| blob | 951089865e57bc1c777c4b5e84f19541f345f0cc |
1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * U T I L S *
6 * *
7 * C Implementation File *
8 * *
9 * Copyright (C) 1992-2017, Free Software Foundation, Inc. *
10 * *
11 * GNAT is free software; you can redistribute it and/or modify it under *
12 * terms of the GNU General Public License as published by the Free Soft- *
13 * ware Foundation; either version 3, or (at your option) any later ver- *
14 * sion. GNAT is distributed in the hope that it will be useful, but WITH- *
15 * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY *
16 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License *
17 * for more details. You should have received a copy of the GNU General *
18 * Public License along with GCC; see the file COPYING3. If not see *
19 * <http://www.gnu.org/licenses/>. *
20 * *
21 * GNAT was originally developed by the GNAT team at New York University. *
22 * Extensive contributions were provided by Ada Core Technologies Inc. *
23 * *
24 ****************************************************************************/
60 /* If nonzero, pretend we are allocating at global level. */
63 /* The default alignment of "double" floating-point types, i.e. floating
64 point types whose size is equal to 64 bits, or 0 if this alignment is
65 not specifically capped. */
68 /* The default alignment of "double" or larger scalar types, i.e. scalar
69 types whose size is greater or equal to 64 bits, or 0 if this alignment
70 is not specifically capped. */
73 /* True if floating-point arithmetics may use wider intermediate results. */
76 /* Tree nodes for the various types and decls we create. */
79 /* Functions to call for each of the possible raise reasons. */
82 /* Likewise, but with extra info for each of the possible raise reasons. */
85 /* Forward declarations for handlers of attributes. */
102 /* Fake handler for attributes we don't properly support, typically because
103 they'd require dragging a lot of the common-c front-end circuitry. */
106 /* Table of machine-independent internal attributes for Ada. We support
107 this minimal set of attributes to accommodate the needs of builtins. */
109 {
110 /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler,
111 affects_type_identity } */
145 /* ??? format and format_arg are heavy and not supported, which actually
146 prevents support for stdio builtins, which we however declare as part
147 of the common builtins.def contents. */
152 };
154 /* Associates a GNAT tree node to a GCC tree node. It is used in
155 `save_gnu_tree', `get_gnu_tree' and `present_gnu_tree'. See documentation
156 of `save_gnu_tree' for more info. */
159 #define GET_GNU_TREE(GNAT_ENTITY) \
160 associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id]
162 #define SET_GNU_TREE(GNAT_ENTITY,VAL) \
163 associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] = (VAL)
165 #define PRESENT_GNU_TREE(GNAT_ENTITY) \
166 (associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] != NULL_TREE)
168 /* Associates a GNAT entity to a GCC tree node used as a dummy, if any. */
171 #define GET_DUMMY_NODE(GNAT_ENTITY) \
172 dummy_node_table[(GNAT_ENTITY) - First_Node_Id]
174 #define SET_DUMMY_NODE(GNAT_ENTITY,VAL) \
175 dummy_node_table[(GNAT_ENTITY) - First_Node_Id] = (VAL)
177 #define PRESENT_DUMMY_NODE(GNAT_ENTITY) \
178 (dummy_node_table[(GNAT_ENTITY) - First_Node_Id] != NULL_TREE)
180 /* This variable keeps a table for types for each precision so that we only
181 allocate each of them once. Signed and unsigned types are kept separate.
183 Note that these types are only used when fold-const requests something
184 special. Perhaps we should NOT share these types; we'll see how it
185 goes later. */
188 /* Likewise for float types, but record these by mode. */
191 /* For each binding contour we allocate a binding_level structure to indicate
192 the binding depth. */
195 /* The binding level containing this one (the enclosing binding level). */
197 /* The BLOCK node for this level. */
198 tree block;
199 /* If nonzero, the setjmp buffer that needs to be updated for any
200 variable-sized definition within this context. */
201 tree jmpbuf_decl;
202 };
204 /* The binding level currently in effect. */
207 /* A chain of gnat_binding_level structures awaiting reuse. */
210 /* The context to be used for global declarations. */
213 /* An array of global declarations. */
216 /* An array of builtin function declarations. */
219 /* A chain of unused BLOCK nodes. */
222 /* A hash table of padded types. It is modelled on the generic type
223 hash table in tree.c, which must thus be used as a reference. */
227 tree type;
228 };
231 {
235 };
249 /* Linked list used as a queue to defer the initialization of the DECL_CONTEXT
250 of ..._DECL nodes and of the TYPE_CONTEXT of ..._TYPE nodes. */
251 struct deferred_decl_context_node
252 {
253 /* The ..._DECL node to work on. */
254 tree decl;
256 /* The corresponding entity's Scope. */
257 Entity_Id gnat_scope;
259 /* The value of force_global when DECL was pushed. */
262 /* The list of ..._TYPE nodes to propagate the context to. */
265 /* The next queue item. */
267 };
271 /* Defer the initialization of DECL's DECL_CONTEXT attribute, scheduling to
272 feed it with the elaboration of GNAT_SCOPE. */
276 /* Defer the initialization of TYPE's TYPE_CONTEXT attribute, scheduling to
277 feed it with the DECL_CONTEXT computed as part of N as soon as it is
278 computed. */
280 tree type);
281 \f
282 /* Initialize data structures of the utils.c module. */
284 void
286 {
287 /* Initialize the association of GNAT nodes to GCC trees. */
290 /* Initialize the association of GNAT nodes to GCC trees as dummies. */
293 /* Initialize the hash table of padded types. */
295 }
297 /* Destroy data structures of the utils.c module. */
299 void
301 {
302 /* Destroy the association of GNAT nodes to GCC trees. */
306 /* Destroy the association of GNAT nodes to GCC trees as dummies. */
310 /* Destroy the hash table of padded types. */
313 }
314 \f
315 /* GNAT_ENTITY is a GNAT tree node for an entity. Associate GNU_DECL, a GCC
316 tree node, with GNAT_ENTITY. If GNU_DECL is not a ..._DECL node, abort.
317 If NO_CHECK is true, the latter check is suppressed.
319 If GNU_DECL is zero, reset a previous association. */
321 void
323 {
324 /* Check that GNAT_ENTITY is not already defined and that it is being set
325 to something which is a decl. If that is not the case, this usually
326 means GNAT_ENTITY is defined twice, but occasionally is due to some
327 Gigi problem. */
333 }
335 /* GNAT_ENTITY is a GNAT tree node for an entity. Return the GCC tree node
336 that was associated with it. If there is no such tree node, abort.
338 In some cases, such as delayed elaboration or expressions that need to
339 be elaborated only once, GNAT_ENTITY is really not an entity. */
341 tree
343 {
346 }
348 /* Return nonzero if a GCC tree has been associated with GNAT_ENTITY. */
350 bool
352 {
354 }
355 \f
356 /* Make a dummy type corresponding to GNAT_TYPE. */
358 tree
360 {
364 /* If there was no equivalent type (can only happen when just annotating
365 types) or underlying type, go back to the original type. */
369 /* If it there already a dummy type, use that one. Else make one. */
373 /* If this is a record, make a RECORD_TYPE or UNION_TYPE; else make
374 an ENUMERAL_TYPE. */
387 /* Create a debug type so that debug info consumers only see an unspecified
388 type. */
390 {
396 }
399 }
401 /* Return the dummy type that was made for GNAT_TYPE, if any. */
403 tree
405 {
407 }
409 /* Build dummy fat and thin pointer types whose designated type is specified
410 by GNAT_DESIG_TYPE/GNU_DESIG_TYPE and attach them to the latter. */
412 void
414 {
429 /* Build a stub DECL to trigger the special processing for fat pointer types
430 in gnat_pushdecl. */
433 gnu_fat_type);
441 /* Suppress debug info until after the type is completed. */
451 }
452 \f
453 /* Return true if we are in the global binding level. */
455 bool
457 {
459 }
461 /* Enter a new binding level. */
463 void
465 {
468 /* Reuse a struct for this binding level, if there is one. */
470 {
473 }
474 else
477 /* Use a free BLOCK, if any; otherwise, allocate one. */
479 {
483 }
484 else
487 /* Point the BLOCK we just made to its parent. */
495 /* Add this level to the front of the chain (stack) of active levels. */
499 }
501 /* Set SUPERCONTEXT of the BLOCK for the current binding level to FNDECL
502 and point FNDECL to this BLOCK. */
504 void
506 {
510 }
512 /* Set the jmpbuf_decl for the current binding level to DECL. */
514 void
516 {
518 }
520 /* Get the jmpbuf_decl, if any, for the current binding level. */
522 tree
524 {
526 }
528 /* Exit a binding level. Set any BLOCK into the current code group. */
530 void
532 {
539 /* If this is a function-level BLOCK don't do anything. Otherwise, if there
540 are no variables free the block and merge its subblocks into those of its
541 parent block. Otherwise, add it to the list of its parent. */
543 ;
545 {
551 }
552 else
553 {
558 }
560 /* Free this binding structure. */
564 }
566 /* Exit a binding level and discard the associated BLOCK. */
568 void
570 {
577 /* Free this binding structure. */
581 }
582 \f
583 /* Set the context of TYPE and its parallel types (if any) to CONTEXT. */
585 static void
587 {
593 {
596 /* Give a context to the parallel types and their stub decl, if any.
597 Some parallel types seems to be present in multiple parallel type
598 chains, so don't mess with their context if they already have one. */
600 {
604 }
607 }
608 }
610 /* Return the innermost scope, starting at GNAT_NODE, we are be interested in
611 the debug info, or Empty if there is no such scope. If not NULL, set
612 IS_SUBPROGRAM to whether the returned entity is a subprogram. */
614 Entity_Id
616 {
617 Entity_Id gnat_entity;
625 else
629 {
631 {
637 /* If the scope is a subprogram, then just rely on
638 current_function_decl, so that we don't have to defer
639 anything. This is needed because other places rely on the
640 validity of the DECL_CONTEXT attribute of FUNCTION_DECL nodes. */
650 /* By default, we are not interested in this particular scope: go to
651 the outer one. */
653 }
656 }
659 }
661 /* If N is NULL, set TYPE's context to CONTEXT. Defer this to the processing
662 of N otherwise. */
664 static void
667 {
670 else
672 }
674 /* Return global_context, but create it first if need be. */
676 static tree
678 {
680 {
681 global_context
684 }
687 }
689 /* Record DECL as belonging to the current lexical scope and use GNAT_NODE
690 for location information and flag propagation. */
692 void
694 {
698 /* If explicitely asked to make DECL global or if it's an imported nested
699 object, short-circuit the regular Scope-based context computation. */
701 {
702 /* Rely on the GNAT scope, or fallback to the current_function_decl if
703 the GNAT scope reached the global scope, if it reached a subprogram
704 or the declaration is a subprogram or a variable (for them we skip
705 intermediate context types because the subprogram body elaboration
706 machinery and the inliner both expect a subprogram context).
708 Falling back to current_function_decl is necessary for implicit
709 subprograms created by gigi, such as the elaboration subprograms. */
711 const Entity_Id gnat_scope
715 && !context_is_subprogram
718 /* Always assume the scope has not been elaborated, thus defer the
719 context propagation to the time its elaboration will be
720 available. */
721 deferred_decl_context
724 /* External declarations (when force_global > 0) may not be in a
725 local context. */
728 }
730 /* If either we are forced to be in global mode or if both the GNAT scope and
731 the current_function_decl did not help in determining the context, use the
732 global scope. */
736 /* Functions imported in another function are not really nested.
737 For really nested functions mark them initially as needing
738 a static chain for uses of that flag before unnesting;
739 lower_nested_functions will then recompute it. */
742 && context
752 /* Set the location of DECL and emit a declaration for it. */
758 /* Put the declaration on the list. The list of declarations is in reverse
759 order. The list will be reversed later. Put global declarations in the
760 globals list and local ones in the current block. But skip TYPE_DECLs
761 for UNCONSTRAINED_ARRAY_TYPE in both cases, as they will cause trouble
762 with the debugger and aren't needed anyway. */
765 {
766 /* External declarations must go to the binding level they belong to.
767 This will make corresponding imported entities are available in the
768 debugger at the proper time. */
775 else
776 {
779 }
780 }
782 /* For the declaration of a type, set its name either if it isn't already
783 set or if the previous type name was not derived from a source name.
784 We'd rather have the type named with a real name and all the pointer
785 types to the same object have the same node, except when the names are
786 both derived from source names. */
788 {
791 /* Array and pointer types aren't tagged types in the C sense so we need
792 to generate a typedef in DWARF for them and make sure it is preserved,
793 unless the type is artificial. */
797 ;
798 /* For array and pointer types, create the DECL_ORIGINAL_TYPE that will
799 generate the typedef in DWARF. Also do that for fat pointer types
800 because, even though they are tagged types in the C sense, they are
801 still XUP types attached to the base array type at this point. */
806 {
811 deferred_decl_context);
817 else
819 /* Array types need to have a name so that they can be related to
820 their GNAT encodings. */
824 }
828 ;
829 else
832 /* Propagate the name to all the variants, this is needed for the type
833 qualifiers machinery to work properly (see check_qualified_type).
834 Also propagate the context to them. Note that it will be propagated
835 to all parallel types too thanks to gnat_set_type_context. */
838 /* ??? Because of the previous kludge, we can have variants of fat
839 pointer types with different names. */
843 {
847 deferred_decl_context);
848 }
849 }
850 }
851 \f
852 /* Create a record type that contains a SIZE bytes long field of TYPE with a
853 starting bit position so that it is aligned to ALIGN bits, and leaving at
854 least ROOM bytes free before the field. BASE_ALIGN is the alignment the
855 record is guaranteed to get. GNAT_NODE is used for the position of the
856 associated TYPE_DECL. */
858 tree
861 {
862 /* We will be crafting a record type with one field at a position set to be
863 the next multiple of ALIGN past record'address + room bytes. We use a
864 record placeholder to express record'address. */
868 tree record_addr_st
871 /* The diagram below summarizes the shape of what we manipulate:
873 <--------- pos ---------->
874 { +------------+-------------+-----------------+
875 record =>{ |############| ... | field (type) |
876 { +------------+-------------+-----------------+
877 |<-- room -->|<- voffset ->|<---- size ----->|
878 o o
879 | |
880 record_addr vblock_addr
882 Every length is in sizetype bytes there, except "pos" which has to be
883 set as a bit position in the GCC tree for the record. */
893 /* Compute VOFFSET and then POS. The next byte position multiple of some
894 alignment after some address is obtained by "and"ing the alignment minus
895 1 with the two's complement of the address. */
900 /* POS = (ROOM + VOFFSET) * BIT_PER_UNIT, in bitsizetype. */
904 bitsize_unit_node);
906 /* Craft the GCC record representation. We exceptionally do everything
907 manually here because 1) our generic circuitry is not quite ready to
908 handle the complex position/size expressions we are setting up, 2) we
909 have a strong simplifying factor at hand: we know the maximum possible
910 value of voffset, and 3) we have to set/reset at least the sizes in
911 accordance with this maximum value anyway, as we need them to convey
912 what should be "alloc"ated for this type.
914 Use -1 as the 'addressable' indication for the field to prevent the
915 creation of a bitfield. We don't need one, it would have damaging
916 consequences on the alignment computation, and create_field_decl would
917 make one without this special argument, for instance because of the
918 complex position expression. */
929 bitsize_unit_node),
938 /* Declare it now since it will never be declared otherwise. This is
939 necessary to ensure that its subtrees are properly marked. */
943 }
945 /* TYPE is a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE that is being used
946 as the field type of a packed record if IN_RECORD is true, or as the
947 component type of a packed array if IN_RECORD is false. See if we can
948 rewrite it either as a type that has non-BLKmode, which we can pack
949 tighter in the packed record case, or as a smaller type with at most
950 MAX_ALIGN alignment if the value is non-zero. If so, return the new
951 type; if not, return the original type. */
953 tree
955 {
961 /* No point in doing anything if the size is zero. */
967 /* Copy the name and flags from the old type to that of the new.
968 Note that we rely on the pointer equality created here for
969 TYPE_NAME to look through conversions in various places. */
977 /* If we are in a record and have a small size, set the alignment to
978 try for an integral mode. Otherwise set it to try for a smaller
979 type with BLKmode. */
981 {
985 }
986 else
987 {
988 /* Do not try to shrink the size if the RM size is not constant. */
993 /* Round the RM size up to a unit boundary to get the minimal size
994 for a BLKmode record. Give up if it's already the size and we
995 don't need to lower the alignment. */
1005 }
1009 /* Now copy the fields, keeping the position and size as we don't want
1010 to change the layout by propagating the packedness downwards. */
1013 {
1022 /* However, for the last field in a not already packed record type
1023 that is of an aggregate type, we need to use the RM size in the
1024 packable version of the record type, see finish_record_type. */
1032 else
1035 new_field
1048 }
1056 /* If this is a padding record, we never want to make the size smaller
1057 than what was specified. For QUAL_UNION_TYPE, also copy the size. */
1059 {
1063 }
1064 else
1065 {
1068 }
1075 /* Try harder to get a packable type if necessary, for example
1076 in case the record itself contains a BLKmode field. */
1081 /* If neither mode nor size nor alignment shrunk, return the old type. */
1086 }
1088 /* Return true if TYPE has an unsigned representation. This needs to be used
1089 when the representation of types whose precision is not equal to their size
1090 is manipulated based on the RM size. */
1094 {
1095 /* This is the common case. */
1099 /* See the E_Signed_Integer_Subtype case of gnat_to_gnu_entity. */
1105 }
1107 /* Given a type TYPE, return a new type whose size is appropriate for SIZE.
1108 If TYPE is the best type, return it. Otherwise, make a new type. We
1109 only support new integral and pointer types. FOR_BIASED is true if
1110 we are making a biased type. */
1112 tree
1114 {
1117 tree new_type;
1119 /* If size indicates an error, just return TYPE to avoid propagating
1120 the error. Likewise if it's too large to represent. */
1127 {
1134 /* Integer types with precision 0 are forbidden. */
1138 /* Only do something if the type isn't a packed array type and doesn't
1139 already have the proper size and the size isn't too large. */
1147 /* The type should be an unsigned type if the original type is unsigned
1148 or if the lower bound is constant and non-negative or if the type is
1149 biased, see E_Signed_Integer_Subtype case of gnat_to_gnu_entity. */
1152 else
1157 /* Copy the name to show that it's essentially the same type and
1158 not a subrange type. */
1165 /* Do something if this is a fat pointer, in which case we
1166 may need to return the thin pointer. */
1168 {
1169 scalar_int_mode p_mode;
1173 return
1174 build_pointer_type_for_mode
1177 }
1181 /* Only do something if this is a thin pointer, in which case we
1182 may need to return the fat pointer. */
1184 return
1190 }
1193 }
1195 /* See if the data pointed to by the hash table slot is marked. */
1197 int
1199 {
1201 }
1203 /* Return true iff the padded types are equivalent. */
1205 bool
1207 {
1216 /* We consider that the padded types are equivalent if they pad the same type
1217 and have the same size, alignment, RM size and storage order. Taking the
1218 mode into account is redundant since it is determined by the others. */
1219 return
1225 }
1227 /* Look up the padded TYPE in the hash table and return its canonical version
1228 if it exists; otherwise, insert it into the hash table. */
1230 static tree
1232 {
1233 hashval_t hashcode;
1236 hashcode
1253 }
1255 /* Ensure that TYPE has SIZE and ALIGN. Make and return a new padded type
1256 if needed. We have already verified that SIZE and ALIGN are large enough.
1257 GNAT_ENTITY is used to name the resulting record and to issue a warning.
1258 IS_COMPONENT_TYPE is true if this is being done for the component type of
1259 an array. IS_USER_TYPE is true if the original type needs to be completed.
1260 DEFINITION is true if this type is being defined. SET_RM_SIZE is true if
1261 the RM size of the resulting type is to be set to SIZE too; in this case,
1262 the padded type is canonicalized before being returned. */
1264 tree
1268 {
1273 /* If TYPE is a padded type, see if it agrees with any size and alignment
1274 we were given. If so, return the original type. Otherwise, strip
1275 off the padding, since we will either be returning the inner type
1276 or repadding it. If no size or alignment is specified, use that of
1277 the original padded type. */
1279 {
1293 }
1295 /* If the size is either not being changed or is being made smaller (which
1296 is not done here and is only valid for bitfields anyway), show the size
1297 isn't changing. Likewise, clear the alignment if it isn't being
1298 changed. Then return if we aren't doing anything. */
1311 /* If requested, complete the original type and give it a name. */
1318 gnat_entity);
1320 /* We used to modify the record in place in some cases, but that could
1321 generate incorrect debugging information. So make a new record
1322 type and name. */
1326 /* ??? Padding types around packed array implementation types will be
1327 considered as root types in the array descriptor language hook (see
1328 gnat_get_array_descr_info). Give them the original packed array type
1329 name so that the one coming from sources appears in the debugging
1330 information. */
1343 bitsize_unit_node));
1345 /* If we are changing the alignment and the input type is a record with
1346 BLKmode and a small constant size, try to make a form that has an
1347 integral mode. This might allow the padding record to also have an
1348 integral mode, which will be much more efficient. There is no point
1349 in doing so if a size is specified unless it is also a small constant
1350 size and it is incorrect to do so if we cannot guarantee that the mode
1351 will be naturally aligned since the field must always be addressable.
1353 ??? This might not always be a win when done for a stand-alone object:
1354 since the nominal and the effective type of the object will now have
1355 different modes, a VIEW_CONVERT_EXPR will be required for converting
1356 between them and it might be hard to overcome afterwards, including
1357 at the RTL level when the stand-alone object is accessed as a whole. */
1365 && (!size
1368 {
1373 }
1375 /* Now create the field with the original size. */
1380 /* We will output additional debug info manually below. */
1386 /* Set the RM size if requested. */
1388 {
1389 tree canonical_pad_type;
1393 /* If the padded type is complete and has constant size, we canonicalize
1394 it by means of the hash table. This is consistent with the language
1395 semantics and ensures that gigi and the middle-end have a common view
1396 of these padded types. */
1399 {
1402 }
1403 }
1405 /* Unless debugging information isn't being written for the input type,
1406 write a record that shows what we are a subtype of and also make a
1407 variable that indicates our size, if still variable. */
1413 {
1417 /* A variable that holds the size is required even with no encoding since
1418 it will be referenced by debugging information attributes. At global
1419 level, we need a single variable across all translation units. */
1423 {
1424 /* Whether or not gnat_entity comes from source, this XVZ variable is
1425 is a compilation artifact. */
1426 size_unit
1432 }
1434 /* There is no need to show what we are a subtype of when outputting as
1435 few encodings as possible: regular debugging infomation makes this
1436 redundant. */
1438 {
1452 }
1453 }
1455 built:
1456 /* If a simple size was explicitly given, maybe issue a warning. */
1463 /* But don't do it if we are just annotating types and the type is tagged or
1464 concurrent, since these types aren't fully laid out in this mode. */
1466 {
1467 Entity_Id gnat_type
1468 = is_component_type
1473 }
1475 /* Take the original size as the maximum size of the input if there was an
1476 unconstrained record involved and round it up to the specified alignment,
1477 if one was specified, but only for aggregate types. */
1490 {
1493 /* For a packed array, post the message on the original array type. */
1504 /* Generate message only for entities that come from source, since
1505 if we have an entity created by expansion, the message will be
1506 generated for some other corresponding source entity. */
1508 {
1517 }
1518 }
1521 }
1523 /* Return a copy of the padded TYPE but with reverse storage order. */
1525 tree
1527 {
1531 {
1532 /* If the inner type is not scalar then the function does nothing. */
1536 }
1538 /* This is required for the canonicalization. */
1548 }
1549 \f
1550 /* Relate the alias sets of GNU_NEW_TYPE and GNU_OLD_TYPE according to OP.
1551 If this is a multi-dimensional array type, do this recursively.
1553 OP may be
1554 - ALIAS_SET_COPY: the new set is made a copy of the old one.
1555 - ALIAS_SET_SUPERSET: the new set is made a superset of the old one.
1556 - ALIAS_SET_SUBSET: the new set is made a subset of the old one. */
1558 void
1560 {
1561 /* Remove any padding from GNU_OLD_TYPE. It doesn't matter in the case
1562 of a one-dimensional array, since the padding has the same alias set
1563 as the field type, but if it's a multi-dimensional array, we need to
1564 see the inner types. */
1570 /* Unconstrained array types are deemed incomplete and would thus be given
1571 alias set 0. Retrieve the underlying array type. */
1573 gnu_old_type
1576 gnu_new_type
1585 {
1587 /* The alias set shouldn't be copied between array types with different
1588 aliasing settings because this can break the aliasing relationship
1589 between the array type and its element type. */
1601 {
1605 /* Do nothing if the alias sets conflict. This ensures that we
1606 never call record_alias_subset several times for the same pair
1607 or at all for alias set 0. */
1609 {
1612 else
1614 }
1615 }
1620 }
1623 }
1624 \f
1625 /* Record TYPE as a builtin type for Ada. NAME is the name of the type.
1626 ARTIFICIAL_P is true if the type was generated by the compiler. */
1628 void
1630 {
1639 }
1640 \f
1641 /* Finish constructing the character type CHAR_TYPE.
1643 In Ada character types are enumeration types and, as a consequence, are
1644 represented in the front-end by integral types holding the positions of
1645 the enumeration values as defined by the language, which means that the
1646 integral types are unsigned.
1648 Unfortunately the signedness of 'char' in C is implementation-defined
1649 and GCC even has the option -fsigned-char to toggle it at run time.
1650 Since GNAT's philosophy is to be compatible with C by default, to wit
1651 Interfaces.C.char is defined as a mere copy of Character, we may need
1652 to declare character types as signed types in GENERIC and generate the
1653 necessary adjustments to make them behave as unsigned types.
1655 The overall strategy is as follows: if 'char' is unsigned, do nothing;
1656 if 'char' is signed, translate character types of CHAR_TYPE_SIZE and
1657 character subtypes with RM_Size = Esize = CHAR_TYPE_SIZE into signed
1658 types. The idea is to ensure that the bit pattern contained in the
1659 Esize'd objects is not changed, even though the numerical value will
1660 be interpreted differently depending on the signedness. */
1662 void
1664 {
1668 /* Make a copy of a generic unsigned version since we'll modify it. */
1669 tree unsigned_char_type
1671 ? unsigned_char_type_node
1674 /* Create an unsigned version of the type and set it as debug type. */
1680 /* If this is a subtype, make the debug type a subtype of the debug type
1681 of the base type and convert literal RM bounds to unsigned. */
1683 {
1696 }
1698 /* Adjust the RM bounds of the original type to unsigned; that's especially
1699 important for types since they are implicit in this case. */
1702 }
1704 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
1705 finish constructing the record type as a fat pointer type. */
1707 void
1709 {
1710 /* Make sure we can put it into a register. */
1714 /* Show what it really is. */
1717 /* Do not emit debug info for it since the types of its fields may still be
1718 incomplete at this point. */
1721 /* Force type_contains_placeholder_p to return true on it. Although the
1722 PLACEHOLDER_EXPRs are referenced only indirectly, this isn't a pointer
1723 type but the representation of the unconstrained array. */
1725 }
1727 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
1728 finish constructing the record or union type. If REP_LEVEL is zero, this
1729 record has no representation clause and so will be entirely laid out here.
1730 If REP_LEVEL is one, this record has a representation clause and has been
1731 laid out already; only set the sizes and alignment. If REP_LEVEL is two,
1732 this record is derived from a parent record and thus inherits its layout;
1733 only make a pass on the fields to finalize them. DEBUG_INFO_P is true if
1734 additional debug info needs to be output for this type. */
1736 void
1739 {
1747 tree field;
1751 /* Always attach the TYPE_STUB_DECL for a record type. It is required to
1752 generate debug info and have a parallel type. */
1755 /* Globally initialize the record first. If this is a rep'ed record,
1756 that just means some initializations; otherwise, layout the record. */
1758 {
1768 /* For all-repped records with a size specified, lay the QUAL_UNION_TYPE
1769 out just like a UNION_TYPE, since the size will be fixed. */
1772 }
1773 else
1774 {
1775 /* Ensure there isn't a size already set. There can be in an error
1776 case where there is a rep clause but all fields have errors and
1777 no longer have a position. */
1780 /* Ensure we use the traditional GCC layout for bitfields when we need
1781 to pack the record type or have a representation clause. The other
1782 possible layout (Microsoft C compiler), if available, would prevent
1783 efficient packing in almost all cases. */
1784 #ifdef TARGET_MS_BITFIELD_LAYOUT
1789 ATTR_FLAG_TYPE_IN_PLACE);
1790 #endif
1793 }
1795 /* At this point, the position and size of each field is known. It was
1796 either set before entry by a rep clause, or by laying out the type above.
1798 We now run a pass over the fields (in reverse order for QUAL_UNION_TYPEs)
1799 to compute the Ada size; the GCC size and alignment (for rep'ed records
1800 that are not padding types); and the mode (for rep'ed records). We also
1801 clear the DECL_BIT_FIELD indication for the cases we know have not been
1802 handled yet, and adjust DECL_NONADDRESSABLE_P accordingly. */
1808 {
1812 tree this_ada_size;
1819 else
1822 /* Clear DECL_BIT_FIELD for the cases layout_decl does not handle. */
1825 {
1828 /* In the general case, type alignment is required. */
1830 {
1831 /* The enclosing record type must be sufficiently aligned.
1832 Otherwise, if no alignment was specified for it and it
1833 has been laid out already, bump its alignment to the
1834 desired one if this is compatible with its size and
1835 maximum alignment, if any. */
1837 {
1840 }
1846 {
1850 }
1851 }
1853 /* In the non-strict alignment case, only byte alignment is. */
1858 }
1860 /* If we still have DECL_BIT_FIELD set at this point, we know that the
1861 field is technically not addressable. Except that it can actually
1862 be addressed if it is BLKmode and happens to be properly aligned. */
1868 /* A type must be as aligned as its most aligned field that is not
1869 a bit-field. But this is already enforced by layout_type. */
1875 {
1882 ada_size
1890 /* Since we know here that all fields are sorted in order of
1891 increasing bit position, the size of the record is one
1892 higher than the ending bit of the last field processed
1893 unless we have a rep clause, since in that case we might
1894 have a field outside a QUAL_UNION_TYPE that has a higher ending
1895 position. So use a MAX in that case. Also, if this field is a
1896 QUAL_UNION_TYPE, we need to take into account the previous size in
1897 the case of empty variants. */
1898 ada_size
1901 size
1908 }
1909 }
1915 {
1916 /* If this is a padding record, we never want to make the size smaller
1917 than what was specified in it, if any. */
1921 /* Now set any of the values we've just computed that apply. */
1927 {
1928 tree size_unit = had_size_unit
1932 bitsize_unit_node));
1940 }
1941 }
1943 /* Reset the TYPE_MAX_ALIGN field since it's private to gigi. */
1948 }
1950 /* Append PARALLEL_TYPE on the chain of parallel types of TYPE. If
1951 PARRALEL_TYPE has no context and its computation is not deferred yet, also
1952 propagate TYPE's context to PARALLEL_TYPE's or defer its propagation to the
1953 moment TYPE will get a context. */
1955 void
1957 {
1965 /* If PARALLEL_TYPE already has a context, we are done. */
1969 /* Otherwise, try to get one from TYPE's context. If so, simply propagate
1970 it to PARALLEL_TYPE. */
1974 /* Otherwise TYPE has not context yet. We know it will have one thanks to
1975 gnat_pushdecl and then its context will be propagated to PARALLEL_TYPE,
1976 so we have nothing to do in this case. */
1977 }
1979 /* Return true if TYPE has a parallel type. */
1981 static bool
1983 {
1987 }
1989 /* Wrap up compilation of RECORD_TYPE, i.e. output additional debug info
1990 associated with it. It need not be invoked directly in most cases as
1991 finish_record_type takes care of doing so. */
1993 void
1995 {
1997 tree field;
1999 /* If this is a padded type, the bulk of the debug info has already been
2000 generated for the field's type. */
2004 /* If the type already has a parallel type (XVS type), then we're done. */
2009 {
2010 /* We need to make an XVE/XVU record if any field has variable size,
2011 whether or not the record does. For example, if we have a union,
2012 it may be that all fields, rounded up to the alignment, have the
2013 same size, in which case we'll use that size. But the debug
2014 output routines (except Dwarf2) won't be able to output the fields,
2015 so we need to make the special record. */
2017 /* If a field has a non-constant qualifier, the record will have
2018 variable size too. */
2021 {
2024 }
2025 }
2027 /* If this record type is of variable size, make a parallel record type that
2028 will tell the debugger how the former is laid out (see exp_dbug.ads). */
2030 {
2031 tree new_record_type
2038 new_name
2052 /* Now scan all the fields, replacing each field with a new field
2053 corresponding to the new encoding. */
2056 {
2064 /* See how the position was modified from the last position.
2066 There are two basic cases we support: a value was added
2067 to the last position or the last position was rounded to
2068 a boundary and they something was added. Check for the
2069 first case first. If not, see if there is any evidence
2070 of rounding. If so, round the last position and retry.
2072 If this is a union, the position can be taken as zero. */
2075 else
2081 {
2087 }
2092 && tree_fits_uhwi_p
2094 {
2096 unsigned HOST_WIDE_INT addend
2098 align
2104 }
2106 {
2110 }
2112 /* If we can't compute a position, set it to zero.
2114 ??? We really should abort here, but it's too much work
2115 to get this correct for all cases. */
2119 /* See if this type is variable-sized and make a pointer type
2120 and indicate the indirection if so. Beware that the debug
2121 back-end may adjust the position computed above according
2122 to the alignment of the field type, i.e. the pointer type
2123 in this case, if we don't preventively counter that. */
2125 {
2128 {
2131 }
2133 }
2135 /* Make a new field name, if necessary. */
2137 {
2143 else
2147 }
2149 new_field
2155 /* If old_field is a QUAL_UNION_TYPE, take its size as being
2156 zero. The only time it's not the last field of the record
2157 is when there are other components at fixed positions after
2158 it (meaning there was a rep clause for every field) and we
2159 want to be able to encode them. */
2163 ? bitsize_zero_node
2166 }
2171 }
2172 }
2174 /* Utility function of above to merge LAST_SIZE, the previous size of a record
2175 with FIRST_BIT and SIZE that describe a field. SPECIAL is true if this
2176 represents a QUAL_UNION_TYPE in which case we must look for COND_EXPRs and
2177 replace a value of zero with the old size. If HAS_REP is true, we take the
2178 MAX of the end position of this field with LAST_SIZE. In all other cases,
2179 we use FIRST_BIT plus SIZE. Return an expression for the size. */
2181 static tree
2184 {
2186 tree new_size;
2189 {
2193 }
2195 else
2206 /* We don't need any NON_VALUE_EXPRs and they can confuse us (especially
2207 when fed through substitute_in_expr) into thinking that a constant
2208 size is not constant. */
2213 }
2215 /* Return the bit position of FIELD, in bits from the start of the record,
2216 and fold it as much as possible. This is a tree of type bitsizetype. */
2218 static tree
2220 {
2226 else
2230 }
2232 /* Utility function of above to see if OP0 and OP1, both of SIZETYPE, are
2233 related by the addition of a constant. Return that constant if so. */
2235 static tree
2237 {
2244 {
2248 }
2249 else
2260 }
2262 /* Utility function of above to split a tree OP which may be a sum, into a
2263 constant part, which is returned, and a variable part, which is stored
2264 in *PVAR. *PVAR may be bitsize_zero_node. All operations must be of
2265 bitsizetype. */
2267 static tree
2269 {
2270 /* Strip conversions in order to ease the tree traversal and maximize the
2271 potential for constant or plus/minus discovery. We need to be careful
2272 to always return and set *pvar to bitsizetype trees, but it's worth
2273 the effort. */
2279 {
2282 }
2284 {
2295 }
2296 else
2298 }
2299 \f
2300 /* Return a copy of TYPE but safe to modify in any way. */
2302 tree
2304 {
2307 /* Unshare the language-specific data. */
2309 {
2312 }
2314 /* And the contents of the language-specific slot if needed. */
2317 {
2322 }
2324 /* copy_node clears this field instead of copying it, because it is
2325 aliased with TREE_CHAIN. */
2335 }
2336 \f
2337 /* Return a subtype of sizetype with range MIN to MAX and whose
2338 TYPE_INDEX_TYPE is INDEX. GNAT_NODE is used for the position
2339 of the associated TYPE_DECL. */
2341 tree
2343 {
2344 /* First build a type for the desired range. */
2347 /* Then set the index type. */
2352 }
2354 /* Return a subtype of TYPE with range MIN to MAX. If TYPE is NULL,
2355 sizetype is used. */
2357 tree
2359 {
2360 tree range_type;
2365 /* First build a type with the base range. */
2369 /* Then set the actual range. */
2374 }
2375 \f
2376 /* Return a TYPE_DECL node suitable for the TYPE_STUB_DECL field of TYPE.
2377 NAME gives the name of the type to be used in the declaration. */
2379 tree
2381 {
2386 }
2388 /* Return a TYPE_DECL node for TYPE. NAME gives the name of the type to be
2389 used in the declaration. ARTIFICIAL_P is true if the declaration was
2390 generated by the compiler. DEBUG_INFO_P is true if we need to write
2391 debug information about this type. GNAT_NODE is used for the position
2392 of the decl. */
2394 tree
2396 Node_Id gnat_node)
2397 {
2399 bool is_named
2401 tree type_decl;
2403 /* Only the builtin TYPE_STUB_DECL should be used for dummy types. */
2406 /* If the type hasn't been named yet, we're naming it; preserve an existing
2407 TYPE_STUB_DECL that has been attached to it for some purpose. */
2409 {
2412 }
2413 else
2419 /* Add this decl to the current binding level. */
2422 /* If we're naming the type, equate the TYPE_STUB_DECL to the name. This
2423 causes the name to be also viewed as a "tag" by the debug back-end, with
2424 the advantage that no DW_TAG_typedef is emitted for artificial "tagged"
2425 types in DWARF.
2427 Note that if "type" is used as a DECL_ORIGINAL_TYPE, it may be referenced
2428 from multiple contexts, and "type_decl" references a copy of it: in such a
2429 case, do not mess TYPE_STUB_DECL: we do not want to re-use the TYPE_DECL
2430 with the mechanism above. */
2434 /* Do not generate debug info for UNCONSTRAINED_ARRAY_TYPE that the
2435 back-end doesn't support, and for others if we don't need to. */
2440 }
2441 \f
2442 /* Return a VAR_DECL or CONST_DECL node.
2444 NAME gives the name of the variable. ASM_NAME is its assembler name
2445 (if provided). TYPE is its data type (a GCC ..._TYPE node). INIT is
2446 the GCC tree for an optional initial expression; NULL_TREE if none.
2448 CONST_FLAG is true if this variable is constant, in which case we might
2449 return a CONST_DECL node unless CONST_DECL_ALLOWED_P is false.
2451 PUBLIC_FLAG is true if this is for a reference to a public entity or for a
2452 definition to be made visible outside of the current compilation unit, for
2453 instance variable definitions in a package specification.
2455 EXTERN_FLAG is true when processing an external variable declaration (as
2456 opposed to a definition: no storage is to be allocated for the variable).
2458 STATIC_FLAG is only relevant when not at top level and indicates whether
2459 to always allocate storage to the variable.
2461 VOLATILE_FLAG is true if this variable is declared as volatile.
2463 ARTIFICIAL_P is true if the variable was generated by the compiler.
2465 DEBUG_INFO_P is true if we need to write debug information for it.
2467 ATTR_LIST is the list of attributes to be attached to the variable.
2469 GNAT_NODE is used for the position of the decl. */
2471 tree
2477 {
2478 /* Whether the object has static storage duration, either explicitly or by
2479 virtue of being declared at the global level. */
2482 /* Whether the initializer is constant: for an external object or an object
2483 with static storage duration, we check that the initializer is a valid
2484 constant expression for initializing a static variable; otherwise, we
2485 only check that it is constant. */
2486 const bool init_const
2487 = (init
2491 != NULL_TREE
2494 /* Whether we will make TREE_CONSTANT the DECL we produce here, in which
2495 case the initializer may be used in lieu of the DECL node (as done in
2496 Identifier_to_gnu). This is useful to prevent the need of elaboration
2497 code when an identifier for which such a DECL is made is in turn used
2498 as an initializer. We used to rely on CONST_DECL vs VAR_DECL for this,
2499 but extra constraints apply to this choice (see below) and they are not
2500 relevant to the distinction we wish to make. */
2503 /* The actual DECL node. CONST_DECL was initially intended for enumerals
2504 and may be used for scalars in general but not for aggregates. */
2505 tree var_decl
2507 (constant_p
2508 && const_decl_allowed_p
2512 /* Detect constants created by the front-end to hold 'reference to function
2513 calls for stabilization purposes. This is needed for renaming. */
2515 {
2526 }
2528 /* If this is external, throw away any initializations (they will be done
2529 elsewhere) unless this is a constant for which we would like to remain
2530 able to get the initializer. If we are defining a global here, leave a
2531 constant initialization and save any variable elaborations for the
2532 elaboration routine. If we are just annotating types, throw away the
2533 initialization if it isn't a constant. */
2538 /* At the global level, a non-constant initializer generates elaboration
2539 statements. Check that such statements are allowed, that is to say,
2540 not violating a No_Elaboration_Code restriction. */
2544 /* Attach the initializer, if any. */
2547 /* Directly set some flags. */
2554 /* The object is public if it is external or if it is declared public
2555 and has static storage duration. */
2558 /* We need to allocate static storage for an object with static storage
2559 duration if it isn't external. */
2569 /* Ada doesn't feature Fortran-like COMMON variables so we shouldn't
2570 try to fiddle with DECL_COMMON. However, on platforms that don't
2571 support global BSS sections, uninitialized global variables would
2572 go in DATA instead, thus increasing the size of the executable. */
2579 /* Do not emit debug info for a CONST_DECL if optimization isn't enabled,
2580 since we will create an associated variable. Likewise for an external
2581 constant whose initializer is not absolute, because this would mean a
2582 global relocation in a read-only section which runs afoul of the PE-COFF
2583 run-time relocation mechanism. */
2586 || (extern_flag
2587 && constant_p
2588 && init
2593 /* ??? Some attributes cannot be applied to CONST_DECLs. */
2597 /* Add this decl to the current binding level. */
2601 {
2602 /* Let the target mangle the name if this isn't a verbatim asm. */
2607 }
2610 }
2611 \f
2612 /* Return true if TYPE, an aggregate type, contains (or is) an array. */
2614 static bool
2616 {
2618 {
2622 {
2623 tree field;
2629 }
2636 }
2637 }
2639 /* Return a FIELD_DECL node. NAME is the field's name, TYPE is its type and
2640 RECORD_TYPE is the type of the enclosing record. If SIZE is nonzero, it
2641 is the specified size of the field. If POS is nonzero, it is the bit
2642 position. PACKED is 1 if the enclosing record is packed, -1 if it has
2643 Component_Alignment of Storage_Unit. If ADDRESSABLE is nonzero, it
2644 means we are allowed to take the address of the field; if it is negative,
2645 we should not make a bitfield, which is used by make_aligning_type. */
2647 tree
2650 {
2656 /* If FIELD_TYPE is BLKmode, we must ensure this is aligned to at least a
2657 byte boundary since GCC cannot handle less-aligned BLKmode bitfields.
2658 Likewise for an aggregate without specified position that contains an
2659 array, because in this case slices of variable length of this array
2660 must be handled by GCC and variable-sized objects need to be aligned
2661 to at least a byte boundary. */
2663 || (!pos
2668 /* If a size is specified, use it. Otherwise, if the record type is packed
2669 compute a size to use, which may differ from the object's natural size.
2670 We always set a size in this case to trigger the checks for bitfield
2671 creation below, which is typically required when no position has been
2672 specified. */
2676 {
2680 }
2682 /* If we may, according to ADDRESSABLE, make a bitfield if a size is
2683 specified for two reasons: first if the size differs from the natural
2684 size. Second, if the alignment is insufficient. There are a number of
2685 ways the latter can be true.
2687 We never make a bitfield if the type of the field has a nonconstant size,
2688 because no such entity requiring bitfield operations should reach here.
2690 We do *preventively* make a bitfield when there might be the need for it
2691 but we don't have all the necessary information to decide, as is the case
2692 of a field with no specified position in a packed record.
2694 We also don't look at STRICT_ALIGNMENT here, and rely on later processing
2695 in layout_decl or finish_record_type to clear the bit_field indication if
2696 it is in fact not needed. */
2698 && size
2703 || packed
2706 {
2710 {
2714 else
2716 }
2717 }
2721 /* Bump the alignment if need be, either for bitfield/packing purposes or
2722 to satisfy the type requirements if no such consideration applies. When
2723 we get the alignment from the type, indicate if this is from an explicit
2724 user request, which prevents stor-layout from lowering it later on. */
2725 {
2726 unsigned int bit_align
2733 {
2736 }
2737 }
2740 {
2741 /* We need to pass in the alignment the DECL is known to have.
2742 This is the lowest-order bit set in POS, but no more than
2743 the alignment of the record, if one is specified. Note
2744 that an alignment of 0 is taken as infinite. */
2749 else
2763 }
2765 /* In addition to what our caller says, claim the field is addressable if we
2766 know that its type is not suitable.
2768 The field may also be "technically" nonaddressable, meaning that even if
2769 we attempt to take the field's address we will actually get the address
2770 of a copy. This is the case for true bitfields, but the DECL_BIT_FIELD
2771 value we have at this point is not accurate enough, so we don't account
2772 for this here and let finish_record_type decide. */
2779 }
2780 \f
2781 /* Return a PARM_DECL node with NAME and TYPE. */
2783 tree
2785 {
2788 /* Honor TARGET_PROMOTE_PROTOTYPES like the C compiler, as not doing so
2789 can lead to various ABI violations. */
2793 {
2794 /* We have to be careful about biased types here. Make a subtype
2795 of integer_type_node with the proper biasing. */
2798 {
2799 tree subtype
2806 }
2807 else
2809 }
2813 }
2814 \f
2815 /* Process the attributes in ATTR_LIST for NODE, which is either a DECL or
2816 a TYPE. If IN_PLACE is true, the tree pointed to by NODE should not be
2817 changed. GNAT_NODE is used for the position of error messages. */
2819 void
2821 Node_Id gnat_node)
2822 {
2827 {
2836 {
2839 }
2845 else
2852 {
2855 }
2856 else
2875 }
2878 }
2880 /* Return true if VALUE is a known to be a multiple of FACTOR, which must be
2881 a power of 2. */
2883 bool
2885 {
2894 }
2896 /* Return whether GNAT_NODE is a defining identifier for a renaming that comes
2897 from the parameter association for the instantiation of a generic. We do
2898 not want to emit source location for them: the code generated for their
2899 initialization is likely to disturb debugging. */
2901 bool
2903 {
2910 /* Get the object declaration of the renamed object, if any and if the
2911 renamed object is a mere identifier. */
2921 return
2925 }
2927 /* Defer the initialization of DECL's DECL_CONTEXT attribute, scheduling to
2928 feed it with the elaboration of GNAT_SCOPE. */
2932 {
2935 new_node
2944 }
2946 /* Defer the initialization of TYPE's TYPE_CONTEXT attribute, scheduling to
2947 feed it with the DECL_CONTEXT computed as part of N as soon as it is
2948 computed. */
2950 static void
2952 {
2954 }
2956 /* Get the GENERIC node corresponding to GNAT_SCOPE, if available. Return
2957 NULL_TREE if it is not available. */
2959 static tree
2961 {
2962 tree context;
2966 else
2970 {
2973 /* Skip dummy types: only the final ones can appear in the context
2974 chain. */
2978 /* ..._TYPE nodes are more useful than TYPE_DECL nodes in the context
2979 chain. */
2980 else
2982 }
2985 }
2987 /* Try to process all deferred nodes in the queue. Keep in the queue the ones
2988 that cannot be processed yet, remove the other ones. If FORCE is true,
2989 force the processing for all nodes, use the global context when nodes don't
2990 have a GNU translation. */
2992 void
2994 {
2999 {
3002 Entity_Id gnat_scope;
3006 /* If FORCE, get the innermost elaborated scope. Otherwise, just try to
3007 get the first scope. */
3010 {
3015 }
3017 /* Imported declarations must not be in a local context (i.e. not inside
3018 a function). */
3020 {
3024 {
3027 }
3028 }
3030 /* If FORCE, we want to get rid of all nodes in the queue: in case there
3031 was no elaborated scope, use the global context. */
3036 {
3037 tree t;
3042 /* Propagate it to the TYPE_CONTEXT attributes of the requested
3043 ..._TYPE nodes. */
3045 {
3047 }
3049 }
3051 /* If this node has been successfuly processed, remove it from the
3052 queue. Then move to the next node. */
3054 {
3058 }
3059 else
3061 }
3062 }
3064 /* Return VALUE scaled by the biggest power-of-2 factor of EXPR. */
3066 static unsigned int
3068 {
3072 /* Peel conversions around EXPR and try to extract bodies from function
3073 calls: it is possible to get the scale factor from size functions. */
3078 /* Sometimes we get PLUS_EXPR (BIT_AND_EXPR (..., X), Y), where Y is a
3079 multiple of the scale factor we are looking for. */
3083 {
3086 }
3088 /* An expression which is a bitwise AND with a mask has a power-of-2 factor
3089 corresponding to the number of trailing zeros of the mask. */
3092 {
3097 {
3100 i++;
3101 }
3102 }
3104 /* If the addend is not a multiple of the factor we found, give up. In
3105 theory we could find a smaller common factor but it's useless for our
3106 needs. This situation arises when dealing with a field F1 with no
3107 alignment requirement but that is following a field F2 with such
3108 requirements. As long as we have F2's offset, we don't need alignment
3109 information to compute F1's. */
3114 }
3116 /* Given two consecutive field decls PREV_FIELD and CURR_FIELD, return true
3117 unless we can prove these 2 fields are laid out in such a way that no gap
3118 exist between the end of PREV_FIELD and the beginning of CURR_FIELD. OFFSET
3119 is the distance in bits between the end of PREV_FIELD and the starting
3120 position of CURR_FIELD. It is ignored if null. */
3122 static bool
3124 {
3125 /* If this is the first field of the record, there cannot be any gap */
3129 /* If the previous field is a union type, then return false: The only
3130 time when such a field is not the last field of the record is when
3131 there are other components at fixed positions after it (meaning there
3132 was a rep clause for every field), in which case we don't want the
3133 alignment constraint to override them. */
3137 /* If the distance between the end of prev_field and the beginning of
3138 curr_field is constant, then there is a gap if the value of this
3139 constant is not null. */
3143 /* If the size and position of the previous field are constant,
3144 then check the sum of this size and position. There will be a gap
3145 iff it is not multiple of the current field alignment. */
3152 /* If both the position and size of the previous field are multiples
3153 of the current field alignment, there cannot be any gap. */
3158 /* Fallback, return that there may be a potential gap */
3160 }
3162 /* Return a LABEL_DECL with NAME. GNAT_NODE is used for the position of
3163 the decl. */
3165 tree
3167 {
3168 tree label_decl
3173 /* Add this decl to the current binding level. */
3177 }
3178 \f
3179 /* Return a FUNCTION_DECL node. NAME is the name of the subprogram, ASM_NAME
3180 its assembler name, TYPE its type (a FUNCTION_TYPE node), PARAM_DECL_LIST
3181 the list of its parameters (a list of PARM_DECL nodes chained through the
3182 DECL_CHAIN field).
3184 INLINE_STATUS describes the inline flags to be set on the FUNCTION_DECL.
3186 PUBLIC_FLAG is true if this is for a reference to a public entity or for a
3187 definition to be made visible outside of the current compilation unit.
3189 EXTERN_FLAG is true when processing an external subprogram declaration.
3191 ARTIFICIAL_P is true if the subprogram was generated by the compiler.
3193 DEBUG_INFO_P is true if we need to write debug information for it.
3195 DEFINITION is true if the subprogram is to be considered as a definition.
3197 ATTR_LIST is the list of attributes to be attached to the subprogram.
3199 GNAT_NODE is used for the position of the decl. */
3201 tree
3206 Node_Id gnat_node)
3207 {
3221 {
3231 {
3235 ATTR_FLAG_TYPE_IN_PLACE);
3237 /* Inline_Always guarantees that every direct call is inlined and
3238 that there is no indirect reference to the subprogram, so the
3239 instance in the original package (as well as its clones in the
3240 client packages created for inter-unit inlining) can be made
3241 private, which causes the out-of-line body to be eliminated. */
3243 }
3245 /* ... fall through ... */
3254 }
3258 /* Once everything is processed, finish the subprogram declaration. */
3261 /* Add this decl to the current binding level. */
3264 /* Output the assembler code and/or RTL for the declaration. */
3268 }
3270 /* Given a subprogram declaration DECL, its assembler name and its type,
3271 finish constructing the subprogram declaration from ASM_NAME and TYPE. */
3273 void
3275 {
3276 tree result_decl
3289 {
3290 /* Let the target mangle the name if this isn't a verbatim asm. */
3296 /* The expand_main_function circuitry expects "main_identifier_node" to
3297 designate the DECL_NAME of the 'main' entry point, in turn expected
3298 to be declared as the "main" function literally by default. Ada
3299 program entry points are typically declared with a different name
3300 within the binder generated file, exported as 'main' to satisfy the
3301 system expectations. Force main_identifier_node in this case. */
3304 }
3305 }
3306 \f
3307 /* Set up the framework for generating code for SUBPROG_DECL, a subprogram
3308 body. This routine needs to be invoked before processing the declarations
3309 appearing in the subprogram. */
3311 void
3313 {
3314 tree param_decl;
3318 /* This function is being defined. */
3321 /* The failure of this assertion will likely come from a wrong context for
3322 the subprogram body, e.g. another procedure for a procedure declared at
3323 library level. */
3328 /* Enter a new binding level and show that all the parameters belong to
3329 this function. */
3337 }
3339 /* Finish translating the current subprogram and set its BODY. */
3341 void
3343 {
3346 /* Attach the BLOCK for this level to the function and pop the level. */
3351 /* Mark the RESULT_DECL as being in this subprogram. */
3354 /* The body should be a BIND_EXPR whose BLOCK is the top-level one. */
3356 {
3359 }
3364 }
3366 /* Wrap up compilation of SUBPROG_DECL, a subprogram body. */
3368 void
3370 {
3371 /* We cannot track the location of errors past this point. */
3374 /* If we're only annotating types, don't actually compile this function. */
3378 /* Dump functions before gimplification. */
3383 else
3384 /* Register this function with cgraph just far enough to get it
3385 added to our parent's nested function list. */
3387 }
3389 tree
3391 {
3394 }
3396 /* Return an integer type with the number of bits of precision given by
3397 PRECISION. UNSIGNEDP is nonzero if the type is unsigned; otherwise
3398 it is a signed type. */
3400 tree
3402 {
3403 tree t;
3412 else
3420 {
3423 }
3426 }
3428 /* Likewise for floating-point types. */
3430 static tree
3432 {
3433 tree t;
3445 {
3448 }
3451 }
3453 /* Return a data type that has machine mode MODE. UNSIGNEDP selects
3454 an unsigned type; otherwise a signed type is returned. */
3456 tree
3458 {
3468 scalar_float_mode float_mode;
3471 float_mode);
3473 scalar_int_mode int_mode;
3478 {
3483 }
3486 }
3488 /* Return the signed or unsigned version of TYPE_NODE, a scalar type, the
3489 signedness being specified by UNSIGNEDP. */
3491 tree
3493 {
3500 {
3503 }
3507 {
3510 }
3513 }
3515 /* Return 1 if the types T1 and T2 are compatible, i.e. if they can be
3516 transparently converted to each other. */
3518 int
3520 {
3523 /* This is the default criterion. */
3527 /* We only check structural equivalence here. */
3531 /* Vector types are also compatible if they have the same number of subparts
3532 and the same form of (scalar) element type. */
3539 /* Array types are also compatible if they are constrained and have the same
3540 domain(s), the same component type and the same scalar storage order. */
3556 }
3558 /* Return true if EXPR is a useless type conversion. */
3560 bool
3562 {
3570 }
3572 /* Return true if T, a FUNCTION_TYPE, has the specified list of flags. */
3574 bool
3577 {
3582 }
3583 \f
3584 /* EXP is an expression for the size of an object. If this size contains
3585 discriminant references, replace them with the maximum (if MAX_P) or
3586 minimum (if !MAX_P) possible value of the discriminant. */
3588 tree
3590 {
3596 {
3603 {
3617 }
3621 /* If this contains a PLACEHOLDER_EXPR, it is the thing we want to
3622 modify. Otherwise, we treat it like a variable. */
3624 {
3627 return
3630 }
3650 {
3655 /* Special-case wanting the maximum value of a MIN_EXPR.
3656 In that case, if one side overflows, return the other. */
3658 {
3664 }
3666 /* Likewise, handle a MINUS_EXPR or PLUS_EXPR with the LHS
3667 overflowing and the RHS a variable. */
3674 /* If we are going to subtract a "negative" value in an unsigned type,
3675 do the operation as an addition of the negated value, in order to
3676 avoid creating a spurious overflow below. */
3682 {
3685 }
3690 /* We need to detect overflows so we call size_binop here. */
3692 }
3696 {
3723 {
3730 return
3733 }
3738 }
3740 /* Other tree classes cannot happen. */
3743 }
3746 }
3747 \f
3748 /* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE.
3749 EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs.
3750 Return a constructor for the template. */
3752 tree
3754 {
3757 tree field;
3769 /* First make the list for a CONSTRUCTOR for the template. Go down the
3770 field list of the template instead of the type chain because this
3771 array might be an Ada array of arrays and we can't tell where the
3772 nested arrays stop being the underlying object. */
3775 (bound_list
3779 {
3782 /* If we have a bound list, get the bounds from there. Likewise
3783 for an ARRAY_TYPE. Otherwise, if expr is a PARM_DECL with
3784 DECL_BY_COMPONENT_PTR_P, use the bounds of the field in the template.
3785 This will give us a maximum range. */
3793 else
3799 /* If either MIN or MAX involve a PLACEHOLDER_EXPR, we must
3800 substitute it from OBJECT. */
3806 }
3809 }
3810 \f
3811 /* Return true if TYPE is suitable for the element type of a vector. */
3813 static bool
3815 {
3816 machine_mode mode;
3830 }
3832 /* Return a vector type given the SIZE and the INNER_TYPE, or NULL_TREE if
3833 this is not possible. If ATTRIBUTE is non-zero, we are processing the
3834 attribute declaration and want to issue error messages on failure. */
3836 static tree
3838 {
3842 /* Silently punt on variable sizes. We can't make vector types for them,
3843 need to ignore them on front-end generated subtypes of unconstrained
3844 base types, and this attribute is for binding implementors, not end
3845 users, so we should never get there from legitimate explicit uses. */
3851 {
3856 }
3860 {
3864 }
3867 {
3871 }
3875 {
3879 }
3882 }
3884 /* Return a vector type whose representative array type is ARRAY_TYPE, or
3885 NULL_TREE if this is not possible. If ATTRIBUTE is non-zero, we are
3886 processing the attribute and want to issue error messages on failure. */
3888 static tree
3890 {
3893 attribute);
3899 }
3900 \f
3901 /* Build a type to be used to represent an aliased object whose nominal type
3902 is an unconstrained array. This consists of a RECORD_TYPE containing a
3903 field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an ARRAY_TYPE.
3904 If ARRAY_TYPE is that of an unconstrained array, this is used to represent
3905 an arbitrary unconstrained object. Use NAME as the name of the record.
3906 DEBUG_INFO_P is true if we need to write debug information for the type. */
3908 tree
3911 {
3912 tree decl;
3914 tree template_field
3917 tree array_field
3926 /* Declare it now since it will never be declared otherwise. This is
3927 necessary to ensure that its subtrees are properly marked. */
3930 /* template_type will not be used elsewhere than here, so to keep the debug
3931 info clean and in order to avoid scoping issues, make decl its
3932 context. */
3936 }
3938 /* Same, taking a thin or fat pointer type instead of a template type. */
3940 tree
3943 {
3944 tree template_type;
3948 template_type
3953 return
3955 }
3956 \f
3957 /* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE.
3958 In the normal case this is just two adjustments, but we have more to
3959 do if NEW_TYPE is an UNCONSTRAINED_ARRAY_TYPE. */
3961 void
3963 {
3966 tree t;
3968 /* If this is the main variant, process all the other variants first. */
3973 /* If no pointers and no references, we are done. */
3977 /* Merge the old type qualifiers in the new type.
3979 Each old variant has qualifiers for specific reasons, and the new
3980 designated type as well. Each set of qualifiers represents useful
3981 information grabbed at some point, and merging the two simply unifies
3982 these inputs into the final type description.
3984 Consider for instance a volatile type frozen after an access to constant
3985 type designating it; after the designated type's freeze, we get here with
3986 a volatile NEW_TYPE and a dummy OLD_TYPE with a readonly variant, created
3987 when the access type was processed. We will make a volatile and readonly
3988 designated type, because that's what it really is.
3990 We might also get here for a non-dummy OLD_TYPE variant with different
3991 qualifiers than those of NEW_TYPE, for instance in some cases of pointers
3992 to private record type elaboration (see the comments around the call to
3993 this routine in gnat_to_gnu_entity <E_Access_Type>). We have to merge
3994 the qualifiers in those cases too, to avoid accidentally discarding the
3995 initial set, and will often end up with OLD_TYPE == NEW_TYPE then. */
3996 new_type
4000 /* If old type and new type are identical, there is nothing to do. */
4004 /* Otherwise, first handle the simple case. */
4006 {
4009 /* If pointer or reference already points to new type, nothing to do.
4010 This can happen as update_pointer_to can be invoked multiple times
4011 on the same couple of types because of the type variants. */
4016 /* Chain PTR and its variants at the end. */
4019 {
4023 }
4024 else
4027 /* Now adjust them. */
4030 {
4034 }
4036 /* Chain REF and its variants at the end. */
4039 {
4043 }
4044 else
4047 /* Now adjust them. */
4054 }
4056 /* Now deal with the unconstrained array case. In this case the pointer
4057 is actually a record where both fields are pointers to dummy nodes.
4058 Turn them into pointers to the correct types using update_pointer_to.
4059 Likewise for the pointer to the object record (thin pointer). */
4060 else
4061 {
4066 /* If PTR already points to NEW_TYPE, nothing to do. This can happen
4067 since update_pointer_to can be invoked multiple times on the same
4068 couple of types because of the type variants. */
4072 update_pointer_to
4076 update_pointer_to
4085 }
4086 }
4087 \f
4088 /* Convert EXPR, a pointer to a constrained array, into a pointer to an
4089 unconstrained one. This involves making or finding a template. */
4091 static tree
4093 {
4097 tree template_addr;
4101 /* If EXPR is null, make a fat pointer that contains a null pointer to the
4102 array (compare_fat_pointers ensures that this is the full discriminant)
4103 and a valid pointer to the bounds. This latter property is necessary
4104 since the compiler can hoist the load of the bounds done through it. */
4106 {
4112 else
4113 {
4114 /* The template type can still be dummy at this point so we build an
4115 empty constructor. The middle-end will fill it in with zeros. */
4120 }
4126 /* Do not set TREE_CONSTANT so as to force T to static memory. */
4131 }
4133 /* If EXPR is a thin pointer, make template and data from the record. */
4135 {
4140 /* If we have a TYPE_UNCONSTRAINED_ARRAY attached to the RECORD_TYPE,
4141 the thin pointer value has been shifted so we shift it back to get
4142 the template address. */
4144 {
4145 template_addr
4148 byte_position
4150 template_addr
4152 template_addr);
4153 }
4155 /* Otherwise we explicitly take the address of the fields. */
4156 else
4157 {
4159 template_addr
4165 }
4166 }
4168 /* Otherwise, build the constructor for the template. */
4169 else
4170 template_addr
4173 expr));
4175 /* The final result is a constructor for the fat pointer.
4177 If EXPR is an argument of a foreign convention subprogram, the type it
4178 points to is directly the component type. In this case, the expression
4179 type may not match the corresponding FIELD_DECL type at this point, so we
4180 call "convert" here to fix that up if necessary. This type consistency is
4181 required, for instance because it ensures that possible later folding of
4182 COMPONENT_REFs against this constructor always yields something of the
4183 same type as the initial reference.
4185 Note that the call to "build_template" above is still fine because it
4186 will only refer to the provided TEMPLATE_TYPE in this case. */
4190 }
4191 \f
4192 /* Create an expression whose value is that of EXPR,
4193 converted to type TYPE. The TREE_TYPE of the value
4194 is always TYPE. This function implements all reasonable
4195 conversions; callers should filter out those that are
4196 not permitted by the language being compiled. */
4198 tree
4200 {
4205 /* If the expression is already of the right type, we are done. */
4209 /* If both input and output have padding and are of variable size, do this
4210 as an unchecked conversion. Likewise if one is a mere variant of the
4211 other, so we avoid a pointless unpad/repad sequence. */
4219 ;
4221 /* If the output type has padding, convert to the inner type and make a
4222 constructor to build the record, unless a variable size is involved. */
4224 {
4227 /* If we previously converted from another type and our type is
4228 of variable size, remove the conversion to avoid the need for
4229 variable-sized temporaries. Likewise for a conversion between
4230 original and packable version. */
4238 /* If we are just removing the padding from expr, convert the original
4239 object if we have variable size in order to avoid the need for some
4240 variable-sized temporaries. Likewise if the padding is a variant
4241 of the other, so we avoid a pointless unpad/repad sequence. */
4252 /* If the inner type is of self-referential size and the expression type
4253 is a record, do this as an unchecked conversion. But first pad the
4254 expression if possible to have the same size on both sides. */
4257 {
4261 expr);
4263 }
4265 /* If we are converting between array types with variable size, do the
4266 final conversion as an unchecked conversion, again to avoid the need
4267 for some variable-sized temporaries. If valid, this conversion is
4268 very likely purely technical and without real effects. */
4275 expr),
4282 }
4284 /* If the input type has padding, remove it and convert to the output type.
4285 The conditions ordering is arranged to ensure that the output type is not
4286 a padding type here, as it is not clear whether the conversion would
4287 always be correct if this was to happen. */
4289 {
4290 tree unpadded;
4292 /* If we have just converted to this padded type, just get the
4293 inner expression. */
4297 /* Otherwise, build an explicit component reference. */
4298 else
4302 }
4304 /* If the input is a biased type, convert first to the base type and add
4305 the bias. Note that the bias must go through a full conversion to the
4306 base type, lest it is itself a biased value; this happens for subtypes
4307 of biased types. */
4314 /* If the input is a justified modular type, we need to extract the actual
4315 object before converting it to any other type with the exceptions of an
4316 unconstrained array or of a mere type variant. It is useful to avoid the
4317 extraction and conversion in the type variant case because it could end
4318 up replacing a VAR_DECL expr by a constructor and we might be about the
4319 take the address of the result. */
4323 return
4326 /* If converting to a type that contains a template, convert to the data
4327 type and then build the template. */
4329 {
4334 /* If the source already has a template, get a reference to the
4335 associated array only, as we are going to rebuild a template
4336 for the target type anyway. */
4346 }
4348 /* There are some cases of expressions that we process specially. */
4350 {
4355 /* Just set its type here. For TRANSFORM_EXPR, we will do the actual
4356 conversion in gnat_expand_expr. NULL_EXPR does not represent
4357 and actual value, so no conversion is needed. */
4363 /* If we are converting a STRING_CST to another constrained array type,
4364 just make a new one in the proper type. */
4368 {
4372 }
4376 /* If we are converting a VECTOR_CST to a mere type variant, just make
4377 a new one in the proper type. */
4379 {
4383 }
4387 /* If we are converting a CONSTRUCTOR to a mere type variant, or to
4388 another padding type around the same type, just make a new one in
4389 the proper type. */
4396 {
4401 }
4403 /* Likewise for a conversion between original and packable version, or
4404 conversion between types of the same size and with the same list of
4405 fields, but we have to work harder to preserve type consistency. */
4411 {
4420 /* Whether we need to clear TREE_CONSTANT et al. on the output
4421 constructor when we convert in place. */
4425 {
4426 /* Skip the missing fields in the CONSTRUCTOR. */
4428 {
4431 }
4432 /* The field must be the same. */
4435 constructor_elt elt
4439 /* If packing has made this field a bitfield and the input
4440 value couldn't be emitted statically any more, we need to
4441 clear TREE_CONSTANT on our output. */
4451 }
4453 /* If we have been able to match and convert all the input fields
4454 to their output type, convert in place now. We'll fallback to a
4455 view conversion downstream otherwise. */
4457 {
4464 }
4465 }
4467 /* Likewise for a conversion between array type and vector type with a
4468 compatible representative array. */
4472 etype))
4473 {
4478 tree value;
4480 /* Build a VECTOR_CST from a *constant* array constructor. */
4482 {
4485 /* Iterate through elements and check if all constructor
4486 elements are *_CSTs. */
4489 {
4492 }
4497 }
4499 /* Otherwise, build a regular vector constructor. */
4502 {
4505 }
4510 }
4514 /* First retrieve the underlying array. */
4521 {
4522 /* GCC 4.x is very sensitive to type consistency overall, and view
4523 conversions thus are very frequent. Even though just "convert"ing
4524 the inner operand to the output type is fine in most cases, it
4525 might expose unexpected input/output type mismatches in special
4526 circumstances so we avoid such recursive calls when we can. */
4529 /* If we are converting back to the original type, we can just
4530 lift the input conversion. This is a common occurrence with
4531 switches back-and-forth amongst type variants. */
4535 /* Otherwise, if we're converting between two aggregate or vector
4536 types, we might be allowed to substitute the VIEW_CONVERT_EXPR
4537 target type in place or to just convert the inner expression. */
4540 {
4541 /* If we are converting between mere variants, we can just
4542 substitute the VIEW_CONVERT_EXPR in place. */
4546 /* Otherwise, we may just bypass the input view conversion unless
4547 one of the types is a fat pointer, which is handled by
4548 specialized code below which relies on exact type matching. */
4552 }
4555 }
4559 }
4561 /* Check for converting to a pointer to an unconstrained array. */
4565 /* If we are converting between two aggregate or vector types that are mere
4566 variants, just make a VIEW_CONVERT_EXPR. Likewise when we are converting
4567 to a vector type from its representative array type. */
4574 etype)))
4577 /* If we are converting between tagged types, try to upcast properly. */
4580 {
4588 }
4590 /* If we are converting from a smaller form of record type back to it, just
4591 make a VIEW_CONVERT_EXPR. But first pad the expression to have the same
4592 size on both sides. */
4595 {
4598 expr);
4600 }
4602 /* In all other cases of related types, make a NOP_EXPR. */
4607 {
4617 /* If the output is a biased type, convert first to the base type and
4618 subtract the bias. Note that the bias itself must go through a full
4619 conversion to the base type, lest it is a biased value; this happens
4620 for subtypes of biased types. */
4628 /* ... fall through ... */
4632 /* If we are converting an additive expression to an integer type
4633 with lower precision, be wary of the optimization that can be
4634 applied by convert_to_integer. There are 2 problematic cases:
4635 - if the first operand was originally of a biased type,
4636 because we could be recursively called to convert it
4637 to an intermediate type and thus rematerialize the
4638 additive operator endlessly,
4639 - if the expression contains a placeholder, because an
4640 intermediate conversion that changes the sign could
4641 be inserted and thus introduce an artificial overflow
4642 at compile time when the placeholder is substituted. */
4647 {
4654 }
4660 /* If converting between two thin pointers, adjust if needed to account
4661 for differing offsets from the base pointer, depending on whether
4662 there is a TYPE_UNCONSTRAINED_ARRAY attached to the record type. */
4664 {
4665 tree etype_pos
4669 tree type_pos
4681 }
4683 /* If converting fat pointer to normal or thin pointer, get the pointer
4684 to the array and then convert it. */
4695 {
4701 expr));
4703 }
4705 /* ... fall through ... */
4708 /* In these cases, assume the front-end has validated the conversion.
4709 If the conversion is valid, it will be a bit-wise conversion, so
4710 it can be viewed as an unchecked conversion. */
4714 /* This is a either a conversion between a tagged type and some
4715 subtype, which we have to mark as a UNION_TYPE because of
4716 overlapping fields or a conversion of an Unchecked_Union. */
4720 /* If the input is a VECTOR_TYPE, convert to the representative
4721 array type first. */
4723 {
4727 }
4729 /* If EXPR is a constrained array, take its address, convert it to a
4730 fat pointer, and then dereference it. Likewise if EXPR is a
4731 record containing both a template and a constrained array.
4732 Note that a record representing a justified modular type
4733 always represents a packed constrained array. */
4738 return
4739 build_unary_op
4745 /* Do something very similar for converting one unconstrained
4746 array to another. */
4748 return
4753 else
4761 }
4762 }
4764 /* Create an expression whose value is that of EXPR converted to the common
4765 index type, which is sizetype. EXPR is supposed to be in the base type
4766 of the GNAT index type. Calling it is equivalent to doing
4768 convert (sizetype, expr)
4770 but we try to distribute the type conversion with the knowledge that EXPR
4771 cannot overflow in its type. This is a best-effort approach and we fall
4772 back to the above expression as soon as difficulties are encountered.
4774 This is necessary to overcome issues that arise when the GNAT base index
4775 type and the GCC common index type (sizetype) don't have the same size,
4776 which is quite frequent on 64-bit architectures. In this case, and if
4777 the GNAT base index type is signed but the iteration type of the loop has
4778 been forced to unsigned, the loop scalar evolution engine cannot compute
4779 a simple evolution for the general induction variables associated with the
4780 array indices, because it will preserve the wrap-around semantics in the
4781 unsigned type of their "inner" part. As a result, many loop optimizations
4782 are blocked.
4784 The solution is to use a special (basic) induction variable that is at
4785 least as large as sizetype, and to express the aforementioned general
4786 induction variables in terms of this induction variable, eliminating
4787 the problematic intermediate truncation to the GNAT base index type.
4788 This is possible as long as the original expression doesn't overflow
4789 and if the middle-end hasn't introduced artificial overflows in the
4790 course of the various simplification it can make to the expression. */
4792 tree
4794 {
4798 /* If the type is unsigned, overflow is allowed so we cannot be sure that
4799 EXPR doesn't overflow. Keep it simple if optimization is disabled. */
4804 {
4806 /* The main effect of the function: replace a loop parameter with its
4807 associated special induction variable. */
4812 CASE_CONVERT:
4813 {
4815 /* Bail out as soon as we suspect some sort of type frobbing. */
4819 }
4821 /* ... fall through ... */
4845 }
4848 }
4849 \f
4850 /* Remove all conversions that are done in EXP. This includes converting
4851 from a padded type or to a justified modular type. If TRUE_ADDRESS
4852 is true, always return the address of the containing object even if
4853 the address is not bit-aligned. */
4855 tree
4857 {
4859 {
4864 return
4873 CASE_CONVERT:
4880 }
4883 }
4884 \f
4885 /* If EXP's type is an UNCONSTRAINED_ARRAY_TYPE, return an expression that
4886 refers to the underlying array. If it has TYPE_CONTAINS_TEMPLATE_P,
4887 likewise return an expression pointing to the underlying array. */
4889 tree
4891 {
4896 {
4899 {
4907 {
4908 tree op1
4913 tree op2
4922 }
4923 else
4924 {
4931 }
4932 }
4941 /* If this is a padded type and it contains a template, convert to the
4942 unpadded type first. */
4946 {
4950 }
4953 {
4954 /* If the array initializer is a box, return NULL_TREE. */
4962 /* If the array type is padded, convert to the unpadded type. */
4965 }
4970 }
4973 }
4974 \f
4975 /* Return true if EXPR is an expression that can be folded as an operand
4976 of a VIEW_CONVERT_EXPR. See ada-tree.h for a complete rationale. */
4978 static bool
4980 {
4983 /* The folder will fold NOP_EXPRs between integral types with the same
4984 precision (in the middle-end's sense). We cannot allow it if the
4985 types don't have the same precision in the Ada sense as well. */
4992 /* Defer to the folder for non-integral conversions. */
4996 /* Only fold conversions that preserve both precisions. */
5002 }
5004 /* Return an expression that does an unchecked conversion of EXPR to TYPE.
5005 If NOTRUNC_P is true, truncation operations should be suppressed.
5007 Special care is required with (source or target) integral types whose
5008 precision is not equal to their size, to make sure we fetch or assign
5009 the value bits whose location might depend on the endianness, e.g.
5011 Rmsize : constant := 8;
5012 subtype Int is Integer range 0 .. 2 ** Rmsize - 1;
5014 type Bit_Array is array (1 .. Rmsize) of Boolean;
5015 pragma Pack (Bit_Array);
5017 function To_Bit_Array is new Unchecked_Conversion (Int, Bit_Array);
5019 Value : Int := 2#1000_0001#;
5020 Vbits : Bit_Array := To_Bit_Array (Value);
5022 we expect the 8 bits at Vbits'Address to always contain Value, while
5023 their original location depends on the endianness, at Value'Address
5024 on a little-endian architecture but not on a big-endian one.
5026 One pitfall is that we cannot use TYPE_UNSIGNED directly to decide how
5027 the bits between the precision and the size are filled, because of the
5028 trick used in the E_Signed_Integer_Subtype case of gnat_to_gnu_entity.
5029 So we use the special predicate type_unsigned_for_rm above. */
5031 tree
5033 {
5037 tree tem;
5040 /* If the expression is already of the right type, we are done. */
5044 /* If both types are integral just do a normal conversion.
5045 Likewise for a conversion to an unconstrained array. */
5053 {
5055 {
5060 }
5063 {
5069 }
5070 else
5072 }
5074 /* If we are converting to an integral type whose precision is not equal
5075 to its size, first unchecked convert to a record type that contains a
5076 field of the given precision. Then extract the result from the field.
5078 There is a subtlety if the source type is an aggregate type with reverse
5079 storage order because its representation is not contiguous in the native
5080 storage order, i.e. a direct unchecked conversion to an integral type
5081 with N bits of precision cannot read the first N bits of the aggregate
5082 type. To overcome it, we do an unchecked conversion to an integral type
5083 with reverse storage order and return the resulting value. This also
5084 ensures that the result of the unchecked conversion doesn't depend on
5085 the endianness of the target machine, but only on the storage order of
5086 the aggregate type.
5088 Finally, for the sake of consistency, we do the unchecked conversion
5089 to an integral type with reverse storage order as soon as the source
5090 type is an aggregate type with reverse storage order, even if there
5091 are no considerations of precision or size involved. */
5098 {
5109 else
5121 }
5123 /* Similarly if we are converting from an integral type whose precision is
5124 not equal to its size, first copy into a field of the given precision
5125 and unchecked convert the record type.
5127 The same considerations as above apply if the target type is an aggregate
5128 type with reverse storage order and we also proceed similarly. */
5135 {
5148 else
5161 }
5163 /* If we are converting from a scalar type to a type with a different size,
5164 we need to pad to have the same size on both sides.
5166 ??? We cannot do it unconditionally because unchecked conversions are
5167 used liberally by the front-end to implement polymorphism, e.g. in:
5169 S191s : constant ada__tags__addr_ptr := ada__tags__addr_ptr!(S190s);
5170 return p___size__4 (p__object!(S191s.all));
5172 so we skip all expressions that are references. */
5177 {
5179 {
5182 expr);
5184 }
5185 else
5186 {
5191 }
5192 }
5194 /* We have a special case when we are converting between two unconstrained
5195 array types. In that case, take the address, convert the fat pointer
5196 types, and dereference. */
5201 expr)));
5203 /* Another special case is when we are converting to a vector type from its
5204 representative array type; this a regular conversion. */
5208 etype))
5211 /* And, if the array type is not the representative, we try to build an
5212 intermediate vector type of which the array type is the representative
5213 and to do the unchecked conversion between the vector types, in order
5214 to enable further simplifications in the middle-end. */
5218 {
5221 }
5223 /* If we are converting a CONSTRUCTOR to a more aligned RECORD_TYPE, bump
5224 the alignment of the CONSTRUCTOR to speed up the copy operation. */
5228 {
5231 expr);
5233 }
5235 /* Otherwise, just build a VIEW_CONVERT_EXPR of the expression. */
5236 else
5237 {
5243 else
5245 }
5247 /* If the result is a non-biased integral type whose precision is not equal
5248 to its size, sign- or zero-extend the result. But we need not do this
5249 if the input is also an integral type and both are unsigned or both are
5250 signed and have the same precision. */
5263 {
5264 tree base_type
5267 tree shift_expr
5271 expr
5276 shift_expr),
5277 shift_expr));
5278 }
5280 /* An unchecked conversion should never raise Constraint_Error. The code
5281 below assumes that GCC's conversion routines overflow the same way that
5282 the underlying hardware does. This is probably true. In the rare case
5283 when it is false, we can rely on the fact that such conversions are
5284 erroneous anyway. */
5288 /* If the sizes of the types differ and this is an VIEW_CONVERT_EXPR,
5289 show no longer constant. */
5292 OEP_ONLY_CONST))
5296 }
5297 \f
5298 /* Return the appropriate GCC tree code for the specified GNAT_TYPE,
5299 the latter being a record type as predicated by Is_Record_Type. */
5301 enum tree_code
5303 {
5306 /* Return UNION_TYPE if it's an Unchecked_Union whose non-discriminant
5307 fields are all in the variant part. Otherwise, return RECORD_TYPE. */
5312 component_list
5322 }
5324 /* Return true if GNAT_TYPE is a "double" floating-point type, i.e. whose
5325 size is equal to 64 bits, or an array of such a type. Set ALIGN_CLAUSE
5326 according to the presence of an alignment clause on the type or, if it
5327 is an array, on the component type. */
5329 bool
5331 {
5337 {
5341 }
5350 }
5352 /* Return true if GNAT_TYPE is a "double" or larger scalar type, i.e. whose
5353 size is greater or equal to 64 bits, or an array of such a type. Set
5354 ALIGN_CLAUSE according to the presence of an alignment clause on the
5355 type or, if it is an array, on the component type. */
5357 bool
5359 {
5365 {
5369 }
5378 }
5380 /* Return true if GNU_TYPE is suitable as the type of a non-aliased
5381 component of an aggregate type. */
5383 bool
5385 {
5386 /* If the type is passed by reference, we may have pointers to the
5387 component so it cannot be made non-aliased. */
5391 /* We used to say that any component of aggregate type is aliased
5392 because the front-end may take 'Reference of it. The front-end
5393 has been enhanced in the meantime so as to use a renaming instead
5394 in most cases, but the back-end can probably take the address of
5395 such a component too so we go for the conservative stance.
5397 For instance, we might need the address of any array type, even
5398 if normally passed by copy, to construct a fat pointer if the
5399 component is used as an actual for an unconstrained formal.
5401 Likewise for record types: even if a specific record subtype is
5402 passed by copy, the parent type might be passed by ref (e.g. if
5403 it's of variable size) and we might take the address of a child
5404 component to pass to a parent formal. We have no way to check
5405 for such conditions here. */
5410 }
5412 /* Return true if TYPE is a smaller form of ORIG_TYPE. */
5414 bool
5416 {
5419 /* We're not interested in variants here. */
5423 /* Like a variant, a packable version keeps the original TYPE_NAME. */
5434 }
5436 /* Return whether EXPR, which is the renamed object in an object renaming
5437 declaration, can be materialized as a reference (with a REFERENCE_TYPE).
5438 This should be synchronized with Exp_Dbug.Debug_Renaming_Declaration. */
5440 bool
5442 {
5444 {
5448 {
5457 {
5461 const Uint bitpos
5469 }
5473 {
5481 }
5489 };
5490 }
5491 }
5493 /* Perform final processing on global declarations. */
5497 void
5499 {
5501 tree iter;
5503 /* If we have declared types as used at the global level, insert them in
5504 the global hash table. We use a dummy variable for this purpose, but
5505 we need to build it unconditionally to avoid -fcompare-debug issues. */
5507 {
5512 dummy_global
5514 void_type_node);
5523 {
5526 }
5527 }
5529 /* Output debug information for all global type declarations first. This
5530 ensures that global types whose compilation hasn't been finalized yet,
5531 for example pointers to Taft amendment types, have their compilation
5532 finalized in the right context. */
5537 /* Output imported functions. */
5546 /* Then output the global variables. We need to do that after the debug
5547 information for global types is emitted so that they are finalized. Skip
5548 external global variables, unless we need to emit debug info for them:
5549 this is useful for imported variables, for instance. */
5555 /* Output the imported modules/declarations. In GNAT, these are only
5556 materializing subprogram. */
5561 }
5563 /* ************************************************************************
5564 * * GCC builtins support *
5565 * ************************************************************************ */
5567 /* The general scheme is fairly simple:
5569 For each builtin function/type to be declared, gnat_install_builtins calls
5570 internal facilities which eventually get to gnat_pushdecl, which in turn
5571 tracks the so declared builtin function decls in the 'builtin_decls' global
5572 datastructure. When an Intrinsic subprogram declaration is processed, we
5573 search this global datastructure to retrieve the associated BUILT_IN DECL
5574 node. */
5576 /* Search the chain of currently available builtin declarations for a node
5577 corresponding to function NAME (an IDENTIFIER_NODE). Return the first node
5578 found, if any, or NULL_TREE otherwise. */
5579 tree
5581 {
5583 tree decl;
5590 }
5592 /* The code below eventually exposes gnat_install_builtins, which declares
5593 the builtin types and functions we might need, either internally or as
5594 user accessible facilities.
5596 ??? This is a first implementation shot, still in rough shape. It is
5597 heavily inspired from the "C" family implementation, with chunks copied
5598 verbatim from there.
5600 Two obvious improvement candidates are:
5601 o Use a more efficient name/decl mapping scheme
5602 o Devise a middle-end infrastructure to avoid having to copy
5603 pieces between front-ends. */
5605 /* ----------------------------------------------------------------------- *
5606 * BUILTIN ELEMENTARY TYPES *
5607 * ----------------------------------------------------------------------- */
5609 /* Standard data types to be used in builtin argument declarations. */
5611 enum c_tree_index
5612 {
5614 CTI_STRING_TYPE,
5615 CTI_CONST_STRING_TYPE,
5617 CTI_MAX
5618 };
5622 #define signed_size_type_node c_global_trees[CTI_SIGNED_SIZE_TYPE]
5623 #define string_type_node c_global_trees[CTI_STRING_TYPE]
5624 #define const_string_type_node c_global_trees[CTI_CONST_STRING_TYPE]
5626 /* ??? In addition some attribute handlers, we currently don't support a
5627 (small) number of builtin-types, which in turns inhibits support for a
5628 number of builtin functions. */
5629 #define wint_type_node void_type_node
5630 #define intmax_type_node void_type_node
5631 #define uintmax_type_node void_type_node
5633 /* Used to help initialize the builtin-types.def table. When a type of
5634 the correct size doesn't exist, use error_mark_node instead of NULL.
5635 The later results in segfaults even when a decl using the type doesn't
5636 get invoked. */
5638 static tree
5640 {
5643 }
5645 /* Build/push the elementary type decls that builtin functions/types
5646 will need. */
5648 static void
5650 {
5655 const_string_type_node
5658 }
5660 /* ----------------------------------------------------------------------- *
5661 * BUILTIN FUNCTION TYPES *
5662 * ----------------------------------------------------------------------- */
5664 /* Now, builtin function types per se. */
5666 enum c_builtin_type
5667 {
5668 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
5669 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
5670 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
5671 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
5672 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
5673 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
5674 #define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME,
5675 #define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5676 ARG6) NAME,
5677 #define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5678 ARG6, ARG7) NAME,
5679 #define DEF_FUNCTION_TYPE_8(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5680 ARG6, ARG7, ARG8) NAME,
5681 #define DEF_FUNCTION_TYPE_9(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5682 ARG6, ARG7, ARG8, ARG9) NAME,
5683 #define DEF_FUNCTION_TYPE_10(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5684 ARG6, ARG7, ARG8, ARG9, ARG10) NAME,
5685 #define DEF_FUNCTION_TYPE_11(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5686 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) NAME,
5687 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
5688 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
5689 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
5690 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
5691 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
5692 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5693 NAME,
5694 #define DEF_FUNCTION_TYPE_VAR_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5695 ARG6) NAME,
5696 #define DEF_FUNCTION_TYPE_VAR_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5697 ARG6, ARG7) NAME,
5698 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
5700 #undef DEF_PRIMITIVE_TYPE
5701 #undef DEF_FUNCTION_TYPE_0
5702 #undef DEF_FUNCTION_TYPE_1
5703 #undef DEF_FUNCTION_TYPE_2
5704 #undef DEF_FUNCTION_TYPE_3
5705 #undef DEF_FUNCTION_TYPE_4
5706 #undef DEF_FUNCTION_TYPE_5
5707 #undef DEF_FUNCTION_TYPE_6
5708 #undef DEF_FUNCTION_TYPE_7
5709 #undef DEF_FUNCTION_TYPE_8
5710 #undef DEF_FUNCTION_TYPE_9
5711 #undef DEF_FUNCTION_TYPE_10
5712 #undef DEF_FUNCTION_TYPE_11
5713 #undef DEF_FUNCTION_TYPE_VAR_0
5714 #undef DEF_FUNCTION_TYPE_VAR_1
5715 #undef DEF_FUNCTION_TYPE_VAR_2
5716 #undef DEF_FUNCTION_TYPE_VAR_3
5717 #undef DEF_FUNCTION_TYPE_VAR_4
5718 #undef DEF_FUNCTION_TYPE_VAR_5
5719 #undef DEF_FUNCTION_TYPE_VAR_6
5720 #undef DEF_FUNCTION_TYPE_VAR_7
5721 #undef DEF_POINTER_TYPE
5722 BT_LAST
5723 };
5727 /* A temporary array used in communication with def_fn_type. */
5730 /* A helper function for install_builtin_types. Build function type
5731 for DEF with return type RET and N arguments. If VAR is true, then the
5732 function should be variadic after those N arguments.
5734 Takes special care not to ICE if any of the types involved are
5735 error_mark_node, which indicates that said type is not in fact available
5736 (see builtin_type_for_size). In which case the function type as a whole
5737 should be error_mark_node. */
5739 static void
5741 {
5742 tree t;
5749 {
5755 }
5762 else
5765 egress:
5768 }
5770 /* Build the builtin function types and install them in the builtin_types
5771 array for later use in builtin function decls. */
5773 static void
5775 {
5776 tree va_list_ref_type_node;
5777 tree va_list_arg_type_node;
5780 {
5783 }
5784 else
5785 {
5788 }
5790 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
5791 builtin_types[ENUM] = VALUE;
5792 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \
5793 def_fn_type (ENUM, RETURN, 0, 0);
5794 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \
5795 def_fn_type (ENUM, RETURN, 0, 1, ARG1);
5796 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \
5797 def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2);
5798 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
5799 def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3);
5800 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
5801 def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4);
5802 #define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5803 def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
5804 #define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5805 ARG6) \
5806 def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
5807 #define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5808 ARG6, ARG7) \
5809 def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
5810 #define DEF_FUNCTION_TYPE_8(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5811 ARG6, ARG7, ARG8) \
5812 def_fn_type (ENUM, RETURN, 0, 8, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5813 ARG7, ARG8);
5814 #define DEF_FUNCTION_TYPE_9(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5815 ARG6, ARG7, ARG8, ARG9) \
5816 def_fn_type (ENUM, RETURN, 0, 9, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5817 ARG7, ARG8, ARG9);
5818 #define DEF_FUNCTION_TYPE_10(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5,\
5819 ARG6, ARG7, ARG8, ARG9, ARG10) \
5820 def_fn_type (ENUM, RETURN, 0, 10, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5821 ARG7, ARG8, ARG9, ARG10);
5822 #define DEF_FUNCTION_TYPE_11(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5,\
5823 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) \
5824 def_fn_type (ENUM, RETURN, 0, 11, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5825 ARG7, ARG8, ARG9, ARG10, ARG11);
5826 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \
5827 def_fn_type (ENUM, RETURN, 1, 0);
5828 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \
5829 def_fn_type (ENUM, RETURN, 1, 1, ARG1);
5830 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \
5831 def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2);
5832 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
5833 def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3);
5834 #define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
5835 def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
5836 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5837 def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
5838 #define DEF_FUNCTION_TYPE_VAR_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5839 ARG6) \
5840 def_fn_type (ENUM, RETURN, 1, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
5841 #define DEF_FUNCTION_TYPE_VAR_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5842 ARG6, ARG7) \
5843 def_fn_type (ENUM, RETURN, 1, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
5844 #define DEF_POINTER_TYPE(ENUM, TYPE) \
5845 builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
5849 #undef DEF_PRIMITIVE_TYPE
5850 #undef DEF_FUNCTION_TYPE_0
5851 #undef DEF_FUNCTION_TYPE_1
5852 #undef DEF_FUNCTION_TYPE_2
5853 #undef DEF_FUNCTION_TYPE_3
5854 #undef DEF_FUNCTION_TYPE_4
5855 #undef DEF_FUNCTION_TYPE_5
5856 #undef DEF_FUNCTION_TYPE_6
5857 #undef DEF_FUNCTION_TYPE_7
5858 #undef DEF_FUNCTION_TYPE_8
5859 #undef DEF_FUNCTION_TYPE_9
5860 #undef DEF_FUNCTION_TYPE_10
5861 #undef DEF_FUNCTION_TYPE_11
5862 #undef DEF_FUNCTION_TYPE_VAR_0
5863 #undef DEF_FUNCTION_TYPE_VAR_1
5864 #undef DEF_FUNCTION_TYPE_VAR_2
5865 #undef DEF_FUNCTION_TYPE_VAR_3
5866 #undef DEF_FUNCTION_TYPE_VAR_4
5867 #undef DEF_FUNCTION_TYPE_VAR_5
5868 #undef DEF_FUNCTION_TYPE_VAR_6
5869 #undef DEF_FUNCTION_TYPE_VAR_7
5870 #undef DEF_POINTER_TYPE
5872 }
5874 /* ----------------------------------------------------------------------- *
5875 * BUILTIN ATTRIBUTES *
5876 * ----------------------------------------------------------------------- */
5878 enum built_in_attribute
5879 {
5880 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
5881 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
5882 #define DEF_ATTR_STRING(ENUM, VALUE) ENUM,
5883 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
5884 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
5886 #undef DEF_ATTR_NULL_TREE
5887 #undef DEF_ATTR_INT
5888 #undef DEF_ATTR_STRING
5889 #undef DEF_ATTR_IDENT
5890 #undef DEF_ATTR_TREE_LIST
5891 ATTR_LAST
5892 };
5896 static void
5898 {
5899 /* Fill in the built_in_attributes array. */
5900 #define DEF_ATTR_NULL_TREE(ENUM) \
5901 built_in_attributes[(int) ENUM] = NULL_TREE;
5902 #define DEF_ATTR_INT(ENUM, VALUE) \
5903 built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
5904 #define DEF_ATTR_STRING(ENUM, VALUE) \
5905 built_in_attributes[(int) ENUM] = build_string (strlen (VALUE), VALUE);
5906 #define DEF_ATTR_IDENT(ENUM, STRING) \
5907 built_in_attributes[(int) ENUM] = get_identifier (STRING);
5908 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
5909 built_in_attributes[(int) ENUM] \
5910 = tree_cons (built_in_attributes[(int) PURPOSE], \
5911 built_in_attributes[(int) VALUE], \
5912 built_in_attributes[(int) CHAIN]);
5914 #undef DEF_ATTR_NULL_TREE
5915 #undef DEF_ATTR_INT
5916 #undef DEF_ATTR_STRING
5917 #undef DEF_ATTR_IDENT
5918 #undef DEF_ATTR_TREE_LIST
5919 }
5921 /* Handle a "const" attribute; arguments as in
5922 struct attribute_spec.handler. */
5924 static tree
5928 {
5931 else
5935 }
5937 /* Handle a "nothrow" attribute; arguments as in
5938 struct attribute_spec.handler. */
5940 static tree
5944 {
5947 else
5951 }
5953 /* Handle a "pure" attribute; arguments as in
5954 struct attribute_spec.handler. */
5956 static tree
5959 {
5962 /* TODO: support types. */
5963 else
5964 {
5968 }
5971 }
5973 /* Handle a "no vops" attribute; arguments as in
5974 struct attribute_spec.handler. */
5976 static tree
5980 {
5984 }
5986 /* Helper for nonnull attribute handling; fetch the operand number
5987 from the attribute argument list. */
5989 static bool
5991 {
5992 /* Verify the arg number is a constant. */
5998 }
6000 /* Handle the "nonnull" attribute. */
6001 static tree
6005 {
6009 /* If no arguments are specified, all pointer arguments should be
6010 non-null. Verify a full prototype is given so that the arguments
6011 will have the correct types when we actually check them later.
6012 Avoid diagnosing type-generic built-ins since those have no
6013 prototype. */
6015 {
6019 {
6022 }
6024 }
6026 /* Argument list specified. Verify that each argument number references
6027 a pointer argument. */
6029 {
6033 {
6038 }
6041 {
6042 function_args_iterator iter;
6043 tree argument;
6047 {
6051 }
6055 {
6061 }
6064 {
6070 }
6071 }
6072 }
6075 }
6077 /* Handle a "sentinel" attribute. */
6079 static tree
6082 {
6084 {
6089 }
6090 else
6091 {
6093 {
6098 }
6099 }
6102 {
6106 {
6109 }
6110 else
6111 {
6113 {
6116 }
6117 }
6118 }
6121 }
6123 /* Handle a "noreturn" attribute; arguments as in
6124 struct attribute_spec.handler. */
6126 static tree
6129 {
6132 /* See FIXME comment in c_common_attribute_table. */
6138 = build_pointer_type
6141 else
6142 {
6146 }
6149 }
6151 /* Handle a "noinline" attribute; arguments as in
6152 struct attribute_spec.handler. */
6154 static tree
6158 {
6160 {
6162 {
6166 }
6167 else
6169 }
6170 else
6171 {
6174 }
6177 }
6179 /* Handle a "noclone" attribute; arguments as in
6180 struct attribute_spec.handler. */
6182 static tree
6186 {
6188 {
6191 }
6194 }
6196 /* Handle a "leaf" attribute; arguments as in
6197 struct attribute_spec.handler. */
6199 static tree
6202 {
6204 {
6207 }
6209 {
6212 }
6215 }
6217 /* Handle a "always_inline" attribute; arguments as in
6218 struct attribute_spec.handler. */
6220 static tree
6223 {
6225 {
6226 /* Set the attribute and mark it for disregarding inline limits. */
6228 }
6229 else
6230 {
6233 }
6236 }
6238 /* Handle a "malloc" attribute; arguments as in
6239 struct attribute_spec.handler. */
6241 static tree
6244 {
6248 else
6249 {
6253 }
6256 }
6258 /* Fake handler for attributes we don't properly support. */
6260 tree
6266 {
6268 }
6270 /* Handle a "type_generic" attribute. */
6272 static tree
6276 {
6277 /* Ensure we have a function type. */
6280 /* Ensure we have a variadic function. */
6284 }
6286 /* Handle a "vector_size" attribute; arguments as in
6287 struct attribute_spec.handler. */
6289 static tree
6292 {
6294 tree vector_type;
6298 /* We need to provide for vector pointers, vector arrays, and
6299 functions returning vectors. For example:
6301 __attribute__((vector_size(16))) short *foo;
6303 In this case, the mode is SI, but the type being modified is
6304 HI, so we need to look further. */
6314 /* Build back pointers if needed. */
6318 }
6320 /* Handle a "vector_type" attribute; arguments as in
6321 struct attribute_spec.handler. */
6323 static tree
6326 {
6328 tree vector_type;
6333 {
6337 }
6347 }
6349 /* ----------------------------------------------------------------------- *
6350 * BUILTIN FUNCTIONS *
6351 * ----------------------------------------------------------------------- */
6353 /* Worker for DEF_BUILTIN. Possibly define a builtin function with one or two
6354 names. Does not declare a non-__builtin_ function if flag_no_builtin, or
6355 if nonansi_p and flag_no_nonansi_builtin. */
6357 static void
6365 {
6366 tree decl;
6369 /* Preserve an already installed decl. It most likely was setup in advance
6370 (e.g. as part of the internal builtins) for specific reasons. */
6381 fnattrs);
6383 /* ??? This is normally further controlled by command-line options
6384 like -fno-builtin, but we don't have them for Ada. */
6389 }
6395 /* Install what the common builtins.def offers. */
6397 static void
6399 {
6400 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
6401 NONANSI_P, ATTRS, IMPLICIT, COND) \
6402 if (NAME && COND) \
6403 def_builtin_1 (ENUM, NAME, CLASS, \
6404 builtin_types[(int) TYPE], \
6405 builtin_types[(int) LIBTYPE], \
6406 BOTH_P, FALLBACK_P, NONANSI_P, \
6407 built_in_attributes[(int) ATTRS], IMPLICIT);
6409 }
6411 /* ----------------------------------------------------------------------- *
6412 * BUILTIN FUNCTIONS *
6413 * ----------------------------------------------------------------------- */
6415 /* Install the builtin functions we might need. */
6417 void
6419 {
6424 /* Install builtins used by generic middle-end pieces first. Some of these
6425 know about internal specificities and control attributes accordingly, for
6426 instance __builtin_alloca vs no-throw and -fstack-check. We will ignore
6427 the generic definition from builtins.def. */
6430 /* Now, install the target specific builtins, such as the AltiVec family on
6431 ppc, and the common set as exposed by builtins.def. */
6434 }