| blob | df88ce7849e658305f9579e38bcc277746ffbace |
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, and for E_Record_Subtype with cloned subtype because
316 it's actually a use of the cloned subtype, see below. */
318 && is_type
325 {
326 /* Ensure that we are in a subprogram mentioned in the Scope chain of
327 this entity, our current scope is global, or we encountered a task
328 or entry (where we can't currently accurately check scoping). */
331 {
334 }
339 {
344 gnat_temp
356 && (current_function_decl
358 {
361 }
362 }
364 /* This abort means the Itype has an incorrect scope, i.e. that its
365 scope does not correspond to the subprogram it is declared in. */
367 }
369 /* If we've already processed this entity, return what we got last time.
370 If we are defining the node, we should not have already processed it.
371 In that case, we will abort below when we try to save a new GCC tree
372 for this object. We also need to handle the case of getting a dummy
373 type when a Full_View exists but be careful so as not to trigger its
374 premature elaboration. */
377 {
386 {
387 gnu_decl
391 }
394 }
396 /* If this is a numeric or enumeral type, or an access type, a nonzero Esize
397 must be specified unless it was specified by the programmer. Exceptions
398 are for access-to-protected-subprogram types and all access subtypes, as
399 another GNAT type is used to lay out the GCC type for them. */
411 /* The RM size must be specified for all discrete and fixed-point types. */
415 /* If we get here, it means we have not yet done anything with this entity.
416 If we are not defining it, it must be a type or an entity that is defined
417 elsewhere or externally, otherwise we should have defined it already. */
419 || type_annotate_only
420 || is_type
427 /* Get the name of the entity and set up the line number and filename of
428 the original definition for use in any decl we make. Make sure we do not
429 inherit another source location. */
435 /* For cases when we are not defining (i.e., we are referencing from
436 another compilation unit) public entities, show we are at global level
437 for the purpose of computing scopes. Don't do this for components or
438 discriminants since the relevant test is whether or not the record is
439 being defined. */
447 /* Handle any attributes directly attached to the entity. */
451 /* Do some common processing for types. */
453 {
454 /* Compute the equivalent type to be used in gigi. */
457 /* Machine_Attributes on types are expected to be propagated to
458 subtypes. The corresponding Gigi_Rep_Items are only attached
459 to the first subtype though, so we handle the propagation here. */
466 /* Compute a default value for the size of an elementary type. */
468 {
478 else
483 }
484 }
487 {
490 {
491 /* The GNAT record where the component was defined. */
494 /* If the entity is a discriminant of an extended tagged type used to
495 rename a discriminant of the parent type, return the latter. */
499 {
500 gnu_decl
505 }
507 /* If the entity is an inherited component (in the case of extended
508 tagged record types), just return the original entity, which must
509 be a FIELD_DECL. Likewise for discriminants. If the entity is a
510 non-girder discriminant (in the case of derived untagged record
511 types), return the stored discriminant it renames. */
514 {
515 gnu_decl
518 /* GNU_DECL contains a PLACEHOLDER_EXPR for discriminants. */
522 }
524 /* Otherwise, if we are not defining this and we have no GCC type
525 for the containing record, make one for it. Then we should
526 have made our own equivalent. */
528 {
529 /* ??? If this is in a record whose scope is a protected
530 type and we have an Original_Record_Component, use it.
531 This is a workaround for major problems in protected type
532 handling. */
536 {
537 gnu_decl
541 }
542 else
543 {
546 }
550 }
552 /* Here we have no GCC type and this is a reference rather than a
553 definition. This should never happen. Most likely the cause is
554 reference before declaration in the GNAT tree for gnat_entity. */
556 }
559 /* Ignore constant definitions already marked with the error node. See
560 the N_Object_Declaration case of gnat_to_gnu for the rationale. */
564 {
567 }
569 /* Ignore deferred constant definitions without address clause since
570 they are processed fully in the front-end. If No_Initialization
571 is set, this is not a deferred constant but a constant whose value
572 is built manually. And constants that are renamings are handled
573 like variables. */
575 && !gnu_expr
579 {
583 }
585 /* If this is a use of a deferred constant without address clause,
586 get its full definition. */
590 {
591 gnu_decl
595 }
597 /* If we have a constant that we are not defining, get the expression it
598 was defined to represent. This is necessary to avoid generating dumb
599 elaboration code in simple cases, but we may throw it away later if it
600 is not a constant. But do not retrieve it if it is an allocator since
601 the designated type might still be dummy at this point. */
607 /* The expression may contain N_Expression_With_Actions nodes and
608 thus object declarations from other units. Discard them. */
609 gnu_expr
612 /* ... fall through ... */
618 {
620 /* Always create a variable for volatile objects and variables seen
621 constant but with a Linker_Section pragma. */
622 bool const_flag
635 /* We implement RM 13.3(19) for exported and imported (non-constant)
636 objects by making them volatile. */
637 bool volatile_flag
644 tree gnu_object_size;
646 /* We need to translate the renamed object even though we are only
647 referencing the renaming. But it may contain a call for which
648 we'll generate a temporary to hold the return value and which
649 is part of the definition of the renaming, so discard it. */
651 {
655 else
657 }
659 /* Get the type after elaborating the renamed object. */
663 else
664 {
667 /* If this is a standard exception definition, use the standard
668 exception type. This is necessary to make sure that imported
669 and exported views of exceptions are merged in LTO mode. */
673 }
675 /* For a debug renaming declaration, build a debug-only entity. */
677 {
678 /* Force a non-null value to make sure the symbol is retained. */
682 integer_minus_one_node));
690 }
692 /* If this is a loop variable, its type should be the base type.
693 This is because the code for processing a loop determines whether
694 a normal loop end test can be done by comparing the bounds of the
695 loop against those of the base type, which is presumed to be the
696 size used for computation. But this is not correct when the size
697 of the subtype is smaller than the type. */
701 /* Reject non-renamed objects whose type is an unconstrained array or
702 any object whose type is a dummy type or void. */
707 {
710 force_global--;
712 }
714 /* If an alignment is specified, use it if valid. Note that exceptions
715 are objects but don't have an alignment. We must do this before we
716 validate the size, since the alignment can affect the size. */
718 {
724 /* No point in changing the type if there is an address clause
725 as the final type of the object will be a reference type. */
728 else
729 {
732 gnu_type
736 /* If a padding record was made, declare it now since it will
737 never be declared otherwise. This is necessary to ensure
738 that its subtrees are properly marked. */
742 }
743 }
745 /* If we are defining the object, see if it has a Size and validate it
746 if so. If we are not defining the object and a Size clause applies,
747 simply retrieve the value. We don't want to ignore the clause and
748 it is expected to have been validated already. Then get the new
749 type, if any. */
758 {
759 gnu_type
765 }
767 /* If this object has self-referential size, it must be a record with
768 a default discriminant. We are supposed to allocate an object of
769 the maximum size in this case, unless it is a constant with an
770 initializing expression, in which case we can get the size from
771 that. Note that the resulting size may still be a variable, so
772 this may end up with an indirect allocation. */
775 {
777 {
780 {
781 /* If the initializing expression is itself a constant,
782 despite having a nominal type with self-referential
783 size, we can get the size directly from it. */
785 && TYPE_IS_PADDING_P
789 || DECL_READONLY_ONCE_ELAB
792 else
793 gnu_size
795 }
796 else
798 }
799 /* We may have no GNU_EXPR because No_Initialization is
800 set even though there's an Expression. */
805 gnu_size
807 (Etype
809 else
810 {
813 }
815 /* If the size isn't constant and we are at global level, call
816 elaborate_expression_1 to make a variable for it rather than
817 calculating it each time. */
821 }
823 /* If the size is zero byte, make it one byte since some linkers have
824 troubles with zero-sized objects. If the object will have a
825 template, that will make it nonzero so don't bother. Also avoid
826 doing that for an object renaming or an object with an address
827 clause, as we would lose useful information on the view size
828 (e.g. for null array slices) and we are not allocating the object
829 here anyway. */
841 /* If this is an object with no specified size and alignment, and
842 if either it is atomic or we are not optimizing alignment for
843 space and it is composite and not an exception, an Out parameter
844 or a reference to another object, and the size of its type is a
845 constant, set the alignment to the smallest one which is not
846 smaller than the size, with an appropriate cap. */
855 && !imported_p
859 {
862 /* No point in promoting the alignment if this doesn't prevent
863 BLKmode access to the object, in particular block copy, as
864 this will for example disable the NRV optimization for it.
865 No point in jumping through all the hoops needed in order
866 to support BIGGEST_ALIGNMENT if we don't really have to.
867 So we cap to the smallest alignment that corresponds to
868 a known efficient memory access pattern of the target. */
870 {
873 }
874 else
875 {
878 }
885 else
888 /* But make sure not to under-align the object. */
892 /* And honor the minimum valid atomic alignment, if any. */
893 #ifdef MINIMUM_ATOMIC_ALIGNMENT
896 #endif
897 }
899 /* If the object is set to have atomic components, find the component
900 type and validate it.
902 ??? Note that we ignore Has_Volatile_Components on objects; it's
903 not at all clear what to do in that case. */
905 {
914 }
916 /* If this is an aliased object with an unconstrained array nominal
917 subtype, make a type that includes the template. We will either
918 allocate or create a variable of that type, see below. */
922 {
924 gnu_type
926 gnu_type,
929 debug_info_p);
930 }
932 /* ??? If this is an object of CW type initialized to a value, try to
933 ensure that the object is sufficient aligned for this value, but
934 without pessimizing the allocation. This is a kludge necessary
935 because we don't support dynamic alignment. */
942 #ifdef MINIMUM_ATOMIC_ALIGNMENT
943 /* If the size is a constant and no alignment is specified, force
944 the alignment to be the minimum valid atomic alignment. The
945 restriction on constant size avoids problems with variable-size
946 temporaries; if the size is variable, there's no issue with
947 atomic access. Also don't do this for a constant, since it isn't
948 necessary and can interfere with constant replacement. Finally,
949 do not do it for Out parameters since that creates an
950 size inconsistency with In parameters. */
960 #endif
962 /* Make a new type with the desired size and alignment, if needed.
963 But do not take into account alignment promotions to compute the
964 size of the object. */
967 {
973 /* If a padding record was made, declare it now since it will
974 never be declared otherwise. This is necessary to ensure
975 that its subtrees are properly marked. */
979 }
981 /* Now check if the type of the object allows atomic access. */
985 /* If this is a renaming, avoid as much as possible to create a new
986 object. However, in some cases, creating it is required because
987 renaming can be applied to objects that are not names in Ada.
988 This processing needs to be applied to the raw expression so as
989 to make it more likely to rename the underlying object. */
991 {
992 /* If the renamed object had padding, strip off the reference to
993 the inner object and reset our type. */
996 /* Strip useless conversions around the object. */
998 {
1001 }
1003 /* Or else, if the renamed object has an unconstrained type with
1004 default discriminant, use the padded type. */
1008 /* Case 1: if this is a constant renaming stemming from a function
1009 call, treat it as a normal object whose initial value is what
1010 is being renamed. RM 3.3 says that the result of evaluating a
1011 function call is a constant object. Therefore, it can be the
1012 inner object of a constant renaming and the renaming must be
1013 fully instantiated, i.e. it cannot be a reference to (part of)
1014 an existing object. And treat other rvalues (addresses, null
1015 expressions, constructors and literals) the same way. */
1019 /* Expand_Dispatching_Call can prepend a comparison of the tags
1020 before the call to "=". */
1031 /* We need to detect the case where a temporary is created to
1032 hold the return value, since we cannot safely rename it at
1033 top level as it lives only in the elaboration routine. */
1036 /* We also need to detect the case where the front-end creates
1037 a dangling 'reference to a function call at top level and
1038 substitutes it in the renaming, for example:
1040 q__b : boolean renames r__f.e (1);
1042 can be rewritten into:
1044 q__R1s : constant q__A2s := r__f'reference;
1045 [...]
1046 q__b : boolean renames q__R1s.all.e (1);
1048 We cannot safely rename the rewritten expression since the
1049 underlying object lives only in the elaboration routine. */
1051 && (inner
1055 ;
1057 /* Case 2: if the renaming entity need not be materialized, use
1058 the elaborated renamed expression for the renaming. But this
1059 means that the caller is responsible for evaluating the address
1060 of the renaming in the correct place for the definition case to
1061 instantiate the SAVE_EXPRs. */
1063 {
1066 gnu_decl
1070 /* We cannot evaluate the first arm of a COMPOUND_EXPR in the
1071 correct place for this case. */
1074 /* No DECL_EXPR will be created so the expression needs to be
1075 marked manually because it will likely be shared. */
1079 /* This assertion will fail if the renamed object isn't aligned
1080 enough as to make it possible to honor the alignment set on
1081 the renaming. */
1083 {
1088 }
1090 /* The expression might not be a DECL so save it manually. */
1095 }
1097 /* Case 3: otherwise, make a constant pointer to the object we
1098 are renaming and attach the object to the pointer after it is
1099 elaborated. The object will be referenced directly instead
1100 of indirectly via the pointer to avoid aliasing problems with
1101 non-addressable entities. The pointer is called a "renaming"
1102 pointer in this case. Note that we also need to preserve the
1103 volatility of the renamed object through the indirection. */
1104 else
1105 {
1109 gnu_type
1118 renamed_obj
1122 /* The expression needs to be marked manually because it will
1123 likely be shared, even for a definition since the ADDR_EXPR
1124 built below can cause the first few nodes to be folded. */
1131 else
1132 {
1133 gnu_expr
1136 gnu_expr
1138 gnu_expr);
1139 }
1140 }
1141 }
1143 /* If we are defining an aliased object whose nominal subtype is
1144 unconstrained, the object is a record that contains both the
1145 template and the object. If there is an initializer, it will
1146 have already been converted to the right type, but we need to
1147 create the template if there is no initializer. */
1149 && !gnu_expr
1152 /* Beware that padding might have been introduced above. */
1155 == RECORD_TYPE
1156 && TYPE_CONTAINS_TEMPLATE_P
1158 {
1159 tree template_field
1167 NULL_TREE);
1170 }
1172 /* Convert the expression to the type of the object if need be. */
1176 /* If this is a pointer that doesn't have an initializing expression,
1177 initialize it to NULL, unless the object is declared imported as
1178 per RM B.1(24). */
1181 && !gnu_expr
1185 /* If we are defining the object and it has an Address clause, we must
1186 either get the address expression from the saved GCC tree for the
1187 object if it has a Freeze node, or elaborate the address expression
1188 here since the front-end has guaranteed that the elaboration has no
1189 effects in this case. */
1191 {
1194 tree gnu_address
1200 /* Convert the type of the object to a reference type that can
1201 alias everything as per RM 13.3(19). */
1204 gnu_type
1208 const_flag
1214 /* If this is an aliased object with an unconstrained array nominal
1215 subtype, then it can overlay only another aliased object with an
1216 unconstrained array nominal subtype and compatible template. */
1220 {
1224 /* This is the pattern built for a regular object. */
1228 /* This is the pattern built for an overaligned object. */
1231 == PLUS_EXPR
1234 gnu_address
1238 else
1239 {
1242 gnat_entity);
1245 }
1246 }
1248 /* If we don't have an initializing expression for the underlying
1249 variable, the initializing expression for the pointer is the
1250 specified address. Otherwise, we have to make a COMPOUND_EXPR
1251 to assign both the address and the initial value. */
1254 else
1255 gnu_expr
1259 NULL_TREE,
1260 gnu_address),
1261 gnu_expr),
1262 gnu_address);
1263 }
1265 /* If it has an address clause and we are not defining it, mark it
1266 as an indirect object. Likewise for Stdcall objects that are
1267 imported. */
1270 {
1271 /* Convert the type of the object to a reference type that can
1272 alias everything as per RM 13.3(19). */
1275 gnu_type
1282 /* No point in taking the address of an initializing expression
1283 that isn't going to be used. */
1286 /* If it has an address clause whose value is known at compile
1287 time, make the object a CONST_DECL. This will avoid a
1288 useless dereference. */
1290 {
1291 Node_Id gnat_address
1295 {
1298 }
1299 }
1300 }
1302 /* If we are at top level and this object is of variable size,
1303 make the actual type a hidden pointer to the real type and
1304 make the initializer be a memory allocation and initialization.
1305 Likewise for objects we aren't defining (presumed to be
1306 external references from other packages), but there we do
1307 not set up an initialization.
1309 If the object's size overflows, make an allocator too, so that
1310 Storage_Error gets raised. Note that we will never free
1311 such memory, so we presume it never will get allocated. */
1314 || !definition
1316 || (gnu_size
1318 size_binop
1320 bitsize_unit_node)),
1322 || !definition
1324 {
1333 /* In case this was a aliased object whose nominal subtype is
1334 unconstrained, the pointer above will be a thin pointer and
1335 build_allocator will automatically make the template.
1337 If we have a template initializer only (that we made above),
1338 pretend there is none and rely on what build_allocator creates
1339 again anyway. Otherwise (if we have a full initializer), get
1340 the data part and feed that to build_allocator.
1342 If we are elaborating a mutable object, tell build_allocator to
1343 ignore a possibly simpler size from the initializer, if any, as
1344 we must allocate the maximum possible size in this case. */
1346 {
1351 {
1352 gnu_alloc_type
1358 else
1359 gnu_expr
1360 = build_component_ref
1364 }
1369 gnat_entity);
1371 gnu_expr
1374 }
1375 else
1377 }
1379 /* If this object would go into the stack and has an alignment larger
1380 than the largest stack alignment the back-end can honor, resort to
1381 a variable of "aligning type". */
1384 && !imported_p
1385 && !static_flag
1387 {
1388 /* Create the new variable. No need for extra room before the
1389 aligned field as this is in automatic storage. */
1390 tree gnu_new_type
1394 tree gnu_new_var
1399 gnat_entity);
1401 /* Initialize the aligned field if we have an initializer. */
1403 add_stmt_with_node
1405 build_component_ref
1408 gnu_expr),
1409 gnat_entity);
1411 /* And setup this entity as a reference to the aligned field. */
1413 gnu_expr
1414 = build_unary_op
1424 }
1426 /* If this is an aliased object with an unconstrained array nominal
1427 subtype, we make its type a thin reference, i.e. the reference
1428 counterpart of a thin pointer, so it points to the array part.
1429 This is aimed to make it easier for the debugger to decode the
1430 object. Note that we have to do it this late because of the
1431 couple of allocation adjustments that might be made above. */
1435 {
1436 /* In case the object with the template has already been allocated
1437 just above, we have nothing to do here. */
1439 {
1440 /* This variable is a GNAT encoding used by Workbench: let it
1441 go through the debugging information but mark it as
1442 artificial: users are not interested in it. */
1443 tree gnu_unc_var
1459 }
1462 gnu_type
1464 }
1466 /* Convert the expression to the type of the object if need be. */
1470 /* If this name is external or a name was specified, use it, but don't
1471 use the Interface_Name with an address clause (see cd30005). */
1477 /* If this is an aggregate constant initialized to a constant, force it
1478 to be statically allocated. This saves an initialization copy. */
1480 && const_flag
1489 /* Deal with a pragma Linker_Section on a constant or variable. */
1495 /* Now create the variable or the constant and set various flags. */
1496 gnu_decl
1507 /* If we are defining an Out parameter and optimization isn't enabled,
1508 create a fake PARM_DECL for debugging purposes and make it point to
1509 the VAR_DECL. Suppress debug info for the latter but make sure it
1510 will live in memory so that it can be accessed from within the
1511 debugger through the PARM_DECL. */
1513 && definition
1514 && debug_info_p
1515 && !optimize
1517 {
1524 }
1526 /* If this is a loop parameter, set the corresponding flag. */
1530 /* If this is a renaming pointer, attach the renamed object to it. */
1534 /* If this is a constant and we are defining it or it generates a real
1535 symbol at the object level and we are referencing it, we may want
1536 or need to have a true variable to represent it:
1537 - if optimization isn't enabled, for debugging purposes,
1538 - if the constant is public and not overlaid on something else,
1539 - if its address is taken,
1540 - if either itself or its type is aliased. */
1549 {
1550 tree gnu_corr_var
1558 }
1560 /* If this is a constant, even if we don't need a true variable, we
1561 may need to avoid returning the initializer in every case. That
1562 can happen for the address of a (constant) constructor because,
1563 upon dereferencing it, the constructor will be reinjected in the
1564 tree, which may not be valid in every case; see lvalue_required_p
1565 for more details. */
1569 /* If this object is declared in a block that contains a block with an
1570 exception handler, and we aren't using the GCC exception mechanism,
1571 we must force this variable in memory in order to avoid an invalid
1572 optimization. */
1577 /* If this is a local variable with non-BLKmode and aggregate type,
1578 and optimization isn't enabled, then force it in memory so that
1579 a register won't be allocated to it with possible subparts left
1580 uninitialized and reaching the register allocator. */
1590 /* If we are defining an object with variable size or an object with
1591 fixed size that will be dynamically allocated, and we are using the
1592 front-end setjmp/longjmp exception mechanism, update the setjmp
1593 buffer. */
1606 gnat_entity);
1608 /* Back-annotate Esize and Alignment of the object if not already
1609 known. Note that we pick the values of the type, not those of
1610 the object, to shield ourselves from low-level platform-dependent
1611 adjustments like alignment promotion. This is both consistent with
1612 all the treatment above, where alignment and size are set on the
1613 type of the object and not on the object directly, and makes it
1614 possible to support all confirming representation clauses. */
1616 used_by_ref);
1617 }
1621 /* Return a TYPE_DECL for "void" that we previously made. */
1626 /* A special case: for the types Character and Wide_Character in
1627 Standard, we do not list all the literals. So if the literals
1628 are not specified, make this an integer type. */
1630 {
1633 else
1637 /* Set TYPE_STRING_FLAG for Character and Wide_Character types.
1638 This is needed by the DWARF-2 back-end to distinguish between
1639 unsigned integer types and character types. */
1642 /* This flag is needed by the call just below. */
1646 }
1647 else
1648 {
1649 /* We have a list of enumeral constants in First_Literal. We make a
1650 CONST_DECL for each one and build into GNU_LITERAL_LIST the list
1651 to be placed into TYPE_FIELDS. Each node is itself a TREE_LIST
1652 whose TREE_VALUE is the literal name and whose TREE_PURPOSE is the
1653 value of the literal. But when we have a regular boolean type, we
1654 simplify this a little by using a BOOLEAN_TYPE. */
1659 Entity_Id gnat_literal;
1672 {
1673 tree gnu_value
1675 /* Do not generate debug info for individual enumerators. */
1676 tree gnu_literal
1682 gnu_list
1684 }
1689 /* Note that the bounds are updated at the end of this function
1690 to avoid an infinite recursion since they refer to the type. */
1692 }
1696 /* For integer types, just make a signed type the appropriate number
1697 of bits. */
1703 {
1704 /* Small_Value is the scale factor. */
1710 /* Try to decode the scale factor and to save it for the fixed-point
1711 types debug hook. */
1713 /* There are various ways to describe the scale factor, however there
1714 are cases where back-end internals cannot hold it. In such cases,
1715 we output invalid scale factor for such cases (i.e. the 0/0
1716 rational constant) but we expect GNAT to output GNAT encodings,
1717 then. Thus, keep this in sync with
1718 Exp_Dbug.Is_Handled_Scale_Factor. */
1720 /* When encoded as 1/2**N or 1/10**N, describe the scale factor as a
1721 binary or decimal scale: it is easier to read for humans. */
1725 {
1726 /* Given RM restrictions on 'Small values, we assume here that
1727 the denominator fits in an int. */
1730 const tree exponent
1733 scale_factor
1735 integer_one_node,
1738 }
1740 /* Default to arbitrary scale factors descriptions. */
1741 else
1742 {
1747 {
1748 const tree gnu_num
1751 const tree gnu_den
1756 }
1757 else
1758 /* If compiler internals cannot represent arbitrary scale
1759 factors, output an invalid scale factor so that debugger
1760 don't try to handle them but so that we still have a type
1761 in the output. Note that GNAT */
1763 }
1767 }
1771 {
1772 /* For modular types, make the unsigned type of the proper number
1773 of bits and then set up the modulus, if required. */
1776 /* Packed Array Impl. Types are supposed to be subtypes only. */
1781 /* Get the modulus in this type. If it overflows, assume it is because
1782 it is equal to 2**Esize. Note that there is no overflow checking
1783 done on unsigned type, so we detect the overflow by looking for
1784 a modulus of zero, which is otherwise invalid. */
1788 {
1793 }
1795 /* If the upper bound is not maximal, make an extra subtype. */
1798 {
1805 }
1806 }
1815 /* For integral subtypes, we make a new INTEGER_TYPE. Note that we do
1816 not want to call create_range_type since we would like each subtype
1817 node to be distinct. ??? Historically this was in preparation for
1818 when memory aliasing is implemented, but that's obsolete now given
1819 the call to relate_alias_sets below.
1821 The TREE_TYPE field of the INTEGER_TYPE points to the base type;
1822 this fact is used by the arithmetic conversion functions.
1824 We elaborate the Ancestor_Subtype if it is not in the current unit
1825 and one of our bounds is non-static. We do this to ensure consistent
1826 naming in the case where several subtypes share the same bounds, by
1827 elaborating the first such subtype first, thus using its name. */
1836 /* Set the precision to the Esize except for bit-packed arrays. */
1841 /* First subtypes of Character are treated as Character; otherwise
1842 this should be an unsigned type if the base type is unsigned or
1843 if the lower bound is constant and non-negative or if the type
1844 is biased. However, even if the lower bound is constant and
1845 non-negative, we use a signed type for a subtype with the same
1846 size as its signed base type, because this eliminates useless
1847 conversions to it and gives more leeway to the optimizer; but
1848 this means that we will need to explicitly test for this case
1849 when we change the representation based on the RM size. */
1861 else
1865 SET_TYPE_RM_MIN_VALUE
1868 debug_info_p));
1870 SET_TYPE_RM_MAX_VALUE
1873 debug_info_p));
1878 /* Do the same processing for Character subtypes as for types. */
1880 {
1885 }
1887 /* Inherit our alias set from what we're a subtype of. Subtypes
1888 are not different types and a pointer can designate any instance
1889 within a subtype hierarchy. */
1892 /* One of the above calls might have caused us to be elaborated,
1893 so don't blow up if so. */
1895 {
1898 }
1900 /* Attach the TYPE_STUB_DECL in case we have a parallel type. */
1904 /* For a packed array, make the original array type a parallel/debug
1905 type. */
1909 discrete_type:
1911 /* We have to handle clauses that under-align the type specially. */
1914 && Present
1917 {
1921 }
1923 /* If the type we are dealing with represents a bit-packed array,
1924 we need to have the bits left justified on big-endian targets
1925 and right justified on little-endian targets. We also need to
1926 ensure that when the value is read (e.g. for comparison of two
1927 such values), we only get the good bits, since the unused bits
1928 are uninitialized. Both goals are accomplished by wrapping up
1929 the modular type in an enclosing record type. */
1932 {
1935 /* Set the RM size before wrapping up the original type. */
1940 /* Strip the ___XP suffix for standard DWARF. */
1944 /* Create a stripped-down declaration, mainly for debugging. */
1946 gnat_entity);
1948 /* Now save it and build the enclosing record type. */
1958 /* Propagate the alignment of the modular type to the record type,
1959 unless there is an alignment clause that under-aligns the type.
1960 This means that bit-packed arrays are given "ceil" alignment for
1961 their size by default, which may seem counter-intuitive but makes
1962 it possible to overlay them on modular types easily. */
1966 /* Propagate the reverse storage order flag to the record type so
1967 that the required byte swapping is performed when retrieving the
1968 enclosed modular value. */
1974 /* Don't declare the field as addressable since we won't be taking
1975 its address and this would prevent create_field_decl from making
1976 a bitfield. */
1977 gnu_field
1981 /* We will output additional debug info manually below. */
1987 {
1988 /* Make the original array type a parallel/debug type. */
1991 /* Since GNU_TYPE is a padding type around the packed array
1992 implementation type, the padded type is its debug type. */
1995 }
1996 }
1998 /* If the type we are dealing with has got a smaller alignment than the
1999 natural one, we need to wrap it up in a record type and misalign the
2000 latter; we reuse the padding machinery for this purpose. */
2002 {
2005 /* Set the RM size before wrapping the type. */
2008 gnu_type
2014 }
2019 /* The type of the Low and High bounds can be our type if this is
2020 a type from Standard, so set them at the end of the function. */
2027 /* See the E_Signed_Integer_Subtype case for the rationale. */
2044 SET_TYPE_RM_MIN_VALUE
2047 debug_info_p));
2049 SET_TYPE_RM_MAX_VALUE
2052 debug_info_p));
2054 /* Inherit our alias set from what we're a subtype of, as for
2055 integer subtypes. */
2058 /* One of the above calls might have caused us to be elaborated,
2059 so don't blow up if so. */
2063 /* Array Types and Subtypes
2065 Unconstrained array types are represented by E_Array_Type and
2066 constrained array types are represented by E_Array_Subtype. There
2067 are no actual objects of an unconstrained array type; all we have
2068 are pointers to that type.
2070 The following fields are defined on array types and subtypes:
2072 Component_Type Component type of the array.
2073 Number_Dimensions Number of dimensions (an int).
2074 First_Index Type of first index. */
2077 {
2078 const bool convention_fortran_p
2081 tree gnu_template_type;
2082 tree gnu_ptr_template;
2089 tree comp_type;
2091 /* Create the type for the component now, as it simplifies breaking
2092 type reference loops. */
2093 comp_type
2096 {
2097 /* As a side effect, the type may have been translated. */
2100 }
2102 /* We complete an existing dummy fat pointer type in place. This both
2103 avoids further complex adjustments in update_pointer_to and yields
2104 better debugging information in DWARF by leveraging the support for
2105 incomplete declarations of "tagged" types in the DWARF back-end. */
2108 {
2111 /* Save the contents of the dummy type for update_pointer_to. */
2113 gnu_ptr_template =
2116 }
2117 else
2118 {
2122 }
2124 /* Make a node for the array. If we are not defining the array
2125 suppress expanding incomplete types. */
2129 {
2130 defer_incomplete_level++;
2132 }
2134 /* Build the fat pointer type. Use a "void *" object instead of
2135 a pointer to the array type since we don't have the array type
2136 yet (it will reference the fat pointer via the bounds). */
2137 tem
2145 {
2146 /* We are going to lay it out again so reset the alias set. */
2152 {
2155 }
2156 }
2157 else
2158 {
2161 }
2163 /* Build a reference to the template from a PLACEHOLDER_EXPR that
2164 is the fat pointer. This will be used to access the individual
2165 fields once we build them. */
2169 gnu_template_reference
2174 /* Now create the GCC type for each index and add the fields for that
2175 index to the template. */
2181 {
2184 tree gnu_index_base_type
2189 /* Make the FIELD_DECLs for the low and high bounds of this
2190 type and then make extractions of these fields from the
2191 template. */
2194 gnu_index_base_type,
2202 gnu_index_base_type,
2210 /* We can't use build_component_ref here since the template type
2211 isn't complete yet. */
2214 NULL_TREE);
2217 NULL_TREE);
2223 /* Compute the size of this dimension. See the E_Array_Subtype
2224 case below for the rationale. */
2225 gnu_high
2229 gnu_max,
2232 /* Make a range type with the new range in the Ada base type.
2233 Then make an index type with the size range in sizetype. */
2237 gnu_orig_min,
2238 gnu_orig_max),
2239 gnat_entity);
2241 /* Update the maximum size of the array in elements. */
2243 {
2244 tree gnu_min
2246 tree gnu_max
2248 tree gnu_this_max
2255 else
2256 gnu_max_size
2258 }
2262 }
2264 /* Install all the fields into the template. */
2269 gnu_template_fields
2272 debug_info_p);
2275 /* If Component_Size is not already specified, annotate it with the
2276 size of the component. */
2281 /* Compute the maximum size of the array in units and bits. */
2283 {
2289 }
2290 else
2293 /* Now build the array type. */
2296 {
2304 }
2306 /* If an alignment is specified, use it if valid. But ignore it
2307 for the original type of packed array types. If the alignment
2308 was requested with an explicit alignment clause, state so. */
2311 {
2314 gnat_entity,
2318 }
2320 /* Tag top-level ARRAY_TYPE nodes for packed arrays and their
2321 implementation types as such so that the debug information back-end
2322 can output the appropriate description for them. */
2330 /* Adjust the type of the pointer-to-array field of the fat pointer
2331 and record the aliasing relationships if necessary. */
2336 /* The result type is an UNCONSTRAINED_ARRAY_TYPE that indicates the
2337 corresponding fat pointer. */
2344 /* If the maximum size doesn't overflow, use it. */
2350 {
2355 }
2360 /* If told to generate GNAT encodings for them (GDB rely on them at the
2361 moment): give the fat pointer type a name. If this is a packed
2362 array, tell the debugger how to interpret the underlying bits. */
2365 else
2367 tree xup_name
2372 gnat_entity);
2374 /* Create the type to be designated by thin pointers: a record type for
2375 the array and its template. We used to shift the fields to have the
2376 template at a negative offset, but this was somewhat of a kludge; we
2377 now shift thin pointer values explicitly but only those which have a
2378 TYPE_UNCONSTRAINED_ARRAY attached to the designated RECORD_TYPE.
2379 Note that GDB can handle standard DWARF information for them, so we
2380 don't have to name them as a GNAT encoding, except if specifically
2381 asked to. */
2382 tree xut_name
2387 debug_info_p);
2391 }
2396 /* This is the actual data type for array variables. Multidimensional
2397 arrays are implemented as arrays of arrays. Note that arrays which
2398 have sparse enumeration subtypes as index components create sparse
2399 arrays, which is obviously space inefficient but so much easier to
2400 code for now.
2402 Also note that the subtype never refers to the unconstrained array
2403 type, which is somewhat at variance with Ada semantics.
2405 First check to see if this is simply a renaming of the array type.
2406 If so, the result is the array type. */
2410 ;
2411 else
2412 {
2414 const bool convention_fortran_p
2423 /* First create the GCC type for each index and find out whether
2424 special types are needed for debugging information. */
2427 gnat_base_index
2433 {
2435 tree gnu_index_base_type
2437 tree gnu_orig_min
2440 tree gnu_orig_max
2445 tree gnu_base_index_type
2447 tree gnu_base_index_base_type
2449 tree gnu_base_orig_min
2452 tree gnu_base_orig_max
2455 tree gnu_high;
2457 /* See if the base array type is already flat. If it is, we
2458 are probably compiling an ACATS test but it will cause the
2459 code below to malfunction if we don't handle it specially. */
2463 {
2467 }
2469 /* Similarly, if one of the values overflows in sizetype and the
2470 range is null, use 1..0 for the sizetype bounds. */
2475 {
2479 }
2481 /* If the minimum and maximum values both overflow in sizetype,
2482 but the difference in the original type does not overflow in
2483 sizetype, ignore the overflow indication. */
2487 && !TREE_OVERFLOW
2490 gnu_orig_max,
2491 gnu_orig_min))))
2492 {
2496 }
2498 /* Compute the size of this dimension in the general case. We
2499 need to provide GCC with an upper bound to use but have to
2500 deal with the "superflat" case. There are three ways to do
2501 this. If we can prove that the array can never be superflat,
2502 we can just use the high bound of the index type. */
2505 /* Bit-Packed Array Impl. Types are never superflat. */
2507 && Is_Bit_Packed_Array
2511 /* Otherwise, if the high bound is constant but the low bound is
2512 not, we use the expression (hb >= lb) ? lb : hb + 1 for the
2513 lower bound. Note that the comparison must be done in the
2514 original type to avoid any overflow during the conversion. */
2517 {
2519 gnu_min
2522 boolean_type_node,
2523 gnu_orig_max,
2524 gnu_orig_min),
2525 gnu_min,
2527 size_one_node));
2528 }
2530 /* Finally we use (hb >= lb) ? hb : lb - 1 for the upper bound
2531 in all the other cases. Note that, here as well as above,
2532 the condition used in the comparison must be equivalent to
2533 the condition (length != 0). This is relied upon in order
2534 to optimize array comparisons in compare_arrays. Moreover
2535 we use int_const_binop for the shift by 1 if the bound is
2536 constant to avoid any unwanted overflow. */
2537 else
2538 gnu_high
2541 boolean_type_node,
2542 gnu_orig_max,
2543 gnu_orig_min),
2544 gnu_max,
2547 size_one_node)
2549 size_one_node));
2551 /* Reuse the index type for the range type. Then make an index
2552 type with the size range in sizetype. */
2555 gnat_entity);
2557 /* Update the maximum size of the array in elements. Here we
2558 see if any constraint on the index type of the base type
2559 can be used in the case of self-referential bound on the
2560 index type of the subtype. We look for a non-"infinite"
2561 and non-self-referential bound from any type involved and
2562 handle each bound separately. */
2564 {
2567 tree gnu_base_base_min
2570 tree gnu_base_base_max
2591 else
2592 {
2593 tree gnu_this_max;
2595 /* Use int_const_binop if the bounds are constant to
2596 avoid any unwanted overflow. */
2599 gnu_this_max
2602 gnu_base_max,
2603 gnu_base_min));
2604 else
2605 gnu_this_max
2608 gnu_base_max,
2609 gnu_base_min));
2611 gnu_max_size
2613 }
2614 }
2616 /* We need special types for debugging information to point to
2617 the index types if they have variable bounds, are not integer
2618 types, are biased or are wider than sizetype. These are GNAT
2619 encodings, so we have to include them only when all encodings
2620 are requested. */
2630 }
2632 /* Then flatten: create the array of arrays. For an array type
2633 used to implement a packed array, get the component type from
2634 the original array type since the representation clauses that
2635 can affect it are on the latter. */
2638 {
2643 /* One of the above calls might have caused us to be elaborated,
2644 so don't blow up if so. */
2646 {
2649 }
2650 }
2651 else
2652 {
2654 debug_info_p);
2656 /* One of the above calls might have caused us to be elaborated,
2657 so don't blow up if so. */
2659 {
2662 }
2663 }
2665 /* Compute the maximum size of the array in units and bits. */
2667 {
2673 }
2674 else
2677 /* Now build the array type. */
2679 {
2688 }
2690 /* Strip the ___XP suffix for standard DWARF. */
2693 {
2694 Entity_Id gnat_original_array_type
2697 gnu_entity_name
2699 }
2701 /* Attach the TYPE_STUB_DECL in case we have a parallel type. */
2705 /* If this is a multi-dimensional array and we are at global level,
2706 we need to make a variable corresponding to the stride of the
2707 inner dimensions. */
2709 {
2710 tree gnu_arr_type;
2715 {
2725 /* ??? For now, store the size as a multiple of the
2726 alignment of the element type in bytes so that we
2727 can see the alignment from the tree. */
2735 /* ??? create_type_decl is not invoked on the inner types so
2736 the MULT_EXPR node built above will never be marked. */
2738 }
2739 }
2741 /* If we need to write out a record type giving the names of the
2742 bounds for debugging purposes, do it now and make the record
2743 type a parallel type. This is not needed for a packed array
2744 since the bounds are conveyed by the original array type. */
2746 && debug_info_p
2748 {
2751 tree gnu_field;
2757 {
2761 /* Make sure to reference the types themselves, and not just
2762 their names, as the debugger may fall back on them. */
2768 }
2772 }
2774 /* If this is a packed array type, make the original array type a
2775 parallel/debug type. Otherwise, if such GNAT encodings are
2776 required, do it for the base array type if it isn't artificial to
2777 make sure it is kept in the debug info. */
2779 {
2782 gnat_entity);
2783 else
2784 {
2785 tree gnu_base_decl
2792 }
2793 }
2799 /* Tag top-level ARRAY_TYPE nodes for packed arrays and their
2800 implementation types as such so that the debug information back-end
2801 can output the appropriate description for them. */
2806 /* If the size is self-referential and the maximum size doesn't
2807 overflow, use it. */
2809 && gnu_max_size
2814 {
2820 }
2822 /* Set our alias set to that of our base type. This gives all
2823 array subtypes the same alias set. */
2826 /* If this is a packed type, make this type the same as the packed
2827 array type, but do some adjusting in the type first. */
2829 {
2830 Entity_Id gnat_index;
2831 tree gnu_inner;
2833 /* First finish the type we had been making so that we output
2834 debugging information for it. */
2837 {
2838 const int quals
2839 = TYPE_QUAL_VOLATILE
2842 }
2843 /* Make it artificial only if the base type was artificial too.
2844 That's sort of "morally" true and will make it possible for
2845 the debugger to look it up by name in DWARF, which is needed
2846 in order to decode the packed array type. */
2847 gnu_decl
2851 gnat_entity);
2853 /* Save it as our equivalent in case the call below elaborates
2854 this type again. */
2857 gnu_decl
2872 /* We need to attach the index type to the type we just made so
2873 that the actual bounds can later be put into a template. */
2878 {
2880 {
2881 /* The TYPE_ACTUAL_BOUNDS field is overloaded with the
2882 TYPE_MODULUS for modular types so we make an extra
2883 subtype if necessary. */
2885 {
2886 tree gnu_subtype
2895 }
2899 /* Check for other cases of overloading. */
2901 }
2906 SET_TYPE_ACTUAL_BOUNDS
2913 SET_TYPE_ACTUAL_BOUNDS
2919 }
2920 }
2921 }
2925 /* Create the type for a string literal. */
2926 {
2927 Entity_Id gnat_full_type
2932 tree gnu_string_array_type
2934 tree gnu_string_index_type
2937 tree gnu_lower_bound
2940 tree gnu_length
2942 gnu_string_index_type);
2943 tree gnu_upper_bound
2945 gnu_lower_bound,
2948 integer_one_node)));
2949 tree gnu_index_type
2953 gnu_lower_bound,
2954 gnu_upper_bound),
2955 gnat_entity);
2957 gnu_type
2960 gnu_index_type);
2964 }
2967 /* Record Types and Subtypes
2969 The following fields are defined on record types:
2971 Has_Discriminants True if the record has discriminants
2972 First_Discriminant Points to head of list of discriminants
2973 First_Entity Points to head of list of fields
2974 Is_Tagged_Type True if the record is tagged
2976 Implementation of Ada records and discriminated records:
2978 A record type definition is transformed into the equivalent of a C
2979 struct definition. The fields that are the discriminants which are
2980 found in the Full_Type_Declaration node and the elements of the
2981 Component_List found in the Record_Type_Definition node. The
2982 Component_List can be a recursive structure since each Variant of
2983 the Variant_Part of the Component_List has a Component_List.
2985 Processing of a record type definition comprises starting the list of
2986 field declarations here from the discriminants and the calling the
2987 function components_to_record to add the rest of the fields from the
2988 component list and return the gnu type node. The function
2989 components_to_record will call itself recursively as it traverses
2990 the tree. */
2994 {
2995 gnu_type
2996 = build_complex_type
2997 (get_unpadded_type
3000 (Component_List
3001 (Type_Definition
3005 }
3007 {
3010 Node_Id gnat_constr;
3013 tree gnu_get_parent;
3014 /* Set PACKED in keeping with gnat_to_gnu_field. */
3015 const int packed
3024 const bool is_extension
3030 /* See if all fields have a rep clause. Stop when we find one
3031 that doesn't. */
3039 {
3042 }
3044 /* If this is a record extension, go a level further to find the
3045 record definition. Also, verify we have a Parent_Subtype. */
3047 {
3054 }
3056 /* Make a node for the record. If we are not defining the record,
3057 suppress expanding incomplete types. */
3066 {
3067 defer_incomplete_level++;
3069 }
3071 /* If both a size and rep clause were specified, put the size on
3072 the record type now so that it can get the proper layout. */
3077 /* Always set the alignment on the record type here so that it can
3078 get the proper layout. */
3083 else
3084 {
3087 /* If a type needs strict alignment, the minimum size will be the
3088 type size instead of the RM size (see validate_size). Cap the
3089 alignment lest it causes this type size to become too large. */
3091 {
3096 }
3097 }
3099 /* If we have a Parent_Subtype, make a field for the parent. If
3100 this record has rep clauses, force the position to zero. */
3102 {
3105 tree gnu_parent;
3108 /* A major complexity here is that the parent subtype will
3109 reference our discriminants in its Stored_Constraint list.
3110 But those must reference the parent component of this record
3111 which is precisely of the parent subtype we have not built yet!
3112 To break the circle we first build a dummy COMPONENT_REF which
3113 represents the "get to the parent" operation and initialize
3114 each of those discriminants to a COMPONENT_REF of the above
3115 dummy parent referencing the corresponding discriminant of the
3116 base type of the parent subtype. */
3121 gnu_dummy_parent_type),
3122 NULL_TREE);
3129 {
3130 tree gnu_field
3133 save_gnu_tree
3138 }
3140 /* Then we build the parent subtype. If it has discriminants but
3141 the type itself has unknown discriminants, this means that it
3142 doesn't contain information about how the discriminants are
3143 derived from those of the ancestor type, so it cannot be used
3144 directly. Instead it is built by cloning the parent subtype
3145 of the underlying record view of the type, for which the above
3146 derivation of discriminants has been made explicit. */
3149 {
3152 /* If we are defining the type, the underlying record
3153 view must already have been elaborated at this point.
3154 Otherwise do it now as its parent subtype cannot be
3155 technically elaborated on its own. */
3158 else
3163 /* Substitute the "get to the parent" of the type for that
3164 of its underlying record view in the cloned type. */
3169 {
3171 tree gnu_ref
3174 gnu_parent
3176 }
3177 }
3178 else
3181 /* The parent field needs strict alignment so, if it is to
3182 be created with a component clause below, then we need
3183 to apply the same adjustment as in gnat_to_gnu_field. */
3185 {
3186 /* ??? For historical reasons, we do it on strict-alignment
3187 platforms only, where it is really required. This means
3188 that a confirming representation clause will change the
3189 behavior of the compiler on the other platforms. */
3192 else
3193 parent_packed
3195 }
3197 /* Finally we fix up both kinds of twisted COMPONENT_REF we have
3198 initially built. The discriminants must reference the fields
3199 of the parent subtype and not those of its base type for the
3200 placeholder machinery to properly work. */
3202 {
3203 /* The actual parent subtype is the full view. */
3205 {
3208 else
3210 }
3216 {
3217 Entity_Id field;
3226 }
3227 }
3229 /* The "get to the parent" COMPONENT_REF must be given its
3230 proper type... */
3233 /* ...and reference the _Parent field of this record. */
3234 gnu_field
3237 has_rep
3239 has_rep
3245 }
3247 /* Make the fields for the discriminants and put them into the record
3248 unless it's an Unchecked_Union. */
3253 {
3254 /* If this is a record extension and this discriminant is the
3255 renaming of another discriminant, we've handled it above. */
3260 gnu_field
3262 debug_info_p);
3264 /* Make an expression using a PLACEHOLDER_EXPR from the
3265 FIELD_DECL node just created and link that with the
3266 corresponding GNAT defining identifier. */
3274 {
3277 }
3278 }
3280 /* If we have a derived untagged type that renames discriminants in
3281 the parent type, the (stored) discriminants are just a copy of the
3282 discriminants of the parent type. This means that any constraints
3283 added by the renaming in the derivation are disregarded as far as
3284 the layout of the derived type is concerned. To rescue them, we
3285 change the type of the (stored) discriminants to a subtype with
3286 the bounds of the type of the visible discriminants. */
3288 && !is_extension
3294 /* Ignore access discriminants. */
3297 {
3300 tree gnu_ref
3304 /* GNU_REF must be an expression using a PLACEHOLDER_EXPR built
3305 just above for one of the stored discriminants. */
3309 {
3311 tree gnu_subtype
3322 }
3323 }
3325 /* If this is a derived type with discriminants and these discriminants
3326 affect the initial shape it has inherited, factor them in. But for
3327 an Unchecked_Union (it must be an Itype), just process the type. */
3329 && !is_extension
3336 {
3337 tree gnu_parent_type
3346 /* Set the layout of the type to match that of the parent type,
3347 doing required substitutions. */
3351 }
3352 else
3353 {
3354 /* Add the fields into the record type and finish it up. */
3361 NULL);
3363 /* If there are entities in the chain corresponding to components
3364 that we did not elaborate, ensure we elaborate their types if
3365 they are Itypes. */
3374 }
3376 /* Fill in locations of fields. */
3379 /* If this is a record type associated with an exception definition,
3380 equate its fields to those of the standard exception type. This
3381 will make it possible to convert between them. */
3383 {
3384 tree gnu_std_field;
3387 gnu_field;
3392 }
3393 }
3397 /* If an equivalent type is present, that is what we should use.
3398 Otherwise, fall through to handle this like a record subtype
3399 since it may have constraints. */
3401 {
3405 }
3407 /* ... fall through ... */
3410 /* If Cloned_Subtype is Present it means this record subtype has
3411 identical layout to that type or subtype and we should use
3412 that GCC type for this one. The front end guarantees that
3413 the component list is shared. */
3415 {
3420 }
3422 /* Otherwise, first ensure the base type is elaborated. Then, if we are
3423 changing the type, make a new type with each field having the type of
3424 the field in the new subtype but the position computed by transforming
3425 every discriminant reference according to the constraints. We don't
3426 see any difference between private and non-private type here since
3427 derivations from types should have been deferred until the completion
3428 of the private type. */
3429 else
3430 {
3434 {
3435 defer_incomplete_level++;
3437 }
3439 tree gnu_base_type
3443 {
3446 }
3448 /* If this is a record subtype associated with a dispatch table,
3449 strip the suffix. This is necessary to make sure 2 different
3450 subtypes associated with the imported and exported views of a
3451 dispatch table are properly merged in LTO mode. */
3453 {
3460 }
3462 /* When the subtype has discriminants and these discriminants affect
3463 the initial shape it has inherited, factor them in. But for an
3464 Unchecked_Union (it must be an Itype), just return the type. */
3470 {
3473 tree gnu_unpad_base_type;
3484 /* Set the size, alignment and alias set of the type to match
3485 those of the base type, doing required substitutions. */
3487 gnu_subst_list);
3491 else
3494 /* Set the layout of the type to match that of the base type,
3495 doing required substitutions. We will output debug info
3496 manually below so pass false as last argument. */
3501 /* Fill in locations of fields. */
3504 /* If debugging information is being written for the type and if
3505 we are asked to output such encodings, write a record that
3506 shows what we are a subtype of and also make a variable that
3507 indicates our size, if still variable. */
3509 {
3511 tree gnu_unpad_base_name
3519 build_reference_type
3521 gnu_subtype_marker,
3538 }
3539 }
3541 /* Otherwise, go down all the components in the new type and make
3542 them equivalent to those in the base type. */
3543 else
3544 {
3554 gnat_to_gnu_field_decl
3557 }
3558 }
3563 /* Use the special descriptor type for dispatch tables if needed,
3564 that is to say for the Prim_Ptr of a-tags.ads and its clones.
3565 Note that we are only required to do so for static tables in
3566 order to be compatible with the C++ ABI, but Ada 2005 allows
3567 to extend library level tagged types at the local level so
3568 we do it in the non-static case as well. */
3571 {
3575 }
3577 /* ... fall through ... */
3584 {
3585 /* The designated type and its equivalent type for gigi. */
3588 /* Whether it comes from a limited with. */
3589 const bool is_from_limited_with
3592 /* Whether it is a completed Taft Amendment type. Such a type is to
3593 be treated as coming from a limited with clause if it is not in
3594 the main unit, i.e. we break potential circularities here in case
3595 the body of an external unit is loaded for inter-unit inlining. */
3596 const bool is_completed_taft_type
3600 /* The "full view" of the designated type. If this is an incomplete
3601 entity from a limited with, treat its non-limited view as the full
3602 view. Otherwise, if this is an incomplete or private type, use the
3603 full view. In the former case, we might point to a private type,
3604 in which case, we need its full view. Also, we want to look at the
3605 actual type used for the representation, so this takes a total of
3606 three steps. */
3607 Entity_Id gnat_desig_full_direct_first
3608 = (is_from_limited_with
3612 Entity_Id gnat_desig_full_direct
3613 = ((is_from_limited_with
3618 Entity_Id gnat_desig_full
3620 /* The type actually used to represent the designated type, either
3621 gnat_desig_full or gnat_desig_equiv. */
3622 Entity_Id gnat_desig_rep;
3623 /* We want to know if we'll be seeing the freeze node for any
3624 incomplete type we may be pointing to. */
3625 const bool in_main_unit
3629 /* True if we make a dummy type here. */
3631 /* The mode to be used for the pointer type. */
3632 scalar_int_mode p_mode;
3633 /* The GCC type used for the designated type. */
3640 /* If either the designated type or its full view is an unconstrained
3641 array subtype, replace it with the type it's a subtype of. This
3642 avoids problems with multiple copies of unconstrained array types.
3643 Likewise, if the designated type is a subtype of an incomplete
3644 record type, use the parent type to avoid order of elaboration
3645 issues. This can lose some code efficiency, but there is no
3646 alternative. */
3657 /* Set the type that's the representation of the designated type. */
3658 gnat_desig_rep
3661 /* If we already know what the full type is, use it. */
3665 /* Get the type of the thing we are to point to and build a pointer to
3666 it. If it is a reference to an incomplete or private type with a
3667 full view that is a record, an array or an access, make a dummy type
3668 and get the actual type later when we have verified it is safe. */
3675 /* Likewise if this is a reference to a record, an array or a
3676 subprogram type and we are to defer elaborating incomplete
3677 types. We do this because this access type may be the full
3678 view of a private type. */
3685 /* If this is a reference from a limited_with type back to our
3686 main unit and there's a freeze node for it, either we have
3687 already processed the declaration and made the dummy type,
3688 in which case we just reuse the latter, or we have not yet,
3689 in which case we make the dummy type and it will be reused
3690 when the declaration is finally processed. In both cases,
3691 the pointer eventually created below will be automatically
3692 adjusted when the freeze node is processed. */
3693 || (in_main_unit
3694 && is_from_limited_with
3696 {
3699 }
3701 /* Otherwise handle the case of a pointer to itself. */
3703 {
3704 gnu_type
3708 }
3710 /* If expansion is disabled, the equivalent type of a concurrent type
3711 is absent, so we use the void pointer type. */
3715 /* If the ultimately designated type is an incomplete type with no full
3716 view, we use the void pointer type in LTO mode to avoid emitting a
3717 dummy type in the GIMPLE IR. We cannot do that in regular mode as
3718 the name of the dummy type in used by GDB for a global lookup. */
3724 /* Finally, handle the default case where we can just elaborate our
3725 designated type. */
3726 else
3729 /* It is possible that a call to gnat_to_gnu_type above resolved our
3730 type. If so, just return it. */
3732 {
3735 }
3737 /* Access-to-unconstrained-array types need a special treatment. */
3739 {
3740 /* If the processing above got something that has a pointer, then
3741 we are done. This could have happened either because the type
3742 was elaborated or because somebody else executed the code. */
3747 }
3749 /* If we haven't done it yet, build the pointer type the usual way. */
3751 {
3752 /* Modify the designated type if we are pointing only to constant
3753 objects, but don't do it for a dummy type. */
3756 gnu_desig_type
3759 gnu_type
3762 }
3764 /* If the designated type is not declared in the main unit and we made
3765 a dummy node for it, save our definition, elaborate the actual type
3766 and replace the dummy type we made with the actual one. But if we
3767 are to defer actually looking up the actual type, make an entry in
3768 the deferred list instead. If this is from a limited with, we may
3769 have to defer until the end of the current unit. */
3771 {
3773 gnu_type
3779 gnat_entity);
3786 && !is_from_limited_with
3788 {
3791 }
3792 else
3793 {
3803 }
3804 }
3805 }
3810 /* If we are just annotating types and have no equivalent record type,
3811 just use the void pointer type. */
3815 /* The run-time representation is the equivalent type. */
3816 else
3817 {
3820 }
3822 /* The designated subtype must be elaborated as well, if it does
3823 not have its own freeze node. */
3834 /* We treat this as identical to its base type; any constraint is
3835 meaningful only to the front-end. */
3839 /* The designated subtype must be elaborated as well, if it does
3840 not have its own freeze node. But designated subtypes created
3841 for constrained components of records with discriminants are
3842 not frozen by the front-end and not elaborated here, because
3843 their use may appear before the base type is frozen and it is
3844 not clear that they are needed in gigi. With the current model,
3845 there is no correct place where they could be elaborated. */
3850 {
3851 /* If we are to defer elaborating incomplete types, make a dummy
3852 type node and elaborate it later. */
3854 {
3857 p->old_type
3862 }
3867 }
3870 /* Subprogram Entities
3872 The following access functions are defined for subprograms:
3874 Etype Return type or Standard_Void_Type.
3875 First_Formal The first formal parameter.
3876 Is_Imported Indicates that the subprogram has appeared in
3877 an INTERFACE or IMPORT pragma. For now we
3878 assume that the external language is C.
3879 Is_Exported Likewise but for an EXPORT pragma.
3880 Is_Inlined True if the subprogram is to be inlined.
3882 Each parameter is first checked by calling must_pass_by_ref on its
3883 type to determine if it is passed by reference. For parameters which
3884 are copied in, if they are Ada In Out or Out parameters, their return
3885 value becomes part of a record which becomes the return type of the
3886 function (C function - note that this applies only to Ada procedures
3887 so there is no Ada return type). Additional code to store back the
3888 parameters will be generated on the caller side. This transformation
3889 is done here, not in the front-end.
3891 The intended result of the transformation can be seen from the
3892 equivalent source rewritings that follow:
3894 struct temp {int a,b};
3895 procedure P (A,B: In Out ...) is temp P (int A,B)
3896 begin {
3897 .. ..
3898 end P; return {A,B};
3899 }
3901 temp t;
3902 P(X,Y); t = P(X,Y);
3903 X = t.a , Y = t.b;
3905 For subprogram types we need to perform mainly the same conversions to
3906 GCC form that are needed for procedures and function declarations. The
3907 only difference is that at the end, we make a type declaration instead
3908 of a function declaration. */
3913 {
3914 tree gnu_ext_name
3916 enum inline_status_t inline_status
3918 ? is_suppressed
3920 ? is_required
3923 /* Subprograms marked both Intrinsic and Always_Inline need not
3924 have a body of their own. */
3925 bool extern_flag
3927 || imported_p
3930 tree gnu_param_list;
3932 /* A parameter may refer to this type, so defer completion of any
3933 incomplete types. */
3935 {
3936 defer_incomplete_level++;
3938 }
3940 /* If the subprogram has an alias, it is probably inherited, so
3941 we can use the original one. If the original "subprogram"
3942 is actually an enumeration literal, it may be the first use
3943 of its type, so we must elaborate that type now. */
3945 {
3952 gnu_decl
3955 /* Elaborate any Itypes in the parameters of this entity. */
3962 /* Materialize renamed subprograms in the debugging information
3963 when the renamed object is compile time known. We can consider
3964 such renamings as imported declarations.
3966 Because the parameters in generics instantiation are generally
3967 materialized as renamings, we ofter end up having both the
3968 renamed subprogram and the renaming in the same context and with
3969 the same name: in this case, renaming is both useless debug-wise
3970 and potentially harmful as name resolution in the debugger could
3971 return twice the same entity! So avoid this case. */
3980 && gnu_decl
3982 {
3987 }
3990 }
3992 /* Get the GCC tree for the (underlying) subprogram type. If the
3993 entity is an actual subprogram, also get the parameter list. */
3994 gnu_type
3998 {
4002 }
4004 /* Deal with platform-specific calling conventions. */
4006 prepend_one_attribute
4009 gnat_entity);
4011 prepend_one_attribute
4014 gnat_entity);
4016 /* If we should request stack realignment for a foreign convention
4017 subprogram, do so. Note that this applies to task entry points
4018 in particular. */
4021 prepend_one_attribute
4024 gnat_entity);
4026 /* Deal with a pragma Linker_Section on a subprogram. */
4032 /* If we are defining the subprogram and it has an Address clause
4033 we must get the address expression from the saved GCC tree for the
4034 subprogram if it has a Freeze_Node. Otherwise, we elaborate
4035 the address expression here since the front-end has guaranteed
4036 in that case that the elaboration has no effects. If there is
4037 an Address clause and we are not defining the object, just
4038 make it a constant. */
4040 {
4044 gnu_address
4051 /* Convert the type of the object to a reference type that can
4052 alias everything as per RM 13.3(19). */
4053 gnu_type
4058 gnu_decl
4064 }
4066 /* If this is a mere subprogram type, just create the declaration. */
4068 {
4071 gnu_decl
4074 }
4076 /* Otherwise create the subprogram declaration with the external name,
4077 the type and the parameter list. However, if this a reference to
4078 the allocation routines, reuse the canonical declaration nodes as
4079 they come with special properties. */
4080 else
4081 {
4086 else
4087 {
4088 gnu_decl
4093 debug_info_p,
4095 gnat_entity);
4099 }
4100 }
4101 }
4112 {
4113 const bool is_from_limited_with
4115 /* Get the "full view" of this entity. If this is an incomplete
4116 entity from a limited with, treat its non-limited view as the
4117 full view. Otherwise, use either the full view or the underlying
4118 full view, whichever is present. This is used in all the tests
4119 below. */
4120 const Entity_Id full_view
4121 = is_from_limited_with
4129 /* If this is an incomplete type with no full view, it must be a Taft
4130 Amendment type or an incomplete type coming from a limited context,
4131 in which cases we return a dummy type. Otherwise, we just get the
4132 type from its Etype. */
4134 {
4136 {
4139 }
4140 else
4141 {
4142 gnu_decl
4145 }
4146 }
4148 /* Or else, if we already made a type for the full view, reuse it. */
4152 /* Or else, if we are not defining the type or there is no freeze
4153 node on it, get the type for the full view. Likewise if this is
4154 a limited_with'ed type not declared in the main unit, which can
4155 happen for incomplete formal types instantiated on a type coming
4156 from a limited_with clause. */
4159 || (is_from_limited_with
4161 {
4164 }
4166 /* Otherwise, make a dummy type entry which will be replaced later.
4167 Save it as the full declaration's type so we can do any needed
4168 updates when we see it. */
4169 else
4170 {
4176 }
4177 }
4181 /* Class-wide types are always transformed into their root type. */
4190 /* If we are just annotating types and have no equivalent record type,
4191 just return void_type, except for root types that have discriminants
4192 because the discriminants will very likely be used in the declarative
4193 part of the associated body so they need to be translated. */
4195 {
4198 {
4200 Entity_Id gnat_field;
4202 /* This is a minimal version of the E_Record_Type handling. */
4209 {
4210 tree gnu_field
4222 }
4226 }
4227 else
4229 }
4231 /* Concurrent types are always transformed into their record type. */
4232 else
4243 /* Nothing at all to do here, so just return an ERROR_MARK and claim
4244 we've already saved it, so we don't try to. */
4250 /* This is a SPARK annotation that only reaches here when compiling in
4251 ASIS mode. */
4259 }
4261 /* If we had a case where we evaluated another type and it might have
4262 defined this one, handle it here. */
4264 {
4267 }
4269 /* If we are processing a type and there is either no decl for it or
4270 we just made one, do some common processing for the type, such as
4271 handling alignment and possible padding. */
4273 {
4276 /* Process the attributes, if not already done. Note that the type is
4277 already defined so we cannot pass true for IN_PLACE here. */
4280 /* ??? Don't set the size for a String_Literal since it is either
4281 confirming or we don't handle it properly (if the low bound is
4282 non-constant). */
4284 {
4287 gnu_size
4290 }
4292 /* If a size was specified, see if we can make a new type of that size
4293 by rearranging the type, for example from a fat to a thin pointer. */
4295 {
4296 gnu_type
4303 }
4305 /* If the alignment has not already been processed and this is not
4306 an unconstrained array type, see if an alignment is specified.
4307 If not, we pick a default alignment for atomic objects. */
4309 ;
4311 {
4315 /* Warn on suspiciously large alignments. This should catch
4316 errors about the (alignment,byte)/(size,bit) discrepancy. */
4318 {
4319 tree size;
4321 /* If a size was specified, take it into account. Otherwise
4322 use the RM size for records or unions as the type size has
4323 already been adjusted to the alignment. */
4329 else
4332 /* Consider an alignment as suspicious if the alignment/size
4333 ratio is greater or equal to the byte/bit ratio. */
4338 gnat_entity);
4339 }
4340 }
4351 /* See if we need to pad the type. If we did, and made a record,
4352 the name of the new type may be changed. So get it back for
4353 us when we make the new TYPE_DECL below. */
4361 /* Now set the RM size of the type. We cannot do it before padding
4362 because we need to accept arbitrary RM sizes on integral types. */
4365 /* If we are at global level, GCC will have applied variable_size to
4366 the type, but that won't have done anything. So, if it's not
4367 a constant or self-referential, call elaborate_expression_1 to
4368 make a variable for the size rather than calculating it each time.
4369 Handle both the RM size and the actual size. */
4374 {
4381 /* ??? For now, store the size as a multiple of the alignment in
4382 bytes so that we can see the alignment from the tree. */
4388 /* ??? gnu_type may come from an existing type so the MULT_EXPR node
4389 may not be marked by the call to create_type_decl below. */
4393 {
4398 {
4402 /* If the position of the variant part is constant, subtract
4403 it from the size of the type of the parent to get the new
4404 size. This manual CSE reduces the data size. */
4406 {
4414 }
4415 else
4416 {
4422 /* ??? For now, store the size as a multiple of the
4423 alignment in bytes so that we can see the alignment
4424 from the tree. */
4431 /* ??? For now, store the offset as a multiple of the
4432 alignment in bytes so that we can see the alignment
4433 from the tree. */
4437 DECL_OFFSET_ALIGN
4439 }
4443 }
4447 else
4448 ada_size
4452 }
4453 }
4455 /* Similarly, if this is a record type or subtype at global level, call
4456 elaborate_expression_2 on any field position. Skip any fields that
4457 we haven't made trees for to avoid problems with class-wide types. */
4462 {
4465 /* ??? For now, store the offset as a multiple of the alignment
4466 in bytes so that we can see the alignment from the tree. */
4469 {
4476 /* ??? The context of gnu_field is not necessarily gnu_type
4477 so the MULT_EXPR node built above may not be marked by
4478 the call to create_type_decl below. */
4480 }
4481 }
4486 /* If this is not an unconstrained array type, set some flags. */
4488 {
4489 /* Tell the middle-end that objects of tagged types are guaranteed to
4490 be properly aligned. This is necessary because conversions to the
4491 class-wide type are translated into conversions to the root type,
4492 which can be less aligned than some of its derived types. */
4497 /* Record whether the type is passed by reference. */
4501 /* Record whether an alignment clause was specified. */
4505 /* Record whether a pragma Universal_Aliasing was specified. */
4509 /* If it is passed by reference, force BLKmode to ensure that
4510 objects of this type will always be put in memory. */
4513 }
4515 /* If this is a derived type, relate its alias set to that of its parent
4516 to avoid troubles when a call to an inherited primitive is inlined in
4517 a context where a derived object is accessed. The inlined code works
4518 on the parent view so the resulting code may access the same object
4519 using both the parent and the derived alias sets, which thus have to
4520 conflict. As the same issue arises with component references, the
4521 parent alias set also has to conflict with composite types enclosing
4522 derived components. For instance, if we have:
4524 type D is new T;
4525 type R is record
4526 Component : D;
4527 end record;
4529 we want T to conflict with both D and R, in addition to R being a
4530 superset of D by record/component construction.
4532 One way to achieve this is to perform an alias set copy from the
4533 parent to the derived type. This is not quite appropriate, though,
4534 as we don't want separate derived types to conflict with each other:
4536 type I1 is new Integer;
4537 type I2 is new Integer;
4539 We want I1 and I2 to both conflict with Integer but we do not want
4540 I1 to conflict with I2, and an alias set copy on derivation would
4541 have that effect.
4543 The option chosen is to make the alias set of the derived type a
4544 superset of that of its parent type. It trivially fulfills the
4545 simple requirement for the Integer derivation example above, and
4546 the component case as well by superset transitivity:
4548 superset superset
4549 R ----------> D ----------> T
4551 However, for composite types, conversions between derived types are
4552 translated into VIEW_CONVERT_EXPRs so a sequence like:
4554 type Comp1 is new Comp;
4555 type Comp2 is new Comp;
4556 procedure Proc (C : Comp1);
4558 C : Comp2;
4559 Proc (Comp1 (C));
4561 is translated into:
4563 C : Comp2;
4564 Proc ((Comp1 &) &VIEW_CONVERT_EXPR <Comp1> (C));
4566 and gimplified into:
4568 C : Comp2;
4569 Comp1 *C.0;
4570 C.0 = (Comp1 *) &C;
4571 Proc (C.0);
4573 i.e. generates code involving type punning. Therefore, Comp1 needs
4574 to conflict with Comp2 and an alias set copy is required.
4576 The language rules ensure the parent type is already frozen here. */
4580 {
4582 /* For constrained packed array subtypes, the implementation type is
4583 used instead of the nominal type. */
4591 }
4594 {
4595 const int quals
4596 = TYPE_QUAL_VOLATILE
4599 }
4604 gnat_entity);
4605 else
4606 {
4609 }
4610 }
4612 /* If we got a type that is not dummy, back-annotate the alignment of the
4613 type if not already in the tree. Likewise for the size, if any. */
4615 {
4619 {
4623 /* If the default alignment of "double" or larger scalar types is
4624 specifically capped and this is not an array with an alignment
4625 clause on the component type, return the cap. */
4627 is_capped_double
4630 is_capped_double
4632 else
4637 else
4641 }
4644 {
4647 /* If the size is self-referential, annotate the maximum value. */
4651 /* If we are just annotating types and the type is tagged, the tag
4652 and the parent components are not generated by the front-end so
4653 alignment and sizes must be adjusted if there is no rep clause. */
4660 {
4661 tree offset;
4664 {
4668 }
4669 else
4670 {
4671 unsigned int align
4675 }
4678 offset
4686 }
4688 /* If there is a rep clause, only adjust alignment and Esize. */
4690 {
4691 unsigned int align
4696 }
4698 /* Otherwise no adjustment is needed. */
4699 else
4701 }
4705 }
4707 /* If we haven't already, associate the ..._DECL node that we just made with
4708 the input GNAT entity node. */
4712 /* Now we are sure gnat_entity has a corresponding ..._DECL node,
4713 eliminate as many deferred computations as possible. */
4716 /* If this is an enumeration or floating-point type, we were not able to set
4717 the bounds since they refer to the type. These are always static. */
4720 {
4724 /* If this is a padded type, we need to use the underlying type. */
4728 /* If this is a floating point type and we haven't set a floating
4729 point type yet, use this in the evaluation of the bounds. */
4737 {
4738 /* Enumeration types have specific RM bounds. */
4741 }
4742 else
4743 {
4744 /* Floating-point types don't have specific RM bounds. */
4747 }
4748 }
4750 /* If we deferred processing of incomplete types, re-enable it. If there
4751 were no other disables and we have deferred types to process, do so. */
4755 {
4758 /* We are back to level 0 for the deferring of incomplete types.
4759 But processing these incomplete types below may itself require
4760 deferring, so preserve what we have and restart from scratch. */
4765 {
4772 }
4773 }
4775 /* If we are not defining this type, see if it's on one of the lists of
4776 incomplete types. If so, handle the list entry now. */
4778 {
4783 {
4787 }
4793 {
4799 }
4800 }
4803 force_global--;
4805 /* If this is a packed array type whose original array type is itself
4806 an Itype without freeze node, make sure the latter is processed. */
4814 }
4816 /* Similar, but if the returned value is a COMPONENT_REF, return the
4817 FIELD_DECL. */
4819 tree
4821 {
4828 }
4830 /* Similar, but GNAT_ENTITY is assumed to refer to a GNAT type. Return
4831 the GCC type corresponding to that entity. */
4833 tree
4835 {
4836 tree gnu_decl;
4838 /* The back end never attempts to annotate generic types. */
4846 }
4848 /* Similar, but GNAT_ENTITY is assumed to refer to a GNAT type. Return
4849 the unpadded version of the GCC type corresponding to that entity. */
4851 tree
4853 {
4860 }
4862 /* Return whether the E_Subprogram_Type/E_Function/E_Procedure GNAT_ENTITY is
4863 a C++ imported method or equivalent.
4865 We use the predicate on 32-bit x86/Windows to find out whether we need to
4866 use the "thiscall" calling convention for GNAT_ENTITY. This convention is
4867 used for C++ methods (functions with METHOD_TYPE) by the back-end. */
4869 bool
4871 {
4872 /* A constructor is a method on the C++ side. We deal with it now because
4873 it is declared without the 'this' parameter in the sources and, although
4874 the front-end will create a version with the 'this' parameter for code
4875 generation purposes, we want to return true for both versions. */
4879 /* Check that the subprogram has C++ convention. */
4883 /* And that the type of the first parameter (indirectly) has it too. */
4894 /* This is the main case: a C++ virtual method imported as a primitive
4895 operation of a tagged type. */
4899 /* This is set on the E_Subprogram_Type built for a dispatching call. */
4903 /* A thunk needs to be handled like its associated primitive operation. */
4907 /* Now on to the annoying case: a C++ non-virtual method, imported either
4908 as a non-primitive operation of a tagged type or as a primitive operation
4909 of an untagged type. We cannot reliably differentiate these cases from
4910 their static member or regular function equivalents in Ada, so we ask
4911 the C++ side through the mangled name of the function, as the implicit
4912 'this' parameter is not encoded in the mangled name of a method. */
4914 {
4921 DMGL_GNU_V3
4922 | DMGL_TYPES
4923 | DMGL_PARAMS
4929 /* We need to release MEM once we have a successful demangling. */
4936 {
4937 /* Make sure there is at least one parameter in C++ too. */
4939 {
4942 n_ada_args++;
4948 n_cpp_args++;
4954 }
4955 else
4957 }
4962 }
4965 }
4967 /* Finalize the processing of From_Limited_With incomplete types. */
4969 void
4971 {
4978 {
4982 {
4987 }
4990 }
4991 }
4993 /* Return the equivalent type to be used for GNAT_ENTITY, if it's a kind
4994 of type (such E_Task_Type) that has a different type which Gigi uses
4995 for its representation. If the type does not have a special type for
4996 its representation, return GNAT_ENTITY. */
4998 Entity_Id
5000 {
5007 {
5033 }
5036 }
5038 /* Return a GCC tree for a type corresponding to the component type of the
5039 array type or subtype GNAT_ARRAY. DEFINITION is true if this component
5040 is for an array being defined. DEBUG_INFO_P is true if we need to write
5041 debug information for other types that we may create in the process. */
5043 static tree
5046 {
5049 tree gnu_comp_size;
5052 /* If an alignment is specified, use it as a cap on the component type
5053 so that it can be honored for the whole type. But ignore it for the
5054 original type of packed array types. */
5058 else
5061 /* Try to get a smaller form of the component if needed. */
5074 /* Get and validate any specified Component_Size. */
5075 gnu_comp_size
5080 /* If the array has aliased components and the component size can be zero,
5081 force at least unit size to ensure that the components have distinct
5082 addresses. */
5088 gnu_comp_size
5091 /* If the component type is a RECORD_TYPE that has a self-referential size,
5092 then use the maximum size for the component size. */
5098 /* Honor the component size. This is not needed for bit-packed arrays. */
5100 {
5106 else
5112 /* If a padding record was made, declare it now since it will never be
5113 declared otherwise. This is necessary to ensure that its subtrees
5114 are properly marked. */
5117 gnat_array);
5118 }
5120 /* If the component type is a padded type made for a non-bit-packed array
5121 of scalars with reverse storage order, we need to propagate the reverse
5122 storage order to the padding type since it is the innermost enclosing
5123 aggregate type around the scalar. */
5131 {
5132 const int quals
5133 = TYPE_QUAL_VOLATILE
5136 }
5139 }
5141 /* Return a GCC tree for a parameter corresponding to GNAT_PARAM, to be placed
5142 in the parameter list of GNAT_SUBPROG. GNU_PARAM_TYPE is the GCC tree for
5143 the type of the parameter. FIRST is true if this is the first parameter in
5144 the list of GNAT_SUBPROG. Also set CICO to true if the parameter must use
5145 the copy-in copy-out implementation mechanism.
5147 The returned tree is a PARM_DECL, except for the cases where no parameter
5148 needs to be actually passed to the subprogram; the type of this "shadow"
5149 parameter is then returned instead. */
5151 static tree
5154 {
5160 /* The parameter can be indirectly modified if its address is taken. */
5166 tree gnu_param;
5168 /* Make sure to use the proper SLOC for vector ABI warnings. */
5172 /* Builtins are expanded inline and there is no real call sequence involved.
5173 So the type expected by the underlying expander is always the type of the
5174 argument "as is". */
5179 /* Handle the first parameter of a valued procedure specially: it's a copy
5180 mechanism for which the parameter is never allocated. */
5182 {
5186 }
5188 /* Or else, see if a Mechanism was supplied that forced this parameter
5189 to be passed one way or another. */
5191 ;
5193 /* Positive mechanism means by copy for sufficiently small parameters. */
5195 {
5200 else
5202 }
5204 /* Otherwise, it's an unsupported mechanism so error out. */
5205 else
5206 {
5209 }
5211 /* If this is either a foreign function or if the underlying type won't
5212 be passed by reference and is as aligned as the original type, strip
5213 off possible padding type. */
5215 {
5224 }
5226 /* If this is a read-only parameter, make a variant of the type that is
5227 read-only. ??? However, if this is a self-referential type, the type
5228 can be very complex, so skip it for now. */
5232 /* For foreign conventions, pass arrays as pointers to the element type.
5233 First check for unconstrained array and get the underlying array. */
5235 gnu_param_type
5238 /* Arrays are passed as pointers to element type for foreign conventions. */
5240 {
5241 /* Strip off any multi-dimensional entries, then strip
5242 off the last array to get the component type. */
5251 gnu_param_type
5255 }
5257 /* Fat pointers are passed as thin pointers for foreign conventions. */
5259 gnu_param_type
5262 /* If we were requested or muss pass by reference, do so.
5263 If we were requested to pass by copy, do so.
5264 Otherwise, for foreign conventions, pass In Out or Out parameters
5265 or aggregates by reference. For COBOL and Fortran, pass all
5266 integer and FP types that way too. For Convention Ada, use
5267 the standard Ada default. */
5271 && ((foreign
5273 || (foreign
5278 || (!foreign
5280 {
5281 /* We take advantage of 6.2(12) by considering that references built for
5282 parameters whose type isn't by-ref and for which the mechanism hasn't
5283 been forced to by-ref allow only a restricted form of aliasing. */
5284 restricted_aliasing_p
5288 }
5290 /* Pass In Out or Out parameters using copy-in copy-out mechanism. */
5299 /* If this is an Out parameter that isn't passed by reference and isn't
5300 a pointer or aggregate, we don't make a PARM_DECL for it. Instead,
5301 it will be a VAR_DECL created when we process the procedure, so just
5302 return its type. For the special parameter of a valued procedure,
5303 never pass it in.
5305 An exception is made to cover the RM-6.4.1 rule requiring "by copy"
5306 Out parameters with discriminants or implicit initial values to be
5307 handled like In Out parameters. These type are normally built as
5308 aggregates, hence passed by reference, except for some packed arrays
5309 which end up encoded in special integer types. Note that scalars can
5310 be given implicit initial values using the Default_Value aspect.
5312 The exception we need to make is then for packed arrays of records
5313 with discriminants or implicit initial values. We have no light/easy
5314 way to check for the latter case, so we merely check for packed arrays
5315 of records. This may lead to useless copy-in operations, but in very
5316 rare cases only, as these would be exceptions in a set of already
5317 exceptional situations. */
5319 && !by_ref
5320 && (by_return
5339 /* If no Mechanism was specified, indicate what we're using, then
5340 back-annotate it. */
5346 }
5348 /* Associate GNAT_SUBPROG with GNU_TYPE, which must be a dummy type, so that
5349 GNAT_SUBPROG is updated when GNU_TYPE is completed.
5351 Ada 2012 (AI05-019) says that freezing a subprogram does not always freeze
5352 the corresponding profile, which means that, by the time the freeze node
5353 of the subprogram is encountered, types involved in its profile may still
5354 be not yet frozen. That's why we need to update GNAT_SUBPROG when we see
5355 the freeze node of types involved in its profile, either types of formal
5356 parameters or the return type. */
5358 static void
5360 {
5368 {
5373 }
5375 /* Even if there is already a slot for GNU_TYPE, we need to set the flag
5376 because the vector might have been just emptied by update_profiles_with.
5377 This can happen when there are 2 freeze nodes associated with different
5378 views of the same type; the type will be really complete only after the
5379 second freeze node is encountered. */
5384 /* Make sure GNAT_SUBPROG is not associated twice with the same dummy type,
5385 since this would mean updating twice its profile. */
5387 {
5391 /* Entity_Id is a simple integer so we can implement a stable order on
5392 the vector with an ordered insertion scheme and binary search. */
5394 {
5401 else
5403 }
5405 /* l == u and therefore is the insertion point. */
5407 }
5408 else
5412 }
5414 /* Update the GCC tree previously built for the profile of GNAT_SUBPROG. */
5416 static void
5418 {
5419 tree gnu_param_list;
5424 {
5425 /* Builtins cannot have their address taken so we can reset them. */
5430 }
5436 /* If GNAT_SUBPROG is an actual subprogram, GNU_SUBPROG is a FUNCTION_DECL
5437 and needs to be adjusted too. */
5439 {
5441 tree gnu_ext_name
5446 }
5447 }
5449 /* Update the GCC trees previously built for the profiles involving GNU_TYPE,
5450 a dummy type which appears in profiles. */
5452 void
5454 {
5462 /* The flag needs to be reset before calling update_profile, in case
5463 associate_subprog_with_dummy_type is again invoked on GNU_TYPE. */
5472 }
5474 /* Return the GCC tree for GNAT_TYPE present in the profile of a subprogram.
5476 Ada 2012 (AI05-0151) says that incomplete types coming from a limited
5477 context may now appear as parameter and result types. As a consequence,
5478 we may need to defer their translation until after a freeze node is seen
5479 or to the end of the current unit. We also aim at handling temporarily
5480 incomplete types created by the usual delayed elaboration scheme. */
5482 static tree
5484 {
5485 /* This is the same logic as the E_Access_Type case of gnat_to_gnu_entity
5486 so the rationale is exposed in that place. These processings probably
5487 ought to be merged at some point. */
5489 const bool is_from_limited_with
5492 Entity_Id gnat_full_direct_first
5493 = (is_from_limited_with
5497 Entity_Id gnat_full_direct
5498 = ((is_from_limited_with
5506 tree gnu_type;
5512 && ((!in_main_unit
5519 {
5523 {
5530 }
5531 }
5536 else
5539 /* Access-to-unconstrained-array types need a special treatment. */
5541 {
5544 }
5547 }
5549 /* Return a GCC tree for a subprogram type corresponding to GNAT_SUBPROG.
5550 DEFINITION is true if this is for a subprogram being defined. DEBUG_INFO_P
5551 is true if we need to write debug information for other types that we may
5552 create in the process. Also set PARAM_LIST to the list of parameters.
5553 If GNAT_SUBPROG is bound to a GCC builtin, return the DECL for the builtin
5554 directly instead of its type. */
5556 static tree
5559 {
5562 Entity_Id gnat_param;
5565 tree gnu_return_type;
5568 /* Non-null for subprograms containing parameters passed by copy-in copy-out
5569 (In Out or Out parameters not passed by reference), in which case it is
5570 the list of nodes used to specify the values of the In Out/Out parameters
5571 that are returned as a record upon procedure return. The TREE_PURPOSE of
5572 an element of this list is a FIELD_DECL of the record and the TREE_VALUE
5573 is the PARM_DECL corresponding to that field. This list will be saved in
5574 the TYPE_CI_CO_LIST field of the FUNCTION_TYPE node we create. */
5577 /* Fields in return type of procedure with copy-in copy-out parameters. */
5579 /* The semantics of "pure" in Ada essentially matches that of "const"
5580 in the back-end. In particular, both properties are orthogonal to
5581 the "nothrow" property if the EH circuitry is explicit in the
5582 internal representation of the back-end. If we are to completely
5583 hide the EH circuitry from it, we need to declare that calls to pure
5584 Ada subprograms that can throw have side effects since they can
5585 trigger an "abnormal" transfer of control flow; thus they can be
5586 neither "const" nor "pure" in the back-end sense. */
5594 /* Look into the return type and get its associated GCC tree if it is not
5595 void, and then compute various flags for the subprogram type. But make
5596 sure not to do this processing multiple times. */
5603 {
5608 }
5610 else
5611 {
5612 /* For foreign convention subprograms, return System.Address as void *
5613 or equivalent. Note that this comprises GCC builtins. */
5617 else
5620 /* If this function returns by reference, make the actual return type
5621 the reference type and make a note of that. */
5623 {
5626 }
5628 /* If the return type is an unconstrained array type, the return value
5629 will be allocated on the secondary stack so the actual return type
5630 is the fat pointer type. */
5632 {
5635 }
5637 /* This is the same unconstrained array case, but for a dummy type. */
5640 {
5643 }
5645 /* Likewise, if the return type requires a transient scope, the return
5646 value will also be allocated on the secondary stack so the actual
5647 return type is the reference type. */
5649 {
5652 }
5654 /* If the Mechanism is By_Reference, ensure this function uses the
5655 target's by-invisible-reference mechanism, which may not be the
5656 same as above (e.g. it might be passing an extra parameter). */
5660 /* Likewise, if the return type is itself By_Reference. */
5664 /* If the type is a padded type and the underlying type would not be
5665 passed by reference or the function has a foreign convention, return
5666 the underlying type. */
5668 && (!default_pass_by_ref
5673 /* If the return type is unconstrained, it must have a maximum size.
5674 Use the padded type as the effective return type. And ensure the
5675 function uses the target's by-invisible-reference mechanism to
5676 avoid copying too much data when it returns. */
5678 {
5682 /* If the size overflows to 0, set it to an arbitrary positive
5683 value so that assignments in the type are preserved. Their
5684 actual size is independent of this positive value. */
5688 {
5691 }
5697 /* Declare it now since it will never be declared otherwise. This
5698 is necessary to ensure that its subtrees are properly marked. */
5705 }
5707 /* If the return type has a size that overflows, we usually cannot have
5708 a function that returns that type. This usage doesn't really make
5709 sense anyway, so issue an error here. */
5714 {
5719 }
5721 /* If the return type is incomplete, there are 2 cases: if the function
5722 returns by reference, then the return type is only linked indirectly
5723 in the profile, so the profile can be seen as complete since it need
5724 not be further modified, only the reference types need be adjusted;
5725 otherwise the profile is incomplete and need be adjusted too. */
5727 {
5730 }
5734 || return_by_direct_ref_p
5735 || return_by_invisi_ref_p
5737 }
5739 /* A procedure (something that doesn't return anything) shouldn't be
5740 considered const since there would be no reason for calling such a
5741 subprogram. Note that procedures with Out (or In Out) parameters
5742 have already been converted into a function with a return type.
5743 Similarly, if the function returns an unconstrained type, then the
5744 function will allocate the return value on the secondary stack and
5745 thus calls to it cannot be CSE'ed, lest the stack be reclaimed. */
5749 /* Loop over the parameters and get their associated GCC tree. While doing
5750 this, build a copy-in copy-out structure if we need one. */
5754 {
5755 const bool mech_is_by_ref
5762 /* Fetch an existing parameter with complete type and reuse it. But we
5763 didn't save the CICO property so we can only do it for In parameters
5764 or parameters passed by reference. */
5769 {
5772 }
5774 /* Otherwise translate the parameter type and act accordingly. */
5775 else
5776 {
5779 /* For foreign convention subprograms, pass System.Address as void *
5780 or equivalent. Note that this comprises GCC builtins. */
5784 else
5787 /* If the parameter type is incomplete, there are 2 cases: if it is
5788 passed by reference, then the type is only linked indirectly in
5789 the profile, so the profile can be seen as complete since it need
5790 not be further modified, only the reference type need be adjusted;
5791 otherwise the profile is incomplete and need be adjusted too. */
5793 {
5794 Node_Id gnat_decl;
5798 && TYPE_IS_FAT_POINTER_P
5801 {
5803 gnu_param
5813 }
5815 /* ??? This is a kludge to support null procedures in spec taking
5816 a parameter with an untagged incomplete type coming from a
5817 limited context. The front-end creates a body without knowing
5818 anything about the non-limited view, which is illegal Ada and
5819 cannot be supported. Create a parameter with a fake type. */
5827 else
5828 {
5829 /* Build a minimal PARM_DECL without DECL_ARG_TYPE so that
5830 Call_to_gnu will stop if it encounters the PARM_DECL. */
5831 gnu_param
5833 gnu_param_type);
5835 gnu_param_type);
5837 }
5838 }
5840 /* Otherwise build the parameter declaration normally. */
5841 else
5842 {
5843 gnu_param
5847 /* We are returned either a PARM_DECL or a type if no parameter
5848 needs to be passed; in either case, adjust the type. */
5851 else
5852 {
5855 }
5856 }
5857 }
5859 /* If we have a GCC tree for the parameter, register it. */
5862 {
5863 gnu_param_type_list
5868 /* If a parameter is a pointer, a function may modify memory through
5869 it and thus shouldn't be considered a const function. Also, the
5870 memory may be modified between two calls, so they can't be CSE'ed.
5871 The latter case also handles by-ref parameters. */
5875 }
5877 /* If the parameter uses the copy-in copy-out mechanism, allocate a field
5878 for it in the return type and register the association. */
5880 {
5882 {
5885 /* If this is a function, we also need a field for the
5886 return value to be placed. */
5888 {
5889 tree gnu_field
5891 gnu_return_type,
5897 gnu_cico_list
5899 }
5902 /* Set a default alignment to speed up accesses. But we should
5903 not increase the size of the structure too much, lest it does
5904 not fit in return registers anymore. */
5907 }
5909 tree gnu_field
5918 }
5919 }
5921 /* If the subprogram uses the copy-in copy-out mechanism, possibly adjust
5922 and finish up the return type. */
5924 {
5925 /* If we have a CICO list but it has only one entry, we convert
5926 this function into a function that returns this object. */
5930 /* Do not finalize the return type if the subprogram is stubbed
5931 since structures are incomplete for the back-end. */
5933 {
5937 /* Try to promote the mode of the return type if it is passed
5938 in registers, again to speed up accesses. */
5941 NULL_TREE))
5942 {
5943 unsigned int size
5946 scalar_int_mode mode;
5951 {
5959 }
5960 }
5964 }
5967 }
5969 /* The lists have been built in reverse. */
5975 /* If the profile is incomplete, we only set the (temporary) return and
5976 parameter types; otherwise, we build the full type. In either case,
5977 we reuse an already existing GCC tree that we built previously here. */
5979 {
5981 ;
5982 else
5989 }
5990 else
5991 {
5993 {
6002 }
6003 else
6004 {
6005 gnu_type
6008 /* GNU_TYPE may be shared since GCC hashes types. Unshare it if it
6009 has a different TYPE_CI_CO_LIST or flags. */
6011 return_unconstrained_p,
6012 return_by_direct_ref_p,
6013 return_by_invisi_ref_p))
6014 {
6020 }
6021 }
6029 /* If this subprogram is expectedly bound to a GCC builtin, fetch the
6030 corresponding DECL node and check the parameter association. */
6033 {
6037 /* If we have a builtin DECL for that function, use it. Check if
6038 the profiles are compatible and warn if they are not. Note that
6039 the checker is expected to post diagnostics in this case. */
6041 {
6042 intrin_binding_t inb
6046 post_error
6048 gnat_subprog);
6051 }
6053 /* Inability to find the builtin DECL most often indicates a genuine
6054 mistake, but imports of unregistered intrinsics are sometimes used
6055 on purpose to allow hooking in alternate bodies; we post a warning
6056 conditioned on Wshadow in this case, to let developers be notified
6057 on demand without risking false positives with common default sets
6058 of options. */
6061 }
6062 }
6065 }
6067 /* Return the external name for GNAT_SUBPROG given its entity name. */
6069 static tree
6071 {
6074 /* If there was no specified Interface_Name and the external and
6075 internal names of the subprogram are the same, only use the
6076 internal name to allow disambiguation of nested subprograms. */
6081 }
6083 /* Like build_qualified_type, but TYPE_QUALS is added to the existing
6084 qualifiers on TYPE. */
6086 static tree
6088 {
6089 /* Qualifiers must be put on the associated array type. */
6094 }
6096 /* Set TYPE_NONALIASED_COMPONENT on an array type built by means of
6097 build_nonshared_array_type. */
6099 static void
6101 {
6104 }
6106 /* Set TYPE_REVERSE_STORAGE_ORDER on an array type built by means of
6107 build_nonshared_array_type. */
6109 static void
6111 {
6114 }
6116 /* Return true if DISCR1 and DISCR2 represent the same discriminant. */
6118 static bool
6120 {
6127 return
6129 }
6131 /* Return true if the array type GNU_TYPE, which represents a dimension of
6132 GNAT_TYPE, has a non-aliased component in the back-end sense. */
6134 static bool
6136 {
6137 /* If the array type is not the innermost dimension of the GNAT type,
6138 then it has a non-aliased component. */
6143 /* If the array type has an aliased component in the front-end sense,
6144 then it also has an aliased component in the back-end sense. */
6148 /* If this is a derived type, then it has a non-aliased component if
6149 and only if its parent type also has one. */
6151 {
6155 gnu_parent_type
6160 }
6162 /* Otherwise, rely exclusively on properties of the element type. */
6164 }
6166 /* Return true if GNAT_ADDRESS is a value known at compile-time. */
6168 static bool
6170 {
6171 /* Handle reference to a constant. */
6174 {
6178 }
6180 /* Catch System'To_Address. */
6185 }
6187 /* Return true if GNAT_RANGE, a N_Range node, cannot be superflat, i.e. if the
6188 inequality HB >= LB-1 is true. LB and HB are the low and high bounds. */
6190 static bool
6192 {
6194 Node_Id scalar_range;
6197 /* If the low bound is not constant, try to find an upper bound. */
6206 /* If the high bound is not constant, try to find a lower bound. */
6215 /* If we have failed to find constant bounds, punt. */
6220 /* We need at least a signed 64-bit type to catch most cases. */
6226 /* If the low bound is the smallest integer, nothing can be smaller. */
6232 }
6234 /* Return true if GNU_EXPR is (essentially) the address of a CONSTRUCTOR. */
6236 static bool
6238 {
6246 }
6248 /* Return true if the size in units represented by GNU_SIZE can be handled by
6249 an allocation. If STATIC_P is true, consider only what can be done with a
6250 static allocation. */
6252 static bool
6254 {
6255 /* We can allocate a fixed size if it is a valid for the middle-end. */
6259 /* We can allocate a variable size if this isn't a static allocation. */
6260 else
6262 }
6264 /* Return true if GNU_EXPR needs a conversion to GNU_TYPE when used as the
6265 initial value of an object of GNU_TYPE. */
6267 static bool
6269 {
6270 /* Do not convert if the object's type is unconstrained because this would
6271 generate useless evaluations of the CONSTRUCTOR to compute the size. */
6276 /* Do not convert if the object's type is a padding record whose field is of
6277 self-referential size because we want to copy only the actual data. */
6281 /* Do not convert a call to a function that returns with variable size since
6282 we want to use the return slot optimization in this case. */
6287 /* Do not convert to a record type with a variant part from a record type
6288 without one, to keep the object simpler. */
6295 /* In all the other cases, convert the expression to the object's type. */
6297 }
6298 \f
6299 /* Given GNAT_ENTITY, elaborate all expressions that are required to
6300 be elaborated at the point of its definition, but do nothing else. */
6302 void
6304 {
6306 {
6313 {
6317 /* ??? Tests to avoid Constraint_Error in static expressions
6318 are needed until after the front stops generating bogus
6319 conversions on bounds of real types. */
6327 }
6334 {
6335 Node_Id gnat_discriminant_expr;
6336 Entity_Id gnat_field;
6340 gnat_discriminant_expr
6345 /* Ignore access discriminants. */
6350 }
6353 }
6354 }
6355 \f
6356 /* Prepend to ATTR_LIST an entry for an attribute with provided TYPE,
6357 NAME, ARGS and ERROR_POINT. */
6359 static void
6362 tree attr_name,
6363 tree attr_args,
6364 Node_Id attr_error_point)
6365 {
6375 }
6377 /* Prepend to ATTR_LIST an entry for an attribute provided by GNAT_PRAGMA. */
6379 static void
6381 {
6386 /* Map the pragma at hand. Skip if this isn't one we know how to handle. */
6388 {
6419 }
6421 /* See what arguments we have and turn them into GCC trees for attribute
6422 handlers. These expect identifier for strings. We handle at most two
6423 arguments and static expressions only. */
6425 {
6431 {
6435 {
6439 }
6442 }
6446 {
6451 }
6452 }
6454 /* Prepend to the list. Make a list of the argument we might have, as GCC
6455 expects it. */
6457 gnu_arg1
6461 }
6463 /* Prepend to ATTR_LIST the list of attributes for GNAT_ENTITY, if any. */
6465 static void
6467 {
6468 Node_Id gnat_temp;
6470 /* Attributes are stored as Representation Item pragmas. */
6476 }
6477 \f
6478 /* Given a GNAT tree GNAT_EXPR, for an expression which is a value within a
6479 type definition (either a bound or a discriminant value) for GNAT_ENTITY,
6480 return the GCC tree to use for that expression. S is the suffix to use
6481 if a variable needs to be created and DEFINITION is true if this is done
6482 for a definition of GNAT_ENTITY. If NEED_VALUE is true, we need a result;
6483 otherwise, we are just elaborating the expression for side-effects. If
6484 NEED_DEBUG is true, we need a variable for debugging purposes even if it
6485 isn't needed for code generation. */
6487 static tree
6490 {
6491 tree gnu_expr;
6493 /* If we already elaborated this expression (e.g. it was involved
6494 in the definition of a private type), use the old value. */
6498 /* If we don't need a value and this is static or a discriminant,
6499 we don't need to do anything. */
6506 /* If it's a static expression, we don't need a variable for debugging. */
6510 /* Otherwise, convert this tree to its GCC equivalent and elaborate it. */
6514 /* Save the expression in case we try to elaborate this entity again. Since
6515 it's not a DECL, don't check it. Don't save if it's a discriminant. */
6520 }
6522 /* Similar, but take a GNU expression and always return a result. */
6524 static tree
6527 {
6532 /* If GNU_EXPR contains a placeholder, just return it. We rely on the fact
6533 that an expression cannot contain both a discriminant and a variable. */
6537 /* If GNU_EXPR is neither a constant nor based on a read-only variable, make
6538 a variable that is initialized to contain the expression when the package
6539 containing the definition is elaborated. If this entity is defined at top
6540 level, replace the expression by the variable; otherwise use a SAVE_EXPR
6541 if this is necessary. */
6544 else
6545 {
6546 /* Skip any conversions and simple constant arithmetics to see if the
6547 expression is based on a read-only variable. */
6555 expr_variable_p
6556 = !(inner
6559 }
6561 /* We only need to use the variable if we are in a global context since GCC
6562 can do the right thing in the local case. However, when not optimizing,
6563 use it for bounds of loop iteration scheme to avoid code duplication. */
6564 use_variable = expr_variable_p
6565 && (expr_global_p
6566 || (!optimize
6567 && definition
6572 /* Now create it, possibly only for debugging purposes. */
6574 {
6575 /* The following variable creation can happen when processing the body
6576 of subprograms that are defined out of the extended main unit and
6577 inlined. In this case, we are not at the global scope, and thus the
6578 new variable must not be tagged "external", as we used to do here as
6579 soon as DEFINITION was false. */
6580 tree gnu_decl
6587 /* Using this variable at debug time (if need_debug is true) requires a
6588 proper location. The back-end will compute a location for this
6589 variable only if the variable is used by the generated code.
6590 Returning the variable ensures the caller will use it in generated
6591 code. Note that there is no need for a location if the debug info
6592 contains an integer constant.
6593 TODO: when the encoding-based debug scheme is dropped, move this
6594 condition to the top-level IF block: we will not need to create a
6595 variable anymore in such cases, then. */
6598 }
6601 }
6603 /* Similar, but take an alignment factor and make it explicit in the tree. */
6605 static tree
6608 {
6610 return
6613 gnu_expr,
6614 unit_align),
6616 need_debug),
6617 unit_align);
6618 }
6620 /* Structure to hold internal data for elaborate_reference. */
6622 struct er_data
6623 {
6624 Entity_Id entity;
6627 };
6629 /* Wrapper function around elaborate_expression_1 for elaborate_reference. */
6631 static tree
6633 {
6637 /* This is what elaborate_expression_1 does if NEED_DEBUG is false. */
6641 /* If this is a COMPONENT_REF of a fat pointer, elaborate the entire fat
6642 pointer. This may be more efficient, but will also allow us to more
6643 easily find the match for the PLACEHOLDER_EXPR. */
6651 return
6653 }
6655 /* Elaborate the reference REF to be used as renamed object for GNAT_ENTITY.
6656 DEFINITION is true if this is done for a definition of GNAT_ENTITY and
6657 INIT is set to the first arm of a COMPOUND_EXPR present in REF, if any. */
6659 static tree
6662 {
6665 }
6666 \f
6667 /* Given a GNU tree and a GNAT list of choices, generate an expression to test
6668 the value passed against the list of choices. */
6670 static tree
6672 {
6673 Node_Id choice;
6674 Node_Id gnat_temp;
6679 {
6681 {
6686 this_test
6701 this_test
6712 /* This represents either a subtype range, an enumeration
6713 literal, or a constant Ekind says which. If an enumeration
6714 literal or constant, fall through to the next case. */
6717 {
6723 this_test
6731 }
6733 /* ... fall through ... */
6748 }
6752 else
6755 }
6758 }
6759 \f
6760 /* Adjust PACKED setting as passed to gnat_to_gnu_field for a field of
6761 type FIELD_TYPE to be placed in RECORD_TYPE. Return the result. */
6763 static int
6765 {
6766 /* If the field contains an item of variable size, we cannot pack it
6767 because we cannot create temporaries of non-fixed size in case
6768 we need to take the address of the field. See addressable_p and
6769 the notes on the addressability issues for further details. */
6773 /* In the other cases, we can honor the packing. */
6777 /* If the alignment of the record is specified and the field type
6778 is over-aligned, request Storage_Unit alignment for the field. */
6783 /* Likewise if the maximum alignment of the record is specified. */
6789 }
6791 /* Return a GCC tree for a field corresponding to GNAT_FIELD to be
6792 placed in GNU_RECORD_TYPE.
6794 PACKED is 1 if the enclosing record is packed or -1 if the enclosing
6795 record has Component_Alignment of Storage_Unit.
6797 DEFINITION is true if this field is for a record being defined.
6799 DEBUG_INFO_P is true if we need to write debug information for types
6800 that we may create in the process. */
6802 static tree
6805 {
6808 const bool is_atomic
6811 const bool is_independent
6813 const bool is_volatile
6816 /* We used to consider that volatile fields also require strict alignment,
6817 but that was an interpolation and would cause us to reject a pragma
6818 volatile on a packed record type containing boolean components, while
6819 there is no basis to do so in the RM. In such cases, the writes will
6820 involve load-modify-store sequences, but that's OK for volatile. The
6821 only constraint is the implementation advice whereby only the bits of
6822 the components should be accessed if they both start and end on byte
6823 boundaries, but that should be guaranteed by the GCC memory model. */
6824 const bool needs_strict_alignment
6830 /* If this field requires strict alignment, we cannot pack it because
6831 it would very likely be under-aligned in the record. */
6834 else
6837 /* If a size is specified, use it. Otherwise, if the record type is packed,
6838 use the official RM size. See "Handling of Type'Size Values" in Einfo
6839 for further details. */
6846 else
6849 /* If we have a specified size that is smaller than that of the field's type,
6850 or a position is specified, and the field's type is a record that doesn't
6851 require strict alignment, see if we can get either an integral mode form
6852 of the type or a smaller form. If we can, show a size was specified for
6853 the field if there wasn't one already, so we know to make this a bitfield
6854 and avoid making things wider.
6856 Changing to an integral mode form is useful when the record is packed as
6857 we can then place the field at a non-byte-aligned position and so achieve
6858 tighter packing. This is in addition required if the field shares a byte
6859 with another field and the front-end lets the back-end handle the access
6860 to the field, because GCC cannot handle non-byte-aligned BLKmode fields.
6862 Changing to a smaller form is required if the specified size is smaller
6863 than that of the field's type and the type contains sub-fields that are
6864 padded, in order to avoid generating accesses to these sub-fields that
6865 are wider than the field.
6867 We avoid the transformation if it is not required or potentially useful,
6868 as it might entail an increase of the field's alignment and have ripple
6869 effects on the outer record type. A typical case is a field known to be
6870 byte-aligned and not to share a byte with another field. */
6876 || (gnu_size
6882 {
6885 {
6889 }
6890 }
6896 {
6904 /* Ensure the position does not overlap with the parent subtype, if there
6905 is one. This test is omitted if the parent of the tagged type has a
6906 full rep clause since, in this case, component clauses are allowed to
6907 overlay the space allocated for the parent type and the front-end has
6908 checked that there are no overlapping components. */
6910 {
6915 post_error_ne_tree
6918 }
6920 /* If this field needs strict alignment, make sure that the record is
6921 sufficiently aligned and that the position and size are consistent
6922 with the type. But don't do it if we are just annotating types and
6923 the field's type is tagged, since tagged types aren't fully laid out
6924 in this mode. Also, note that atomic implies volatile so the inner
6925 test sequences ordering is significant here. */
6928 {
6934 /* If the position is not a multiple of the alignment of the type,
6935 then error out and reset the position. */
6938 {
6950 else
6954 type_align);
6956 }
6959 {
6963 /* If the size is lower than that of the type, or greater for
6964 atomic and aliased, then error out and reset the size. */
6966 {
6978 else
6982 gnu_type_size);
6984 }
6986 /* Likewise if the size is not a multiple of a byte, */
6988 bitsize_unit_node)))
6989 {
6998 else
7003 }
7004 }
7005 }
7006 }
7008 /* If the record has rep clauses and this is the tag field, make a rep
7009 clause for it as well. */
7012 {
7015 }
7017 else
7018 {
7021 /* If we are packing the record and the field is BLKmode, round the
7022 size up to a byte boundary. */
7025 }
7027 /* We need to make the size the maximum for the type if it is
7028 self-referential and an unconstrained type. In that case, we can't
7029 pack the field since we can't make a copy to align it. */
7031 && !gnu_size
7034 {
7037 }
7039 /* If a size is specified, adjust the field's type to it. */
7041 {
7042 tree orig_field_type;
7044 /* If the field's type is justified modular, we would need to remove
7045 the wrapper to (better) meet the layout requirements. However we
7046 can do so only if the field is not aliased to preserve the unique
7047 layout, if it has the same storage order as the enclosing record
7048 and if the prescribed size is not greater than that of the packed
7049 array to preserve the justification. */
7059 /* Similarly if the field's type is a misaligned integral type, but
7060 there is no restriction on the size as there is no justification. */
7066 gnu_field_type
7074 /* If a padding record was made, declare it now since it will never be
7075 declared otherwise. This is necessary to ensure that its subtrees
7076 are properly marked. */
7081 }
7083 /* Otherwise (or if there was an error), don't specify a position. */
7084 else
7087 /* If the field's type is a padded type made for a scalar field of a record
7088 type with reverse storage order, we need to propagate the reverse storage
7089 order to the padding type since it is the innermost enclosing aggregate
7090 type around the scalar. */
7099 /* Now create the decl for the field. */
7100 gnu_field
7108 {
7113 }
7116 }
7117 \f
7118 /* Return true if at least one member of COMPONENT_LIST needs strict
7119 alignment. */
7121 static bool
7123 {
7124 Node_Id component_decl;
7129 {
7137 }
7140 }
7142 /* Return true if TYPE is a type with variable size or a padding type with a
7143 field of variable size or a record that has a field with such a type. */
7145 static bool
7147 {
7148 tree field;
7165 }
7166 \f
7167 /* Return true if FIELD is an artificial field. */
7169 static bool
7171 {
7172 /* These fields are generated by the front-end proper. */
7176 /* These fields are generated by gigi. */
7181 }
7183 /* Return true if FIELD is a non-artificial field with self-referential
7184 size. */
7186 static bool
7188 {
7196 }
7198 /* Return true if FIELD is a non-artificial field with variable size. */
7200 static bool
7202 {
7210 }
7212 /* qsort comparer for the bit positions of two record components. */
7214 static int
7216 {
7219 const int ret
7223 }
7225 /* Reverse function from gnat_to_gnu_field: return the GNAT field present in
7226 either GNAT_COMPONENT_LIST or the discriminants of GNAT_RECORD_TYPE, and
7227 corresponding to the GNU tree GNU_FIELD. */
7229 static Entity_Id
7231 Entity_Id gnat_record_type)
7232 {
7240 {
7244 }
7254 }
7256 /* Issue a warning for the problematic placement of GNU_FIELD present in
7257 either GNAT_COMPONENT_LIST or the discriminants of GNAT_RECORD_TYPE.
7258 IN_VARIANT is true if GNAT_COMPONENT_LIST is the list of a variant.
7259 DO_REORDER is true if fields of GNAT_RECORD_TYPE are being reordered. */
7261 static void
7265 {
7270 = in_variant
7280 = do_reorder
7284 Entity_Id gnat_field
7292 }
7294 /* Structure holding information for a given variant. */
7296 {
7297 /* The record type of the variant. */
7298 tree type;
7300 /* The name of the variant. */
7301 tree name;
7303 /* The qualifier of the variant. */
7304 tree qual;
7306 /* Whether the variant has a rep clause. */
7309 /* Whether the variant is packed. */
7314 /* Translate and chain GNAT_COMPONENT_LIST present in GNAT_RECORD_TYPE to
7315 GNU_FIELD_LIST, set the result as the field list of GNU_RECORD_TYPE and
7316 finish it up. Return true if GNU_RECORD_TYPE has a rep clause that affects
7317 the layout (see below). When called from gnat_to_gnu_entity during the
7318 processing of a record definition, the GCC node for the parent, if any,
7319 will be the single field of GNU_RECORD_TYPE and the GCC nodes for the
7320 discriminants will be on GNU_FIELD_LIST. The other call to this function
7321 is a recursive call for the component list of a variant and, in this case,
7322 GNU_FIELD_LIST is empty.
7324 PACKED is 1 if this is for a packed record or -1 if this is for a record
7325 with Component_Alignment of Storage_Unit.
7327 DEFINITION is true if we are defining this record type.
7329 CANCEL_ALIGNMENT is true if the alignment should be zeroed before laying
7330 out the record. This means the alignment only serves to force fields to
7331 be bitfields, but not to require the record to be that aligned. This is
7332 used for variants.
7334 ALL_REP is true if a rep clause is present for all the fields.
7336 UNCHECKED_UNION is true if we are building this type for a record with a
7337 Pragma Unchecked_Union.
7339 ARTIFICIAL is true if this is a type that was generated by the compiler.
7341 DEBUG_INFO is true if we need to write debug information about the type.
7343 MAYBE_UNUSED is true if this type may be unused in the end; this doesn't
7344 mean that its contents may be unused as well, only the container itself.
7346 FIRST_FREE_POS, if nonzero, is the first (lowest) free field position in
7347 the outer record type down to this variant level. It is nonzero only if
7348 all the fields down to this level have a rep clause and ALL_REP is false.
7350 P_GNU_REP_LIST, if nonzero, is a pointer to a list to which each field
7351 with a rep clause is to be added; in this case, that is all that should
7352 be done with such fields and the return value will be false. */
7354 static bool
7361 {
7362 const bool needs_xv_encodings
7374 /* For each component referenced in a component declaration create a GCC
7375 field and add it to the list, skipping pragmas in the GNAT list. */
7382 {
7386 /* If present, the _Parent field must have been created as the single
7387 field of the record type. Put it before any other fields. */
7389 {
7392 }
7393 else
7394 {
7398 /* If this is the _Tag field, put it before any other fields. */
7402 /* If this is the _Controller field, put it before the other
7403 fields except for the _Tag or _Parent field. */
7405 {
7408 }
7410 /* If this is a regular field, put it after the other fields. */
7411 else
7412 {
7418 /* And record information for the final layout. */
7423 }
7424 }
7427 }
7429 /* At the end of the component list there may be a variant part. */
7432 /* We create a QUAL_UNION_TYPE for the variant part since the variants are
7433 mutually exclusive and should go in the same memory. To do this we need
7434 to treat each variant as a record whose elements are created from the
7435 component list for the variant. So here we create the records from the
7436 lists for the variants and put them all into the QUAL_UNION_TYPE.
7437 If this is an Unchecked_Union, we make a UNION_TYPE instead or
7438 use GNU_RECORD_TYPE if there are no fields so far. */
7440 {
7444 tree gnu_var_name
7455 gnu_union_name
7458 /* Reuse the enclosing union if this is an Unchecked_Union whose fields
7459 are all in the variant part, to match the layout of C unions. There
7460 is an associated check below. */
7463 else
7464 {
7465 gnu_union_type
7473 }
7475 /* If all the fields down to this level have a rep clause, find out
7476 whether all the fields at this level also have one. If so, then
7477 compute the new first free position to be passed downward. */
7480 {
7482 gnu_field;
7485 {
7488 this_first_free_pos
7490 }
7491 else
7492 {
7495 }
7496 }
7498 /* We build the variants in two passes. The bulk of the work is done in
7499 the first pass, that is to say translating the GNAT nodes, building
7500 the container types and computing the associated properties. However
7501 we cannot finish up the container types during this pass because we
7502 don't know where the variant part will be placed until the end. */
7506 {
7511 vinfo_t vinfo;
7519 /* Set the alignment of the inner type in case we need to make
7520 inner objects into bitfields, but then clear it out so the
7521 record actually gets only the alignment required. */
7527 /* Similarly, if the outer record has a size specified and all
7528 the fields have a rep clause, we can propagate the size. */
7530 {
7534 }
7536 /* Add the fields into the record type for the variant. Note that
7537 we aren't sure to really use it at this point, see below. */
7538 has_rep
7544 all_rep || this_first_free_pos
7547 /* Translate the qualifier and annotate the GNAT node. */
7551 /* Deal with packedness like in gnat_to_gnu_field. */
7553 {
7556 }
7557 else
7558 field_packed
7561 /* Push this variant onto the stack for the second pass. */
7569 /* Compute the global properties that will determine the placement of
7570 the variant part. */
7574 }
7576 /* Round up the first free position to the alignment of the variant part
7577 for the variants without rep clause. This will guarantee a consistent
7578 layout independently of the placement of the variant part. */
7582 /* In the second pass, the container types are adjusted if necessary and
7583 finished up, then the corresponding fields of the variant part are
7584 built with their qualifier, unless this is an unchecked union. */
7586 {
7590 /* If this is an Unchecked_Union whose fields are all in the variant
7591 part and we have a single field with no representation clause or
7592 placed at offset zero, use the field directly to match the layout
7593 of C unions. */
7595 && gnu_field_list
7599 {
7602 }
7603 else
7604 {
7605 /* Finalize the variant type now. We used to throw away empty
7606 record types but we no longer do that because we need them to
7607 generate complete debug info for the variant; otherwise, the
7608 union type definition will be lacking the fields associated
7609 with these empty variants. */
7611 {
7612 /* The variant part will be at offset 0 so we need to ensure
7613 that the fields are laid out starting from the first free
7614 position at this level. */
7616 tree gnu_rep_part;
7620 gnu_rep_part
7622 this_first_free_pos);
7627 }
7634 gnu_field
7636 gnu_union_type,
7637 all_rep_and_size
7646 }
7650 }
7652 /* Only make the QUAL_UNION_TYPE if there are non-empty variants. */
7654 {
7658 {
7662 }
7667 /* If GNU_UNION_TYPE is our record type, it means we must have an
7668 Unchecked_Union with no fields. Verify that and, if so, just
7669 return. */
7671 {
7673 && !gnu_field_list
7676 }
7681 /* Deal with packedness like in gnat_to_gnu_field. */
7684 else
7685 union_field_packed
7688 gnu_variant_part
7690 all_rep_and_size
7696 }
7697 }
7699 /* Scan GNU_FIELD_LIST and see if any fields have rep clauses. If they do,
7700 pull them out and put them onto the appropriate list.
7702 Similarly, pull out the fields with zero size and no rep clause, as they
7703 would otherwise modify the layout and thus very likely run afoul of the
7704 Ada semantics, which are different from those of C here.
7706 Finally, if there is an aliased field placed in the list after fields
7707 with self-referential size, pull out the latter in the same way.
7709 Optionally, if the reordering mechanism is enabled, pull out the fields
7710 with self-referential size, variable size and fixed size not a multiple
7711 of a byte, so that they don't cause the regular fields to be either at
7712 self-referential/variable offset or misaligned. Note, in the latter
7713 case, that this can only happen in packed record types so the alignment
7714 is effectively capped to the byte for the whole record.
7716 Optionally, if the layout warning is enabled, keep track of the above 4
7717 different kinds of fields and issue a warning if some of them would be
7718 (or are being) reordered by the reordering mechanism.
7720 ??? If we reorder fields, the debugging information will be affected and
7721 the debugger print fields in a different order from the source code. */
7722 const bool do_reorder
7726 const bool w_reorder
7728 && Warn_On_Questionable_Layout
7740 #define MOVE_FROM_FIELD_LIST_TO(LIST) \
7741 do { \
7742 if (gnu_last) \
7743 DECL_CHAIN (gnu_last) = gnu_next; \
7744 else \
7745 gnu_field_list = gnu_next; \
7746 \
7747 DECL_CHAIN (gnu_field) = (LIST); \
7748 (LIST) = gnu_field; \
7749 } while (0)
7753 {
7757 {
7760 }
7763 {
7773 }
7776 {
7779 }
7781 /* We don't need further processing in default mode. */
7783 {
7786 }
7789 {
7791 {
7795 do_reorder);
7796 else
7798 }
7801 {
7804 }
7805 }
7808 {
7810 {
7814 do_reorder);
7815 else
7817 }
7820 {
7823 }
7824 }
7826 else
7827 {
7828 /* If the field has no size, then it cannot be bit-packed. */
7829 const unsigned int bitp_size
7834 /* If the field is bit-packed, we move it to a temporary list that
7835 contains the contiguously preceding bit-packed fields, because
7836 we want to be able to put them back if the misalignment happens
7837 to cancel itself after several bit-packed fields. */
7839 {
7843 {
7846 }
7849 {
7852 }
7853 }
7855 /* No more bit-packed fields, move the existing ones to the end or
7856 put them back at their original location. */
7858 {
7862 {
7866 gnat_component_list,
7868 do_reorder);
7875 }
7876 else
7877 {
7878 /* Rechain the temporary list in front of GNU_FIELD. */
7881 {
7886 else
7890 }
7891 }
7892 }
7894 else
7896 }
7899 }
7901 #undef MOVE_FROM_FIELD_LIST_TO
7905 /* If permitted, we reorder the fields as follows:
7907 1) all (groups of) fields whose length is fixed and multiple of a byte,
7908 2) the remaining fields whose length is fixed and not multiple of a byte,
7909 3) the remaining fields whose length doesn't depend on discriminants,
7910 4) all fields whose length depends on discriminants,
7911 5) the variant part,
7913 within the record and within each variant recursively. */
7916 {
7917 /* If we have pending bit-packed fields, warn if they would be moved
7918 to after regular fields. */
7926 }
7929 {
7930 /* If we have pending bit-packed fields on the temporary list, we put
7931 them either on the bit-packed list or back on the regular list. */
7933 {
7936 else
7938 }
7940 gnu_field_list
7944 }
7946 /* Otherwise, if there is an aliased field placed after a field whose length
7947 depends on discriminants, we put all the fields of the latter sort, last.
7948 We need to do this in case an object of this record type is mutable. */
7952 /* If P_REP_LIST is nonzero, this means that we are asked to move the fields
7953 in our REP list to the previous level because this level needs them in
7954 order to do a correct layout, i.e. avoid having overlapping fields. */
7958 /* Deal with the annoying case of an extension of a record with variable size
7959 and partial rep clause, for which the _Parent field is forced at offset 0
7960 and has variable size, which we do not support below. Note that we cannot
7961 do it if the field has fixed size because we rely on the presence of the
7962 REP part built below to trigger the reordering of the fields in a derived
7963 record type when all the fields have a fixed position. */
7967 && !variants_have_rep
7968 && first_free_pos
7971 {
7975 }
7977 /* Otherwise, sort the fields by bit position and put them into their own
7978 record, before the others, if we also have fields without rep clause. */
7980 {
7985 /* If all the fields have a rep clause, we can do a flat layout. */
7986 layout_with_rep = !gnu_field_list
7988 gnu_rep_type
7992 gnu_field;
7998 /* Put the fields in the list in order of increasing position, which
7999 means we start from the end. */
8002 {
8006 }
8010 else
8011 {
8016 /* If FIRST_FREE_POS is nonzero, we need to ensure that the fields
8017 without rep clause are laid out starting from this position.
8018 Therefore, we force it as a minimal size on the REP part. */
8019 gnu_rep_part
8022 /* Chain the REP part at the beginning of the field list. */
8025 }
8026 }
8028 /* Chain the variant part at the end of the field list. */
8040 /* Chain the fields with zero size at the beginning of the field list. */
8046 }
8047 \f
8048 /* Given GNU_SIZE, a GCC tree representing a size, return a Uint to be
8049 placed into an Esize, Component_Bit_Offset, or Component_Size value
8050 in the GNAT tree. */
8052 static Uint
8054 {
8056 TCode tcode;
8060 /* See if we've already saved the value for this node. */
8062 {
8070 }
8071 else
8074 /* If we do not return inside this switch, TCODE will be set to the
8075 code to be used in a call to Create_Node. */
8077 {
8079 /* For negative values, build NEGATE_EXPR of the opposite. Such values
8080 can appear for discriminants in expressions for variants. */
8082 {
8086 }
8087 else
8092 /* The only case we handle here is a simple discriminant reference. */
8094 {
8098 /* Climb up the chain of successive extensions, if any. */
8105 {
8106 /* Fall through to common processing as a FIELD_DECL. */
8109 }
8110 else
8112 }
8113 else
8122 CASE_CONVERT:
8126 /* Now just list the operations we handle. */
8156 /* Fold conversions from bytes to bits into inner operations. */
8159 {
8163 {
8166 wide_int op1;
8169 else
8173 }
8174 }
8179 /* For negative values in sizetype, build NEGATE_EXPR of the opposite.
8180 Such values appear in expressions with aligning patterns. Note that,
8181 since sizetype is unsigned, we have to jump through some hoops. */
8183 {
8187 {
8190 }
8191 }
8195 /* In regular mode, inline back only if symbolic annotation is requested
8196 in order to avoid memory explosion on big discriminated record types.
8197 But not in ASIS mode, as symbolic annotation is required for DDA. */
8199 {
8202 }
8203 else
8208 }
8210 /* Now get each of the operands that's relevant for this code. If any
8211 cannot be expressed as a repinfo node, say we can't. */
8214 {
8218 }
8222 /* Save the result in the cache. */
8224 {
8226 /* We can't assume the hash table data hasn't moved since the initial
8227 look up, so we have to search again. Allocating and inserting an
8228 entry at that point would be an alternative, but then we'd better
8229 discard the entry if we decided not to cache it. */
8235 }
8238 }
8240 /* Given GNAT_ENTITY, an object (constant, variable, parameter, exception)
8241 and GNU_TYPE, its corresponding GCC type, set Esize and Alignment to the
8242 size and alignment used by Gigi. Prefer SIZE over TYPE_SIZE if non-null.
8243 BY_REF is true if the object is used by reference. */
8245 void
8247 {
8249 {
8252 else
8254 }
8257 {
8266 }
8271 }
8273 /* Return first element of field list whose TREE_PURPOSE is the same as ELEM.
8274 Return NULL_TREE if there is no such element in the list. */
8276 static tree
8278 {
8280 {
8285 }
8287 }
8289 /* Given GNAT_ENTITY, a record type, and GNU_TYPE, its corresponding GCC type,
8290 set Component_Bit_Offset and Esize of the components to the position and
8291 size used by Gigi. */
8293 static void
8295 {
8296 /* For an extension, the inherited components have not been translated because
8297 they are fetched from the _Parent component on the fly. */
8298 const bool is_extension
8301 /* We operate by first making a list of all fields and their position (we
8302 can get the size easily) and then update all the sizes in the tree. */
8303 tree gnu_list
8314 {
8316 gnu_list);
8318 {
8319 tree parent_offset;
8321 /* If we are just annotating types and the type is tagged, the tag
8322 and the parent components are not generated by the front-end so
8323 we need to add the appropriate offset to each component without
8324 representation clause. */
8328 {
8329 /* For a component appearing in the current extension, the
8330 offset is the size of the parent. */
8333 parent_offset
8335 bitsizetype);
8336 else
8340 parent_offset
8343 }
8344 else
8347 Set_Component_Bit_Offset
8349 annotate_value
8353 parent_offset)));
8357 }
8359 {
8360 /* If there is no entry, this is an inherited component whose
8361 position is the same as in the parent type. */
8364 /* If we are just annotating types, discriminants renaming those of
8365 the parent have no entry so deal with them specifically. */
8375 }
8376 }
8377 }
8378 \f
8379 /* Scan all fields in GNU_TYPE and return a TREE_LIST where TREE_PURPOSE is
8380 the FIELD_DECL and TREE_VALUE a TREE_VEC containing the byte position, the
8381 value to be placed into DECL_OFFSET_ALIGN and the bit position. The list
8382 of fields is flattened, except for variant parts if DO_NOT_FLATTEN_VARIANT
8383 is set to true. GNU_POS is to be added to the position, GNU_BITPOS to the
8384 bit position, OFFSET_ALIGN is the present offset alignment. GNU_LIST is a
8385 pre-existing list to be chained to the newly created entries. */
8387 static tree
8390 {
8391 tree gnu_field;
8394 gnu_field;
8396 {
8401 unsigned int our_offset_align
8410 /* Recurse on internal fields, flattening the nested fields except for
8411 those in the variant part, if requested. */
8413 {
8417 gnu_list
8421 else
8422 gnu_list
8426 }
8427 }
8430 }
8432 /* Return a list describing the substitutions needed to reflect the
8433 discriminant substitutions from GNAT_TYPE to GNAT_SUBTYPE. They can
8434 be in any order. The values in an element of the list are in the form
8435 of operands to SUBSTITUTE_IN_EXPR. DEFINITION is true if this is for
8436 a definition of GNAT_SUBTYPE. */
8440 {
8442 Entity_Id gnat_discrim;
8443 Node_Id gnat_constr;
8450 /* Ignore access discriminants. */
8452 {
8455 elaborate_expression
8461 }
8464 }
8466 /* Scan all fields in QUAL_UNION_TYPE and return a list describing the
8467 variants of QUAL_UNION_TYPE that are still relevant after applying
8468 the substitutions described in SUBST_LIST. GNU_LIST is a pre-existing
8469 list to be prepended to the newly created entries. */
8474 {
8475 tree gnu_field;
8478 gnu_field;
8480 {
8488 /* If the new qualifier is not unconditionally false, its variant may
8489 still be accessed. */
8491 {
8497 /* Recurse on the variant subpart of the variant, if any. */
8503 /* If the new qualifier is unconditionally true, the subsequent
8504 variants cannot be accessed. */
8507 }
8508 }
8511 }
8512 \f
8513 /* UINT_SIZE is a Uint giving the specified size for an object of GNU_TYPE
8514 corresponding to GNAT_OBJECT. If the size is valid, return an INTEGER_CST
8515 corresponding to its value. Otherwise, return NULL_TREE. KIND is set to
8516 VAR_DECL if we are specifying the size of an object, TYPE_DECL for the
8517 size of a type, and FIELD_DECL for the size of a field. COMPONENT_P is
8518 true if we are being called to process the Component_Size of GNAT_OBJECT;
8519 this is used only for error messages. ZERO_OK is true if a size of zero
8520 is permitted; if ZERO_OK is false, it means that a size of zero should be
8521 treated as an unspecified size. */
8523 static tree
8526 {
8527 Node_Id gnat_error_node;
8530 /* Return 0 if no size was specified. */
8534 /* Ignore a negative size since that corresponds to our back-annotation. */
8538 /* Find the node to use for error messages. */
8545 else
8548 /* Get the size as an INTEGER_CST. Issue an error if a size was specified
8549 but cannot be represented in bitsizetype. */
8552 {
8555 gnat_object);
8556 else
8558 gnat_object);
8560 }
8562 /* Ignore a zero size if it is not permitted. */
8566 /* The size of objects is always a multiple of a byte. */
8569 {
8573 else
8577 }
8579 /* If this is an integral type or a packed array type, the front-end has
8580 already verified the size, so we need not do it here (which would mean
8581 checking against the bounds). However, if this is an aliased object,
8582 it may not be smaller than the type of the object. */
8587 /* If the object is a record that contains a template, add the size of the
8588 template to the specified size. */
8594 /* If a type needs strict alignment, a component of this type in
8595 a packed record cannot be packed and thus uses the type size. */
8598 else
8601 /* Modify the size of a discriminated type to be the maximum size. */
8605 /* If this is an access type or a fat pointer, the minimum size is that given
8606 by the smallest integral mode that's valid for pointers. */
8608 {
8613 }
8615 /* Issue an error either if the default size of the object isn't a constant
8616 or if the new size is smaller than it. */
8620 {
8622 post_error_ne_tree
8625 else
8626 post_error_ne_tree
8630 }
8633 }
8634 \f
8635 /* Similarly, but both validate and process a value of RM size. This routine
8636 is only called for types. */
8638 static void
8640 {
8641 Node_Id gnat_attr_node;
8644 /* Do nothing if no size was specified. */
8648 /* Ignore a negative size since that corresponds to our back-annotation. */
8652 /* Only issue an error if a Value_Size clause was explicitly given.
8653 Otherwise, we'd be duplicating an error on the Size clause. */
8654 gnat_attr_node
8657 /* Get the size as an INTEGER_CST. Issue an error if a size was specified
8658 but cannot be represented in bitsizetype. */
8661 {
8664 gnat_entity);
8666 }
8668 /* Ignore a zero size unless a Value_Size clause exists, or a size clause
8669 exists, or this is an integer type, in which case the front-end will
8670 have always set it. */
8679 /* If the old size is self-referential, get the maximum size. */
8683 /* Issue an error either if the old size of the object isn't a constant or
8684 if the new size is smaller than it. The front-end has already verified
8685 this for scalar and packed array types. */
8693 && TYPE_PACKED_ARRAY_TYPE_P
8696 {
8698 post_error_ne_tree
8702 }
8704 /* Otherwise, set the RM size proper for integral types... */
8711 /* ...or the Ada size for record and union types. */
8715 }
8716 \f
8717 /* ALIGNMENT is a Uint giving the alignment specified for GNAT_ENTITY,
8718 a type or object whose present alignment is ALIGN. If this alignment is
8719 valid, return it. Otherwise, give an error and return ALIGN. */
8721 static unsigned int
8723 {
8726 Node_Id gnat_error_node;
8728 /* Don't worry about checking alignment if alignment was not specified
8729 by the source program and we already posted an error for this entity. */
8733 /* Post the error on the alignment clause if any. Note, for the implicit
8734 base type of an array type, the alignment clause is on the first
8735 subtype. */
8743 gnat_error_node =
8746 else
8749 /* Within GCC, an alignment is an integer, so we must make sure a value is
8750 specified that fits in that range. Also, there is an upper bound to
8751 alignments we can support/allow. */
8759 {
8763 /* If the default alignment of "double" or larger scalar types is
8764 specifically capped and the new alignment is above the cap, do
8765 not post an error and change the alignment only if there is an
8766 alignment clause; this makes it possible to have the associated
8767 GCC type overaligned by default for performance reasons. */
8769 {
8770 Entity_Id gnat_type
8772 is_capped_double
8774 }
8776 {
8777 Entity_Id gnat_type
8779 is_capped_double
8781 }
8782 else
8786 {
8789 }
8790 else
8791 {
8798 }
8799 }
8800 else
8801 {
8805 }
8808 }
8809 \f
8810 /* Verify that TYPE is something we can implement atomically. If not, issue
8811 an error for GNAT_ENTITY. COMPONENT_P is true if we are being called to
8812 process a component type. */
8814 static void
8816 {
8818 Node_Id gnat_node;
8819 machine_mode mode;
8822 tree size;
8824 /* If this is an anonymous base type, nothing to check, the error will be
8825 reported on the source type if need be. */
8834 /* Consider all aligned floating-point types atomic and any aligned types
8835 that are represented by integers no wider than a machine word. */
8836 scalar_int_mode int_mode;
8843 /* For the moment, also allow anything that has an alignment equal to its
8844 size and which is smaller than a word. */
8855 {
8856 unsigned char pragma_id
8861 {
8864 }
8865 }
8873 else
8876 }
8877 \f
8879 /* Helper for the intrin compatibility checks family. Evaluate whether
8880 two types are definitely incompatible. */
8882 static bool
8884 {
8899 {
8906 /* Assume designated types are ok. We'd need to account for char * and
8907 void * variants to do better, which could rapidly get messy and isn't
8908 clearly worth the effort. */
8913 }
8916 }
8918 /* Helper for intrin_profiles_compatible_p, to perform compatibility checks
8919 on the Ada/builtin argument lists for the INB binding. */
8921 static bool
8923 {
8929 /* Sequence position of the last argument we checked. */
8933 {
8937 /* If we've exhausted both lists simultaneously, we're done. */
8941 /* If one list is shorter than the other, they fail to match. */
8945 /* If we're done with the Ada args and not with the internal builtin
8946 args, or the other way around, complain. */
8949 {
8952 }
8956 {
8960 }
8962 /* Otherwise, check that types match for the current argument. */
8963 argpos ++;
8965 {
8969 }
8974 }
8977 }
8979 /* Helper for intrin_profiles_compatible_p, to perform compatibility checks
8980 on the Ada/builtin return values for the INB binding. */
8982 static bool
8984 {
8988 /* Accept function imported as procedure, common and convenient. */
8993 /* Check return types compatibility otherwise. Note that this
8994 handles void/void as well. */
8996 {
9000 }
9003 }
9005 /* Check and return whether the Ada and gcc builtin profiles bound by INB are
9006 compatible. Issue relevant warnings when they are not.
9008 This is intended as a light check to diagnose the most obvious cases, not
9009 as a full fledged type compatibility predicate. It is the programmer's
9010 responsibility to ensure correctness of the Ada declarations in Imports,
9011 especially when binding straight to a compiler internal. */
9013 static bool
9015 {
9016 /* Check compatibility on return values and argument lists, each responsible
9017 for posting warnings as appropriate. Ensure use of the proper sloc for
9018 this purpose. */
9031 }
9032 \f
9033 /* Return a FIELD_DECL node modeled on OLD_FIELD. FIELD_TYPE is its type
9034 and RECORD_TYPE is the type of the parent. If SIZE is nonzero, it is the
9035 specified size for this field. POS_LIST is a position list describing
9036 the layout of OLD_FIELD and SUBST_LIST a substitution list to be applied
9037 to this layout. */
9039 static tree
9043 {
9055 /* If the position is now a constant, we can set it as the position of the
9056 field when we make it. Otherwise, we need to deal with it specially. */
9059 else
9062 new_field
9068 {
9070 /* Finalize the position. */
9079 }
9087 }
9089 /* Create the REP part of RECORD_TYPE with REP_TYPE. If MIN_SIZE is nonzero,
9090 it is the minimal size the REP_PART must have. */
9092 static tree
9094 {
9095 tree field;
9105 }
9107 /* Return the REP part of RECORD_TYPE, if any. Otherwise return NULL. */
9109 static tree
9111 {
9114 /* The REP part is the first field, internal, another record, and its name
9115 starts with an 'R'. */
9123 }
9125 /* Return the variant part of RECORD_TYPE, if any. Otherwise return NULL. */
9127 tree
9129 {
9130 tree field;
9132 /* The variant part is the only internal field that is a qualified union. */
9139 }
9141 /* Return a new variant part modeled on OLD_VARIANT_PART. VARIANT_LIST is
9142 the list of variants to be used and RECORD_TYPE is the type of the parent.
9143 POS_LIST is a position list describing the layout of fields present in
9144 OLD_VARIANT_PART and SUBST_LIST a substitution list to be applied to this
9145 layout. DEBUG_INFO_P is true if we need to write debug information. */
9147 static tree
9153 {
9161 /* First create the type of the variant part from that of the old one. */
9167 /* If the position of the variant part is constant, subtract it from the
9168 size of the type of the parent to get the new size. This manual CSE
9169 reduces the code size when not optimizing. */
9173 {
9183 first_bit));
9186 }
9187 else
9190 /* Now finish up the new variants and populate the union type. */
9192 {
9196 /* Skip variants that don't belong to this nesting level. */
9200 /* Retrieve the list of fields already added to the new variant. */
9204 /* If the old variant had a variant subpart, we need to create a new
9205 variant subpart and add it to the field list. */
9209 {
9210 tree new_variant_subpart
9213 debug_info_p);
9216 }
9218 /* Finish up the new variant and create the field. */
9224 new_field
9232 }
9234 /* Finish up the union type and create the variant part. Note that we don't
9235 reverse the field list because VARIANT_LIST has been traversed in reverse
9236 order. */
9242 new_variant_part
9248 /* With multiple discriminants it is possible for an inner variant to be
9249 statically selected while outer ones are not; in this case, the list
9250 of fields of the inner variant is not flattened and we end up with a
9251 qualified union with a single member. Drop the useless container. */
9253 {
9262 }
9265 }
9267 /* Copy the size (and alignment and alias set) from OLD_TYPE to NEW_TYPE,
9268 which are both RECORD_TYPE, after applying the substitutions described
9269 in SUBST_LIST. */
9271 static void
9274 {
9298 SET_TYPE_ADA_SIZE
9302 /* Finalize the size. */
9305 }
9307 /* Return true if DISC is a stored discriminant of RECORD_TYPE. */
9311 {
9316 else
9318 }
9320 /* Copy the layout from {GNAT,GNU}_OLD_TYPE to {GNAT,GNU}_NEW_TYPE, which are
9321 both record types, after applying the substitutions described in SUBST_LIST.
9322 DEBUG_INFO_P is true if we need to write debug information for NEW_TYPE. */
9324 static void
9326 Entity_Id gnat_old_type,
9327 tree gnu_new_type,
9328 tree gnu_old_type,
9331 {
9337 /* Look for REP and variant parts in the old type. */
9341 /* If there is a variant part, we must compute whether the constraints
9342 statically select a particular variant. If so, we simply drop the
9343 qualified union and flatten the list of fields. Otherwise we will
9344 build a new qualified union for the variants that are still relevant. */
9346 {
9353 /* If all the qualifiers are unconditionally true, the innermost variant
9354 is statically selected. */
9358 {
9361 }
9363 /* Otherwise, create the new variants. */
9366 {
9369 tree suffix
9378 gnu_subst_list);
9380 }
9381 }
9382 else
9383 {
9386 }
9388 /* Make a list of fields and their position in the old type. */
9389 tree gnu_pos_list
9395 /* Now go down every component in the new type and compute its size and
9396 position from those of the component in the old type and the stored
9397 constraints of the new type. */
9410 {
9419 /* If the type is the same, retrieve the GCC type from the
9420 old field to take into account possible adjustments. */
9423 else
9426 /* If there was a component clause, the field types must be the same
9427 for the old and new types, so copy the data from the old field to
9428 avoid recomputation here. Also if the field is justified modular
9429 and the optimization in gnat_to_gnu_field was applied. */
9435 {
9438 }
9440 /* If the old field was packed and of constant size, we have to get the
9441 old size here as it might differ from what the Etype conveys and the
9442 latter might overlap with the following field. Try to arrange the
9443 type for possible better packing along the way. */
9446 {
9452 }
9454 else
9457 /* If the context of the old field is the old type or its REP part,
9458 put the field directly in the new type; otherwise look up the
9459 context in the variant list and put the field either in the new
9460 type if there is a selected variant or in one new variant. */
9464 else
9465 {
9468 tree rep_part;
9478 else
9479 /* The front-end may pass us "ghost" components if it fails to
9480 recognize that a constrain statically selects a particular
9481 variant. Discard them. */
9483 }
9485 /* Now create the new field modeled on the old one. */
9486 gnu_field
9492 /* If the context is a variant, put it in the new variant directly. */
9494 {
9497 }
9499 /* To match the layout crafted in components_to_record, if this is
9500 the _Tag or _Parent field, put it before any other fields. */
9504 /* Similarly, if this is the _Controller field, put it before the
9505 other fields except for the _Tag or _Parent field. */
9507 {
9510 }
9512 /* Otherwise, put it after the other fields. */
9513 else
9514 {
9521 }
9523 /* For a stored discriminant in a derived type, replace the field. */
9525 {
9528 }
9529 else
9531 }
9533 /* If there is no variant list or a selected variant and the fields all have
9534 constant position, put them in order of increasing position to match that
9535 of constant CONSTRUCTORs. */
9537 {
9548 {
9551 }
9552 }
9554 /* If there is a variant list and no selected variant, we need to create the
9555 nest of variant parts from the old nest. */
9557 {
9558 tree new_variant_part
9564 }
9571 /* If NEW_TYPE is a subtype, it inherits all the attributes from OLD_TYPE.
9572 Otherwise sizes and alignment must be computed independently. */
9574 {
9577 }
9578 else
9581 /* Now go through the entities again looking for Itypes that we have not yet
9582 elaborated (e.g. Etypes of fields that have Original_Components). */
9591 }
9593 /* Associate to GNU_TYPE, the translation of GNAT_ENTITY, which is
9594 the implementation type of a packed array type (Is_Packed_Array_Impl_Type),
9595 the original array type if it has been translated. This association is a
9596 parallel type for GNAT encodings or a debug type for standard DWARF. Note
9597 that for standard DWARF, we also want to get the original type name. */
9599 static void
9601 {
9602 Entity_Id gnat_original_array_type
9604 tree gnu_original_array_type;
9615 {
9623 }
9624 else
9626 }
9627 \f
9628 /* Given a type T, a FIELD_DECL F, and a replacement value R, return an
9629 equivalent type with adjusted size expressions where all occurrences
9630 of references to F in a PLACEHOLDER_EXPR have been replaced by R.
9632 The function doesn't update the layout of the type, i.e. it assumes
9633 that the substitution is purely formal. That's why the replacement
9634 value R must itself contain a PLACEHOLDER_EXPR. */
9636 tree
9638 {
9639 tree nt;
9644 {
9650 /* First the domain types of arrays. */
9653 {
9665 SET_TYPE_INDEX_TYPE
9669 }
9671 /* Then the subtypes. */
9674 {
9686 }
9698 /* These should never show up here. */
9702 {
9722 }
9727 {
9729 tree field;
9731 /* Start out with no fields, make new fields, and chain them
9732 in. If we haven't actually changed the type of any field,
9733 discard everything we've done and return the old type. */
9738 {
9743 {
9746 }
9750 {
9753 }
9755 /* Do the substitution inside the qualifier, if any. */
9757 {
9760 {
9763 }
9764 }
9771 }
9781 }
9785 }
9786 }
9787 \f
9788 /* Return the RM size of GNU_TYPE. This is the actual number of bits
9789 needed to represent the object. */
9791 tree
9793 {
9794 /* For integral types, we store the RM size explicitly. */
9798 /* Return the RM size of the actual data plus the size of the template. */
9801 return
9806 /* For record or union types, we store the size explicitly. */
9812 /* For other types, this is just the size. */
9814 }
9815 \f
9816 /* Return the name to be used for GNAT_ENTITY. If a type, create a
9817 fully-qualified name, possibly with type information encoding.
9818 Otherwise, return the name. */
9822 {
9825 }
9827 tree
9829 {
9832 }
9834 /* Return an identifier representing the external name to be used for
9835 GNAT_ENTITY. If SUFFIX is specified, the name is followed by "___"
9836 and the specified suffix. */
9838 tree
9840 {
9848 /* A variable using the Stdcall convention lives in a DLL. We adjust
9849 its name to use the jump table, the _imp__NAME contains the address
9850 for the NAME variable. */
9853 {
9859 }
9862 }
9864 /* Given GNU_NAME, an IDENTIFIER_NODE containing a name and SUFFIX, a
9865 string, return a new IDENTIFIER_NODE that is the concatenation of
9866 the name followed by "___" and the specified suffix. */
9868 tree
9870 {
9877 }
9879 /* Initialize data structures of the decl.c module. */
9881 void
9883 {
9884 /* Initialize the cache of annotated values. */
9887 /* Initialize the association of dummy types with subprograms. */
9889 }
9891 /* Destroy data structures of the decl.c module. */
9893 void
9895 {
9896 /* Destroy the cache of annotated values. */
9900 /* Destroy the association of dummy types with subprograms. */
9903 }