| blob | eae23d281b09e6c6732e6327cbe17d0b5dc896d7 |
1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * U T I L S *
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 ****************************************************************************/
60 /* If nonzero, pretend we are allocating at global level. */
63 /* The default alignment of "double" floating-point types, i.e. floating
64 point types whose size is equal to 64 bits, or 0 if this alignment is
65 not specifically capped. */
68 /* The default alignment of "double" or larger scalar types, i.e. scalar
69 types whose size is greater or equal to 64 bits, or 0 if this alignment
70 is not specifically capped. */
73 /* True if floating-point arithmetics may use wider intermediate results. */
76 /* Tree nodes for the various types and decls we create. */
79 /* Functions to call for each of the possible raise reasons. */
82 /* Likewise, but with extra info for each of the possible raise reasons. */
85 /* Forward declarations for handlers of attributes. */
102 /* Fake handler for attributes we don't properly support, typically because
103 they'd require dragging a lot of the common-c front-end circuitry. */
106 /* Table of machine-independent internal attributes for Ada. We support
107 this minimal set of attributes to accommodate the needs of builtins. */
109 {
110 /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler,
111 affects_type_identity, exclusions } */
145 /* ??? format and format_arg are heavy and not supported, which actually
146 prevents support for stdio builtins, which we however declare as part
147 of the common builtins.def contents. */
149 NULL },
151 NULL },
154 };
156 /* Associates a GNAT tree node to a GCC tree node. It is used in
157 `save_gnu_tree', `get_gnu_tree' and `present_gnu_tree'. See documentation
158 of `save_gnu_tree' for more info. */
161 #define GET_GNU_TREE(GNAT_ENTITY) \
162 associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id]
164 #define SET_GNU_TREE(GNAT_ENTITY,VAL) \
165 associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] = (VAL)
167 #define PRESENT_GNU_TREE(GNAT_ENTITY) \
168 (associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] != NULL_TREE)
170 /* Associates a GNAT entity to a GCC tree node used as a dummy, if any. */
173 #define GET_DUMMY_NODE(GNAT_ENTITY) \
174 dummy_node_table[(GNAT_ENTITY) - First_Node_Id]
176 #define SET_DUMMY_NODE(GNAT_ENTITY,VAL) \
177 dummy_node_table[(GNAT_ENTITY) - First_Node_Id] = (VAL)
179 #define PRESENT_DUMMY_NODE(GNAT_ENTITY) \
180 (dummy_node_table[(GNAT_ENTITY) - First_Node_Id] != NULL_TREE)
182 /* This variable keeps a table for types for each precision so that we only
183 allocate each of them once. Signed and unsigned types are kept separate.
185 Note that these types are only used when fold-const requests something
186 special. Perhaps we should NOT share these types; we'll see how it
187 goes later. */
190 /* Likewise for float types, but record these by mode. */
193 /* For each binding contour we allocate a binding_level structure to indicate
194 the binding depth. */
197 /* The binding level containing this one (the enclosing binding level). */
199 /* The BLOCK node for this level. */
200 tree block;
201 /* If nonzero, the setjmp buffer that needs to be updated for any
202 variable-sized definition within this context. */
203 tree jmpbuf_decl;
204 };
206 /* The binding level currently in effect. */
209 /* A chain of gnat_binding_level structures awaiting reuse. */
212 /* The context to be used for global declarations. */
215 /* An array of global declarations. */
218 /* An array of builtin function declarations. */
221 /* A chain of unused BLOCK nodes. */
224 /* A hash table of padded types. It is modelled on the generic type
225 hash table in tree.c, which must thus be used as a reference. */
228 {
229 hashval_t hash;
230 tree type;
231 };
234 {
238 static int
240 {
242 }
243 };
256 /* Linked list used as a queue to defer the initialization of the DECL_CONTEXT
257 of ..._DECL nodes and of the TYPE_CONTEXT of ..._TYPE nodes. */
258 struct deferred_decl_context_node
259 {
260 /* The ..._DECL node to work on. */
261 tree decl;
263 /* The corresponding entity's Scope. */
264 Entity_Id gnat_scope;
266 /* The value of force_global when DECL was pushed. */
269 /* The list of ..._TYPE nodes to propagate the context to. */
272 /* The next queue item. */
274 };
278 /* Defer the initialization of DECL's DECL_CONTEXT attribute, scheduling to
279 feed it with the elaboration of GNAT_SCOPE. */
283 /* Defer the initialization of TYPE's TYPE_CONTEXT attribute, scheduling to
284 feed it with the DECL_CONTEXT computed as part of N as soon as it is
285 computed. */
287 tree type);
288 \f
289 /* Initialize data structures of the utils.c module. */
291 void
293 {
294 /* Initialize the association of GNAT nodes to GCC trees. */
297 /* Initialize the association of GNAT nodes to GCC trees as dummies. */
300 /* Initialize the hash table of padded types. */
302 }
304 /* Destroy data structures of the utils.c module. */
306 void
308 {
309 /* Destroy the association of GNAT nodes to GCC trees. */
313 /* Destroy the association of GNAT nodes to GCC trees as dummies. */
317 /* Destroy the hash table of padded types. */
320 }
321 \f
322 /* GNAT_ENTITY is a GNAT tree node for an entity. Associate GNU_DECL, a GCC
323 tree node, with GNAT_ENTITY. If GNU_DECL is not a ..._DECL node, abort.
324 If NO_CHECK is true, the latter check is suppressed.
326 If GNU_DECL is zero, reset a previous association. */
328 void
330 {
331 /* Check that GNAT_ENTITY is not already defined and that it is being set
332 to something which is a decl. If that is not the case, this usually
333 means GNAT_ENTITY is defined twice, but occasionally is due to some
334 Gigi problem. */
340 }
342 /* GNAT_ENTITY is a GNAT tree node for an entity. Return the GCC tree node
343 that was associated with it. If there is no such tree node, abort.
345 In some cases, such as delayed elaboration or expressions that need to
346 be elaborated only once, GNAT_ENTITY is really not an entity. */
348 tree
350 {
353 }
355 /* Return nonzero if a GCC tree has been associated with GNAT_ENTITY. */
357 bool
359 {
361 }
362 \f
363 /* Make a dummy type corresponding to GNAT_TYPE. */
365 tree
367 {
371 /* If there was no equivalent type (can only happen when just annotating
372 types) or underlying type, go back to the original type. */
376 /* If it there already a dummy type, use that one. Else make one. */
380 /* If this is a record, make a RECORD_TYPE or UNION_TYPE; else make
381 an ENUMERAL_TYPE. */
394 /* Create a debug type so that debug info consumers only see an unspecified
395 type. */
397 {
403 }
406 }
408 /* Return the dummy type that was made for GNAT_TYPE, if any. */
410 tree
412 {
414 }
416 /* Build dummy fat and thin pointer types whose designated type is specified
417 by GNAT_DESIG_TYPE/GNU_DESIG_TYPE and attach them to the latter. */
419 void
421 {
436 /* Build a stub DECL to trigger the special processing for fat pointer types
437 in gnat_pushdecl. */
440 gnu_fat_type);
448 /* Suppress debug info until after the type is completed. */
458 }
459 \f
460 /* Return true if we are in the global binding level. */
462 bool
464 {
466 }
468 /* Enter a new binding level. */
470 void
472 {
475 /* Reuse a struct for this binding level, if there is one. */
477 {
480 }
481 else
484 /* Use a free BLOCK, if any; otherwise, allocate one. */
486 {
490 }
491 else
494 /* Point the BLOCK we just made to its parent. */
502 /* Add this level to the front of the chain (stack) of active levels. */
506 }
508 /* Set SUPERCONTEXT of the BLOCK for the current binding level to FNDECL
509 and point FNDECL to this BLOCK. */
511 void
513 {
517 }
519 /* Set the jmpbuf_decl for the current binding level to DECL. */
521 void
523 {
525 }
527 /* Get the jmpbuf_decl, if any, for the current binding level. */
529 tree
531 {
533 }
535 /* Exit a binding level. Set any BLOCK into the current code group. */
537 void
539 {
546 /* If this is a function-level BLOCK don't do anything. Otherwise, if there
547 are no variables free the block and merge its subblocks into those of its
548 parent block. Otherwise, add it to the list of its parent. */
550 ;
552 {
558 }
559 else
560 {
565 }
567 /* Free this binding structure. */
571 }
573 /* Exit a binding level and discard the associated BLOCK. */
575 void
577 {
584 /* Free this binding structure. */
588 }
589 \f
590 /* Set the context of TYPE and its parallel types (if any) to CONTEXT. */
592 static void
594 {
600 {
603 /* Give a context to the parallel types and their stub decl, if any.
604 Some parallel types seems to be present in multiple parallel type
605 chains, so don't mess with their context if they already have one. */
607 {
611 }
614 }
615 }
617 /* Return the innermost scope, starting at GNAT_NODE, we are be interested in
618 the debug info, or Empty if there is no such scope. If not NULL, set
619 IS_SUBPROGRAM to whether the returned entity is a subprogram. */
621 Entity_Id
623 {
624 Entity_Id gnat_entity;
632 else
636 {
638 {
644 /* If the scope is a subprogram, then just rely on
645 current_function_decl, so that we don't have to defer
646 anything. This is needed because other places rely on the
647 validity of the DECL_CONTEXT attribute of FUNCTION_DECL nodes. */
657 /* By default, we are not interested in this particular scope: go to
658 the outer one. */
660 }
663 }
666 }
668 /* If N is NULL, set TYPE's context to CONTEXT. Defer this to the processing
669 of N otherwise. */
671 static void
674 {
677 else
679 }
681 /* Return global_context, but create it first if need be. */
683 static tree
685 {
687 {
688 global_context
691 }
694 }
696 /* Record DECL as belonging to the current lexical scope and use GNAT_NODE
697 for location information and flag propagation. */
699 void
701 {
705 /* If explicitely asked to make DECL global or if it's an imported nested
706 object, short-circuit the regular Scope-based context computation. */
708 {
709 /* Rely on the GNAT scope, or fallback to the current_function_decl if
710 the GNAT scope reached the global scope, if it reached a subprogram
711 or the declaration is a subprogram or a variable (for them we skip
712 intermediate context types because the subprogram body elaboration
713 machinery and the inliner both expect a subprogram context).
715 Falling back to current_function_decl is necessary for implicit
716 subprograms created by gigi, such as the elaboration subprograms. */
718 const Entity_Id gnat_scope
722 && !context_is_subprogram
725 /* Always assume the scope has not been elaborated, thus defer the
726 context propagation to the time its elaboration will be
727 available. */
728 deferred_decl_context
731 /* External declarations (when force_global > 0) may not be in a
732 local context. */
735 }
737 /* If either we are forced to be in global mode or if both the GNAT scope and
738 the current_function_decl did not help in determining the context, use the
739 global scope. */
743 /* Functions imported in another function are not really nested.
744 For really nested functions mark them initially as needing
745 a static chain for uses of that flag before unnesting;
746 lower_nested_functions will then recompute it. */
749 && context
759 /* Set the location of DECL and emit a declaration for it. */
765 /* Put the declaration on the list. The list of declarations is in reverse
766 order. The list will be reversed later. Put global declarations in the
767 globals list and local ones in the current block. But skip TYPE_DECLs
768 for UNCONSTRAINED_ARRAY_TYPE in both cases, as they will cause trouble
769 with the debugger and aren't needed anyway. */
772 {
773 /* External declarations must go to the binding level they belong to.
774 This will make corresponding imported entities are available in the
775 debugger at the proper time. */
782 else
783 {
786 }
787 }
789 /* For the declaration of a type, set its name either if it isn't already
790 set or if the previous type name was not derived from a source name.
791 We'd rather have the type named with a real name and all the pointer
792 types to the same object have the same node, except when the names are
793 both derived from source names. */
795 {
798 /* Array and pointer types aren't tagged types in the C sense so we need
799 to generate a typedef in DWARF for them and make sure it is preserved,
800 unless the type is artificial. */
804 ;
805 /* For array and pointer types, create the DECL_ORIGINAL_TYPE that will
806 generate the typedef in DWARF. Also do that for fat pointer types
807 because, even though they are tagged types in the C sense, they are
808 still XUP types attached to the base array type at this point. */
813 {
818 deferred_decl_context);
824 else
826 /* Array types need to have a name so that they can be related to
827 their GNAT encodings. */
831 }
835 ;
836 else
839 /* Propagate the name to all the variants, this is needed for the type
840 qualifiers machinery to work properly (see check_qualified_type).
841 Also propagate the context to them. Note that it will be propagated
842 to all parallel types too thanks to gnat_set_type_context. */
845 /* ??? Because of the previous kludge, we can have variants of fat
846 pointer types with different names. */
850 {
854 deferred_decl_context);
855 }
856 }
857 }
858 \f
859 /* Create a record type that contains a SIZE bytes long field of TYPE with a
860 starting bit position so that it is aligned to ALIGN bits, and leaving at
861 least ROOM bytes free before the field. BASE_ALIGN is the alignment the
862 record is guaranteed to get. GNAT_NODE is used for the position of the
863 associated TYPE_DECL. */
865 tree
868 {
869 /* We will be crafting a record type with one field at a position set to be
870 the next multiple of ALIGN past record'address + room bytes. We use a
871 record placeholder to express record'address. */
875 tree record_addr_st
878 /* The diagram below summarizes the shape of what we manipulate:
880 <--------- pos ---------->
881 { +------------+-------------+-----------------+
882 record =>{ |############| ... | field (type) |
883 { +------------+-------------+-----------------+
884 |<-- room -->|<- voffset ->|<---- size ----->|
885 o o
886 | |
887 record_addr vblock_addr
889 Every length is in sizetype bytes there, except "pos" which has to be
890 set as a bit position in the GCC tree for the record. */
900 /* Compute VOFFSET and then POS. The next byte position multiple of some
901 alignment after some address is obtained by "and"ing the alignment minus
902 1 with the two's complement of the address. */
907 /* POS = (ROOM + VOFFSET) * BIT_PER_UNIT, in bitsizetype. */
911 bitsize_unit_node);
913 /* Craft the GCC record representation. We exceptionally do everything
914 manually here because 1) our generic circuitry is not quite ready to
915 handle the complex position/size expressions we are setting up, 2) we
916 have a strong simplifying factor at hand: we know the maximum possible
917 value of voffset, and 3) we have to set/reset at least the sizes in
918 accordance with this maximum value anyway, as we need them to convey
919 what should be "alloc"ated for this type.
921 Use -1 as the 'addressable' indication for the field to prevent the
922 creation of a bitfield. We don't need one, it would have damaging
923 consequences on the alignment computation, and create_field_decl would
924 make one without this special argument, for instance because of the
925 complex position expression. */
936 bitsize_unit_node),
945 /* Declare it now since it will never be declared otherwise. This is
946 necessary to ensure that its subtrees are properly marked. */
950 }
952 /* TYPE is a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE that is being used
953 as the field type of a packed record if IN_RECORD is true, or as the
954 component type of a packed array if IN_RECORD is false. See if we can
955 rewrite it either as a type that has non-BLKmode, which we can pack
956 tighter in the packed record case, or as a smaller type with at most
957 MAX_ALIGN alignment if the value is non-zero. If so, return the new
958 type; if not, return the original type. */
960 tree
962 {
968 /* No point in doing anything if the size is zero. */
974 /* Copy the name and flags from the old type to that of the new.
975 Note that we rely on the pointer equality created here for
976 TYPE_NAME to look through conversions in various places. */
984 /* If we are in a record and have a small size, set the alignment to
985 try for an integral mode. Otherwise set it to try for a smaller
986 type with BLKmode. */
988 {
992 }
993 else
994 {
995 /* Do not try to shrink the size if the RM size is not constant. */
1000 /* Round the RM size up to a unit boundary to get the minimal size
1001 for a BLKmode record. Give up if it's already the size and we
1002 don't need to lower the alignment. */
1012 }
1016 /* Now copy the fields, keeping the position and size as we don't want
1017 to change the layout by propagating the packedness downwards. */
1020 {
1029 /* However, for the last field in a not already packed record type
1030 that is of an aggregate type, we need to use the RM size in the
1031 packable version of the record type, see finish_record_type. */
1039 else
1042 new_field
1055 }
1063 /* If this is a padding record, we never want to make the size smaller
1064 than what was specified. For QUAL_UNION_TYPE, also copy the size. */
1066 {
1070 }
1071 else
1072 {
1075 }
1082 /* Try harder to get a packable type if necessary, for example
1083 in case the record itself contains a BLKmode field. */
1089 /* If neither mode nor size nor alignment shrunk, return the old type. */
1094 }
1096 /* Return true if TYPE has an unsigned representation. This needs to be used
1097 when the representation of types whose precision is not equal to their size
1098 is manipulated based on the RM size. */
1102 {
1103 /* This is the common case. */
1107 /* See the E_Signed_Integer_Subtype case of gnat_to_gnu_entity. */
1113 }
1115 /* Given a type TYPE, return a new type whose size is appropriate for SIZE.
1116 If TYPE is the best type, return it. Otherwise, make a new type. We
1117 only support new integral and pointer types. FOR_BIASED is true if
1118 we are making a biased type. */
1120 tree
1122 {
1125 tree new_type;
1127 /* If size indicates an error, just return TYPE to avoid propagating
1128 the error. Likewise if it's too large to represent. */
1135 {
1142 /* Integer types with precision 0 are forbidden. */
1146 /* Only do something if the type isn't a packed array type and doesn't
1147 already have the proper size and the size isn't too large. */
1155 /* The type should be an unsigned type if the original type is unsigned
1156 or if the lower bound is constant and non-negative or if the type is
1157 biased, see E_Signed_Integer_Subtype case of gnat_to_gnu_entity. */
1160 else
1165 /* Copy the name to show that it's essentially the same type and
1166 not a subrange type. */
1173 /* Do something if this is a fat pointer, in which case we
1174 may need to return the thin pointer. */
1176 {
1177 scalar_int_mode p_mode;
1181 return
1182 build_pointer_type_for_mode
1185 }
1189 /* Only do something if this is a thin pointer, in which case we
1190 may need to return the fat pointer. */
1192 return
1198 }
1201 }
1203 /* Return true iff the padded types are equivalent. */
1205 bool
1207 {
1216 /* We consider that the padded types are equivalent if they pad the same type
1217 and have the same size, alignment, RM size and storage order. Taking the
1218 mode into account is redundant since it is determined by the others. */
1219 return
1225 }
1227 /* Compute the hash value for the padded TYPE. */
1229 static hashval_t
1231 {
1232 hashval_t hashcode;
1234 hashcode
1241 }
1243 /* Look up the padded TYPE in the hash table and return its canonical version
1244 if it exists; otherwise, insert it into the hash table. */
1246 static tree
1248 {
1257 {
1262 }
1265 }
1267 /* Ensure that TYPE has SIZE and ALIGN. Make and return a new padded type
1268 if needed. We have already verified that SIZE and ALIGN are large enough.
1269 GNAT_ENTITY is used to name the resulting record and to issue a warning.
1270 IS_COMPONENT_TYPE is true if this is being done for the component type of
1271 an array. IS_USER_TYPE is true if the original type needs to be completed.
1272 DEFINITION is true if this type is being defined. SET_RM_SIZE is true if
1273 the RM size of the resulting type is to be set to SIZE too; in this case,
1274 the padded type is canonicalized before being returned. */
1276 tree
1280 {
1285 /* If TYPE is a padded type, see if it agrees with any size and alignment
1286 we were given. If so, return the original type. Otherwise, strip
1287 off the padding, since we will either be returning the inner type
1288 or repadding it. If no size or alignment is specified, use that of
1289 the original padded type. */
1291 {
1305 }
1307 /* If the size is either not being changed or is being made smaller (which
1308 is not done here and is only valid for bitfields anyway), show the size
1309 isn't changing. Likewise, clear the alignment if it isn't being
1310 changed. Then return if we aren't doing anything. */
1323 /* If requested, complete the original type and give it a name. */
1330 gnat_entity);
1332 /* We used to modify the record in place in some cases, but that could
1333 generate incorrect debugging information. So make a new record
1334 type and name. */
1338 /* ??? Padding types around packed array implementation types will be
1339 considered as root types in the array descriptor language hook (see
1340 gnat_get_array_descr_info). Give them the original packed array type
1341 name so that the one coming from sources appears in the debugging
1342 information. */
1355 bitsize_unit_node));
1357 /* If we are changing the alignment and the input type is a record with
1358 BLKmode and a small constant size, try to make a form that has an
1359 integral mode. This might allow the padding record to also have an
1360 integral mode, which will be much more efficient. There is no point
1361 in doing so if a size is specified unless it is also a small constant
1362 size and it is incorrect to do so if we cannot guarantee that the mode
1363 will be naturally aligned since the field must always be addressable.
1365 ??? This might not always be a win when done for a stand-alone object:
1366 since the nominal and the effective type of the object will now have
1367 different modes, a VIEW_CONVERT_EXPR will be required for converting
1368 between them and it might be hard to overcome afterwards, including
1369 at the RTL level when the stand-alone object is accessed as a whole. */
1377 && (!size
1380 {
1385 }
1387 /* Now create the field with the original size. */
1392 /* We will output additional debug info manually below. */
1395 /* Set the RM size if requested. */
1397 {
1400 /* If the padded type is complete and has constant size, we canonicalize
1401 it by means of the hash table. This is consistent with the language
1402 semantics and ensures that gigi and the middle-end have a common view
1403 of these padded types. */
1405 {
1408 {
1411 }
1412 }
1413 }
1418 /* Unless debugging information isn't being written for the input type,
1419 write a record that shows what we are a subtype of and also make a
1420 variable that indicates our size, if still variable. */
1426 {
1430 /* A variable that holds the size is required even with no encoding since
1431 it will be referenced by debugging information attributes. At global
1432 level, we need a single variable across all translation units. */
1436 {
1437 /* Whether or not gnat_entity comes from source, this XVZ variable is
1438 is a compilation artifact. */
1439 size_unit
1445 }
1447 /* There is no need to show what we are a subtype of when outputting as
1448 few encodings as possible: regular debugging infomation makes this
1449 redundant. */
1451 {
1465 }
1466 }
1468 built:
1469 /* If a simple size was explicitly given, maybe issue a warning. */
1476 /* But don't do it if we are just annotating types and the type is tagged or
1477 concurrent, since these types aren't fully laid out in this mode. */
1479 {
1480 Entity_Id gnat_type
1481 = is_component_type
1486 }
1488 /* Take the original size as the maximum size of the input if there was an
1489 unconstrained record involved and round it up to the specified alignment,
1490 if one was specified, but only for aggregate types. */
1503 {
1506 /* For a packed array, post the message on the original array type. */
1517 /* Generate message only for entities that come from source, since
1518 if we have an entity created by expansion, the message will be
1519 generated for some other corresponding source entity. */
1521 {
1530 }
1531 }
1534 }
1536 /* Return true if padded TYPE was built with an RM size. */
1538 bool
1540 {
1541 /* This is required for the lookup. */
1552 /* The types built with an RM size are the canonicalized ones. */
1554 }
1556 /* Return a copy of the padded TYPE but with reverse storage order. */
1558 tree
1560 {
1562 {
1563 /* If the inner type is not scalar then the function does nothing. */
1567 }
1569 /* This is required for the canonicalization. */
1578 }
1579 \f
1580 /* Relate the alias sets of GNU_NEW_TYPE and GNU_OLD_TYPE according to OP.
1581 If this is a multi-dimensional array type, do this recursively.
1583 OP may be
1584 - ALIAS_SET_COPY: the new set is made a copy of the old one.
1585 - ALIAS_SET_SUPERSET: the new set is made a superset of the old one.
1586 - ALIAS_SET_SUBSET: the new set is made a subset of the old one. */
1588 void
1590 {
1591 /* Remove any padding from GNU_OLD_TYPE. It doesn't matter in the case
1592 of a one-dimensional array, since the padding has the same alias set
1593 as the field type, but if it's a multi-dimensional array, we need to
1594 see the inner types. */
1600 /* Unconstrained array types are deemed incomplete and would thus be given
1601 alias set 0. Retrieve the underlying array type. */
1603 gnu_old_type
1606 gnu_new_type
1615 {
1617 /* The alias set shouldn't be copied between array types with different
1618 aliasing settings because this can break the aliasing relationship
1619 between the array type and its element type. */
1631 {
1635 /* Do nothing if the alias sets conflict. This ensures that we
1636 never call record_alias_subset several times for the same pair
1637 or at all for alias set 0. */
1639 {
1642 else
1644 }
1645 }
1650 }
1653 }
1654 \f
1655 /* Record TYPE as a builtin type for Ada. NAME is the name of the type.
1656 ARTIFICIAL_P is true if the type was generated by the compiler. */
1658 void
1660 {
1669 }
1670 \f
1671 /* Finish constructing the character type CHAR_TYPE.
1673 In Ada character types are enumeration types and, as a consequence, are
1674 represented in the front-end by integral types holding the positions of
1675 the enumeration values as defined by the language, which means that the
1676 integral types are unsigned.
1678 Unfortunately the signedness of 'char' in C is implementation-defined
1679 and GCC even has the option -fsigned-char to toggle it at run time.
1680 Since GNAT's philosophy is to be compatible with C by default, to wit
1681 Interfaces.C.char is defined as a mere copy of Character, we may need
1682 to declare character types as signed types in GENERIC and generate the
1683 necessary adjustments to make them behave as unsigned types.
1685 The overall strategy is as follows: if 'char' is unsigned, do nothing;
1686 if 'char' is signed, translate character types of CHAR_TYPE_SIZE and
1687 character subtypes with RM_Size = Esize = CHAR_TYPE_SIZE into signed
1688 types. The idea is to ensure that the bit pattern contained in the
1689 Esize'd objects is not changed, even though the numerical value will
1690 be interpreted differently depending on the signedness. */
1692 void
1694 {
1698 /* Make a copy of a generic unsigned version since we'll modify it. */
1699 tree unsigned_char_type
1701 ? unsigned_char_type_node
1704 /* Create an unsigned version of the type and set it as debug type. */
1710 /* If this is a subtype, make the debug type a subtype of the debug type
1711 of the base type and convert literal RM bounds to unsigned. */
1713 {
1726 }
1728 /* Adjust the RM bounds of the original type to unsigned; that's especially
1729 important for types since they are implicit in this case. */
1732 }
1734 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
1735 finish constructing the record type as a fat pointer type. */
1737 void
1739 {
1740 /* Make sure we can put it into a register. */
1744 /* Show what it really is. */
1747 /* Do not emit debug info for it since the types of its fields may still be
1748 incomplete at this point. */
1751 /* Force type_contains_placeholder_p to return true on it. Although the
1752 PLACEHOLDER_EXPRs are referenced only indirectly, this isn't a pointer
1753 type but the representation of the unconstrained array. */
1755 }
1757 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
1758 finish constructing the record or union type. If REP_LEVEL is zero, this
1759 record has no representation clause and so will be entirely laid out here.
1760 If REP_LEVEL is one, this record has a representation clause and has been
1761 laid out already; only set the sizes and alignment. If REP_LEVEL is two,
1762 this record is derived from a parent record and thus inherits its layout;
1763 only make a pass on the fields to finalize them. DEBUG_INFO_P is true if
1764 additional debug info needs to be output for this type. */
1766 void
1769 {
1777 tree field;
1781 /* Always attach the TYPE_STUB_DECL for a record type. It is required to
1782 generate debug info and have a parallel type. */
1785 /* Globally initialize the record first. If this is a rep'ed record,
1786 that just means some initializations; otherwise, layout the record. */
1788 {
1798 /* For all-repped records with a size specified, lay the QUAL_UNION_TYPE
1799 out just like a UNION_TYPE, since the size will be fixed. */
1802 }
1803 else
1804 {
1805 /* Ensure there isn't a size already set. There can be in an error
1806 case where there is a rep clause but all fields have errors and
1807 no longer have a position. */
1810 /* Ensure we use the traditional GCC layout for bitfields when we need
1811 to pack the record type or have a representation clause. The other
1812 possible layout (Microsoft C compiler), if available, would prevent
1813 efficient packing in almost all cases. */
1814 #ifdef TARGET_MS_BITFIELD_LAYOUT
1819 ATTR_FLAG_TYPE_IN_PLACE);
1820 #endif
1823 }
1825 /* At this point, the position and size of each field is known. It was
1826 either set before entry by a rep clause, or by laying out the type above.
1828 We now run a pass over the fields (in reverse order for QUAL_UNION_TYPEs)
1829 to compute the Ada size; the GCC size and alignment (for rep'ed records
1830 that are not padding types); and the mode (for rep'ed records). We also
1831 clear the DECL_BIT_FIELD indication for the cases we know have not been
1832 handled yet, and adjust DECL_NONADDRESSABLE_P accordingly. */
1838 {
1842 tree this_ada_size;
1849 else
1852 /* Clear DECL_BIT_FIELD for the cases layout_decl does not handle. */
1855 {
1858 /* In the general case, type alignment is required. */
1860 {
1861 /* The enclosing record type must be sufficiently aligned.
1862 Otherwise, if no alignment was specified for it and it
1863 has been laid out already, bump its alignment to the
1864 desired one if this is compatible with its size and
1865 maximum alignment, if any. */
1867 {
1870 }
1876 {
1880 }
1881 }
1883 /* In the non-strict alignment case, only byte alignment is. */
1888 }
1890 /* If we still have DECL_BIT_FIELD set at this point, we know that the
1891 field is technically not addressable. Except that it can actually
1892 be addressed if it is BLKmode and happens to be properly aligned. */
1898 /* A type must be as aligned as its most aligned field that is not
1899 a bit-field. But this is already enforced by layout_type. */
1905 {
1912 ada_size
1920 /* Since we know here that all fields are sorted in order of
1921 increasing bit position, the size of the record is one
1922 higher than the ending bit of the last field processed
1923 unless we have a rep clause, since in that case we might
1924 have a field outside a QUAL_UNION_TYPE that has a higher ending
1925 position. So use a MAX in that case. Also, if this field is a
1926 QUAL_UNION_TYPE, we need to take into account the previous size in
1927 the case of empty variants. */
1928 ada_size
1931 size
1938 }
1939 }
1945 {
1946 /* If this is a padding record, we never want to make the size smaller
1947 than what was specified in it, if any. */
1951 /* Now set any of the values we've just computed that apply. */
1957 {
1958 tree size_unit = had_size_unit
1962 bitsize_unit_node));
1970 }
1971 }
1973 /* Reset the TYPE_MAX_ALIGN field since it's private to gigi. */
1978 }
1980 /* Append PARALLEL_TYPE on the chain of parallel types of TYPE. If
1981 PARRALEL_TYPE has no context and its computation is not deferred yet, also
1982 propagate TYPE's context to PARALLEL_TYPE's or defer its propagation to the
1983 moment TYPE will get a context. */
1985 void
1987 {
1995 /* If PARALLEL_TYPE already has a context, we are done. */
1999 /* Otherwise, try to get one from TYPE's context. If so, simply propagate
2000 it to PARALLEL_TYPE. */
2004 /* Otherwise TYPE has not context yet. We know it will have one thanks to
2005 gnat_pushdecl and then its context will be propagated to PARALLEL_TYPE,
2006 so we have nothing to do in this case. */
2007 }
2009 /* Return true if TYPE has a parallel type. */
2011 static bool
2013 {
2017 }
2019 /* Wrap up compilation of RECORD_TYPE, i.e. output additional debug info
2020 associated with it. It need not be invoked directly in most cases as
2021 finish_record_type takes care of doing so. */
2023 void
2025 {
2027 tree field;
2029 /* If this is a padded type, the bulk of the debug info has already been
2030 generated for the field's type. */
2034 /* If the type already has a parallel type (XVS type), then we're done. */
2039 {
2040 /* We need to make an XVE/XVU record if any field has variable size,
2041 whether or not the record does. For example, if we have a union,
2042 it may be that all fields, rounded up to the alignment, have the
2043 same size, in which case we'll use that size. But the debug
2044 output routines (except Dwarf2) won't be able to output the fields,
2045 so we need to make the special record. */
2047 /* If a field has a non-constant qualifier, the record will have
2048 variable size too. */
2051 {
2054 }
2055 }
2057 /* If this record type is of variable size, make a parallel record type that
2058 will tell the debugger how the former is laid out (see exp_dbug.ads). */
2060 {
2061 tree new_record_type
2068 new_name
2082 /* Now scan all the fields, replacing each field with a new field
2083 corresponding to the new encoding. */
2086 {
2094 /* See how the position was modified from the last position.
2096 There are two basic cases we support: a value was added
2097 to the last position or the last position was rounded to
2098 a boundary and they something was added. Check for the
2099 first case first. If not, see if there is any evidence
2100 of rounding. If so, round the last position and retry.
2102 If this is a union, the position can be taken as zero. */
2105 else
2111 {
2117 }
2122 && tree_fits_uhwi_p
2124 {
2126 unsigned HOST_WIDE_INT addend
2128 align
2134 }
2136 {
2140 }
2142 /* If we can't compute a position, set it to zero.
2144 ??? We really should abort here, but it's too much work
2145 to get this correct for all cases. */
2149 /* See if this type is variable-sized and make a pointer type
2150 and indicate the indirection if so. Beware that the debug
2151 back-end may adjust the position computed above according
2152 to the alignment of the field type, i.e. the pointer type
2153 in this case, if we don't preventively counter that. */
2155 {
2158 {
2161 }
2163 }
2165 /* Make a new field name, if necessary. */
2167 {
2173 else
2177 }
2179 new_field
2185 /* If old_field is a QUAL_UNION_TYPE, take its size as being
2186 zero. The only time it's not the last field of the record
2187 is when there are other components at fixed positions after
2188 it (meaning there was a rep clause for every field) and we
2189 want to be able to encode them. */
2193 ? bitsize_zero_node
2196 }
2201 }
2202 }
2204 /* Utility function of above to merge LAST_SIZE, the previous size of a record
2205 with FIRST_BIT and SIZE that describe a field. SPECIAL is true if this
2206 represents a QUAL_UNION_TYPE in which case we must look for COND_EXPRs and
2207 replace a value of zero with the old size. If HAS_REP is true, we take the
2208 MAX of the end position of this field with LAST_SIZE. In all other cases,
2209 we use FIRST_BIT plus SIZE. Return an expression for the size. */
2211 static tree
2214 {
2216 tree new_size;
2219 {
2223 }
2225 else
2236 /* We don't need any NON_VALUE_EXPRs and they can confuse us (especially
2237 when fed through substitute_in_expr) into thinking that a constant
2238 size is not constant. */
2243 }
2245 /* Return the bit position of FIELD, in bits from the start of the record,
2246 and fold it as much as possible. This is a tree of type bitsizetype. */
2248 static tree
2250 {
2256 else
2260 }
2262 /* Utility function of above to see if OP0 and OP1, both of SIZETYPE, are
2263 related by the addition of a constant. Return that constant if so. */
2265 static tree
2267 {
2274 {
2278 }
2279 else
2290 }
2292 /* Utility function of above to split a tree OP which may be a sum, into a
2293 constant part, which is returned, and a variable part, which is stored
2294 in *PVAR. *PVAR may be bitsize_zero_node. All operations must be of
2295 bitsizetype. */
2297 static tree
2299 {
2300 /* Strip conversions in order to ease the tree traversal and maximize the
2301 potential for constant or plus/minus discovery. We need to be careful
2302 to always return and set *pvar to bitsizetype trees, but it's worth
2303 the effort. */
2309 {
2312 }
2314 {
2325 }
2326 else
2328 }
2329 \f
2330 /* Return a copy of TYPE but safe to modify in any way. */
2332 tree
2334 {
2337 /* Unshare the language-specific data. */
2339 {
2342 }
2344 /* And the contents of the language-specific slot if needed. */
2347 {
2352 }
2354 /* copy_node clears this field instead of copying it, because it is
2355 aliased with TREE_CHAIN. */
2365 }
2366 \f
2367 /* Return a subtype of sizetype with range MIN to MAX and whose
2368 TYPE_INDEX_TYPE is INDEX. GNAT_NODE is used for the position
2369 of the associated TYPE_DECL. */
2371 tree
2373 {
2374 /* First build a type for the desired range. */
2377 /* Then set the index type. */
2382 }
2384 /* Return a subtype of TYPE with range MIN to MAX. If TYPE is NULL,
2385 sizetype is used. */
2387 tree
2389 {
2390 tree range_type;
2395 /* First build a type with the base range. */
2399 /* Then set the actual range. */
2404 }
2405 \f
2406 /* Return a TYPE_DECL node suitable for the TYPE_STUB_DECL field of TYPE.
2407 NAME gives the name of the type to be used in the declaration. */
2409 tree
2411 {
2416 }
2418 /* Return a TYPE_DECL node for TYPE. NAME gives the name of the type to be
2419 used in the declaration. ARTIFICIAL_P is true if the declaration was
2420 generated by the compiler. DEBUG_INFO_P is true if we need to write
2421 debug information about this type. GNAT_NODE is used for the position
2422 of the decl. */
2424 tree
2426 Node_Id gnat_node)
2427 {
2429 bool is_named
2431 tree type_decl;
2433 /* Only the builtin TYPE_STUB_DECL should be used for dummy types. */
2436 /* If the type hasn't been named yet, we're naming it; preserve an existing
2437 TYPE_STUB_DECL that has been attached to it for some purpose. */
2439 {
2442 }
2443 else
2449 /* Add this decl to the current binding level. */
2452 /* If we're naming the type, equate the TYPE_STUB_DECL to the name. This
2453 causes the name to be also viewed as a "tag" by the debug back-end, with
2454 the advantage that no DW_TAG_typedef is emitted for artificial "tagged"
2455 types in DWARF.
2457 Note that if "type" is used as a DECL_ORIGINAL_TYPE, it may be referenced
2458 from multiple contexts, and "type_decl" references a copy of it: in such a
2459 case, do not mess TYPE_STUB_DECL: we do not want to re-use the TYPE_DECL
2460 with the mechanism above. */
2464 /* Do not generate debug info for UNCONSTRAINED_ARRAY_TYPE that the
2465 back-end doesn't support, and for others if we don't need to. */
2470 }
2471 \f
2472 /* Return a VAR_DECL or CONST_DECL node.
2474 NAME gives the name of the variable. ASM_NAME is its assembler name
2475 (if provided). TYPE is its data type (a GCC ..._TYPE node). INIT is
2476 the GCC tree for an optional initial expression; NULL_TREE if none.
2478 CONST_FLAG is true if this variable is constant, in which case we might
2479 return a CONST_DECL node unless CONST_DECL_ALLOWED_P is false.
2481 PUBLIC_FLAG is true if this is for a reference to a public entity or for a
2482 definition to be made visible outside of the current compilation unit, for
2483 instance variable definitions in a package specification.
2485 EXTERN_FLAG is true when processing an external variable declaration (as
2486 opposed to a definition: no storage is to be allocated for the variable).
2488 STATIC_FLAG is only relevant when not at top level and indicates whether
2489 to always allocate storage to the variable.
2491 VOLATILE_FLAG is true if this variable is declared as volatile.
2493 ARTIFICIAL_P is true if the variable was generated by the compiler.
2495 DEBUG_INFO_P is true if we need to write debug information for it.
2497 ATTR_LIST is the list of attributes to be attached to the variable.
2499 GNAT_NODE is used for the position of the decl. */
2501 tree
2507 {
2508 /* Whether the object has static storage duration, either explicitly or by
2509 virtue of being declared at the global level. */
2512 /* Whether the initializer is constant: for an external object or an object
2513 with static storage duration, we check that the initializer is a valid
2514 constant expression for initializing a static variable; otherwise, we
2515 only check that it is constant. */
2516 const bool init_const
2517 = (init
2521 != NULL_TREE
2524 /* Whether we will make TREE_CONSTANT the DECL we produce here, in which
2525 case the initializer may be used in lieu of the DECL node (as done in
2526 Identifier_to_gnu). This is useful to prevent the need of elaboration
2527 code when an identifier for which such a DECL is made is in turn used
2528 as an initializer. We used to rely on CONST_DECL vs VAR_DECL for this,
2529 but extra constraints apply to this choice (see below) and they are not
2530 relevant to the distinction we wish to make. */
2533 /* The actual DECL node. CONST_DECL was initially intended for enumerals
2534 and may be used for scalars in general but not for aggregates. */
2535 tree var_decl
2537 (constant_p
2538 && const_decl_allowed_p
2542 /* Detect constants created by the front-end to hold 'reference to function
2543 calls for stabilization purposes. This is needed for renaming. */
2545 {
2556 }
2558 /* If this is external, throw away any initializations (they will be done
2559 elsewhere) unless this is a constant for which we would like to remain
2560 able to get the initializer. If we are defining a global here, leave a
2561 constant initialization and save any variable elaborations for the
2562 elaboration routine. If we are just annotating types, throw away the
2563 initialization if it isn't a constant. */
2568 /* At the global level, a non-constant initializer generates elaboration
2569 statements. Check that such statements are allowed, that is to say,
2570 not violating a No_Elaboration_Code restriction. */
2574 /* Attach the initializer, if any. */
2577 /* Directly set some flags. */
2584 /* The object is public if it is external or if it is declared public
2585 and has static storage duration. */
2588 /* We need to allocate static storage for an object with static storage
2589 duration if it isn't external. */
2599 /* Ada doesn't feature Fortran-like COMMON variables so we shouldn't
2600 try to fiddle with DECL_COMMON. However, on platforms that don't
2601 support global BSS sections, uninitialized global variables would
2602 go in DATA instead, thus increasing the size of the executable. */
2609 /* Do not emit debug info for a CONST_DECL if optimization isn't enabled,
2610 since we will create an associated variable. Likewise for an external
2611 constant whose initializer is not absolute, because this would mean a
2612 global relocation in a read-only section which runs afoul of the PE-COFF
2613 run-time relocation mechanism. */
2616 || (extern_flag
2617 && constant_p
2618 && init
2623 /* ??? Some attributes cannot be applied to CONST_DECLs. */
2627 /* Add this decl to the current binding level. */
2631 {
2632 /* Let the target mangle the name if this isn't a verbatim asm. */
2637 }
2640 }
2641 \f
2642 /* Return true if TYPE, an aggregate type, contains (or is) an array. */
2644 static bool
2646 {
2648 {
2652 {
2653 tree field;
2659 }
2666 }
2667 }
2669 /* Return a FIELD_DECL node. NAME is the field's name, TYPE is its type and
2670 RECORD_TYPE is the type of the enclosing record. If SIZE is nonzero, it
2671 is the specified size of the field. If POS is nonzero, it is the bit
2672 position. PACKED is 1 if the enclosing record is packed, -1 if it has
2673 Component_Alignment of Storage_Unit. If ADDRESSABLE is nonzero, it
2674 means we are allowed to take the address of the field; if it is negative,
2675 we should not make a bitfield, which is used by make_aligning_type. */
2677 tree
2680 {
2686 /* If FIELD_TYPE is BLKmode, we must ensure this is aligned to at least a
2687 byte boundary since GCC cannot handle less-aligned BLKmode bitfields.
2688 Likewise for an aggregate without specified position that contains an
2689 array, because in this case slices of variable length of this array
2690 must be handled by GCC and variable-sized objects need to be aligned
2691 to at least a byte boundary. */
2693 || (!pos
2698 /* If a size is specified, use it. Otherwise, if the record type is packed
2699 compute a size to use, which may differ from the object's natural size.
2700 We always set a size in this case to trigger the checks for bitfield
2701 creation below, which is typically required when no position has been
2702 specified. */
2706 {
2710 }
2712 /* If we may, according to ADDRESSABLE, make a bitfield if a size is
2713 specified for two reasons: first if the size differs from the natural
2714 size. Second, if the alignment is insufficient. There are a number of
2715 ways the latter can be true.
2717 We never make a bitfield if the type of the field has a nonconstant size,
2718 because no such entity requiring bitfield operations should reach here.
2720 We do *preventively* make a bitfield when there might be the need for it
2721 but we don't have all the necessary information to decide, as is the case
2722 of a field with no specified position in a packed record.
2724 We also don't look at STRICT_ALIGNMENT here, and rely on later processing
2725 in layout_decl or finish_record_type to clear the bit_field indication if
2726 it is in fact not needed. */
2728 && size
2733 || packed
2736 {
2740 {
2744 else
2746 }
2747 }
2751 /* Bump the alignment if need be, either for bitfield/packing purposes or
2752 to satisfy the type requirements if no such consideration applies. When
2753 we get the alignment from the type, indicate if this is from an explicit
2754 user request, which prevents stor-layout from lowering it later on. */
2755 {
2756 unsigned int bit_align
2763 {
2766 }
2767 }
2770 {
2771 /* We need to pass in the alignment the DECL is known to have.
2772 This is the lowest-order bit set in POS, but no more than
2773 the alignment of the record, if one is specified. Note
2774 that an alignment of 0 is taken as infinite. */
2779 else
2793 }
2795 /* In addition to what our caller says, claim the field is addressable if we
2796 know that its type is not suitable.
2798 The field may also be "technically" nonaddressable, meaning that even if
2799 we attempt to take the field's address we will actually get the address
2800 of a copy. This is the case for true bitfields, but the DECL_BIT_FIELD
2801 value we have at this point is not accurate enough, so we don't account
2802 for this here and let finish_record_type decide. */
2809 }
2810 \f
2811 /* Return a PARM_DECL node with NAME and TYPE. */
2813 tree
2815 {
2818 /* Honor TARGET_PROMOTE_PROTOTYPES like the C compiler, as not doing so
2819 can lead to various ABI violations. */
2823 {
2824 /* We have to be careful about biased types here. Make a subtype
2825 of integer_type_node with the proper biasing. */
2828 {
2829 tree subtype
2836 }
2837 else
2839 }
2843 }
2844 \f
2845 /* Process the attributes in ATTR_LIST for NODE, which is either a DECL or
2846 a TYPE. If IN_PLACE is true, the tree pointed to by NODE should not be
2847 changed. GNAT_NODE is used for the position of error messages. */
2849 void
2851 Node_Id gnat_node)
2852 {
2857 {
2866 {
2869 }
2875 else
2882 {
2885 }
2886 else
2905 }
2908 }
2910 /* Return true if VALUE is a known to be a multiple of FACTOR, which must be
2911 a power of 2. */
2913 bool
2915 {
2924 }
2926 /* Return whether GNAT_NODE is a defining identifier for a renaming that comes
2927 from the parameter association for the instantiation of a generic. We do
2928 not want to emit source location for them: the code generated for their
2929 initialization is likely to disturb debugging. */
2931 bool
2933 {
2940 /* Get the object declaration of the renamed object, if any and if the
2941 renamed object is a mere identifier. */
2951 return
2955 }
2957 /* Defer the initialization of DECL's DECL_CONTEXT attribute, scheduling to
2958 feed it with the elaboration of GNAT_SCOPE. */
2962 {
2965 new_node
2974 }
2976 /* Defer the initialization of TYPE's TYPE_CONTEXT attribute, scheduling to
2977 feed it with the DECL_CONTEXT computed as part of N as soon as it is
2978 computed. */
2980 static void
2982 {
2984 }
2986 /* Get the GENERIC node corresponding to GNAT_SCOPE, if available. Return
2987 NULL_TREE if it is not available. */
2989 static tree
2991 {
2992 tree context;
2996 else
3000 {
3003 /* Skip dummy types: only the final ones can appear in the context
3004 chain. */
3008 /* ..._TYPE nodes are more useful than TYPE_DECL nodes in the context
3009 chain. */
3010 else
3012 }
3015 }
3017 /* Try to process all deferred nodes in the queue. Keep in the queue the ones
3018 that cannot be processed yet, remove the other ones. If FORCE is true,
3019 force the processing for all nodes, use the global context when nodes don't
3020 have a GNU translation. */
3022 void
3024 {
3029 {
3032 Entity_Id gnat_scope;
3036 /* If FORCE, get the innermost elaborated scope. Otherwise, just try to
3037 get the first scope. */
3040 {
3045 }
3047 /* Imported declarations must not be in a local context (i.e. not inside
3048 a function). */
3050 {
3054 {
3057 }
3058 }
3060 /* If FORCE, we want to get rid of all nodes in the queue: in case there
3061 was no elaborated scope, use the global context. */
3066 {
3067 tree t;
3072 /* Propagate it to the TYPE_CONTEXT attributes of the requested
3073 ..._TYPE nodes. */
3075 {
3077 }
3079 }
3081 /* If this node has been successfuly processed, remove it from the
3082 queue. Then move to the next node. */
3084 {
3088 }
3089 else
3091 }
3092 }
3094 /* Return VALUE scaled by the biggest power-of-2 factor of EXPR. */
3096 static unsigned int
3098 {
3102 /* Peel conversions around EXPR and try to extract bodies from function
3103 calls: it is possible to get the scale factor from size functions. */
3108 /* Sometimes we get PLUS_EXPR (BIT_AND_EXPR (..., X), Y), where Y is a
3109 multiple of the scale factor we are looking for. */
3113 {
3116 }
3118 /* An expression which is a bitwise AND with a mask has a power-of-2 factor
3119 corresponding to the number of trailing zeros of the mask. */
3122 {
3127 {
3130 i++;
3131 }
3132 }
3134 /* If the addend is not a multiple of the factor we found, give up. In
3135 theory we could find a smaller common factor but it's useless for our
3136 needs. This situation arises when dealing with a field F1 with no
3137 alignment requirement but that is following a field F2 with such
3138 requirements. As long as we have F2's offset, we don't need alignment
3139 information to compute F1's. */
3144 }
3146 /* Given two consecutive field decls PREV_FIELD and CURR_FIELD, return true
3147 unless we can prove these 2 fields are laid out in such a way that no gap
3148 exist between the end of PREV_FIELD and the beginning of CURR_FIELD. OFFSET
3149 is the distance in bits between the end of PREV_FIELD and the starting
3150 position of CURR_FIELD. It is ignored if null. */
3152 static bool
3154 {
3155 /* If this is the first field of the record, there cannot be any gap */
3159 /* If the previous field is a union type, then return false: The only
3160 time when such a field is not the last field of the record is when
3161 there are other components at fixed positions after it (meaning there
3162 was a rep clause for every field), in which case we don't want the
3163 alignment constraint to override them. */
3167 /* If the distance between the end of prev_field and the beginning of
3168 curr_field is constant, then there is a gap if the value of this
3169 constant is not null. */
3173 /* If the size and position of the previous field are constant,
3174 then check the sum of this size and position. There will be a gap
3175 iff it is not multiple of the current field alignment. */
3182 /* If both the position and size of the previous field are multiples
3183 of the current field alignment, there cannot be any gap. */
3188 /* Fallback, return that there may be a potential gap */
3190 }
3192 /* Return a LABEL_DECL with NAME. GNAT_NODE is used for the position of
3193 the decl. */
3195 tree
3197 {
3198 tree label_decl
3203 /* Add this decl to the current binding level. */
3207 }
3208 \f
3209 /* Return a FUNCTION_DECL node. NAME is the name of the subprogram, ASM_NAME
3210 its assembler name, TYPE its type (a FUNCTION_TYPE node), PARAM_DECL_LIST
3211 the list of its parameters (a list of PARM_DECL nodes chained through the
3212 DECL_CHAIN field).
3214 INLINE_STATUS describes the inline flags to be set on the FUNCTION_DECL.
3216 PUBLIC_FLAG is true if this is for a reference to a public entity or for a
3217 definition to be made visible outside of the current compilation unit.
3219 EXTERN_FLAG is true when processing an external subprogram declaration.
3221 ARTIFICIAL_P is true if the subprogram was generated by the compiler.
3223 DEBUG_INFO_P is true if we need to write debug information for it.
3225 DEFINITION is true if the subprogram is to be considered as a definition.
3227 ATTR_LIST is the list of attributes to be attached to the subprogram.
3229 GNAT_NODE is used for the position of the decl. */
3231 tree
3236 Node_Id gnat_node)
3237 {
3251 {
3261 {
3265 ATTR_FLAG_TYPE_IN_PLACE);
3267 /* Inline_Always guarantees that every direct call is inlined and
3268 that there is no indirect reference to the subprogram, so the
3269 instance in the original package (as well as its clones in the
3270 client packages created for inter-unit inlining) can be made
3271 private, which causes the out-of-line body to be eliminated. */
3273 }
3275 /* ... fall through ... */
3284 }
3288 /* Once everything is processed, finish the subprogram declaration. */
3291 /* Add this decl to the current binding level. */
3294 /* Output the assembler code and/or RTL for the declaration. */
3298 }
3300 /* Given a subprogram declaration DECL, its assembler name and its type,
3301 finish constructing the subprogram declaration from ASM_NAME and TYPE. */
3303 void
3305 {
3306 tree result_decl
3319 {
3320 /* Let the target mangle the name if this isn't a verbatim asm. */
3326 /* The expand_main_function circuitry expects "main_identifier_node" to
3327 designate the DECL_NAME of the 'main' entry point, in turn expected
3328 to be declared as the "main" function literally by default. Ada
3329 program entry points are typically declared with a different name
3330 within the binder generated file, exported as 'main' to satisfy the
3331 system expectations. Force main_identifier_node in this case. */
3334 }
3335 }
3336 \f
3337 /* Set up the framework for generating code for SUBPROG_DECL, a subprogram
3338 body. This routine needs to be invoked before processing the declarations
3339 appearing in the subprogram. */
3341 void
3343 {
3344 tree param_decl;
3348 /* This function is being defined. */
3351 /* The failure of this assertion will likely come from a wrong context for
3352 the subprogram body, e.g. another procedure for a procedure declared at
3353 library level. */
3358 /* Enter a new binding level and show that all the parameters belong to
3359 this function. */
3367 }
3369 /* Finish translating the current subprogram and set its BODY. */
3371 void
3373 {
3376 /* Attach the BLOCK for this level to the function and pop the level. */
3381 /* Mark the RESULT_DECL as being in this subprogram. */
3384 /* The body should be a BIND_EXPR whose BLOCK is the top-level one. */
3386 {
3389 }
3394 }
3396 /* Wrap up compilation of SUBPROG_DECL, a subprogram body. */
3398 void
3400 {
3401 /* We cannot track the location of errors past this point. */
3404 /* If we're only annotating types, don't actually compile this function. */
3408 /* Dump functions before gimplification. */
3413 else
3414 /* Register this function with cgraph just far enough to get it
3415 added to our parent's nested function list. */
3417 }
3419 tree
3421 {
3424 }
3426 /* Return an integer type with the number of bits of precision given by
3427 PRECISION. UNSIGNEDP is nonzero if the type is unsigned; otherwise
3428 it is a signed type. */
3430 tree
3432 {
3433 tree t;
3442 else
3450 {
3453 }
3456 }
3458 /* Likewise for floating-point types. */
3460 static tree
3462 {
3463 tree t;
3475 {
3478 }
3481 }
3483 /* Return a data type that has machine mode MODE. UNSIGNEDP selects
3484 an unsigned type; otherwise a signed type is returned. */
3486 tree
3488 {
3498 scalar_float_mode float_mode;
3501 float_mode);
3503 scalar_int_mode int_mode;
3508 {
3513 }
3516 }
3518 /* Return the signed or unsigned version of TYPE_NODE, a scalar type, the
3519 signedness being specified by UNSIGNEDP. */
3521 tree
3523 {
3530 {
3533 }
3537 {
3540 }
3543 }
3545 /* Return 1 if the types T1 and T2 are compatible, i.e. if they can be
3546 transparently converted to each other. */
3548 int
3550 {
3553 /* This is the default criterion. */
3557 /* We only check structural equivalence here. */
3561 /* Vector types are also compatible if they have the same number of subparts
3562 and the same form of (scalar) element type. */
3569 /* Array types are also compatible if they are constrained and have the same
3570 domain(s), the same component type and the same scalar storage order. */
3586 }
3588 /* Return true if EXPR is a useless type conversion. */
3590 bool
3592 {
3600 }
3602 /* Return true if T, a FUNCTION_TYPE, has the specified list of flags. */
3604 bool
3607 {
3612 }
3613 \f
3614 /* EXP is an expression for the size of an object. If this size contains
3615 discriminant references, replace them with the maximum (if MAX_P) or
3616 minimum (if !MAX_P) possible value of the discriminant. */
3618 tree
3620 {
3626 {
3637 {
3651 }
3655 /* If this contains a PLACEHOLDER_EXPR, it is the thing we want to
3656 modify. Otherwise, we treat it like a variable. */
3658 {
3661 return
3664 }
3684 {
3689 /* Special-case wanting the maximum value of a MIN_EXPR.
3690 In that case, if one side overflows, return the other. */
3692 {
3698 }
3700 /* Likewise, handle a MINUS_EXPR or PLUS_EXPR with the LHS
3701 overflowing and the RHS a variable. */
3708 /* If we are going to subtract a "negative" value in an unsigned type,
3709 do the operation as an addition of the negated value, in order to
3710 avoid creating a spurious overflow below. */
3716 {
3719 }
3724 /* We need to detect overflows so we call size_binop here. */
3726 }
3730 {
3757 {
3764 return
3767 }
3772 }
3774 /* Other tree classes cannot happen. */
3777 }
3780 }
3781 \f
3782 /* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE.
3783 EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs.
3784 Return a constructor for the template. */
3786 tree
3788 {
3791 tree field;
3803 /* First make the list for a CONSTRUCTOR for the template. Go down the
3804 field list of the template instead of the type chain because this
3805 array might be an Ada array of arrays and we can't tell where the
3806 nested arrays stop being the underlying object. */
3809 (bound_list
3813 {
3816 /* If we have a bound list, get the bounds from there. Likewise
3817 for an ARRAY_TYPE. Otherwise, if expr is a PARM_DECL with
3818 DECL_BY_COMPONENT_PTR_P, use the bounds of the field in the template.
3819 This will give us a maximum range. */
3827 else
3833 /* If either MIN or MAX involve a PLACEHOLDER_EXPR, we must
3834 substitute it from OBJECT. */
3840 }
3843 }
3844 \f
3845 /* Return true if TYPE is suitable for the element type of a vector. */
3847 static bool
3849 {
3850 machine_mode mode;
3864 }
3866 /* Return a vector type given the SIZE and the INNER_TYPE, or NULL_TREE if
3867 this is not possible. If ATTRIBUTE is non-zero, we are processing the
3868 attribute declaration and want to issue error messages on failure. */
3870 static tree
3872 {
3876 /* Silently punt on variable sizes. We can't make vector types for them,
3877 need to ignore them on front-end generated subtypes of unconstrained
3878 base types, and this attribute is for binding implementors, not end
3879 users, so we should never get there from legitimate explicit uses. */
3885 {
3890 }
3894 {
3898 }
3901 {
3905 }
3909 {
3913 }
3916 }
3918 /* Return a vector type whose representative array type is ARRAY_TYPE, or
3919 NULL_TREE if this is not possible. If ATTRIBUTE is non-zero, we are
3920 processing the attribute and want to issue error messages on failure. */
3922 static tree
3924 {
3927 attribute);
3933 }
3934 \f
3935 /* Build a type to be used to represent an aliased object whose nominal type
3936 is an unconstrained array. This consists of a RECORD_TYPE containing a
3937 field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an ARRAY_TYPE.
3938 If ARRAY_TYPE is that of an unconstrained array, this is used to represent
3939 an arbitrary unconstrained object. Use NAME as the name of the record.
3940 DEBUG_INFO_P is true if we need to write debug information for the type. */
3942 tree
3945 {
3946 tree decl;
3948 tree template_field
3951 tree array_field
3960 /* Declare it now since it will never be declared otherwise. This is
3961 necessary to ensure that its subtrees are properly marked. */
3964 /* template_type will not be used elsewhere than here, so to keep the debug
3965 info clean and in order to avoid scoping issues, make decl its
3966 context. */
3970 }
3972 /* Same, taking a thin or fat pointer type instead of a template type. */
3974 tree
3977 {
3978 tree template_type;
3982 template_type
3987 return
3989 }
3990 \f
3991 /* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE.
3992 In the normal case this is just two adjustments, but we have more to
3993 do if NEW_TYPE is an UNCONSTRAINED_ARRAY_TYPE. */
3995 void
3997 {
4000 tree t;
4002 /* If this is the main variant, process all the other variants first. */
4007 /* If no pointers and no references, we are done. */
4011 /* Merge the old type qualifiers in the new type.
4013 Each old variant has qualifiers for specific reasons, and the new
4014 designated type as well. Each set of qualifiers represents useful
4015 information grabbed at some point, and merging the two simply unifies
4016 these inputs into the final type description.
4018 Consider for instance a volatile type frozen after an access to constant
4019 type designating it; after the designated type's freeze, we get here with
4020 a volatile NEW_TYPE and a dummy OLD_TYPE with a readonly variant, created
4021 when the access type was processed. We will make a volatile and readonly
4022 designated type, because that's what it really is.
4024 We might also get here for a non-dummy OLD_TYPE variant with different
4025 qualifiers than those of NEW_TYPE, for instance in some cases of pointers
4026 to private record type elaboration (see the comments around the call to
4027 this routine in gnat_to_gnu_entity <E_Access_Type>). We have to merge
4028 the qualifiers in those cases too, to avoid accidentally discarding the
4029 initial set, and will often end up with OLD_TYPE == NEW_TYPE then. */
4030 new_type
4034 /* If old type and new type are identical, there is nothing to do. */
4038 /* Otherwise, first handle the simple case. */
4040 {
4043 /* If pointer or reference already points to new type, nothing to do.
4044 This can happen as update_pointer_to can be invoked multiple times
4045 on the same couple of types because of the type variants. */
4050 /* Chain PTR and its variants at the end. */
4053 {
4057 }
4058 else
4061 /* Now adjust them. */
4064 {
4068 }
4070 /* Chain REF and its variants at the end. */
4073 {
4077 }
4078 else
4081 /* Now adjust them. */
4088 }
4090 /* Now deal with the unconstrained array case. In this case the pointer
4091 is actually a record where both fields are pointers to dummy nodes.
4092 Turn them into pointers to the correct types using update_pointer_to.
4093 Likewise for the pointer to the object record (thin pointer). */
4094 else
4095 {
4100 /* If PTR already points to NEW_TYPE, nothing to do. This can happen
4101 since update_pointer_to can be invoked multiple times on the same
4102 couple of types because of the type variants. */
4106 update_pointer_to
4110 update_pointer_to
4119 }
4120 }
4121 \f
4122 /* Convert EXPR, a pointer to a constrained array, into a pointer to an
4123 unconstrained one. This involves making or finding a template. */
4125 static tree
4127 {
4131 tree template_addr;
4135 /* If EXPR is null, make a fat pointer that contains a null pointer to the
4136 array (compare_fat_pointers ensures that this is the full discriminant)
4137 and a valid pointer to the bounds. This latter property is necessary
4138 since the compiler can hoist the load of the bounds done through it. */
4140 {
4146 else
4147 {
4148 /* The template type can still be dummy at this point so we build an
4149 empty constructor. The middle-end will fill it in with zeros. */
4154 }
4160 /* Do not set TREE_CONSTANT so as to force T to static memory. */
4165 }
4167 /* If EXPR is a thin pointer, make template and data from the record. */
4169 {
4174 /* If we have a TYPE_UNCONSTRAINED_ARRAY attached to the RECORD_TYPE,
4175 the thin pointer value has been shifted so we shift it back to get
4176 the template address. */
4178 {
4179 template_addr
4182 byte_position
4184 template_addr
4186 template_addr);
4187 }
4189 /* Otherwise we explicitly take the address of the fields. */
4190 else
4191 {
4193 template_addr
4199 }
4200 }
4202 /* Otherwise, build the constructor for the template. */
4203 else
4204 template_addr
4207 expr));
4209 /* The final result is a constructor for the fat pointer.
4211 If EXPR is an argument of a foreign convention subprogram, the type it
4212 points to is directly the component type. In this case, the expression
4213 type may not match the corresponding FIELD_DECL type at this point, so we
4214 call "convert" here to fix that up if necessary. This type consistency is
4215 required, for instance because it ensures that possible later folding of
4216 COMPONENT_REFs against this constructor always yields something of the
4217 same type as the initial reference.
4219 Note that the call to "build_template" above is still fine because it
4220 will only refer to the provided TEMPLATE_TYPE in this case. */
4224 }
4225 \f
4226 /* Create an expression whose value is that of EXPR,
4227 converted to type TYPE. The TREE_TYPE of the value
4228 is always TYPE. This function implements all reasonable
4229 conversions; callers should filter out those that are
4230 not permitted by the language being compiled. */
4232 tree
4234 {
4239 /* If the expression is already of the right type, we are done. */
4243 /* If both input and output have padding and are of variable size, do this
4244 as an unchecked conversion. Likewise if one is a mere variant of the
4245 other, so we avoid a pointless unpad/repad sequence. */
4253 ;
4255 /* If the output type has padding, convert to the inner type and make a
4256 constructor to build the record, unless a variable size is involved. */
4258 {
4259 /* If we previously converted from another type and our type is
4260 of variable size, remove the conversion to avoid the need for
4261 variable-sized temporaries. Likewise for a conversion between
4262 original and packable version. */
4270 /* If we are just removing the padding from expr, convert the original
4271 object if we have variable size in order to avoid the need for some
4272 variable-sized temporaries. Likewise if the padding is a variant
4273 of the other, so we avoid a pointless unpad/repad sequence. */
4284 /* If the inner type is of self-referential size and the expression type
4285 is a record, do this as an unchecked conversion unless both types are
4286 essentially the same. But first pad the expression if possible to
4287 have the same size on both sides. */
4292 {
4296 expr);
4298 }
4300 /* If we are converting between array types with variable size, do the
4301 final conversion as an unchecked conversion, again to avoid the need
4302 for some variable-sized temporaries. If valid, this conversion is
4303 very likely purely technical and without real effects. */
4310 expr),
4315 /* If converting to the inner type has already created a CONSTRUCTOR with
4316 the right size, then reuse it instead of creating another one. This
4317 can happen for the padding type built to overalign local variables. */
4329 }
4331 /* If the input type has padding, remove it and convert to the output type.
4332 The conditions ordering is arranged to ensure that the output type is not
4333 a padding type here, as it is not clear whether the conversion would
4334 always be correct if this was to happen. */
4336 {
4337 tree unpadded;
4339 /* If we have just converted to this padded type, just get the
4340 inner expression. */
4344 /* Otherwise, build an explicit component reference. */
4345 else
4349 }
4351 /* If the input is a biased type, convert first to the base type and add
4352 the bias. Note that the bias must go through a full conversion to the
4353 base type, lest it is itself a biased value; this happens for subtypes
4354 of biased types. */
4361 /* If the input is a justified modular type, we need to extract the actual
4362 object before converting it to any other type with the exceptions of an
4363 unconstrained array or of a mere type variant. It is useful to avoid the
4364 extraction and conversion in the type variant case because it could end
4365 up replacing a VAR_DECL expr by a constructor and we might be about the
4366 take the address of the result. */
4370 return
4373 /* If converting to a type that contains a template, convert to the data
4374 type and then build the template. */
4376 {
4381 /* If the source already has a template, get a reference to the
4382 associated array only, as we are going to rebuild a template
4383 for the target type anyway. */
4393 }
4395 /* There are some cases of expressions that we process specially. */
4397 {
4402 /* Just set its type here. For TRANSFORM_EXPR, we will do the actual
4403 conversion in gnat_expand_expr. NULL_EXPR does not represent
4404 and actual value, so no conversion is needed. */
4410 /* If we are converting a STRING_CST to another constrained array type,
4411 just make a new one in the proper type. */
4415 {
4419 }
4423 /* If we are converting a VECTOR_CST to a mere type variant, just make
4424 a new one in the proper type. */
4426 {
4430 }
4434 /* If we are converting a CONSTRUCTOR to a mere type variant, or to
4435 another padding type around the same type, just make a new one in
4436 the proper type. */
4443 {
4448 }
4450 /* Likewise for a conversion between original and packable version, or
4451 conversion between types of the same size and with the same list of
4452 fields, but we have to work harder to preserve type consistency. */
4458 {
4467 /* Whether we need to clear TREE_CONSTANT et al. on the output
4468 constructor when we convert in place. */
4472 {
4473 /* Skip the missing fields in the CONSTRUCTOR. */
4475 {
4478 }
4479 /* The field must be the same. */
4482 constructor_elt elt
4486 /* If packing has made this field a bitfield and the input
4487 value couldn't be emitted statically any more, we need to
4488 clear TREE_CONSTANT on our output. */
4498 }
4500 /* If we have been able to match and convert all the input fields
4501 to their output type, convert in place now. We'll fallback to a
4502 view conversion downstream otherwise. */
4504 {
4511 }
4512 }
4514 /* Likewise for a conversion between array type and vector type with a
4515 compatible representative array. */
4519 etype))
4520 {
4525 tree value;
4527 /* Build a VECTOR_CST from a *constant* array constructor. */
4529 {
4532 /* Iterate through elements and check if all constructor
4533 elements are *_CSTs. */
4536 {
4539 }
4544 }
4546 /* Otherwise, build a regular vector constructor. */
4549 {
4552 }
4557 }
4561 /* First retrieve the underlying array. */
4568 {
4569 /* GCC 4.x is very sensitive to type consistency overall, and view
4570 conversions thus are very frequent. Even though just "convert"ing
4571 the inner operand to the output type is fine in most cases, it
4572 might expose unexpected input/output type mismatches in special
4573 circumstances so we avoid such recursive calls when we can. */
4576 /* If we are converting back to the original type, we can just
4577 lift the input conversion. This is a common occurrence with
4578 switches back-and-forth amongst type variants. */
4582 /* Otherwise, if we're converting between two aggregate or vector
4583 types, we might be allowed to substitute the VIEW_CONVERT_EXPR
4584 target type in place or to just convert the inner expression. */
4587 {
4588 /* If we are converting between mere variants, we can just
4589 substitute the VIEW_CONVERT_EXPR in place. */
4593 /* Otherwise, we may just bypass the input view conversion unless
4594 one of the types is a fat pointer, which is handled by
4595 specialized code below which relies on exact type matching. */
4599 }
4602 }
4606 }
4608 /* Check for converting to a pointer to an unconstrained array. */
4612 /* If we are converting between two aggregate or vector types that are mere
4613 variants, just make a VIEW_CONVERT_EXPR. Likewise when we are converting
4614 to a vector type from its representative array type. */
4621 etype)))
4624 /* If we are converting between tagged types, try to upcast properly. */
4627 {
4635 }
4637 /* If we are converting from a smaller form of record type back to it, just
4638 make a VIEW_CONVERT_EXPR. But first pad the expression to have the same
4639 size on both sides. */
4642 {
4645 expr);
4647 }
4649 /* In all other cases of related types, make a NOP_EXPR. */
4654 {
4664 /* If the output is a biased type, convert first to the base type and
4665 subtract the bias. Note that the bias itself must go through a full
4666 conversion to the base type, lest it is a biased value; this happens
4667 for subtypes of biased types. */
4675 /* ... fall through ... */
4679 /* If we are converting an additive expression to an integer type
4680 with lower precision, be wary of the optimization that can be
4681 applied by convert_to_integer. There are 2 problematic cases:
4682 - if the first operand was originally of a biased type,
4683 because we could be recursively called to convert it
4684 to an intermediate type and thus rematerialize the
4685 additive operator endlessly,
4686 - if the expression contains a placeholder, because an
4687 intermediate conversion that changes the sign could
4688 be inserted and thus introduce an artificial overflow
4689 at compile time when the placeholder is substituted. */
4694 {
4701 }
4707 /* If converting between two thin pointers, adjust if needed to account
4708 for differing offsets from the base pointer, depending on whether
4709 there is a TYPE_UNCONSTRAINED_ARRAY attached to the record type. */
4711 {
4712 tree etype_pos
4716 tree type_pos
4728 }
4730 /* If converting fat pointer to normal or thin pointer, get the pointer
4731 to the array and then convert it. */
4741 /* Do a normal conversion between scalar and justified modular type. */
4743 {
4749 expr));
4751 }
4753 /* In these cases, assume the front-end has validated the conversion.
4754 If the conversion is valid, it will be a bit-wise conversion, so
4755 it can be viewed as an unchecked conversion. */
4759 /* Do a normal conversion between unconstrained and constrained array
4760 type, assuming the latter is a constrained version of the former. */
4764 {
4772 }
4774 /* In these cases, assume the front-end has validated the conversion.
4775 If the conversion is valid, it will be a bit-wise conversion, so
4776 it can be viewed as an unchecked conversion. */
4780 /* This is a either a conversion between a tagged type and some
4781 subtype, which we have to mark as a UNION_TYPE because of
4782 overlapping fields or a conversion of an Unchecked_Union. */
4786 /* If the input is a VECTOR_TYPE, convert to the representative
4787 array type first. */
4789 {
4793 }
4795 /* If EXPR is a constrained array, take its address, convert it to a
4796 fat pointer, and then dereference it. Likewise if EXPR is a
4797 record containing both a template and a constrained array.
4798 Note that a record representing a justified modular type
4799 always represents a packed constrained array. */
4804 return
4805 build_unary_op
4811 /* Do something very similar for converting one unconstrained
4812 array to another. */
4814 return
4819 else
4827 }
4828 }
4830 /* Create an expression whose value is that of EXPR converted to the common
4831 index type, which is sizetype. EXPR is supposed to be in the base type
4832 of the GNAT index type. Calling it is equivalent to doing
4834 convert (sizetype, expr)
4836 but we try to distribute the type conversion with the knowledge that EXPR
4837 cannot overflow in its type. This is a best-effort approach and we fall
4838 back to the above expression as soon as difficulties are encountered.
4840 This is necessary to overcome issues that arise when the GNAT base index
4841 type and the GCC common index type (sizetype) don't have the same size,
4842 which is quite frequent on 64-bit architectures. In this case, and if
4843 the GNAT base index type is signed but the iteration type of the loop has
4844 been forced to unsigned, the loop scalar evolution engine cannot compute
4845 a simple evolution for the general induction variables associated with the
4846 array indices, because it will preserve the wrap-around semantics in the
4847 unsigned type of their "inner" part. As a result, many loop optimizations
4848 are blocked.
4850 The solution is to use a special (basic) induction variable that is at
4851 least as large as sizetype, and to express the aforementioned general
4852 induction variables in terms of this induction variable, eliminating
4853 the problematic intermediate truncation to the GNAT base index type.
4854 This is possible as long as the original expression doesn't overflow
4855 and if the middle-end hasn't introduced artificial overflows in the
4856 course of the various simplification it can make to the expression. */
4858 tree
4860 {
4864 /* If the type is unsigned, overflow is allowed so we cannot be sure that
4865 EXPR doesn't overflow. Keep it simple if optimization is disabled. */
4870 {
4872 /* The main effect of the function: replace a loop parameter with its
4873 associated special induction variable. */
4878 CASE_CONVERT:
4879 {
4881 /* Bail out as soon as we suspect some sort of type frobbing. */
4885 }
4887 /* ... fall through ... */
4911 }
4914 }
4915 \f
4916 /* Remove all conversions that are done in EXP. This includes converting
4917 from a padded type or to a justified modular type. If TRUE_ADDRESS
4918 is true, always return the address of the containing object even if
4919 the address is not bit-aligned. */
4921 tree
4923 {
4925 {
4930 return
4939 CASE_CONVERT:
4946 }
4949 }
4950 \f
4951 /* If EXP's type is an UNCONSTRAINED_ARRAY_TYPE, return an expression that
4952 refers to the underlying array. If it has TYPE_CONTAINS_TEMPLATE_P,
4953 likewise return an expression pointing to the underlying array. */
4955 tree
4957 {
4962 {
4965 {
4973 {
4974 tree op1
4979 tree op2
4988 }
4989 else
4990 {
4997 }
4998 }
5007 /* If this is a padded type and it contains a template, convert to the
5008 unpadded type first. */
5012 {
5016 }
5019 {
5020 /* If the array initializer is a box, return NULL_TREE. */
5028 /* If the array type is padded, convert to the unpadded type. */
5031 }
5036 }
5039 }
5040 \f
5041 /* Return true if EXPR is an expression that can be folded as an operand
5042 of a VIEW_CONVERT_EXPR. See ada-tree.h for a complete rationale. */
5044 static bool
5046 {
5049 /* The folder will fold NOP_EXPRs between integral types with the same
5050 precision (in the middle-end's sense). We cannot allow it if the
5051 types don't have the same precision in the Ada sense as well. */
5058 /* Defer to the folder for non-integral conversions. */
5062 /* Only fold conversions that preserve both precisions. */
5068 }
5070 /* Return an expression that does an unchecked conversion of EXPR to TYPE.
5071 If NOTRUNC_P is true, truncation operations should be suppressed.
5073 Special care is required with (source or target) integral types whose
5074 precision is not equal to their size, to make sure we fetch or assign
5075 the value bits whose location might depend on the endianness, e.g.
5077 Rmsize : constant := 8;
5078 subtype Int is Integer range 0 .. 2 ** Rmsize - 1;
5080 type Bit_Array is array (1 .. Rmsize) of Boolean;
5081 pragma Pack (Bit_Array);
5083 function To_Bit_Array is new Unchecked_Conversion (Int, Bit_Array);
5085 Value : Int := 2#1000_0001#;
5086 Vbits : Bit_Array := To_Bit_Array (Value);
5088 we expect the 8 bits at Vbits'Address to always contain Value, while
5089 their original location depends on the endianness, at Value'Address
5090 on a little-endian architecture but not on a big-endian one.
5092 One pitfall is that we cannot use TYPE_UNSIGNED directly to decide how
5093 the bits between the precision and the size are filled, because of the
5094 trick used in the E_Signed_Integer_Subtype case of gnat_to_gnu_entity.
5095 So we use the special predicate type_unsigned_for_rm above. */
5097 tree
5099 {
5103 tree tem;
5106 /* If the expression is already of the right type, we are done. */
5110 /* If both types are integral just do a normal conversion.
5111 Likewise for a conversion to an unconstrained array. */
5119 {
5121 {
5126 }
5129 {
5135 }
5136 else
5138 }
5140 /* If we are converting to an integral type whose precision is not equal
5141 to its size, first unchecked convert to a record type that contains a
5142 field of the given precision. Then extract the result from the field.
5144 There is a subtlety if the source type is an aggregate type with reverse
5145 storage order because its representation is not contiguous in the native
5146 storage order, i.e. a direct unchecked conversion to an integral type
5147 with N bits of precision cannot read the first N bits of the aggregate
5148 type. To overcome it, we do an unchecked conversion to an integral type
5149 with reverse storage order and return the resulting value. This also
5150 ensures that the result of the unchecked conversion doesn't depend on
5151 the endianness of the target machine, but only on the storage order of
5152 the aggregate type.
5154 Finally, for the sake of consistency, we do the unchecked conversion
5155 to an integral type with reverse storage order as soon as the source
5156 type is an aggregate type with reverse storage order, even if there
5157 are no considerations of precision or size involved. */
5164 {
5175 else
5187 }
5189 /* Similarly if we are converting from an integral type whose precision is
5190 not equal to its size, first copy into a field of the given precision
5191 and unchecked convert the record type.
5193 The same considerations as above apply if the target type is an aggregate
5194 type with reverse storage order and we also proceed similarly. */
5201 {
5214 else
5227 }
5229 /* If we are converting from a scalar type to a type with a different size,
5230 we need to pad to have the same size on both sides.
5232 ??? We cannot do it unconditionally because unchecked conversions are
5233 used liberally by the front-end to implement polymorphism, e.g. in:
5235 S191s : constant ada__tags__addr_ptr := ada__tags__addr_ptr!(S190s);
5236 return p___size__4 (p__object!(S191s.all));
5238 so we skip all expressions that are references. */
5243 {
5245 {
5248 expr);
5250 }
5251 else
5252 {
5257 }
5258 }
5260 /* We have a special case when we are converting between two unconstrained
5261 array types. In that case, take the address, convert the fat pointer
5262 types, and dereference. */
5267 expr)));
5269 /* Another special case is when we are converting to a vector type from its
5270 representative array type; this a regular conversion. */
5274 etype))
5277 /* And, if the array type is not the representative, we try to build an
5278 intermediate vector type of which the array type is the representative
5279 and to do the unchecked conversion between the vector types, in order
5280 to enable further simplifications in the middle-end. */
5284 {
5287 }
5289 /* If we are converting a CONSTRUCTOR to a more aligned RECORD_TYPE, bump
5290 the alignment of the CONSTRUCTOR to speed up the copy operation. */
5294 {
5297 expr);
5299 }
5301 /* Otherwise, just build a VIEW_CONVERT_EXPR of the expression. */
5302 else
5303 {
5309 else
5311 }
5313 /* If the result is a non-biased integral type whose precision is not equal
5314 to its size, sign- or zero-extend the result. But we need not do this
5315 if the input is also an integral type and both are unsigned or both are
5316 signed and have the same precision. */
5329 {
5332 else
5333 {
5334 tree base_type
5337 tree shift_expr
5341 expr
5346 expr),
5347 shift_expr),
5348 shift_expr));
5349 }
5350 }
5352 /* An unchecked conversion should never raise Constraint_Error. The code
5353 below assumes that GCC's conversion routines overflow the same way that
5354 the underlying hardware does. This is probably true. In the rare case
5355 when it is false, we can rely on the fact that such conversions are
5356 erroneous anyway. */
5360 /* If the sizes of the types differ and this is an VIEW_CONVERT_EXPR,
5361 show no longer constant. */
5364 OEP_ONLY_CONST))
5368 }
5369 \f
5370 /* Return the appropriate GCC tree code for the specified GNAT_TYPE,
5371 the latter being a record type as predicated by Is_Record_Type. */
5373 enum tree_code
5375 {
5378 /* Return UNION_TYPE if it's an Unchecked_Union whose non-discriminant
5379 fields are all in the variant part. Otherwise, return RECORD_TYPE. */
5384 component_list
5394 }
5396 /* Return true if GNAT_TYPE is a "double" floating-point type, i.e. whose
5397 size is equal to 64 bits, or an array of such a type. Set ALIGN_CLAUSE
5398 according to the presence of an alignment clause on the type or, if it
5399 is an array, on the component type. */
5401 bool
5403 {
5409 {
5413 }
5422 }
5424 /* Return true if GNAT_TYPE is a "double" or larger scalar type, i.e. whose
5425 size is greater or equal to 64 bits, or an array of such a type. Set
5426 ALIGN_CLAUSE according to the presence of an alignment clause on the
5427 type or, if it is an array, on the component type. */
5429 bool
5431 {
5437 {
5441 }
5450 }
5452 /* Return true if GNU_TYPE is suitable as the type of a non-aliased
5453 component of an aggregate type. */
5455 bool
5457 {
5458 /* If the type is passed by reference, we may have pointers to the
5459 component so it cannot be made non-aliased. */
5463 /* We used to say that any component of aggregate type is aliased
5464 because the front-end may take 'Reference of it. The front-end
5465 has been enhanced in the meantime so as to use a renaming instead
5466 in most cases, but the back-end can probably take the address of
5467 such a component too so we go for the conservative stance.
5469 For instance, we might need the address of any array type, even
5470 if normally passed by copy, to construct a fat pointer if the
5471 component is used as an actual for an unconstrained formal.
5473 Likewise for record types: even if a specific record subtype is
5474 passed by copy, the parent type might be passed by ref (e.g. if
5475 it's of variable size) and we might take the address of a child
5476 component to pass to a parent formal. We have no way to check
5477 for such conditions here. */
5482 }
5484 /* Return true if TYPE is a smaller form of ORIG_TYPE. */
5486 bool
5488 {
5491 /* We're not interested in variants here. */
5495 /* Like a variant, a packable version keeps the original TYPE_NAME. */
5506 }
5508 /* Return whether EXPR, which is the renamed object in an object renaming
5509 declaration, can be materialized as a reference (with a REFERENCE_TYPE).
5510 This should be synchronized with Exp_Dbug.Debug_Renaming_Declaration. */
5512 bool
5514 {
5516 {
5520 {
5529 {
5533 const Uint bitpos
5541 }
5545 {
5553 }
5561 };
5562 }
5563 }
5565 /* Perform final processing on global declarations. */
5569 void
5571 {
5573 tree iter;
5575 /* If we have declared types as used at the global level, insert them in
5576 the global hash table. We use a dummy variable for this purpose, but
5577 we need to build it unconditionally to avoid -fcompare-debug issues. */
5579 {
5584 dummy_global
5586 void_type_node);
5595 {
5598 }
5599 }
5601 /* Output debug information for all global type declarations first. This
5602 ensures that global types whose compilation hasn't been finalized yet,
5603 for example pointers to Taft amendment types, have their compilation
5604 finalized in the right context. */
5609 /* Output imported functions. */
5618 /* Then output the global variables. We need to do that after the debug
5619 information for global types is emitted so that they are finalized. Skip
5620 external global variables, unless we need to emit debug info for them:
5621 this is useful for imported variables, for instance. */
5627 /* Output the imported modules/declarations. In GNAT, these are only
5628 materializing subprogram. */
5633 }
5635 /* ************************************************************************
5636 * * GCC builtins support *
5637 * ************************************************************************ */
5639 /* The general scheme is fairly simple:
5641 For each builtin function/type to be declared, gnat_install_builtins calls
5642 internal facilities which eventually get to gnat_pushdecl, which in turn
5643 tracks the so declared builtin function decls in the 'builtin_decls' global
5644 datastructure. When an Intrinsic subprogram declaration is processed, we
5645 search this global datastructure to retrieve the associated BUILT_IN DECL
5646 node. */
5648 /* Search the chain of currently available builtin declarations for a node
5649 corresponding to function NAME (an IDENTIFIER_NODE). Return the first node
5650 found, if any, or NULL_TREE otherwise. */
5651 tree
5653 {
5655 tree decl;
5662 }
5664 /* The code below eventually exposes gnat_install_builtins, which declares
5665 the builtin types and functions we might need, either internally or as
5666 user accessible facilities.
5668 ??? This is a first implementation shot, still in rough shape. It is
5669 heavily inspired from the "C" family implementation, with chunks copied
5670 verbatim from there.
5672 Two obvious improvement candidates are:
5673 o Use a more efficient name/decl mapping scheme
5674 o Devise a middle-end infrastructure to avoid having to copy
5675 pieces between front-ends. */
5677 /* ----------------------------------------------------------------------- *
5678 * BUILTIN ELEMENTARY TYPES *
5679 * ----------------------------------------------------------------------- */
5681 /* Standard data types to be used in builtin argument declarations. */
5683 enum c_tree_index
5684 {
5686 CTI_STRING_TYPE,
5687 CTI_CONST_STRING_TYPE,
5689 CTI_MAX
5690 };
5694 #define signed_size_type_node c_global_trees[CTI_SIGNED_SIZE_TYPE]
5695 #define string_type_node c_global_trees[CTI_STRING_TYPE]
5696 #define const_string_type_node c_global_trees[CTI_CONST_STRING_TYPE]
5698 /* ??? In addition some attribute handlers, we currently don't support a
5699 (small) number of builtin-types, which in turns inhibits support for a
5700 number of builtin functions. */
5701 #define wint_type_node void_type_node
5702 #define intmax_type_node void_type_node
5703 #define uintmax_type_node void_type_node
5705 /* Used to help initialize the builtin-types.def table. When a type of
5706 the correct size doesn't exist, use error_mark_node instead of NULL.
5707 The later results in segfaults even when a decl using the type doesn't
5708 get invoked. */
5710 static tree
5712 {
5715 }
5717 /* Build/push the elementary type decls that builtin functions/types
5718 will need. */
5720 static void
5722 {
5727 const_string_type_node
5730 }
5732 /* ----------------------------------------------------------------------- *
5733 * BUILTIN FUNCTION TYPES *
5734 * ----------------------------------------------------------------------- */
5736 /* Now, builtin function types per se. */
5738 enum c_builtin_type
5739 {
5740 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
5741 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
5742 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
5743 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
5744 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
5745 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
5746 #define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME,
5747 #define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5748 ARG6) NAME,
5749 #define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5750 ARG6, ARG7) NAME,
5751 #define DEF_FUNCTION_TYPE_8(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5752 ARG6, ARG7, ARG8) NAME,
5753 #define DEF_FUNCTION_TYPE_9(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5754 ARG6, ARG7, ARG8, ARG9) NAME,
5755 #define DEF_FUNCTION_TYPE_10(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5756 ARG6, ARG7, ARG8, ARG9, ARG10) NAME,
5757 #define DEF_FUNCTION_TYPE_11(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5758 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) NAME,
5759 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
5760 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
5761 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
5762 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
5763 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
5764 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5765 NAME,
5766 #define DEF_FUNCTION_TYPE_VAR_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5767 ARG6) NAME,
5768 #define DEF_FUNCTION_TYPE_VAR_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5769 ARG6, ARG7) NAME,
5770 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
5772 #undef DEF_PRIMITIVE_TYPE
5773 #undef DEF_FUNCTION_TYPE_0
5774 #undef DEF_FUNCTION_TYPE_1
5775 #undef DEF_FUNCTION_TYPE_2
5776 #undef DEF_FUNCTION_TYPE_3
5777 #undef DEF_FUNCTION_TYPE_4
5778 #undef DEF_FUNCTION_TYPE_5
5779 #undef DEF_FUNCTION_TYPE_6
5780 #undef DEF_FUNCTION_TYPE_7
5781 #undef DEF_FUNCTION_TYPE_8
5782 #undef DEF_FUNCTION_TYPE_9
5783 #undef DEF_FUNCTION_TYPE_10
5784 #undef DEF_FUNCTION_TYPE_11
5785 #undef DEF_FUNCTION_TYPE_VAR_0
5786 #undef DEF_FUNCTION_TYPE_VAR_1
5787 #undef DEF_FUNCTION_TYPE_VAR_2
5788 #undef DEF_FUNCTION_TYPE_VAR_3
5789 #undef DEF_FUNCTION_TYPE_VAR_4
5790 #undef DEF_FUNCTION_TYPE_VAR_5
5791 #undef DEF_FUNCTION_TYPE_VAR_6
5792 #undef DEF_FUNCTION_TYPE_VAR_7
5793 #undef DEF_POINTER_TYPE
5794 BT_LAST
5795 };
5799 /* A temporary array used in communication with def_fn_type. */
5802 /* A helper function for install_builtin_types. Build function type
5803 for DEF with return type RET and N arguments. If VAR is true, then the
5804 function should be variadic after those N arguments.
5806 Takes special care not to ICE if any of the types involved are
5807 error_mark_node, which indicates that said type is not in fact available
5808 (see builtin_type_for_size). In which case the function type as a whole
5809 should be error_mark_node. */
5811 static void
5813 {
5814 tree t;
5821 {
5827 }
5834 else
5837 egress:
5840 }
5842 /* Build the builtin function types and install them in the builtin_types
5843 array for later use in builtin function decls. */
5845 static void
5847 {
5848 tree va_list_ref_type_node;
5849 tree va_list_arg_type_node;
5852 {
5855 }
5856 else
5857 {
5860 }
5862 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
5863 builtin_types[ENUM] = VALUE;
5864 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \
5865 def_fn_type (ENUM, RETURN, 0, 0);
5866 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \
5867 def_fn_type (ENUM, RETURN, 0, 1, ARG1);
5868 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \
5869 def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2);
5870 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
5871 def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3);
5872 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
5873 def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4);
5874 #define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5875 def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
5876 #define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5877 ARG6) \
5878 def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
5879 #define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5880 ARG6, ARG7) \
5881 def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
5882 #define DEF_FUNCTION_TYPE_8(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5883 ARG6, ARG7, ARG8) \
5884 def_fn_type (ENUM, RETURN, 0, 8, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5885 ARG7, ARG8);
5886 #define DEF_FUNCTION_TYPE_9(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5887 ARG6, ARG7, ARG8, ARG9) \
5888 def_fn_type (ENUM, RETURN, 0, 9, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5889 ARG7, ARG8, ARG9);
5890 #define DEF_FUNCTION_TYPE_10(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5,\
5891 ARG6, ARG7, ARG8, ARG9, ARG10) \
5892 def_fn_type (ENUM, RETURN, 0, 10, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5893 ARG7, ARG8, ARG9, ARG10);
5894 #define DEF_FUNCTION_TYPE_11(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5,\
5895 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) \
5896 def_fn_type (ENUM, RETURN, 0, 11, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5897 ARG7, ARG8, ARG9, ARG10, ARG11);
5898 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \
5899 def_fn_type (ENUM, RETURN, 1, 0);
5900 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \
5901 def_fn_type (ENUM, RETURN, 1, 1, ARG1);
5902 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \
5903 def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2);
5904 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
5905 def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3);
5906 #define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
5907 def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
5908 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5909 def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
5910 #define DEF_FUNCTION_TYPE_VAR_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5911 ARG6) \
5912 def_fn_type (ENUM, RETURN, 1, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
5913 #define DEF_FUNCTION_TYPE_VAR_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5914 ARG6, ARG7) \
5915 def_fn_type (ENUM, RETURN, 1, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
5916 #define DEF_POINTER_TYPE(ENUM, TYPE) \
5917 builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
5921 #undef DEF_PRIMITIVE_TYPE
5922 #undef DEF_FUNCTION_TYPE_0
5923 #undef DEF_FUNCTION_TYPE_1
5924 #undef DEF_FUNCTION_TYPE_2
5925 #undef DEF_FUNCTION_TYPE_3
5926 #undef DEF_FUNCTION_TYPE_4
5927 #undef DEF_FUNCTION_TYPE_5
5928 #undef DEF_FUNCTION_TYPE_6
5929 #undef DEF_FUNCTION_TYPE_7
5930 #undef DEF_FUNCTION_TYPE_8
5931 #undef DEF_FUNCTION_TYPE_9
5932 #undef DEF_FUNCTION_TYPE_10
5933 #undef DEF_FUNCTION_TYPE_11
5934 #undef DEF_FUNCTION_TYPE_VAR_0
5935 #undef DEF_FUNCTION_TYPE_VAR_1
5936 #undef DEF_FUNCTION_TYPE_VAR_2
5937 #undef DEF_FUNCTION_TYPE_VAR_3
5938 #undef DEF_FUNCTION_TYPE_VAR_4
5939 #undef DEF_FUNCTION_TYPE_VAR_5
5940 #undef DEF_FUNCTION_TYPE_VAR_6
5941 #undef DEF_FUNCTION_TYPE_VAR_7
5942 #undef DEF_POINTER_TYPE
5944 }
5946 /* ----------------------------------------------------------------------- *
5947 * BUILTIN ATTRIBUTES *
5948 * ----------------------------------------------------------------------- */
5950 enum built_in_attribute
5951 {
5952 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
5953 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
5954 #define DEF_ATTR_STRING(ENUM, VALUE) ENUM,
5955 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
5956 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
5958 #undef DEF_ATTR_NULL_TREE
5959 #undef DEF_ATTR_INT
5960 #undef DEF_ATTR_STRING
5961 #undef DEF_ATTR_IDENT
5962 #undef DEF_ATTR_TREE_LIST
5963 ATTR_LAST
5964 };
5968 static void
5970 {
5971 /* Fill in the built_in_attributes array. */
5972 #define DEF_ATTR_NULL_TREE(ENUM) \
5973 built_in_attributes[(int) ENUM] = NULL_TREE;
5974 #define DEF_ATTR_INT(ENUM, VALUE) \
5975 built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
5976 #define DEF_ATTR_STRING(ENUM, VALUE) \
5977 built_in_attributes[(int) ENUM] = build_string (strlen (VALUE), VALUE);
5978 #define DEF_ATTR_IDENT(ENUM, STRING) \
5979 built_in_attributes[(int) ENUM] = get_identifier (STRING);
5980 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
5981 built_in_attributes[(int) ENUM] \
5982 = tree_cons (built_in_attributes[(int) PURPOSE], \
5983 built_in_attributes[(int) VALUE], \
5984 built_in_attributes[(int) CHAIN]);
5986 #undef DEF_ATTR_NULL_TREE
5987 #undef DEF_ATTR_INT
5988 #undef DEF_ATTR_STRING
5989 #undef DEF_ATTR_IDENT
5990 #undef DEF_ATTR_TREE_LIST
5991 }
5993 /* Handle a "const" attribute; arguments as in
5994 struct attribute_spec.handler. */
5996 static tree
6000 {
6003 else
6007 }
6009 /* Handle a "nothrow" attribute; arguments as in
6010 struct attribute_spec.handler. */
6012 static tree
6016 {
6019 else
6023 }
6025 /* Handle a "pure" attribute; arguments as in
6026 struct attribute_spec.handler. */
6028 static tree
6031 {
6034 /* TODO: support types. */
6035 else
6036 {
6040 }
6043 }
6045 /* Handle a "no vops" attribute; arguments as in
6046 struct attribute_spec.handler. */
6048 static tree
6052 {
6056 }
6058 /* Helper for nonnull attribute handling; fetch the operand number
6059 from the attribute argument list. */
6061 static bool
6063 {
6064 /* Verify the arg number is a constant. */
6070 }
6072 /* Handle the "nonnull" attribute. */
6073 static tree
6077 {
6081 /* If no arguments are specified, all pointer arguments should be
6082 non-null. Verify a full prototype is given so that the arguments
6083 will have the correct types when we actually check them later.
6084 Avoid diagnosing type-generic built-ins since those have no
6085 prototype. */
6087 {
6091 {
6094 }
6096 }
6098 /* Argument list specified. Verify that each argument number references
6099 a pointer argument. */
6101 {
6105 {
6110 }
6113 {
6114 function_args_iterator iter;
6115 tree argument;
6119 {
6123 }
6127 {
6133 }
6136 {
6142 }
6143 }
6144 }
6147 }
6149 /* Handle a "sentinel" attribute. */
6151 static tree
6154 {
6156 {
6161 }
6162 else
6163 {
6165 {
6170 }
6171 }
6174 {
6178 {
6181 }
6182 else
6183 {
6185 {
6188 }
6189 }
6190 }
6193 }
6195 /* Handle a "noreturn" attribute; arguments as in
6196 struct attribute_spec.handler. */
6198 static tree
6201 {
6204 /* See FIXME comment in c_common_attribute_table. */
6210 = build_pointer_type
6213 else
6214 {
6218 }
6221 }
6223 /* Handle a "noinline" attribute; arguments as in
6224 struct attribute_spec.handler. */
6226 static tree
6230 {
6232 {
6234 {
6238 }
6239 else
6241 }
6242 else
6243 {
6246 }
6249 }
6251 /* Handle a "noclone" attribute; arguments as in
6252 struct attribute_spec.handler. */
6254 static tree
6258 {
6260 {
6263 }
6266 }
6268 /* Handle a "leaf" attribute; arguments as in
6269 struct attribute_spec.handler. */
6271 static tree
6274 {
6276 {
6279 }
6281 {
6284 }
6287 }
6289 /* Handle a "always_inline" attribute; arguments as in
6290 struct attribute_spec.handler. */
6292 static tree
6295 {
6297 {
6298 /* Set the attribute and mark it for disregarding inline limits. */
6300 }
6301 else
6302 {
6305 }
6308 }
6310 /* Handle a "malloc" attribute; arguments as in
6311 struct attribute_spec.handler. */
6313 static tree
6316 {
6320 else
6321 {
6325 }
6328 }
6330 /* Fake handler for attributes we don't properly support. */
6332 tree
6338 {
6340 }
6342 /* Handle a "type_generic" attribute. */
6344 static tree
6348 {
6349 /* Ensure we have a function type. */
6352 /* Ensure we have a variadic function. */
6356 }
6358 /* Handle a "vector_size" attribute; arguments as in
6359 struct attribute_spec.handler. */
6361 static tree
6364 {
6366 tree vector_type;
6370 /* We need to provide for vector pointers, vector arrays, and
6371 functions returning vectors. For example:
6373 __attribute__((vector_size(16))) short *foo;
6375 In this case, the mode is SI, but the type being modified is
6376 HI, so we need to look further. */
6386 /* Build back pointers if needed. */
6390 }
6392 /* Handle a "vector_type" attribute; arguments as in
6393 struct attribute_spec.handler. */
6395 static tree
6398 {
6400 tree vector_type;
6405 {
6409 }
6419 }
6421 /* ----------------------------------------------------------------------- *
6422 * BUILTIN FUNCTIONS *
6423 * ----------------------------------------------------------------------- */
6425 /* Worker for DEF_BUILTIN. Possibly define a builtin function with one or two
6426 names. Does not declare a non-__builtin_ function if flag_no_builtin, or
6427 if nonansi_p and flag_no_nonansi_builtin. */
6429 static void
6437 {
6438 tree decl;
6441 /* Preserve an already installed decl. It most likely was setup in advance
6442 (e.g. as part of the internal builtins) for specific reasons. */
6453 fnattrs);
6455 /* ??? This is normally further controlled by command-line options
6456 like -fno-builtin, but we don't have them for Ada. */
6461 }
6467 /* Install what the common builtins.def offers. */
6469 static void
6471 {
6472 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
6473 NONANSI_P, ATTRS, IMPLICIT, COND) \
6474 if (NAME && COND) \
6475 def_builtin_1 (ENUM, NAME, CLASS, \
6476 builtin_types[(int) TYPE], \
6477 builtin_types[(int) LIBTYPE], \
6478 BOTH_P, FALLBACK_P, NONANSI_P, \
6479 built_in_attributes[(int) ATTRS], IMPLICIT);
6481 }
6483 /* ----------------------------------------------------------------------- *
6484 * BUILTIN FUNCTIONS *
6485 * ----------------------------------------------------------------------- */
6487 /* Install the builtin functions we might need. */
6489 void
6491 {
6496 /* Install builtins used by generic middle-end pieces first. Some of these
6497 know about internal specificities and control attributes accordingly, for
6498 instance __builtin_alloca vs no-throw and -fstack-check. We will ignore
6499 the generic definition from builtins.def. */
6502 /* Now, install the target specific builtins, such as the AltiVec family on
6503 ppc, and the common set as exposed by builtins.def. */
6506 }