| blob | e7b5c7783b1f1c702130c8879c79b7e329764b09 |
1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * U T I L S *
6 * *
7 * C Implementation File *
8 * *
9 * Copyright (C) 1992-2023, 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 ****************************************************************************/
62 /* If nonzero, pretend we are allocating at global level. */
65 /* The default alignment of "double" floating-point types, i.e. floating
66 point types whose size is equal to 64 bits, or 0 if this alignment is
67 not specifically capped. */
70 /* The default alignment of "double" or larger scalar types, i.e. scalar
71 types whose size is greater or equal to 64 bits, or 0 if this alignment
72 is not specifically capped. */
75 /* True if floating-point arithmetics may use wider intermediate results. */
78 /* Tree nodes for the various types and decls we create. */
81 /* Functions to call for each of the possible raise reasons. */
84 /* Likewise, but with extra info for each of the possible raise reasons. */
87 /* Forward declarations for handlers of attributes. */
120 {
124 };
127 {
131 };
133 /* Fake handler for attributes we don't properly support, typically because
134 they'd require dragging a lot of the common-c front-end circuitry. */
137 /* Table of machine-independent internal attributes for Ada. We support
138 this minimal set of attributes to accommodate the needs of builtins. */
140 {
141 /* { name, min_len, max_len, decl_req, type_req, fn_type_req,
142 affects_type_identity, handler, exclude } */
160 handle_stack_protect_attribute,
161 attr_stack_protect_exclusions },
163 handle_no_stack_protector_attribute,
164 attr_stack_protect_exclusions },
209 /* ??? format and format_arg are heavy and not supported, which actually
210 prevents support for stdio builtins, which we however declare as part
211 of the common builtins.def contents. */
217 /* This is handled entirely in the front end. */
223 };
225 /* Associates a GNAT tree node to a GCC tree node. It is used in
226 `save_gnu_tree', `get_gnu_tree' and `present_gnu_tree'. See documentation
227 of `save_gnu_tree' for more info. */
230 #define GET_GNU_TREE(GNAT_ENTITY) \
231 associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id]
233 #define SET_GNU_TREE(GNAT_ENTITY,VAL) \
234 associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] = (VAL)
236 #define PRESENT_GNU_TREE(GNAT_ENTITY) \
237 (associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] != NULL_TREE)
239 /* Associates a GNAT entity to a GCC tree node used as a dummy, if any. */
242 #define GET_DUMMY_NODE(GNAT_ENTITY) \
243 dummy_node_table[(GNAT_ENTITY) - First_Node_Id]
245 #define SET_DUMMY_NODE(GNAT_ENTITY,VAL) \
246 dummy_node_table[(GNAT_ENTITY) - First_Node_Id] = (VAL)
248 #define PRESENT_DUMMY_NODE(GNAT_ENTITY) \
249 (dummy_node_table[(GNAT_ENTITY) - First_Node_Id] != NULL_TREE)
251 /* This variable keeps a table for types for each precision so that we only
252 allocate each of them once. Signed and unsigned types are kept separate.
254 Note that these types are only used when fold-const requests something
255 special. Perhaps we should NOT share these types; we'll see how it
256 goes later. */
259 /* Likewise for float types, but record these by mode. */
262 /* For each binding contour we allocate a binding_level structure to indicate
263 the binding depth. */
266 /* The binding level containing this one (the enclosing binding level). */
268 /* The BLOCK node for this level. */
269 tree block;
270 };
272 /* The binding level currently in effect. */
275 /* A chain of gnat_binding_level structures awaiting reuse. */
278 /* The context to be used for global declarations. */
281 /* An array of global declarations. */
284 /* An array of builtin function declarations. */
287 /* A chain of unused BLOCK nodes. */
290 /* A hash table of packable types. It is modelled on the generic type
291 hash table in tree.cc, which must thus be used as a reference. */
294 {
295 hashval_t hash;
296 tree type;
297 };
300 {
304 static int
306 {
308 }
309 };
313 /* A hash table of padded types. It is modelled on the generic type
314 hash table in tree.cc, which must thus be used as a reference. */
317 {
318 hashval_t hash;
319 tree type;
320 };
323 {
327 static int
329 {
331 }
332 };
344 /* Linked list used as a queue to defer the initialization of the DECL_CONTEXT
345 of ..._DECL nodes and of the TYPE_CONTEXT of ..._TYPE nodes. */
346 struct deferred_decl_context_node
347 {
348 /* The ..._DECL node to work on. */
349 tree decl;
351 /* The corresponding entity's Scope. */
352 Entity_Id gnat_scope;
354 /* The value of force_global when DECL was pushed. */
357 /* The list of ..._TYPE nodes to propagate the context to. */
360 /* The next queue item. */
362 };
366 /* Defer the initialization of DECL's DECL_CONTEXT attribute, scheduling to
367 feed it with the elaboration of GNAT_SCOPE. */
371 /* Defer the initialization of TYPE's TYPE_CONTEXT attribute, scheduling to
372 feed it with the DECL_CONTEXT computed as part of N as soon as it is
373 computed. */
375 tree type);
377 /* Initialize data structures of the utils.cc module. */
379 void
381 {
382 /* Initialize the association of GNAT nodes to GCC trees. */
385 /* Initialize the association of GNAT nodes to GCC trees as dummies. */
388 /* Initialize the hash table of packable types. */
391 /* Initialize the hash table of padded types. */
393 }
395 /* Destroy data structures of the utils.cc module. */
397 void
399 {
400 /* Destroy the association of GNAT nodes to GCC trees. */
404 /* Destroy the association of GNAT nodes to GCC trees as dummies. */
408 /* Destroy the hash table of packable types. */
412 /* Destroy the hash table of padded types. */
415 }
417 /* GNAT_ENTITY is a GNAT tree node for an entity. Associate GNU_DECL, a GCC
418 tree node, with GNAT_ENTITY. If GNU_DECL is not a ..._DECL node, abort.
419 If NO_CHECK is true, the latter check is suppressed.
421 If GNU_DECL is zero, reset a previous association. */
423 void
425 {
426 /* Check that GNAT_ENTITY is not already defined and that it is being set
427 to something which is a decl. If that is not the case, this usually
428 means GNAT_ENTITY is defined twice, but occasionally is due to some
429 Gigi problem. */
435 }
437 /* GNAT_ENTITY is a GNAT tree node for an entity. Return the GCC tree node
438 that was associated with it. If there is no such tree node, abort.
440 In some cases, such as delayed elaboration or expressions that need to
441 be elaborated only once, GNAT_ENTITY is really not an entity. */
443 tree
445 {
448 }
450 /* Return nonzero if a GCC tree has been associated with GNAT_ENTITY. */
452 bool
454 {
456 }
458 /* Make a dummy type corresponding to GNAT_TYPE. */
460 tree
462 {
466 /* If there was no equivalent type (can only happen when just annotating
467 types) or underlying type, go back to the original type. */
471 /* If it there already a dummy type, use that one. Else make one. */
475 /* If this is a record, make a RECORD_TYPE or UNION_TYPE; else make
476 an ENUMERAL_TYPE. */
489 NULL_TREE),
490 ATTR_FLAG_TYPE_IN_PLACE);
494 /* Create a debug type so that debuggers only see an unspecified type. */
496 {
501 }
504 }
506 /* Return the dummy type that was made for GNAT_TYPE, if any. */
508 tree
510 {
512 }
514 /* Build dummy fat and thin pointer types whose designated type is specified
515 by GNAT_DESIG_TYPE/GNU_DESIG_TYPE and attach them to the latter. */
517 void
519 {
534 /* Build a stub DECL to trigger the special processing for fat pointer types
535 in gnat_pushdecl. */
538 gnu_fat_type);
546 /* Suppress debug info until after the type is completed. */
556 }
558 /* Return true if we are in the global binding level. */
560 bool
562 {
564 }
566 /* Enter a new binding level. */
568 void
570 {
573 /* Reuse a struct for this binding level, if there is one. */
575 {
578 }
579 else
582 /* Use a free BLOCK, if any; otherwise, allocate one. */
584 {
588 }
589 else
592 /* Point the BLOCK we just made to its parent. */
600 /* Add this level to the front of the chain (stack) of active levels. */
603 }
605 /* Set SUPERCONTEXT of the BLOCK for the current binding level to FNDECL
606 and point FNDECL to this BLOCK. */
608 void
610 {
614 }
616 /* Exit a binding level. Set any BLOCK into the current code group. */
618 void
620 {
627 /* If this is a function-level BLOCK don't do anything. Otherwise, if there
628 are no variables free the block and merge its subblocks into those of its
629 parent block. Otherwise, add it to the list of its parent. */
631 ;
633 {
639 }
640 else
641 {
646 }
648 /* Free this binding structure. */
652 }
654 /* Exit a binding level and discard the associated BLOCK. */
656 void
658 {
665 /* Free this binding structure. */
669 }
671 /* Set the context of TYPE and its parallel types (if any) to CONTEXT. */
673 static void
675 {
681 {
684 /* Give a context to the parallel types and their stub decl, if any.
685 Some parallel types seems to be present in multiple parallel type
686 chains, so don't mess with their context if they already have one. */
688 {
692 }
695 }
696 }
698 /* Return the innermost scope, starting at GNAT_NODE, we are be interested in
699 the debug info, or Empty if there is no such scope. If not NULL, set
700 IS_SUBPROGRAM to whether the returned entity is a subprogram. */
702 Entity_Id
704 {
705 Entity_Id gnat_entity;
713 else
717 {
719 {
725 /* If the scope is a subprogram, then just rely on
726 current_function_decl, so that we don't have to defer
727 anything. This is needed because other places rely on the
728 validity of the DECL_CONTEXT attribute of FUNCTION_DECL nodes. */
738 /* By default, we are not interested in this particular scope: go to
739 the outer one. */
741 }
744 }
747 }
749 /* If N is NULL, set TYPE's context to CONTEXT. Defer this to the processing
750 of N otherwise. */
752 static void
755 {
758 else
760 }
762 /* Return global_context, but create it first if need be. */
764 static tree
766 {
768 {
769 global_context
772 }
775 }
777 /* Record DECL as belonging to the current lexical scope and use GNAT_NODE
778 for location information and flag propagation. */
780 void
782 {
786 /* If explicitly asked to make DECL global or if it's an imported nested
787 object, short-circuit the regular Scope-based context computation. */
789 {
790 /* Rely on the GNAT scope, or fallback to the current_function_decl if
791 the GNAT scope reached the global scope, if it reached a subprogram
792 or the declaration is a subprogram or a variable (for them we skip
793 intermediate context types because the subprogram body elaboration
794 machinery and the inliner both expect a subprogram context).
796 Falling back to current_function_decl is necessary for implicit
797 subprograms created by gigi, such as the elaboration subprograms. */
799 const Entity_Id gnat_scope
803 && !context_is_subprogram
806 /* Always assume the scope has not been elaborated, thus defer the
807 context propagation to the time its elaboration will be
808 available. */
809 deferred_decl_context
812 /* External declarations (when force_global > 0) may not be in a
813 local context. */
816 }
818 /* If either we are forced to be in global mode or if both the GNAT scope and
819 the current_function_decl did not help in determining the context, use the
820 global scope. */
824 /* Functions imported in another function are not really nested.
825 For really nested functions mark them initially as needing
826 a static chain for uses of that flag before unnesting;
827 lower_nested_functions will then recompute it. */
830 && context
838 /* Disable warnings for compiler-generated entities or explicit request. */
844 /* Set the location of DECL and emit a declaration for it. */
850 /* Put the declaration on the list. The list of declarations is in reverse
851 order. The list will be reversed later. Put global declarations in the
852 globals list and local ones in the current block. But skip TYPE_DECLs
853 for UNCONSTRAINED_ARRAY_TYPE in both cases, as they will cause trouble
854 with the debugger and aren't needed anyway. */
857 {
858 /* External declarations must go to the binding level they belong to.
859 This will make corresponding imported entities are available in the
860 debugger at the proper time. */
867 else
868 {
871 }
872 }
874 /* Pointer types aren't named types in the C sense so we need to generate a
875 typedef in DWARF for them. Also do that for fat pointer types because,
876 even though they are named types in the C sense, they are still the XUP
877 types created for the base array type at this point. */
878 #define TYPE_IS_POINTER_P(NODE) \
879 (TREE_CODE (NODE) == POINTER_TYPE || TYPE_IS_FAT_POINTER_P (NODE))
881 /* For the declaration of a type, set its name either if it isn't already
882 set or if the previous type name was not derived from a source name.
883 We'd rather have the type named with a real name and all the pointer
884 types to the same object have the same node, except when the names are
885 both derived from source names. */
887 {
890 /* For pointer types, make sure the typedef is generated and preserved
891 in DWARF, unless the type is artificial. */
894 ;
895 /* For pointer types, create the DECL_ORIGINAL_TYPE that will generate
896 the typedef in DWARF. */
898 {
903 deferred_decl_context);
909 else
911 /* Remark the canonical fat pointer type as artificial. */
915 }
919 ;
920 else
923 /* Propagate the name to all the variants, this is needed for the type
924 qualifiers machinery to work properly (see check_qualified_type).
925 Also propagate the context to them. Note that it will be propagated
926 to all parallel types too thanks to gnat_set_type_context. */
929 /* Skip it for pointer types to preserve the typedef. */
933 {
937 deferred_decl_context);
938 }
939 }
941 #undef TYPE_IS_POINTER_P
942 }
944 /* Create a record type that contains a SIZE bytes long field of TYPE with a
945 starting bit position so that it is aligned to ALIGN bits, and leaving at
946 least ROOM bytes free before the field. BASE_ALIGN is the alignment the
947 record is guaranteed to get. GNAT_NODE is used for the position of the
948 associated TYPE_DECL. */
950 tree
953 {
954 /* We will be crafting a record type with one field at a position set to be
955 the next multiple of ALIGN past record'address + room bytes. We use a
956 record placeholder to express record'address. */
960 tree record_addr_st
963 /* The diagram below summarizes the shape of what we manipulate:
965 <--------- pos ---------->
966 { +------------+-------------+-----------------+
967 record =>{ |############| ... | field (type) |
968 { +------------+-------------+-----------------+
969 |<-- room -->|<- voffset ->|<---- size ----->|
970 o o
971 | |
972 record_addr vblock_addr
974 Every length is in sizetype bytes there, except "pos" which has to be
975 set as a bit position in the GCC tree for the record. */
985 /* Compute VOFFSET and then POS. The next byte position multiple of some
986 alignment after some address is obtained by "and"ing the alignment minus
987 1 with the two's complement of the address. */
992 /* POS = (ROOM + VOFFSET) * BIT_PER_UNIT, in bitsizetype. */
996 bitsize_unit_node);
998 /* Craft the GCC record representation. We exceptionally do everything
999 manually here because 1) our generic circuitry is not quite ready to
1000 handle the complex position/size expressions we are setting up, 2) we
1001 have a strong simplifying factor at hand: we know the maximum possible
1002 value of voffset, and 3) we have to set/reset at least the sizes in
1003 accordance with this maximum value anyway, as we need them to convey
1004 what should be "alloc"ated for this type.
1006 Use -1 as the 'addressable' indication for the field to prevent the
1007 creation of a bitfield. We don't need one, it would have damaging
1008 consequences on the alignment computation, and create_field_decl would
1009 make one without this special argument, for instance because of the
1010 complex position expression. */
1021 bitsize_unit_node),
1030 /* Declare it now since it will never be declared otherwise. This is
1031 necessary to ensure that its subtrees are properly marked. */
1035 }
1037 /* Return true iff the packable types are equivalent. */
1039 bool
1041 {
1050 /* We consider that packable types are equivalent if they have the same name,
1051 size, alignment, RM size and storage order. Taking the mode into account
1052 is redundant since it is determined by the others. */
1053 return
1059 }
1061 /* Compute the hash value for the packable TYPE. */
1063 static hashval_t
1065 {
1066 hashval_t hashcode;
1072 hashcode
1076 }
1078 /* Look up the packable TYPE in the hash table and return its canonical version
1079 if it exists; otherwise, insert it into the hash table. */
1081 static tree
1083 {
1092 {
1097 }
1100 }
1102 /* TYPE is an ARRAY_TYPE that is being used as the type of a field in a packed
1103 record. See if we can rewrite it as a type that has non-BLKmode, which we
1104 can pack tighter in the packed record. If so, return the new type; if not,
1105 return the original type. */
1107 static tree
1109 {
1114 /* No point in doing anything if the size is either zero or too large for an
1115 integral mode, or if the type already has non-BLKmode. */
1119 /* Punt if the component type is an aggregate type for now. */
1135 }
1137 /* TYPE is a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE that is being used
1138 as the type of a field in a packed record if IN_RECORD is true, or as
1139 the component type of a packed array if IN_RECORD is false. See if we
1140 can rewrite it either as a type that has non-BLKmode, which we can pack
1141 tighter in the packed record case, or as a smaller type with at most
1142 MAX_ALIGN alignment if the value is non-zero. If so, return the new
1143 type; if not, return the original type. */
1145 tree
1147 {
1153 /* No point in doing anything if the size is zero. */
1159 /* Copy the name and flags from the old type to that of the new.
1160 Note that we rely on the pointer equality created here for
1161 TYPE_NAME to look through conversions in various places. */
1170 /* If we are in a record and have a small size, set the alignment to
1171 try for an integral mode. Otherwise set it to try for a smaller
1172 type with BLKmode. */
1174 {
1178 }
1179 else
1180 {
1183 /* Do not try to shrink the size if the RM size is not constant. */
1187 /* Round the RM size up to a unit boundary to get the minimal size
1188 for a BLKmode record. Give up if it's already the size and we
1189 don't need to lower the alignment. */
1199 }
1203 /* Now copy the fields, keeping the position and size as we don't want
1204 to change the layout by propagating the packedness downwards. */
1207 {
1213 {
1216 new_field_type
1223 }
1225 /* However, for the last field in a not already packed record type
1226 that is of an aggregate type, we need to use the RM size in the
1227 packable version of the record type, see finish_record_type. */
1235 else
1236 {
1239 /* Make sure not to use too small a type for the size. */
1242 }
1244 /* This is a layout with full representation, alignment and size clauses
1245 so we simply pass 0 as PACKED like gnat_to_gnu_field in this case. */
1246 new_field
1258 }
1260 /* If this is a padding record, we never want to make the size smaller
1261 than what was specified. For QUAL_UNION_TYPE, also copy the size. */
1263 {
1267 }
1268 else
1269 {
1272 }
1285 /* Try harder to get a packable type if necessary, for example in case
1286 the record itself contains a BLKmode field. */
1292 /* If neither mode nor size nor alignment shrunk, return the old type. */
1296 /* If the packable type is named, we canonicalize it by means of the hash
1297 table. This is consistent with the language semantics and ensures that
1298 gigi and the middle-end have a common view of these packable types. */
1299 return
1301 }
1303 /* Return true if TYPE has an unsigned representation. This needs to be used
1304 when the representation of types whose precision is not equal to their size
1305 is manipulated based on the RM size. */
1309 {
1310 /* This is the common case. */
1314 /* See the E_Signed_Integer_Subtype case of gnat_to_gnu_entity. */
1320 }
1322 /* Given a type TYPE, return a new type whose size is appropriate for SIZE.
1323 If TYPE is the best type, return it. Otherwise, make a new type. We
1324 only support new integral and pointer types. FOR_BIASED is true if
1325 we are making a biased type. */
1327 tree
1329 {
1332 tree new_type;
1334 /* If size indicates an error, just return TYPE to avoid propagating
1335 the error. Likewise if it's too large to represent. */
1342 {
1344 /* Do not mess with boolean types that have foreign convention. */
1348 /* ... fall through ... */
1355 /* Integer types with precision 0 are forbidden. */
1359 /* Only do something if the type is not a bit-packed array type and does
1360 not already have the proper size and the size is not too large. */
1368 /* The type should be an unsigned type if the original type is unsigned
1369 or if the lower bound is constant and non-negative or if the type is
1370 biased, see E_Signed_Integer_Subtype case of gnat_to_gnu_entity. */
1373 else
1378 /* Copy the name to show that it's essentially the same type and
1379 not a subrange type. */
1386 /* Do something if this is a fat pointer, in which case we
1387 may need to return the thin pointer. */
1389 {
1390 scalar_int_mode p_mode;
1394 return
1395 build_pointer_type_for_mode
1398 }
1402 /* Only do something if this is a thin pointer, in which case we
1403 may need to return the fat pointer. */
1405 return
1411 }
1414 }
1416 /* Return true iff the padded types are equivalent. */
1418 bool
1420 {
1429 /* We consider that padded types are equivalent if they pad the same type
1430 and have the same size, alignment, RM size and storage order. Taking the
1431 mode into account is redundant since it is determined by the others. */
1432 return
1438 }
1440 /* Compute the hash value for the padded TYPE. */
1442 static hashval_t
1444 {
1445 hashval_t hashcode;
1447 hashcode
1452 hashcode
1456 }
1458 /* Look up the padded TYPE in the hash table and return its canonical version
1459 if it exists; otherwise, insert it into the hash table. */
1461 static tree
1463 {
1472 {
1477 }
1480 }
1482 /* Ensure that TYPE has SIZE and ALIGN. Make and return a new padded type
1483 if needed. We have already verified that SIZE and ALIGN are large enough.
1484 GNAT_ENTITY is used to name the resulting record and to issue a warning.
1485 IS_COMPONENT_TYPE is true if this is being done for the component type of
1486 an array. DEFINITION is true if this type is being defined. SET_RM_SIZE
1487 is true if the RM size of the resulting type is to be set to SIZE too; in
1488 this case, the padded type is canonicalized before being returned.
1490 Note that, if TYPE is an array, then we pad it even if it has already got
1491 an alignment of ALIGN, provided that it's larger than the alignment of the
1492 element type. This ensures that the size of the type is a multiple of its
1493 alignment as required by the GCC type system, and alleviates the oddity of
1494 the larger alignment, which is used to implement alignment clauses present
1495 on unconstrained array types. */
1497 tree
1501 {
1503 unsigned int orig_align
1509 /* If TYPE is a padded type, see if it agrees with any size and alignment
1510 we were given. If so, return the original type. Otherwise, strip
1511 off the padding, since we will either be returning the inner type
1512 or repadding it. If no size or alignment is specified, use that of
1513 the original padded type. */
1515 {
1528 orig_align
1532 }
1534 /* If the size is either not being changed or is being made smaller (which
1535 is not done here and is only valid for bitfields anyway), show the size
1536 isn't changing. Likewise, clear the alignment if it isn't being
1537 changed. Then return if we aren't doing anything. */
1550 /* We used to modify the record in place in some cases, but that could
1551 generate incorrect debugging information. So make a new record
1552 type and name. */
1564 bitsize_unit_node));
1566 /* If we are changing the alignment and the input type is a record with
1567 BLKmode and a small constant size, try to make a form that has an
1568 integral mode. This might allow the padding record to also have an
1569 integral mode, which will be much more efficient. There is no point
1570 in doing so if a size is specified unless it is also a small constant
1571 size and it is incorrect to do so if we cannot guarantee that the mode
1572 will be naturally aligned since the field must always be addressable.
1574 ??? This might not always be a win when done for a stand-alone object:
1575 since the nominal and the effective type of the object will now have
1576 different modes, a VIEW_CONVERT_EXPR will be required for converting
1577 between them and it might be hard to overcome afterwards, including
1578 at the RTL level when the stand-alone object is accessed as a whole. */
1587 && (!size
1590 {
1595 }
1597 /* Now create the field with the original size. */
1602 /* We will output additional debug info manually below. */
1605 /* Set the RM size if requested. */
1607 {
1610 /* If the padded type is complete and has constant size, we canonicalize
1611 it by means of the hash table. This is consistent with the language
1612 semantics and ensures that gigi and the middle-end have a common view
1613 of these padded types. */
1615 {
1618 {
1621 }
1622 }
1623 }
1625 /* Make the inner type the debug type of the padded type. */
1629 /* Unless debugging information isn't being written for the input type,
1630 write a record that shows what we are a subtype of and also make a
1631 variable that indicates our size, if still variable. */
1637 {
1641 /* A variable that holds the size is required even with no encoding since
1642 it will be referenced by debugging information attributes. At global
1643 level, we need a single variable across all translation units. */
1647 {
1648 /* Whether or not gnat_entity comes from source, this XVZ variable is
1649 is a compilation artifact. */
1650 size_unit
1656 }
1658 /* There is no need to show what we are a subtype of when outputting as
1659 few encodings as possible: regular debugging infomation makes this
1660 redundant. */
1662 {
1676 }
1677 }
1679 built:
1680 /* If a simple size was explicitly given, maybe issue a warning. */
1687 /* But don't do it if we are just annotating types and the type is tagged or
1688 concurrent, since these types aren't fully laid out in this mode. */
1690 {
1691 Entity_Id gnat_type
1692 = is_component_type
1697 }
1699 /* Take the original size as the maximum size of the input if there was an
1700 unconstrained record involved and round it up to the specified alignment,
1701 if one was specified, but only for aggregate types. */
1714 {
1715 Node_Id gnat_error_node;
1717 /* For a packed array, post the message on the original array type. */
1729 else
1732 /* Generate message only for entities that come from source, since
1733 if we have an entity created by expansion, the message will be
1734 generated for some other corresponding source entity. */
1736 {
1745 }
1746 }
1749 }
1751 /* Return true if padded TYPE was built with an RM size. */
1753 bool
1755 {
1756 /* This is required for the lookup. */
1767 /* The types built with an RM size are the canonicalized ones. */
1769 }
1771 /* Return a copy of the padded TYPE but with reverse storage order. */
1773 tree
1775 {
1777 {
1778 /* If the inner type is not scalar then the function does nothing. */
1782 }
1784 /* This is required for the canonicalization. */
1793 }
1795 /* Relate the alias sets of GNU_NEW_TYPE and GNU_OLD_TYPE according to OP.
1796 If this is a multi-dimensional array type, do this recursively.
1798 OP may be
1799 - ALIAS_SET_COPY: the new set is made a copy of the old one.
1800 - ALIAS_SET_SUPERSET: the new set is made a superset of the old one.
1801 - ALIAS_SET_SUBSET: the new set is made a subset of the old one. */
1803 void
1805 {
1806 /* Remove any padding from GNU_OLD_TYPE. It doesn't matter in the case
1807 of a one-dimensional array, since the padding has the same alias set
1808 as the field type, but if it's a multi-dimensional array, we need to
1809 see the inner types. */
1815 /* Unconstrained array types are deemed incomplete and would thus be given
1816 alias set 0. Retrieve the underlying array type. */
1818 gnu_old_type
1821 gnu_new_type
1830 {
1832 /* The alias set shouldn't be copied between array types with different
1833 aliasing settings because this can break the aliasing relationship
1834 between the array type and its element type. */
1846 {
1850 /* Do nothing if the alias sets conflict. This ensures that we
1851 never call record_alias_subset several times for the same pair
1852 or at all for alias set 0. */
1854 {
1857 else
1859 }
1860 }
1865 }
1868 }
1870 /* Record TYPE as a builtin type for Ada. NAME is the name of the type.
1871 ARTIFICIAL_P is true if the type was generated by the compiler. */
1873 void
1875 {
1884 }
1886 /* Finish constructing the character type CHAR_TYPE.
1888 In Ada character types are enumeration types and, as a consequence, are
1889 represented in the front-end by integral types holding the positions of
1890 the enumeration values as defined by the language, which means that the
1891 integral types are unsigned.
1893 Unfortunately the signedness of 'char' in C is implementation-defined
1894 and GCC even has the option -f[un]signed-char to toggle it at run time.
1895 Since GNAT's philosophy is to be compatible with C by default, to wit
1896 Interfaces.C.char is defined as a mere copy of Character, we may need
1897 to declare character types as signed types in GENERIC and generate the
1898 necessary adjustments to make them behave as unsigned types.
1900 The overall strategy is as follows: if 'char' is unsigned, do nothing;
1901 if 'char' is signed, translate character types of CHAR_TYPE_SIZE and
1902 character subtypes with RM_Size = Esize = CHAR_TYPE_SIZE into signed
1903 types. The idea is to ensure that the bit pattern contained in the
1904 Esize'd objects is not changed, even though the numerical value will
1905 be interpreted differently depending on the signedness. */
1907 void
1909 {
1913 /* Make a copy of a generic unsigned version since we'll modify it. */
1914 tree unsigned_char_type
1916 ? unsigned_char_type_node
1919 /* Create an unsigned version of the type and set it as debug type. */
1925 /* If this is a subtype, make the debug type a subtype of the debug type
1926 of the base type and convert literal RM bounds to unsigned. */
1928 {
1941 }
1943 /* Adjust the RM bounds of the original type to unsigned; that's especially
1944 important for types since they are implicit in this case. */
1947 }
1949 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
1950 finish constructing the record type as a fat pointer type. */
1952 void
1954 {
1955 /* Make sure we can put it into a register. */
1959 /* Show what it really is. */
1962 /* Do not emit debug info for it since the types of its fields may still be
1963 incomplete at this point. */
1966 /* Force type_contains_placeholder_p to return true on it. Although the
1967 PLACEHOLDER_EXPRs are referenced only indirectly, this isn't a pointer
1968 type but the representation of the unconstrained array. */
1970 }
1972 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
1973 finish constructing the record or union type. If REP_LEVEL is zero, this
1974 record has no representation clause and so will be entirely laid out here.
1975 If REP_LEVEL is one, this record has a representation clause and has been
1976 laid out already; only set the sizes and alignment. If REP_LEVEL is two,
1977 this record is derived from a parent record and thus inherits its layout;
1978 only make a pass on the fields to finalize them. DEBUG_INFO_P is true if
1979 additional debug info needs to be output for this type. */
1981 void
1984 {
1988 /* For all-repped records with a size specified, lay the QUAL_UNION_TYPE
1989 out just like a UNION_TYPE, since the size will be fixed. */
1990 const enum tree_code code
1996 tree field;
2000 /* Always attach the TYPE_STUB_DECL for a record type. It is required to
2001 generate debug info and have a parallel type. */
2004 /* Globally initialize the record first. If this is a rep'ed record,
2005 that just means some initializations; otherwise, layout the record. */
2007 {
2013 }
2014 else
2015 {
2016 /* Ensure there isn't a size already set. There can be in an error
2017 case where there is a rep clause but all fields have errors and
2018 no longer have a position. */
2021 /* Ensure we use the traditional GCC layout for bitfields when we need
2022 to pack the record type or have a representation clause. The other
2023 possible layout (Microsoft C compiler), if available, would prevent
2024 efficient packing in almost all cases. */
2025 #ifdef TARGET_MS_BITFIELD_LAYOUT
2030 ATTR_FLAG_TYPE_IN_PLACE);
2031 #endif
2034 }
2036 /* At this point, the position and size of each field is known. It was
2037 either set before entry by a rep clause, or by laying out the type above.
2039 We now run a pass over the fields (in reverse order for QUAL_UNION_TYPEs)
2040 to compute the Ada size; the GCC size and alignment (for rep'ed records
2041 that are not padding types); and the mode (for rep'ed records). We also
2042 clear the DECL_BIT_FIELD indication for the cases we know have not been
2043 handled yet, and adjust DECL_NONADDRESSABLE_P accordingly. */
2049 {
2053 tree this_ada_size;
2060 else
2065 /* Clear DECL_BIT_FIELD for the cases layout_decl does not handle. */
2068 {
2071 /* In the general case, type alignment is required. */
2073 {
2074 /* The enclosing record type must be sufficiently aligned.
2075 Otherwise, if no alignment was specified for it and it
2076 has been laid out already, bump its alignment to the
2077 desired one if this is compatible with its size and
2078 maximum alignment, if any. */
2080 {
2083 }
2089 {
2093 }
2094 }
2096 /* In the non-strict alignment case, only byte alignment is. */
2101 }
2103 /* Clear DECL_BIT_FIELD_TYPE for a variant part at offset 0, it's simply
2104 not supported by the DECL_BIT_FIELD_REPRESENTATIVE machinery because
2105 the variant part is always the last field in the list. */
2109 /* If we still have DECL_BIT_FIELD set at this point, we know that the
2110 field is technically not addressable. Except that it can actually
2111 be addressed if it is BLKmode and happens to be properly aligned. */
2117 /* A type must be as aligned as its most aligned field that is not
2118 a bit-field. But this is already enforced by layout_type. */
2124 {
2131 ada_size
2139 /* Since we know here that all fields are sorted in order of
2140 increasing bit position, the size of the record is one
2141 higher than the ending bit of the last field processed
2142 unless we have a rep clause, because we might be processing
2143 the REP part of a record with a variant part for which the
2144 variant part has a rep clause but not the fixed part, in
2145 which case this REP part may contain overlapping fields
2146 and thus needs to be treated like a union tyoe above, so
2147 use a MAX in that case. Also, if this field is a variant
2148 part, we need to take into account the previous size in
2149 the case of empty variants. */
2150 ada_size
2152 variant_part);
2153 size
2159 }
2160 }
2165 /* We need to set the regular sizes if REP_LEVEL is one. */
2167 {
2168 /* We round TYPE_SIZE and TYPE_SIZE_UNIT up to TYPE_ALIGN separately
2169 to avoid having very large masking constants in TYPE_SIZE_UNIT. */
2172 /* If this is a padding record, we never want to make the size smaller
2173 than what was specified in it, if any. */
2176 else
2181 tree size_unit
2186 }
2188 /* We need to set the Ada size if REP_LEVEL is zero or one. */
2190 {
2191 /* Now set any of the values we've just computed that apply. */
2195 }
2197 /* We need to set the mode if REP_LEVEL is one or two. */
2199 {
2202 }
2204 /* Reset the TYPE_MAX_ALIGN field since it's private to gigi. */
2209 }
2211 /* Append PARALLEL_TYPE on the chain of parallel types of TYPE. If
2212 PARRALEL_TYPE has no context and its computation is not deferred yet, also
2213 propagate TYPE's context to PARALLEL_TYPE's or defer its propagation to the
2214 moment TYPE will get a context. */
2216 void
2218 {
2226 /* If PARALLEL_TYPE already has a context, we are done. */
2230 /* Otherwise, try to get one from TYPE's context. If so, simply propagate
2231 it to PARALLEL_TYPE. */
2235 /* Otherwise TYPE has not context yet. We know it will have one thanks to
2236 gnat_pushdecl and then its context will be propagated to PARALLEL_TYPE,
2237 so we have nothing to do in this case. */
2238 }
2240 /* Return true if TYPE has a parallel type. */
2242 static bool
2244 {
2248 }
2250 /* Wrap up compilation of RECORD_TYPE, i.e. output additional debug info
2251 associated with it. It need not be invoked directly in most cases as
2252 finish_record_type takes care of doing so. */
2254 void
2256 {
2258 tree field;
2260 /* If this is a padded type, the bulk of the debug info has already been
2261 generated for the field's type. */
2265 /* If the type already has a parallel type (XVS type), then we're done. */
2270 {
2271 /* We need to make an XVE/XVU record if any field has variable size,
2272 whether or not the record does. For example, if we have a union,
2273 it may be that all fields, rounded up to the alignment, have the
2274 same size, in which case we'll use that size. But the debug
2275 output routines (except Dwarf2) won't be able to output the fields,
2276 so we need to make the special record. */
2278 /* If a field has a non-constant qualifier, the record will have
2279 variable size too. */
2282 {
2285 }
2286 }
2288 /* If this record type is of variable size, make a parallel record type that
2289 will tell the debugger how the former is laid out (see exp_dbug.ads). */
2291 {
2292 tree new_record_type
2298 new_name
2312 /* Now scan all the fields, replacing each field with a new field
2313 corresponding to the new encoding. */
2315 old_field;
2317 {
2325 /* See how the position was modified from the last position.
2327 There are two basic cases we support: a value was added
2328 to the last position or the last position was rounded to
2329 a boundary and they something was added. Check for the
2330 first case first. If not, see if there is any evidence
2331 of rounding. If so, round the last position and retry.
2333 If this is a union, the position can be taken as zero. */
2336 else
2340 ;
2343 {
2349 }
2353 && tree_fits_uhwi_p
2355 {
2357 unsigned HOST_WIDE_INT addend
2359 align
2365 }
2366 else
2367 {
2371 }
2373 /* See if this type is variable-sized and make a pointer type
2374 and indicate the indirection if so. Beware that the debug
2375 back-end may adjust the position computed above according
2376 to the alignment of the field type, i.e. the pointer type
2377 in this case, if we don't preventively counter that. */
2379 {
2384 /* ??? Kludge to work around a bug in Workbench's debugger. */
2386 {
2390 }
2391 }
2393 /* If we can't compute a position, set it to zero.
2395 ??? We really should abort here, but it's too much work
2396 to get this correct for all cases. */
2400 /* Make a new field name, if necessary. */
2402 {
2408 else
2412 }
2414 new_field
2417 /* The specified position is not the actual position of the field
2418 but the gap with the previous field, so the computation of the
2419 bit-field status may be incorrect. We adjust it manually to
2420 avoid generating useless attributes for the field in DWARF. */
2423 {
2426 }
2430 /* If old_field is a QUAL_UNION_TYPE, take its size as being
2431 zero. The only time it's not the last field of the record
2432 is when there are other components at fixed positions after
2433 it (meaning there was a rep clause for every field) and we
2434 want to be able to encode them. */
2438 ? bitsize_zero_node
2440 }
2445 }
2446 }
2448 /* Utility function of above to merge LAST_SIZE, the previous size of a record
2449 with FIRST_BIT and SIZE that describe a field. If MAX is true, we take the
2450 MAX of the end position of this field with LAST_SIZE. In all other cases,
2451 we use FIRST_BIT plus SIZE. SPECIAL is true if it's for a QUAL_UNION_TYPE,
2452 in which case we must look for COND_EXPRs and replace a value of zero with
2453 the old size. Return an expression for the size. */
2455 static tree
2457 {
2459 tree new_size;
2462 {
2466 }
2468 else
2479 /* We don't need any NON_VALUE_EXPRs and they can confuse us (especially
2480 when fed through SUBSTITUTE_IN_EXPR) into thinking that a constant
2481 size is not constant. */
2486 }
2488 /* Convert the size expression EXPR to TYPE and fold the result. */
2490 static tree
2492 {
2493 /* We assume that size expressions do not wrap around. */
2500 }
2502 /* Return the bit position of FIELD, in bits from the start of the record,
2503 and fold it as much as possible. This is a tree of type bitsizetype. */
2505 static tree
2507 {
2511 }
2513 /* Utility function of above to see if OP0 and OP1, both of SIZETYPE, are
2514 related by the addition of a constant. Return that constant if so. */
2516 static tree
2518 {
2525 {
2529 }
2530 else
2541 }
2543 /* Utility function of above to split a tree OP which may be a sum, into a
2544 constant part, which is returned, and a variable part, which is stored
2545 in *PVAR. *PVAR may be bitsize_zero_node. All operations must be of
2546 bitsizetype. */
2548 static tree
2550 {
2551 /* Strip conversions in order to ease the tree traversal and maximize the
2552 potential for constant or plus/minus discovery. We need to be careful
2553 to always return and set *pvar to bitsizetype trees, but it's worth
2554 the effort. */
2560 {
2563 }
2565 {
2576 }
2577 else
2579 }
2581 /* Return a copy of TYPE but safe to modify in any way. */
2583 tree
2585 {
2588 /* Unshare the language-specific data. */
2590 {
2593 }
2595 /* And the contents of the language-specific slot if needed. */
2598 {
2603 }
2605 /* copy_node clears this field instead of copying it, because it is
2606 aliased with TREE_CHAIN. */
2616 }
2618 /* Return a subtype of sizetype with range MIN to MAX and whose
2619 TYPE_INDEX_TYPE is INDEX. GNAT_NODE is used for the position
2620 of the associated TYPE_DECL. */
2622 tree
2624 {
2625 /* First build a type for the desired range. */
2628 /* Then set the index type. */
2633 }
2635 /* Return a subtype of TYPE with range MIN to MAX. If TYPE is NULL,
2636 sizetype is used. */
2638 tree
2640 {
2641 tree range_type;
2646 /* First build a type with the base range. */
2650 /* Then set the actual range. */
2655 }
2657 /* Return an extra subtype of TYPE with range MIN to MAX. */
2659 tree
2661 {
2673 }
2675 /* Return a TYPE_DECL node suitable for the TYPE_STUB_DECL field of TYPE.
2676 NAME gives the name of the type to be used in the declaration. */
2678 tree
2680 {
2685 }
2687 /* Return a TYPE_DECL node for TYPE. NAME gives the name of the type to be
2688 used in the declaration. ARTIFICIAL_P is true if the declaration was
2689 generated by the compiler. DEBUG_INFO_P is true if we need to write
2690 debug information about this type. GNAT_NODE is used for the position
2691 of the decl. */
2693 tree
2695 Node_Id gnat_node)
2696 {
2698 bool is_named
2700 tree type_decl;
2702 /* Only the builtin TYPE_STUB_DECL should be used for dummy types. */
2705 /* If the type hasn't been named yet, we're naming it; preserve an existing
2706 TYPE_STUB_DECL that has been attached to it for some purpose. */
2708 {
2711 }
2712 else
2718 /* Add this decl to the current binding level. */
2721 /* If we're naming the type, equate the TYPE_STUB_DECL to the name. This
2722 causes the name to be also viewed as a "tag" by the debug back-end, with
2723 the advantage that no DW_TAG_typedef is emitted for artificial "tagged"
2724 types in DWARF.
2726 Note that if "type" is used as a DECL_ORIGINAL_TYPE, it may be referenced
2727 from multiple contexts, and "type_decl" references a copy of it: in such a
2728 case, do not mess TYPE_STUB_DECL: we do not want to re-use the TYPE_DECL
2729 with the mechanism above. */
2733 /* Do not generate debug info for UNCONSTRAINED_ARRAY_TYPE that the
2734 back-end doesn't support, and for others if we don't need to. */
2739 }
2741 /* Return a VAR_DECL or CONST_DECL node.
2743 NAME gives the name of the variable. ASM_NAME is its assembler name
2744 (if provided). TYPE is its data type (a GCC ..._TYPE node). INIT is
2745 the GCC tree for an optional initial expression; NULL_TREE if none.
2747 CONST_FLAG is true if this variable is constant, in which case we might
2748 return a CONST_DECL node unless CONST_DECL_ALLOWED_P is false.
2750 PUBLIC_FLAG is true if this is for a reference to a public entity or for a
2751 definition to be made visible outside of the current compilation unit, for
2752 instance variable definitions in a package specification.
2754 EXTERN_FLAG is true when processing an external variable declaration (as
2755 opposed to a definition: no storage is to be allocated for the variable).
2757 STATIC_FLAG is only relevant when not at top level and indicates whether
2758 to always allocate storage to the variable.
2760 VOLATILE_FLAG is true if this variable is declared as volatile.
2762 ARTIFICIAL_P is true if the variable was generated by the compiler.
2764 DEBUG_INFO_P is true if we need to write debug information for it.
2766 ATTR_LIST is the list of attributes to be attached to the variable.
2768 GNAT_NODE is used for the position of the decl. */
2770 tree
2776 {
2777 /* Whether the object has static storage duration, either explicitly or by
2778 virtue of being declared at the global level. */
2781 /* Whether the initializer is constant: for an external object or an object
2782 with static storage duration, we check that the initializer is a valid
2783 constant expression for initializing a static variable; otherwise, we
2784 only check that it is constant. */
2785 const bool init_const
2786 = (init
2790 != NULL_TREE
2793 /* Whether we will make TREE_CONSTANT the DECL we produce here, in which
2794 case the initializer may be used in lieu of the DECL node (as done in
2795 Identifier_to_gnu). This is useful to prevent the need of elaboration
2796 code when an identifier for which such a DECL is made is in turn used
2797 as an initializer. We used to rely on CONST_DECL vs VAR_DECL for this,
2798 but extra constraints apply to this choice (see below) and they are not
2799 relevant to the distinction we wish to make. */
2802 /* The actual DECL node. CONST_DECL was initially intended for enumerals
2803 and may be used for scalars in general but not for aggregates. */
2804 tree var_decl
2806 (constant_p
2807 && const_decl_allowed_p
2811 /* Detect constants created by the front-end to hold 'reference to function
2812 calls for stabilization purposes. This is needed for renaming. */
2814 {
2825 }
2827 /* If this is external, throw away any initializations (they will be done
2828 elsewhere) unless this is a constant for which we would like to remain
2829 able to get the initializer. If we are defining a global here, leave a
2830 constant initialization and save any variable elaborations for the
2831 elaboration routine. If we are just annotating types, throw away the
2832 initialization if it isn't a constant. */
2837 /* At the global level, a non-constant initializer generates elaboration
2838 statements. Check that such statements are allowed, that is to say,
2839 not violating a No_Elaboration_Code restriction. */
2843 /* Attach the initializer, if any. */
2846 /* Directly set some flags. */
2853 /* The object is public if it is external or if it is declared public
2854 and has static storage duration. */
2857 /* We need to allocate static storage for an object with static storage
2858 duration if it isn't external. */
2868 /* Ada doesn't feature Fortran-like COMMON variables so we shouldn't
2869 try to fiddle with DECL_COMMON. However, on platforms that don't
2870 support global BSS sections, uninitialized global variables would
2871 go in DATA instead, thus increasing the size of the executable. */
2878 /* Do not emit debug info if not requested, or for an external constant whose
2879 initializer is not absolute because this would require a global relocation
2880 in a read-only section which runs afoul of the PE-COFF run-time relocation
2881 mechanism. */
2883 || (extern_flag
2884 && constant_p
2885 && init
2890 /* ??? Some attributes cannot be applied to CONST_DECLs. */
2894 /* Add this decl to the current binding level. */
2898 {
2899 /* Let the target mangle the name if this isn't a verbatim asm. */
2904 }
2907 }
2909 /* Return true if TYPE, an aggregate type, contains (or is) an array. */
2911 static bool
2913 {
2915 {
2919 {
2920 tree field;
2926 }
2933 }
2934 }
2936 /* Return true if TYPE is a type with variable size or a padding type with a
2937 field of variable size or a record that has a field with such a type. */
2939 bool
2941 {
2942 tree field;
2959 }
2961 /* Return a FIELD_DECL node. NAME is the field's name, TYPE is its type and
2962 RECORD_TYPE is the type of the enclosing record. If SIZE is nonzero, it
2963 is the specified size of the field. If POS is nonzero, it is the bit
2964 position. PACKED is 1 if the enclosing record is packed, -1 if it has
2965 Component_Alignment of Storage_Unit. If ADDRESSABLE is nonzero, it
2966 means we are allowed to take the address of the field; if it is negative,
2967 we should not make a bitfield, which is used by make_aligning_type. */
2969 tree
2972 {
2978 /* If a size is specified, use it. Otherwise, if the record type is packed
2979 compute a size to use, which may differ from the object's natural size.
2980 We always set a size in this case to trigger the checks for bitfield
2981 creation below, which is typically required when no position has been
2982 specified. */
2986 {
2990 }
2992 /* If we may, according to ADDRESSABLE, then make a bitfield when the size
2993 is specified for two reasons: first, when it differs from the natural
2994 size; second, when the alignment is insufficient.
2996 We never make a bitfield if the type of the field has a nonconstant size,
2997 because no such entity requiring bitfield operations should reach here.
2999 We do *preventively* make a bitfield when there might be the need for it
3000 but we don't have all the necessary information to decide, as is the case
3001 of a field in a packed record.
3003 We also don't look at STRICT_ALIGNMENT here, and rely on later processing
3004 in layout_decl or finish_record_type to clear the bit_field indication if
3005 it is in fact not needed. */
3007 && size
3010 && (packed
3015 {
3019 {
3023 else
3025 }
3026 }
3030 /* If FIELD_TYPE has BLKmode, we must ensure this is aligned to at least
3031 a byte boundary since GCC cannot handle less aligned BLKmode bitfields.
3032 Likewise if it has a variable size and no specified position because
3033 variable-sized objects need to be aligned to at least a byte boundary.
3034 Likewise for an aggregate without specified position that contains an
3035 array because, in this case, slices of variable length of this array
3036 must be handled by GCC and have variable size. */
3039 || (!pos
3044 /* Bump the alignment if need be, either for bitfield/packing purposes or
3045 to satisfy the type requirements if no such considerations apply. When
3046 we get the alignment from the type, indicate if this is from an explicit
3047 user request, which prevents stor-layout from lowering it later on. */
3048 else
3049 {
3050 const unsigned int field_align
3053 : packed
3054 ? BITS_PER_UNIT
3060 {
3063 }
3064 }
3067 {
3068 /* We need to pass in the alignment the DECL is known to have.
3069 This is the lowest-order bit set in POS, but no more than
3070 the alignment of the record, if one is specified. Note
3071 that an alignment of 0 is taken as infinite. */
3076 else
3090 }
3092 /* In addition to what our caller says, claim the field is addressable if we
3093 know that its type is not suitable.
3095 The field may also be "technically" nonaddressable, meaning that even if
3096 we attempt to take the field's address we will actually get the address
3097 of a copy. This is the case for true bitfields, but the DECL_BIT_FIELD
3098 value we have at this point is not accurate enough, so we don't account
3099 for this here and let finish_record_type decide. */
3103 /* Note that there is a trade-off in making a field nonaddressable because
3104 this will cause type-based alias analysis to use the same alias set for
3105 accesses to the field as for accesses to the whole record: while doing
3106 so will make it more likely to disambiguate accesses to other objects
3107 and accesses to the field, it will make it less likely to disambiguate
3108 accesses to the other fields of the record and accesses to the field.
3109 If the record is fully static, then the trade-off is irrelevant since
3110 the fields of the record can always be disambiguated by their offsets
3111 but, if the record is dynamic, then it can become problematic. */
3115 }
3117 /* Return a PARM_DECL node with NAME and TYPE. */
3119 tree
3121 {
3124 /* Honor TARGET_PROMOTE_PROTOTYPES like the C compiler, as not doing so
3125 can lead to various ABI violations. */
3129 {
3130 /* We have to be careful about biased types here. Make a subtype
3131 of integer_type_node with the proper biasing. */
3134 {
3135 tree subtype
3142 }
3143 else
3145 }
3149 }
3151 /* Process the attributes in ATTR_LIST for NODE, which is either a DECL or
3152 a TYPE. If IN_PLACE is true, the tree pointed to by NODE should not be
3153 changed. GNAT_NODE is used for the position of error messages. */
3155 void
3157 Node_Id gnat_node)
3158 {
3163 {
3172 {
3175 }
3181 else
3188 {
3191 }
3192 else
3211 }
3214 }
3216 /* Return true if VALUE is a known to be a multiple of FACTOR, which must be
3217 a power of 2. */
3219 bool
3221 {
3232 }
3234 /* Defer the initialization of DECL's DECL_CONTEXT attribute, scheduling to
3235 feed it with the elaboration of GNAT_SCOPE. */
3239 {
3242 new_node
3251 }
3253 /* Defer the initialization of TYPE's TYPE_CONTEXT attribute, scheduling to
3254 feed it with the DECL_CONTEXT computed as part of N as soon as it is
3255 computed. */
3257 static void
3259 {
3261 }
3263 /* Get the GENERIC node corresponding to GNAT_SCOPE, if available. Return
3264 NULL_TREE if it is not available. */
3266 static tree
3268 {
3269 tree context;
3273 else
3277 {
3280 /* Skip dummy types: only the final ones can appear in the context
3281 chain. */
3285 /* ..._TYPE nodes are more useful than TYPE_DECL nodes in the context
3286 chain. */
3287 else
3289 }
3292 }
3294 /* Try to process all deferred nodes in the queue. Keep in the queue the ones
3295 that cannot be processed yet, remove the other ones. If FORCE is true,
3296 force the processing for all nodes, use the global context when nodes don't
3297 have a GNU translation. */
3299 void
3301 {
3306 {
3309 Entity_Id gnat_scope;
3313 /* If FORCE, get the innermost elaborated scope. Otherwise, just try to
3314 get the first scope. */
3317 {
3322 }
3324 /* Imported declarations must not be in a local context (i.e. not inside
3325 a function). */
3327 {
3331 {
3334 }
3335 }
3337 /* If FORCE, we want to get rid of all nodes in the queue: in case there
3338 was no elaborated scope, use the global context. */
3343 {
3344 tree t;
3349 /* Propagate it to the TYPE_CONTEXT attributes of the requested
3350 ..._TYPE nodes. */
3352 {
3354 }
3356 }
3358 /* If this node has been successfuly processed, remove it from the
3359 queue. Then move to the next node. */
3361 {
3365 }
3366 else
3368 }
3369 }
3371 /* Return VALUE scaled by the biggest power-of-2 factor of EXPR. */
3373 static unsigned int
3375 {
3379 /* Peel conversions around EXPR and try to extract bodies from function
3380 calls: it is possible to get the scale factor from size functions. */
3385 /* Sometimes we get PLUS_EXPR (BIT_AND_EXPR (..., X), Y), where Y is a
3386 multiple of the scale factor we are looking for. */
3390 {
3393 }
3395 /* An expression which is a bitwise AND with a mask has a power-of-2 factor
3396 corresponding to the number of trailing zeros of the mask. */
3399 {
3404 {
3407 i++;
3408 }
3409 }
3411 /* If the addend is not a multiple of the factor we found, give up. In
3412 theory we could find a smaller common factor but it's useless for our
3413 needs. This situation arises when dealing with a field F1 with no
3414 alignment requirement but that is following a field F2 with such
3415 requirements. As long as we have F2's offset, we don't need alignment
3416 information to compute F1's. */
3421 }
3423 /* Return a LABEL_DECL with NAME. GNAT_NODE is used for the position of
3424 the decl. */
3426 tree
3428 {
3429 tree label_decl
3434 /* Add this decl to the current binding level. */
3438 }
3440 /* Return a FUNCTION_DECL node. NAME is the name of the subprogram, ASM_NAME
3441 its assembler name, TYPE its type (a FUNCTION_TYPE or METHOD_TYPE node),
3442 PARAM_DECL_LIST the list of its parameters (a list of PARM_DECL nodes
3443 chained through the DECL_CHAIN field).
3445 INLINE_STATUS describes the inline flags to be set on the FUNCTION_DECL.
3447 PUBLIC_FLAG is true if this is for a reference to a public entity or for a
3448 definition to be made visible outside of the current compilation unit.
3450 EXTERN_FLAG is true when processing an external subprogram declaration.
3452 ARTIFICIAL_P is true if the subprogram was generated by the compiler.
3454 DEBUG_INFO_P is true if we need to write debug information for it.
3456 DEFINITION is true if the subprogram is to be considered as a definition.
3458 ATTR_LIST is the list of attributes to be attached to the subprogram.
3460 GNAT_NODE is used for the position of the decl. */
3462 tree
3467 Node_Id gnat_node)
3468 {
3479 {
3489 {
3493 ATTR_FLAG_TYPE_IN_PLACE);
3495 /* Inline_Always guarantees that every direct call is inlined and
3496 that there is no indirect reference to the subprogram, so the
3497 instance in the original package (as well as its clones in the
3498 client packages created for inter-unit inlining) can be made
3499 private, which causes the out-of-line body to be eliminated. */
3501 }
3503 /* ... fall through ... */
3508 /* ... fall through ... */
3518 }
3522 /* Once everything is processed, finish the subprogram declaration. */
3525 /* Add this decl to the current binding level. */
3528 /* Output the assembler code and/or RTL for the declaration. */
3532 }
3534 /* Given a subprogram declaration DECL, its assembler name and its type,
3535 finish constructing the subprogram declaration from ASM_NAME and TYPE. */
3537 void
3539 {
3540 /* DECL_ARGUMENTS is set by the caller, but not its context. */
3542 param_decl;
3546 tree result_decl
3556 /* Propagate the "pure" property. */
3559 /* Propagate the "noreturn" property. */
3563 {
3564 /* Let the target mangle the name if this isn't a verbatim asm. */
3570 /* The expand_main_function circuitry expects "main_identifier_node" to
3571 designate the DECL_NAME of the 'main' entry point, in turn expected
3572 to be declared as the "main" function literally by default. Ada
3573 program entry points are typically declared with a different name
3574 within the binder generated file, exported as 'main' to satisfy the
3575 system expectations. Force main_identifier_node in this case. */
3578 }
3579 }
3581 /* Set up the framework for generating code for SUBPROG_DECL, a subprogram
3582 body. This routine needs to be invoked before processing the declarations
3583 appearing in the subprogram. */
3585 void
3587 {
3590 /* This function is being defined. */
3593 /* The failure of this assertion will likely come from a wrong context for
3594 the subprogram body, e.g. another procedure for a procedure declared at
3595 library level. */
3600 /* Enter a new binding level and show that all the parameters belong to
3601 this function. */
3603 }
3605 /* Finish translating the current subprogram and set its BODY. */
3607 void
3609 {
3612 /* Attach the BLOCK for this level to the function and pop the level. */
3617 /* The body should be a BIND_EXPR whose BLOCK is the top-level one. */
3619 {
3622 }
3627 }
3629 /* Wrap up compilation of SUBPROG_DECL, a subprogram body. */
3631 void
3633 {
3634 /* We cannot track the location of errors past this point. */
3637 /* If we're only annotating types, don't actually compile this function. */
3641 /* Dump functions before gimplification. */
3646 else
3647 /* Register this function with cgraph just far enough to get it
3648 added to our parent's nested function list. */
3650 }
3652 tree
3654 {
3657 }
3659 /* Return an integer type with the number of bits of precision given by
3660 PRECISION. UNSIGNEDP is nonzero if the type is unsigned; otherwise
3661 it is a signed type. */
3663 tree
3665 {
3666 tree t;
3675 else
3683 {
3686 }
3689 }
3691 /* Likewise for floating-point types. */
3693 static tree
3695 {
3696 tree t;
3708 {
3711 }
3714 }
3716 /* Return a data type that has machine mode MODE. UNSIGNEDP selects
3717 an unsigned type; otherwise a signed type is returned. */
3719 tree
3721 {
3731 scalar_float_mode float_mode;
3734 float_mode);
3736 scalar_int_mode int_mode;
3741 {
3746 }
3749 }
3751 /* Return the signed or unsigned version of TYPE_NODE, a scalar type, the
3752 signedness being specified by UNSIGNEDP. */
3754 tree
3756 {
3763 {
3766 }
3770 {
3773 }
3776 }
3778 /* Return 1 if the types T1 and T2 are compatible, i.e. if they can be
3779 transparently converted to each other. */
3781 int
3783 {
3786 /* This is the default criterion. */
3790 /* We only check structural equivalence here. */
3794 /* Vector types are also compatible if they have the same number of subparts
3795 and the same form of (scalar) element type. */
3802 /* Array types are also compatible if they are constrained and have the same
3803 domain(s), the same component type and the same scalar storage order. */
3819 }
3821 /* Return true if EXPR is a useless type conversion. */
3823 bool
3825 {
3833 }
3835 /* Return true if T, a {FUNCTION,METHOD}_TYPE, has the specified flags. */
3837 bool
3840 {
3844 }
3846 /* Try to compute the maximum (if MAX_P) or minimum (if !MAX_P) value for the
3847 expression EXP, for very simple expressions. Substitute variable references
3848 with their respective type's min/max values. Return the computed value if
3849 any, or EXP if no value can be computed. */
3851 tree
3853 {
3859 {
3863 max_p
3869 {
3870 tree t;
3875 }
3910 }
3915 {
3930 }
3935 }
3937 }
3940 /* EXP is an expression for the size of an object. If this size contains
3941 discriminant references, replace them with the maximum (if MAX_P) or
3942 minimum (if !MAX_P) possible value of the discriminant.
3944 Note that the expression may have already been gimplified,in which case
3945 COND_EXPRs have VOID_TYPE and no operands, and this must be handled. */
3947 tree
3949 {
3955 {
3966 {
3977 /* This is used to remove possible placeholder in call args. */
3981 }
3985 /* If this contains a PLACEHOLDER_EXPR, it is the thing we want to
3986 modify. Otherwise, we treat it like a variable. */
3988 {
3990 tree val
3992 max_p
3995 /* Walk down the extra subtypes to get more restrictive bounds. */
3997 {
4003 else
4007 }
4010 }
4037 /* If we have a multiply-add with a "negative" value in an unsigned
4038 type, do a multiply-subtract with the negated value, in order to
4039 avoid creating a spurious overflow below. */
4046 {
4053 }
4059 {
4060 /* If the op0 has overflowed and the op1 is a variable,
4061 propagate the overflow by returning the op0. */
4067 /* If we have a "negative" value in an unsigned type, do the
4068 opposite operation on the negated value, in order to avoid
4069 creating a spurious overflow below. */
4074 {
4077 }
4078 }
4083 /* We need to detect overflows so we call size_binop here. */
4088 {
4115 {
4126 /* If we have the MAX of a "negative" value in an unsigned type
4127 and zero for a length expression, just return zero. */
4138 }
4143 }
4145 /* Other tree classes cannot happen. */
4148 }
4151 }
4153 /* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE.
4154 EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs.
4155 Return a constructor for the template. */
4157 tree
4159 {
4162 tree field;
4174 /* First make the list for a CONSTRUCTOR for the template. Go down
4175 the field list of the template instead of the type chain because
4176 this array might be an Ada array of array and we can't tell where
4177 the nested array stop being the underlying object. */
4179 field;
4181 {
4184 /* If we have a bound list, get the bounds from there. Likewise
4185 for an ARRAY_TYPE. Otherwise, if expr is a PARM_DECL with
4186 DECL_BY_COMPONENT_PTR_P, use the bounds of the field in the
4187 template, but this will only give us a maximum range. */
4189 {
4192 }
4194 {
4197 }
4201 else
4207 /* If either MIN or MAX involve a PLACEHOLDER_EXPR, we must
4208 substitute it from OBJECT. */
4214 }
4217 }
4219 /* Return true if TYPE is suitable for the element type of a vector. */
4221 static bool
4223 {
4224 machine_mode mode;
4238 }
4240 /* Return a vector type given the SIZE and the INNER_TYPE, or NULL_TREE if
4241 this is not possible. If ATTRIBUTE is non-zero, we are processing the
4242 attribute declaration and want to issue error messages on failure. */
4244 static tree
4246 {
4250 /* Silently punt on variable sizes. We can't make vector types for them,
4251 need to ignore them on front-end generated subtypes of unconstrained
4252 base types, and this attribute is for binding implementors, not end
4253 users, so we should never get there from legitimate explicit uses. */
4259 {
4264 }
4268 {
4272 }
4275 {
4279 }
4283 {
4287 }
4290 }
4292 /* Return a vector type whose representative array type is ARRAY_TYPE, or
4293 NULL_TREE if this is not possible. If ATTRIBUTE is non-zero, we are
4294 processing the attribute and want to issue error messages on failure. */
4296 static tree
4298 {
4301 attribute);
4307 }
4309 /* Build a type to be used to represent an aliased object whose nominal type
4310 is an unconstrained array. This consists of a RECORD_TYPE containing a
4311 field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an ARRAY_TYPE.
4312 If ARRAY_TYPE is that of an unconstrained array, this is used to represent
4313 an arbitrary unconstrained object. Use NAME as the name of the record.
4314 DEBUG_INFO_P is true if we need to write debug information for the type. */
4316 tree
4319 {
4321 tree template_field
4324 tree array_field
4333 /* Declare it now since it will never be declared otherwise. This is
4334 necessary to ensure that its subtrees are properly marked. */
4338 }
4340 /* Same, taking a thin or fat pointer type instead of a template type. */
4342 tree
4345 {
4346 tree template_type;
4350 template_type
4355 return
4357 }
4359 /* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE.
4360 In the normal case this is just two adjustments, but we have more to
4361 do if NEW_TYPE is an UNCONSTRAINED_ARRAY_TYPE. */
4363 void
4365 {
4368 tree t;
4370 /* If this is the main variant, process all the other variants first. */
4375 /* If no pointers and no references, we are done. */
4379 /* Merge the old type qualifiers in the new type.
4381 Each old variant has qualifiers for specific reasons, and the new
4382 designated type as well. Each set of qualifiers represents useful
4383 information grabbed at some point, and merging the two simply unifies
4384 these inputs into the final type description.
4386 Consider for instance a volatile type frozen after an access to constant
4387 type designating it; after the designated type's freeze, we get here with
4388 a volatile NEW_TYPE and a dummy OLD_TYPE with a readonly variant, created
4389 when the access type was processed. We will make a volatile and readonly
4390 designated type, because that's what it really is.
4392 We might also get here for a non-dummy OLD_TYPE variant with different
4393 qualifiers than those of NEW_TYPE, for instance in some cases of pointers
4394 to private record type elaboration (see the comments around the call to
4395 this routine in gnat_to_gnu_entity <E_Access_Type>). We have to merge
4396 the qualifiers in those cases too, to avoid accidentally discarding the
4397 initial set, and will often end up with OLD_TYPE == NEW_TYPE then. */
4398 new_type
4402 /* If old type and new type are identical, there is nothing to do. */
4406 /* Otherwise, first handle the simple case. */
4408 {
4411 /* If pointer or reference already points to new type, nothing to do.
4412 This can happen as update_pointer_to can be invoked multiple times
4413 on the same couple of types because of the type variants. */
4418 /* Chain PTR and its variants at the end. */
4421 {
4425 }
4426 else
4429 /* Now adjust them. */
4432 {
4437 }
4439 /* Chain REF and its variants at the end. */
4442 {
4446 }
4447 else
4450 /* Now adjust them. */
4453 {
4456 }
4460 }
4462 /* Now deal with the unconstrained array case. In this case the pointer
4463 is actually a record where both fields are pointers to dummy nodes.
4464 Turn them into pointers to the correct types using update_pointer_to.
4465 Likewise for the pointer to the object record (thin pointer). */
4466 else
4467 {
4472 /* If PTR already points to NEW_TYPE, nothing to do. This can happen
4473 since update_pointer_to can be invoked multiple times on the same
4474 couple of types because of the type variants. */
4478 update_pointer_to
4482 update_pointer_to
4491 }
4492 }
4494 /* Convert EXPR, a pointer to a constrained array, into a pointer to an
4495 unconstrained one. This involves making or finding a template. */
4497 static tree
4499 {
4503 tree template_addr;
4507 /* If EXPR is null, make a fat pointer that contains a null pointer to the
4508 array (compare_fat_pointers ensures that this is the full discriminant)
4509 and a valid pointer to the bounds. This latter property is necessary
4510 since the compiler can hoist the load of the bounds done through it. */
4512 {
4518 else
4519 {
4520 /* The template type can still be dummy at this point so we build an
4521 empty constructor. The middle-end will fill it in with zeros. */
4526 }
4532 /* Do not set TREE_CONSTANT so as to force T to static memory. */
4537 }
4539 /* If EXPR is a thin pointer, make template and data from the record. */
4541 {
4546 /* If we have a TYPE_UNCONSTRAINED_ARRAY attached to the RECORD_TYPE,
4547 the thin pointer value has been shifted so we shift it back to get
4548 the template address. */
4550 {
4551 template_addr
4554 byte_position
4556 template_addr
4558 template_addr);
4559 }
4561 /* Otherwise we explicitly take the address of the fields. */
4562 else
4563 {
4565 template_addr
4571 }
4572 }
4574 /* Otherwise, build the constructor for the template. */
4575 else
4576 template_addr
4579 expr));
4581 /* The final result is a constructor for the fat pointer.
4583 If EXPR is an argument of a foreign convention subprogram, the type it
4584 points to is directly the component type. In this case, the expression
4585 type may not match the corresponding FIELD_DECL type at this point, so we
4586 call "convert" here to fix that up if necessary. This type consistency is
4587 required, for instance because it ensures that possible later folding of
4588 COMPONENT_REFs against this constructor always yields something of the
4589 same type as the initial reference.
4591 Note that the call to "build_template" above is still fine because it
4592 will only refer to the provided TEMPLATE_TYPE in this case. */
4596 }
4598 /* Create an expression whose value is that of EXPR,
4599 converted to type TYPE. The TREE_TYPE of the value
4600 is always TYPE. This function implements all reasonable
4601 conversions; callers should filter out those that are
4602 not permitted by the language being compiled. */
4604 tree
4606 {
4611 /* If the expression is already of the right type, we are done. */
4615 /* If both input and output have padding and are of variable size, do this
4616 as an unchecked conversion. Likewise if one is a mere variant of the
4617 other, so we avoid a pointless unpad/repad sequence. */
4625 ;
4627 /* If the output type has padding, convert to the inner type and make a
4628 constructor to build the record, unless a variable size is involved. */
4630 {
4631 /* If we previously converted from another type and our type is
4632 of variable size, remove the conversion to avoid the need for
4633 variable-sized temporaries. Likewise for a conversion between
4634 original and packable version. */
4642 /* If we are just removing the padding from expr, convert the original
4643 object if we have variable size in order to avoid the need for some
4644 variable-sized temporaries. Likewise if the padding is a variant
4645 of the other, so we avoid a pointless unpad/repad sequence. */
4656 /* If the inner type is of self-referential size and the expression type
4657 is a record, do this as an unchecked conversion unless both types are
4658 essentially the same. */
4665 /* If we are converting between array types with variable size, do the
4666 final conversion as an unchecked conversion, again to avoid the need
4667 for some variable-sized temporaries. If valid, this conversion is
4668 very likely purely technical and without real effects. */
4675 expr),
4680 /* If converting to the inner type has already created a CONSTRUCTOR with
4681 the right size, then reuse it instead of creating another one. This
4682 can happen for the padding type built to overalign local variables. */
4694 }
4696 /* If the input type has padding, remove it and convert to the output type.
4697 The conditions ordering is arranged to ensure that the output type is not
4698 a padding type here, as it is not clear whether the conversion would
4699 always be correct if this was to happen. */
4701 {
4702 tree unpadded;
4704 /* If we have just converted to this padded type, just get the
4705 inner expression. */
4709 /* Otherwise, build an explicit component reference. */
4710 else
4714 }
4716 /* If the input is a biased type, convert first to the base type and add
4717 the bias. Note that the bias must go through a full conversion to the
4718 base type, lest it is itself a biased value; this happens for subtypes
4719 of biased types. */
4726 /* If the input is a justified modular type, we need to extract the actual
4727 object before converting it to an other type with the exceptions of an
4728 [unconstrained] array or a mere type variant. It is useful to avoid
4729 the extraction and conversion in these cases because it could end up
4730 replacing a VAR_DECL by a constructor and we might be about the take
4731 the address of the result. */
4736 return
4739 /* If converting to a type that contains a template, convert to the data
4740 type and then build the template. */
4742 {
4747 /* If the source already has a template, get a reference to the
4748 associated array only, as we are going to rebuild a template
4749 for the target type anyway. */
4759 }
4761 /* There are some cases of expressions that we process specially. */
4763 {
4768 /* Just set its type here. For TRANSFORM_EXPR, we will do the actual
4769 conversion in gnat_expand_expr. NULL_EXPR does not represent
4770 and actual value, so no conversion is needed. */
4776 /* If we are converting a STRING_CST to another constrained array type,
4777 just make a new one in the proper type. */
4781 {
4785 }
4789 /* If we are converting a VECTOR_CST to a mere type variant, just make
4790 a new one in the proper type. */
4792 {
4796 }
4800 /* If we are converting a CONSTRUCTOR to a mere type variant, or to
4801 another padding type around the same type, just make a new one in
4802 the proper type. */
4809 {
4814 }
4816 /* Likewise for a conversion between original and packable version, or
4817 conversion between types of the same size and with the same list of
4818 fields, but we have to work harder to preserve type consistency. */
4824 {
4833 /* Whether we need to clear TREE_CONSTANT et al. on the output
4834 constructor when we convert in place. */
4838 {
4839 /* Skip the missing fields in the CONSTRUCTOR. */
4841 {
4844 }
4845 /* The field must be the same. */
4848 constructor_elt elt
4852 /* If packing has made this field a bitfield and the input
4853 value couldn't be emitted statically any more, we need to
4854 clear TREE_CONSTANT on our output. */
4864 }
4866 /* If we have been able to match and convert all the input fields
4867 to their output type, convert in place now. We'll fallback to a
4868 view conversion downstream otherwise. */
4870 {
4877 }
4878 }
4880 /* Likewise for a conversion between array type and vector type with a
4881 compatible representative array. */
4885 etype))
4886 {
4891 tree value;
4893 /* Build a VECTOR_CST from a *constant* array constructor. */
4895 {
4898 /* Iterate through elements and check if all constructor
4899 elements are *_CSTs. */
4902 {
4905 }
4910 }
4912 /* Otherwise, build a regular vector constructor. */
4915 {
4918 }
4923 }
4927 /* First retrieve the underlying array. */
4934 {
4935 /* GCC 4.x is very sensitive to type consistency overall, and view
4936 conversions thus are very frequent. Even though just "convert"ing
4937 the inner operand to the output type is fine in most cases, it
4938 might expose unexpected input/output type mismatches in special
4939 circumstances so we avoid such recursive calls when we can. */
4942 /* If we are converting back to the original type, we can just
4943 lift the input conversion. This is a common occurrence with
4944 switches back-and-forth amongst type variants. */
4948 /* Otherwise, if we're converting between two aggregate or vector
4949 types, we might be allowed to substitute the VIEW_CONVERT_EXPR
4950 target type in place or to just convert the inner expression. */
4953 {
4954 /* If we are converting between mere variants, we can just
4955 substitute the VIEW_CONVERT_EXPR in place. */
4959 /* Otherwise, we may just bypass the input view conversion unless
4960 one of the types is a fat pointer, which is handled by
4961 specialized code below which relies on exact type matching. */
4965 }
4968 }
4972 }
4974 /* Check for converting to a pointer to an unconstrained array. */
4978 /* If we are converting between two aggregate or vector types that are mere
4979 variants, just make a VIEW_CONVERT_EXPR. Likewise when we are converting
4980 to a vector type from its representative array type. */
4987 etype)))
4990 /* If we are converting between tagged types, try to upcast properly.
4991 But don't do it if we are just annotating types since tagged types
4992 aren't fully laid out in this mode. */
4996 {
5004 }
5006 /* If we are converting from a smaller form of record type back to it, just
5007 make a VIEW_CONVERT_EXPR. But first pad the expression to have the same
5008 size on both sides. */
5011 {
5014 expr);
5016 }
5018 /* In all other cases of related types, make a NOP_EXPR. */
5023 {
5033 /* If the output is a biased type, convert first to the base type and
5034 subtract the bias. Note that the bias itself must go through a full
5035 conversion to the base type, lest it is a biased value; this happens
5036 for subtypes of biased types. */
5044 /* If we are converting an additive expression to an integer type
5045 with lower precision, be wary of the optimization that can be
5046 applied by convert_to_integer. There are 2 problematic cases:
5047 - if the first operand was originally of a biased type,
5048 because we could be recursively called to convert it
5049 to an intermediate type and thus rematerialize the
5050 additive operator endlessly,
5051 - if the expression contains a placeholder, because an
5052 intermediate conversion that changes the sign could
5053 be inserted and thus introduce an artificial overflow
5054 at compile time when the placeholder is substituted. */
5058 {
5065 }
5067 /* ... fall through ... */
5073 /* Do not use convert_to_integer with boolean types. */
5078 /* If converting between two thin pointers, adjust if needed to account
5079 for differing offsets from the base pointer, depending on whether
5080 there is a TYPE_UNCONSTRAINED_ARRAY attached to the record type. */
5082 {
5083 tree etype_pos
5087 tree type_pos
5099 }
5101 /* If converting fat pointer to normal or thin pointer, get the pointer
5102 to the array and then convert it. */
5112 /* Do a normal conversion between scalar and justified modular type. */
5114 {
5120 expr));
5122 }
5124 /* In these cases, assume the front-end has validated the conversion.
5125 If the conversion is valid, it will be a bit-wise conversion, so
5126 it can be viewed as an unchecked conversion. */
5130 /* Do a normal conversion between unconstrained and constrained array
5131 type, assuming the latter is a constrained version of the former. */
5135 {
5143 }
5145 /* In these cases, assume the front-end has validated the conversion.
5146 If the conversion is valid, it will be a bit-wise conversion, so
5147 it can be viewed as an unchecked conversion. */
5151 /* This is a either a conversion between a tagged type and some
5152 subtype, which we have to mark as a UNION_TYPE because of
5153 overlapping fields or a conversion of an Unchecked_Union. */
5157 /* If the input is a VECTOR_TYPE, convert to the representative
5158 array type first. */
5160 {
5164 }
5166 /* If EXPR is a constrained array, take its address, convert it to a
5167 fat pointer, and then dereference it. Likewise if EXPR is a
5168 record containing both a template and a constrained array.
5169 Note that a record representing a justified modular type
5170 always represents a packed constrained array. */
5175 return
5176 build_unary_op
5182 /* Do something very similar for converting one unconstrained
5183 array to another. */
5185 return
5190 else
5198 }
5199 }
5201 /* Create an expression whose value is that of EXPR converted to the common
5202 index type, which is sizetype. EXPR is supposed to be in the base type
5203 of the GNAT index type. Calling it is equivalent to doing
5205 convert (sizetype, expr)
5207 but we try to distribute the type conversion with the knowledge that EXPR
5208 cannot overflow in its type. This is a best-effort approach and we fall
5209 back to the above expression as soon as difficulties are encountered.
5211 This is necessary to overcome issues that arise when the GNAT base index
5212 type and the GCC common index type (sizetype) don't have the same size,
5213 which is quite frequent on 64-bit architectures. In this case, and if
5214 the GNAT base index type is signed but the iteration type of the loop has
5215 been forced to unsigned, the loop scalar evolution engine cannot compute
5216 a simple evolution for the general induction variables associated with the
5217 array indices, because it will preserve the wrap-around semantics in the
5218 unsigned type of their "inner" part. As a result, many loop optimizations
5219 are blocked.
5221 The solution is to use a special (basic) induction variable that is at
5222 least as large as sizetype, and to express the aforementioned general
5223 induction variables in terms of this induction variable, eliminating
5224 the problematic intermediate truncation to the GNAT base index type.
5225 This is possible as long as the original expression doesn't overflow
5226 and if the middle-end hasn't introduced artificial overflows in the
5227 course of the various simplification it can make to the expression. */
5229 tree
5231 {
5235 /* If the type is unsigned, overflow is allowed so we cannot be sure that
5236 EXPR doesn't overflow. Keep it simple if optimization is disabled. */
5241 {
5243 /* The main effect of the function: replace a loop parameter with its
5244 associated special induction variable. */
5249 CASE_CONVERT:
5250 {
5252 /* Bail out as soon as we suspect some sort of type frobbing. */
5256 }
5258 /* ... fall through ... */
5282 }
5285 }
5287 /* Remove all conversions that are done in EXP. This includes converting
5288 from a padded type or to a justified modular type. If TRUE_ADDRESS
5289 is true, always return the address of the containing object even if
5290 the address is not bit-aligned. */
5292 tree
5294 {
5296 {
5301 return
5310 CASE_CONVERT:
5317 }
5320 }
5322 /* If EXP's type is an UNCONSTRAINED_ARRAY_TYPE, return an expression that
5323 refers to the underlying array. If it has TYPE_CONTAINS_TEMPLATE_P,
5324 likewise return an expression pointing to the underlying array. */
5326 tree
5328 {
5333 {
5336 {
5344 {
5345 tree op1
5350 tree op2
5359 }
5360 else
5361 {
5368 }
5369 }
5372 {
5376 }
5385 /* If this is a padded type and it contains a template, convert to the
5386 unpadded type first. */
5390 {
5394 }
5397 {
5398 /* If the array initializer is a box, return NULL_TREE. */
5405 /* If the array is padded, remove the padding. */
5407 }
5412 }
5415 }
5417 /* Return true if EXPR is an expression that can be folded as an operand
5418 of a VIEW_CONVERT_EXPR. See ada-tree.h for a complete rationale. */
5420 static bool
5422 {
5425 /* The folder will fold NOP_EXPRs between integral types with the same
5426 precision (in the middle-end's sense). We cannot allow it if the
5427 types don't have the same precision in the Ada sense as well. */
5434 /* Defer to the folder for non-integral conversions. */
5438 /* Only fold conversions that preserve both precisions. */
5444 }
5446 /* Return an expression that does an unchecked conversion of EXPR to TYPE.
5447 If NOTRUNC_P is true, truncation operations should be suppressed.
5449 Special care is required with (source or target) integral types whose
5450 precision is not equal to their size, to make sure we fetch or assign
5451 the value bits whose location might depend on the endianness, e.g.
5453 Rmsize : constant := 8;
5454 subtype Int is Integer range 0 .. 2 ** Rmsize - 1;
5456 type Bit_Array is array (1 .. Rmsize) of Boolean;
5457 pragma Pack (Bit_Array);
5459 function To_Bit_Array is new Unchecked_Conversion (Int, Bit_Array);
5461 Value : Int := 2#1000_0001#;
5462 Vbits : Bit_Array := To_Bit_Array (Value);
5464 we expect the 8 bits at Vbits'Address to always contain Value, while
5465 their original location depends on the endianness, at Value'Address
5466 on a little-endian architecture but not on a big-endian one.
5468 One pitfall is that we cannot use TYPE_UNSIGNED directly to decide how
5469 the bits between the precision and the size are filled, because of the
5470 trick used in the E_Signed_Integer_Subtype case of gnat_to_gnu_entity.
5471 So we use the special predicate type_unsigned_for_rm above. */
5473 tree
5475 {
5479 const bool ebiased
5481 const bool biased
5483 const bool ereverse
5485 const bool reverse
5487 tree tem;
5490 /* If the expression is already of the right type, we are done. */
5494 /* If both types are integral or regular pointer, then just do a normal
5495 conversion. Likewise for a conversion to an unconstrained array. */
5503 {
5505 {
5510 }
5513 {
5519 }
5520 else
5522 }
5524 /* If we are converting to an integral type whose precision is not equal
5525 to its size, first unchecked convert to a record type that contains a
5526 field of the given precision. Then extract the result from the field.
5528 There is a subtlety if the source type is an aggregate type with reverse
5529 storage order because its representation is not contiguous in the native
5530 storage order, i.e. a direct unchecked conversion to an integral type
5531 with N bits of precision cannot read the first N bits of the aggregate
5532 type. To overcome it, we do an unchecked conversion to an integral type
5533 with reverse storage order and return the resulting value. This also
5534 ensures that the result of the unchecked conversion doesn't depend on
5535 the endianness of the target machine, but only on the storage order of
5536 the aggregate type.
5538 Finally, for the sake of consistency, we do the unchecked conversion
5539 to an integral type with reverse storage order as soon as the source
5540 type is an aggregate type with reverse storage order, even if there
5541 are no considerations of precision or size involved. Ultimately, we
5542 further extend this processing to any scalar type. */
5549 {
5556 {
5557 const unsigned HOST_WIDE_INT prec
5561 else
5564 }
5565 else
5576 }
5578 /* Similarly if we are converting from an integral type whose precision is
5579 not equal to its size, first copy into a field of the given precision
5580 and unchecked convert the record type.
5582 The same considerations as above apply if the target type is an aggregate
5583 type with reverse storage order and we also proceed similarly. */
5590 {
5599 {
5600 const unsigned HOST_WIDE_INT prec
5604 else
5607 }
5608 else
5620 }
5622 /* If we are converting between fixed-size types with different sizes, we
5623 need to pad to have the same size on both sides.
5625 ??? We cannot do it unconditionally because unchecked conversions are
5626 used liberally by the front-end to implement interface thunks:
5628 type ada__tags__addr_ptr is access system.address;
5629 S191s : constant ada__tags__addr_ptr := ada__tags__addr_ptr!(S190s);
5630 return p___size__4 (p__object!(S191s.all));
5632 so we need to skip dereferences. */
5640 {
5642 {
5645 expr);
5647 }
5648 else
5649 {
5654 NULL_TREE);
5655 }
5656 }
5658 /* Likewise if we are converting from a fixed-size type to a type with self-
5659 referential size. We use the max size to do the padding in this case. */
5666 {
5670 {
5673 expr);
5675 }
5676 else
5677 {
5682 NULL_TREE);
5683 }
5684 }
5686 /* We have a special case when we are converting between two unconstrained
5687 array types. In that case, take the address, convert the fat pointer
5688 types, and dereference. */
5693 expr)));
5695 /* Another special case is when we are converting to a vector type from its
5696 representative array type; this a regular conversion. */
5700 etype))
5703 /* And, if the array type is not the representative, we try to build an
5704 intermediate vector type of which the array type is the representative
5705 and to do the unchecked conversion between the vector types, in order
5706 to enable further simplifications in the middle-end. */
5710 {
5713 }
5715 /* If we are converting a CONSTRUCTOR to a more aligned aggregate type, bump
5716 the alignment of the CONSTRUCTOR to speed up the copy operation. But do
5717 not do it for a conversion between original and packable version to avoid
5718 an infinite recursion. */
5723 {
5726 expr);
5728 }
5730 /* If we are converting a CONSTRUCTOR to a larger aggregate type, bump the
5731 size of the CONSTRUCTOR to make sure there are enough allocated bytes.
5732 But do not do it for a conversion between original and packable version
5733 to avoid an infinite recursion. */
5740 {
5743 expr);
5745 }
5747 /* If we are converting a string constant to a pointer to character, make
5748 sure that the string is not folded into an integer constant. */
5754 /* Otherwise, just build a VIEW_CONVERT_EXPR of the expression. */
5755 else
5756 {
5762 else
5764 }
5766 /* If the result is a non-biased integral type whose precision is not equal
5767 to its size, sign- or zero-extend the result. But we need not do this
5768 if the input is also an integral type and both are unsigned or both are
5769 signed and have the same precision. */
5770 tree type_rm_size;
5772 && !biased
5783 {
5786 else
5787 {
5788 tree base_type
5791 tree shift_expr
5795 expr
5800 expr),
5801 shift_expr),
5802 shift_expr));
5803 }
5804 }
5806 /* An unchecked conversion should never raise Constraint_Error. The code
5807 below assumes that GCC's conversion routines overflow the same way that
5808 the underlying hardware does. This is probably true. In the rare case
5809 when it is false, we can rely on the fact that such conversions are
5810 erroneous anyway. */
5814 /* If the sizes of the types differ and this is an VIEW_CONVERT_EXPR,
5815 show no longer constant. */
5818 OEP_ONLY_CONST))
5822 }
5824 /* Return the appropriate GCC tree code for the specified GNAT_TYPE,
5825 the latter being a record type as predicated by Is_Record_Type. */
5827 enum tree_code
5829 {
5832 /* Return UNION_TYPE if it's an Unchecked_Union whose non-discriminant
5833 fields are all in the variant part. Otherwise, return RECORD_TYPE. */
5838 component_list
5848 }
5850 /* Return true if GNAT_TYPE is a "double" floating-point type, i.e. whose
5851 size is equal to 64 bits, or an array of such a type. Set ALIGN_CLAUSE
5852 according to the presence of an alignment clause on the type or, if it
5853 is an array, on the component type. */
5855 bool
5857 {
5863 {
5867 }
5876 }
5878 /* Return true if GNAT_TYPE is a "double" or larger scalar type, i.e. whose
5879 size is greater or equal to 64 bits, or an array of such a type. Set
5880 ALIGN_CLAUSE according to the presence of an alignment clause on the
5881 type or, if it is an array, on the component type. */
5883 bool
5885 {
5891 {
5895 }
5904 }
5906 /* Return true if GNU_TYPE is suitable as the type of a non-aliased
5907 component of an aggregate type. */
5909 bool
5911 {
5912 /* If the type is passed by reference, we may have pointers to the
5913 component so it cannot be made non-aliased. */
5917 /* We used to say that any component of aggregate type is aliased
5918 because the front-end may take 'Reference of it. The front-end
5919 has been enhanced in the meantime so as to use a renaming instead
5920 in most cases, but the back-end can probably take the address of
5921 such a component too so we go for the conservative stance.
5923 For instance, we might need the address of any array type, even
5924 if normally passed by copy, to construct a fat pointer if the
5925 component is used as an actual for an unconstrained formal.
5927 Likewise for record types: even if a specific record subtype is
5928 passed by copy, the parent type might be passed by ref (e.g. if
5929 it's of variable size) and we might take the address of a child
5930 component to pass to a parent formal. We have no way to check
5931 for such conditions here. */
5936 }
5938 /* Return true if TYPE is a smaller form of ORIG_TYPE. */
5940 bool
5942 {
5945 /* We're not interested in variants here. */
5949 /* Like a variant, a packable version keeps the original TYPE_NAME. */
5960 }
5962 /* Return whether EXPR, which is the renamed object in an object renaming
5963 declaration, can be materialized as a reference (with a REFERENCE_TYPE).
5964 This should be synchronized with Exp_Dbug.Debug_Renaming_Declaration. */
5966 bool
5968 {
5970 {
5974 {
5983 {
5987 const Uint bitpos
5994 }
5998 {
6006 }
6014 };
6015 }
6016 }
6018 /* Perform final processing on global declarations. */
6022 void
6024 {
6026 tree iter;
6028 /* If we have declared types as used at the global level, insert them in
6029 the global hash table. We use a dummy variable for this purpose, but
6030 we need to build it unconditionally to avoid -fcompare-debug issues. */
6032 {
6037 dummy_global
6039 void_type_node);
6048 {
6051 }
6052 }
6054 /* First output the integral global variables, so that they can be referenced
6055 as bounds by the global dynamic types. Skip external variables, unless we
6056 really need to emit debug info for them:, e.g. imported variables. */
6063 /* Now output debug information for the global type declarations. This
6064 ensures that global types whose compilation hasn't been finalized yet,
6065 for example pointers to Taft amendment types, have their compilation
6066 finalized in the right context. */
6071 /* Then output the other global variables. We need to do that after the
6072 information for global types is emitted so that they are finalized. */
6079 /* Output debug information for the global constants. */
6084 /* Output it for the imported functions. */
6093 /* Output it for the imported modules/declarations. In GNAT, these are only
6094 materializing subprogram. */
6099 }
6101 /* ************************************************************************
6102 * * GCC builtins support *
6103 * ************************************************************************ */
6105 /* The general scheme is fairly simple:
6107 For each builtin function/type to be declared, gnat_install_builtins calls
6108 internal facilities which eventually get to gnat_pushdecl, which in turn
6109 tracks the so declared builtin function decls in the 'builtin_decls' global
6110 datastructure. When an Intrinsic subprogram declaration is processed, we
6111 search this global datastructure to retrieve the associated BUILT_IN DECL
6112 node. */
6114 /* Search the chain of currently available builtin declarations for a node
6115 corresponding to function NAME (an IDENTIFIER_NODE). Return the first node
6116 found, if any, or NULL_TREE otherwise. */
6117 tree
6119 {
6121 tree decl;
6128 }
6130 /* The code below eventually exposes gnat_install_builtins, which declares
6131 the builtin types and functions we might need, either internally or as
6132 user accessible facilities.
6134 ??? This is a first implementation shot, still in rough shape. It is
6135 heavily inspired from the "C" family implementation, with chunks copied
6136 verbatim from there.
6138 Two obvious improvement candidates are:
6139 o Use a more efficient name/decl mapping scheme
6140 o Devise a middle-end infrastructure to avoid having to copy
6141 pieces between front-ends. */
6143 /* ----------------------------------------------------------------------- *
6144 * BUILTIN ELEMENTARY TYPES *
6145 * ----------------------------------------------------------------------- */
6147 /* Standard data types to be used in builtin argument declarations. */
6149 enum c_tree_index
6150 {
6152 CTI_STRING_TYPE,
6153 CTI_CONST_STRING_TYPE,
6155 CTI_MAX
6156 };
6160 #define signed_size_type_node c_global_trees[CTI_SIGNED_SIZE_TYPE]
6161 #define string_type_node c_global_trees[CTI_STRING_TYPE]
6162 #define const_string_type_node c_global_trees[CTI_CONST_STRING_TYPE]
6164 /* ??? In addition some attribute handlers, we currently don't support a
6165 (small) number of builtin-types, which in turns inhibits support for a
6166 number of builtin functions. */
6167 #define wint_type_node void_type_node
6168 #define intmax_type_node void_type_node
6169 #define uintmax_type_node void_type_node
6171 /* Used to help initialize the builtin-types.def table. When a type of
6172 the correct size doesn't exist, use error_mark_node instead of NULL.
6173 The later results in segfaults even when a decl using the type doesn't
6174 get invoked. */
6176 static tree
6178 {
6181 }
6183 /* Build/push the elementary type decls that builtin functions/types
6184 will need. */
6186 static void
6188 {
6193 const_string_type_node
6196 }
6198 /* ----------------------------------------------------------------------- *
6199 * BUILTIN FUNCTION TYPES *
6200 * ----------------------------------------------------------------------- */
6202 /* Now, builtin function types per se. */
6204 enum c_builtin_type
6205 {
6206 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
6207 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
6208 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
6209 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
6210 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
6211 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
6212 #define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME,
6213 #define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
6214 ARG6) NAME,
6215 #define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
6216 ARG6, ARG7) NAME,
6217 #define DEF_FUNCTION_TYPE_8(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
6218 ARG6, ARG7, ARG8) NAME,
6219 #define DEF_FUNCTION_TYPE_9(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
6220 ARG6, ARG7, ARG8, ARG9) NAME,
6221 #define DEF_FUNCTION_TYPE_10(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
6222 ARG6, ARG7, ARG8, ARG9, ARG10) NAME,
6223 #define DEF_FUNCTION_TYPE_11(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
6224 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) NAME,
6225 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
6226 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
6227 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
6228 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
6229 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
6230 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
6231 NAME,
6232 #define DEF_FUNCTION_TYPE_VAR_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
6233 ARG6) NAME,
6234 #define DEF_FUNCTION_TYPE_VAR_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
6235 ARG6, ARG7) NAME,
6236 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
6239 #undef DEF_PRIMITIVE_TYPE
6240 #undef DEF_FUNCTION_TYPE_0
6241 #undef DEF_FUNCTION_TYPE_1
6242 #undef DEF_FUNCTION_TYPE_2
6243 #undef DEF_FUNCTION_TYPE_3
6244 #undef DEF_FUNCTION_TYPE_4
6245 #undef DEF_FUNCTION_TYPE_5
6246 #undef DEF_FUNCTION_TYPE_6
6247 #undef DEF_FUNCTION_TYPE_7
6248 #undef DEF_FUNCTION_TYPE_8
6249 #undef DEF_FUNCTION_TYPE_9
6250 #undef DEF_FUNCTION_TYPE_10
6251 #undef DEF_FUNCTION_TYPE_11
6252 #undef DEF_FUNCTION_TYPE_VAR_0
6253 #undef DEF_FUNCTION_TYPE_VAR_1
6254 #undef DEF_FUNCTION_TYPE_VAR_2
6255 #undef DEF_FUNCTION_TYPE_VAR_3
6256 #undef DEF_FUNCTION_TYPE_VAR_4
6257 #undef DEF_FUNCTION_TYPE_VAR_5
6258 #undef DEF_FUNCTION_TYPE_VAR_6
6259 #undef DEF_FUNCTION_TYPE_VAR_7
6260 #undef DEF_POINTER_TYPE
6261 BT_LAST
6262 };
6266 /* A temporary array used in communication with def_fn_type. */
6269 /* A helper function for install_builtin_types. Build function type
6270 for DEF with return type RET and N arguments. If VAR is true, then the
6271 function should be variadic after those N arguments.
6273 Takes special care not to ICE if any of the types involved are
6274 error_mark_node, which indicates that said type is not in fact available
6275 (see builtin_type_for_size). In which case the function type as a whole
6276 should be error_mark_node. */
6278 static void
6280 {
6281 tree t;
6288 {
6294 }
6301 else
6304 egress:
6307 }
6309 /* Build the builtin function types and install them in the builtin_types
6310 array for later use in builtin function decls. */
6312 static void
6314 {
6315 tree va_list_ref_type_node;
6316 tree va_list_arg_type_node;
6319 {
6322 }
6323 else
6324 {
6327 }
6329 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
6330 builtin_types[ENUM] = VALUE;
6331 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \
6332 def_fn_type (ENUM, RETURN, 0, 0);
6333 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \
6334 def_fn_type (ENUM, RETURN, 0, 1, ARG1);
6335 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \
6336 def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2);
6337 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
6338 def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3);
6339 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
6340 def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4);
6341 #define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
6342 def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
6343 #define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
6344 ARG6) \
6345 def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
6346 #define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
6347 ARG6, ARG7) \
6348 def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
6349 #define DEF_FUNCTION_TYPE_8(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
6350 ARG6, ARG7, ARG8) \
6351 def_fn_type (ENUM, RETURN, 0, 8, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
6352 ARG7, ARG8);
6353 #define DEF_FUNCTION_TYPE_9(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
6354 ARG6, ARG7, ARG8, ARG9) \
6355 def_fn_type (ENUM, RETURN, 0, 9, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
6356 ARG7, ARG8, ARG9);
6357 #define DEF_FUNCTION_TYPE_10(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5,\
6358 ARG6, ARG7, ARG8, ARG9, ARG10) \
6359 def_fn_type (ENUM, RETURN, 0, 10, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
6360 ARG7, ARG8, ARG9, ARG10);
6361 #define DEF_FUNCTION_TYPE_11(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5,\
6362 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) \
6363 def_fn_type (ENUM, RETURN, 0, 11, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
6364 ARG7, ARG8, ARG9, ARG10, ARG11);
6365 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \
6366 def_fn_type (ENUM, RETURN, 1, 0);
6367 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \
6368 def_fn_type (ENUM, RETURN, 1, 1, ARG1);
6369 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \
6370 def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2);
6371 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
6372 def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3);
6373 #define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
6374 def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
6375 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
6376 def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
6377 #define DEF_FUNCTION_TYPE_VAR_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
6378 ARG6) \
6379 def_fn_type (ENUM, RETURN, 1, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
6380 #define DEF_FUNCTION_TYPE_VAR_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
6381 ARG6, ARG7) \
6382 def_fn_type (ENUM, RETURN, 1, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
6383 #define DEF_POINTER_TYPE(ENUM, TYPE) \
6384 builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
6389 #undef DEF_PRIMITIVE_TYPE
6390 #undef DEF_FUNCTION_TYPE_0
6391 #undef DEF_FUNCTION_TYPE_1
6392 #undef DEF_FUNCTION_TYPE_2
6393 #undef DEF_FUNCTION_TYPE_3
6394 #undef DEF_FUNCTION_TYPE_4
6395 #undef DEF_FUNCTION_TYPE_5
6396 #undef DEF_FUNCTION_TYPE_6
6397 #undef DEF_FUNCTION_TYPE_7
6398 #undef DEF_FUNCTION_TYPE_8
6399 #undef DEF_FUNCTION_TYPE_9
6400 #undef DEF_FUNCTION_TYPE_10
6401 #undef DEF_FUNCTION_TYPE_11
6402 #undef DEF_FUNCTION_TYPE_VAR_0
6403 #undef DEF_FUNCTION_TYPE_VAR_1
6404 #undef DEF_FUNCTION_TYPE_VAR_2
6405 #undef DEF_FUNCTION_TYPE_VAR_3
6406 #undef DEF_FUNCTION_TYPE_VAR_4
6407 #undef DEF_FUNCTION_TYPE_VAR_5
6408 #undef DEF_FUNCTION_TYPE_VAR_6
6409 #undef DEF_FUNCTION_TYPE_VAR_7
6410 #undef DEF_POINTER_TYPE
6412 }
6414 /* ----------------------------------------------------------------------- *
6415 * BUILTIN ATTRIBUTES *
6416 * ----------------------------------------------------------------------- */
6418 enum built_in_attribute
6419 {
6420 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
6421 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
6422 #define DEF_ATTR_STRING(ENUM, VALUE) ENUM,
6423 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
6424 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
6426 #undef DEF_ATTR_NULL_TREE
6427 #undef DEF_ATTR_INT
6428 #undef DEF_ATTR_STRING
6429 #undef DEF_ATTR_IDENT
6430 #undef DEF_ATTR_TREE_LIST
6431 ATTR_LAST
6432 };
6436 static void
6438 {
6439 /* Fill in the built_in_attributes array. */
6440 #define DEF_ATTR_NULL_TREE(ENUM) \
6441 built_in_attributes[(int) ENUM] = NULL_TREE;
6442 #define DEF_ATTR_INT(ENUM, VALUE) \
6443 built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
6444 #define DEF_ATTR_STRING(ENUM, VALUE) \
6445 built_in_attributes[(int) ENUM] = build_string (strlen (VALUE), VALUE);
6446 #define DEF_ATTR_IDENT(ENUM, STRING) \
6447 built_in_attributes[(int) ENUM] = get_identifier (STRING);
6448 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
6449 built_in_attributes[(int) ENUM] \
6450 = tree_cons (built_in_attributes[(int) PURPOSE], \
6451 built_in_attributes[(int) VALUE], \
6452 built_in_attributes[(int) CHAIN]);
6454 #undef DEF_ATTR_NULL_TREE
6455 #undef DEF_ATTR_INT
6456 #undef DEF_ATTR_STRING
6457 #undef DEF_ATTR_IDENT
6458 #undef DEF_ATTR_TREE_LIST
6459 }
6461 /* Handle a "const" attribute; arguments as in
6462 struct attribute_spec.handler. */
6464 static tree
6468 {
6471 else
6475 }
6477 /* Handle a "nothrow" attribute; arguments as in
6478 struct attribute_spec.handler. */
6480 static tree
6484 {
6487 else
6491 }
6493 /* Handle a "expected_throw" attribute; arguments as in
6494 struct attribute_spec.handler. */
6496 static tree
6500 {
6503 else
6507 }
6509 /* Handle a "pure" attribute; arguments as in
6510 struct attribute_spec.handler. */
6512 static tree
6515 {
6518 /* TODO: support types. */
6519 else
6520 {
6524 }
6527 }
6529 /* Handle a "no vops" attribute; arguments as in
6530 struct attribute_spec.handler. */
6532 static tree
6536 {
6540 }
6542 /* Helper for nonnull attribute handling; fetch the operand number
6543 from the attribute argument list. */
6545 static bool
6547 {
6548 /* Verify the arg number is a constant. */
6554 }
6556 /* Handle the "nonnull" attribute. */
6557 static tree
6561 {
6565 /* If no arguments are specified, all pointer arguments should be
6566 non-null. Verify a full prototype is given so that the arguments
6567 will have the correct types when we actually check them later.
6568 Avoid diagnosing type-generic built-ins since those have no
6569 prototype. */
6571 {
6575 {
6579 }
6581 }
6583 /* Argument list specified. Verify that each argument number references
6584 a pointer argument. */
6586 {
6590 {
6595 }
6598 {
6599 function_args_iterator iter;
6600 tree argument;
6604 {
6608 }
6612 {
6618 }
6621 {
6627 }
6628 }
6629 }
6632 }
6634 /* Handle a "sentinel" attribute. */
6636 static tree
6639 {
6641 {
6646 }
6647 else
6648 {
6650 {
6655 }
6656 }
6659 {
6663 {
6666 }
6667 else
6668 {
6670 {
6673 }
6674 }
6675 }
6678 }
6680 /* Handle a "noreturn" attribute; arguments as in
6681 struct attribute_spec.handler. */
6683 static tree
6686 {
6689 /* See FIXME comment in c_common_attribute_table. */
6695 = build_pointer_type
6697 else
6698 {
6702 }
6705 }
6707 /* Handle a "stack_protect" attribute; arguments as in
6708 struct attribute_spec.handler. */
6710 static tree
6713 {
6715 {
6718 }
6721 }
6723 /* Handle a "no_stack_protector" attribute; arguments as in
6724 struct attribute_spec.handler. */
6726 static tree
6729 {
6731 {
6734 }
6737 }
6739 /* Handle a "strub" attribute; arguments as in
6740 struct attribute_spec.handler. */
6742 static tree
6744 {
6747 }
6749 /* Handle a "noinline" attribute; arguments as in
6750 struct attribute_spec.handler. */
6752 static tree
6756 {
6758 {
6760 {
6764 }
6765 else
6767 }
6768 else
6769 {
6772 }
6775 }
6777 /* Handle a "noclone" attribute; arguments as in
6778 struct attribute_spec.handler. */
6780 static tree
6784 {
6786 {
6789 }
6792 }
6794 /* Handle a "no_icf" attribute; arguments as in
6795 struct attribute_spec.handler. */
6797 static tree
6801 {
6803 {
6806 }
6809 }
6811 /* Handle a "noipa" attribute; arguments as in
6812 struct attribute_spec.handler. */
6814 static tree
6816 {
6818 {
6821 }
6824 }
6826 /* Handle a "leaf" attribute; arguments as in
6827 struct attribute_spec.handler. */
6829 static tree
6832 {
6834 {
6837 }
6839 {
6842 }
6845 }
6847 /* Handle a "always_inline" attribute; arguments as in
6848 struct attribute_spec.handler. */
6850 static tree
6853 {
6855 {
6856 /* Set the attribute and mark it for disregarding inline limits. */
6858 }
6859 else
6860 {
6863 }
6866 }
6868 /* Handle a "malloc" attribute; arguments as in
6869 struct attribute_spec.handler. */
6871 static tree
6874 {
6878 else
6879 {
6883 }
6886 }
6888 /* Fake handler for attributes we don't properly support. */
6890 tree
6896 {
6898 }
6900 /* Handle a "type_generic" attribute. */
6902 static tree
6906 {
6907 /* Ensure we have a function type. */
6910 /* Ensure we have a variadic function. */
6914 }
6916 /* Handle a "flatten" attribute; arguments as in
6917 struct attribute_spec.handler. */
6919 static tree
6921 tree args ATTRIBUTE_UNUSED,
6923 {
6925 /* Do nothing else, just set the attribute. We'll get at
6926 it later with lookup_attribute. */
6927 ;
6928 else
6929 {
6932 }
6935 }
6937 /* Handle a "used" attribute; arguments as in
6938 struct attribute_spec.handler. */
6940 static tree
6943 {
6949 {
6954 }
6955 else
6956 {
6959 }
6962 }
6964 /* Handle a "cold" and attribute; arguments as in
6965 struct attribute_spec.handler. */
6967 static tree
6970 {
6973 {
6974 /* Attribute cold processing is done later with lookup_attribute. */
6975 }
6976 else
6977 {
6980 }
6983 }
6985 /* Handle a "hot" and attribute; arguments as in
6986 struct attribute_spec.handler. */
6988 static tree
6991 {
6994 {
6995 /* Attribute hot processing is done later with lookup_attribute. */
6996 }
6997 else
6998 {
7001 }
7004 }
7006 /* Handle a "simd" attribute. */
7008 static tree
7010 {
7012 {
7016 {
7020 {
7024 }
7028 OMP_CLAUSE_NOTINBRANCH);
7031 OMP_CLAUSE_INBRANCH);
7032 else
7033 {
7038 }
7039 }
7044 }
7045 else
7046 {
7049 }
7052 }
7054 /* Handle a "target" attribute. */
7056 static tree
7059 {
7060 /* Ensure we have a function type. */
7062 {
7065 }
7067 {
7071 }
7075 /* Check that there's no empty string in values of the attribute. */
7077 {
7082 {
7085 }
7086 }
7089 }
7091 /* Handle a "target_clones" attribute. */
7093 static tree
7096 {
7097 /* Ensure we have a function type. */
7099 {
7101 {
7105 }
7107 {
7111 }
7112 else
7113 /* Do not inline functions with multiple clone targets. */
7115 }
7116 else
7117 {
7120 }
7122 }
7124 /* Handle a "vector_size" attribute; arguments as in
7125 struct attribute_spec.handler. */
7127 static tree
7130 {
7132 tree vector_type;
7136 /* We need to provide for vector pointers, vector arrays, and
7137 functions returning vectors. For example:
7139 __attribute__((vector_size(16))) short *foo;
7141 In this case, the mode is SI, but the type being modified is
7142 HI, so we need to look further. */
7152 /* Build back pointers if needed. */
7156 }
7158 /* Handle a "vector_type" attribute; arguments as in
7159 struct attribute_spec.handler. */
7161 static tree
7164 {
7166 tree vector_type;
7171 {
7175 }
7185 }
7187 /* Handle a "zero_call_used_regs" attribute; arguments as in
7188 struct attribute_spec.handler. */
7190 static tree
7194 {
7199 {
7204 }
7206 /* pragma Machine_Attribute turns string arguments into identifiers.
7207 Reverse it. */
7213 {
7218 }
7224 {
7227 }
7230 {
7235 }
7238 }
7240 /* ----------------------------------------------------------------------- *
7241 * BUILTIN FUNCTIONS *
7242 * ----------------------------------------------------------------------- */
7244 /* Worker for DEF_BUILTIN. Possibly define a builtin function with one or two
7245 names. Does not declare a non-__builtin_ function if flag_no_builtin, or
7246 if nonansi_p and flag_no_nonansi_builtin. */
7248 static void
7256 {
7257 tree decl;
7260 /* Preserve an already installed decl. It most likely was setup in advance
7261 (e.g. as part of the internal builtins) for specific reasons. */
7274 fnattrs);
7276 /* ??? This is normally further controlled by command-line options
7277 like -fno-builtin, but we don't have them for Ada. */
7282 }
7289 /* Install what the common builtins.def offers plus our local additions.
7291 Note that ada-builtins.def is included first so that locally redefined
7292 built-in functions take precedence over the commonly defined ones. */
7294 static void
7296 {
7297 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
7298 NONANSI_P, ATTRS, IMPLICIT, COND) \
7299 if (NAME && COND) \
7300 def_builtin_1 (ENUM, NAME, CLASS, \
7301 builtin_types[(int) TYPE], \
7302 builtin_types[(int) LIBTYPE], \
7303 BOTH_P, FALLBACK_P, NONANSI_P, \
7304 built_in_attributes[(int) ATTRS], IMPLICIT);
7305 #define DEF_ADA_BUILTIN(ENUM, NAME, TYPE, ATTRS) \
7307 false, false, false, ATTRS, true, true)
7310 }
7312 /* ----------------------------------------------------------------------- *
7313 * BUILTIN FUNCTIONS *
7314 * ----------------------------------------------------------------------- */
7316 /* Install the builtin functions we might need. */
7318 void
7320 {
7325 /* Install builtins used by generic middle-end pieces first. Some of these
7326 know about internal specificities and control attributes accordingly, for
7327 instance __builtin_alloca vs no-throw and -fstack-check. We will ignore
7328 the generic definition from builtins.def. */
7331 /* Now, install the target specific builtins, such as the AltiVec family on
7332 ppc, and the common set as exposed by builtins.def. */
7335 }