| blob | f626e6186d23f1a69be7cc98f749c0d3b024d79e |
1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * D E C L *
6 * *
7 * C Implementation File *
8 * *
9 * Copyright (C) 1992-2017, Free Software Foundation, Inc. *
10 * *
11 * GNAT is free software; you can redistribute it and/or modify it under *
12 * terms of the GNU General Public License as published by the Free Soft- *
13 * ware Foundation; either version 3, or (at your option) any later ver- *
14 * sion. GNAT is distributed in the hope that it will be useful, but WITH- *
15 * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY *
16 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License *
17 * for more details. You should have received a copy of the GNU General *
18 * Public License along with GCC; see the file COPYING3. If not see *
19 * <http://www.gnu.org/licenses/>. *
20 * *
21 * GNAT was originally developed by the GNAT team at New York University. *
22 * Extensive contributions were provided by Ada Core Technologies Inc. *
23 * *
24 ****************************************************************************/
55 /* "stdcall" and "thiscall" conventions should be processed in a specific way
56 on 32-bit x86/Windows only. The macros below are helpers to avoid having
57 to check for a Windows specific attribute throughout this unit. */
59 #if TARGET_DLLIMPORT_DECL_ATTRIBUTES
60 #ifdef TARGET_64BIT
61 #define Has_Stdcall_Convention(E) \
62 (!TARGET_64BIT && Convention (E) == Convention_Stdcall)
63 #define Has_Thiscall_Convention(E) \
64 (!TARGET_64BIT && is_cplusplus_method (E))
65 #else
66 #define Has_Stdcall_Convention(E) (Convention (E) == Convention_Stdcall)
67 #define Has_Thiscall_Convention(E) (is_cplusplus_method (E))
68 #endif
69 #else
70 #define Has_Stdcall_Convention(E) 0
71 #define Has_Thiscall_Convention(E) 0
72 #endif
76 /* Stack realignment is necessary for functions with foreign conventions when
77 the ABI doesn't mandate as much as what the compiler assumes - that is, up
78 to PREFERRED_STACK_BOUNDARY.
80 Such realignment can be requested with a dedicated function type attribute
81 on the targets that support it. We define FOREIGN_FORCE_REALIGN_STACK to
82 characterize the situations where the attribute should be set. We rely on
83 compiler configuration settings for 'main' to decide. */
85 #ifdef MAIN_STACK_BOUNDARY
86 #define FOREIGN_FORCE_REALIGN_STACK \
87 (MAIN_STACK_BOUNDARY < PREFERRED_STACK_BOUNDARY)
88 #else
89 #define FOREIGN_FORCE_REALIGN_STACK 0
90 #endif
92 struct incomplete
93 {
95 tree old_type;
96 Entity_Id full_type;
97 };
99 /* These variables are used to defer recursively expanding incomplete types
100 while we are processing a record, an array or a subprogram type. */
104 /* This variable is used to delay expanding types coming from a limited with
105 clause and completed Taft Amendment types until the end of the spec. */
109 tree discriminant;
110 tree replacement;
115 /* The type of the variant. */
116 tree type;
118 /* The associated field. */
119 tree field;
121 /* The value of the qualifier. */
122 tree qual;
124 /* The type of the variant after transformation. */
125 tree new_type;
129 /* A map used to cache the result of annotate_value. */
131 {
134 {
136 }
140 {
142 }
144 static int
146 {
148 }
149 };
153 /* A map used to associate a dummy type with a list of subprogram entities. */
155 {
158 };
160 void
162 {
163 }
165 void
167 {
169 }
172 {
175 {
177 }
181 {
183 }
185 static int
187 {
189 }
190 };
223 tree *);
247 /* The relevant constituents of a subprogram binding to a GCC builtin. Used
248 to pass around calls performing profile compatibility checks. */
257 \f
258 /* Given GNAT_ENTITY, a GNAT defining identifier node, which denotes some Ada
259 entity, return the equivalent GCC tree for that entity (a ..._DECL node)
260 and associate the ..._DECL node with the input GNAT defining identifier.
262 If GNAT_ENTITY is a variable or a constant declaration, GNU_EXPR gives its
263 initial value (in GCC tree form). This is optional for a variable. For
264 a renamed entity, GNU_EXPR gives the object being renamed.
266 DEFINITION is true if this call is intended for a definition. This is used
267 for separate compilation where it is necessary to know whether an external
268 declaration or a definition must be created if the GCC equivalent was not
269 created previously. */
271 tree
273 {
274 /* Contains the kind of the input GNAT node. */
276 /* True if this is a type. */
278 /* True if this is an artificial entity. */
280 /* True if debug info is requested for this entity. */
282 /* True if this entity is to be considered as imported. */
283 const bool imported_p
285 /* For a type, contains the equivalent GNAT node to be used in gigi. */
287 /* Temporary used to walk the GNAT tree. */
288 Entity_Id gnat_temp;
289 /* Contains the GCC DECL node which is equivalent to the input GNAT node.
290 This node will be associated with the GNAT node by calling at the end
291 of the `switch' statement. */
293 /* Contains the GCC type to be used for the GCC node. */
295 /* Contains the GCC size tree to be used for the GCC node. */
297 /* Contains the GCC name to be used for the GCC node. */
298 tree gnu_entity_name;
299 /* True if we have already saved gnu_decl as a GNAT association. */
301 /* True if we incremented defer_incomplete_level. */
303 /* True if we incremented force_global. */
305 /* True if we should check to see if elaborated during processing. */
307 /* True if we made GNU_DECL and its type here. */
309 /* Size and alignment of the GCC node, if meaningful. */
311 /* Contains the list of attributes directly attached to the entity. */
314 /* Since a use of an Itype is a definition, process it as such if it is in
315 the main unit, except for E_Access_Subtype because it's actually a use
316 of its base type, and for E_Record_Subtype with cloned subtype because
317 it's actually a use of the cloned subtype, see below. */
319 && is_type
326 {
327 /* Ensure that we are in a subprogram mentioned in the Scope chain of
328 this entity, our current scope is global, or we encountered a task
329 or entry (where we can't currently accurately check scoping). */
332 {
335 }
340 {
345 gnat_temp
357 && (current_function_decl
359 {
362 }
363 }
365 /* This abort means the Itype has an incorrect scope, i.e. that its
366 scope does not correspond to the subprogram it is declared in. */
368 }
370 /* If we've already processed this entity, return what we got last time.
371 If we are defining the node, we should not have already processed it.
372 In that case, we will abort below when we try to save a new GCC tree
373 for this object. We also need to handle the case of getting a dummy
374 type when a Full_View exists but be careful so as not to trigger its
375 premature elaboration. */
378 {
387 {
388 gnu_decl
392 }
395 }
397 /* If this is a numeric or enumeral type, or an access type, a nonzero Esize
398 must be specified unless it was specified by the programmer. Exceptions
399 are for access-to-protected-subprogram types and all access subtypes, as
400 another GNAT type is used to lay out the GCC type for them. */
412 /* The RM size must be specified for all discrete and fixed-point types. */
416 /* If we get here, it means we have not yet done anything with this entity.
417 If we are not defining it, it must be a type or an entity that is defined
418 elsewhere or externally, otherwise we should have defined it already. */
420 || type_annotate_only
421 || is_type
428 /* Get the name of the entity and set up the line number and filename of
429 the original definition for use in any decl we make. Make sure we do not
430 inherit another source location. */
436 /* For cases when we are not defining (i.e., we are referencing from
437 another compilation unit) public entities, show we are at global level
438 for the purpose of computing scopes. Don't do this for components or
439 discriminants since the relevant test is whether or not the record is
440 being defined. */
448 /* Handle any attributes directly attached to the entity. */
452 /* Do some common processing for types. */
454 {
455 /* Compute the equivalent type to be used in gigi. */
458 /* Machine_Attributes on types are expected to be propagated to
459 subtypes. The corresponding Gigi_Rep_Items are only attached
460 to the first subtype though, so we handle the propagation here. */
467 /* Compute a default value for the size of an elementary type. */
469 {
479 else
484 }
485 }
488 {
491 {
492 /* The GNAT record where the component was defined. */
495 /* If the entity is a discriminant of an extended tagged type used to
496 rename a discriminant of the parent type, return the latter. */
500 {
501 gnu_decl
506 }
508 /* If the entity is an inherited component (in the case of extended
509 tagged record types), just return the original entity, which must
510 be a FIELD_DECL. Likewise for discriminants. If the entity is a
511 non-girder discriminant (in the case of derived untagged record
512 types), return the stored discriminant it renames. */
515 {
516 gnu_decl
519 /* GNU_DECL contains a PLACEHOLDER_EXPR for discriminants. */
523 }
525 /* Otherwise, if we are not defining this and we have no GCC type
526 for the containing record, make one for it. Then we should
527 have made our own equivalent. */
529 {
530 /* ??? If this is in a record whose scope is a protected
531 type and we have an Original_Record_Component, use it.
532 This is a workaround for major problems in protected type
533 handling. */
537 {
538 gnu_decl
542 }
543 else
544 {
547 }
551 }
553 /* Here we have no GCC type and this is a reference rather than a
554 definition. This should never happen. Most likely the cause is
555 reference before declaration in the GNAT tree for gnat_entity. */
557 }
560 /* Ignore constant definitions already marked with the error node. See
561 the N_Object_Declaration case of gnat_to_gnu for the rationale. */
565 {
568 }
570 /* Ignore deferred constant definitions without address clause since
571 they are processed fully in the front-end. If No_Initialization
572 is set, this is not a deferred constant but a constant whose value
573 is built manually. And constants that are renamings are handled
574 like variables. */
576 && !gnu_expr
580 {
584 }
586 /* If this is a use of a deferred constant without address clause,
587 get its full definition. */
591 {
592 gnu_decl
596 }
598 /* If we have a constant that we are not defining, get the expression it
599 was defined to represent. This is necessary to avoid generating dumb
600 elaboration code in simple cases, but we may throw it away later if it
601 is not a constant. But do not retrieve it if it is an allocator since
602 the designated type might still be dummy at this point. */
608 /* The expression may contain N_Expression_With_Actions nodes and
609 thus object declarations from other units. Discard them. */
610 gnu_expr
613 /* ... fall through ... */
619 {
621 /* Always create a variable for volatile objects and variables seen
622 constant but with a Linker_Section pragma. */
623 bool const_flag
636 /* We implement RM 13.3(19) for exported and imported (non-constant)
637 objects by making them volatile. */
638 bool volatile_flag
645 tree gnu_object_size;
647 /* We need to translate the renamed object even though we are only
648 referencing the renaming. But it may contain a call for which
649 we'll generate a temporary to hold the return value and which
650 is part of the definition of the renaming, so discard it. */
652 {
656 else
658 }
660 /* Get the type after elaborating the renamed object. */
664 else
665 {
668 /* If this is a standard exception definition, use the standard
669 exception type. This is necessary to make sure that imported
670 and exported views of exceptions are merged in LTO mode. */
674 }
676 /* For a debug renaming declaration, build a debug-only entity. */
678 {
679 /* Force a non-null value to make sure the symbol is retained. */
683 integer_minus_one_node));
691 }
693 /* If this is a loop variable, its type should be the base type.
694 This is because the code for processing a loop determines whether
695 a normal loop end test can be done by comparing the bounds of the
696 loop against those of the base type, which is presumed to be the
697 size used for computation. But this is not correct when the size
698 of the subtype is smaller than the type. */
702 /* Reject non-renamed objects whose type is an unconstrained array or
703 any object whose type is a dummy type or void. */
708 {
711 force_global--;
713 }
715 /* If an alignment is specified, use it if valid. Note that exceptions
716 are objects but don't have an alignment. We must do this before we
717 validate the size, since the alignment can affect the size. */
719 {
725 /* No point in changing the type if there is an address clause
726 as the final type of the object will be a reference type. */
729 else
730 {
733 gnu_type
737 /* If a padding record was made, declare it now since it will
738 never be declared otherwise. This is necessary to ensure
739 that its subtrees are properly marked. */
743 }
744 }
746 /* If we are defining the object, see if it has a Size and validate it
747 if so. If we are not defining the object and a Size clause applies,
748 simply retrieve the value. We don't want to ignore the clause and
749 it is expected to have been validated already. Then get the new
750 type, if any. */
759 {
760 gnu_type
766 }
768 /* If this object has self-referential size, it must be a record with
769 a default discriminant. We are supposed to allocate an object of
770 the maximum size in this case, unless it is a constant with an
771 initializing expression, in which case we can get the size from
772 that. Note that the resulting size may still be a variable, so
773 this may end up with an indirect allocation. */
776 {
778 {
781 {
782 /* If the initializing expression is itself a constant,
783 despite having a nominal type with self-referential
784 size, we can get the size directly from it. */
786 && TYPE_IS_PADDING_P
790 || DECL_READONLY_ONCE_ELAB
793 else
794 gnu_size
796 }
797 else
799 }
800 /* We may have no GNU_EXPR because No_Initialization is
801 set even though there's an Expression. */
806 gnu_size
808 (Etype
810 else
811 {
814 }
816 /* If the size isn't constant and we are at global level, call
817 elaborate_expression_1 to make a variable for it rather than
818 calculating it each time. */
822 }
824 /* If the size is zero byte, make it one byte since some linkers have
825 troubles with zero-sized objects. If the object will have a
826 template, that will make it nonzero so don't bother. Also avoid
827 doing that for an object renaming or an object with an address
828 clause, as we would lose useful information on the view size
829 (e.g. for null array slices) and we are not allocating the object
830 here anyway. */
842 /* If this is an object with no specified size and alignment, and
843 if either it is atomic or we are not optimizing alignment for
844 space and it is composite and not an exception, an Out parameter
845 or a reference to another object, and the size of its type is a
846 constant, set the alignment to the smallest one which is not
847 smaller than the size, with an appropriate cap. */
856 && !imported_p
862 /* If the object is set to have atomic components, find the component
863 type and validate it.
865 ??? Note that we ignore Has_Volatile_Components on objects; it's
866 not at all clear what to do in that case. */
868 {
877 }
879 /* If this is an aliased object with an unconstrained array nominal
880 subtype, make a type that includes the template. We will either
881 allocate or create a variable of that type, see below. */
885 {
887 gnu_type
889 gnu_type,
892 debug_info_p);
893 }
895 /* ??? If this is an object of CW type initialized to a value, try to
896 ensure that the object is sufficient aligned for this value, but
897 without pessimizing the allocation. This is a kludge necessary
898 because we don't support dynamic alignment. */
905 #ifdef MINIMUM_ATOMIC_ALIGNMENT
906 /* If the size is a constant and no alignment is specified, force
907 the alignment to be the minimum valid atomic alignment. The
908 restriction on constant size avoids problems with variable-size
909 temporaries; if the size is variable, there's no issue with
910 atomic access. Also don't do this for a constant, since it isn't
911 necessary and can interfere with constant replacement. Finally,
912 do not do it for Out parameters since that creates an
913 size inconsistency with In parameters. */
923 #endif
925 /* Make a new type with the desired size and alignment, if needed.
926 But do not take into account alignment promotions to compute the
927 size of the object. */
930 {
936 /* If a padding record was made, declare it now since it will
937 never be declared otherwise. This is necessary to ensure
938 that its subtrees are properly marked. */
942 }
944 /* Now check if the type of the object allows atomic access. */
948 /* If this is a renaming, avoid as much as possible to create a new
949 object. However, in some cases, creating it is required because
950 renaming can be applied to objects that are not names in Ada.
951 This processing needs to be applied to the raw expression so as
952 to make it more likely to rename the underlying object. */
954 {
955 /* If the renamed object had padding, strip off the reference to
956 the inner object and reset our type. */
959 /* Strip useless conversions around the object. */
961 {
964 }
966 /* Or else, if the renamed object has an unconstrained type with
967 default discriminant, use the padded type. */
971 /* Case 1: if this is a constant renaming stemming from a function
972 call, treat it as a normal object whose initial value is what
973 is being renamed. RM 3.3 says that the result of evaluating a
974 function call is a constant object. Therefore, it can be the
975 inner object of a constant renaming and the renaming must be
976 fully instantiated, i.e. it cannot be a reference to (part of)
977 an existing object. And treat other rvalues (addresses, null
978 expressions, constructors and literals) the same way. */
982 /* Expand_Dispatching_Call can prepend a comparison of the tags
983 before the call to "=". */
994 /* We need to detect the case where a temporary is created to
995 hold the return value, since we cannot safely rename it at
996 top level as it lives only in the elaboration routine. */
999 /* We also need to detect the case where the front-end creates
1000 a dangling 'reference to a function call at top level and
1001 substitutes it in the renaming, for example:
1003 q__b : boolean renames r__f.e (1);
1005 can be rewritten into:
1007 q__R1s : constant q__A2s := r__f'reference;
1008 [...]
1009 q__b : boolean renames q__R1s.all.e (1);
1011 We cannot safely rename the rewritten expression since the
1012 underlying object lives only in the elaboration routine. */
1014 && (inner
1018 ;
1020 /* Case 2: if the renaming entity need not be materialized, use
1021 the elaborated renamed expression for the renaming. But this
1022 means that the caller is responsible for evaluating the address
1023 of the renaming in the correct place for the definition case to
1024 instantiate the SAVE_EXPRs. */
1026 {
1029 gnu_decl
1033 /* We cannot evaluate the first arm of a COMPOUND_EXPR in the
1034 correct place for this case. */
1037 /* No DECL_EXPR will be created so the expression needs to be
1038 marked manually because it will likely be shared. */
1042 /* This assertion will fail if the renamed object isn't aligned
1043 enough as to make it possible to honor the alignment set on
1044 the renaming. */
1046 {
1051 }
1053 /* The expression might not be a DECL so save it manually. */
1058 }
1060 /* Case 3: otherwise, make a constant pointer to the object we
1061 are renaming and attach the object to the pointer after it is
1062 elaborated. The object will be referenced directly instead
1063 of indirectly via the pointer to avoid aliasing problems with
1064 non-addressable entities. The pointer is called a "renaming"
1065 pointer in this case. Note that we also need to preserve the
1066 volatility of the renamed object through the indirection. */
1067 else
1068 {
1072 gnu_type
1081 renamed_obj
1085 /* The expression needs to be marked manually because it will
1086 likely be shared, even for a definition since the ADDR_EXPR
1087 built below can cause the first few nodes to be folded. */
1094 else
1095 {
1096 gnu_expr
1099 gnu_expr
1101 gnu_expr);
1102 }
1103 }
1104 }
1106 /* If we are defining an aliased object whose nominal subtype is
1107 unconstrained, the object is a record that contains both the
1108 template and the object. If there is an initializer, it will
1109 have already been converted to the right type, but we need to
1110 create the template if there is no initializer. */
1112 && !gnu_expr
1115 /* Beware that padding might have been introduced above. */
1118 == RECORD_TYPE
1119 && TYPE_CONTAINS_TEMPLATE_P
1121 {
1122 tree template_field
1130 NULL_TREE);
1133 }
1135 /* Convert the expression to the type of the object if need be. */
1139 /* If this is a pointer that doesn't have an initializing expression,
1140 initialize it to NULL, unless the object is declared imported as
1141 per RM B.1(24). */
1144 && !gnu_expr
1148 /* If we are defining the object and it has an Address clause, we must
1149 either get the address expression from the saved GCC tree for the
1150 object if it has a Freeze node, or elaborate the address expression
1151 here since the front-end has guaranteed that the elaboration has no
1152 effects in this case. */
1154 {
1157 tree gnu_address
1163 /* Convert the type of the object to a reference type that can
1164 alias everything as per RM 13.3(19). */
1167 gnu_type
1171 const_flag
1177 /* If this is an aliased object with an unconstrained array nominal
1178 subtype, then it can overlay only another aliased object with an
1179 unconstrained array nominal subtype and compatible template. */
1183 {
1187 /* This is the pattern built for a regular object. */
1191 /* This is the pattern built for an overaligned object. */
1194 == PLUS_EXPR
1197 gnu_address
1201 else
1202 {
1205 gnat_entity);
1208 }
1209 }
1211 /* If we don't have an initializing expression for the underlying
1212 variable, the initializing expression for the pointer is the
1213 specified address. Otherwise, we have to make a COMPOUND_EXPR
1214 to assign both the address and the initial value. */
1217 else
1218 gnu_expr
1222 NULL_TREE,
1223 gnu_address),
1224 gnu_expr),
1225 gnu_address);
1226 }
1228 /* If it has an address clause and we are not defining it, mark it
1229 as an indirect object. Likewise for Stdcall objects that are
1230 imported. */
1233 {
1234 /* Convert the type of the object to a reference type that can
1235 alias everything as per RM 13.3(19). */
1238 gnu_type
1245 /* No point in taking the address of an initializing expression
1246 that isn't going to be used. */
1249 /* If it has an address clause whose value is known at compile
1250 time, make the object a CONST_DECL. This will avoid a
1251 useless dereference. */
1253 {
1254 Node_Id gnat_address
1258 {
1261 }
1262 }
1263 }
1265 /* If we are at top level and this object is of variable size,
1266 make the actual type a hidden pointer to the real type and
1267 make the initializer be a memory allocation and initialization.
1268 Likewise for objects we aren't defining (presumed to be
1269 external references from other packages), but there we do
1270 not set up an initialization.
1272 If the object's size overflows, make an allocator too, so that
1273 Storage_Error gets raised. Note that we will never free
1274 such memory, so we presume it never will get allocated. */
1277 || !definition
1279 || (gnu_size
1281 size_binop
1283 bitsize_unit_node)),
1285 || !definition
1287 {
1296 /* In case this was a aliased object whose nominal subtype is
1297 unconstrained, the pointer above will be a thin pointer and
1298 build_allocator will automatically make the template.
1300 If we have a template initializer only (that we made above),
1301 pretend there is none and rely on what build_allocator creates
1302 again anyway. Otherwise (if we have a full initializer), get
1303 the data part and feed that to build_allocator.
1305 If we are elaborating a mutable object, tell build_allocator to
1306 ignore a possibly simpler size from the initializer, if any, as
1307 we must allocate the maximum possible size in this case. */
1309 {
1314 {
1315 gnu_alloc_type
1321 else
1322 gnu_expr
1323 = build_component_ref
1327 }
1332 gnat_entity);
1334 gnu_expr
1337 }
1338 else
1340 }
1342 /* If this object would go into the stack and has an alignment larger
1343 than the largest stack alignment the back-end can honor, resort to
1344 a variable of "aligning type". */
1347 && !imported_p
1348 && !static_flag
1350 {
1351 /* Create the new variable. No need for extra room before the
1352 aligned field as this is in automatic storage. */
1353 tree gnu_new_type
1357 tree gnu_new_var
1362 gnat_entity);
1364 /* Initialize the aligned field if we have an initializer. */
1366 add_stmt_with_node
1368 build_component_ref
1371 gnu_expr),
1372 gnat_entity);
1374 /* And setup this entity as a reference to the aligned field. */
1376 gnu_expr
1377 = build_unary_op
1387 }
1389 /* If this is an aggregate constant initialized to a constant, force it
1390 to be statically allocated. This saves an initialization copy. */
1392 && const_flag
1393 && gnu_expr
1402 /* If this is an aliased object with an unconstrained array nominal
1403 subtype, we make its type a thin reference, i.e. the reference
1404 counterpart of a thin pointer, so it points to the array part.
1405 This is aimed to make it easier for the debugger to decode the
1406 object. Note that we have to do it this late because of the
1407 couple of allocation adjustments that might be made above. */
1411 {
1412 /* In case the object with the template has already been allocated
1413 just above, we have nothing to do here. */
1415 {
1416 /* This variable is a GNAT encoding used by Workbench: let it
1417 go through the debugging information but mark it as
1418 artificial: users are not interested in it. */
1419 tree gnu_unc_var
1435 }
1438 gnu_type
1440 }
1442 /* Convert the expression to the type of the object if need be. */
1446 /* If this name is external or a name was specified, use it, but don't
1447 use the Interface_Name with an address clause (see cd30005). */
1453 /* Deal with a pragma Linker_Section on a constant or variable. */
1459 /* Now create the variable or the constant and set various flags. */
1460 gnu_decl
1471 /* If we are defining an Out parameter and optimization isn't enabled,
1472 create a fake PARM_DECL for debugging purposes and make it point to
1473 the VAR_DECL. Suppress debug info for the latter but make sure it
1474 will live in memory so that it can be accessed from within the
1475 debugger through the PARM_DECL. */
1477 && definition
1478 && debug_info_p
1479 && !optimize
1481 {
1488 }
1490 /* If this is a loop parameter, set the corresponding flag. */
1494 /* If this is a renaming pointer, attach the renamed object to it. */
1498 /* If this is a constant and we are defining it or it generates a real
1499 symbol at the object level and we are referencing it, we may want
1500 or need to have a true variable to represent it:
1501 - if optimization isn't enabled, for debugging purposes,
1502 - if the constant is public and not overlaid on something else,
1503 - if its address is taken,
1504 - if either itself or its type is aliased. */
1513 {
1514 tree gnu_corr_var
1522 }
1524 /* If this is a constant, even if we don't need a true variable, we
1525 may need to avoid returning the initializer in every case. That
1526 can happen for the address of a (constant) constructor because,
1527 upon dereferencing it, the constructor will be reinjected in the
1528 tree, which may not be valid in every case; see lvalue_required_p
1529 for more details. */
1533 /* If this object is declared in a block that contains a block with an
1534 exception handler, and we aren't using the GCC exception mechanism,
1535 we must force this variable in memory in order to avoid an invalid
1536 optimization. */
1541 /* If this is a local variable with non-BLKmode and aggregate type,
1542 and optimization isn't enabled, then force it in memory so that
1543 a register won't be allocated to it with possible subparts left
1544 uninitialized and reaching the register allocator. */
1554 /* If we are defining an object with variable size or an object with
1555 fixed size that will be dynamically allocated, and we are using the
1556 front-end setjmp/longjmp exception mechanism, update the setjmp
1557 buffer. */
1570 gnat_entity);
1572 /* Back-annotate Esize and Alignment of the object if not already
1573 known. Note that we pick the values of the type, not those of
1574 the object, to shield ourselves from low-level platform-dependent
1575 adjustments like alignment promotion. This is both consistent with
1576 all the treatment above, where alignment and size are set on the
1577 type of the object and not on the object directly, and makes it
1578 possible to support all confirming representation clauses. */
1580 used_by_ref);
1581 }
1585 /* Return a TYPE_DECL for "void" that we previously made. */
1590 /* A special case: for the types Character and Wide_Character in
1591 Standard, we do not list all the literals. So if the literals
1592 are not specified, make this an integer type. */
1594 {
1597 else
1601 /* Set TYPE_STRING_FLAG for Character and Wide_Character types.
1602 This is needed by the DWARF-2 back-end to distinguish between
1603 unsigned integer types and character types. */
1606 /* This flag is needed by the call just below. */
1610 }
1611 else
1612 {
1613 /* We have a list of enumeral constants in First_Literal. We make a
1614 CONST_DECL for each one and build into GNU_LITERAL_LIST the list
1615 to be placed into TYPE_FIELDS. Each node is itself a TREE_LIST
1616 whose TREE_VALUE is the literal name and whose TREE_PURPOSE is the
1617 value of the literal. But when we have a regular boolean type, we
1618 simplify this a little by using a BOOLEAN_TYPE. */
1623 Entity_Id gnat_literal;
1636 {
1637 tree gnu_value
1639 /* Do not generate debug info for individual enumerators. */
1640 tree gnu_literal
1646 gnu_list
1648 }
1653 /* Note that the bounds are updated at the end of this function
1654 to avoid an infinite recursion since they refer to the type. */
1656 }
1660 /* For integer types, just make a signed type the appropriate number
1661 of bits. */
1667 {
1668 /* Small_Value is the scale factor. */
1674 /* Try to decode the scale factor and to save it for the fixed-point
1675 types debug hook. */
1677 /* There are various ways to describe the scale factor, however there
1678 are cases where back-end internals cannot hold it. In such cases,
1679 we output invalid scale factor for such cases (i.e. the 0/0
1680 rational constant) but we expect GNAT to output GNAT encodings,
1681 then. Thus, keep this in sync with
1682 Exp_Dbug.Is_Handled_Scale_Factor. */
1684 /* When encoded as 1/2**N or 1/10**N, describe the scale factor as a
1685 binary or decimal scale: it is easier to read for humans. */
1689 {
1690 /* Given RM restrictions on 'Small values, we assume here that
1691 the denominator fits in an int. */
1694 const tree exponent
1697 scale_factor
1699 integer_one_node,
1702 }
1704 /* Default to arbitrary scale factors descriptions. */
1705 else
1706 {
1711 {
1712 const tree gnu_num
1715 const tree gnu_den
1720 }
1721 else
1722 /* If compiler internals cannot represent arbitrary scale
1723 factors, output an invalid scale factor so that debugger
1724 don't try to handle them but so that we still have a type
1725 in the output. Note that GNAT */
1727 }
1731 }
1735 {
1736 /* For modular types, make the unsigned type of the proper number
1737 of bits and then set up the modulus, if required. */
1740 /* Packed Array Impl. Types are supposed to be subtypes only. */
1745 /* Get the modulus in this type. If it overflows, assume it is because
1746 it is equal to 2**Esize. Note that there is no overflow checking
1747 done on unsigned type, so we detect the overflow by looking for
1748 a modulus of zero, which is otherwise invalid. */
1752 {
1757 }
1759 /* If the upper bound is not maximal, make an extra subtype. */
1762 {
1769 }
1770 }
1779 /* For integral subtypes, we make a new INTEGER_TYPE. Note that we do
1780 not want to call create_range_type since we would like each subtype
1781 node to be distinct. ??? Historically this was in preparation for
1782 when memory aliasing is implemented, but that's obsolete now given
1783 the call to relate_alias_sets below.
1785 The TREE_TYPE field of the INTEGER_TYPE points to the base type;
1786 this fact is used by the arithmetic conversion functions.
1788 We elaborate the Ancestor_Subtype if it is not in the current unit
1789 and one of our bounds is non-static. We do this to ensure consistent
1790 naming in the case where several subtypes share the same bounds, by
1791 elaborating the first such subtype first, thus using its name. */
1800 /* Set the precision to the Esize except for bit-packed arrays. */
1805 /* First subtypes of Character are treated as Character; otherwise
1806 this should be an unsigned type if the base type is unsigned or
1807 if the lower bound is constant and non-negative or if the type
1808 is biased. However, even if the lower bound is constant and
1809 non-negative, we use a signed type for a subtype with the same
1810 size as its signed base type, because this eliminates useless
1811 conversions to it and gives more leeway to the optimizer; but
1812 this means that we will need to explicitly test for this case
1813 when we change the representation based on the RM size. */
1825 else
1829 SET_TYPE_RM_MIN_VALUE
1832 debug_info_p));
1834 SET_TYPE_RM_MAX_VALUE
1837 debug_info_p));
1842 /* Do the same processing for Character subtypes as for types. */
1844 {
1849 }
1851 /* Inherit our alias set from what we're a subtype of. Subtypes
1852 are not different types and a pointer can designate any instance
1853 within a subtype hierarchy. */
1856 /* One of the above calls might have caused us to be elaborated,
1857 so don't blow up if so. */
1859 {
1862 }
1864 /* Attach the TYPE_STUB_DECL in case we have a parallel type. */
1868 /* For a packed array, make the original array type a parallel/debug
1869 type. */
1873 discrete_type:
1875 /* We have to handle clauses that under-align the type specially. */
1878 && Present
1881 {
1885 }
1887 /* If the type we are dealing with represents a bit-packed array,
1888 we need to have the bits left justified on big-endian targets
1889 and right justified on little-endian targets. We also need to
1890 ensure that when the value is read (e.g. for comparison of two
1891 such values), we only get the good bits, since the unused bits
1892 are uninitialized. Both goals are accomplished by wrapping up
1893 the modular type in an enclosing record type. */
1896 {
1899 /* Set the RM size before wrapping up the original type. */
1904 /* Strip the ___XP suffix for standard DWARF. */
1908 /* Create a stripped-down declaration, mainly for debugging. */
1910 gnat_entity);
1912 /* Now save it and build the enclosing record type. */
1922 /* Propagate the alignment of the modular type to the record type,
1923 unless there is an alignment clause that under-aligns the type.
1924 This means that bit-packed arrays are given "ceil" alignment for
1925 their size by default, which may seem counter-intuitive but makes
1926 it possible to overlay them on modular types easily. */
1930 /* Propagate the reverse storage order flag to the record type so
1931 that the required byte swapping is performed when retrieving the
1932 enclosed modular value. */
1938 /* Don't declare the field as addressable since we won't be taking
1939 its address and this would prevent create_field_decl from making
1940 a bitfield. */
1941 gnu_field
1945 /* We will output additional debug info manually below. */
1951 {
1952 /* Make the original array type a parallel/debug type. */
1955 /* Since GNU_TYPE is a padding type around the packed array
1956 implementation type, the padded type is its debug type. */
1959 }
1960 }
1962 /* If the type we are dealing with has got a smaller alignment than the
1963 natural one, we need to wrap it up in a record type and misalign the
1964 latter; we reuse the padding machinery for this purpose. */
1966 {
1969 /* Set the RM size before wrapping the type. */
1972 gnu_type
1978 }
1983 /* The type of the Low and High bounds can be our type if this is
1984 a type from Standard, so set them at the end of the function. */
1991 /* See the E_Signed_Integer_Subtype case for the rationale. */
2008 SET_TYPE_RM_MIN_VALUE
2011 debug_info_p));
2013 SET_TYPE_RM_MAX_VALUE
2016 debug_info_p));
2018 /* Inherit our alias set from what we're a subtype of, as for
2019 integer subtypes. */
2022 /* One of the above calls might have caused us to be elaborated,
2023 so don't blow up if so. */
2027 /* Array Types and Subtypes
2029 Unconstrained array types are represented by E_Array_Type and
2030 constrained array types are represented by E_Array_Subtype. There
2031 are no actual objects of an unconstrained array type; all we have
2032 are pointers to that type.
2034 The following fields are defined on array types and subtypes:
2036 Component_Type Component type of the array.
2037 Number_Dimensions Number of dimensions (an int).
2038 First_Index Type of first index. */
2041 {
2042 const bool convention_fortran_p
2045 tree gnu_template_type;
2046 tree gnu_ptr_template;
2053 tree comp_type;
2055 /* Create the type for the component now, as it simplifies breaking
2056 type reference loops. */
2057 comp_type
2060 {
2061 /* As a side effect, the type may have been translated. */
2064 }
2066 /* We complete an existing dummy fat pointer type in place. This both
2067 avoids further complex adjustments in update_pointer_to and yields
2068 better debugging information in DWARF by leveraging the support for
2069 incomplete declarations of "tagged" types in the DWARF back-end. */
2072 {
2075 /* Save the contents of the dummy type for update_pointer_to. */
2077 gnu_ptr_template =
2080 }
2081 else
2082 {
2086 }
2088 /* Make a node for the array. If we are not defining the array
2089 suppress expanding incomplete types. */
2093 {
2094 defer_incomplete_level++;
2096 }
2098 /* Build the fat pointer type. Use a "void *" object instead of
2099 a pointer to the array type since we don't have the array type
2100 yet (it will reference the fat pointer via the bounds). */
2101 tem
2109 {
2110 /* We are going to lay it out again so reset the alias set. */
2116 {
2119 }
2120 }
2121 else
2122 {
2125 }
2127 /* Build a reference to the template from a PLACEHOLDER_EXPR that
2128 is the fat pointer. This will be used to access the individual
2129 fields once we build them. */
2133 gnu_template_reference
2138 /* Now create the GCC type for each index and add the fields for that
2139 index to the template. */
2145 {
2148 tree gnu_index_base_type
2153 /* Make the FIELD_DECLs for the low and high bounds of this
2154 type and then make extractions of these fields from the
2155 template. */
2158 gnu_index_base_type,
2166 gnu_index_base_type,
2174 /* We can't use build_component_ref here since the template type
2175 isn't complete yet. */
2178 NULL_TREE);
2181 NULL_TREE);
2187 /* Compute the size of this dimension. See the E_Array_Subtype
2188 case below for the rationale. */
2189 gnu_high
2193 gnu_max,
2196 /* Make a range type with the new range in the Ada base type.
2197 Then make an index type with the size range in sizetype. */
2201 gnu_orig_min,
2202 gnu_orig_max),
2203 gnat_entity);
2205 /* Update the maximum size of the array in elements. */
2207 {
2208 tree gnu_min
2210 tree gnu_max
2212 tree gnu_this_max
2219 else
2220 gnu_max_size
2222 }
2226 }
2228 /* Install all the fields into the template. */
2233 gnu_template_fields
2236 debug_info_p);
2239 /* If Component_Size is not already specified, annotate it with the
2240 size of the component. */
2245 /* Compute the maximum size of the array in units and bits. */
2247 {
2253 }
2254 else
2257 /* Now build the array type. */
2260 {
2268 }
2270 /* If an alignment is specified, use it if valid. But ignore it
2271 for the original type of packed array types. If the alignment
2272 was requested with an explicit alignment clause, state so. */
2275 {
2278 gnat_entity,
2282 }
2284 /* Tag top-level ARRAY_TYPE nodes for packed arrays and their
2285 implementation types as such so that the debug information back-end
2286 can output the appropriate description for them. */
2294 /* Adjust the type of the pointer-to-array field of the fat pointer
2295 and record the aliasing relationships if necessary. */
2300 /* The result type is an UNCONSTRAINED_ARRAY_TYPE that indicates the
2301 corresponding fat pointer. */
2308 /* If the maximum size doesn't overflow, use it. */
2314 {
2319 }
2324 /* If told to generate GNAT encodings for them (GDB rely on them at the
2325 moment): give the fat pointer type a name. If this is a packed
2326 array, tell the debugger how to interpret the underlying bits. */
2329 else
2331 tree xup_name
2336 gnat_entity);
2338 /* Create the type to be designated by thin pointers: a record type for
2339 the array and its template. We used to shift the fields to have the
2340 template at a negative offset, but this was somewhat of a kludge; we
2341 now shift thin pointer values explicitly but only those which have a
2342 TYPE_UNCONSTRAINED_ARRAY attached to the designated RECORD_TYPE.
2343 Note that GDB can handle standard DWARF information for them, so we
2344 don't have to name them as a GNAT encoding, except if specifically
2345 asked to. */
2346 tree xut_name
2351 debug_info_p);
2355 }
2360 /* This is the actual data type for array variables. Multidimensional
2361 arrays are implemented as arrays of arrays. Note that arrays which
2362 have sparse enumeration subtypes as index components create sparse
2363 arrays, which is obviously space inefficient but so much easier to
2364 code for now.
2366 Also note that the subtype never refers to the unconstrained array
2367 type, which is somewhat at variance with Ada semantics.
2369 First check to see if this is simply a renaming of the array type.
2370 If so, the result is the array type. */
2374 ;
2375 else
2376 {
2378 const bool convention_fortran_p
2387 /* First create the GCC type for each index and find out whether
2388 special types are needed for debugging information. */
2391 gnat_base_index
2397 {
2399 tree gnu_index_base_type
2401 tree gnu_orig_min
2404 tree gnu_orig_max
2409 tree gnu_base_index_type
2411 tree gnu_base_index_base_type
2413 tree gnu_base_orig_min
2416 tree gnu_base_orig_max
2419 tree gnu_high;
2421 /* See if the base array type is already flat. If it is, we
2422 are probably compiling an ACATS test but it will cause the
2423 code below to malfunction if we don't handle it specially. */
2427 {
2431 }
2433 /* Similarly, if one of the values overflows in sizetype and the
2434 range is null, use 1..0 for the sizetype bounds. */
2439 {
2443 }
2445 /* If the minimum and maximum values both overflow in sizetype,
2446 but the difference in the original type does not overflow in
2447 sizetype, ignore the overflow indication. */
2451 && !TREE_OVERFLOW
2454 gnu_orig_max,
2455 gnu_orig_min))))
2456 {
2460 }
2462 /* Compute the size of this dimension in the general case. We
2463 need to provide GCC with an upper bound to use but have to
2464 deal with the "superflat" case. There are three ways to do
2465 this. If we can prove that the array can never be superflat,
2466 we can just use the high bound of the index type. */
2469 /* Bit-Packed Array Impl. Types are never superflat. */
2471 && Is_Bit_Packed_Array
2475 /* Otherwise, if the high bound is constant but the low bound is
2476 not, we use the expression (hb >= lb) ? lb : hb + 1 for the
2477 lower bound. Note that the comparison must be done in the
2478 original type to avoid any overflow during the conversion. */
2481 {
2483 gnu_min
2486 boolean_type_node,
2487 gnu_orig_max,
2488 gnu_orig_min),
2489 gnu_min,
2491 size_one_node));
2492 }
2494 /* Finally we use (hb >= lb) ? hb : lb - 1 for the upper bound
2495 in all the other cases. Note that, here as well as above,
2496 the condition used in the comparison must be equivalent to
2497 the condition (length != 0). This is relied upon in order
2498 to optimize array comparisons in compare_arrays. Moreover
2499 we use int_const_binop for the shift by 1 if the bound is
2500 constant to avoid any unwanted overflow. */
2501 else
2502 gnu_high
2505 boolean_type_node,
2506 gnu_orig_max,
2507 gnu_orig_min),
2508 gnu_max,
2511 size_one_node)
2513 size_one_node));
2515 /* Reuse the index type for the range type. Then make an index
2516 type with the size range in sizetype. */
2519 gnat_entity);
2521 /* Update the maximum size of the array in elements. Here we
2522 see if any constraint on the index type of the base type
2523 can be used in the case of self-referential bound on the
2524 index type of the subtype. We look for a non-"infinite"
2525 and non-self-referential bound from any type involved and
2526 handle each bound separately. */
2528 {
2531 tree gnu_base_base_min
2534 tree gnu_base_base_max
2555 else
2556 {
2557 tree gnu_this_max;
2559 /* Use int_const_binop if the bounds are constant to
2560 avoid any unwanted overflow. */
2563 gnu_this_max
2566 gnu_base_max,
2567 gnu_base_min));
2568 else
2569 gnu_this_max
2572 gnu_base_max,
2573 gnu_base_min));
2575 gnu_max_size
2577 }
2578 }
2580 /* We need special types for debugging information to point to
2581 the index types if they have variable bounds, are not integer
2582 types, are biased or are wider than sizetype. These are GNAT
2583 encodings, so we have to include them only when all encodings
2584 are requested. */
2594 }
2596 /* Then flatten: create the array of arrays. For an array type
2597 used to implement a packed array, get the component type from
2598 the original array type since the representation clauses that
2599 can affect it are on the latter. */
2602 {
2607 /* One of the above calls might have caused us to be elaborated,
2608 so don't blow up if so. */
2610 {
2613 }
2614 }
2615 else
2616 {
2618 debug_info_p);
2620 /* One of the above calls might have caused us to be elaborated,
2621 so don't blow up if so. */
2623 {
2626 }
2627 }
2629 /* Compute the maximum size of the array in units and bits. */
2631 {
2637 }
2638 else
2641 /* Now build the array type. */
2643 {
2652 }
2654 /* Strip the ___XP suffix for standard DWARF. */
2657 {
2658 Entity_Id gnat_original_array_type
2661 gnu_entity_name
2663 }
2665 /* Attach the TYPE_STUB_DECL in case we have a parallel type. */
2669 /* If this is a multi-dimensional array and we are at global level,
2670 we need to make a variable corresponding to the stride of the
2671 inner dimensions. */
2673 {
2674 tree gnu_arr_type;
2679 {
2689 /* ??? For now, store the size as a multiple of the
2690 alignment of the element type in bytes so that we
2691 can see the alignment from the tree. */
2699 /* ??? create_type_decl is not invoked on the inner types so
2700 the MULT_EXPR node built above will never be marked. */
2702 }
2703 }
2705 /* If we need to write out a record type giving the names of the
2706 bounds for debugging purposes, do it now and make the record
2707 type a parallel type. This is not needed for a packed array
2708 since the bounds are conveyed by the original array type. */
2710 && debug_info_p
2712 {
2715 tree gnu_field;
2721 {
2725 /* Make sure to reference the types themselves, and not just
2726 their names, as the debugger may fall back on them. */
2732 }
2736 }
2738 /* If this is a packed array type, make the original array type a
2739 parallel/debug type. Otherwise, if such GNAT encodings are
2740 required, do it for the base array type if it isn't artificial to
2741 make sure it is kept in the debug info. */
2743 {
2746 gnat_entity);
2747 else
2748 {
2749 tree gnu_base_decl
2756 }
2757 }
2763 /* Tag top-level ARRAY_TYPE nodes for packed arrays and their
2764 implementation types as such so that the debug information back-end
2765 can output the appropriate description for them. */
2770 /* If the size is self-referential and the maximum size doesn't
2771 overflow, use it. */
2773 && gnu_max_size
2778 {
2784 }
2786 /* Set our alias set to that of our base type. This gives all
2787 array subtypes the same alias set. */
2790 /* If this is a packed type, make this type the same as the packed
2791 array type, but do some adjusting in the type first. */
2793 {
2794 Entity_Id gnat_index;
2795 tree gnu_inner;
2797 /* First finish the type we had been making so that we output
2798 debugging information for it. */
2801 {
2802 const int quals
2803 = TYPE_QUAL_VOLATILE
2806 }
2807 /* Make it artificial only if the base type was artificial too.
2808 That's sort of "morally" true and will make it possible for
2809 the debugger to look it up by name in DWARF, which is needed
2810 in order to decode the packed array type. */
2811 gnu_decl
2815 gnat_entity);
2817 /* Save it as our equivalent in case the call below elaborates
2818 this type again. */
2821 gnu_decl
2836 /* We need to attach the index type to the type we just made so
2837 that the actual bounds can later be put into a template. */
2842 {
2844 {
2845 /* The TYPE_ACTUAL_BOUNDS field is overloaded with the
2846 TYPE_MODULUS for modular types so we make an extra
2847 subtype if necessary. */
2849 {
2850 tree gnu_subtype
2859 }
2863 /* Check for other cases of overloading. */
2865 }
2870 SET_TYPE_ACTUAL_BOUNDS
2877 SET_TYPE_ACTUAL_BOUNDS
2883 }
2884 }
2885 }
2889 /* Create the type for a string literal. */
2890 {
2891 Entity_Id gnat_full_type
2896 tree gnu_string_array_type
2898 tree gnu_string_index_type
2901 tree gnu_lower_bound
2904 tree gnu_length
2906 gnu_string_index_type);
2907 tree gnu_upper_bound
2909 gnu_lower_bound,
2912 integer_one_node)));
2913 tree gnu_index_type
2917 gnu_lower_bound,
2918 gnu_upper_bound),
2919 gnat_entity);
2921 gnu_type
2924 gnu_index_type);
2928 }
2931 /* Record Types and Subtypes
2933 The following fields are defined on record types:
2935 Has_Discriminants True if the record has discriminants
2936 First_Discriminant Points to head of list of discriminants
2937 First_Entity Points to head of list of fields
2938 Is_Tagged_Type True if the record is tagged
2940 Implementation of Ada records and discriminated records:
2942 A record type definition is transformed into the equivalent of a C
2943 struct definition. The fields that are the discriminants which are
2944 found in the Full_Type_Declaration node and the elements of the
2945 Component_List found in the Record_Type_Definition node. The
2946 Component_List can be a recursive structure since each Variant of
2947 the Variant_Part of the Component_List has a Component_List.
2949 Processing of a record type definition comprises starting the list of
2950 field declarations here from the discriminants and the calling the
2951 function components_to_record to add the rest of the fields from the
2952 component list and return the gnu type node. The function
2953 components_to_record will call itself recursively as it traverses
2954 the tree. */
2958 {
2959 gnu_type
2960 = build_complex_type
2961 (get_unpadded_type
2964 (Component_List
2965 (Type_Definition
2969 }
2971 {
2974 Node_Id gnat_constr;
2977 tree gnu_get_parent;
2978 /* Set PACKED in keeping with gnat_to_gnu_field. */
2979 const int packed
2988 const bool is_extension
2994 /* See if all fields have a rep clause. Stop when we find one
2995 that doesn't. */
3003 {
3006 }
3008 /* If this is a record extension, go a level further to find the
3009 record definition. Also, verify we have a Parent_Subtype. */
3011 {
3018 }
3020 /* Make a node for the record. If we are not defining the record,
3021 suppress expanding incomplete types. */
3030 {
3031 defer_incomplete_level++;
3033 }
3035 /* If both a size and rep clause were specified, put the size on
3036 the record type now so that it can get the proper layout. */
3041 /* Always set the alignment on the record type here so that it can
3042 get the proper layout. */
3047 else
3048 {
3051 /* If a type needs strict alignment, the minimum size will be the
3052 type size instead of the RM size (see validate_size). Cap the
3053 alignment lest it causes this type size to become too large. */
3055 {
3060 }
3061 }
3063 /* If we have a Parent_Subtype, make a field for the parent. If
3064 this record has rep clauses, force the position to zero. */
3066 {
3069 tree gnu_parent;
3072 /* A major complexity here is that the parent subtype will
3073 reference our discriminants in its Stored_Constraint list.
3074 But those must reference the parent component of this record
3075 which is precisely of the parent subtype we have not built yet!
3076 To break the circle we first build a dummy COMPONENT_REF which
3077 represents the "get to the parent" operation and initialize
3078 each of those discriminants to a COMPONENT_REF of the above
3079 dummy parent referencing the corresponding discriminant of the
3080 base type of the parent subtype. */
3085 gnu_dummy_parent_type),
3086 NULL_TREE);
3093 {
3094 tree gnu_field
3097 save_gnu_tree
3102 }
3104 /* Then we build the parent subtype. If it has discriminants but
3105 the type itself has unknown discriminants, this means that it
3106 doesn't contain information about how the discriminants are
3107 derived from those of the ancestor type, so it cannot be used
3108 directly. Instead it is built by cloning the parent subtype
3109 of the underlying record view of the type, for which the above
3110 derivation of discriminants has been made explicit. */
3113 {
3116 /* If we are defining the type, the underlying record
3117 view must already have been elaborated at this point.
3118 Otherwise do it now as its parent subtype cannot be
3119 technically elaborated on its own. */
3122 else
3127 /* Substitute the "get to the parent" of the type for that
3128 of its underlying record view in the cloned type. */
3133 {
3135 tree gnu_ref
3138 gnu_parent
3140 }
3141 }
3142 else
3145 /* The parent field needs strict alignment so, if it is to
3146 be created with a component clause below, then we need
3147 to apply the same adjustment as in gnat_to_gnu_field. */
3149 {
3150 /* ??? For historical reasons, we do it on strict-alignment
3151 platforms only, where it is really required. This means
3152 that a confirming representation clause will change the
3153 behavior of the compiler on the other platforms. */
3156 else
3157 parent_packed
3159 }
3161 /* Finally we fix up both kinds of twisted COMPONENT_REF we have
3162 initially built. The discriminants must reference the fields
3163 of the parent subtype and not those of its base type for the
3164 placeholder machinery to properly work. */
3166 {
3167 /* The actual parent subtype is the full view. */
3169 {
3172 else
3174 }
3180 {
3181 Entity_Id field;
3190 }
3191 }
3193 /* The "get to the parent" COMPONENT_REF must be given its
3194 proper type... */
3197 /* ...and reference the _Parent field of this record. */
3198 gnu_field
3201 has_rep
3203 has_rep
3209 }
3211 /* Make the fields for the discriminants and put them into the record
3212 unless it's an Unchecked_Union. */
3217 {
3218 /* If this is a record extension and this discriminant is the
3219 renaming of another discriminant, we've handled it above. */
3224 gnu_field
3226 debug_info_p);
3228 /* Make an expression using a PLACEHOLDER_EXPR from the
3229 FIELD_DECL node just created and link that with the
3230 corresponding GNAT defining identifier. */
3238 {
3241 }
3242 }
3244 /* If we have a derived untagged type that renames discriminants in
3245 the parent type, the (stored) discriminants are just a copy of the
3246 discriminants of the parent type. This means that any constraints
3247 added by the renaming in the derivation are disregarded as far as
3248 the layout of the derived type is concerned. To rescue them, we
3249 change the type of the (stored) discriminants to a subtype with
3250 the bounds of the type of the visible discriminants. */
3252 && !is_extension
3258 /* Ignore access discriminants. */
3261 {
3264 tree gnu_ref
3268 /* GNU_REF must be an expression using a PLACEHOLDER_EXPR built
3269 just above for one of the stored discriminants. */
3273 {
3275 tree gnu_subtype
3286 }
3287 }
3289 /* If this is a derived type with discriminants and these discriminants
3290 affect the initial shape it has inherited, factor them in. */
3292 && !is_extension
3300 {
3301 tree gnu_parent_type
3310 /* Set the layout of the type to match that of the parent type,
3311 doing required substitutions. If we are in minimal GNAT
3312 encodings mode, we don't need debug info for the inner record
3313 types, as they will be part of the embedding variant record's
3314 debug info. */
3315 copy_and_substitute_in_layout
3317 gnu_subst_list,
3319 }
3320 else
3321 {
3322 /* Add the fields into the record type and finish it up. */
3329 NULL);
3331 /* If there are entities in the chain corresponding to components
3332 that we did not elaborate, ensure we elaborate their types if
3333 they are Itypes. */
3342 }
3344 /* Fill in locations of fields. */
3347 /* If this is a record type associated with an exception definition,
3348 equate its fields to those of the standard exception type. This
3349 will make it possible to convert between them. */
3351 {
3352 tree gnu_std_field;
3355 gnu_field;
3360 }
3361 }
3365 /* If an equivalent type is present, that is what we should use.
3366 Otherwise, fall through to handle this like a record subtype
3367 since it may have constraints. */
3369 {
3373 }
3375 /* ... fall through ... */
3378 /* If Cloned_Subtype is Present it means this record subtype has
3379 identical layout to that type or subtype and we should use
3380 that GCC type for this one. The front end guarantees that
3381 the component list is shared. */
3383 {
3388 }
3390 /* Otherwise, first ensure the base type is elaborated. Then, if we are
3391 changing the type, make a new type with each field having the type of
3392 the field in the new subtype but the position computed by transforming
3393 every discriminant reference according to the constraints. We don't
3394 see any difference between private and non-private type here since
3395 derivations from types should have been deferred until the completion
3396 of the private type. */
3397 else
3398 {
3402 {
3403 defer_incomplete_level++;
3405 }
3407 tree gnu_base_type
3411 {
3414 }
3416 /* If this is a record subtype associated with a dispatch table,
3417 strip the suffix. This is necessary to make sure 2 different
3418 subtypes associated with the imported and exported views of a
3419 dispatch table are properly merged in LTO mode. */
3421 {
3428 }
3430 /* When the subtype has discriminants and these discriminants affect
3431 the initial shape it has inherited, factor them in. But for an
3432 Unchecked_Union (it must be an Itype), just return the type. */
3438 {
3441 tree gnu_unpad_base_type;
3446 {
3447 /* Use the ultimate base record type as the debug type.
3448 Subtypes and derived types bring no useful
3449 information. */
3453 tree gnu_debug_type
3456 }
3462 /* Set the size, alignment and alias set of the type to match
3463 those of the base type, doing required substitutions. */
3465 gnu_subst_list);
3469 else
3472 /* Set the layout of the type to match that of the base type,
3473 doing required substitutions. We will output debug info
3474 manually below so pass false as last argument. */
3479 /* Fill in locations of fields. */
3482 /* If debugging information is being written for the type and if
3483 we are asked to output such encodings, write a record that
3484 shows what we are a subtype of and also make a variable that
3485 indicates our size, if still variable. */
3487 {
3489 tree gnu_unpad_base_name
3497 build_reference_type
3499 gnu_subtype_marker,
3516 }
3517 }
3519 /* Otherwise, go down all the components in the new type and make
3520 them equivalent to those in the base type. */
3521 else
3522 {
3532 gnat_to_gnu_field_decl
3535 }
3536 }
3541 /* Use the special descriptor type for dispatch tables if needed,
3542 that is to say for the Prim_Ptr of a-tags.ads and its clones.
3543 Note that we are only required to do so for static tables in
3544 order to be compatible with the C++ ABI, but Ada 2005 allows
3545 to extend library level tagged types at the local level so
3546 we do it in the non-static case as well. */
3549 {
3553 }
3555 /* ... fall through ... */
3562 {
3563 /* The designated type and its equivalent type for gigi. */
3566 /* Whether it comes from a limited with. */
3567 const bool is_from_limited_with
3570 /* Whether it is a completed Taft Amendment type. Such a type is to
3571 be treated as coming from a limited with clause if it is not in
3572 the main unit, i.e. we break potential circularities here in case
3573 the body of an external unit is loaded for inter-unit inlining. */
3574 const bool is_completed_taft_type
3578 /* The "full view" of the designated type. If this is an incomplete
3579 entity from a limited with, treat its non-limited view as the full
3580 view. Otherwise, if this is an incomplete or private type, use the
3581 full view. In the former case, we might point to a private type,
3582 in which case, we need its full view. Also, we want to look at the
3583 actual type used for the representation, so this takes a total of
3584 three steps. */
3585 Entity_Id gnat_desig_full_direct_first
3586 = (is_from_limited_with
3590 Entity_Id gnat_desig_full_direct
3591 = ((is_from_limited_with
3596 Entity_Id gnat_desig_full
3598 /* The type actually used to represent the designated type, either
3599 gnat_desig_full or gnat_desig_equiv. */
3600 Entity_Id gnat_desig_rep;
3601 /* We want to know if we'll be seeing the freeze node for any
3602 incomplete type we may be pointing to. */
3603 const bool in_main_unit
3607 /* True if we make a dummy type here. */
3609 /* The mode to be used for the pointer type. */
3610 scalar_int_mode p_mode;
3611 /* The GCC type used for the designated type. */
3618 /* If either the designated type or its full view is an unconstrained
3619 array subtype, replace it with the type it's a subtype of. This
3620 avoids problems with multiple copies of unconstrained array types.
3621 Likewise, if the designated type is a subtype of an incomplete
3622 record type, use the parent type to avoid order of elaboration
3623 issues. This can lose some code efficiency, but there is no
3624 alternative. */
3635 /* Set the type that's the representation of the designated type. */
3636 gnat_desig_rep
3639 /* If we already know what the full type is, use it. */
3643 /* Get the type of the thing we are to point to and build a pointer to
3644 it. If it is a reference to an incomplete or private type with a
3645 full view that is a record, an array or an access, make a dummy type
3646 and get the actual type later when we have verified it is safe. */
3653 /* Likewise if this is a reference to a record, an array or a
3654 subprogram type and we are to defer elaborating incomplete
3655 types. We do this because this access type may be the full
3656 view of a private type. */
3663 /* If this is a reference from a limited_with type back to our
3664 main unit and there's a freeze node for it, either we have
3665 already processed the declaration and made the dummy type,
3666 in which case we just reuse the latter, or we have not yet,
3667 in which case we make the dummy type and it will be reused
3668 when the declaration is finally processed. In both cases,
3669 the pointer eventually created below will be automatically
3670 adjusted when the freeze node is processed. */
3671 || (in_main_unit
3672 && is_from_limited_with
3674 {
3677 }
3679 /* Otherwise handle the case of a pointer to itself. */
3681 {
3682 gnu_type
3686 }
3688 /* If expansion is disabled, the equivalent type of a concurrent type
3689 is absent, so we use the void pointer type. */
3693 /* If the ultimately designated type is an incomplete type with no full
3694 view, we use the void pointer type in LTO mode to avoid emitting a
3695 dummy type in the GIMPLE IR. We cannot do that in regular mode as
3696 the name of the dummy type in used by GDB for a global lookup. */
3702 /* Finally, handle the default case where we can just elaborate our
3703 designated type. */
3704 else
3707 /* It is possible that a call to gnat_to_gnu_type above resolved our
3708 type. If so, just return it. */
3710 {
3713 }
3715 /* Access-to-unconstrained-array types need a special treatment. */
3717 {
3718 /* If the processing above got something that has a pointer, then
3719 we are done. This could have happened either because the type
3720 was elaborated or because somebody else executed the code. */
3725 }
3727 /* If we haven't done it yet, build the pointer type the usual way. */
3729 {
3730 /* Modify the designated type if we are pointing only to constant
3731 objects, but don't do it for a dummy type. */
3734 gnu_desig_type
3737 gnu_type
3740 }
3742 /* If the designated type is not declared in the main unit and we made
3743 a dummy node for it, save our definition, elaborate the actual type
3744 and replace the dummy type we made with the actual one. But if we
3745 are to defer actually looking up the actual type, make an entry in
3746 the deferred list instead. If this is from a limited with, we may
3747 have to defer until the end of the current unit. */
3749 {
3751 gnu_type
3757 gnat_entity);
3764 && !is_from_limited_with
3766 {
3769 }
3770 else
3771 {
3781 }
3782 }
3783 }
3788 /* If we are just annotating types and have no equivalent record type,
3789 just use the void pointer type. */
3793 /* The run-time representation is the equivalent type. */
3794 else
3795 {
3798 }
3800 /* The designated subtype must be elaborated as well, if it does
3801 not have its own freeze node. */
3812 /* We treat this as identical to its base type; any constraint is
3813 meaningful only to the front-end. */
3817 /* The designated subtype must be elaborated as well, if it does
3818 not have its own freeze node. But designated subtypes created
3819 for constrained components of records with discriminants are
3820 not frozen by the front-end and not elaborated here, because
3821 their use may appear before the base type is frozen and it is
3822 not clear that they are needed in gigi. With the current model,
3823 there is no correct place where they could be elaborated. */
3828 {
3829 /* If we are to defer elaborating incomplete types, make a dummy
3830 type node and elaborate it later. */
3832 {
3835 p->old_type
3840 }
3845 }
3848 /* Subprogram Entities
3850 The following access functions are defined for subprograms:
3852 Etype Return type or Standard_Void_Type.
3853 First_Formal The first formal parameter.
3854 Is_Imported Indicates that the subprogram has appeared in
3855 an INTERFACE or IMPORT pragma. For now we
3856 assume that the external language is C.
3857 Is_Exported Likewise but for an EXPORT pragma.
3858 Is_Inlined True if the subprogram is to be inlined.
3860 Each parameter is first checked by calling must_pass_by_ref on its
3861 type to determine if it is passed by reference. For parameters which
3862 are copied in, if they are Ada In Out or Out parameters, their return
3863 value becomes part of a record which becomes the return type of the
3864 function (C function - note that this applies only to Ada procedures
3865 so there is no Ada return type). Additional code to store back the
3866 parameters will be generated on the caller side. This transformation
3867 is done here, not in the front-end.
3869 The intended result of the transformation can be seen from the
3870 equivalent source rewritings that follow:
3872 struct temp {int a,b};
3873 procedure P (A,B: In Out ...) is temp P (int A,B)
3874 begin {
3875 .. ..
3876 end P; return {A,B};
3877 }
3879 temp t;
3880 P(X,Y); t = P(X,Y);
3881 X = t.a , Y = t.b;
3883 For subprogram types we need to perform mainly the same conversions to
3884 GCC form that are needed for procedures and function declarations. The
3885 only difference is that at the end, we make a type declaration instead
3886 of a function declaration. */
3891 {
3892 tree gnu_ext_name
3894 enum inline_status_t inline_status
3896 ? is_suppressed
3898 ? is_required
3901 /* Subprograms marked both Intrinsic and Always_Inline need not
3902 have a body of their own. */
3903 bool extern_flag
3905 || imported_p
3908 tree gnu_param_list;
3910 /* A parameter may refer to this type, so defer completion of any
3911 incomplete types. */
3913 {
3914 defer_incomplete_level++;
3916 }
3918 /* If the subprogram has an alias, it is probably inherited, so
3919 we can use the original one. If the original "subprogram"
3920 is actually an enumeration literal, it may be the first use
3921 of its type, so we must elaborate that type now. */
3923 {
3930 gnu_decl
3933 /* Elaborate any Itypes in the parameters of this entity. */
3940 /* Materialize renamed subprograms in the debugging information
3941 when the renamed object is compile time known. We can consider
3942 such renamings as imported declarations.
3944 Because the parameters in generics instantiation are generally
3945 materialized as renamings, we ofter end up having both the
3946 renamed subprogram and the renaming in the same context and with
3947 the same name: in this case, renaming is both useless debug-wise
3948 and potentially harmful as name resolution in the debugger could
3949 return twice the same entity! So avoid this case. */
3958 && gnu_decl
3960 {
3965 }
3968 }
3970 /* Get the GCC tree for the (underlying) subprogram type. If the
3971 entity is an actual subprogram, also get the parameter list. */
3972 gnu_type
3976 {
3980 }
3982 /* Deal with platform-specific calling conventions. */
3984 prepend_one_attribute
3987 gnat_entity);
3989 prepend_one_attribute
3992 gnat_entity);
3994 /* If we should request stack realignment for a foreign convention
3995 subprogram, do so. Note that this applies to task entry points
3996 in particular. */
3999 prepend_one_attribute
4002 gnat_entity);
4004 /* Deal with a pragma Linker_Section on a subprogram. */
4010 /* If we are defining the subprogram and it has an Address clause
4011 we must get the address expression from the saved GCC tree for the
4012 subprogram if it has a Freeze_Node. Otherwise, we elaborate
4013 the address expression here since the front-end has guaranteed
4014 in that case that the elaboration has no effects. If there is
4015 an Address clause and we are not defining the object, just
4016 make it a constant. */
4018 {
4022 gnu_address
4029 /* Convert the type of the object to a reference type that can
4030 alias everything as per RM 13.3(19). */
4031 gnu_type
4036 gnu_decl
4042 }
4044 /* If this is a mere subprogram type, just create the declaration. */
4046 {
4049 gnu_decl
4052 }
4054 /* Otherwise create the subprogram declaration with the external name,
4055 the type and the parameter list. However, if this a reference to
4056 the allocation routines, reuse the canonical declaration nodes as
4057 they come with special properties. */
4058 else
4059 {
4064 else
4065 {
4066 gnu_decl
4071 debug_info_p,
4073 gnat_entity);
4077 }
4078 }
4079 }
4090 {
4091 const bool is_from_limited_with
4093 /* Get the "full view" of this entity. If this is an incomplete
4094 entity from a limited with, treat its non-limited view as the
4095 full view. Otherwise, use either the full view or the underlying
4096 full view, whichever is present. This is used in all the tests
4097 below. */
4098 const Entity_Id full_view
4099 = is_from_limited_with
4107 /* If this is an incomplete type with no full view, it must be a Taft
4108 Amendment type or an incomplete type coming from a limited context,
4109 in which cases we return a dummy type. Otherwise, we just get the
4110 type from its Etype. */
4112 {
4114 {
4117 }
4118 else
4119 {
4120 gnu_decl
4123 }
4124 }
4126 /* Or else, if we already made a type for the full view, reuse it. */
4130 /* Or else, if we are not defining the type or there is no freeze
4131 node on it, get the type for the full view. Likewise if this is
4132 a limited_with'ed type not declared in the main unit, which can
4133 happen for incomplete formal types instantiated on a type coming
4134 from a limited_with clause. */
4137 || (is_from_limited_with
4139 {
4142 }
4144 /* Otherwise, make a dummy type entry which will be replaced later.
4145 Save it as the full declaration's type so we can do any needed
4146 updates when we see it. */
4147 else
4148 {
4154 }
4155 }
4159 /* Class-wide types are always transformed into their root type. */
4168 /* If we are just annotating types and have no equivalent record type,
4169 just return void_type, except for root types that have discriminants
4170 because the discriminants will very likely be used in the declarative
4171 part of the associated body so they need to be translated. */
4173 {
4176 {
4178 Entity_Id gnat_field;
4180 /* This is a minimal version of the E_Record_Type handling. */
4187 {
4188 tree gnu_field
4200 }
4204 }
4205 else
4207 }
4209 /* Concurrent types are always transformed into their record type. */
4210 else
4221 /* Nothing at all to do here, so just return an ERROR_MARK and claim
4222 we've already saved it, so we don't try to. */
4228 /* This is a SPARK annotation that only reaches here when compiling in
4229 ASIS mode. */
4237 }
4239 /* If we had a case where we evaluated another type and it might have
4240 defined this one, handle it here. */
4242 {
4245 }
4247 /* If we are processing a type and there is either no decl for it or
4248 we just made one, do some common processing for the type, such as
4249 handling alignment and possible padding. */
4251 {
4254 /* Process the attributes, if not already done. Note that the type is
4255 already defined so we cannot pass true for IN_PLACE here. */
4258 /* ??? Don't set the size for a String_Literal since it is either
4259 confirming or we don't handle it properly (if the low bound is
4260 non-constant). */
4262 {
4265 gnu_size
4268 }
4270 /* If a size was specified, see if we can make a new type of that size
4271 by rearranging the type, for example from a fat to a thin pointer. */
4273 {
4274 gnu_type
4281 }
4283 /* If the alignment has not already been processed and this is not
4284 an unconstrained array type, see if an alignment is specified.
4285 If not, we pick a default alignment for atomic objects. */
4287 ;
4289 {
4293 /* Warn on suspiciously large alignments. This should catch
4294 errors about the (alignment,byte)/(size,bit) discrepancy. */
4296 {
4297 tree size;
4299 /* If a size was specified, take it into account. Otherwise
4300 use the RM size for records or unions as the type size has
4301 already been adjusted to the alignment. */
4307 else
4310 /* Consider an alignment as suspicious if the alignment/size
4311 ratio is greater or equal to the byte/bit ratio. */
4316 gnat_entity);
4317 }
4318 }
4329 /* See if we need to pad the type. If we did, and made a record,
4330 the name of the new type may be changed. So get it back for
4331 us when we make the new TYPE_DECL below. */
4339 /* Now set the RM size of the type. We cannot do it before padding
4340 because we need to accept arbitrary RM sizes on integral types. */
4343 /* If we are at global level, GCC will have applied variable_size to
4344 the type, but that won't have done anything. So, if it's not
4345 a constant or self-referential, call elaborate_expression_1 to
4346 make a variable for the size rather than calculating it each time.
4347 Handle both the RM size and the actual size. */
4352 {
4359 /* ??? For now, store the size as a multiple of the alignment in
4360 bytes so that we can see the alignment from the tree. */
4366 /* ??? gnu_type may come from an existing type so the MULT_EXPR node
4367 may not be marked by the call to create_type_decl below. */
4371 {
4376 {
4380 /* If the position of the variant part is constant, subtract
4381 it from the size of the type of the parent to get the new
4382 size. This manual CSE reduces the data size. */
4384 {
4392 }
4393 else
4394 {
4400 /* ??? For now, store the size as a multiple of the
4401 alignment in bytes so that we can see the alignment
4402 from the tree. */
4409 /* ??? For now, store the offset as a multiple of the
4410 alignment in bytes so that we can see the alignment
4411 from the tree. */
4415 DECL_OFFSET_ALIGN
4417 }
4421 }
4425 else
4426 ada_size
4430 }
4431 }
4433 /* Similarly, if this is a record type or subtype at global level, call
4434 elaborate_expression_2 on any field position. Skip any fields that
4435 we haven't made trees for to avoid problems with class-wide types. */
4440 {
4443 /* ??? For now, store the offset as a multiple of the alignment
4444 in bytes so that we can see the alignment from the tree. */
4447 {
4454 /* ??? The context of gnu_field is not necessarily gnu_type
4455 so the MULT_EXPR node built above may not be marked by
4456 the call to create_type_decl below. */
4458 }
4459 }
4464 /* If this is not an unconstrained array type, set some flags. */
4466 {
4467 /* Tell the middle-end that objects of tagged types are guaranteed to
4468 be properly aligned. This is necessary because conversions to the
4469 class-wide type are translated into conversions to the root type,
4470 which can be less aligned than some of its derived types. */
4475 /* Record whether the type is passed by reference. */
4479 /* Record whether an alignment clause was specified. */
4483 /* Record whether a pragma Universal_Aliasing was specified. */
4487 /* If it is passed by reference, force BLKmode to ensure that
4488 objects of this type will always be put in memory. */
4491 }
4493 /* If this is a derived type, relate its alias set to that of its parent
4494 to avoid troubles when a call to an inherited primitive is inlined in
4495 a context where a derived object is accessed. The inlined code works
4496 on the parent view so the resulting code may access the same object
4497 using both the parent and the derived alias sets, which thus have to
4498 conflict. As the same issue arises with component references, the
4499 parent alias set also has to conflict with composite types enclosing
4500 derived components. For instance, if we have:
4502 type D is new T;
4503 type R is record
4504 Component : D;
4505 end record;
4507 we want T to conflict with both D and R, in addition to R being a
4508 superset of D by record/component construction.
4510 One way to achieve this is to perform an alias set copy from the
4511 parent to the derived type. This is not quite appropriate, though,
4512 as we don't want separate derived types to conflict with each other:
4514 type I1 is new Integer;
4515 type I2 is new Integer;
4517 We want I1 and I2 to both conflict with Integer but we do not want
4518 I1 to conflict with I2, and an alias set copy on derivation would
4519 have that effect.
4521 The option chosen is to make the alias set of the derived type a
4522 superset of that of its parent type. It trivially fulfills the
4523 simple requirement for the Integer derivation example above, and
4524 the component case as well by superset transitivity:
4526 superset superset
4527 R ----------> D ----------> T
4529 However, for composite types, conversions between derived types are
4530 translated into VIEW_CONVERT_EXPRs so a sequence like:
4532 type Comp1 is new Comp;
4533 type Comp2 is new Comp;
4534 procedure Proc (C : Comp1);
4536 C : Comp2;
4537 Proc (Comp1 (C));
4539 is translated into:
4541 C : Comp2;
4542 Proc ((Comp1 &) &VIEW_CONVERT_EXPR <Comp1> (C));
4544 and gimplified into:
4546 C : Comp2;
4547 Comp1 *C.0;
4548 C.0 = (Comp1 *) &C;
4549 Proc (C.0);
4551 i.e. generates code involving type punning. Therefore, Comp1 needs
4552 to conflict with Comp2 and an alias set copy is required.
4554 The language rules ensure the parent type is already frozen here. */
4558 {
4560 /* For constrained packed array subtypes, the implementation type is
4561 used instead of the nominal type. */
4569 }
4571 /* Finally get to the appropriate variant, except for the implementation
4572 type of a packed array because the GNU type might be further adjusted
4573 when the original array type is itself processed. */
4576 {
4577 const int quals
4578 = TYPE_QUAL_VOLATILE
4581 }
4586 gnat_entity);
4587 else
4588 {
4591 }
4592 }
4594 /* If we got a type that is not dummy, back-annotate the alignment of the
4595 type if not already in the tree. Likewise for the size, if any. */
4597 {
4601 {
4605 /* If the default alignment of "double" or larger scalar types is
4606 specifically capped and this is not an array with an alignment
4607 clause on the component type, return the cap. */
4609 is_capped_double
4612 is_capped_double
4614 else
4619 else
4623 }
4626 {
4629 /* If the size is self-referential, annotate the maximum value. */
4633 /* If we are just annotating types and the type is tagged, the tag
4634 and the parent components are not generated by the front-end so
4635 alignment and sizes must be adjusted if there is no rep clause. */
4642 {
4643 tree offset;
4646 {
4650 }
4651 else
4652 {
4653 unsigned int align
4657 }
4660 offset
4668 }
4670 /* If there is a rep clause, only adjust alignment and Esize. */
4672 {
4673 unsigned int align
4678 }
4680 /* Otherwise no adjustment is needed. */
4681 else
4683 }
4687 }
4689 /* If we haven't already, associate the ..._DECL node that we just made with
4690 the input GNAT entity node. */
4694 /* Now we are sure gnat_entity has a corresponding ..._DECL node,
4695 eliminate as many deferred computations as possible. */
4698 /* If this is an enumeration or floating-point type, we were not able to set
4699 the bounds since they refer to the type. These are always static. */
4702 {
4706 /* If this is a padded type, we need to use the underlying type. */
4710 /* If this is a floating point type and we haven't set a floating
4711 point type yet, use this in the evaluation of the bounds. */
4719 {
4720 /* Enumeration types have specific RM bounds. */
4723 }
4724 else
4725 {
4726 /* Floating-point types don't have specific RM bounds. */
4729 }
4730 }
4732 /* If we deferred processing of incomplete types, re-enable it. If there
4733 were no other disables and we have deferred types to process, do so. */
4737 {
4740 /* We are back to level 0 for the deferring of incomplete types.
4741 But processing these incomplete types below may itself require
4742 deferring, so preserve what we have and restart from scratch. */
4747 {
4754 }
4755 }
4757 /* If we are not defining this type, see if it's on one of the lists of
4758 incomplete types. If so, handle the list entry now. */
4760 {
4765 {
4769 }
4775 {
4781 }
4782 }
4785 force_global--;
4787 /* If this is a packed array type whose original array type is itself
4788 an Itype without freeze node, make sure the latter is processed. */
4796 }
4798 /* Similar, but if the returned value is a COMPONENT_REF, return the
4799 FIELD_DECL. */
4801 tree
4803 {
4810 }
4812 /* Similar, but GNAT_ENTITY is assumed to refer to a GNAT type. Return
4813 the GCC type corresponding to that entity. */
4815 tree
4817 {
4818 tree gnu_decl;
4820 /* The back end never attempts to annotate generic types. */
4828 }
4830 /* Similar, but GNAT_ENTITY is assumed to refer to a GNAT type. Return
4831 the unpadded version of the GCC type corresponding to that entity. */
4833 tree
4835 {
4842 }
4844 /* Return whether the E_Subprogram_Type/E_Function/E_Procedure GNAT_ENTITY is
4845 a C++ imported method or equivalent.
4847 We use the predicate on 32-bit x86/Windows to find out whether we need to
4848 use the "thiscall" calling convention for GNAT_ENTITY. This convention is
4849 used for C++ methods (functions with METHOD_TYPE) by the back-end. */
4851 bool
4853 {
4854 /* A constructor is a method on the C++ side. We deal with it now because
4855 it is declared without the 'this' parameter in the sources and, although
4856 the front-end will create a version with the 'this' parameter for code
4857 generation purposes, we want to return true for both versions. */
4861 /* Check that the subprogram has C++ convention. */
4865 /* And that the type of the first parameter (indirectly) has it too. */
4876 /* This is the main case: a C++ virtual method imported as a primitive
4877 operation of a tagged type. */
4881 /* This is set on the E_Subprogram_Type built for a dispatching call. */
4885 /* A thunk needs to be handled like its associated primitive operation. */
4889 /* Now on to the annoying case: a C++ non-virtual method, imported either
4890 as a non-primitive operation of a tagged type or as a primitive operation
4891 of an untagged type. We cannot reliably differentiate these cases from
4892 their static member or regular function equivalents in Ada, so we ask
4893 the C++ side through the mangled name of the function, as the implicit
4894 'this' parameter is not encoded in the mangled name of a method. */
4896 {
4903 DMGL_GNU_V3
4904 | DMGL_TYPES
4905 | DMGL_PARAMS
4911 /* We need to release MEM once we have a successful demangling. */
4918 {
4919 /* Make sure there is at least one parameter in C++ too. */
4921 {
4924 n_ada_args++;
4930 n_cpp_args++;
4936 }
4937 else
4939 }
4944 }
4947 }
4949 /* Finalize the processing of From_Limited_With incomplete types. */
4951 void
4953 {
4960 {
4964 {
4969 }
4972 }
4973 }
4975 /* Return the equivalent type to be used for GNAT_ENTITY, if it's a kind
4976 of type (such E_Task_Type) that has a different type which Gigi uses
4977 for its representation. If the type does not have a special type for
4978 its representation, return GNAT_ENTITY. */
4980 Entity_Id
4982 {
4989 {
5015 }
5018 }
5020 /* Return a GCC tree for a type corresponding to the component type of the
5021 array type or subtype GNAT_ARRAY. DEFINITION is true if this component
5022 is for an array being defined. DEBUG_INFO_P is true if we need to write
5023 debug information for other types that we may create in the process. */
5025 static tree
5028 {
5031 tree gnu_comp_size;
5034 /* If an alignment is specified, use it as a cap on the component type
5035 so that it can be honored for the whole type. But ignore it for the
5036 original type of packed array types. */
5040 else
5043 /* Try to get a smaller form of the component if needed. */
5056 /* Get and validate any specified Component_Size. */
5057 gnu_comp_size
5062 /* If the array has aliased components and the component size can be zero,
5063 force at least unit size to ensure that the components have distinct
5064 addresses. */
5070 gnu_comp_size
5073 /* If the component type is a RECORD_TYPE that has a self-referential size,
5074 then use the maximum size for the component size. */
5080 /* Honor the component size. This is not needed for bit-packed arrays. */
5082 {
5088 else
5094 /* If a padding record was made, declare it now since it will never be
5095 declared otherwise. This is necessary to ensure that its subtrees
5096 are properly marked. */
5099 gnat_array);
5100 }
5102 /* If the component type is a padded type made for a non-bit-packed array
5103 of scalars with reverse storage order, we need to propagate the reverse
5104 storage order to the padding type since it is the innermost enclosing
5105 aggregate type around the scalar. */
5113 {
5114 const int quals
5115 = TYPE_QUAL_VOLATILE
5118 }
5121 }
5123 /* Return a GCC tree for a parameter corresponding to GNAT_PARAM, to be placed
5124 in the parameter list of GNAT_SUBPROG. GNU_PARAM_TYPE is the GCC tree for
5125 the type of the parameter. FIRST is true if this is the first parameter in
5126 the list of GNAT_SUBPROG. Also set CICO to true if the parameter must use
5127 the copy-in copy-out implementation mechanism.
5129 The returned tree is a PARM_DECL, except for the cases where no parameter
5130 needs to be actually passed to the subprogram; the type of this "shadow"
5131 parameter is then returned instead. */
5133 static tree
5136 {
5142 /* The parameter can be indirectly modified if its address is taken. */
5148 tree gnu_param;
5150 /* Make sure to use the proper SLOC for vector ABI warnings. */
5154 /* Builtins are expanded inline and there is no real call sequence involved.
5155 So the type expected by the underlying expander is always the type of the
5156 argument "as is". */
5161 /* Handle the first parameter of a valued procedure specially: it's a copy
5162 mechanism for which the parameter is never allocated. */
5164 {
5168 }
5170 /* Or else, see if a Mechanism was supplied that forced this parameter
5171 to be passed one way or another. */
5173 ;
5175 /* Positive mechanism means by copy for sufficiently small parameters. */
5177 {
5182 else
5184 }
5186 /* Otherwise, it's an unsupported mechanism so error out. */
5187 else
5188 {
5191 }
5193 /* If this is either a foreign function or if the underlying type won't
5194 be passed by reference and is as aligned as the original type, strip
5195 off possible padding type. */
5197 {
5206 }
5208 /* If this is a read-only parameter, make a variant of the type that is
5209 read-only. ??? However, if this is a self-referential type, the type
5210 can be very complex, so skip it for now. */
5214 /* For foreign conventions, pass arrays as pointers to the element type.
5215 First check for unconstrained array and get the underlying array. */
5217 gnu_param_type
5220 /* Arrays are passed as pointers to element type for foreign conventions. */
5222 {
5223 /* Strip off any multi-dimensional entries, then strip
5224 off the last array to get the component type. */
5233 gnu_param_type
5237 }
5239 /* Fat pointers are passed as thin pointers for foreign conventions. */
5241 gnu_param_type
5244 /* If we were requested or muss pass by reference, do so.
5245 If we were requested to pass by copy, do so.
5246 Otherwise, for foreign conventions, pass In Out or Out parameters
5247 or aggregates by reference. For COBOL and Fortran, pass all
5248 integer and FP types that way too. For Convention Ada, use
5249 the standard Ada default. */
5253 && ((foreign
5255 || (foreign
5260 || (!foreign
5262 {
5263 /* We take advantage of 6.2(12) by considering that references built for
5264 parameters whose type isn't by-ref and for which the mechanism hasn't
5265 been forced to by-ref allow only a restricted form of aliasing. */
5266 restricted_aliasing_p
5270 }
5272 /* Pass In Out or Out parameters using copy-in copy-out mechanism. */
5281 /* If this is an Out parameter that isn't passed by reference and isn't
5282 a pointer or aggregate, we don't make a PARM_DECL for it. Instead,
5283 it will be a VAR_DECL created when we process the procedure, so just
5284 return its type. For the special parameter of a valued procedure,
5285 never pass it in.
5287 An exception is made to cover the RM-6.4.1 rule requiring "by copy"
5288 Out parameters with discriminants or implicit initial values to be
5289 handled like In Out parameters. These type are normally built as
5290 aggregates, hence passed by reference, except for some packed arrays
5291 which end up encoded in special integer types. Note that scalars can
5292 be given implicit initial values using the Default_Value aspect.
5294 The exception we need to make is then for packed arrays of records
5295 with discriminants or implicit initial values. We have no light/easy
5296 way to check for the latter case, so we merely check for packed arrays
5297 of records. This may lead to useless copy-in operations, but in very
5298 rare cases only, as these would be exceptions in a set of already
5299 exceptional situations. */
5301 && !by_ref
5302 && (by_return
5321 /* If no Mechanism was specified, indicate what we're using, then
5322 back-annotate it. */
5328 }
5330 /* Associate GNAT_SUBPROG with GNU_TYPE, which must be a dummy type, so that
5331 GNAT_SUBPROG is updated when GNU_TYPE is completed.
5333 Ada 2012 (AI05-019) says that freezing a subprogram does not always freeze
5334 the corresponding profile, which means that, by the time the freeze node
5335 of the subprogram is encountered, types involved in its profile may still
5336 be not yet frozen. That's why we need to update GNAT_SUBPROG when we see
5337 the freeze node of types involved in its profile, either types of formal
5338 parameters or the return type. */
5340 static void
5342 {
5350 {
5355 }
5357 /* Even if there is already a slot for GNU_TYPE, we need to set the flag
5358 because the vector might have been just emptied by update_profiles_with.
5359 This can happen when there are 2 freeze nodes associated with different
5360 views of the same type; the type will be really complete only after the
5361 second freeze node is encountered. */
5366 /* Make sure GNAT_SUBPROG is not associated twice with the same dummy type,
5367 since this would mean updating twice its profile. */
5369 {
5373 /* Entity_Id is a simple integer so we can implement a stable order on
5374 the vector with an ordered insertion scheme and binary search. */
5376 {
5383 else
5385 }
5387 /* l == u and therefore is the insertion point. */
5389 }
5390 else
5394 }
5396 /* Update the GCC tree previously built for the profile of GNAT_SUBPROG. */
5398 static void
5400 {
5401 tree gnu_param_list;
5406 {
5407 /* Builtins cannot have their address taken so we can reset them. */
5412 }
5418 /* If GNAT_SUBPROG is an actual subprogram, GNU_SUBPROG is a FUNCTION_DECL
5419 and needs to be adjusted too. */
5421 {
5423 tree gnu_ext_name
5428 }
5429 }
5431 /* Update the GCC trees previously built for the profiles involving GNU_TYPE,
5432 a dummy type which appears in profiles. */
5434 void
5436 {
5444 /* The flag needs to be reset before calling update_profile, in case
5445 associate_subprog_with_dummy_type is again invoked on GNU_TYPE. */
5454 }
5456 /* Return the GCC tree for GNAT_TYPE present in the profile of a subprogram.
5458 Ada 2012 (AI05-0151) says that incomplete types coming from a limited
5459 context may now appear as parameter and result types. As a consequence,
5460 we may need to defer their translation until after a freeze node is seen
5461 or to the end of the current unit. We also aim at handling temporarily
5462 incomplete types created by the usual delayed elaboration scheme. */
5464 static tree
5466 {
5467 /* This is the same logic as the E_Access_Type case of gnat_to_gnu_entity
5468 so the rationale is exposed in that place. These processings probably
5469 ought to be merged at some point. */
5471 const bool is_from_limited_with
5474 Entity_Id gnat_full_direct_first
5475 = (is_from_limited_with
5479 Entity_Id gnat_full_direct
5480 = ((is_from_limited_with
5488 tree gnu_type;
5494 && ((!in_main_unit
5501 {
5505 {
5512 }
5513 }
5518 else
5521 /* Access-to-unconstrained-array types need a special treatment. */
5523 {
5526 }
5529 }
5531 /* Return a GCC tree for a subprogram type corresponding to GNAT_SUBPROG.
5532 DEFINITION is true if this is for a subprogram being defined. DEBUG_INFO_P
5533 is true if we need to write debug information for other types that we may
5534 create in the process. Also set PARAM_LIST to the list of parameters.
5535 If GNAT_SUBPROG is bound to a GCC builtin, return the DECL for the builtin
5536 directly instead of its type. */
5538 static tree
5541 {
5544 Entity_Id gnat_param;
5547 tree gnu_return_type;
5550 /* Non-null for subprograms containing parameters passed by copy-in copy-out
5551 (In Out or Out parameters not passed by reference), in which case it is
5552 the list of nodes used to specify the values of the In Out/Out parameters
5553 that are returned as a record upon procedure return. The TREE_PURPOSE of
5554 an element of this list is a FIELD_DECL of the record and the TREE_VALUE
5555 is the PARM_DECL corresponding to that field. This list will be saved in
5556 the TYPE_CI_CO_LIST field of the FUNCTION_TYPE node we create. */
5559 /* Fields in return type of procedure with copy-in copy-out parameters. */
5561 /* The semantics of "pure" in Ada essentially matches that of "const"
5562 in the back-end. In particular, both properties are orthogonal to
5563 the "nothrow" property if the EH circuitry is explicit in the
5564 internal representation of the back-end. If we are to completely
5565 hide the EH circuitry from it, we need to declare that calls to pure
5566 Ada subprograms that can throw have side effects since they can
5567 trigger an "abnormal" transfer of control flow; thus they can be
5568 neither "const" nor "pure" in the back-end sense. */
5576 /* Look into the return type and get its associated GCC tree if it is not
5577 void, and then compute various flags for the subprogram type. But make
5578 sure not to do this processing multiple times. */
5585 {
5590 }
5592 else
5593 {
5594 /* For foreign convention subprograms, return System.Address as void *
5595 or equivalent. Note that this comprises GCC builtins. */
5599 else
5602 /* If this function returns by reference, make the actual return type
5603 the reference type and make a note of that. */
5605 {
5608 }
5610 /* If the return type is an unconstrained array type, the return value
5611 will be allocated on the secondary stack so the actual return type
5612 is the fat pointer type. */
5614 {
5617 }
5619 /* This is the same unconstrained array case, but for a dummy type. */
5622 {
5625 }
5627 /* Likewise, if the return type requires a transient scope, the return
5628 value will also be allocated on the secondary stack so the actual
5629 return type is the reference type. */
5631 {
5634 }
5636 /* If the Mechanism is By_Reference, ensure this function uses the
5637 target's by-invisible-reference mechanism, which may not be the
5638 same as above (e.g. it might be passing an extra parameter). */
5642 /* Likewise, if the return type is itself By_Reference. */
5646 /* If the type is a padded type and the underlying type would not be
5647 passed by reference or the function has a foreign convention, return
5648 the underlying type. */
5650 && (!default_pass_by_ref
5655 /* If the return type is unconstrained, it must have a maximum size.
5656 Use the padded type as the effective return type. And ensure the
5657 function uses the target's by-invisible-reference mechanism to
5658 avoid copying too much data when it returns. */
5660 {
5664 /* If the size overflows to 0, set it to an arbitrary positive
5665 value so that assignments in the type are preserved. Their
5666 actual size is independent of this positive value. */
5670 {
5673 }
5679 /* Declare it now since it will never be declared otherwise. This
5680 is necessary to ensure that its subtrees are properly marked. */
5687 }
5689 /* If the return type has a size that overflows, we usually cannot have
5690 a function that returns that type. This usage doesn't really make
5691 sense anyway, so issue an error here. */
5696 {
5701 }
5703 /* If the return type is incomplete, there are 2 cases: if the function
5704 returns by reference, then the return type is only linked indirectly
5705 in the profile, so the profile can be seen as complete since it need
5706 not be further modified, only the reference types need be adjusted;
5707 otherwise the profile is incomplete and need be adjusted too. */
5709 {
5712 }
5716 || return_by_direct_ref_p
5717 || return_by_invisi_ref_p
5719 }
5721 /* A procedure (something that doesn't return anything) shouldn't be
5722 considered const since there would be no reason for calling such a
5723 subprogram. Note that procedures with Out (or In Out) parameters
5724 have already been converted into a function with a return type.
5725 Similarly, if the function returns an unconstrained type, then the
5726 function will allocate the return value on the secondary stack and
5727 thus calls to it cannot be CSE'ed, lest the stack be reclaimed. */
5731 /* Loop over the parameters and get their associated GCC tree. While doing
5732 this, build a copy-in copy-out structure if we need one. */
5736 {
5737 const bool mech_is_by_ref
5744 /* Fetch an existing parameter with complete type and reuse it. But we
5745 didn't save the CICO property so we can only do it for In parameters
5746 or parameters passed by reference. */
5751 {
5754 }
5756 /* Otherwise translate the parameter type and act accordingly. */
5757 else
5758 {
5761 /* For foreign convention subprograms, pass System.Address as void *
5762 or equivalent. Note that this comprises GCC builtins. */
5766 else
5769 /* If the parameter type is incomplete, there are 2 cases: if it is
5770 passed by reference, then the type is only linked indirectly in
5771 the profile, so the profile can be seen as complete since it need
5772 not be further modified, only the reference type need be adjusted;
5773 otherwise the profile is incomplete and need be adjusted too. */
5775 {
5776 Node_Id gnat_decl;
5780 && TYPE_IS_FAT_POINTER_P
5783 {
5785 gnu_param
5795 }
5797 /* ??? This is a kludge to support null procedures in spec taking
5798 a parameter with an untagged incomplete type coming from a
5799 limited context. The front-end creates a body without knowing
5800 anything about the non-limited view, which is illegal Ada and
5801 cannot be supported. Create a parameter with a fake type. */
5809 else
5810 {
5811 /* Build a minimal PARM_DECL without DECL_ARG_TYPE so that
5812 Call_to_gnu will stop if it encounters the PARM_DECL. */
5813 gnu_param
5815 gnu_param_type);
5817 gnu_param_type);
5819 }
5820 }
5822 /* Otherwise build the parameter declaration normally. */
5823 else
5824 {
5825 gnu_param
5829 /* We are returned either a PARM_DECL or a type if no parameter
5830 needs to be passed; in either case, adjust the type. */
5833 else
5834 {
5837 }
5838 }
5839 }
5841 /* If we have a GCC tree for the parameter, register it. */
5844 {
5845 gnu_param_type_list
5850 /* If a parameter is a pointer, a function may modify memory through
5851 it and thus shouldn't be considered a const function. Also, the
5852 memory may be modified between two calls, so they can't be CSE'ed.
5853 The latter case also handles by-ref parameters. */
5857 }
5859 /* If the parameter uses the copy-in copy-out mechanism, allocate a field
5860 for it in the return type and register the association. */
5862 {
5864 {
5867 /* If this is a function, we also need a field for the
5868 return value to be placed. */
5870 {
5871 tree gnu_field
5873 gnu_return_type,
5879 gnu_cico_list
5881 }
5884 /* Set a default alignment to speed up accesses. But we should
5885 not increase the size of the structure too much, lest it does
5886 not fit in return registers anymore. */
5889 }
5891 tree gnu_field
5900 }
5901 }
5903 /* If the subprogram uses the copy-in copy-out mechanism, possibly adjust
5904 and finish up the return type. */
5906 {
5907 /* If we have a CICO list but it has only one entry, we convert
5908 this function into a function that returns this object. */
5912 /* Do not finalize the return type if the subprogram is stubbed
5913 since structures are incomplete for the back-end. */
5915 {
5919 /* Try to promote the mode of the return type if it is passed
5920 in registers, again to speed up accesses. */
5923 NULL_TREE))
5924 {
5925 unsigned int size
5928 scalar_int_mode mode;
5933 {
5941 }
5942 }
5946 }
5949 }
5951 /* The lists have been built in reverse. */
5957 /* If the profile is incomplete, we only set the (temporary) return and
5958 parameter types; otherwise, we build the full type. In either case,
5959 we reuse an already existing GCC tree that we built previously here. */
5961 {
5963 ;
5964 else
5971 }
5972 else
5973 {
5975 {
5984 }
5985 else
5986 {
5987 gnu_type
5990 /* GNU_TYPE may be shared since GCC hashes types. Unshare it if it
5991 has a different TYPE_CI_CO_LIST or flags. */
5993 return_unconstrained_p,
5994 return_by_direct_ref_p,
5995 return_by_invisi_ref_p))
5996 {
6002 }
6003 }
6011 /* If this subprogram is expectedly bound to a GCC builtin, fetch the
6012 corresponding DECL node and check the parameter association. */
6015 {
6019 /* If we have a builtin DECL for that function, use it. Check if
6020 the profiles are compatible and warn if they are not. Note that
6021 the checker is expected to post diagnostics in this case. */
6023 {
6024 intrin_binding_t inb
6028 post_error
6030 gnat_subprog);
6033 }
6035 /* Inability to find the builtin DECL most often indicates a genuine
6036 mistake, but imports of unregistered intrinsics are sometimes used
6037 on purpose to allow hooking in alternate bodies; we post a warning
6038 conditioned on Wshadow in this case, to let developers be notified
6039 on demand without risking false positives with common default sets
6040 of options. */
6043 }
6044 }
6047 }
6049 /* Return the external name for GNAT_SUBPROG given its entity name. */
6051 static tree
6053 {
6056 /* If there was no specified Interface_Name and the external and
6057 internal names of the subprogram are the same, only use the
6058 internal name to allow disambiguation of nested subprograms. */
6063 }
6065 /* Like build_qualified_type, but TYPE_QUALS is added to the existing
6066 qualifiers on TYPE. */
6068 static tree
6070 {
6071 /* Qualifiers must be put on the associated array type. */
6076 }
6078 /* Set TYPE_NONALIASED_COMPONENT on an array type built by means of
6079 build_nonshared_array_type. */
6081 static void
6083 {
6086 }
6088 /* Set TYPE_REVERSE_STORAGE_ORDER on an array type built by means of
6089 build_nonshared_array_type. */
6091 static void
6093 {
6096 }
6098 /* Return true if DISCR1 and DISCR2 represent the same discriminant. */
6100 static bool
6102 {
6109 return
6111 }
6113 /* Return true if the array type GNU_TYPE, which represents a dimension of
6114 GNAT_TYPE, has a non-aliased component in the back-end sense. */
6116 static bool
6118 {
6119 /* If the array type is not the innermost dimension of the GNAT type,
6120 then it has a non-aliased component. */
6125 /* If the array type has an aliased component in the front-end sense,
6126 then it also has an aliased component in the back-end sense. */
6130 /* If this is a derived type, then it has a non-aliased component if
6131 and only if its parent type also has one. */
6133 {
6137 gnu_parent_type
6142 }
6144 /* Otherwise, rely exclusively on properties of the element type. */
6146 }
6148 /* Return true if GNAT_ADDRESS is a value known at compile-time. */
6150 static bool
6152 {
6153 /* Handle reference to a constant. */
6156 {
6160 }
6162 /* Catch System'To_Address. */
6167 }
6169 /* Return true if GNAT_RANGE, a N_Range node, cannot be superflat, i.e. if the
6170 inequality HB >= LB-1 is true. LB and HB are the low and high bounds. */
6172 static bool
6174 {
6176 Node_Id scalar_range;
6179 /* If the low bound is not constant, try to find an upper bound. */
6188 /* If the high bound is not constant, try to find a lower bound. */
6197 /* If we have failed to find constant bounds, punt. */
6202 /* We need at least a signed 64-bit type to catch most cases. */
6208 /* If the low bound is the smallest integer, nothing can be smaller. */
6214 }
6216 /* Return true if GNU_EXPR is (essentially) the address of a CONSTRUCTOR. */
6218 static bool
6220 {
6228 }
6230 /* Return true if the size in units represented by GNU_SIZE can be handled by
6231 an allocation. If STATIC_P is true, consider only what can be done with a
6232 static allocation. */
6234 static bool
6236 {
6237 /* We can allocate a fixed size if it is a valid for the middle-end. */
6241 /* We can allocate a variable size if this isn't a static allocation. */
6242 else
6244 }
6246 /* Return true if GNU_EXPR needs a conversion to GNU_TYPE when used as the
6247 initial value of an object of GNU_TYPE. */
6249 static bool
6251 {
6252 /* Do not convert if the object's type is unconstrained because this would
6253 generate useless evaluations of the CONSTRUCTOR to compute the size. */
6258 /* Do not convert if the object's type is a padding record whose field is of
6259 self-referential size because we want to copy only the actual data. */
6263 /* Do not convert a call to a function that returns with variable size since
6264 we want to use the return slot optimization in this case. */
6269 /* Do not convert to a record type with a variant part from a record type
6270 without one, to keep the object simpler. */
6277 /* In all the other cases, convert the expression to the object's type. */
6279 }
6280 \f
6281 /* Given GNAT_ENTITY, elaborate all expressions that are required to
6282 be elaborated at the point of its definition, but do nothing else. */
6284 void
6286 {
6288 {
6295 {
6299 /* ??? Tests to avoid Constraint_Error in static expressions
6300 are needed until after the front stops generating bogus
6301 conversions on bounds of real types. */
6309 }
6316 {
6317 Node_Id gnat_discriminant_expr;
6318 Entity_Id gnat_field;
6322 gnat_discriminant_expr
6327 /* Ignore access discriminants. */
6332 }
6335 }
6336 }
6337 \f
6338 /* Prepend to ATTR_LIST an entry for an attribute with provided TYPE,
6339 NAME, ARGS and ERROR_POINT. */
6341 static void
6344 tree attr_name,
6345 tree attr_args,
6346 Node_Id attr_error_point)
6347 {
6357 }
6359 /* Prepend to ATTR_LIST an entry for an attribute provided by GNAT_PRAGMA. */
6361 static void
6363 {
6368 /* Map the pragma at hand. Skip if this isn't one we know how to handle. */
6370 {
6401 }
6403 /* See what arguments we have and turn them into GCC trees for attribute
6404 handlers. These expect identifier for strings. We handle at most two
6405 arguments and static expressions only. */
6407 {
6413 {
6417 {
6421 }
6424 }
6428 {
6433 }
6434 }
6436 /* Prepend to the list. Make a list of the argument we might have, as GCC
6437 expects it. */
6439 gnu_arg1
6443 }
6445 /* Prepend to ATTR_LIST the list of attributes for GNAT_ENTITY, if any. */
6447 static void
6449 {
6450 Node_Id gnat_temp;
6452 /* Attributes are stored as Representation Item pragmas. */
6458 }
6459 \f
6460 /* Given a GNAT tree GNAT_EXPR, for an expression which is a value within a
6461 type definition (either a bound or a discriminant value) for GNAT_ENTITY,
6462 return the GCC tree to use for that expression. S is the suffix to use
6463 if a variable needs to be created and DEFINITION is true if this is done
6464 for a definition of GNAT_ENTITY. If NEED_VALUE is true, we need a result;
6465 otherwise, we are just elaborating the expression for side-effects. If
6466 NEED_DEBUG is true, we need a variable for debugging purposes even if it
6467 isn't needed for code generation. */
6469 static tree
6472 {
6473 tree gnu_expr;
6475 /* If we already elaborated this expression (e.g. it was involved
6476 in the definition of a private type), use the old value. */
6480 /* If we don't need a value and this is static or a discriminant,
6481 we don't need to do anything. */
6488 /* If it's a static expression, we don't need a variable for debugging. */
6492 /* Otherwise, convert this tree to its GCC equivalent and elaborate it. */
6496 /* Save the expression in case we try to elaborate this entity again. Since
6497 it's not a DECL, don't check it. Don't save if it's a discriminant. */
6502 }
6504 /* Similar, but take a GNU expression and always return a result. */
6506 static tree
6509 {
6514 /* If GNU_EXPR contains a placeholder, just return it. We rely on the fact
6515 that an expression cannot contain both a discriminant and a variable. */
6519 /* If GNU_EXPR is neither a constant nor based on a read-only variable, make
6520 a variable that is initialized to contain the expression when the package
6521 containing the definition is elaborated. If this entity is defined at top
6522 level, replace the expression by the variable; otherwise use a SAVE_EXPR
6523 if this is necessary. */
6526 else
6527 {
6528 /* Skip any conversions and simple constant arithmetics to see if the
6529 expression is based on a read-only variable. */
6537 expr_variable_p
6538 = !(inner
6541 }
6543 /* We only need to use the variable if we are in a global context since GCC
6544 can do the right thing in the local case. However, when not optimizing,
6545 use it for bounds of loop iteration scheme to avoid code duplication. */
6546 use_variable = expr_variable_p
6547 && (expr_global_p
6548 || (!optimize
6549 && definition
6554 /* Now create it, possibly only for debugging purposes. */
6556 {
6557 /* The following variable creation can happen when processing the body
6558 of subprograms that are defined out of the extended main unit and
6559 inlined. In this case, we are not at the global scope, and thus the
6560 new variable must not be tagged "external", as we used to do here as
6561 soon as DEFINITION was false. */
6562 tree gnu_decl
6569 /* Using this variable at debug time (if need_debug is true) requires a
6570 proper location. The back-end will compute a location for this
6571 variable only if the variable is used by the generated code.
6572 Returning the variable ensures the caller will use it in generated
6573 code. Note that there is no need for a location if the debug info
6574 contains an integer constant.
6575 TODO: when the encoding-based debug scheme is dropped, move this
6576 condition to the top-level IF block: we will not need to create a
6577 variable anymore in such cases, then. */
6580 }
6583 }
6585 /* Similar, but take an alignment factor and make it explicit in the tree. */
6587 static tree
6590 {
6592 return
6595 gnu_expr,
6596 unit_align),
6598 need_debug),
6599 unit_align);
6600 }
6602 /* Structure to hold internal data for elaborate_reference. */
6604 struct er_data
6605 {
6606 Entity_Id entity;
6609 };
6611 /* Wrapper function around elaborate_expression_1 for elaborate_reference. */
6613 static tree
6615 {
6619 /* This is what elaborate_expression_1 does if NEED_DEBUG is false. */
6623 /* If this is a COMPONENT_REF of a fat pointer, elaborate the entire fat
6624 pointer. This may be more efficient, but will also allow us to more
6625 easily find the match for the PLACEHOLDER_EXPR. */
6633 return
6635 }
6637 /* Elaborate the reference REF to be used as renamed object for GNAT_ENTITY.
6638 DEFINITION is true if this is done for a definition of GNAT_ENTITY and
6639 INIT is set to the first arm of a COMPOUND_EXPR present in REF, if any. */
6641 static tree
6644 {
6647 }
6648 \f
6649 /* Given a GNU tree and a GNAT list of choices, generate an expression to test
6650 the value passed against the list of choices. */
6652 static tree
6654 {
6655 Node_Id choice;
6656 Node_Id gnat_temp;
6661 {
6663 {
6668 this_test
6683 this_test
6694 /* This represents either a subtype range, an enumeration
6695 literal, or a constant Ekind says which. If an enumeration
6696 literal or constant, fall through to the next case. */
6699 {
6705 this_test
6713 }
6715 /* ... fall through ... */
6730 }
6734 else
6737 }
6740 }
6741 \f
6742 /* Adjust PACKED setting as passed to gnat_to_gnu_field for a field of
6743 type FIELD_TYPE to be placed in RECORD_TYPE. Return the result. */
6745 static int
6747 {
6748 /* If the field contains an item of variable size, we cannot pack it
6749 because we cannot create temporaries of non-fixed size in case
6750 we need to take the address of the field. See addressable_p and
6751 the notes on the addressability issues for further details. */
6755 /* In the other cases, we can honor the packing. */
6759 /* If the alignment of the record is specified and the field type
6760 is over-aligned, request Storage_Unit alignment for the field. */
6765 /* Likewise if the maximum alignment of the record is specified. */
6771 }
6773 /* Return a GCC tree for a field corresponding to GNAT_FIELD to be
6774 placed in GNU_RECORD_TYPE.
6776 PACKED is 1 if the enclosing record is packed or -1 if the enclosing
6777 record has Component_Alignment of Storage_Unit.
6779 DEFINITION is true if this field is for a record being defined.
6781 DEBUG_INFO_P is true if we need to write debug information for types
6782 that we may create in the process. */
6784 static tree
6787 {
6790 const bool is_atomic
6793 const bool is_independent
6795 const bool is_volatile
6798 /* We used to consider that volatile fields also require strict alignment,
6799 but that was an interpolation and would cause us to reject a pragma
6800 volatile on a packed record type containing boolean components, while
6801 there is no basis to do so in the RM. In such cases, the writes will
6802 involve load-modify-store sequences, but that's OK for volatile. The
6803 only constraint is the implementation advice whereby only the bits of
6804 the components should be accessed if they both start and end on byte
6805 boundaries, but that should be guaranteed by the GCC memory model. */
6806 const bool needs_strict_alignment
6812 /* If this field requires strict alignment, we cannot pack it because
6813 it would very likely be under-aligned in the record. */
6816 else
6819 /* If a size is specified, use it. Otherwise, if the record type is packed,
6820 use the official RM size. See "Handling of Type'Size Values" in Einfo
6821 for further details. */
6828 else
6831 /* If we have a specified size that is smaller than that of the field's type,
6832 or a position is specified, and the field's type is a record that doesn't
6833 require strict alignment, see if we can get either an integral mode form
6834 of the type or a smaller form. If we can, show a size was specified for
6835 the field if there wasn't one already, so we know to make this a bitfield
6836 and avoid making things wider.
6838 Changing to an integral mode form is useful when the record is packed as
6839 we can then place the field at a non-byte-aligned position and so achieve
6840 tighter packing. This is in addition required if the field shares a byte
6841 with another field and the front-end lets the back-end handle the access
6842 to the field, because GCC cannot handle non-byte-aligned BLKmode fields.
6844 Changing to a smaller form is required if the specified size is smaller
6845 than that of the field's type and the type contains sub-fields that are
6846 padded, in order to avoid generating accesses to these sub-fields that
6847 are wider than the field.
6849 We avoid the transformation if it is not required or potentially useful,
6850 as it might entail an increase of the field's alignment and have ripple
6851 effects on the outer record type. A typical case is a field known to be
6852 byte-aligned and not to share a byte with another field. */
6858 || (gnu_size
6864 {
6867 {
6871 }
6872 }
6875 {
6876 const unsigned int align
6879 gnu_field_type
6883 }
6886 {
6894 /* Ensure the position does not overlap with the parent subtype, if there
6895 is one. This test is omitted if the parent of the tagged type has a
6896 full rep clause since, in this case, component clauses are allowed to
6897 overlay the space allocated for the parent type and the front-end has
6898 checked that there are no overlapping components. */
6900 {
6905 post_error_ne_tree
6908 }
6910 /* If this field needs strict alignment, make sure that the record is
6911 sufficiently aligned and that the position and size are consistent
6912 with the type. But don't do it if we are just annotating types and
6913 the field's type is tagged, since tagged types aren't fully laid out
6914 in this mode. Also, note that atomic implies volatile so the inner
6915 test sequences ordering is significant here. */
6918 {
6924 /* If the position is not a multiple of the alignment of the type,
6925 then error out and reset the position. */
6928 {
6940 else
6944 type_align);
6946 }
6949 {
6953 /* If the size is lower than that of the type, or greater for
6954 atomic and aliased, then error out and reset the size. */
6956 {
6968 else
6972 gnu_type_size);
6974 }
6976 /* Likewise if the size is not a multiple of a byte, */
6978 bitsize_unit_node)))
6979 {
6988 else
6993 }
6994 }
6995 }
6996 }
6998 /* If the record has rep clauses and this is the tag field, make a rep
6999 clause for it as well. */
7002 {
7005 }
7007 else
7008 {
7011 /* If we are packing the record and the field is BLKmode, round the
7012 size up to a byte boundary. */
7015 }
7017 /* We need to make the size the maximum for the type if it is
7018 self-referential and an unconstrained type. In that case, we can't
7019 pack the field since we can't make a copy to align it. */
7021 && !gnu_size
7024 {
7027 }
7029 /* If a size is specified, adjust the field's type to it. */
7031 {
7032 tree orig_field_type;
7034 /* If the field's type is justified modular, we would need to remove
7035 the wrapper to (better) meet the layout requirements. However we
7036 can do so only if the field is not aliased to preserve the unique
7037 layout, if it has the same storage order as the enclosing record
7038 and if the prescribed size is not greater than that of the packed
7039 array to preserve the justification. */
7049 /* Similarly if the field's type is a misaligned integral type, but
7050 there is no restriction on the size as there is no justification. */
7056 gnu_field_type
7064 /* If a padding record was made, declare it now since it will never be
7065 declared otherwise. This is necessary to ensure that its subtrees
7066 are properly marked. */
7071 }
7073 /* Otherwise (or if there was an error), don't specify a position. */
7074 else
7077 /* If the field's type is a padded type made for a scalar field of a record
7078 type with reverse storage order, we need to propagate the reverse storage
7079 order to the padding type since it is the innermost enclosing aggregate
7080 type around the scalar. */
7089 /* Now create the decl for the field. */
7090 gnu_field
7098 {
7103 }
7106 }
7107 \f
7108 /* Return true if at least one member of COMPONENT_LIST needs strict
7109 alignment. */
7111 static bool
7113 {
7114 Node_Id component_decl;
7119 {
7127 }
7130 }
7132 /* Return true if TYPE is a type with variable size or a padding type with a
7133 field of variable size or a record that has a field with such a type. */
7135 static bool
7137 {
7138 tree field;
7155 }
7156 \f
7157 /* Return true if FIELD is an artificial field. */
7159 static bool
7161 {
7162 /* These fields are generated by the front-end proper. */
7166 /* These fields are generated by gigi. */
7171 }
7173 /* Return true if FIELD is a non-artificial field with self-referential
7174 size. */
7176 static bool
7178 {
7186 }
7188 /* Return true if FIELD is a non-artificial field with variable size. */
7190 static bool
7192 {
7200 }
7202 /* qsort comparer for the bit positions of two record components. */
7204 static int
7206 {
7209 const int ret
7213 }
7215 /* Reverse function from gnat_to_gnu_field: return the GNAT field present in
7216 either GNAT_COMPONENT_LIST or the discriminants of GNAT_RECORD_TYPE, and
7217 corresponding to the GNU tree GNU_FIELD. */
7219 static Entity_Id
7221 Entity_Id gnat_record_type)
7222 {
7230 {
7234 }
7244 }
7246 /* Issue a warning for the problematic placement of GNU_FIELD present in
7247 either GNAT_COMPONENT_LIST or the discriminants of GNAT_RECORD_TYPE.
7248 IN_VARIANT is true if GNAT_COMPONENT_LIST is the list of a variant.
7249 DO_REORDER is true if fields of GNAT_RECORD_TYPE are being reordered. */
7251 static void
7255 {
7260 = in_variant
7270 = do_reorder
7274 Entity_Id gnat_field
7282 }
7284 /* Structure holding information for a given variant. */
7286 {
7287 /* The record type of the variant. */
7288 tree type;
7290 /* The name of the variant. */
7291 tree name;
7293 /* The qualifier of the variant. */
7294 tree qual;
7296 /* Whether the variant has a rep clause. */
7299 /* Whether the variant is packed. */
7304 /* Translate and chain GNAT_COMPONENT_LIST present in GNAT_RECORD_TYPE to
7305 GNU_FIELD_LIST, set the result as the field list of GNU_RECORD_TYPE and
7306 finish it up. Return true if GNU_RECORD_TYPE has a rep clause that affects
7307 the layout (see below). When called from gnat_to_gnu_entity during the
7308 processing of a record definition, the GCC node for the parent, if any,
7309 will be the single field of GNU_RECORD_TYPE and the GCC nodes for the
7310 discriminants will be on GNU_FIELD_LIST. The other call to this function
7311 is a recursive call for the component list of a variant and, in this case,
7312 GNU_FIELD_LIST is empty.
7314 PACKED is 1 if this is for a packed record or -1 if this is for a record
7315 with Component_Alignment of Storage_Unit.
7317 DEFINITION is true if we are defining this record type.
7319 CANCEL_ALIGNMENT is true if the alignment should be zeroed before laying
7320 out the record. This means the alignment only serves to force fields to
7321 be bitfields, but not to require the record to be that aligned. This is
7322 used for variants.
7324 ALL_REP is true if a rep clause is present for all the fields.
7326 UNCHECKED_UNION is true if we are building this type for a record with a
7327 Pragma Unchecked_Union.
7329 ARTIFICIAL is true if this is a type that was generated by the compiler.
7331 DEBUG_INFO is true if we need to write debug information about the type.
7333 MAYBE_UNUSED is true if this type may be unused in the end; this doesn't
7334 mean that its contents may be unused as well, only the container itself.
7336 FIRST_FREE_POS, if nonzero, is the first (lowest) free field position in
7337 the outer record type down to this variant level. It is nonzero only if
7338 all the fields down to this level have a rep clause and ALL_REP is false.
7340 P_GNU_REP_LIST, if nonzero, is a pointer to a list to which each field
7341 with a rep clause is to be added; in this case, that is all that should
7342 be done with such fields and the return value will be false. */
7344 static bool
7351 {
7352 const bool needs_xv_encodings
7364 /* For each component referenced in a component declaration create a GCC
7365 field and add it to the list, skipping pragmas in the GNAT list. */
7372 {
7376 /* If present, the _Parent field must have been created as the single
7377 field of the record type. Put it before any other fields. */
7379 {
7382 }
7383 else
7384 {
7388 /* If this is the _Tag field, put it before any other fields. */
7392 /* If this is the _Controller field, put it before the other
7393 fields except for the _Tag or _Parent field. */
7395 {
7398 }
7400 /* If this is a regular field, put it after the other fields. */
7401 else
7402 {
7408 /* And record information for the final layout. */
7413 }
7414 }
7417 }
7419 /* At the end of the component list there may be a variant part. */
7422 /* We create a QUAL_UNION_TYPE for the variant part since the variants are
7423 mutually exclusive and should go in the same memory. To do this we need
7424 to treat each variant as a record whose elements are created from the
7425 component list for the variant. So here we create the records from the
7426 lists for the variants and put them all into the QUAL_UNION_TYPE.
7427 If this is an Unchecked_Union, we make a UNION_TYPE instead or
7428 use GNU_RECORD_TYPE if there are no fields so far. */
7430 {
7434 tree gnu_var_name
7445 gnu_union_name
7448 /* Reuse the enclosing union if this is an Unchecked_Union whose fields
7449 are all in the variant part, to match the layout of C unions. There
7450 is an associated check below. */
7453 else
7454 {
7455 gnu_union_type
7463 }
7465 /* If all the fields down to this level have a rep clause, find out
7466 whether all the fields at this level also have one. If so, then
7467 compute the new first free position to be passed downward. */
7470 {
7472 gnu_field;
7475 {
7478 this_first_free_pos
7480 }
7481 else
7482 {
7485 }
7486 }
7488 /* We build the variants in two passes. The bulk of the work is done in
7489 the first pass, that is to say translating the GNAT nodes, building
7490 the container types and computing the associated properties. However
7491 we cannot finish up the container types during this pass because we
7492 don't know where the variant part will be placed until the end. */
7496 {
7501 vinfo_t vinfo;
7509 /* Set the alignment of the inner type in case we need to make
7510 inner objects into bitfields, but then clear it out so the
7511 record actually gets only the alignment required. */
7517 /* Similarly, if the outer record has a size specified and all
7518 the fields have a rep clause, we can propagate the size. */
7520 {
7524 }
7526 /* Add the fields into the record type for the variant. Note that
7527 we aren't sure to really use it at this point, see below. */
7528 has_rep
7534 all_rep || this_first_free_pos
7537 /* Translate the qualifier and annotate the GNAT node. */
7541 /* Deal with packedness like in gnat_to_gnu_field. */
7543 {
7546 }
7547 else
7548 field_packed
7551 /* Push this variant onto the stack for the second pass. */
7559 /* Compute the global properties that will determine the placement of
7560 the variant part. */
7564 }
7566 /* Round up the first free position to the alignment of the variant part
7567 for the variants without rep clause. This will guarantee a consistent
7568 layout independently of the placement of the variant part. */
7572 /* In the second pass, the container types are adjusted if necessary and
7573 finished up, then the corresponding fields of the variant part are
7574 built with their qualifier, unless this is an unchecked union. */
7576 {
7580 /* If this is an Unchecked_Union whose fields are all in the variant
7581 part and we have a single field with no representation clause or
7582 placed at offset zero, use the field directly to match the layout
7583 of C unions. */
7585 && gnu_field_list
7589 {
7592 }
7593 else
7594 {
7595 /* Finalize the variant type now. We used to throw away empty
7596 record types but we no longer do that because we need them to
7597 generate complete debug info for the variant; otherwise, the
7598 union type definition will be lacking the fields associated
7599 with these empty variants. */
7601 {
7602 /* The variant part will be at offset 0 so we need to ensure
7603 that the fields are laid out starting from the first free
7604 position at this level. */
7606 tree gnu_rep_part;
7610 gnu_rep_part
7612 this_first_free_pos);
7617 }
7624 gnu_field
7626 gnu_union_type,
7627 all_rep_and_size
7636 }
7640 }
7642 /* Only make the QUAL_UNION_TYPE if there are non-empty variants. */
7644 {
7648 {
7652 }
7657 /* If GNU_UNION_TYPE is our record type, it means we must have an
7658 Unchecked_Union with no fields. Verify that and, if so, just
7659 return. */
7661 {
7663 && !gnu_field_list
7666 }
7671 /* Deal with packedness like in gnat_to_gnu_field. */
7674 else
7675 union_field_packed
7678 gnu_variant_part
7680 all_rep_and_size
7686 }
7687 }
7689 /* Scan GNU_FIELD_LIST and see if any fields have rep clauses. If they do,
7690 pull them out and put them onto the appropriate list.
7692 Similarly, pull out the fields with zero size and no rep clause, as they
7693 would otherwise modify the layout and thus very likely run afoul of the
7694 Ada semantics, which are different from those of C here.
7696 Finally, if there is an aliased field placed in the list after fields
7697 with self-referential size, pull out the latter in the same way.
7699 Optionally, if the reordering mechanism is enabled, pull out the fields
7700 with self-referential size, variable size and fixed size not a multiple
7701 of a byte, so that they don't cause the regular fields to be either at
7702 self-referential/variable offset or misaligned. Note, in the latter
7703 case, that this can only happen in packed record types so the alignment
7704 is effectively capped to the byte for the whole record. But we don't
7705 do it for non-packed record types if pragma Optimize_Alignment (Space)
7706 is specified because this can prevent alignment gaps from being filled.
7708 Optionally, if the layout warning is enabled, keep track of the above 4
7709 different kinds of fields and issue a warning if some of them would be
7710 (or are being) reordered by the reordering mechanism.
7712 ??? If we reorder fields, the debugging information will be affected and
7713 the debugger print fields in a different order from the source code. */
7714 const bool do_reorder
7720 const bool w_reorder
7722 && Warn_On_Questionable_Layout
7734 #define MOVE_FROM_FIELD_LIST_TO(LIST) \
7735 do { \
7736 if (gnu_last) \
7737 DECL_CHAIN (gnu_last) = gnu_next; \
7738 else \
7739 gnu_field_list = gnu_next; \
7740 \
7741 DECL_CHAIN (gnu_field) = (LIST); \
7742 (LIST) = gnu_field; \
7743 } while (0)
7747 {
7751 {
7754 }
7757 {
7767 }
7770 {
7773 }
7775 /* We don't need further processing in default mode. */
7777 {
7780 }
7783 {
7785 {
7789 do_reorder);
7790 else
7792 }
7795 {
7798 }
7799 }
7802 {
7804 {
7808 do_reorder);
7809 else
7811 }
7814 {
7817 }
7818 }
7820 else
7821 {
7822 /* If the field has no size, then it cannot be bit-packed. */
7823 const unsigned int bitp_size
7828 /* If the field is bit-packed, we move it to a temporary list that
7829 contains the contiguously preceding bit-packed fields, because
7830 we want to be able to put them back if the misalignment happens
7831 to cancel itself after several bit-packed fields. */
7833 {
7837 {
7840 }
7843 {
7846 }
7847 }
7849 /* No more bit-packed fields, move the existing ones to the end or
7850 put them back at their original location. */
7852 {
7856 {
7860 gnat_component_list,
7862 do_reorder);
7869 }
7870 else
7871 {
7872 /* Rechain the temporary list in front of GNU_FIELD. */
7875 {
7880 else
7884 }
7885 }
7886 }
7888 else
7890 }
7893 }
7895 #undef MOVE_FROM_FIELD_LIST_TO
7899 /* If permitted, we reorder the fields as follows:
7901 1) all (groups of) fields whose length is fixed and multiple of a byte,
7902 2) the remaining fields whose length is fixed and not multiple of a byte,
7903 3) the remaining fields whose length doesn't depend on discriminants,
7904 4) all fields whose length depends on discriminants,
7905 5) the variant part,
7907 within the record and within each variant recursively. */
7910 {
7911 /* If we have pending bit-packed fields, warn if they would be moved
7912 to after regular fields. */
7920 }
7923 {
7924 /* If we have pending bit-packed fields on the temporary list, we put
7925 them either on the bit-packed list or back on the regular list. */
7927 {
7930 else
7932 }
7934 gnu_field_list
7938 }
7940 /* Otherwise, if there is an aliased field placed after a field whose length
7941 depends on discriminants, we put all the fields of the latter sort, last.
7942 We need to do this in case an object of this record type is mutable. */
7946 /* If P_REP_LIST is nonzero, this means that we are asked to move the fields
7947 in our REP list to the previous level because this level needs them in
7948 order to do a correct layout, i.e. avoid having overlapping fields. */
7952 /* Deal with the annoying case of an extension of a record with variable size
7953 and partial rep clause, for which the _Parent field is forced at offset 0
7954 and has variable size, which we do not support below. Note that we cannot
7955 do it if the field has fixed size because we rely on the presence of the
7956 REP part built below to trigger the reordering of the fields in a derived
7957 record type when all the fields have a fixed position. */
7961 && !variants_have_rep
7962 && first_free_pos
7965 {
7969 }
7971 /* Otherwise, sort the fields by bit position and put them into their own
7972 record, before the others, if we also have fields without rep clause. */
7974 {
7979 /* If all the fields have a rep clause, we can do a flat layout. */
7980 layout_with_rep = !gnu_field_list
7982 gnu_rep_type
7986 gnu_field;
7992 /* Put the fields in the list in order of increasing position, which
7993 means we start from the end. */
7996 {
8000 }
8004 else
8005 {
8010 /* If FIRST_FREE_POS is nonzero, we need to ensure that the fields
8011 without rep clause are laid out starting from this position.
8012 Therefore, we force it as a minimal size on the REP part. */
8013 gnu_rep_part
8016 /* Chain the REP part at the beginning of the field list. */
8019 }
8020 }
8022 /* Chain the variant part at the end of the field list. */
8034 /* Chain the fields with zero size at the beginning of the field list. */
8040 }
8041 \f
8042 /* Given GNU_SIZE, a GCC tree representing a size, return a Uint to be
8043 placed into an Esize, Component_Bit_Offset, or Component_Size value
8044 in the GNAT tree. */
8046 static Uint
8048 {
8050 TCode tcode;
8054 /* See if we've already saved the value for this node. */
8056 {
8064 }
8065 else
8068 /* If we do not return inside this switch, TCODE will be set to the
8069 code to be used in a call to Create_Node. */
8071 {
8073 /* For negative values, build NEGATE_EXPR of the opposite. Such values
8074 can appear for discriminants in expressions for variants. */
8076 {
8080 }
8081 else
8086 /* The only case we handle here is a simple discriminant reference. */
8088 {
8092 /* Climb up the chain of successive extensions, if any. */
8099 {
8100 /* Fall through to common processing as a FIELD_DECL. */
8103 }
8104 else
8106 }
8107 else
8116 CASE_CONVERT:
8120 /* Now just list the operations we handle. */
8150 /* Fold conversions from bytes to bits into inner operations. */
8153 {
8157 {
8160 widest_int op1;
8164 else
8169 }
8170 }
8175 /* For negative values in sizetype, build NEGATE_EXPR of the opposite.
8176 Such values appear in expressions with aligning patterns. Note that,
8177 since sizetype is unsigned, we have to jump through some hoops. */
8179 {
8184 {
8187 }
8188 }
8192 /* In regular mode, inline back only if symbolic annotation is requested
8193 in order to avoid memory explosion on big discriminated record types.
8194 But not in ASIS mode, as symbolic annotation is required for DDA. */
8196 {
8199 }
8200 else
8205 }
8207 /* Now get each of the operands that's relevant for this code. If any
8208 cannot be expressed as a repinfo node, say we can't. */
8211 {
8215 }
8219 /* Save the result in the cache. */
8221 {
8223 /* We can't assume the hash table data hasn't moved since the initial
8224 look up, so we have to search again. Allocating and inserting an
8225 entry at that point would be an alternative, but then we'd better
8226 discard the entry if we decided not to cache it. */
8232 }
8235 }
8237 /* Given GNAT_ENTITY, an object (constant, variable, parameter, exception)
8238 and GNU_TYPE, its corresponding GCC type, set Esize and Alignment to the
8239 size and alignment used by Gigi. Prefer SIZE over TYPE_SIZE if non-null.
8240 BY_REF is true if the object is used by reference. */
8242 void
8244 {
8246 {
8249 else
8251 }
8254 {
8263 }
8268 }
8270 /* Return first element of field list whose TREE_PURPOSE is the same as ELEM.
8271 Return NULL_TREE if there is no such element in the list. */
8273 static tree
8275 {
8277 {
8282 }
8284 }
8286 /* Given GNAT_ENTITY, a record type, and GNU_TYPE, its corresponding GCC type,
8287 set Component_Bit_Offset and Esize of the components to the position and
8288 size used by Gigi. */
8290 static void
8292 {
8293 /* For an extension, the inherited components have not been translated because
8294 they are fetched from the _Parent component on the fly. */
8295 const bool is_extension
8298 /* We operate by first making a list of all fields and their position (we
8299 can get the size easily) and then update all the sizes in the tree. */
8300 tree gnu_list
8311 {
8313 gnu_list);
8315 {
8316 tree parent_offset;
8318 /* If we are just annotating types and the type is tagged, the tag
8319 and the parent components are not generated by the front-end so
8320 we need to add the appropriate offset to each component without
8321 representation clause. */
8325 {
8326 /* For a component appearing in the current extension, the
8327 offset is the size of the parent. */
8330 parent_offset
8332 bitsizetype);
8333 else
8337 parent_offset
8340 }
8341 else
8344 Set_Component_Bit_Offset
8346 annotate_value
8350 parent_offset)));
8354 }
8356 {
8357 /* If there is no entry, this is an inherited component whose
8358 position is the same as in the parent type. */
8361 /* If we are just annotating types, discriminants renaming those of
8362 the parent have no entry so deal with them specifically. */
8372 }
8373 }
8374 }
8375 \f
8376 /* Scan all fields in GNU_TYPE and return a TREE_LIST where TREE_PURPOSE is
8377 the FIELD_DECL and TREE_VALUE a TREE_VEC containing the byte position, the
8378 value to be placed into DECL_OFFSET_ALIGN and the bit position. The list
8379 of fields is flattened, except for variant parts if DO_NOT_FLATTEN_VARIANT
8380 is set to true. GNU_POS is to be added to the position, GNU_BITPOS to the
8381 bit position, OFFSET_ALIGN is the present offset alignment. GNU_LIST is a
8382 pre-existing list to be chained to the newly created entries. */
8384 static tree
8387 {
8388 tree gnu_field;
8391 gnu_field;
8393 {
8398 unsigned int our_offset_align
8407 /* Recurse on internal fields, flattening the nested fields except for
8408 those in the variant part, if requested. */
8410 {
8414 gnu_list
8418 else
8419 gnu_list
8423 }
8424 }
8427 }
8429 /* Return a list describing the substitutions needed to reflect the
8430 discriminant substitutions from GNAT_TYPE to GNAT_SUBTYPE. They can
8431 be in any order. The values in an element of the list are in the form
8432 of operands to SUBSTITUTE_IN_EXPR. DEFINITION is true if this is for
8433 a definition of GNAT_SUBTYPE. */
8437 {
8439 Entity_Id gnat_discrim;
8440 Node_Id gnat_constr;
8447 /* Ignore access discriminants. */
8449 {
8452 elaborate_expression
8458 }
8461 }
8463 /* Scan all fields in QUAL_UNION_TYPE and return a list describing the
8464 variants of QUAL_UNION_TYPE that are still relevant after applying
8465 the substitutions described in SUBST_LIST. GNU_LIST is a pre-existing
8466 list to be prepended to the newly created entries. */
8471 {
8472 tree gnu_field;
8475 gnu_field;
8477 {
8485 /* If the new qualifier is not unconditionally false, its variant may
8486 still be accessed. */
8488 {
8494 /* Recurse on the variant subpart of the variant, if any. */
8500 /* If the new qualifier is unconditionally true, the subsequent
8501 variants cannot be accessed. */
8504 }
8505 }
8508 }
8509 \f
8510 /* UINT_SIZE is a Uint giving the specified size for an object of GNU_TYPE
8511 corresponding to GNAT_OBJECT. If the size is valid, return an INTEGER_CST
8512 corresponding to its value. Otherwise, return NULL_TREE. KIND is set to
8513 VAR_DECL if we are specifying the size of an object, TYPE_DECL for the
8514 size of a type, and FIELD_DECL for the size of a field. COMPONENT_P is
8515 true if we are being called to process the Component_Size of GNAT_OBJECT;
8516 this is used only for error messages. ZERO_OK is true if a size of zero
8517 is permitted; if ZERO_OK is false, it means that a size of zero should be
8518 treated as an unspecified size. */
8520 static tree
8523 {
8524 Node_Id gnat_error_node;
8527 /* Return 0 if no size was specified. */
8531 /* Ignore a negative size since that corresponds to our back-annotation. */
8535 /* Find the node to use for error messages. */
8542 else
8545 /* Get the size as an INTEGER_CST. Issue an error if a size was specified
8546 but cannot be represented in bitsizetype. */
8549 {
8552 gnat_object);
8553 else
8555 gnat_object);
8557 }
8559 /* Ignore a zero size if it is not permitted. */
8563 /* The size of objects is always a multiple of a byte. */
8566 {
8570 else
8574 }
8576 /* If this is an integral type or a packed array type, the front-end has
8577 already verified the size, so we need not do it here (which would mean
8578 checking against the bounds). However, if this is an aliased object,
8579 it may not be smaller than the type of the object. */
8584 /* If the object is a record that contains a template, add the size of the
8585 template to the specified size. */
8591 /* If a type needs strict alignment, a component of this type in
8592 a packed record cannot be packed and thus uses the type size. */
8595 else
8598 /* Modify the size of a discriminated type to be the maximum size. */
8602 /* If this is an access type or a fat pointer, the minimum size is that given
8603 by the smallest integral mode that's valid for pointers. */
8605 {
8610 }
8612 /* Issue an error either if the default size of the object isn't a constant
8613 or if the new size is smaller than it. */
8617 {
8619 post_error_ne_tree
8622 else
8623 post_error_ne_tree
8627 }
8630 }
8631 \f
8632 /* Similarly, but both validate and process a value of RM size. This routine
8633 is only called for types. */
8635 static void
8637 {
8638 Node_Id gnat_attr_node;
8641 /* Do nothing if no size was specified. */
8645 /* Ignore a negative size since that corresponds to our back-annotation. */
8649 /* Only issue an error if a Value_Size clause was explicitly given.
8650 Otherwise, we'd be duplicating an error on the Size clause. */
8651 gnat_attr_node
8654 /* Get the size as an INTEGER_CST. Issue an error if a size was specified
8655 but cannot be represented in bitsizetype. */
8658 {
8661 gnat_entity);
8663 }
8665 /* Ignore a zero size unless a Value_Size clause exists, or a size clause
8666 exists, or this is an integer type, in which case the front-end will
8667 have always set it. */
8676 /* If the old size is self-referential, get the maximum size. */
8680 /* Issue an error either if the old size of the object isn't a constant or
8681 if the new size is smaller than it. The front-end has already verified
8682 this for scalar and packed array types. */
8690 && TYPE_PACKED_ARRAY_TYPE_P
8693 {
8695 post_error_ne_tree
8699 }
8701 /* Otherwise, set the RM size proper for integral types... */
8708 /* ...or the Ada size for record and union types. */
8712 }
8713 \f
8714 /* ALIGNMENT is a Uint giving the alignment specified for GNAT_ENTITY,
8715 a type or object whose present alignment is ALIGN. If this alignment is
8716 valid, return it. Otherwise, give an error and return ALIGN. */
8718 static unsigned int
8720 {
8723 Node_Id gnat_error_node;
8725 /* Don't worry about checking alignment if alignment was not specified
8726 by the source program and we already posted an error for this entity. */
8730 /* Post the error on the alignment clause if any. Note, for the implicit
8731 base type of an array type, the alignment clause is on the first
8732 subtype. */
8740 gnat_error_node =
8743 else
8746 /* Within GCC, an alignment is an integer, so we must make sure a value is
8747 specified that fits in that range. Also, there is an upper bound to
8748 alignments we can support/allow. */
8756 {
8760 /* If the default alignment of "double" or larger scalar types is
8761 specifically capped and the new alignment is above the cap, do
8762 not post an error and change the alignment only if there is an
8763 alignment clause; this makes it possible to have the associated
8764 GCC type overaligned by default for performance reasons. */
8766 {
8767 Entity_Id gnat_type
8769 is_capped_double
8771 }
8773 {
8774 Entity_Id gnat_type
8776 is_capped_double
8778 }
8779 else
8783 {
8786 }
8787 else
8788 {
8795 }
8796 }
8797 else
8798 {
8802 }
8805 }
8806 \f
8807 /* Promote the alignment of GNU_TYPE corresponding to GNAT_ENTITY. Return
8808 a positive value on success or zero on failure. */
8810 static unsigned int
8812 {
8815 /* No point in promoting the alignment if this doesn't prevent BLKmode access
8816 to the object, in particular block copy, as this will for example disable
8817 the NRV optimization for it. No point in jumping through all the hoops
8818 needed in order to support BIGGEST_ALIGNMENT if we don't really have to.
8819 So we cap to the smallest alignment that corresponds to a known efficient
8820 memory access pattern, except for Atomic and Volatile_Full_Access. */
8822 {
8825 }
8826 else
8827 {
8830 }
8832 /* Do the promotion within the above limits. */
8838 else
8841 /* But make sure not to under-align the object. */
8845 /* And honor the minimum valid atomic alignment, if any. */
8846 #ifdef MINIMUM_ATOMIC_ALIGNMENT
8849 #endif
8852 }
8853 \f
8854 /* Verify that TYPE is something we can implement atomically. If not, issue
8855 an error for GNAT_ENTITY. COMPONENT_P is true if we are being called to
8856 process a component type. */
8858 static void
8860 {
8862 Node_Id gnat_node;
8863 machine_mode mode;
8866 tree size;
8868 /* If this is an anonymous base type, nothing to check, the error will be
8869 reported on the source type if need be. */
8878 /* Consider all aligned floating-point types atomic and any aligned types
8879 that are represented by integers no wider than a machine word. */
8880 scalar_int_mode int_mode;
8887 /* For the moment, also allow anything that has an alignment equal to its
8888 size and which is smaller than a word. */
8899 {
8900 unsigned char pragma_id
8905 {
8908 }
8909 }
8917 else
8920 }
8921 \f
8923 /* Helper for the intrin compatibility checks family. Evaluate whether
8924 two types are definitely incompatible. */
8926 static bool
8928 {
8943 {
8950 /* Assume designated types are ok. We'd need to account for char * and
8951 void * variants to do better, which could rapidly get messy and isn't
8952 clearly worth the effort. */
8957 }
8960 }
8962 /* Helper for intrin_profiles_compatible_p, to perform compatibility checks
8963 on the Ada/builtin argument lists for the INB binding. */
8965 static bool
8967 {
8973 /* Sequence position of the last argument we checked. */
8977 {
8981 /* If we've exhausted both lists simultaneously, we're done. */
8985 /* If one list is shorter than the other, they fail to match. */
8989 /* If we're done with the Ada args and not with the internal builtin
8990 args, or the other way around, complain. */
8993 {
8996 }
9000 {
9004 }
9006 /* Otherwise, check that types match for the current argument. */
9007 argpos ++;
9009 {
9013 }
9018 }
9021 }
9023 /* Helper for intrin_profiles_compatible_p, to perform compatibility checks
9024 on the Ada/builtin return values for the INB binding. */
9026 static bool
9028 {
9032 /* Accept function imported as procedure, common and convenient. */
9037 /* Check return types compatibility otherwise. Note that this
9038 handles void/void as well. */
9040 {
9044 }
9047 }
9049 /* Check and return whether the Ada and gcc builtin profiles bound by INB are
9050 compatible. Issue relevant warnings when they are not.
9052 This is intended as a light check to diagnose the most obvious cases, not
9053 as a full fledged type compatibility predicate. It is the programmer's
9054 responsibility to ensure correctness of the Ada declarations in Imports,
9055 especially when binding straight to a compiler internal. */
9057 static bool
9059 {
9060 /* Check compatibility on return values and argument lists, each responsible
9061 for posting warnings as appropriate. Ensure use of the proper sloc for
9062 this purpose. */
9075 }
9076 \f
9077 /* Return a FIELD_DECL node modeled on OLD_FIELD. FIELD_TYPE is its type
9078 and RECORD_TYPE is the type of the parent. If SIZE is nonzero, it is the
9079 specified size for this field. POS_LIST is a position list describing
9080 the layout of OLD_FIELD and SUBST_LIST a substitution list to be applied
9081 to this layout. */
9083 static tree
9087 {
9099 /* If the position is now a constant, we can set it as the position of the
9100 field when we make it. Otherwise, we need to deal with it specially. */
9103 else
9106 new_field
9112 {
9114 /* Finalize the position. */
9123 }
9131 }
9133 /* Create the REP part of RECORD_TYPE with REP_TYPE. If MIN_SIZE is nonzero,
9134 it is the minimal size the REP_PART must have. */
9136 static tree
9138 {
9139 tree field;
9149 }
9151 /* Return the REP part of RECORD_TYPE, if any. Otherwise return NULL. */
9153 static tree
9155 {
9158 /* The REP part is the first field, internal, another record, and its name
9159 starts with an 'R'. */
9167 }
9169 /* Return the variant part of RECORD_TYPE, if any. Otherwise return NULL. */
9171 tree
9173 {
9174 tree field;
9176 /* The variant part is the only internal field that is a qualified union. */
9183 }
9185 /* Return a new variant part modeled on OLD_VARIANT_PART. VARIANT_LIST is
9186 the list of variants to be used and RECORD_TYPE is the type of the parent.
9187 POS_LIST is a position list describing the layout of fields present in
9188 OLD_VARIANT_PART and SUBST_LIST a substitution list to be applied to this
9189 layout. DEBUG_INFO_P is true if we need to write debug information. */
9191 static tree
9197 {
9205 /* First create the type of the variant part from that of the old one. */
9211 /* If the position of the variant part is constant, subtract it from the
9212 size of the type of the parent to get the new size. This manual CSE
9213 reduces the code size when not optimizing. */
9217 {
9227 first_bit));
9230 }
9231 else
9234 /* Now finish up the new variants and populate the union type. */
9236 {
9240 /* Skip variants that don't belong to this nesting level. */
9244 /* Retrieve the list of fields already added to the new variant. */
9248 /* If the old variant had a variant subpart, we need to create a new
9249 variant subpart and add it to the field list. */
9253 {
9254 tree new_variant_subpart
9257 debug_info_p);
9260 }
9262 /* Finish up the new variant and create the field. */
9268 new_field
9276 }
9278 /* Finish up the union type and create the variant part. Note that we don't
9279 reverse the field list because VARIANT_LIST has been traversed in reverse
9280 order. */
9286 new_variant_part
9292 /* With multiple discriminants it is possible for an inner variant to be
9293 statically selected while outer ones are not; in this case, the list
9294 of fields of the inner variant is not flattened and we end up with a
9295 qualified union with a single member. Drop the useless container. */
9297 {
9306 }
9309 }
9311 /* Copy the size (and alignment and alias set) from OLD_TYPE to NEW_TYPE,
9312 which are both RECORD_TYPE, after applying the substitutions described
9313 in SUBST_LIST. */
9315 static void
9318 {
9342 SET_TYPE_ADA_SIZE
9346 /* Finalize the size. */
9349 }
9351 /* Return true if DISC is a stored discriminant of RECORD_TYPE. */
9355 {
9362 else
9364 }
9366 /* Copy the layout from {GNAT,GNU}_OLD_TYPE to {GNAT,GNU}_NEW_TYPE, which are
9367 both record types, after applying the substitutions described in SUBST_LIST.
9368 DEBUG_INFO_P is true if we need to write debug information for NEW_TYPE. */
9370 static void
9372 Entity_Id gnat_old_type,
9373 tree gnu_new_type,
9374 tree gnu_old_type,
9377 {
9383 /* Look for REP and variant parts in the old type. */
9387 /* If there is a variant part, we must compute whether the constraints
9388 statically select a particular variant. If so, we simply drop the
9389 qualified union and flatten the list of fields. Otherwise we will
9390 build a new qualified union for the variants that are still relevant. */
9392 {
9399 /* If all the qualifiers are unconditionally true, the innermost variant
9400 is statically selected. */
9404 {
9407 }
9409 /* Otherwise, create the new variants. */
9412 {
9415 tree suffix
9424 gnu_subst_list);
9426 }
9427 }
9428 else
9429 {
9432 }
9434 /* Make a list of fields and their position in the old type. */
9435 tree gnu_pos_list
9441 /* Now go down every component in the new type and compute its size and
9442 position from those of the component in the old type and the stored
9443 constraints of the new type. */
9456 {
9465 /* If the type is the same, retrieve the GCC type from the
9466 old field to take into account possible adjustments. */
9469 else
9472 /* If there was a component clause, the field types must be the same
9473 for the old and new types, so copy the data from the old field to
9474 avoid recomputation here. Also if the field is justified modular
9475 and the optimization in gnat_to_gnu_field was applied. */
9481 {
9484 }
9486 /* If the old field was packed and of constant size, we have to get the
9487 old size here as it might differ from what the Etype conveys and the
9488 latter might overlap with the following field. Try to arrange the
9489 type for possible better packing along the way. */
9492 {
9498 }
9500 else
9503 /* If the context of the old field is the old type or its REP part,
9504 put the field directly in the new type; otherwise look up the
9505 context in the variant list and put the field either in the new
9506 type if there is a selected variant or in one new variant. */
9510 else
9511 {
9514 tree rep_part;
9524 else
9525 /* The front-end may pass us "ghost" components if it fails to
9526 recognize that a constrain statically selects a particular
9527 variant. Discard them. */
9529 }
9531 /* Now create the new field modeled on the old one. */
9532 gnu_field
9538 /* If the context is a variant, put it in the new variant directly. */
9540 {
9543 }
9545 /* To match the layout crafted in components_to_record, if this is
9546 the _Tag or _Parent field, put it before any other fields. */
9550 /* Similarly, if this is the _Controller field, put it before the
9551 other fields except for the _Tag or _Parent field. */
9553 {
9556 }
9558 /* Otherwise, put it after the other fields. */
9559 else
9560 {
9567 }
9569 /* For a stored discriminant in a derived type, replace the field. */
9571 {
9574 }
9575 else
9577 }
9579 /* If there is no variant list or a selected variant and the fields all have
9580 constant position, put them in order of increasing position to match that
9581 of constant CONSTRUCTORs. */
9583 {
9594 {
9597 }
9598 }
9600 /* If there is a variant list and no selected variant, we need to create the
9601 nest of variant parts from the old nest. */
9603 {
9604 tree new_variant_part
9610 }
9617 /* If NEW_TYPE is a subtype, it inherits all the attributes from OLD_TYPE.
9618 Otherwise sizes and alignment must be computed independently. */
9620 {
9623 }
9624 else
9627 /* Now go through the entities again looking for Itypes that we have not yet
9628 elaborated (e.g. Etypes of fields that have Original_Components). */
9637 }
9639 /* Associate to GNU_TYPE, the translation of GNAT_ENTITY, which is
9640 the implementation type of a packed array type (Is_Packed_Array_Impl_Type),
9641 the original array type if it has been translated. This association is a
9642 parallel type for GNAT encodings or a debug type for standard DWARF. Note
9643 that for standard DWARF, we also want to get the original type name. */
9645 static void
9647 {
9648 Entity_Id gnat_original_array_type
9650 tree gnu_original_array_type;
9661 {
9669 }
9670 else
9672 }
9673 \f
9674 /* Given a type T, a FIELD_DECL F, and a replacement value R, return an
9675 equivalent type with adjusted size expressions where all occurrences
9676 of references to F in a PLACEHOLDER_EXPR have been replaced by R.
9678 The function doesn't update the layout of the type, i.e. it assumes
9679 that the substitution is purely formal. That's why the replacement
9680 value R must itself contain a PLACEHOLDER_EXPR. */
9682 tree
9684 {
9685 tree nt;
9690 {
9696 /* First the domain types of arrays. */
9699 {
9711 SET_TYPE_INDEX_TYPE
9715 }
9717 /* Then the subtypes. */
9720 {
9732 }
9744 /* These should never show up here. */
9748 {
9768 }
9773 {
9775 tree field;
9777 /* Start out with no fields, make new fields, and chain them
9778 in. If we haven't actually changed the type of any field,
9779 discard everything we've done and return the old type. */
9784 {
9789 {
9792 }
9796 {
9799 }
9801 /* Do the substitution inside the qualifier, if any. */
9803 {
9806 {
9809 }
9810 }
9817 }
9827 }
9831 }
9832 }
9833 \f
9834 /* Return the RM size of GNU_TYPE. This is the actual number of bits
9835 needed to represent the object. */
9837 tree
9839 {
9840 /* For integral types, we store the RM size explicitly. */
9844 /* Return the RM size of the actual data plus the size of the template. */
9847 return
9852 /* For record or union types, we store the size explicitly. */
9858 /* For other types, this is just the size. */
9860 }
9861 \f
9862 /* Return the name to be used for GNAT_ENTITY. If a type, create a
9863 fully-qualified name, possibly with type information encoding.
9864 Otherwise, return the name. */
9868 {
9871 }
9873 tree
9875 {
9878 }
9880 /* Return an identifier representing the external name to be used for
9881 GNAT_ENTITY. If SUFFIX is specified, the name is followed by "___"
9882 and the specified suffix. */
9884 tree
9886 {
9894 /* A variable using the Stdcall convention lives in a DLL. We adjust
9895 its name to use the jump table, the _imp__NAME contains the address
9896 for the NAME variable. */
9899 {
9905 }
9908 }
9910 /* Given GNU_NAME, an IDENTIFIER_NODE containing a name and SUFFIX, a
9911 string, return a new IDENTIFIER_NODE that is the concatenation of
9912 the name followed by "___" and the specified suffix. */
9914 tree
9916 {
9923 }
9925 /* Initialize data structures of the decl.c module. */
9927 void
9929 {
9930 /* Initialize the cache of annotated values. */
9933 /* Initialize the association of dummy types with subprograms. */
9935 }
9937 /* Destroy data structures of the decl.c module. */
9939 void
9941 {
9942 /* Destroy the cache of annotated values. */
9946 /* Destroy the association of dummy types with subprograms. */
9949 }