheme to avoid code duplication. */
6561 use_variable = expr_variable_p
6562 && (expr_global_p
6563 || (!optimize
6564 && definition
6569 /* Now create it, possibly only for debugging purposes. */
6571 {
6572 /* The following variable creation can happen when processing the body
6573 of subprograms that are defined out of the extended main unit and
6574 inlined. In this case, we are not at the global scope, and thus the
6575 new variable must not be tagged "external", as we used to do here as
6576 soon as DEFINITION was false. */
6577 tree gnu_decl
6584 /* Using this variable at debug time (if need_debug is true) requires a
6585 proper location. The back-end will compute a location for this
6586 variable only if the variable is used by the generated code.
6587 Returning the variable ensures the caller will use it in generated
6588 code. Note that there is no need for a location if the debug info
6589 contains an integer constant.
6590 TODO: when the encoding-based debug scheme is dropped, move this
6591 condition to the top-level IF block: we will not need to create a
6592 variable anymore in such cases, then. */
6595 }
6598 }
6600 /* Similar, but take an alignment factor and make it explicit in the tree. */
6602 static tree
6605 {
6607 return
6610 gnu_expr,
6611 unit_align),
6613 need_debug),
6614 unit_align);
6615 }
6617 /* Structure to hold internal data for elaborate_reference. */
6619 struct er_data
6620 {
6621 Entity_Id entity;
6624 };
6626 /* Wrapper function around elaborate_expression_1 for elaborate_reference. */
6628 static tree
6630 {
6634 /* This is what elaborate_expression_1 does if NEED_DEBUG is false. */
6638 /* If this is a COMPONENT_REF of a fat pointer, elaborate the entire fat
6639 pointer. This may be more efficient, but will also allow us to more
6640 easily find the match for the PLACEHOLDER_EXPR. */
6648 return
6650 }
6652 /* Elaborate the reference REF to be used as renamed object for GNAT_ENTITY.
6653 DEFINITION is true if this is done for a definition of GNAT_ENTITY and
6654 INIT is set to the first arm of a COMPOUND_EXPR present in REF, if any. */
6656 static tree
6659 {
6662 }
6663 \f
6664 /* Given a GNU tree and a GNAT list of choices, generate an expression to test
6665 the value passed against the list of choices. */
6667 static tree
6669 {
6670 Node_Id choice;
6671 Node_Id gnat_temp;
6676 {
6678 {
6683 this_test
6698 this_test
6709 /* This represents either a subtype range, an enumeration
6710 literal, or a constant Ekind says which. If an enumeration
6711 literal or constant, fall through to the next case. */
6714 {
6720 this_test
6728 }
6730 /* ... fall through ... */
6745 }
6749 else
6752 }
6755 }
6756 \f
6757 /* Adjust PACKED setting as passed to gnat_to_gnu_field for a field of
6758 type FIELD_TYPE to be placed in RECORD_TYPE. Return the result. */
6760 static int
6762 {
6763 /* If the field contains an item of variable size, we cannot pack it
6764 because we cannot create temporaries of non-fixed size in case
6765 we need to take the address of the field. See addressable_p and
6766 the notes on the addressability issues for further details. */
6770 /* In the other cases, we can honor the packing. */
6774 /* If the alignment of the record is specified and the field type
6775 is over-aligned, request Storage_Unit alignment for the field. */
6780 /* Likewise if the maximum alignment of the record is specified. */
6786 }
6788 /* Return a GCC tree for a field corresponding to GNAT_FIELD to be
6789 placed in GNU_RECORD_TYPE.
6791 PACKED is 1 if the enclosing record is packed or -1 if the enclosing
6792 record has Component_Alignment of Storage_Unit.
6794 DEFINITION is true if this field is for a record being defined.
6796 DEBUG_INFO_P is true if we need to write debug information for types
6797 that we may create in the process. */
6799 static tree
6802 {
6805 const bool is_atomic
6808 const bool is_independent
6810 const bool is_volatile
6813 /* We used to consider that volatile fields also require strict alignment,
6814 but that was an interpolation and would cause us to reject a pragma
6815 volatile on a packed record type containing boolean components, while
6816 there is no basis to do so in the RM. In such cases, the writes will
6817 involve load-modify-store sequences, but that's OK for volatile. The
6818 only constraint is the implementation advice whereby only the bits of
6819 the components should be accessed if they both start and end on byte
6820 boundaries, but that should be guaranteed by the GCC memory model. */
6821 const bool needs_strict_alignment
6827 /* If this field requires strict alignment, we cannot pack it because
6828 it would very likely be under-aligned in the record. */
6831 else
6834 /* If a size is specified, use it. Otherwise, if the record type is packed,
6835 use the official RM size. See "Handling of Type'Size Values" in Einfo
6836 for further details. */
6843 else
6846 /* If we have a specified size that is smaller than that of the field's type,
6847 or a position is specified, and the field's type is a record that doesn't
6848 require strict alignment, see if we can get either an integral mode form
6849 of the type or a smaller form. If we can, show a size was specified for
6850 the field if there wasn't one already, so we know to make this a bitfield
6851 and avoid making things wider.
6853 Changing to an integral mode form is useful when the record is packed as
6854 we can then place the field at a non-byte-aligned position and so achieve
6855 tighter packing. This is in addition required if the field shares a byte
6856 with another field and the front-end lets the back-end handle the access
6857 to the field, because GCC cannot handle non-byte-aligned BLKmode fields.
6859 Changing to a smaller form is required if the specified size is smaller
6860 than that of the field's type and the type contains sub-fields that are
6861 padded, in order to avoid generating accesses to these sub-fields that
6862 are wider than the field.
6864 We avoid the transformation if it is not required or potentially useful,
6865 as it might entail an increase of the field's alignment and have ripple
6866 effects on the outer record type. A typical case is a field known to be
6867 byte-aligned and not to share a byte with another field. */
6873 || (gnu_size
6879 {
6882 {
6886 }
6887 }
6893 {
6901 /* Ensure the position does not overlap with the parent subtype, if there
6902 is one. This test is omitted if the parent of the tagged type has a
6903 full rep clause since, in this case, component clauses are allowed to
6904 overlay the space allocated for the parent type and the front-end has
6905 checked that there are no overlapping components. */
6907 {
6912 post_error_ne_tree
6915 }
6917 /* If this field needs strict alignment, make sure that the record is
6918 sufficiently aligned and that the position and size are consistent
6919 with the type. But don't do it if we are just annotating types and
6920 the field's type is tagged, since tagged types aren't fully laid out
6921 in this mode. Also, note that atomic implies volatile so the inner
6922 test sequences ordering is significant here. */
6925 {
6931 /* If the position is not a multiple of the alignment of the type,
6932 then error out and reset the position. */
6935 {
6947 else
6951 type_align);
6953 }
6956 {
6960 /* If the size is lower than that of the type, or greater for
6961 atomic and aliased, then error out and reset the size. */
6963 {
6975 else
6979 gnu_type_size);
6981 }
6983 /* Likewise if the size is not a multiple of a byte, */
6985 bitsize_unit_node)))
6986 {
6995 else
7000 }
7001 }
7002 }
7003 }
7005 /* If the record has rep clauses and this is the tag field, make a rep
7006 clause for it as well. */
7009 {
7012 }
7014 else
7015 {
7018 /* If we are packing the record and the field is BLKmode, round the
7019 size up to a byte boundary. */
7022 }
7024 /* We need to make the size the maximum for the type if it is
7025 self-referential and an unconstrained type. In that case, we can't
7026 pack the field since we can't make a copy to align it. */
7028 && !gnu_size
7031 {
7034 }
7036 /* If a size is specified, adjust the field's type to it. */
7038 {
7039 tree orig_field_type;
7041 /* If the field's type is justified modular, we would need to remove
7042 the wrapper to (better) meet the layout requirements. However we
7043 can do so only if the field is not aliased to preserve the unique
7044 layout, if it has the same storage order as the enclosing record
7045 and if the prescribed size is not greater than that of the packed
7046 array to preserve the justification. */
7056 /* Similarly if the field's type is a misaligned integral type, but
7057 there is no restriction on the size as there is no justification. */
7063 gnu_field_type
7071 /* If a padding record was made, declare it now since it will never be
7072 declared otherwise. This is necessary to ensure that its subtrees
7073 are properly marked. */
7078 }
7080 /* Otherwise (or if there was an error), don't specify a position. */
7081 else
7084 /* If the field's type is a padded type made for a scalar field of a record
7085 type with reverse storage order, we need to propagate the reverse storage
7086 order to the padding type since it is the innermost enclosing aggregate
7087 type around the scalar. */
7096 /* Now create the decl for the field. */
7097 gnu_field
7105 {
7110 }
7113 }
7114 \f
7115 /* Return true if at least one member of COMPONENT_LIST needs strict
7116 alignment. */
7118 static bool
7120 {
7121 Node_Id component_decl;
7126 {
7134 }
7137 }
7139 /* Return true if TYPE is a type with variable size or a padding type with a
7140 field of variable size or a record that has a field with such a type. */
7142 static bool
7144 {
7145 tree field;
7162 }
7163 \f
7164 /* Return true if FIELD is an artificial field. */
7166 static bool
7168 {
7169 /* These fields are generated by the front-end proper. */
7173 /* These fields are generated by gigi. */
7178 }
7180 /* Return true if FIELD is a non-artificial field with self-referential
7181 size. */
7183 static bool
7185 {
7193 }
7195 /* Return true if FIELD is a non-artificial field with variable size. */
7197 static bool
7199 {
7207 }
7209 /* qsort comparer for the bit positions of two record components. */
7211 static int
7213 {
7216 const int ret
7220 }
7222 /* Reverse function from gnat_to_gnu_field: return the GNAT field present in
7223 either GNAT_COMPONENT_LIST or the discriminants of GNAT_RECORD_TYPE, and
7224 corresponding to the GNU tree GNU_FIELD. */
7226 static Entity_Id
7228 Entity_Id gnat_record_type)
7229 {
7237 {
7241 }
7251 }
7253 /* Issue a warning for the problematic placement of GNU_FIELD present in
7254 either GNAT_COMPONENT_LIST or the discriminants of GNAT_RECORD_TYPE.
7255 IN_VARIANT is true if GNAT_COMPONENT_LIST is the list of a variant.
7256 DO_REORDER is true if fields of GNAT_RECORD_TYPE are being reordered. */
7258 static void
7262 {
7264 = in_variant
7274 = do_reorder
7277 Entity_Id gnat_field
7285 }
7287 /* Structure holding information for a given variant. */
7289 {
7290 /* The record type of the variant. */
7291 tree type;
7293 /* The name of the variant. */
7294 tree name;
7296 /* The qualifier of the variant. */
7297 tree qual;
7299 /* Whether the variant has a rep clause. */
7302 /* Whether the variant is packed. */
7307 /* Translate and chain GNAT_COMPONENT_LIST present in GNAT_RECORD_TYPE to
7308 GNU_FIELD_LIST, set the result as the field list of GNU_RECORD_TYPE and
7309 finish it up. Return true if GNU_RECORD_TYPE has a rep clause that affects
7310 the layout (see below). When called from gnat_to_gnu_entity during the
7311 processing of a record definition, the GCC node for the parent, if any,
7312 will be the single field of GNU_RECORD_TYPE and the GCC nodes for the
7313 discriminants will be on GNU_FIELD_LIST. The other call to this function
7314 is a recursive call for the component list of a variant and, in this case,
7315 GNU_FIELD_LIST is empty.
7317 PACKED is 1 if this is for a packed record or -1 if this is for a record
7318 with Component_Alignment of Storage_Unit.
7320 DEFINITION is true if we are defining this record type.
7322 CANCEL_ALIGNMENT is true if the alignment should be zeroed before laying
7323 out the record. This means the alignment only serves to force fields to
7324 be bitfields, but not to require the record to be that aligned. This is
7325 used for variants.
7327 ALL_REP is true if a rep clause is present for all the fields.
7329 UNCHECKED_UNION is true if we are building this type for a record with a
7330 Pragma Unchecked_Union.
7332 ARTIFICIAL is true if this is a type that was generated by the compiler.
7334 DEBUG_INFO is true if we need to write debug information about the type.
7336 MAYBE_UNUSED is true if this type may be unused in the end; this doesn't
7337 mean that its contents may be unused as well, only the container itself.
7339 FIRST_FREE_POS, if nonzero, is the first (lowest) free field position in
7340 the outer record type down to this variant level. It is nonzero only if
7341 all the fields down to this level have a rep clause and ALL_REP is false.
7343 P_GNU_REP_LIST, if nonzero, is a pointer to a list to which each field
7344 with a rep clause is to be added; in this case, that is all that should
7345 be done with such fields and the return value will be false. */
7347 static bool
7354 {
7355 const bool needs_xv_encodings
7367 /* For each component referenced in a component declaration create a GCC
7368 field and add it to the list, skipping pragmas in the GNAT list. */
7375 {
7379 /* If present, the _Parent field must have been created as the single
7380 field of the record type. Put it before any other fields. */
7382 {
7385 }
7386 else
7387 {
7391 /* If this is the _Tag field, put it before any other fields. */
7395 /* If this is the _Controller field, put it before the other
7396 fields except for the _Tag or _Parent field. */
7398 {
7401 }
7403 /* If this is a regular field, put it after the other fields. */
7404 else
7405 {
7411 /* And record information for the final layout. */
7416 }
7417 }
7420 }
7422 /* At the end of the component list there may be a variant part. */
7425 /* We create a QUAL_UNION_TYPE for the variant part since the variants are
7426 mutually exclusive and should go in the same memory. To do this we need
7427 to treat each variant as a record whose elements are created from the
7428 component list for the variant. So here we create the records from the
7429 lists for the variants and put them all into the QUAL_UNION_TYPE.
7430 If this is an Unchecked_Union, we make a UNION_TYPE instead or
7431 use GNU_RECORD_TYPE if there are no fields so far. */
7433 {
7437 tree gnu_var_name
7448 gnu_union_name
7451 /* Reuse the enclosing union if this is an Unchecked_Union whose fields
7452 are all in the variant part, to match the layout of C unions. There
7453 is an associated check below. */
7456 else
7457 {
7458 gnu_union_type
7466 }
7468 /* If all the fields down to this level have a rep clause, find out
7469 whether all the fields at this level also have one. If so, then
7470 compute the new first free position to be passed downward. */
7473 {
7475 gnu_field;
7478 {
7481 this_first_free_pos
7483 }
7484 else
7485 {
7488 }
7489 }
7491 /* We build the variants in two passes. The bulk of the work is done in
7492 the first pass, that is to say translating the GNAT nodes, building
7493 the container types and computing the associated properties. However
7494 we cannot finish up the container types during this pass because we
7495 don't know where the variant part will be placed until the end. */
7499 {
7504 vinfo_t vinfo;
7512 /* Set the alignment of the inner type in case we need to make
7513 inner objects into bitfields, but then clear it out so the
7514 record actually gets only the alignment required. */
7520 /* Similarly, if the outer record has a size specified and all
7521 the fields have a rep clause, we can propagate the size. */
7523 {
7527 }
7529 /* Add the fields into the record type for the variant. Note that
7530 we aren't sure to really use it at this point, see below. */
7531 has_rep
7537 all_rep || this_first_free_pos
7540 /* Translate the qualifier and annotate the GNAT node. */
7544 /* Deal with packedness like in gnat_to_gnu_field. */
7546 {
7549 }
7550 else
7551 field_packed
7554 /* Push this variant onto the stack for the second pass. */
7562 /* Compute the global properties that will determine the placement of
7563 the variant part. */
7567 }
7569 /* Round up the first free position to the alignment of the variant part
7570 for the variants without rep clause. This will guarantee a consistent
7571 layout independently of the placement of the variant part. */
7575 /* In the second pass, the container types are adjusted if necessary and
7576 finished up, then the corresponding fields of the variant part are
7577 built with their qualifier, unless this is an unchecked union. */
7579 {
7583 /* If this is an Unchecked_Union whose fields are all in the variant
7584 part and we have a single field with no representation clause or
7585 placed at offset zero, use the field directly to match the layout
7586 of C unions. */
7588 && gnu_field_list
7592 {
7595 }
7596 else
7597 {
7598 /* Finalize the variant type now. We used to throw away empty
7599 record types but we no longer do that because we need them to
7600 generate complete debug info for the variant; otherwise, the
7601 union type definition will be lacking the fields associated
7602 with these empty variants. */
7604 {
7605 /* The variant part will be at offset 0 so we need to ensure
7606 that the fields are laid out starting from the first free
7607 position at this level. */
7609 tree gnu_rep_part;
7613 gnu_rep_part
7615 this_first_free_pos);
7620 }
7627 gnu_field
7629 gnu_union_type,
7630 all_rep_and_size
7639 }
7643 }
7645 /* Only make the QUAL_UNION_TYPE if there are non-empty variants. */
7647 {
7651 {
7655 }
7660 /* If GNU_UNION_TYPE is our record type, it means we must have an
7661 Unchecked_Union with no fields. Verify that and, if so, just
7662 return. */
7664 {
7666 && !gnu_field_list
7669 }
7674 /* Deal with packedness like in gnat_to_gnu_field. */
7677 else
7678 union_field_packed
7681 gnu_variant_part
7683 all_rep_and_size
7689 }
7690 }
7692 /* Scan GNU_FIELD_LIST and see if any fields have rep clauses. If they do,
7693 pull them out and put them onto the appropriate list. We have to do it
7694 in a separate pass since we want to handle the discriminants but can't
7695 play with them until we've used them in debugging data above.
7697 Similarly, pull out the fields with zero size and no rep clause, as they
7698 would otherwise modify the layout and thus very likely run afoul of the
7699 Ada semantics, which are different from those of C here.
7701 Finally, if there is an aliased field placed in the list after fields
7702 with self-referential size, pull out the latter in the same way.
7704 Optionally, if the reordering mechanism is enabled, pull out the fields
7705 with self-referential size, variable size and fixed size not a multiple
7706 of a byte, so that they don't cause the regular fields to be either at
7707 self-referential/variable offset or misaligned. Note, in the latter
7708 case, that this can only happen in packed record types so the alignment
7709 is effectively capped to the byte for the whole record.
7711 Optionally, if the layout warning is enabled, keep track of the above 4
7712 different kinds of fields and issue a warning if some of them would be
7713 (or are being) reordered by the reordering mechanism.
7715 Finally, pull out the fields whose size is not a multiple of a byte, so
7716 that they don't cause the regular fields to be misaligned. As this can
7717 only happen in packed record types, the alignment is capped to the byte.
7719 ??? If we reorder them, debugging information will be wrong but there is
7720 nothing that can be done about this at the moment. */
7722 const bool w_reorder
7723 = Warn_On_Questionable_Layout
7735 #define MOVE_FROM_FIELD_LIST_TO(LIST) \
7736 do { \
7737 if (gnu_last) \
7738 DECL_CHAIN (gnu_last) = gnu_next; \
7739 else \
7740 gnu_field_list = gnu_next; \
7741 \
7742 DECL_CHAIN (gnu_field) = (LIST); \
7743 (LIST) = gnu_field; \
7744 } while (0)
7748 {
7752 {
7755 }
7758 {
7768 }
7771 {
7774 }
7776 /* We don't need further processing in default mode. */
7778 {
7781 }
7784 {
7786 {
7790 do_reorder);
7791 else
7793 }
7796 {
7799 }
7800 }
7803 {
7805 {
7809 do_reorder);
7810 else
7812 }
7815 {
7818 }
7819 }
7821 else
7822 {
7823 /* If the field has no size, then it cannot be bit-packed. */
7824 const unsigned int bitp_size
7829 /* If the field is bit-packed, we move it to a temporary list that
7830 contains the contiguously preceding bit-packed fields, because
7831 we want to be able to put them back if the misalignment happens
7832 to cancel itself after several bit-packed fields. */
7834 {
7838 {
7841 }
7844 {
7847 }
7848 }
7850 /* No more bit-packed fields, move the existing ones to the end or
7851 put them back at their original location. */
7853 {
7857 {
7861 gnat_component_list,
7863 do_reorder);
7870 }
7871 else
7872 {
7873 /* Rechain the temporary list in front of GNU_FIELD. */
7876 {
7881 else
7885 }
7886 }
7887 }
7889 else
7891 }
7894 }
7896 #undef MOVE_FROM_FIELD_LIST_TO
7900 /* If permitted, we reorder the fields as follows:
7902 1) all (groups of) fields whose length is fixed and multiple of a byte,
7903 2) the remaining fields whose length is fixed and not multiple of a byte,
7904 3) the remaining fields whose length doesn't depend on discriminants,
7905 4) all fields whose length depends on discriminants,
7906 5) the variant part,
7908 within the record and within each variant recursively. */
7911 {
7912 /* If we have pending bit-packed fields, warn if they would be moved
7913 to after regular fields. */
7921 }
7924 {
7925 /* If we have pending bit-packed fields on the temporary list, we put
7926 them either on the bit-packed list or back on the regular list. */
7928 {
7931 else
7933 }
7935 gnu_field_list
7939 }
7941 /* Otherwise, if there is an aliased field placed after a field whose length
7942 depends on discriminants, we put all the fields of the latter sort, last.
7943 We need to do this in case an object of this record type is mutable. */
7947 /* If P_REP_LIST is nonzero, this means that we are asked to move the fields
7948 in our REP list to the previous level because this level needs them in
7949 order to do a correct layout, i.e. avoid having overlapping fields. */
7953 /* Deal with the annoying case of an extension of a record with variable size
7954 and partial rep clause, for which the _Parent field is forced at offset 0
7955 and has variable size, which we do not support below. Note that we cannot
7956 do it if the field has fixed size because we rely on the presence of the
7957 REP part built below to trigger the reordering of the fields in a derived
7958 record type when all the fields have a fixed position. */
7962 && !variants_have_rep
7963 && first_free_pos
7966 {
7970 }
7972 /* Otherwise, sort the fields by bit position and put them into their own
7973 record, before the others, if we also have fields without rep clause. */
7975 {
7980 /* If all the fields have a rep clause, we can do a flat layout. */
7981 layout_with_rep = !gnu_field_list
7983 gnu_rep_type
7987 gnu_field;
7993 /* Put the fields in the list in order of increasing position, which
7994 means we start from the end. */
7997 {
8001 }
8005 else
8006 {
8011 /* If FIRST_FREE_POS is nonzero, we need to ensure that the fields
8012 without rep clause are laid out starting from this position.
8013 Therefore, we force it as a minimal size on the REP part. */
8014 gnu_rep_part
8017 /* Chain the REP part at the beginning of the field list. */
8020 }
8021 }
8023 /* Chain the variant part at the end of the field list. */
8035 /* Chain the fields with zero size at the beginning of the field list. */
8041 }
8042 \f
8043 /* Given GNU_SIZE, a GCC tree representing a size, return a Uint to be
8044 placed into an Esize, Component_Bit_Offset, or Component_Size value
8045 in the GNAT tree. */
8047 static Uint
8049 {
8050 TCode tcode;
8055 /* See if we've already saved the value for this node. */
8057 {
8065 }
8066 else
8069 /* If we do not return inside this switch, TCODE will be set to the
8070 code to use for a Create_Node operand and LEN (set above) will be
8071 the number of recursive calls for us to make. */
8074 {
8076 /* For negative values, build NEGATE_EXPR of the opposite. Such values
8077 can appear for discriminants in expressions for variants. */
8079 {
8082 }
8087 /* The only case we handle here is a simple discriminant reference. */
8089 {
8092 /* Climb up the chain of successive extensions, if any. */
8099 return
8101 }
8108 /* Now just list the operations we handle. */
8139 /* For negative values in sizetype, build NEGATE_EXPR of the opposite.
8140 Such values appear in expressions with aligning patterns. Note that,
8141 since sizetype is unsigned, we have to jump through some hoops. */
8143 {
8147 {
8150 }
8151 }
8155 /* In regular mode, inline back only if symbolic annotation is requested
8156 in order to avoid memory explosion on big discriminated record types.
8157 But not in ASIS mode, as symbolic annotation is required for DDA. */
8159 {
8163 }
8164 else
8167 /* Fall through... */
8171 }
8173 /* Now get each of the operands that's relevant for this code. If any
8174 cannot be expressed as a repinfo node, say we can't. */
8179 {
8182 else
8186 }
8190 /* Save the result in the cache. */
8192 {
8194 /* We can't assume the hash table data hasn't moved since the initial
8195 look up, so we have to search again. Allocating and inserting an
8196 entry at that point would be an alternative, but then we'd better
8197 discard the entry if we decided not to cache it. */
8203 }
8206 }
8208 /* Given GNAT_ENTITY, an object (constant, variable, parameter, exception)
8209 and GNU_TYPE, its corresponding GCC type, set Esize and Alignment to the
8210 size and alignment used by Gigi. Prefer SIZE over TYPE_SIZE if non-null.
8211 BY_REF is true if the object is used by reference. */
8213 void
8215 {
8217 {
8220 else
8222 }
8225 {
8234 }
8239 }
8241 /* Return first element of field list whose TREE_PURPOSE is the same as ELEM.
8242 Return NULL_TREE if there is no such element in the list. */
8244 static tree
8246 {
8248 {
8253 }
8255 }
8257 /* Given GNAT_ENTITY, a record type, and GNU_TYPE, its corresponding GCC type,
8258 set Component_Bit_Offset and Esize of the components to the position and
8259 size used by Gigi. */
8261 static void
8263 {
8264 /* For an extension, the inherited components have not been translated because
8265 they are fetched from the _Parent component on the fly. */
8266 const bool is_extension
8269 /* We operate by first making a list of all fields and their position (we
8270 can get the size easily) and then update all the sizes in the tree. */
8271 tree gnu_list
8282 {
8284 gnu_list);
8286 {
8287 tree parent_offset;
8289 /* If we are just annotating types and the type is tagged, the tag
8290 and the parent components are not generated by the front-end so
8291 we need to add the appropriate offset to each component without
8292 representation clause. */
8296 {
8297 /* For a component appearing in the current extension, the
8298 offset is the size of the parent. */
8301 parent_offset
8303 bitsizetype);
8304 else
8308 parent_offset
8311 }
8312 else
8315 Set_Component_Bit_Offset
8317 annotate_value
8321 parent_offset)));
8325 }
8327 {
8328 /* If there is no entry, this is an inherited component whose
8329 position is the same as in the parent type. */
8332 /* If we are just annotating types, discriminants renaming those of
8333 the parent have no entry so deal with them specifically. */
8343 }
8344 }
8345 }
8346 \f
8347 /* Scan all fields in GNU_TYPE and return a TREE_LIST where TREE_PURPOSE is
8348 the FIELD_DECL and TREE_VALUE a TREE_VEC containing the byte position, the
8349 value to be placed into DECL_OFFSET_ALIGN and the bit position. The list
8350 of fields is flattened, except for variant parts if DO_NOT_FLATTEN_VARIANT
8351 is set to true. GNU_POS is to be added to the position, GNU_BITPOS to the
8352 bit position, OFFSET_ALIGN is the present offset alignment. GNU_LIST is a
8353 pre-existing list to be chained to the newly created entries. */
8355 static tree
8358 {
8359 tree gnu_field;
8362 gnu_field;
8364 {
8369 unsigned int our_offset_align
8378 /* Recurse on internal fields, flattening the nested fields except for
8379 those in the variant part, if requested. */
8381 {
8385 gnu_list
8389 else
8390 gnu_list
8394 }
8395 }
8398 }
8400 /* Return a list describing the substitutions needed to reflect the
8401 discriminant substitutions from GNAT_TYPE to GNAT_SUBTYPE. They can
8402 be in any order. The values in an element of the list are in the form
8403 of operands to SUBSTITUTE_IN_EXPR. DEFINITION is true if this is for
8404 a definition of GNAT_SUBTYPE. */
8408 {
8410 Entity_Id gnat_discrim;
8411 Node_Id gnat_constr;
8418 /* Ignore access discriminants. */
8420 {
8423 elaborate_expression
8429 }
8432 }
8434 /* Scan all fields in QUAL_UNION_TYPE and return a list describing the
8435 variants of QUAL_UNION_TYPE that are still relevant after applying
8436 the substitutions described in SUBST_LIST. GNU_LIST is a pre-existing
8437 list to be prepended to the newly created entries. */
8442 {
8443 tree gnu_field;
8446 gnu_field;
8448 {
8456 /* If the new qualifier is not unconditionally false, its variant may
8457 still be accessed. */
8459 {
8465 /* Recurse on the variant subpart of the variant, if any. */
8471 /* If the new qualifier is unconditionally true, the subsequent
8472 variants cannot be accessed. */
8475 }
8476 }
8479 }
8480 \f
8481 /* UINT_SIZE is a Uint giving the specified size for an object of GNU_TYPE
8482 corresponding to GNAT_OBJECT. If the size is valid, return an INTEGER_CST
8483 corresponding to its value. Otherwise, return NULL_TREE. KIND is set to
8484 VAR_DECL if we are specifying the size of an object, TYPE_DECL for the
8485 size of a type, and FIELD_DECL for the size of a field. COMPONENT_P is
8486 true if we are being called to process the Component_Size of GNAT_OBJECT;
8487 this is used only for error messages. ZERO_OK is true if a size of zero
8488 is permitted; if ZERO_OK is false, it means that a size of zero should be
8489 treated as an unspecified size. */
8491 static tree
8494 {
8495 Node_Id gnat_error_node;
8498 /* Return 0 if no size was specified. */
8502 /* Ignore a negative size since that corresponds to our back-annotation. */
8506 /* Find the node to use for error messages. */
8513 else
8516 /* Get the size as an INTEGER_CST. Issue an error if a size was specified
8517 but cannot be represented in bitsizetype. */
8520 {
8523 gnat_object);
8524 else
8526 gnat_object);
8528 }
8530 /* Ignore a zero size if it is not permitted. */
8534 /* The size of objects is always a multiple of a byte. */
8537 {
8541 else
8545 }
8547 /* If this is an integral type or a packed array type, the front-end has
8548 already verified the size, so we need not do it here (which would mean
8549 checking against the bounds). However, if this is an aliased object,
8550 it may not be smaller than the type of the object. */
8555 /* If the object is a record that contains a template, add the size of the
8556 template to the specified size. */
8562 /* If a type needs strict alignment, a component of this type in
8563 a packed record cannot be packed and thus uses the type size. */
8566 else
8569 /* Modify the size of a discriminated type to be the maximum size. */
8573 /* If this is an access type or a fat pointer, the minimum size is that given
8574 by the smallest integral mode that's valid for pointers. */
8576 {
8581 }
8583 /* Issue an error either if the default size of the object isn't a constant
8584 or if the new size is smaller than it. */
8588 {
8590 post_error_ne_tree
8593 else
8594 post_error_ne_tree
8598 }
8601 }
8602 \f
8603 /* Similarly, but both validate and process a value of RM size. This routine
8604 is only called for types. */
8606 static void
8608 {
8609 Node_Id gnat_attr_node;
8612 /* Do nothing if no size was specified. */
8616 /* Ignore a negative size since that corresponds to our back-annotation. */
8620 /* Only issue an error if a Value_Size clause was explicitly given.
8621 Otherwise, we'd be duplicating an error on the Size clause. */
8622 gnat_attr_node
8625 /* Get the size as an INTEGER_CST. Issue an error if a size was specified
8626 but cannot be represented in bitsizetype. */
8629 {
8632 gnat_entity);
8634 }
8636 /* Ignore a zero size unless a Value_Size clause exists, or a size clause
8637 exists, or this is an integer type, in which case the front-end will
8638 have always set it. */
8647 /* If the old size is self-referential, get the maximum size. */
8651 /* Issue an error either if the old size of the object isn't a constant or
8652 if the new size is smaller than it. The front-end has already verified
8653 this for scalar and packed array types. */
8661 && TYPE_PACKED_ARRAY_TYPE_P
8664 {
8666 post_error_ne_tree
8670 }
8672 /* Otherwise, set the RM size proper for integral types... */
8679 /* ...or the Ada size for record and union types. */
8683 }
8684 \f
8685 /* ALIGNMENT is a Uint giving the alignment specified for GNAT_ENTITY,
8686 a type or object whose present alignment is ALIGN. If this alignment is
8687 valid, return it. Otherwise, give an error and return ALIGN. */
8689 static unsigned int
8691 {
8694 Node_Id gnat_error_node;
8696 /* Don't worry about checking alignment if alignment was not specified
8697 by the source program and we already posted an error for this entity. */
8701 /* Post the error on the alignment clause if any. Note, for the implicit
8702 base type of an array type, the alignment clause is on the first
8703 subtype. */
8711 gnat_error_node =
8714 else
8717 /* Within GCC, an alignment is an integer, so we must make sure a value is
8718 specified that fits in that range. Also, there is an upper bound to
8719 alignments we can support/allow. */
8727 {
8731 /* If the default alignment of "double" or larger scalar types is
8732 specifically capped and the new alignment is above the cap, do
8733 not post an error and change the alignment only if there is an
8734 alignment clause; this makes it possible to have the associated
8735 GCC type overaligned by default for performance reasons. */
8737 {
8738 Entity_Id gnat_type
8740 is_capped_double
8742 }
8744 {
8745 Entity_Id gnat_type
8747 is_capped_double
8749 }
8750 else
8754 {
8757 }
8758 else
8759 {
8766 }
8767 }
8768 else
8769 {
8773 }
8776 }
8777 \f
8778 /* Verify that TYPE is something we can implement atomically. If not, issue
8779 an error for GNAT_ENTITY. COMPONENT_P is true if we are being called to
8780 process a component type. */
8782 static void
8784 {
8786 Node_Id gnat_node;
8787 machine_mode mode;
8790 tree size;
8792 /* If this is an anonymous base type, nothing to check, the error will be
8793 reported on the source type if need be. */
8802 /* Consider all aligned floating-point types atomic and any aligned types
8803 that are represented by integers no wider than a machine word. */
8804 scalar_int_mode int_mode;
8811 /* For the moment, also allow anything that has an alignment equal to its
8812 size and which is smaller than a word. */
8823 {
8824 unsigned char pragma_id
8829 {
8832 }
8833 }
8841 else
8844 }
8845 \f
8847 /* Helper for the intrin compatibility checks family. Evaluate whether
8848 two types are definitely incompatible. */
8850 static bool
8852 {
8867 {
8874 /* Assume designated types are ok. We'd need to account for char * and
8875 void * variants to do better, which could rapidly get messy and isn't
8876 clearly worth the effort. */
8881 }
8884 }
8886 /* Helper for intrin_profiles_compatible_p, to perform compatibility checks
8887 on the Ada/builtin argument lists for the INB binding. */
8889 static bool
8891 {
8897 /* Sequence position of the last argument we checked. */
8901 {
8905 /* If we've exhausted both lists simultaneously, we're done. */
8909 /* If one list is shorter than the other, they fail to match. */
8913 /* If we're done with the Ada args and not with the internal builtin
8914 args, or the other way around, complain. */
8917 {
8920 }
8924 {
8928 }
8930 /* Otherwise, check that types match for the current argument. */
8931 argpos ++;
8933 {
8937 }
8942 }
8945 }
8947 /* Helper for intrin_profiles_compatible_p, to perform compatibility checks
8948 on the Ada/builtin return values for the INB binding. */
8950 static bool
8952 {
8956 /* Accept function imported as procedure, common and convenient. */
8961 /* Check return types compatibility otherwise. Note that this
8962 handles void/void as well. */
8964 {
8968 }
8971 }
8973 /* Check and return whether the Ada and gcc builtin profiles bound by INB are
8974 compatible. Issue relevant warnings when they are not.
8976 This is intended as a light check to diagnose the most obvious cases, not
8977 as a full fledged type compatibility predicate. It is the programmer's
8978 responsibility to ensure correctness of the Ada declarations in Imports,
8979 especially when binding straight to a compiler internal. */
8981 static bool
8983 {
8984 /* Check compatibility on return values and argument lists, each responsible
8985 for posting warnings as appropriate. Ensure use of the proper sloc for
8986 this purpose. */
8999 }
9000 \f
9001 /* Return a FIELD_DECL node modeled on OLD_FIELD. FIELD_TYPE is its type
9002 and RECORD_TYPE is the type of the parent. If SIZE is nonzero, it is the
9003 specified size for this field. POS_LIST is a position list describing
9004 the layout of OLD_FIELD and SUBST_LIST a substitution list to be applied
9005 to this layout. */
9007 static tree
9011 {
9023 /* If the position is now a constant, we can set it as the position of the
9024 field when we make it. Otherwise, we need to deal with it specially. */
9027 else
9030 new_field
9036 {
9038 /* Finalize the position. */
9047 }
9055 }
9057 /* Create the REP part of RECORD_TYPE with REP_TYPE. If MIN_SIZE is nonzero,
9058 it is the minimal size the REP_PART must have. */
9060 static tree
9062 {
9063 tree field;
9073 }
9075 /* Return the REP part of RECORD_TYPE, if any. Otherwise return NULL. */
9077 static tree
9079 {
9082 /* The REP part is the first field, internal, another record, and its name
9083 starts with an 'R'. */
9091 }
9093 /* Return the variant part of RECORD_TYPE, if any. Otherwise return NULL. */
9095 tree
9097 {
9098 tree field;
9100 /* The variant part is the only internal field that is a qualified union. */
9107 }
9109 /* Return a new variant part modeled on OLD_VARIANT_PART. VARIANT_LIST is
9110 the list of variants to be used and RECORD_TYPE is the type of the parent.
9111 POS_LIST is a position list describing the layout of fields present in
9112 OLD_VARIANT_PART and SUBST_LIST a substitution list to be applied to this
9113 layout. DEBUG_INFO_P is true if we need to write debug information. */
9115 static tree
9121 {
9129 /* First create the type of the variant part from that of the old one. */
9135 /* If the position of the variant part is constant, subtract it from the
9136 size of the type of the parent to get the new size. This manual CSE
9137 reduces the code size when not optimizing. */
9141 {
9151 first_bit));
9154 }
9155 else
9158 /* Now finish up the new variants and populate the union type. */
9160 {
9164 /* Skip variants that don't belong to this nesting level. */
9168 /* Retrieve the list of fields already added to the new variant. */
9172 /* If the old variant had a variant subpart, we need to create a new
9173 variant subpart and add it to the field list. */
9177 {
9178 tree new_variant_subpart
9181 debug_info_p);
9184 }
9186 /* Finish up the new variant and create the field. */
9192 new_field
9200 }
9202 /* Finish up the union type and create the variant part. Note that we don't
9203 reverse the field list because VARIANT_LIST has been traversed in reverse
9204 order. */
9210 new_variant_part
9216 /* With multiple discriminants it is possible for an inner variant to be
9217 statically selected while outer ones are not; in this case, the list
9218 of fields of the inner variant is not flattened and we end up with a
9219 qualified union with a single member. Drop the useless container. */
9221 {
9230 }
9233 }
9235 /* Copy the size (and alignment and alias set) from OLD_TYPE to NEW_TYPE,
9236 which are both RECORD_TYPE, after applying the substitutions described
9237 in SUBST_LIST. */
9239 static void
9242 {
9266 SET_TYPE_ADA_SIZE
9270 /* Finalize the size. */
9273 }
9275 /* Return true if DISC is a stored discriminant of RECORD_TYPE. */
9279 {
9284 else
9286 }
9288 /* Copy the layout from {GNAT,GNU}_OLD_TYPE to {GNAT,GNU}_NEW_TYPE, which are
9289 both record types, after applying the substitutions described in SUBST_LIST.
9290 DEBUG_INFO_P is true if we need to write debug information for NEW_TYPE. */
9292 static void
9294 Entity_Id gnat_old_type,
9295 tree gnu_new_type,
9296 tree gnu_old_type,
9299 {
9305 /* Look for REP and variant parts in the old type. */
9309 /* If there is a variant part, we must compute whether the constraints
9310 statically select a particular variant. If so, we simply drop the
9311 qualified union and flatten the list of fields. Otherwise we will
9312 build a new qualified union for the variants that are still relevant. */
9314 {
9321 /* If all the qualifiers are unconditionally true, the innermost variant
9322 is statically selected. */
9326 {
9329 }
9331 /* Otherwise, create the new variants. */
9334 {
9337 tree suffix
9346 gnu_subst_list);
9348 }
9349 }
9350 else
9351 {
9354 }
9356 /* Make a list of fields and their position in the old type. */
9357 tree gnu_pos_list
9363 /* Now go down every component in the new type and compute its size and
9364 position from those of the component in the old type and the stored
9365 constraints of the new type. */
9378 {
9387 /* If the type is the same, retrieve the GCC type from the
9388 old field to take into account possible adjustments. */
9391 else
9394 /* If there was a component clause, the field types must be the same
9395 for the old and new types, so copy the data from the old field to
9396 avoid recomputation here. Also if the field is justified modular
9397 and the optimization in gnat_to_gnu_field was applied. */
9403 {
9406 }
9408 /* If the old field was packed and of constant size, we have to get the
9409 old size here as it might differ from what the Etype conveys and the
9410 latter might overlap with the following field. Try to arrange the
9411 type for possible better packing along the way. */
9414 {
9420 }
9422 else
9425 /* If the context of the old field is the old type or its REP part,
9426 put the field directly in the new type; otherwise look up the
9427 context in the variant list and put the field either in the new
9428 type if there is a selected variant or in one new variant. */
9432 else
9433 {
9436 tree rep_part;
9446 else
9447 /* The front-end may pass us "ghost" components if it fails to
9448 recognize that a constrain statically selects a particular
9449 variant. Discard them. */
9451 }
9453 /* Now create the new field modeled on the old one. */
9454 gnu_field
9460 /* If the context is a variant, put it in the new variant directly. */
9462 {
9465 }
9467 /* To match the layout crafted in components_to_record, if this is
9468 the _Tag or _Parent field, put it before any other fields. */
9472 /* Similarly, if this is the _Controller field, put it before the
9473 other fields except for the _Tag or _Parent field. */
9475 {
9478 }
9480 /* Otherwise, put it after the other fields. */
9481 else
9482 {
9489 }
9491 /* For a stored discriminant in a derived type, replace the field. */
9493 {
9496 }
9497 else
9499 }
9501 /* If there is a variant list, a selected variant and the fields all have a
9502 constant position, put them in order of increasing position to match that
9503 of constant CONSTRUCTORs. Likewise if there is no variant list but a REP
9504 part, since the latter has been flattened in the process. */
9507 {
9518 {
9521 }
9522 }
9524 /* If there is a variant list and no selected variant, we need to create the
9525 nest of variant parts from the old nest. */
9527 {
9528 tree new_variant_part
9534 }
9541 /* If NEW_TYPE is a subtype, it inherits all the attributes from OLD_TYPE.
9542 Otherwise sizes and alignment must be computed independently. */
9544 {
9547 }
9548 else
9551 /* Now go through the entities again looking for Itypes that we have not yet
9552 elaborated (e.g. Etypes of fields that have Original_Components). */
9561 }
9563 /* Associate to GNU_TYPE, the translation of GNAT_ENTITY, which is
9564 the implementation type of a packed array type (Is_Packed_Array_Impl_Type),
9565 the original array type if it has been translated. This association is a
9566 parallel type for GNAT encodings or a debug type for standard DWARF. Note
9567 that for standard DWARF, we also want to get the original type name. */
9569 static void
9571 {
9572 Entity_Id gnat_original_array_type
9574 tree gnu_original_array_type;
9585 {
9593 }
9594 else
9596 }
9597 \f
9598 /* Given a type T, a FIELD_DECL F, and a replacement value R, return an
9599 equivalent type with adjusted size expressions where all occurrences
9600 of references to F in a PLACEHOLDER_EXPR have been replaced by R.
9602 The function doesn't update the layout of the type, i.e. it assumes
9603 that the substitution is purely formal. That's why the replacement
9604 value R must itself contain a PLACEHOLDER_EXPR. */
9606 tree
9608 {
9609 tree nt;
9614 {
9620 /* First the domain types of arrays. */
9623 {
9635 SET_TYPE_INDEX_TYPE
9639 }
9641 /* Then the subtypes. */
9644 {
9656 }
9668 /* These should never show up here. */
9672 {
9692 }
9697 {
9699 tree field;
9701 /* Start out with no fields, make new fields, and chain them
9702 in. If we haven't actually changed the type of any field,
9703 discard everything we've done and return the old type. */
9708 {
9713 {
9716 }
9720 {
9723 }
9725 /* Do the substitution inside the qualifier, if any. */
9727 {
9730 {
9733 }
9734 }
9741 }
9751 }
9755 }
9756 }
9757 \f
9758 /* Return the RM size of GNU_TYPE. This is the actual number of bits
9759 needed to represent the object. */
9761 tree
9763 {
9764 /* For integral types, we store the RM size explicitly. */
9768 /* Return the RM size of the actual data plus the size of the template. */
9771 return
9776 /* For record or union types, we store the size explicitly. */
9782 /* For other types, this is just the size. */
9784 }
9785 \f
9786 /* Return the name to be used for GNAT_ENTITY. If a type, create a
9787 fully-qualified name, possibly with type information encoding.
9788 Otherwise, return the name. */
9792 {
9795 }
9797 tree
9799 {
9802 }
9804 /* Return an identifier representing the external name to be used for
9805 GNAT_ENTITY. If SUFFIX is specified, the name is followed by "___"
9806 and the specified suffix. */
9808 tree
9810 {
9818 /* A variable using the Stdcall convention lives in a DLL. We adjust
9819 its name to use the jump table, the _imp__NAME contains the address
9820 for the NAME variable. */
9823 {
9829 }
9832 }
9834 /* Given GNU_NAME, an IDENTIFIER_NODE containing a name and SUFFIX, a
9835 string, return a new IDENTIFIER_NODE that is the concatenation of
9836 the name followed by "___" and the specified suffix. */
9838 tree
9840 {
9847 }
9849 /* Initialize data structures of the decl.c module. */
9851 void
9853 {
9854 /* Initialize the cache of annotated values. */
9857 /* Initialize the association of dummy types with subprograms. */
9859 }
9861 /* Destroy data structures of the decl.c module. */
9863 void
9865 {
9866 /* Destroy the cache of annotated values. */
9870 /* Destroy the association of dummy types with subprograms. */
9873 }