| blob | bfd3388c56a09938876560f894f3ebef74b47dab |
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 } */
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. */
152 };
154 /* Associates a GNAT tree node to a GCC tree node. It is used in
155 `save_gnu_tree', `get_gnu_tree' and `present_gnu_tree'. See documentation
156 of `save_gnu_tree' for more info. */
159 #define GET_GNU_TREE(GNAT_ENTITY) \
160 associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id]
162 #define SET_GNU_TREE(GNAT_ENTITY,VAL) \
163 associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] = (VAL)
165 #define PRESENT_GNU_TREE(GNAT_ENTITY) \
166 (associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] != NULL_TREE)
168 /* Associates a GNAT entity to a GCC tree node used as a dummy, if any. */
171 #define GET_DUMMY_NODE(GNAT_ENTITY) \
172 dummy_node_table[(GNAT_ENTITY) - First_Node_Id]
174 #define SET_DUMMY_NODE(GNAT_ENTITY,VAL) \
175 dummy_node_table[(GNAT_ENTITY) - First_Node_Id] = (VAL)
177 #define PRESENT_DUMMY_NODE(GNAT_ENTITY) \
178 (dummy_node_table[(GNAT_ENTITY) - First_Node_Id] != NULL_TREE)
180 /* This variable keeps a table for types for each precision so that we only
181 allocate each of them once. Signed and unsigned types are kept separate.
183 Note that these types are only used when fold-const requests something
184 special. Perhaps we should NOT share these types; we'll see how it
185 goes later. */
188 /* Likewise for float types, but record these by mode. */
191 /* For each binding contour we allocate a binding_level structure to indicate
192 the binding depth. */
195 /* The binding level containing this one (the enclosing binding level). */
197 /* The BLOCK node for this level. */
198 tree block;
199 /* If nonzero, the setjmp buffer that needs to be updated for any
200 variable-sized definition within this context. */
201 tree jmpbuf_decl;
202 };
204 /* The binding level currently in effect. */
207 /* A chain of gnat_binding_level structures awaiting reuse. */
210 /* The context to be used for global declarations. */
213 /* An array of global declarations. */
216 /* An array of builtin function declarations. */
219 /* A chain of unused BLOCK nodes. */
222 /* A hash table of padded types. It is modelled on the generic type
223 hash table in tree.c, which must thus be used as a reference. */
226 {
227 hashval_t hash;
228 tree type;
229 };
232 {
236 static int
238 {
240 }
241 };
254 /* Linked list used as a queue to defer the initialization of the DECL_CONTEXT
255 of ..._DECL nodes and of the TYPE_CONTEXT of ..._TYPE nodes. */
256 struct deferred_decl_context_node
257 {
258 /* The ..._DECL node to work on. */
259 tree decl;
261 /* The corresponding entity's Scope. */
262 Entity_Id gnat_scope;
264 /* The value of force_global when DECL was pushed. */
267 /* The list of ..._TYPE nodes to propagate the context to. */
270 /* The next queue item. */
272 };
276 /* Defer the initialization of DECL's DECL_CONTEXT attribute, scheduling to
277 feed it with the elaboration of GNAT_SCOPE. */
281 /* Defer the initialization of TYPE's TYPE_CONTEXT attribute, scheduling to
282 feed it with the DECL_CONTEXT computed as part of N as soon as it is
283 computed. */
285 tree type);
286 \f
287 /* Initialize data structures of the utils.c module. */
289 void
291 {
292 /* Initialize the association of GNAT nodes to GCC trees. */
295 /* Initialize the association of GNAT nodes to GCC trees as dummies. */
298 /* Initialize the hash table of padded types. */
300 }
302 /* Destroy data structures of the utils.c module. */
304 void
306 {
307 /* Destroy the association of GNAT nodes to GCC trees. */
311 /* Destroy the association of GNAT nodes to GCC trees as dummies. */
315 /* Destroy the hash table of padded types. */
318 }
319 \f
320 /* GNAT_ENTITY is a GNAT tree node for an entity. Associate GNU_DECL, a GCC
321 tree node, with GNAT_ENTITY. If GNU_DECL is not a ..._DECL node, abort.
322 If NO_CHECK is true, the latter check is suppressed.
324 If GNU_DECL is zero, reset a previous association. */
326 void
328 {
329 /* Check that GNAT_ENTITY is not already defined and that it is being set
330 to something which is a decl. If that is not the case, this usually
331 means GNAT_ENTITY is defined twice, but occasionally is due to some
332 Gigi problem. */
338 }
340 /* GNAT_ENTITY is a GNAT tree node for an entity. Return the GCC tree node
341 that was associated with it. If there is no such tree node, abort.
343 In some cases, such as delayed elaboration or expressions that need to
344 be elaborated only once, GNAT_ENTITY is really not an entity. */
346 tree
348 {
351 }
353 /* Return nonzero if a GCC tree has been associated with GNAT_ENTITY. */
355 bool
357 {
359 }
360 \f
361 /* Make a dummy type corresponding to GNAT_TYPE. */
363 tree
365 {
369 /* If there was no equivalent type (can only happen when just annotating
370 types) or underlying type, go back to the original type. */
374 /* If it there already a dummy type, use that one. Else make one. */
378 /* If this is a record, make a RECORD_TYPE or UNION_TYPE; else make
379 an ENUMERAL_TYPE. */
392 /* Create a debug type so that debug info consumers only see an unspecified
393 type. */
395 {
401 }
404 }
406 /* Return the dummy type that was made for GNAT_TYPE, if any. */
408 tree
410 {
412 }
414 /* Build dummy fat and thin pointer types whose designated type is specified
415 by GNAT_DESIG_TYPE/GNU_DESIG_TYPE and attach them to the latter. */
417 void
419 {
434 /* Build a stub DECL to trigger the special processing for fat pointer types
435 in gnat_pushdecl. */
438 gnu_fat_type);
446 /* Suppress debug info until after the type is completed. */
456 }
457 \f
458 /* Return true if we are in the global binding level. */
460 bool
462 {
464 }
466 /* Enter a new binding level. */
468 void
470 {
473 /* Reuse a struct for this binding level, if there is one. */
475 {
478 }
479 else
482 /* Use a free BLOCK, if any; otherwise, allocate one. */
484 {
488 }
489 else
492 /* Point the BLOCK we just made to its parent. */
500 /* Add this level to the front of the chain (stack) of active levels. */
504 }
506 /* Set SUPERCONTEXT of the BLOCK for the current binding level to FNDECL
507 and point FNDECL to this BLOCK. */
509 void
511 {
515 }
517 /* Set the jmpbuf_decl for the current binding level to DECL. */
519 void
521 {
523 }
525 /* Get the jmpbuf_decl, if any, for the current binding level. */
527 tree
529 {
531 }
533 /* Exit a binding level. Set any BLOCK into the current code group. */
535 void
537 {
544 /* If this is a function-level BLOCK don't do anything. Otherwise, if there
545 are no variables free the block and merge its subblocks into those of its
546 parent block. Otherwise, add it to the list of its parent. */
548 ;
550 {
556 }
557 else
558 {
563 }
565 /* Free this binding structure. */
569 }
571 /* Exit a binding level and discard the associated BLOCK. */
573 void
575 {
582 /* Free this binding structure. */
586 }
587 \f
588 /* Set the context of TYPE and its parallel types (if any) to CONTEXT. */
590 static void
592 {
598 {
601 /* Give a context to the parallel types and their stub decl, if any.
602 Some parallel types seems to be present in multiple parallel type
603 chains, so don't mess with their context if they already have one. */
605 {
609 }
612 }
613 }
615 /* Return the innermost scope, starting at GNAT_NODE, we are be interested in
616 the debug info, or Empty if there is no such scope. If not NULL, set
617 IS_SUBPROGRAM to whether the returned entity is a subprogram. */
619 Entity_Id
621 {
622 Entity_Id gnat_entity;
630 else
634 {
636 {
642 /* If the scope is a subprogram, then just rely on
643 current_function_decl, so that we don't have to defer
644 anything. This is needed because other places rely on the
645 validity of the DECL_CONTEXT attribute of FUNCTION_DECL nodes. */
655 /* By default, we are not interested in this particular scope: go to
656 the outer one. */
658 }
661 }
664 }
666 /* If N is NULL, set TYPE's context to CONTEXT. Defer this to the processing
667 of N otherwise. */
669 static void
672 {
675 else
677 }
679 /* Return global_context, but create it first if need be. */
681 static tree
683 {
685 {
686 global_context
689 }
692 }
694 /* Record DECL as belonging to the current lexical scope and use GNAT_NODE
695 for location information and flag propagation. */
697 void
699 {
703 /* If explicitely asked to make DECL global or if it's an imported nested
704 object, short-circuit the regular Scope-based context computation. */
706 {
707 /* Rely on the GNAT scope, or fallback to the current_function_decl if
708 the GNAT scope reached the global scope, if it reached a subprogram
709 or the declaration is a subprogram or a variable (for them we skip
710 intermediate context types because the subprogram body elaboration
711 machinery and the inliner both expect a subprogram context).
713 Falling back to current_function_decl is necessary for implicit
714 subprograms created by gigi, such as the elaboration subprograms. */
716 const Entity_Id gnat_scope
720 && !context_is_subprogram
723 /* Always assume the scope has not been elaborated, thus defer the
724 context propagation to the time its elaboration will be
725 available. */
726 deferred_decl_context
729 /* External declarations (when force_global > 0) may not be in a
730 local context. */
733 }
735 /* If either we are forced to be in global mode or if both the GNAT scope and
736 the current_function_decl did not help in determining the context, use the
737 global scope. */
741 /* Functions imported in another function are not really nested.
742 For really nested functions mark them initially as needing
743 a static chain for uses of that flag before unnesting;
744 lower_nested_functions will then recompute it. */
747 && context
757 /* Set the location of DECL and emit a declaration for it. */
763 /* Put the declaration on the list. The list of declarations is in reverse
764 order. The list will be reversed later. Put global declarations in the
765 globals list and local ones in the current block. But skip TYPE_DECLs
766 for UNCONSTRAINED_ARRAY_TYPE in both cases, as they will cause trouble
767 with the debugger and aren't needed anyway. */
770 {
771 /* External declarations must go to the binding level they belong to.
772 This will make corresponding imported entities are available in the
773 debugger at the proper time. */
780 else
781 {
784 }
785 }
787 /* For the declaration of a type, set its name either if it isn't already
788 set or if the previous type name was not derived from a source name.
789 We'd rather have the type named with a real name and all the pointer
790 types to the same object have the same node, except when the names are
791 both derived from source names. */
793 {
796 /* Array and pointer types aren't tagged types in the C sense so we need
797 to generate a typedef in DWARF for them and make sure it is preserved,
798 unless the type is artificial. */
802 ;
803 /* For array and pointer types, create the DECL_ORIGINAL_TYPE that will
804 generate the typedef in DWARF. Also do that for fat pointer types
805 because, even though they are tagged types in the C sense, they are
806 still XUP types attached to the base array type at this point. */
811 {
816 deferred_decl_context);
822 else
824 /* Array types need to have a name so that they can be related to
825 their GNAT encodings. */
829 }
833 ;
834 else
837 /* Propagate the name to all the variants, this is needed for the type
838 qualifiers machinery to work properly (see check_qualified_type).
839 Also propagate the context to them. Note that it will be propagated
840 to all parallel types too thanks to gnat_set_type_context. */
843 /* ??? Because of the previous kludge, we can have variants of fat
844 pointer types with different names. */
848 {
852 deferred_decl_context);
853 }
854 }
855 }
856 \f
857 /* Create a record type that contains a SIZE bytes long field of TYPE with a
858 starting bit position so that it is aligned to ALIGN bits, and leaving at
859 least ROOM bytes free before the field. BASE_ALIGN is the alignment the
860 record is guaranteed to get. GNAT_NODE is used for the position of the
861 associated TYPE_DECL. */
863 tree
866 {
867 /* We will be crafting a record type with one field at a position set to be
868 the next multiple of ALIGN past record'address + room bytes. We use a
869 record placeholder to express record'address. */
873 tree record_addr_st
876 /* The diagram below summarizes the shape of what we manipulate:
878 <--------- pos ---------->
879 { +------------+-------------+-----------------+
880 record =>{ |############| ... | field (type) |
881 { +------------+-------------+-----------------+
882 |<-- room -->|<- voffset ->|<---- size ----->|
883 o o
884 | |
885 record_addr vblock_addr
887 Every length is in sizetype bytes there, except "pos" which has to be
888 set as a bit position in the GCC tree for the record. */
898 /* Compute VOFFSET and then POS. The next byte position multiple of some
899 alignment after some address is obtained by "and"ing the alignment minus
900 1 with the two's complement of the address. */
905 /* POS = (ROOM + VOFFSET) * BIT_PER_UNIT, in bitsizetype. */
909 bitsize_unit_node);
911 /* Craft the GCC record representation. We exceptionally do everything
912 manually here because 1) our generic circuitry is not quite ready to
913 handle the complex position/size expressions we are setting up, 2) we
914 have a strong simplifying factor at hand: we know the maximum possible
915 value of voffset, and 3) we have to set/reset at least the sizes in
916 accordance with this maximum value anyway, as we need them to convey
917 what should be "alloc"ated for this type.
919 Use -1 as the 'addressable' indication for the field to prevent the
920 creation of a bitfield. We don't need one, it would have damaging
921 consequences on the alignment computation, and create_field_decl would
922 make one without this special argument, for instance because of the
923 complex position expression. */
934 bitsize_unit_node),
943 /* Declare it now since it will never be declared otherwise. This is
944 necessary to ensure that its subtrees are properly marked. */
948 }
950 /* TYPE is a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE that is being used
951 as the field type of a packed record if IN_RECORD is true, or as the
952 component type of a packed array if IN_RECORD is false. See if we can
953 rewrite it either as a type that has non-BLKmode, which we can pack
954 tighter in the packed record case, or as a smaller type with at most
955 MAX_ALIGN alignment if the value is non-zero. If so, return the new
956 type; if not, return the original type. */
958 tree
960 {
966 /* No point in doing anything if the size is zero. */
972 /* Copy the name and flags from the old type to that of the new.
973 Note that we rely on the pointer equality created here for
974 TYPE_NAME to look through conversions in various places. */
982 /* If we are in a record and have a small size, set the alignment to
983 try for an integral mode. Otherwise set it to try for a smaller
984 type with BLKmode. */
986 {
990 }
991 else
992 {
993 /* Do not try to shrink the size if the RM size is not constant. */
998 /* Round the RM size up to a unit boundary to get the minimal size
999 for a BLKmode record. Give up if it's already the size and we
1000 don't need to lower the alignment. */
1010 }
1014 /* Now copy the fields, keeping the position and size as we don't want
1015 to change the layout by propagating the packedness downwards. */
1018 {
1027 /* However, for the last field in a not already packed record type
1028 that is of an aggregate type, we need to use the RM size in the
1029 packable version of the record type, see finish_record_type. */
1037 else
1040 new_field
1053 }
1061 /* If this is a padding record, we never want to make the size smaller
1062 than what was specified. For QUAL_UNION_TYPE, also copy the size. */
1064 {
1068 }
1069 else
1070 {
1073 }
1080 /* Try harder to get a packable type if necessary, for example
1081 in case the record itself contains a BLKmode field. */
1087 /* If neither mode nor size nor alignment shrunk, return the old type. */
1092 }
1094 /* Return true if TYPE has an unsigned representation. This needs to be used
1095 when the representation of types whose precision is not equal to their size
1096 is manipulated based on the RM size. */
1100 {
1101 /* This is the common case. */
1105 /* See the E_Signed_Integer_Subtype case of gnat_to_gnu_entity. */
1111 }
1113 /* Given a type TYPE, return a new type whose size is appropriate for SIZE.
1114 If TYPE is the best type, return it. Otherwise, make a new type. We
1115 only support new integral and pointer types. FOR_BIASED is true if
1116 we are making a biased type. */
1118 tree
1120 {
1123 tree new_type;
1125 /* If size indicates an error, just return TYPE to avoid propagating
1126 the error. Likewise if it's too large to represent. */
1133 {
1140 /* Integer types with precision 0 are forbidden. */
1144 /* Only do something if the type isn't a packed array type and doesn't
1145 already have the proper size and the size isn't too large. */
1153 /* The type should be an unsigned type if the original type is unsigned
1154 or if the lower bound is constant and non-negative or if the type is
1155 biased, see E_Signed_Integer_Subtype case of gnat_to_gnu_entity. */
1158 else
1163 /* Copy the name to show that it's essentially the same type and
1164 not a subrange type. */
1171 /* Do something if this is a fat pointer, in which case we
1172 may need to return the thin pointer. */
1174 {
1175 scalar_int_mode p_mode;
1179 return
1180 build_pointer_type_for_mode
1183 }
1187 /* Only do something if this is a thin pointer, in which case we
1188 may need to return the fat pointer. */
1190 return
1196 }
1199 }
1201 /* Return true iff the padded types are equivalent. */
1203 bool
1205 {
1214 /* We consider that the padded types are equivalent if they pad the same type
1215 and have the same size, alignment, RM size and storage order. Taking the
1216 mode into account is redundant since it is determined by the others. */
1217 return
1223 }
1225 /* Look up the padded TYPE in the hash table and return its canonical version
1226 if it exists; otherwise, insert it into the hash table. */
1228 static tree
1230 {
1231 hashval_t hashcode;
1234 hashcode
1251 }
1253 /* Ensure that TYPE has SIZE and ALIGN. Make and return a new padded type
1254 if needed. We have already verified that SIZE and ALIGN are large enough.
1255 GNAT_ENTITY is used to name the resulting record and to issue a warning.
1256 IS_COMPONENT_TYPE is true if this is being done for the component type of
1257 an array. IS_USER_TYPE is true if the original type needs to be completed.
1258 DEFINITION is true if this type is being defined. SET_RM_SIZE is true if
1259 the RM size of the resulting type is to be set to SIZE too; in this case,
1260 the padded type is canonicalized before being returned. */
1262 tree
1266 {
1271 /* If TYPE is a padded type, see if it agrees with any size and alignment
1272 we were given. If so, return the original type. Otherwise, strip
1273 off the padding, since we will either be returning the inner type
1274 or repadding it. If no size or alignment is specified, use that of
1275 the original padded type. */
1277 {
1291 }
1293 /* If the size is either not being changed or is being made smaller (which
1294 is not done here and is only valid for bitfields anyway), show the size
1295 isn't changing. Likewise, clear the alignment if it isn't being
1296 changed. Then return if we aren't doing anything. */
1309 /* If requested, complete the original type and give it a name. */
1316 gnat_entity);
1318 /* We used to modify the record in place in some cases, but that could
1319 generate incorrect debugging information. So make a new record
1320 type and name. */
1324 /* ??? Padding types around packed array implementation types will be
1325 considered as root types in the array descriptor language hook (see
1326 gnat_get_array_descr_info). Give them the original packed array type
1327 name so that the one coming from sources appears in the debugging
1328 information. */
1341 bitsize_unit_node));
1343 /* If we are changing the alignment and the input type is a record with
1344 BLKmode and a small constant size, try to make a form that has an
1345 integral mode. This might allow the padding record to also have an
1346 integral mode, which will be much more efficient. There is no point
1347 in doing so if a size is specified unless it is also a small constant
1348 size and it is incorrect to do so if we cannot guarantee that the mode
1349 will be naturally aligned since the field must always be addressable.
1351 ??? This might not always be a win when done for a stand-alone object:
1352 since the nominal and the effective type of the object will now have
1353 different modes, a VIEW_CONVERT_EXPR will be required for converting
1354 between them and it might be hard to overcome afterwards, including
1355 at the RTL level when the stand-alone object is accessed as a whole. */
1363 && (!size
1366 {
1371 }
1373 /* Now create the field with the original size. */
1378 /* We will output additional debug info manually below. */
1384 /* Set the RM size if requested. */
1386 {
1387 tree canonical_pad_type;
1391 /* If the padded type is complete and has constant size, we canonicalize
1392 it by means of the hash table. This is consistent with the language
1393 semantics and ensures that gigi and the middle-end have a common view
1394 of these padded types. */
1397 {
1400 }
1401 }
1403 /* Unless debugging information isn't being written for the input type,
1404 write a record that shows what we are a subtype of and also make a
1405 variable that indicates our size, if still variable. */
1411 {
1415 /* A variable that holds the size is required even with no encoding since
1416 it will be referenced by debugging information attributes. At global
1417 level, we need a single variable across all translation units. */
1421 {
1422 /* Whether or not gnat_entity comes from source, this XVZ variable is
1423 is a compilation artifact. */
1424 size_unit
1430 }
1432 /* There is no need to show what we are a subtype of when outputting as
1433 few encodings as possible: regular debugging infomation makes this
1434 redundant. */
1436 {
1450 }
1451 }
1453 built:
1454 /* If a simple size was explicitly given, maybe issue a warning. */
1461 /* But don't do it if we are just annotating types and the type is tagged or
1462 concurrent, since these types aren't fully laid out in this mode. */
1464 {
1465 Entity_Id gnat_type
1466 = is_component_type
1471 }
1473 /* Take the original size as the maximum size of the input if there was an
1474 unconstrained record involved and round it up to the specified alignment,
1475 if one was specified, but only for aggregate types. */
1488 {
1491 /* For a packed array, post the message on the original array type. */
1502 /* Generate message only for entities that come from source, since
1503 if we have an entity created by expansion, the message will be
1504 generated for some other corresponding source entity. */
1506 {
1515 }
1516 }
1519 }
1521 /* Return a copy of the padded TYPE but with reverse storage order. */
1523 tree
1525 {
1529 {
1530 /* If the inner type is not scalar then the function does nothing. */
1534 }
1536 /* This is required for the canonicalization. */
1546 }
1547 \f
1548 /* Relate the alias sets of GNU_NEW_TYPE and GNU_OLD_TYPE according to OP.
1549 If this is a multi-dimensional array type, do this recursively.
1551 OP may be
1552 - ALIAS_SET_COPY: the new set is made a copy of the old one.
1553 - ALIAS_SET_SUPERSET: the new set is made a superset of the old one.
1554 - ALIAS_SET_SUBSET: the new set is made a subset of the old one. */
1556 void
1558 {
1559 /* Remove any padding from GNU_OLD_TYPE. It doesn't matter in the case
1560 of a one-dimensional array, since the padding has the same alias set
1561 as the field type, but if it's a multi-dimensional array, we need to
1562 see the inner types. */
1568 /* Unconstrained array types are deemed incomplete and would thus be given
1569 alias set 0. Retrieve the underlying array type. */
1571 gnu_old_type
1574 gnu_new_type
1583 {
1585 /* The alias set shouldn't be copied between array types with different
1586 aliasing settings because this can break the aliasing relationship
1587 between the array type and its element type. */
1599 {
1603 /* Do nothing if the alias sets conflict. This ensures that we
1604 never call record_alias_subset several times for the same pair
1605 or at all for alias set 0. */
1607 {
1610 else
1612 }
1613 }
1618 }
1621 }
1622 \f
1623 /* Record TYPE as a builtin type for Ada. NAME is the name of the type.
1624 ARTIFICIAL_P is true if the type was generated by the compiler. */
1626 void
1628 {
1637 }
1638 \f
1639 /* Finish constructing the character type CHAR_TYPE.
1641 In Ada character types are enumeration types and, as a consequence, are
1642 represented in the front-end by integral types holding the positions of
1643 the enumeration values as defined by the language, which means that the
1644 integral types are unsigned.
1646 Unfortunately the signedness of 'char' in C is implementation-defined
1647 and GCC even has the option -fsigned-char to toggle it at run time.
1648 Since GNAT's philosophy is to be compatible with C by default, to wit
1649 Interfaces.C.char is defined as a mere copy of Character, we may need
1650 to declare character types as signed types in GENERIC and generate the
1651 necessary adjustments to make them behave as unsigned types.
1653 The overall strategy is as follows: if 'char' is unsigned, do nothing;
1654 if 'char' is signed, translate character types of CHAR_TYPE_SIZE and
1655 character subtypes with RM_Size = Esize = CHAR_TYPE_SIZE into signed
1656 types. The idea is to ensure that the bit pattern contained in the
1657 Esize'd objects is not changed, even though the numerical value will
1658 be interpreted differently depending on the signedness. */
1660 void
1662 {
1666 /* Make a copy of a generic unsigned version since we'll modify it. */
1667 tree unsigned_char_type
1669 ? unsigned_char_type_node
1672 /* Create an unsigned version of the type and set it as debug type. */
1678 /* If this is a subtype, make the debug type a subtype of the debug type
1679 of the base type and convert literal RM bounds to unsigned. */
1681 {
1694 }
1696 /* Adjust the RM bounds of the original type to unsigned; that's especially
1697 important for types since they are implicit in this case. */
1700 }
1702 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
1703 finish constructing the record type as a fat pointer type. */
1705 void
1707 {
1708 /* Make sure we can put it into a register. */
1712 /* Show what it really is. */
1715 /* Do not emit debug info for it since the types of its fields may still be
1716 incomplete at this point. */
1719 /* Force type_contains_placeholder_p to return true on it. Although the
1720 PLACEHOLDER_EXPRs are referenced only indirectly, this isn't a pointer
1721 type but the representation of the unconstrained array. */
1723 }
1725 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
1726 finish constructing the record or union type. If REP_LEVEL is zero, this
1727 record has no representation clause and so will be entirely laid out here.
1728 If REP_LEVEL is one, this record has a representation clause and has been
1729 laid out already; only set the sizes and alignment. If REP_LEVEL is two,
1730 this record is derived from a parent record and thus inherits its layout;
1731 only make a pass on the fields to finalize them. DEBUG_INFO_P is true if
1732 additional debug info needs to be output for this type. */
1734 void
1737 {
1745 tree field;
1749 /* Always attach the TYPE_STUB_DECL for a record type. It is required to
1750 generate debug info and have a parallel type. */
1753 /* Globally initialize the record first. If this is a rep'ed record,
1754 that just means some initializations; otherwise, layout the record. */
1756 {
1766 /* For all-repped records with a size specified, lay the QUAL_UNION_TYPE
1767 out just like a UNION_TYPE, since the size will be fixed. */
1770 }
1771 else
1772 {
1773 /* Ensure there isn't a size already set. There can be in an error
1774 case where there is a rep clause but all fields have errors and
1775 no longer have a position. */
1778 /* Ensure we use the traditional GCC layout for bitfields when we need
1779 to pack the record type or have a representation clause. The other
1780 possible layout (Microsoft C compiler), if available, would prevent
1781 efficient packing in almost all cases. */
1782 #ifdef TARGET_MS_BITFIELD_LAYOUT
1787 ATTR_FLAG_TYPE_IN_PLACE);
1788 #endif
1791 }
1793 /* At this point, the position and size of each field is known. It was
1794 either set before entry by a rep clause, or by laying out the type above.
1796 We now run a pass over the fields (in reverse order for QUAL_UNION_TYPEs)
1797 to compute the Ada size; the GCC size and alignment (for rep'ed records
1798 that are not padding types); and the mode (for rep'ed records). We also
1799 clear the DECL_BIT_FIELD indication for the cases we know have not been
1800 handled yet, and adjust DECL_NONADDRESSABLE_P accordingly. */
1806 {
1810 tree this_ada_size;
1817 else
1820 /* Clear DECL_BIT_FIELD for the cases layout_decl does not handle. */
1823 {
1826 /* In the general case, type alignment is required. */
1828 {
1829 /* The enclosing record type must be sufficiently aligned.
1830 Otherwise, if no alignment was specified for it and it
1831 has been laid out already, bump its alignment to the
1832 desired one if this is compatible with its size and
1833 maximum alignment, if any. */
1835 {
1838 }
1844 {
1848 }
1849 }
1851 /* In the non-strict alignment case, only byte alignment is. */
1856 }
1858 /* If we still have DECL_BIT_FIELD set at this point, we know that the
1859 field is technically not addressable. Except that it can actually
1860 be addressed if it is BLKmode and happens to be properly aligned. */
1866 /* A type must be as aligned as its most aligned field that is not
1867 a bit-field. But this is already enforced by layout_type. */
1873 {
1880 ada_size
1888 /* Since we know here that all fields are sorted in order of
1889 increasing bit position, the size of the record is one
1890 higher than the ending bit of the last field processed
1891 unless we have a rep clause, since in that case we might
1892 have a field outside a QUAL_UNION_TYPE that has a higher ending
1893 position. So use a MAX in that case. Also, if this field is a
1894 QUAL_UNION_TYPE, we need to take into account the previous size in
1895 the case of empty variants. */
1896 ada_size
1899 size
1906 }
1907 }
1913 {
1914 /* If this is a padding record, we never want to make the size smaller
1915 than what was specified in it, if any. */
1919 /* Now set any of the values we've just computed that apply. */
1925 {
1926 tree size_unit = had_size_unit
1930 bitsize_unit_node));
1938 }
1939 }
1941 /* Reset the TYPE_MAX_ALIGN field since it's private to gigi. */
1946 }
1948 /* Append PARALLEL_TYPE on the chain of parallel types of TYPE. If
1949 PARRALEL_TYPE has no context and its computation is not deferred yet, also
1950 propagate TYPE's context to PARALLEL_TYPE's or defer its propagation to the
1951 moment TYPE will get a context. */
1953 void
1955 {
1963 /* If PARALLEL_TYPE already has a context, we are done. */
1967 /* Otherwise, try to get one from TYPE's context. If so, simply propagate
1968 it to PARALLEL_TYPE. */
1972 /* Otherwise TYPE has not context yet. We know it will have one thanks to
1973 gnat_pushdecl and then its context will be propagated to PARALLEL_TYPE,
1974 so we have nothing to do in this case. */
1975 }
1977 /* Return true if TYPE has a parallel type. */
1979 static bool
1981 {
1985 }
1987 /* Wrap up compilation of RECORD_TYPE, i.e. output additional debug info
1988 associated with it. It need not be invoked directly in most cases as
1989 finish_record_type takes care of doing so. */
1991 void
1993 {
1995 tree field;
1997 /* If this is a padded type, the bulk of the debug info has already been
1998 generated for the field's type. */
2002 /* If the type already has a parallel type (XVS type), then we're done. */
2007 {
2008 /* We need to make an XVE/XVU record if any field has variable size,
2009 whether or not the record does. For example, if we have a union,
2010 it may be that all fields, rounded up to the alignment, have the
2011 same size, in which case we'll use that size. But the debug
2012 output routines (except Dwarf2) won't be able to output the fields,
2013 so we need to make the special record. */
2015 /* If a field has a non-constant qualifier, the record will have
2016 variable size too. */
2019 {
2022 }
2023 }
2025 /* If this record type is of variable size, make a parallel record type that
2026 will tell the debugger how the former is laid out (see exp_dbug.ads). */
2028 {
2029 tree new_record_type
2036 new_name
2050 /* Now scan all the fields, replacing each field with a new field
2051 corresponding to the new encoding. */
2054 {
2062 /* See how the position was modified from the last position.
2064 There are two basic cases we support: a value was added
2065 to the last position or the last position was rounded to
2066 a boundary and they something was added. Check for the
2067 first case first. If not, see if there is any evidence
2068 of rounding. If so, round the last position and retry.
2070 If this is a union, the position can be taken as zero. */
2073 else
2079 {
2085 }
2090 && tree_fits_uhwi_p
2092 {
2094 unsigned HOST_WIDE_INT addend
2096 align
2102 }
2104 {
2108 }
2110 /* If we can't compute a position, set it to zero.
2112 ??? We really should abort here, but it's too much work
2113 to get this correct for all cases. */
2117 /* See if this type is variable-sized and make a pointer type
2118 and indicate the indirection if so. Beware that the debug
2119 back-end may adjust the position computed above according
2120 to the alignment of the field type, i.e. the pointer type
2121 in this case, if we don't preventively counter that. */
2123 {
2126 {
2129 }
2131 }
2133 /* Make a new field name, if necessary. */
2135 {
2141 else
2145 }
2147 new_field
2153 /* If old_field is a QUAL_UNION_TYPE, take its size as being
2154 zero. The only time it's not the last field of the record
2155 is when there are other components at fixed positions after
2156 it (meaning there was a rep clause for every field) and we
2157 want to be able to encode them. */
2161 ? bitsize_zero_node
2164 }
2169 }
2170 }
2172 /* Utility function of above to merge LAST_SIZE, the previous size of a record
2173 with FIRST_BIT and SIZE that describe a field. SPECIAL is true if this
2174 represents a QUAL_UNION_TYPE in which case we must look for COND_EXPRs and
2175 replace a value of zero with the old size. If HAS_REP is true, we take the
2176 MAX of the end position of this field with LAST_SIZE. In all other cases,
2177 we use FIRST_BIT plus SIZE. Return an expression for the size. */
2179 static tree
2182 {
2184 tree new_size;
2187 {
2191 }
2193 else
2204 /* We don't need any NON_VALUE_EXPRs and they can confuse us (especially
2205 when fed through substitute_in_expr) into thinking that a constant
2206 size is not constant. */
2211 }
2213 /* Return the bit position of FIELD, in bits from the start of the record,
2214 and fold it as much as possible. This is a tree of type bitsizetype. */
2216 static tree
2218 {
2224 else
2228 }
2230 /* Utility function of above to see if OP0 and OP1, both of SIZETYPE, are
2231 related by the addition of a constant. Return that constant if so. */
2233 static tree
2235 {
2242 {
2246 }
2247 else
2258 }
2260 /* Utility function of above to split a tree OP which may be a sum, into a
2261 constant part, which is returned, and a variable part, which is stored
2262 in *PVAR. *PVAR may be bitsize_zero_node. All operations must be of
2263 bitsizetype. */
2265 static tree
2267 {
2268 /* Strip conversions in order to ease the tree traversal and maximize the
2269 potential for constant or plus/minus discovery. We need to be careful
2270 to always return and set *pvar to bitsizetype trees, but it's worth
2271 the effort. */
2277 {
2280 }
2282 {
2293 }
2294 else
2296 }
2297 \f
2298 /* Return a copy of TYPE but safe to modify in any way. */
2300 tree
2302 {
2305 /* Unshare the language-specific data. */
2307 {
2310 }
2312 /* And the contents of the language-specific slot if needed. */
2315 {
2320 }
2322 /* copy_node clears this field instead of copying it, because it is
2323 aliased with TREE_CHAIN. */
2333 }
2334 \f
2335 /* Return a subtype of sizetype with range MIN to MAX and whose
2336 TYPE_INDEX_TYPE is INDEX. GNAT_NODE is used for the position
2337 of the associated TYPE_DECL. */
2339 tree
2341 {
2342 /* First build a type for the desired range. */
2345 /* Then set the index type. */
2350 }
2352 /* Return a subtype of TYPE with range MIN to MAX. If TYPE is NULL,
2353 sizetype is used. */
2355 tree
2357 {
2358 tree range_type;
2363 /* First build a type with the base range. */
2367 /* Then set the actual range. */
2372 }
2373 \f
2374 /* Return a TYPE_DECL node suitable for the TYPE_STUB_DECL field of TYPE.
2375 NAME gives the name of the type to be used in the declaration. */
2377 tree
2379 {
2384 }
2386 /* Return a TYPE_DECL node for TYPE. NAME gives the name of the type to be
2387 used in the declaration. ARTIFICIAL_P is true if the declaration was
2388 generated by the compiler. DEBUG_INFO_P is true if we need to write
2389 debug information about this type. GNAT_NODE is used for the position
2390 of the decl. */
2392 tree
2394 Node_Id gnat_node)
2395 {
2397 bool is_named
2399 tree type_decl;
2401 /* Only the builtin TYPE_STUB_DECL should be used for dummy types. */
2404 /* If the type hasn't been named yet, we're naming it; preserve an existing
2405 TYPE_STUB_DECL that has been attached to it for some purpose. */
2407 {
2410 }
2411 else
2417 /* Add this decl to the current binding level. */
2420 /* If we're naming the type, equate the TYPE_STUB_DECL to the name. This
2421 causes the name to be also viewed as a "tag" by the debug back-end, with
2422 the advantage that no DW_TAG_typedef is emitted for artificial "tagged"
2423 types in DWARF.
2425 Note that if "type" is used as a DECL_ORIGINAL_TYPE, it may be referenced
2426 from multiple contexts, and "type_decl" references a copy of it: in such a
2427 case, do not mess TYPE_STUB_DECL: we do not want to re-use the TYPE_DECL
2428 with the mechanism above. */
2432 /* Do not generate debug info for UNCONSTRAINED_ARRAY_TYPE that the
2433 back-end doesn't support, and for others if we don't need to. */
2438 }
2439 \f
2440 /* Return a VAR_DECL or CONST_DECL node.
2442 NAME gives the name of the variable. ASM_NAME is its assembler name
2443 (if provided). TYPE is its data type (a GCC ..._TYPE node). INIT is
2444 the GCC tree for an optional initial expression; NULL_TREE if none.
2446 CONST_FLAG is true if this variable is constant, in which case we might
2447 return a CONST_DECL node unless CONST_DECL_ALLOWED_P is false.
2449 PUBLIC_FLAG is true if this is for a reference to a public entity or for a
2450 definition to be made visible outside of the current compilation unit, for
2451 instance variable definitions in a package specification.
2453 EXTERN_FLAG is true when processing an external variable declaration (as
2454 opposed to a definition: no storage is to be allocated for the variable).
2456 STATIC_FLAG is only relevant when not at top level and indicates whether
2457 to always allocate storage to the variable.
2459 VOLATILE_FLAG is true if this variable is declared as volatile.
2461 ARTIFICIAL_P is true if the variable was generated by the compiler.
2463 DEBUG_INFO_P is true if we need to write debug information for it.
2465 ATTR_LIST is the list of attributes to be attached to the variable.
2467 GNAT_NODE is used for the position of the decl. */
2469 tree
2475 {
2476 /* Whether the object has static storage duration, either explicitly or by
2477 virtue of being declared at the global level. */
2480 /* Whether the initializer is constant: for an external object or an object
2481 with static storage duration, we check that the initializer is a valid
2482 constant expression for initializing a static variable; otherwise, we
2483 only check that it is constant. */
2484 const bool init_const
2485 = (init
2489 != NULL_TREE
2492 /* Whether we will make TREE_CONSTANT the DECL we produce here, in which
2493 case the initializer may be used in lieu of the DECL node (as done in
2494 Identifier_to_gnu). This is useful to prevent the need of elaboration
2495 code when an identifier for which such a DECL is made is in turn used
2496 as an initializer. We used to rely on CONST_DECL vs VAR_DECL for this,
2497 but extra constraints apply to this choice (see below) and they are not
2498 relevant to the distinction we wish to make. */
2501 /* The actual DECL node. CONST_DECL was initially intended for enumerals
2502 and may be used for scalars in general but not for aggregates. */
2503 tree var_decl
2505 (constant_p
2506 && const_decl_allowed_p
2510 /* Detect constants created by the front-end to hold 'reference to function
2511 calls for stabilization purposes. This is needed for renaming. */
2513 {
2524 }
2526 /* If this is external, throw away any initializations (they will be done
2527 elsewhere) unless this is a constant for which we would like to remain
2528 able to get the initializer. If we are defining a global here, leave a
2529 constant initialization and save any variable elaborations for the
2530 elaboration routine. If we are just annotating types, throw away the
2531 initialization if it isn't a constant. */
2536 /* At the global level, a non-constant initializer generates elaboration
2537 statements. Check that such statements are allowed, that is to say,
2538 not violating a No_Elaboration_Code restriction. */
2542 /* Attach the initializer, if any. */
2545 /* Directly set some flags. */
2552 /* The object is public if it is external or if it is declared public
2553 and has static storage duration. */
2556 /* We need to allocate static storage for an object with static storage
2557 duration if it isn't external. */
2567 /* Ada doesn't feature Fortran-like COMMON variables so we shouldn't
2568 try to fiddle with DECL_COMMON. However, on platforms that don't
2569 support global BSS sections, uninitialized global variables would
2570 go in DATA instead, thus increasing the size of the executable. */
2577 /* Do not emit debug info for a CONST_DECL if optimization isn't enabled,
2578 since we will create an associated variable. Likewise for an external
2579 constant whose initializer is not absolute, because this would mean a
2580 global relocation in a read-only section which runs afoul of the PE-COFF
2581 run-time relocation mechanism. */
2584 || (extern_flag
2585 && constant_p
2586 && init
2591 /* ??? Some attributes cannot be applied to CONST_DECLs. */
2595 /* Add this decl to the current binding level. */
2599 {
2600 /* Let the target mangle the name if this isn't a verbatim asm. */
2605 }
2608 }
2609 \f
2610 /* Return true if TYPE, an aggregate type, contains (or is) an array. */
2612 static bool
2614 {
2616 {
2620 {
2621 tree field;
2627 }
2634 }
2635 }
2637 /* Return a FIELD_DECL node. NAME is the field's name, TYPE is its type and
2638 RECORD_TYPE is the type of the enclosing record. If SIZE is nonzero, it
2639 is the specified size of the field. If POS is nonzero, it is the bit
2640 position. PACKED is 1 if the enclosing record is packed, -1 if it has
2641 Component_Alignment of Storage_Unit. If ADDRESSABLE is nonzero, it
2642 means we are allowed to take the address of the field; if it is negative,
2643 we should not make a bitfield, which is used by make_aligning_type. */
2645 tree
2648 {
2654 /* If FIELD_TYPE is BLKmode, we must ensure this is aligned to at least a
2655 byte boundary since GCC cannot handle less-aligned BLKmode bitfields.
2656 Likewise for an aggregate without specified position that contains an
2657 array, because in this case slices of variable length of this array
2658 must be handled by GCC and variable-sized objects need to be aligned
2659 to at least a byte boundary. */
2661 || (!pos
2666 /* If a size is specified, use it. Otherwise, if the record type is packed
2667 compute a size to use, which may differ from the object's natural size.
2668 We always set a size in this case to trigger the checks for bitfield
2669 creation below, which is typically required when no position has been
2670 specified. */
2674 {
2678 }
2680 /* If we may, according to ADDRESSABLE, make a bitfield if a size is
2681 specified for two reasons: first if the size differs from the natural
2682 size. Second, if the alignment is insufficient. There are a number of
2683 ways the latter can be true.
2685 We never make a bitfield if the type of the field has a nonconstant size,
2686 because no such entity requiring bitfield operations should reach here.
2688 We do *preventively* make a bitfield when there might be the need for it
2689 but we don't have all the necessary information to decide, as is the case
2690 of a field with no specified position in a packed record.
2692 We also don't look at STRICT_ALIGNMENT here, and rely on later processing
2693 in layout_decl or finish_record_type to clear the bit_field indication if
2694 it is in fact not needed. */
2696 && size
2701 || packed
2704 {
2708 {
2712 else
2714 }
2715 }
2719 /* Bump the alignment if need be, either for bitfield/packing purposes or
2720 to satisfy the type requirements if no such consideration applies. When
2721 we get the alignment from the type, indicate if this is from an explicit
2722 user request, which prevents stor-layout from lowering it later on. */
2723 {
2724 unsigned int bit_align
2731 {
2734 }
2735 }
2738 {
2739 /* We need to pass in the alignment the DECL is known to have.
2740 This is the lowest-order bit set in POS, but no more than
2741 the alignment of the record, if one is specified. Note
2742 that an alignment of 0 is taken as infinite. */
2747 else
2761 }
2763 /* In addition to what our caller says, claim the field is addressable if we
2764 know that its type is not suitable.
2766 The field may also be "technically" nonaddressable, meaning that even if
2767 we attempt to take the field's address we will actually get the address
2768 of a copy. This is the case for true bitfields, but the DECL_BIT_FIELD
2769 value we have at this point is not accurate enough, so we don't account
2770 for this here and let finish_record_type decide. */
2777 }
2778 \f
2779 /* Return a PARM_DECL node with NAME and TYPE. */
2781 tree
2783 {
2786 /* Honor TARGET_PROMOTE_PROTOTYPES like the C compiler, as not doing so
2787 can lead to various ABI violations. */
2791 {
2792 /* We have to be careful about biased types here. Make a subtype
2793 of integer_type_node with the proper biasing. */
2796 {
2797 tree subtype
2804 }
2805 else
2807 }
2811 }
2812 \f
2813 /* Process the attributes in ATTR_LIST for NODE, which is either a DECL or
2814 a TYPE. If IN_PLACE is true, the tree pointed to by NODE should not be
2815 changed. GNAT_NODE is used for the position of error messages. */
2817 void
2819 Node_Id gnat_node)
2820 {
2825 {
2834 {
2837 }
2843 else
2850 {
2853 }
2854 else
2873 }
2876 }
2878 /* Return true if VALUE is a known to be a multiple of FACTOR, which must be
2879 a power of 2. */
2881 bool
2883 {
2892 }
2894 /* Return whether GNAT_NODE is a defining identifier for a renaming that comes
2895 from the parameter association for the instantiation of a generic. We do
2896 not want to emit source location for them: the code generated for their
2897 initialization is likely to disturb debugging. */
2899 bool
2901 {
2908 /* Get the object declaration of the renamed object, if any and if the
2909 renamed object is a mere identifier. */
2919 return
2923 }
2925 /* Defer the initialization of DECL's DECL_CONTEXT attribute, scheduling to
2926 feed it with the elaboration of GNAT_SCOPE. */
2930 {
2933 new_node
2942 }
2944 /* Defer the initialization of TYPE's TYPE_CONTEXT attribute, scheduling to
2945 feed it with the DECL_CONTEXT computed as part of N as soon as it is
2946 computed. */
2948 static void
2950 {
2952 }
2954 /* Get the GENERIC node corresponding to GNAT_SCOPE, if available. Return
2955 NULL_TREE if it is not available. */
2957 static tree
2959 {
2960 tree context;
2964 else
2968 {
2971 /* Skip dummy types: only the final ones can appear in the context
2972 chain. */
2976 /* ..._TYPE nodes are more useful than TYPE_DECL nodes in the context
2977 chain. */
2978 else
2980 }
2983 }
2985 /* Try to process all deferred nodes in the queue. Keep in the queue the ones
2986 that cannot be processed yet, remove the other ones. If FORCE is true,
2987 force the processing for all nodes, use the global context when nodes don't
2988 have a GNU translation. */
2990 void
2992 {
2997 {
3000 Entity_Id gnat_scope;
3004 /* If FORCE, get the innermost elaborated scope. Otherwise, just try to
3005 get the first scope. */
3008 {
3013 }
3015 /* Imported declarations must not be in a local context (i.e. not inside
3016 a function). */
3018 {
3022 {
3025 }
3026 }
3028 /* If FORCE, we want to get rid of all nodes in the queue: in case there
3029 was no elaborated scope, use the global context. */
3034 {
3035 tree t;
3040 /* Propagate it to the TYPE_CONTEXT attributes of the requested
3041 ..._TYPE nodes. */
3043 {
3045 }
3047 }
3049 /* If this node has been successfuly processed, remove it from the
3050 queue. Then move to the next node. */
3052 {
3056 }
3057 else
3059 }
3060 }
3062 /* Return VALUE scaled by the biggest power-of-2 factor of EXPR. */
3064 static unsigned int
3066 {
3070 /* Peel conversions around EXPR and try to extract bodies from function
3071 calls: it is possible to get the scale factor from size functions. */
3076 /* Sometimes we get PLUS_EXPR (BIT_AND_EXPR (..., X), Y), where Y is a
3077 multiple of the scale factor we are looking for. */
3081 {
3084 }
3086 /* An expression which is a bitwise AND with a mask has a power-of-2 factor
3087 corresponding to the number of trailing zeros of the mask. */
3090 {
3095 {
3098 i++;
3099 }
3100 }
3102 /* If the addend is not a multiple of the factor we found, give up. In
3103 theory we could find a smaller common factor but it's useless for our
3104 needs. This situation arises when dealing with a field F1 with no
3105 alignment requirement but that is following a field F2 with such
3106 requirements. As long as we have F2's offset, we don't need alignment
3107 information to compute F1's. */
3112 }
3114 /* Given two consecutive field decls PREV_FIELD and CURR_FIELD, return true
3115 unless we can prove these 2 fields are laid out in such a way that no gap
3116 exist between the end of PREV_FIELD and the beginning of CURR_FIELD. OFFSET
3117 is the distance in bits between the end of PREV_FIELD and the starting
3118 position of CURR_FIELD. It is ignored if null. */
3120 static bool
3122 {
3123 /* If this is the first field of the record, there cannot be any gap */
3127 /* If the previous field is a union type, then return false: The only
3128 time when such a field is not the last field of the record is when
3129 there are other components at fixed positions after it (meaning there
3130 was a rep clause for every field), in which case we don't want the
3131 alignment constraint to override them. */
3135 /* If the distance between the end of prev_field and the beginning of
3136 curr_field is constant, then there is a gap if the value of this
3137 constant is not null. */
3141 /* If the size and position of the previous field are constant,
3142 then check the sum of this size and position. There will be a gap
3143 iff it is not multiple of the current field alignment. */
3150 /* If both the position and size of the previous field are multiples
3151 of the current field alignment, there cannot be any gap. */
3156 /* Fallback, return that there may be a potential gap */
3158 }
3160 /* Return a LABEL_DECL with NAME. GNAT_NODE is used for the position of
3161 the decl. */
3163 tree
3165 {
3166 tree label_decl
3171 /* Add this decl to the current binding level. */
3175 }
3176 \f
3177 /* Return a FUNCTION_DECL node. NAME is the name of the subprogram, ASM_NAME
3178 its assembler name, TYPE its type (a FUNCTION_TYPE node), PARAM_DECL_LIST
3179 the list of its parameters (a list of PARM_DECL nodes chained through the
3180 DECL_CHAIN field).
3182 INLINE_STATUS describes the inline flags to be set on the FUNCTION_DECL.
3184 PUBLIC_FLAG is true if this is for a reference to a public entity or for a
3185 definition to be made visible outside of the current compilation unit.
3187 EXTERN_FLAG is true when processing an external subprogram declaration.
3189 ARTIFICIAL_P is true if the subprogram was generated by the compiler.
3191 DEBUG_INFO_P is true if we need to write debug information for it.
3193 DEFINITION is true if the subprogram is to be considered as a definition.
3195 ATTR_LIST is the list of attributes to be attached to the subprogram.
3197 GNAT_NODE is used for the position of the decl. */
3199 tree
3204 Node_Id gnat_node)
3205 {
3219 {
3229 {
3233 ATTR_FLAG_TYPE_IN_PLACE);
3235 /* Inline_Always guarantees that every direct call is inlined and
3236 that there is no indirect reference to the subprogram, so the
3237 instance in the original package (as well as its clones in the
3238 client packages created for inter-unit inlining) can be made
3239 private, which causes the out-of-line body to be eliminated. */
3241 }
3243 /* ... fall through ... */
3252 }
3256 /* Once everything is processed, finish the subprogram declaration. */
3259 /* Add this decl to the current binding level. */
3262 /* Output the assembler code and/or RTL for the declaration. */
3266 }
3268 /* Given a subprogram declaration DECL, its assembler name and its type,
3269 finish constructing the subprogram declaration from ASM_NAME and TYPE. */
3271 void
3273 {
3274 tree result_decl
3287 {
3288 /* Let the target mangle the name if this isn't a verbatim asm. */
3294 /* The expand_main_function circuitry expects "main_identifier_node" to
3295 designate the DECL_NAME of the 'main' entry point, in turn expected
3296 to be declared as the "main" function literally by default. Ada
3297 program entry points are typically declared with a different name
3298 within the binder generated file, exported as 'main' to satisfy the
3299 system expectations. Force main_identifier_node in this case. */
3302 }
3303 }
3304 \f
3305 /* Set up the framework for generating code for SUBPROG_DECL, a subprogram
3306 body. This routine needs to be invoked before processing the declarations
3307 appearing in the subprogram. */
3309 void
3311 {
3312 tree param_decl;
3316 /* This function is being defined. */
3319 /* The failure of this assertion will likely come from a wrong context for
3320 the subprogram body, e.g. another procedure for a procedure declared at
3321 library level. */
3326 /* Enter a new binding level and show that all the parameters belong to
3327 this function. */
3335 }
3337 /* Finish translating the current subprogram and set its BODY. */
3339 void
3341 {
3344 /* Attach the BLOCK for this level to the function and pop the level. */
3349 /* Mark the RESULT_DECL as being in this subprogram. */
3352 /* The body should be a BIND_EXPR whose BLOCK is the top-level one. */
3354 {
3357 }
3362 }
3364 /* Wrap up compilation of SUBPROG_DECL, a subprogram body. */
3366 void
3368 {
3369 /* We cannot track the location of errors past this point. */
3372 /* If we're only annotating types, don't actually compile this function. */
3376 /* Dump functions before gimplification. */
3381 else
3382 /* Register this function with cgraph just far enough to get it
3383 added to our parent's nested function list. */
3385 }
3387 tree
3389 {
3392 }
3394 /* Return an integer type with the number of bits of precision given by
3395 PRECISION. UNSIGNEDP is nonzero if the type is unsigned; otherwise
3396 it is a signed type. */
3398 tree
3400 {
3401 tree t;
3410 else
3418 {
3421 }
3424 }
3426 /* Likewise for floating-point types. */
3428 static tree
3430 {
3431 tree t;
3443 {
3446 }
3449 }
3451 /* Return a data type that has machine mode MODE. UNSIGNEDP selects
3452 an unsigned type; otherwise a signed type is returned. */
3454 tree
3456 {
3466 scalar_float_mode float_mode;
3469 float_mode);
3471 scalar_int_mode int_mode;
3476 {
3481 }
3484 }
3486 /* Return the signed or unsigned version of TYPE_NODE, a scalar type, the
3487 signedness being specified by UNSIGNEDP. */
3489 tree
3491 {
3498 {
3501 }
3505 {
3508 }
3511 }
3513 /* Return 1 if the types T1 and T2 are compatible, i.e. if they can be
3514 transparently converted to each other. */
3516 int
3518 {
3521 /* This is the default criterion. */
3525 /* We only check structural equivalence here. */
3529 /* Vector types are also compatible if they have the same number of subparts
3530 and the same form of (scalar) element type. */
3537 /* Array types are also compatible if they are constrained and have the same
3538 domain(s), the same component type and the same scalar storage order. */
3554 }
3556 /* Return true if EXPR is a useless type conversion. */
3558 bool
3560 {
3568 }
3570 /* Return true if T, a FUNCTION_TYPE, has the specified list of flags. */
3572 bool
3575 {
3580 }
3581 \f
3582 /* EXP is an expression for the size of an object. If this size contains
3583 discriminant references, replace them with the maximum (if MAX_P) or
3584 minimum (if !MAX_P) possible value of the discriminant. */
3586 tree
3588 {
3594 {
3605 {
3619 }
3623 /* If this contains a PLACEHOLDER_EXPR, it is the thing we want to
3624 modify. Otherwise, we treat it like a variable. */
3626 {
3629 return
3632 }
3652 {
3657 /* Special-case wanting the maximum value of a MIN_EXPR.
3658 In that case, if one side overflows, return the other. */
3660 {
3666 }
3668 /* Likewise, handle a MINUS_EXPR or PLUS_EXPR with the LHS
3669 overflowing and the RHS a variable. */
3676 /* If we are going to subtract a "negative" value in an unsigned type,
3677 do the operation as an addition of the negated value, in order to
3678 avoid creating a spurious overflow below. */
3684 {
3687 }
3692 /* We need to detect overflows so we call size_binop here. */
3694 }
3698 {
3725 {
3732 return
3735 }
3740 }
3742 /* Other tree classes cannot happen. */
3745 }
3748 }
3749 \f
3750 /* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE.
3751 EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs.
3752 Return a constructor for the template. */
3754 tree
3756 {
3759 tree field;
3771 /* First make the list for a CONSTRUCTOR for the template. Go down the
3772 field list of the template instead of the type chain because this
3773 array might be an Ada array of arrays and we can't tell where the
3774 nested arrays stop being the underlying object. */
3777 (bound_list
3781 {
3784 /* If we have a bound list, get the bounds from there. Likewise
3785 for an ARRAY_TYPE. Otherwise, if expr is a PARM_DECL with
3786 DECL_BY_COMPONENT_PTR_P, use the bounds of the field in the template.
3787 This will give us a maximum range. */
3795 else
3801 /* If either MIN or MAX involve a PLACEHOLDER_EXPR, we must
3802 substitute it from OBJECT. */
3808 }
3811 }
3812 \f
3813 /* Return true if TYPE is suitable for the element type of a vector. */
3815 static bool
3817 {
3818 machine_mode mode;
3832 }
3834 /* Return a vector type given the SIZE and the INNER_TYPE, or NULL_TREE if
3835 this is not possible. If ATTRIBUTE is non-zero, we are processing the
3836 attribute declaration and want to issue error messages on failure. */
3838 static tree
3840 {
3844 /* Silently punt on variable sizes. We can't make vector types for them,
3845 need to ignore them on front-end generated subtypes of unconstrained
3846 base types, and this attribute is for binding implementors, not end
3847 users, so we should never get there from legitimate explicit uses. */
3853 {
3858 }
3862 {
3866 }
3869 {
3873 }
3877 {
3881 }
3884 }
3886 /* Return a vector type whose representative array type is ARRAY_TYPE, or
3887 NULL_TREE if this is not possible. If ATTRIBUTE is non-zero, we are
3888 processing the attribute and want to issue error messages on failure. */
3890 static tree
3892 {
3895 attribute);
3901 }
3902 \f
3903 /* Build a type to be used to represent an aliased object whose nominal type
3904 is an unconstrained array. This consists of a RECORD_TYPE containing a
3905 field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an ARRAY_TYPE.
3906 If ARRAY_TYPE is that of an unconstrained array, this is used to represent
3907 an arbitrary unconstrained object. Use NAME as the name of the record.
3908 DEBUG_INFO_P is true if we need to write debug information for the type. */
3910 tree
3913 {
3914 tree decl;
3916 tree template_field
3919 tree array_field
3928 /* Declare it now since it will never be declared otherwise. This is
3929 necessary to ensure that its subtrees are properly marked. */
3932 /* template_type will not be used elsewhere than here, so to keep the debug
3933 info clean and in order to avoid scoping issues, make decl its
3934 context. */
3938 }
3940 /* Same, taking a thin or fat pointer type instead of a template type. */
3942 tree
3945 {
3946 tree template_type;
3950 template_type
3955 return
3957 }
3958 \f
3959 /* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE.
3960 In the normal case this is just two adjustments, but we have more to
3961 do if NEW_TYPE is an UNCONSTRAINED_ARRAY_TYPE. */
3963 void
3965 {
3968 tree t;
3970 /* If this is the main variant, process all the other variants first. */
3975 /* If no pointers and no references, we are done. */
3979 /* Merge the old type qualifiers in the new type.
3981 Each old variant has qualifiers for specific reasons, and the new
3982 designated type as well. Each set of qualifiers represents useful
3983 information grabbed at some point, and merging the two simply unifies
3984 these inputs into the final type description.
3986 Consider for instance a volatile type frozen after an access to constant
3987 type designating it; after the designated type's freeze, we get here with
3988 a volatile NEW_TYPE and a dummy OLD_TYPE with a readonly variant, created
3989 when the access type was processed. We will make a volatile and readonly
3990 designated type, because that's what it really is.
3992 We might also get here for a non-dummy OLD_TYPE variant with different
3993 qualifiers than those of NEW_TYPE, for instance in some cases of pointers
3994 to private record type elaboration (see the comments around the call to
3995 this routine in gnat_to_gnu_entity <E_Access_Type>). We have to merge
3996 the qualifiers in those cases too, to avoid accidentally discarding the
3997 initial set, and will often end up with OLD_TYPE == NEW_TYPE then. */
3998 new_type
4002 /* If old type and new type are identical, there is nothing to do. */
4006 /* Otherwise, first handle the simple case. */
4008 {
4011 /* If pointer or reference already points to new type, nothing to do.
4012 This can happen as update_pointer_to can be invoked multiple times
4013 on the same couple of types because of the type variants. */
4018 /* Chain PTR and its variants at the end. */
4021 {
4025 }
4026 else
4029 /* Now adjust them. */
4032 {
4036 }
4038 /* Chain REF and its variants at the end. */
4041 {
4045 }
4046 else
4049 /* Now adjust them. */
4056 }
4058 /* Now deal with the unconstrained array case. In this case the pointer
4059 is actually a record where both fields are pointers to dummy nodes.
4060 Turn them into pointers to the correct types using update_pointer_to.
4061 Likewise for the pointer to the object record (thin pointer). */
4062 else
4063 {
4068 /* If PTR already points to NEW_TYPE, nothing to do. This can happen
4069 since update_pointer_to can be invoked multiple times on the same
4070 couple of types because of the type variants. */
4074 update_pointer_to
4078 update_pointer_to
4087 }
4088 }
4089 \f
4090 /* Convert EXPR, a pointer to a constrained array, into a pointer to an
4091 unconstrained one. This involves making or finding a template. */
4093 static tree
4095 {
4099 tree template_addr;
4103 /* If EXPR is null, make a fat pointer that contains a null pointer to the
4104 array (compare_fat_pointers ensures that this is the full discriminant)
4105 and a valid pointer to the bounds. This latter property is necessary
4106 since the compiler can hoist the load of the bounds done through it. */
4108 {
4114 else
4115 {
4116 /* The template type can still be dummy at this point so we build an
4117 empty constructor. The middle-end will fill it in with zeros. */
4122 }
4128 /* Do not set TREE_CONSTANT so as to force T to static memory. */
4133 }
4135 /* If EXPR is a thin pointer, make template and data from the record. */
4137 {
4142 /* If we have a TYPE_UNCONSTRAINED_ARRAY attached to the RECORD_TYPE,
4143 the thin pointer value has been shifted so we shift it back to get
4144 the template address. */
4146 {
4147 template_addr
4150 byte_position
4152 template_addr
4154 template_addr);
4155 }
4157 /* Otherwise we explicitly take the address of the fields. */
4158 else
4159 {
4161 template_addr
4167 }
4168 }
4170 /* Otherwise, build the constructor for the template. */
4171 else
4172 template_addr
4175 expr));
4177 /* The final result is a constructor for the fat pointer.
4179 If EXPR is an argument of a foreign convention subprogram, the type it
4180 points to is directly the component type. In this case, the expression
4181 type may not match the corresponding FIELD_DECL type at this point, so we
4182 call "convert" here to fix that up if necessary. This type consistency is
4183 required, for instance because it ensures that possible later folding of
4184 COMPONENT_REFs against this constructor always yields something of the
4185 same type as the initial reference.
4187 Note that the call to "build_template" above is still fine because it
4188 will only refer to the provided TEMPLATE_TYPE in this case. */
4192 }
4193 \f
4194 /* Create an expression whose value is that of EXPR,
4195 converted to type TYPE. The TREE_TYPE of the value
4196 is always TYPE. This function implements all reasonable
4197 conversions; callers should filter out those that are
4198 not permitted by the language being compiled. */
4200 tree
4202 {
4207 /* If the expression is already of the right type, we are done. */
4211 /* If both input and output have padding and are of variable size, do this
4212 as an unchecked conversion. Likewise if one is a mere variant of the
4213 other, so we avoid a pointless unpad/repad sequence. */
4221 ;
4223 /* If the output type has padding, convert to the inner type and make a
4224 constructor to build the record, unless a variable size is involved. */
4226 {
4227 /* If we previously converted from another type and our type is
4228 of variable size, remove the conversion to avoid the need for
4229 variable-sized temporaries. Likewise for a conversion between
4230 original and packable version. */
4238 /* If we are just removing the padding from expr, convert the original
4239 object if we have variable size in order to avoid the need for some
4240 variable-sized temporaries. Likewise if the padding is a variant
4241 of the other, so we avoid a pointless unpad/repad sequence. */
4252 /* If the inner type is of self-referential size and the expression type
4253 is a record, do this as an unchecked conversion unless both types are
4254 essentially the same. But first pad the expression if possible to
4255 have the same size on both sides. */
4260 {
4264 expr);
4266 }
4268 /* If we are converting between array types with variable size, do the
4269 final conversion as an unchecked conversion, again to avoid the need
4270 for some variable-sized temporaries. If valid, this conversion is
4271 very likely purely technical and without real effects. */
4278 expr),
4283 /* If converting to the inner type has already created a CONSTRUCTOR with
4284 the right size, then reuse it instead of creating another one. This
4285 can happen for the padding type built to overalign local variables. */
4297 }
4299 /* If the input type has padding, remove it and convert to the output type.
4300 The conditions ordering is arranged to ensure that the output type is not
4301 a padding type here, as it is not clear whether the conversion would
4302 always be correct if this was to happen. */
4304 {
4305 tree unpadded;
4307 /* If we have just converted to this padded type, just get the
4308 inner expression. */
4312 /* Otherwise, build an explicit component reference. */
4313 else
4317 }
4319 /* If the input is a biased type, convert first to the base type and add
4320 the bias. Note that the bias must go through a full conversion to the
4321 base type, lest it is itself a biased value; this happens for subtypes
4322 of biased types. */
4329 /* If the input is a justified modular type, we need to extract the actual
4330 object before converting it to any other type with the exceptions of an
4331 unconstrained array or of a mere type variant. It is useful to avoid the
4332 extraction and conversion in the type variant case because it could end
4333 up replacing a VAR_DECL expr by a constructor and we might be about the
4334 take the address of the result. */
4338 return
4341 /* If converting to a type that contains a template, convert to the data
4342 type and then build the template. */
4344 {
4349 /* If the source already has a template, get a reference to the
4350 associated array only, as we are going to rebuild a template
4351 for the target type anyway. */
4361 }
4363 /* There are some cases of expressions that we process specially. */
4365 {
4370 /* Just set its type here. For TRANSFORM_EXPR, we will do the actual
4371 conversion in gnat_expand_expr. NULL_EXPR does not represent
4372 and actual value, so no conversion is needed. */
4378 /* If we are converting a STRING_CST to another constrained array type,
4379 just make a new one in the proper type. */
4383 {
4387 }
4391 /* If we are converting a VECTOR_CST to a mere type variant, just make
4392 a new one in the proper type. */
4394 {
4398 }
4402 /* If we are converting a CONSTRUCTOR to a mere type variant, or to
4403 another padding type around the same type, just make a new one in
4404 the proper type. */
4411 {
4416 }
4418 /* Likewise for a conversion between original and packable version, or
4419 conversion between types of the same size and with the same list of
4420 fields, but we have to work harder to preserve type consistency. */
4426 {
4435 /* Whether we need to clear TREE_CONSTANT et al. on the output
4436 constructor when we convert in place. */
4440 {
4441 /* Skip the missing fields in the CONSTRUCTOR. */
4443 {
4446 }
4447 /* The field must be the same. */
4450 constructor_elt elt
4454 /* If packing has made this field a bitfield and the input
4455 value couldn't be emitted statically any more, we need to
4456 clear TREE_CONSTANT on our output. */
4466 }
4468 /* If we have been able to match and convert all the input fields
4469 to their output type, convert in place now. We'll fallback to a
4470 view conversion downstream otherwise. */
4472 {
4479 }
4480 }
4482 /* Likewise for a conversion between array type and vector type with a
4483 compatible representative array. */
4487 etype))
4488 {
4493 tree value;
4495 /* Build a VECTOR_CST from a *constant* array constructor. */
4497 {
4500 /* Iterate through elements and check if all constructor
4501 elements are *_CSTs. */
4504 {
4507 }
4512 }
4514 /* Otherwise, build a regular vector constructor. */
4517 {
4520 }
4525 }
4529 /* First retrieve the underlying array. */
4536 {
4537 /* GCC 4.x is very sensitive to type consistency overall, and view
4538 conversions thus are very frequent. Even though just "convert"ing
4539 the inner operand to the output type is fine in most cases, it
4540 might expose unexpected input/output type mismatches in special
4541 circumstances so we avoid such recursive calls when we can. */
4544 /* If we are converting back to the original type, we can just
4545 lift the input conversion. This is a common occurrence with
4546 switches back-and-forth amongst type variants. */
4550 /* Otherwise, if we're converting between two aggregate or vector
4551 types, we might be allowed to substitute the VIEW_CONVERT_EXPR
4552 target type in place or to just convert the inner expression. */
4555 {
4556 /* If we are converting between mere variants, we can just
4557 substitute the VIEW_CONVERT_EXPR in place. */
4561 /* Otherwise, we may just bypass the input view conversion unless
4562 one of the types is a fat pointer, which is handled by
4563 specialized code below which relies on exact type matching. */
4567 }
4570 }
4574 }
4576 /* Check for converting to a pointer to an unconstrained array. */
4580 /* If we are converting between two aggregate or vector types that are mere
4581 variants, just make a VIEW_CONVERT_EXPR. Likewise when we are converting
4582 to a vector type from its representative array type. */
4589 etype)))
4592 /* If we are converting between tagged types, try to upcast properly. */
4595 {
4603 }
4605 /* If we are converting from a smaller form of record type back to it, just
4606 make a VIEW_CONVERT_EXPR. But first pad the expression to have the same
4607 size on both sides. */
4610 {
4613 expr);
4615 }
4617 /* In all other cases of related types, make a NOP_EXPR. */
4622 {
4632 /* If the output is a biased type, convert first to the base type and
4633 subtract the bias. Note that the bias itself must go through a full
4634 conversion to the base type, lest it is a biased value; this happens
4635 for subtypes of biased types. */
4643 /* ... fall through ... */
4647 /* If we are converting an additive expression to an integer type
4648 with lower precision, be wary of the optimization that can be
4649 applied by convert_to_integer. There are 2 problematic cases:
4650 - if the first operand was originally of a biased type,
4651 because we could be recursively called to convert it
4652 to an intermediate type and thus rematerialize the
4653 additive operator endlessly,
4654 - if the expression contains a placeholder, because an
4655 intermediate conversion that changes the sign could
4656 be inserted and thus introduce an artificial overflow
4657 at compile time when the placeholder is substituted. */
4662 {
4669 }
4675 /* If converting between two thin pointers, adjust if needed to account
4676 for differing offsets from the base pointer, depending on whether
4677 there is a TYPE_UNCONSTRAINED_ARRAY attached to the record type. */
4679 {
4680 tree etype_pos
4684 tree type_pos
4696 }
4698 /* If converting fat pointer to normal or thin pointer, get the pointer
4699 to the array and then convert it. */
4710 {
4716 expr));
4718 }
4720 /* ... fall through ... */
4723 /* In these cases, assume the front-end has validated the conversion.
4724 If the conversion is valid, it will be a bit-wise conversion, so
4725 it can be viewed as an unchecked conversion. */
4729 /* This is a either a conversion between a tagged type and some
4730 subtype, which we have to mark as a UNION_TYPE because of
4731 overlapping fields or a conversion of an Unchecked_Union. */
4735 /* If the input is a VECTOR_TYPE, convert to the representative
4736 array type first. */
4738 {
4742 }
4744 /* If EXPR is a constrained array, take its address, convert it to a
4745 fat pointer, and then dereference it. Likewise if EXPR is a
4746 record containing both a template and a constrained array.
4747 Note that a record representing a justified modular type
4748 always represents a packed constrained array. */
4753 return
4754 build_unary_op
4760 /* Do something very similar for converting one unconstrained
4761 array to another. */
4763 return
4768 else
4776 }
4777 }
4779 /* Create an expression whose value is that of EXPR converted to the common
4780 index type, which is sizetype. EXPR is supposed to be in the base type
4781 of the GNAT index type. Calling it is equivalent to doing
4783 convert (sizetype, expr)
4785 but we try to distribute the type conversion with the knowledge that EXPR
4786 cannot overflow in its type. This is a best-effort approach and we fall
4787 back to the above expression as soon as difficulties are encountered.
4789 This is necessary to overcome issues that arise when the GNAT base index
4790 type and the GCC common index type (sizetype) don't have the same size,
4791 which is quite frequent on 64-bit architectures. In this case, and if
4792 the GNAT base index type is signed but the iteration type of the loop has
4793 been forced to unsigned, the loop scalar evolution engine cannot compute
4794 a simple evolution for the general induction variables associated with the
4795 array indices, because it will preserve the wrap-around semantics in the
4796 unsigned type of their "inner" part. As a result, many loop optimizations
4797 are blocked.
4799 The solution is to use a special (basic) induction variable that is at
4800 least as large as sizetype, and to express the aforementioned general
4801 induction variables in terms of this induction variable, eliminating
4802 the problematic intermediate truncation to the GNAT base index type.
4803 This is possible as long as the original expression doesn't overflow
4804 and if the middle-end hasn't introduced artificial overflows in the
4805 course of the various simplification it can make to the expression. */
4807 tree
4809 {
4813 /* If the type is unsigned, overflow is allowed so we cannot be sure that
4814 EXPR doesn't overflow. Keep it simple if optimization is disabled. */
4819 {
4821 /* The main effect of the function: replace a loop parameter with its
4822 associated special induction variable. */
4827 CASE_CONVERT:
4828 {
4830 /* Bail out as soon as we suspect some sort of type frobbing. */
4834 }
4836 /* ... fall through ... */
4860 }
4863 }
4864 \f
4865 /* Remove all conversions that are done in EXP. This includes converting
4866 from a padded type or to a justified modular type. If TRUE_ADDRESS
4867 is true, always return the address of the containing object even if
4868 the address is not bit-aligned. */
4870 tree
4872 {
4874 {
4879 return
4888 CASE_CONVERT:
4895 }
4898 }
4899 \f
4900 /* If EXP's type is an UNCONSTRAINED_ARRAY_TYPE, return an expression that
4901 refers to the underlying array. If it has TYPE_CONTAINS_TEMPLATE_P,
4902 likewise return an expression pointing to the underlying array. */
4904 tree
4906 {
4911 {
4914 {
4922 {
4923 tree op1
4928 tree op2
4937 }
4938 else
4939 {
4946 }
4947 }
4956 /* If this is a padded type and it contains a template, convert to the
4957 unpadded type first. */
4961 {
4965 }
4968 {
4969 /* If the array initializer is a box, return NULL_TREE. */
4977 /* If the array type is padded, convert to the unpadded type. */
4980 }
4985 }
4988 }
4989 \f
4990 /* Return true if EXPR is an expression that can be folded as an operand
4991 of a VIEW_CONVERT_EXPR. See ada-tree.h for a complete rationale. */
4993 static bool
4995 {
4998 /* The folder will fold NOP_EXPRs between integral types with the same
4999 precision (in the middle-end's sense). We cannot allow it if the
5000 types don't have the same precision in the Ada sense as well. */
5007 /* Defer to the folder for non-integral conversions. */
5011 /* Only fold conversions that preserve both precisions. */
5017 }
5019 /* Return an expression that does an unchecked conversion of EXPR to TYPE.
5020 If NOTRUNC_P is true, truncation operations should be suppressed.
5022 Special care is required with (source or target) integral types whose
5023 precision is not equal to their size, to make sure we fetch or assign
5024 the value bits whose location might depend on the endianness, e.g.
5026 Rmsize : constant := 8;
5027 subtype Int is Integer range 0 .. 2 ** Rmsize - 1;
5029 type Bit_Array is array (1 .. Rmsize) of Boolean;
5030 pragma Pack (Bit_Array);
5032 function To_Bit_Array is new Unchecked_Conversion (Int, Bit_Array);
5034 Value : Int := 2#1000_0001#;
5035 Vbits : Bit_Array := To_Bit_Array (Value);
5037 we expect the 8 bits at Vbits'Address to always contain Value, while
5038 their original location depends on the endianness, at Value'Address
5039 on a little-endian architecture but not on a big-endian one.
5041 One pitfall is that we cannot use TYPE_UNSIGNED directly to decide how
5042 the bits between the precision and the size are filled, because of the
5043 trick used in the E_Signed_Integer_Subtype case of gnat_to_gnu_entity.
5044 So we use the special predicate type_unsigned_for_rm above. */
5046 tree
5048 {
5052 tree tem;
5055 /* If the expression is already of the right type, we are done. */
5059 /* If both types are integral just do a normal conversion.
5060 Likewise for a conversion to an unconstrained array. */
5068 {
5070 {
5075 }
5078 {
5084 }
5085 else
5087 }
5089 /* If we are converting to an integral type whose precision is not equal
5090 to its size, first unchecked convert to a record type that contains a
5091 field of the given precision. Then extract the result from the field.
5093 There is a subtlety if the source type is an aggregate type with reverse
5094 storage order because its representation is not contiguous in the native
5095 storage order, i.e. a direct unchecked conversion to an integral type
5096 with N bits of precision cannot read the first N bits of the aggregate
5097 type. To overcome it, we do an unchecked conversion to an integral type
5098 with reverse storage order and return the resulting value. This also
5099 ensures that the result of the unchecked conversion doesn't depend on
5100 the endianness of the target machine, but only on the storage order of
5101 the aggregate type.
5103 Finally, for the sake of consistency, we do the unchecked conversion
5104 to an integral type with reverse storage order as soon as the source
5105 type is an aggregate type with reverse storage order, even if there
5106 are no considerations of precision or size involved. */
5113 {
5124 else
5136 }
5138 /* Similarly if we are converting from an integral type whose precision is
5139 not equal to its size, first copy into a field of the given precision
5140 and unchecked convert the record type.
5142 The same considerations as above apply if the target type is an aggregate
5143 type with reverse storage order and we also proceed similarly. */
5150 {
5163 else
5176 }
5178 /* If we are converting from a scalar type to a type with a different size,
5179 we need to pad to have the same size on both sides.
5181 ??? We cannot do it unconditionally because unchecked conversions are
5182 used liberally by the front-end to implement polymorphism, e.g. in:
5184 S191s : constant ada__tags__addr_ptr := ada__tags__addr_ptr!(S190s);
5185 return p___size__4 (p__object!(S191s.all));
5187 so we skip all expressions that are references. */
5192 {
5194 {
5197 expr);
5199 }
5200 else
5201 {
5206 }
5207 }
5209 /* We have a special case when we are converting between two unconstrained
5210 array types. In that case, take the address, convert the fat pointer
5211 types, and dereference. */
5216 expr)));
5218 /* Another special case is when we are converting to a vector type from its
5219 representative array type; this a regular conversion. */
5223 etype))
5226 /* And, if the array type is not the representative, we try to build an
5227 intermediate vector type of which the array type is the representative
5228 and to do the unchecked conversion between the vector types, in order
5229 to enable further simplifications in the middle-end. */
5233 {
5236 }
5238 /* If we are converting a CONSTRUCTOR to a more aligned RECORD_TYPE, bump
5239 the alignment of the CONSTRUCTOR to speed up the copy operation. */
5243 {
5246 expr);
5248 }
5250 /* Otherwise, just build a VIEW_CONVERT_EXPR of the expression. */
5251 else
5252 {
5258 else
5260 }
5262 /* If the result is a non-biased integral type whose precision is not equal
5263 to its size, sign- or zero-extend the result. But we need not do this
5264 if the input is also an integral type and both are unsigned or both are
5265 signed and have the same precision. */
5278 {
5281 else
5282 {
5283 tree base_type
5286 tree shift_expr
5290 expr
5295 expr),
5296 shift_expr),
5297 shift_expr));
5298 }
5299 }
5301 /* An unchecked conversion should never raise Constraint_Error. The code
5302 below assumes that GCC's conversion routines overflow the same way that
5303 the underlying hardware does. This is probably true. In the rare case
5304 when it is false, we can rely on the fact that such conversions are
5305 erroneous anyway. */
5309 /* If the sizes of the types differ and this is an VIEW_CONVERT_EXPR,
5310 show no longer constant. */
5313 OEP_ONLY_CONST))
5317 }
5318 \f
5319 /* Return the appropriate GCC tree code for the specified GNAT_TYPE,
5320 the latter being a record type as predicated by Is_Record_Type. */
5322 enum tree_code
5324 {
5327 /* Return UNION_TYPE if it's an Unchecked_Union whose non-discriminant
5328 fields are all in the variant part. Otherwise, return RECORD_TYPE. */
5333 component_list
5343 }
5345 /* Return true if GNAT_TYPE is a "double" floating-point type, i.e. whose
5346 size is equal to 64 bits, or an array of such a type. Set ALIGN_CLAUSE
5347 according to the presence of an alignment clause on the type or, if it
5348 is an array, on the component type. */
5350 bool
5352 {
5358 {
5362 }
5371 }
5373 /* Return true if GNAT_TYPE is a "double" or larger scalar type, i.e. whose
5374 size is greater or equal to 64 bits, or an array of such a type. Set
5375 ALIGN_CLAUSE according to the presence of an alignment clause on the
5376 type or, if it is an array, on the component type. */
5378 bool
5380 {
5386 {
5390 }
5399 }
5401 /* Return true if GNU_TYPE is suitable as the type of a non-aliased
5402 component of an aggregate type. */
5404 bool
5406 {
5407 /* If the type is passed by reference, we may have pointers to the
5408 component so it cannot be made non-aliased. */
5412 /* We used to say that any component of aggregate type is aliased
5413 because the front-end may take 'Reference of it. The front-end
5414 has been enhanced in the meantime so as to use a renaming instead
5415 in most cases, but the back-end can probably take the address of
5416 such a component too so we go for the conservative stance.
5418 For instance, we might need the address of any array type, even
5419 if normally passed by copy, to construct a fat pointer if the
5420 component is used as an actual for an unconstrained formal.
5422 Likewise for record types: even if a specific record subtype is
5423 passed by copy, the parent type might be passed by ref (e.g. if
5424 it's of variable size) and we might take the address of a child
5425 component to pass to a parent formal. We have no way to check
5426 for such conditions here. */
5431 }
5433 /* Return true if TYPE is a smaller form of ORIG_TYPE. */
5435 bool
5437 {
5440 /* We're not interested in variants here. */
5444 /* Like a variant, a packable version keeps the original TYPE_NAME. */
5455 }
5457 /* Return whether EXPR, which is the renamed object in an object renaming
5458 declaration, can be materialized as a reference (with a REFERENCE_TYPE).
5459 This should be synchronized with Exp_Dbug.Debug_Renaming_Declaration. */
5461 bool
5463 {
5465 {
5469 {
5478 {
5482 const Uint bitpos
5490 }
5494 {
5502 }
5510 };
5511 }
5512 }
5514 /* Perform final processing on global declarations. */
5518 void
5520 {
5522 tree iter;
5524 /* If we have declared types as used at the global level, insert them in
5525 the global hash table. We use a dummy variable for this purpose, but
5526 we need to build it unconditionally to avoid -fcompare-debug issues. */
5528 {
5533 dummy_global
5535 void_type_node);
5544 {
5547 }
5548 }
5550 /* Output debug information for all global type declarations first. This
5551 ensures that global types whose compilation hasn't been finalized yet,
5552 for example pointers to Taft amendment types, have their compilation
5553 finalized in the right context. */
5558 /* Output imported functions. */
5567 /* Then output the global variables. We need to do that after the debug
5568 information for global types is emitted so that they are finalized. Skip
5569 external global variables, unless we need to emit debug info for them:
5570 this is useful for imported variables, for instance. */
5576 /* Output the imported modules/declarations. In GNAT, these are only
5577 materializing subprogram. */
5582 }
5584 /* ************************************************************************
5585 * * GCC builtins support *
5586 * ************************************************************************ */
5588 /* The general scheme is fairly simple:
5590 For each builtin function/type to be declared, gnat_install_builtins calls
5591 internal facilities which eventually get to gnat_pushdecl, which in turn
5592 tracks the so declared builtin function decls in the 'builtin_decls' global
5593 datastructure. When an Intrinsic subprogram declaration is processed, we
5594 search this global datastructure to retrieve the associated BUILT_IN DECL
5595 node. */
5597 /* Search the chain of currently available builtin declarations for a node
5598 corresponding to function NAME (an IDENTIFIER_NODE). Return the first node
5599 found, if any, or NULL_TREE otherwise. */
5600 tree
5602 {
5604 tree decl;
5611 }
5613 /* The code below eventually exposes gnat_install_builtins, which declares
5614 the builtin types and functions we might need, either internally or as
5615 user accessible facilities.
5617 ??? This is a first implementation shot, still in rough shape. It is
5618 heavily inspired from the "C" family implementation, with chunks copied
5619 verbatim from there.
5621 Two obvious improvement candidates are:
5622 o Use a more efficient name/decl mapping scheme
5623 o Devise a middle-end infrastructure to avoid having to copy
5624 pieces between front-ends. */
5626 /* ----------------------------------------------------------------------- *
5627 * BUILTIN ELEMENTARY TYPES *
5628 * ----------------------------------------------------------------------- */
5630 /* Standard data types to be used in builtin argument declarations. */
5632 enum c_tree_index
5633 {
5635 CTI_STRING_TYPE,
5636 CTI_CONST_STRING_TYPE,
5638 CTI_MAX
5639 };
5643 #define signed_size_type_node c_global_trees[CTI_SIGNED_SIZE_TYPE]
5644 #define string_type_node c_global_trees[CTI_STRING_TYPE]
5645 #define const_string_type_node c_global_trees[CTI_CONST_STRING_TYPE]
5647 /* ??? In addition some attribute handlers, we currently don't support a
5648 (small) number of builtin-types, which in turns inhibits support for a
5649 number of builtin functions. */
5650 #define wint_type_node void_type_node
5651 #define intmax_type_node void_type_node
5652 #define uintmax_type_node void_type_node
5654 /* Used to help initialize the builtin-types.def table. When a type of
5655 the correct size doesn't exist, use error_mark_node instead of NULL.
5656 The later results in segfaults even when a decl using the type doesn't
5657 get invoked. */
5659 static tree
5661 {
5664 }
5666 /* Build/push the elementary type decls that builtin functions/types
5667 will need. */
5669 static void
5671 {
5676 const_string_type_node
5679 }
5681 /* ----------------------------------------------------------------------- *
5682 * BUILTIN FUNCTION TYPES *
5683 * ----------------------------------------------------------------------- */
5685 /* Now, builtin function types per se. */
5687 enum c_builtin_type
5688 {
5689 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
5690 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
5691 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
5692 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
5693 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
5694 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
5695 #define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME,
5696 #define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5697 ARG6) NAME,
5698 #define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5699 ARG6, ARG7) NAME,
5700 #define DEF_FUNCTION_TYPE_8(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5701 ARG6, ARG7, ARG8) NAME,
5702 #define DEF_FUNCTION_TYPE_9(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5703 ARG6, ARG7, ARG8, ARG9) NAME,
5704 #define DEF_FUNCTION_TYPE_10(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5705 ARG6, ARG7, ARG8, ARG9, ARG10) NAME,
5706 #define DEF_FUNCTION_TYPE_11(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5707 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) NAME,
5708 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
5709 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
5710 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
5711 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
5712 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
5713 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5714 NAME,
5715 #define DEF_FUNCTION_TYPE_VAR_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5716 ARG6) NAME,
5717 #define DEF_FUNCTION_TYPE_VAR_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5718 ARG6, ARG7) NAME,
5719 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
5721 #undef DEF_PRIMITIVE_TYPE
5722 #undef DEF_FUNCTION_TYPE_0
5723 #undef DEF_FUNCTION_TYPE_1
5724 #undef DEF_FUNCTION_TYPE_2
5725 #undef DEF_FUNCTION_TYPE_3
5726 #undef DEF_FUNCTION_TYPE_4
5727 #undef DEF_FUNCTION_TYPE_5
5728 #undef DEF_FUNCTION_TYPE_6
5729 #undef DEF_FUNCTION_TYPE_7
5730 #undef DEF_FUNCTION_TYPE_8
5731 #undef DEF_FUNCTION_TYPE_9
5732 #undef DEF_FUNCTION_TYPE_10
5733 #undef DEF_FUNCTION_TYPE_11
5734 #undef DEF_FUNCTION_TYPE_VAR_0
5735 #undef DEF_FUNCTION_TYPE_VAR_1
5736 #undef DEF_FUNCTION_TYPE_VAR_2
5737 #undef DEF_FUNCTION_TYPE_VAR_3
5738 #undef DEF_FUNCTION_TYPE_VAR_4
5739 #undef DEF_FUNCTION_TYPE_VAR_5
5740 #undef DEF_FUNCTION_TYPE_VAR_6
5741 #undef DEF_FUNCTION_TYPE_VAR_7
5742 #undef DEF_POINTER_TYPE
5743 BT_LAST
5744 };
5748 /* A temporary array used in communication with def_fn_type. */
5751 /* A helper function for install_builtin_types. Build function type
5752 for DEF with return type RET and N arguments. If VAR is true, then the
5753 function should be variadic after those N arguments.
5755 Takes special care not to ICE if any of the types involved are
5756 error_mark_node, which indicates that said type is not in fact available
5757 (see builtin_type_for_size). In which case the function type as a whole
5758 should be error_mark_node. */
5760 static void
5762 {
5763 tree t;
5770 {
5776 }
5783 else
5786 egress:
5789 }
5791 /* Build the builtin function types and install them in the builtin_types
5792 array for later use in builtin function decls. */
5794 static void
5796 {
5797 tree va_list_ref_type_node;
5798 tree va_list_arg_type_node;
5801 {
5804 }
5805 else
5806 {
5809 }
5811 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
5812 builtin_types[ENUM] = VALUE;
5813 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \
5814 def_fn_type (ENUM, RETURN, 0, 0);
5815 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \
5816 def_fn_type (ENUM, RETURN, 0, 1, ARG1);
5817 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \
5818 def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2);
5819 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
5820 def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3);
5821 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
5822 def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4);
5823 #define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5824 def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
5825 #define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5826 ARG6) \
5827 def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
5828 #define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5829 ARG6, ARG7) \
5830 def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
5831 #define DEF_FUNCTION_TYPE_8(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5832 ARG6, ARG7, ARG8) \
5833 def_fn_type (ENUM, RETURN, 0, 8, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5834 ARG7, ARG8);
5835 #define DEF_FUNCTION_TYPE_9(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5836 ARG6, ARG7, ARG8, ARG9) \
5837 def_fn_type (ENUM, RETURN, 0, 9, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5838 ARG7, ARG8, ARG9);
5839 #define DEF_FUNCTION_TYPE_10(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5,\
5840 ARG6, ARG7, ARG8, ARG9, ARG10) \
5841 def_fn_type (ENUM, RETURN, 0, 10, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5842 ARG7, ARG8, ARG9, ARG10);
5843 #define DEF_FUNCTION_TYPE_11(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5,\
5844 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) \
5845 def_fn_type (ENUM, RETURN, 0, 11, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5846 ARG7, ARG8, ARG9, ARG10, ARG11);
5847 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \
5848 def_fn_type (ENUM, RETURN, 1, 0);
5849 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \
5850 def_fn_type (ENUM, RETURN, 1, 1, ARG1);
5851 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \
5852 def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2);
5853 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
5854 def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3);
5855 #define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
5856 def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
5857 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5858 def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
5859 #define DEF_FUNCTION_TYPE_VAR_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5860 ARG6) \
5861 def_fn_type (ENUM, RETURN, 1, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
5862 #define DEF_FUNCTION_TYPE_VAR_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5863 ARG6, ARG7) \
5864 def_fn_type (ENUM, RETURN, 1, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
5865 #define DEF_POINTER_TYPE(ENUM, TYPE) \
5866 builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
5870 #undef DEF_PRIMITIVE_TYPE
5871 #undef DEF_FUNCTION_TYPE_0
5872 #undef DEF_FUNCTION_TYPE_1
5873 #undef DEF_FUNCTION_TYPE_2
5874 #undef DEF_FUNCTION_TYPE_3
5875 #undef DEF_FUNCTION_TYPE_4
5876 #undef DEF_FUNCTION_TYPE_5
5877 #undef DEF_FUNCTION_TYPE_6
5878 #undef DEF_FUNCTION_TYPE_7
5879 #undef DEF_FUNCTION_TYPE_8
5880 #undef DEF_FUNCTION_TYPE_9
5881 #undef DEF_FUNCTION_TYPE_10
5882 #undef DEF_FUNCTION_TYPE_11
5883 #undef DEF_FUNCTION_TYPE_VAR_0
5884 #undef DEF_FUNCTION_TYPE_VAR_1
5885 #undef DEF_FUNCTION_TYPE_VAR_2
5886 #undef DEF_FUNCTION_TYPE_VAR_3
5887 #undef DEF_FUNCTION_TYPE_VAR_4
5888 #undef DEF_FUNCTION_TYPE_VAR_5
5889 #undef DEF_FUNCTION_TYPE_VAR_6
5890 #undef DEF_FUNCTION_TYPE_VAR_7
5891 #undef DEF_POINTER_TYPE
5893 }
5895 /* ----------------------------------------------------------------------- *
5896 * BUILTIN ATTRIBUTES *
5897 * ----------------------------------------------------------------------- */
5899 enum built_in_attribute
5900 {
5901 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
5902 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
5903 #define DEF_ATTR_STRING(ENUM, VALUE) ENUM,
5904 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
5905 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
5907 #undef DEF_ATTR_NULL_TREE
5908 #undef DEF_ATTR_INT
5909 #undef DEF_ATTR_STRING
5910 #undef DEF_ATTR_IDENT
5911 #undef DEF_ATTR_TREE_LIST
5912 ATTR_LAST
5913 };
5917 static void
5919 {
5920 /* Fill in the built_in_attributes array. */
5921 #define DEF_ATTR_NULL_TREE(ENUM) \
5922 built_in_attributes[(int) ENUM] = NULL_TREE;
5923 #define DEF_ATTR_INT(ENUM, VALUE) \
5924 built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
5925 #define DEF_ATTR_STRING(ENUM, VALUE) \
5926 built_in_attributes[(int) ENUM] = build_string (strlen (VALUE), VALUE);
5927 #define DEF_ATTR_IDENT(ENUM, STRING) \
5928 built_in_attributes[(int) ENUM] = get_identifier (STRING);
5929 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
5930 built_in_attributes[(int) ENUM] \
5931 = tree_cons (built_in_attributes[(int) PURPOSE], \
5932 built_in_attributes[(int) VALUE], \
5933 built_in_attributes[(int) CHAIN]);
5935 #undef DEF_ATTR_NULL_TREE
5936 #undef DEF_ATTR_INT
5937 #undef DEF_ATTR_STRING
5938 #undef DEF_ATTR_IDENT
5939 #undef DEF_ATTR_TREE_LIST
5940 }
5942 /* Handle a "const" attribute; arguments as in
5943 struct attribute_spec.handler. */
5945 static tree
5949 {
5952 else
5956 }
5958 /* Handle a "nothrow" attribute; arguments as in
5959 struct attribute_spec.handler. */
5961 static tree
5965 {
5968 else
5972 }
5974 /* Handle a "pure" attribute; arguments as in
5975 struct attribute_spec.handler. */
5977 static tree
5980 {
5983 /* TODO: support types. */
5984 else
5985 {
5989 }
5992 }
5994 /* Handle a "no vops" attribute; arguments as in
5995 struct attribute_spec.handler. */
5997 static tree
6001 {
6005 }
6007 /* Helper for nonnull attribute handling; fetch the operand number
6008 from the attribute argument list. */
6010 static bool
6012 {
6013 /* Verify the arg number is a constant. */
6019 }
6021 /* Handle the "nonnull" attribute. */
6022 static tree
6026 {
6030 /* If no arguments are specified, all pointer arguments should be
6031 non-null. Verify a full prototype is given so that the arguments
6032 will have the correct types when we actually check them later.
6033 Avoid diagnosing type-generic built-ins since those have no
6034 prototype. */
6036 {
6040 {
6043 }
6045 }
6047 /* Argument list specified. Verify that each argument number references
6048 a pointer argument. */
6050 {
6054 {
6059 }
6062 {
6063 function_args_iterator iter;
6064 tree argument;
6068 {
6072 }
6076 {
6082 }
6085 {
6091 }
6092 }
6093 }
6096 }
6098 /* Handle a "sentinel" attribute. */
6100 static tree
6103 {
6105 {
6110 }
6111 else
6112 {
6114 {
6119 }
6120 }
6123 {
6127 {
6130 }
6131 else
6132 {
6134 {
6137 }
6138 }
6139 }
6142 }
6144 /* Handle a "noreturn" attribute; arguments as in
6145 struct attribute_spec.handler. */
6147 static tree
6150 {
6153 /* See FIXME comment in c_common_attribute_table. */
6159 = build_pointer_type
6162 else
6163 {
6167 }
6170 }
6172 /* Handle a "noinline" attribute; arguments as in
6173 struct attribute_spec.handler. */
6175 static tree
6179 {
6181 {
6183 {
6187 }
6188 else
6190 }
6191 else
6192 {
6195 }
6198 }
6200 /* Handle a "noclone" attribute; arguments as in
6201 struct attribute_spec.handler. */
6203 static tree
6207 {
6209 {
6212 }
6215 }
6217 /* Handle a "leaf" attribute; arguments as in
6218 struct attribute_spec.handler. */
6220 static tree
6223 {
6225 {
6228 }
6230 {
6233 }
6236 }
6238 /* Handle a "always_inline" attribute; arguments as in
6239 struct attribute_spec.handler. */
6241 static tree
6244 {
6246 {
6247 /* Set the attribute and mark it for disregarding inline limits. */
6249 }
6250 else
6251 {
6254 }
6257 }
6259 /* Handle a "malloc" attribute; arguments as in
6260 struct attribute_spec.handler. */
6262 static tree
6265 {
6269 else
6270 {
6274 }
6277 }
6279 /* Fake handler for attributes we don't properly support. */
6281 tree
6287 {
6289 }
6291 /* Handle a "type_generic" attribute. */
6293 static tree
6297 {
6298 /* Ensure we have a function type. */
6301 /* Ensure we have a variadic function. */
6305 }
6307 /* Handle a "vector_size" attribute; arguments as in
6308 struct attribute_spec.handler. */
6310 static tree
6313 {
6315 tree vector_type;
6319 /* We need to provide for vector pointers, vector arrays, and
6320 functions returning vectors. For example:
6322 __attribute__((vector_size(16))) short *foo;
6324 In this case, the mode is SI, but the type being modified is
6325 HI, so we need to look further. */
6335 /* Build back pointers if needed. */
6339 }
6341 /* Handle a "vector_type" attribute; arguments as in
6342 struct attribute_spec.handler. */
6344 static tree
6347 {
6349 tree vector_type;
6354 {
6358 }
6368 }
6370 /* ----------------------------------------------------------------------- *
6371 * BUILTIN FUNCTIONS *
6372 * ----------------------------------------------------------------------- */
6374 /* Worker for DEF_BUILTIN. Possibly define a builtin function with one or two
6375 names. Does not declare a non-__builtin_ function if flag_no_builtin, or
6376 if nonansi_p and flag_no_nonansi_builtin. */
6378 static void
6386 {
6387 tree decl;
6390 /* Preserve an already installed decl. It most likely was setup in advance
6391 (e.g. as part of the internal builtins) for specific reasons. */
6402 fnattrs);
6404 /* ??? This is normally further controlled by command-line options
6405 like -fno-builtin, but we don't have them for Ada. */
6410 }
6416 /* Install what the common builtins.def offers. */
6418 static void
6420 {
6421 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
6422 NONANSI_P, ATTRS, IMPLICIT, COND) \
6423 if (NAME && COND) \
6424 def_builtin_1 (ENUM, NAME, CLASS, \
6425 builtin_types[(int) TYPE], \
6426 builtin_types[(int) LIBTYPE], \
6427 BOTH_P, FALLBACK_P, NONANSI_P, \
6428 built_in_attributes[(int) ATTRS], IMPLICIT);
6430 }
6432 /* ----------------------------------------------------------------------- *
6433 * BUILTIN FUNCTIONS *
6434 * ----------------------------------------------------------------------- */
6436 /* Install the builtin functions we might need. */
6438 void
6440 {
6445 /* Install builtins used by generic middle-end pieces first. Some of these
6446 know about internal specificities and control attributes accordingly, for
6447 instance __builtin_alloca vs no-throw and -fstack-check. We will ignore
6448 the generic definition from builtins.def. */
6451 /* Now, install the target specific builtins, such as the AltiVec family on
6452 ppc, and the common set as exposed by builtins.def. */
6455 }