| blob | 1c83a08d5bdd63885500a9f0c908aff5a8e6260c |
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. */
1085 /* If neither mode nor size nor alignment shrunk, return the old type. */
1090 }
1092 /* Return true if TYPE has an unsigned representation. This needs to be used
1093 when the representation of types whose precision is not equal to their size
1094 is manipulated based on the RM size. */
1098 {
1099 /* This is the common case. */
1103 /* See the E_Signed_Integer_Subtype case of gnat_to_gnu_entity. */
1109 }
1111 /* Given a type TYPE, return a new type whose size is appropriate for SIZE.
1112 If TYPE is the best type, return it. Otherwise, make a new type. We
1113 only support new integral and pointer types. FOR_BIASED is true if
1114 we are making a biased type. */
1116 tree
1118 {
1121 tree new_type;
1123 /* If size indicates an error, just return TYPE to avoid propagating
1124 the error. Likewise if it's too large to represent. */
1131 {
1138 /* Integer types with precision 0 are forbidden. */
1142 /* Only do something if the type isn't a packed array type and doesn't
1143 already have the proper size and the size isn't too large. */
1151 /* The type should be an unsigned type if the original type is unsigned
1152 or if the lower bound is constant and non-negative or if the type is
1153 biased, see E_Signed_Integer_Subtype case of gnat_to_gnu_entity. */
1156 else
1161 /* Copy the name to show that it's essentially the same type and
1162 not a subrange type. */
1169 /* Do something if this is a fat pointer, in which case we
1170 may need to return the thin pointer. */
1172 {
1173 scalar_int_mode p_mode;
1177 return
1178 build_pointer_type_for_mode
1181 }
1185 /* Only do something if this is a thin pointer, in which case we
1186 may need to return the fat pointer. */
1188 return
1194 }
1197 }
1199 /* Return true iff the padded types are equivalent. */
1201 bool
1203 {
1212 /* We consider that the padded types are equivalent if they pad the same type
1213 and have the same size, alignment, RM size and storage order. Taking the
1214 mode into account is redundant since it is determined by the others. */
1215 return
1221 }
1223 /* Look up the padded TYPE in the hash table and return its canonical version
1224 if it exists; otherwise, insert it into the hash table. */
1226 static tree
1228 {
1229 hashval_t hashcode;
1232 hashcode
1249 }
1251 /* Ensure that TYPE has SIZE and ALIGN. Make and return a new padded type
1252 if needed. We have already verified that SIZE and ALIGN are large enough.
1253 GNAT_ENTITY is used to name the resulting record and to issue a warning.
1254 IS_COMPONENT_TYPE is true if this is being done for the component type of
1255 an array. IS_USER_TYPE is true if the original type needs to be completed.
1256 DEFINITION is true if this type is being defined. SET_RM_SIZE is true if
1257 the RM size of the resulting type is to be set to SIZE too; in this case,
1258 the padded type is canonicalized before being returned. */
1260 tree
1264 {
1269 /* If TYPE is a padded type, see if it agrees with any size and alignment
1270 we were given. If so, return the original type. Otherwise, strip
1271 off the padding, since we will either be returning the inner type
1272 or repadding it. If no size or alignment is specified, use that of
1273 the original padded type. */
1275 {
1289 }
1291 /* If the size is either not being changed or is being made smaller (which
1292 is not done here and is only valid for bitfields anyway), show the size
1293 isn't changing. Likewise, clear the alignment if it isn't being
1294 changed. Then return if we aren't doing anything. */
1307 /* If requested, complete the original type and give it a name. */
1314 gnat_entity);
1316 /* We used to modify the record in place in some cases, but that could
1317 generate incorrect debugging information. So make a new record
1318 type and name. */
1322 /* ??? Padding types around packed array implementation types will be
1323 considered as root types in the array descriptor language hook (see
1324 gnat_get_array_descr_info). Give them the original packed array type
1325 name so that the one coming from sources appears in the debugging
1326 information. */
1339 bitsize_unit_node));
1341 /* If we are changing the alignment and the input type is a record with
1342 BLKmode and a small constant size, try to make a form that has an
1343 integral mode. This might allow the padding record to also have an
1344 integral mode, which will be much more efficient. There is no point
1345 in doing so if a size is specified unless it is also a small constant
1346 size and it is incorrect to do so if we cannot guarantee that the mode
1347 will be naturally aligned since the field must always be addressable.
1349 ??? This might not always be a win when done for a stand-alone object:
1350 since the nominal and the effective type of the object will now have
1351 different modes, a VIEW_CONVERT_EXPR will be required for converting
1352 between them and it might be hard to overcome afterwards, including
1353 at the RTL level when the stand-alone object is accessed as a whole. */
1361 && (!size
1364 {
1369 }
1371 /* Now create the field with the original size. */
1376 /* We will output additional debug info manually below. */
1382 /* Set the RM size if requested. */
1384 {
1385 tree canonical_pad_type;
1389 /* If the padded type is complete and has constant size, we canonicalize
1390 it by means of the hash table. This is consistent with the language
1391 semantics and ensures that gigi and the middle-end have a common view
1392 of these padded types. */
1395 {
1398 }
1399 }
1401 /* Unless debugging information isn't being written for the input type,
1402 write a record that shows what we are a subtype of and also make a
1403 variable that indicates our size, if still variable. */
1409 {
1413 /* A variable that holds the size is required even with no encoding since
1414 it will be referenced by debugging information attributes. At global
1415 level, we need a single variable across all translation units. */
1419 {
1420 /* Whether or not gnat_entity comes from source, this XVZ variable is
1421 is a compilation artifact. */
1422 size_unit
1428 }
1430 /* There is no need to show what we are a subtype of when outputting as
1431 few encodings as possible: regular debugging infomation makes this
1432 redundant. */
1434 {
1448 }
1449 }
1451 built:
1452 /* If a simple size was explicitly given, maybe issue a warning. */
1459 /* But don't do it if we are just annotating types and the type is tagged or
1460 concurrent, since these types aren't fully laid out in this mode. */
1462 {
1463 Entity_Id gnat_type
1464 = is_component_type
1469 }
1471 /* Take the original size as the maximum size of the input if there was an
1472 unconstrained record involved and round it up to the specified alignment,
1473 if one was specified, but only for aggregate types. */
1486 {
1489 /* For a packed array, post the message on the original array type. */
1500 /* Generate message only for entities that come from source, since
1501 if we have an entity created by expansion, the message will be
1502 generated for some other corresponding source entity. */
1504 {
1513 }
1514 }
1517 }
1519 /* Return a copy of the padded TYPE but with reverse storage order. */
1521 tree
1523 {
1527 {
1528 /* If the inner type is not scalar then the function does nothing. */
1532 }
1534 /* This is required for the canonicalization. */
1544 }
1545 \f
1546 /* Relate the alias sets of GNU_NEW_TYPE and GNU_OLD_TYPE according to OP.
1547 If this is a multi-dimensional array type, do this recursively.
1549 OP may be
1550 - ALIAS_SET_COPY: the new set is made a copy of the old one.
1551 - ALIAS_SET_SUPERSET: the new set is made a superset of the old one.
1552 - ALIAS_SET_SUBSET: the new set is made a subset of the old one. */
1554 void
1556 {
1557 /* Remove any padding from GNU_OLD_TYPE. It doesn't matter in the case
1558 of a one-dimensional array, since the padding has the same alias set
1559 as the field type, but if it's a multi-dimensional array, we need to
1560 see the inner types. */
1566 /* Unconstrained array types are deemed incomplete and would thus be given
1567 alias set 0. Retrieve the underlying array type. */
1569 gnu_old_type
1572 gnu_new_type
1581 {
1583 /* The alias set shouldn't be copied between array types with different
1584 aliasing settings because this can break the aliasing relationship
1585 between the array type and its element type. */
1597 {
1601 /* Do nothing if the alias sets conflict. This ensures that we
1602 never call record_alias_subset several times for the same pair
1603 or at all for alias set 0. */
1605 {
1608 else
1610 }
1611 }
1616 }
1619 }
1620 \f
1621 /* Record TYPE as a builtin type for Ada. NAME is the name of the type.
1622 ARTIFICIAL_P is true if the type was generated by the compiler. */
1624 void
1626 {
1635 }
1636 \f
1637 /* Finish constructing the character type CHAR_TYPE.
1639 In Ada character types are enumeration types and, as a consequence, are
1640 represented in the front-end by integral types holding the positions of
1641 the enumeration values as defined by the language, which means that the
1642 integral types are unsigned.
1644 Unfortunately the signedness of 'char' in C is implementation-defined
1645 and GCC even has the option -fsigned-char to toggle it at run time.
1646 Since GNAT's philosophy is to be compatible with C by default, to wit
1647 Interfaces.C.char is defined as a mere copy of Character, we may need
1648 to declare character types as signed types in GENERIC and generate the
1649 necessary adjustments to make them behave as unsigned types.
1651 The overall strategy is as follows: if 'char' is unsigned, do nothing;
1652 if 'char' is signed, translate character types of CHAR_TYPE_SIZE and
1653 character subtypes with RM_Size = Esize = CHAR_TYPE_SIZE into signed
1654 types. The idea is to ensure that the bit pattern contained in the
1655 Esize'd objects is not changed, even though the numerical value will
1656 be interpreted differently depending on the signedness. */
1658 void
1660 {
1664 /* Make a copy of a generic unsigned version since we'll modify it. */
1665 tree unsigned_char_type
1667 ? unsigned_char_type_node
1670 /* Create an unsigned version of the type and set it as debug type. */
1676 /* If this is a subtype, make the debug type a subtype of the debug type
1677 of the base type and convert literal RM bounds to unsigned. */
1679 {
1692 }
1694 /* Adjust the RM bounds of the original type to unsigned; that's especially
1695 important for types since they are implicit in this case. */
1698 }
1700 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
1701 finish constructing the record type as a fat pointer type. */
1703 void
1705 {
1706 /* Make sure we can put it into a register. */
1710 /* Show what it really is. */
1713 /* Do not emit debug info for it since the types of its fields may still be
1714 incomplete at this point. */
1717 /* Force type_contains_placeholder_p to return true on it. Although the
1718 PLACEHOLDER_EXPRs are referenced only indirectly, this isn't a pointer
1719 type but the representation of the unconstrained array. */
1721 }
1723 /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST,
1724 finish constructing the record or union type. If REP_LEVEL is zero, this
1725 record has no representation clause and so will be entirely laid out here.
1726 If REP_LEVEL is one, this record has a representation clause and has been
1727 laid out already; only set the sizes and alignment. If REP_LEVEL is two,
1728 this record is derived from a parent record and thus inherits its layout;
1729 only make a pass on the fields to finalize them. DEBUG_INFO_P is true if
1730 additional debug info needs to be output for this type. */
1732 void
1735 {
1743 tree field;
1747 /* Always attach the TYPE_STUB_DECL for a record type. It is required to
1748 generate debug info and have a parallel type. */
1751 /* Globally initialize the record first. If this is a rep'ed record,
1752 that just means some initializations; otherwise, layout the record. */
1754 {
1764 /* For all-repped records with a size specified, lay the QUAL_UNION_TYPE
1765 out just like a UNION_TYPE, since the size will be fixed. */
1768 }
1769 else
1770 {
1771 /* Ensure there isn't a size already set. There can be in an error
1772 case where there is a rep clause but all fields have errors and
1773 no longer have a position. */
1776 /* Ensure we use the traditional GCC layout for bitfields when we need
1777 to pack the record type or have a representation clause. The other
1778 possible layout (Microsoft C compiler), if available, would prevent
1779 efficient packing in almost all cases. */
1780 #ifdef TARGET_MS_BITFIELD_LAYOUT
1785 ATTR_FLAG_TYPE_IN_PLACE);
1786 #endif
1789 }
1791 /* At this point, the position and size of each field is known. It was
1792 either set before entry by a rep clause, or by laying out the type above.
1794 We now run a pass over the fields (in reverse order for QUAL_UNION_TYPEs)
1795 to compute the Ada size; the GCC size and alignment (for rep'ed records
1796 that are not padding types); and the mode (for rep'ed records). We also
1797 clear the DECL_BIT_FIELD indication for the cases we know have not been
1798 handled yet, and adjust DECL_NONADDRESSABLE_P accordingly. */
1804 {
1808 tree this_ada_size;
1815 else
1818 /* Clear DECL_BIT_FIELD for the cases layout_decl does not handle. */
1821 {
1824 /* In the general case, type alignment is required. */
1826 {
1827 /* The enclosing record type must be sufficiently aligned.
1828 Otherwise, if no alignment was specified for it and it
1829 has been laid out already, bump its alignment to the
1830 desired one if this is compatible with its size and
1831 maximum alignment, if any. */
1833 {
1836 }
1842 {
1846 }
1847 }
1849 /* In the non-strict alignment case, only byte alignment is. */
1854 }
1856 /* If we still have DECL_BIT_FIELD set at this point, we know that the
1857 field is technically not addressable. Except that it can actually
1858 be addressed if it is BLKmode and happens to be properly aligned. */
1864 /* A type must be as aligned as its most aligned field that is not
1865 a bit-field. But this is already enforced by layout_type. */
1871 {
1878 ada_size
1886 /* Since we know here that all fields are sorted in order of
1887 increasing bit position, the size of the record is one
1888 higher than the ending bit of the last field processed
1889 unless we have a rep clause, since in that case we might
1890 have a field outside a QUAL_UNION_TYPE that has a higher ending
1891 position. So use a MAX in that case. Also, if this field is a
1892 QUAL_UNION_TYPE, we need to take into account the previous size in
1893 the case of empty variants. */
1894 ada_size
1897 size
1904 }
1905 }
1911 {
1912 /* If this is a padding record, we never want to make the size smaller
1913 than what was specified in it, if any. */
1917 /* Now set any of the values we've just computed that apply. */
1923 {
1924 tree size_unit = had_size_unit
1928 bitsize_unit_node));
1936 }
1937 }
1939 /* Reset the TYPE_MAX_ALIGN field since it's private to gigi. */
1944 }
1946 /* Append PARALLEL_TYPE on the chain of parallel types of TYPE. If
1947 PARRALEL_TYPE has no context and its computation is not deferred yet, also
1948 propagate TYPE's context to PARALLEL_TYPE's or defer its propagation to the
1949 moment TYPE will get a context. */
1951 void
1953 {
1961 /* If PARALLEL_TYPE already has a context, we are done. */
1965 /* Otherwise, try to get one from TYPE's context. If so, simply propagate
1966 it to PARALLEL_TYPE. */
1970 /* Otherwise TYPE has not context yet. We know it will have one thanks to
1971 gnat_pushdecl and then its context will be propagated to PARALLEL_TYPE,
1972 so we have nothing to do in this case. */
1973 }
1975 /* Return true if TYPE has a parallel type. */
1977 static bool
1979 {
1983 }
1985 /* Wrap up compilation of RECORD_TYPE, i.e. output additional debug info
1986 associated with it. It need not be invoked directly in most cases as
1987 finish_record_type takes care of doing so. */
1989 void
1991 {
1993 tree field;
1995 /* If this is a padded type, the bulk of the debug info has already been
1996 generated for the field's type. */
2000 /* If the type already has a parallel type (XVS type), then we're done. */
2005 {
2006 /* We need to make an XVE/XVU record if any field has variable size,
2007 whether or not the record does. For example, if we have a union,
2008 it may be that all fields, rounded up to the alignment, have the
2009 same size, in which case we'll use that size. But the debug
2010 output routines (except Dwarf2) won't be able to output the fields,
2011 so we need to make the special record. */
2013 /* If a field has a non-constant qualifier, the record will have
2014 variable size too. */
2017 {
2020 }
2021 }
2023 /* If this record type is of variable size, make a parallel record type that
2024 will tell the debugger how the former is laid out (see exp_dbug.ads). */
2026 {
2027 tree new_record_type
2034 new_name
2048 /* Now scan all the fields, replacing each field with a new field
2049 corresponding to the new encoding. */
2052 {
2060 /* See how the position was modified from the last position.
2062 There are two basic cases we support: a value was added
2063 to the last position or the last position was rounded to
2064 a boundary and they something was added. Check for the
2065 first case first. If not, see if there is any evidence
2066 of rounding. If so, round the last position and retry.
2068 If this is a union, the position can be taken as zero. */
2071 else
2077 {
2083 }
2088 && tree_fits_uhwi_p
2090 {
2092 unsigned HOST_WIDE_INT addend
2094 align
2100 }
2102 {
2106 }
2108 /* If we can't compute a position, set it to zero.
2110 ??? We really should abort here, but it's too much work
2111 to get this correct for all cases. */
2115 /* See if this type is variable-sized and make a pointer type
2116 and indicate the indirection if so. Beware that the debug
2117 back-end may adjust the position computed above according
2118 to the alignment of the field type, i.e. the pointer type
2119 in this case, if we don't preventively counter that. */
2121 {
2124 {
2127 }
2129 }
2131 /* Make a new field name, if necessary. */
2133 {
2139 else
2143 }
2145 new_field
2151 /* If old_field is a QUAL_UNION_TYPE, take its size as being
2152 zero. The only time it's not the last field of the record
2153 is when there are other components at fixed positions after
2154 it (meaning there was a rep clause for every field) and we
2155 want to be able to encode them. */
2159 ? bitsize_zero_node
2162 }
2167 }
2168 }
2170 /* Utility function of above to merge LAST_SIZE, the previous size of a record
2171 with FIRST_BIT and SIZE that describe a field. SPECIAL is true if this
2172 represents a QUAL_UNION_TYPE in which case we must look for COND_EXPRs and
2173 replace a value of zero with the old size. If HAS_REP is true, we take the
2174 MAX of the end position of this field with LAST_SIZE. In all other cases,
2175 we use FIRST_BIT plus SIZE. Return an expression for the size. */
2177 static tree
2180 {
2182 tree new_size;
2185 {
2189 }
2191 else
2202 /* We don't need any NON_VALUE_EXPRs and they can confuse us (especially
2203 when fed through substitute_in_expr) into thinking that a constant
2204 size is not constant. */
2209 }
2211 /* Return the bit position of FIELD, in bits from the start of the record,
2212 and fold it as much as possible. This is a tree of type bitsizetype. */
2214 static tree
2216 {
2222 else
2226 }
2228 /* Utility function of above to see if OP0 and OP1, both of SIZETYPE, are
2229 related by the addition of a constant. Return that constant if so. */
2231 static tree
2233 {
2240 {
2244 }
2245 else
2256 }
2258 /* Utility function of above to split a tree OP which may be a sum, into a
2259 constant part, which is returned, and a variable part, which is stored
2260 in *PVAR. *PVAR may be bitsize_zero_node. All operations must be of
2261 bitsizetype. */
2263 static tree
2265 {
2266 /* Strip conversions in order to ease the tree traversal and maximize the
2267 potential for constant or plus/minus discovery. We need to be careful
2268 to always return and set *pvar to bitsizetype trees, but it's worth
2269 the effort. */
2275 {
2278 }
2280 {
2291 }
2292 else
2294 }
2295 \f
2296 /* Return a copy of TYPE but safe to modify in any way. */
2298 tree
2300 {
2303 /* Unshare the language-specific data. */
2305 {
2308 }
2310 /* And the contents of the language-specific slot if needed. */
2313 {
2318 }
2320 /* copy_node clears this field instead of copying it, because it is
2321 aliased with TREE_CHAIN. */
2331 }
2332 \f
2333 /* Return a subtype of sizetype with range MIN to MAX and whose
2334 TYPE_INDEX_TYPE is INDEX. GNAT_NODE is used for the position
2335 of the associated TYPE_DECL. */
2337 tree
2339 {
2340 /* First build a type for the desired range. */
2343 /* Then set the index type. */
2348 }
2350 /* Return a subtype of TYPE with range MIN to MAX. If TYPE is NULL,
2351 sizetype is used. */
2353 tree
2355 {
2356 tree range_type;
2361 /* First build a type with the base range. */
2365 /* Then set the actual range. */
2370 }
2371 \f
2372 /* Return a TYPE_DECL node suitable for the TYPE_STUB_DECL field of TYPE.
2373 NAME gives the name of the type to be used in the declaration. */
2375 tree
2377 {
2382 }
2384 /* Return a TYPE_DECL node for TYPE. NAME gives the name of the type to be
2385 used in the declaration. ARTIFICIAL_P is true if the declaration was
2386 generated by the compiler. DEBUG_INFO_P is true if we need to write
2387 debug information about this type. GNAT_NODE is used for the position
2388 of the decl. */
2390 tree
2392 Node_Id gnat_node)
2393 {
2395 bool is_named
2397 tree type_decl;
2399 /* Only the builtin TYPE_STUB_DECL should be used for dummy types. */
2402 /* If the type hasn't been named yet, we're naming it; preserve an existing
2403 TYPE_STUB_DECL that has been attached to it for some purpose. */
2405 {
2408 }
2409 else
2415 /* Add this decl to the current binding level. */
2418 /* If we're naming the type, equate the TYPE_STUB_DECL to the name. This
2419 causes the name to be also viewed as a "tag" by the debug back-end, with
2420 the advantage that no DW_TAG_typedef is emitted for artificial "tagged"
2421 types in DWARF.
2423 Note that if "type" is used as a DECL_ORIGINAL_TYPE, it may be referenced
2424 from multiple contexts, and "type_decl" references a copy of it: in such a
2425 case, do not mess TYPE_STUB_DECL: we do not want to re-use the TYPE_DECL
2426 with the mechanism above. */
2430 /* Do not generate debug info for UNCONSTRAINED_ARRAY_TYPE that the
2431 back-end doesn't support, and for others if we don't need to. */
2436 }
2437 \f
2438 /* Return a VAR_DECL or CONST_DECL node.
2440 NAME gives the name of the variable. ASM_NAME is its assembler name
2441 (if provided). TYPE is its data type (a GCC ..._TYPE node). INIT is
2442 the GCC tree for an optional initial expression; NULL_TREE if none.
2444 CONST_FLAG is true if this variable is constant, in which case we might
2445 return a CONST_DECL node unless CONST_DECL_ALLOWED_P is false.
2447 PUBLIC_FLAG is true if this is for a reference to a public entity or for a
2448 definition to be made visible outside of the current compilation unit, for
2449 instance variable definitions in a package specification.
2451 EXTERN_FLAG is true when processing an external variable declaration (as
2452 opposed to a definition: no storage is to be allocated for the variable).
2454 STATIC_FLAG is only relevant when not at top level and indicates whether
2455 to always allocate storage to the variable.
2457 VOLATILE_FLAG is true if this variable is declared as volatile.
2459 ARTIFICIAL_P is true if the variable was generated by the compiler.
2461 DEBUG_INFO_P is true if we need to write debug information for it.
2463 ATTR_LIST is the list of attributes to be attached to the variable.
2465 GNAT_NODE is used for the position of the decl. */
2467 tree
2473 {
2474 /* Whether the object has static storage duration, either explicitly or by
2475 virtue of being declared at the global level. */
2478 /* Whether the initializer is constant: for an external object or an object
2479 with static storage duration, we check that the initializer is a valid
2480 constant expression for initializing a static variable; otherwise, we
2481 only check that it is constant. */
2482 const bool init_const
2483 = (init
2487 != NULL_TREE
2490 /* Whether we will make TREE_CONSTANT the DECL we produce here, in which
2491 case the initializer may be used in lieu of the DECL node (as done in
2492 Identifier_to_gnu). This is useful to prevent the need of elaboration
2493 code when an identifier for which such a DECL is made is in turn used
2494 as an initializer. We used to rely on CONST_DECL vs VAR_DECL for this,
2495 but extra constraints apply to this choice (see below) and they are not
2496 relevant to the distinction we wish to make. */
2499 /* The actual DECL node. CONST_DECL was initially intended for enumerals
2500 and may be used for scalars in general but not for aggregates. */
2501 tree var_decl
2503 (constant_p
2504 && const_decl_allowed_p
2508 /* Detect constants created by the front-end to hold 'reference to function
2509 calls for stabilization purposes. This is needed for renaming. */
2511 {
2522 }
2524 /* If this is external, throw away any initializations (they will be done
2525 elsewhere) unless this is a constant for which we would like to remain
2526 able to get the initializer. If we are defining a global here, leave a
2527 constant initialization and save any variable elaborations for the
2528 elaboration routine. If we are just annotating types, throw away the
2529 initialization if it isn't a constant. */
2534 /* At the global level, a non-constant initializer generates elaboration
2535 statements. Check that such statements are allowed, that is to say,
2536 not violating a No_Elaboration_Code restriction. */
2540 /* Attach the initializer, if any. */
2543 /* Directly set some flags. */
2550 /* The object is public if it is external or if it is declared public
2551 and has static storage duration. */
2554 /* We need to allocate static storage for an object with static storage
2555 duration if it isn't external. */
2565 /* Ada doesn't feature Fortran-like COMMON variables so we shouldn't
2566 try to fiddle with DECL_COMMON. However, on platforms that don't
2567 support global BSS sections, uninitialized global variables would
2568 go in DATA instead, thus increasing the size of the executable. */
2575 /* Do not emit debug info for a CONST_DECL if optimization isn't enabled,
2576 since we will create an associated variable. Likewise for an external
2577 constant whose initializer is not absolute, because this would mean a
2578 global relocation in a read-only section which runs afoul of the PE-COFF
2579 run-time relocation mechanism. */
2582 || (extern_flag
2583 && constant_p
2584 && init
2589 /* ??? Some attributes cannot be applied to CONST_DECLs. */
2593 /* Add this decl to the current binding level. */
2597 {
2598 /* Let the target mangle the name if this isn't a verbatim asm. */
2603 }
2606 }
2607 \f
2608 /* Return true if TYPE, an aggregate type, contains (or is) an array. */
2610 static bool
2612 {
2614 {
2618 {
2619 tree field;
2625 }
2632 }
2633 }
2635 /* Return a FIELD_DECL node. NAME is the field's name, TYPE is its type and
2636 RECORD_TYPE is the type of the enclosing record. If SIZE is nonzero, it
2637 is the specified size of the field. If POS is nonzero, it is the bit
2638 position. PACKED is 1 if the enclosing record is packed, -1 if it has
2639 Component_Alignment of Storage_Unit. If ADDRESSABLE is nonzero, it
2640 means we are allowed to take the address of the field; if it is negative,
2641 we should not make a bitfield, which is used by make_aligning_type. */
2643 tree
2646 {
2652 /* If FIELD_TYPE is BLKmode, we must ensure this is aligned to at least a
2653 byte boundary since GCC cannot handle less-aligned BLKmode bitfields.
2654 Likewise for an aggregate without specified position that contains an
2655 array, because in this case slices of variable length of this array
2656 must be handled by GCC and variable-sized objects need to be aligned
2657 to at least a byte boundary. */
2659 || (!pos
2664 /* If a size is specified, use it. Otherwise, if the record type is packed
2665 compute a size to use, which may differ from the object's natural size.
2666 We always set a size in this case to trigger the checks for bitfield
2667 creation below, which is typically required when no position has been
2668 specified. */
2672 {
2676 }
2678 /* If we may, according to ADDRESSABLE, make a bitfield if a size is
2679 specified for two reasons: first if the size differs from the natural
2680 size. Second, if the alignment is insufficient. There are a number of
2681 ways the latter can be true.
2683 We never make a bitfield if the type of the field has a nonconstant size,
2684 because no such entity requiring bitfield operations should reach here.
2686 We do *preventively* make a bitfield when there might be the need for it
2687 but we don't have all the necessary information to decide, as is the case
2688 of a field with no specified position in a packed record.
2690 We also don't look at STRICT_ALIGNMENT here, and rely on later processing
2691 in layout_decl or finish_record_type to clear the bit_field indication if
2692 it is in fact not needed. */
2694 && size
2699 || packed
2702 {
2706 {
2710 else
2712 }
2713 }
2717 /* Bump the alignment if need be, either for bitfield/packing purposes or
2718 to satisfy the type requirements if no such consideration applies. When
2719 we get the alignment from the type, indicate if this is from an explicit
2720 user request, which prevents stor-layout from lowering it later on. */
2721 {
2722 unsigned int bit_align
2729 {
2732 }
2733 }
2736 {
2737 /* We need to pass in the alignment the DECL is known to have.
2738 This is the lowest-order bit set in POS, but no more than
2739 the alignment of the record, if one is specified. Note
2740 that an alignment of 0 is taken as infinite. */
2745 else
2759 }
2761 /* In addition to what our caller says, claim the field is addressable if we
2762 know that its type is not suitable.
2764 The field may also be "technically" nonaddressable, meaning that even if
2765 we attempt to take the field's address we will actually get the address
2766 of a copy. This is the case for true bitfields, but the DECL_BIT_FIELD
2767 value we have at this point is not accurate enough, so we don't account
2768 for this here and let finish_record_type decide. */
2775 }
2776 \f
2777 /* Return a PARM_DECL node with NAME and TYPE. */
2779 tree
2781 {
2784 /* Honor TARGET_PROMOTE_PROTOTYPES like the C compiler, as not doing so
2785 can lead to various ABI violations. */
2789 {
2790 /* We have to be careful about biased types here. Make a subtype
2791 of integer_type_node with the proper biasing. */
2794 {
2795 tree subtype
2802 }
2803 else
2805 }
2809 }
2810 \f
2811 /* Process the attributes in ATTR_LIST for NODE, which is either a DECL or
2812 a TYPE. If IN_PLACE is true, the tree pointed to by NODE should not be
2813 changed. GNAT_NODE is used for the position of error messages. */
2815 void
2817 Node_Id gnat_node)
2818 {
2823 {
2832 {
2835 }
2841 else
2848 {
2851 }
2852 else
2871 }
2874 }
2876 /* Return true if VALUE is a known to be a multiple of FACTOR, which must be
2877 a power of 2. */
2879 bool
2881 {
2890 }
2892 /* Return whether GNAT_NODE is a defining identifier for a renaming that comes
2893 from the parameter association for the instantiation of a generic. We do
2894 not want to emit source location for them: the code generated for their
2895 initialization is likely to disturb debugging. */
2897 bool
2899 {
2906 /* Get the object declaration of the renamed object, if any and if the
2907 renamed object is a mere identifier. */
2917 return
2921 }
2923 /* Defer the initialization of DECL's DECL_CONTEXT attribute, scheduling to
2924 feed it with the elaboration of GNAT_SCOPE. */
2928 {
2931 new_node
2940 }
2942 /* Defer the initialization of TYPE's TYPE_CONTEXT attribute, scheduling to
2943 feed it with the DECL_CONTEXT computed as part of N as soon as it is
2944 computed. */
2946 static void
2948 {
2950 }
2952 /* Get the GENERIC node corresponding to GNAT_SCOPE, if available. Return
2953 NULL_TREE if it is not available. */
2955 static tree
2957 {
2958 tree context;
2962 else
2966 {
2969 /* Skip dummy types: only the final ones can appear in the context
2970 chain. */
2974 /* ..._TYPE nodes are more useful than TYPE_DECL nodes in the context
2975 chain. */
2976 else
2978 }
2981 }
2983 /* Try to process all deferred nodes in the queue. Keep in the queue the ones
2984 that cannot be processed yet, remove the other ones. If FORCE is true,
2985 force the processing for all nodes, use the global context when nodes don't
2986 have a GNU translation. */
2988 void
2990 {
2995 {
2998 Entity_Id gnat_scope;
3002 /* If FORCE, get the innermost elaborated scope. Otherwise, just try to
3003 get the first scope. */
3006 {
3011 }
3013 /* Imported declarations must not be in a local context (i.e. not inside
3014 a function). */
3016 {
3020 {
3023 }
3024 }
3026 /* If FORCE, we want to get rid of all nodes in the queue: in case there
3027 was no elaborated scope, use the global context. */
3032 {
3033 tree t;
3038 /* Propagate it to the TYPE_CONTEXT attributes of the requested
3039 ..._TYPE nodes. */
3041 {
3043 }
3045 }
3047 /* If this node has been successfuly processed, remove it from the
3048 queue. Then move to the next node. */
3050 {
3054 }
3055 else
3057 }
3058 }
3060 /* Return VALUE scaled by the biggest power-of-2 factor of EXPR. */
3062 static unsigned int
3064 {
3068 /* Peel conversions around EXPR and try to extract bodies from function
3069 calls: it is possible to get the scale factor from size functions. */
3074 /* Sometimes we get PLUS_EXPR (BIT_AND_EXPR (..., X), Y), where Y is a
3075 multiple of the scale factor we are looking for. */
3079 {
3082 }
3084 /* An expression which is a bitwise AND with a mask has a power-of-2 factor
3085 corresponding to the number of trailing zeros of the mask. */
3088 {
3093 {
3096 i++;
3097 }
3098 }
3100 /* If the addend is not a multiple of the factor we found, give up. In
3101 theory we could find a smaller common factor but it's useless for our
3102 needs. This situation arises when dealing with a field F1 with no
3103 alignment requirement but that is following a field F2 with such
3104 requirements. As long as we have F2's offset, we don't need alignment
3105 information to compute F1's. */
3110 }
3112 /* Given two consecutive field decls PREV_FIELD and CURR_FIELD, return true
3113 unless we can prove these 2 fields are laid out in such a way that no gap
3114 exist between the end of PREV_FIELD and the beginning of CURR_FIELD. OFFSET
3115 is the distance in bits between the end of PREV_FIELD and the starting
3116 position of CURR_FIELD. It is ignored if null. */
3118 static bool
3120 {
3121 /* If this is the first field of the record, there cannot be any gap */
3125 /* If the previous field is a union type, then return false: The only
3126 time when such a field is not the last field of the record is when
3127 there are other components at fixed positions after it (meaning there
3128 was a rep clause for every field), in which case we don't want the
3129 alignment constraint to override them. */
3133 /* If the distance between the end of prev_field and the beginning of
3134 curr_field is constant, then there is a gap if the value of this
3135 constant is not null. */
3139 /* If the size and position of the previous field are constant,
3140 then check the sum of this size and position. There will be a gap
3141 iff it is not multiple of the current field alignment. */
3148 /* If both the position and size of the previous field are multiples
3149 of the current field alignment, there cannot be any gap. */
3154 /* Fallback, return that there may be a potential gap */
3156 }
3158 /* Return a LABEL_DECL with NAME. GNAT_NODE is used for the position of
3159 the decl. */
3161 tree
3163 {
3164 tree label_decl
3169 /* Add this decl to the current binding level. */
3173 }
3174 \f
3175 /* Return a FUNCTION_DECL node. NAME is the name of the subprogram, ASM_NAME
3176 its assembler name, TYPE its type (a FUNCTION_TYPE node), PARAM_DECL_LIST
3177 the list of its parameters (a list of PARM_DECL nodes chained through the
3178 DECL_CHAIN field).
3180 INLINE_STATUS describes the inline flags to be set on the FUNCTION_DECL.
3182 PUBLIC_FLAG is true if this is for a reference to a public entity or for a
3183 definition to be made visible outside of the current compilation unit.
3185 EXTERN_FLAG is true when processing an external subprogram declaration.
3187 ARTIFICIAL_P is true if the subprogram was generated by the compiler.
3189 DEBUG_INFO_P is true if we need to write debug information for it.
3191 DEFINITION is true if the subprogram is to be considered as a definition.
3193 ATTR_LIST is the list of attributes to be attached to the subprogram.
3195 GNAT_NODE is used for the position of the decl. */
3197 tree
3202 Node_Id gnat_node)
3203 {
3217 {
3227 {
3231 ATTR_FLAG_TYPE_IN_PLACE);
3233 /* Inline_Always guarantees that every direct call is inlined and
3234 that there is no indirect reference to the subprogram, so the
3235 instance in the original package (as well as its clones in the
3236 client packages created for inter-unit inlining) can be made
3237 private, which causes the out-of-line body to be eliminated. */
3239 }
3241 /* ... fall through ... */
3250 }
3254 /* Once everything is processed, finish the subprogram declaration. */
3257 /* Add this decl to the current binding level. */
3260 /* Output the assembler code and/or RTL for the declaration. */
3264 }
3266 /* Given a subprogram declaration DECL, its assembler name and its type,
3267 finish constructing the subprogram declaration from ASM_NAME and TYPE. */
3269 void
3271 {
3272 tree result_decl
3285 {
3286 /* Let the target mangle the name if this isn't a verbatim asm. */
3292 /* The expand_main_function circuitry expects "main_identifier_node" to
3293 designate the DECL_NAME of the 'main' entry point, in turn expected
3294 to be declared as the "main" function literally by default. Ada
3295 program entry points are typically declared with a different name
3296 within the binder generated file, exported as 'main' to satisfy the
3297 system expectations. Force main_identifier_node in this case. */
3300 }
3301 }
3302 \f
3303 /* Set up the framework for generating code for SUBPROG_DECL, a subprogram
3304 body. This routine needs to be invoked before processing the declarations
3305 appearing in the subprogram. */
3307 void
3309 {
3310 tree param_decl;
3314 /* This function is being defined. */
3317 /* The failure of this assertion will likely come from a wrong context for
3318 the subprogram body, e.g. another procedure for a procedure declared at
3319 library level. */
3324 /* Enter a new binding level and show that all the parameters belong to
3325 this function. */
3333 }
3335 /* Finish translating the current subprogram and set its BODY. */
3337 void
3339 {
3342 /* Attach the BLOCK for this level to the function and pop the level. */
3347 /* Mark the RESULT_DECL as being in this subprogram. */
3350 /* The body should be a BIND_EXPR whose BLOCK is the top-level one. */
3352 {
3355 }
3360 }
3362 /* Wrap up compilation of SUBPROG_DECL, a subprogram body. */
3364 void
3366 {
3367 /* We cannot track the location of errors past this point. */
3370 /* If we're only annotating types, don't actually compile this function. */
3374 /* Dump functions before gimplification. */
3379 else
3380 /* Register this function with cgraph just far enough to get it
3381 added to our parent's nested function list. */
3383 }
3385 tree
3387 {
3390 }
3392 /* Return an integer type with the number of bits of precision given by
3393 PRECISION. UNSIGNEDP is nonzero if the type is unsigned; otherwise
3394 it is a signed type. */
3396 tree
3398 {
3399 tree t;
3408 else
3416 {
3419 }
3422 }
3424 /* Likewise for floating-point types. */
3426 static tree
3428 {
3429 tree t;
3441 {
3444 }
3447 }
3449 /* Return a data type that has machine mode MODE. UNSIGNEDP selects
3450 an unsigned type; otherwise a signed type is returned. */
3452 tree
3454 {
3464 scalar_float_mode float_mode;
3467 float_mode);
3469 scalar_int_mode int_mode;
3474 {
3479 }
3482 }
3484 /* Return the signed or unsigned version of TYPE_NODE, a scalar type, the
3485 signedness being specified by UNSIGNEDP. */
3487 tree
3489 {
3496 {
3499 }
3503 {
3506 }
3509 }
3511 /* Return 1 if the types T1 and T2 are compatible, i.e. if they can be
3512 transparently converted to each other. */
3514 int
3516 {
3519 /* This is the default criterion. */
3523 /* We only check structural equivalence here. */
3527 /* Vector types are also compatible if they have the same number of subparts
3528 and the same form of (scalar) element type. */
3535 /* Array types are also compatible if they are constrained and have the same
3536 domain(s), the same component type and the same scalar storage order. */
3552 }
3554 /* Return true if EXPR is a useless type conversion. */
3556 bool
3558 {
3566 }
3568 /* Return true if T, a FUNCTION_TYPE, has the specified list of flags. */
3570 bool
3573 {
3578 }
3579 \f
3580 /* EXP is an expression for the size of an object. If this size contains
3581 discriminant references, replace them with the maximum (if MAX_P) or
3582 minimum (if !MAX_P) possible value of the discriminant. */
3584 tree
3586 {
3592 {
3599 {
3613 }
3617 /* If this contains a PLACEHOLDER_EXPR, it is the thing we want to
3618 modify. Otherwise, we treat it like a variable. */
3620 {
3623 return
3626 }
3646 {
3651 /* Special-case wanting the maximum value of a MIN_EXPR.
3652 In that case, if one side overflows, return the other. */
3654 {
3660 }
3662 /* Likewise, handle a MINUS_EXPR or PLUS_EXPR with the LHS
3663 overflowing and the RHS a variable. */
3670 /* If we are going to subtract a "negative" value in an unsigned type,
3671 do the operation as an addition of the negated value, in order to
3672 avoid creating a spurious overflow below. */
3678 {
3681 }
3686 /* We need to detect overflows so we call size_binop here. */
3688 }
3692 {
3719 {
3726 return
3729 }
3734 }
3736 /* Other tree classes cannot happen. */
3739 }
3742 }
3743 \f
3744 /* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE.
3745 EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs.
3746 Return a constructor for the template. */
3748 tree
3750 {
3753 tree field;
3765 /* First make the list for a CONSTRUCTOR for the template. Go down the
3766 field list of the template instead of the type chain because this
3767 array might be an Ada array of arrays and we can't tell where the
3768 nested arrays stop being the underlying object. */
3771 (bound_list
3775 {
3778 /* If we have a bound list, get the bounds from there. Likewise
3779 for an ARRAY_TYPE. Otherwise, if expr is a PARM_DECL with
3780 DECL_BY_COMPONENT_PTR_P, use the bounds of the field in the template.
3781 This will give us a maximum range. */
3789 else
3795 /* If either MIN or MAX involve a PLACEHOLDER_EXPR, we must
3796 substitute it from OBJECT. */
3802 }
3805 }
3806 \f
3807 /* Return true if TYPE is suitable for the element type of a vector. */
3809 static bool
3811 {
3812 machine_mode mode;
3826 }
3828 /* Return a vector type given the SIZE and the INNER_TYPE, or NULL_TREE if
3829 this is not possible. If ATTRIBUTE is non-zero, we are processing the
3830 attribute declaration and want to issue error messages on failure. */
3832 static tree
3834 {
3838 /* Silently punt on variable sizes. We can't make vector types for them,
3839 need to ignore them on front-end generated subtypes of unconstrained
3840 base types, and this attribute is for binding implementors, not end
3841 users, so we should never get there from legitimate explicit uses. */
3847 {
3852 }
3856 {
3860 }
3863 {
3867 }
3871 {
3875 }
3878 }
3880 /* Return a vector type whose representative array type is ARRAY_TYPE, or
3881 NULL_TREE if this is not possible. If ATTRIBUTE is non-zero, we are
3882 processing the attribute and want to issue error messages on failure. */
3884 static tree
3886 {
3889 attribute);
3895 }
3896 \f
3897 /* Build a type to be used to represent an aliased object whose nominal type
3898 is an unconstrained array. This consists of a RECORD_TYPE containing a
3899 field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an ARRAY_TYPE.
3900 If ARRAY_TYPE is that of an unconstrained array, this is used to represent
3901 an arbitrary unconstrained object. Use NAME as the name of the record.
3902 DEBUG_INFO_P is true if we need to write debug information for the type. */
3904 tree
3907 {
3908 tree decl;
3910 tree template_field
3913 tree array_field
3922 /* Declare it now since it will never be declared otherwise. This is
3923 necessary to ensure that its subtrees are properly marked. */
3926 /* template_type will not be used elsewhere than here, so to keep the debug
3927 info clean and in order to avoid scoping issues, make decl its
3928 context. */
3932 }
3934 /* Same, taking a thin or fat pointer type instead of a template type. */
3936 tree
3939 {
3940 tree template_type;
3944 template_type
3949 return
3951 }
3952 \f
3953 /* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE.
3954 In the normal case this is just two adjustments, but we have more to
3955 do if NEW_TYPE is an UNCONSTRAINED_ARRAY_TYPE. */
3957 void
3959 {
3962 tree t;
3964 /* If this is the main variant, process all the other variants first. */
3969 /* If no pointers and no references, we are done. */
3973 /* Merge the old type qualifiers in the new type.
3975 Each old variant has qualifiers for specific reasons, and the new
3976 designated type as well. Each set of qualifiers represents useful
3977 information grabbed at some point, and merging the two simply unifies
3978 these inputs into the final type description.
3980 Consider for instance a volatile type frozen after an access to constant
3981 type designating it; after the designated type's freeze, we get here with
3982 a volatile NEW_TYPE and a dummy OLD_TYPE with a readonly variant, created
3983 when the access type was processed. We will make a volatile and readonly
3984 designated type, because that's what it really is.
3986 We might also get here for a non-dummy OLD_TYPE variant with different
3987 qualifiers than those of NEW_TYPE, for instance in some cases of pointers
3988 to private record type elaboration (see the comments around the call to
3989 this routine in gnat_to_gnu_entity <E_Access_Type>). We have to merge
3990 the qualifiers in those cases too, to avoid accidentally discarding the
3991 initial set, and will often end up with OLD_TYPE == NEW_TYPE then. */
3992 new_type
3996 /* If old type and new type are identical, there is nothing to do. */
4000 /* Otherwise, first handle the simple case. */
4002 {
4005 /* If pointer or reference already points to new type, nothing to do.
4006 This can happen as update_pointer_to can be invoked multiple times
4007 on the same couple of types because of the type variants. */
4012 /* Chain PTR and its variants at the end. */
4015 {
4019 }
4020 else
4023 /* Now adjust them. */
4026 {
4030 }
4032 /* Chain REF and its variants at the end. */
4035 {
4039 }
4040 else
4043 /* Now adjust them. */
4050 }
4052 /* Now deal with the unconstrained array case. In this case the pointer
4053 is actually a record where both fields are pointers to dummy nodes.
4054 Turn them into pointers to the correct types using update_pointer_to.
4055 Likewise for the pointer to the object record (thin pointer). */
4056 else
4057 {
4062 /* If PTR already points to NEW_TYPE, nothing to do. This can happen
4063 since update_pointer_to can be invoked multiple times on the same
4064 couple of types because of the type variants. */
4068 update_pointer_to
4072 update_pointer_to
4081 }
4082 }
4083 \f
4084 /* Convert EXPR, a pointer to a constrained array, into a pointer to an
4085 unconstrained one. This involves making or finding a template. */
4087 static tree
4089 {
4093 tree template_addr;
4097 /* If EXPR is null, make a fat pointer that contains a null pointer to the
4098 array (compare_fat_pointers ensures that this is the full discriminant)
4099 and a valid pointer to the bounds. This latter property is necessary
4100 since the compiler can hoist the load of the bounds done through it. */
4102 {
4108 else
4109 {
4110 /* The template type can still be dummy at this point so we build an
4111 empty constructor. The middle-end will fill it in with zeros. */
4116 }
4122 /* Do not set TREE_CONSTANT so as to force T to static memory. */
4127 }
4129 /* If EXPR is a thin pointer, make template and data from the record. */
4131 {
4136 /* If we have a TYPE_UNCONSTRAINED_ARRAY attached to the RECORD_TYPE,
4137 the thin pointer value has been shifted so we shift it back to get
4138 the template address. */
4140 {
4141 template_addr
4144 byte_position
4146 template_addr
4148 template_addr);
4149 }
4151 /* Otherwise we explicitly take the address of the fields. */
4152 else
4153 {
4155 template_addr
4161 }
4162 }
4164 /* Otherwise, build the constructor for the template. */
4165 else
4166 template_addr
4169 expr));
4171 /* The final result is a constructor for the fat pointer.
4173 If EXPR is an argument of a foreign convention subprogram, the type it
4174 points to is directly the component type. In this case, the expression
4175 type may not match the corresponding FIELD_DECL type at this point, so we
4176 call "convert" here to fix that up if necessary. This type consistency is
4177 required, for instance because it ensures that possible later folding of
4178 COMPONENT_REFs against this constructor always yields something of the
4179 same type as the initial reference.
4181 Note that the call to "build_template" above is still fine because it
4182 will only refer to the provided TEMPLATE_TYPE in this case. */
4186 }
4187 \f
4188 /* Create an expression whose value is that of EXPR,
4189 converted to type TYPE. The TREE_TYPE of the value
4190 is always TYPE. This function implements all reasonable
4191 conversions; callers should filter out those that are
4192 not permitted by the language being compiled. */
4194 tree
4196 {
4201 /* If the expression is already of the right type, we are done. */
4205 /* If both input and output have padding and are of variable size, do this
4206 as an unchecked conversion. Likewise if one is a mere variant of the
4207 other, so we avoid a pointless unpad/repad sequence. */
4215 ;
4217 /* If the output type has padding, convert to the inner type and make a
4218 constructor to build the record, unless a variable size is involved. */
4220 {
4223 /* If we previously converted from another type and our type is
4224 of variable size, remove the conversion to avoid the need for
4225 variable-sized temporaries. Likewise for a conversion between
4226 original and packable version. */
4234 /* If we are just removing the padding from expr, convert the original
4235 object if we have variable size in order to avoid the need for some
4236 variable-sized temporaries. Likewise if the padding is a variant
4237 of the other, so we avoid a pointless unpad/repad sequence. */
4248 /* If the inner type is of self-referential size and the expression type
4249 is a record, do this as an unchecked conversion. But first pad the
4250 expression if possible to have the same size on both sides. */
4253 {
4257 expr);
4259 }
4261 /* If we are converting between array types with variable size, do the
4262 final conversion as an unchecked conversion, again to avoid the need
4263 for some variable-sized temporaries. If valid, this conversion is
4264 very likely purely technical and without real effects. */
4271 expr),
4278 }
4280 /* If the input type has padding, remove it and convert to the output type.
4281 The conditions ordering is arranged to ensure that the output type is not
4282 a padding type here, as it is not clear whether the conversion would
4283 always be correct if this was to happen. */
4285 {
4286 tree unpadded;
4288 /* If we have just converted to this padded type, just get the
4289 inner expression. */
4293 /* Otherwise, build an explicit component reference. */
4294 else
4298 }
4300 /* If the input is a biased type, convert first to the base type and add
4301 the bias. Note that the bias must go through a full conversion to the
4302 base type, lest it is itself a biased value; this happens for subtypes
4303 of biased types. */
4310 /* If the input is a justified modular type, we need to extract the actual
4311 object before converting it to any other type with the exceptions of an
4312 unconstrained array or of a mere type variant. It is useful to avoid the
4313 extraction and conversion in the type variant case because it could end
4314 up replacing a VAR_DECL expr by a constructor and we might be about the
4315 take the address of the result. */
4319 return
4322 /* If converting to a type that contains a template, convert to the data
4323 type and then build the template. */
4325 {
4330 /* If the source already has a template, get a reference to the
4331 associated array only, as we are going to rebuild a template
4332 for the target type anyway. */
4342 }
4344 /* There are some cases of expressions that we process specially. */
4346 {
4351 /* Just set its type here. For TRANSFORM_EXPR, we will do the actual
4352 conversion in gnat_expand_expr. NULL_EXPR does not represent
4353 and actual value, so no conversion is needed. */
4359 /* If we are converting a STRING_CST to another constrained array type,
4360 just make a new one in the proper type. */
4364 {
4368 }
4372 /* If we are converting a VECTOR_CST to a mere type variant, just make
4373 a new one in the proper type. */
4375 {
4379 }
4383 /* If we are converting a CONSTRUCTOR to a mere type variant, or to
4384 another padding type around the same type, just make a new one in
4385 the proper type. */
4392 {
4397 }
4399 /* Likewise for a conversion between original and packable version, or
4400 conversion between types of the same size and with the same list of
4401 fields, but we have to work harder to preserve type consistency. */
4407 {
4416 /* Whether we need to clear TREE_CONSTANT et al. on the output
4417 constructor when we convert in place. */
4421 {
4422 /* Skip the missing fields in the CONSTRUCTOR. */
4424 {
4427 }
4428 /* The field must be the same. */
4431 constructor_elt elt
4435 /* If packing has made this field a bitfield and the input
4436 value couldn't be emitted statically any more, we need to
4437 clear TREE_CONSTANT on our output. */
4447 }
4449 /* If we have been able to match and convert all the input fields
4450 to their output type, convert in place now. We'll fallback to a
4451 view conversion downstream otherwise. */
4453 {
4460 }
4461 }
4463 /* Likewise for a conversion between array type and vector type with a
4464 compatible representative array. */
4468 etype))
4469 {
4474 tree value;
4476 /* Build a VECTOR_CST from a *constant* array constructor. */
4478 {
4481 /* Iterate through elements and check if all constructor
4482 elements are *_CSTs. */
4485 {
4488 }
4493 }
4495 /* Otherwise, build a regular vector constructor. */
4498 {
4501 }
4506 }
4510 /* First retrieve the underlying array. */
4517 {
4518 /* GCC 4.x is very sensitive to type consistency overall, and view
4519 conversions thus are very frequent. Even though just "convert"ing
4520 the inner operand to the output type is fine in most cases, it
4521 might expose unexpected input/output type mismatches in special
4522 circumstances so we avoid such recursive calls when we can. */
4525 /* If we are converting back to the original type, we can just
4526 lift the input conversion. This is a common occurrence with
4527 switches back-and-forth amongst type variants. */
4531 /* Otherwise, if we're converting between two aggregate or vector
4532 types, we might be allowed to substitute the VIEW_CONVERT_EXPR
4533 target type in place or to just convert the inner expression. */
4536 {
4537 /* If we are converting between mere variants, we can just
4538 substitute the VIEW_CONVERT_EXPR in place. */
4542 /* Otherwise, we may just bypass the input view conversion unless
4543 one of the types is a fat pointer, which is handled by
4544 specialized code below which relies on exact type matching. */
4548 }
4551 }
4555 }
4557 /* Check for converting to a pointer to an unconstrained array. */
4561 /* If we are converting between two aggregate or vector types that are mere
4562 variants, just make a VIEW_CONVERT_EXPR. Likewise when we are converting
4563 to a vector type from its representative array type. */
4570 etype)))
4573 /* If we are converting between tagged types, try to upcast properly. */
4576 {
4584 }
4586 /* If we are converting from a smaller form of record type back to it, just
4587 make a VIEW_CONVERT_EXPR. But first pad the expression to have the same
4588 size on both sides. */
4591 {
4594 expr);
4596 }
4598 /* In all other cases of related types, make a NOP_EXPR. */
4603 {
4613 /* If the output is a biased type, convert first to the base type and
4614 subtract the bias. Note that the bias itself must go through a full
4615 conversion to the base type, lest it is a biased value; this happens
4616 for subtypes of biased types. */
4624 /* ... fall through ... */
4628 /* If we are converting an additive expression to an integer type
4629 with lower precision, be wary of the optimization that can be
4630 applied by convert_to_integer. There are 2 problematic cases:
4631 - if the first operand was originally of a biased type,
4632 because we could be recursively called to convert it
4633 to an intermediate type and thus rematerialize the
4634 additive operator endlessly,
4635 - if the expression contains a placeholder, because an
4636 intermediate conversion that changes the sign could
4637 be inserted and thus introduce an artificial overflow
4638 at compile time when the placeholder is substituted. */
4643 {
4650 }
4656 /* If converting between two thin pointers, adjust if needed to account
4657 for differing offsets from the base pointer, depending on whether
4658 there is a TYPE_UNCONSTRAINED_ARRAY attached to the record type. */
4660 {
4661 tree etype_pos
4665 tree type_pos
4677 }
4679 /* If converting fat pointer to normal or thin pointer, get the pointer
4680 to the array and then convert it. */
4691 {
4697 expr));
4699 }
4701 /* ... fall through ... */
4704 /* In these cases, assume the front-end has validated the conversion.
4705 If the conversion is valid, it will be a bit-wise conversion, so
4706 it can be viewed as an unchecked conversion. */
4710 /* This is a either a conversion between a tagged type and some
4711 subtype, which we have to mark as a UNION_TYPE because of
4712 overlapping fields or a conversion of an Unchecked_Union. */
4716 /* If the input is a VECTOR_TYPE, convert to the representative
4717 array type first. */
4719 {
4723 }
4725 /* If EXPR is a constrained array, take its address, convert it to a
4726 fat pointer, and then dereference it. Likewise if EXPR is a
4727 record containing both a template and a constrained array.
4728 Note that a record representing a justified modular type
4729 always represents a packed constrained array. */
4734 return
4735 build_unary_op
4741 /* Do something very similar for converting one unconstrained
4742 array to another. */
4744 return
4749 else
4757 }
4758 }
4760 /* Create an expression whose value is that of EXPR converted to the common
4761 index type, which is sizetype. EXPR is supposed to be in the base type
4762 of the GNAT index type. Calling it is equivalent to doing
4764 convert (sizetype, expr)
4766 but we try to distribute the type conversion with the knowledge that EXPR
4767 cannot overflow in its type. This is a best-effort approach and we fall
4768 back to the above expression as soon as difficulties are encountered.
4770 This is necessary to overcome issues that arise when the GNAT base index
4771 type and the GCC common index type (sizetype) don't have the same size,
4772 which is quite frequent on 64-bit architectures. In this case, and if
4773 the GNAT base index type is signed but the iteration type of the loop has
4774 been forced to unsigned, the loop scalar evolution engine cannot compute
4775 a simple evolution for the general induction variables associated with the
4776 array indices, because it will preserve the wrap-around semantics in the
4777 unsigned type of their "inner" part. As a result, many loop optimizations
4778 are blocked.
4780 The solution is to use a special (basic) induction variable that is at
4781 least as large as sizetype, and to express the aforementioned general
4782 induction variables in terms of this induction variable, eliminating
4783 the problematic intermediate truncation to the GNAT base index type.
4784 This is possible as long as the original expression doesn't overflow
4785 and if the middle-end hasn't introduced artificial overflows in the
4786 course of the various simplification it can make to the expression. */
4788 tree
4790 {
4794 /* If the type is unsigned, overflow is allowed so we cannot be sure that
4795 EXPR doesn't overflow. Keep it simple if optimization is disabled. */
4800 {
4802 /* The main effect of the function: replace a loop parameter with its
4803 associated special induction variable. */
4808 CASE_CONVERT:
4809 {
4811 /* Bail out as soon as we suspect some sort of type frobbing. */
4815 }
4817 /* ... fall through ... */
4841 }
4844 }
4845 \f
4846 /* Remove all conversions that are done in EXP. This includes converting
4847 from a padded type or to a justified modular type. If TRUE_ADDRESS
4848 is true, always return the address of the containing object even if
4849 the address is not bit-aligned. */
4851 tree
4853 {
4855 {
4860 return
4869 CASE_CONVERT:
4876 }
4879 }
4880 \f
4881 /* If EXP's type is an UNCONSTRAINED_ARRAY_TYPE, return an expression that
4882 refers to the underlying array. If it has TYPE_CONTAINS_TEMPLATE_P,
4883 likewise return an expression pointing to the underlying array. */
4885 tree
4887 {
4892 {
4895 {
4903 {
4904 tree op1
4909 tree op2
4918 }
4919 else
4920 {
4927 }
4928 }
4937 /* If this is a padded type and it contains a template, convert to the
4938 unpadded type first. */
4942 {
4946 }
4949 {
4950 /* If the array initializer is a box, return NULL_TREE. */
4958 /* If the array type is padded, convert to the unpadded type. */
4961 }
4966 }
4969 }
4970 \f
4971 /* Return true if EXPR is an expression that can be folded as an operand
4972 of a VIEW_CONVERT_EXPR. See ada-tree.h for a complete rationale. */
4974 static bool
4976 {
4979 /* The folder will fold NOP_EXPRs between integral types with the same
4980 precision (in the middle-end's sense). We cannot allow it if the
4981 types don't have the same precision in the Ada sense as well. */
4988 /* Defer to the folder for non-integral conversions. */
4992 /* Only fold conversions that preserve both precisions. */
4998 }
5000 /* Return an expression that does an unchecked conversion of EXPR to TYPE.
5001 If NOTRUNC_P is true, truncation operations should be suppressed.
5003 Special care is required with (source or target) integral types whose
5004 precision is not equal to their size, to make sure we fetch or assign
5005 the value bits whose location might depend on the endianness, e.g.
5007 Rmsize : constant := 8;
5008 subtype Int is Integer range 0 .. 2 ** Rmsize - 1;
5010 type Bit_Array is array (1 .. Rmsize) of Boolean;
5011 pragma Pack (Bit_Array);
5013 function To_Bit_Array is new Unchecked_Conversion (Int, Bit_Array);
5015 Value : Int := 2#1000_0001#;
5016 Vbits : Bit_Array := To_Bit_Array (Value);
5018 we expect the 8 bits at Vbits'Address to always contain Value, while
5019 their original location depends on the endianness, at Value'Address
5020 on a little-endian architecture but not on a big-endian one.
5022 One pitfall is that we cannot use TYPE_UNSIGNED directly to decide how
5023 the bits between the precision and the size are filled, because of the
5024 trick used in the E_Signed_Integer_Subtype case of gnat_to_gnu_entity.
5025 So we use the special predicate type_unsigned_for_rm above. */
5027 tree
5029 {
5033 tree tem;
5036 /* If the expression is already of the right type, we are done. */
5040 /* If both types are integral just do a normal conversion.
5041 Likewise for a conversion to an unconstrained array. */
5049 {
5051 {
5056 }
5059 {
5065 }
5066 else
5068 }
5070 /* If we are converting to an integral type whose precision is not equal
5071 to its size, first unchecked convert to a record type that contains a
5072 field of the given precision. Then extract the result from the field.
5074 There is a subtlety if the source type is an aggregate type with reverse
5075 storage order because its representation is not contiguous in the native
5076 storage order, i.e. a direct unchecked conversion to an integral type
5077 with N bits of precision cannot read the first N bits of the aggregate
5078 type. To overcome it, we do an unchecked conversion to an integral type
5079 with reverse storage order and return the resulting value. This also
5080 ensures that the result of the unchecked conversion doesn't depend on
5081 the endianness of the target machine, but only on the storage order of
5082 the aggregate type.
5084 Finally, for the sake of consistency, we do the unchecked conversion
5085 to an integral type with reverse storage order as soon as the source
5086 type is an aggregate type with reverse storage order, even if there
5087 are no considerations of precision or size involved. */
5094 {
5105 else
5117 }
5119 /* Similarly if we are converting from an integral type whose precision is
5120 not equal to its size, first copy into a field of the given precision
5121 and unchecked convert the record type.
5123 The same considerations as above apply if the target type is an aggregate
5124 type with reverse storage order and we also proceed similarly. */
5131 {
5144 else
5157 }
5159 /* If we are converting from a scalar type to a type with a different size,
5160 we need to pad to have the same size on both sides.
5162 ??? We cannot do it unconditionally because unchecked conversions are
5163 used liberally by the front-end to implement polymorphism, e.g. in:
5165 S191s : constant ada__tags__addr_ptr := ada__tags__addr_ptr!(S190s);
5166 return p___size__4 (p__object!(S191s.all));
5168 so we skip all expressions that are references. */
5173 {
5175 {
5178 expr);
5180 }
5181 else
5182 {
5187 }
5188 }
5190 /* We have a special case when we are converting between two unconstrained
5191 array types. In that case, take the address, convert the fat pointer
5192 types, and dereference. */
5197 expr)));
5199 /* Another special case is when we are converting to a vector type from its
5200 representative array type; this a regular conversion. */
5204 etype))
5207 /* And, if the array type is not the representative, we try to build an
5208 intermediate vector type of which the array type is the representative
5209 and to do the unchecked conversion between the vector types, in order
5210 to enable further simplifications in the middle-end. */
5214 {
5217 }
5219 /* If we are converting a CONSTRUCTOR to a more aligned RECORD_TYPE, bump
5220 the alignment of the CONSTRUCTOR to speed up the copy operation. */
5224 {
5227 expr);
5229 }
5231 /* Otherwise, just build a VIEW_CONVERT_EXPR of the expression. */
5232 else
5233 {
5239 else
5241 }
5243 /* If the result is a non-biased integral type whose precision is not equal
5244 to its size, sign- or zero-extend the result. But we need not do this
5245 if the input is also an integral type and both are unsigned or both are
5246 signed and have the same precision. */
5259 {
5262 else
5263 {
5264 tree base_type
5267 tree shift_expr
5271 expr
5276 expr),
5277 shift_expr),
5278 shift_expr));
5279 }
5280 }
5282 /* An unchecked conversion should never raise Constraint_Error. The code
5283 below assumes that GCC's conversion routines overflow the same way that
5284 the underlying hardware does. This is probably true. In the rare case
5285 when it is false, we can rely on the fact that such conversions are
5286 erroneous anyway. */
5290 /* If the sizes of the types differ and this is an VIEW_CONVERT_EXPR,
5291 show no longer constant. */
5294 OEP_ONLY_CONST))
5298 }
5299 \f
5300 /* Return the appropriate GCC tree code for the specified GNAT_TYPE,
5301 the latter being a record type as predicated by Is_Record_Type. */
5303 enum tree_code
5305 {
5308 /* Return UNION_TYPE if it's an Unchecked_Union whose non-discriminant
5309 fields are all in the variant part. Otherwise, return RECORD_TYPE. */
5314 component_list
5324 }
5326 /* Return true if GNAT_TYPE is a "double" floating-point type, i.e. whose
5327 size is equal to 64 bits, or an array of such a type. Set ALIGN_CLAUSE
5328 according to the presence of an alignment clause on the type or, if it
5329 is an array, on the component type. */
5331 bool
5333 {
5339 {
5343 }
5352 }
5354 /* Return true if GNAT_TYPE is a "double" or larger scalar type, i.e. whose
5355 size is greater or equal to 64 bits, or an array of such a type. Set
5356 ALIGN_CLAUSE according to the presence of an alignment clause on the
5357 type or, if it is an array, on the component type. */
5359 bool
5361 {
5367 {
5371 }
5380 }
5382 /* Return true if GNU_TYPE is suitable as the type of a non-aliased
5383 component of an aggregate type. */
5385 bool
5387 {
5388 /* If the type is passed by reference, we may have pointers to the
5389 component so it cannot be made non-aliased. */
5393 /* We used to say that any component of aggregate type is aliased
5394 because the front-end may take 'Reference of it. The front-end
5395 has been enhanced in the meantime so as to use a renaming instead
5396 in most cases, but the back-end can probably take the address of
5397 such a component too so we go for the conservative stance.
5399 For instance, we might need the address of any array type, even
5400 if normally passed by copy, to construct a fat pointer if the
5401 component is used as an actual for an unconstrained formal.
5403 Likewise for record types: even if a specific record subtype is
5404 passed by copy, the parent type might be passed by ref (e.g. if
5405 it's of variable size) and we might take the address of a child
5406 component to pass to a parent formal. We have no way to check
5407 for such conditions here. */
5412 }
5414 /* Return true if TYPE is a smaller form of ORIG_TYPE. */
5416 bool
5418 {
5421 /* We're not interested in variants here. */
5425 /* Like a variant, a packable version keeps the original TYPE_NAME. */
5436 }
5438 /* Return whether EXPR, which is the renamed object in an object renaming
5439 declaration, can be materialized as a reference (with a REFERENCE_TYPE).
5440 This should be synchronized with Exp_Dbug.Debug_Renaming_Declaration. */
5442 bool
5444 {
5446 {
5450 {
5459 {
5463 const Uint bitpos
5471 }
5475 {
5483 }
5491 };
5492 }
5493 }
5495 /* Perform final processing on global declarations. */
5499 void
5501 {
5503 tree iter;
5505 /* If we have declared types as used at the global level, insert them in
5506 the global hash table. We use a dummy variable for this purpose, but
5507 we need to build it unconditionally to avoid -fcompare-debug issues. */
5509 {
5514 dummy_global
5516 void_type_node);
5525 {
5528 }
5529 }
5531 /* Output debug information for all global type declarations first. This
5532 ensures that global types whose compilation hasn't been finalized yet,
5533 for example pointers to Taft amendment types, have their compilation
5534 finalized in the right context. */
5539 /* Output imported functions. */
5548 /* Then output the global variables. We need to do that after the debug
5549 information for global types is emitted so that they are finalized. Skip
5550 external global variables, unless we need to emit debug info for them:
5551 this is useful for imported variables, for instance. */
5557 /* Output the imported modules/declarations. In GNAT, these are only
5558 materializing subprogram. */
5563 }
5565 /* ************************************************************************
5566 * * GCC builtins support *
5567 * ************************************************************************ */
5569 /* The general scheme is fairly simple:
5571 For each builtin function/type to be declared, gnat_install_builtins calls
5572 internal facilities which eventually get to gnat_pushdecl, which in turn
5573 tracks the so declared builtin function decls in the 'builtin_decls' global
5574 datastructure. When an Intrinsic subprogram declaration is processed, we
5575 search this global datastructure to retrieve the associated BUILT_IN DECL
5576 node. */
5578 /* Search the chain of currently available builtin declarations for a node
5579 corresponding to function NAME (an IDENTIFIER_NODE). Return the first node
5580 found, if any, or NULL_TREE otherwise. */
5581 tree
5583 {
5585 tree decl;
5592 }
5594 /* The code below eventually exposes gnat_install_builtins, which declares
5595 the builtin types and functions we might need, either internally or as
5596 user accessible facilities.
5598 ??? This is a first implementation shot, still in rough shape. It is
5599 heavily inspired from the "C" family implementation, with chunks copied
5600 verbatim from there.
5602 Two obvious improvement candidates are:
5603 o Use a more efficient name/decl mapping scheme
5604 o Devise a middle-end infrastructure to avoid having to copy
5605 pieces between front-ends. */
5607 /* ----------------------------------------------------------------------- *
5608 * BUILTIN ELEMENTARY TYPES *
5609 * ----------------------------------------------------------------------- */
5611 /* Standard data types to be used in builtin argument declarations. */
5613 enum c_tree_index
5614 {
5616 CTI_STRING_TYPE,
5617 CTI_CONST_STRING_TYPE,
5619 CTI_MAX
5620 };
5624 #define signed_size_type_node c_global_trees[CTI_SIGNED_SIZE_TYPE]
5625 #define string_type_node c_global_trees[CTI_STRING_TYPE]
5626 #define const_string_type_node c_global_trees[CTI_CONST_STRING_TYPE]
5628 /* ??? In addition some attribute handlers, we currently don't support a
5629 (small) number of builtin-types, which in turns inhibits support for a
5630 number of builtin functions. */
5631 #define wint_type_node void_type_node
5632 #define intmax_type_node void_type_node
5633 #define uintmax_type_node void_type_node
5635 /* Used to help initialize the builtin-types.def table. When a type of
5636 the correct size doesn't exist, use error_mark_node instead of NULL.
5637 The later results in segfaults even when a decl using the type doesn't
5638 get invoked. */
5640 static tree
5642 {
5645 }
5647 /* Build/push the elementary type decls that builtin functions/types
5648 will need. */
5650 static void
5652 {
5657 const_string_type_node
5660 }
5662 /* ----------------------------------------------------------------------- *
5663 * BUILTIN FUNCTION TYPES *
5664 * ----------------------------------------------------------------------- */
5666 /* Now, builtin function types per se. */
5668 enum c_builtin_type
5669 {
5670 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
5671 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
5672 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
5673 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
5674 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
5675 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
5676 #define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME,
5677 #define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5678 ARG6) NAME,
5679 #define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5680 ARG6, ARG7) NAME,
5681 #define DEF_FUNCTION_TYPE_8(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5682 ARG6, ARG7, ARG8) NAME,
5683 #define DEF_FUNCTION_TYPE_9(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5684 ARG6, ARG7, ARG8, ARG9) NAME,
5685 #define DEF_FUNCTION_TYPE_10(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5686 ARG6, ARG7, ARG8, ARG9, ARG10) NAME,
5687 #define DEF_FUNCTION_TYPE_11(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5688 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) NAME,
5689 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
5690 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
5691 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
5692 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
5693 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
5694 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5695 NAME,
5696 #define DEF_FUNCTION_TYPE_VAR_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5697 ARG6) NAME,
5698 #define DEF_FUNCTION_TYPE_VAR_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5699 ARG6, ARG7) NAME,
5700 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
5702 #undef DEF_PRIMITIVE_TYPE
5703 #undef DEF_FUNCTION_TYPE_0
5704 #undef DEF_FUNCTION_TYPE_1
5705 #undef DEF_FUNCTION_TYPE_2
5706 #undef DEF_FUNCTION_TYPE_3
5707 #undef DEF_FUNCTION_TYPE_4
5708 #undef DEF_FUNCTION_TYPE_5
5709 #undef DEF_FUNCTION_TYPE_6
5710 #undef DEF_FUNCTION_TYPE_7
5711 #undef DEF_FUNCTION_TYPE_8
5712 #undef DEF_FUNCTION_TYPE_9
5713 #undef DEF_FUNCTION_TYPE_10
5714 #undef DEF_FUNCTION_TYPE_11
5715 #undef DEF_FUNCTION_TYPE_VAR_0
5716 #undef DEF_FUNCTION_TYPE_VAR_1
5717 #undef DEF_FUNCTION_TYPE_VAR_2
5718 #undef DEF_FUNCTION_TYPE_VAR_3
5719 #undef DEF_FUNCTION_TYPE_VAR_4
5720 #undef DEF_FUNCTION_TYPE_VAR_5
5721 #undef DEF_FUNCTION_TYPE_VAR_6
5722 #undef DEF_FUNCTION_TYPE_VAR_7
5723 #undef DEF_POINTER_TYPE
5724 BT_LAST
5725 };
5729 /* A temporary array used in communication with def_fn_type. */
5732 /* A helper function for install_builtin_types. Build function type
5733 for DEF with return type RET and N arguments. If VAR is true, then the
5734 function should be variadic after those N arguments.
5736 Takes special care not to ICE if any of the types involved are
5737 error_mark_node, which indicates that said type is not in fact available
5738 (see builtin_type_for_size). In which case the function type as a whole
5739 should be error_mark_node. */
5741 static void
5743 {
5744 tree t;
5751 {
5757 }
5764 else
5767 egress:
5770 }
5772 /* Build the builtin function types and install them in the builtin_types
5773 array for later use in builtin function decls. */
5775 static void
5777 {
5778 tree va_list_ref_type_node;
5779 tree va_list_arg_type_node;
5782 {
5785 }
5786 else
5787 {
5790 }
5792 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
5793 builtin_types[ENUM] = VALUE;
5794 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \
5795 def_fn_type (ENUM, RETURN, 0, 0);
5796 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \
5797 def_fn_type (ENUM, RETURN, 0, 1, ARG1);
5798 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \
5799 def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2);
5800 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
5801 def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3);
5802 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
5803 def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4);
5804 #define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5805 def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
5806 #define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5807 ARG6) \
5808 def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
5809 #define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5810 ARG6, ARG7) \
5811 def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
5812 #define DEF_FUNCTION_TYPE_8(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5813 ARG6, ARG7, ARG8) \
5814 def_fn_type (ENUM, RETURN, 0, 8, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5815 ARG7, ARG8);
5816 #define DEF_FUNCTION_TYPE_9(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5817 ARG6, ARG7, ARG8, ARG9) \
5818 def_fn_type (ENUM, RETURN, 0, 9, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5819 ARG7, ARG8, ARG9);
5820 #define DEF_FUNCTION_TYPE_10(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5,\
5821 ARG6, ARG7, ARG8, ARG9, ARG10) \
5822 def_fn_type (ENUM, RETURN, 0, 10, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5823 ARG7, ARG8, ARG9, ARG10);
5824 #define DEF_FUNCTION_TYPE_11(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5,\
5825 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) \
5826 def_fn_type (ENUM, RETURN, 0, 11, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \
5827 ARG7, ARG8, ARG9, ARG10, ARG11);
5828 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \
5829 def_fn_type (ENUM, RETURN, 1, 0);
5830 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \
5831 def_fn_type (ENUM, RETURN, 1, 1, ARG1);
5832 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \
5833 def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2);
5834 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
5835 def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3);
5836 #define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
5837 def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
5838 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
5839 def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
5840 #define DEF_FUNCTION_TYPE_VAR_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5841 ARG6) \
5842 def_fn_type (ENUM, RETURN, 1, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
5843 #define DEF_FUNCTION_TYPE_VAR_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
5844 ARG6, ARG7) \
5845 def_fn_type (ENUM, RETURN, 1, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
5846 #define DEF_POINTER_TYPE(ENUM, TYPE) \
5847 builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
5851 #undef DEF_PRIMITIVE_TYPE
5852 #undef DEF_FUNCTION_TYPE_0
5853 #undef DEF_FUNCTION_TYPE_1
5854 #undef DEF_FUNCTION_TYPE_2
5855 #undef DEF_FUNCTION_TYPE_3
5856 #undef DEF_FUNCTION_TYPE_4
5857 #undef DEF_FUNCTION_TYPE_5
5858 #undef DEF_FUNCTION_TYPE_6
5859 #undef DEF_FUNCTION_TYPE_7
5860 #undef DEF_FUNCTION_TYPE_8
5861 #undef DEF_FUNCTION_TYPE_9
5862 #undef DEF_FUNCTION_TYPE_10
5863 #undef DEF_FUNCTION_TYPE_11
5864 #undef DEF_FUNCTION_TYPE_VAR_0
5865 #undef DEF_FUNCTION_TYPE_VAR_1
5866 #undef DEF_FUNCTION_TYPE_VAR_2
5867 #undef DEF_FUNCTION_TYPE_VAR_3
5868 #undef DEF_FUNCTION_TYPE_VAR_4
5869 #undef DEF_FUNCTION_TYPE_VAR_5
5870 #undef DEF_FUNCTION_TYPE_VAR_6
5871 #undef DEF_FUNCTION_TYPE_VAR_7
5872 #undef DEF_POINTER_TYPE
5874 }
5876 /* ----------------------------------------------------------------------- *
5877 * BUILTIN ATTRIBUTES *
5878 * ----------------------------------------------------------------------- */
5880 enum built_in_attribute
5881 {
5882 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
5883 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
5884 #define DEF_ATTR_STRING(ENUM, VALUE) ENUM,
5885 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
5886 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
5888 #undef DEF_ATTR_NULL_TREE
5889 #undef DEF_ATTR_INT
5890 #undef DEF_ATTR_STRING
5891 #undef DEF_ATTR_IDENT
5892 #undef DEF_ATTR_TREE_LIST
5893 ATTR_LAST
5894 };
5898 static void
5900 {
5901 /* Fill in the built_in_attributes array. */
5902 #define DEF_ATTR_NULL_TREE(ENUM) \
5903 built_in_attributes[(int) ENUM] = NULL_TREE;
5904 #define DEF_ATTR_INT(ENUM, VALUE) \
5905 built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
5906 #define DEF_ATTR_STRING(ENUM, VALUE) \
5907 built_in_attributes[(int) ENUM] = build_string (strlen (VALUE), VALUE);
5908 #define DEF_ATTR_IDENT(ENUM, STRING) \
5909 built_in_attributes[(int) ENUM] = get_identifier (STRING);
5910 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
5911 built_in_attributes[(int) ENUM] \
5912 = tree_cons (built_in_attributes[(int) PURPOSE], \
5913 built_in_attributes[(int) VALUE], \
5914 built_in_attributes[(int) CHAIN]);
5916 #undef DEF_ATTR_NULL_TREE
5917 #undef DEF_ATTR_INT
5918 #undef DEF_ATTR_STRING
5919 #undef DEF_ATTR_IDENT
5920 #undef DEF_ATTR_TREE_LIST
5921 }
5923 /* Handle a "const" attribute; arguments as in
5924 struct attribute_spec.handler. */
5926 static tree
5930 {
5933 else
5937 }
5939 /* Handle a "nothrow" attribute; arguments as in
5940 struct attribute_spec.handler. */
5942 static tree
5946 {
5949 else
5953 }
5955 /* Handle a "pure" attribute; arguments as in
5956 struct attribute_spec.handler. */
5958 static tree
5961 {
5964 /* TODO: support types. */
5965 else
5966 {
5970 }
5973 }
5975 /* Handle a "no vops" attribute; arguments as in
5976 struct attribute_spec.handler. */
5978 static tree
5982 {
5986 }
5988 /* Helper for nonnull attribute handling; fetch the operand number
5989 from the attribute argument list. */
5991 static bool
5993 {
5994 /* Verify the arg number is a constant. */
6000 }
6002 /* Handle the "nonnull" attribute. */
6003 static tree
6007 {
6011 /* If no arguments are specified, all pointer arguments should be
6012 non-null. Verify a full prototype is given so that the arguments
6013 will have the correct types when we actually check them later.
6014 Avoid diagnosing type-generic built-ins since those have no
6015 prototype. */
6017 {
6021 {
6024 }
6026 }
6028 /* Argument list specified. Verify that each argument number references
6029 a pointer argument. */
6031 {
6035 {
6040 }
6043 {
6044 function_args_iterator iter;
6045 tree argument;
6049 {
6053 }
6057 {
6063 }
6066 {
6072 }
6073 }
6074 }
6077 }
6079 /* Handle a "sentinel" attribute. */
6081 static tree
6084 {
6086 {
6091 }
6092 else
6093 {
6095 {
6100 }
6101 }
6104 {
6108 {
6111 }
6112 else
6113 {
6115 {
6118 }
6119 }
6120 }
6123 }
6125 /* Handle a "noreturn" attribute; arguments as in
6126 struct attribute_spec.handler. */
6128 static tree
6131 {
6134 /* See FIXME comment in c_common_attribute_table. */
6140 = build_pointer_type
6143 else
6144 {
6148 }
6151 }
6153 /* Handle a "noinline" attribute; arguments as in
6154 struct attribute_spec.handler. */
6156 static tree
6160 {
6162 {
6164 {
6168 }
6169 else
6171 }
6172 else
6173 {
6176 }
6179 }
6181 /* Handle a "noclone" attribute; arguments as in
6182 struct attribute_spec.handler. */
6184 static tree
6188 {
6190 {
6193 }
6196 }
6198 /* Handle a "leaf" attribute; arguments as in
6199 struct attribute_spec.handler. */
6201 static tree
6204 {
6206 {
6209 }
6211 {
6214 }
6217 }
6219 /* Handle a "always_inline" attribute; arguments as in
6220 struct attribute_spec.handler. */
6222 static tree
6225 {
6227 {
6228 /* Set the attribute and mark it for disregarding inline limits. */
6230 }
6231 else
6232 {
6235 }
6238 }
6240 /* Handle a "malloc" attribute; arguments as in
6241 struct attribute_spec.handler. */
6243 static tree
6246 {
6250 else
6251 {
6255 }
6258 }
6260 /* Fake handler for attributes we don't properly support. */
6262 tree
6268 {
6270 }
6272 /* Handle a "type_generic" attribute. */
6274 static tree
6278 {
6279 /* Ensure we have a function type. */
6282 /* Ensure we have a variadic function. */
6286 }
6288 /* Handle a "vector_size" attribute; arguments as in
6289 struct attribute_spec.handler. */
6291 static tree
6294 {
6296 tree vector_type;
6300 /* We need to provide for vector pointers, vector arrays, and
6301 functions returning vectors. For example:
6303 __attribute__((vector_size(16))) short *foo;
6305 In this case, the mode is SI, but the type being modified is
6306 HI, so we need to look further. */
6316 /* Build back pointers if needed. */
6320 }
6322 /* Handle a "vector_type" attribute; arguments as in
6323 struct attribute_spec.handler. */
6325 static tree
6328 {
6330 tree vector_type;
6335 {
6339 }
6349 }
6351 /* ----------------------------------------------------------------------- *
6352 * BUILTIN FUNCTIONS *
6353 * ----------------------------------------------------------------------- */
6355 /* Worker for DEF_BUILTIN. Possibly define a builtin function with one or two
6356 names. Does not declare a non-__builtin_ function if flag_no_builtin, or
6357 if nonansi_p and flag_no_nonansi_builtin. */
6359 static void
6367 {
6368 tree decl;
6371 /* Preserve an already installed decl. It most likely was setup in advance
6372 (e.g. as part of the internal builtins) for specific reasons. */
6383 fnattrs);
6385 /* ??? This is normally further controlled by command-line options
6386 like -fno-builtin, but we don't have them for Ada. */
6391 }
6397 /* Install what the common builtins.def offers. */
6399 static void
6401 {
6402 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
6403 NONANSI_P, ATTRS, IMPLICIT, COND) \
6404 if (NAME && COND) \
6405 def_builtin_1 (ENUM, NAME, CLASS, \
6406 builtin_types[(int) TYPE], \
6407 builtin_types[(int) LIBTYPE], \
6408 BOTH_P, FALLBACK_P, NONANSI_P, \
6409 built_in_attributes[(int) ATTRS], IMPLICIT);
6411 }
6413 /* ----------------------------------------------------------------------- *
6414 * BUILTIN FUNCTIONS *
6415 * ----------------------------------------------------------------------- */
6417 /* Install the builtin functions we might need. */
6419 void
6421 {
6426 /* Install builtins used by generic middle-end pieces first. Some of these
6427 know about internal specificities and control attributes accordingly, for
6428 instance __builtin_alloca vs no-throw and -fstack-check. We will ignore
6429 the generic definition from builtins.def. */
6432 /* Now, install the target specific builtins, such as the AltiVec family on
6433 ppc, and the common set as exposed by builtins.def. */
6436 }