| blob | abc71f5e53ef45326e6463e9c1c21d04c097d4de |
1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * T R A N S *
6 * *
7 * C Implementation File *
8 * *
9 * Copyright (C) 1992-2008, 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 2, 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 distributed with GNAT; see file COPYING. If not, write *
19 * to the Free Software Foundation, 51 Franklin Street, Fifth Floor, *
20 * Boston, MA 02110-1301, USA. *
21 * *
22 * GNAT was originally developed by the GNAT team at New York University. *
23 * Extensive contributions were provided by Ada Core Technologies Inc. *
24 * *
25 ****************************************************************************/
65 /* We should avoid allocating more than ALLOCA_THRESHOLD bytes via alloca,
66 for fear of running out of stack space. If we need more, we use xmalloc
67 instead. */
68 #define ALLOCA_THRESHOLD 1000
70 /* Let code below know whether we are targetting VMS without need of
71 intrusive preprocessor directives. */
72 #ifndef TARGET_ABI_OPEN_VMS
73 #define TARGET_ABI_OPEN_VMS 0
74 #endif
90 /* Current filename without path. */
93 /* If true, then gigi is being called on an analyzed but unexpanded
94 tree, and the only purpose of the call is to properly annotate
95 types with representation information. */
98 /* When not optimizing, we cache the 'First, 'Last and 'Length attributes
99 of unconstrained array IN parameters to avoid emitting a great deal of
100 redundant instructions to recompute them each time. */
102 {
105 tree first;
106 tree last;
107 tree length;
108 };
116 {
118 };
120 #define f_parm_attr_cache \
121 DECL_STRUCT_FUNCTION (current_function_decl)->language->parm_attr_cache
123 /* A structure used to gather together information about a statement group.
124 We use this to gather related statements, for example the "then" part
125 of a IF. In the case where it represents a lexical scope, we may also
126 have a BLOCK node corresponding to it and/or cleanups. */
133 };
137 /* List of unused struct stmt_group nodes. */
140 /* A structure used to record information on elaboration procedures
141 we've made and need to process.
143 ??? gnat_node should be Node_Id, but gengtype gets confused. */
149 };
153 /* Free list of TREE_LIST nodes used for stacks. */
156 /* List of TREE_LIST nodes representing a stack of exception pointer
157 variables. TREE_VALUE is the VAR_DECL that stores the address of
158 the raised exception. Nonzero means we are in an exception
159 handler. Not used in the zero-cost case. */
162 /* List of TREE_LIST nodes used to store the current elaboration procedure
163 decl. TREE_VALUE is the decl. */
166 /* Variable that stores a list of labels to be used as a goto target instead of
167 a return in some functions. See processing for N_Subprogram_Body. */
170 /* List of TREE_LIST nodes representing a stack of LOOP_STMT nodes.
171 TREE_VALUE of each entry is the label of the corresponding LOOP_STMT. */
174 /* List of TREE_LIST nodes representing labels for switch statements.
175 TREE_VALUE of each entry is the label at the end of the switch. */
178 /* List of TREE_LIST nodes containing the stacks for N_{Push,Pop}_*_Label. */
183 /* Map GNAT tree codes to GCC tree codes for simple expressions. */
186 /* Current node being treated, in case abort called. */
187 Node_Id error_gnat_node;
220 /* Hooks for debug info back-ends, only supported and used in a restricted set
221 of configurations. */
224 \f
225 /* This is the main program of the back-end. It sets up all the table
226 structures and then generates code. */
228 void
237 {
238 tree gnu_standard_long_long_float;
239 tree gnu_standard_exception_type;
258 {
259 /* Use the identifier table to make a permanent copy of the filename as
260 the name table gets reallocated after Gigi returns but before all the
261 debugging information is output. The __gnat_to_canonical_file_spec
262 call translates filenames from pragmas Source_Reference that contain
263 host style syntax not understood by gdb. */
265 = IDENTIFIER_POINTER
266 (get_identifier
267 (__gnat_to_canonical_file_spec
270 /* We rely on the order isomorphism between files and line maps. */
273 /* We create the line map for a source file at once, with a fixed number
274 of columns chosen to avoid jumping over the next power of 2. */
279 }
281 /* Initialize ourselves. */
287 /* If we are just annotating types, give VOID_TYPE zero sizes to avoid
288 errors. */
290 {
293 }
295 /* If the GNU type extensions to DWARF are available, setup the hooks. */
296 #if defined (DWARF2_DEBUGGING_INFO) && defined (DWARF2_GNU_TYPE_EXTENSIONS)
297 /* We condition the name demangling and the generation of type encoding
298 strings on -gdwarf+ and always set descriptive types on. */
300 {
303 }
305 #endif
307 /* Enable GNAT stack checking method if needed */
311 /* Give names and make TYPE_DECLs for common types. */
321 /* Save the type we made for integer as the type for Standard.Integer.
322 Then make the rest of the standard types. Note that some of these
323 may be subtypes. */
328 gnu_constraint_error_label_stack
333 gnu_standard_long_long_float
335 gnu_standard_exception_type
340 /* Process any Pragma Ident for the main unit. */
341 #ifdef ASM_OUTPUT_IDENT
343 ASM_OUTPUT_IDENT
346 #endif
348 /* If we are using the GCC exception mechanism, let GCC know. */
356 /* Now see if we have any elaboration procedures to deal with. */
358 {
361 /* Unshare SAVE_EXPRs between subprograms. These are not unshared by
362 the gimplifier for obvious reasons, but it turns out that we need to
363 unshare them for the global level because of SAVE_EXPRs made around
364 checks for global objects and around allocators for global objects
365 of variable size, in order to prevent node sharing in the underlying
366 expression. Note that this implicitly assumes that the SAVE_EXPR
367 nodes themselves are not shared between subprograms, which would be
368 an upstream bug for which we would not change the outcome. */
371 /* Process the function as others, but for indicating this is an
372 elab proc, to be discarded if empty, then propagate the status
373 up to the GNAT tree node. */
379 }
381 /* We cannot track the location of errors past this point. */
383 }
384 \f
385 /* Return a positive value if an lvalue is required for GNAT_NODE.
386 GNU_TYPE is the type that will be used for GNAT_NODE in the
387 translated GNU tree. ALIASED indicates whether the underlying
388 object represented by GNAT_NODE is aliased in the Ada sense.
390 The function climbs up the GNAT tree starting from the node and
391 returns 1 upon encountering a node that effectively requires an
392 lvalue downstream. It returns int instead of bool to facilitate
393 usage in non purely binary logic contexts. */
395 static int
397 {
401 {
406 {
412 }
420 /* Only the array expression can require an lvalue. */
424 /* ??? Consider that referencing an indexed component with a
425 non-constant index forces the whole aggregate to memory.
426 Note that N_Integer_Literal is conservative, any static
427 expression in the RM sense could probably be accepted. */
434 /* ... fall through ... */
437 /* Only the array expression can require an lvalue. */
449 /* We need to make a real renaming only if the constant object is
450 aliased or if we may use a renaming pointer; otherwise we can
451 optimize and return the rvalue. We make an exception if the object
452 is an identifier since in this case the rvalue can be propagated
453 attached to the CONST_DECL. */
455 /* This should match the constant case of the renaming code. */
461 }
464 }
466 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Identifier,
467 to a GCC tree, which is returned. GNU_RESULT_TYPE_P is a pointer
468 to where we should place the result type. */
470 static tree
472 {
476 /* Whether we should require an lvalue for GNAT_NODE. Needed in
477 specific circumstances only, so evaluated lazily. < 0 means
478 unknown, > 0 means known true, 0 means known false. */
481 /* If GNAT_NODE is a constant, whether we should use the initialization
482 value instead of the constant entity, typically for scalars with an
483 address clause when the parent doesn't require an lvalue. */
486 /* If the Etype of this node does not equal the Etype of the Entity,
487 something is wrong with the entity map, probably in generic
488 instantiation. However, this does not apply to types. Since we sometime
489 have strange Ekind's, just do this test for objects. Also, if the Etype of
490 the Entity is private, the Etype of the N_Identifier is allowed to be the
491 full type and also we consider a packed array type to be the same as the
492 original type. Similarly, a class-wide type is equivalent to a subtype of
493 itself. Finally, if the types are Itypes, one may be a copy of the other,
494 which is also legal. */
517 /* If this is a reference to a deferred constant whose partial view is an
518 unconstrained private type, the proper type is on the full view of the
519 constant, not on the full view of the type, which may be unconstrained.
521 This may be a reference to a type, for example in the prefix of the
522 attribute Position, generated for dispatching code (see Make_DT in
523 exp_disp,adb). In that case we need the type itself, not is parent,
524 in particular if it is a derived type */
529 {
532 }
533 else
534 {
535 /* We want to use the Actual_Subtype if it has already been elaborated,
536 otherwise the Etype. Avoid using Actual_Subtype for packed arrays to
537 simplify things. */
545 else
547 }
549 /* Expand the type of this identifier first, in case it is an enumeral
550 literal, which only get made when the type is expanded. There is no
551 order-of-elaboration issue here. */
554 /* If this is a non-imported scalar constant with an address clause,
555 retrieve the value instead of a pointer to be dereferenced unless
556 an lvalue is required. This is generally more efficient and actually
557 required if this is a static expression because it might be used
558 in a context where a dereference is inappropriate, such as a case
559 statement alternative or a record discriminant. There is no possible
560 volatile-ness short-circuit here since Volatile constants must be imported
561 per C.6. */
565 {
569 }
572 {
573 /* If this is a deferred constant, the initializer is attached to
574 the full view. */
579 }
580 else
583 /* If we are in an exception handler, force this variable into memory to
584 ensure optimization does not remove stores that appear redundant but are
585 actually needed in case an exception occurs.
587 ??? Note that we need not do this if the variable is declared within the
588 handler, only if it is referenced in the handler and declared in an
589 enclosing block, but we have no way of testing that right now.
591 ??? We used to essentially set the TREE_ADDRESSABLE flag on the variable
592 here, but it can now be removed by the Tree aliasing machinery if the
593 address of the variable is never taken. All we can do is to make the
594 variable volatile, which might incur the generation of temporaries just
595 to access the memory in some circumstances. This can be avoided for
596 variables of non-constant size because they are automatically allocated
597 to memory. There might be no way of allocating a proper temporary for
598 them in any case. We only do this for SJLJ though. */
604 /* Some objects (such as parameters passed by reference, globals of
605 variable size, and renamed objects) actually represent the address
606 of the object. In that case, we must do the dereference. Likewise,
607 deal with parameters to foreign convention subprograms. */
612 {
614 tree renamed_obj;
618 gnu_result
621 gnu_result));
623 /* If it's a renaming pointer and we are at the right binding level,
624 we can reference the renamed object directly, since the renamed
625 expression has been protected against multiple evaluations. */
632 /* Return the underlying CST for a CONST_DECL like a few lines below,
633 after dereferencing in this case. */
638 else
642 }
644 /* The GNAT tree has the type of a function as the type of its result. Also
645 use the type of the result if the Etype is a subtype which is nominally
646 unconstrained. But remove any padding from the resulting type. */
649 {
654 }
656 /* If we have a constant declaration and its initializer at hand,
657 try to return the latter to avoid the need to call fold in lots
658 of places and the need of elaboration code if this Id is used as
659 an initializer itself. */
663 {
664 tree object
668 /* If there is a corresponding variable, we only want to return
669 the CST value if an lvalue is not required. Evaluate this
670 now if we have not already done so. */
677 }
681 }
682 \f
683 /* Subroutine of gnat_to_gnu to process gnat_node, an N_Pragma. Return
684 any statements we generate. */
686 static tree
688 {
689 Node_Id gnat_temp;
692 /* Check for (and ignore) unrecognized pragma and do nothing if we are just
693 annotating types. */
699 {
701 /* Do nothing at top level: all such variables are already viewable. */
708 {
714 #ifdef ASM_COMMENT_START
716 #endif
721 /* Use the value only if it fits into a normal register,
722 otherwise use the address. */
731 #ifdef ASM_COMMENT_START
737 NULL);
740 #endif
742 asm_constraint,
743 NULL_TREE,
744 tree_cons
748 NULL_TREE);
752 }
758 {
771 }
778 }
781 }
782 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Attribute,
783 to a GCC tree, which is returned. GNU_RESULT_TYPE_P is a pointer to
784 where we should place the result type. ATTRIBUTE is the attribute ID. */
786 static tree
788 {
790 tree gnu_result_type;
791 tree gnu_expr;
796 /* If the input is a NULL_EXPR, make a new one. */
798 {
802 }
805 {
808 /* These are just conversions until since representation clauses for
809 enumerations are handled in the front end. */
810 {
817 }
822 /* These just add or subject the constant 1. Representation clauses for
823 enumerations are handled in the front-end. */
828 {
830 gnu_expr
831 = emit_check
833 gnu_expr,
834 attribute == Attr_Pred
838 }
840 gnu_result
849 /* Conversions don't change something's address but can cause us to miss
850 the COMPONENT_REF case below, so strip them off. */
854 /* If we are taking 'Address of an unconstrained object, this is the
855 pointer to the underlying array. */
859 /* If we are building a static dispatch table, we have to honor
860 TARGET_VTABLE_USES_DESCRIPTORS if we want to be compatible
861 with the C++ ABI. We do it in the non-static case as well,
862 see gnat_to_gnu_entity, case E_Access_Subprogram_Type. */
865 {
867 /* Descriptors can only be built here for top-level functions. */
873 /* If we're not going to build the descriptor, we have to retrieve
874 the one which will be built by the linker (or by the compiler
875 later if a static chain is requested). */
877 {
880 gnu_result);
882 }
887 {
889 {
893 }
894 else
899 }
903 }
905 /* ... fall through ... */
911 gnu_result
918 /* For 'Code_Address, find an inner ADDR_EXPR and mark it so that we
919 don't try to build a trampoline. */
921 {
929 }
931 /* For other address attributes applied to a nested function,
932 find an inner ADDR_EXPR and annotate it so that we can issue
933 a useful warning with -Wtrampolines. */
935 {
939 ;
943 {
946 /* Check that we're not violating the No_Implicit_Dynamic_Code
947 restriction. Be conservative if we don't know anything
948 about the trampoline strategy for the target. */
950 }
951 }
955 {
956 tree gnu_obj_type;
961 /* If this is an unconstrained array, we know the object must have been
962 allocated with the template in front of the object. So compute the
963 template address.*/
965 gnu_ptr
967 (TYPE_OBJECT_RECORD_TYPE
969 gnu_ptr);
974 {
977 tree gnu_byte_offset
985 }
988 }
997 /* Remove NOPS from gnu_expr and conversions from gnu_prefix.
998 We only use GNU_EXPR to see if a COMPONENT_REF was involved. */
1006 /* Replace an unconstrained array type with the type of the underlying
1007 array. We can't do this with a call to maybe_unconstrained_array
1008 since we may have a TYPE_DECL. For 'Max_Size_In_Storage_Elements,
1009 use the record type that will be used to allocate the object and its
1010 template. */
1012 {
1016 }
1018 /* If we're looking for the size of a field, return the field size.
1019 Otherwise, if the prefix is an object, or if 'Object_Size or
1020 'Max_Size_In_Storage_Elements has been specified, the result is the
1021 GCC size of the type. Otherwise, the result is the RM_Size of the
1022 type. */
1028 {
1029 /* If this is a padded type, the GCC size isn't relevant to the
1030 programmer. Normally, what we want is the RM_Size, which was set
1031 from the specified size, but if it was not set, we want the size
1032 of the relevant field. Using the MAX of those two produces the
1033 right result in all case. Don't use the size of the field if it's
1034 a self-referential type, since that's never what's wanted. */
1038 {
1042 gnu_result
1045 }
1047 {
1053 {
1057 }
1060 }
1061 else
1063 }
1064 else
1069 /* Deal with a self-referential size by returning the maximum size for a
1070 type and by qualifying the size with the object for 'Size of an
1071 object. */
1073 {
1076 else
1078 }
1080 /* If the type contains a template, subtract its size. */
1088 /* Always perform division using unsigned arithmetic as the size cannot
1089 be negative, but may be an overflowed positive value. This provides
1090 correct results for sizes up to 512 MB.
1092 ??? Size should be calculated in storage elements directly. */
1122 {
1129 else
1130 gnu_result
1131 = build_binary_op
1133 build_binary_op
1145 }
1147 /* ... fall through ... */
1150 {
1157 /* Make sure any implicit dereference gets done. */
1160 /* We treat unconstrained array In parameters specially. */
1170 {
1172 tree gnu_type_temp;
1178 ;
1181 }
1188 /* When not optimizing, look up the slot associated with the parameter
1189 and the dimension in the cache and create a new one on failure. */
1191 {
1197 {
1202 }
1203 }
1205 /* Return the cached expression or build a new one. */
1207 {
1209 {
1212 }
1214 gnu_result
1216 }
1219 {
1221 {
1224 }
1226 gnu_result
1228 }
1231 {
1233 {
1236 }
1237 else
1238 {
1239 /* We used to compute the length as max (hb - lb + 1, 0),
1240 which could overflow for some cases of empty arrays, e.g.
1241 when lb == index_type'first. We now compute the length as
1242 (hb < lb) ? 0 : hb - lb + 1, which would only overflow in
1243 much rarer cases, for extremely large arrays we expect
1244 never to encounter in practice. In addition, the former
1245 computation required the use of potentially constraining
1246 signed arithmetic while the latter doesn't. */
1250 tree index_type
1252 tree lb
1254 tree hb
1257 gnu_result
1258 = build3
1262 build_binary_op
1266 }
1267 }
1269 /* If this has a PLACEHOLDER_EXPR, qualify it by the object we are
1270 handling. Note that these attributes could not have been used on
1271 an unconstrained array type. */
1273 gnu_prefix);
1275 /* Cache the expression we have just computed. Since we want to do it
1276 at runtime, we force the use of a SAVE_EXPR and let the gimplifier
1277 create the temporary. */
1279 {
1280 gnu_result
1287 else
1289 }
1291 }
1298 {
1299 HOST_WIDE_INT bitsize;
1300 HOST_WIDE_INT bitpos;
1301 tree gnu_offset;
1302 tree gnu_field_bitpos;
1303 tree gnu_field_offset;
1304 tree gnu_inner;
1312 /* We can have 'Bit on any object, but if it isn't a COMPONENT_REF,
1313 the result is 0. Don't allow 'Bit on a bare component, though. */
1317 {
1320 }
1322 else
1331 {
1339 {
1340 gnu_field_bitpos
1343 gnu_field_offset
1346 }
1347 }
1349 {
1352 }
1353 else
1354 {
1357 }
1360 {
1375 bitsize_one_node);
1381 }
1383 /* If this has a PLACEHOLDER_EXPR, qualify it by the object
1384 we are handling. */
1387 }
1391 {
1399 }
1427 /* Note this size cannot be self-referential. */
1434 /* This is just a zero cast to the pointer type for
1435 our prefix and dereferenced. */
1437 gnu_result
1440 integer_zero_node));
1445 {
1452 {
1457 ;
1458 }
1466 && (DECL_BY_COMPONENT_PTR_P
1470 }
1474 /* Say we have an unimplemented attribute. Then set the value to be
1475 returned to be a zero and hope that's something we can convert to the
1476 type of this attribute. */
1481 }
1483 /* If this is an attribute where the prefix was unused, force a use of it if
1484 it has a side-effect. But don't do it if the prefix is just an entity
1485 name. However, if an access check is needed, we must do it. See second
1486 example in AARM 11.6(5.e). */
1494 }
1495 \f
1496 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Case_Statement,
1497 to a GCC tree, which is returned. */
1499 static tree
1501 {
1502 tree gnu_result;
1503 tree gnu_expr;
1504 Node_Id gnat_when;
1509 /* The range of values in a case statement is determined by the rules in
1510 RM 5.4(7-9). In almost all cases, this range is represented by the Etype
1511 of the expression. One exception arises in the case of a simple name that
1512 is parenthesized. This still has the Etype of the name, but since it is
1513 not a name, para 7 does not apply, and we need to go to the base type.
1514 This is the only case where parenthesization affects the dynamic
1515 semantics (i.e. the range of possible values at runtime that is covered
1516 by the others alternative.
1518 Another exception is if the subtype of the expression is non-static. In
1519 that case, we also have to use the base type. */
1525 /* We build a SWITCH_EXPR that contains the code with interspersed
1526 CASE_LABEL_EXPRs for each label. */
1533 {
1534 Node_Id gnat_choice;
1537 /* First compile all the different case choices for the current WHEN
1538 alternative. */
1541 {
1545 {
1560 /* This represents either a subtype range or a static value of
1561 some kind; Ekind says which. */
1563 {
1569 }
1571 /* ... fall through ... */
1583 }
1585 /* If the case value is a subtype that raises Constraint_Error at
1586 run-time because of a wrong bound, then gnu_low or gnu_high is
1587 not transtaleted into an INTEGER_CST. In such a case, we need
1588 to ensure that the when statement is not added in the tree,
1589 otherwise it will crash the gimplifier. */
1592 {
1596 gnat_choice);
1597 choices_added++;
1598 }
1599 }
1601 /* Push a binding level here in case variables are declared as we want
1602 them to be local to this set of statements instead of to the block
1603 containing the Case statement. */
1605 {
1609 }
1610 }
1612 /* Now emit a definition of the label all the cases branched to. */
1620 }
1621 \f
1622 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Loop_Statement,
1623 to a GCC tree, which is returned. */
1625 static tree
1627 {
1628 /* ??? It would be nice to use "build" here, but there's no build5. */
1634 tree gnu_result;
1643 /* Save the end label of this LOOP_STMT in a stack so that the corresponding
1644 N_Exit_Statement can find it. */
1648 /* Set the condition that under which the loop should continue.
1649 For "LOOP .... END LOOP;" the condition is always true. */
1651 ;
1652 /* The case "WHILE condition LOOP ..... END LOOP;" */
1656 else
1657 {
1658 /* We have an iteration scheme. */
1673 /* We know the loop variable will not overflow if GNU_LAST is a constant
1674 and is not equal to GNU_LIMIT. If it might overflow, we have to move
1675 the limit test to the end of the loop. In that case, we have to test
1676 for an empty loop outside the loop. */
1680 {
1681 gnu_cond_expr
1687 }
1689 /* Open a new nesting level that will surround the loop to declare the
1690 loop index variable. */
1694 /* Declare the loop index and set it to its initial value. */
1699 /* The loop variable might be a padded type, so use `convert' to get a
1700 reference to the inner variable if so. */
1703 /* Set either the top or bottom exit condition as appropriate depending
1704 on whether or not we know an overflow cannot occur. */
1709 else
1718 gnu_loop_var,
1720 integer_one_node));
1722 gnat_iter_scheme);
1723 }
1725 /* If the loop was named, have the name point to this loop. In this case,
1726 the association is not a ..._DECL node, but the end label from this
1727 LOOP_STMT. */
1732 /* Make the loop body into its own block, so any allocated storage will be
1733 released every iteration. This is needed for stack allocation. */
1737 /* If we declared a variable, then we are in a statement group for that
1738 declaration. Add the LOOP_STMT to it and make that the "loop". */
1740 {
1744 }
1746 /* If we have an outer COND_EXPR, that's our result and this loop is its
1747 "true" statement. Otherwise, the result is the LOOP_STMT. */
1749 {
1753 }
1754 else
1760 }
1761 \f
1762 /* Emit statements to establish __gnat_handle_vms_condition as a VMS condition
1763 handler for the current function. */
1765 /* This is implemented by issuing a call to the appropriate VMS specific
1766 builtin. To avoid having VMS specific sections in the global gigi decls
1767 array, we maintain the decls of interest here. We can't declare them
1768 inside the function because we must mark them never to be GC'd, which we
1769 can only do at the global level. */
1774 static void
1776 {
1777 tree establish_stmt;
1779 /* Elaborate the required decls on the first call. Check on the decl for
1780 the gnat condition handler to decide, as this is one we create so we are
1781 sure that it will be non null on subsequent calls. The builtin decl is
1782 looked up so remains null on targets where it is not implemented yet. */
1784 {
1785 vms_builtin_establish_handler_decl
1786 = builtin_decl_for
1789 gnat_vms_condition_handler_decl
1791 NULL_TREE,
1793 ptr_void_type_node,
1794 ptr_void_type_node,
1795 NULL_TREE),
1797 }
1799 /* Do nothing if the establish builtin is not available, which might happen
1800 on targets where the facility is not implemented. */
1804 establish_stmt
1806 build_unary_op
1808 gnat_vms_condition_handler_decl));
1811 }
1812 \f
1813 /* Subroutine of gnat_to_gnu to process gnat_node, an N_Subprogram_Body. We
1814 don't return anything. */
1816 static void
1818 {
1819 /* Defining identifier of a parameter to the subprogram. */
1820 Entity_Id gnat_param;
1821 /* The defining identifier for the subprogram body. Note that if a
1822 specification has appeared before for this body, then the identifier
1823 occurring in that specification will also be a defining identifier and all
1824 the calls to this subprogram will point to that specification. */
1825 Entity_Id gnat_subprog_id
1828 /* The FUNCTION_DECL node corresponding to the subprogram spec. */
1829 tree gnu_subprog_decl;
1830 /* The FUNCTION_TYPE node corresponding to the subprogram spec. */
1831 tree gnu_subprog_type;
1832 tree gnu_cico_list;
1833 tree gnu_result;
1836 /* If this is a generic object or if it has been eliminated,
1837 ignore it. */
1843 /* If this subprogram acts as its own spec, define it. Otherwise, just get
1844 the already-elaborated tree node. However, if this subprogram had its
1845 elaboration deferred, we will already have made a tree node for it. So
1846 treat it as not being defined in that case. Such a subprogram cannot
1847 have an address clause or a freeze node, so this test is safe, though it
1848 does disable some otherwise-useful error checking. */
1849 gnu_subprog_decl
1856 /* Propagate the debug mode. */
1860 /* Set the line number in the decl to correspond to that of the body so that
1861 the line number notes are written correctly. */
1864 /* Initialize the information structure for the function. */
1872 /* If there are Out parameters, we need to ensure that the return statement
1873 properly copies them out. We do this by making a new block and converting
1874 any inner return into a goto to a label at the end of the block. */
1878 /* Get a tree corresponding to the code for the subprogram. */
1882 /* See if there are any parameters for which we don't yet have GCC entities.
1883 These must be for Out parameters for which we will be making VAR_DECL
1884 nodes here. Fill them in to TYPE_CI_CO_LIST, which must contain the empty
1885 entry as well. We can match up the entries because TYPE_CI_CO_LIST is in
1886 the order of the parameters. */
1891 {
1892 /* Skip any entries that have been already filled in; they must
1893 correspond to In Out parameters. */
1896 ;
1898 /* Do any needed references for padded types. */
1902 }
1904 /* On VMS, establish our condition handler to possibly turn a condition into
1905 the corresponding exception if the subprogram has a foreign convention or
1906 is exported.
1908 To ensure proper execution of local finalizations on condition instances,
1909 we must turn a condition into the corresponding exception even if there
1910 is no applicable Ada handler, and need at least one condition handler per
1911 possible call chain involving GNAT code. OTOH, establishing the handler
1912 has a cost so we want to minimize the number of subprograms into which
1913 this happens. The foreign or exported condition is expected to satisfy
1914 all the constraints. */
1921 /* Generate the code of the subprogram itself. A return statement will be
1922 present and any Out parameters will be handled there. */
1927 /* If we populated the parameter attributes cache, we need to make sure
1928 that the cached expressions are evaluated on all possible paths. */
1931 {
1938 {
1945 }
1949 }
1951 /* If we made a special return label, we need to make a block that contains
1952 the definition of that label and the copying to the return value. That
1953 block first contains the function, then the label and copy statement. */
1955 {
1956 tree gnu_retval;
1967 else
1969 gnu_cico_list);
1974 add_stmt_with_node
1976 gnat_node);
1979 }
1983 /* Set the end location. */
1984 Sloc_to_locus
1992 /* Disconnect the trees for parameters that we made variables for from the
1993 GNAT entities since these are unusable after we end the function. */
2004 }
2005 \f
2006 /* Subroutine of gnat_to_gnu to translate gnat_node, either an N_Function_Call
2007 or an N_Procedure_Call_Statement, to a GCC tree, which is returned.
2008 GNU_RESULT_TYPE_P is a pointer to where we should place the result type.
2009 If GNU_TARGET is non-null, this must be a function call and the result
2010 of the call is to be placed into that object. */
2012 static tree
2014 {
2015 tree gnu_result;
2016 /* The GCC node corresponding to the GNAT subprogram name. This can either
2017 be a FUNCTION_DECL node if we are dealing with a standard subprogram call,
2018 or an indirect reference expression (an INDIRECT_REF node) pointing to a
2019 subprogram. */
2021 /* The FUNCTION_TYPE node giving the GCC type of the subprogram. */
2024 gnu_subprog_node);
2025 Entity_Id gnat_formal;
2026 Node_Id gnat_actual;
2031 tree gnu_subprog_call;
2034 {
2041 }
2045 /* If we are calling a stubbed function, make this into a raise of
2046 Program_Error. Elaborate all our args first. */
2049 {
2055 {
2056 tree call_expr
2058 N_Raise_Program_Error);
2061 {
2064 }
2065 else
2067 }
2068 }
2070 /* If we are calling by supplying a pointer to a target, set up that
2071 pointer as the first argument. Use GNU_TARGET if one was passed;
2072 otherwise, make a target by building a variable of the maximum size
2073 of the type. */
2075 {
2076 tree gnu_real_ret_type
2080 {
2081 tree gnu_obj_type
2087 /* ??? We may be about to create a static temporary if we happen to
2088 be at the global binding level. That's a regression from what
2089 the 3.x back-end would generate in the same situation, but we
2090 don't have a mechanism in Gigi for creating automatic variables
2091 in the elaboration routines. */
2092 gnu_target
2095 gnat_node);
2096 }
2098 gnu_actual_list
2102 gnu_target,
2104 NULL_TREE);
2106 }
2108 /* The only way we can be making a call via an access type is if Name is an
2109 explicit dereference. In that case, get the list of formal args from the
2110 type the access type is pointing to. Otherwise, get the formals from
2111 entity being called. */
2115 /* Assume here that this must be 'Elab_Body or 'Elab_Spec. */
2117 else
2120 /* Create the list of the actual parameters as GCC expects it, namely a chain
2121 of TREE_LIST nodes in which the TREE_VALUE field of each node is a
2122 parameter-expression and the TREE_PURPOSE field is null. Skip Out
2123 parameters not passed by reference and don't need to be copied in. */
2128 {
2129 tree gnu_formal
2133 /* We must suppress conversions that can cause the creation of a
2134 temporary in the Out or In Out case because we need the real
2135 object in this case, either to pass its address if it's passed
2136 by reference or as target of the back copy done after the call
2137 if it uses the copy-in copy-out mechanism. We do it in the In
2138 case too, except for an unchecked conversion because it alone
2139 can cause the actual to be misaligned and the addressability
2140 test is applied to the real object. */
2141 bool suppress_type_conversion
2146 Node_Id gnat_name = (suppress_type_conversion
2149 tree gnu_actual;
2151 /* If it's possible we may need to use this expression twice, make sure
2152 that any side-effects are handled via SAVE_EXPRs. Likewise if we need
2153 to force side-effects before the call.
2154 ??? This is more conservative than we need since we don't need to do
2155 this for pass-by-ref with no conversion. */
2159 /* If we are passing a non-addressable parameter by reference, pass the
2160 address of a copy. In the Out or In Out case, set up to copy back
2161 out after the call. */
2169 {
2172 /* If the type is by_reference, a copy is not allowed. */
2174 post_error
2177 /* For users of Starlet we issue a warning because the
2178 interface apparently assumes that by-ref parameters
2179 outlive the procedure invocation. The code still
2180 will not work as intended, but we cannot do much
2181 better since other low-level parts of the back-end
2182 would allocate temporaries at will because of the
2183 misalignment if we did not do so here. */
2185 {
2186 post_error
2188 post_error_ne
2192 gnat_formal);
2193 }
2195 /* Remove any unpadding from the object and reset the copy. */
2199 && (TYPE_IS_PADDING_P
2203 /* Otherwise convert to the nominal type of the object if it's
2204 a record type. There are several cases in which we need to
2205 make the temporary using this type instead of the actual type
2206 of the object if they are distinct, because the expectations
2207 of the callee would otherwise not be met:
2208 - if it's a justified modular type,
2209 - if the actual type is a smaller packable version of it. */
2213 gnu_name_type)))
2216 /* Make a SAVE_EXPR to both properly account for potential side
2217 effects and handle the creation of a temporary copy. Special
2218 code in gnat_gimplify_expr ensures that the same temporary is
2219 used as the object and copied back after the call if needed. */
2223 /* Set up to move the copy back to the original. */
2225 {
2227 gnu_name);
2230 }
2231 }
2233 /* Start from the real object and build the actual. */
2236 /* If this was a procedure call, we may not have removed any padding.
2237 So do it here for the part we will use as an input, if any. */
2242 gnu_actual);
2244 /* Do any needed conversions for the actual and make sure that it is
2245 in range of the formal's type. */
2247 {
2248 /* Put back the conversion we suppressed above in the computation
2249 of the real object. Note that we treat a conversion between
2250 aggregate types as if it is an unchecked conversion here. */
2251 gnu_actual
2253 gnu_actual,
2261 }
2262 else
2263 {
2268 /* We may have suppressed a conversion to the Etype of the actual
2269 since the parent is a procedure call. So put it back here.
2270 ??? We use the reverse order compared to the case above because
2271 of an awkward interaction with the check and actually don't put
2272 back the conversion at all if a check is emitted. This is also
2273 done for the conversion to the formal's type just below. */
2276 gnu_actual);
2277 }
2282 /* Unless this is an In parameter, we must remove any justified modular
2283 building from GNU_NAME to get an lvalue. */
2289 gnu_name);
2291 /* If we have not saved a GCC object for the formal, it means it is an
2292 Out parameter not passed by reference and that does not need to be
2293 copied in. Otherwise, look at the PARM_DECL to see if it is passed by
2294 reference. */
2298 {
2300 {
2301 /* In Out or Out parameters passed by reference don't use the
2302 copy-in copy-out mechanism so the address of the real object
2303 must be passed to the function. */
2306 /* If we have a padded type, be sure we've removed padding. */
2311 gnu_actual);
2313 /* If we have the constructed subtype of an aliased object
2314 with an unconstrained nominal subtype, the type of the
2315 actual includes the template, although it is formally
2316 constrained. So we need to convert it back to the real
2317 constructed subtype to retrieve the constrained part
2318 and takes its address. */
2325 gnu_actual);
2326 }
2328 /* The symmetry of the paths to the type of an entity is broken here
2329 since arguments don't know that they will be passed by ref. */
2332 }
2336 {
2343 {
2346 }
2348 /* Take the address of the object and convert to the proper pointer
2349 type. We'd like to actually compute the address of the beginning
2350 of the array using an ADDR_EXPR of an ARRAY_REF, but there's a
2351 possibility that the ARRAY_REF might return a constant and we'd be
2352 getting the wrong address. Neither approach is exactly correct,
2353 but this is the most likely to work in all cases. */
2356 gnu_actual));
2357 }
2361 {
2362 /* If arg is 'Null_Parameter, pass zero descriptor. */
2367 integer_zero_node);
2368 else
2371 gnat_formal));
2372 }
2373 else
2374 {
2383 /* If this is 'Null_Parameter, pass a zero even though we are
2384 dereferencing it. */
2389 BITS_PER_WORD))
2390 gnu_actual
2395 integer_zero_node),
2397 else
2399 }
2402 }
2405 gnu_subprog_addr,
2409 /* If we return by passing a target, the result is the target after the
2410 call. We must not emit the call directly here because this might be
2411 evaluated as part of an expression with conditions to control whether
2412 the call should be emitted or not. */
2414 {
2415 /* Conceptually, what we need is a COMPOUND_EXPR with the call followed
2416 by the target object converted to the proper type. Doing so would
2417 potentially be very inefficient, however, as this expression might
2418 end up wrapped into an outer SAVE_EXPR later on, which would incur a
2419 pointless temporary copy of the whole object.
2421 What we do instead is build a COMPOUND_EXPR returning the address of
2422 the target, and then dereference. Wrapping the COMPOUND_EXPR into a
2423 SAVE_EXPR later on then only incurs a pointer copy. */
2425 tree gnu_result_type
2428 /* Build and return
2429 (result_type) *[gnu_subprog_call (&gnu_target, ...), &gnu_target] */
2431 tree gnu_target_address
2435 gnu_result
2439 gnu_result
2442 gnu_result),
2447 }
2449 /* If it is a function call, the result is the call expression unless
2450 a target is specified, in which case we copy the result into the target
2451 and return the assignment statement. */
2453 {
2456 /* If the function returns an unconstrained array or by reference,
2457 we have to de-dereference the pointer. */
2465 else
2469 }
2471 /* If this is the case where the GNAT tree contains a procedure call
2472 but the Ada procedure has copy in copy out parameters, the special
2473 parameter passing mechanism must be used. */
2475 {
2476 /* List of FIELD_DECLs associated with the PARM_DECLs of the copy
2477 in copy out parameters. */
2482 {
2483 tree gnu_name;
2488 /* If any of the names had side-effects, ensure they are all
2489 evaluated before the call. */
2495 }
2499 else
2506 /* If we are dealing with a copy in copy out parameter, we must
2507 retrieve its value from the record returned in the call. */
2513 || (DECL_BY_DESCRIPTOR_P
2516 {
2517 /* Get the value to assign to this Out or In Out parameter. It is
2518 either the result of the function if there is only a single such
2519 parameter or the appropriate field from the record returned. */
2520 tree gnu_result
2526 /* If the actual is a conversion, get the inner expression, which
2527 will be the real destination, and convert the result to the
2528 type of the actual parameter. */
2529 tree gnu_actual
2532 /* If the result is a padded type, remove the padding. */
2537 gnu_result);
2539 /* If the actual is a type conversion, the real target object is
2540 denoted by the inner Expression and we need to convert the
2541 result to the associated type.
2542 We also need to convert our gnu assignment target to this type
2543 if the corresponding GNU_NAME was constructed from the GNAT
2544 conversion node and not from the inner Expression. */
2546 {
2547 gnu_result
2548 = convert_with_check
2556 }
2558 /* Unchecked conversions as actuals for Out parameters are not
2559 allowed in user code because they are not variables, but do
2560 occur in front-end expansions. The associated GNU_NAME is
2561 always obtained from the inner expression in such cases. */
2564 gnu_result,
2566 else
2567 {
2575 }
2583 }
2584 }
2585 else
2590 }
2591 \f
2592 /* Subroutine of gnat_to_gnu to translate gnat_node, an
2593 N_Handled_Sequence_Of_Statements, to a GCC tree, which is returned. */
2595 static tree
2597 {
2600 /* If just annotating, ignore all EH and cleanups. */
2604 bool setjmp_longjmp
2610 tree gnu_result;
2611 tree gnu_expr;
2612 Node_Id gnat_temp;
2614 /* The GCC exception handling mechanism can handle both ZCX and SJLJ schemes
2615 and we have our own SJLJ mechanism. To call the GCC mechanism, we call
2616 add_cleanup, and when we leave the binding, end_stmt_group will create
2617 the TRY_FINALLY_EXPR.
2619 ??? The region level calls down there have been specifically put in place
2620 for a ZCX context and currently the order in which things are emitted
2621 (region/handlers) is different from the SJLJ case. Instead of putting
2622 other calls with different conditions at other places for the SJLJ case,
2623 it seems cleaner to reorder things for the SJLJ case and generalize the
2624 condition to make it not ZCX specific.
2626 If there are any exceptions or cleanup processing involved, we need an
2627 outer statement group (for Setjmp_Longjmp) and binding level. */
2629 {
2632 }
2634 /* If using setjmp_longjmp, make the variables for the setjmp buffer and save
2635 area for address of previous buffer. Do this first since we need to have
2636 the setjmp buf known for any decls in this block. */
2638 {
2643 gnat_node);
2646 /* The __builtin_setjmp receivers will immediately reinstall it. Now
2647 because of the unstructured form of EH used by setjmp_longjmp, there
2648 might be forward edges going to __builtin_setjmp receivers on which
2649 it is uninitialized, although they will never be actually taken. */
2659 /* When we exit this block, restore the saved value. */
2662 }
2664 /* If we are to call a function when exiting this block, add a cleanup
2665 to the binding level we made above. Note that add_cleanup is FIFO
2666 so we must register this cleanup after the EH cleanup just above. */
2671 /* Now build the tree for the declarations and statements inside this block.
2672 If this is SJLJ, set our jmp_buf as the current buffer. */
2678 gnu_jmpbuf_decl)));
2684 /* Generate code for each statement in the block. */
2692 /* Now generate code for the two exception models, if either is relevant for
2693 this block. */
2695 {
2697 tree gnu_handler;
2699 /* Make a binding level for the exception handling declarations and code
2700 and set up gnu_except_ptr_stack for the handlers to use. */
2706 NULL_TREE,
2711 /* Generate code for each handler. The N_Exception_Handler case does the
2712 real work and returns a COND_EXPR for each handler, which we chain
2713 together here. */
2716 {
2719 /* If this is the first one, set it as the outer one. Otherwise,
2720 point the "else" part of the previous handler to us. Then point
2721 to our "else" part. */
2724 else
2728 }
2730 /* If none of the exception handlers did anything, re-raise but do not
2731 defer abortion. */
2738 else
2741 /* End the binding level dedicated to the exception handlers and get the
2742 whole statement group. */
2747 /* If the setjmp returns 1, we restore our incoming longjmp value and
2748 then check the handlers. */
2751 gnu_jmpsave_decl),
2752 gnat_node);
2756 /* This block is now "if (setjmp) ... <handlers> else <block>". */
2758 (build_call_1_expr
2761 gnu_jmpbuf_decl))),
2763 }
2765 {
2766 tree gnu_handlers;
2768 /* First make a block containing the handlers. */
2776 /* Now make the TRY_CATCH_EXPR for the block. */
2779 }
2780 else
2783 /* Now close our outer block, if we had to make one. */
2785 {
2789 }
2792 }
2793 \f
2794 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Exception_Handler,
2795 to a GCC tree, which is returned. This is the variant for Setjmp_Longjmp
2796 exception handling. */
2798 static tree
2800 {
2801 /* Unless this is "Others" or the special "Non-Ada" exception for Ada, make
2802 an "if" statement to select the proper exceptions. For "Others", exclude
2803 exceptions where Handled_By_Others is nonzero unless the All_Others flag
2804 is set. For "Non-ada", accept an exception if "Lang" is 'V'. */
2807 Node_Id gnat_temp;
2811 {
2812 tree this_choice;
2815 {
2818 else
2819 this_choice
2820 = build_binary_op
2822 convert
2824 build_component_ref
2825 (build_unary_op
2830 integer_zero_node);
2831 }
2835 {
2837 tree gnu_expr;
2839 /* Exception may be a renaming. Recover original exception which is
2840 the one elaborated and registered. */
2846 this_choice
2847 = build_binary_op
2852 /* If this is the distinguished exception "Non_Ada_Error" (and we are
2853 in VMS mode), also allow a non-Ada exception (a VMS condition) t
2854 match. */
2856 {
2857 tree gnu_comp
2858 = build_component_ref
2863 this_choice
2864 = build_binary_op
2868 this_choice);
2869 }
2870 }
2871 else
2876 }
2879 }
2880 \f
2881 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Exception_Handler,
2882 to a GCC tree, which is returned. This is the variant for ZCX. */
2884 static tree
2886 {
2888 tree gnu_expr;
2889 tree gnu_etype;
2890 tree gnu_current_exc_ptr;
2891 tree gnu_incoming_exc_ptr;
2892 Node_Id gnat_temp;
2894 /* We build a TREE_LIST of nodes representing what exception types this
2895 handler can catch, with special cases for others and all others cases.
2897 Each exception type is actually identified by a pointer to the exception
2898 id, or to a dummy object for "others" and "all others".
2900 Care should be taken to ensure that the control flow impact of "others"
2901 and "all others" is known to GCC. lang_eh_type_covers is doing the trick
2902 currently. */
2905 {
2907 {
2908 tree gnu_expr
2911 gnu_etype
2913 }
2916 {
2919 /* Exception may be a renaming. Recover original exception which is
2920 the one elaborated and registered. */
2927 /* The Non_Ada_Error case for VMS exceptions is handled
2928 by the personality routine. */
2929 }
2930 else
2933 /* The GCC interface expects NULL to be passed for catch all handlers, so
2934 it would be quite tempting to set gnu_etypes_list to NULL if gnu_etype
2935 is integer_zero_node. It would not work, however, because GCC's
2936 notion of "catch all" is stronger than our notion of "others". Until
2937 we correctly use the cleanup interface as well, doing that would
2938 prevent the "all others" handlers from being seen, because nothing
2939 can be caught beyond a catch all from GCC's point of view. */
2941 }
2946 /* Expand a call to the begin_handler hook at the beginning of the handler,
2947 and arrange for a call to the end_handler hook to occur on every possible
2948 exit path.
2950 The hooks expect a pointer to the low level occurrence. This is required
2951 for our stack management scheme because a raise inside the handler pushes
2952 a new occurrence on top of the stack, which means that this top does not
2953 necessarily match the occurrence this handler was dealing with.
2955 The EXC_PTR_EXPR object references the exception occurrence being
2956 propagated. Upon handler entry, this is the exception for which the
2957 handler is triggered. This might not be the case upon handler exit,
2958 however, as we might have a new occurrence propagated by the handler's
2959 body, and the end_handler hook called as a cleanup in this context.
2961 We use a local variable to retrieve the incoming value at handler entry
2962 time, and reuse it to feed the end_handler hook's argument at exit. */
2967 gnat_node);
2970 gnu_incoming_exc_ptr),
2971 gnat_node);
2972 /* ??? We don't seem to have an End_Label at hand to set the location. */
2974 Empty);
2980 }
2981 \f
2982 /* Subroutine of gnat_to_gnu to generate code for an N_Compilation unit. */
2984 static void
2986 {
2987 /* Make the decl for the elaboration procedure. */
2992 tree gnu_elab_proc_decl
2993 = create_subprog_decl
2997 gnat_unit_entity);
3007 /* For a body, first process the spec if there is one. */
3011 {
3014 }
3019 {
3026 }
3032 /* Process any pragmas and actions following the unit. */
3037 /* Save away what we've made so far and record this potential elaboration
3038 procedure. */
3048 /* Generate elaboration code for this unit, if necessary, and say whether
3049 we did or not. */
3052 /* Invalidate the global renaming pointers. This is necessary because
3053 stabilization of the renamed entities may create SAVE_EXPRs which
3054 have been tied to a specific elaboration routine just above. */
3056 }
3057 \f
3058 /* This function is the driver of the GNAT to GCC tree transformation
3059 process. It is the entry point of the tree transformer. GNAT_NODE is the
3060 root of some GNAT tree. Return the root of the corresponding GCC tree.
3061 If this is an expression, return the GCC equivalent of the expression. If
3062 it is a statement, return the statement. In the case when called for a
3063 statement, it may also add statements to the current statement group, in
3064 which case anything it returns is to be interpreted as occurring after
3065 anything `it already added. */
3067 tree
3069 {
3073 tree gnu_expr;
3075 Node_Id gnat_temp;
3077 /* Save node number for error message and set location information. */
3085 /* If this node is a non-static subexpression and we are only
3086 annotating types, make this into a NULL_EXPR. */
3093 N_Raise_Constraint_Error));
3095 /* If this is a Statement and we are at top level, it must be part of the
3096 elaboration procedure, so mark us as being in that procedure and push our
3097 context.
3099 If we are in the elaboration procedure, check if we are violating a
3100 No_Elaboration_Code restriction by having a statement there. */
3111 {
3113 {
3118 }
3120 /* Don't check for a possible No_Elaboration_Code restriction violation
3121 on N_Handled_Sequence_Of_Statements, as we want to signal an error on
3122 every nested real statement instead. This also avoids triggering
3123 spurious errors on dummy (empty) sequences created by the front-end
3124 for package bodies in some cases. */
3129 }
3132 {
3133 /********************************/
3134 /* Chapter 2: Lexical Elements: */
3135 /********************************/
3145 {
3146 tree gnu_type;
3148 /* Get the type of the result, looking inside any padding and
3149 justified modular types. Then get the value in that type. */
3158 /* If the result overflows (meaning it doesn't fit in its base type),
3159 abort. We would like to check that the value is within the range
3160 of the subtype, but that causes problems with subtypes whose usage
3161 will raise Constraint_Error and with biased representation, so
3162 we don't. */
3164 }
3168 /* If a Entity is present, it means that this was one of the
3169 literals in a user-defined character type. In that case,
3170 just return the value in the CONST_DECL. Otherwise, use the
3171 character code. In that case, the base type should be an
3172 INTEGER_TYPE, but we won't bother checking for that. */
3176 else
3177 gnu_result
3178 = build_int_cst_type
3183 /* If this is of a fixed-point type, the value we want is the
3184 value of the corresponding integer. */
3186 {
3189 gnu_result_type);
3191 }
3193 /* We should never see a Vax_Float type literal, since the front end
3194 is supposed to transform these using appropriate conversions */
3198 else
3199 {
3204 /* If the real value is zero, so is the result. Otherwise,
3205 convert it to a machine number if it isn't already. That
3206 forces BASE to 0 or 2 and simplifies the rest of our logic. */
3209 else
3210 {
3212 ur_realval
3216 gnu_result
3219 /* If we have a base of zero, divide by the denominator.
3220 Otherwise, the base must be 2 and we scale the value, which
3221 we know can fit in the mantissa of the type (hence the use
3222 of that type above). */
3224 gnu_result
3227 gnu_result,
3229 gnu_result_type));
3230 else
3231 {
3232 REAL_VALUE_TYPE tmp;
3238 }
3239 }
3241 /* Now see if we need to negate the result. Do it this way to
3242 properly handle -0. */
3244 gnu_result
3246 gnu_result);
3247 }
3254 {
3261 else
3264 /* Build the string with the characters in the literal. Note
3265 that Ada strings are 1-origin. */
3269 /* Put a null at the end of the string in case it's in a context
3270 where GCC will want to treat it as a C string. */
3275 /* Strings in GCC don't normally have types, but we want
3276 this to not be converted to the array type. */
3281 }
3282 else
3283 {
3284 /* Build a list consisting of each character, then make
3285 the aggregate. */
3293 {
3294 gnu_list
3299 gnu_list);
3303 }
3305 gnu_result
3307 }
3314 /**************************************/
3315 /* Chapter 3: Declarations and Types: */
3316 /**************************************/
3333 /* If we are just annotating types and this object has an unconstrained
3334 or task type, don't elaborate it. */
3345 && (!type_annotate_only
3347 {
3352 /* If this object has its elaboration delayed, we must force
3353 evaluation of GNU_EXPR right now and save it for when the object
3354 is frozen. */
3356 {
3359 gnu_expr
3364 else
3368 }
3369 }
3370 else
3383 /* Don't do anything if this renaming is handled by the front end or if
3384 we are just annotating types and this object has a composite or task
3385 type, don't elaborate it. We return the result in case it has any
3386 SAVE_EXPRs in it that need to be evaluated here. */
3388 && ! (type_annotate_only
3392 gnu_result
3395 else
3408 /* These are fully handled in the front end. */
3412 /*************************************/
3413 /* Chapter 4: Names and Expressions: */
3414 /*************************************/
3423 {
3425 tree gnu_type;
3433 /* If we got a padded type, remove it too. */
3436 gnu_array_object
3438 gnu_array_object);
3442 /* First compute the number of dimensions of the array, then
3443 fill the expression array, the order depending on whether
3444 this is a Convention_Fortran array or not. */
3449 ;
3458 else
3466 {
3472 gnu_expr
3473 = emit_index_check
3480 }
3481 }
3487 {
3488 tree gnu_type;
3494 /* Do any implicit dereferences of the prefix and do any needed
3495 range check. */
3500 {
3501 /* Get the bounds of the slice. */
3502 tree gnu_index_type
3506 /* Get the permitted bounds. */
3507 tree gnu_base_index_type
3513 /* Check to see that the minimum slice value is in range. */
3515 gnu_min_expr,
3516 gnu_base_min_expr,
3517 gnu_base_max_expr);
3519 /* Check to see that the maximum slice value is in range. */
3521 gnu_max_expr,
3522 gnu_base_min_expr,
3523 gnu_base_max_expr);
3525 /* Derive a good type to convert everything to. */
3528 /* Build a compound expression that does the range checks and
3529 returns the low bound. */
3534 /* Build a conditional expression that does the range check and
3535 returns the low bound if the slice is not empty (max >= min),
3536 and returns the naked low bound otherwise (max < min), unless
3537 it is non-constant and the high bound is; this prevents VRP
3538 from inferring bogus ranges on the unlikely path. */
3542 gnu_max_expr),
3544 gnu_min_expr)),
3545 gnu_expr,
3549 }
3550 else
3551 /* Simply return the naked low bound. */
3556 }
3560 {
3564 tree gnu_field;
3568 {
3573 }
3577 /* For discriminant references in tagged types always substitute the
3578 corresponding discriminant as the actual selected component. */
3584 /* For discriminant references of untagged types always substitute the
3585 corresponding stored discriminant. */
3590 /* Handle extracting the real or imaginary part of a complex.
3591 The real part is the first field and the imaginary the last. */
3597 else
3598 {
3601 /* If there are discriminants, the prefix might be
3602 evaluated more than once, which is a problem if it has
3603 side-effects. */
3610 gnu_result
3614 }
3618 }
3622 {
3623 /* The attribute designator (like an enumeration value). */
3626 /* The Elab_Spec and Elab_Body attributes are special in that
3627 Prefix is a unit, not an object with a GCC equivalent. Similarly
3628 for Elaborated, since that variable isn't otherwise known. */
3632 attribute == Attr_Elab_Body
3635 gnat_node));
3638 }
3642 /* Like 'Access as far as we are concerned. */
3650 {
3651 tree gnu_aggr_type;
3653 /* ??? It is wrong to evaluate the type now, but there doesn't
3654 seem to be any other practical way of doing it. */
3658 gnu_aggr_type = gnu_result_type
3663 gnu_aggr_type
3671 gnu_result
3674 gnu_aggr_type);
3677 gnu_aggr_type,
3680 gnu_result
3681 = build_binary_op
3686 (Next
3688 else
3692 }
3700 else
3707 /* Get the operand expression. */
3711 gnu_result
3723 /* If the result is a pointer type, see if we are improperly
3724 converting to a stricter alignment. */
3727 {
3733 post_error_ne_tree_2
3737 }
3739 /* If we are converting a descriptor to a function pointer, first
3740 build the pointer. */
3752 {
3755 tree gnu_low;
3756 tree gnu_high;
3758 /* GNAT_RANGE is either an N_Range node or an identifier
3759 denoting a subtype. */
3761 {
3764 }
3767 {
3772 }
3773 else
3778 /* If LOW and HIGH are identical, perform an equality test.
3779 Otherwise, ensure that GNU_OBJECT is only evaluated once
3780 and perform a full range test. */
3784 else
3785 {
3787 gnu_result
3793 }
3797 }
3805 ? RDIV_EXPR
3812 /* These can either be operations on booleans or on modular types.
3813 Fall through for boolean types since that's the way GNU_CODES is
3814 set up. */
3816 Modular_Integer_Kind))
3817 {
3818 enum tree_code code
3829 }
3831 /* ... fall through ... */
3843 {
3846 tree gnu_type;
3852 /* If this is a comparison operator, convert any references to
3853 an unconstrained array value into a reference to the
3854 actual array. */
3856 {
3859 }
3861 /* If the result type is a private type, its full view may be a
3862 numeric subtype. The representation we need is that of its base
3863 type, given that it is the result of an arithmetic operation. */
3865 gnu_type = gnu_result_type
3868 /* If this is a shift whose count is not guaranteed to be correct,
3869 we need to adjust the shift count. */
3872 {
3874 tree gnu_max_shift
3882 gnu_rhs
3883 = build_binary_op
3886 gnu_count_type,
3887 gnu_max_shift,
3889 integer_one_node)),
3890 gnu_rhs);
3891 }
3893 /* For right shifts, the type says what kind of shift to do,
3894 so we may need to choose a different type. In this case,
3895 we have to ignore integer overflow lest it propagates all
3896 the way down and causes a CE to be explicitly raised. */
3899 {
3902 }
3905 {
3908 }
3911 {
3917 }
3921 /* If this is a logical shift with the shift count not verified,
3922 we must return zero if it is too large. We cannot compensate
3923 above in this case. */
3927 gnu_result
3928 = build_cond_expr
3931 gnu_rhs,
3935 gnu_result);
3936 }
3940 {
3943 tree gnu_false
3950 }
3959 /* This case can apply to a boolean or a modular type.
3960 Fall through for a boolean operand since GNU_CODES is set
3961 up to handle this. */
3965 {
3969 gnu_expr);
3971 }
3973 /* ... fall through ... */
3980 else
3989 {
3991 tree gnu_type;
3996 /* The Expression operand can either be an N_Identifier or
3997 Expanded_Name, which must represent a type, or a
3998 N_Qualified_Expression, which contains both the object type and an
3999 initial value for the object. */
4004 {
4005 Entity_Id gnat_desig_type
4017 {
4020 }
4021 else
4022 {
4028 }
4029 }
4030 else
4037 ignore_init_type);
4038 }
4041 /***************************/
4042 /* Chapter 5: Statements: */
4043 /***************************/
4055 /* Get the LHS and RHS of the statement and convert any reference to an
4056 unconstrained array into a reference to the underlying array.
4057 If we are not to do range checking and the RHS is an N_Function_Call,
4058 pass the LHS to the call function. */
4061 /* If the type has a size that overflows, convert this into raise of
4062 Storage_Error: execution shouldn't have gotten here anyway. */
4066 N_Raise_Storage_Error);
4071 else
4072 {
4073 gnu_rhs
4076 /* If range check is needed, emit code to generate it */
4080 gnu_result
4082 }
4086 {
4089 /* Make the outer COND_EXPR. Avoid non-determinism. */
4098 /* Now make a COND_EXPR for each of the "else if" parts. Put each
4099 into the previous "else" part and point to where to put any
4100 outer "else". Also avoid non-determinism. */
4104 {
4114 }
4117 }
4141 gnu_result
4151 {
4152 /* The gnu function type of the subprogram currently processed. */
4154 /* The return value from the subprogram. */
4156 /* The place to put the return value. */
4157 tree gnu_lhs;
4159 /* If we are dealing with a "return;" from an Ada procedure with
4160 parameters passed by copy in copy out, we need to return a record
4161 containing the final values of these parameters. If the list
4162 contains only one entry, return just that entry.
4164 For a full description of the copy in copy out parameter mechanism,
4165 see the part of the gnat_to_gnu_entity routine dealing with the
4166 translation of subprograms.
4168 But if we have a return label defined, convert this into
4169 a branch to that label. */
4172 {
4176 }
4179 {
4183 else
4184 gnu_ret_val
4187 }
4189 /* If the Ada subprogram is a function, we just need to return the
4190 expression. If the subprogram returns an unconstrained
4191 array, we have to allocate a new version of the result and
4192 return it. If we return by reference, return a pointer. */
4195 {
4196 /* If the current function returns by target pointer and we
4197 are doing a call, pass that target to the call. */
4200 {
4201 gnu_lhs
4206 }
4207 else
4208 {
4212 /* The original return type was unconstrained so dereference
4213 the TARGET pointer in the actual return value's type. */
4214 gnu_lhs
4217 else
4220 /* Do not remove the padding from GNU_RET_VAL if the inner
4221 type is self-referential since we want to allocate the fixed
4222 size in that case. */
4226 && (TYPE_IS_PADDING_P
4228 && (CONTAINS_PLACEHOLDER_P
4234 gnu_ret_val
4238 {
4240 gnu_ret_val
4242 gnu_ret_val,
4247 }
4248 }
4249 }
4250 else
4251 /* If the Ada subprogram is a regular procedure, just return. */
4255 {
4261 }
4264 }
4272 /****************************/
4273 /* Chapter 6: Subprograms: */
4274 /****************************/
4277 /* Unless there is a freeze node, declare the subprogram. We consider
4278 this a "definition" even though we're not generating code for
4279 the subprogram because we will be making the corresponding GCC
4280 node here. */
4289 /* This subprogram doesn't exist for code generation purposes, but we
4290 have to elaborate the types of any parameters and result, unless
4291 they are imported types (nothing to generate in this case). */
4293 /* Process the parameter types first. */
4296 = First_Formal_With_Extras
4305 /* Then the result type, set to Standard_Void_Type for procedures. */
4307 {
4308 Entity_Id gnat_temp_type
4313 }
4319 /* For a child unit identifier go up a level to get the
4320 specification. We get this when we try to find the spec of
4321 a child unit package that is the compilation unit being compiled. */
4335 /*************************/
4336 /* Chapter 7: Packages: */
4337 /*************************/
4353 /* If this is the body of a generic package - do nothing */
4355 {
4358 }
4369 /*********************************/
4370 /* Chapter 8: Visibility Rules: */
4371 /*********************************/
4375 /* Nothing to do here - but these may appear in list of declarations */
4379 /***********************/
4380 /* Chapter 9: Tasks: */
4381 /***********************/
4392 /***********************************************************/
4393 /* Chapter 10: Program Structure and Compilation Issues: */
4394 /***********************************************************/
4398 /* This is not called for the main unit, which is handled in function
4399 gigi above. */
4411 /* Simply process whatever unit is being inserted. */
4419 /***************************/
4420 /* Chapter 11: Exceptions: */
4421 /***************************/
4424 /* If there is an At_End procedure attached to this node, and the EH
4425 mechanism is SJLJ, we must have at least a corresponding At_End
4426 handler, unless the No_Exception_Handlers restriction is set. */
4441 else
4462 gnu_constraint_error_label_stack
4467 gnu_storage_error_label_stack
4472 gnu_program_error_label_stack
4476 /*******************************/
4477 /* Chapter 12: Generic Units: */
4478 /*******************************/
4488 /* These nodes can appear on a declaration list but there is nothing to
4489 to be done with them. */
4493 /***************************************************/
4494 /* Chapter 13: Representation Clauses and */
4495 /* Implementation-Dependent Features: */
4496 /***************************************************/
4502 /* The only one we need deal with is for 'Address. For the others, SEM
4503 puts the information elsewhere. We need only deal with 'Address
4504 if the object has a Freeze_Node (which it never will currently). */
4509 /* Get the value to use as the address and save it as the
4510 equivalent for GNAT_TEMP. When the object is frozen,
4511 gnat_to_gnu_entity will do the right thing. */
4519 /* We do nothing with these. SEM puts the information elsewhere. */
4525 {
4535 /* First retrieve the 3 operand lists built by the front-end. */
4538 {
4545 }
4549 {
4556 }
4560 gnu_clobbers
4563 gnu_clobbers);
4565 /* Then perform some standard checking and processing on the
4566 operands. In particular, mark them addressable if needed. */
4571 oconstraints
4575 {
4577 constraint
4583 {
4584 /* If the operand is going to end up in memory,
4585 mark it addressable. Note that we don't test
4586 allows_mem like in the input case below; this
4587 is modelled on the C front-end. */
4591 }
4592 else
4596 }
4599 {
4601 constraint
4607 {
4608 /* If the operand is going to end up in memory,
4609 mark it addressable. */
4613 }
4614 else
4618 }
4624 }
4625 else
4630 /***************************************************/
4631 /* Added Nodes */
4632 /***************************************************/
4650 {
4653 tree gnu_obj_type;
4655 tree gnu_obj_size;
4657 unsigned int default_allocator_alignment
4660 /* If this is a thin pointer, we must dereference it to create
4661 a fat pointer, then go back below to a thin pointer. The
4662 reason for this is that we need a fat pointer someplace in
4663 order to properly compute the size. */
4667 gnu_ptr));
4669 /* If this is an unconstrained array, we know the object must
4670 have been allocated with the template in front of the object.
4671 So pass the template address, but get the total size. Do this
4672 by converting to a thin pointer. */
4674 gnu_ptr
4676 (TYPE_OBJECT_RECORD_TYPE
4678 gnu_ptr);
4683 {
4684 gnu_actual_obj_type
4688 gnu_actual_obj_type
4690 gnu_actual_obj_type,
4692 }
4693 else
4701 {
4704 tree gnu_byte_offset
4712 }
4714 /* If the object was allocated from the default storage pool, the
4715 alignment was greater than what the allocator provides, and this
4716 is not a fat or thin pointer, what we have in gnu_ptr here is an
4717 address dynamically adjusted to match the alignment requirement
4718 (see build_allocator). What we need to pass to free is the
4719 initial allocator's return value, which has been stored just in
4720 front of the block we have. */
4725 {
4726 /* We set GNU_PTR
4727 as * (void **)((void *)GNU_PTR - (void *)sizeof(void *))
4728 in two steps: */
4730 /* GNU_PTR (void *)
4731 = (void *)GNU_PTR - (void *)sizeof (void *)) */
4732 gnu_ptr
4733 = build_binary_op
4738 /* GNU_PTR (void *) = *(void **)GNU_PTR */
4739 gnu_ptr
4740 = build_unary_op
4743 gnu_ptr));
4744 }
4749 gnat_node);
4750 }
4757 {
4760 }
4763 gnu_result
4767 /* If the type is VOID, this is a statement, so we need to
4768 generate the code for the call. Handle a Condition, if there
4769 is one. */
4771 {
4778 }
4779 else
4784 {
4789 /* No need for any warning in this case. */
4791 ;
4793 /* If the result is a pointer type, see if we are either converting
4794 from a non-pointer or from a pointer to a type with a different
4795 alias set and warn if so. If the result is defined in the same
4796 unit as this unchecked conversion, we can allow this because we
4797 can know to make the pointer type behave properly. */
4801 {
4816 {
4817 post_error_ne
4820 post_error
4822 gnat_node);
4823 post_error_ne
4826 }
4827 }
4829 /* But if the result is a fat pointer type, we have no mechanism to
4830 do that, so we unconditionally warn in problematic cases. */
4832 {
4833 tree gnu_source_array_type
4837 tree gnu_target_array_type
4849 {
4850 post_error_ne
4853 post_error
4855 gnat_node);
4856 }
4857 }
4858 }
4871 }
4873 /* If we pushed our level as part of processing the elaboration routine,
4874 pop it back now. */
4876 {
4881 }
4883 /* Set the location information on the result if it is a real expression.
4884 References can be reused for multiple GNAT nodes and they would get
4885 the location information of their last use. Note that we may have
4886 no result if we tried to build a CALL_EXPR node to a procedure with
4887 no side-effects and optimization is enabled. */
4894 /* If we're supposed to return something of void_type, it means we have
4895 something we're elaborating for effect, so just return. */
4899 /* If the result is a constant that overflows, raise constraint error. */
4902 {
4905 gnu_result
4908 N_Raise_Constraint_Error));
4909 }
4911 /* If our result has side-effects and is of an unconstrained type,
4912 make a SAVE_EXPR so that we can be sure it will only be referenced
4913 once. Note we must do this before any conversions. */
4919 /* Now convert the result to the result type, unless we are in one of the
4920 following cases:
4922 1. If this is the Name of an assignment statement or a parameter of
4923 a procedure call, return the result almost unmodified since the
4924 RHS will have to be converted to our type in that case, unless
4925 the result type has a simpler size. Similarly, don't convert
4926 integral types that are the operands of an unchecked conversion
4927 since we need to ignore those conversions (for 'Valid).
4929 2. If we have a label (which doesn't have any well-defined type), a
4930 field or an error, return the result almost unmodified. Also don't
4931 do the conversion if the result type involves a PLACEHOLDER_EXPR in
4932 its size since those are the cases where the front end may have the
4933 type wrong due to "instantiating" the unconstrained record with
4934 discriminant values. Similarly, if the two types are record types
4935 with the same name don't convert. This will be the case when we are
4936 converting from a packable version of a type to its original type and
4937 we need those conversions to be NOPs in order for assignments into
4938 these types to work properly.
4940 3. If the type is void or if we have no result, return error_mark_node
4941 to show we have no result.
4943 4. Finally, if the type of the result is already correct. */
4963 && (CONTAINS_PLACEHOLDER_P
4967 {
4968 /* Remove padding only if the inner object is of self-referential
4969 size: in that case it must be an object of unconstrained type
4970 with a default discriminant and we want to avoid copying too
4971 much data. */
4977 gnu_result);
4978 }
4991 {
4992 /* Remove any padding. */
4996 gnu_result);
4997 }
5005 /* We don't need any NOP_EXPR or NON_LVALUE_EXPR on the result. */
5012 }
5013 \f
5014 /* Subroutine of above to push the exception label stack. GNU_STACK is
5015 a pointer to the stack to update and GNAT_LABEL, if present, is the
5016 label to push onto the stack. */
5018 static void
5020 {
5026 }
5027 \f
5028 /* Record the current code position in GNAT_NODE. */
5030 static void
5032 {
5037 }
5039 /* Insert the code for GNAT_NODE at the position saved for that node. */
5041 static void
5043 {
5046 }
5047 \f
5048 /* Start a new statement group chained to the previous group. */
5050 void
5052 {
5055 /* First see if we can get one from the free list. */
5058 else
5064 }
5066 /* Add GNU_STMT to the current statement group. */
5068 void
5070 {
5072 }
5074 /* Similar, but set the location of GNU_STMT to that of GNAT_NODE. */
5076 void
5078 {
5082 }
5084 /* Add a declaration statement for GNU_DECL to the current statement group.
5085 Get SLOC from Entity_Id. */
5087 void
5089 {
5093 /* If this is a variable that Gigi is to ignore, we may have been given
5094 an ERROR_MARK. So test for it. We also might have been given a
5095 reference for a renaming. So only do something for a decl. Also
5096 ignore a TYPE_DECL for an UNCONSTRAINED_ARRAY_TYPE. */
5104 /* If we are global, we don't want to actually output the DECL_EXPR for
5105 this decl since we already have evaluated the expressions in the
5106 sizes and positions as globals and doing it again would be wrong. */
5108 {
5109 /* Mark everything as used to prevent node sharing with subprograms.
5110 Note that walk_tree knows how to deal with TYPE_DECL, but neither
5111 VAR_DECL nor CONST_DECL. This appears to be somewhat arbitrary. */
5115 {
5119 }
5120 /* In any case, we have to deal with our own TYPE_ADA_SIZE field. */
5127 }
5128 else
5131 /* If this is a variable and an initializer is attached to it, it must be
5132 valid for the context. Similar to init_const in create_var_decl_1. */
5139 {
5140 /* If GNU_DECL has a padded type, convert it to the unpadded
5141 type so the assignment is done properly. */
5144 else
5151 {
5154 }
5157 }
5158 }
5160 /* Callback for walk_tree to mark the visited trees rooted at *TP. */
5162 static tree
5164 {
5168 /* Don't mark a dummy type as visited because we want to mark its sizes
5169 and fields once it's filled in. */
5177 }
5179 /* Utility function to unshare expressions wrapped up in a SAVE_EXPR. */
5181 static tree
5184 {
5191 }
5193 /* Mark nodes rooted at *TP with TREE_VISITED and types as having their
5194 sized gimplified. We use this to indicate all variable sizes and
5195 positions in global types may not be shared by any subprogram. */
5197 void
5199 {
5201 }
5203 /* Add GNU_CLEANUP, a cleanup action, to the current code group and
5204 set its location to that of GNAT_NODE if present. */
5206 static void
5208 {
5212 }
5214 /* Set the BLOCK node corresponding to the current code group to GNU_BLOCK. */
5216 void
5218 {
5221 }
5223 /* Return code corresponding to the current code group. It is normally
5224 a STATEMENT_LIST, but may also be a BIND_EXPR or TRY_FINALLY_EXPR if
5225 BLOCK or cleanups were set. */
5227 tree
5229 {
5233 /* If this is a null list, allocate a new STATEMENT_LIST. Then, if there
5234 are cleanups, make a TRY_FINALLY_EXPR. Last, if there is a BLOCK,
5235 make a BIND_EXPR. Note that we nest in that because the cleanup may
5236 reference variables in the block. */
5248 /* Remove this group from the stack and add it to the free list. */
5254 }
5256 /* Add a list of statements from GNAT_LIST, a possibly-empty list of
5257 statements.*/
5259 static void
5261 {
5262 Node_Id gnat_node;
5268 }
5270 /* Build a tree from GNAT_LIST, a possibly-empty list of statements.
5271 If BINDING_P is true, push and pop a binding level around the list. */
5273 static tree
5275 {
5285 }
5286 \f
5287 /* Push and pop routines for stacks. We keep a free list around so we
5288 don't waste tree nodes. */
5290 static void
5292 {
5296 {
5301 }
5302 else
5306 }
5308 static void
5310 {
5316 }
5317 \f
5318 /* Generate GIMPLE in place for the expression at *EXPR_P. */
5320 int
5323 {
5325 tree op;
5331 {
5333 /* If this is for a scalar, just make a VAR_DECL for it. If for
5334 an aggregate, get a null pointer of the appropriate type and
5335 dereference it. */
5339 integer_zero_node));
5340 else
5341 {
5344 }
5350 /* We should only do this if we are just elaborating for side-effects,
5351 but we can't know that yet. */
5358 /* If we're taking the address of a constant CONSTRUCTOR, force it to
5359 be put into static memory. We know it's going to be readonly given
5360 the semantics we have and it's required to be static memory in
5361 the case when the reference is in an elaboration procedure. */
5363 {
5374 }
5376 /* If we are taking the address of a SAVE_EXPR, we are typically
5377 processing a misaligned argument to be passed by reference in a
5378 procedure call. We just mark the operand as addressable + not
5379 readonly here and let the common gimplifier code perform the
5380 temporary creation, initialization, and "instantiation" in place of
5381 the SAVE_EXPR in further operands, in particular in the copy back
5382 code inserted after the call. */
5384 {
5387 }
5389 /* We let the gimplifier process &COND_EXPR and expect it to yield the
5390 address of the selected operand when it is addressable. Besides, we
5391 also expect addressable_p to only let COND_EXPRs where both arms are
5392 addressable reach here. */
5394 ;
5396 /* Otherwise, if we are taking the address of something that is neither
5397 reference, declaration, or constant, make a variable for the operand
5398 here and then take its address. If we don't do it this way, we may
5399 confuse the gimplifier because it needs to know the variable is
5400 addressable at this point. This duplicates code in
5401 internal_get_tmp_var, which is unfortunate. */
5405 {
5407 gimple stmt;
5418 }
5420 /* ... fall through ... */
5424 }
5425 }
5427 /* Generate GIMPLE in place for the statement at *STMT_P. */
5429 static enum gimplify_status
5431 {
5435 {
5441 {
5444 tree t;
5446 /* Set to emit the statements of the loop. */
5449 /* We first emit the start label and then a conditional jump to
5450 the end label if there's a top condition, then the body of the
5451 loop, then a conditional branch to the end label, then the update,
5452 if any, and finally a jump to the start label and the definition
5453 of the end label. */
5455 gnu_start_label),
5456 stmt_p);
5463 void_type_node,
5464 gnu_end_label)),
5465 stmt_p);
5474 void_type_node,
5475 gnu_end_label)),
5476 stmt_p);
5486 gnu_end_label),
5487 stmt_p);
5489 }
5492 /* Build a statement to jump to the corresponding end label, then
5493 see if it needs to be conditional. */
5502 }
5503 }
5504 \f
5505 /* Force references to each of the entities in packages withed by GNAT_NODE.
5506 Operate recursively but check that we aren't elaborating something more
5507 than once.
5509 This routine is exclusively called in type_annotate mode, to compute DDA
5510 information for types in withed units, for ASIS use. */
5512 static void
5514 {
5517 /* Process each unit only once. As we trace the context of all relevant
5518 units transitively, including generic bodies, we may encounter the
5519 same generic unit repeatedly. */
5523 /* Save entities in all context units. A body may have an implicit_with
5524 on its own spec, if the context includes a child unit, so don't save
5525 the spec twice. */
5532 {
5536 {
5553 }
5555 {
5556 Node_Id gnat_body
5559 /* Retrieve compilation unit node of generic body. */
5564 /* If body is available, elaborate its context. */
5567 }
5568 }
5572 }
5573 \f
5574 /* Do the processing of N_Freeze_Entity, GNAT_NODE. */
5576 static void
5578 {
5580 tree gnu_old;
5581 tree gnu_new;
5582 tree gnu_init
5587 /* If this is a package, need to generate code for the package. */
5589 {
5590 insert_code_for
5594 }
5596 /* Check for old definition after the above call. This Freeze_Node
5597 might be for one its Itypes. */
5598 gnu_old
5601 /* If this entity has an Address representation clause, GNU_OLD is the
5602 address, so discard it here. */
5606 /* Don't do anything for class-wide types they are always
5607 transformed into their root type. */
5613 /* Don't do anything for subprograms that may have been elaborated before
5614 their freeze nodes. This can happen, for example because of an inner call
5615 in an instance body, or a previous compilation of a spec for inlining
5616 purposes. */
5621 || (gnu_old
5626 /* If we have a non-dummy type old tree, we have nothing to do, except
5627 aborting if this is the public view of a private type whose full view was
5628 not delayed, as this node was never delayed as it should have been. We
5629 let this happen for concurrent types and their Corresponding_Record_Type,
5630 however, because each might legitimately be elaborated before it's own
5631 freeze node, e.g. while processing the other. */
5635 {
5643 }
5645 /* Reset the saved tree, if any, and elaborate the object or type for real.
5646 If there is a full declaration, elaborate it and copy the type to
5647 GNAT_ENTITY. Likewise if this is the record subtype corresponding to
5648 a class wide type or subtype. */
5650 {
5659 }
5663 {
5666 /* Propagate back-annotations from full view to partial view. */
5676 /* The above call may have defined this entity (the simplest example
5677 of this is when we have a private enumeral type since the bounds
5678 will have the public view. */
5684 }
5685 else
5688 /* If we've made any pointers to the old version of this type, we
5689 have to update them. */
5693 }
5694 \f
5695 /* Process the list of inlined subprograms of GNAT_NODE, which is an
5696 N_Compilation_Unit. */
5698 static void
5700 {
5701 Entity_Id gnat_entity;
5702 Node_Id gnat_body;
5704 /* If we can inline, generate RTL for all the inlined subprograms.
5705 Define the entity first so we set DECL_EXTERNAL. */
5710 {
5714 {
5715 /* ??? This really should always be Present. */
5719 gnat_body
5721 }
5724 {
5727 }
5728 }
5729 }
5730 \f
5731 /* Elaborate decls in the lists GNAT_DECLS and GNAT_DECLS2, if present.
5732 We make two passes, one to elaborate anything other than bodies (but
5733 we declare a function if there was no spec). The second pass
5734 elaborates the bodies.
5736 GNAT_END_LIST gives the element in the list past the end. Normally,
5737 this is Empty, but can be First_Real_Statement for a
5738 Handled_Sequence_Of_Statements.
5740 We make a complete pass through both lists if PASS1P is true, then make
5741 the second pass over both lists if PASS2P is true. The lists usually
5742 correspond to the public and private parts of a package. */
5744 static void
5747 {
5749 Node_Id gnat_decl;
5759 {
5760 /* For package specs, we recurse inside the declarations,
5761 thus taking the two pass approach inside the boundary. */
5769 /* Similarly for any declarations in the actions of a
5770 freeze node. */
5772 {
5775 }
5777 /* Package bodies with freeze nodes get their elaboration deferred
5778 until the freeze node, but the code must be placed in the right
5779 place, so record the code position now. */
5787 (Corresponding_Spec
5790 record_code_position
5793 /* We defer most subprogram bodies to the second pass. */
5795 {
5797 {
5803 }
5804 }
5805 /* For bodies and stubs that act as their own specs, the entity
5806 itself must be elaborated in the first pass, because it may
5807 be used in other declarations. */
5809 {
5810 Node_Id gnat_subprog_id =
5817 }
5819 /* Concurrent stubs stand for the corresponding subprogram bodies,
5820 which are deferred like other bodies. */
5823 ;
5824 else
5826 }
5828 /* Here we elaborate everything we deferred above except for package bodies,
5829 which are elaborated at their freeze nodes. Note that we must also
5830 go inside things (package specs and freeze nodes) the first pass did. */
5836 {
5852 }
5853 }
5854 \f
5855 /* Emit code for a range check. GNU_EXPR is the expression to be checked,
5856 GNAT_RANGE_TYPE the gnat type or subtype containing the bounds against
5857 which we have to check. */
5859 static tree
5861 {
5867 /* If GNU_EXPR has GNAT_RANGE_TYPE as its base type, no check is needed.
5868 This can for example happen when translating 'Val or 'Value. */
5872 /* If GNU_EXPR has an integral type that is narrower than GNU_RANGE_TYPE,
5873 we can't do anything since we might be truncating the bounds. No
5874 check is needed in this case. */
5880 /* Checked expressions must be evaluated only once. */
5883 /* There's no good type to use here, so we might as well use
5884 integer_type_node. Note that the form of the check is
5885 (not (expr >= lo)) or (not (expr <= hi))
5886 the reason for this slightly convoluted form is that NaNs
5887 are not considered to be in range in the float case. */
5888 return emit_check
5890 invert_truthvalue
5894 invert_truthvalue
5898 gnu_high)))),
5900 }
5901 \f
5902 /* Emit code for an index check. GNU_ARRAY_OBJECT is the array object
5903 which we are about to index, GNU_EXPR is the index expression to be
5904 checked, GNU_LOW and GNU_HIGH are the lower and upper bounds
5905 against which GNU_EXPR has to be checked. Note that for index
5906 checking we cannot use the emit_range_check function (although very
5907 similar code needs to be generated in both cases) since for index
5908 checking the array type against which we are checking the indices
5909 may be unconstrained and consequently we need to retrieve the
5910 actual index bounds from the array object itself
5911 (GNU_ARRAY_OBJECT). The place where we need to do that is in
5912 subprograms having unconstrained array formal parameters */
5914 static tree
5916 tree gnu_expr,
5917 tree gnu_low,
5918 tree gnu_high)
5919 {
5920 tree gnu_expr_check;
5922 /* Checked expressions must be evaluated only once. */
5925 /* Must do this computation in the base type in case the expression's
5926 type is an unsigned subtypes. */
5929 /* If GNU_LOW or GNU_HIGH are a PLACEHOLDER_EXPR, qualify them by
5930 the object we are handling. */
5934 /* There's no good type to use here, so we might as well use
5935 integer_type_node. */
5936 return emit_check
5939 gnu_expr_check,
5941 gnu_low)),
5943 gnu_expr_check,
5945 gnu_high))),
5947 }
5948 \f
5949 /* GNU_COND contains the condition corresponding to an access, discriminant or
5950 range check of value GNU_EXPR. Build a COND_EXPR that returns GNU_EXPR if
5951 GNU_COND is false and raises a CONSTRAINT_ERROR if GNU_COND is true.
5952 REASON is the code that says why the exception was raised. */
5954 static tree
5956 {
5957 tree gnu_call;
5958 tree gnu_result;
5962 /* Use an outer COMPOUND_EXPR to make sure that GNU_EXPR will get evaluated
5963 in front of the comparison in case it ends up being a SAVE_EXPR. Put the
5964 whole thing inside its own SAVE_EXPR so the inner SAVE_EXPR doesn't leak
5965 out. */
5969 gnu_expr);
5971 /* If GNU_EXPR has side effects, make the outer COMPOUND_EXPR and
5972 protect it. Otherwise, show GNU_RESULT has no side effects: we
5973 don't need to evaluate it just for the check. */
5975 gnu_result
5977 else
5980 /* ??? Unfortunately, if we don't put a SAVE_EXPR around this whole thing,
5981 we will repeatedly do the test. It would be nice if GCC was able
5982 to optimize this and only do it once. */
5984 }
5985 \f
5986 /* Return an expression that converts GNU_EXPR to GNAT_TYPE, doing
5987 overflow checks if OVERFLOW_P is nonzero and range checks if
5988 RANGE_P is nonzero. GNAT_TYPE is known to be an integral type.
5989 If TRUNCATE_P is nonzero, do a float to integer conversion with
5990 truncation; otherwise round. */
5992 static tree
5995 {
6002 /* If we are not doing any checks, the output is an integral type, and
6003 the input is not a floating type, just do the conversion. This
6004 shortcut is required to avoid problems with packed array types
6005 and simplifies code in all cases anyway. */
6010 /* First convert the expression to its base type. This
6011 will never generate code, but makes the tests below much simpler.
6012 But don't do this if converting from an integer type to an unconstrained
6013 array type since then we need to get the bounds from the original
6014 (unpacked) type. */
6018 /* If overflow checks are requested, we need to be sure the result will
6019 fit in the output base type. But don't do this if the input
6020 is integer and the output floating-point. */
6023 {
6024 /* Ensure GNU_EXPR only gets evaluated once. */
6032 /* Convert the lower bounds to signed types, so we're sure we're
6033 comparing them properly. Likewise, convert the upper bounds
6034 to unsigned types. */
6048 /* Check each bound separately and only if the result bound
6049 is tighter than the bound on the input type. Note that all the
6050 types are base types, so the bounds must be constant. Also,
6051 the comparison is done in the base type of the input, which
6052 always has the proper signedness. First check for input
6053 integer (which means output integer), output float (which means
6054 both float), or mixed, in which case we always compare.
6055 Note that we have to do the comparison which would *fail* in the
6056 case of an error since if it's an FP comparison and one of the
6057 values is a NaN or Inf, the comparison will fail. */
6064 gnu_cond
6065 = invert_truthvalue
6068 gnu_out_lb)));
6076 gnu_cond
6078 invert_truthvalue
6080 gnu_input,
6082 gnu_out_ub))));
6086 CE_Overflow_Check_Failed);
6087 }
6089 /* Now convert to the result base type. If this is a non-truncating
6090 float-to-integer conversion, round. */
6093 {
6099 /* The following calculations depend on proper rounding to even
6100 of each arithmetic operation. In order to prevent excess
6101 precision from spoiling this property, use the widest hardware
6102 floating-point type.
6104 FIXME: For maximum efficiency, this should only be done for machines
6105 and types where intermediates may have extra precision. */
6108 /* FIXME: Should not have padding in the first place */
6113 /* Compute the exact value calc_type'Pred (0.5) at compile time. */
6117 half_minus_pred_half);
6120 /* If the input is strictly negative, subtract this value
6121 and otherwise add it from the input. For 0.5, the result
6122 is exactly between 1.0 and the machine number preceding 1.0
6123 (for calc_type). Since the last bit of 1.0 is even, this 0.5
6124 will round to 1.0, while all other number with an absolute
6125 value less than 0.5 round to 0.0. For larger numbers exactly
6126 halfway between integers, rounding will always be correct as
6127 the true mathematical result will be closer to the higher
6128 integer compared to the lower one. So, this constant works
6129 for all floating-point numbers.
6131 The reason to use the same constant with subtract/add instead
6132 of a positive and negative constant is to allow the comparison
6133 to be scheduled in parallel with retrieval of the constant and
6134 conversion of the input to the calc_type (if necessary).
6135 */
6142 gnu_add_pred_half
6144 gnu_subtract_pred_half
6148 }
6154 else
6157 /* Finally, do the range check if requested. Note that if the
6158 result type is a modular type, the range check is actually
6159 an overflow check. */
6167 }
6168 \f
6169 /* Return true if TYPE is a smaller packable version of RECORD_TYPE. */
6171 static bool
6173 {
6176 /* We're not interested in variants here. */
6180 /* Like a variant, a packable version keeps the original TYPE_NAME. */
6191 }
6193 /* Return true if GNU_EXPR can be directly addressed. This is the case
6194 unless it is an expression involving computation or if it involves a
6195 reference to a bitfield or to an object not sufficiently aligned for
6196 its type. If GNU_TYPE is non-null, return true only if GNU_EXPR can
6197 be directly addressed as an object of this type.
6199 *** Notes on addressability issues in the Ada compiler ***
6201 This predicate is necessary in order to bridge the gap between Gigi
6202 and the middle-end about addressability of GENERIC trees. A tree
6203 is said to be addressable if it can be directly addressed, i.e. if
6204 its address can be taken, is a multiple of the type's alignment on
6205 strict-alignment architectures and returns the first storage unit
6206 assigned to the object represented by the tree.
6208 In the C family of languages, everything is in practice addressable
6209 at the language level, except for bit-fields. This means that these
6210 compilers will take the address of any tree that doesn't represent
6211 a bit-field reference and expect the result to be the first storage
6212 unit assigned to the object. Even in cases where this will result
6213 in unaligned accesses at run time, nothing is supposed to be done
6214 and the program is considered as erroneous instead (see PR c/18287).
6216 The implicit assumptions made in the middle-end are in keeping with
6217 the C viewpoint described above:
6218 - the address of a bit-field reference is supposed to be never
6219 taken; the compiler (generally) will stop on such a construct,
6220 - any other tree is addressable if it is formally addressable,
6221 i.e. if it is formally allowed to be the operand of ADDR_EXPR.
6223 In Ada, the viewpoint is the opposite one: nothing is addressable
6224 at the language level unless explicitly declared so. This means
6225 that the compiler will both make sure that the trees representing
6226 references to addressable ("aliased" in Ada parlance) objects are
6227 addressable and make no real attempts at ensuring that the trees
6228 representing references to non-addressable objects are addressable.
6230 In the first case, Ada is effectively equivalent to C and handing
6231 down the direct result of applying ADDR_EXPR to these trees to the
6232 middle-end works flawlessly. In the second case, Ada cannot afford
6233 to consider the program as erroneous if the address of trees that
6234 are not addressable is requested for technical reasons, unlike C;
6235 as a consequence, the Ada compiler must arrange for either making
6236 sure that this address is not requested in the middle-end or for
6237 compensating by inserting temporaries if it is requested in Gigi.
6239 The first goal can be achieved because the middle-end should not
6240 request the address of non-addressable trees on its own; the only
6241 exception is for the invocation of low-level block operations like
6242 memcpy, for which the addressability requirements are lower since
6243 the type's alignment can be disregarded. In practice, this means
6244 that Gigi must make sure that such operations cannot be applied to
6245 non-BLKmode bit-fields.
6247 The second goal is achieved by means of the addressable_p predicate
6248 and by inserting SAVE_EXPRs around trees deemed non-addressable.
6249 They will be turned during gimplification into proper temporaries
6250 whose address will be used in lieu of that of the original tree. */
6252 static bool
6254 {
6255 /* The size of the real type of the object must not be smaller than
6256 that of the expected type, otherwise an indirect access in the
6257 latter type would be larger than the object. Only records need
6258 to be considered in practice. */
6265 {
6270 /* All DECLs are addressable: if they are in a register, we can force
6271 them to memory. */
6285 /* We accept &COND_EXPR as soon as both operands are addressable and
6286 expect the outcome to be the address of the selected operand. */
6292 /* Even with DECL_BIT_FIELD cleared, we have to ensure that
6293 the field is sufficiently aligned, in case it is subject
6294 to a pragma Component_Alignment. But we don't need to
6295 check the alignment of the containing record, as it is
6296 guaranteed to be not smaller than that of its most
6297 aligned field that is not a bit-field. */
6298 && (!STRICT_ALIGNMENT
6301 /* The field of a padding record is always addressable. */
6315 {
6316 /* This is addressable if we can avoid a copy. */
6320 && (!STRICT_ALIGNMENT
6325 && (!STRICT_ALIGNMENT
6331 }
6335 }
6336 }
6337 \f
6338 /* Do the processing for the declaration of a GNAT_ENTITY, a type. If
6339 a separate Freeze node exists, delay the bulk of the processing. Otherwise
6340 make a GCC type for GNAT_ENTITY and set up the correspondence. */
6342 void
6344 {
6345 tree gnu_old
6347 tree gnu_new;
6349 /* If we are to delay elaboration of this type, just do any
6350 elaborations needed for expressions within the declaration and
6351 make a dummy type entry for this node and its Full_View (if
6352 any) in case something points to it. Don't do this if it
6353 has already been done (the only way that can happen is if
6354 the private completion is also delayed). */
6360 {
6364 {
6373 }
6376 }
6378 /* If we saved away a dummy type for this node it means that this
6379 made the type that corresponds to the full type of an incomplete
6380 type. Clear that type for now and then update the type in the
6381 pointers. */
6383 {
6388 }
6390 /* Now fully elaborate the type. */
6394 /* If we have an old type and we've made pointers to this type,
6395 update those pointers. */
6400 /* If this is a record type corresponding to a task or protected type
6401 that is a completion of an incomplete type, perform a similar update
6402 on the type. */
6403 /* ??? Including protected types here is a guess. */
6408 {
6409 tree gnu_task_old
6419 }
6420 }
6421 \f
6422 /* GNAT_ENTITY is the type of the resulting constructors,
6423 GNAT_ASSOC is the front of the Component_Associations of an N_Aggregate,
6424 and GNU_TYPE is the GCC type of the corresponding record.
6426 Return a CONSTRUCTOR to build the record. */
6428 static tree
6430 {
6433 /* We test for GNU_FIELD being empty in the case where a variant
6434 was the last thing since we don't take things off GNAT_ASSOC in
6435 that case. We check GNAT_ASSOC in case we have a variant, but it
6436 has no fields. */
6440 {
6445 /* The expander is supposed to put a single component selector name
6446 in every record component association */
6449 /* Ignore fields that have Corresponding_Discriminants since we'll
6450 be setting that field in the parent. */
6455 /* Also ignore discriminants of Unchecked_Unions. */
6460 /* Before assigning a value in an aggregate make sure range checks
6461 are done if required. Then convert to the type of the field. */
6467 /* Add the field and expression to the list. */
6469 }
6473 #ifdef ENABLE_CHECKING
6474 {
6475 tree gnu_field;
6477 /* Verify every entry in GNU_LIST was used. */
6480 }
6481 #endif
6484 }
6486 /* Builds a possibly nested constructor for array aggregates. GNAT_EXPR
6487 is the first element of an array aggregate. It may itself be an
6488 aggregate (an array or record aggregate). GNU_ARRAY_TYPE is the gnu type
6489 corresponding to the array aggregate. GNAT_COMPONENT_TYPE is the type
6490 of the array component. It is needed for range checking. */
6492 static tree
6494 Entity_Id gnat_component_type)
6495 {
6498 tree gnu_expr;
6501 {
6502 /* If the expression is itself an array aggregate then first build the
6503 innermost constructor if it is part of our array (multi-dimensional
6504 case). */
6511 gnat_component_type);
6512 else
6513 {
6516 /* before assigning the element to the array make sure it is
6517 in range */
6520 }
6522 gnu_expr_list
6524 gnu_expr_list);
6527 }
6530 }
6531 \f
6532 /* Subroutine of assoc_to_constructor: VALUES is a list of field associations,
6533 some of which are from RECORD_TYPE. Return a CONSTRUCTOR consisting
6534 of the associations that are from RECORD_TYPE. If we see an internal
6535 record, make a recursive call to fill it in as well. */
6537 static tree
6539 {
6544 {
6547 /* _Parent is an internal field, but may have values in the aggregate,
6548 so check for values first. */
6550 {
6553 }
6556 {
6561 }
6562 else
6563 /* If we have a record subtype, the names will match, but not the
6564 actual FIELD_DECLs. */
6567 {
6570 }
6576 }
6579 }
6580 \f
6581 /* EXP is to be treated as an array or record. Handle the cases when it is
6582 an access object and perform the required dereferences. */
6584 static tree
6586 {
6587 /* If the type is a pointer, dereference it. */
6592 /* If we got a padded type, remove it too. */
6598 }
6599 \f
6600 /* Protect EXP from multiple evaluation. This may make a SAVE_EXPR. */
6602 tree
6604 {
6607 /* If this has no side effects, we don't need to do anything. */
6611 /* If it is a conversion, protect what's inside the conversion.
6612 Similarly, if we're indirectly referencing something, we only
6613 actually need to protect the address since the data itself can't
6614 change in these situations. */
6623 /* If EXP is a fat pointer or something that can be placed into a register,
6624 just make a SAVE_EXPR. */
6628 /* Otherwise, dereference, protect the address, and re-reference. */
6629 else
6630 return
6634 exp)));
6635 }
6636 \f
6637 /* This is equivalent to stabilize_reference in tree.c, but we know how to
6638 handle our own nodes and we take extra arguments. FORCE says whether to
6639 force evaluation of everything. We set SUCCESS to true unless we walk
6640 through something we don't know how to stabilize. */
6642 tree
6644 {
6647 tree result;
6649 /* Assume we'll success unless proven otherwise. */
6653 {
6658 /* No action is needed in this case. */
6662 CASE_CONVERT:
6666 result
6669 success));
6676 force));
6682 success),
6689 success),
6691 force),
6693 force));
6700 success),
6702 force),
6711 /* This generates better code than the scheme in protect_multiple_eval
6712 because large objects will be returned via invisible reference in
6713 most ABIs so the temporary will directly be filled by the callee. */
6718 /* Constructors with 1 element are used extensively to formally
6719 convert objects to special wrapping types. */
6722 {
6723 tree index
6725 tree value
6727 result
6730 force));
6731 }
6732 else
6733 {
6736 }
6742 /* ... Fallthru to failure ... */
6744 /* If arg isn't a kind of lvalue we recognize, make no change.
6745 Caller should recognize the error for an invalid lvalue. */
6749 }
6753 /* TREE_THIS_VOLATILE and TREE_SIDE_EFFECTS attached to the initial
6754 expression may not be sustained across some paths, such as the way via
6755 build1 for INDIRECT_REF. We re-populate those flags here for the general
6756 case, which is consistent with the GCC version of this routine.
6758 Special care should be taken regarding TREE_SIDE_EFFECTS, because some
6759 paths introduce side effects where there was none initially (e.g. calls
6760 to save_expr), and we also want to keep track of that. */
6766 }
6768 /* Wrapper around maybe_stabilize_reference, for common uses without
6769 lvalue restrictions and without need to examine the success
6770 indication. */
6772 static tree
6774 {
6777 }
6779 /* Similar to stabilize_reference_1 in tree.c, but supports an extra
6780 arg to force a SAVE_EXPR for everything. */
6782 static tree
6784 {
6787 tree result;
6789 /* We cannot ignore const expressions because it might be a reference
6790 to a const array but whose index contains side-effects. But we can
6791 ignore things that are actual constant or that already have been
6792 handled by this function. */
6798 {
6807 /* If this is a COMPONENT_REF of a fat pointer, save the entire
6808 fat pointer. This may be more efficient, but will also allow
6809 us to more easily find the match for the PLACEHOLDER_EXPR. */
6814 force),
6818 else
6823 /* Constants need no processing. In fact, we should never reach
6824 here. */
6828 /* Recursively stabilize each operand. */
6832 force));
6836 /* Recursively stabilize each operand. */
6839 force));
6844 }
6851 }
6852 \f
6853 /* Convert SLOC into LOCUS. Return true if SLOC corresponds to a source code
6854 location and false if it doesn't. In the former case, set the Gigi global
6855 variable REF_FILENAME to the simple debug file name as given by sinput. */
6857 bool
6859 {
6864 {
6868 }
6869 else
6870 {
6876 /* Translate the location according to the line-map.h formula. */
6880 }
6882 ref_filename
6883 = IDENTIFIER_POINTER
6884 (get_identifier
6888 }
6890 /* Similar to set_expr_location, but start with the Sloc of GNAT_NODE and
6891 don't do anything if it doesn't correspond to a source location. */
6893 static void
6895 {
6896 location_t locus;
6902 }
6903 \f
6904 /* Return a colon-separated list of encodings contained in encoded Ada
6905 name. */
6909 {
6915 }
6917 /* Extract the Ada name from an encoded name. */
6921 {
6927 }
6928 \f
6929 /* Post an error message. MSG is the error message, properly annotated.
6930 NODE is the node at which to post the error and the node to use for the
6931 "&" substitution. */
6933 void
6935 {
6936 String_Template temp;
6937 Fat_Pointer fp;
6943 }
6945 /* Similar, but NODE is the node at which to post the error and ENT
6946 is the node to use for the "&" substitution. */
6948 void
6950 {
6951 String_Template temp;
6952 Fat_Pointer fp;
6958 }
6960 /* Similar, but NODE is the node at which to post the error, ENT is the node
6961 to use for the "&" substitution, and N is the number to use for the ^. */
6963 void
6965 {
6966 String_Template temp;
6967 Fat_Pointer fp;
6975 }
6976 \f
6977 /* Similar to post_error_ne_num, but T is a GCC tree representing the
6978 number to write. If the tree represents a constant that fits within
6979 a host integer, the text inside curly brackets in MSG will be output
6980 (presumably including a '^'). Otherwise that text will not be output
6981 and the text inside square brackets will be output instead. */
6983 void
6985 {
6988 Fat_Pointer fp;
6996 #if HOST_BITS_PER_WIDE_INT > HOST_BITS_PER_INT
6997 &&
6998 compare_tree_int
7000 #endif
7001 )
7002 {
7005 }
7006 else
7010 {
7016 ;
7017 else
7019 }
7026 }
7028 /* Similar to post_error_ne_tree, except that NUM is a second
7029 integer to write in the message. */
7031 void
7033 Node_Id node,
7034 Entity_Id ent,
7035 tree t,
7037 {
7040 }
7041 \f
7042 /* Initialize the table that maps GNAT codes to GCC codes for simple
7043 binary and unary operations. */
7045 static void
7047 {
7073 }
7075 /* Return a label to branch to for the exception type in KIND or NULL_TREE
7076 if none. */
7078 tree
7080 {
7087 else
7089 }