| blob | 21e12658380a5a36862f63e038986777944e2c5c |
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 /* Return true if TYPE has an unsigned representation. This needs to be used
1074 when the representation of types whose precision is not equal to their size
1075 is manipulated based on the RM size. */
1079 {
1080 /* This is the common case. */
1084 /* See the E_Signed_Integer_Subtype case of gnat_to_gnu_entity. */
1090 }
1092 /* Given a type TYPE, return a new type whose size is appropriate for SIZE.
1093 If TYPE is the best type, return it. Otherwise, make a new type. We
1094 only support new integral and pointer types. FOR_BIASED is true if
1095 we are making a biased type. */
1097 tree
1099 {
1102 tree new_type;
1104 /* If size indicates an error, just return TYPE to avoid propagating
1105 the error. Likewise if it's too large to represent. */
1112 {
1119 /* Integer types with precision 0 are forbidden. */
1123 /* Only do something if the type isn't a packed array type and doesn't
1124 already have the proper size and the size isn't too large. */
1132 /* The type should be an unsigned type if the original type is unsigned
1133 or if the lower bound is constant and non-negative or if the type is
1134 biased, see E_Signed_Integer_Subtype case of gnat_to_gnu_entity. */
1137 else
1142 /* Copy the name to show that it's essentially the same type and
1143 not a subrange type. */
1150 /* Do something if this is a fat pointer, in which case we
1151 may need to return the thin pointer. */
1153 {
1157 return
1158 build_pointer_type_for_mode
1161 }
1165 /* Only do something if this is a thin pointer, in which case we
1166 may need to return the fat pointer. */
1168 return
1174 }
1177 }
1179 /* See if the data pointed to by the hash table slot is marked. */
1181 int
1183 {
1185 }
1187 /* Return true iff the padded types are equivalent. */
1189 bool
1191 {
1200 /* We consider that the padded types are equivalent if they pad the same type
1201 and have the same size, alignment, RM size and storage order. Taking the
1202 mode into account is redundant since it is determined by the others. */
1203 return
1209 }
1211 /* Look up the padded TYPE in the hash table and return its canonical version
1212 if it exists; otherwise, insert it into the hash table. */
1214 static tree
1216 {
1217 hashval_t hashcode;
1220 hashcode
1237 }
1239 /* Ensure that TYPE has SIZE and ALIGN. Make and return a new padded type
1240 if needed. We have already verified that SIZE and ALIGN are large enough.
1241 GNAT_ENTITY is used to name the resulting record and to issue a warning.
1242 IS_COMPONENT_TYPE is true if this is being done for the component type of
1243 an array. IS_USER_TYPE is true if the original type needs to be completed.
1244 DEFINITION is true if this type is being defined. SET_RM_SIZE is true if
1245 the RM size of the resulting type is to be set to SIZE too; in this case,
1246 the padded type is canonicalized before being returned. */
1248 tree
1252 {
1257 /* If TYPE is a padded type, see if it agrees with any size and alignment
1258 we were given. If so, return the original type. Otherwise, strip
1259 off the padding, since we will either be returning the inner type
1260 or repadding it. If no size or alignment is specified, use that of
1261 the original padded type. */
1263 {
1277 }
1279 /* If the size is either not being changed or is being made smaller (which
1280 is not done here and is only valid for bitfields anyway), show the size
1281 isn't changing. Likewise, clear the alignment if it isn't being
1282 changed. Then return if we aren't doing anything. */
1295 /* If requested, complete the original type and give it a name. */
1302 gnat_entity);
1304 /* We used to modify the record in place in some cases, but that could
1305 generate incorrect debugging information. So make a new record
1306 type and name. */
1310 /* ??? Padding types around packed array implementation types will be
1311 considered as root types in the array descriptor language hook (see
1312 gnat_get_array_descr_info). Give them the original packed array type
1313 name so that the one coming from sources appears in the debugging
1314 information. */
1327 bitsize_unit_node));
1329 /* If we are changing the alignment and the input type is a record with
1330 BLKmode and a small constant size, try to make a form that has an
1331 integral mode. This might allow the padding record to also have an
1332 integral mode, which will be much more efficient. There is no point
1333 in doing so if a size is specified unless it is also a small constant
1334 size and it is incorrect to do so if we cannot guarantee that the mode
1335 will be naturally aligned since the field must always be addressable.
1337 ??? This might not always be a win when done for a stand-alone object:
1338 since the nominal and the effective type of the object will now have
1339 different modes, a VIEW_CONVERT_EXPR will be required for converting
1340 between them and it might be hard to overcome afterwards, including
1341 at the RTL level when the stand-alone object is accessed as a whole. */
1349 && (!size
1352 {
1357 }
1359 /* Now create the field with the original size. */
1364 /* We will output additional debug info manually below. */
1370 /* Set the RM size if requested. */
1372 {
1373 tree canonical_pad_type;
1377 /* If the padded type is complete and has constant size, we canonicalize
1378 it by means of the hash table. This is consistent with the language
1379 semantics and ensures that gigi and the middle-end have a common view
1380 of these padded types. */
1383 {
1386 }
1387 }
1389 /* Unless debugging information isn't being written for the input type,
1390 write a record that shows what we are a subtype of and also make a
1391 variable that indicates our size, if still variable. */
1397 {
1401 /* A variable that holds the size is required even with no encoding since
1402 it will be referenced by debugging information attributes. At global
1403 level, we need a single variable across all translation units. */
1407 {
1408 /* Whether or not gnat_entity comes from source, this XVZ variable is
1409 is a compilation artifact. */
1410 size_unit
1416 }
1418 /* There is no need to show what we are a subtype of when outputting as
1419 few encodings as possible: regular debugging infomation makes this
1420 redundant. */
1422 {
1436 }
1437 }
1439 built:
1440 /* If a simple size was explicitly given, maybe issue a warning. */
1447 /* But don't do it if we are just annotating types and the type is tagged or
1448 concurrent, since these types aren't fully laid out in this mode. */
1450 {
1451 Entity_Id gnat_type
1452 = is_component_type
1457 }
1459 /* Take the original size as the maximum size of the input if there was an
1460 unconstrained record involved and round it up to the specified alignment,
1461 if one was specified, but only for aggregate types. */
1474 {
1477 /* For a packed array, post the message on the original array type. */
1488 /* Generate message only for entities that come from source, since
1489 if we have an entity created by expansion, the message will be
1490 generated for some other corresponding source entity. */
1492 {
1501 }
1502 }
1505 }
1507 /* Return a copy of the padded TYPE but with reverse storage order. */
1509 tree
1511 {
1515 {
1516 /* If the inner type is not scalar then the function does nothing. */
1520 }
1522 /* This is required for the canonicalization. */
1532 }
1533 \f
1534 /* Relate the alias sets of GNU_NEW_TYPE and GNU_OLD_TYPE according to OP.
1535 If this is a multi-dimensional array type, do this recursively.
1537 OP may be
1538 - ALIAS_SET_COPY: the new set is made a copy of the old one.
1539 - ALIAS_SET_SUPERSET: the new set is made a superset of the old one.
1540 - ALIAS_SET_SUBSET: the new set is made a subset of the old one. */
1542 void
1544 {
1545 /* Remove any padding from GNU_OLD_TYPE. It doesn't matter in the case
1546 of a one-dimensional array, since the padding has the same alias set
1547 as the field type, but if it's a multi-dimensional array, we need to
1548 see the inner types. */
1554 /* Unconstrained array types are deemed incomplete and would thus be given
1555 alias set 0. Retrieve the underlying array type. */
1557 gnu_old_type
1560 gnu_new_type
1569 {
1571 /* The alias set shouldn't be copied between array types with different
1572 aliasing settings because this can break the aliasing relationship
1573 between the array type and its element type. */
1585 {
1589 /* Do nothing if the alias sets conflict. This ensures that we
1590 never call record_alias_subset several times for the same pair
1591 or at all for alias set 0. */
1593 {
1596 else
1598 }
1599 }
1604 }
1607 }
1608 \f
1609 /* Record TYPE as a builtin type for Ada. NAME is the name of the type.
1610 ARTIFICIAL_P is true if the type was generated by the compiler. */
1612 void
1614 {
1623 }
1624 \f
1625 /* Finish constructing the character type CHAR_TYPE.
1627 In Ada character types are enumeration types and, as a consequence, are
1628 represented in the front-end by integral types holding the positions of
1629 the enumeration values as defined by the language, which means that the
1630 integral types are unsigned.
1632 Unfortunately the signedness of 'char' in C is implementation-defined
1633 and GCC even has the option -fsigned-char to toggle it at run time.
1634 Since GNAT's philosophy is to be compatible with C by default, to wit
1635 Interfaces.C.char is defined as a mere copy of Character, we may need
1636 to declare character types as signed types in GENERIC and generate the
1637 necessary adjustments to make them behave as unsigned types.
1639 The overall strategy is as follows: if 'char' is unsigned, do nothing;
1640 if 'char' is signed, translate character types of CHAR_TYPE_SIZE and
1641 character subtypes with RM_Size = Esize = CHAR_TYPE_SIZE into signed
1642 types. The idea is to ensure that the bit pattern contained in the
1643 Esize'd objects is not changed, even though the numerical value will
1644 be interpreted differently depending on the signedness.
1646 For character types, the bounds are implicit and, therefore, need to
1647 be adjusted. Morever, the debug info needs the unsigned version. */
1649 void
1651 {
1655 /* Make a copy of a generic unsigned version since we'll modify it. */
1656 tree unsigned_char_type
1658 ? unsigned_char_type_node
1668 }
1670 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
1671 finish constructing the record type as a fat pointer type. */
1673 void
1675 {
1676 /* Make sure we can put it into a register. */
1680 /* Show what it really is. */
1683 /* Do not emit debug info for it since the types of its fields may still be
1684 incomplete at this point. */
1687 /* Force type_contains_placeholder_p to return true on it. Although the
1688 PLACEHOLDER_EXPRs are referenced only indirectly, this isn't a pointer
1689 type but the representation of the unconstrained array. */
1691 }
1693 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
1694 finish constructing the record or union type. If REP_LEVEL is zero, this
1695 record has no representation clause and so will be entirely laid out here.
1696 If REP_LEVEL is one, this record has a representation clause and has been
1697 laid out already; only set the sizes and alignment. If REP_LEVEL is two,
1698 this record is derived from a parent record and thus inherits its layout;
1699 only make a pass on the fields to finalize them. DEBUG_INFO_P is true if
1700 additional debug info needs to be output for this type. */
1702 void
1705 {
1713 tree field;
1717 /* Always attach the TYPE_STUB_DECL for a record type. It is required to
1718 generate debug info and have a parallel type. */
1721 /* Globally initialize the record first. If this is a rep'ed record,
1722 that just means some initializations; otherwise, layout the record. */
1724 {
1734 /* For all-repped records with a size specified, lay the QUAL_UNION_TYPE
1735 out just like a UNION_TYPE, since the size will be fixed. */
1738 }
1739 else
1740 {
1741 /* Ensure there isn't a size already set. There can be in an error
1742 case where there is a rep clause but all fields have errors and
1743 no longer have a position. */
1746 /* Ensure we use the traditional GCC layout for bitfields when we need
1747 to pack the record type or have a representation clause. The other
1748 possible layout (Microsoft C compiler), if available, would prevent
1749 efficient packing in almost all cases. */
1750 #ifdef TARGET_MS_BITFIELD_LAYOUT
1755 ATTR_FLAG_TYPE_IN_PLACE);
1756 #endif
1759 }
1761 /* At this point, the position and size of each field is known. It was
1762 either set before entry by a rep clause, or by laying out the type above.
1764 We now run a pass over the fields (in reverse order for QUAL_UNION_TYPEs)
1765 to compute the Ada size; the GCC size and alignment (for rep'ed records
1766 that are not padding types); and the mode (for rep'ed records). We also
1767 clear the DECL_BIT_FIELD indication for the cases we know have not been
1768 handled yet, and adjust DECL_NONADDRESSABLE_P accordingly. */
1774 {
1778 tree this_ada_size;
1785 else
1788 /* Clear DECL_BIT_FIELD for the cases layout_decl does not handle. */
1791 {
1794 /* In the general case, type alignment is required. */
1796 {
1797 /* The enclosing record type must be sufficiently aligned.
1798 Otherwise, if no alignment was specified for it and it
1799 has been laid out already, bump its alignment to the
1800 desired one if this is compatible with its size and
1801 maximum alignment, if any. */
1803 {
1806 }
1812 {
1816 }
1817 }
1819 /* In the non-strict alignment case, only byte alignment is. */
1824 }
1826 /* If we still have DECL_BIT_FIELD set at this point, we know that the
1827 field is technically not addressable. Except that it can actually
1828 be addressed if it is BLKmode and happens to be properly aligned. */
1834 /* A type must be as aligned as its most aligned field that is not
1835 a bit-field. But this is already enforced by layout_type. */
1841 {
1848 ada_size
1856 /* Since we know here that all fields are sorted in order of
1857 increasing bit position, the size of the record is one
1858 higher than the ending bit of the last field processed
1859 unless we have a rep clause, since in that case we might
1860 have a field outside a QUAL_UNION_TYPE that has a higher ending
1861 position. So use a MAX in that case. Also, if this field is a
1862 QUAL_UNION_TYPE, we need to take into account the previous size in
1863 the case of empty variants. */
1864 ada_size
1867 size
1874 }
1875 }
1881 {
1882 /* If this is a padding record, we never want to make the size smaller
1883 than what was specified in it, if any. */
1887 /* Now set any of the values we've just computed that apply. */
1893 {
1894 tree size_unit = had_size_unit
1898 bitsize_unit_node));
1906 }
1907 }
1909 /* Reset the TYPE_MAX_ALIGN field since it's private to gigi. */
1914 }
1916 /* Append PARALLEL_TYPE on the chain of parallel types of TYPE. If
1917 PARRALEL_TYPE has no context and its computation is not deferred yet, also
1918 propagate TYPE's context to PARALLEL_TYPE's or defer its propagation to the
1919 moment TYPE will get a context. */
1921 void
1923 {
1931 /* If PARALLEL_TYPE already has a context, we are done. */
1935 /* Otherwise, try to get one from TYPE's context. If so, simply propagate
1936 it to PARALLEL_TYPE. */
1940 /* Otherwise TYPE has not context yet. We know it will have one thanks to
1941 gnat_pushdecl and then its context will be propagated to PARALLEL_TYPE,
1942 so we have nothing to do in this case. */
1943 }
1945 /* Return true if TYPE has a parallel type. */
1947 static bool
1949 {
1953 }
1955 /* Wrap up compilation of RECORD_TYPE, i.e. output additional debug info
1956 associated with it. It need not be invoked directly in most cases as
1957 finish_record_type takes care of doing so. */
1959 void
1961 {
1963 tree field;
1965 /* If this is a padded type, the bulk of the debug info has already been
1966 generated for the field's type. */
1970 /* If the type already has a parallel type (XVS type), then we're done. */
1975 {
1976 /* We need to make an XVE/XVU record if any field has variable size,
1977 whether or not the record does. For example, if we have a union,
1978 it may be that all fields, rounded up to the alignment, have the
1979 same size, in which case we'll use that size. But the debug
1980 output routines (except Dwarf2) won't be able to output the fields,
1981 so we need to make the special record. */
1983 /* If a field has a non-constant qualifier, the record will have
1984 variable size too. */
1987 {
1990 }
1991 }
1993 /* If this record type is of variable size, make a parallel record type that
1994 will tell the debugger how the former is laid out (see exp_dbug.ads). */
1996 {
1997 tree new_record_type
2004 new_name
2018 /* Now scan all the fields, replacing each field with a new field
2019 corresponding to the new encoding. */
2022 {
2030 /* We're going to do some pattern matching below so remove as many
2031 conversions as possible. */
2034 /* See how the position was modified from the last position.
2036 There are two basic cases we support: a value was added
2037 to the last position or the last position was rounded to
2038 a boundary and they something was added. Check for the
2039 first case first. If not, see if there is any evidence
2040 of rounding. If so, round the last position and retry.
2042 If this is a union, the position can be taken as zero. */
2045 else
2051 {
2057 }
2062 && tree_fits_uhwi_p
2064 {
2066 unsigned HOST_WIDE_INT addend
2068 align
2074 }
2076 {
2080 }
2082 /* If we can't compute a position, set it to zero.
2084 ??? We really should abort here, but it's too much work
2085 to get this correct for all cases. */
2089 /* See if this type is variable-sized and make a pointer type
2090 and indicate the indirection if so. Beware that the debug
2091 back-end may adjust the position computed above according
2092 to the alignment of the field type, i.e. the pointer type
2093 in this case, if we don't preventively counter that. */
2095 {
2098 {
2101 }
2103 }
2105 /* Make a new field name, if necessary. */
2107 {
2113 else
2117 }
2119 new_field
2125 /* If old_field is a QUAL_UNION_TYPE, take its size as being
2126 zero. The only time it's not the last field of the record
2127 is when there are other components at fixed positions after
2128 it (meaning there was a rep clause for every field) and we
2129 want to be able to encode them. */
2133 ? bitsize_zero_node
2136 }
2141 }
2142 }
2144 /* Utility function of above to merge LAST_SIZE, the previous size of a record
2145 with FIRST_BIT and SIZE that describe a field. SPECIAL is true if this
2146 represents a QUAL_UNION_TYPE in which case we must look for COND_EXPRs and
2147 replace a value of zero with the old size. If HAS_REP is true, we take the
2148 MAX of the end position of this field with LAST_SIZE. In all other cases,
2149 we use FIRST_BIT plus SIZE. Return an expression for the size. */
2151 static tree
2154 {
2156 tree new_size;
2159 {
2163 }
2165 else
2176 /* We don't need any NON_VALUE_EXPRs and they can confuse us (especially
2177 when fed through substitute_in_expr) into thinking that a constant
2178 size is not constant. */
2183 }
2185 /* Utility function of above to see if OP0 and OP1, both of SIZETYPE, are
2186 related by the addition of a constant. Return that constant if so. */
2188 static tree
2190 {
2200 else
2202 }
2204 /* Utility function of above to split a tree OP which may be a sum, into a
2205 constant part, which is returned, and a variable part, which is stored
2206 in *PVAR. *PVAR may be bitsize_zero_node. All operations must be of
2207 bitsizetype. */
2209 static tree
2211 {
2212 /* Strip conversions in order to ease the tree traversal and maximize the
2213 potential for constant or plus/minus discovery. We need to be careful
2214 to always return and set *pvar to bitsizetype trees, but it's worth
2215 the effort. */
2221 {
2224 }
2226 {
2237 }
2238 else
2240 }
2241 \f
2242 /* Return a copy of TYPE but safe to modify in any way. */
2244 tree
2246 {
2249 /* Unshare the language-specific data. */
2251 {
2254 }
2256 /* And the contents of the language-specific slot if needed. */
2259 {
2264 }
2266 /* copy_node clears this field instead of copying it, because it is
2267 aliased with TREE_CHAIN. */
2277 }
2278 \f
2279 /* Return a subtype of sizetype with range MIN to MAX and whose
2280 TYPE_INDEX_TYPE is INDEX. GNAT_NODE is used for the position
2281 of the associated TYPE_DECL. */
2283 tree
2285 {
2286 /* First build a type for the desired range. */
2289 /* Then set the index type. */
2294 }
2296 /* Return a subtype of TYPE with range MIN to MAX. If TYPE is NULL,
2297 sizetype is used. */
2299 tree
2301 {
2302 tree range_type;
2307 /* First build a type with the base range. */
2311 /* Then set the actual range. */
2316 }
2317 \f
2318 /* Return a TYPE_DECL node suitable for the TYPE_STUB_DECL field of TYPE.
2319 NAME gives the name of the type to be used in the declaration. */
2321 tree
2323 {
2328 }
2330 /* Return a TYPE_DECL node for TYPE. NAME gives the name of the type to be
2331 used in the declaration. ARTIFICIAL_P is true if the declaration was
2332 generated by the compiler. DEBUG_INFO_P is true if we need to write
2333 debug information about this type. GNAT_NODE is used for the position
2334 of the decl. */
2336 tree
2338 Node_Id gnat_node)
2339 {
2341 bool is_named
2343 tree type_decl;
2345 /* Only the builtin TYPE_STUB_DECL should be used for dummy types. */
2348 /* If the type hasn't been named yet, we're naming it; preserve an existing
2349 TYPE_STUB_DECL that has been attached to it for some purpose. */
2351 {
2354 }
2355 else
2361 /* Add this decl to the current binding level. */
2364 /* If we're naming the type, equate the TYPE_STUB_DECL to the name. This
2365 causes the name to be also viewed as a "tag" by the debug back-end, with
2366 the advantage that no DW_TAG_typedef is emitted for artificial "tagged"
2367 types in DWARF.
2369 Note that if "type" is used as a DECL_ORIGINAL_TYPE, it may be referenced
2370 from multiple contexts, and "type_decl" references a copy of it: in such a
2371 case, do not mess TYPE_STUB_DECL: we do not want to re-use the TYPE_DECL
2372 with the mechanism above. */
2376 /* Do not generate debug info for UNCONSTRAINED_ARRAY_TYPE that the
2377 back-end doesn't support, and for others if we don't need to. */
2382 }
2383 \f
2384 /* Return a VAR_DECL or CONST_DECL node.
2386 NAME gives the name of the variable. ASM_NAME is its assembler name
2387 (if provided). TYPE is its data type (a GCC ..._TYPE node). INIT is
2388 the GCC tree for an optional initial expression; NULL_TREE if none.
2390 CONST_FLAG is true if this variable is constant, in which case we might
2391 return a CONST_DECL node unless CONST_DECL_ALLOWED_P is false.
2393 PUBLIC_FLAG is true if this is for a reference to a public entity or for a
2394 definition to be made visible outside of the current compilation unit, for
2395 instance variable definitions in a package specification.
2397 EXTERN_FLAG is true when processing an external variable declaration (as
2398 opposed to a definition: no storage is to be allocated for the variable).
2400 STATIC_FLAG is only relevant when not at top level and indicates whether
2401 to always allocate storage to the variable.
2403 VOLATILE_FLAG is true if this variable is declared as volatile.
2405 ARTIFICIAL_P is true if the variable was generated by the compiler.
2407 DEBUG_INFO_P is true if we need to write debug information for it.
2409 ATTR_LIST is the list of attributes to be attached to the variable.
2411 GNAT_NODE is used for the position of the decl. */
2413 tree
2419 {
2420 /* Whether the object has static storage duration, either explicitly or by
2421 virtue of being declared at the global level. */
2424 /* Whether the initializer is constant: for an external object or an object
2425 with static storage duration, we check that the initializer is a valid
2426 constant expression for initializing a static variable; otherwise, we
2427 only check that it is constant. */
2428 const bool init_const
2429 = (init
2433 != NULL_TREE
2436 /* Whether we will make TREE_CONSTANT the DECL we produce here, in which
2437 case the initializer may be used in lieu of the DECL node (as done in
2438 Identifier_to_gnu). This is useful to prevent the need of elaboration
2439 code when an identifier for which such a DECL is made is in turn used
2440 as an initializer. We used to rely on CONST_DECL vs VAR_DECL for this,
2441 but extra constraints apply to this choice (see below) and they are not
2442 relevant to the distinction we wish to make. */
2445 /* The actual DECL node. CONST_DECL was initially intended for enumerals
2446 and may be used for scalars in general but not for aggregates. */
2447 tree var_decl
2449 (constant_p
2450 && const_decl_allowed_p
2454 /* Detect constants created by the front-end to hold 'reference to function
2455 calls for stabilization purposes. This is needed for renaming. */
2457 {
2468 }
2470 /* If this is external, throw away any initializations (they will be done
2471 elsewhere) unless this is a constant for which we would like to remain
2472 able to get the initializer. If we are defining a global here, leave a
2473 constant initialization and save any variable elaborations for the
2474 elaboration routine. If we are just annotating types, throw away the
2475 initialization if it isn't a constant. */
2478 {
2481 /* In LTO mode, also clear TREE_READONLY the same way add_decl_expr
2482 would do it if the initializer was not thrown away here, as the
2483 WPA phase requires a consistent view across compilation units. */
2485 {
2488 }
2489 }
2491 /* At the global level, a non-constant initializer generates elaboration
2492 statements. Check that such statements are allowed, that is to say,
2493 not violating a No_Elaboration_Code restriction. */
2497 /* Attach the initializer, if any. */
2500 /* Directly set some flags. */
2507 /* The object is public if it is external or if it is declared public
2508 and has static storage duration. */
2511 /* We need to allocate static storage for an object with static storage
2512 duration if it isn't external. */
2522 /* Ada doesn't feature Fortran-like COMMON variables so we shouldn't
2523 try to fiddle with DECL_COMMON. However, on platforms that don't
2524 support global BSS sections, uninitialized global variables would
2525 go in DATA instead, thus increasing the size of the executable. */
2532 /* Do not emit debug info for a CONST_DECL if optimization isn't enabled,
2533 since we will create an associated variable. Likewise for an external
2534 constant whose initializer is not absolute, because this would mean a
2535 global relocation in a read-only section which runs afoul of the PE-COFF
2536 run-time relocation mechanism. */
2539 || (extern_flag
2540 && constant_p
2541 && init
2546 /* ??? Some attributes cannot be applied to CONST_DECLs. */
2550 /* Add this decl to the current binding level. */
2554 {
2555 /* Let the target mangle the name if this isn't a verbatim asm. */
2560 }
2563 }
2564 \f
2565 /* Return true if TYPE, an aggregate type, contains (or is) an array. */
2567 static bool
2569 {
2571 {
2575 {
2576 tree field;
2582 }
2589 }
2590 }
2592 /* Return a FIELD_DECL node. NAME is the field's name, TYPE is its type and
2593 RECORD_TYPE is the type of the enclosing record. If SIZE is nonzero, it
2594 is the specified size of the field. If POS is nonzero, it is the bit
2595 position. PACKED is 1 if the enclosing record is packed, -1 if it has
2596 Component_Alignment of Storage_Unit. If ADDRESSABLE is nonzero, it
2597 means we are allowed to take the address of the field; if it is negative,
2598 we should not make a bitfield, which is used by make_aligning_type. */
2600 tree
2603 {
2609 /* If FIELD_TYPE is BLKmode, we must ensure this is aligned to at least a
2610 byte boundary since GCC cannot handle less-aligned BLKmode bitfields.
2611 Likewise for an aggregate without specified position that contains an
2612 array, because in this case slices of variable length of this array
2613 must be handled by GCC and variable-sized objects need to be aligned
2614 to at least a byte boundary. */
2616 || (!pos
2621 /* If a size is specified, use it. Otherwise, if the record type is packed
2622 compute a size to use, which may differ from the object's natural size.
2623 We always set a size in this case to trigger the checks for bitfield
2624 creation below, which is typically required when no position has been
2625 specified. */
2629 {
2633 }
2635 /* If we may, according to ADDRESSABLE, make a bitfield if a size is
2636 specified for two reasons: first if the size differs from the natural
2637 size. Second, if the alignment is insufficient. There are a number of
2638 ways the latter can be true.
2640 We never make a bitfield if the type of the field has a nonconstant size,
2641 because no such entity requiring bitfield operations should reach here.
2643 We do *preventively* make a bitfield when there might be the need for it
2644 but we don't have all the necessary information to decide, as is the case
2645 of a field with no specified position in a packed record.
2647 We also don't look at STRICT_ALIGNMENT here, and rely on later processing
2648 in layout_decl or finish_record_type to clear the bit_field indication if
2649 it is in fact not needed. */
2651 && size
2656 || packed
2659 {
2663 {
2667 else
2669 }
2670 }
2674 /* Bump the alignment if need be, either for bitfield/packing purposes or
2675 to satisfy the type requirements if no such consideration applies. When
2676 we get the alignment from the type, indicate if this is from an explicit
2677 user request, which prevents stor-layout from lowering it later on. */
2678 {
2679 unsigned int bit_align
2686 {
2689 }
2690 }
2693 {
2694 /* We need to pass in the alignment the DECL is known to have.
2695 This is the lowest-order bit set in POS, but no more than
2696 the alignment of the record, if one is specified. Note
2697 that an alignment of 0 is taken as infinite. */
2702 else
2716 }
2718 /* In addition to what our caller says, claim the field is addressable if we
2719 know that its type is not suitable.
2721 The field may also be "technically" nonaddressable, meaning that even if
2722 we attempt to take the field's address we will actually get the address
2723 of a copy. This is the case for true bitfields, but the DECL_BIT_FIELD
2724 value we have at this point is not accurate enough, so we don't account
2725 for this here and let finish_record_type decide. */
2732 }
2733 \f
2734 /* Return a PARM_DECL node with NAME and TYPE. */
2736 tree
2738 {
2741 /* Honor TARGET_PROMOTE_PROTOTYPES like the C compiler, as not doing so
2742 can lead to various ABI violations. */
2746 {
2747 /* We have to be careful about biased types here. Make a subtype
2748 of integer_type_node with the proper biasing. */
2751 {
2752 tree subtype
2759 }
2760 else
2762 }
2766 }
2767 \f
2768 /* Process the attributes in ATTR_LIST for NODE, which is either a DECL or
2769 a TYPE. If IN_PLACE is true, the tree pointed to by NODE should not be
2770 changed. GNAT_NODE is used for the position of error messages. */
2772 void
2774 Node_Id gnat_node)
2775 {
2780 {
2789 {
2792 }
2798 else
2805 {
2808 }
2809 else
2828 }
2831 }
2833 /* Return true if VALUE is a known to be a multiple of FACTOR, which must be
2834 a power of 2. */
2836 bool
2838 {
2847 }
2849 /* Return whether GNAT_NODE is a defining identifier for a renaming that comes
2850 from the parameter association for the instantiation of a generic. We do
2851 not want to emit source location for them: the code generated for their
2852 initialization is likely to disturb debugging. */
2854 bool
2856 {
2863 /* Get the object declaration of the renamed object, if any and if the
2864 renamed object is a mere identifier. */
2874 return
2878 }
2880 /* Defer the initialization of DECL's DECL_CONTEXT attribute, scheduling to
2881 feed it with the elaboration of GNAT_SCOPE. */
2885 {
2888 new_node
2897 }
2899 /* Defer the initialization of TYPE's TYPE_CONTEXT attribute, scheduling to
2900 feed it with the DECL_CONTEXT computed as part of N as soon as it is
2901 computed. */
2903 static void
2905 {
2907 }
2909 /* Get the GENERIC node corresponding to GNAT_SCOPE, if available. Return
2910 NULL_TREE if it is not available. */
2912 static tree
2914 {
2915 tree context;
2919 else
2923 {
2926 /* Skip dummy types: only the final ones can appear in the context
2927 chain. */
2931 /* ..._TYPE nodes are more useful than TYPE_DECL nodes in the context
2932 chain. */
2933 else
2935 }
2938 }
2940 /* Try to process all deferred nodes in the queue. Keep in the queue the ones
2941 that cannot be processed yet, remove the other ones. If FORCE is true,
2942 force the processing for all nodes, use the global context when nodes don't
2943 have a GNU translation. */
2945 void
2947 {
2952 {
2955 Entity_Id gnat_scope;
2959 /* If FORCE, get the innermost elaborated scope. Otherwise, just try to
2960 get the first scope. */
2963 {
2968 }
2970 /* Imported declarations must not be in a local context (i.e. not inside
2971 a function). */
2973 {
2977 {
2980 }
2981 }
2983 /* If FORCE, we want to get rid of all nodes in the queue: in case there
2984 was no elaborated scope, use the global context. */
2989 {
2990 tree t;
2995 /* Propagate it to the TYPE_CONTEXT attributes of the requested
2996 ..._TYPE nodes. */
2998 {
3000 }
3002 }
3004 /* If this node has been successfuly processed, remove it from the
3005 queue. Then move to the next node. */
3007 {
3011 }
3012 else
3014 }
3015 }
3018 /* Return VALUE scaled by the biggest power-of-2 factor of EXPR. */
3020 static unsigned int
3022 {
3026 /* Peel conversions around EXPR and try to extract bodies from function
3027 calls: it is possible to get the scale factor from size functions. */
3032 /* Sometimes we get PLUS_EXPR (BIT_AND_EXPR (..., X), Y), where Y is a
3033 multiple of the scale factor we are looking for. */
3037 {
3040 }
3042 /* An expression which is a bitwise AND with a mask has a power-of-2 factor
3043 corresponding to the number of trailing zeros of the mask. */
3046 {
3051 {
3054 i++;
3055 }
3056 }
3058 /* If the addend is not a multiple of the factor we found, give up. In
3059 theory we could find a smaller common factor but it's useless for our
3060 needs. This situation arises when dealing with a field F1 with no
3061 alignment requirement but that is following a field F2 with such
3062 requirements. As long as we have F2's offset, we don't need alignment
3063 information to compute F1's. */
3068 }
3070 /* Given two consecutive field decls PREV_FIELD and CURR_FIELD, return true
3071 unless we can prove these 2 fields are laid out in such a way that no gap
3072 exist between the end of PREV_FIELD and the beginning of CURR_FIELD. OFFSET
3073 is the distance in bits between the end of PREV_FIELD and the starting
3074 position of CURR_FIELD. It is ignored if null. */
3076 static bool
3078 {
3079 /* If this is the first field of the record, there cannot be any gap */
3083 /* If the previous field is a union type, then return false: The only
3084 time when such a field is not the last field of the record is when
3085 there are other components at fixed positions after it (meaning there
3086 was a rep clause for every field), in which case we don't want the
3087 alignment constraint to override them. */
3091 /* If the distance between the end of prev_field and the beginning of
3092 curr_field is constant, then there is a gap if the value of this
3093 constant is not null. */
3097 /* If the size and position of the previous field are constant,
3098 then check the sum of this size and position. There will be a gap
3099 iff it is not multiple of the current field alignment. */
3106 /* If both the position and size of the previous field are multiples
3107 of the current field alignment, there cannot be any gap. */
3112 /* Fallback, return that there may be a potential gap */
3114 }
3116 /* Return a LABEL_DECL with NAME. GNAT_NODE is used for the position of
3117 the decl. */
3119 tree
3121 {
3122 tree label_decl
3127 /* Add this decl to the current binding level. */
3131 }
3132 \f
3133 /* Return a FUNCTION_DECL node. NAME is the name of the subprogram, ASM_NAME
3134 its assembler name, TYPE its type (a FUNCTION_TYPE node), PARAM_DECL_LIST
3135 the list of its parameters (a list of PARM_DECL nodes chained through the
3136 DECL_CHAIN field).
3138 INLINE_STATUS describes the inline flags to be set on the FUNCTION_DECL.
3140 PUBLIC_FLAG is true if this is for a reference to a public entity or for a
3141 definition to be made visible outside of the current compilation unit.
3143 EXTERN_FLAG is true when processing an external subprogram declaration.
3145 ARTIFICIAL_P is true if the subprogram was generated by the compiler.
3147 DEBUG_INFO_P is true if we need to write debug information for it.
3149 ATTR_LIST is the list of attributes to be attached to the subprogram.
3151 GNAT_NODE is used for the position of the decl. */
3153 tree
3158 {
3170 {
3183 ATTR_FLAG_TYPE_IN_PLACE);
3185 /* ... fall through ... */
3194 }
3198 /* Once everything is processed, finish the subprogram declaration. */
3201 /* Add this decl to the current binding level. */
3204 /* Output the assembler code and/or RTL for the declaration. */
3208 }
3210 /* Given a subprogram declaration DECL, its assembler name and its type,
3211 finish constructing the subprogram declaration from ASM_NAME and TYPE. */
3213 void
3215 {
3216 tree result_decl
3229 {
3230 /* Let the target mangle the name if this isn't a verbatim asm. */
3236 /* The expand_main_function circuitry expects "main_identifier_node" to
3237 designate the DECL_NAME of the 'main' entry point, in turn expected
3238 to be declared as the "main" function literally by default. Ada
3239 program entry points are typically declared with a different name
3240 within the binder generated file, exported as 'main' to satisfy the
3241 system expectations. Force main_identifier_node in this case. */
3244 }
3245 }
3246 \f
3247 /* Set up the framework for generating code for SUBPROG_DECL, a subprogram
3248 body. This routine needs to be invoked before processing the declarations
3249 appearing in the subprogram. */
3251 void
3253 {
3254 tree param_decl;
3258 /* This function is being defined. */
3261 /* The failure of this assertion will likely come from a wrong context for
3262 the subprogram body, e.g. another procedure for a procedure declared at
3263 library level. */
3268 /* Enter a new binding level and show that all the parameters belong to
3269 this function. */
3277 }
3279 /* Finish translating the current subprogram and set its BODY. */
3281 void
3283 {
3286 /* Attach the BLOCK for this level to the function and pop the level. */
3291 /* Mark the RESULT_DECL as being in this subprogram. */
3294 /* The body should be a BIND_EXPR whose BLOCK is the top-level one. */
3296 {
3299 }
3304 }
3306 /* Wrap up compilation of SUBPROG_DECL, a subprogram body. */
3308 void
3310 {
3311 /* We cannot track the location of errors past this point. */
3314 /* If we're only annotating types, don't actually compile this function. */
3318 /* Dump functions before gimplification. */
3323 else
3324 /* Register this function with cgraph just far enough to get it
3325 added to our parent's nested function list. */
3327 }
3329 tree
3331 {
3334 }
3336 /* Return an integer type with the number of bits of precision given by
3337 PRECISION. UNSIGNEDP is nonzero if the type is unsigned; otherwise
3338 it is a signed type. */
3340 tree
3342 {
3343 tree t;
3352 else
3359 {
3362 }
3365 }
3367 /* Likewise for floating-point types. */
3369 static tree
3371 {
3372 tree t;
3384 {
3387 }
3390 }
3392 /* Return a data type that has machine mode MODE. UNSIGNEDP selects
3393 an unsigned type; otherwise a signed type is returned. */
3395 tree
3397 {
3414 {
3419 }
3422 }
3424 /* Return the signed or unsigned version of TYPE_NODE, a scalar type, the
3425 signedness being specified by UNSIGNEDP. */
3427 tree
3429 {
3436 {
3439 }
3443 {
3446 }
3449 }
3451 /* Return 1 if the types T1 and T2 are compatible, i.e. if they can be
3452 transparently converted to each other. */
3454 int
3456 {
3459 /* This is the default criterion. */
3463 /* We only check structural equivalence here. */
3467 /* Vector types are also compatible if they have the same number of subparts
3468 and the same form of (scalar) element type. */
3475 /* Array types are also compatible if they are constrained and have the same
3476 domain(s), the same component type and the same scalar storage order. */
3492 }
3494 /* Return true if EXPR is a useless type conversion. */
3496 bool
3498 {
3506 }
3508 /* Return true if T, a FUNCTION_TYPE, has the specified list of flags. */
3510 bool
3513 {
3518 }
3519 \f
3520 /* EXP is an expression for the size of an object. If this size contains
3521 discriminant references, replace them with the maximum (if MAX_P) or
3522 minimum (if !MAX_P) possible value of the discriminant. */
3524 tree
3526 {
3531 {
3538 {
3552 }
3556 /* If this contains a PLACEHOLDER_EXPR, it is the thing we want to
3557 modify. Otherwise, we treat it like a variable. */
3559 {
3563 }
3579 {
3584 /* Special-case wanting the maximum value of a MIN_EXPR.
3585 In that case, if one side overflows, return the other. */
3587 {
3593 }
3595 /* Likewise, handle a MINUS_EXPR or PLUS_EXPR with the LHS
3596 overflowing and the RHS a variable. */
3603 /* If we are going to subtract a "negative" value in an unsigned type,
3604 do the operation as an addition of the negated value, in order to
3605 avoid creating a spurious overflow below. */
3611 {
3614 }
3616 /* We need to detect overflows so we call size_binop here. */
3618 }
3622 {
3646 }
3648 /* Other tree classes cannot happen. */
3651 }
3654 }
3655 \f
3656 /* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE.
3657 EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs.
3658 Return a constructor for the template. */
3660 tree
3662 {
3665 tree field;
3677 /* First make the list for a CONSTRUCTOR for the template. Go down the
3678 field list of the template instead of the type chain because this
3679 array might be an Ada array of arrays and we can't tell where the
3680 nested arrays stop being the underlying object. */
3683 (bound_list
3687 {
3690 /* If we have a bound list, get the bounds from there. Likewise
3691 for an ARRAY_TYPE. Otherwise, if expr is a PARM_DECL with
3692 DECL_BY_COMPONENT_PTR_P, use the bounds of the field in the template.
3693 This will give us a maximum range. */
3701 else
3707 /* If either MIN or MAX involve a PLACEHOLDER_EXPR, we must
3708 substitute it from OBJECT. */
3714 }
3717 }
3718 \f
3719 /* Return true if TYPE is suitable for the element type of a vector. */
3721 static bool
3723 {
3724 machine_mode mode;
3738 }
3740 /* Return a vector type given the SIZE and the INNER_TYPE, or NULL_TREE if
3741 this is not possible. If ATTRIBUTE is non-zero, we are processing the
3742 attribute declaration and want to issue error messages on failure. */
3744 static tree
3746 {
3750 /* Silently punt on variable sizes. We can't make vector types for them,
3751 need to ignore them on front-end generated subtypes of unconstrained
3752 base types, and this attribute is for binding implementors, not end
3753 users, so we should never get there from legitimate explicit uses. */
3759 {
3764 }
3768 {
3772 }
3775 {
3779 }
3783 {
3787 }
3790 }
3792 /* Return a vector type whose representative array type is ARRAY_TYPE, or
3793 NULL_TREE if this is not possible. If ATTRIBUTE is non-zero, we are
3794 processing the attribute and want to issue error messages on failure. */
3796 static tree
3798 {
3801 attribute);
3807 }
3808 \f
3809 /* Build a type to be used to represent an aliased object whose nominal type
3810 is an unconstrained array. This consists of a RECORD_TYPE containing a
3811 field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an ARRAY_TYPE.
3812 If ARRAY_TYPE is that of an unconstrained array, this is used to represent
3813 an arbitrary unconstrained object. Use NAME as the name of the record.
3814 DEBUG_INFO_P is true if we need to write debug information for the type. */
3816 tree
3819 {
3820 tree decl;
3822 tree template_field
3825 tree array_field
3834 /* Declare it now since it will never be declared otherwise. This is
3835 necessary to ensure that its subtrees are properly marked. */
3838 /* template_type will not be used elsewhere than here, so to keep the debug
3839 info clean and in order to avoid scoping issues, make decl its
3840 context. */
3844 }
3846 /* Same, taking a thin or fat pointer type instead of a template type. */
3848 tree
3851 {
3852 tree template_type;
3856 template_type
3861 return
3863 }
3864 \f
3865 /* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE.
3866 In the normal case this is just two adjustments, but we have more to
3867 do if NEW_TYPE is an UNCONSTRAINED_ARRAY_TYPE. */
3869 void
3871 {
3874 tree t;
3876 /* If this is the main variant, process all the other variants first. */
3881 /* If no pointers and no references, we are done. */
3885 /* Merge the old type qualifiers in the new type.
3887 Each old variant has qualifiers for specific reasons, and the new
3888 designated type as well. Each set of qualifiers represents useful
3889 information grabbed at some point, and merging the two simply unifies
3890 these inputs into the final type description.
3892 Consider for instance a volatile type frozen after an access to constant
3893 type designating it; after the designated type's freeze, we get here with
3894 a volatile NEW_TYPE and a dummy OLD_TYPE with a readonly variant, created
3895 when the access type was processed. We will make a volatile and readonly
3896 designated type, because that's what it really is.
3898 We might also get here for a non-dummy OLD_TYPE variant with different
3899 qualifiers than those of NEW_TYPE, for instance in some cases of pointers
3900 to private record type elaboration (see the comments around the call to
3901 this routine in gnat_to_gnu_entity <E_Access_Type>). We have to merge
3902 the qualifiers in those cases too, to avoid accidentally discarding the
3903 initial set, and will often end up with OLD_TYPE == NEW_TYPE then. */
3904 new_type
3908 /* If old type and new type are identical, there is nothing to do. */
3912 /* Otherwise, first handle the simple case. */
3914 {
3917 /* If pointer or reference already points to new type, nothing to do.
3918 This can happen as update_pointer_to can be invoked multiple times
3919 on the same couple of types because of the type variants. */
3924 /* Chain PTR and its variants at the end. */
3927 {
3931 }
3932 else
3935 /* Now adjust them. */
3938 {
3942 }
3944 /* Chain REF and its variants at the end. */
3947 {
3951 }
3952 else
3955 /* Now adjust them. */
3962 }
3964 /* Now deal with the unconstrained array case. In this case the pointer
3965 is actually a record where both fields are pointers to dummy nodes.
3966 Turn them into pointers to the correct types using update_pointer_to.
3967 Likewise for the pointer to the object record (thin pointer). */
3968 else
3969 {
3974 /* If PTR already points to NEW_TYPE, nothing to do. This can happen
3975 since update_pointer_to can be invoked multiple times on the same
3976 couple of types because of the type variants. */
3980 update_pointer_to
3984 update_pointer_to
3993 }
3994 }
3995 \f
3996 /* Convert EXPR, a pointer to a constrained array, into a pointer to an
3997 unconstrained one. This involves making or finding a template. */
3999 static tree
4001 {
4005 tree template_addr;
4009 /* If EXPR is null, make a fat pointer that contains a null pointer to the
4010 array (compare_fat_pointers ensures that this is the full discriminant)
4011 and a valid pointer to the bounds. This latter property is necessary
4012 since the compiler can hoist the load of the bounds done through it. */
4014 {
4020 else
4021 {
4022 /* The template type can still be dummy at this point so we build an
4023 empty constructor. The middle-end will fill it in with zeros. */
4028 }
4034 /* Do not set TREE_CONSTANT so as to force T to static memory. */
4039 }
4041 /* If EXPR is a thin pointer, make template and data from the record. */
4043 {
4048 /* If we have a TYPE_UNCONSTRAINED_ARRAY attached to the RECORD_TYPE,
4049 the thin pointer value has been shifted so we shift it back to get
4050 the template address. */
4052 {
4053 template_addr
4056 byte_position
4058 template_addr
4060 template_addr);
4061 }
4063 /* Otherwise we explicitly take the address of the fields. */
4064 else
4065 {
4067 template_addr
4073 }
4074 }
4076 /* Otherwise, build the constructor for the template. */
4077 else
4078 template_addr
4081 expr));
4083 /* The final result is a constructor for the fat pointer.
4085 If EXPR is an argument of a foreign convention subprogram, the type it
4086 points to is directly the component type. In this case, the expression
4087 type may not match the corresponding FIELD_DECL type at this point, so we
4088 call "convert" here to fix that up if necessary. This type consistency is
4089 required, for instance because it ensures that possible later folding of
4090 COMPONENT_REFs against this constructor always yields something of the
4091 same type as the initial reference.
4093 Note that the call to "build_template" above is still fine because it
4094 will only refer to the provided TEMPLATE_TYPE in this case. */
4098 }
4099 \f
4100 /* Create an expression whose value is that of EXPR,
4101 converted to type TYPE. The TREE_TYPE of the value
4102 is always TYPE. This function implements all reasonable
4103 conversions; callers should filter out those that are
4104 not permitted by the language being compiled. */
4106 tree
4108 {
4113 /* If the expression is already of the right type, we are done. */
4117 /* If both input and output have padding and are of variable size, do this
4118 as an unchecked conversion. Likewise if one is a mere variant of the
4119 other, so we avoid a pointless unpad/repad sequence. */
4127 ;
4129 /* If the output type has padding, convert to the inner type and make a
4130 constructor to build the record, unless a variable size is involved. */
4132 {
4135 /* If we previously converted from another type and our type is
4136 of variable size, remove the conversion to avoid the need for
4137 variable-sized temporaries. Likewise for a conversion between
4138 original and packable version. */
4146 /* If we are just removing the padding from expr, convert the original
4147 object if we have variable size in order to avoid the need for some
4148 variable-sized temporaries. Likewise if the padding is a variant
4149 of the other, so we avoid a pointless unpad/repad sequence. */
4160 /* If the inner type is of self-referential size and the expression type
4161 is a record, do this as an unchecked conversion. But first pad the
4162 expression if possible to have the same size on both sides. */
4165 {
4169 expr);
4171 }
4173 /* If we are converting between array types with variable size, do the
4174 final conversion as an unchecked conversion, again to avoid the need
4175 for some variable-sized temporaries. If valid, this conversion is
4176 very likely purely technical and without real effects. */
4183 expr),
4190 }
4192 /* If the input type has padding, remove it and convert to the output type.
4193 The conditions ordering is arranged to ensure that the output type is not
4194 a padding type here, as it is not clear whether the conversion would
4195 always be correct if this was to happen. */
4197 {
4198 tree unpadded;
4200 /* If we have just converted to this padded type, just get the
4201 inner expression. */
4205 /* Otherwise, build an explicit component reference. */
4206 else
4210 }
4212 /* If the input is a biased type, convert first to the base type and add
4213 the bias. Note that the bias must go through a full conversion to the
4214 base type, lest it is itself a biased value; this happens for subtypes
4215 of biased types. */
4222 /* If the input is a justified modular type, we need to extract the actual
4223 object before converting it to any other type with the exceptions of an
4224 unconstrained array or of a mere type variant. It is useful to avoid the
4225 extraction and conversion in the type variant case because it could end
4226 up replacing a VAR_DECL expr by a constructor and we might be about the
4227 take the address of the result. */
4231 return
4234 /* If converting to a type that contains a template, convert to the data
4235 type and then build the template. */
4237 {
4242 /* If the source already has a template, get a reference to the
4243 associated array only, as we are going to rebuild a template
4244 for the target type anyway. */
4254 }
4256 /* There are some cases of expressions that we process specially. */
4258 {
4263 /* Just set its type here. For TRANSFORM_EXPR, we will do the actual
4264 conversion in gnat_expand_expr. NULL_EXPR does not represent
4265 and actual value, so no conversion is needed. */
4271 /* If we are converting a STRING_CST to another constrained array type,
4272 just make a new one in the proper type. */
4276 {
4280 }
4284 /* If we are converting a VECTOR_CST to a mere type variant, just make
4285 a new one in the proper type. */
4287 {
4291 }
4295 /* If we are converting a CONSTRUCTOR to a mere type variant, or to
4296 another padding type around the same type, just make a new one in
4297 the proper type. */
4304 {
4309 }
4311 /* Likewise for a conversion between original and packable version, or
4312 conversion between types of the same size and with the same list of
4313 fields, but we have to work harder to preserve type consistency. */
4319 {
4328 /* Whether we need to clear TREE_CONSTANT et al. on the output
4329 constructor when we convert in place. */
4333 {
4334 /* Skip the missing fields in the CONSTRUCTOR. */
4336 {
4339 }
4340 /* The field must be the same. */
4343 constructor_elt elt
4347 /* If packing has made this field a bitfield and the input
4348 value couldn't be emitted statically any more, we need to
4349 clear TREE_CONSTANT on our output. */
4359 }
4361 /* If we have been able to match and convert all the input fields
4362 to their output type, convert in place now. We'll fallback to a
4363 view conversion downstream otherwise. */
4365 {
4372 }
4373 }
4375 /* Likewise for a conversion between array type and vector type with a
4376 compatible representative array. */
4380 etype))
4381 {
4386 tree value;
4388 /* Build a VECTOR_CST from a *constant* array constructor. */
4390 {
4393 /* Iterate through elements and check if all constructor
4394 elements are *_CSTs. */
4397 {
4400 }
4405 }
4407 /* Otherwise, build a regular vector constructor. */
4410 {
4413 }
4418 }
4422 /* First retrieve the underlying array. */
4429 {
4430 /* GCC 4.x is very sensitive to type consistency overall, and view
4431 conversions thus are very frequent. Even though just "convert"ing
4432 the inner operand to the output type is fine in most cases, it
4433 might expose unexpected input/output type mismatches in special
4434 circumstances so we avoid such recursive calls when we can. */
4437 /* If we are converting back to the original type, we can just
4438 lift the input conversion. This is a common occurrence with
4439 switches back-and-forth amongst type variants. */
4443 /* Otherwise, if we're converting between two aggregate or vector
4444 types, we might be allowed to substitute the VIEW_CONVERT_EXPR
4445 target type in place or to just convert the inner expression. */
4448 {
4449 /* If we are converting between mere variants, we can just
4450 substitute the VIEW_CONVERT_EXPR in place. */
4454 /* Otherwise, we may just bypass the input view conversion unless
4455 one of the types is a fat pointer, which is handled by
4456 specialized code below which relies on exact type matching. */
4460 }
4463 }
4467 }
4469 /* Check for converting to a pointer to an unconstrained array. */
4473 /* If we are converting between two aggregate or vector types that are mere
4474 variants, just make a VIEW_CONVERT_EXPR. Likewise when we are converting
4475 to a vector type from its representative array type. */
4482 etype)))
4485 /* If we are converting between tagged types, try to upcast properly. */
4488 {
4496 }
4498 /* If we are converting from a smaller form of record type back to it, just
4499 make a VIEW_CONVERT_EXPR. But first pad the expression to have the same
4500 size on both sides. */
4503 {
4506 expr);
4508 }
4510 /* In all other cases of related types, make a NOP_EXPR. */
4515 {
4525 /* If the output is a biased type, convert first to the base type and
4526 subtract the bias. Note that the bias itself must go through a full
4527 conversion to the base type, lest it is a biased value; this happens
4528 for subtypes of biased types. */
4536 /* ... fall through ... */
4540 /* If we are converting an additive expression to an integer type
4541 with lower precision, be wary of the optimization that can be
4542 applied by convert_to_integer. There are 2 problematic cases:
4543 - if the first operand was originally of a biased type,
4544 because we could be recursively called to convert it
4545 to an intermediate type and thus rematerialize the
4546 additive operator endlessly,
4547 - if the expression contains a placeholder, because an
4548 intermediate conversion that changes the sign could
4549 be inserted and thus introduce an artificial overflow
4550 at compile time when the placeholder is substituted. */
4555 {
4562 }
4568 /* If converting between two thin pointers, adjust if needed to account
4569 for differing offsets from the base pointer, depending on whether
4570 there is a TYPE_UNCONSTRAINED_ARRAY attached to the record type. */
4572 {
4573 tree etype_pos
4577 tree type_pos
4589 }
4591 /* If converting fat pointer to normal or thin pointer, get the pointer
4592 to the array and then convert it. */
4603 {
4609 expr));
4611 }
4613 /* ... fall through ... */
4616 /* In these cases, assume the front-end has validated the conversion.
4617 If the conversion is valid, it will be a bit-wise conversion, so
4618 it can be viewed as an unchecked conversion. */
4622 /* This is a either a conversion between a tagged type and some
4623 subtype, which we have to mark as a UNION_TYPE because of
4624 overlapping fields or a conversion of an Unchecked_Union. */
4628 /* If the input is a VECTOR_TYPE, convert to the representative
4629 array type first. */
4631 {
4635 }
4637 /* If EXPR is a constrained array, take its address, convert it to a
4638 fat pointer, and then dereference it. Likewise if EXPR is a
4639 record containing both a template and a constrained array.
4640 Note that a record representing a justified modular type
4641 always represents a packed constrained array. */
4646 return
4647 build_unary_op
4653 /* Do something very similar for converting one unconstrained
4654 array to another. */
4656 return
4661 else
4669 }
4670 }
4672 /* Create an expression whose value is that of EXPR converted to the common
4673 index type, which is sizetype. EXPR is supposed to be in the base type
4674 of the GNAT index type. Calling it is equivalent to doing
4676 convert (sizetype, expr)
4678 but we try to distribute the type conversion with the knowledge that EXPR
4679 cannot overflow in its type. This is a best-effort approach and we fall
4680 back to the above expression as soon as difficulties are encountered.
4682 This is necessary to overcome issues that arise when the GNAT base index
4683 type and the GCC common index type (sizetype) don't have the same size,
4684 which is quite frequent on 64-bit architectures. In this case, and if
4685 the GNAT base index type is signed but the iteration type of the loop has
4686 been forced to unsigned, the loop scalar evolution engine cannot compute
4687 a simple evolution for the general induction variables associated with the
4688 array indices, because it will preserve the wrap-around semantics in the
4689 unsigned type of their "inner" part. As a result, many loop optimizations
4690 are blocked.
4692 The solution is to use a special (basic) induction variable that is at
4693 least as large as sizetype, and to express the aforementioned general
4694 induction variables in terms of this induction variable, eliminating
4695 the problematic intermediate truncation to the GNAT base index type.
4696 This is possible as long as the original expression doesn't overflow
4697 and if the middle-end hasn't introduced artificial overflows in the
4698 course of the various simplification it can make to the expression. */
4700 tree
4702 {
4706 /* If the type is unsigned, overflow is allowed so we cannot be sure that
4707 EXPR doesn't overflow. Keep it simple if optimization is disabled. */
4712 {
4714 /* The main effect of the function: replace a loop parameter with its
4715 associated special induction variable. */
4720 CASE_CONVERT:
4721 {
4723 /* Bail out as soon as we suspect some sort of type frobbing. */
4727 }
4729 /* ... fall through ... */
4753 }
4756 }
4757 \f
4758 /* Remove all conversions that are done in EXP. This includes converting
4759 from a padded type or to a justified modular type. If TRUE_ADDRESS
4760 is true, always return the address of the containing object even if
4761 the address is not bit-aligned. */
4763 tree
4765 {
4767 {
4772 return
4781 CASE_CONVERT:
4788 }
4791 }
4792 \f
4793 /* If EXP's type is an UNCONSTRAINED_ARRAY_TYPE, return an expression that
4794 refers to the underlying array. If it has TYPE_CONTAINS_TEMPLATE_P,
4795 likewise return an expression pointing to the underlying array. */
4797 tree
4799 {
4804 {
4807 {
4815 {
4816 tree op1
4821 tree op2
4830 }
4831 else
4832 {
4839 }
4840 }
4849 /* If this is a padded type and it contains a template, convert to the
4850 unpadded type first. */
4854 {
4858 }
4861 {
4862 /* If the array initializer is a box, return NULL_TREE. */
4870 /* If the array type is padded, convert to the unpadded type. */
4873 }
4878 }
4881 }
4882 \f
4883 /* Return true if EXPR is an expression that can be folded as an operand
4884 of a VIEW_CONVERT_EXPR. See ada-tree.h for a complete rationale. */
4886 static bool
4888 {
4891 /* The folder will fold NOP_EXPRs between integral types with the same
4892 precision (in the middle-end's sense). We cannot allow it if the
4893 types don't have the same precision in the Ada sense as well. */
4900 /* Defer to the folder for non-integral conversions. */
4904 /* Only fold conversions that preserve both precisions. */
4910 }
4912 /* Return an expression that does an unchecked conversion of EXPR to TYPE.
4913 If NOTRUNC_P is true, truncation operations should be suppressed.
4915 Special care is required with (source or target) integral types whose
4916 precision is not equal to their size, to make sure we fetch or assign
4917 the value bits whose location might depend on the endianness, e.g.
4919 Rmsize : constant := 8;
4920 subtype Int is Integer range 0 .. 2 ** Rmsize - 1;
4922 type Bit_Array is array (1 .. Rmsize) of Boolean;
4923 pragma Pack (Bit_Array);
4925 function To_Bit_Array is new Unchecked_Conversion (Int, Bit_Array);
4927 Value : Int := 2#1000_0001#;
4928 Vbits : Bit_Array := To_Bit_Array (Value);
4930 we expect the 8 bits at Vbits'Address to always contain Value, while
4931 their original location depends on the endianness, at Value'Address
4932 on a little-endian architecture but not on a big-endian one.
4934 One pitfall is that we cannot use TYPE_UNSIGNED directly to decide how
4935 the bits between the precision and the size are filled, because of the
4936 trick used in the E_Signed_Integer_Subtype case of gnat_to_gnu_entity.
4937 So we use the special predicate type_unsigned_for_rm above. */
4939 tree
4941 {
4945 tree tem;
4948 /* If the expression is already of the right type, we are done. */
4952 /* If both types are integral just do a normal conversion.
4953 Likewise for a conversion to an unconstrained array. */
4961 {
4963 {
4968 }
4971 {
4977 }
4978 else
4980 }
4982 /* If we are converting to an integral type whose precision is not equal
4983 to its size, first unchecked convert to a record type that contains a
4984 field of the given precision. Then extract the result from the field.
4986 There is a subtlety if the source type is an aggregate type with reverse
4987 storage order because its representation is not contiguous in the native
4988 storage order, i.e. a direct unchecked conversion to an integral type
4989 with N bits of precision cannot read the first N bits of the aggregate
4990 type. To overcome it, we do an unchecked conversion to an integral type
4991 with reverse storage order and return the resulting value. This also
4992 ensures that the result of the unchecked conversion doesn't depend on
4993 the endianness of the target machine, but only on the storage order of
4994 the aggregate type.
4996 Finally, for the sake of consistency, we do the unchecked conversion
4997 to an integral type with reverse storage order as soon as the source
4998 type is an aggregate type with reverse storage order, even if there
4999 are no considerations of precision or size involved. */
5006 {
5017 else
5029 }
5031 /* Similarly if we are converting from an integral type whose precision is
5032 not equal to its size, first copy into a field of the given precision
5033 and unchecked convert the record type.
5035 The same considerations as above apply if the target type is an aggregate
5036 type with reverse storage order and we also proceed similarly. */
5043 {
5056 else
5069 }
5071 /* If we are converting from a scalar type to a type with a different size,
5072 we need to pad to have the same size on both sides.
5074 ??? We cannot do it unconditionally because unchecked conversions are
5075 used liberally by the front-end to implement polymorphism, e.g. in:
5077 S191s : constant ada__tags__addr_ptr := ada__tags__addr_ptr!(S190s);
5078 return p___size__4 (p__object!(S191s.all));
5080 so we skip all expressions that are references. */
5085 {
5087 {
5090 expr);
5092 }
5093 else
5094 {
5099 }
5100 }
5102 /* We have a special case when we are converting between two unconstrained
5103 array types. In that case, take the address, convert the fat pointer
5104 types, and dereference. */
5109 expr)));
5111 /* Another special case is when we are converting to a vector type from its
5112 representative array type; this a regular conversion. */
5116 etype))
5119 /* And, if the array type is not the representative, we try to build an
5120 intermediate vector type of which the array type is the representative
5121 and to do the unchecked conversion between the vector types, in order
5122 to enable further simplifications in the middle-end. */
5126 {
5129 }
5131 /* If we are converting a CONSTRUCTOR to a more aligned RECORD_TYPE, bump
5132 the alignment of the CONSTRUCTOR to speed up the copy operation. */
5136 {
5139 expr);
5141 }
5143 /* Otherwise, just build a VIEW_CONVERT_EXPR of the expression. */
5144 else
5145 {
5151 else
5153 }
5155 /* If the result is a non-biased integral type whose precision is not equal
5156 to its size, sign- or zero-extend the result. But we need not do this
5157 if the input is also an integral type and both are unsigned or both are
5158 signed and have the same precision. */
5171 {
5172 tree base_type
5175 tree shift_expr
5179 expr
5184 shift_expr),
5185 shift_expr));
5186 }
5188 /* An unchecked conversion should never raise Constraint_Error. The code
5189 below assumes that GCC's conversion routines overflow the same way that
5190 the underlying hardware does. This is probably true. In the rare case
5191 when it is false, we can rely on the fact that such conversions are
5192 erroneous anyway. */
5196 /* If the sizes of the types differ and this is an VIEW_CONVERT_EXPR,
5197 show no longer constant. */
5200 OEP_ONLY_CONST))
5204 }
5205 \f
5206 /* Return the appropriate GCC tree code for the specified GNAT_TYPE,
5207 the latter being a record type as predicated by Is_Record_Type. */
5209 enum tree_code
5211 {
5214 /* Return UNION_TYPE if it's an Unchecked_Union whose non-discriminant
5215 fields are all in the variant part. Otherwise, return RECORD_TYPE. */
5220 component_list
5230 }
5232 /* Return true if GNAT_TYPE is a "double" floating-point type, i.e. whose
5233 size is equal to 64 bits, or an array of such a type. Set ALIGN_CLAUSE
5234 according to the presence of an alignment clause on the type or, if it
5235 is an array, on the component type. */
5237 bool
5239 {
5245 {
5249 }
5258 }
5260 /* Return true if GNAT_TYPE is a "double" or larger scalar type, i.e. whose
5261 size is greater or equal to 64 bits, or an array of such a type. Set
5262 ALIGN_CLAUSE according to the presence of an alignment clause on the
5263 type or, if it is an array, on the component type. */
5265 bool
5267 {
5273 {
5277 }
5286 }
5288 /* Return true if GNU_TYPE is suitable as the type of a non-aliased
5289 component of an aggregate type. */
5291 bool
5293 {
5294 /* If the type is passed by reference, we may have pointers to the
5295 component so it cannot be made non-aliased. */
5299 /* We used to say that any component of aggregate type is aliased
5300 because the front-end may take 'Reference of it. The front-end
5301 has been enhanced in the meantime so as to use a renaming instead
5302 in most cases, but the back-end can probably take the address of
5303 such a component too so we go for the conservative stance.
5305 For instance, we might need the address of any array type, even
5306 if normally passed by copy, to construct a fat pointer if the
5307 component is used as an actual for an unconstrained formal.
5309 Likewise for record types: even if a specific record subtype is
5310 passed by copy, the parent type might be passed by ref (e.g. if
5311 it's of variable size) and we might take the address of a child
5312 component to pass to a parent formal. We have no way to check
5313 for such conditions here. */
5318 }
5320 /* Return true if TYPE is a smaller form of ORIG_TYPE. */
5322 bool
5324 {
5327 /* We're not interested in variants here. */
5331 /* Like a variant, a packable version keeps the original TYPE_NAME. */
5342 }
5344 /* Perform final processing on global declarations. */
5348 void
5350 {
5352 tree iter;
5354 /* If we have declared types as used at the global level, insert them in
5355 the global hash table. We use a dummy variable for this purpose, but
5356 we need to build it unconditionally to avoid -fcompare-debug issues. */
5358 {
5363 dummy_global
5365 void_type_node);
5374 {
5377 }
5378 }
5380 /* Output debug information for all global type declarations first. This
5381 ensures that global types whose compilation hasn't been finalized yet,
5382 for example pointers to Taft amendment types, have their compilation
5383 finalized in the right context. */
5388 /* Then output the global variables. We need to do that after the debug
5389 information for global types is emitted so that they are finalized. */
5394 /* Output the imported modules/declarations. In GNAT, these are only
5395 materializing subprogram. */
5400 }
5402 /* ************************************************************************
5403 * * GCC builtins support *
5404 * ************************************************************************ */
5406 /* The general scheme is fairly simple:
5408 For each builtin function/type to be declared, gnat_install_builtins calls
5409 internal facilities which eventually get to gnat_pushdecl, which in turn
5410 tracks the so declared builtin function decls in the 'builtin_decls' global
5411 datastructure. When an Intrinsic subprogram declaration is processed, we
5412 search this global datastructure to retrieve the associated BUILT_IN DECL
5413 node. */
5415 /* Search the chain of currently available builtin declarations for a node
5416 corresponding to function NAME (an IDENTIFIER_NODE). Return the first node
5417 found, if any, or NULL_TREE otherwise. */
5418 tree
5420 {
5422 tree decl;
5429 }
5431 /* The code below eventually exposes gnat_install_builtins, which declares
5432 the builtin types and functions we might need, either internally or as
5433 user accessible facilities.
5435 ??? This is a first implementation shot, still in rough shape. It is
5436 heavily inspired from the "C" family implementation, with chunks copied
5437 verbatim from there.
5439 Two obvious improvement candidates are:
5440 o Use a more efficient name/decl mapping scheme
5441 o Devise a middle-end infrastructure to avoid having to copy
5442 pieces between front-ends. */
5444 /* ----------------------------------------------------------------------- *
5445 * BUILTIN ELEMENTARY TYPES *
5446 * ----------------------------------------------------------------------- */
5448 /* Standard data types to be used in builtin argument declarations. */
5450 enum c_tree_index
5451 {
5453 CTI_STRING_TYPE,
5454 CTI_CONST_STRING_TYPE,
5456 CTI_MAX
5457 };
5461 #define signed_size_type_node c_global_trees[CTI_SIGNED_SIZE_TYPE]
5462 #define string_type_node c_global_trees[CTI_STRING_TYPE]
5463 #define const_string_type_node c_global_trees[CTI_CONST_STRING_TYPE]
5465 /* ??? In addition some attribute handlers, we currently don't support a
5466 (small) number of builtin-types, which in turns inhibits support for a
5467 number of builtin functions. */
5468 #define wint_type_node void_type_node
5469 #define intmax_type_node void_type_node
5470 #define uintmax_type_node void_type_node
5472 /* Used to help initialize the builtin-types.def table. When a type of
5473 the correct size doesn't exist, use error_mark_node instead of NULL.
5474 The later results in segfaults even when a decl using the type doesn't
5475 get invoked. */
5477 static tree
5479 {
5482 }
5484 /* Build/push the elementary type decls that builtin functions/types
5485 will need. */
5487 static void
5489 {
5494 const_string_type_node
5497 }
5499 /* ----------------------------------------------------------------------- *
5500 * BUILTIN FUNCTION TYPES *
5501 * ----------------------------------------------------------------------- */
5503 /* Now, builtin function types per se. */
5505 enum c_builtin_type
5506 {
5507 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
5508 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
5509 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
5510 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
5511 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
5512 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
5513 #define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME,
5514 #define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5515 ARG6) NAME,
5516 #define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5517 ARG6, ARG7) NAME,
5518 #define DEF_FUNCTION_TYPE_8(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5519 ARG6, ARG7, ARG8) NAME,
5520 #define DEF_FUNCTION_TYPE_9(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5521 ARG6, ARG7, ARG8, ARG9) NAME,
5522 #define DEF_FUNCTION_TYPE_10(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5523 ARG6, ARG7, ARG8, ARG9, ARG10) NAME,
5524 #define DEF_FUNCTION_TYPE_11(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5525 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) NAME,
5526 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
5527 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
5528 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
5529 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
5530 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
5531 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5532 NAME,
5533 #define DEF_FUNCTION_TYPE_VAR_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5534 ARG6) NAME,
5535 #define DEF_FUNCTION_TYPE_VAR_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5536 ARG6, ARG7) NAME,
5537 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
5539 #undef DEF_PRIMITIVE_TYPE
5540 #undef DEF_FUNCTION_TYPE_0
5541 #undef DEF_FUNCTION_TYPE_1
5542 #undef DEF_FUNCTION_TYPE_2
5543 #undef DEF_FUNCTION_TYPE_3
5544 #undef DEF_FUNCTION_TYPE_4
5545 #undef DEF_FUNCTION_TYPE_5
5546 #undef DEF_FUNCTION_TYPE_6
5547 #undef DEF_FUNCTION_TYPE_7
5548 #undef DEF_FUNCTION_TYPE_8
5549 #undef DEF_FUNCTION_TYPE_9
5550 #undef DEF_FUNCTION_TYPE_10
5551 #undef DEF_FUNCTION_TYPE_11
5552 #undef DEF_FUNCTION_TYPE_VAR_0
5553 #undef DEF_FUNCTION_TYPE_VAR_1
5554 #undef DEF_FUNCTION_TYPE_VAR_2
5555 #undef DEF_FUNCTION_TYPE_VAR_3
5556 #undef DEF_FUNCTION_TYPE_VAR_4
5557 #undef DEF_FUNCTION_TYPE_VAR_5
5558 #undef DEF_FUNCTION_TYPE_VAR_6
5559 #undef DEF_FUNCTION_TYPE_VAR_7
5560 #undef DEF_POINTER_TYPE
5561 BT_LAST
5562 };
5566 /* A temporary array used in communication with def_fn_type. */
5569 /* A helper function for install_builtin_types. Build function type
5570 for DEF with return type RET and N arguments. If VAR is true, then the
5571 function should be variadic after those N arguments.
5573 Takes special care not to ICE if any of the types involved are
5574 error_mark_node, which indicates that said type is not in fact available
5575 (see builtin_type_for_size). In which case the function type as a whole
5576 should be error_mark_node. */
5578 static void
5580 {
5581 tree t;
5588 {
5594 }
5601 else
5604 egress:
5607 }
5609 /* Build the builtin function types and install them in the builtin_types
5610 array for later use in builtin function decls. */
5612 static void
5614 {
5615 tree va_list_ref_type_node;
5616 tree va_list_arg_type_node;
5619 {
5622 }
5623 else
5624 {
5627 }
5629 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
5630 builtin_types[ENUM] = VALUE;
5631 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \
5632 def_fn_type (ENUM, RETURN, 0, 0);
5633 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \
5634 def_fn_type (ENUM, RETURN, 0, 1, ARG1);
5635 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \
5636 def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2);
5637 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
5638 def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3);
5639 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
5640 def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4);
5641 #define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5642 def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
5643 #define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5644 ARG6) \
5645 def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
5646 #define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5647 ARG6, ARG7) \
5648 def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
5649 #define DEF_FUNCTION_TYPE_8(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5650 ARG6, ARG7, ARG8) \
5651 def_fn_type (ENUM, RETURN, 0, 8, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5652 ARG7, ARG8);
5653 #define DEF_FUNCTION_TYPE_9(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5654 ARG6, ARG7, ARG8, ARG9) \
5655 def_fn_type (ENUM, RETURN, 0, 9, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5656 ARG7, ARG8, ARG9);
5657 #define DEF_FUNCTION_TYPE_10(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5,\
5658 ARG6, ARG7, ARG8, ARG9, ARG10) \
5659 def_fn_type (ENUM, RETURN, 0, 10, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5660 ARG7, ARG8, ARG9, ARG10);
5661 #define DEF_FUNCTION_TYPE_11(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5,\
5662 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) \
5663 def_fn_type (ENUM, RETURN, 0, 11, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5664 ARG7, ARG8, ARG9, ARG10, ARG11);
5665 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \
5666 def_fn_type (ENUM, RETURN, 1, 0);
5667 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \
5668 def_fn_type (ENUM, RETURN, 1, 1, ARG1);
5669 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \
5670 def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2);
5671 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
5672 def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3);
5673 #define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
5674 def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
5675 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5676 def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
5677 #define DEF_FUNCTION_TYPE_VAR_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5678 ARG6) \
5679 def_fn_type (ENUM, RETURN, 1, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
5680 #define DEF_FUNCTION_TYPE_VAR_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5681 ARG6, ARG7) \
5682 def_fn_type (ENUM, RETURN, 1, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
5683 #define DEF_POINTER_TYPE(ENUM, TYPE) \
5684 builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
5688 #undef DEF_PRIMITIVE_TYPE
5689 #undef DEF_FUNCTION_TYPE_0
5690 #undef DEF_FUNCTION_TYPE_1
5691 #undef DEF_FUNCTION_TYPE_2
5692 #undef DEF_FUNCTION_TYPE_3
5693 #undef DEF_FUNCTION_TYPE_4
5694 #undef DEF_FUNCTION_TYPE_5
5695 #undef DEF_FUNCTION_TYPE_6
5696 #undef DEF_FUNCTION_TYPE_7
5697 #undef DEF_FUNCTION_TYPE_8
5698 #undef DEF_FUNCTION_TYPE_9
5699 #undef DEF_FUNCTION_TYPE_10
5700 #undef DEF_FUNCTION_TYPE_11
5701 #undef DEF_FUNCTION_TYPE_VAR_0
5702 #undef DEF_FUNCTION_TYPE_VAR_1
5703 #undef DEF_FUNCTION_TYPE_VAR_2
5704 #undef DEF_FUNCTION_TYPE_VAR_3
5705 #undef DEF_FUNCTION_TYPE_VAR_4
5706 #undef DEF_FUNCTION_TYPE_VAR_5
5707 #undef DEF_FUNCTION_TYPE_VAR_6
5708 #undef DEF_FUNCTION_TYPE_VAR_7
5709 #undef DEF_POINTER_TYPE
5711 }
5713 /* ----------------------------------------------------------------------- *
5714 * BUILTIN ATTRIBUTES *
5715 * ----------------------------------------------------------------------- */
5717 enum built_in_attribute
5718 {
5719 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
5720 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
5721 #define DEF_ATTR_STRING(ENUM, VALUE) ENUM,
5722 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
5723 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
5725 #undef DEF_ATTR_NULL_TREE
5726 #undef DEF_ATTR_INT
5727 #undef DEF_ATTR_STRING
5728 #undef DEF_ATTR_IDENT
5729 #undef DEF_ATTR_TREE_LIST
5730 ATTR_LAST
5731 };
5735 static void
5737 {
5738 /* Fill in the built_in_attributes array. */
5739 #define DEF_ATTR_NULL_TREE(ENUM) \
5740 built_in_attributes[(int) ENUM] = NULL_TREE;
5741 #define DEF_ATTR_INT(ENUM, VALUE) \
5742 built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
5743 #define DEF_ATTR_STRING(ENUM, VALUE) \
5744 built_in_attributes[(int) ENUM] = build_string (strlen (VALUE), VALUE);
5745 #define DEF_ATTR_IDENT(ENUM, STRING) \
5746 built_in_attributes[(int) ENUM] = get_identifier (STRING);
5747 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
5748 built_in_attributes[(int) ENUM] \
5749 = tree_cons (built_in_attributes[(int) PURPOSE], \
5750 built_in_attributes[(int) VALUE], \
5751 built_in_attributes[(int) CHAIN]);
5753 #undef DEF_ATTR_NULL_TREE
5754 #undef DEF_ATTR_INT
5755 #undef DEF_ATTR_STRING
5756 #undef DEF_ATTR_IDENT
5757 #undef DEF_ATTR_TREE_LIST
5758 }
5760 /* Handle a "const" attribute; arguments as in
5761 struct attribute_spec.handler. */
5763 static tree
5767 {
5770 else
5774 }
5776 /* Handle a "nothrow" attribute; arguments as in
5777 struct attribute_spec.handler. */
5779 static tree
5783 {
5786 else
5790 }
5792 /* Handle a "pure" attribute; arguments as in
5793 struct attribute_spec.handler. */
5795 static tree
5798 {
5801 /* TODO: support types. */
5802 else
5803 {
5807 }
5810 }
5812 /* Handle a "no vops" attribute; arguments as in
5813 struct attribute_spec.handler. */
5815 static tree
5819 {
5823 }
5825 /* Helper for nonnull attribute handling; fetch the operand number
5826 from the attribute argument list. */
5828 static bool
5830 {
5831 /* Verify the arg number is a constant. */
5837 }
5839 /* Handle the "nonnull" attribute. */
5840 static tree
5844 {
5848 /* If no arguments are specified, all pointer arguments should be
5849 non-null. Verify a full prototype is given so that the arguments
5850 will have the correct types when we actually check them later.
5851 Avoid diagnosing type-generic built-ins since those have no
5852 prototype. */
5854 {
5858 {
5861 }
5863 }
5865 /* Argument list specified. Verify that each argument number references
5866 a pointer argument. */
5868 {
5872 {
5877 }
5880 {
5881 function_args_iterator iter;
5882 tree argument;
5886 {
5890 }
5894 {
5900 }
5903 {
5909 }
5910 }
5911 }
5914 }
5916 /* Handle a "sentinel" attribute. */
5918 static tree
5921 {
5923 {
5928 }
5929 else
5930 {
5932 {
5937 }
5938 }
5941 {
5945 {
5948 }
5949 else
5950 {
5952 {
5955 }
5956 }
5957 }
5960 }
5962 /* Handle a "noreturn" attribute; arguments as in
5963 struct attribute_spec.handler. */
5965 static tree
5968 {
5971 /* See FIXME comment in c_common_attribute_table. */
5977 = build_pointer_type
5980 else
5981 {
5985 }
5988 }
5990 /* Handle a "noinline" attribute; arguments as in
5991 struct attribute_spec.handler. */
5993 static tree
5997 {
5999 {
6001 {
6005 }
6006 else
6008 }
6009 else
6010 {
6013 }
6016 }
6018 /* Handle a "noclone" attribute; arguments as in
6019 struct attribute_spec.handler. */
6021 static tree
6025 {
6027 {
6030 }
6033 }
6035 /* Handle a "leaf" attribute; arguments as in
6036 struct attribute_spec.handler. */
6038 static tree
6041 {
6043 {
6046 }
6048 {
6051 }
6054 }
6056 /* Handle a "always_inline" attribute; arguments as in
6057 struct attribute_spec.handler. */
6059 static tree
6062 {
6064 {
6065 /* Set the attribute and mark it for disregarding inline limits. */
6067 }
6068 else
6069 {
6072 }
6075 }
6077 /* Handle a "malloc" attribute; arguments as in
6078 struct attribute_spec.handler. */
6080 static tree
6083 {
6087 else
6088 {
6092 }
6095 }
6097 /* Fake handler for attributes we don't properly support. */
6099 tree
6105 {
6107 }
6109 /* Handle a "type_generic" attribute. */
6111 static tree
6115 {
6116 /* Ensure we have a function type. */
6119 /* Ensure we have a variadic function. */
6123 }
6125 /* Handle a "vector_size" attribute; arguments as in
6126 struct attribute_spec.handler. */
6128 static tree
6131 {
6133 tree vector_type;
6137 /* We need to provide for vector pointers, vector arrays, and
6138 functions returning vectors. For example:
6140 __attribute__((vector_size(16))) short *foo;
6142 In this case, the mode is SI, but the type being modified is
6143 HI, so we need to look further. */
6153 /* Build back pointers if needed. */
6157 }
6159 /* Handle a "vector_type" attribute; arguments as in
6160 struct attribute_spec.handler. */
6162 static tree
6165 {
6167 tree vector_type;
6172 {
6176 }
6186 }
6188 /* Return whether EXPR, which is the renamed object in an object renaming
6189 declaration, can be materialized as a reference (REFERENCE_TYPE). This
6190 should be synchronized with Exp_Dbug.Debug_Renaming_Declaration. */
6192 bool
6194 {
6196 {
6198 {
6204 {
6208 const Uint bitpos
6216 }
6220 {
6228 }
6236 };
6237 }
6238 }
6240 /* ----------------------------------------------------------------------- *
6241 * BUILTIN FUNCTIONS *
6242 * ----------------------------------------------------------------------- */
6244 /* Worker for DEF_BUILTIN. Possibly define a builtin function with one or two
6245 names. Does not declare a non-__builtin_ function if flag_no_builtin, or
6246 if nonansi_p and flag_no_nonansi_builtin. */
6248 static void
6256 {
6257 tree decl;
6260 /* Preserve an already installed decl. It most likely was setup in advance
6261 (e.g. as part of the internal builtins) for specific reasons. */
6272 fnattrs);
6274 /* ??? This is normally further controlled by command-line options
6275 like -fno-builtin, but we don't have them for Ada. */
6280 }
6286 /* Install what the common builtins.def offers. */
6288 static void
6290 {
6291 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
6292 NONANSI_P, ATTRS, IMPLICIT, COND) \
6293 if (NAME && COND) \
6294 def_builtin_1 (ENUM, NAME, CLASS, \
6295 builtin_types[(int) TYPE], \
6296 builtin_types[(int) LIBTYPE], \
6297 BOTH_P, FALLBACK_P, NONANSI_P, \
6298 built_in_attributes[(int) ATTRS], IMPLICIT);
6300 }
6302 /* ----------------------------------------------------------------------- *
6303 * BUILTIN FUNCTIONS *
6304 * ----------------------------------------------------------------------- */
6306 /* Install the builtin functions we might need. */
6308 void
6310 {
6315 /* Install builtins used by generic middle-end pieces first. Some of these
6316 know about internal specificities and control attributes accordingly, for
6317 instance __builtin_alloca vs no-throw and -fstack-check. We will ignore
6318 the generic definition from builtins.def. */
6321 /* Now, install the target specific builtins, such as the AltiVec family on
6322 ppc, and the common set as exposed by builtins.def. */
6325 }