| blob | 4d61f52e0e46e082de6ac158576c67639c5db630 |
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 {
796 deferred_decl_context);
802 else
804 /* Array types need to have a name so that they can be related to
805 their GNAT encodings. */
809 }
813 ;
814 else
817 /* Propagate the name to all the variants, this is needed for the type
818 qualifiers machinery to work properly (see check_qualified_type).
819 Also propagate the context to them. Note that it will be propagated
820 to all parallel types too thanks to gnat_set_type_context. */
823 /* ??? Because of the previous kludge, we can have variants of fat
824 pointer types with different names. */
828 {
832 deferred_decl_context);
833 }
834 }
835 }
836 \f
837 /* Create a record type that contains a SIZE bytes long field of TYPE with a
838 starting bit position so that it is aligned to ALIGN bits, and leaving at
839 least ROOM bytes free before the field. BASE_ALIGN is the alignment the
840 record is guaranteed to get. GNAT_NODE is used for the position of the
841 associated TYPE_DECL. */
843 tree
846 {
847 /* We will be crafting a record type with one field at a position set to be
848 the next multiple of ALIGN past record'address + room bytes. We use a
849 record placeholder to express record'address. */
853 tree record_addr_st
856 /* The diagram below summarizes the shape of what we manipulate:
858 <--------- pos ---------->
859 { +------------+-------------+-----------------+
860 record =>{ |############| ... | field (type) |
861 { +------------+-------------+-----------------+
862 |<-- room -->|<- voffset ->|<---- size ----->|
863 o o
864 | |
865 record_addr vblock_addr
867 Every length is in sizetype bytes there, except "pos" which has to be
868 set as a bit position in the GCC tree for the record. */
878 /* Compute VOFFSET and then POS. The next byte position multiple of some
879 alignment after some address is obtained by "and"ing the alignment minus
880 1 with the two's complement of the address. */
885 /* POS = (ROOM + VOFFSET) * BIT_PER_UNIT, in bitsizetype. */
889 bitsize_unit_node);
891 /* Craft the GCC record representation. We exceptionally do everything
892 manually here because 1) our generic circuitry is not quite ready to
893 handle the complex position/size expressions we are setting up, 2) we
894 have a strong simplifying factor at hand: we know the maximum possible
895 value of voffset, and 3) we have to set/reset at least the sizes in
896 accordance with this maximum value anyway, as we need them to convey
897 what should be "alloc"ated for this type.
899 Use -1 as the 'addressable' indication for the field to prevent the
900 creation of a bitfield. We don't need one, it would have damaging
901 consequences on the alignment computation, and create_field_decl would
902 make one without this special argument, for instance because of the
903 complex position expression. */
914 bitsize_unit_node),
923 /* Declare it now since it will never be declared otherwise. This is
924 necessary to ensure that its subtrees are properly marked. */
928 }
930 /* TYPE is a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE that is being used
931 as the field type of a packed record if IN_RECORD is true, or as the
932 component type of a packed array if IN_RECORD is false. See if we can
933 rewrite it either as a type that has non-BLKmode, which we can pack
934 tighter in the packed record case, or as a smaller type with at most
935 MAX_ALIGN alignment if the value is non-zero. If so, return the new
936 type; if not, return the original type. */
938 tree
940 {
946 /* No point in doing anything if the size is zero. */
952 /* Copy the name and flags from the old type to that of the new.
953 Note that we rely on the pointer equality created here for
954 TYPE_NAME to look through conversions in various places. */
962 /* If we are in a record and have a small size, set the alignment to
963 try for an integral mode. Otherwise set it to try for a smaller
964 type with BLKmode. */
966 {
970 }
971 else
972 {
973 /* Do not try to shrink the size if the RM size is not constant. */
978 /* Round the RM size up to a unit boundary to get the minimal size
979 for a BLKmode record. Give up if it's already the size and we
980 don't need to lower the alignment. */
990 }
994 /* Now copy the fields, keeping the position and size as we don't want
995 to change the layout by propagating the packedness downwards. */
998 {
1007 /* However, for the last field in a not already packed record type
1008 that is of an aggregate type, we need to use the RM size in the
1009 packable version of the record type, see finish_record_type. */
1017 else
1020 new_field
1033 }
1041 /* If this is a padding record, we never want to make the size smaller
1042 than what was specified. For QUAL_UNION_TYPE, also copy the size. */
1044 {
1048 }
1049 else
1050 {
1053 }
1060 /* Try harder to get a packable type if necessary, for example
1061 in case the record itself contains a BLKmode field. */
1066 /* If neither mode nor size nor alignment shrunk, return the old type. */
1071 }
1073 /* Given a type TYPE, return a new type whose size is appropriate for SIZE.
1074 If TYPE is the best type, return it. Otherwise, make a new type. We
1075 only support new integral and pointer types. FOR_BIASED is true if
1076 we are making a biased type. */
1078 tree
1080 {
1083 tree new_type;
1085 /* If size indicates an error, just return TYPE to avoid propagating
1086 the error. Likewise if it's too large to represent. */
1093 {
1100 /* Integer types with precision 0 are forbidden. */
1104 /* Only do something if the type isn't a packed array type and doesn't
1105 already have the proper size and the size isn't too large. */
1113 /* The type should be an unsigned type if the original type is unsigned
1114 or if the lower bound is constant and non-negative or if the type is
1115 biased, see E_Signed_Integer_Subtype case of gnat_to_gnu_entity. */
1121 else
1126 /* Copy the name to show that it's essentially the same type and
1127 not a subrange type. */
1134 /* Do something if this is a fat pointer, in which case we
1135 may need to return the thin pointer. */
1137 {
1141 return
1142 build_pointer_type_for_mode
1145 }
1149 /* Only do something if this is a thin pointer, in which case we
1150 may need to return the fat pointer. */
1152 return
1158 }
1161 }
1163 /* See if the data pointed to by the hash table slot is marked. */
1165 int
1167 {
1169 }
1171 /* Return true iff the padded types are equivalent. */
1173 bool
1175 {
1184 /* We consider that the padded types are equivalent if they pad the same type
1185 and have the same size, alignment, RM size and storage order. Taking the
1186 mode into account is redundant since it is determined by the others. */
1187 return
1193 }
1195 /* Look up the padded TYPE in the hash table and return its canonical version
1196 if it exists; otherwise, insert it into the hash table. */
1198 static tree
1200 {
1201 hashval_t hashcode;
1204 hashcode
1221 }
1223 /* Ensure that TYPE has SIZE and ALIGN. Make and return a new padded type
1224 if needed. We have already verified that SIZE and ALIGN are large enough.
1225 GNAT_ENTITY is used to name the resulting record and to issue a warning.
1226 IS_COMPONENT_TYPE is true if this is being done for the component type of
1227 an array. IS_USER_TYPE is true if the original type needs to be completed.
1228 DEFINITION is true if this type is being defined. SET_RM_SIZE is true if
1229 the RM size of the resulting type is to be set to SIZE too; in this case,
1230 the padded type is canonicalized before being returned. */
1232 tree
1236 {
1241 /* If TYPE is a padded type, see if it agrees with any size and alignment
1242 we were given. If so, return the original type. Otherwise, strip
1243 off the padding, since we will either be returning the inner type
1244 or repadding it. If no size or alignment is specified, use that of
1245 the original padded type. */
1247 {
1261 }
1263 /* If the size is either not being changed or is being made smaller (which
1264 is not done here and is only valid for bitfields anyway), show the size
1265 isn't changing. Likewise, clear the alignment if it isn't being
1266 changed. Then return if we aren't doing anything. */
1279 /* If requested, complete the original type and give it a name. */
1286 gnat_entity);
1288 /* We used to modify the record in place in some cases, but that could
1289 generate incorrect debugging information. So make a new record
1290 type and name. */
1294 /* ??? Padding types around packed array implementation types will be
1295 considered as root types in the array descriptor language hook (see
1296 gnat_get_array_descr_info). Give them the original packed array type
1297 name so that the one coming from sources appears in the debugging
1298 information. */
1311 bitsize_unit_node));
1313 /* If we are changing the alignment and the input type is a record with
1314 BLKmode and a small constant size, try to make a form that has an
1315 integral mode. This might allow the padding record to also have an
1316 integral mode, which will be much more efficient. There is no point
1317 in doing so if a size is specified unless it is also a small constant
1318 size and it is incorrect to do so if we cannot guarantee that the mode
1319 will be naturally aligned since the field must always be addressable.
1321 ??? This might not always be a win when done for a stand-alone object:
1322 since the nominal and the effective type of the object will now have
1323 different modes, a VIEW_CONVERT_EXPR will be required for converting
1324 between them and it might be hard to overcome afterwards, including
1325 at the RTL level when the stand-alone object is accessed as a whole. */
1333 && (!size
1336 {
1341 }
1343 /* Now create the field with the original size. */
1348 /* We will output additional debug info manually below. */
1354 /* Set the RM size if requested. */
1356 {
1357 tree canonical_pad_type;
1361 /* If the padded type is complete and has constant size, we canonicalize
1362 it by means of the hash table. This is consistent with the language
1363 semantics and ensures that gigi and the middle-end have a common view
1364 of these padded types. */
1367 {
1370 }
1371 }
1373 /* Unless debugging information isn't being written for the input type,
1374 write a record that shows what we are a subtype of and also make a
1375 variable that indicates our size, if still variable. */
1381 {
1385 /* A variable that holds the size is required even with no encoding since
1386 it will be referenced by debugging information attributes. At global
1387 level, we need a single variable across all translation units. */
1391 {
1392 /* Whether or not gnat_entity comes from source, this XVZ variable is
1393 is a compilation artifact. */
1394 size_unit
1400 }
1402 /* There is no need to show what we are a subtype of when outputting as
1403 few encodings as possible: regular debugging infomation makes this
1404 redundant. */
1406 {
1420 }
1421 }
1423 built:
1424 /* If a simple size was explicitly given, maybe issue a warning. */
1431 /* But don't do it if we are just annotating types and the type is tagged or
1432 concurrent, since these types aren't fully laid out in this mode. */
1434 {
1435 Entity_Id gnat_type
1436 = is_component_type
1441 }
1443 /* Take the original size as the maximum size of the input if there was an
1444 unconstrained record involved and round it up to the specified alignment,
1445 if one was specified, but only for aggregate types. */
1458 {
1461 /* For a packed array, post the message on the original array type. */
1472 /* Generate message only for entities that come from source, since
1473 if we have an entity created by expansion, the message will be
1474 generated for some other corresponding source entity. */
1476 {
1485 }
1486 }
1489 }
1491 /* Return a copy of the padded TYPE but with reverse storage order. */
1493 tree
1495 {
1499 {
1500 /* If the inner type is not scalar then the function does nothing. */
1504 }
1506 /* This is required for the canonicalization. */
1516 }
1517 \f
1518 /* Relate the alias sets of GNU_NEW_TYPE and GNU_OLD_TYPE according to OP.
1519 If this is a multi-dimensional array type, do this recursively.
1521 OP may be
1522 - ALIAS_SET_COPY: the new set is made a copy of the old one.
1523 - ALIAS_SET_SUPERSET: the new set is made a superset of the old one.
1524 - ALIAS_SET_SUBSET: the new set is made a subset of the old one. */
1526 void
1528 {
1529 /* Remove any padding from GNU_OLD_TYPE. It doesn't matter in the case
1530 of a one-dimensional array, since the padding has the same alias set
1531 as the field type, but if it's a multi-dimensional array, we need to
1532 see the inner types. */
1538 /* Unconstrained array types are deemed incomplete and would thus be given
1539 alias set 0. Retrieve the underlying array type. */
1541 gnu_old_type
1544 gnu_new_type
1553 {
1555 /* The alias set shouldn't be copied between array types with different
1556 aliasing settings because this can break the aliasing relationship
1557 between the array type and its element type. */
1569 {
1573 /* Do nothing if the alias sets conflict. This ensures that we
1574 never call record_alias_subset several times for the same pair
1575 or at all for alias set 0. */
1577 {
1580 else
1582 }
1583 }
1588 }
1591 }
1592 \f
1593 /* Record TYPE as a builtin type for Ada. NAME is the name of the type.
1594 ARTIFICIAL_P is true if the type was generated by the compiler. */
1596 void
1598 {
1607 }
1608 \f
1609 /* Finish constructing the character type CHAR_TYPE.
1611 In Ada character types are enumeration types and, as a consequence, are
1612 represented in the front-end by integral types holding the positions of
1613 the enumeration values as defined by the language, which means that the
1614 integral types are unsigned.
1616 Unfortunately the signedness of 'char' in C is implementation-defined
1617 and GCC even has the option -fsigned-char to toggle it at run time.
1618 Since GNAT's philosophy is to be compatible with C by default, to wit
1619 Interfaces.C.char is defined as a mere copy of Character, we may need
1620 to declare character types as signed types in GENERIC and generate the
1621 necessary adjustments to make them behave as unsigned types.
1623 The overall strategy is as follows: if 'char' is unsigned, do nothing;
1624 if 'char' is signed, translate character types of CHAR_TYPE_SIZE and
1625 character subtypes with RM_Size = Esize = CHAR_TYPE_SIZE into signed
1626 types. The idea is to ensure that the bit pattern contained in the
1627 Esize'd objects is not changed, even though the numerical value will
1628 be interpreted differently depending on the signedness.
1630 For character types, the bounds are implicit and, therefore, need to
1631 be adjusted. Morever, the debug info needs the unsigned version. */
1633 void
1635 {
1639 /* Make a copy of a generic unsigned version since we'll modify it. */
1640 tree unsigned_char_type
1642 ? unsigned_char_type_node
1652 }
1654 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
1655 finish constructing the record type as a fat pointer type. */
1657 void
1659 {
1660 /* Make sure we can put it into a register. */
1664 /* Show what it really is. */
1667 /* Do not emit debug info for it since the types of its fields may still be
1668 incomplete at this point. */
1671 /* Force type_contains_placeholder_p to return true on it. Although the
1672 PLACEHOLDER_EXPRs are referenced only indirectly, this isn't a pointer
1673 type but the representation of the unconstrained array. */
1675 }
1677 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
1678 finish constructing the record or union type. If REP_LEVEL is zero, this
1679 record has no representation clause and so will be entirely laid out here.
1680 If REP_LEVEL is one, this record has a representation clause and has been
1681 laid out already; only set the sizes and alignment. If REP_LEVEL is two,
1682 this record is derived from a parent record and thus inherits its layout;
1683 only make a pass on the fields to finalize them. DEBUG_INFO_P is true if
1684 additional debug info needs to be output for this type. */
1686 void
1689 {
1697 tree field;
1701 /* Always attach the TYPE_STUB_DECL for a record type. It is required to
1702 generate debug info and have a parallel type. */
1705 /* Globally initialize the record first. If this is a rep'ed record,
1706 that just means some initializations; otherwise, layout the record. */
1708 {
1718 /* For all-repped records with a size specified, lay the QUAL_UNION_TYPE
1719 out just like a UNION_TYPE, since the size will be fixed. */
1722 }
1723 else
1724 {
1725 /* Ensure there isn't a size already set. There can be in an error
1726 case where there is a rep clause but all fields have errors and
1727 no longer have a position. */
1730 /* Ensure we use the traditional GCC layout for bitfields when we need
1731 to pack the record type or have a representation clause. The other
1732 possible layout (Microsoft C compiler), if available, would prevent
1733 efficient packing in almost all cases. */
1734 #ifdef TARGET_MS_BITFIELD_LAYOUT
1739 ATTR_FLAG_TYPE_IN_PLACE);
1740 #endif
1743 }
1745 /* At this point, the position and size of each field is known. It was
1746 either set before entry by a rep clause, or by laying out the type above.
1748 We now run a pass over the fields (in reverse order for QUAL_UNION_TYPEs)
1749 to compute the Ada size; the GCC size and alignment (for rep'ed records
1750 that are not padding types); and the mode (for rep'ed records). We also
1751 clear the DECL_BIT_FIELD indication for the cases we know have not been
1752 handled yet, and adjust DECL_NONADDRESSABLE_P accordingly. */
1758 {
1762 tree this_ada_size;
1769 else
1772 /* Clear DECL_BIT_FIELD for the cases layout_decl does not handle. */
1775 {
1778 /* In the general case, type alignment is required. */
1780 {
1781 /* The enclosing record type must be sufficiently aligned.
1782 Otherwise, if no alignment was specified for it and it
1783 has been laid out already, bump its alignment to the
1784 desired one if this is compatible with its size and
1785 maximum alignment, if any. */
1787 {
1790 }
1796 {
1800 }
1801 }
1803 /* In the non-strict alignment case, only byte alignment is. */
1808 }
1810 /* If we still have DECL_BIT_FIELD set at this point, we know that the
1811 field is technically not addressable. Except that it can actually
1812 be addressed if it is BLKmode and happens to be properly aligned. */
1818 /* A type must be as aligned as its most aligned field that is not
1819 a bit-field. But this is already enforced by layout_type. */
1825 {
1832 ada_size
1840 /* Since we know here that all fields are sorted in order of
1841 increasing bit position, the size of the record is one
1842 higher than the ending bit of the last field processed
1843 unless we have a rep clause, since in that case we might
1844 have a field outside a QUAL_UNION_TYPE that has a higher ending
1845 position. So use a MAX in that case. Also, if this field is a
1846 QUAL_UNION_TYPE, we need to take into account the previous size in
1847 the case of empty variants. */
1848 ada_size
1851 size
1858 }
1859 }
1865 {
1866 /* If this is a padding record, we never want to make the size smaller
1867 than what was specified in it, if any. */
1871 /* Now set any of the values we've just computed that apply. */
1877 {
1878 tree size_unit = had_size_unit
1882 bitsize_unit_node));
1890 }
1891 }
1893 /* Reset the TYPE_MAX_ALIGN field since it's private to gigi. */
1898 }
1900 /* Append PARALLEL_TYPE on the chain of parallel types of TYPE. If
1901 PARRALEL_TYPE has no context and its computation is not deferred yet, also
1902 propagate TYPE's context to PARALLEL_TYPE's or defer its propagation to the
1903 moment TYPE will get a context. */
1905 void
1907 {
1915 /* If PARALLEL_TYPE already has a context, we are done. */
1919 /* Otherwise, try to get one from TYPE's context. If so, simply propagate
1920 it to PARALLEL_TYPE. */
1924 /* Otherwise TYPE has not context yet. We know it will have one thanks to
1925 gnat_pushdecl and then its context will be propagated to PARALLEL_TYPE,
1926 so we have nothing to do in this case. */
1927 }
1929 /* Return true if TYPE has a parallel type. */
1931 static bool
1933 {
1937 }
1939 /* Wrap up compilation of RECORD_TYPE, i.e. output additional debug info
1940 associated with it. It need not be invoked directly in most cases as
1941 finish_record_type takes care of doing so. */
1943 void
1945 {
1947 tree field;
1949 /* If this is a padded type, the bulk of the debug info has already been
1950 generated for the field's type. */
1954 /* If the type already has a parallel type (XVS type), then we're done. */
1959 {
1960 /* We need to make an XVE/XVU record if any field has variable size,
1961 whether or not the record does. For example, if we have a union,
1962 it may be that all fields, rounded up to the alignment, have the
1963 same size, in which case we'll use that size. But the debug
1964 output routines (except Dwarf2) won't be able to output the fields,
1965 so we need to make the special record. */
1967 /* If a field has a non-constant qualifier, the record will have
1968 variable size too. */
1971 {
1974 }
1975 }
1977 /* If this record type is of variable size, make a parallel record type that
1978 will tell the debugger how the former is laid out (see exp_dbug.ads). */
1980 {
1981 tree new_record_type
1988 new_name
2002 /* Now scan all the fields, replacing each field with a new field
2003 corresponding to the new encoding. */
2006 {
2014 /* We're going to do some pattern matching below so remove as many
2015 conversions as possible. */
2018 /* See how the position was modified from the last position.
2020 There are two basic cases we support: a value was added
2021 to the last position or the last position was rounded to
2022 a boundary and they something was added. Check for the
2023 first case first. If not, see if there is any evidence
2024 of rounding. If so, round the last position and retry.
2026 If this is a union, the position can be taken as zero. */
2029 else
2035 {
2041 }
2046 && tree_fits_uhwi_p
2048 {
2050 unsigned HOST_WIDE_INT addend
2052 align
2058 }
2060 {
2064 }
2066 /* If we can't compute a position, set it to zero.
2068 ??? We really should abort here, but it's too much work
2069 to get this correct for all cases. */
2073 /* See if this type is variable-sized and make a pointer type
2074 and indicate the indirection if so. Beware that the debug
2075 back-end may adjust the position computed above according
2076 to the alignment of the field type, i.e. the pointer type
2077 in this case, if we don't preventively counter that. */
2079 {
2082 {
2085 }
2087 }
2089 /* Make a new field name, if necessary. */
2091 {
2097 else
2101 }
2103 new_field
2109 /* If old_field is a QUAL_UNION_TYPE, take its size as being
2110 zero. The only time it's not the last field of the record
2111 is when there are other components at fixed positions after
2112 it (meaning there was a rep clause for every field) and we
2113 want to be able to encode them. */
2117 ? bitsize_zero_node
2120 }
2125 }
2126 }
2128 /* Utility function of above to merge LAST_SIZE, the previous size of a record
2129 with FIRST_BIT and SIZE that describe a field. SPECIAL is true if this
2130 represents a QUAL_UNION_TYPE in which case we must look for COND_EXPRs and
2131 replace a value of zero with the old size. If HAS_REP is true, we take the
2132 MAX of the end position of this field with LAST_SIZE. In all other cases,
2133 we use FIRST_BIT plus SIZE. Return an expression for the size. */
2135 static tree
2138 {
2140 tree new_size;
2143 {
2147 }
2149 else
2160 /* We don't need any NON_VALUE_EXPRs and they can confuse us (especially
2161 when fed through substitute_in_expr) into thinking that a constant
2162 size is not constant. */
2167 }
2169 /* Utility function of above to see if OP0 and OP1, both of SIZETYPE, are
2170 related by the addition of a constant. Return that constant if so. */
2172 static tree
2174 {
2184 else
2186 }
2188 /* Utility function of above to split a tree OP which may be a sum, into a
2189 constant part, which is returned, and a variable part, which is stored
2190 in *PVAR. *PVAR may be bitsize_zero_node. All operations must be of
2191 bitsizetype. */
2193 static tree
2195 {
2196 /* Strip conversions in order to ease the tree traversal and maximize the
2197 potential for constant or plus/minus discovery. We need to be careful
2198 to always return and set *pvar to bitsizetype trees, but it's worth
2199 the effort. */
2205 {
2208 }
2210 {
2221 }
2222 else
2224 }
2225 \f
2226 /* Return a copy of TYPE but safe to modify in any way. */
2228 tree
2230 {
2233 /* Unshare the language-specific data. */
2235 {
2238 }
2240 /* And the contents of the language-specific slot if needed. */
2243 {
2248 }
2250 /* copy_node clears this field instead of copying it, because it is
2251 aliased with TREE_CHAIN. */
2261 }
2262 \f
2263 /* Return a subtype of sizetype with range MIN to MAX and whose
2264 TYPE_INDEX_TYPE is INDEX. GNAT_NODE is used for the position
2265 of the associated TYPE_DECL. */
2267 tree
2269 {
2270 /* First build a type for the desired range. */
2273 /* Then set the index type. */
2278 }
2280 /* Return a subtype of TYPE with range MIN to MAX. If TYPE is NULL,
2281 sizetype is used. */
2283 tree
2285 {
2286 tree range_type;
2291 /* First build a type with the base range. */
2295 /* Then set the actual range. */
2300 }
2301 \f
2302 /* Return a TYPE_DECL node suitable for the TYPE_STUB_DECL field of TYPE.
2303 NAME gives the name of the type to be used in the declaration. */
2305 tree
2307 {
2312 }
2314 /* Return a TYPE_DECL node for TYPE. NAME gives the name of the type to be
2315 used in the declaration. ARTIFICIAL_P is true if the declaration was
2316 generated by the compiler. DEBUG_INFO_P is true if we need to write
2317 debug information about this type. GNAT_NODE is used for the position
2318 of the decl. */
2320 tree
2322 Node_Id gnat_node)
2323 {
2325 bool is_named
2327 tree type_decl;
2329 /* Only the builtin TYPE_STUB_DECL should be used for dummy types. */
2332 /* If the type hasn't been named yet, we're naming it; preserve an existing
2333 TYPE_STUB_DECL that has been attached to it for some purpose. */
2335 {
2338 }
2339 else
2345 /* Add this decl to the current binding level. */
2348 /* If we're naming the type, equate the TYPE_STUB_DECL to the name. This
2349 causes the name to be also viewed as a "tag" by the debug back-end, with
2350 the advantage that no DW_TAG_typedef is emitted for artificial "tagged"
2351 types in DWARF.
2353 Note that if "type" is used as a DECL_ORIGINAL_TYPE, it may be referenced
2354 from multiple contexts, and "type_decl" references a copy of it: in such a
2355 case, do not mess TYPE_STUB_DECL: we do not want to re-use the TYPE_DECL
2356 with the mechanism above. */
2360 /* Do not generate debug info for UNCONSTRAINED_ARRAY_TYPE that the
2361 back-end doesn't support, and for others if we don't need to. */
2366 }
2367 \f
2368 /* Return a VAR_DECL or CONST_DECL node.
2370 NAME gives the name of the variable. ASM_NAME is its assembler name
2371 (if provided). TYPE is its data type (a GCC ..._TYPE node). INIT is
2372 the GCC tree for an optional initial expression; NULL_TREE if none.
2374 CONST_FLAG is true if this variable is constant, in which case we might
2375 return a CONST_DECL node unless CONST_DECL_ALLOWED_P is false.
2377 PUBLIC_FLAG is true if this is for a reference to a public entity or for a
2378 definition to be made visible outside of the current compilation unit, for
2379 instance variable definitions in a package specification.
2381 EXTERN_FLAG is true when processing an external variable declaration (as
2382 opposed to a definition: no storage is to be allocated for the variable).
2384 STATIC_FLAG is only relevant when not at top level and indicates whether
2385 to always allocate storage to the variable.
2387 VOLATILE_FLAG is true if this variable is declared as volatile.
2389 ARTIFICIAL_P is true if the variable was generated by the compiler.
2391 DEBUG_INFO_P is true if we need to write debug information for it.
2393 ATTR_LIST is the list of attributes to be attached to the variable.
2395 GNAT_NODE is used for the position of the decl. */
2397 tree
2403 {
2404 /* Whether the object has static storage duration, either explicitly or by
2405 virtue of being declared at the global level. */
2408 /* Whether the initializer is constant: for an external object or an object
2409 with static storage duration, we check that the initializer is a valid
2410 constant expression for initializing a static variable; otherwise, we
2411 only check that it is constant. */
2412 const bool init_const
2413 = (init
2417 != NULL_TREE
2420 /* Whether we will make TREE_CONSTANT the DECL we produce here, in which
2421 case the initializer may be used in lieu of the DECL node (as done in
2422 Identifier_to_gnu). This is useful to prevent the need of elaboration
2423 code when an identifier for which such a DECL is made is in turn used
2424 as an initializer. We used to rely on CONST_DECL vs VAR_DECL for this,
2425 but extra constraints apply to this choice (see below) and they are not
2426 relevant to the distinction we wish to make. */
2429 /* The actual DECL node. CONST_DECL was initially intended for enumerals
2430 and may be used for scalars in general but not for aggregates. */
2431 tree var_decl
2433 (constant_p
2434 && const_decl_allowed_p
2438 /* Detect constants created by the front-end to hold 'reference to function
2439 calls for stabilization purposes. This is needed for renaming. */
2441 {
2452 }
2454 /* If this is external, throw away any initializations (they will be done
2455 elsewhere) unless this is a constant for which we would like to remain
2456 able to get the initializer. If we are defining a global here, leave a
2457 constant initialization and save any variable elaborations for the
2458 elaboration routine. If we are just annotating types, throw away the
2459 initialization if it isn't a constant. */
2462 {
2465 /* In LTO mode, also clear TREE_READONLY the same way add_decl_expr
2466 would do it if the initializer was not thrown away here, as the
2467 WPA phase requires a consistent view across compilation units. */
2469 {
2472 }
2473 }
2475 /* At the global level, a non-constant initializer generates elaboration
2476 statements. Check that such statements are allowed, that is to say,
2477 not violating a No_Elaboration_Code restriction. */
2481 /* Attach the initializer, if any. */
2484 /* Directly set some flags. */
2491 /* The object is public if it is external or if it is declared public
2492 and has static storage duration. */
2495 /* We need to allocate static storage for an object with static storage
2496 duration if it isn't external. */
2506 /* Ada doesn't feature Fortran-like COMMON variables so we shouldn't
2507 try to fiddle with DECL_COMMON. However, on platforms that don't
2508 support global BSS sections, uninitialized global variables would
2509 go in DATA instead, thus increasing the size of the executable. */
2516 /* Do not emit debug info for a CONST_DECL if optimization isn't enabled,
2517 since we will create an associated variable. Likewise for an external
2518 constant whose initializer is not absolute, because this would mean a
2519 global relocation in a read-only section which runs afoul of the PE-COFF
2520 run-time relocation mechanism. */
2523 || (extern_flag
2524 && constant_p
2525 && init
2530 /* ??? Some attributes cannot be applied to CONST_DECLs. */
2534 /* Add this decl to the current binding level. */
2538 {
2539 /* Let the target mangle the name if this isn't a verbatim asm. */
2544 }
2547 }
2548 \f
2549 /* Return true if TYPE, an aggregate type, contains (or is) an array. */
2551 static bool
2553 {
2555 {
2559 {
2560 tree field;
2566 }
2573 }
2574 }
2576 /* Return a FIELD_DECL node. NAME is the field's name, TYPE is its type and
2577 RECORD_TYPE is the type of the enclosing record. If SIZE is nonzero, it
2578 is the specified size of the field. If POS is nonzero, it is the bit
2579 position. PACKED is 1 if the enclosing record is packed, -1 if it has
2580 Component_Alignment of Storage_Unit. If ADDRESSABLE is nonzero, it
2581 means we are allowed to take the address of the field; if it is negative,
2582 we should not make a bitfield, which is used by make_aligning_type. */
2584 tree
2587 {
2593 /* If FIELD_TYPE is BLKmode, we must ensure this is aligned to at least a
2594 byte boundary since GCC cannot handle less-aligned BLKmode bitfields.
2595 Likewise for an aggregate without specified position that contains an
2596 array, because in this case slices of variable length of this array
2597 must be handled by GCC and variable-sized objects need to be aligned
2598 to at least a byte boundary. */
2600 || (!pos
2605 /* If a size is specified, use it. Otherwise, if the record type is packed
2606 compute a size to use, which may differ from the object's natural size.
2607 We always set a size in this case to trigger the checks for bitfield
2608 creation below, which is typically required when no position has been
2609 specified. */
2613 {
2617 }
2619 /* If we may, according to ADDRESSABLE, make a bitfield if a size is
2620 specified for two reasons: first if the size differs from the natural
2621 size. Second, if the alignment is insufficient. There are a number of
2622 ways the latter can be true.
2624 We never make a bitfield if the type of the field has a nonconstant size,
2625 because no such entity requiring bitfield operations should reach here.
2627 We do *preventively* make a bitfield when there might be the need for it
2628 but we don't have all the necessary information to decide, as is the case
2629 of a field with no specified position in a packed record.
2631 We also don't look at STRICT_ALIGNMENT here, and rely on later processing
2632 in layout_decl or finish_record_type to clear the bit_field indication if
2633 it is in fact not needed. */
2635 && size
2640 || packed
2643 {
2647 {
2651 else
2653 }
2654 }
2658 /* Bump the alignment if need be, either for bitfield/packing purposes or
2659 to satisfy the type requirements if no such consideration applies. When
2660 we get the alignment from the type, indicate if this is from an explicit
2661 user request, which prevents stor-layout from lowering it later on. */
2662 {
2663 unsigned int bit_align
2670 {
2673 }
2674 }
2677 {
2678 /* We need to pass in the alignment the DECL is known to have.
2679 This is the lowest-order bit set in POS, but no more than
2680 the alignment of the record, if one is specified. Note
2681 that an alignment of 0 is taken as infinite. */
2686 else
2700 }
2702 /* In addition to what our caller says, claim the field is addressable if we
2703 know that its type is not suitable.
2705 The field may also be "technically" nonaddressable, meaning that even if
2706 we attempt to take the field's address we will actually get the address
2707 of a copy. This is the case for true bitfields, but the DECL_BIT_FIELD
2708 value we have at this point is not accurate enough, so we don't account
2709 for this here and let finish_record_type decide. */
2716 }
2717 \f
2718 /* Return a PARM_DECL node with NAME and TYPE. */
2720 tree
2722 {
2725 /* Honor TARGET_PROMOTE_PROTOTYPES like the C compiler, as not doing so
2726 can lead to various ABI violations. */
2730 {
2731 /* We have to be careful about biased types here. Make a subtype
2732 of integer_type_node with the proper biasing. */
2735 {
2736 tree subtype
2743 }
2744 else
2746 }
2750 }
2751 \f
2752 /* Process the attributes in ATTR_LIST for NODE, which is either a DECL or
2753 a TYPE. If IN_PLACE is true, the tree pointed to by NODE should not be
2754 changed. GNAT_NODE is used for the position of error messages. */
2756 void
2758 Node_Id gnat_node)
2759 {
2764 {
2773 {
2776 }
2782 else
2789 {
2792 }
2793 else
2812 }
2815 }
2817 /* Return true if VALUE is a known to be a multiple of FACTOR, which must be
2818 a power of 2. */
2820 bool
2822 {
2831 }
2833 /* Return whether GNAT_NODE is a defining identifier for a renaming that comes
2834 from the parameter association for the instantiation of a generic. We do
2835 not want to emit source location for them: the code generated for their
2836 initialization is likely to disturb debugging. */
2838 bool
2840 {
2847 /* Get the object declaration of the renamed object, if any and if the
2848 renamed object is a mere identifier. */
2858 return
2862 }
2864 /* Defer the initialization of DECL's DECL_CONTEXT attribute, scheduling to
2865 feed it with the elaboration of GNAT_SCOPE. */
2869 {
2872 new_node
2881 }
2883 /* Defer the initialization of TYPE's TYPE_CONTEXT attribute, scheduling to
2884 feed it with the DECL_CONTEXT computed as part of N as soon as it is
2885 computed. */
2887 static void
2889 {
2891 }
2893 /* Get the GENERIC node corresponding to GNAT_SCOPE, if available. Return
2894 NULL_TREE if it is not available. */
2896 static tree
2898 {
2899 tree context;
2903 else
2907 {
2910 /* Skip dummy types: only the final ones can appear in the context
2911 chain. */
2915 /* ..._TYPE nodes are more useful than TYPE_DECL nodes in the context
2916 chain. */
2917 else
2919 }
2922 }
2924 /* Try to process all deferred nodes in the queue. Keep in the queue the ones
2925 that cannot be processed yet, remove the other ones. If FORCE is true,
2926 force the processing for all nodes, use the global context when nodes don't
2927 have a GNU translation. */
2929 void
2931 {
2936 {
2939 Entity_Id gnat_scope;
2943 /* If FORCE, get the innermost elaborated scope. Otherwise, just try to
2944 get the first scope. */
2947 {
2952 }
2954 /* Imported declarations must not be in a local context (i.e. not inside
2955 a function). */
2957 {
2961 {
2964 }
2965 }
2967 /* If FORCE, we want to get rid of all nodes in the queue: in case there
2968 was no elaborated scope, use the global context. */
2973 {
2974 tree t;
2979 /* Propagate it to the TYPE_CONTEXT attributes of the requested
2980 ..._TYPE nodes. */
2982 {
2984 }
2986 }
2988 /* If this node has been successfuly processed, remove it from the
2989 queue. Then move to the next node. */
2991 {
2995 }
2996 else
2998 }
2999 }
3002 /* Return VALUE scaled by the biggest power-of-2 factor of EXPR. */
3004 static unsigned int
3006 {
3010 /* Peel conversions around EXPR and try to extract bodies from function
3011 calls: it is possible to get the scale factor from size functions. */
3016 /* Sometimes we get PLUS_EXPR (BIT_AND_EXPR (..., X), Y), where Y is a
3017 multiple of the scale factor we are looking for. */
3021 {
3024 }
3026 /* An expression which is a bitwise AND with a mask has a power-of-2 factor
3027 corresponding to the number of trailing zeros of the mask. */
3030 {
3035 {
3038 i++;
3039 }
3040 }
3042 /* If the addend is not a multiple of the factor we found, give up. In
3043 theory we could find a smaller common factor but it's useless for our
3044 needs. This situation arises when dealing with a field F1 with no
3045 alignment requirement but that is following a field F2 with such
3046 requirements. As long as we have F2's offset, we don't need alignment
3047 information to compute F1's. */
3052 }
3054 /* Given two consecutive field decls PREV_FIELD and CURR_FIELD, return true
3055 unless we can prove these 2 fields are laid out in such a way that no gap
3056 exist between the end of PREV_FIELD and the beginning of CURR_FIELD. OFFSET
3057 is the distance in bits between the end of PREV_FIELD and the starting
3058 position of CURR_FIELD. It is ignored if null. */
3060 static bool
3062 {
3063 /* If this is the first field of the record, there cannot be any gap */
3067 /* If the previous field is a union type, then return false: The only
3068 time when such a field is not the last field of the record is when
3069 there are other components at fixed positions after it (meaning there
3070 was a rep clause for every field), in which case we don't want the
3071 alignment constraint to override them. */
3075 /* If the distance between the end of prev_field and the beginning of
3076 curr_field is constant, then there is a gap if the value of this
3077 constant is not null. */
3081 /* If the size and position of the previous field are constant,
3082 then check the sum of this size and position. There will be a gap
3083 iff it is not multiple of the current field alignment. */
3090 /* If both the position and size of the previous field are multiples
3091 of the current field alignment, there cannot be any gap. */
3096 /* Fallback, return that there may be a potential gap */
3098 }
3100 /* Return a LABEL_DECL with NAME. GNAT_NODE is used for the position of
3101 the decl. */
3103 tree
3105 {
3106 tree label_decl
3111 /* Add this decl to the current binding level. */
3115 }
3116 \f
3117 /* Return a FUNCTION_DECL node. NAME is the name of the subprogram, ASM_NAME
3118 its assembler name, TYPE its type (a FUNCTION_TYPE node), PARAM_DECL_LIST
3119 the list of its parameters (a list of PARM_DECL nodes chained through the
3120 DECL_CHAIN field).
3122 INLINE_STATUS describes the inline flags to be set on the FUNCTION_DECL.
3124 PUBLIC_FLAG is true if this is for a reference to a public entity or for a
3125 definition to be made visible outside of the current compilation unit.
3127 EXTERN_FLAG is true when processing an external subprogram declaration.
3129 ARTIFICIAL_P is true if the subprogram was generated by the compiler.
3131 DEBUG_INFO_P is true if we need to write debug information for it.
3133 ATTR_LIST is the list of attributes to be attached to the subprogram.
3135 GNAT_NODE is used for the position of the decl. */
3137 tree
3142 {
3154 {
3167 ATTR_FLAG_TYPE_IN_PLACE);
3169 /* fall through */
3178 }
3182 /* Once everything is processed, finish the subprogram declaration. */
3185 /* Add this decl to the current binding level. */
3188 /* Output the assembler code and/or RTL for the declaration. */
3192 }
3194 /* Given a subprogram declaration DECL, its assembler name and its type,
3195 finish constructing the subprogram declaration from ASM_NAME and TYPE. */
3197 void
3199 {
3200 tree result_decl
3213 {
3214 /* Let the target mangle the name if this isn't a verbatim asm. */
3220 /* The expand_main_function circuitry expects "main_identifier_node" to
3221 designate the DECL_NAME of the 'main' entry point, in turn expected
3222 to be declared as the "main" function literally by default. Ada
3223 program entry points are typically declared with a different name
3224 within the binder generated file, exported as 'main' to satisfy the
3225 system expectations. Force main_identifier_node in this case. */
3228 }
3229 }
3230 \f
3231 /* Set up the framework for generating code for SUBPROG_DECL, a subprogram
3232 body. This routine needs to be invoked before processing the declarations
3233 appearing in the subprogram. */
3235 void
3237 {
3238 tree param_decl;
3242 /* This function is being defined. */
3245 /* The failure of this assertion will likely come from a wrong context for
3246 the subprogram body, e.g. another procedure for a procedure declared at
3247 library level. */
3252 /* Enter a new binding level and show that all the parameters belong to
3253 this function. */
3261 }
3263 /* Finish translating the current subprogram and set its BODY. */
3265 void
3267 {
3270 /* Attach the BLOCK for this level to the function and pop the level. */
3275 /* Mark the RESULT_DECL as being in this subprogram. */
3278 /* The body should be a BIND_EXPR whose BLOCK is the top-level one. */
3280 {
3283 }
3288 }
3290 /* Wrap up compilation of SUBPROG_DECL, a subprogram body. */
3292 void
3294 {
3295 /* We cannot track the location of errors past this point. */
3298 /* If we're only annotating types, don't actually compile this function. */
3302 /* Dump functions before gimplification. */
3307 else
3308 /* Register this function with cgraph just far enough to get it
3309 added to our parent's nested function list. */
3311 }
3313 tree
3315 {
3318 }
3320 /* Return an integer type with the number of bits of precision given by
3321 PRECISION. UNSIGNEDP is nonzero if the type is unsigned; otherwise
3322 it is a signed type. */
3324 tree
3326 {
3327 tree t;
3336 else
3343 {
3346 }
3349 }
3351 /* Likewise for floating-point types. */
3353 static tree
3355 {
3356 tree t;
3368 {
3371 }
3374 }
3376 /* Return a data type that has machine mode MODE. UNSIGNEDP selects
3377 an unsigned type; otherwise a signed type is returned. */
3379 tree
3381 {
3398 {
3403 }
3406 }
3408 /* Return the signed or unsigned version of TYPE_NODE, a scalar type, the
3409 signedness being specified by UNSIGNEDP. */
3411 tree
3413 {
3420 {
3423 }
3427 {
3430 }
3433 }
3435 /* Return 1 if the types T1 and T2 are compatible, i.e. if they can be
3436 transparently converted to each other. */
3438 int
3440 {
3443 /* This is the default criterion. */
3447 /* We only check structural equivalence here. */
3451 /* Vector types are also compatible if they have the same number of subparts
3452 and the same form of (scalar) element type. */
3459 /* Array types are also compatible if they are constrained and have the same
3460 domain(s), the same component type and the same scalar storage order. */
3476 }
3478 /* Return true if EXPR is a useless type conversion. */
3480 bool
3482 {
3490 }
3492 /* Return true if T, a FUNCTION_TYPE, has the specified list of flags. */
3494 bool
3497 {
3502 }
3503 \f
3504 /* EXP is an expression for the size of an object. If this size contains
3505 discriminant references, replace them with the maximum (if MAX_P) or
3506 minimum (if !MAX_P) possible value of the discriminant. */
3508 tree
3510 {
3515 {
3522 {
3536 }
3540 /* If this contains a PLACEHOLDER_EXPR, it is the thing we want to
3541 modify. Otherwise, we treat it like a variable. */
3543 {
3547 }
3563 {
3568 /* Special-case wanting the maximum value of a MIN_EXPR.
3569 In that case, if one side overflows, return the other. */
3571 {
3577 }
3579 /* Likewise, handle a MINUS_EXPR or PLUS_EXPR with the LHS
3580 overflowing and the RHS a variable. */
3587 /* If we are going to subtract a "negative" value in an unsigned type,
3588 do the operation as an addition of the negated value, in order to
3589 avoid creating a spurious overflow below. */
3595 {
3598 }
3600 /* We need to detect overflows so we call size_binop here. */
3602 }
3606 {
3630 }
3632 /* Other tree classes cannot happen. */
3635 }
3638 }
3639 \f
3640 /* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE.
3641 EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs.
3642 Return a constructor for the template. */
3644 tree
3646 {
3649 tree field;
3661 /* First make the list for a CONSTRUCTOR for the template. Go down the
3662 field list of the template instead of the type chain because this
3663 array might be an Ada array of arrays and we can't tell where the
3664 nested arrays stop being the underlying object. */
3667 (bound_list
3671 {
3674 /* If we have a bound list, get the bounds from there. Likewise
3675 for an ARRAY_TYPE. Otherwise, if expr is a PARM_DECL with
3676 DECL_BY_COMPONENT_PTR_P, use the bounds of the field in the template.
3677 This will give us a maximum range. */
3685 else
3691 /* If either MIN or MAX involve a PLACEHOLDER_EXPR, we must
3692 substitute it from OBJECT. */
3698 }
3701 }
3702 \f
3703 /* Return true if TYPE is suitable for the element type of a vector. */
3705 static bool
3707 {
3708 machine_mode mode;
3722 }
3724 /* Return a vector type given the SIZE and the INNER_TYPE, or NULL_TREE if
3725 this is not possible. If ATTRIBUTE is non-zero, we are processing the
3726 attribute declaration and want to issue error messages on failure. */
3728 static tree
3730 {
3734 /* Silently punt on variable sizes. We can't make vector types for them,
3735 need to ignore them on front-end generated subtypes of unconstrained
3736 base types, and this attribute is for binding implementors, not end
3737 users, so we should never get there from legitimate explicit uses. */
3743 {
3748 }
3752 {
3756 }
3759 {
3763 }
3767 {
3771 }
3774 }
3776 /* Return a vector type whose representative array type is ARRAY_TYPE, or
3777 NULL_TREE if this is not possible. If ATTRIBUTE is non-zero, we are
3778 processing the attribute and want to issue error messages on failure. */
3780 static tree
3782 {
3785 attribute);
3791 }
3792 \f
3793 /* Build a type to be used to represent an aliased object whose nominal type
3794 is an unconstrained array. This consists of a RECORD_TYPE containing a
3795 field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an ARRAY_TYPE.
3796 If ARRAY_TYPE is that of an unconstrained array, this is used to represent
3797 an arbitrary unconstrained object. Use NAME as the name of the record.
3798 DEBUG_INFO_P is true if we need to write debug information for the type. */
3800 tree
3803 {
3804 tree decl;
3806 tree template_field
3809 tree array_field
3818 /* Declare it now since it will never be declared otherwise. This is
3819 necessary to ensure that its subtrees are properly marked. */
3822 /* template_type will not be used elsewhere than here, so to keep the debug
3823 info clean and in order to avoid scoping issues, make decl its
3824 context. */
3828 }
3830 /* Same, taking a thin or fat pointer type instead of a template type. */
3832 tree
3835 {
3836 tree template_type;
3840 template_type
3845 return
3847 }
3848 \f
3849 /* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE.
3850 In the normal case this is just two adjustments, but we have more to
3851 do if NEW_TYPE is an UNCONSTRAINED_ARRAY_TYPE. */
3853 void
3855 {
3858 tree t;
3860 /* If this is the main variant, process all the other variants first. */
3865 /* If no pointers and no references, we are done. */
3869 /* Merge the old type qualifiers in the new type.
3871 Each old variant has qualifiers for specific reasons, and the new
3872 designated type as well. Each set of qualifiers represents useful
3873 information grabbed at some point, and merging the two simply unifies
3874 these inputs into the final type description.
3876 Consider for instance a volatile type frozen after an access to constant
3877 type designating it; after the designated type's freeze, we get here with
3878 a volatile NEW_TYPE and a dummy OLD_TYPE with a readonly variant, created
3879 when the access type was processed. We will make a volatile and readonly
3880 designated type, because that's what it really is.
3882 We might also get here for a non-dummy OLD_TYPE variant with different
3883 qualifiers than those of NEW_TYPE, for instance in some cases of pointers
3884 to private record type elaboration (see the comments around the call to
3885 this routine in gnat_to_gnu_entity <E_Access_Type>). We have to merge
3886 the qualifiers in those cases too, to avoid accidentally discarding the
3887 initial set, and will often end up with OLD_TYPE == NEW_TYPE then. */
3888 new_type
3892 /* If old type and new type are identical, there is nothing to do. */
3896 /* Otherwise, first handle the simple case. */
3898 {
3901 /* If pointer or reference already points to new type, nothing to do.
3902 This can happen as update_pointer_to can be invoked multiple times
3903 on the same couple of types because of the type variants. */
3908 /* Chain PTR and its variants at the end. */
3911 {
3915 }
3916 else
3919 /* Now adjust them. */
3922 {
3926 }
3928 /* Chain REF and its variants at the end. */
3931 {
3935 }
3936 else
3939 /* Now adjust them. */
3946 }
3948 /* Now deal with the unconstrained array case. In this case the pointer
3949 is actually a record where both fields are pointers to dummy nodes.
3950 Turn them into pointers to the correct types using update_pointer_to.
3951 Likewise for the pointer to the object record (thin pointer). */
3952 else
3953 {
3958 /* If PTR already points to NEW_TYPE, nothing to do. This can happen
3959 since update_pointer_to can be invoked multiple times on the same
3960 couple of types because of the type variants. */
3964 update_pointer_to
3968 update_pointer_to
3977 }
3978 }
3979 \f
3980 /* Convert EXPR, a pointer to a constrained array, into a pointer to an
3981 unconstrained one. This involves making or finding a template. */
3983 static tree
3985 {
3989 tree template_addr;
3993 /* If EXPR is null, make a fat pointer that contains a null pointer to the
3994 array (compare_fat_pointers ensures that this is the full discriminant)
3995 and a valid pointer to the bounds. This latter property is necessary
3996 since the compiler can hoist the load of the bounds done through it. */
3998 {
4004 else
4005 {
4006 /* The template type can still be dummy at this point so we build an
4007 empty constructor. The middle-end will fill it in with zeros. */
4012 }
4018 /* Do not set TREE_CONSTANT so as to force T to static memory. */
4023 }
4025 /* If EXPR is a thin pointer, make template and data from the record. */
4027 {
4032 /* If we have a TYPE_UNCONSTRAINED_ARRAY attached to the RECORD_TYPE,
4033 the thin pointer value has been shifted so we shift it back to get
4034 the template address. */
4036 {
4037 template_addr
4040 byte_position
4042 template_addr
4044 template_addr);
4045 }
4047 /* Otherwise we explicitly take the address of the fields. */
4048 else
4049 {
4051 template_addr
4057 }
4058 }
4060 /* Otherwise, build the constructor for the template. */
4061 else
4062 template_addr
4065 expr));
4067 /* The final result is a constructor for the fat pointer.
4069 If EXPR is an argument of a foreign convention subprogram, the type it
4070 points to is directly the component type. In this case, the expression
4071 type may not match the corresponding FIELD_DECL type at this point, so we
4072 call "convert" here to fix that up if necessary. This type consistency is
4073 required, for instance because it ensures that possible later folding of
4074 COMPONENT_REFs against this constructor always yields something of the
4075 same type as the initial reference.
4077 Note that the call to "build_template" above is still fine because it
4078 will only refer to the provided TEMPLATE_TYPE in this case. */
4082 }
4083 \f
4084 /* Create an expression whose value is that of EXPR,
4085 converted to type TYPE. The TREE_TYPE of the value
4086 is always TYPE. This function implements all reasonable
4087 conversions; callers should filter out those that are
4088 not permitted by the language being compiled. */
4090 tree
4092 {
4097 /* If the expression is already of the right type, we are done. */
4101 /* If both input and output have padding and are of variable size, do this
4102 as an unchecked conversion. Likewise if one is a mere variant of the
4103 other, so we avoid a pointless unpad/repad sequence. */
4111 ;
4113 /* If the output type has padding, convert to the inner type and make a
4114 constructor to build the record, unless a variable size is involved. */
4116 {
4119 /* If we previously converted from another type and our type is
4120 of variable size, remove the conversion to avoid the need for
4121 variable-sized temporaries. Likewise for a conversion between
4122 original and packable version. */
4130 /* If we are just removing the padding from expr, convert the original
4131 object if we have variable size in order to avoid the need for some
4132 variable-sized temporaries. Likewise if the padding is a variant
4133 of the other, so we avoid a pointless unpad/repad sequence. */
4144 /* If the inner type is of self-referential size and the expression type
4145 is a record, do this as an unchecked conversion. But first pad the
4146 expression if possible to have the same size on both sides. */
4149 {
4153 expr);
4155 }
4157 /* If we are converting between array types with variable size, do the
4158 final conversion as an unchecked conversion, again to avoid the need
4159 for some variable-sized temporaries. If valid, this conversion is
4160 very likely purely technical and without real effects. */
4167 expr),
4174 }
4176 /* If the input type has padding, remove it and convert to the output type.
4177 The conditions ordering is arranged to ensure that the output type is not
4178 a padding type here, as it is not clear whether the conversion would
4179 always be correct if this was to happen. */
4181 {
4182 tree unpadded;
4184 /* If we have just converted to this padded type, just get the
4185 inner expression. */
4189 /* Otherwise, build an explicit component reference. */
4190 else
4194 }
4196 /* If the input is a biased type, adjust first. */
4203 /* If the input is a justified modular type, we need to extract the actual
4204 object before converting it to any other type with the exceptions of an
4205 unconstrained array or of a mere type variant. It is useful to avoid the
4206 extraction and conversion in the type variant case because it could end
4207 up replacing a VAR_DECL expr by a constructor and we might be about the
4208 take the address of the result. */
4212 return
4215 /* If converting to a type that contains a template, convert to the data
4216 type and then build the template. */
4218 {
4223 /* If the source already has a template, get a reference to the
4224 associated array only, as we are going to rebuild a template
4225 for the target type anyway. */
4235 }
4237 /* There are some cases of expressions that we process specially. */
4239 {
4244 /* Just set its type here. For TRANSFORM_EXPR, we will do the actual
4245 conversion in gnat_expand_expr. NULL_EXPR does not represent
4246 and actual value, so no conversion is needed. */
4252 /* If we are converting a STRING_CST to another constrained array type,
4253 just make a new one in the proper type. */
4257 {
4261 }
4265 /* If we are converting a VECTOR_CST to a mere type variant, just make
4266 a new one in the proper type. */
4268 {
4272 }
4274 /* fall through */
4277 /* If we are converting a CONSTRUCTOR to a mere type variant, or to
4278 another padding type around the same type, just make a new one in
4279 the proper type. */
4286 {
4291 }
4293 /* Likewise for a conversion between original and packable version, or
4294 conversion between types of the same size and with the same list of
4295 fields, but we have to work harder to preserve type consistency. */
4301 {
4310 /* Whether we need to clear TREE_CONSTANT et al. on the output
4311 constructor when we convert in place. */
4315 {
4316 /* Skip the missing fields in the CONSTRUCTOR. */
4318 {
4321 }
4322 /* The field must be the same. */
4325 constructor_elt elt
4329 /* If packing has made this field a bitfield and the input
4330 value couldn't be emitted statically any more, we need to
4331 clear TREE_CONSTANT on our output. */
4341 }
4343 /* If we have been able to match and convert all the input fields
4344 to their output type, convert in place now. We'll fallback to a
4345 view conversion downstream otherwise. */
4347 {
4354 }
4355 }
4357 /* Likewise for a conversion between array type and vector type with a
4358 compatible representative array. */
4362 etype))
4363 {
4368 tree value;
4370 /* Build a VECTOR_CST from a *constant* array constructor. */
4372 {
4375 /* Iterate through elements and check if all constructor
4376 elements are *_CSTs. */
4379 {
4382 }
4387 }
4389 /* Otherwise, build a regular vector constructor. */
4392 {
4395 }
4400 }
4404 /* First retrieve the underlying array. */
4411 {
4412 /* GCC 4.x is very sensitive to type consistency overall, and view
4413 conversions thus are very frequent. Even though just "convert"ing
4414 the inner operand to the output type is fine in most cases, it
4415 might expose unexpected input/output type mismatches in special
4416 circumstances so we avoid such recursive calls when we can. */
4419 /* If we are converting back to the original type, we can just
4420 lift the input conversion. This is a common occurrence with
4421 switches back-and-forth amongst type variants. */
4425 /* Otherwise, if we're converting between two aggregate or vector
4426 types, we might be allowed to substitute the VIEW_CONVERT_EXPR
4427 target type in place or to just convert the inner expression. */
4430 {
4431 /* If we are converting between mere variants, we can just
4432 substitute the VIEW_CONVERT_EXPR in place. */
4436 /* Otherwise, we may just bypass the input view conversion unless
4437 one of the types is a fat pointer, which is handled by
4438 specialized code below which relies on exact type matching. */
4442 }
4445 }
4449 }
4451 /* Check for converting to a pointer to an unconstrained array. */
4455 /* If we are converting between two aggregate or vector types that are mere
4456 variants, just make a VIEW_CONVERT_EXPR. Likewise when we are converting
4457 to a vector type from its representative array type. */
4464 etype)))
4467 /* If we are converting between tagged types, try to upcast properly. */
4470 {
4478 }
4480 /* If we are converting from a smaller form of record type back to it, just
4481 make a VIEW_CONVERT_EXPR. But first pad the expression to have the same
4482 size on both sides. */
4485 {
4488 expr);
4490 }
4492 /* In all other cases of related types, make a NOP_EXPR. */
4497 {
4513 /* fall through */
4517 /* If we are converting an additive expression to an integer type
4518 with lower precision, be wary of the optimization that can be
4519 applied by convert_to_integer. There are 2 problematic cases:
4520 - if the first operand was originally of a biased type,
4521 because we could be recursively called to convert it
4522 to an intermediate type and thus rematerialize the
4523 additive operator endlessly,
4524 - if the expression contains a placeholder, because an
4525 intermediate conversion that changes the sign could
4526 be inserted and thus introduce an artificial overflow
4527 at compile time when the placeholder is substituted. */
4532 {
4539 }
4545 /* If converting between two thin pointers, adjust if needed to account
4546 for differing offsets from the base pointer, depending on whether
4547 there is a TYPE_UNCONSTRAINED_ARRAY attached to the record type. */
4549 {
4550 tree etype_pos
4554 tree type_pos
4566 }
4568 /* If converting fat pointer to normal or thin pointer, get the pointer
4569 to the array and then convert it. */
4580 {
4586 expr));
4588 }
4590 /* fall through */
4593 /* In these cases, assume the front-end has validated the conversion.
4594 If the conversion is valid, it will be a bit-wise conversion, so
4595 it can be viewed as an unchecked conversion. */
4599 /* This is a either a conversion between a tagged type and some
4600 subtype, which we have to mark as a UNION_TYPE because of
4601 overlapping fields or a conversion of an Unchecked_Union. */
4605 /* If the input is a VECTOR_TYPE, convert to the representative
4606 array type first. */
4608 {
4612 }
4614 /* If EXPR is a constrained array, take its address, convert it to a
4615 fat pointer, and then dereference it. Likewise if EXPR is a
4616 record containing both a template and a constrained array.
4617 Note that a record representing a justified modular type
4618 always represents a packed constrained array. */
4623 return
4624 build_unary_op
4630 /* Do something very similar for converting one unconstrained
4631 array to another. */
4633 return
4638 else
4646 }
4647 }
4649 /* Create an expression whose value is that of EXPR converted to the common
4650 index type, which is sizetype. EXPR is supposed to be in the base type
4651 of the GNAT index type. Calling it is equivalent to doing
4653 convert (sizetype, expr)
4655 but we try to distribute the type conversion with the knowledge that EXPR
4656 cannot overflow in its type. This is a best-effort approach and we fall
4657 back to the above expression as soon as difficulties are encountered.
4659 This is necessary to overcome issues that arise when the GNAT base index
4660 type and the GCC common index type (sizetype) don't have the same size,
4661 which is quite frequent on 64-bit architectures. In this case, and if
4662 the GNAT base index type is signed but the iteration type of the loop has
4663 been forced to unsigned, the loop scalar evolution engine cannot compute
4664 a simple evolution for the general induction variables associated with the
4665 array indices, because it will preserve the wrap-around semantics in the
4666 unsigned type of their "inner" part. As a result, many loop optimizations
4667 are blocked.
4669 The solution is to use a special (basic) induction variable that is at
4670 least as large as sizetype, and to express the aforementioned general
4671 induction variables in terms of this induction variable, eliminating
4672 the problematic intermediate truncation to the GNAT base index type.
4673 This is possible as long as the original expression doesn't overflow
4674 and if the middle-end hasn't introduced artificial overflows in the
4675 course of the various simplification it can make to the expression. */
4677 tree
4679 {
4683 /* If the type is unsigned, overflow is allowed so we cannot be sure that
4684 EXPR doesn't overflow. Keep it simple if optimization is disabled. */
4689 {
4691 /* The main effect of the function: replace a loop parameter with its
4692 associated special induction variable. */
4697 CASE_CONVERT:
4698 {
4700 /* Bail out as soon as we suspect some sort of type frobbing. */
4704 }
4706 /* fall through */
4730 }
4733 }
4734 \f
4735 /* Remove all conversions that are done in EXP. This includes converting
4736 from a padded type or to a justified modular type. If TRUE_ADDRESS
4737 is true, always return the address of the containing object even if
4738 the address is not bit-aligned. */
4740 tree
4742 {
4744 {
4749 return
4758 CASE_CONVERT:
4765 }
4768 }
4769 \f
4770 /* If EXP's type is an UNCONSTRAINED_ARRAY_TYPE, return an expression that
4771 refers to the underlying array. If it has TYPE_CONTAINS_TEMPLATE_P,
4772 likewise return an expression pointing to the underlying array. */
4774 tree
4776 {
4781 {
4784 {
4792 {
4793 tree op1
4798 tree op2
4807 }
4808 else
4809 {
4816 }
4817 }
4826 /* If this is a padded type and it contains a template, convert to the
4827 unpadded type first. */
4831 {
4835 }
4838 {
4839 /* If the array initializer is a box, return NULL_TREE. */
4847 /* If the array type is padded, convert to the unpadded type. */
4850 }
4855 }
4858 }
4859 \f
4860 /* Return true if EXPR is an expression that can be folded as an operand
4861 of a VIEW_CONVERT_EXPR. See ada-tree.h for a complete rationale. */
4863 static bool
4865 {
4868 /* The folder will fold NOP_EXPRs between integral types with the same
4869 precision (in the middle-end's sense). We cannot allow it if the
4870 types don't have the same precision in the Ada sense as well. */
4877 /* Defer to the folder for non-integral conversions. */
4881 /* Only fold conversions that preserve both precisions. */
4887 }
4889 /* Return an expression that does an unchecked conversion of EXPR to TYPE.
4890 If NOTRUNC_P is true, truncation operations should be suppressed.
4892 Special care is required with (source or target) integral types whose
4893 precision is not equal to their size, to make sure we fetch or assign
4894 the value bits whose location might depend on the endianness, e.g.
4896 Rmsize : constant := 8;
4897 subtype Int is Integer range 0 .. 2 ** Rmsize - 1;
4899 type Bit_Array is array (1 .. Rmsize) of Boolean;
4900 pragma Pack (Bit_Array);
4902 function To_Bit_Array is new Unchecked_Conversion (Int, Bit_Array);
4904 Value : Int := 2#1000_0001#;
4905 Vbits : Bit_Array := To_Bit_Array (Value);
4907 we expect the 8 bits at Vbits'Address to always contain Value, while
4908 their original location depends on the endianness, at Value'Address
4909 on a little-endian architecture but not on a big-endian one. */
4911 tree
4913 {
4917 tree tem;
4920 /* If the expression is already of the right type, we are done. */
4924 /* If both types are integral just do a normal conversion.
4925 Likewise for a conversion to an unconstrained array. */
4933 {
4935 {
4940 }
4943 {
4949 }
4950 else
4952 }
4954 /* If we are converting to an integral type whose precision is not equal
4955 to its size, first unchecked convert to a record type that contains a
4956 field of the given precision. Then extract the result from the field.
4958 There is a subtlety if the source type is an aggregate type with reverse
4959 storage order because its representation is not contiguous in the native
4960 storage order, i.e. a direct unchecked conversion to an integral type
4961 with N bits of precision cannot read the first N bits of the aggregate
4962 type. To overcome it, we do an unchecked conversion to an integral type
4963 with reverse storage order and return the resulting value. This also
4964 ensures that the result of the unchecked conversion doesn't depend on
4965 the endianness of the target machine, but only on the storage order of
4966 the aggregate type.
4968 Finally, for the sake of consistency, we do the unchecked conversion
4969 to an integral type with reverse storage order as soon as the source
4970 type is an aggregate type with reverse storage order, even if there
4971 are no considerations of precision or size involved. */
4978 {
4989 else
5001 }
5003 /* Similarly if we are converting from an integral type whose precision is
5004 not equal to its size, first copy into a field of the given precision
5005 and unchecked convert the record type.
5007 The same considerations as above apply if the target type is an aggregate
5008 type with reverse storage order and we also proceed similarly. */
5015 {
5028 else
5041 }
5043 /* If we are converting from a scalar type to a type with a different size,
5044 we need to pad to have the same size on both sides.
5046 ??? We cannot do it unconditionally because unchecked conversions are
5047 used liberally by the front-end to implement polymorphism, e.g. in:
5049 S191s : constant ada__tags__addr_ptr := ada__tags__addr_ptr!(S190s);
5050 return p___size__4 (p__object!(S191s.all));
5052 so we skip all expressions that are references. */
5057 {
5059 {
5062 expr);
5064 }
5065 else
5066 {
5071 }
5072 }
5074 /* We have a special case when we are converting between two unconstrained
5075 array types. In that case, take the address, convert the fat pointer
5076 types, and dereference. */
5081 expr)));
5083 /* Another special case is when we are converting to a vector type from its
5084 representative array type; this a regular conversion. */
5088 etype))
5091 /* And, if the array type is not the representative, we try to build an
5092 intermediate vector type of which the array type is the representative
5093 and to do the unchecked conversion between the vector types, in order
5094 to enable further simplifications in the middle-end. */
5098 {
5101 }
5103 /* If we are converting a CONSTRUCTOR to a more aligned RECORD_TYPE, bump
5104 the alignment of the CONSTRUCTOR to speed up the copy operation. */
5108 {
5111 expr);
5113 }
5115 /* Otherwise, just build a VIEW_CONVERT_EXPR of the expression. */
5116 else
5117 {
5123 else
5125 }
5127 /* If the result is an integral type whose precision is not equal to its
5128 size, sign- or zero-extend the result. We need not do this if the input
5129 is an integral type of the same precision and signedness or if the output
5130 is a biased type or if both the input and output are unsigned, or if the
5131 lower bound is constant and non-negative, see E_Signed_Integer_Subtype
5132 case of gnat_to_gnu_entity. */
5148 {
5149 tree base_type
5152 tree shift_expr
5156 expr
5161 shift_expr),
5162 shift_expr));
5163 }
5165 /* An unchecked conversion should never raise Constraint_Error. The code
5166 below assumes that GCC's conversion routines overflow the same way that
5167 the underlying hardware does. This is probably true. In the rare case
5168 when it is false, we can rely on the fact that such conversions are
5169 erroneous anyway. */
5173 /* If the sizes of the types differ and this is an VIEW_CONVERT_EXPR,
5174 show no longer constant. */
5177 OEP_ONLY_CONST))
5181 }
5182 \f
5183 /* Return the appropriate GCC tree code for the specified GNAT_TYPE,
5184 the latter being a record type as predicated by Is_Record_Type. */
5186 enum tree_code
5188 {
5191 /* Return UNION_TYPE if it's an Unchecked_Union whose non-discriminant
5192 fields are all in the variant part. Otherwise, return RECORD_TYPE. */
5197 component_list
5207 }
5209 /* Return true if GNAT_TYPE is a "double" floating-point type, i.e. whose
5210 size is equal to 64 bits, or an array of such a type. Set ALIGN_CLAUSE
5211 according to the presence of an alignment clause on the type or, if it
5212 is an array, on the component type. */
5214 bool
5216 {
5222 {
5226 }
5235 }
5237 /* Return true if GNAT_TYPE is a "double" or larger scalar type, i.e. whose
5238 size is greater or equal to 64 bits, or an array of such a type. Set
5239 ALIGN_CLAUSE according to the presence of an alignment clause on the
5240 type or, if it is an array, on the component type. */
5242 bool
5244 {
5250 {
5254 }
5263 }
5265 /* Return true if GNU_TYPE is suitable as the type of a non-aliased
5266 component of an aggregate type. */
5268 bool
5270 {
5271 /* If the type is passed by reference, we may have pointers to the
5272 component so it cannot be made non-aliased. */
5276 /* We used to say that any component of aggregate type is aliased
5277 because the front-end may take 'Reference of it. The front-end
5278 has been enhanced in the meantime so as to use a renaming instead
5279 in most cases, but the back-end can probably take the address of
5280 such a component too so we go for the conservative stance.
5282 For instance, we might need the address of any array type, even
5283 if normally passed by copy, to construct a fat pointer if the
5284 component is used as an actual for an unconstrained formal.
5286 Likewise for record types: even if a specific record subtype is
5287 passed by copy, the parent type might be passed by ref (e.g. if
5288 it's of variable size) and we might take the address of a child
5289 component to pass to a parent formal. We have no way to check
5290 for such conditions here. */
5295 }
5297 /* Return true if TYPE is a smaller form of ORIG_TYPE. */
5299 bool
5301 {
5304 /* We're not interested in variants here. */
5308 /* Like a variant, a packable version keeps the original TYPE_NAME. */
5319 }
5321 /* Perform final processing on global declarations. */
5325 void
5327 {
5329 tree iter;
5331 /* If we have declared types as used at the global level, insert them in
5332 the global hash table. We use a dummy variable for this purpose, but
5333 we need to build it unconditionally to avoid -fcompare-debug issues. */
5335 {
5340 dummy_global
5342 void_type_node);
5351 {
5354 }
5355 }
5357 /* Output debug information for all global type declarations first. This
5358 ensures that global types whose compilation hasn't been finalized yet,
5359 for example pointers to Taft amendment types, have their compilation
5360 finalized in the right context. */
5365 /* Then output the global variables. We need to do that after the debug
5366 information for global types is emitted so that they are finalized. */
5371 /* Output the imported modules/declarations. In GNAT, these are only
5372 materializing subprogram. */
5377 }
5379 /* ************************************************************************
5380 * * GCC builtins support *
5381 * ************************************************************************ */
5383 /* The general scheme is fairly simple:
5385 For each builtin function/type to be declared, gnat_install_builtins calls
5386 internal facilities which eventually get to gnat_pushdecl, which in turn
5387 tracks the so declared builtin function decls in the 'builtin_decls' global
5388 datastructure. When an Intrinsic subprogram declaration is processed, we
5389 search this global datastructure to retrieve the associated BUILT_IN DECL
5390 node. */
5392 /* Search the chain of currently available builtin declarations for a node
5393 corresponding to function NAME (an IDENTIFIER_NODE). Return the first node
5394 found, if any, or NULL_TREE otherwise. */
5395 tree
5397 {
5399 tree decl;
5406 }
5408 /* The code below eventually exposes gnat_install_builtins, which declares
5409 the builtin types and functions we might need, either internally or as
5410 user accessible facilities.
5412 ??? This is a first implementation shot, still in rough shape. It is
5413 heavily inspired from the "C" family implementation, with chunks copied
5414 verbatim from there.
5416 Two obvious improvement candidates are:
5417 o Use a more efficient name/decl mapping scheme
5418 o Devise a middle-end infrastructure to avoid having to copy
5419 pieces between front-ends. */
5421 /* ----------------------------------------------------------------------- *
5422 * BUILTIN ELEMENTARY TYPES *
5423 * ----------------------------------------------------------------------- */
5425 /* Standard data types to be used in builtin argument declarations. */
5427 enum c_tree_index
5428 {
5430 CTI_STRING_TYPE,
5431 CTI_CONST_STRING_TYPE,
5433 CTI_MAX
5434 };
5438 #define signed_size_type_node c_global_trees[CTI_SIGNED_SIZE_TYPE]
5439 #define string_type_node c_global_trees[CTI_STRING_TYPE]
5440 #define const_string_type_node c_global_trees[CTI_CONST_STRING_TYPE]
5442 /* ??? In addition some attribute handlers, we currently don't support a
5443 (small) number of builtin-types, which in turns inhibits support for a
5444 number of builtin functions. */
5445 #define wint_type_node void_type_node
5446 #define intmax_type_node void_type_node
5447 #define uintmax_type_node void_type_node
5449 /* Used to help initialize the builtin-types.def table. When a type of
5450 the correct size doesn't exist, use error_mark_node instead of NULL.
5451 The later results in segfaults even when a decl using the type doesn't
5452 get invoked. */
5454 static tree
5456 {
5459 }
5461 /* Build/push the elementary type decls that builtin functions/types
5462 will need. */
5464 static void
5466 {
5471 const_string_type_node
5474 }
5476 /* ----------------------------------------------------------------------- *
5477 * BUILTIN FUNCTION TYPES *
5478 * ----------------------------------------------------------------------- */
5480 /* Now, builtin function types per se. */
5482 enum c_builtin_type
5483 {
5484 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
5485 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
5486 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
5487 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
5488 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
5489 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
5490 #define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME,
5491 #define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5492 ARG6) NAME,
5493 #define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5494 ARG6, ARG7) NAME,
5495 #define DEF_FUNCTION_TYPE_8(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5496 ARG6, ARG7, ARG8) NAME,
5497 #define DEF_FUNCTION_TYPE_9(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5498 ARG6, ARG7, ARG8, ARG9) NAME,
5499 #define DEF_FUNCTION_TYPE_10(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5500 ARG6, ARG7, ARG8, ARG9, ARG10) NAME,
5501 #define DEF_FUNCTION_TYPE_11(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5502 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) NAME,
5503 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
5504 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
5505 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
5506 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
5507 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
5508 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5509 NAME,
5510 #define DEF_FUNCTION_TYPE_VAR_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5511 ARG6) NAME,
5512 #define DEF_FUNCTION_TYPE_VAR_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5513 ARG6, ARG7) NAME,
5514 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
5516 #undef DEF_PRIMITIVE_TYPE
5517 #undef DEF_FUNCTION_TYPE_0
5518 #undef DEF_FUNCTION_TYPE_1
5519 #undef DEF_FUNCTION_TYPE_2
5520 #undef DEF_FUNCTION_TYPE_3
5521 #undef DEF_FUNCTION_TYPE_4
5522 #undef DEF_FUNCTION_TYPE_5
5523 #undef DEF_FUNCTION_TYPE_6
5524 #undef DEF_FUNCTION_TYPE_7
5525 #undef DEF_FUNCTION_TYPE_8
5526 #undef DEF_FUNCTION_TYPE_9
5527 #undef DEF_FUNCTION_TYPE_10
5528 #undef DEF_FUNCTION_TYPE_11
5529 #undef DEF_FUNCTION_TYPE_VAR_0
5530 #undef DEF_FUNCTION_TYPE_VAR_1
5531 #undef DEF_FUNCTION_TYPE_VAR_2
5532 #undef DEF_FUNCTION_TYPE_VAR_3
5533 #undef DEF_FUNCTION_TYPE_VAR_4
5534 #undef DEF_FUNCTION_TYPE_VAR_5
5535 #undef DEF_FUNCTION_TYPE_VAR_6
5536 #undef DEF_FUNCTION_TYPE_VAR_7
5537 #undef DEF_POINTER_TYPE
5538 BT_LAST
5539 };
5543 /* A temporary array used in communication with def_fn_type. */
5546 /* A helper function for install_builtin_types. Build function type
5547 for DEF with return type RET and N arguments. If VAR is true, then the
5548 function should be variadic after those N arguments.
5550 Takes special care not to ICE if any of the types involved are
5551 error_mark_node, which indicates that said type is not in fact available
5552 (see builtin_type_for_size). In which case the function type as a whole
5553 should be error_mark_node. */
5555 static void
5557 {
5558 tree t;
5565 {
5571 }
5578 else
5581 egress:
5584 }
5586 /* Build the builtin function types and install them in the builtin_types
5587 array for later use in builtin function decls. */
5589 static void
5591 {
5592 tree va_list_ref_type_node;
5593 tree va_list_arg_type_node;
5596 {
5599 }
5600 else
5601 {
5604 }
5606 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
5607 builtin_types[ENUM] = VALUE;
5608 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \
5609 def_fn_type (ENUM, RETURN, 0, 0);
5610 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \
5611 def_fn_type (ENUM, RETURN, 0, 1, ARG1);
5612 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \
5613 def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2);
5614 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
5615 def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3);
5616 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
5617 def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4);
5618 #define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5619 def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
5620 #define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5621 ARG6) \
5622 def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
5623 #define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5624 ARG6, ARG7) \
5625 def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
5626 #define DEF_FUNCTION_TYPE_8(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5627 ARG6, ARG7, ARG8) \
5628 def_fn_type (ENUM, RETURN, 0, 8, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5629 ARG7, ARG8);
5630 #define DEF_FUNCTION_TYPE_9(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5631 ARG6, ARG7, ARG8, ARG9) \
5632 def_fn_type (ENUM, RETURN, 0, 9, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5633 ARG7, ARG8, ARG9);
5634 #define DEF_FUNCTION_TYPE_10(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5,\
5635 ARG6, ARG7, ARG8, ARG9, ARG10) \
5636 def_fn_type (ENUM, RETURN, 0, 10, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5637 ARG7, ARG8, ARG9, ARG10);
5638 #define DEF_FUNCTION_TYPE_11(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5,\
5639 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) \
5640 def_fn_type (ENUM, RETURN, 0, 11, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5641 ARG7, ARG8, ARG9, ARG10, ARG11);
5642 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \
5643 def_fn_type (ENUM, RETURN, 1, 0);
5644 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \
5645 def_fn_type (ENUM, RETURN, 1, 1, ARG1);
5646 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \
5647 def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2);
5648 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
5649 def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3);
5650 #define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
5651 def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
5652 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5653 def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
5654 #define DEF_FUNCTION_TYPE_VAR_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5655 ARG6) \
5656 def_fn_type (ENUM, RETURN, 1, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
5657 #define DEF_FUNCTION_TYPE_VAR_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5658 ARG6, ARG7) \
5659 def_fn_type (ENUM, RETURN, 1, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
5660 #define DEF_POINTER_TYPE(ENUM, TYPE) \
5661 builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
5665 #undef DEF_PRIMITIVE_TYPE
5666 #undef DEF_FUNCTION_TYPE_0
5667 #undef DEF_FUNCTION_TYPE_1
5668 #undef DEF_FUNCTION_TYPE_2
5669 #undef DEF_FUNCTION_TYPE_3
5670 #undef DEF_FUNCTION_TYPE_4
5671 #undef DEF_FUNCTION_TYPE_5
5672 #undef DEF_FUNCTION_TYPE_6
5673 #undef DEF_FUNCTION_TYPE_7
5674 #undef DEF_FUNCTION_TYPE_8
5675 #undef DEF_FUNCTION_TYPE_9
5676 #undef DEF_FUNCTION_TYPE_10
5677 #undef DEF_FUNCTION_TYPE_11
5678 #undef DEF_FUNCTION_TYPE_VAR_0
5679 #undef DEF_FUNCTION_TYPE_VAR_1
5680 #undef DEF_FUNCTION_TYPE_VAR_2
5681 #undef DEF_FUNCTION_TYPE_VAR_3
5682 #undef DEF_FUNCTION_TYPE_VAR_4
5683 #undef DEF_FUNCTION_TYPE_VAR_5
5684 #undef DEF_FUNCTION_TYPE_VAR_6
5685 #undef DEF_FUNCTION_TYPE_VAR_7
5686 #undef DEF_POINTER_TYPE
5688 }
5690 /* ----------------------------------------------------------------------- *
5691 * BUILTIN ATTRIBUTES *
5692 * ----------------------------------------------------------------------- */
5694 enum built_in_attribute
5695 {
5696 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
5697 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
5698 #define DEF_ATTR_STRING(ENUM, VALUE) ENUM,
5699 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
5700 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
5702 #undef DEF_ATTR_NULL_TREE
5703 #undef DEF_ATTR_INT
5704 #undef DEF_ATTR_STRING
5705 #undef DEF_ATTR_IDENT
5706 #undef DEF_ATTR_TREE_LIST
5707 ATTR_LAST
5708 };
5712 static void
5714 {
5715 /* Fill in the built_in_attributes array. */
5716 #define DEF_ATTR_NULL_TREE(ENUM) \
5717 built_in_attributes[(int) ENUM] = NULL_TREE;
5718 #define DEF_ATTR_INT(ENUM, VALUE) \
5719 built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
5720 #define DEF_ATTR_STRING(ENUM, VALUE) \
5721 built_in_attributes[(int) ENUM] = build_string (strlen (VALUE), VALUE);
5722 #define DEF_ATTR_IDENT(ENUM, STRING) \
5723 built_in_attributes[(int) ENUM] = get_identifier (STRING);
5724 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
5725 built_in_attributes[(int) ENUM] \
5726 = tree_cons (built_in_attributes[(int) PURPOSE], \
5727 built_in_attributes[(int) VALUE], \
5728 built_in_attributes[(int) CHAIN]);
5730 #undef DEF_ATTR_NULL_TREE
5731 #undef DEF_ATTR_INT
5732 #undef DEF_ATTR_STRING
5733 #undef DEF_ATTR_IDENT
5734 #undef DEF_ATTR_TREE_LIST
5735 }
5737 /* Handle a "const" attribute; arguments as in
5738 struct attribute_spec.handler. */
5740 static tree
5744 {
5747 else
5751 }
5753 /* Handle a "nothrow" attribute; arguments as in
5754 struct attribute_spec.handler. */
5756 static tree
5760 {
5763 else
5767 }
5769 /* Handle a "pure" attribute; arguments as in
5770 struct attribute_spec.handler. */
5772 static tree
5775 {
5778 /* TODO: support types. */
5779 else
5780 {
5784 }
5787 }
5789 /* Handle a "no vops" attribute; arguments as in
5790 struct attribute_spec.handler. */
5792 static tree
5796 {
5800 }
5802 /* Helper for nonnull attribute handling; fetch the operand number
5803 from the attribute argument list. */
5805 static bool
5807 {
5808 /* Verify the arg number is a constant. */
5814 }
5816 /* Handle the "nonnull" attribute. */
5817 static tree
5821 {
5825 /* If no arguments are specified, all pointer arguments should be
5826 non-null. Verify a full prototype is given so that the arguments
5827 will have the correct types when we actually check them later.
5828 Avoid diagnosing type-generic built-ins since those have no
5829 prototype. */
5831 {
5835 {
5838 }
5840 }
5842 /* Argument list specified. Verify that each argument number references
5843 a pointer argument. */
5845 {
5849 {
5854 }
5857 {
5858 function_args_iterator iter;
5859 tree argument;
5863 {
5867 }
5871 {
5877 }
5880 {
5886 }
5887 }
5888 }
5891 }
5893 /* Handle a "sentinel" attribute. */
5895 static tree
5898 {
5900 {
5905 }
5906 else
5907 {
5909 {
5914 }
5915 }
5918 {
5922 {
5925 }
5926 else
5927 {
5929 {
5932 }
5933 }
5934 }
5937 }
5939 /* Handle a "noreturn" attribute; arguments as in
5940 struct attribute_spec.handler. */
5942 static tree
5945 {
5948 /* See FIXME comment in c_common_attribute_table. */
5954 = build_pointer_type
5957 else
5958 {
5962 }
5965 }
5967 /* Handle a "noinline" attribute; arguments as in
5968 struct attribute_spec.handler. */
5970 static tree
5974 {
5976 {
5978 {
5982 }
5983 else
5985 }
5986 else
5987 {
5990 }
5993 }
5995 /* Handle a "noclone" attribute; arguments as in
5996 struct attribute_spec.handler. */
5998 static tree
6002 {
6004 {
6007 }
6010 }
6012 /* Handle a "leaf" attribute; arguments as in
6013 struct attribute_spec.handler. */
6015 static tree
6018 {
6020 {
6023 }
6025 {
6028 }
6031 }
6033 /* Handle a "always_inline" attribute; arguments as in
6034 struct attribute_spec.handler. */
6036 static tree
6039 {
6041 {
6042 /* Set the attribute and mark it for disregarding inline limits. */
6044 }
6045 else
6046 {
6049 }
6052 }
6054 /* Handle a "malloc" attribute; arguments as in
6055 struct attribute_spec.handler. */
6057 static tree
6060 {
6064 else
6065 {
6069 }
6072 }
6074 /* Fake handler for attributes we don't properly support. */
6076 tree
6082 {
6084 }
6086 /* Handle a "type_generic" attribute. */
6088 static tree
6092 {
6093 /* Ensure we have a function type. */
6096 /* Ensure we have a variadic function. */
6100 }
6102 /* Handle a "vector_size" attribute; arguments as in
6103 struct attribute_spec.handler. */
6105 static tree
6108 {
6110 tree vector_type;
6114 /* We need to provide for vector pointers, vector arrays, and
6115 functions returning vectors. For example:
6117 __attribute__((vector_size(16))) short *foo;
6119 In this case, the mode is SI, but the type being modified is
6120 HI, so we need to look further. */
6130 /* Build back pointers if needed. */
6134 }
6136 /* Handle a "vector_type" attribute; arguments as in
6137 struct attribute_spec.handler. */
6139 static tree
6142 {
6144 tree vector_type;
6149 {
6153 }
6163 }
6165 /* ----------------------------------------------------------------------- *
6166 * BUILTIN FUNCTIONS *
6167 * ----------------------------------------------------------------------- */
6169 /* Worker for DEF_BUILTIN. Possibly define a builtin function with one or two
6170 names. Does not declare a non-__builtin_ function if flag_no_builtin, or
6171 if nonansi_p and flag_no_nonansi_builtin. */
6173 static void
6181 {
6182 tree decl;
6185 /* Preserve an already installed decl. It most likely was setup in advance
6186 (e.g. as part of the internal builtins) for specific reasons. */
6197 fnattrs);
6199 /* ??? This is normally further controlled by command-line options
6200 like -fno-builtin, but we don't have them for Ada. */
6205 }
6211 /* Install what the common builtins.def offers. */
6213 static void
6215 {
6216 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
6217 NONANSI_P, ATTRS, IMPLICIT, COND) \
6218 if (NAME && COND) \
6219 def_builtin_1 (ENUM, NAME, CLASS, \
6220 builtin_types[(int) TYPE], \
6221 builtin_types[(int) LIBTYPE], \
6222 BOTH_P, FALLBACK_P, NONANSI_P, \
6223 built_in_attributes[(int) ATTRS], IMPLICIT);
6225 }
6227 /* ----------------------------------------------------------------------- *
6228 * BUILTIN FUNCTIONS *
6229 * ----------------------------------------------------------------------- */
6231 /* Install the builtin functions we might need. */
6233 void
6235 {
6240 /* Install builtins used by generic middle-end pieces first. Some of these
6241 know about internal specificities and control attributes accordingly, for
6242 instance __builtin_alloca vs no-throw and -fstack-check. We will ignore
6243 the generic definition from builtins.def. */
6246 /* Now, install the target specific builtins, such as the AltiVec family on
6247 ppc, and the common set as exposed by builtins.def. */
6250 }