| blob | 1f1e4d3b81481d0536a280cb824810c08f4d2522 |
1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * U T I L S *
6 * *
7 * C Implementation File *
8 * *
9 * Copyright (C) 1992-2016, 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. */
227 tree type;
228 };
231 {
235 };
248 /* Linked list used as a queue to defer the initialization of the DECL_CONTEXT
249 of ..._DECL nodes and of the TYPE_CONTEXT of ..._TYPE nodes. */
250 struct deferred_decl_context_node
251 {
252 /* The ..._DECL node to work on. */
253 tree decl;
255 /* The corresponding entity's Scope. */
256 Entity_Id gnat_scope;
258 /* The value of force_global when DECL was pushed. */
261 /* The list of ..._TYPE nodes to propagate the context to. */
264 /* The next queue item. */
266 };
270 /* Defer the initialization of DECL's DECL_CONTEXT attribute, scheduling to
271 feed it with the elaboration of GNAT_SCOPE. */
275 /* Defer the initialization of TYPE's TYPE_CONTEXT attribute, scheduling to
276 feed it with the DECL_CONTEXT computed as part of N as soon as it is
277 computed. */
279 tree type);
280 \f
281 /* Initialize data structures of the utils.c module. */
283 void
285 {
286 /* Initialize the association of GNAT nodes to GCC trees. */
289 /* Initialize the association of GNAT nodes to GCC trees as dummies. */
292 /* Initialize the hash table of padded types. */
294 }
296 /* Destroy data structures of the utils.c module. */
298 void
300 {
301 /* Destroy the association of GNAT nodes to GCC trees. */
305 /* Destroy the association of GNAT nodes to GCC trees as dummies. */
309 /* Destroy the hash table of padded types. */
312 }
313 \f
314 /* GNAT_ENTITY is a GNAT tree node for an entity. Associate GNU_DECL, a GCC
315 tree node, with GNAT_ENTITY. If GNU_DECL is not a ..._DECL node, abort.
316 If NO_CHECK is true, the latter check is suppressed.
318 If GNU_DECL is zero, reset a previous association. */
320 void
322 {
323 /* Check that GNAT_ENTITY is not already defined and that it is being set
324 to something which is a decl. If that is not the case, this usually
325 means GNAT_ENTITY is defined twice, but occasionally is due to some
326 Gigi problem. */
332 }
334 /* GNAT_ENTITY is a GNAT tree node for an entity. Return the GCC tree node
335 that was associated with it. If there is no such tree node, abort.
337 In some cases, such as delayed elaboration or expressions that need to
338 be elaborated only once, GNAT_ENTITY is really not an entity. */
340 tree
342 {
345 }
347 /* Return nonzero if a GCC tree has been associated with GNAT_ENTITY. */
349 bool
351 {
353 }
354 \f
355 /* Make a dummy type corresponding to GNAT_TYPE. */
357 tree
359 {
361 tree gnu_type;
363 /* If there was no equivalent type (can only happen when just annotating
364 types) or underlying type, go back to the original type. */
368 /* If it there already a dummy type, use that one. Else make one. */
372 /* If this is a record, make a RECORD_TYPE or UNION_TYPE; else make
373 an ENUMERAL_TYPE. */
387 }
389 /* Return the dummy type that was made for GNAT_TYPE, if any. */
391 tree
393 {
395 }
397 /* Build dummy fat and thin pointer types whose designated type is specified
398 by GNAT_DESIG_TYPE/GNU_DESIG_TYPE and attach them to the latter. */
400 void
402 {
417 /* Build a stub DECL to trigger the special processing for fat pointer types
418 in gnat_pushdecl. */
421 gnu_fat_type);
429 /* Suppress debug info until after the type is completed. */
439 }
440 \f
441 /* Return true if we are in the global binding level. */
443 bool
445 {
447 }
449 /* Enter a new binding level. */
451 void
453 {
456 /* Reuse a struct for this binding level, if there is one. */
458 {
461 }
462 else
465 /* Use a free BLOCK, if any; otherwise, allocate one. */
467 {
471 }
472 else
475 /* Point the BLOCK we just made to its parent. */
483 /* Add this level to the front of the chain (stack) of active levels. */
487 }
489 /* Set SUPERCONTEXT of the BLOCK for the current binding level to FNDECL
490 and point FNDECL to this BLOCK. */
492 void
494 {
498 }
500 /* Set the jmpbuf_decl for the current binding level to DECL. */
502 void
504 {
506 }
508 /* Get the jmpbuf_decl, if any, for the current binding level. */
510 tree
512 {
514 }
516 /* Exit a binding level. Set any BLOCK into the current code group. */
518 void
520 {
527 /* If this is a function-level BLOCK don't do anything. Otherwise, if there
528 are no variables free the block and merge its subblocks into those of its
529 parent block. Otherwise, add it to the list of its parent. */
531 ;
533 {
539 }
540 else
541 {
546 }
548 /* Free this binding structure. */
552 }
554 /* Exit a binding level and discard the associated BLOCK. */
556 void
558 {
565 /* Free this binding structure. */
569 }
570 \f
571 /* Set the context of TYPE and its parallel types (if any) to CONTEXT. */
573 static void
575 {
581 {
584 /* Give a context to the parallel types and their stub decl, if any.
585 Some parallel types seems to be present in multiple parallel type
586 chains, so don't mess with their context if they already have one. */
588 {
592 }
595 }
596 }
598 /* Return the innermost scope, starting at GNAT_NODE, we are be interested in
599 the debug info, or Empty if there is no such scope. If not NULL, set
600 IS_SUBPROGRAM to whether the returned entity is a subprogram. */
602 Entity_Id
604 {
605 Entity_Id gnat_entity;
613 else
617 {
619 {
625 /* If the scope is a subprogram, then just rely on
626 current_function_decl, so that we don't have to defer
627 anything. This is needed because other places rely on the
628 validity of the DECL_CONTEXT attribute of FUNCTION_DECL nodes. */
638 /* By default, we are not interested in this particular scope: go to
639 the outer one. */
641 }
644 }
647 }
649 /* If N is NULL, set TYPE's context to CONTEXT. Defer this to the processing
650 of N otherwise. */
652 static void
655 {
658 else
660 }
662 /* Return global_context, but create it first if need be. */
664 static tree
666 {
668 {
671 }
674 }
676 /* Record DECL as belonging to the current lexical scope and use GNAT_NODE
677 for location information and flag propagation. */
679 void
681 {
685 /* If explicitely asked to make DECL global or if it's an imported nested
686 object, short-circuit the regular Scope-based context computation. */
688 {
689 /* Rely on the GNAT scope, or fallback to the current_function_decl if
690 the GNAT scope reached the global scope, if it reached a subprogram
691 or the declaration is a subprogram or a variable (for them we skip
692 intermediate context types because the subprogram body elaboration
693 machinery and the inliner both expect a subprogram context).
695 Falling back to current_function_decl is necessary for implicit
696 subprograms created by gigi, such as the elaboration subprograms. */
698 const Entity_Id gnat_scope
702 && !context_is_subprogram
705 /* Always assume the scope has not been elaborated, thus defer the
706 context propagation to the time its elaboration will be
707 available. */
708 deferred_decl_context
711 /* External declarations (when force_global > 0) may not be in a
712 local context. */
715 }
717 /* If either we are forced to be in global mode or if both the GNAT scope and
718 the current_function_decl did not help in determining the context, use the
719 global scope. */
723 /* Functions imported in another function are not really nested.
724 For really nested functions mark them initially as needing
725 a static chain for uses of that flag before unnesting;
726 lower_nested_functions will then recompute it. */
729 && context
739 /* Set the location of DECL and emit a declaration for it. */
745 /* Put the declaration on the list. The list of declarations is in reverse
746 order. The list will be reversed later. Put global declarations in the
747 globals list and local ones in the current block. But skip TYPE_DECLs
748 for UNCONSTRAINED_ARRAY_TYPE in both cases, as they will cause trouble
749 with the debugger and aren't needed anyway. */
752 {
754 {
757 }
760 else
761 {
764 }
765 }
767 /* For the declaration of a type, set its name either if it isn't already
768 set or if the previous type name was not derived from a source name.
769 We'd rather have the type named with a real name and all the pointer
770 types to the same object have the same node, except when the names are
771 both derived from source names. */
773 {
776 /* Array and pointer types aren't tagged types in the C sense so we need
777 to generate a typedef in DWARF for them and make sure it is preserved,
778 unless the type is artificial. */
782 ;
783 /* For array and pointer types, create the DECL_ORIGINAL_TYPE that will
784 generate the typedef in DWARF. Also do that for fat pointer types
785 because, even though they are tagged types in the C sense, they are
786 still XUP types attached to the base array type at this point. */
791 {
792 tree tt;
793 /* ??? Copy and original type are not supposed to be variant but we
794 really need a variant for the placeholder machinery to work. */
797 else
798 {
799 /* TYPE_NEXT_PTR_TO is a chain of main variants. */
804 }
808 deferred_decl_context);
815 else
817 /* Array types need to have a name so that they can be related to
818 their GNAT encodings. */
822 }
826 ;
827 else
830 /* Propagate the name to all the variants, this is needed for the type
831 qualifiers machinery to work properly (see check_qualified_type).
832 Also propagate the context to them. Note that it will be propagated
833 to all parallel types too thanks to gnat_set_type_context. */
836 /* ??? Because of the previous kludge, we can have variants of fat
837 pointer types with different names. */
841 {
845 deferred_decl_context);
846 }
847 }
848 }
849 \f
850 /* Create a record type that contains a SIZE bytes long field of TYPE with a
851 starting bit position so that it is aligned to ALIGN bits, and leaving at
852 least ROOM bytes free before the field. BASE_ALIGN is the alignment the
853 record is guaranteed to get. GNAT_NODE is used for the position of the
854 associated TYPE_DECL. */
856 tree
859 {
860 /* We will be crafting a record type with one field at a position set to be
861 the next multiple of ALIGN past record'address + room bytes. We use a
862 record placeholder to express record'address. */
866 tree record_addr_st
869 /* The diagram below summarizes the shape of what we manipulate:
871 <--------- pos ---------->
872 { +------------+-------------+-----------------+
873 record =>{ |############| ... | field (type) |
874 { +------------+-------------+-----------------+
875 |<-- room -->|<- voffset ->|<---- size ----->|
876 o o
877 | |
878 record_addr vblock_addr
880 Every length is in sizetype bytes there, except "pos" which has to be
881 set as a bit position in the GCC tree for the record. */
891 /* Compute VOFFSET and then POS. The next byte position multiple of some
892 alignment after some address is obtained by "and"ing the alignment minus
893 1 with the two's complement of the address. */
898 /* POS = (ROOM + VOFFSET) * BIT_PER_UNIT, in bitsizetype. */
902 bitsize_unit_node);
904 /* Craft the GCC record representation. We exceptionally do everything
905 manually here because 1) our generic circuitry is not quite ready to
906 handle the complex position/size expressions we are setting up, 2) we
907 have a strong simplifying factor at hand: we know the maximum possible
908 value of voffset, and 3) we have to set/reset at least the sizes in
909 accordance with this maximum value anyway, as we need them to convey
910 what should be "alloc"ated for this type.
912 Use -1 as the 'addressable' indication for the field to prevent the
913 creation of a bitfield. We don't need one, it would have damaging
914 consequences on the alignment computation, and create_field_decl would
915 make one without this special argument, for instance because of the
916 complex position expression. */
927 bitsize_unit_node),
936 /* Declare it now since it will never be declared otherwise. This is
937 necessary to ensure that its subtrees are properly marked. */
941 }
943 /* TYPE is a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE that is being used
944 as the field type of a packed record if IN_RECORD is true, or as the
945 component type of a packed array if IN_RECORD is false. See if we can
946 rewrite it either as a type that has non-BLKmode, which we can pack
947 tighter in the packed record case, or as a smaller type with at most
948 MAX_ALIGN alignment if the value is non-zero. If so, return the new
949 type; if not, return the original type. */
951 tree
953 {
959 /* No point in doing anything if the size is zero. */
965 /* Copy the name and flags from the old type to that of the new.
966 Note that we rely on the pointer equality created here for
967 TYPE_NAME to look through conversions in various places. */
975 /* If we are in a record and have a small size, set the alignment to
976 try for an integral mode. Otherwise set it to try for a smaller
977 type with BLKmode. */
979 {
983 }
984 else
985 {
986 /* Do not try to shrink the size if the RM size is not constant. */
991 /* Round the RM size up to a unit boundary to get the minimal size
992 for a BLKmode record. Give up if it's already the size and we
993 don't need to lower the alignment. */
1003 }
1007 /* Now copy the fields, keeping the position and size as we don't want
1008 to change the layout by propagating the packedness downwards. */
1011 {
1020 /* However, for the last field in a not already packed record type
1021 that is of an aggregate type, we need to use the RM size in the
1022 packable version of the record type, see finish_record_type. */
1030 else
1033 new_field
1046 }
1054 /* If this is a padding record, we never want to make the size smaller
1055 than what was specified. For QUAL_UNION_TYPE, also copy the size. */
1057 {
1061 }
1062 else
1063 {
1066 }
1073 /* Try harder to get a packable type if necessary, for example
1074 in case the record itself contains a BLKmode field. */
1079 /* If neither mode nor size nor alignment shrunk, return the old type. */
1084 }
1086 /* Given a type TYPE, return a new type whose size is appropriate for SIZE.
1087 If TYPE is the best type, return it. Otherwise, make a new type. We
1088 only support new integral and pointer types. FOR_BIASED is true if
1089 we are making a biased type. */
1091 tree
1093 {
1096 tree new_type;
1098 /* If size indicates an error, just return TYPE to avoid propagating
1099 the error. Likewise if it's too large to represent. */
1106 {
1113 /* Integer types with precision 0 are forbidden. */
1117 /* Only do something if the type isn't a packed array type and doesn't
1118 already have the proper size and the size isn't too large. */
1126 /* The type should be an unsigned type if the original type is unsigned
1127 or if the lower bound is constant and non-negative or if the type is
1128 biased, see E_Signed_Integer_Subtype case of gnat_to_gnu_entity. */
1134 else
1139 /* Copy the name to show that it's essentially the same type and
1140 not a subrange type. */
1147 /* Do something if this is a fat pointer, in which case we
1148 may need to return the thin pointer. */
1150 {
1154 return
1155 build_pointer_type_for_mode
1158 }
1162 /* Only do something if this is a thin pointer, in which case we
1163 may need to return the fat pointer. */
1165 return
1171 }
1174 }
1176 /* See if the data pointed to by the hash table slot is marked. */
1178 int
1180 {
1182 }
1184 /* Return true iff the padded types are equivalent. */
1186 bool
1188 {
1197 /* We consider that the padded types are equivalent if they pad the same type
1198 and have the same size, alignment, RM size and storage order. Taking the
1199 mode into account is redundant since it is determined by the others. */
1200 return
1206 }
1208 /* Look up the padded TYPE in the hash table and return its canonical version
1209 if it exists; otherwise, insert it into the hash table. */
1211 static tree
1213 {
1214 hashval_t hashcode;
1217 hashcode
1234 }
1236 /* Ensure that TYPE has SIZE and ALIGN. Make and return a new padded type
1237 if needed. We have already verified that SIZE and ALIGN are large enough.
1238 GNAT_ENTITY is used to name the resulting record and to issue a warning.
1239 IS_COMPONENT_TYPE is true if this is being done for the component type of
1240 an array. IS_USER_TYPE is true if the original type needs to be completed.
1241 DEFINITION is true if this type is being defined. SET_RM_SIZE is true if
1242 the RM size of the resulting type is to be set to SIZE too; in this case,
1243 the padded type is canonicalized before being returned. */
1245 tree
1249 {
1254 /* If TYPE is a padded type, see if it agrees with any size and alignment
1255 we were given. If so, return the original type. Otherwise, strip
1256 off the padding, since we will either be returning the inner type
1257 or repadding it. If no size or alignment is specified, use that of
1258 the original padded type. */
1260 {
1274 }
1276 /* If the size is either not being changed or is being made smaller (which
1277 is not done here and is only valid for bitfields anyway), show the size
1278 isn't changing. Likewise, clear the alignment if it isn't being
1279 changed. Then return if we aren't doing anything. */
1292 /* If requested, complete the original type and give it a name. */
1299 gnat_entity);
1301 /* We used to modify the record in place in some cases, but that could
1302 generate incorrect debugging information. So make a new record
1303 type and name. */
1307 /* ??? Padding types around packed array implementation types will be
1308 considered as root types in the array descriptor language hook (see
1309 gnat_get_array_descr_info). Give them the original packed array type
1310 name so that the one coming from sources appears in the debugging
1311 information. */
1324 bitsize_unit_node));
1326 /* If we are changing the alignment and the input type is a record with
1327 BLKmode and a small constant size, try to make a form that has an
1328 integral mode. This might allow the padding record to also have an
1329 integral mode, which will be much more efficient. There is no point
1330 in doing so if a size is specified unless it is also a small constant
1331 size and it is incorrect to do so if we cannot guarantee that the mode
1332 will be naturally aligned since the field must always be addressable.
1334 ??? This might not always be a win when done for a stand-alone object:
1335 since the nominal and the effective type of the object will now have
1336 different modes, a VIEW_CONVERT_EXPR will be required for converting
1337 between them and it might be hard to overcome afterwards, including
1338 at the RTL level when the stand-alone object is accessed as a whole. */
1346 && (!size
1349 {
1354 }
1356 /* Now create the field with the original size. */
1361 /* We will output additional debug info manually below. */
1367 /* Set the RM size if requested. */
1369 {
1370 tree canonical_pad_type;
1374 /* If the padded type is complete and has constant size, we canonicalize
1375 it by means of the hash table. This is consistent with the language
1376 semantics and ensures that gigi and the middle-end have a common view
1377 of these padded types. */
1380 {
1383 }
1384 }
1386 /* Unless debugging information isn't being written for the input type,
1387 write a record that shows what we are a subtype of and also make a
1388 variable that indicates our size, if still variable. */
1394 {
1398 /* A variable that holds the size is required even with no encoding since
1399 it will be referenced by debugging information attributes. At global
1400 level, we need a single variable across all translation units. */
1404 {
1405 /* Whether or not gnat_entity comes from source, this XVZ variable is
1406 is a compilation artifact. */
1407 size_unit
1413 }
1415 /* There is no need to show what we are a subtype of when outputting as
1416 few encodings as possible: regular debugging infomation makes this
1417 redundant. */
1419 {
1433 }
1434 }
1436 built:
1437 /* If a simple size was explicitly given, maybe issue a warning. */
1444 /* But don't do it if we are just annotating types and the type is tagged or
1445 concurrent, since these types aren't fully laid out in this mode. */
1447 {
1448 Entity_Id gnat_type
1449 = is_component_type
1454 }
1456 /* Take the original size as the maximum size of the input if there was an
1457 unconstrained record involved and round it up to the specified alignment,
1458 if one was specified, but only for aggregate types. */
1471 {
1474 /* For a packed array, post the message on the original array type. */
1485 /* Generate message only for entities that come from source, since
1486 if we have an entity created by expansion, the message will be
1487 generated for some other corresponding source entity. */
1489 {
1498 }
1499 }
1502 }
1504 /* Return a copy of the padded TYPE but with reverse storage order. */
1506 tree
1508 {
1512 {
1513 /* If the inner type is not scalar then the function does nothing. */
1517 }
1519 /* This is required for the canonicalization. */
1529 }
1530 \f
1531 /* Relate the alias sets of GNU_NEW_TYPE and GNU_OLD_TYPE according to OP.
1532 If this is a multi-dimensional array type, do this recursively.
1534 OP may be
1535 - ALIAS_SET_COPY: the new set is made a copy of the old one.
1536 - ALIAS_SET_SUPERSET: the new set is made a superset of the old one.
1537 - ALIAS_SET_SUBSET: the new set is made a subset of the old one. */
1539 void
1541 {
1542 /* Remove any padding from GNU_OLD_TYPE. It doesn't matter in the case
1543 of a one-dimensional array, since the padding has the same alias set
1544 as the field type, but if it's a multi-dimensional array, we need to
1545 see the inner types. */
1551 /* Unconstrained array types are deemed incomplete and would thus be given
1552 alias set 0. Retrieve the underlying array type. */
1554 gnu_old_type
1557 gnu_new_type
1566 {
1568 /* The alias set shouldn't be copied between array types with different
1569 aliasing settings because this can break the aliasing relationship
1570 between the array type and its element type. */
1582 {
1586 /* Do nothing if the alias sets conflict. This ensures that we
1587 never call record_alias_subset several times for the same pair
1588 or at all for alias set 0. */
1590 {
1593 else
1595 }
1596 }
1601 }
1604 }
1605 \f
1606 /* Record TYPE as a builtin type for Ada. NAME is the name of the type.
1607 ARTIFICIAL_P is true if the type was generated by the compiler. */
1609 void
1611 {
1620 }
1621 \f
1622 /* Finish constructing the character type CHAR_TYPE.
1624 In Ada character types are enumeration types and, as a consequence, are
1625 represented in the front-end by integral types holding the positions of
1626 the enumeration values as defined by the language, which means that the
1627 integral types are unsigned.
1629 Unfortunately the signedness of 'char' in C is implementation-defined
1630 and GCC even has the option -fsigned-char to toggle it at run time.
1631 Since GNAT's philosophy is to be compatible with C by default, to wit
1632 Interfaces.C.char is defined as a mere copy of Character, we may need
1633 to declare character types as signed types in GENERIC and generate the
1634 necessary adjustments to make them behave as unsigned types.
1636 The overall strategy is as follows: if 'char' is unsigned, do nothing;
1637 if 'char' is signed, translate character types of CHAR_TYPE_SIZE and
1638 character subtypes with RM_Size = Esize = CHAR_TYPE_SIZE into signed
1639 types. The idea is to ensure that the bit pattern contained in the
1640 Esize'd objects is not changed, even though the numerical value will
1641 be interpreted differently depending on the signedness.
1643 For character types, the bounds are implicit and, therefore, need to
1644 be adjusted. Morever, the debug info needs the unsigned version. */
1646 void
1648 {
1652 /* Make a copy of a generic unsigned version since we'll modify it. */
1653 tree unsigned_char_type
1655 ? unsigned_char_type_node
1665 }
1667 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
1668 finish constructing the record type as a fat pointer type. */
1670 void
1672 {
1673 /* Make sure we can put it into a register. */
1677 /* Show what it really is. */
1680 /* Do not emit debug info for it since the types of its fields may still be
1681 incomplete at this point. */
1684 /* Force type_contains_placeholder_p to return true on it. Although the
1685 PLACEHOLDER_EXPRs are referenced only indirectly, this isn't a pointer
1686 type but the representation of the unconstrained array. */
1688 }
1690 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
1691 finish constructing the record or union type. If REP_LEVEL is zero, this
1692 record has no representation clause and so will be entirely laid out here.
1693 If REP_LEVEL is one, this record has a representation clause and has been
1694 laid out already; only set the sizes and alignment. If REP_LEVEL is two,
1695 this record is derived from a parent record and thus inherits its layout;
1696 only make a pass on the fields to finalize them. DEBUG_INFO_P is true if
1697 additional debug info needs to be output for this type. */
1699 void
1702 {
1710 tree field;
1714 /* Always attach the TYPE_STUB_DECL for a record type. It is required to
1715 generate debug info and have a parallel type. */
1718 /* Globally initialize the record first. If this is a rep'ed record,
1719 that just means some initializations; otherwise, layout the record. */
1721 {
1731 /* For all-repped records with a size specified, lay the QUAL_UNION_TYPE
1732 out just like a UNION_TYPE, since the size will be fixed. */
1735 }
1736 else
1737 {
1738 /* Ensure there isn't a size already set. There can be in an error
1739 case where there is a rep clause but all fields have errors and
1740 no longer have a position. */
1743 /* Ensure we use the traditional GCC layout for bitfields when we need
1744 to pack the record type or have a representation clause. The other
1745 possible layout (Microsoft C compiler), if available, would prevent
1746 efficient packing in almost all cases. */
1747 #ifdef TARGET_MS_BITFIELD_LAYOUT
1752 ATTR_FLAG_TYPE_IN_PLACE);
1753 #endif
1756 }
1758 /* At this point, the position and size of each field is known. It was
1759 either set before entry by a rep clause, or by laying out the type above.
1761 We now run a pass over the fields (in reverse order for QUAL_UNION_TYPEs)
1762 to compute the Ada size; the GCC size and alignment (for rep'ed records
1763 that are not padding types); and the mode (for rep'ed records). We also
1764 clear the DECL_BIT_FIELD indication for the cases we know have not been
1765 handled yet, and adjust DECL_NONADDRESSABLE_P accordingly. */
1771 {
1775 tree this_ada_size;
1782 else
1785 /* Clear DECL_BIT_FIELD for the cases layout_decl does not handle. */
1788 {
1791 /* In the general case, type alignment is required. */
1793 {
1794 /* The enclosing record type must be sufficiently aligned.
1795 Otherwise, if no alignment was specified for it and it
1796 has been laid out already, bump its alignment to the
1797 desired one if this is compatible with its size and
1798 maximum alignment, if any. */
1800 {
1803 }
1809 {
1813 }
1814 }
1816 /* In the non-strict alignment case, only byte alignment is. */
1821 }
1823 /* If we still have DECL_BIT_FIELD set at this point, we know that the
1824 field is technically not addressable. Except that it can actually
1825 be addressed if it is BLKmode and happens to be properly aligned. */
1831 /* A type must be as aligned as its most aligned field that is not
1832 a bit-field. But this is already enforced by layout_type. */
1838 {
1845 ada_size
1853 /* Since we know here that all fields are sorted in order of
1854 increasing bit position, the size of the record is one
1855 higher than the ending bit of the last field processed
1856 unless we have a rep clause, since in that case we might
1857 have a field outside a QUAL_UNION_TYPE that has a higher ending
1858 position. So use a MAX in that case. Also, if this field is a
1859 QUAL_UNION_TYPE, we need to take into account the previous size in
1860 the case of empty variants. */
1861 ada_size
1864 size
1871 }
1872 }
1878 {
1879 /* If this is a padding record, we never want to make the size smaller
1880 than what was specified in it, if any. */
1884 /* Now set any of the values we've just computed that apply. */
1890 {
1891 tree size_unit = had_size_unit
1895 bitsize_unit_node));
1903 }
1904 }
1906 /* Reset the TYPE_MAX_ALIGN field since it's private to gigi. */
1911 }
1913 /* Append PARALLEL_TYPE on the chain of parallel types of TYPE. If
1914 PARRALEL_TYPE has no context and its computation is not deferred yet, also
1915 propagate TYPE's context to PARALLEL_TYPE's or defer its propagation to the
1916 moment TYPE will get a context. */
1918 void
1920 {
1928 /* If PARALLEL_TYPE already has a context, we are done. */
1932 /* Otherwise, try to get one from TYPE's context. If so, simply propagate
1933 it to PARALLEL_TYPE. */
1937 /* Otherwise TYPE has not context yet. We know it will have one thanks to
1938 gnat_pushdecl and then its context will be propagated to PARALLEL_TYPE,
1939 so we have nothing to do in this case. */
1940 }
1942 /* Return true if TYPE has a parallel type. */
1944 static bool
1946 {
1950 }
1952 /* Wrap up compilation of RECORD_TYPE, i.e. output additional debug info
1953 associated with it. It need not be invoked directly in most cases as
1954 finish_record_type takes care of doing so. */
1956 void
1958 {
1960 tree field;
1962 /* If this is a padded type, the bulk of the debug info has already been
1963 generated for the field's type. */
1967 /* If the type already has a parallel type (XVS type), then we're done. */
1972 {
1973 /* We need to make an XVE/XVU record if any field has variable size,
1974 whether or not the record does. For example, if we have a union,
1975 it may be that all fields, rounded up to the alignment, have the
1976 same size, in which case we'll use that size. But the debug
1977 output routines (except Dwarf2) won't be able to output the fields,
1978 so we need to make the special record. */
1980 /* If a field has a non-constant qualifier, the record will have
1981 variable size too. */
1984 {
1987 }
1988 }
1990 /* If this record type is of variable size, make a parallel record type that
1991 will tell the debugger how the former is laid out (see exp_dbug.ads). */
1993 {
1994 tree new_record_type
2001 new_name
2015 /* Now scan all the fields, replacing each field with a new field
2016 corresponding to the new encoding. */
2019 {
2027 /* We're going to do some pattern matching below so remove as many
2028 conversions as possible. */
2031 /* See how the position was modified from the last position.
2033 There are two basic cases we support: a value was added
2034 to the last position or the last position was rounded to
2035 a boundary and they something was added. Check for the
2036 first case first. If not, see if there is any evidence
2037 of rounding. If so, round the last position and retry.
2039 If this is a union, the position can be taken as zero. */
2042 else
2048 {
2054 }
2059 && tree_fits_uhwi_p
2061 {
2063 unsigned HOST_WIDE_INT addend
2065 align
2071 }
2073 {
2077 }
2079 /* If we can't compute a position, set it to zero.
2081 ??? We really should abort here, but it's too much work
2082 to get this correct for all cases. */
2086 /* See if this type is variable-sized and make a pointer type
2087 and indicate the indirection if so. Beware that the debug
2088 back-end may adjust the position computed above according
2089 to the alignment of the field type, i.e. the pointer type
2090 in this case, if we don't preventively counter that. */
2092 {
2095 {
2098 }
2100 }
2102 /* Make a new field name, if necessary. */
2104 {
2110 else
2114 }
2116 new_field
2122 /* If old_field is a QUAL_UNION_TYPE, take its size as being
2123 zero. The only time it's not the last field of the record
2124 is when there are other components at fixed positions after
2125 it (meaning there was a rep clause for every field) and we
2126 want to be able to encode them. */
2130 ? bitsize_zero_node
2133 }
2138 }
2139 }
2141 /* Utility function of above to merge LAST_SIZE, the previous size of a record
2142 with FIRST_BIT and SIZE that describe a field. SPECIAL is true if this
2143 represents a QUAL_UNION_TYPE in which case we must look for COND_EXPRs and
2144 replace a value of zero with the old size. If HAS_REP is true, we take the
2145 MAX of the end position of this field with LAST_SIZE. In all other cases,
2146 we use FIRST_BIT plus SIZE. Return an expression for the size. */
2148 static tree
2151 {
2153 tree new_size;
2156 {
2160 }
2162 else
2173 /* We don't need any NON_VALUE_EXPRs and they can confuse us (especially
2174 when fed through substitute_in_expr) into thinking that a constant
2175 size is not constant. */
2180 }
2182 /* Utility function of above to see if OP0 and OP1, both of SIZETYPE, are
2183 related by the addition of a constant. Return that constant if so. */
2185 static tree
2187 {
2197 else
2199 }
2201 /* Utility function of above to split a tree OP which may be a sum, into a
2202 constant part, which is returned, and a variable part, which is stored
2203 in *PVAR. *PVAR may be bitsize_zero_node. All operations must be of
2204 bitsizetype. */
2206 static tree
2208 {
2209 /* Strip conversions in order to ease the tree traversal and maximize the
2210 potential for constant or plus/minus discovery. We need to be careful
2211 to always return and set *pvar to bitsizetype trees, but it's worth
2212 the effort. */
2218 {
2221 }
2223 {
2234 }
2235 else
2237 }
2238 \f
2239 /* Return a copy of TYPE but safe to modify in any way. */
2241 tree
2243 {
2246 /* Unshare the language-specific data. */
2248 {
2251 }
2253 /* And the contents of the language-specific slot if needed. */
2256 {
2261 }
2263 /* copy_node clears this field instead of copying it, because it is
2264 aliased with TREE_CHAIN. */
2274 }
2275 \f
2276 /* Return a subtype of sizetype with range MIN to MAX and whose
2277 TYPE_INDEX_TYPE is INDEX. GNAT_NODE is used for the position
2278 of the associated TYPE_DECL. */
2280 tree
2282 {
2283 /* First build a type for the desired range. */
2286 /* Then set the index type. */
2291 }
2293 /* Return a subtype of TYPE with range MIN to MAX. If TYPE is NULL,
2294 sizetype is used. */
2296 tree
2298 {
2299 tree range_type;
2304 /* First build a type with the base range. */
2308 /* Then set the actual range. */
2313 }
2314 \f
2315 /* Return a TYPE_DECL node suitable for the TYPE_STUB_DECL field of TYPE.
2316 NAME gives the name of the type to be used in the declaration. */
2318 tree
2320 {
2325 }
2327 /* Return a TYPE_DECL node for TYPE. NAME gives the name of the type to be
2328 used in the declaration. ARTIFICIAL_P is true if the declaration was
2329 generated by the compiler. DEBUG_INFO_P is true if we need to write
2330 debug information about this type. GNAT_NODE is used for the position
2331 of the decl. */
2333 tree
2335 Node_Id gnat_node)
2336 {
2338 bool is_named
2340 tree type_decl;
2342 /* Only the builtin TYPE_STUB_DECL should be used for dummy types. */
2345 /* If the type hasn't been named yet, we're naming it; preserve an existing
2346 TYPE_STUB_DECL that has been attached to it for some purpose. */
2348 {
2351 }
2352 else
2358 /* Add this decl to the current binding level. */
2361 /* If we're naming the type, equate the TYPE_STUB_DECL to the name. This
2362 causes the name to be also viewed as a "tag" by the debug back-end, with
2363 the advantage that no DW_TAG_typedef is emitted for artificial "tagged"
2364 types in DWARF.
2366 Note that if "type" is used as a DECL_ORIGINAL_TYPE, it may be referenced
2367 from multiple contexts, and "type_decl" references a copy of it: in such a
2368 case, do not mess TYPE_STUB_DECL: we do not want to re-use the TYPE_DECL
2369 with the mechanism above. */
2373 /* Do not generate debug info for UNCONSTRAINED_ARRAY_TYPE that the
2374 back-end doesn't support, and for others if we don't need to. */
2379 }
2380 \f
2381 /* Return a VAR_DECL or CONST_DECL node.
2383 NAME gives the name of the variable. ASM_NAME is its assembler name
2384 (if provided). TYPE is its data type (a GCC ..._TYPE node). INIT is
2385 the GCC tree for an optional initial expression; NULL_TREE if none.
2387 CONST_FLAG is true if this variable is constant, in which case we might
2388 return a CONST_DECL node unless CONST_DECL_ALLOWED_P is false.
2390 PUBLIC_FLAG is true if this is for a reference to a public entity or for a
2391 definition to be made visible outside of the current compilation unit, for
2392 instance variable definitions in a package specification.
2394 EXTERN_FLAG is true when processing an external variable declaration (as
2395 opposed to a definition: no storage is to be allocated for the variable).
2397 STATIC_FLAG is only relevant when not at top level and indicates whether
2398 to always allocate storage to the variable.
2400 VOLATILE_FLAG is true if this variable is declared as volatile.
2402 ARTIFICIAL_P is true if the variable was generated by the compiler.
2404 DEBUG_INFO_P is true if we need to write debug information for it.
2406 ATTR_LIST is the list of attributes to be attached to the variable.
2408 GNAT_NODE is used for the position of the decl. */
2410 tree
2416 {
2417 /* Whether the object has static storage duration, either explicitly or by
2418 virtue of being declared at the global level. */
2421 /* Whether the initializer is constant: for an external object or an object
2422 with static storage duration, we check that the initializer is a valid
2423 constant expression for initializing a static variable; otherwise, we
2424 only check that it is constant. */
2425 const bool init_const
2426 = (init
2430 != NULL_TREE
2433 /* Whether we will make TREE_CONSTANT the DECL we produce here, in which
2434 case the initializer may be used in lieu of the DECL node (as done in
2435 Identifier_to_gnu). This is useful to prevent the need of elaboration
2436 code when an identifier for which such a DECL is made is in turn used
2437 as an initializer. We used to rely on CONST_DECL vs VAR_DECL for this,
2438 but extra constraints apply to this choice (see below) and they are not
2439 relevant to the distinction we wish to make. */
2442 /* The actual DECL node. CONST_DECL was initially intended for enumerals
2443 and may be used for scalars in general but not for aggregates. */
2444 tree var_decl
2450 /* Detect constants created by the front-end to hold 'reference to function
2451 calls for stabilization purposes. This is needed for renaming. */
2453 {
2464 }
2466 /* If this is external, throw away any initializations (they will be done
2467 elsewhere) unless this is a constant for which we would like to remain
2468 able to get the initializer. If we are defining a global here, leave a
2469 constant initialization and save any variable elaborations for the
2470 elaboration routine. If we are just annotating types, throw away the
2471 initialization if it isn't a constant. */
2476 /* At the global level, a non-constant initializer generates elaboration
2477 statements. Check that such statements are allowed, that is to say,
2478 not violating a No_Elaboration_Code restriction. */
2482 /* Attach the initializer, if any. */
2485 /* Directly set some flags. */
2492 /* The object is public if it is external or if it is declared public
2493 and has static storage duration. */
2496 /* We need to allocate static storage for an object with static storage
2497 duration if it isn't external. */
2507 /* Ada doesn't feature Fortran-like COMMON variables so we shouldn't
2508 try to fiddle with DECL_COMMON. However, on platforms that don't
2509 support global BSS sections, uninitialized global variables would
2510 go in DATA instead, thus increasing the size of the executable. */
2517 /* Do not emit debug info for a CONST_DECL if optimization isn't enabled,
2518 since we will create an associated variable. Likewise for an external
2519 constant whose initializer is not absolute, because this would mean a
2520 global relocation in a read-only section which runs afoul of the PE-COFF
2521 run-time relocation mechanism. */
2524 || (extern_flag
2525 && constant_p
2526 && init
2531 /* ??? Some attributes cannot be applied to CONST_DECLs. */
2535 /* Add this decl to the current binding level. */
2539 {
2540 /* Let the target mangle the name if this isn't a verbatim asm. */
2545 }
2548 }
2549 \f
2550 /* Return true if TYPE, an aggregate type, contains (or is) an array. */
2552 static bool
2554 {
2556 {
2560 {
2561 tree field;
2567 }
2574 }
2575 }
2577 /* Return a FIELD_DECL node. NAME is the field's name, TYPE is its type and
2578 RECORD_TYPE is the type of the enclosing record. If SIZE is nonzero, it
2579 is the specified size of the field. If POS is nonzero, it is the bit
2580 position. PACKED is 1 if the enclosing record is packed, -1 if it has
2581 Component_Alignment of Storage_Unit. If ADDRESSABLE is nonzero, it
2582 means we are allowed to take the address of the field; if it is negative,
2583 we should not make a bitfield, which is used by make_aligning_type. */
2585 tree
2588 {
2594 /* If FIELD_TYPE is BLKmode, we must ensure this is aligned to at least a
2595 byte boundary since GCC cannot handle less-aligned BLKmode bitfields.
2596 Likewise for an aggregate without specified position that contains an
2597 array, because in this case slices of variable length of this array
2598 must be handled by GCC and variable-sized objects need to be aligned
2599 to at least a byte boundary. */
2601 || (!pos
2606 /* If a size is specified, use it. Otherwise, if the record type is packed
2607 compute a size to use, which may differ from the object's natural size.
2608 We always set a size in this case to trigger the checks for bitfield
2609 creation below, which is typically required when no position has been
2610 specified. */
2614 {
2618 }
2620 /* If we may, according to ADDRESSABLE, make a bitfield if a size is
2621 specified for two reasons: first if the size differs from the natural
2622 size. Second, if the alignment is insufficient. There are a number of
2623 ways the latter can be true.
2625 We never make a bitfield if the type of the field has a nonconstant size,
2626 because no such entity requiring bitfield operations should reach here.
2628 We do *preventively* make a bitfield when there might be the need for it
2629 but we don't have all the necessary information to decide, as is the case
2630 of a field with no specified position in a packed record.
2632 We also don't look at STRICT_ALIGNMENT here, and rely on later processing
2633 in layout_decl or finish_record_type to clear the bit_field indication if
2634 it is in fact not needed. */
2636 && size
2641 || packed
2644 {
2648 {
2652 else
2654 }
2655 }
2659 /* Bump the alignment if need be, either for bitfield/packing purposes or
2660 to satisfy the type requirements if no such consideration applies. When
2661 we get the alignment from the type, indicate if this is from an explicit
2662 user request, which prevents stor-layout from lowering it later on. */
2663 {
2664 unsigned int bit_align
2671 {
2674 }
2675 }
2678 {
2679 /* We need to pass in the alignment the DECL is known to have.
2680 This is the lowest-order bit set in POS, but no more than
2681 the alignment of the record, if one is specified. Note
2682 that an alignment of 0 is taken as infinite. */
2687 else
2701 }
2703 /* In addition to what our caller says, claim the field is addressable if we
2704 know that its type is not suitable.
2706 The field may also be "technically" nonaddressable, meaning that even if
2707 we attempt to take the field's address we will actually get the address
2708 of a copy. This is the case for true bitfields, but the DECL_BIT_FIELD
2709 value we have at this point is not accurate enough, so we don't account
2710 for this here and let finish_record_type decide. */
2717 }
2718 \f
2719 /* Return a PARM_DECL node with NAME and TYPE. */
2721 tree
2723 {
2726 /* Honor TARGET_PROMOTE_PROTOTYPES like the C compiler, as not doing so
2727 can lead to various ABI violations. */
2731 {
2732 /* We have to be careful about biased types here. Make a subtype
2733 of integer_type_node with the proper biasing. */
2736 {
2737 tree subtype
2744 }
2745 else
2747 }
2751 }
2752 \f
2753 /* Process the attributes in ATTR_LIST for NODE, which is either a DECL or
2754 a TYPE. If IN_PLACE is true, the tree pointed to by NODE should not be
2755 changed. GNAT_NODE is used for the position of error messages. */
2757 void
2759 Node_Id gnat_node)
2760 {
2765 {
2774 {
2777 }
2783 else
2790 {
2793 }
2794 else
2813 }
2816 }
2818 /* Return true if VALUE is a known to be a multiple of FACTOR, which must be
2819 a power of 2. */
2821 bool
2823 {
2832 }
2834 /* Return whether GNAT_NODE is a defining identifier for a renaming that comes
2835 from the parameter association for the instantiation of a generic. We do
2836 not want to emit source location for them: the code generated for their
2837 initialization is likely to disturb debugging. */
2839 bool
2841 {
2848 /* Get the object declaration of the renamed object, if any and if the
2849 renamed object is a mere identifier. */
2859 return
2863 }
2865 /* Defer the initialization of DECL's DECL_CONTEXT attribute, scheduling to
2866 feed it with the elaboration of GNAT_SCOPE. */
2870 {
2873 new_node
2882 }
2884 /* Defer the initialization of TYPE's TYPE_CONTEXT attribute, scheduling to
2885 feed it with the DECL_CONTEXT computed as part of N as soon as it is
2886 computed. */
2888 static void
2890 {
2892 }
2894 /* Get the GENERIC node corresponding to GNAT_SCOPE, if available. Return
2895 NULL_TREE if it is not available. */
2897 static tree
2899 {
2900 tree context;
2904 else
2908 {
2911 /* Skip dummy types: only the final ones can appear in the context
2912 chain. */
2916 /* ..._TYPE nodes are more useful than TYPE_DECL nodes in the context
2917 chain. */
2918 else
2920 }
2923 }
2925 /* Try to process all deferred nodes in the queue. Keep in the queue the ones
2926 that cannot be processed yet, remove the other ones. If FORCE is true,
2927 force the processing for all nodes, use the global context when nodes don't
2928 have a GNU translation. */
2930 void
2932 {
2937 {
2940 Entity_Id gnat_scope;
2944 /* If FORCE, get the innermost elaborated scope. Otherwise, just try to
2945 get the first scope. */
2948 {
2953 }
2955 /* Imported declarations must not be in a local context (i.e. not inside
2956 a function). */
2958 {
2962 {
2965 }
2966 }
2968 /* If FORCE, we want to get rid of all nodes in the queue: in case there
2969 was no elaborated scope, use the global context. */
2974 {
2975 tree t;
2980 /* Propagate it to the TYPE_CONTEXT attributes of the requested
2981 ..._TYPE nodes. */
2983 {
2985 }
2987 }
2989 /* If this node has been successfuly processed, remove it from the
2990 queue. Then move to the next node. */
2992 {
2996 }
2997 else
2999 }
3000 }
3003 /* Return VALUE scaled by the biggest power-of-2 factor of EXPR. */
3005 static unsigned int
3007 {
3011 /* Peel conversions around EXPR and try to extract bodies from function
3012 calls: it is possible to get the scale factor from size functions. */
3017 /* Sometimes we get PLUS_EXPR (BIT_AND_EXPR (..., X), Y), where Y is a
3018 multiple of the scale factor we are looking for. */
3022 {
3025 }
3027 /* An expression which is a bitwise AND with a mask has a power-of-2 factor
3028 corresponding to the number of trailing zeros of the mask. */
3031 {
3036 {
3039 i++;
3040 }
3041 }
3043 /* If the addend is not a multiple of the factor we found, give up. In
3044 theory we could find a smaller common factor but it's useless for our
3045 needs. This situation arises when dealing with a field F1 with no
3046 alignment requirement but that is following a field F2 with such
3047 requirements. As long as we have F2's offset, we don't need alignment
3048 information to compute F1's. */
3053 }
3055 /* Given two consecutive field decls PREV_FIELD and CURR_FIELD, return true
3056 unless we can prove these 2 fields are laid out in such a way that no gap
3057 exist between the end of PREV_FIELD and the beginning of CURR_FIELD. OFFSET
3058 is the distance in bits between the end of PREV_FIELD and the starting
3059 position of CURR_FIELD. It is ignored if null. */
3061 static bool
3063 {
3064 /* If this is the first field of the record, there cannot be any gap */
3068 /* If the previous field is a union type, then return false: The only
3069 time when such a field is not the last field of the record is when
3070 there are other components at fixed positions after it (meaning there
3071 was a rep clause for every field), in which case we don't want the
3072 alignment constraint to override them. */
3076 /* If the distance between the end of prev_field and the beginning of
3077 curr_field is constant, then there is a gap if the value of this
3078 constant is not null. */
3082 /* If the size and position of the previous field are constant,
3083 then check the sum of this size and position. There will be a gap
3084 iff it is not multiple of the current field alignment. */
3091 /* If both the position and size of the previous field are multiples
3092 of the current field alignment, there cannot be any gap. */
3097 /* Fallback, return that there may be a potential gap */
3099 }
3101 /* Return a LABEL_DECL with NAME. GNAT_NODE is used for the position of
3102 the decl. */
3104 tree
3106 {
3107 tree label_decl
3112 /* Add this decl to the current binding level. */
3116 }
3117 \f
3118 /* Return a FUNCTION_DECL node. NAME is the name of the subprogram, ASM_NAME
3119 its assembler name, TYPE its type (a FUNCTION_TYPE node), PARAM_DECL_LIST
3120 the list of its parameters (a list of PARM_DECL nodes chained through the
3121 DECL_CHAIN field).
3123 INLINE_STATUS describes the inline flags to be set on the FUNCTION_DECL.
3125 PUBLIC_FLAG is true if this is for a reference to a public entity or for a
3126 definition to be made visible outside of the current compilation unit.
3128 EXTERN_FLAG is true when processing an external subprogram declaration.
3130 ARTIFICIAL_P is true if the subprogram was generated by the compiler.
3132 DEBUG_INFO_P is true if we need to write debug information for it.
3134 ATTR_LIST is the list of attributes to be attached to the subprogram.
3136 GNAT_NODE is used for the position of the decl. */
3138 tree
3143 {
3155 {
3168 ATTR_FLAG_TYPE_IN_PLACE);
3170 /* ... fall through ... */
3179 }
3183 /* Once everything is processed, finish the subprogram declaration. */
3186 /* Add this decl to the current binding level. */
3189 /* Output the assembler code and/or RTL for the declaration. */
3193 }
3195 /* Given a subprogram declaration DECL, its assembler name and its type,
3196 finish constructing the subprogram declaration from ASM_NAME and TYPE. */
3198 void
3200 {
3201 tree result_decl
3214 {
3215 /* Let the target mangle the name if this isn't a verbatim asm. */
3221 /* The expand_main_function circuitry expects "main_identifier_node" to
3222 designate the DECL_NAME of the 'main' entry point, in turn expected
3223 to be declared as the "main" function literally by default. Ada
3224 program entry points are typically declared with a different name
3225 within the binder generated file, exported as 'main' to satisfy the
3226 system expectations. Force main_identifier_node in this case. */
3229 }
3230 }
3231 \f
3232 /* Set up the framework for generating code for SUBPROG_DECL, a subprogram
3233 body. This routine needs to be invoked before processing the declarations
3234 appearing in the subprogram. */
3236 void
3238 {
3239 tree param_decl;
3243 /* This function is being defined. */
3246 /* The failure of this assertion will likely come from a wrong context for
3247 the subprogram body, e.g. another procedure for a procedure declared at
3248 library level. */
3253 /* Enter a new binding level and show that all the parameters belong to
3254 this function. */
3262 }
3264 /* Finish translating the current subprogram and set its BODY. */
3266 void
3268 {
3271 /* Attach the BLOCK for this level to the function and pop the level. */
3276 /* Mark the RESULT_DECL as being in this subprogram. */
3279 /* The body should be a BIND_EXPR whose BLOCK is the top-level one. */
3281 {
3284 }
3289 }
3291 /* Wrap up compilation of SUBPROG_DECL, a subprogram body. */
3293 void
3295 {
3296 /* We cannot track the location of errors past this point. */
3299 /* If we're only annotating types, don't actually compile this function. */
3303 /* Dump functions before gimplification. */
3308 else
3309 /* Register this function with cgraph just far enough to get it
3310 added to our parent's nested function list. */
3312 }
3314 tree
3316 {
3319 }
3321 /* Return an integer type with the number of bits of precision given by
3322 PRECISION. UNSIGNEDP is nonzero if the type is unsigned; otherwise
3323 it is a signed type. */
3325 tree
3327 {
3328 tree t;
3337 else
3344 {
3347 }
3350 }
3352 /* Likewise for floating-point types. */
3354 static tree
3356 {
3357 tree t;
3369 {
3372 }
3375 }
3377 /* Return a data type that has machine mode MODE. UNSIGNEDP selects
3378 an unsigned type; otherwise a signed type is returned. */
3380 tree
3382 {
3399 {
3404 }
3407 }
3409 /* Return the signed or unsigned version of TYPE_NODE, a scalar type, the
3410 signedness being specified by UNSIGNEDP. */
3412 tree
3414 {
3421 {
3424 }
3428 {
3431 }
3434 }
3436 /* Return 1 if the types T1 and T2 are compatible, i.e. if they can be
3437 transparently converted to each other. */
3439 int
3441 {
3444 /* This is the default criterion. */
3448 /* We only check structural equivalence here. */
3452 /* Vector types are also compatible if they have the same number of subparts
3453 and the same form of (scalar) element type. */
3460 /* Array types are also compatible if they are constrained and have the same
3461 domain(s), the same component type and the same scalar storage order. */
3477 }
3479 /* Return true if EXPR is a useless type conversion. */
3481 bool
3483 {
3491 }
3493 /* Return true if T, a FUNCTION_TYPE, has the specified list of flags. */
3495 bool
3498 {
3503 }
3504 \f
3505 /* EXP is an expression for the size of an object. If this size contains
3506 discriminant references, replace them with the maximum (if MAX_P) or
3507 minimum (if !MAX_P) possible value of the discriminant. */
3509 tree
3511 {
3516 {
3523 {
3537 }
3541 /* If this contains a PLACEHOLDER_EXPR, it is the thing we want to
3542 modify. Otherwise, we treat it like a variable. */
3544 {
3548 }
3564 {
3569 /* Special-case wanting the maximum value of a MIN_EXPR.
3570 In that case, if one side overflows, return the other. */
3572 {
3578 }
3580 /* Likewise, handle a MINUS_EXPR or PLUS_EXPR with the LHS
3581 overflowing and the RHS a variable. */
3588 /* If we are going to subtract a "negative" value in an unsigned type,
3589 do the operation as an addition of the negated value, in order to
3590 avoid creating a spurious overflow below. */
3596 {
3599 }
3601 /* We need to detect overflows so we call size_binop here. */
3603 }
3607 {
3631 }
3633 /* Other tree classes cannot happen. */
3636 }
3639 }
3640 \f
3641 /* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE.
3642 EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs.
3643 Return a constructor for the template. */
3645 tree
3647 {
3650 tree field;
3662 /* First make the list for a CONSTRUCTOR for the template. Go down the
3663 field list of the template instead of the type chain because this
3664 array might be an Ada array of arrays and we can't tell where the
3665 nested arrays stop being the underlying object. */
3668 (bound_list
3672 {
3675 /* If we have a bound list, get the bounds from there. Likewise
3676 for an ARRAY_TYPE. Otherwise, if expr is a PARM_DECL with
3677 DECL_BY_COMPONENT_PTR_P, use the bounds of the field in the template.
3678 This will give us a maximum range. */
3686 else
3692 /* If either MIN or MAX involve a PLACEHOLDER_EXPR, we must
3693 substitute it from OBJECT. */
3699 }
3702 }
3703 \f
3704 /* Return true if TYPE is suitable for the element type of a vector. */
3706 static bool
3708 {
3709 machine_mode mode;
3723 }
3725 /* Return a vector type given the SIZE and the INNER_TYPE, or NULL_TREE if
3726 this is not possible. If ATTRIBUTE is non-zero, we are processing the
3727 attribute declaration and want to issue error messages on failure. */
3729 static tree
3731 {
3735 /* Silently punt on variable sizes. We can't make vector types for them,
3736 need to ignore them on front-end generated subtypes of unconstrained
3737 base types, and this attribute is for binding implementors, not end
3738 users, so we should never get there from legitimate explicit uses. */
3744 {
3749 }
3753 {
3757 }
3760 {
3764 }
3768 {
3772 }
3775 }
3777 /* Return a vector type whose representative array type is ARRAY_TYPE, or
3778 NULL_TREE if this is not possible. If ATTRIBUTE is non-zero, we are
3779 processing the attribute and want to issue error messages on failure. */
3781 static tree
3783 {
3786 attribute);
3792 }
3793 \f
3794 /* Build a type to be used to represent an aliased object whose nominal type
3795 is an unconstrained array. This consists of a RECORD_TYPE containing a
3796 field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an ARRAY_TYPE.
3797 If ARRAY_TYPE is that of an unconstrained array, this is used to represent
3798 an arbitrary unconstrained object. Use NAME as the name of the record.
3799 DEBUG_INFO_P is true if we need to write debug information for the type. */
3801 tree
3804 {
3805 tree decl;
3807 tree template_field
3810 tree array_field
3819 /* Declare it now since it will never be declared otherwise. This is
3820 necessary to ensure that its subtrees are properly marked. */
3823 /* template_type will not be used elsewhere than here, so to keep the debug
3824 info clean and in order to avoid scoping issues, make decl its
3825 context. */
3829 }
3831 /* Same, taking a thin or fat pointer type instead of a template type. */
3833 tree
3836 {
3837 tree template_type;
3841 template_type
3846 return
3848 }
3849 \f
3850 /* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE.
3851 In the normal case this is just two adjustments, but we have more to
3852 do if NEW_TYPE is an UNCONSTRAINED_ARRAY_TYPE. */
3854 void
3856 {
3859 tree t;
3861 /* If this is the main variant, process all the other variants first. */
3866 /* If no pointers and no references, we are done. */
3870 /* Merge the old type qualifiers in the new type.
3872 Each old variant has qualifiers for specific reasons, and the new
3873 designated type as well. Each set of qualifiers represents useful
3874 information grabbed at some point, and merging the two simply unifies
3875 these inputs into the final type description.
3877 Consider for instance a volatile type frozen after an access to constant
3878 type designating it; after the designated type's freeze, we get here with
3879 a volatile NEW_TYPE and a dummy OLD_TYPE with a readonly variant, created
3880 when the access type was processed. We will make a volatile and readonly
3881 designated type, because that's what it really is.
3883 We might also get here for a non-dummy OLD_TYPE variant with different
3884 qualifiers than those of NEW_TYPE, for instance in some cases of pointers
3885 to private record type elaboration (see the comments around the call to
3886 this routine in gnat_to_gnu_entity <E_Access_Type>). We have to merge
3887 the qualifiers in those cases too, to avoid accidentally discarding the
3888 initial set, and will often end up with OLD_TYPE == NEW_TYPE then. */
3889 new_type
3893 /* If old type and new type are identical, there is nothing to do. */
3897 /* Otherwise, first handle the simple case. */
3899 {
3902 /* If pointer or reference already points to new type, nothing to do.
3903 This can happen as update_pointer_to can be invoked multiple times
3904 on the same couple of types because of the type variants. */
3909 /* Chain PTR and its variants at the end. */
3912 {
3916 }
3917 else
3920 /* Now adjust them. */
3923 {
3927 }
3929 /* Chain REF and its variants at the end. */
3932 {
3936 }
3937 else
3940 /* Now adjust them. */
3947 }
3949 /* Now deal with the unconstrained array case. In this case the pointer
3950 is actually a record where both fields are pointers to dummy nodes.
3951 Turn them into pointers to the correct types using update_pointer_to.
3952 Likewise for the pointer to the object record (thin pointer). */
3953 else
3954 {
3959 /* If PTR already points to NEW_TYPE, nothing to do. This can happen
3960 since update_pointer_to can be invoked multiple times on the same
3961 couple of types because of the type variants. */
3965 update_pointer_to
3969 update_pointer_to
3978 }
3979 }
3980 \f
3981 /* Convert EXPR, a pointer to a constrained array, into a pointer to an
3982 unconstrained one. This involves making or finding a template. */
3984 static tree
3986 {
3990 tree template_addr;
3994 /* If EXPR is null, make a fat pointer that contains a null pointer to the
3995 array (compare_fat_pointers ensures that this is the full discriminant)
3996 and a valid pointer to the bounds. This latter property is necessary
3997 since the compiler can hoist the load of the bounds done through it. */
3999 {
4005 else
4006 {
4007 /* The template type can still be dummy at this point so we build an
4008 empty constructor. The middle-end will fill it in with zeros. */
4013 }
4019 /* Do not set TREE_CONSTANT so as to force T to static memory. */
4024 }
4026 /* If EXPR is a thin pointer, make template and data from the record. */
4028 {
4033 /* If we have a TYPE_UNCONSTRAINED_ARRAY attached to the RECORD_TYPE,
4034 the thin pointer value has been shifted so we shift it back to get
4035 the template address. */
4037 {
4038 template_addr
4041 byte_position
4043 template_addr
4045 template_addr);
4046 }
4048 /* Otherwise we explicitly take the address of the fields. */
4049 else
4050 {
4052 template_addr
4058 }
4059 }
4061 /* Otherwise, build the constructor for the template. */
4062 else
4063 template_addr
4066 expr));
4068 /* The final result is a constructor for the fat pointer.
4070 If EXPR is an argument of a foreign convention subprogram, the type it
4071 points to is directly the component type. In this case, the expression
4072 type may not match the corresponding FIELD_DECL type at this point, so we
4073 call "convert" here to fix that up if necessary. This type consistency is
4074 required, for instance because it ensures that possible later folding of
4075 COMPONENT_REFs against this constructor always yields something of the
4076 same type as the initial reference.
4078 Note that the call to "build_template" above is still fine because it
4079 will only refer to the provided TEMPLATE_TYPE in this case. */
4083 }
4084 \f
4085 /* Create an expression whose value is that of EXPR,
4086 converted to type TYPE. The TREE_TYPE of the value
4087 is always TYPE. This function implements all reasonable
4088 conversions; callers should filter out those that are
4089 not permitted by the language being compiled. */
4091 tree
4093 {
4098 /* If the expression is already of the right type, we are done. */
4102 /* If both input and output have padding and are of variable size, do this
4103 as an unchecked conversion. Likewise if one is a mere variant of the
4104 other, so we avoid a pointless unpad/repad sequence. */
4112 ;
4114 /* If the output type has padding, convert to the inner type and make a
4115 constructor to build the record, unless a variable size is involved. */
4117 {
4120 /* If we previously converted from another type and our type is
4121 of variable size, remove the conversion to avoid the need for
4122 variable-sized temporaries. Likewise for a conversion between
4123 original and packable version. */
4131 /* If we are just removing the padding from expr, convert the original
4132 object if we have variable size in order to avoid the need for some
4133 variable-sized temporaries. Likewise if the padding is a variant
4134 of the other, so we avoid a pointless unpad/repad sequence. */
4145 /* If the inner type is of self-referential size and the expression type
4146 is a record, do this as an unchecked conversion. But first pad the
4147 expression if possible to have the same size on both sides. */
4150 {
4154 expr);
4156 }
4158 /* If we are converting between array types with variable size, do the
4159 final conversion as an unchecked conversion, again to avoid the need
4160 for some variable-sized temporaries. If valid, this conversion is
4161 very likely purely technical and without real effects. */
4168 expr),
4175 }
4177 /* If the input type has padding, remove it and convert to the output type.
4178 The conditions ordering is arranged to ensure that the output type is not
4179 a padding type here, as it is not clear whether the conversion would
4180 always be correct if this was to happen. */
4182 {
4183 tree unpadded;
4185 /* If we have just converted to this padded type, just get the
4186 inner expression. */
4190 /* Otherwise, build an explicit component reference. */
4191 else
4195 }
4197 /* If the input is a biased type, adjust first. */
4204 /* If the input is a justified modular type, we need to extract the actual
4205 object before converting it to any other type with the exceptions of an
4206 unconstrained array or of a mere type variant. It is useful to avoid the
4207 extraction and conversion in the type variant case because it could end
4208 up replacing a VAR_DECL expr by a constructor and we might be about the
4209 take the address of the result. */
4213 return
4216 /* If converting to a type that contains a template, convert to the data
4217 type and then build the template. */
4219 {
4224 /* If the source already has a template, get a reference to the
4225 associated array only, as we are going to rebuild a template
4226 for the target type anyway. */
4236 }
4238 /* There are some cases of expressions that we process specially. */
4240 {
4245 /* Just set its type here. For TRANSFORM_EXPR, we will do the actual
4246 conversion in gnat_expand_expr. NULL_EXPR does not represent
4247 and actual value, so no conversion is needed. */
4253 /* If we are converting a STRING_CST to another constrained array type,
4254 just make a new one in the proper type. */
4258 {
4262 }
4266 /* If we are converting a VECTOR_CST to a mere type variant, just make
4267 a new one in the proper type. */
4269 {
4273 }
4276 /* If we are converting a CONSTRUCTOR to a mere type variant, or to
4277 another padding type around the same type, just make a new one in
4278 the proper type. */
4285 {
4290 }
4292 /* Likewise for a conversion between original and packable version, or
4293 conversion between types of the same size and with the same list of
4294 fields, but we have to work harder to preserve type consistency. */
4300 {
4309 /* Whether we need to clear TREE_CONSTANT et al. on the output
4310 constructor when we convert in place. */
4314 {
4315 /* Skip the missing fields in the CONSTRUCTOR. */
4317 {
4320 }
4321 /* The field must be the same. */
4324 constructor_elt elt
4328 /* If packing has made this field a bitfield and the input
4329 value couldn't be emitted statically any more, we need to
4330 clear TREE_CONSTANT on our output. */
4340 }
4342 /* If we have been able to match and convert all the input fields
4343 to their output type, convert in place now. We'll fallback to a
4344 view conversion downstream otherwise. */
4346 {
4353 }
4354 }
4356 /* Likewise for a conversion between array type and vector type with a
4357 compatible representative array. */
4361 etype))
4362 {
4367 tree value;
4369 /* Build a VECTOR_CST from a *constant* array constructor. */
4371 {
4374 /* Iterate through elements and check if all constructor
4375 elements are *_CSTs. */
4378 {
4381 }
4386 }
4388 /* Otherwise, build a regular vector constructor. */
4391 {
4394 }
4399 }
4403 /* First retrieve the underlying array. */
4410 {
4411 /* GCC 4.x is very sensitive to type consistency overall, and view
4412 conversions thus are very frequent. Even though just "convert"ing
4413 the inner operand to the output type is fine in most cases, it
4414 might expose unexpected input/output type mismatches in special
4415 circumstances so we avoid such recursive calls when we can. */
4418 /* If we are converting back to the original type, we can just
4419 lift the input conversion. This is a common occurrence with
4420 switches back-and-forth amongst type variants. */
4424 /* Otherwise, if we're converting between two aggregate or vector
4425 types, we might be allowed to substitute the VIEW_CONVERT_EXPR
4426 target type in place or to just convert the inner expression. */
4429 {
4430 /* If we are converting between mere variants, we can just
4431 substitute the VIEW_CONVERT_EXPR in place. */
4435 /* Otherwise, we may just bypass the input view conversion unless
4436 one of the types is a fat pointer, which is handled by
4437 specialized code below which relies on exact type matching. */
4441 }
4444 }
4448 }
4450 /* Check for converting to a pointer to an unconstrained array. */
4454 /* If we are converting between two aggregate or vector types that are mere
4455 variants, just make a VIEW_CONVERT_EXPR. Likewise when we are converting
4456 to a vector type from its representative array type. */
4463 etype)))
4466 /* If we are converting between tagged types, try to upcast properly. */
4469 {
4477 }
4479 /* If we are converting from a smaller form of record type back to it, just
4480 make a VIEW_CONVERT_EXPR. But first pad the expression to have the same
4481 size on both sides. */
4484 {
4487 expr);
4489 }
4491 /* In all other cases of related types, make a NOP_EXPR. */
4496 {
4512 /* ... fall through ... */
4516 /* If we are converting an additive expression to an integer type
4517 with lower precision, be wary of the optimization that can be
4518 applied by convert_to_integer. There are 2 problematic cases:
4519 - if the first operand was originally of a biased type,
4520 because we could be recursively called to convert it
4521 to an intermediate type and thus rematerialize the
4522 additive operator endlessly,
4523 - if the expression contains a placeholder, because an
4524 intermediate conversion that changes the sign could
4525 be inserted and thus introduce an artificial overflow
4526 at compile time when the placeholder is substituted. */
4531 {
4538 }
4544 /* If converting between two thin pointers, adjust if needed to account
4545 for differing offsets from the base pointer, depending on whether
4546 there is a TYPE_UNCONSTRAINED_ARRAY attached to the record type. */
4548 {
4549 tree etype_pos
4553 tree type_pos
4565 }
4567 /* If converting fat pointer to normal or thin pointer, get the pointer
4568 to the array and then convert it. */
4579 {
4585 expr));
4587 }
4589 /* ... fall through ... */
4592 /* In these cases, assume the front-end has validated the conversion.
4593 If the conversion is valid, it will be a bit-wise conversion, so
4594 it can be viewed as an unchecked conversion. */
4598 /* This is a either a conversion between a tagged type and some
4599 subtype, which we have to mark as a UNION_TYPE because of
4600 overlapping fields or a conversion of an Unchecked_Union. */
4604 /* If the input is a VECTOR_TYPE, convert to the representative
4605 array type first. */
4607 {
4611 }
4613 /* If EXPR is a constrained array, take its address, convert it to a
4614 fat pointer, and then dereference it. Likewise if EXPR is a
4615 record containing both a template and a constrained array.
4616 Note that a record representing a justified modular type
4617 always represents a packed constrained array. */
4622 return
4623 build_unary_op
4629 /* Do something very similar for converting one unconstrained
4630 array to another. */
4632 return
4637 else
4645 }
4646 }
4648 /* Create an expression whose value is that of EXPR converted to the common
4649 index type, which is sizetype. EXPR is supposed to be in the base type
4650 of the GNAT index type. Calling it is equivalent to doing
4652 convert (sizetype, expr)
4654 but we try to distribute the type conversion with the knowledge that EXPR
4655 cannot overflow in its type. This is a best-effort approach and we fall
4656 back to the above expression as soon as difficulties are encountered.
4658 This is necessary to overcome issues that arise when the GNAT base index
4659 type and the GCC common index type (sizetype) don't have the same size,
4660 which is quite frequent on 64-bit architectures. In this case, and if
4661 the GNAT base index type is signed but the iteration type of the loop has
4662 been forced to unsigned, the loop scalar evolution engine cannot compute
4663 a simple evolution for the general induction variables associated with the
4664 array indices, because it will preserve the wrap-around semantics in the
4665 unsigned type of their "inner" part. As a result, many loop optimizations
4666 are blocked.
4668 The solution is to use a special (basic) induction variable that is at
4669 least as large as sizetype, and to express the aforementioned general
4670 induction variables in terms of this induction variable, eliminating
4671 the problematic intermediate truncation to the GNAT base index type.
4672 This is possible as long as the original expression doesn't overflow
4673 and if the middle-end hasn't introduced artificial overflows in the
4674 course of the various simplification it can make to the expression. */
4676 tree
4678 {
4682 /* If the type is unsigned, overflow is allowed so we cannot be sure that
4683 EXPR doesn't overflow. Keep it simple if optimization is disabled. */
4688 {
4690 /* The main effect of the function: replace a loop parameter with its
4691 associated special induction variable. */
4696 CASE_CONVERT:
4697 {
4699 /* Bail out as soon as we suspect some sort of type frobbing. */
4703 }
4705 /* ... fall through ... */
4729 }
4732 }
4733 \f
4734 /* Remove all conversions that are done in EXP. This includes converting
4735 from a padded type or to a justified modular type. If TRUE_ADDRESS
4736 is true, always return the address of the containing object even if
4737 the address is not bit-aligned. */
4739 tree
4741 {
4743 {
4748 return
4757 CASE_CONVERT:
4764 }
4767 }
4768 \f
4769 /* If EXP's type is an UNCONSTRAINED_ARRAY_TYPE, return an expression that
4770 refers to the underlying array. If it has TYPE_CONTAINS_TEMPLATE_P,
4771 likewise return an expression pointing to the underlying array. */
4773 tree
4775 {
4780 {
4783 {
4791 {
4792 tree op1
4797 tree op2
4806 }
4807 else
4808 {
4815 }
4816 }
4825 /* If this is a padded type and it contains a template, convert to the
4826 unpadded type first. */
4830 {
4834 }
4837 {
4838 /* If the array initializer is a box, return NULL_TREE. */
4846 /* If the array type is padded, convert to the unpadded type. */
4849 }
4854 }
4857 }
4858 \f
4859 /* Return true if EXPR is an expression that can be folded as an operand
4860 of a VIEW_CONVERT_EXPR. See ada-tree.h for a complete rationale. */
4862 static bool
4864 {
4867 /* The folder will fold NOP_EXPRs between integral types with the same
4868 precision (in the middle-end's sense). We cannot allow it if the
4869 types don't have the same precision in the Ada sense as well. */
4876 /* Defer to the folder for non-integral conversions. */
4880 /* Only fold conversions that preserve both precisions. */
4886 }
4888 /* Return an expression that does an unchecked conversion of EXPR to TYPE.
4889 If NOTRUNC_P is true, truncation operations should be suppressed.
4891 Special care is required with (source or target) integral types whose
4892 precision is not equal to their size, to make sure we fetch or assign
4893 the value bits whose location might depend on the endianness, e.g.
4895 Rmsize : constant := 8;
4896 subtype Int is Integer range 0 .. 2 ** Rmsize - 1;
4898 type Bit_Array is array (1 .. Rmsize) of Boolean;
4899 pragma Pack (Bit_Array);
4901 function To_Bit_Array is new Unchecked_Conversion (Int, Bit_Array);
4903 Value : Int := 2#1000_0001#;
4904 Vbits : Bit_Array := To_Bit_Array (Value);
4906 we expect the 8 bits at Vbits'Address to always contain Value, while
4907 their original location depends on the endianness, at Value'Address
4908 on a little-endian architecture but not on a big-endian one. */
4910 tree
4912 {
4916 tree tem;
4919 /* If the expression is already of the right type, we are done. */
4923 /* If both types are integral just do a normal conversion.
4924 Likewise for a conversion to an unconstrained array. */
4932 {
4934 {
4939 }
4942 {
4948 }
4949 else
4951 }
4953 /* If we are converting to an integral type whose precision is not equal
4954 to its size, first unchecked convert to a record type that contains a
4955 field of the given precision. Then extract the result from the field.
4957 There is a subtlety if the source type is an aggregate type with reverse
4958 storage order because its representation is not contiguous in the native
4959 storage order, i.e. a direct unchecked conversion to an integral type
4960 with N bits of precision cannot read the first N bits of the aggregate
4961 type. To overcome it, we do an unchecked conversion to an integral type
4962 with reverse storage order and return the resulting value. This also
4963 ensures that the result of the unchecked conversion doesn't depend on
4964 the endianness of the target machine, but only on the storage order of
4965 the aggregate type.
4967 Finally, for the sake of consistency, we do the unchecked conversion
4968 to an integral type with reverse storage order as soon as the source
4969 type is an aggregate type with reverse storage order, even if there
4970 are no considerations of precision or size involved. */
4977 {
4988 else
5000 }
5002 /* Similarly if we are converting from an integral type whose precision is
5003 not equal to its size, first copy into a field of the given precision
5004 and unchecked convert the record type.
5006 The same considerations as above apply if the target type is an aggregate
5007 type with reverse storage order and we also proceed similarly. */
5014 {
5027 else
5040 }
5042 /* If we are converting from a scalar type to a type with a different size,
5043 we need to pad to have the same size on both sides.
5045 ??? We cannot do it unconditionally because unchecked conversions are
5046 used liberally by the front-end to implement polymorphism, e.g. in:
5048 S191s : constant ada__tags__addr_ptr := ada__tags__addr_ptr!(S190s);
5049 return p___size__4 (p__object!(S191s.all));
5051 so we skip all expressions that are references. */
5056 {
5058 {
5061 expr);
5063 }
5064 else
5065 {
5070 }
5071 }
5073 /* We have a special case when we are converting between two unconstrained
5074 array types. In that case, take the address, convert the fat pointer
5075 types, and dereference. */
5080 expr)));
5082 /* Another special case is when we are converting to a vector type from its
5083 representative array type; this a regular conversion. */
5087 etype))
5090 /* And, if the array type is not the representative, we try to build an
5091 intermediate vector type of which the array type is the representative
5092 and to do the unchecked conversion between the vector types, in order
5093 to enable further simplifications in the middle-end. */
5097 {
5100 }
5102 /* If we are converting a CONSTRUCTOR to a more aligned RECORD_TYPE, bump
5103 the alignment of the CONSTRUCTOR to speed up the copy operation. */
5107 {
5110 expr);
5112 }
5114 /* Otherwise, just build a VIEW_CONVERT_EXPR of the expression. */
5115 else
5116 {
5122 else
5124 }
5126 /* If the result is an integral type whose precision is not equal to its
5127 size, sign- or zero-extend the result. We need not do this if the input
5128 is an integral type of the same precision and signedness or if the output
5129 is a biased type or if both the input and output are unsigned, or if the
5130 lower bound is constant and non-negative, see E_Signed_Integer_Subtype
5131 case of gnat_to_gnu_entity. */
5147 {
5148 tree base_type
5151 tree shift_expr
5155 expr
5160 shift_expr),
5161 shift_expr));
5162 }
5164 /* An unchecked conversion should never raise Constraint_Error. The code
5165 below assumes that GCC's conversion routines overflow the same way that
5166 the underlying hardware does. This is probably true. In the rare case
5167 when it is false, we can rely on the fact that such conversions are
5168 erroneous anyway. */
5172 /* If the sizes of the types differ and this is an VIEW_CONVERT_EXPR,
5173 show no longer constant. */
5176 OEP_ONLY_CONST))
5180 }
5181 \f
5182 /* Return the appropriate GCC tree code for the specified GNAT_TYPE,
5183 the latter being a record type as predicated by Is_Record_Type. */
5185 enum tree_code
5187 {
5190 /* Return UNION_TYPE if it's an Unchecked_Union whose non-discriminant
5191 fields are all in the variant part. Otherwise, return RECORD_TYPE. */
5196 component_list
5206 }
5208 /* Return true if GNAT_TYPE is a "double" floating-point type, i.e. whose
5209 size is equal to 64 bits, or an array of such a type. Set ALIGN_CLAUSE
5210 according to the presence of an alignment clause on the type or, if it
5211 is an array, on the component type. */
5213 bool
5215 {
5221 {
5225 }
5234 }
5236 /* Return true if GNAT_TYPE is a "double" or larger scalar type, i.e. whose
5237 size is greater or equal to 64 bits, or an array of such a type. Set
5238 ALIGN_CLAUSE according to the presence of an alignment clause on the
5239 type or, if it is an array, on the component type. */
5241 bool
5243 {
5249 {
5253 }
5262 }
5264 /* Return true if GNU_TYPE is suitable as the type of a non-aliased
5265 component of an aggregate type. */
5267 bool
5269 {
5270 /* If the type is passed by reference, we may have pointers to the
5271 component so it cannot be made non-aliased. */
5275 /* We used to say that any component of aggregate type is aliased
5276 because the front-end may take 'Reference of it. The front-end
5277 has been enhanced in the meantime so as to use a renaming instead
5278 in most cases, but the back-end can probably take the address of
5279 such a component too so we go for the conservative stance.
5281 For instance, we might need the address of any array type, even
5282 if normally passed by copy, to construct a fat pointer if the
5283 component is used as an actual for an unconstrained formal.
5285 Likewise for record types: even if a specific record subtype is
5286 passed by copy, the parent type might be passed by ref (e.g. if
5287 it's of variable size) and we might take the address of a child
5288 component to pass to a parent formal. We have no way to check
5289 for such conditions here. */
5294 }
5296 /* Return true if TYPE is a smaller form of ORIG_TYPE. */
5298 bool
5300 {
5303 /* We're not interested in variants here. */
5307 /* Like a variant, a packable version keeps the original TYPE_NAME. */
5318 }
5320 /* Perform final processing on global declarations. */
5324 void
5326 {
5328 tree iter;
5330 /* If we have declared types as used at the global level, insert them in
5331 the global hash table. We use a dummy variable for this purpose, but
5332 we need to build it unconditionally to avoid -fcompare-debug issues. */
5334 {
5339 dummy_global
5341 void_type_node);
5350 {
5353 }
5354 }
5356 /* Output debug information for all global type declarations first. This
5357 ensures that global types whose compilation hasn't been finalized yet,
5358 for example pointers to Taft amendment types, have their compilation
5359 finalized in the right context. */
5364 /* Then output the global variables. We need to do that after the debug
5365 information for global types is emitted so that they are finalized. */
5370 /* Output the imported modules/declarations. In GNAT, these are only
5371 materializing subprogram. */
5376 }
5378 /* ************************************************************************
5379 * * GCC builtins support *
5380 * ************************************************************************ */
5382 /* The general scheme is fairly simple:
5384 For each builtin function/type to be declared, gnat_install_builtins calls
5385 internal facilities which eventually get to gnat_pushdecl, which in turn
5386 tracks the so declared builtin function decls in the 'builtin_decls' global
5387 datastructure. When an Intrinsic subprogram declaration is processed, we
5388 search this global datastructure to retrieve the associated BUILT_IN DECL
5389 node. */
5391 /* Search the chain of currently available builtin declarations for a node
5392 corresponding to function NAME (an IDENTIFIER_NODE). Return the first node
5393 found, if any, or NULL_TREE otherwise. */
5394 tree
5396 {
5398 tree decl;
5405 }
5407 /* The code below eventually exposes gnat_install_builtins, which declares
5408 the builtin types and functions we might need, either internally or as
5409 user accessible facilities.
5411 ??? This is a first implementation shot, still in rough shape. It is
5412 heavily inspired from the "C" family implementation, with chunks copied
5413 verbatim from there.
5415 Two obvious improvement candidates are:
5416 o Use a more efficient name/decl mapping scheme
5417 o Devise a middle-end infrastructure to avoid having to copy
5418 pieces between front-ends. */
5420 /* ----------------------------------------------------------------------- *
5421 * BUILTIN ELEMENTARY TYPES *
5422 * ----------------------------------------------------------------------- */
5424 /* Standard data types to be used in builtin argument declarations. */
5426 enum c_tree_index
5427 {
5429 CTI_STRING_TYPE,
5430 CTI_CONST_STRING_TYPE,
5432 CTI_MAX
5433 };
5437 #define signed_size_type_node c_global_trees[CTI_SIGNED_SIZE_TYPE]
5438 #define string_type_node c_global_trees[CTI_STRING_TYPE]
5439 #define const_string_type_node c_global_trees[CTI_CONST_STRING_TYPE]
5441 /* ??? In addition some attribute handlers, we currently don't support a
5442 (small) number of builtin-types, which in turns inhibits support for a
5443 number of builtin functions. */
5444 #define wint_type_node void_type_node
5445 #define intmax_type_node void_type_node
5446 #define uintmax_type_node void_type_node
5448 /* Build the void_list_node (void_type_node having been created). */
5450 static tree
5452 {
5455 }
5457 /* Used to help initialize the builtin-types.def table. When a type of
5458 the correct size doesn't exist, use error_mark_node instead of NULL.
5459 The later results in segfaults even when a decl using the type doesn't
5460 get invoked. */
5462 static tree
5464 {
5467 }
5469 /* Build/push the elementary type decls that builtin functions/types
5470 will need. */
5472 static void
5474 {
5480 const_string_type_node
5483 }
5485 /* ----------------------------------------------------------------------- *
5486 * BUILTIN FUNCTION TYPES *
5487 * ----------------------------------------------------------------------- */
5489 /* Now, builtin function types per se. */
5491 enum c_builtin_type
5492 {
5493 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
5494 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
5495 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
5496 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
5497 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
5498 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
5499 #define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME,
5500 #define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5501 ARG6) NAME,
5502 #define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5503 ARG6, ARG7) NAME,
5504 #define DEF_FUNCTION_TYPE_8(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5505 ARG6, ARG7, ARG8) NAME,
5506 #define DEF_FUNCTION_TYPE_9(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5507 ARG6, ARG7, ARG8, ARG9) NAME,
5508 #define DEF_FUNCTION_TYPE_10(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5509 ARG6, ARG7, ARG8, ARG9, ARG10) NAME,
5510 #define DEF_FUNCTION_TYPE_11(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5511 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) NAME,
5512 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
5513 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
5514 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
5515 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
5516 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
5517 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5518 NAME,
5519 #define DEF_FUNCTION_TYPE_VAR_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5520 ARG6) NAME,
5521 #define DEF_FUNCTION_TYPE_VAR_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5522 ARG6, ARG7) NAME,
5523 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
5525 #undef DEF_PRIMITIVE_TYPE
5526 #undef DEF_FUNCTION_TYPE_0
5527 #undef DEF_FUNCTION_TYPE_1
5528 #undef DEF_FUNCTION_TYPE_2
5529 #undef DEF_FUNCTION_TYPE_3
5530 #undef DEF_FUNCTION_TYPE_4
5531 #undef DEF_FUNCTION_TYPE_5
5532 #undef DEF_FUNCTION_TYPE_6
5533 #undef DEF_FUNCTION_TYPE_7
5534 #undef DEF_FUNCTION_TYPE_8
5535 #undef DEF_FUNCTION_TYPE_9
5536 #undef DEF_FUNCTION_TYPE_10
5537 #undef DEF_FUNCTION_TYPE_11
5538 #undef DEF_FUNCTION_TYPE_VAR_0
5539 #undef DEF_FUNCTION_TYPE_VAR_1
5540 #undef DEF_FUNCTION_TYPE_VAR_2
5541 #undef DEF_FUNCTION_TYPE_VAR_3
5542 #undef DEF_FUNCTION_TYPE_VAR_4
5543 #undef DEF_FUNCTION_TYPE_VAR_5
5544 #undef DEF_FUNCTION_TYPE_VAR_6
5545 #undef DEF_FUNCTION_TYPE_VAR_7
5546 #undef DEF_POINTER_TYPE
5547 BT_LAST
5548 };
5552 /* A temporary array used in communication with def_fn_type. */
5555 /* A helper function for install_builtin_types. Build function type
5556 for DEF with return type RET and N arguments. If VAR is true, then the
5557 function should be variadic after those N arguments.
5559 Takes special care not to ICE if any of the types involved are
5560 error_mark_node, which indicates that said type is not in fact available
5561 (see builtin_type_for_size). In which case the function type as a whole
5562 should be error_mark_node. */
5564 static void
5566 {
5567 tree t;
5574 {
5580 }
5587 else
5590 egress:
5593 }
5595 /* Build the builtin function types and install them in the builtin_types
5596 array for later use in builtin function decls. */
5598 static void
5600 {
5601 tree va_list_ref_type_node;
5602 tree va_list_arg_type_node;
5605 {
5608 }
5609 else
5610 {
5613 }
5615 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
5616 builtin_types[ENUM] = VALUE;
5617 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \
5618 def_fn_type (ENUM, RETURN, 0, 0);
5619 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \
5620 def_fn_type (ENUM, RETURN, 0, 1, ARG1);
5621 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \
5622 def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2);
5623 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
5624 def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3);
5625 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
5626 def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4);
5627 #define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5628 def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
5629 #define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5630 ARG6) \
5631 def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
5632 #define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5633 ARG6, ARG7) \
5634 def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
5635 #define DEF_FUNCTION_TYPE_8(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5636 ARG6, ARG7, ARG8) \
5637 def_fn_type (ENUM, RETURN, 0, 8, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5638 ARG7, ARG8);
5639 #define DEF_FUNCTION_TYPE_9(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5640 ARG6, ARG7, ARG8, ARG9) \
5641 def_fn_type (ENUM, RETURN, 0, 9, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5642 ARG7, ARG8, ARG9);
5643 #define DEF_FUNCTION_TYPE_10(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5,\
5644 ARG6, ARG7, ARG8, ARG9, ARG10) \
5645 def_fn_type (ENUM, RETURN, 0, 10, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5646 ARG7, ARG8, ARG9, ARG10);
5647 #define DEF_FUNCTION_TYPE_11(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5,\
5648 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) \
5649 def_fn_type (ENUM, RETURN, 0, 11, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5650 ARG7, ARG8, ARG9, ARG10, ARG11);
5651 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \
5652 def_fn_type (ENUM, RETURN, 1, 0);
5653 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \
5654 def_fn_type (ENUM, RETURN, 1, 1, ARG1);
5655 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \
5656 def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2);
5657 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
5658 def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3);
5659 #define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
5660 def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
5661 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5662 def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
5663 #define DEF_FUNCTION_TYPE_VAR_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5664 ARG6) \
5665 def_fn_type (ENUM, RETURN, 1, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
5666 #define DEF_FUNCTION_TYPE_VAR_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5667 ARG6, ARG7) \
5668 def_fn_type (ENUM, RETURN, 1, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
5669 #define DEF_POINTER_TYPE(ENUM, TYPE) \
5670 builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
5674 #undef DEF_PRIMITIVE_TYPE
5675 #undef DEF_FUNCTION_TYPE_0
5676 #undef DEF_FUNCTION_TYPE_1
5677 #undef DEF_FUNCTION_TYPE_2
5678 #undef DEF_FUNCTION_TYPE_3
5679 #undef DEF_FUNCTION_TYPE_4
5680 #undef DEF_FUNCTION_TYPE_5
5681 #undef DEF_FUNCTION_TYPE_6
5682 #undef DEF_FUNCTION_TYPE_7
5683 #undef DEF_FUNCTION_TYPE_8
5684 #undef DEF_FUNCTION_TYPE_9
5685 #undef DEF_FUNCTION_TYPE_10
5686 #undef DEF_FUNCTION_TYPE_11
5687 #undef DEF_FUNCTION_TYPE_VAR_0
5688 #undef DEF_FUNCTION_TYPE_VAR_1
5689 #undef DEF_FUNCTION_TYPE_VAR_2
5690 #undef DEF_FUNCTION_TYPE_VAR_3
5691 #undef DEF_FUNCTION_TYPE_VAR_4
5692 #undef DEF_FUNCTION_TYPE_VAR_5
5693 #undef DEF_FUNCTION_TYPE_VAR_6
5694 #undef DEF_FUNCTION_TYPE_VAR_7
5695 #undef DEF_POINTER_TYPE
5697 }
5699 /* ----------------------------------------------------------------------- *
5700 * BUILTIN ATTRIBUTES *
5701 * ----------------------------------------------------------------------- */
5703 enum built_in_attribute
5704 {
5705 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
5706 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
5707 #define DEF_ATTR_STRING(ENUM, VALUE) ENUM,
5708 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
5709 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
5711 #undef DEF_ATTR_NULL_TREE
5712 #undef DEF_ATTR_INT
5713 #undef DEF_ATTR_STRING
5714 #undef DEF_ATTR_IDENT
5715 #undef DEF_ATTR_TREE_LIST
5716 ATTR_LAST
5717 };
5721 static void
5723 {
5724 /* Fill in the built_in_attributes array. */
5725 #define DEF_ATTR_NULL_TREE(ENUM) \
5726 built_in_attributes[(int) ENUM] = NULL_TREE;
5727 #define DEF_ATTR_INT(ENUM, VALUE) \
5728 built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
5729 #define DEF_ATTR_STRING(ENUM, VALUE) \
5730 built_in_attributes[(int) ENUM] = build_string (strlen (VALUE), VALUE);
5731 #define DEF_ATTR_IDENT(ENUM, STRING) \
5732 built_in_attributes[(int) ENUM] = get_identifier (STRING);
5733 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
5734 built_in_attributes[(int) ENUM] \
5735 = tree_cons (built_in_attributes[(int) PURPOSE], \
5736 built_in_attributes[(int) VALUE], \
5737 built_in_attributes[(int) CHAIN]);
5739 #undef DEF_ATTR_NULL_TREE
5740 #undef DEF_ATTR_INT
5741 #undef DEF_ATTR_STRING
5742 #undef DEF_ATTR_IDENT
5743 #undef DEF_ATTR_TREE_LIST
5744 }
5746 /* Handle a "const" attribute; arguments as in
5747 struct attribute_spec.handler. */
5749 static tree
5753 {
5756 else
5760 }
5762 /* Handle a "nothrow" attribute; arguments as in
5763 struct attribute_spec.handler. */
5765 static tree
5769 {
5772 else
5776 }
5778 /* Handle a "pure" attribute; arguments as in
5779 struct attribute_spec.handler. */
5781 static tree
5784 {
5787 /* TODO: support types. */
5788 else
5789 {
5793 }
5796 }
5798 /* Handle a "no vops" attribute; arguments as in
5799 struct attribute_spec.handler. */
5801 static tree
5805 {
5809 }
5811 /* Helper for nonnull attribute handling; fetch the operand number
5812 from the attribute argument list. */
5814 static bool
5816 {
5817 /* Verify the arg number is a constant. */
5823 }
5825 /* Handle the "nonnull" attribute. */
5826 static tree
5830 {
5834 /* If no arguments are specified, all pointer arguments should be
5835 non-null. Verify a full prototype is given so that the arguments
5836 will have the correct types when we actually check them later.
5837 Avoid diagnosing type-generic built-ins since those have no
5838 prototype. */
5840 {
5844 {
5847 }
5849 }
5851 /* Argument list specified. Verify that each argument number references
5852 a pointer argument. */
5854 {
5858 {
5863 }
5866 {
5867 function_args_iterator iter;
5868 tree argument;
5872 {
5876 }
5880 {
5886 }
5889 {
5895 }
5896 }
5897 }
5900 }
5902 /* Handle a "sentinel" attribute. */
5904 static tree
5907 {
5909 {
5914 }
5915 else
5916 {
5918 {
5923 }
5924 }
5927 {
5931 {
5934 }
5935 else
5936 {
5938 {
5941 }
5942 }
5943 }
5946 }
5948 /* Handle a "noreturn" attribute; arguments as in
5949 struct attribute_spec.handler. */
5951 static tree
5954 {
5957 /* See FIXME comment in c_common_attribute_table. */
5963 = build_pointer_type
5966 else
5967 {
5971 }
5974 }
5976 /* Handle a "noinline" attribute; arguments as in
5977 struct attribute_spec.handler. */
5979 static tree
5983 {
5985 {
5987 {
5991 }
5992 else
5994 }
5995 else
5996 {
5999 }
6002 }
6004 /* Handle a "noclone" attribute; arguments as in
6005 struct attribute_spec.handler. */
6007 static tree
6011 {
6013 {
6016 }
6019 }
6021 /* Handle a "leaf" attribute; arguments as in
6022 struct attribute_spec.handler. */
6024 static tree
6027 {
6029 {
6032 }
6034 {
6037 }
6040 }
6042 /* Handle a "always_inline" attribute; arguments as in
6043 struct attribute_spec.handler. */
6045 static tree
6048 {
6050 {
6051 /* Set the attribute and mark it for disregarding inline limits. */
6053 }
6054 else
6055 {
6058 }
6061 }
6063 /* Handle a "malloc" attribute; arguments as in
6064 struct attribute_spec.handler. */
6066 static tree
6069 {
6073 else
6074 {
6078 }
6081 }
6083 /* Fake handler for attributes we don't properly support. */
6085 tree
6091 {
6093 }
6095 /* Handle a "type_generic" attribute. */
6097 static tree
6101 {
6102 /* Ensure we have a function type. */
6105 /* Ensure we have a variadic function. */
6109 }
6111 /* Handle a "vector_size" attribute; arguments as in
6112 struct attribute_spec.handler. */
6114 static tree
6117 {
6119 tree vector_type;
6123 /* We need to provide for vector pointers, vector arrays, and
6124 functions returning vectors. For example:
6126 __attribute__((vector_size(16))) short *foo;
6128 In this case, the mode is SI, but the type being modified is
6129 HI, so we need to look further. */
6139 /* Build back pointers if needed. */
6143 }
6145 /* Handle a "vector_type" attribute; arguments as in
6146 struct attribute_spec.handler. */
6148 static tree
6151 {
6153 tree vector_type;
6158 {
6162 }
6172 }
6174 /* ----------------------------------------------------------------------- *
6175 * BUILTIN FUNCTIONS *
6176 * ----------------------------------------------------------------------- */
6178 /* Worker for DEF_BUILTIN. Possibly define a builtin function with one or two
6179 names. Does not declare a non-__builtin_ function if flag_no_builtin, or
6180 if nonansi_p and flag_no_nonansi_builtin. */
6182 static void
6190 {
6191 tree decl;
6194 /* Preserve an already installed decl. It most likely was setup in advance
6195 (e.g. as part of the internal builtins) for specific reasons. */
6206 fnattrs);
6208 /* ??? This is normally further controlled by command-line options
6209 like -fno-builtin, but we don't have them for Ada. */
6214 }
6220 /* Install what the common builtins.def offers. */
6222 static void
6224 {
6225 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
6226 NONANSI_P, ATTRS, IMPLICIT, COND) \
6227 if (NAME && COND) \
6228 def_builtin_1 (ENUM, NAME, CLASS, \
6229 builtin_types[(int) TYPE], \
6230 builtin_types[(int) LIBTYPE], \
6231 BOTH_P, FALLBACK_P, NONANSI_P, \
6232 built_in_attributes[(int) ATTRS], IMPLICIT);
6234 }
6236 /* ----------------------------------------------------------------------- *
6237 * BUILTIN FUNCTIONS *
6238 * ----------------------------------------------------------------------- */
6240 /* Install the builtin functions we might need. */
6242 void
6244 {
6249 /* Install builtins used by generic middle-end pieces first. Some of these
6250 know about internal specificities and control attributes accordingly, for
6251 instance __builtin_alloca vs no-throw and -fstack-check. We will ignore
6252 the generic definition from builtins.def. */
6255 /* Now, install the target specific builtins, such as the AltiVec family on
6256 ppc, and the common set as exposed by builtins.def. */
6259 }