| blob | 99453821e419eac433298f940a2b46ed94d309b6 |
1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * U T I L S *
6 * *
7 * C Implementation File *
8 * *
9 * Copyright (C) 1992-2017, Free Software Foundation, Inc. *
10 * *
11 * GNAT is free software; you can redistribute it and/or modify it under *
12 * terms of the GNU General Public License as published by the Free Soft- *
13 * ware Foundation; either version 3, or (at your option) any later ver- *
14 * sion. GNAT is distributed in the hope that it will be useful, but WITH- *
15 * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY *
16 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License *
17 * for more details. You should have received a copy of the GNU General *
18 * Public License along with GCC; see the file COPYING3. If not see *
19 * <http://www.gnu.org/licenses/>. *
20 * *
21 * GNAT was originally developed by the GNAT team at New York University. *
22 * Extensive contributions were provided by Ada Core Technologies Inc. *
23 * *
24 ****************************************************************************/
60 /* If nonzero, pretend we are allocating at global level. */
63 /* The default alignment of "double" floating-point types, i.e. floating
64 point types whose size is equal to 64 bits, or 0 if this alignment is
65 not specifically capped. */
68 /* The default alignment of "double" or larger scalar types, i.e. scalar
69 types whose size is greater or equal to 64 bits, or 0 if this alignment
70 is not specifically capped. */
73 /* True if floating-point arithmetics may use wider intermediate results. */
76 /* Tree nodes for the various types and decls we create. */
79 /* Functions to call for each of the possible raise reasons. */
82 /* Likewise, but with extra info for each of the possible raise reasons. */
85 /* Forward declarations for handlers of attributes. */
102 /* Fake handler for attributes we don't properly support, typically because
103 they'd require dragging a lot of the common-c front-end circuitry. */
106 /* Table of machine-independent internal attributes for Ada. We support
107 this minimal set of attributes to accommodate the needs of builtins. */
109 {
110 /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler,
111 affects_type_identity } */
145 /* ??? format and format_arg are heavy and not supported, which actually
146 prevents support for stdio builtins, which we however declare as part
147 of the common builtins.def contents. */
152 };
154 /* Associates a GNAT tree node to a GCC tree node. It is used in
155 `save_gnu_tree', `get_gnu_tree' and `present_gnu_tree'. See documentation
156 of `save_gnu_tree' for more info. */
159 #define GET_GNU_TREE(GNAT_ENTITY) \
160 associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id]
162 #define SET_GNU_TREE(GNAT_ENTITY,VAL) \
163 associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] = (VAL)
165 #define PRESENT_GNU_TREE(GNAT_ENTITY) \
166 (associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] != NULL_TREE)
168 /* Associates a GNAT entity to a GCC tree node used as a dummy, if any. */
171 #define GET_DUMMY_NODE(GNAT_ENTITY) \
172 dummy_node_table[(GNAT_ENTITY) - First_Node_Id]
174 #define SET_DUMMY_NODE(GNAT_ENTITY,VAL) \
175 dummy_node_table[(GNAT_ENTITY) - First_Node_Id] = (VAL)
177 #define PRESENT_DUMMY_NODE(GNAT_ENTITY) \
178 (dummy_node_table[(GNAT_ENTITY) - First_Node_Id] != NULL_TREE)
180 /* This variable keeps a table for types for each precision so that we only
181 allocate each of them once. Signed and unsigned types are kept separate.
183 Note that these types are only used when fold-const requests something
184 special. Perhaps we should NOT share these types; we'll see how it
185 goes later. */
188 /* Likewise for float types, but record these by mode. */
191 /* For each binding contour we allocate a binding_level structure to indicate
192 the binding depth. */
195 /* The binding level containing this one (the enclosing binding level). */
197 /* The BLOCK node for this level. */
198 tree block;
199 /* If nonzero, the setjmp buffer that needs to be updated for any
200 variable-sized definition within this context. */
201 tree jmpbuf_decl;
202 };
204 /* The binding level currently in effect. */
207 /* A chain of gnat_binding_level structures awaiting reuse. */
210 /* The context to be used for global declarations. */
213 /* An array of global declarations. */
216 /* An array of builtin function declarations. */
219 /* A chain of unused BLOCK nodes. */
222 /* A hash table of padded types. It is modelled on the generic type
223 hash table in tree.c, which must thus be used as a reference. */
227 tree type;
228 };
231 {
235 static int
237 {
239 }
240 };
253 /* Linked list used as a queue to defer the initialization of the DECL_CONTEXT
254 of ..._DECL nodes and of the TYPE_CONTEXT of ..._TYPE nodes. */
255 struct deferred_decl_context_node
256 {
257 /* The ..._DECL node to work on. */
258 tree decl;
260 /* The corresponding entity's Scope. */
261 Entity_Id gnat_scope;
263 /* The value of force_global when DECL was pushed. */
266 /* The list of ..._TYPE nodes to propagate the context to. */
269 /* The next queue item. */
271 };
275 /* Defer the initialization of DECL's DECL_CONTEXT attribute, scheduling to
276 feed it with the elaboration of GNAT_SCOPE. */
280 /* Defer the initialization of TYPE's TYPE_CONTEXT attribute, scheduling to
281 feed it with the DECL_CONTEXT computed as part of N as soon as it is
282 computed. */
284 tree type);
285 \f
286 /* Initialize data structures of the utils.c module. */
288 void
290 {
291 /* Initialize the association of GNAT nodes to GCC trees. */
294 /* Initialize the association of GNAT nodes to GCC trees as dummies. */
297 /* Initialize the hash table of padded types. */
299 }
301 /* Destroy data structures of the utils.c module. */
303 void
305 {
306 /* Destroy the association of GNAT nodes to GCC trees. */
310 /* Destroy the association of GNAT nodes to GCC trees as dummies. */
314 /* Destroy the hash table of padded types. */
317 }
318 \f
319 /* GNAT_ENTITY is a GNAT tree node for an entity. Associate GNU_DECL, a GCC
320 tree node, with GNAT_ENTITY. If GNU_DECL is not a ..._DECL node, abort.
321 If NO_CHECK is true, the latter check is suppressed.
323 If GNU_DECL is zero, reset a previous association. */
325 void
327 {
328 /* Check that GNAT_ENTITY is not already defined and that it is being set
329 to something which is a decl. If that is not the case, this usually
330 means GNAT_ENTITY is defined twice, but occasionally is due to some
331 Gigi problem. */
337 }
339 /* GNAT_ENTITY is a GNAT tree node for an entity. Return the GCC tree node
340 that was associated with it. If there is no such tree node, abort.
342 In some cases, such as delayed elaboration or expressions that need to
343 be elaborated only once, GNAT_ENTITY is really not an entity. */
345 tree
347 {
350 }
352 /* Return nonzero if a GCC tree has been associated with GNAT_ENTITY. */
354 bool
356 {
358 }
359 \f
360 /* Make a dummy type corresponding to GNAT_TYPE. */
362 tree
364 {
368 /* If there was no equivalent type (can only happen when just annotating
369 types) or underlying type, go back to the original type. */
373 /* If it there already a dummy type, use that one. Else make one. */
377 /* If this is a record, make a RECORD_TYPE or UNION_TYPE; else make
378 an ENUMERAL_TYPE. */
391 /* Create a debug type so that debug info consumers only see an unspecified
392 type. */
394 {
400 }
403 }
405 /* Return the dummy type that was made for GNAT_TYPE, if any. */
407 tree
409 {
411 }
413 /* Build dummy fat and thin pointer types whose designated type is specified
414 by GNAT_DESIG_TYPE/GNU_DESIG_TYPE and attach them to the latter. */
416 void
418 {
433 /* Build a stub DECL to trigger the special processing for fat pointer types
434 in gnat_pushdecl. */
437 gnu_fat_type);
445 /* Suppress debug info until after the type is completed. */
455 }
456 \f
457 /* Return true if we are in the global binding level. */
459 bool
461 {
463 }
465 /* Enter a new binding level. */
467 void
469 {
472 /* Reuse a struct for this binding level, if there is one. */
474 {
477 }
478 else
481 /* Use a free BLOCK, if any; otherwise, allocate one. */
483 {
487 }
488 else
491 /* Point the BLOCK we just made to its parent. */
499 /* Add this level to the front of the chain (stack) of active levels. */
503 }
505 /* Set SUPERCONTEXT of the BLOCK for the current binding level to FNDECL
506 and point FNDECL to this BLOCK. */
508 void
510 {
514 }
516 /* Set the jmpbuf_decl for the current binding level to DECL. */
518 void
520 {
522 }
524 /* Get the jmpbuf_decl, if any, for the current binding level. */
526 tree
528 {
530 }
532 /* Exit a binding level. Set any BLOCK into the current code group. */
534 void
536 {
543 /* If this is a function-level BLOCK don't do anything. Otherwise, if there
544 are no variables free the block and merge its subblocks into those of its
545 parent block. Otherwise, add it to the list of its parent. */
547 ;
549 {
555 }
556 else
557 {
562 }
564 /* Free this binding structure. */
568 }
570 /* Exit a binding level and discard the associated BLOCK. */
572 void
574 {
581 /* Free this binding structure. */
585 }
586 \f
587 /* Set the context of TYPE and its parallel types (if any) to CONTEXT. */
589 static void
591 {
597 {
600 /* Give a context to the parallel types and their stub decl, if any.
601 Some parallel types seems to be present in multiple parallel type
602 chains, so don't mess with their context if they already have one. */
604 {
608 }
611 }
612 }
614 /* Return the innermost scope, starting at GNAT_NODE, we are be interested in
615 the debug info, or Empty if there is no such scope. If not NULL, set
616 IS_SUBPROGRAM to whether the returned entity is a subprogram. */
618 Entity_Id
620 {
621 Entity_Id gnat_entity;
629 else
633 {
635 {
641 /* If the scope is a subprogram, then just rely on
642 current_function_decl, so that we don't have to defer
643 anything. This is needed because other places rely on the
644 validity of the DECL_CONTEXT attribute of FUNCTION_DECL nodes. */
654 /* By default, we are not interested in this particular scope: go to
655 the outer one. */
657 }
660 }
663 }
665 /* If N is NULL, set TYPE's context to CONTEXT. Defer this to the processing
666 of N otherwise. */
668 static void
671 {
674 else
676 }
678 /* Return global_context, but create it first if need be. */
680 static tree
682 {
684 {
685 global_context
688 }
691 }
693 /* Record DECL as belonging to the current lexical scope and use GNAT_NODE
694 for location information and flag propagation. */
696 void
698 {
702 /* If explicitely asked to make DECL global or if it's an imported nested
703 object, short-circuit the regular Scope-based context computation. */
705 {
706 /* Rely on the GNAT scope, or fallback to the current_function_decl if
707 the GNAT scope reached the global scope, if it reached a subprogram
708 or the declaration is a subprogram or a variable (for them we skip
709 intermediate context types because the subprogram body elaboration
710 machinery and the inliner both expect a subprogram context).
712 Falling back to current_function_decl is necessary for implicit
713 subprograms created by gigi, such as the elaboration subprograms. */
715 const Entity_Id gnat_scope
719 && !context_is_subprogram
722 /* Always assume the scope has not been elaborated, thus defer the
723 context propagation to the time its elaboration will be
724 available. */
725 deferred_decl_context
728 /* External declarations (when force_global > 0) may not be in a
729 local context. */
732 }
734 /* If either we are forced to be in global mode or if both the GNAT scope and
735 the current_function_decl did not help in determining the context, use the
736 global scope. */
740 /* Functions imported in another function are not really nested.
741 For really nested functions mark them initially as needing
742 a static chain for uses of that flag before unnesting;
743 lower_nested_functions will then recompute it. */
746 && context
756 /* Set the location of DECL and emit a declaration for it. */
762 /* Put the declaration on the list. The list of declarations is in reverse
763 order. The list will be reversed later. Put global declarations in the
764 globals list and local ones in the current block. But skip TYPE_DECLs
765 for UNCONSTRAINED_ARRAY_TYPE in both cases, as they will cause trouble
766 with the debugger and aren't needed anyway. */
769 {
770 /* External declarations must go to the binding level they belong to.
771 This will make corresponding imported entities are available in the
772 debugger at the proper time. */
779 else
780 {
783 }
784 }
786 /* For the declaration of a type, set its name either if it isn't already
787 set or if the previous type name was not derived from a source name.
788 We'd rather have the type named with a real name and all the pointer
789 types to the same object have the same node, except when the names are
790 both derived from source names. */
792 {
795 /* Array and pointer types aren't tagged types in the C sense so we need
796 to generate a typedef in DWARF for them and make sure it is preserved,
797 unless the type is artificial. */
801 ;
802 /* For array and pointer types, create the DECL_ORIGINAL_TYPE that will
803 generate the typedef in DWARF. Also do that for fat pointer types
804 because, even though they are tagged types in the C sense, they are
805 still XUP types attached to the base array type at this point. */
810 {
815 deferred_decl_context);
821 else
823 /* Array types need to have a name so that they can be related to
824 their GNAT encodings. */
828 }
832 ;
833 else
836 /* Propagate the name to all the variants, this is needed for the type
837 qualifiers machinery to work properly (see check_qualified_type).
838 Also propagate the context to them. Note that it will be propagated
839 to all parallel types too thanks to gnat_set_type_context. */
842 /* ??? Because of the previous kludge, we can have variants of fat
843 pointer types with different names. */
847 {
851 deferred_decl_context);
852 }
853 }
854 }
855 \f
856 /* Create a record type that contains a SIZE bytes long field of TYPE with a
857 starting bit position so that it is aligned to ALIGN bits, and leaving at
858 least ROOM bytes free before the field. BASE_ALIGN is the alignment the
859 record is guaranteed to get. GNAT_NODE is used for the position of the
860 associated TYPE_DECL. */
862 tree
865 {
866 /* We will be crafting a record type with one field at a position set to be
867 the next multiple of ALIGN past record'address + room bytes. We use a
868 record placeholder to express record'address. */
872 tree record_addr_st
875 /* The diagram below summarizes the shape of what we manipulate:
877 <--------- pos ---------->
878 { +------------+-------------+-----------------+
879 record =>{ |############| ... | field (type) |
880 { +------------+-------------+-----------------+
881 |<-- room -->|<- voffset ->|<---- size ----->|
882 o o
883 | |
884 record_addr vblock_addr
886 Every length is in sizetype bytes there, except "pos" which has to be
887 set as a bit position in the GCC tree for the record. */
897 /* Compute VOFFSET and then POS. The next byte position multiple of some
898 alignment after some address is obtained by "and"ing the alignment minus
899 1 with the two's complement of the address. */
904 /* POS = (ROOM + VOFFSET) * BIT_PER_UNIT, in bitsizetype. */
908 bitsize_unit_node);
910 /* Craft the GCC record representation. We exceptionally do everything
911 manually here because 1) our generic circuitry is not quite ready to
912 handle the complex position/size expressions we are setting up, 2) we
913 have a strong simplifying factor at hand: we know the maximum possible
914 value of voffset, and 3) we have to set/reset at least the sizes in
915 accordance with this maximum value anyway, as we need them to convey
916 what should be "alloc"ated for this type.
918 Use -1 as the 'addressable' indication for the field to prevent the
919 creation of a bitfield. We don't need one, it would have damaging
920 consequences on the alignment computation, and create_field_decl would
921 make one without this special argument, for instance because of the
922 complex position expression. */
933 bitsize_unit_node),
942 /* Declare it now since it will never be declared otherwise. This is
943 necessary to ensure that its subtrees are properly marked. */
947 }
949 /* TYPE is a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE that is being used
950 as the field type of a packed record if IN_RECORD is true, or as the
951 component type of a packed array if IN_RECORD is false. See if we can
952 rewrite it either as a type that has non-BLKmode, which we can pack
953 tighter in the packed record case, or as a smaller type with at most
954 MAX_ALIGN alignment if the value is non-zero. If so, return the new
955 type; if not, return the original type. */
957 tree
959 {
965 /* No point in doing anything if the size is zero. */
971 /* Copy the name and flags from the old type to that of the new.
972 Note that we rely on the pointer equality created here for
973 TYPE_NAME to look through conversions in various places. */
981 /* If we are in a record and have a small size, set the alignment to
982 try for an integral mode. Otherwise set it to try for a smaller
983 type with BLKmode. */
985 {
989 }
990 else
991 {
992 /* Do not try to shrink the size if the RM size is not constant. */
997 /* Round the RM size up to a unit boundary to get the minimal size
998 for a BLKmode record. Give up if it's already the size and we
999 don't need to lower the alignment. */
1009 }
1013 /* Now copy the fields, keeping the position and size as we don't want
1014 to change the layout by propagating the packedness downwards. */
1017 {
1026 /* However, for the last field in a not already packed record type
1027 that is of an aggregate type, we need to use the RM size in the
1028 packable version of the record type, see finish_record_type. */
1036 else
1039 new_field
1052 }
1060 /* If this is a padding record, we never want to make the size smaller
1061 than what was specified. For QUAL_UNION_TYPE, also copy the size. */
1063 {
1067 }
1068 else
1069 {
1072 }
1079 /* Try harder to get a packable type if necessary, for example
1080 in case the record itself contains a BLKmode field. */
1086 /* If neither mode nor size nor alignment shrunk, return the old type. */
1091 }
1093 /* Return true if TYPE has an unsigned representation. This needs to be used
1094 when the representation of types whose precision is not equal to their size
1095 is manipulated based on the RM size. */
1099 {
1100 /* This is the common case. */
1104 /* See the E_Signed_Integer_Subtype case of gnat_to_gnu_entity. */
1110 }
1112 /* Given a type TYPE, return a new type whose size is appropriate for SIZE.
1113 If TYPE is the best type, return it. Otherwise, make a new type. We
1114 only support new integral and pointer types. FOR_BIASED is true if
1115 we are making a biased type. */
1117 tree
1119 {
1122 tree new_type;
1124 /* If size indicates an error, just return TYPE to avoid propagating
1125 the error. Likewise if it's too large to represent. */
1132 {
1139 /* Integer types with precision 0 are forbidden. */
1143 /* Only do something if the type isn't a packed array type and doesn't
1144 already have the proper size and the size isn't too large. */
1152 /* The type should be an unsigned type if the original type is unsigned
1153 or if the lower bound is constant and non-negative or if the type is
1154 biased, see E_Signed_Integer_Subtype case of gnat_to_gnu_entity. */
1157 else
1162 /* Copy the name to show that it's essentially the same type and
1163 not a subrange type. */
1170 /* Do something if this is a fat pointer, in which case we
1171 may need to return the thin pointer. */
1173 {
1174 scalar_int_mode p_mode;
1178 return
1179 build_pointer_type_for_mode
1182 }
1186 /* Only do something if this is a thin pointer, in which case we
1187 may need to return the fat pointer. */
1189 return
1195 }
1198 }
1200 /* Return true iff the padded types are equivalent. */
1202 bool
1204 {
1213 /* We consider that the padded types are equivalent if they pad the same type
1214 and have the same size, alignment, RM size and storage order. Taking the
1215 mode into account is redundant since it is determined by the others. */
1216 return
1222 }
1224 /* Look up the padded TYPE in the hash table and return its canonical version
1225 if it exists; otherwise, insert it into the hash table. */
1227 static tree
1229 {
1230 hashval_t hashcode;
1233 hashcode
1250 }
1252 /* Ensure that TYPE has SIZE and ALIGN. Make and return a new padded type
1253 if needed. We have already verified that SIZE and ALIGN are large enough.
1254 GNAT_ENTITY is used to name the resulting record and to issue a warning.
1255 IS_COMPONENT_TYPE is true if this is being done for the component type of
1256 an array. IS_USER_TYPE is true if the original type needs to be completed.
1257 DEFINITION is true if this type is being defined. SET_RM_SIZE is true if
1258 the RM size of the resulting type is to be set to SIZE too; in this case,
1259 the padded type is canonicalized before being returned. */
1261 tree
1265 {
1270 /* If TYPE is a padded type, see if it agrees with any size and alignment
1271 we were given. If so, return the original type. Otherwise, strip
1272 off the padding, since we will either be returning the inner type
1273 or repadding it. If no size or alignment is specified, use that of
1274 the original padded type. */
1276 {
1290 }
1292 /* If the size is either not being changed or is being made smaller (which
1293 is not done here and is only valid for bitfields anyway), show the size
1294 isn't changing. Likewise, clear the alignment if it isn't being
1295 changed. Then return if we aren't doing anything. */
1308 /* If requested, complete the original type and give it a name. */
1315 gnat_entity);
1317 /* We used to modify the record in place in some cases, but that could
1318 generate incorrect debugging information. So make a new record
1319 type and name. */
1323 /* ??? Padding types around packed array implementation types will be
1324 considered as root types in the array descriptor language hook (see
1325 gnat_get_array_descr_info). Give them the original packed array type
1326 name so that the one coming from sources appears in the debugging
1327 information. */
1340 bitsize_unit_node));
1342 /* If we are changing the alignment and the input type is a record with
1343 BLKmode and a small constant size, try to make a form that has an
1344 integral mode. This might allow the padding record to also have an
1345 integral mode, which will be much more efficient. There is no point
1346 in doing so if a size is specified unless it is also a small constant
1347 size and it is incorrect to do so if we cannot guarantee that the mode
1348 will be naturally aligned since the field must always be addressable.
1350 ??? This might not always be a win when done for a stand-alone object:
1351 since the nominal and the effective type of the object will now have
1352 different modes, a VIEW_CONVERT_EXPR will be required for converting
1353 between them and it might be hard to overcome afterwards, including
1354 at the RTL level when the stand-alone object is accessed as a whole. */
1362 && (!size
1365 {
1370 }
1372 /* Now create the field with the original size. */
1377 /* We will output additional debug info manually below. */
1383 /* Set the RM size if requested. */
1385 {
1386 tree canonical_pad_type;
1390 /* If the padded type is complete and has constant size, we canonicalize
1391 it by means of the hash table. This is consistent with the language
1392 semantics and ensures that gigi and the middle-end have a common view
1393 of these padded types. */
1396 {
1399 }
1400 }
1402 /* Unless debugging information isn't being written for the input type,
1403 write a record that shows what we are a subtype of and also make a
1404 variable that indicates our size, if still variable. */
1410 {
1414 /* A variable that holds the size is required even with no encoding since
1415 it will be referenced by debugging information attributes. At global
1416 level, we need a single variable across all translation units. */
1420 {
1421 /* Whether or not gnat_entity comes from source, this XVZ variable is
1422 is a compilation artifact. */
1423 size_unit
1429 }
1431 /* There is no need to show what we are a subtype of when outputting as
1432 few encodings as possible: regular debugging infomation makes this
1433 redundant. */
1435 {
1449 }
1450 }
1452 built:
1453 /* If a simple size was explicitly given, maybe issue a warning. */
1460 /* But don't do it if we are just annotating types and the type is tagged or
1461 concurrent, since these types aren't fully laid out in this mode. */
1463 {
1464 Entity_Id gnat_type
1465 = is_component_type
1470 }
1472 /* Take the original size as the maximum size of the input if there was an
1473 unconstrained record involved and round it up to the specified alignment,
1474 if one was specified, but only for aggregate types. */
1487 {
1490 /* For a packed array, post the message on the original array type. */
1501 /* Generate message only for entities that come from source, since
1502 if we have an entity created by expansion, the message will be
1503 generated for some other corresponding source entity. */
1505 {
1514 }
1515 }
1518 }
1520 /* Return a copy of the padded TYPE but with reverse storage order. */
1522 tree
1524 {
1528 {
1529 /* If the inner type is not scalar then the function does nothing. */
1533 }
1535 /* This is required for the canonicalization. */
1545 }
1546 \f
1547 /* Relate the alias sets of GNU_NEW_TYPE and GNU_OLD_TYPE according to OP.
1548 If this is a multi-dimensional array type, do this recursively.
1550 OP may be
1551 - ALIAS_SET_COPY: the new set is made a copy of the old one.
1552 - ALIAS_SET_SUPERSET: the new set is made a superset of the old one.
1553 - ALIAS_SET_SUBSET: the new set is made a subset of the old one. */
1555 void
1557 {
1558 /* Remove any padding from GNU_OLD_TYPE. It doesn't matter in the case
1559 of a one-dimensional array, since the padding has the same alias set
1560 as the field type, but if it's a multi-dimensional array, we need to
1561 see the inner types. */
1567 /* Unconstrained array types are deemed incomplete and would thus be given
1568 alias set 0. Retrieve the underlying array type. */
1570 gnu_old_type
1573 gnu_new_type
1582 {
1584 /* The alias set shouldn't be copied between array types with different
1585 aliasing settings because this can break the aliasing relationship
1586 between the array type and its element type. */
1598 {
1602 /* Do nothing if the alias sets conflict. This ensures that we
1603 never call record_alias_subset several times for the same pair
1604 or at all for alias set 0. */
1606 {
1609 else
1611 }
1612 }
1617 }
1620 }
1621 \f
1622 /* Record TYPE as a builtin type for Ada. NAME is the name of the type.
1623 ARTIFICIAL_P is true if the type was generated by the compiler. */
1625 void
1627 {
1636 }
1637 \f
1638 /* Finish constructing the character type CHAR_TYPE.
1640 In Ada character types are enumeration types and, as a consequence, are
1641 represented in the front-end by integral types holding the positions of
1642 the enumeration values as defined by the language, which means that the
1643 integral types are unsigned.
1645 Unfortunately the signedness of 'char' in C is implementation-defined
1646 and GCC even has the option -fsigned-char to toggle it at run time.
1647 Since GNAT's philosophy is to be compatible with C by default, to wit
1648 Interfaces.C.char is defined as a mere copy of Character, we may need
1649 to declare character types as signed types in GENERIC and generate the
1650 necessary adjustments to make them behave as unsigned types.
1652 The overall strategy is as follows: if 'char' is unsigned, do nothing;
1653 if 'char' is signed, translate character types of CHAR_TYPE_SIZE and
1654 character subtypes with RM_Size = Esize = CHAR_TYPE_SIZE into signed
1655 types. The idea is to ensure that the bit pattern contained in the
1656 Esize'd objects is not changed, even though the numerical value will
1657 be interpreted differently depending on the signedness. */
1659 void
1661 {
1665 /* Make a copy of a generic unsigned version since we'll modify it. */
1666 tree unsigned_char_type
1668 ? unsigned_char_type_node
1671 /* Create an unsigned version of the type and set it as debug type. */
1677 /* If this is a subtype, make the debug type a subtype of the debug type
1678 of the base type and convert literal RM bounds to unsigned. */
1680 {
1693 }
1695 /* Adjust the RM bounds of the original type to unsigned; that's especially
1696 important for types since they are implicit in this case. */
1699 }
1701 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
1702 finish constructing the record type as a fat pointer type. */
1704 void
1706 {
1707 /* Make sure we can put it into a register. */
1711 /* Show what it really is. */
1714 /* Do not emit debug info for it since the types of its fields may still be
1715 incomplete at this point. */
1718 /* Force type_contains_placeholder_p to return true on it. Although the
1719 PLACEHOLDER_EXPRs are referenced only indirectly, this isn't a pointer
1720 type but the representation of the unconstrained array. */
1722 }
1724 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
1725 finish constructing the record or union type. If REP_LEVEL is zero, this
1726 record has no representation clause and so will be entirely laid out here.
1727 If REP_LEVEL is one, this record has a representation clause and has been
1728 laid out already; only set the sizes and alignment. If REP_LEVEL is two,
1729 this record is derived from a parent record and thus inherits its layout;
1730 only make a pass on the fields to finalize them. DEBUG_INFO_P is true if
1731 additional debug info needs to be output for this type. */
1733 void
1736 {
1744 tree field;
1748 /* Always attach the TYPE_STUB_DECL for a record type. It is required to
1749 generate debug info and have a parallel type. */
1752 /* Globally initialize the record first. If this is a rep'ed record,
1753 that just means some initializations; otherwise, layout the record. */
1755 {
1765 /* For all-repped records with a size specified, lay the QUAL_UNION_TYPE
1766 out just like a UNION_TYPE, since the size will be fixed. */
1769 }
1770 else
1771 {
1772 /* Ensure there isn't a size already set. There can be in an error
1773 case where there is a rep clause but all fields have errors and
1774 no longer have a position. */
1777 /* Ensure we use the traditional GCC layout for bitfields when we need
1778 to pack the record type or have a representation clause. The other
1779 possible layout (Microsoft C compiler), if available, would prevent
1780 efficient packing in almost all cases. */
1781 #ifdef TARGET_MS_BITFIELD_LAYOUT
1786 ATTR_FLAG_TYPE_IN_PLACE);
1787 #endif
1790 }
1792 /* At this point, the position and size of each field is known. It was
1793 either set before entry by a rep clause, or by laying out the type above.
1795 We now run a pass over the fields (in reverse order for QUAL_UNION_TYPEs)
1796 to compute the Ada size; the GCC size and alignment (for rep'ed records
1797 that are not padding types); and the mode (for rep'ed records). We also
1798 clear the DECL_BIT_FIELD indication for the cases we know have not been
1799 handled yet, and adjust DECL_NONADDRESSABLE_P accordingly. */
1805 {
1809 tree this_ada_size;
1816 else
1819 /* Clear DECL_BIT_FIELD for the cases layout_decl does not handle. */
1822 {
1825 /* In the general case, type alignment is required. */
1827 {
1828 /* The enclosing record type must be sufficiently aligned.
1829 Otherwise, if no alignment was specified for it and it
1830 has been laid out already, bump its alignment to the
1831 desired one if this is compatible with its size and
1832 maximum alignment, if any. */
1834 {
1837 }
1843 {
1847 }
1848 }
1850 /* In the non-strict alignment case, only byte alignment is. */
1855 }
1857 /* If we still have DECL_BIT_FIELD set at this point, we know that the
1858 field is technically not addressable. Except that it can actually
1859 be addressed if it is BLKmode and happens to be properly aligned. */
1865 /* A type must be as aligned as its most aligned field that is not
1866 a bit-field. But this is already enforced by layout_type. */
1872 {
1879 ada_size
1887 /* Since we know here that all fields are sorted in order of
1888 increasing bit position, the size of the record is one
1889 higher than the ending bit of the last field processed
1890 unless we have a rep clause, since in that case we might
1891 have a field outside a QUAL_UNION_TYPE that has a higher ending
1892 position. So use a MAX in that case. Also, if this field is a
1893 QUAL_UNION_TYPE, we need to take into account the previous size in
1894 the case of empty variants. */
1895 ada_size
1898 size
1905 }
1906 }
1912 {
1913 /* If this is a padding record, we never want to make the size smaller
1914 than what was specified in it, if any. */
1918 /* Now set any of the values we've just computed that apply. */
1924 {
1925 tree size_unit = had_size_unit
1929 bitsize_unit_node));
1937 }
1938 }
1940 /* Reset the TYPE_MAX_ALIGN field since it's private to gigi. */
1945 }
1947 /* Append PARALLEL_TYPE on the chain of parallel types of TYPE. If
1948 PARRALEL_TYPE has no context and its computation is not deferred yet, also
1949 propagate TYPE's context to PARALLEL_TYPE's or defer its propagation to the
1950 moment TYPE will get a context. */
1952 void
1954 {
1962 /* If PARALLEL_TYPE already has a context, we are done. */
1966 /* Otherwise, try to get one from TYPE's context. If so, simply propagate
1967 it to PARALLEL_TYPE. */
1971 /* Otherwise TYPE has not context yet. We know it will have one thanks to
1972 gnat_pushdecl and then its context will be propagated to PARALLEL_TYPE,
1973 so we have nothing to do in this case. */
1974 }
1976 /* Return true if TYPE has a parallel type. */
1978 static bool
1980 {
1984 }
1986 /* Wrap up compilation of RECORD_TYPE, i.e. output additional debug info
1987 associated with it. It need not be invoked directly in most cases as
1988 finish_record_type takes care of doing so. */
1990 void
1992 {
1994 tree field;
1996 /* If this is a padded type, the bulk of the debug info has already been
1997 generated for the field's type. */
2001 /* If the type already has a parallel type (XVS type), then we're done. */
2006 {
2007 /* We need to make an XVE/XVU record if any field has variable size,
2008 whether or not the record does. For example, if we have a union,
2009 it may be that all fields, rounded up to the alignment, have the
2010 same size, in which case we'll use that size. But the debug
2011 output routines (except Dwarf2) won't be able to output the fields,
2012 so we need to make the special record. */
2014 /* If a field has a non-constant qualifier, the record will have
2015 variable size too. */
2018 {
2021 }
2022 }
2024 /* If this record type is of variable size, make a parallel record type that
2025 will tell the debugger how the former is laid out (see exp_dbug.ads). */
2027 {
2028 tree new_record_type
2035 new_name
2049 /* Now scan all the fields, replacing each field with a new field
2050 corresponding to the new encoding. */
2053 {
2061 /* See how the position was modified from the last position.
2063 There are two basic cases we support: a value was added
2064 to the last position or the last position was rounded to
2065 a boundary and they something was added. Check for the
2066 first case first. If not, see if there is any evidence
2067 of rounding. If so, round the last position and retry.
2069 If this is a union, the position can be taken as zero. */
2072 else
2078 {
2084 }
2089 && tree_fits_uhwi_p
2091 {
2093 unsigned HOST_WIDE_INT addend
2095 align
2101 }
2103 {
2107 }
2109 /* If we can't compute a position, set it to zero.
2111 ??? We really should abort here, but it's too much work
2112 to get this correct for all cases. */
2116 /* See if this type is variable-sized and make a pointer type
2117 and indicate the indirection if so. Beware that the debug
2118 back-end may adjust the position computed above according
2119 to the alignment of the field type, i.e. the pointer type
2120 in this case, if we don't preventively counter that. */
2122 {
2125 {
2128 }
2130 }
2132 /* Make a new field name, if necessary. */
2134 {
2140 else
2144 }
2146 new_field
2152 /* If old_field is a QUAL_UNION_TYPE, take its size as being
2153 zero. The only time it's not the last field of the record
2154 is when there are other components at fixed positions after
2155 it (meaning there was a rep clause for every field) and we
2156 want to be able to encode them. */
2160 ? bitsize_zero_node
2163 }
2168 }
2169 }
2171 /* Utility function of above to merge LAST_SIZE, the previous size of a record
2172 with FIRST_BIT and SIZE that describe a field. SPECIAL is true if this
2173 represents a QUAL_UNION_TYPE in which case we must look for COND_EXPRs and
2174 replace a value of zero with the old size. If HAS_REP is true, we take the
2175 MAX of the end position of this field with LAST_SIZE. In all other cases,
2176 we use FIRST_BIT plus SIZE. Return an expression for the size. */
2178 static tree
2181 {
2183 tree new_size;
2186 {
2190 }
2192 else
2203 /* We don't need any NON_VALUE_EXPRs and they can confuse us (especially
2204 when fed through substitute_in_expr) into thinking that a constant
2205 size is not constant. */
2210 }
2212 /* Return the bit position of FIELD, in bits from the start of the record,
2213 and fold it as much as possible. This is a tree of type bitsizetype. */
2215 static tree
2217 {
2223 else
2227 }
2229 /* Utility function of above to see if OP0 and OP1, both of SIZETYPE, are
2230 related by the addition of a constant. Return that constant if so. */
2232 static tree
2234 {
2241 {
2245 }
2246 else
2257 }
2259 /* Utility function of above to split a tree OP which may be a sum, into a
2260 constant part, which is returned, and a variable part, which is stored
2261 in *PVAR. *PVAR may be bitsize_zero_node. All operations must be of
2262 bitsizetype. */
2264 static tree
2266 {
2267 /* Strip conversions in order to ease the tree traversal and maximize the
2268 potential for constant or plus/minus discovery. We need to be careful
2269 to always return and set *pvar to bitsizetype trees, but it's worth
2270 the effort. */
2276 {
2279 }
2281 {
2292 }
2293 else
2295 }
2296 \f
2297 /* Return a copy of TYPE but safe to modify in any way. */
2299 tree
2301 {
2304 /* Unshare the language-specific data. */
2306 {
2309 }
2311 /* And the contents of the language-specific slot if needed. */
2314 {
2319 }
2321 /* copy_node clears this field instead of copying it, because it is
2322 aliased with TREE_CHAIN. */
2332 }
2333 \f
2334 /* Return a subtype of sizetype with range MIN to MAX and whose
2335 TYPE_INDEX_TYPE is INDEX. GNAT_NODE is used for the position
2336 of the associated TYPE_DECL. */
2338 tree
2340 {
2341 /* First build a type for the desired range. */
2344 /* Then set the index type. */
2349 }
2351 /* Return a subtype of TYPE with range MIN to MAX. If TYPE is NULL,
2352 sizetype is used. */
2354 tree
2356 {
2357 tree range_type;
2362 /* First build a type with the base range. */
2366 /* Then set the actual range. */
2371 }
2372 \f
2373 /* Return a TYPE_DECL node suitable for the TYPE_STUB_DECL field of TYPE.
2374 NAME gives the name of the type to be used in the declaration. */
2376 tree
2378 {
2383 }
2385 /* Return a TYPE_DECL node for TYPE. NAME gives the name of the type to be
2386 used in the declaration. ARTIFICIAL_P is true if the declaration was
2387 generated by the compiler. DEBUG_INFO_P is true if we need to write
2388 debug information about this type. GNAT_NODE is used for the position
2389 of the decl. */
2391 tree
2393 Node_Id gnat_node)
2394 {
2396 bool is_named
2398 tree type_decl;
2400 /* Only the builtin TYPE_STUB_DECL should be used for dummy types. */
2403 /* If the type hasn't been named yet, we're naming it; preserve an existing
2404 TYPE_STUB_DECL that has been attached to it for some purpose. */
2406 {
2409 }
2410 else
2416 /* Add this decl to the current binding level. */
2419 /* If we're naming the type, equate the TYPE_STUB_DECL to the name. This
2420 causes the name to be also viewed as a "tag" by the debug back-end, with
2421 the advantage that no DW_TAG_typedef is emitted for artificial "tagged"
2422 types in DWARF.
2424 Note that if "type" is used as a DECL_ORIGINAL_TYPE, it may be referenced
2425 from multiple contexts, and "type_decl" references a copy of it: in such a
2426 case, do not mess TYPE_STUB_DECL: we do not want to re-use the TYPE_DECL
2427 with the mechanism above. */
2431 /* Do not generate debug info for UNCONSTRAINED_ARRAY_TYPE that the
2432 back-end doesn't support, and for others if we don't need to. */
2437 }
2438 \f
2439 /* Return a VAR_DECL or CONST_DECL node.
2441 NAME gives the name of the variable. ASM_NAME is its assembler name
2442 (if provided). TYPE is its data type (a GCC ..._TYPE node). INIT is
2443 the GCC tree for an optional initial expression; NULL_TREE if none.
2445 CONST_FLAG is true if this variable is constant, in which case we might
2446 return a CONST_DECL node unless CONST_DECL_ALLOWED_P is false.
2448 PUBLIC_FLAG is true if this is for a reference to a public entity or for a
2449 definition to be made visible outside of the current compilation unit, for
2450 instance variable definitions in a package specification.
2452 EXTERN_FLAG is true when processing an external variable declaration (as
2453 opposed to a definition: no storage is to be allocated for the variable).
2455 STATIC_FLAG is only relevant when not at top level and indicates whether
2456 to always allocate storage to the variable.
2458 VOLATILE_FLAG is true if this variable is declared as volatile.
2460 ARTIFICIAL_P is true if the variable was generated by the compiler.
2462 DEBUG_INFO_P is true if we need to write debug information for it.
2464 ATTR_LIST is the list of attributes to be attached to the variable.
2466 GNAT_NODE is used for the position of the decl. */
2468 tree
2474 {
2475 /* Whether the object has static storage duration, either explicitly or by
2476 virtue of being declared at the global level. */
2479 /* Whether the initializer is constant: for an external object or an object
2480 with static storage duration, we check that the initializer is a valid
2481 constant expression for initializing a static variable; otherwise, we
2482 only check that it is constant. */
2483 const bool init_const
2484 = (init
2488 != NULL_TREE
2491 /* Whether we will make TREE_CONSTANT the DECL we produce here, in which
2492 case the initializer may be used in lieu of the DECL node (as done in
2493 Identifier_to_gnu). This is useful to prevent the need of elaboration
2494 code when an identifier for which such a DECL is made is in turn used
2495 as an initializer. We used to rely on CONST_DECL vs VAR_DECL for this,
2496 but extra constraints apply to this choice (see below) and they are not
2497 relevant to the distinction we wish to make. */
2500 /* The actual DECL node. CONST_DECL was initially intended for enumerals
2501 and may be used for scalars in general but not for aggregates. */
2502 tree var_decl
2504 (constant_p
2505 && const_decl_allowed_p
2509 /* Detect constants created by the front-end to hold 'reference to function
2510 calls for stabilization purposes. This is needed for renaming. */
2512 {
2523 }
2525 /* If this is external, throw away any initializations (they will be done
2526 elsewhere) unless this is a constant for which we would like to remain
2527 able to get the initializer. If we are defining a global here, leave a
2528 constant initialization and save any variable elaborations for the
2529 elaboration routine. If we are just annotating types, throw away the
2530 initialization if it isn't a constant. */
2535 /* At the global level, a non-constant initializer generates elaboration
2536 statements. Check that such statements are allowed, that is to say,
2537 not violating a No_Elaboration_Code restriction. */
2541 /* Attach the initializer, if any. */
2544 /* Directly set some flags. */
2551 /* The object is public if it is external or if it is declared public
2552 and has static storage duration. */
2555 /* We need to allocate static storage for an object with static storage
2556 duration if it isn't external. */
2566 /* Ada doesn't feature Fortran-like COMMON variables so we shouldn't
2567 try to fiddle with DECL_COMMON. However, on platforms that don't
2568 support global BSS sections, uninitialized global variables would
2569 go in DATA instead, thus increasing the size of the executable. */
2576 /* Do not emit debug info for a CONST_DECL if optimization isn't enabled,
2577 since we will create an associated variable. Likewise for an external
2578 constant whose initializer is not absolute, because this would mean a
2579 global relocation in a read-only section which runs afoul of the PE-COFF
2580 run-time relocation mechanism. */
2583 || (extern_flag
2584 && constant_p
2585 && init
2590 /* ??? Some attributes cannot be applied to CONST_DECLs. */
2594 /* Add this decl to the current binding level. */
2598 {
2599 /* Let the target mangle the name if this isn't a verbatim asm. */
2604 }
2607 }
2608 \f
2609 /* Return true if TYPE, an aggregate type, contains (or is) an array. */
2611 static bool
2613 {
2615 {
2619 {
2620 tree field;
2626 }
2633 }
2634 }
2636 /* Return a FIELD_DECL node. NAME is the field's name, TYPE is its type and
2637 RECORD_TYPE is the type of the enclosing record. If SIZE is nonzero, it
2638 is the specified size of the field. If POS is nonzero, it is the bit
2639 position. PACKED is 1 if the enclosing record is packed, -1 if it has
2640 Component_Alignment of Storage_Unit. If ADDRESSABLE is nonzero, it
2641 means we are allowed to take the address of the field; if it is negative,
2642 we should not make a bitfield, which is used by make_aligning_type. */
2644 tree
2647 {
2653 /* If FIELD_TYPE is BLKmode, we must ensure this is aligned to at least a
2654 byte boundary since GCC cannot handle less-aligned BLKmode bitfields.
2655 Likewise for an aggregate without specified position that contains an
2656 array, because in this case slices of variable length of this array
2657 must be handled by GCC and variable-sized objects need to be aligned
2658 to at least a byte boundary. */
2660 || (!pos
2665 /* If a size is specified, use it. Otherwise, if the record type is packed
2666 compute a size to use, which may differ from the object's natural size.
2667 We always set a size in this case to trigger the checks for bitfield
2668 creation below, which is typically required when no position has been
2669 specified. */
2673 {
2677 }
2679 /* If we may, according to ADDRESSABLE, make a bitfield if a size is
2680 specified for two reasons: first if the size differs from the natural
2681 size. Second, if the alignment is insufficient. There are a number of
2682 ways the latter can be true.
2684 We never make a bitfield if the type of the field has a nonconstant size,
2685 because no such entity requiring bitfield operations should reach here.
2687 We do *preventively* make a bitfield when there might be the need for it
2688 but we don't have all the necessary information to decide, as is the case
2689 of a field with no specified position in a packed record.
2691 We also don't look at STRICT_ALIGNMENT here, and rely on later processing
2692 in layout_decl or finish_record_type to clear the bit_field indication if
2693 it is in fact not needed. */
2695 && size
2700 || packed
2703 {
2707 {
2711 else
2713 }
2714 }
2718 /* Bump the alignment if need be, either for bitfield/packing purposes or
2719 to satisfy the type requirements if no such consideration applies. When
2720 we get the alignment from the type, indicate if this is from an explicit
2721 user request, which prevents stor-layout from lowering it later on. */
2722 {
2723 unsigned int bit_align
2730 {
2733 }
2734 }
2737 {
2738 /* We need to pass in the alignment the DECL is known to have.
2739 This is the lowest-order bit set in POS, but no more than
2740 the alignment of the record, if one is specified. Note
2741 that an alignment of 0 is taken as infinite. */
2746 else
2760 }
2762 /* In addition to what our caller says, claim the field is addressable if we
2763 know that its type is not suitable.
2765 The field may also be "technically" nonaddressable, meaning that even if
2766 we attempt to take the field's address we will actually get the address
2767 of a copy. This is the case for true bitfields, but the DECL_BIT_FIELD
2768 value we have at this point is not accurate enough, so we don't account
2769 for this here and let finish_record_type decide. */
2776 }
2777 \f
2778 /* Return a PARM_DECL node with NAME and TYPE. */
2780 tree
2782 {
2785 /* Honor TARGET_PROMOTE_PROTOTYPES like the C compiler, as not doing so
2786 can lead to various ABI violations. */
2790 {
2791 /* We have to be careful about biased types here. Make a subtype
2792 of integer_type_node with the proper biasing. */
2795 {
2796 tree subtype
2803 }
2804 else
2806 }
2810 }
2811 \f
2812 /* Process the attributes in ATTR_LIST for NODE, which is either a DECL or
2813 a TYPE. If IN_PLACE is true, the tree pointed to by NODE should not be
2814 changed. GNAT_NODE is used for the position of error messages. */
2816 void
2818 Node_Id gnat_node)
2819 {
2824 {
2833 {
2836 }
2842 else
2849 {
2852 }
2853 else
2872 }
2875 }
2877 /* Return true if VALUE is a known to be a multiple of FACTOR, which must be
2878 a power of 2. */
2880 bool
2882 {
2891 }
2893 /* Return whether GNAT_NODE is a defining identifier for a renaming that comes
2894 from the parameter association for the instantiation of a generic. We do
2895 not want to emit source location for them: the code generated for their
2896 initialization is likely to disturb debugging. */
2898 bool
2900 {
2907 /* Get the object declaration of the renamed object, if any and if the
2908 renamed object is a mere identifier. */
2918 return
2922 }
2924 /* Defer the initialization of DECL's DECL_CONTEXT attribute, scheduling to
2925 feed it with the elaboration of GNAT_SCOPE. */
2929 {
2932 new_node
2941 }
2943 /* Defer the initialization of TYPE's TYPE_CONTEXT attribute, scheduling to
2944 feed it with the DECL_CONTEXT computed as part of N as soon as it is
2945 computed. */
2947 static void
2949 {
2951 }
2953 /* Get the GENERIC node corresponding to GNAT_SCOPE, if available. Return
2954 NULL_TREE if it is not available. */
2956 static tree
2958 {
2959 tree context;
2963 else
2967 {
2970 /* Skip dummy types: only the final ones can appear in the context
2971 chain. */
2975 /* ..._TYPE nodes are more useful than TYPE_DECL nodes in the context
2976 chain. */
2977 else
2979 }
2982 }
2984 /* Try to process all deferred nodes in the queue. Keep in the queue the ones
2985 that cannot be processed yet, remove the other ones. If FORCE is true,
2986 force the processing for all nodes, use the global context when nodes don't
2987 have a GNU translation. */
2989 void
2991 {
2996 {
2999 Entity_Id gnat_scope;
3003 /* If FORCE, get the innermost elaborated scope. Otherwise, just try to
3004 get the first scope. */
3007 {
3012 }
3014 /* Imported declarations must not be in a local context (i.e. not inside
3015 a function). */
3017 {
3021 {
3024 }
3025 }
3027 /* If FORCE, we want to get rid of all nodes in the queue: in case there
3028 was no elaborated scope, use the global context. */
3033 {
3034 tree t;
3039 /* Propagate it to the TYPE_CONTEXT attributes of the requested
3040 ..._TYPE nodes. */
3042 {
3044 }
3046 }
3048 /* If this node has been successfuly processed, remove it from the
3049 queue. Then move to the next node. */
3051 {
3055 }
3056 else
3058 }
3059 }
3061 /* Return VALUE scaled by the biggest power-of-2 factor of EXPR. */
3063 static unsigned int
3065 {
3069 /* Peel conversions around EXPR and try to extract bodies from function
3070 calls: it is possible to get the scale factor from size functions. */
3075 /* Sometimes we get PLUS_EXPR (BIT_AND_EXPR (..., X), Y), where Y is a
3076 multiple of the scale factor we are looking for. */
3080 {
3083 }
3085 /* An expression which is a bitwise AND with a mask has a power-of-2 factor
3086 corresponding to the number of trailing zeros of the mask. */
3089 {
3094 {
3097 i++;
3098 }
3099 }
3101 /* If the addend is not a multiple of the factor we found, give up. In
3102 theory we could find a smaller common factor but it's useless for our
3103 needs. This situation arises when dealing with a field F1 with no
3104 alignment requirement but that is following a field F2 with such
3105 requirements. As long as we have F2's offset, we don't need alignment
3106 information to compute F1's. */
3111 }
3113 /* Given two consecutive field decls PREV_FIELD and CURR_FIELD, return true
3114 unless we can prove these 2 fields are laid out in such a way that no gap
3115 exist between the end of PREV_FIELD and the beginning of CURR_FIELD. OFFSET
3116 is the distance in bits between the end of PREV_FIELD and the starting
3117 position of CURR_FIELD. It is ignored if null. */
3119 static bool
3121 {
3122 /* If this is the first field of the record, there cannot be any gap */
3126 /* If the previous field is a union type, then return false: The only
3127 time when such a field is not the last field of the record is when
3128 there are other components at fixed positions after it (meaning there
3129 was a rep clause for every field), in which case we don't want the
3130 alignment constraint to override them. */
3134 /* If the distance between the end of prev_field and the beginning of
3135 curr_field is constant, then there is a gap if the value of this
3136 constant is not null. */
3140 /* If the size and position of the previous field are constant,
3141 then check the sum of this size and position. There will be a gap
3142 iff it is not multiple of the current field alignment. */
3149 /* If both the position and size of the previous field are multiples
3150 of the current field alignment, there cannot be any gap. */
3155 /* Fallback, return that there may be a potential gap */
3157 }
3159 /* Return a LABEL_DECL with NAME. GNAT_NODE is used for the position of
3160 the decl. */
3162 tree
3164 {
3165 tree label_decl
3170 /* Add this decl to the current binding level. */
3174 }
3175 \f
3176 /* Return a FUNCTION_DECL node. NAME is the name of the subprogram, ASM_NAME
3177 its assembler name, TYPE its type (a FUNCTION_TYPE node), PARAM_DECL_LIST
3178 the list of its parameters (a list of PARM_DECL nodes chained through the
3179 DECL_CHAIN field).
3181 INLINE_STATUS describes the inline flags to be set on the FUNCTION_DECL.
3183 PUBLIC_FLAG is true if this is for a reference to a public entity or for a
3184 definition to be made visible outside of the current compilation unit.
3186 EXTERN_FLAG is true when processing an external subprogram declaration.
3188 ARTIFICIAL_P is true if the subprogram was generated by the compiler.
3190 DEBUG_INFO_P is true if we need to write debug information for it.
3192 DEFINITION is true if the subprogram is to be considered as a definition.
3194 ATTR_LIST is the list of attributes to be attached to the subprogram.
3196 GNAT_NODE is used for the position of the decl. */
3198 tree
3203 Node_Id gnat_node)
3204 {
3218 {
3228 {
3232 ATTR_FLAG_TYPE_IN_PLACE);
3234 /* Inline_Always guarantees that every direct call is inlined and
3235 that there is no indirect reference to the subprogram, so the
3236 instance in the original package (as well as its clones in the
3237 client packages created for inter-unit inlining) can be made
3238 private, which causes the out-of-line body to be eliminated. */
3240 }
3242 /* ... fall through ... */
3251 }
3255 /* Once everything is processed, finish the subprogram declaration. */
3258 /* Add this decl to the current binding level. */
3261 /* Output the assembler code and/or RTL for the declaration. */
3265 }
3267 /* Given a subprogram declaration DECL, its assembler name and its type,
3268 finish constructing the subprogram declaration from ASM_NAME and TYPE. */
3270 void
3272 {
3273 tree result_decl
3286 {
3287 /* Let the target mangle the name if this isn't a verbatim asm. */
3293 /* The expand_main_function circuitry expects "main_identifier_node" to
3294 designate the DECL_NAME of the 'main' entry point, in turn expected
3295 to be declared as the "main" function literally by default. Ada
3296 program entry points are typically declared with a different name
3297 within the binder generated file, exported as 'main' to satisfy the
3298 system expectations. Force main_identifier_node in this case. */
3301 }
3302 }
3303 \f
3304 /* Set up the framework for generating code for SUBPROG_DECL, a subprogram
3305 body. This routine needs to be invoked before processing the declarations
3306 appearing in the subprogram. */
3308 void
3310 {
3311 tree param_decl;
3315 /* This function is being defined. */
3318 /* The failure of this assertion will likely come from a wrong context for
3319 the subprogram body, e.g. another procedure for a procedure declared at
3320 library level. */
3325 /* Enter a new binding level and show that all the parameters belong to
3326 this function. */
3334 }
3336 /* Finish translating the current subprogram and set its BODY. */
3338 void
3340 {
3343 /* Attach the BLOCK for this level to the function and pop the level. */
3348 /* Mark the RESULT_DECL as being in this subprogram. */
3351 /* The body should be a BIND_EXPR whose BLOCK is the top-level one. */
3353 {
3356 }
3361 }
3363 /* Wrap up compilation of SUBPROG_DECL, a subprogram body. */
3365 void
3367 {
3368 /* We cannot track the location of errors past this point. */
3371 /* If we're only annotating types, don't actually compile this function. */
3375 /* Dump functions before gimplification. */
3380 else
3381 /* Register this function with cgraph just far enough to get it
3382 added to our parent's nested function list. */
3384 }
3386 tree
3388 {
3391 }
3393 /* Return an integer type with the number of bits of precision given by
3394 PRECISION. UNSIGNEDP is nonzero if the type is unsigned; otherwise
3395 it is a signed type. */
3397 tree
3399 {
3400 tree t;
3409 else
3417 {
3420 }
3423 }
3425 /* Likewise for floating-point types. */
3427 static tree
3429 {
3430 tree t;
3442 {
3445 }
3448 }
3450 /* Return a data type that has machine mode MODE. UNSIGNEDP selects
3451 an unsigned type; otherwise a signed type is returned. */
3453 tree
3455 {
3465 scalar_float_mode float_mode;
3468 float_mode);
3470 scalar_int_mode int_mode;
3475 {
3480 }
3483 }
3485 /* Return the signed or unsigned version of TYPE_NODE, a scalar type, the
3486 signedness being specified by UNSIGNEDP. */
3488 tree
3490 {
3497 {
3500 }
3504 {
3507 }
3510 }
3512 /* Return 1 if the types T1 and T2 are compatible, i.e. if they can be
3513 transparently converted to each other. */
3515 int
3517 {
3520 /* This is the default criterion. */
3524 /* We only check structural equivalence here. */
3528 /* Vector types are also compatible if they have the same number of subparts
3529 and the same form of (scalar) element type. */
3536 /* Array types are also compatible if they are constrained and have the same
3537 domain(s), the same component type and the same scalar storage order. */
3553 }
3555 /* Return true if EXPR is a useless type conversion. */
3557 bool
3559 {
3567 }
3569 /* Return true if T, a FUNCTION_TYPE, has the specified list of flags. */
3571 bool
3574 {
3579 }
3580 \f
3581 /* EXP is an expression for the size of an object. If this size contains
3582 discriminant references, replace them with the maximum (if MAX_P) or
3583 minimum (if !MAX_P) possible value of the discriminant. */
3585 tree
3587 {
3593 {
3604 {
3618 }
3622 /* If this contains a PLACEHOLDER_EXPR, it is the thing we want to
3623 modify. Otherwise, we treat it like a variable. */
3625 {
3628 return
3631 }
3651 {
3656 /* Special-case wanting the maximum value of a MIN_EXPR.
3657 In that case, if one side overflows, return the other. */
3659 {
3665 }
3667 /* Likewise, handle a MINUS_EXPR or PLUS_EXPR with the LHS
3668 overflowing and the RHS a variable. */
3675 /* If we are going to subtract a "negative" value in an unsigned type,
3676 do the operation as an addition of the negated value, in order to
3677 avoid creating a spurious overflow below. */
3683 {
3686 }
3691 /* We need to detect overflows so we call size_binop here. */
3693 }
3697 {
3724 {
3731 return
3734 }
3739 }
3741 /* Other tree classes cannot happen. */
3744 }
3747 }
3748 \f
3749 /* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE.
3750 EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs.
3751 Return a constructor for the template. */
3753 tree
3755 {
3758 tree field;
3770 /* First make the list for a CONSTRUCTOR for the template. Go down the
3771 field list of the template instead of the type chain because this
3772 array might be an Ada array of arrays and we can't tell where the
3773 nested arrays stop being the underlying object. */
3776 (bound_list
3780 {
3783 /* If we have a bound list, get the bounds from there. Likewise
3784 for an ARRAY_TYPE. Otherwise, if expr is a PARM_DECL with
3785 DECL_BY_COMPONENT_PTR_P, use the bounds of the field in the template.
3786 This will give us a maximum range. */
3794 else
3800 /* If either MIN or MAX involve a PLACEHOLDER_EXPR, we must
3801 substitute it from OBJECT. */
3807 }
3810 }
3811 \f
3812 /* Return true if TYPE is suitable for the element type of a vector. */
3814 static bool
3816 {
3817 machine_mode mode;
3831 }
3833 /* Return a vector type given the SIZE and the INNER_TYPE, or NULL_TREE if
3834 this is not possible. If ATTRIBUTE is non-zero, we are processing the
3835 attribute declaration and want to issue error messages on failure. */
3837 static tree
3839 {
3843 /* Silently punt on variable sizes. We can't make vector types for them,
3844 need to ignore them on front-end generated subtypes of unconstrained
3845 base types, and this attribute is for binding implementors, not end
3846 users, so we should never get there from legitimate explicit uses. */
3852 {
3857 }
3861 {
3865 }
3868 {
3872 }
3876 {
3880 }
3883 }
3885 /* Return a vector type whose representative array type is ARRAY_TYPE, or
3886 NULL_TREE if this is not possible. If ATTRIBUTE is non-zero, we are
3887 processing the attribute and want to issue error messages on failure. */
3889 static tree
3891 {
3894 attribute);
3900 }
3901 \f
3902 /* Build a type to be used to represent an aliased object whose nominal type
3903 is an unconstrained array. This consists of a RECORD_TYPE containing a
3904 field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an ARRAY_TYPE.
3905 If ARRAY_TYPE is that of an unconstrained array, this is used to represent
3906 an arbitrary unconstrained object. Use NAME as the name of the record.
3907 DEBUG_INFO_P is true if we need to write debug information for the type. */
3909 tree
3912 {
3913 tree decl;
3915 tree template_field
3918 tree array_field
3927 /* Declare it now since it will never be declared otherwise. This is
3928 necessary to ensure that its subtrees are properly marked. */
3931 /* template_type will not be used elsewhere than here, so to keep the debug
3932 info clean and in order to avoid scoping issues, make decl its
3933 context. */
3937 }
3939 /* Same, taking a thin or fat pointer type instead of a template type. */
3941 tree
3944 {
3945 tree template_type;
3949 template_type
3954 return
3956 }
3957 \f
3958 /* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE.
3959 In the normal case this is just two adjustments, but we have more to
3960 do if NEW_TYPE is an UNCONSTRAINED_ARRAY_TYPE. */
3962 void
3964 {
3967 tree t;
3969 /* If this is the main variant, process all the other variants first. */
3974 /* If no pointers and no references, we are done. */
3978 /* Merge the old type qualifiers in the new type.
3980 Each old variant has qualifiers for specific reasons, and the new
3981 designated type as well. Each set of qualifiers represents useful
3982 information grabbed at some point, and merging the two simply unifies
3983 these inputs into the final type description.
3985 Consider for instance a volatile type frozen after an access to constant
3986 type designating it; after the designated type's freeze, we get here with
3987 a volatile NEW_TYPE and a dummy OLD_TYPE with a readonly variant, created
3988 when the access type was processed. We will make a volatile and readonly
3989 designated type, because that's what it really is.
3991 We might also get here for a non-dummy OLD_TYPE variant with different
3992 qualifiers than those of NEW_TYPE, for instance in some cases of pointers
3993 to private record type elaboration (see the comments around the call to
3994 this routine in gnat_to_gnu_entity <E_Access_Type>). We have to merge
3995 the qualifiers in those cases too, to avoid accidentally discarding the
3996 initial set, and will often end up with OLD_TYPE == NEW_TYPE then. */
3997 new_type
4001 /* If old type and new type are identical, there is nothing to do. */
4005 /* Otherwise, first handle the simple case. */
4007 {
4010 /* If pointer or reference already points to new type, nothing to do.
4011 This can happen as update_pointer_to can be invoked multiple times
4012 on the same couple of types because of the type variants. */
4017 /* Chain PTR and its variants at the end. */
4020 {
4024 }
4025 else
4028 /* Now adjust them. */
4031 {
4035 }
4037 /* Chain REF and its variants at the end. */
4040 {
4044 }
4045 else
4048 /* Now adjust them. */
4055 }
4057 /* Now deal with the unconstrained array case. In this case the pointer
4058 is actually a record where both fields are pointers to dummy nodes.
4059 Turn them into pointers to the correct types using update_pointer_to.
4060 Likewise for the pointer to the object record (thin pointer). */
4061 else
4062 {
4067 /* If PTR already points to NEW_TYPE, nothing to do. This can happen
4068 since update_pointer_to can be invoked multiple times on the same
4069 couple of types because of the type variants. */
4073 update_pointer_to
4077 update_pointer_to
4086 }
4087 }
4088 \f
4089 /* Convert EXPR, a pointer to a constrained array, into a pointer to an
4090 unconstrained one. This involves making or finding a template. */
4092 static tree
4094 {
4098 tree template_addr;
4102 /* If EXPR is null, make a fat pointer that contains a null pointer to the
4103 array (compare_fat_pointers ensures that this is the full discriminant)
4104 and a valid pointer to the bounds. This latter property is necessary
4105 since the compiler can hoist the load of the bounds done through it. */
4107 {
4113 else
4114 {
4115 /* The template type can still be dummy at this point so we build an
4116 empty constructor. The middle-end will fill it in with zeros. */
4121 }
4127 /* Do not set TREE_CONSTANT so as to force T to static memory. */
4132 }
4134 /* If EXPR is a thin pointer, make template and data from the record. */
4136 {
4141 /* If we have a TYPE_UNCONSTRAINED_ARRAY attached to the RECORD_TYPE,
4142 the thin pointer value has been shifted so we shift it back to get
4143 the template address. */
4145 {
4146 template_addr
4149 byte_position
4151 template_addr
4153 template_addr);
4154 }
4156 /* Otherwise we explicitly take the address of the fields. */
4157 else
4158 {
4160 template_addr
4166 }
4167 }
4169 /* Otherwise, build the constructor for the template. */
4170 else
4171 template_addr
4174 expr));
4176 /* The final result is a constructor for the fat pointer.
4178 If EXPR is an argument of a foreign convention subprogram, the type it
4179 points to is directly the component type. In this case, the expression
4180 type may not match the corresponding FIELD_DECL type at this point, so we
4181 call "convert" here to fix that up if necessary. This type consistency is
4182 required, for instance because it ensures that possible later folding of
4183 COMPONENT_REFs against this constructor always yields something of the
4184 same type as the initial reference.
4186 Note that the call to "build_template" above is still fine because it
4187 will only refer to the provided TEMPLATE_TYPE in this case. */
4191 }
4192 \f
4193 /* Create an expression whose value is that of EXPR,
4194 converted to type TYPE. The TREE_TYPE of the value
4195 is always TYPE. This function implements all reasonable
4196 conversions; callers should filter out those that are
4197 not permitted by the language being compiled. */
4199 tree
4201 {
4206 /* If the expression is already of the right type, we are done. */
4210 /* If both input and output have padding and are of variable size, do this
4211 as an unchecked conversion. Likewise if one is a mere variant of the
4212 other, so we avoid a pointless unpad/repad sequence. */
4220 ;
4222 /* If the output type has padding, convert to the inner type and make a
4223 constructor to build the record, unless a variable size is involved. */
4225 {
4226 /* If we previously converted from another type and our type is
4227 of variable size, remove the conversion to avoid the need for
4228 variable-sized temporaries. Likewise for a conversion between
4229 original and packable version. */
4237 /* If we are just removing the padding from expr, convert the original
4238 object if we have variable size in order to avoid the need for some
4239 variable-sized temporaries. Likewise if the padding is a variant
4240 of the other, so we avoid a pointless unpad/repad sequence. */
4251 /* If the inner type is of self-referential size and the expression type
4252 is a record, do this as an unchecked conversion. But first pad the
4253 expression if possible to have the same size on both sides. */
4256 {
4260 expr);
4262 }
4264 /* If we are converting between array types with variable size, do the
4265 final conversion as an unchecked conversion, again to avoid the need
4266 for some variable-sized temporaries. If valid, this conversion is
4267 very likely purely technical and without real effects. */
4274 expr),
4279 /* If converting to the inner type has already created a CONSTRUCTOR with
4280 the right size, then reuse it instead of creating another one. This
4281 can happen for the padding type built to overalign local variables. */
4293 }
4295 /* If the input type has padding, remove it and convert to the output type.
4296 The conditions ordering is arranged to ensure that the output type is not
4297 a padding type here, as it is not clear whether the conversion would
4298 always be correct if this was to happen. */
4300 {
4301 tree unpadded;
4303 /* If we have just converted to this padded type, just get the
4304 inner expression. */
4308 /* Otherwise, build an explicit component reference. */
4309 else
4313 }
4315 /* If the input is a biased type, convert first to the base type and add
4316 the bias. Note that the bias must go through a full conversion to the
4317 base type, lest it is itself a biased value; this happens for subtypes
4318 of biased types. */
4325 /* If the input is a justified modular type, we need to extract the actual
4326 object before converting it to any other type with the exceptions of an
4327 unconstrained array or of a mere type variant. It is useful to avoid the
4328 extraction and conversion in the type variant case because it could end
4329 up replacing a VAR_DECL expr by a constructor and we might be about the
4330 take the address of the result. */
4334 return
4337 /* If converting to a type that contains a template, convert to the data
4338 type and then build the template. */
4340 {
4345 /* If the source already has a template, get a reference to the
4346 associated array only, as we are going to rebuild a template
4347 for the target type anyway. */
4357 }
4359 /* There are some cases of expressions that we process specially. */
4361 {
4366 /* Just set its type here. For TRANSFORM_EXPR, we will do the actual
4367 conversion in gnat_expand_expr. NULL_EXPR does not represent
4368 and actual value, so no conversion is needed. */
4374 /* If we are converting a STRING_CST to another constrained array type,
4375 just make a new one in the proper type. */
4379 {
4383 }
4387 /* If we are converting a VECTOR_CST to a mere type variant, just make
4388 a new one in the proper type. */
4390 {
4394 }
4398 /* If we are converting a CONSTRUCTOR to a mere type variant, or to
4399 another padding type around the same type, just make a new one in
4400 the proper type. */
4407 {
4412 }
4414 /* Likewise for a conversion between original and packable version, or
4415 conversion between types of the same size and with the same list of
4416 fields, but we have to work harder to preserve type consistency. */
4422 {
4431 /* Whether we need to clear TREE_CONSTANT et al. on the output
4432 constructor when we convert in place. */
4436 {
4437 /* Skip the missing fields in the CONSTRUCTOR. */
4439 {
4442 }
4443 /* The field must be the same. */
4446 constructor_elt elt
4450 /* If packing has made this field a bitfield and the input
4451 value couldn't be emitted statically any more, we need to
4452 clear TREE_CONSTANT on our output. */
4462 }
4464 /* If we have been able to match and convert all the input fields
4465 to their output type, convert in place now. We'll fallback to a
4466 view conversion downstream otherwise. */
4468 {
4475 }
4476 }
4478 /* Likewise for a conversion between array type and vector type with a
4479 compatible representative array. */
4483 etype))
4484 {
4489 tree value;
4491 /* Build a VECTOR_CST from a *constant* array constructor. */
4493 {
4496 /* Iterate through elements and check if all constructor
4497 elements are *_CSTs. */
4500 {
4503 }
4508 }
4510 /* Otherwise, build a regular vector constructor. */
4513 {
4516 }
4521 }
4525 /* First retrieve the underlying array. */
4532 {
4533 /* GCC 4.x is very sensitive to type consistency overall, and view
4534 conversions thus are very frequent. Even though just "convert"ing
4535 the inner operand to the output type is fine in most cases, it
4536 might expose unexpected input/output type mismatches in special
4537 circumstances so we avoid such recursive calls when we can. */
4540 /* If we are converting back to the original type, we can just
4541 lift the input conversion. This is a common occurrence with
4542 switches back-and-forth amongst type variants. */
4546 /* Otherwise, if we're converting between two aggregate or vector
4547 types, we might be allowed to substitute the VIEW_CONVERT_EXPR
4548 target type in place or to just convert the inner expression. */
4551 {
4552 /* If we are converting between mere variants, we can just
4553 substitute the VIEW_CONVERT_EXPR in place. */
4557 /* Otherwise, we may just bypass the input view conversion unless
4558 one of the types is a fat pointer, which is handled by
4559 specialized code below which relies on exact type matching. */
4563 }
4566 }
4570 }
4572 /* Check for converting to a pointer to an unconstrained array. */
4576 /* If we are converting between two aggregate or vector types that are mere
4577 variants, just make a VIEW_CONVERT_EXPR. Likewise when we are converting
4578 to a vector type from its representative array type. */
4585 etype)))
4588 /* If we are converting between tagged types, try to upcast properly. */
4591 {
4599 }
4601 /* If we are converting from a smaller form of record type back to it, just
4602 make a VIEW_CONVERT_EXPR. But first pad the expression to have the same
4603 size on both sides. */
4606 {
4609 expr);
4611 }
4613 /* In all other cases of related types, make a NOP_EXPR. */
4618 {
4628 /* If the output is a biased type, convert first to the base type and
4629 subtract the bias. Note that the bias itself must go through a full
4630 conversion to the base type, lest it is a biased value; this happens
4631 for subtypes of biased types. */
4639 /* ... fall through ... */
4643 /* If we are converting an additive expression to an integer type
4644 with lower precision, be wary of the optimization that can be
4645 applied by convert_to_integer. There are 2 problematic cases:
4646 - if the first operand was originally of a biased type,
4647 because we could be recursively called to convert it
4648 to an intermediate type and thus rematerialize the
4649 additive operator endlessly,
4650 - if the expression contains a placeholder, because an
4651 intermediate conversion that changes the sign could
4652 be inserted and thus introduce an artificial overflow
4653 at compile time when the placeholder is substituted. */
4658 {
4665 }
4671 /* If converting between two thin pointers, adjust if needed to account
4672 for differing offsets from the base pointer, depending on whether
4673 there is a TYPE_UNCONSTRAINED_ARRAY attached to the record type. */
4675 {
4676 tree etype_pos
4680 tree type_pos
4692 }
4694 /* If converting fat pointer to normal or thin pointer, get the pointer
4695 to the array and then convert it. */
4706 {
4712 expr));
4714 }
4716 /* ... fall through ... */
4719 /* In these cases, assume the front-end has validated the conversion.
4720 If the conversion is valid, it will be a bit-wise conversion, so
4721 it can be viewed as an unchecked conversion. */
4725 /* This is a either a conversion between a tagged type and some
4726 subtype, which we have to mark as a UNION_TYPE because of
4727 overlapping fields or a conversion of an Unchecked_Union. */
4731 /* If the input is a VECTOR_TYPE, convert to the representative
4732 array type first. */
4734 {
4738 }
4740 /* If EXPR is a constrained array, take its address, convert it to a
4741 fat pointer, and then dereference it. Likewise if EXPR is a
4742 record containing both a template and a constrained array.
4743 Note that a record representing a justified modular type
4744 always represents a packed constrained array. */
4749 return
4750 build_unary_op
4756 /* Do something very similar for converting one unconstrained
4757 array to another. */
4759 return
4764 else
4772 }
4773 }
4775 /* Create an expression whose value is that of EXPR converted to the common
4776 index type, which is sizetype. EXPR is supposed to be in the base type
4777 of the GNAT index type. Calling it is equivalent to doing
4779 convert (sizetype, expr)
4781 but we try to distribute the type conversion with the knowledge that EXPR
4782 cannot overflow in its type. This is a best-effort approach and we fall
4783 back to the above expression as soon as difficulties are encountered.
4785 This is necessary to overcome issues that arise when the GNAT base index
4786 type and the GCC common index type (sizetype) don't have the same size,
4787 which is quite frequent on 64-bit architectures. In this case, and if
4788 the GNAT base index type is signed but the iteration type of the loop has
4789 been forced to unsigned, the loop scalar evolution engine cannot compute
4790 a simple evolution for the general induction variables associated with the
4791 array indices, because it will preserve the wrap-around semantics in the
4792 unsigned type of their "inner" part. As a result, many loop optimizations
4793 are blocked.
4795 The solution is to use a special (basic) induction variable that is at
4796 least as large as sizetype, and to express the aforementioned general
4797 induction variables in terms of this induction variable, eliminating
4798 the problematic intermediate truncation to the GNAT base index type.
4799 This is possible as long as the original expression doesn't overflow
4800 and if the middle-end hasn't introduced artificial overflows in the
4801 course of the various simplification it can make to the expression. */
4803 tree
4805 {
4809 /* If the type is unsigned, overflow is allowed so we cannot be sure that
4810 EXPR doesn't overflow. Keep it simple if optimization is disabled. */
4815 {
4817 /* The main effect of the function: replace a loop parameter with its
4818 associated special induction variable. */
4823 CASE_CONVERT:
4824 {
4826 /* Bail out as soon as we suspect some sort of type frobbing. */
4830 }
4832 /* ... fall through ... */
4856 }
4859 }
4860 \f
4861 /* Remove all conversions that are done in EXP. This includes converting
4862 from a padded type or to a justified modular type. If TRUE_ADDRESS
4863 is true, always return the address of the containing object even if
4864 the address is not bit-aligned. */
4866 tree
4868 {
4870 {
4875 return
4884 CASE_CONVERT:
4891 }
4894 }
4895 \f
4896 /* If EXP's type is an UNCONSTRAINED_ARRAY_TYPE, return an expression that
4897 refers to the underlying array. If it has TYPE_CONTAINS_TEMPLATE_P,
4898 likewise return an expression pointing to the underlying array. */
4900 tree
4902 {
4907 {
4910 {
4918 {
4919 tree op1
4924 tree op2
4933 }
4934 else
4935 {
4942 }
4943 }
4952 /* If this is a padded type and it contains a template, convert to the
4953 unpadded type first. */
4957 {
4961 }
4964 {
4965 /* If the array initializer is a box, return NULL_TREE. */
4973 /* If the array type is padded, convert to the unpadded type. */
4976 }
4981 }
4984 }
4985 \f
4986 /* Return true if EXPR is an expression that can be folded as an operand
4987 of a VIEW_CONVERT_EXPR. See ada-tree.h for a complete rationale. */
4989 static bool
4991 {
4994 /* The folder will fold NOP_EXPRs between integral types with the same
4995 precision (in the middle-end's sense). We cannot allow it if the
4996 types don't have the same precision in the Ada sense as well. */
5003 /* Defer to the folder for non-integral conversions. */
5007 /* Only fold conversions that preserve both precisions. */
5013 }
5015 /* Return an expression that does an unchecked conversion of EXPR to TYPE.
5016 If NOTRUNC_P is true, truncation operations should be suppressed.
5018 Special care is required with (source or target) integral types whose
5019 precision is not equal to their size, to make sure we fetch or assign
5020 the value bits whose location might depend on the endianness, e.g.
5022 Rmsize : constant := 8;
5023 subtype Int is Integer range 0 .. 2 ** Rmsize - 1;
5025 type Bit_Array is array (1 .. Rmsize) of Boolean;
5026 pragma Pack (Bit_Array);
5028 function To_Bit_Array is new Unchecked_Conversion (Int, Bit_Array);
5030 Value : Int := 2#1000_0001#;
5031 Vbits : Bit_Array := To_Bit_Array (Value);
5033 we expect the 8 bits at Vbits'Address to always contain Value, while
5034 their original location depends on the endianness, at Value'Address
5035 on a little-endian architecture but not on a big-endian one.
5037 One pitfall is that we cannot use TYPE_UNSIGNED directly to decide how
5038 the bits between the precision and the size are filled, because of the
5039 trick used in the E_Signed_Integer_Subtype case of gnat_to_gnu_entity.
5040 So we use the special predicate type_unsigned_for_rm above. */
5042 tree
5044 {
5048 tree tem;
5051 /* If the expression is already of the right type, we are done. */
5055 /* If both types are integral just do a normal conversion.
5056 Likewise for a conversion to an unconstrained array. */
5064 {
5066 {
5071 }
5074 {
5080 }
5081 else
5083 }
5085 /* If we are converting to an integral type whose precision is not equal
5086 to its size, first unchecked convert to a record type that contains a
5087 field of the given precision. Then extract the result from the field.
5089 There is a subtlety if the source type is an aggregate type with reverse
5090 storage order because its representation is not contiguous in the native
5091 storage order, i.e. a direct unchecked conversion to an integral type
5092 with N bits of precision cannot read the first N bits of the aggregate
5093 type. To overcome it, we do an unchecked conversion to an integral type
5094 with reverse storage order and return the resulting value. This also
5095 ensures that the result of the unchecked conversion doesn't depend on
5096 the endianness of the target machine, but only on the storage order of
5097 the aggregate type.
5099 Finally, for the sake of consistency, we do the unchecked conversion
5100 to an integral type with reverse storage order as soon as the source
5101 type is an aggregate type with reverse storage order, even if there
5102 are no considerations of precision or size involved. */
5109 {
5120 else
5132 }
5134 /* Similarly if we are converting from an integral type whose precision is
5135 not equal to its size, first copy into a field of the given precision
5136 and unchecked convert the record type.
5138 The same considerations as above apply if the target type is an aggregate
5139 type with reverse storage order and we also proceed similarly. */
5146 {
5159 else
5172 }
5174 /* If we are converting from a scalar type to a type with a different size,
5175 we need to pad to have the same size on both sides.
5177 ??? We cannot do it unconditionally because unchecked conversions are
5178 used liberally by the front-end to implement polymorphism, e.g. in:
5180 S191s : constant ada__tags__addr_ptr := ada__tags__addr_ptr!(S190s);
5181 return p___size__4 (p__object!(S191s.all));
5183 so we skip all expressions that are references. */
5188 {
5190 {
5193 expr);
5195 }
5196 else
5197 {
5202 }
5203 }
5205 /* We have a special case when we are converting between two unconstrained
5206 array types. In that case, take the address, convert the fat pointer
5207 types, and dereference. */
5212 expr)));
5214 /* Another special case is when we are converting to a vector type from its
5215 representative array type; this a regular conversion. */
5219 etype))
5222 /* And, if the array type is not the representative, we try to build an
5223 intermediate vector type of which the array type is the representative
5224 and to do the unchecked conversion between the vector types, in order
5225 to enable further simplifications in the middle-end. */
5229 {
5232 }
5234 /* If we are converting a CONSTRUCTOR to a more aligned RECORD_TYPE, bump
5235 the alignment of the CONSTRUCTOR to speed up the copy operation. */
5239 {
5242 expr);
5244 }
5246 /* Otherwise, just build a VIEW_CONVERT_EXPR of the expression. */
5247 else
5248 {
5254 else
5256 }
5258 /* If the result is a non-biased integral type whose precision is not equal
5259 to its size, sign- or zero-extend the result. But we need not do this
5260 if the input is also an integral type and both are unsigned or both are
5261 signed and have the same precision. */
5274 {
5277 else
5278 {
5279 tree base_type
5282 tree shift_expr
5286 expr
5291 expr),
5292 shift_expr),
5293 shift_expr));
5294 }
5295 }
5297 /* An unchecked conversion should never raise Constraint_Error. The code
5298 below assumes that GCC's conversion routines overflow the same way that
5299 the underlying hardware does. This is probably true. In the rare case
5300 when it is false, we can rely on the fact that such conversions are
5301 erroneous anyway. */
5305 /* If the sizes of the types differ and this is an VIEW_CONVERT_EXPR,
5306 show no longer constant. */
5309 OEP_ONLY_CONST))
5313 }
5314 \f
5315 /* Return the appropriate GCC tree code for the specified GNAT_TYPE,
5316 the latter being a record type as predicated by Is_Record_Type. */
5318 enum tree_code
5320 {
5323 /* Return UNION_TYPE if it's an Unchecked_Union whose non-discriminant
5324 fields are all in the variant part. Otherwise, return RECORD_TYPE. */
5329 component_list
5339 }
5341 /* Return true if GNAT_TYPE is a "double" floating-point type, i.e. whose
5342 size is equal to 64 bits, or an array of such a type. Set ALIGN_CLAUSE
5343 according to the presence of an alignment clause on the type or, if it
5344 is an array, on the component type. */
5346 bool
5348 {
5354 {
5358 }
5367 }
5369 /* Return true if GNAT_TYPE is a "double" or larger scalar type, i.e. whose
5370 size is greater or equal to 64 bits, or an array of such a type. Set
5371 ALIGN_CLAUSE according to the presence of an alignment clause on the
5372 type or, if it is an array, on the component type. */
5374 bool
5376 {
5382 {
5386 }
5395 }
5397 /* Return true if GNU_TYPE is suitable as the type of a non-aliased
5398 component of an aggregate type. */
5400 bool
5402 {
5403 /* If the type is passed by reference, we may have pointers to the
5404 component so it cannot be made non-aliased. */
5408 /* We used to say that any component of aggregate type is aliased
5409 because the front-end may take 'Reference of it. The front-end
5410 has been enhanced in the meantime so as to use a renaming instead
5411 in most cases, but the back-end can probably take the address of
5412 such a component too so we go for the conservative stance.
5414 For instance, we might need the address of any array type, even
5415 if normally passed by copy, to construct a fat pointer if the
5416 component is used as an actual for an unconstrained formal.
5418 Likewise for record types: even if a specific record subtype is
5419 passed by copy, the parent type might be passed by ref (e.g. if
5420 it's of variable size) and we might take the address of a child
5421 component to pass to a parent formal. We have no way to check
5422 for such conditions here. */
5427 }
5429 /* Return true if TYPE is a smaller form of ORIG_TYPE. */
5431 bool
5433 {
5436 /* We're not interested in variants here. */
5440 /* Like a variant, a packable version keeps the original TYPE_NAME. */
5451 }
5453 /* Return whether EXPR, which is the renamed object in an object renaming
5454 declaration, can be materialized as a reference (with a REFERENCE_TYPE).
5455 This should be synchronized with Exp_Dbug.Debug_Renaming_Declaration. */
5457 bool
5459 {
5461 {
5465 {
5474 {
5478 const Uint bitpos
5486 }
5490 {
5498 }
5506 };
5507 }
5508 }
5510 /* Perform final processing on global declarations. */
5514 void
5516 {
5518 tree iter;
5520 /* If we have declared types as used at the global level, insert them in
5521 the global hash table. We use a dummy variable for this purpose, but
5522 we need to build it unconditionally to avoid -fcompare-debug issues. */
5524 {
5529 dummy_global
5531 void_type_node);
5540 {
5543 }
5544 }
5546 /* Output debug information for all global type declarations first. This
5547 ensures that global types whose compilation hasn't been finalized yet,
5548 for example pointers to Taft amendment types, have their compilation
5549 finalized in the right context. */
5554 /* Output imported functions. */
5563 /* Then output the global variables. We need to do that after the debug
5564 information for global types is emitted so that they are finalized. Skip
5565 external global variables, unless we need to emit debug info for them:
5566 this is useful for imported variables, for instance. */
5572 /* Output the imported modules/declarations. In GNAT, these are only
5573 materializing subprogram. */
5578 }
5580 /* ************************************************************************
5581 * * GCC builtins support *
5582 * ************************************************************************ */
5584 /* The general scheme is fairly simple:
5586 For each builtin function/type to be declared, gnat_install_builtins calls
5587 internal facilities which eventually get to gnat_pushdecl, which in turn
5588 tracks the so declared builtin function decls in the 'builtin_decls' global
5589 datastructure. When an Intrinsic subprogram declaration is processed, we
5590 search this global datastructure to retrieve the associated BUILT_IN DECL
5591 node. */
5593 /* Search the chain of currently available builtin declarations for a node
5594 corresponding to function NAME (an IDENTIFIER_NODE). Return the first node
5595 found, if any, or NULL_TREE otherwise. */
5596 tree
5598 {
5600 tree decl;
5607 }
5609 /* The code below eventually exposes gnat_install_builtins, which declares
5610 the builtin types and functions we might need, either internally or as
5611 user accessible facilities.
5613 ??? This is a first implementation shot, still in rough shape. It is
5614 heavily inspired from the "C" family implementation, with chunks copied
5615 verbatim from there.
5617 Two obvious improvement candidates are:
5618 o Use a more efficient name/decl mapping scheme
5619 o Devise a middle-end infrastructure to avoid having to copy
5620 pieces between front-ends. */
5622 /* ----------------------------------------------------------------------- *
5623 * BUILTIN ELEMENTARY TYPES *
5624 * ----------------------------------------------------------------------- */
5626 /* Standard data types to be used in builtin argument declarations. */
5628 enum c_tree_index
5629 {
5631 CTI_STRING_TYPE,
5632 CTI_CONST_STRING_TYPE,
5634 CTI_MAX
5635 };
5639 #define signed_size_type_node c_global_trees[CTI_SIGNED_SIZE_TYPE]
5640 #define string_type_node c_global_trees[CTI_STRING_TYPE]
5641 #define const_string_type_node c_global_trees[CTI_CONST_STRING_TYPE]
5643 /* ??? In addition some attribute handlers, we currently don't support a
5644 (small) number of builtin-types, which in turns inhibits support for a
5645 number of builtin functions. */
5646 #define wint_type_node void_type_node
5647 #define intmax_type_node void_type_node
5648 #define uintmax_type_node void_type_node
5650 /* Used to help initialize the builtin-types.def table. When a type of
5651 the correct size doesn't exist, use error_mark_node instead of NULL.
5652 The later results in segfaults even when a decl using the type doesn't
5653 get invoked. */
5655 static tree
5657 {
5660 }
5662 /* Build/push the elementary type decls that builtin functions/types
5663 will need. */
5665 static void
5667 {
5672 const_string_type_node
5675 }
5677 /* ----------------------------------------------------------------------- *
5678 * BUILTIN FUNCTION TYPES *
5679 * ----------------------------------------------------------------------- */
5681 /* Now, builtin function types per se. */
5683 enum c_builtin_type
5684 {
5685 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
5686 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
5687 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
5688 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
5689 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
5690 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
5691 #define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME,
5692 #define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5693 ARG6) NAME,
5694 #define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5695 ARG6, ARG7) NAME,
5696 #define DEF_FUNCTION_TYPE_8(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5697 ARG6, ARG7, ARG8) NAME,
5698 #define DEF_FUNCTION_TYPE_9(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5699 ARG6, ARG7, ARG8, ARG9) NAME,
5700 #define DEF_FUNCTION_TYPE_10(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5701 ARG6, ARG7, ARG8, ARG9, ARG10) NAME,
5702 #define DEF_FUNCTION_TYPE_11(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5703 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) NAME,
5704 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
5705 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
5706 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
5707 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
5708 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
5709 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5710 NAME,
5711 #define DEF_FUNCTION_TYPE_VAR_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5712 ARG6) NAME,
5713 #define DEF_FUNCTION_TYPE_VAR_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5714 ARG6, ARG7) NAME,
5715 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
5717 #undef DEF_PRIMITIVE_TYPE
5718 #undef DEF_FUNCTION_TYPE_0
5719 #undef DEF_FUNCTION_TYPE_1
5720 #undef DEF_FUNCTION_TYPE_2
5721 #undef DEF_FUNCTION_TYPE_3
5722 #undef DEF_FUNCTION_TYPE_4
5723 #undef DEF_FUNCTION_TYPE_5
5724 #undef DEF_FUNCTION_TYPE_6
5725 #undef DEF_FUNCTION_TYPE_7
5726 #undef DEF_FUNCTION_TYPE_8
5727 #undef DEF_FUNCTION_TYPE_9
5728 #undef DEF_FUNCTION_TYPE_10
5729 #undef DEF_FUNCTION_TYPE_11
5730 #undef DEF_FUNCTION_TYPE_VAR_0
5731 #undef DEF_FUNCTION_TYPE_VAR_1
5732 #undef DEF_FUNCTION_TYPE_VAR_2
5733 #undef DEF_FUNCTION_TYPE_VAR_3
5734 #undef DEF_FUNCTION_TYPE_VAR_4
5735 #undef DEF_FUNCTION_TYPE_VAR_5
5736 #undef DEF_FUNCTION_TYPE_VAR_6
5737 #undef DEF_FUNCTION_TYPE_VAR_7
5738 #undef DEF_POINTER_TYPE
5739 BT_LAST
5740 };
5744 /* A temporary array used in communication with def_fn_type. */
5747 /* A helper function for install_builtin_types. Build function type
5748 for DEF with return type RET and N arguments. If VAR is true, then the
5749 function should be variadic after those N arguments.
5751 Takes special care not to ICE if any of the types involved are
5752 error_mark_node, which indicates that said type is not in fact available
5753 (see builtin_type_for_size). In which case the function type as a whole
5754 should be error_mark_node. */
5756 static void
5758 {
5759 tree t;
5766 {
5772 }
5779 else
5782 egress:
5785 }
5787 /* Build the builtin function types and install them in the builtin_types
5788 array for later use in builtin function decls. */
5790 static void
5792 {
5793 tree va_list_ref_type_node;
5794 tree va_list_arg_type_node;
5797 {
5800 }
5801 else
5802 {
5805 }
5807 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
5808 builtin_types[ENUM] = VALUE;
5809 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \
5810 def_fn_type (ENUM, RETURN, 0, 0);
5811 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \
5812 def_fn_type (ENUM, RETURN, 0, 1, ARG1);
5813 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \
5814 def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2);
5815 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
5816 def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3);
5817 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
5818 def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4);
5819 #define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5820 def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
5821 #define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5822 ARG6) \
5823 def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
5824 #define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5825 ARG6, ARG7) \
5826 def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
5827 #define DEF_FUNCTION_TYPE_8(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5828 ARG6, ARG7, ARG8) \
5829 def_fn_type (ENUM, RETURN, 0, 8, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5830 ARG7, ARG8);
5831 #define DEF_FUNCTION_TYPE_9(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5832 ARG6, ARG7, ARG8, ARG9) \
5833 def_fn_type (ENUM, RETURN, 0, 9, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5834 ARG7, ARG8, ARG9);
5835 #define DEF_FUNCTION_TYPE_10(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5,\
5836 ARG6, ARG7, ARG8, ARG9, ARG10) \
5837 def_fn_type (ENUM, RETURN, 0, 10, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5838 ARG7, ARG8, ARG9, ARG10);
5839 #define DEF_FUNCTION_TYPE_11(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5,\
5840 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) \
5841 def_fn_type (ENUM, RETURN, 0, 11, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5842 ARG7, ARG8, ARG9, ARG10, ARG11);
5843 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \
5844 def_fn_type (ENUM, RETURN, 1, 0);
5845 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \
5846 def_fn_type (ENUM, RETURN, 1, 1, ARG1);
5847 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \
5848 def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2);
5849 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
5850 def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3);
5851 #define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
5852 def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
5853 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5854 def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
5855 #define DEF_FUNCTION_TYPE_VAR_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5856 ARG6) \
5857 def_fn_type (ENUM, RETURN, 1, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
5858 #define DEF_FUNCTION_TYPE_VAR_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5859 ARG6, ARG7) \
5860 def_fn_type (ENUM, RETURN, 1, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
5861 #define DEF_POINTER_TYPE(ENUM, TYPE) \
5862 builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
5866 #undef DEF_PRIMITIVE_TYPE
5867 #undef DEF_FUNCTION_TYPE_0
5868 #undef DEF_FUNCTION_TYPE_1
5869 #undef DEF_FUNCTION_TYPE_2
5870 #undef DEF_FUNCTION_TYPE_3
5871 #undef DEF_FUNCTION_TYPE_4
5872 #undef DEF_FUNCTION_TYPE_5
5873 #undef DEF_FUNCTION_TYPE_6
5874 #undef DEF_FUNCTION_TYPE_7
5875 #undef DEF_FUNCTION_TYPE_8
5876 #undef DEF_FUNCTION_TYPE_9
5877 #undef DEF_FUNCTION_TYPE_10
5878 #undef DEF_FUNCTION_TYPE_11
5879 #undef DEF_FUNCTION_TYPE_VAR_0
5880 #undef DEF_FUNCTION_TYPE_VAR_1
5881 #undef DEF_FUNCTION_TYPE_VAR_2
5882 #undef DEF_FUNCTION_TYPE_VAR_3
5883 #undef DEF_FUNCTION_TYPE_VAR_4
5884 #undef DEF_FUNCTION_TYPE_VAR_5
5885 #undef DEF_FUNCTION_TYPE_VAR_6
5886 #undef DEF_FUNCTION_TYPE_VAR_7
5887 #undef DEF_POINTER_TYPE
5889 }
5891 /* ----------------------------------------------------------------------- *
5892 * BUILTIN ATTRIBUTES *
5893 * ----------------------------------------------------------------------- */
5895 enum built_in_attribute
5896 {
5897 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
5898 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
5899 #define DEF_ATTR_STRING(ENUM, VALUE) ENUM,
5900 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
5901 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
5903 #undef DEF_ATTR_NULL_TREE
5904 #undef DEF_ATTR_INT
5905 #undef DEF_ATTR_STRING
5906 #undef DEF_ATTR_IDENT
5907 #undef DEF_ATTR_TREE_LIST
5908 ATTR_LAST
5909 };
5913 static void
5915 {
5916 /* Fill in the built_in_attributes array. */
5917 #define DEF_ATTR_NULL_TREE(ENUM) \
5918 built_in_attributes[(int) ENUM] = NULL_TREE;
5919 #define DEF_ATTR_INT(ENUM, VALUE) \
5920 built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
5921 #define DEF_ATTR_STRING(ENUM, VALUE) \
5922 built_in_attributes[(int) ENUM] = build_string (strlen (VALUE), VALUE);
5923 #define DEF_ATTR_IDENT(ENUM, STRING) \
5924 built_in_attributes[(int) ENUM] = get_identifier (STRING);
5925 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
5926 built_in_attributes[(int) ENUM] \
5927 = tree_cons (built_in_attributes[(int) PURPOSE], \
5928 built_in_attributes[(int) VALUE], \
5929 built_in_attributes[(int) CHAIN]);
5931 #undef DEF_ATTR_NULL_TREE
5932 #undef DEF_ATTR_INT
5933 #undef DEF_ATTR_STRING
5934 #undef DEF_ATTR_IDENT
5935 #undef DEF_ATTR_TREE_LIST
5936 }
5938 /* Handle a "const" attribute; arguments as in
5939 struct attribute_spec.handler. */
5941 static tree
5945 {
5948 else
5952 }
5954 /* Handle a "nothrow" attribute; arguments as in
5955 struct attribute_spec.handler. */
5957 static tree
5961 {
5964 else
5968 }
5970 /* Handle a "pure" attribute; arguments as in
5971 struct attribute_spec.handler. */
5973 static tree
5976 {
5979 /* TODO: support types. */
5980 else
5981 {
5985 }
5988 }
5990 /* Handle a "no vops" attribute; arguments as in
5991 struct attribute_spec.handler. */
5993 static tree
5997 {
6001 }
6003 /* Helper for nonnull attribute handling; fetch the operand number
6004 from the attribute argument list. */
6006 static bool
6008 {
6009 /* Verify the arg number is a constant. */
6015 }
6017 /* Handle the "nonnull" attribute. */
6018 static tree
6022 {
6026 /* If no arguments are specified, all pointer arguments should be
6027 non-null. Verify a full prototype is given so that the arguments
6028 will have the correct types when we actually check them later.
6029 Avoid diagnosing type-generic built-ins since those have no
6030 prototype. */
6032 {
6036 {
6039 }
6041 }
6043 /* Argument list specified. Verify that each argument number references
6044 a pointer argument. */
6046 {
6050 {
6055 }
6058 {
6059 function_args_iterator iter;
6060 tree argument;
6064 {
6068 }
6072 {
6078 }
6081 {
6087 }
6088 }
6089 }
6092 }
6094 /* Handle a "sentinel" attribute. */
6096 static tree
6099 {
6101 {
6106 }
6107 else
6108 {
6110 {
6115 }
6116 }
6119 {
6123 {
6126 }
6127 else
6128 {
6130 {
6133 }
6134 }
6135 }
6138 }
6140 /* Handle a "noreturn" attribute; arguments as in
6141 struct attribute_spec.handler. */
6143 static tree
6146 {
6149 /* See FIXME comment in c_common_attribute_table. */
6155 = build_pointer_type
6158 else
6159 {
6163 }
6166 }
6168 /* Handle a "noinline" attribute; arguments as in
6169 struct attribute_spec.handler. */
6171 static tree
6175 {
6177 {
6179 {
6183 }
6184 else
6186 }
6187 else
6188 {
6191 }
6194 }
6196 /* Handle a "noclone" attribute; arguments as in
6197 struct attribute_spec.handler. */
6199 static tree
6203 {
6205 {
6208 }
6211 }
6213 /* Handle a "leaf" attribute; arguments as in
6214 struct attribute_spec.handler. */
6216 static tree
6219 {
6221 {
6224 }
6226 {
6229 }
6232 }
6234 /* Handle a "always_inline" attribute; arguments as in
6235 struct attribute_spec.handler. */
6237 static tree
6240 {
6242 {
6243 /* Set the attribute and mark it for disregarding inline limits. */
6245 }
6246 else
6247 {
6250 }
6253 }
6255 /* Handle a "malloc" attribute; arguments as in
6256 struct attribute_spec.handler. */
6258 static tree
6261 {
6265 else
6266 {
6270 }
6273 }
6275 /* Fake handler for attributes we don't properly support. */
6277 tree
6283 {
6285 }
6287 /* Handle a "type_generic" attribute. */
6289 static tree
6293 {
6294 /* Ensure we have a function type. */
6297 /* Ensure we have a variadic function. */
6301 }
6303 /* Handle a "vector_size" attribute; arguments as in
6304 struct attribute_spec.handler. */
6306 static tree
6309 {
6311 tree vector_type;
6315 /* We need to provide for vector pointers, vector arrays, and
6316 functions returning vectors. For example:
6318 __attribute__((vector_size(16))) short *foo;
6320 In this case, the mode is SI, but the type being modified is
6321 HI, so we need to look further. */
6331 /* Build back pointers if needed. */
6335 }
6337 /* Handle a "vector_type" attribute; arguments as in
6338 struct attribute_spec.handler. */
6340 static tree
6343 {
6345 tree vector_type;
6350 {
6354 }
6364 }
6366 /* ----------------------------------------------------------------------- *
6367 * BUILTIN FUNCTIONS *
6368 * ----------------------------------------------------------------------- */
6370 /* Worker for DEF_BUILTIN. Possibly define a builtin function with one or two
6371 names. Does not declare a non-__builtin_ function if flag_no_builtin, or
6372 if nonansi_p and flag_no_nonansi_builtin. */
6374 static void
6382 {
6383 tree decl;
6386 /* Preserve an already installed decl. It most likely was setup in advance
6387 (e.g. as part of the internal builtins) for specific reasons. */
6398 fnattrs);
6400 /* ??? This is normally further controlled by command-line options
6401 like -fno-builtin, but we don't have them for Ada. */
6406 }
6412 /* Install what the common builtins.def offers. */
6414 static void
6416 {
6417 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
6418 NONANSI_P, ATTRS, IMPLICIT, COND) \
6419 if (NAME && COND) \
6420 def_builtin_1 (ENUM, NAME, CLASS, \
6421 builtin_types[(int) TYPE], \
6422 builtin_types[(int) LIBTYPE], \
6423 BOTH_P, FALLBACK_P, NONANSI_P, \
6424 built_in_attributes[(int) ATTRS], IMPLICIT);
6426 }
6428 /* ----------------------------------------------------------------------- *
6429 * BUILTIN FUNCTIONS *
6430 * ----------------------------------------------------------------------- */
6432 /* Install the builtin functions we might need. */
6434 void
6436 {
6441 /* Install builtins used by generic middle-end pieces first. Some of these
6442 know about internal specificities and control attributes accordingly, for
6443 instance __builtin_alloca vs no-throw and -fstack-check. We will ignore
6444 the generic definition from builtins.def. */
6447 /* Now, install the target specific builtins, such as the AltiVec family on
6448 ppc, and the common set as exposed by builtins.def. */
6451 }