1 /****************************************************************************
3 * GNAT COMPILER COMPONENTS *
7 * C Implementation File *
9 * Copyright (C) 1992-2013, Free Software Foundation, Inc. *
11 * GNAT is free software; you can redistribute it and/or modify it under *
12 * terms of the GNU General Public License as published by the Free Soft- *
13 * ware Foundation; either version 3, or (at your option) any later ver- *
14 * sion. GNAT is distributed in the hope that it will be useful, but WITH- *
15 * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY *
16 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License *
17 * for more details. You should have received a copy of the GNU General *
18 * Public License along with GCC; see the file COPYING3. If not see *
19 * <http://www.gnu.org/licenses/>. *
21 * GNAT was originally developed by the GNAT team at New York University. *
22 * Extensive contributions were provided by Ada Core Technologies Inc. *
24 ****************************************************************************/
28 #include "coretypes.h"
31 #include "stor-layout.h"
32 #include "stringpool.h"
37 #include "tree-inline.h"
54 /* Return the base type of TYPE. */
57 get_base_type (tree type)
59 if (TREE_CODE (type) == RECORD_TYPE
60 && TYPE_JUSTIFIED_MODULAR_P (type))
61 type = TREE_TYPE (TYPE_FIELDS (type));
63 while (TREE_TYPE (type)
64 && (TREE_CODE (type) == INTEGER_TYPE
65 || TREE_CODE (type) == REAL_TYPE))
66 type = TREE_TYPE (type);
71 /* EXP is a GCC tree representing an address. See if we can find how
72 strictly the object at that address is aligned. Return that alignment
73 in bits. If we don't know anything about the alignment, return 0. */
76 known_alignment (tree exp)
78 unsigned int this_alignment;
79 unsigned int lhs, rhs;
81 switch (TREE_CODE (exp))
84 case VIEW_CONVERT_EXPR:
86 /* Conversions between pointers and integers don't change the alignment
87 of the underlying object. */
88 this_alignment = known_alignment (TREE_OPERAND (exp, 0));
92 /* The value of a COMPOUND_EXPR is that of it's second operand. */
93 this_alignment = known_alignment (TREE_OPERAND (exp, 1));
98 /* If two address are added, the alignment of the result is the
99 minimum of the two alignments. */
100 lhs = known_alignment (TREE_OPERAND (exp, 0));
101 rhs = known_alignment (TREE_OPERAND (exp, 1));
102 this_alignment = MIN (lhs, rhs);
105 case POINTER_PLUS_EXPR:
106 lhs = known_alignment (TREE_OPERAND (exp, 0));
107 rhs = known_alignment (TREE_OPERAND (exp, 1));
108 /* If we don't know the alignment of the offset, we assume that
111 this_alignment = lhs;
113 this_alignment = MIN (lhs, rhs);
117 /* If there is a choice between two values, use the smallest one. */
118 lhs = known_alignment (TREE_OPERAND (exp, 1));
119 rhs = known_alignment (TREE_OPERAND (exp, 2));
120 this_alignment = MIN (lhs, rhs);
125 unsigned HOST_WIDE_INT c = TREE_INT_CST_LOW (exp);
126 /* The first part of this represents the lowest bit in the constant,
127 but it is originally in bytes, not bits. */
128 this_alignment = MIN (BITS_PER_UNIT * (c & -c), BIGGEST_ALIGNMENT);
133 /* If we know the alignment of just one side, use it. Otherwise,
134 use the product of the alignments. */
135 lhs = known_alignment (TREE_OPERAND (exp, 0));
136 rhs = known_alignment (TREE_OPERAND (exp, 1));
139 this_alignment = rhs;
141 this_alignment = lhs;
143 this_alignment = MIN (lhs * rhs, BIGGEST_ALIGNMENT);
147 /* A bit-and expression is as aligned as the maximum alignment of the
148 operands. We typically get here for a complex lhs and a constant
149 negative power of two on the rhs to force an explicit alignment, so
150 don't bother looking at the lhs. */
151 this_alignment = known_alignment (TREE_OPERAND (exp, 1));
155 this_alignment = expr_align (TREE_OPERAND (exp, 0));
160 tree t = maybe_inline_call_in_expr (exp);
162 return known_alignment (t);
165 /* Fall through... */
168 /* For other pointer expressions, we assume that the pointed-to object
169 is at least as aligned as the pointed-to type. Beware that we can
170 have a dummy type here (e.g. a Taft Amendment type), for which the
171 alignment is meaningless and should be ignored. */
172 if (POINTER_TYPE_P (TREE_TYPE (exp))
173 && !TYPE_IS_DUMMY_P (TREE_TYPE (TREE_TYPE (exp))))
174 this_alignment = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp)));
180 return this_alignment;
183 /* We have a comparison or assignment operation on two types, T1 and T2, which
184 are either both array types or both record types. T1 is assumed to be for
185 the left hand side operand, and T2 for the right hand side. Return the
186 type that both operands should be converted to for the operation, if any.
187 Otherwise return zero. */
190 find_common_type (tree t1, tree t2)
192 /* ??? As of today, various constructs lead to here with types of different
193 sizes even when both constants (e.g. tagged types, packable vs regular
194 component types, padded vs unpadded types, ...). While some of these
195 would better be handled upstream (types should be made consistent before
196 calling into build_binary_op), some others are really expected and we
197 have to be careful. */
199 /* We must avoid writing more than what the target can hold if this is for
200 an assignment and the case of tagged types is handled in build_binary_op
201 so we use the lhs type if it is known to be smaller or of constant size
202 and the rhs type is not, whatever the modes. We also force t1 in case of
203 constant size equality to minimize occurrences of view conversions on the
204 lhs of an assignment, except for the case of record types with a variant
205 part on the lhs but not on the rhs to make the conversion simpler. */
206 if (TREE_CONSTANT (TYPE_SIZE (t1))
207 && (!TREE_CONSTANT (TYPE_SIZE (t2))
208 || tree_int_cst_lt (TYPE_SIZE (t1), TYPE_SIZE (t2))
209 || (TYPE_SIZE (t1) == TYPE_SIZE (t2)
210 && !(TREE_CODE (t1) == RECORD_TYPE
211 && TREE_CODE (t2) == RECORD_TYPE
212 && get_variant_part (t1) != NULL_TREE
213 && get_variant_part (t2) == NULL_TREE))))
216 /* Otherwise, if the lhs type is non-BLKmode, use it. Note that we know
217 that we will not have any alignment problems since, if we did, the
218 non-BLKmode type could not have been used. */
219 if (TYPE_MODE (t1) != BLKmode)
222 /* If the rhs type is of constant size, use it whatever the modes. At
223 this point it is known to be smaller, or of constant size and the
225 if (TREE_CONSTANT (TYPE_SIZE (t2)))
228 /* Otherwise, if the rhs type is non-BLKmode, use it. */
229 if (TYPE_MODE (t2) != BLKmode)
232 /* In this case, both types have variable size and BLKmode. It's
233 probably best to leave the "type mismatch" because changing it
234 could cause a bad self-referential reference. */
238 /* Return an expression tree representing an equality comparison of A1 and A2,
239 two objects of type ARRAY_TYPE. The result should be of type RESULT_TYPE.
241 Two arrays are equal in one of two ways: (1) if both have zero length in
242 some dimension (not necessarily the same dimension) or (2) if the lengths
243 in each dimension are equal and the data is equal. We perform the length
244 tests in as efficient a manner as possible. */
247 compare_arrays (location_t loc, tree result_type, tree a1, tree a2)
249 tree result = convert (result_type, boolean_true_node);
250 tree a1_is_null = convert (result_type, boolean_false_node);
251 tree a2_is_null = convert (result_type, boolean_false_node);
252 tree t1 = TREE_TYPE (a1);
253 tree t2 = TREE_TYPE (a2);
254 bool a1_side_effects_p = TREE_SIDE_EFFECTS (a1);
255 bool a2_side_effects_p = TREE_SIDE_EFFECTS (a2);
256 bool length_zero_p = false;
258 /* If either operand has side-effects, they have to be evaluated only once
259 in spite of the multiple references to the operand in the comparison. */
260 if (a1_side_effects_p)
261 a1 = gnat_protect_expr (a1);
263 if (a2_side_effects_p)
264 a2 = gnat_protect_expr (a2);
266 /* Process each dimension separately and compare the lengths. If any
267 dimension has a length known to be zero, set LENGTH_ZERO_P to true
268 in order to suppress the comparison of the data at the end. */
269 while (TREE_CODE (t1) == ARRAY_TYPE && TREE_CODE (t2) == ARRAY_TYPE)
271 tree lb1 = TYPE_MIN_VALUE (TYPE_DOMAIN (t1));
272 tree ub1 = TYPE_MAX_VALUE (TYPE_DOMAIN (t1));
273 tree lb2 = TYPE_MIN_VALUE (TYPE_DOMAIN (t2));
274 tree ub2 = TYPE_MAX_VALUE (TYPE_DOMAIN (t2));
275 tree length1 = size_binop (PLUS_EXPR, size_binop (MINUS_EXPR, ub1, lb1),
277 tree length2 = size_binop (PLUS_EXPR, size_binop (MINUS_EXPR, ub2, lb2),
279 tree comparison, this_a1_is_null, this_a2_is_null;
281 /* If the length of the first array is a constant, swap our operands
282 unless the length of the second array is the constant zero. */
283 if (TREE_CODE (length1) == INTEGER_CST && !integer_zerop (length2))
288 tem = a1, a1 = a2, a2 = tem;
289 tem = t1, t1 = t2, t2 = tem;
290 tem = lb1, lb1 = lb2, lb2 = tem;
291 tem = ub1, ub1 = ub2, ub2 = tem;
292 tem = length1, length1 = length2, length2 = tem;
293 tem = a1_is_null, a1_is_null = a2_is_null, a2_is_null = tem;
294 btem = a1_side_effects_p, a1_side_effects_p = a2_side_effects_p,
295 a2_side_effects_p = btem;
298 /* If the length of the second array is the constant zero, we can just
299 use the original stored bounds for the first array and see whether
300 last < first holds. */
301 if (integer_zerop (length2))
303 length_zero_p = true;
305 ub1 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
306 lb1 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
308 comparison = fold_build2_loc (loc, LT_EXPR, result_type, ub1, lb1);
309 comparison = SUBSTITUTE_PLACEHOLDER_IN_EXPR (comparison, a1);
310 if (EXPR_P (comparison))
311 SET_EXPR_LOCATION (comparison, loc);
313 this_a1_is_null = comparison;
314 this_a2_is_null = convert (result_type, boolean_true_node);
317 /* Otherwise, if the length is some other constant value, we know that
318 this dimension in the second array cannot be superflat, so we can
319 just use its length computed from the actual stored bounds. */
320 else if (TREE_CODE (length2) == INTEGER_CST)
324 ub1 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
325 lb1 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
326 /* Note that we know that UB2 and LB2 are constant and hence
327 cannot contain a PLACEHOLDER_EXPR. */
328 ub2 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t2)));
329 lb2 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t2)));
330 bt = get_base_type (TREE_TYPE (ub1));
333 = fold_build2_loc (loc, EQ_EXPR, result_type,
334 build_binary_op (MINUS_EXPR, bt, ub1, lb1),
335 build_binary_op (MINUS_EXPR, bt, ub2, lb2));
336 comparison = SUBSTITUTE_PLACEHOLDER_IN_EXPR (comparison, a1);
337 if (EXPR_P (comparison))
338 SET_EXPR_LOCATION (comparison, loc);
341 = fold_build2_loc (loc, LT_EXPR, result_type, ub1, lb1);
343 this_a2_is_null = convert (result_type, boolean_false_node);
346 /* Otherwise, compare the computed lengths. */
349 length1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length1, a1);
350 length2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length2, a2);
353 = fold_build2_loc (loc, EQ_EXPR, result_type, length1, length2);
355 /* If the length expression is of the form (cond ? val : 0), assume
356 that cond is equivalent to (length != 0). That's guaranteed by
357 construction of the array types in gnat_to_gnu_entity. */
358 if (TREE_CODE (length1) == COND_EXPR
359 && integer_zerop (TREE_OPERAND (length1, 2)))
361 = invert_truthvalue_loc (loc, TREE_OPERAND (length1, 0));
363 this_a1_is_null = fold_build2_loc (loc, EQ_EXPR, result_type,
364 length1, size_zero_node);
366 /* Likewise for the second array. */
367 if (TREE_CODE (length2) == COND_EXPR
368 && integer_zerop (TREE_OPERAND (length2, 2)))
370 = invert_truthvalue_loc (loc, TREE_OPERAND (length2, 0));
372 this_a2_is_null = fold_build2_loc (loc, EQ_EXPR, result_type,
373 length2, size_zero_node);
376 /* Append expressions for this dimension to the final expressions. */
377 result = build_binary_op (TRUTH_ANDIF_EXPR, result_type,
380 a1_is_null = build_binary_op (TRUTH_ORIF_EXPR, result_type,
381 this_a1_is_null, a1_is_null);
383 a2_is_null = build_binary_op (TRUTH_ORIF_EXPR, result_type,
384 this_a2_is_null, a2_is_null);
390 /* Unless the length of some dimension is known to be zero, compare the
391 data in the array. */
394 tree type = find_common_type (TREE_TYPE (a1), TREE_TYPE (a2));
399 a1 = convert (type, a1),
400 a2 = convert (type, a2);
403 comparison = fold_build2_loc (loc, EQ_EXPR, result_type, a1, a2);
406 = build_binary_op (TRUTH_ANDIF_EXPR, result_type, result, comparison);
409 /* The result is also true if both sizes are zero. */
410 result = build_binary_op (TRUTH_ORIF_EXPR, result_type,
411 build_binary_op (TRUTH_ANDIF_EXPR, result_type,
412 a1_is_null, a2_is_null),
415 /* If either operand has side-effects, they have to be evaluated before
416 starting the comparison above since the place they would be otherwise
417 evaluated could be wrong. */
418 if (a1_side_effects_p)
419 result = build2 (COMPOUND_EXPR, result_type, a1, result);
421 if (a2_side_effects_p)
422 result = build2 (COMPOUND_EXPR, result_type, a2, result);
427 /* Return an expression tree representing an equality comparison of P1 and P2,
428 two objects of fat pointer type. The result should be of type RESULT_TYPE.
430 Two fat pointers are equal in one of two ways: (1) if both have a null
431 pointer to the array or (2) if they contain the same couple of pointers.
432 We perform the comparison in as efficient a manner as possible. */
435 compare_fat_pointers (location_t loc, tree result_type, tree p1, tree p2)
437 tree p1_array, p2_array, p1_bounds, p2_bounds, same_array, same_bounds;
438 tree p1_array_is_null, p2_array_is_null;
440 /* If either operand has side-effects, they have to be evaluated only once
441 in spite of the multiple references to the operand in the comparison. */
442 p1 = gnat_protect_expr (p1);
443 p2 = gnat_protect_expr (p2);
445 /* The constant folder doesn't fold fat pointer types so we do it here. */
446 if (TREE_CODE (p1) == CONSTRUCTOR)
447 p1_array = (*CONSTRUCTOR_ELTS (p1))[0].value;
449 p1_array = build_component_ref (p1, NULL_TREE,
450 TYPE_FIELDS (TREE_TYPE (p1)), true);
453 = fold_build2_loc (loc, EQ_EXPR, result_type, p1_array,
454 fold_convert_loc (loc, TREE_TYPE (p1_array),
457 if (TREE_CODE (p2) == CONSTRUCTOR)
458 p2_array = (*CONSTRUCTOR_ELTS (p2))[0].value;
460 p2_array = build_component_ref (p2, NULL_TREE,
461 TYPE_FIELDS (TREE_TYPE (p2)), true);
464 = fold_build2_loc (loc, EQ_EXPR, result_type, p2_array,
465 fold_convert_loc (loc, TREE_TYPE (p2_array),
468 /* If one of the pointers to the array is null, just compare the other. */
469 if (integer_zerop (p1_array))
470 return p2_array_is_null;
471 else if (integer_zerop (p2_array))
472 return p1_array_is_null;
474 /* Otherwise, do the fully-fledged comparison. */
476 = fold_build2_loc (loc, EQ_EXPR, result_type, p1_array, p2_array);
478 if (TREE_CODE (p1) == CONSTRUCTOR)
479 p1_bounds = (*CONSTRUCTOR_ELTS (p1))[1].value;
482 = build_component_ref (p1, NULL_TREE,
483 DECL_CHAIN (TYPE_FIELDS (TREE_TYPE (p1))), true);
485 if (TREE_CODE (p2) == CONSTRUCTOR)
486 p2_bounds = (*CONSTRUCTOR_ELTS (p2))[1].value;
489 = build_component_ref (p2, NULL_TREE,
490 DECL_CHAIN (TYPE_FIELDS (TREE_TYPE (p2))), true);
493 = fold_build2_loc (loc, EQ_EXPR, result_type, p1_bounds, p2_bounds);
495 /* P1_ARRAY == P2_ARRAY && (P1_ARRAY == NULL || P1_BOUNDS == P2_BOUNDS). */
496 return build_binary_op (TRUTH_ANDIF_EXPR, result_type, same_array,
497 build_binary_op (TRUTH_ORIF_EXPR, result_type,
498 p1_array_is_null, same_bounds));
501 /* Compute the result of applying OP_CODE to LHS and RHS, where both are of
502 type TYPE. We know that TYPE is a modular type with a nonbinary
506 nonbinary_modular_operation (enum tree_code op_code, tree type, tree lhs,
509 tree modulus = TYPE_MODULUS (type);
510 unsigned int needed_precision = tree_floor_log2 (modulus) + 1;
511 unsigned int precision;
512 bool unsignedp = true;
516 /* If this is an addition of a constant, convert it to a subtraction
517 of a constant since we can do that faster. */
518 if (op_code == PLUS_EXPR && TREE_CODE (rhs) == INTEGER_CST)
520 rhs = fold_build2 (MINUS_EXPR, type, modulus, rhs);
521 op_code = MINUS_EXPR;
524 /* For the logical operations, we only need PRECISION bits. For
525 addition and subtraction, we need one more and for multiplication we
526 need twice as many. But we never want to make a size smaller than
528 if (op_code == PLUS_EXPR || op_code == MINUS_EXPR)
529 needed_precision += 1;
530 else if (op_code == MULT_EXPR)
531 needed_precision *= 2;
533 precision = MAX (needed_precision, TYPE_PRECISION (op_type));
535 /* Unsigned will do for everything but subtraction. */
536 if (op_code == MINUS_EXPR)
539 /* If our type is the wrong signedness or isn't wide enough, make a new
540 type and convert both our operands to it. */
541 if (TYPE_PRECISION (op_type) < precision
542 || TYPE_UNSIGNED (op_type) != unsignedp)
544 /* Copy the node so we ensure it can be modified to make it modular. */
545 op_type = copy_node (gnat_type_for_size (precision, unsignedp));
546 modulus = convert (op_type, modulus);
547 SET_TYPE_MODULUS (op_type, modulus);
548 TYPE_MODULAR_P (op_type) = 1;
549 lhs = convert (op_type, lhs);
550 rhs = convert (op_type, rhs);
553 /* Do the operation, then we'll fix it up. */
554 result = fold_build2 (op_code, op_type, lhs, rhs);
556 /* For multiplication, we have no choice but to do a full modulus
557 operation. However, we want to do this in the narrowest
559 if (op_code == MULT_EXPR)
561 tree div_type = copy_node (gnat_type_for_size (needed_precision, 1));
562 modulus = convert (div_type, modulus);
563 SET_TYPE_MODULUS (div_type, modulus);
564 TYPE_MODULAR_P (div_type) = 1;
565 result = convert (op_type,
566 fold_build2 (TRUNC_MOD_EXPR, div_type,
567 convert (div_type, result), modulus));
570 /* For subtraction, add the modulus back if we are negative. */
571 else if (op_code == MINUS_EXPR)
573 result = gnat_protect_expr (result);
574 result = fold_build3 (COND_EXPR, op_type,
575 fold_build2 (LT_EXPR, boolean_type_node, result,
576 convert (op_type, integer_zero_node)),
577 fold_build2 (PLUS_EXPR, op_type, result, modulus),
581 /* For the other operations, subtract the modulus if we are >= it. */
584 result = gnat_protect_expr (result);
585 result = fold_build3 (COND_EXPR, op_type,
586 fold_build2 (GE_EXPR, boolean_type_node,
588 fold_build2 (MINUS_EXPR, op_type,
593 return convert (type, result);
596 /* This page contains routines that implement the Ada semantics with regard
597 to atomic objects. They are fully piggybacked on the middle-end support
598 for atomic loads and stores.
600 *** Memory barriers and volatile objects ***
602 We implement the weakened form of the C.6(16) clause that was introduced
603 in Ada 2012 (AI05-117). Earlier forms of this clause wouldn't have been
604 implementable without significant performance hits on modern platforms.
606 We also take advantage of the requirements imposed on shared variables by
607 9.10 (conditions for sequential actions) to have non-erroneous execution
608 and consider that C.6(16) and C.6(17) only prescribe an uniform order of
609 volatile updates with regard to sequential actions, i.e. with regard to
610 reads or updates of atomic objects.
612 As such, an update of an atomic object by a task requires that all earlier
613 accesses to volatile objects have completed. Similarly, later accesses to
614 volatile objects cannot be reordered before the update of the atomic object.
615 So, memory barriers both before and after the atomic update are needed.
617 For a read of an atomic object, to avoid seeing writes of volatile objects
618 by a task earlier than by the other tasks, a memory barrier is needed before
619 the atomic read. Finally, to avoid reordering later reads or updates of
620 volatile objects to before the atomic read, a barrier is needed after the
623 So, memory barriers are needed before and after atomic reads and updates.
624 And, in order to simplify the implementation, we use full memory barriers
625 in all cases, i.e. we enforce sequential consistency for atomic accesses. */
627 /* Return the size of TYPE, which must be a positive power of 2. */
630 resolve_atomic_size (tree type)
632 unsigned HOST_WIDE_INT size = tree_to_uhwi (TYPE_SIZE_UNIT (type));
634 if (size == 1 || size == 2 || size == 4 || size == 8 || size == 16)
637 /* We shouldn't reach here without having already detected that the size
638 isn't compatible with an atomic access. */
639 gcc_assert (Serious_Errors_Detected);
644 /* Build an atomic load for the underlying atomic object in SRC. */
647 build_atomic_load (tree src)
651 (build_qualified_type (void_type_node, TYPE_QUAL_VOLATILE));
652 tree mem_model = build_int_cst (integer_type_node, MEMMODEL_SEQ_CST);
658 /* Remove conversions to get the address of the underlying object. */
659 src = remove_conversions (src, false);
660 size = resolve_atomic_size (TREE_TYPE (src));
664 fncode = (int) BUILT_IN_ATOMIC_LOAD_N + exact_log2 (size) + 1;
665 t = builtin_decl_implicit ((enum built_in_function) fncode);
667 addr = build_unary_op (ADDR_EXPR, ptr_type, src);
668 val = build_call_expr (t, 2, addr, mem_model);
670 /* First reinterpret the loaded bits in the original type of the load,
671 then convert to the expected result type. */
672 t = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (src), val);
673 return convert (TREE_TYPE (orig_src), t);
676 /* Build an atomic store from SRC to the underlying atomic object in DEST. */
679 build_atomic_store (tree dest, tree src)
683 (build_qualified_type (void_type_node, TYPE_QUAL_VOLATILE));
684 tree mem_model = build_int_cst (integer_type_node, MEMMODEL_SEQ_CST);
685 tree orig_dest = dest;
686 tree t, int_type, addr;
690 /* Remove conversions to get the address of the underlying object. */
691 dest = remove_conversions (dest, false);
692 size = resolve_atomic_size (TREE_TYPE (dest));
694 return build_binary_op (MODIFY_EXPR, NULL_TREE, orig_dest, src);
696 fncode = (int) BUILT_IN_ATOMIC_STORE_N + exact_log2 (size) + 1;
697 t = builtin_decl_implicit ((enum built_in_function) fncode);
698 int_type = gnat_type_for_size (BITS_PER_UNIT * size, 1);
700 /* First convert the bits to be stored to the original type of the store,
701 then reinterpret them in the effective type. But if the original type
702 is a padded type with the same size, convert to the inner type instead,
703 as we don't want to artificially introduce a CONSTRUCTOR here. */
704 if (TYPE_IS_PADDING_P (TREE_TYPE (dest))
705 && TYPE_SIZE (TREE_TYPE (dest))
706 == TYPE_SIZE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (dest)))))
707 src = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (dest))), src);
709 src = convert (TREE_TYPE (dest), src);
710 src = fold_build1 (VIEW_CONVERT_EXPR, int_type, src);
711 addr = build_unary_op (ADDR_EXPR, ptr_type, dest);
713 return build_call_expr (t, 3, addr, src, mem_model);
716 /* Make a binary operation of kind OP_CODE. RESULT_TYPE is the type
717 desired for the result. Usually the operation is to be performed
718 in that type. For INIT_EXPR and MODIFY_EXPR, RESULT_TYPE must be
719 NULL_TREE. For ARRAY_REF, RESULT_TYPE may be NULL_TREE, in which
720 case the type to be used will be derived from the operands.
722 This function is very much unlike the ones for C and C++ since we
723 have already done any type conversion and matching required. All we
724 have to do here is validate the work done by SEM and handle subtypes. */
727 build_binary_op (enum tree_code op_code, tree result_type,
728 tree left_operand, tree right_operand)
730 tree left_type = TREE_TYPE (left_operand);
731 tree right_type = TREE_TYPE (right_operand);
732 tree left_base_type = get_base_type (left_type);
733 tree right_base_type = get_base_type (right_type);
734 tree operation_type = result_type;
735 tree best_type = NULL_TREE;
736 tree modulus, result;
737 bool has_side_effects = false;
740 && TREE_CODE (operation_type) == RECORD_TYPE
741 && TYPE_JUSTIFIED_MODULAR_P (operation_type))
742 operation_type = TREE_TYPE (TYPE_FIELDS (operation_type));
745 && TREE_CODE (operation_type) == INTEGER_TYPE
746 && TYPE_EXTRA_SUBTYPE_P (operation_type))
747 operation_type = get_base_type (operation_type);
749 modulus = (operation_type
750 && TREE_CODE (operation_type) == INTEGER_TYPE
751 && TYPE_MODULAR_P (operation_type)
752 ? TYPE_MODULUS (operation_type) : NULL_TREE);
758 #ifdef ENABLE_CHECKING
759 gcc_assert (result_type == NULL_TREE);
761 /* If there were integral or pointer conversions on the LHS, remove
762 them; we'll be putting them back below if needed. Likewise for
763 conversions between array and record types, except for justified
764 modular types. But don't do this if the right operand is not
765 BLKmode (for packed arrays) unless we are not changing the mode. */
766 while ((CONVERT_EXPR_P (left_operand)
767 || TREE_CODE (left_operand) == VIEW_CONVERT_EXPR)
768 && (((INTEGRAL_TYPE_P (left_type)
769 || POINTER_TYPE_P (left_type))
770 && (INTEGRAL_TYPE_P (TREE_TYPE
771 (TREE_OPERAND (left_operand, 0)))
772 || POINTER_TYPE_P (TREE_TYPE
773 (TREE_OPERAND (left_operand, 0)))))
774 || (((TREE_CODE (left_type) == RECORD_TYPE
775 && !TYPE_JUSTIFIED_MODULAR_P (left_type))
776 || TREE_CODE (left_type) == ARRAY_TYPE)
777 && ((TREE_CODE (TREE_TYPE
778 (TREE_OPERAND (left_operand, 0)))
780 || (TREE_CODE (TREE_TYPE
781 (TREE_OPERAND (left_operand, 0)))
783 && (TYPE_MODE (right_type) == BLKmode
784 || (TYPE_MODE (left_type)
785 == TYPE_MODE (TREE_TYPE
787 (left_operand, 0))))))))
789 left_operand = TREE_OPERAND (left_operand, 0);
790 left_type = TREE_TYPE (left_operand);
793 /* If a class-wide type may be involved, force use of the RHS type. */
794 if ((TREE_CODE (right_type) == RECORD_TYPE
795 || TREE_CODE (right_type) == UNION_TYPE)
796 && TYPE_ALIGN_OK (right_type))
797 operation_type = right_type;
799 /* If we are copying between padded objects with compatible types, use
800 the padded view of the objects, this is very likely more efficient.
801 Likewise for a padded object that is assigned a constructor, if we
802 can convert the constructor to the inner type, to avoid putting a
803 VIEW_CONVERT_EXPR on the LHS. But don't do so if we wouldn't have
804 actually copied anything. */
805 else if (TYPE_IS_PADDING_P (left_type)
806 && TREE_CONSTANT (TYPE_SIZE (left_type))
807 && ((TREE_CODE (right_operand) == COMPONENT_REF
808 && TYPE_MAIN_VARIANT (left_type)
810 (TREE_TYPE (TREE_OPERAND (right_operand, 0))))
811 || (TREE_CODE (right_operand) == CONSTRUCTOR
812 && !CONTAINS_PLACEHOLDER_P
813 (DECL_SIZE (TYPE_FIELDS (left_type)))))
814 && !integer_zerop (TYPE_SIZE (right_type)))
816 /* We make an exception for a BLKmode type padding a non-BLKmode
817 inner type and do the conversion of the LHS right away, since
818 unchecked_convert wouldn't do it properly. */
819 if (TYPE_MODE (left_type) == BLKmode
820 && TYPE_MODE (right_type) != BLKmode
821 && TREE_CODE (right_operand) != CONSTRUCTOR)
823 operation_type = right_type;
824 left_operand = convert (operation_type, left_operand);
825 left_type = operation_type;
828 operation_type = left_type;
831 /* If we have a call to a function that returns an unconstrained type
832 with default discriminant on the RHS, use the RHS type (which is
833 padded) as we cannot compute the size of the actual assignment. */
834 else if (TREE_CODE (right_operand) == CALL_EXPR
835 && TYPE_IS_PADDING_P (right_type)
836 && CONTAINS_PLACEHOLDER_P
837 (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS (right_type)))))
838 operation_type = right_type;
840 /* Find the best type to use for copying between aggregate types. */
841 else if (((TREE_CODE (left_type) == ARRAY_TYPE
842 && TREE_CODE (right_type) == ARRAY_TYPE)
843 || (TREE_CODE (left_type) == RECORD_TYPE
844 && TREE_CODE (right_type) == RECORD_TYPE))
845 && (best_type = find_common_type (left_type, right_type)))
846 operation_type = best_type;
848 /* Otherwise use the LHS type. */
850 operation_type = left_type;
852 /* Ensure everything on the LHS is valid. If we have a field reference,
853 strip anything that get_inner_reference can handle. Then remove any
854 conversions between types having the same code and mode. And mark
855 VIEW_CONVERT_EXPRs with TREE_ADDRESSABLE. When done, we must have
856 either an INDIRECT_REF, a NULL_EXPR or a DECL node. */
857 result = left_operand;
860 tree restype = TREE_TYPE (result);
862 if (TREE_CODE (result) == COMPONENT_REF
863 || TREE_CODE (result) == ARRAY_REF
864 || TREE_CODE (result) == ARRAY_RANGE_REF)
865 while (handled_component_p (result))
866 result = TREE_OPERAND (result, 0);
867 else if (TREE_CODE (result) == REALPART_EXPR
868 || TREE_CODE (result) == IMAGPART_EXPR
869 || (CONVERT_EXPR_P (result)
870 && (((TREE_CODE (restype)
871 == TREE_CODE (TREE_TYPE
872 (TREE_OPERAND (result, 0))))
873 && (TYPE_MODE (TREE_TYPE
874 (TREE_OPERAND (result, 0)))
875 == TYPE_MODE (restype)))
876 || TYPE_ALIGN_OK (restype))))
877 result = TREE_OPERAND (result, 0);
878 else if (TREE_CODE (result) == VIEW_CONVERT_EXPR)
880 TREE_ADDRESSABLE (result) = 1;
881 result = TREE_OPERAND (result, 0);
887 gcc_assert (TREE_CODE (result) == INDIRECT_REF
888 || TREE_CODE (result) == NULL_EXPR
891 /* Convert the right operand to the operation type unless it is
892 either already of the correct type or if the type involves a
893 placeholder, since the RHS may not have the same record type. */
894 if (operation_type != right_type
895 && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (operation_type)))
897 right_operand = convert (operation_type, right_operand);
898 right_type = operation_type;
901 /* If the left operand is not of the same type as the operation
902 type, wrap it up in a VIEW_CONVERT_EXPR. */
903 if (left_type != operation_type)
904 left_operand = unchecked_convert (operation_type, left_operand, false);
906 has_side_effects = true;
912 operation_type = TREE_TYPE (left_type);
914 /* ... fall through ... */
916 case ARRAY_RANGE_REF:
917 /* First look through conversion between type variants. Note that
918 this changes neither the operation type nor the type domain. */
919 if (TREE_CODE (left_operand) == VIEW_CONVERT_EXPR
920 && TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (left_operand, 0)))
921 == TYPE_MAIN_VARIANT (left_type))
923 left_operand = TREE_OPERAND (left_operand, 0);
924 left_type = TREE_TYPE (left_operand);
927 /* For a range, make sure the element type is consistent. */
928 if (op_code == ARRAY_RANGE_REF
929 && TREE_TYPE (operation_type) != TREE_TYPE (left_type))
930 operation_type = build_array_type (TREE_TYPE (left_type),
931 TYPE_DOMAIN (operation_type));
933 /* Then convert the right operand to its base type. This will prevent
934 unneeded sign conversions when sizetype is wider than integer. */
935 right_operand = convert (right_base_type, right_operand);
936 right_operand = convert_to_index_type (right_operand);
940 case TRUTH_ANDIF_EXPR:
941 case TRUTH_ORIF_EXPR:
945 #ifdef ENABLE_CHECKING
946 gcc_assert (TREE_CODE (get_base_type (result_type)) == BOOLEAN_TYPE);
948 operation_type = left_base_type;
949 left_operand = convert (operation_type, left_operand);
950 right_operand = convert (operation_type, right_operand);
959 #ifdef ENABLE_CHECKING
960 gcc_assert (TREE_CODE (get_base_type (result_type)) == BOOLEAN_TYPE);
962 /* If either operand is a NULL_EXPR, just return a new one. */
963 if (TREE_CODE (left_operand) == NULL_EXPR)
964 return build2 (op_code, result_type,
965 build1 (NULL_EXPR, integer_type_node,
966 TREE_OPERAND (left_operand, 0)),
969 else if (TREE_CODE (right_operand) == NULL_EXPR)
970 return build2 (op_code, result_type,
971 build1 (NULL_EXPR, integer_type_node,
972 TREE_OPERAND (right_operand, 0)),
975 /* If either object is a justified modular types, get the
976 fields from within. */
977 if (TREE_CODE (left_type) == RECORD_TYPE
978 && TYPE_JUSTIFIED_MODULAR_P (left_type))
980 left_operand = convert (TREE_TYPE (TYPE_FIELDS (left_type)),
982 left_type = TREE_TYPE (left_operand);
983 left_base_type = get_base_type (left_type);
986 if (TREE_CODE (right_type) == RECORD_TYPE
987 && TYPE_JUSTIFIED_MODULAR_P (right_type))
989 right_operand = convert (TREE_TYPE (TYPE_FIELDS (right_type)),
991 right_type = TREE_TYPE (right_operand);
992 right_base_type = get_base_type (right_type);
995 /* If both objects are arrays, compare them specially. */
996 if ((TREE_CODE (left_type) == ARRAY_TYPE
997 || (TREE_CODE (left_type) == INTEGER_TYPE
998 && TYPE_HAS_ACTUAL_BOUNDS_P (left_type)))
999 && (TREE_CODE (right_type) == ARRAY_TYPE
1000 || (TREE_CODE (right_type) == INTEGER_TYPE
1001 && TYPE_HAS_ACTUAL_BOUNDS_P (right_type))))
1003 result = compare_arrays (input_location,
1004 result_type, left_operand, right_operand);
1005 if (op_code == NE_EXPR)
1006 result = invert_truthvalue_loc (EXPR_LOCATION (result), result);
1008 gcc_assert (op_code == EQ_EXPR);
1013 /* Otherwise, the base types must be the same, unless they are both fat
1014 pointer types or record types. In the latter case, use the best type
1015 and convert both operands to that type. */
1016 if (left_base_type != right_base_type)
1018 if (TYPE_IS_FAT_POINTER_P (left_base_type)
1019 && TYPE_IS_FAT_POINTER_P (right_base_type))
1021 gcc_assert (TYPE_MAIN_VARIANT (left_base_type)
1022 == TYPE_MAIN_VARIANT (right_base_type));
1023 best_type = left_base_type;
1026 else if (TREE_CODE (left_base_type) == RECORD_TYPE
1027 && TREE_CODE (right_base_type) == RECORD_TYPE)
1029 /* The only way this is permitted is if both types have the same
1030 name. In that case, one of them must not be self-referential.
1031 Use it as the best type. Even better with a fixed size. */
1032 gcc_assert (TYPE_NAME (left_base_type)
1033 && TYPE_NAME (left_base_type)
1034 == TYPE_NAME (right_base_type));
1036 if (TREE_CONSTANT (TYPE_SIZE (left_base_type)))
1037 best_type = left_base_type;
1038 else if (TREE_CONSTANT (TYPE_SIZE (right_base_type)))
1039 best_type = right_base_type;
1040 else if (!CONTAINS_PLACEHOLDER_P (TYPE_SIZE (left_base_type)))
1041 best_type = left_base_type;
1042 else if (!CONTAINS_PLACEHOLDER_P (TYPE_SIZE (right_base_type)))
1043 best_type = right_base_type;
1051 left_operand = convert (best_type, left_operand);
1052 right_operand = convert (best_type, right_operand);
1056 left_operand = convert (left_base_type, left_operand);
1057 right_operand = convert (right_base_type, right_operand);
1060 /* If both objects are fat pointers, compare them specially. */
1061 if (TYPE_IS_FAT_POINTER_P (left_base_type))
1064 = compare_fat_pointers (input_location,
1065 result_type, left_operand, right_operand);
1066 if (op_code == NE_EXPR)
1067 result = invert_truthvalue_loc (EXPR_LOCATION (result), result);
1069 gcc_assert (op_code == EQ_EXPR);
1074 modulus = NULL_TREE;
1081 /* The RHS of a shift can be any type. Also, ignore any modulus
1082 (we used to abort, but this is needed for unchecked conversion
1083 to modular types). Otherwise, processing is the same as normal. */
1084 gcc_assert (operation_type == left_base_type);
1085 modulus = NULL_TREE;
1086 left_operand = convert (operation_type, left_operand);
1092 /* For binary modulus, if the inputs are in range, so are the
1094 if (modulus && integer_pow2p (modulus))
1095 modulus = NULL_TREE;
1099 gcc_assert (TREE_TYPE (result_type) == left_base_type
1100 && TREE_TYPE (result_type) == right_base_type);
1101 left_operand = convert (left_base_type, left_operand);
1102 right_operand = convert (right_base_type, right_operand);
1105 case TRUNC_DIV_EXPR: case TRUNC_MOD_EXPR:
1106 case CEIL_DIV_EXPR: case CEIL_MOD_EXPR:
1107 case FLOOR_DIV_EXPR: case FLOOR_MOD_EXPR:
1108 case ROUND_DIV_EXPR: case ROUND_MOD_EXPR:
1109 /* These always produce results lower than either operand. */
1110 modulus = NULL_TREE;
1113 case POINTER_PLUS_EXPR:
1114 gcc_assert (operation_type == left_base_type
1115 && sizetype == right_base_type);
1116 left_operand = convert (operation_type, left_operand);
1117 right_operand = convert (sizetype, right_operand);
1120 case PLUS_NOMOD_EXPR:
1121 case MINUS_NOMOD_EXPR:
1122 if (op_code == PLUS_NOMOD_EXPR)
1123 op_code = PLUS_EXPR;
1125 op_code = MINUS_EXPR;
1126 modulus = NULL_TREE;
1128 /* ... fall through ... */
1132 /* Avoid doing arithmetics in ENUMERAL_TYPE or BOOLEAN_TYPE like the
1133 other compilers. Contrary to C, Ada doesn't allow arithmetics in
1134 these types but can generate addition/subtraction for Succ/Pred. */
1136 && (TREE_CODE (operation_type) == ENUMERAL_TYPE
1137 || TREE_CODE (operation_type) == BOOLEAN_TYPE))
1138 operation_type = left_base_type = right_base_type
1139 = gnat_type_for_mode (TYPE_MODE (operation_type),
1140 TYPE_UNSIGNED (operation_type));
1142 /* ... fall through ... */
1146 /* The result type should be the same as the base types of the
1147 both operands (and they should be the same). Convert
1148 everything to the result type. */
1150 gcc_assert (operation_type == left_base_type
1151 && left_base_type == right_base_type);
1152 left_operand = convert (operation_type, left_operand);
1153 right_operand = convert (operation_type, right_operand);
1156 if (modulus && !integer_pow2p (modulus))
1158 result = nonbinary_modular_operation (op_code, operation_type,
1159 left_operand, right_operand);
1160 modulus = NULL_TREE;
1162 /* If either operand is a NULL_EXPR, just return a new one. */
1163 else if (TREE_CODE (left_operand) == NULL_EXPR)
1164 return build1 (NULL_EXPR, operation_type, TREE_OPERAND (left_operand, 0));
1165 else if (TREE_CODE (right_operand) == NULL_EXPR)
1166 return build1 (NULL_EXPR, operation_type, TREE_OPERAND (right_operand, 0));
1167 else if (op_code == ARRAY_REF || op_code == ARRAY_RANGE_REF)
1168 result = fold (build4 (op_code, operation_type, left_operand,
1169 right_operand, NULL_TREE, NULL_TREE));
1170 else if (op_code == INIT_EXPR || op_code == MODIFY_EXPR)
1171 result = build2 (op_code, void_type_node, left_operand, right_operand);
1174 = fold_build2 (op_code, operation_type, left_operand, right_operand);
1176 if (TREE_CONSTANT (result))
1178 else if (op_code == ARRAY_REF || op_code == ARRAY_RANGE_REF)
1180 TREE_THIS_NOTRAP (result) = 1;
1181 if (TYPE_VOLATILE (operation_type))
1182 TREE_THIS_VOLATILE (result) = 1;
1185 TREE_CONSTANT (result)
1186 |= (TREE_CONSTANT (left_operand) && TREE_CONSTANT (right_operand));
1188 TREE_SIDE_EFFECTS (result) |= has_side_effects;
1190 /* If we are working with modular types, perform the MOD operation
1191 if something above hasn't eliminated the need for it. */
1193 result = fold_build2 (FLOOR_MOD_EXPR, operation_type, result,
1194 convert (operation_type, modulus));
1196 if (result_type && result_type != operation_type)
1197 result = convert (result_type, result);
1202 /* Similar, but for unary operations. */
1205 build_unary_op (enum tree_code op_code, tree result_type, tree operand)
1207 tree type = TREE_TYPE (operand);
1208 tree base_type = get_base_type (type);
1209 tree operation_type = result_type;
1213 && TREE_CODE (operation_type) == RECORD_TYPE
1214 && TYPE_JUSTIFIED_MODULAR_P (operation_type))
1215 operation_type = TREE_TYPE (TYPE_FIELDS (operation_type));
1218 && TREE_CODE (operation_type) == INTEGER_TYPE
1219 && TYPE_EXTRA_SUBTYPE_P (operation_type))
1220 operation_type = get_base_type (operation_type);
1226 if (!operation_type)
1227 result_type = operation_type = TREE_TYPE (type);
1229 gcc_assert (result_type == TREE_TYPE (type));
1231 result = fold_build1 (op_code, operation_type, operand);
1234 case TRUTH_NOT_EXPR:
1235 #ifdef ENABLE_CHECKING
1236 gcc_assert (TREE_CODE (get_base_type (result_type)) == BOOLEAN_TYPE);
1238 result = invert_truthvalue_loc (EXPR_LOCATION (operand), operand);
1239 /* When not optimizing, fold the result as invert_truthvalue_loc
1240 doesn't fold the result of comparisons. This is intended to undo
1241 the trick used for boolean rvalues in gnat_to_gnu. */
1243 result = fold (result);
1246 case ATTR_ADDR_EXPR:
1248 switch (TREE_CODE (operand))
1251 case UNCONSTRAINED_ARRAY_REF:
1252 result = TREE_OPERAND (operand, 0);
1254 /* Make sure the type here is a pointer, not a reference.
1255 GCC wants pointer types for function addresses. */
1257 result_type = build_pointer_type (type);
1259 /* If the underlying object can alias everything, propagate the
1260 property since we are effectively retrieving the object. */
1261 if (POINTER_TYPE_P (TREE_TYPE (result))
1262 && TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (result)))
1264 if (TREE_CODE (result_type) == POINTER_TYPE
1265 && !TYPE_REF_CAN_ALIAS_ALL (result_type))
1267 = build_pointer_type_for_mode (TREE_TYPE (result_type),
1268 TYPE_MODE (result_type),
1270 else if (TREE_CODE (result_type) == REFERENCE_TYPE
1271 && !TYPE_REF_CAN_ALIAS_ALL (result_type))
1273 = build_reference_type_for_mode (TREE_TYPE (result_type),
1274 TYPE_MODE (result_type),
1281 TREE_TYPE (result) = type = build_pointer_type (type);
1285 /* Fold a compound expression if it has unconstrained array type
1286 since the middle-end cannot handle it. But we don't it in the
1287 general case because it may introduce aliasing issues if the
1288 first operand is an indirect assignment and the second operand
1289 the corresponding address, e.g. for an allocator. */
1290 if (TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
1292 result = build_unary_op (ADDR_EXPR, result_type,
1293 TREE_OPERAND (operand, 1));
1294 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1295 TREE_OPERAND (operand, 0), result);
1301 case ARRAY_RANGE_REF:
1304 /* If this is for 'Address, find the address of the prefix and add
1305 the offset to the field. Otherwise, do this the normal way. */
1306 if (op_code == ATTR_ADDR_EXPR)
1308 HOST_WIDE_INT bitsize;
1309 HOST_WIDE_INT bitpos;
1311 enum machine_mode mode;
1312 int unsignedp, volatilep;
1314 inner = get_inner_reference (operand, &bitsize, &bitpos, &offset,
1315 &mode, &unsignedp, &volatilep,
1318 /* If INNER is a padding type whose field has a self-referential
1319 size, convert to that inner type. We know the offset is zero
1320 and we need to have that type visible. */
1321 if (TYPE_IS_PADDING_P (TREE_TYPE (inner))
1322 && CONTAINS_PLACEHOLDER_P
1323 (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS
1324 (TREE_TYPE (inner))))))
1325 inner = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (inner))),
1328 /* Compute the offset as a byte offset from INNER. */
1330 offset = size_zero_node;
1332 offset = size_binop (PLUS_EXPR, offset,
1333 size_int (bitpos / BITS_PER_UNIT));
1335 /* Take the address of INNER, convert the offset to void *, and
1336 add then. It will later be converted to the desired result
1338 inner = build_unary_op (ADDR_EXPR, NULL_TREE, inner);
1339 inner = convert (ptr_void_type_node, inner);
1340 result = build_binary_op (POINTER_PLUS_EXPR, ptr_void_type_node,
1342 result = convert (build_pointer_type (TREE_TYPE (operand)),
1349 /* If this is just a constructor for a padded record, we can
1350 just take the address of the single field and convert it to
1351 a pointer to our type. */
1352 if (TYPE_IS_PADDING_P (type))
1354 result = (*CONSTRUCTOR_ELTS (operand))[0].value;
1355 result = convert (build_pointer_type (TREE_TYPE (operand)),
1356 build_unary_op (ADDR_EXPR, NULL_TREE, result));
1363 if (AGGREGATE_TYPE_P (type)
1364 && AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (operand, 0))))
1365 return build_unary_op (ADDR_EXPR, result_type,
1366 TREE_OPERAND (operand, 0));
1368 /* ... fallthru ... */
1370 case VIEW_CONVERT_EXPR:
1371 /* If this just a variant conversion or if the conversion doesn't
1372 change the mode, get the result type from this type and go down.
1373 This is needed for conversions of CONST_DECLs, to eventually get
1374 to the address of their CORRESPONDING_VARs. */
1375 if ((TYPE_MAIN_VARIANT (type)
1376 == TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (operand, 0))))
1377 || (TYPE_MODE (type) != BLKmode
1378 && (TYPE_MODE (type)
1379 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (operand, 0))))))
1380 return build_unary_op (ADDR_EXPR,
1381 (result_type ? result_type
1382 : build_pointer_type (type)),
1383 TREE_OPERAND (operand, 0));
1387 operand = DECL_CONST_CORRESPONDING_VAR (operand);
1389 /* ... fall through ... */
1394 /* If we are taking the address of a padded record whose field
1395 contains a template, take the address of the field. */
1396 if (TYPE_IS_PADDING_P (type)
1397 && TREE_CODE (TREE_TYPE (TYPE_FIELDS (type))) == RECORD_TYPE
1398 && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (TYPE_FIELDS (type))))
1400 type = TREE_TYPE (TYPE_FIELDS (type));
1401 operand = convert (type, operand);
1404 gnat_mark_addressable (operand);
1405 result = build_fold_addr_expr (operand);
1408 TREE_CONSTANT (result) = staticp (operand) || TREE_CONSTANT (operand);
1413 tree t = remove_conversions (operand, false);
1414 bool can_never_be_null = DECL_P (t) && DECL_CAN_NEVER_BE_NULL_P (t);
1416 /* If TYPE is a thin pointer, either first retrieve the base if this
1417 is an expression with an offset built for the initialization of an
1418 object with an unconstrained nominal subtype, or else convert to
1420 if (TYPE_IS_THIN_POINTER_P (type))
1422 tree rec_type = TREE_TYPE (type);
1424 if (TREE_CODE (operand) == POINTER_PLUS_EXPR
1425 && TREE_OPERAND (operand, 1)
1426 == byte_position (DECL_CHAIN (TYPE_FIELDS (rec_type)))
1427 && TREE_CODE (TREE_OPERAND (operand, 0)) == NOP_EXPR)
1429 operand = TREE_OPERAND (TREE_OPERAND (operand, 0), 0);
1430 type = TREE_TYPE (operand);
1432 else if (TYPE_UNCONSTRAINED_ARRAY (rec_type))
1435 = convert (TREE_TYPE (TYPE_UNCONSTRAINED_ARRAY (rec_type)),
1437 type = TREE_TYPE (operand);
1441 /* If we want to refer to an unconstrained array, use the appropriate
1442 expression. But this will never survive down to the back-end. */
1443 if (TYPE_IS_FAT_POINTER_P (type))
1445 result = build1 (UNCONSTRAINED_ARRAY_REF,
1446 TYPE_UNCONSTRAINED_ARRAY (type), operand);
1447 TREE_READONLY (result)
1448 = TYPE_READONLY (TYPE_UNCONSTRAINED_ARRAY (type));
1451 /* If we are dereferencing an ADDR_EXPR, return its operand. */
1452 else if (TREE_CODE (operand) == ADDR_EXPR)
1453 result = TREE_OPERAND (operand, 0);
1455 /* Otherwise, build and fold the indirect reference. */
1458 result = build_fold_indirect_ref (operand);
1459 TREE_READONLY (result) = TYPE_READONLY (TREE_TYPE (type));
1462 if (!TYPE_IS_FAT_POINTER_P (type) && TYPE_VOLATILE (TREE_TYPE (type)))
1464 TREE_SIDE_EFFECTS (result) = 1;
1465 if (TREE_CODE (result) == INDIRECT_REF)
1466 TREE_THIS_VOLATILE (result) = TYPE_VOLATILE (TREE_TYPE (result));
1469 if ((TREE_CODE (result) == INDIRECT_REF
1470 || TREE_CODE (result) == UNCONSTRAINED_ARRAY_REF)
1471 && can_never_be_null)
1472 TREE_THIS_NOTRAP (result) = 1;
1480 tree modulus = ((operation_type
1481 && TREE_CODE (operation_type) == INTEGER_TYPE
1482 && TYPE_MODULAR_P (operation_type))
1483 ? TYPE_MODULUS (operation_type) : NULL_TREE);
1484 int mod_pow2 = modulus && integer_pow2p (modulus);
1486 /* If this is a modular type, there are various possibilities
1487 depending on the operation and whether the modulus is a
1488 power of two or not. */
1492 gcc_assert (operation_type == base_type);
1493 operand = convert (operation_type, operand);
1495 /* The fastest in the negate case for binary modulus is
1496 the straightforward code; the TRUNC_MOD_EXPR below
1497 is an AND operation. */
1498 if (op_code == NEGATE_EXPR && mod_pow2)
1499 result = fold_build2 (TRUNC_MOD_EXPR, operation_type,
1500 fold_build1 (NEGATE_EXPR, operation_type,
1504 /* For nonbinary negate case, return zero for zero operand,
1505 else return the modulus minus the operand. If the modulus
1506 is a power of two minus one, we can do the subtraction
1507 as an XOR since it is equivalent and faster on most machines. */
1508 else if (op_code == NEGATE_EXPR && !mod_pow2)
1510 if (integer_pow2p (fold_build2 (PLUS_EXPR, operation_type,
1512 convert (operation_type,
1513 integer_one_node))))
1514 result = fold_build2 (BIT_XOR_EXPR, operation_type,
1517 result = fold_build2 (MINUS_EXPR, operation_type,
1520 result = fold_build3 (COND_EXPR, operation_type,
1521 fold_build2 (NE_EXPR,
1526 integer_zero_node)),
1531 /* For the NOT cases, we need a constant equal to
1532 the modulus minus one. For a binary modulus, we
1533 XOR against the constant and subtract the operand from
1534 that constant for nonbinary modulus. */
1536 tree cnst = fold_build2 (MINUS_EXPR, operation_type, modulus,
1537 convert (operation_type,
1541 result = fold_build2 (BIT_XOR_EXPR, operation_type,
1544 result = fold_build2 (MINUS_EXPR, operation_type,
1552 /* ... fall through ... */
1555 gcc_assert (operation_type == base_type);
1556 result = fold_build1 (op_code, operation_type,
1557 convert (operation_type, operand));
1560 if (result_type && TREE_TYPE (result) != result_type)
1561 result = convert (result_type, result);
1566 /* Similar, but for COND_EXPR. */
1569 build_cond_expr (tree result_type, tree condition_operand,
1570 tree true_operand, tree false_operand)
1572 bool addr_p = false;
1575 /* The front-end verified that result, true and false operands have
1576 same base type. Convert everything to the result type. */
1577 true_operand = convert (result_type, true_operand);
1578 false_operand = convert (result_type, false_operand);
1580 /* If the result type is unconstrained, take the address of the operands and
1581 then dereference the result. Likewise if the result type is passed by
1582 reference, because creating a temporary of this type is not allowed. */
1583 if (TREE_CODE (result_type) == UNCONSTRAINED_ARRAY_TYPE
1584 || TYPE_IS_BY_REFERENCE_P (result_type)
1585 || CONTAINS_PLACEHOLDER_P (TYPE_SIZE (result_type)))
1587 result_type = build_pointer_type (result_type);
1588 true_operand = build_unary_op (ADDR_EXPR, result_type, true_operand);
1589 false_operand = build_unary_op (ADDR_EXPR, result_type, false_operand);
1593 result = fold_build3 (COND_EXPR, result_type, condition_operand,
1594 true_operand, false_operand);
1596 /* If we have a common SAVE_EXPR (possibly surrounded by arithmetics)
1597 in both arms, make sure it gets evaluated by moving it ahead of the
1598 conditional expression. This is necessary because it is evaluated
1599 in only one place at run time and would otherwise be uninitialized
1600 in one of the arms. */
1601 true_operand = skip_simple_arithmetic (true_operand);
1602 false_operand = skip_simple_arithmetic (false_operand);
1604 if (true_operand == false_operand && TREE_CODE (true_operand) == SAVE_EXPR)
1605 result = build2 (COMPOUND_EXPR, result_type, true_operand, result);
1608 result = build_unary_op (INDIRECT_REF, NULL_TREE, result);
1613 /* Similar, but for COMPOUND_EXPR. */
1616 build_compound_expr (tree result_type, tree stmt_operand, tree expr_operand)
1618 bool addr_p = false;
1621 /* If the result type is unconstrained, take the address of the operand and
1622 then dereference the result. Likewise if the result type is passed by
1623 reference, but this is natively handled in the gimplifier. */
1624 if (TREE_CODE (result_type) == UNCONSTRAINED_ARRAY_TYPE
1625 || CONTAINS_PLACEHOLDER_P (TYPE_SIZE (result_type)))
1627 result_type = build_pointer_type (result_type);
1628 expr_operand = build_unary_op (ADDR_EXPR, result_type, expr_operand);
1632 result = fold_build2 (COMPOUND_EXPR, result_type, stmt_operand,
1636 result = build_unary_op (INDIRECT_REF, NULL_TREE, result);
1641 /* Conveniently construct a function call expression. FNDECL names the
1642 function to be called, N is the number of arguments, and the "..."
1643 parameters are the argument expressions. Unlike build_call_expr
1644 this doesn't fold the call, hence it will always return a CALL_EXPR. */
1647 build_call_n_expr (tree fndecl, int n, ...)
1650 tree fntype = TREE_TYPE (fndecl);
1651 tree fn = build1 (ADDR_EXPR, build_pointer_type (fntype), fndecl);
1654 fn = build_call_valist (TREE_TYPE (fntype), fn, n, ap);
1659 /* Call a function that raises an exception and pass the line number and file
1660 name, if requested. MSG says which exception function to call.
1662 GNAT_NODE is the gnat node conveying the source location for which the
1663 error should be signaled, or Empty in which case the error is signaled on
1664 the current ref_file_name/input_line.
1666 KIND says which kind of exception this is for
1667 (N_Raise_{Constraint,Storage,Program}_Error). */
1670 build_call_raise (int msg, Node_Id gnat_node, char kind)
1672 tree fndecl = gnat_raise_decls[msg];
1673 tree label = get_exception_label (kind);
1679 /* If this is to be done as a goto, handle that case. */
1682 Entity_Id local_raise = Get_Local_Raise_Call_Entity ();
1683 tree gnu_result = build1 (GOTO_EXPR, void_type_node, label);
1685 /* If Local_Raise is present, generate
1686 Local_Raise (exception'Identity); */
1687 if (Present (local_raise))
1689 tree gnu_local_raise
1690 = gnat_to_gnu_entity (local_raise, NULL_TREE, 0);
1691 tree gnu_exception_entity
1692 = gnat_to_gnu_entity (Get_RT_Exception_Entity (msg), NULL_TREE, 0);
1694 = build_call_n_expr (gnu_local_raise, 1,
1695 build_unary_op (ADDR_EXPR, NULL_TREE,
1696 gnu_exception_entity));
1698 gnu_result = build2 (COMPOUND_EXPR, void_type_node,
1699 gnu_call, gnu_result);}
1705 = (Debug_Flag_NN || Exception_Locations_Suppressed)
1707 : (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1708 ? IDENTIFIER_POINTER
1709 (get_identifier (Get_Name_String
1711 (Get_Source_File_Index (Sloc (gnat_node))))))
1715 filename = build_string (len, str);
1717 = (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1718 ? Get_Logical_Line_Number (Sloc(gnat_node))
1719 : LOCATION_LINE (input_location);
1721 TREE_TYPE (filename) = build_array_type (unsigned_char_type_node,
1722 build_index_type (size_int (len)));
1725 build_call_n_expr (fndecl, 2,
1727 build_pointer_type (unsigned_char_type_node),
1729 build_int_cst (NULL_TREE, line_number));
1732 /* Similar to build_call_raise, for an index or range check exception as
1733 determined by MSG, with extra information generated of the form
1734 "INDEX out of range FIRST..LAST". */
1737 build_call_raise_range (int msg, Node_Id gnat_node,
1738 tree index, tree first, tree last)
1740 tree fndecl = gnat_raise_decls_ext[msg];
1742 int line_number, column_number;
1747 = (Debug_Flag_NN || Exception_Locations_Suppressed)
1749 : (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1750 ? IDENTIFIER_POINTER
1751 (get_identifier (Get_Name_String
1753 (Get_Source_File_Index (Sloc (gnat_node))))))
1757 filename = build_string (len, str);
1758 if (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1760 line_number = Get_Logical_Line_Number (Sloc (gnat_node));
1761 column_number = Get_Column_Number (Sloc (gnat_node));
1765 line_number = LOCATION_LINE (input_location);
1769 TREE_TYPE (filename) = build_array_type (unsigned_char_type_node,
1770 build_index_type (size_int (len)));
1773 build_call_n_expr (fndecl, 6,
1775 build_pointer_type (unsigned_char_type_node),
1777 build_int_cst (NULL_TREE, line_number),
1778 build_int_cst (NULL_TREE, column_number),
1779 convert (integer_type_node, index),
1780 convert (integer_type_node, first),
1781 convert (integer_type_node, last));
1784 /* Similar to build_call_raise, with extra information about the column
1785 where the check failed. */
1788 build_call_raise_column (int msg, Node_Id gnat_node)
1790 tree fndecl = gnat_raise_decls_ext[msg];
1792 int line_number, column_number;
1797 = (Debug_Flag_NN || Exception_Locations_Suppressed)
1799 : (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1800 ? IDENTIFIER_POINTER
1801 (get_identifier (Get_Name_String
1803 (Get_Source_File_Index (Sloc (gnat_node))))))
1807 filename = build_string (len, str);
1808 if (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1810 line_number = Get_Logical_Line_Number (Sloc (gnat_node));
1811 column_number = Get_Column_Number (Sloc (gnat_node));
1815 line_number = LOCATION_LINE (input_location);
1819 TREE_TYPE (filename) = build_array_type (unsigned_char_type_node,
1820 build_index_type (size_int (len)));
1823 build_call_n_expr (fndecl, 3,
1825 build_pointer_type (unsigned_char_type_node),
1827 build_int_cst (NULL_TREE, line_number),
1828 build_int_cst (NULL_TREE, column_number));
1831 /* qsort comparer for the bit positions of two constructor elements
1832 for record components. */
1835 compare_elmt_bitpos (const PTR rt1, const PTR rt2)
1837 const constructor_elt * const elmt1 = (const constructor_elt * const) rt1;
1838 const constructor_elt * const elmt2 = (const constructor_elt * const) rt2;
1839 const_tree const field1 = elmt1->index;
1840 const_tree const field2 = elmt2->index;
1842 = tree_int_cst_compare (bit_position (field1), bit_position (field2));
1844 return ret ? ret : (int) (DECL_UID (field1) - DECL_UID (field2));
1847 /* Return a CONSTRUCTOR of TYPE whose elements are V. */
1850 gnat_build_constructor (tree type, vec<constructor_elt, va_gc> *v)
1852 bool allconstant = (TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST);
1853 bool side_effects = false;
1854 tree result, obj, val;
1855 unsigned int n_elmts;
1857 /* Scan the elements to see if they are all constant or if any has side
1858 effects, to let us set global flags on the resulting constructor. Count
1859 the elements along the way for possible sorting purposes below. */
1860 FOR_EACH_CONSTRUCTOR_ELT (v, n_elmts, obj, val)
1862 /* The predicate must be in keeping with output_constructor. */
1863 if ((!TREE_CONSTANT (val) && !TREE_STATIC (val))
1864 || (TREE_CODE (type) == RECORD_TYPE
1865 && CONSTRUCTOR_BITFIELD_P (obj)
1866 && !initializer_constant_valid_for_bitfield_p (val))
1867 || !initializer_constant_valid_p (val, TREE_TYPE (val)))
1868 allconstant = false;
1870 if (TREE_SIDE_EFFECTS (val))
1871 side_effects = true;
1874 /* For record types with constant components only, sort field list
1875 by increasing bit position. This is necessary to ensure the
1876 constructor can be output as static data. */
1877 if (allconstant && TREE_CODE (type) == RECORD_TYPE && n_elmts > 1)
1878 v->qsort (compare_elmt_bitpos);
1880 result = build_constructor (type, v);
1881 CONSTRUCTOR_NO_CLEARING (result) = 1;
1882 TREE_CONSTANT (result) = TREE_STATIC (result) = allconstant;
1883 TREE_SIDE_EFFECTS (result) = side_effects;
1884 TREE_READONLY (result) = TYPE_READONLY (type) || allconstant;
1888 /* Return a COMPONENT_REF to access a field that is given by COMPONENT,
1889 an IDENTIFIER_NODE giving the name of the field, or FIELD, a FIELD_DECL,
1890 for the field. Don't fold the result if NO_FOLD_P is true.
1892 We also handle the fact that we might have been passed a pointer to the
1893 actual record and know how to look for fields in variant parts. */
1896 build_simple_component_ref (tree record_variable, tree component,
1897 tree field, bool no_fold_p)
1899 tree record_type = TYPE_MAIN_VARIANT (TREE_TYPE (record_variable));
1900 tree ref, inner_variable;
1902 gcc_assert (RECORD_OR_UNION_TYPE_P (record_type)
1903 && COMPLETE_TYPE_P (record_type)
1904 && (component == NULL_TREE) != (field == NULL_TREE));
1906 /* If no field was specified, look for a field with the specified name in
1907 the current record only. */
1909 for (field = TYPE_FIELDS (record_type);
1911 field = DECL_CHAIN (field))
1912 if (DECL_NAME (field) == component)
1918 /* If this field is not in the specified record, see if we can find a field
1919 in the specified record whose original field is the same as this one. */
1920 if (DECL_CONTEXT (field) != record_type)
1924 /* First loop through normal components. */
1925 for (new_field = TYPE_FIELDS (record_type);
1927 new_field = DECL_CHAIN (new_field))
1928 if (SAME_FIELD_P (field, new_field))
1931 /* Next, see if we're looking for an inherited component in an extension.
1932 If so, look through the extension directly, but not if the type contains
1933 a placeholder, as it might be needed for a later substitution. */
1935 && TREE_CODE (record_variable) == VIEW_CONVERT_EXPR
1936 && TYPE_ALIGN_OK (record_type)
1937 && !type_contains_placeholder_p (record_type)
1938 && TREE_CODE (TREE_TYPE (TREE_OPERAND (record_variable, 0)))
1940 && TYPE_ALIGN_OK (TREE_TYPE (TREE_OPERAND (record_variable, 0))))
1942 ref = build_simple_component_ref (TREE_OPERAND (record_variable, 0),
1943 NULL_TREE, field, no_fold_p);
1948 /* Next, loop through DECL_INTERNAL_P components if we haven't found the
1949 component in the first search. Doing this search in two steps is
1950 required to avoid hidden homonymous fields in the _Parent field. */
1952 for (new_field = TYPE_FIELDS (record_type);
1954 new_field = DECL_CHAIN (new_field))
1955 if (DECL_INTERNAL_P (new_field))
1958 = build_simple_component_ref (record_variable,
1959 NULL_TREE, new_field, no_fold_p);
1960 ref = build_simple_component_ref (field_ref, NULL_TREE, field,
1972 /* If the field's offset has overflowed, do not try to access it, as doing
1973 so may trigger sanity checks deeper in the back-end. Note that we don't
1974 need to warn since this will be done on trying to declare the object. */
1975 if (TREE_CODE (DECL_FIELD_OFFSET (field)) == INTEGER_CST
1976 && TREE_OVERFLOW (DECL_FIELD_OFFSET (field)))
1979 /* Look through conversion between type variants. This is transparent as
1980 far as the field is concerned. */
1981 if (TREE_CODE (record_variable) == VIEW_CONVERT_EXPR
1982 && TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (record_variable, 0)))
1984 inner_variable = TREE_OPERAND (record_variable, 0);
1986 inner_variable = record_variable;
1988 ref = build3 (COMPONENT_REF, TREE_TYPE (field), inner_variable, field,
1991 if (TREE_READONLY (record_variable)
1992 || TREE_READONLY (field)
1993 || TYPE_READONLY (record_type))
1994 TREE_READONLY (ref) = 1;
1996 if (TREE_THIS_VOLATILE (record_variable)
1997 || TREE_THIS_VOLATILE (field)
1998 || TYPE_VOLATILE (record_type))
1999 TREE_THIS_VOLATILE (ref) = 1;
2004 /* The generic folder may punt in this case because the inner array type
2005 can be self-referential, but folding is in fact not problematic. */
2006 if (TREE_CODE (record_variable) == CONSTRUCTOR
2007 && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (record_variable)))
2009 vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (record_variable);
2010 unsigned HOST_WIDE_INT idx;
2012 FOR_EACH_CONSTRUCTOR_ELT (elts, idx, index, value)
2021 /* Like build_simple_component_ref, except that we give an error if the
2022 reference could not be found. */
2025 build_component_ref (tree record_variable, tree component,
2026 tree field, bool no_fold_p)
2028 tree ref = build_simple_component_ref (record_variable, component, field,
2034 /* If FIELD was specified, assume this is an invalid user field so raise
2035 Constraint_Error. Otherwise, we have no type to return so abort. */
2037 return build1 (NULL_EXPR, TREE_TYPE (field),
2038 build_call_raise (CE_Discriminant_Check_Failed, Empty,
2039 N_Raise_Constraint_Error));
2042 /* Helper for build_call_alloc_dealloc, with arguments to be interpreted
2043 identically. Process the case where a GNAT_PROC to call is provided. */
2046 build_call_alloc_dealloc_proc (tree gnu_obj, tree gnu_size, tree gnu_type,
2047 Entity_Id gnat_proc, Entity_Id gnat_pool)
2049 tree gnu_proc = gnat_to_gnu (gnat_proc);
2052 /* A storage pool's underlying type is a record type (for both predefined
2053 storage pools and GNAT simple storage pools). The secondary stack uses
2054 the same mechanism, but its pool object (SS_Pool) is an integer. */
2055 if (Is_Record_Type (Underlying_Type (Etype (gnat_pool))))
2057 /* The size is the third parameter; the alignment is the
2059 Entity_Id gnat_size_type
2060 = Etype (Next_Formal (Next_Formal (First_Formal (gnat_proc))));
2061 tree gnu_size_type = gnat_to_gnu_type (gnat_size_type);
2063 tree gnu_pool = gnat_to_gnu (gnat_pool);
2064 tree gnu_pool_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_pool);
2065 tree gnu_align = size_int (TYPE_ALIGN (gnu_type) / BITS_PER_UNIT);
2067 gnu_size = convert (gnu_size_type, gnu_size);
2068 gnu_align = convert (gnu_size_type, gnu_align);
2070 /* The first arg is always the address of the storage pool; next
2071 comes the address of the object, for a deallocator, then the
2072 size and alignment. */
2074 gnu_call = build_call_n_expr (gnu_proc, 4, gnu_pool_addr, gnu_obj,
2075 gnu_size, gnu_align);
2077 gnu_call = build_call_n_expr (gnu_proc, 3, gnu_pool_addr,
2078 gnu_size, gnu_align);
2081 /* Secondary stack case. */
2084 /* The size is the second parameter. */
2085 Entity_Id gnat_size_type
2086 = Etype (Next_Formal (First_Formal (gnat_proc)));
2087 tree gnu_size_type = gnat_to_gnu_type (gnat_size_type);
2089 gnu_size = convert (gnu_size_type, gnu_size);
2091 /* The first arg is the address of the object, for a deallocator,
2094 gnu_call = build_call_n_expr (gnu_proc, 2, gnu_obj, gnu_size);
2096 gnu_call = build_call_n_expr (gnu_proc, 1, gnu_size);
2102 /* Helper for build_call_alloc_dealloc, to build and return an allocator for
2103 DATA_SIZE bytes aimed at containing a DATA_TYPE object, using the default
2104 __gnat_malloc allocator. Honor DATA_TYPE alignments greater than what the
2108 maybe_wrap_malloc (tree data_size, tree data_type, Node_Id gnat_node)
2110 /* When the DATA_TYPE alignment is stricter than what malloc offers
2111 (super-aligned case), we allocate an "aligning" wrapper type and return
2112 the address of its single data field with the malloc's return value
2113 stored just in front. */
2115 unsigned int data_align = TYPE_ALIGN (data_type);
2116 unsigned int system_allocator_alignment
2117 = get_target_system_allocator_alignment () * BITS_PER_UNIT;
2120 = ((data_align > system_allocator_alignment)
2121 ? make_aligning_type (data_type, data_align, data_size,
2122 system_allocator_alignment,
2123 POINTER_SIZE / BITS_PER_UNIT,
2128 = aligning_type ? TYPE_SIZE_UNIT (aligning_type) : data_size;
2132 /* On VMS, if pointers are 64-bit and the allocator size is 32-bit or
2133 Convention C, allocate 32-bit memory. */
2134 if (TARGET_ABI_OPEN_VMS
2135 && POINTER_SIZE == 64
2136 && Nkind (gnat_node) == N_Allocator
2137 && (UI_To_Int (Esize (Etype (gnat_node))) == 32
2138 || Convention (Etype (gnat_node)) == Convention_C))
2139 malloc_ptr = build_call_n_expr (malloc32_decl, 1, size_to_malloc);
2141 malloc_ptr = build_call_n_expr (malloc_decl, 1, size_to_malloc);
2145 /* Latch malloc's return value and get a pointer to the aligning field
2147 tree storage_ptr = gnat_protect_expr (malloc_ptr);
2149 tree aligning_record_addr
2150 = convert (build_pointer_type (aligning_type), storage_ptr);
2152 tree aligning_record
2153 = build_unary_op (INDIRECT_REF, NULL_TREE, aligning_record_addr);
2156 = build_component_ref (aligning_record, NULL_TREE,
2157 TYPE_FIELDS (aligning_type), false);
2159 tree aligning_field_addr
2160 = build_unary_op (ADDR_EXPR, NULL_TREE, aligning_field);
2162 /* Then arrange to store the allocator's return value ahead
2164 tree storage_ptr_slot_addr
2165 = build_binary_op (POINTER_PLUS_EXPR, ptr_void_type_node,
2166 convert (ptr_void_type_node, aligning_field_addr),
2167 size_int (-(HOST_WIDE_INT) POINTER_SIZE
2170 tree storage_ptr_slot
2171 = build_unary_op (INDIRECT_REF, NULL_TREE,
2172 convert (build_pointer_type (ptr_void_type_node),
2173 storage_ptr_slot_addr));
2176 build2 (COMPOUND_EXPR, TREE_TYPE (aligning_field_addr),
2177 build_binary_op (INIT_EXPR, NULL_TREE,
2178 storage_ptr_slot, storage_ptr),
2179 aligning_field_addr);
2185 /* Helper for build_call_alloc_dealloc, to release a DATA_TYPE object
2186 designated by DATA_PTR using the __gnat_free entry point. */
2189 maybe_wrap_free (tree data_ptr, tree data_type)
2191 /* In the regular alignment case, we pass the data pointer straight to free.
2192 In the superaligned case, we need to retrieve the initial allocator
2193 return value, stored in front of the data block at allocation time. */
2195 unsigned int data_align = TYPE_ALIGN (data_type);
2196 unsigned int system_allocator_alignment
2197 = get_target_system_allocator_alignment () * BITS_PER_UNIT;
2201 if (data_align > system_allocator_alignment)
2203 /* DATA_FRONT_PTR (void *)
2204 = (void *)DATA_PTR - (void *)sizeof (void *)) */
2207 (POINTER_PLUS_EXPR, ptr_void_type_node,
2208 convert (ptr_void_type_node, data_ptr),
2209 size_int (-(HOST_WIDE_INT) POINTER_SIZE / BITS_PER_UNIT));
2211 /* FREE_PTR (void *) = *(void **)DATA_FRONT_PTR */
2214 (INDIRECT_REF, NULL_TREE,
2215 convert (build_pointer_type (ptr_void_type_node), data_front_ptr));
2218 free_ptr = data_ptr;
2220 return build_call_n_expr (free_decl, 1, free_ptr);
2223 /* Build a GCC tree to call an allocation or deallocation function.
2224 If GNU_OBJ is nonzero, it is an object to deallocate. Otherwise,
2225 generate an allocator.
2227 GNU_SIZE is the number of bytes to allocate and GNU_TYPE is the contained
2228 object type, used to determine the to-be-honored address alignment.
2229 GNAT_PROC, if present, is a procedure to call and GNAT_POOL is the storage
2230 pool to use. If not present, malloc and free are used. GNAT_NODE is used
2231 to provide an error location for restriction violation messages. */
2234 build_call_alloc_dealloc (tree gnu_obj, tree gnu_size, tree gnu_type,
2235 Entity_Id gnat_proc, Entity_Id gnat_pool,
2238 gnu_size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (gnu_size, gnu_obj);
2240 /* Explicit proc to call ? This one is assumed to deal with the type
2241 alignment constraints. */
2242 if (Present (gnat_proc))
2243 return build_call_alloc_dealloc_proc (gnu_obj, gnu_size, gnu_type,
2244 gnat_proc, gnat_pool);
2246 /* Otherwise, object to "free" or "malloc" with possible special processing
2247 for alignments stricter than what the default allocator honors. */
2249 return maybe_wrap_free (gnu_obj, gnu_type);
2252 /* Assert that we no longer can be called with this special pool. */
2253 gcc_assert (gnat_pool != -1);
2255 /* Check that we aren't violating the associated restriction. */
2256 if (!(Nkind (gnat_node) == N_Allocator && Comes_From_Source (gnat_node)))
2257 Check_No_Implicit_Heap_Alloc (gnat_node);
2259 return maybe_wrap_malloc (gnu_size, gnu_type, gnat_node);
2263 /* Build a GCC tree that corresponds to allocating an object of TYPE whose
2264 initial value is INIT, if INIT is nonzero. Convert the expression to
2265 RESULT_TYPE, which must be some pointer type, and return the result.
2267 GNAT_PROC and GNAT_POOL optionally give the procedure to call and
2268 the storage pool to use. GNAT_NODE is used to provide an error
2269 location for restriction violation messages. If IGNORE_INIT_TYPE is
2270 true, ignore the type of INIT for the purpose of determining the size;
2271 this will cause the maximum size to be allocated if TYPE is of
2272 self-referential size. */
2275 build_allocator (tree type, tree init, tree result_type, Entity_Id gnat_proc,
2276 Entity_Id gnat_pool, Node_Id gnat_node, bool ignore_init_type)
2278 tree size, storage, storage_deref, storage_init;
2280 /* If the initializer, if present, is a NULL_EXPR, just return a new one. */
2281 if (init && TREE_CODE (init) == NULL_EXPR)
2282 return build1 (NULL_EXPR, result_type, TREE_OPERAND (init, 0));
2284 /* If the initializer, if present, is a COND_EXPR, deal with each branch. */
2285 else if (init && TREE_CODE (init) == COND_EXPR)
2286 return build3 (COND_EXPR, result_type, TREE_OPERAND (init, 0),
2287 build_allocator (type, TREE_OPERAND (init, 1), result_type,
2288 gnat_proc, gnat_pool, gnat_node,
2290 build_allocator (type, TREE_OPERAND (init, 2), result_type,
2291 gnat_proc, gnat_pool, gnat_node,
2294 /* If RESULT_TYPE is a fat or thin pointer, set SIZE to be the sum of the
2295 sizes of the object and its template. Allocate the whole thing and
2296 fill in the parts that are known. */
2297 else if (TYPE_IS_FAT_OR_THIN_POINTER_P (result_type))
2300 = build_unc_object_type_from_ptr (result_type, type,
2301 get_identifier ("ALLOC"), false);
2302 tree template_type = TREE_TYPE (TYPE_FIELDS (storage_type));
2303 tree storage_ptr_type = build_pointer_type (storage_type);
2305 size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TYPE_SIZE_UNIT (storage_type),
2308 /* If the size overflows, pass -1 so Storage_Error will be raised. */
2309 if (TREE_CODE (size) == INTEGER_CST && !valid_constant_size_p (size))
2310 size = size_int (-1);
2312 storage = build_call_alloc_dealloc (NULL_TREE, size, storage_type,
2313 gnat_proc, gnat_pool, gnat_node);
2314 storage = convert (storage_ptr_type, gnat_protect_expr (storage));
2315 storage_deref = build_unary_op (INDIRECT_REF, NULL_TREE, storage);
2316 TREE_THIS_NOTRAP (storage_deref) = 1;
2318 /* If there is an initializing expression, then make a constructor for
2319 the entire object including the bounds and copy it into the object.
2320 If there is no initializing expression, just set the bounds. */
2323 vec<constructor_elt, va_gc> *v;
2326 CONSTRUCTOR_APPEND_ELT (v, TYPE_FIELDS (storage_type),
2327 build_template (template_type, type, init));
2328 CONSTRUCTOR_APPEND_ELT (v, DECL_CHAIN (TYPE_FIELDS (storage_type)),
2331 = build_binary_op (INIT_EXPR, NULL_TREE, storage_deref,
2332 gnat_build_constructor (storage_type, v));
2336 = build_binary_op (INIT_EXPR, NULL_TREE,
2337 build_component_ref (storage_deref, NULL_TREE,
2338 TYPE_FIELDS (storage_type),
2340 build_template (template_type, type, NULL_TREE));
2342 return build2 (COMPOUND_EXPR, result_type,
2343 storage_init, convert (result_type, storage));
2346 size = TYPE_SIZE_UNIT (type);
2348 /* If we have an initializing expression, see if its size is simpler
2349 than the size from the type. */
2350 if (!ignore_init_type && init && TYPE_SIZE_UNIT (TREE_TYPE (init))
2351 && (TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (init))) == INTEGER_CST
2352 || CONTAINS_PLACEHOLDER_P (size)))
2353 size = TYPE_SIZE_UNIT (TREE_TYPE (init));
2355 /* If the size is still self-referential, reference the initializing
2356 expression, if it is present. If not, this must have been a
2357 call to allocate a library-level object, in which case we use
2358 the maximum size. */
2359 if (CONTAINS_PLACEHOLDER_P (size))
2361 if (!ignore_init_type && init)
2362 size = substitute_placeholder_in_expr (size, init);
2364 size = max_size (size, true);
2367 /* If the size overflows, pass -1 so Storage_Error will be raised. */
2368 if (TREE_CODE (size) == INTEGER_CST && !valid_constant_size_p (size))
2369 size = size_int (-1);
2371 storage = convert (result_type,
2372 build_call_alloc_dealloc (NULL_TREE, size, type,
2373 gnat_proc, gnat_pool,
2376 /* If we have an initial value, protect the new address, assign the value
2377 and return the address with a COMPOUND_EXPR. */
2380 storage = gnat_protect_expr (storage);
2381 storage_deref = build_unary_op (INDIRECT_REF, NULL_TREE, storage);
2382 TREE_THIS_NOTRAP (storage_deref) = 1;
2384 = build_binary_op (INIT_EXPR, NULL_TREE, storage_deref, init);
2385 return build2 (COMPOUND_EXPR, result_type, storage_init, storage);
2391 /* Indicate that we need to take the address of T and that it therefore
2392 should not be allocated in a register. Returns true if successful. */
2395 gnat_mark_addressable (tree t)
2398 switch (TREE_CODE (t))
2403 case ARRAY_RANGE_REF:
2406 case VIEW_CONVERT_EXPR:
2407 case NON_LVALUE_EXPR:
2409 t = TREE_OPERAND (t, 0);
2413 t = TREE_OPERAND (t, 1);
2417 TREE_ADDRESSABLE (t) = 1;
2423 TREE_ADDRESSABLE (t) = 1;
2427 TREE_ADDRESSABLE (t) = 1;
2431 return DECL_CONST_CORRESPONDING_VAR (t)
2432 && gnat_mark_addressable (DECL_CONST_CORRESPONDING_VAR (t));
2439 /* Save EXP for later use or reuse. This is equivalent to save_expr in tree.c
2440 but we know how to handle our own nodes. */
2443 gnat_save_expr (tree exp)
2445 tree type = TREE_TYPE (exp);
2446 enum tree_code code = TREE_CODE (exp);
2448 if (TREE_CONSTANT (exp) || code == SAVE_EXPR || code == NULL_EXPR)
2451 if (code == UNCONSTRAINED_ARRAY_REF)
2453 tree t = build1 (code, type, gnat_save_expr (TREE_OPERAND (exp, 0)));
2454 TREE_READONLY (t) = TYPE_READONLY (type);
2458 /* If this is a COMPONENT_REF of a fat pointer, save the entire fat pointer.
2459 This may be more efficient, but will also allow us to more easily find
2460 the match for the PLACEHOLDER_EXPR. */
2461 if (code == COMPONENT_REF
2462 && TYPE_IS_FAT_POINTER_P (TREE_TYPE (TREE_OPERAND (exp, 0))))
2463 return build3 (code, type, gnat_save_expr (TREE_OPERAND (exp, 0)),
2464 TREE_OPERAND (exp, 1), TREE_OPERAND (exp, 2));
2466 return save_expr (exp);
2469 /* Protect EXP for immediate reuse. This is a variant of gnat_save_expr that
2470 is optimized under the assumption that EXP's value doesn't change before
2471 its subsequent reuse(s) except through its potential reevaluation. */
2474 gnat_protect_expr (tree exp)
2476 tree type = TREE_TYPE (exp);
2477 enum tree_code code = TREE_CODE (exp);
2479 if (TREE_CONSTANT (exp) || code == SAVE_EXPR || code == NULL_EXPR)
2482 /* If EXP has no side effects, we theoretically don't need to do anything.
2483 However, we may be recursively passed more and more complex expressions
2484 involving checks which will be reused multiple times and eventually be
2485 unshared for gimplification; in order to avoid a complexity explosion
2486 at that point, we protect any expressions more complex than a simple
2487 arithmetic expression. */
2488 if (!TREE_SIDE_EFFECTS (exp))
2490 tree inner = skip_simple_arithmetic (exp);
2491 if (!EXPR_P (inner) || REFERENCE_CLASS_P (inner))
2495 /* If this is a conversion, protect what's inside the conversion. */
2496 if (code == NON_LVALUE_EXPR
2497 || CONVERT_EXPR_CODE_P (code)
2498 || code == VIEW_CONVERT_EXPR)
2499 return build1 (code, type, gnat_protect_expr (TREE_OPERAND (exp, 0)));
2501 /* If we're indirectly referencing something, we only need to protect the
2502 address since the data itself can't change in these situations. */
2503 if (code == INDIRECT_REF || code == UNCONSTRAINED_ARRAY_REF)
2505 tree t = build1 (code, type, gnat_protect_expr (TREE_OPERAND (exp, 0)));
2506 TREE_READONLY (t) = TYPE_READONLY (type);
2510 /* If this is a COMPONENT_REF of a fat pointer, save the entire fat pointer.
2511 This may be more efficient, but will also allow us to more easily find
2512 the match for the PLACEHOLDER_EXPR. */
2513 if (code == COMPONENT_REF
2514 && TYPE_IS_FAT_POINTER_P (TREE_TYPE (TREE_OPERAND (exp, 0))))
2515 return build3 (code, type, gnat_protect_expr (TREE_OPERAND (exp, 0)),
2516 TREE_OPERAND (exp, 1), TREE_OPERAND (exp, 2));
2518 /* If this is a fat pointer or something that can be placed in a register,
2519 just make a SAVE_EXPR. Likewise for a CALL_EXPR as large objects are
2520 returned via invisible reference in most ABIs so the temporary will
2521 directly be filled by the callee. */
2522 if (TYPE_IS_FAT_POINTER_P (type)
2523 || TYPE_MODE (type) != BLKmode
2524 || code == CALL_EXPR)
2525 return save_expr (exp);
2527 /* Otherwise reference, protect the address and dereference. */
2529 build_unary_op (INDIRECT_REF, type,
2530 save_expr (build_unary_op (ADDR_EXPR,
2531 build_reference_type (type),
2535 /* This is equivalent to stabilize_reference_1 in tree.c but we take an extra
2536 argument to force evaluation of everything. */
2539 gnat_stabilize_reference_1 (tree e, bool force)
2541 enum tree_code code = TREE_CODE (e);
2542 tree type = TREE_TYPE (e);
2545 /* We cannot ignore const expressions because it might be a reference
2546 to a const array but whose index contains side-effects. But we can
2547 ignore things that are actual constant or that already have been
2548 handled by this function. */
2549 if (TREE_CONSTANT (e) || code == SAVE_EXPR)
2552 switch (TREE_CODE_CLASS (code))
2554 case tcc_exceptional:
2555 case tcc_declaration:
2556 case tcc_comparison:
2557 case tcc_expression:
2560 /* If this is a COMPONENT_REF of a fat pointer, save the entire
2561 fat pointer. This may be more efficient, but will also allow
2562 us to more easily find the match for the PLACEHOLDER_EXPR. */
2563 if (code == COMPONENT_REF
2564 && TYPE_IS_FAT_POINTER_P (TREE_TYPE (TREE_OPERAND (e, 0))))
2566 = build3 (code, type,
2567 gnat_stabilize_reference_1 (TREE_OPERAND (e, 0), force),
2568 TREE_OPERAND (e, 1), TREE_OPERAND (e, 2));
2569 /* If the expression has side-effects, then encase it in a SAVE_EXPR
2570 so that it will only be evaluated once. */
2571 /* The tcc_reference and tcc_comparison classes could be handled as
2572 below, but it is generally faster to only evaluate them once. */
2573 else if (TREE_SIDE_EFFECTS (e) || force)
2574 return save_expr (e);
2580 /* Recursively stabilize each operand. */
2582 = build2 (code, type,
2583 gnat_stabilize_reference_1 (TREE_OPERAND (e, 0), force),
2584 gnat_stabilize_reference_1 (TREE_OPERAND (e, 1), force));
2588 /* Recursively stabilize each operand. */
2590 = build1 (code, type,
2591 gnat_stabilize_reference_1 (TREE_OPERAND (e, 0), force));
2598 /* See similar handling in gnat_stabilize_reference. */
2599 TREE_READONLY (result) = TREE_READONLY (e);
2600 TREE_SIDE_EFFECTS (result) |= TREE_SIDE_EFFECTS (e);
2601 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
2603 if (code == INDIRECT_REF
2604 || code == UNCONSTRAINED_ARRAY_REF
2605 || code == ARRAY_REF
2606 || code == ARRAY_RANGE_REF)
2607 TREE_THIS_NOTRAP (result) = TREE_THIS_NOTRAP (e);
2612 /* This is equivalent to stabilize_reference in tree.c but we know how to
2613 handle our own nodes and we take extra arguments. FORCE says whether to
2614 force evaluation of everything. We set SUCCESS to true unless we walk
2615 through something we don't know how to stabilize. */
2618 gnat_stabilize_reference (tree ref, bool force, bool *success)
2620 tree type = TREE_TYPE (ref);
2621 enum tree_code code = TREE_CODE (ref);
2624 /* Assume we'll success unless proven otherwise. */
2634 /* No action is needed in this case. */
2640 case FIX_TRUNC_EXPR:
2641 case VIEW_CONVERT_EXPR:
2643 = build1 (code, type,
2644 gnat_stabilize_reference (TREE_OPERAND (ref, 0), force,
2649 case UNCONSTRAINED_ARRAY_REF:
2650 result = build1 (code, type,
2651 gnat_stabilize_reference_1 (TREE_OPERAND (ref, 0),
2656 result = build3 (COMPONENT_REF, type,
2657 gnat_stabilize_reference (TREE_OPERAND (ref, 0), force,
2659 TREE_OPERAND (ref, 1), NULL_TREE);
2663 result = build3 (BIT_FIELD_REF, type,
2664 gnat_stabilize_reference (TREE_OPERAND (ref, 0), force,
2666 TREE_OPERAND (ref, 1), TREE_OPERAND (ref, 2));
2670 case ARRAY_RANGE_REF:
2671 result = build4 (code, type,
2672 gnat_stabilize_reference (TREE_OPERAND (ref, 0), force,
2674 gnat_stabilize_reference_1 (TREE_OPERAND (ref, 1),
2676 NULL_TREE, NULL_TREE);
2680 result = gnat_stabilize_reference_1 (ref, force);
2684 result = build2 (COMPOUND_EXPR, type,
2685 gnat_stabilize_reference (TREE_OPERAND (ref, 0), force,
2687 gnat_stabilize_reference (TREE_OPERAND (ref, 1), force,
2692 /* Constructors with 1 element are used extensively to formally
2693 convert objects to special wrapping types. */
2694 if (TREE_CODE (type) == RECORD_TYPE
2695 && vec_safe_length (CONSTRUCTOR_ELTS (ref)) == 1)
2697 tree index = (*CONSTRUCTOR_ELTS (ref))[0].index;
2698 tree value = (*CONSTRUCTOR_ELTS (ref))[0].value;
2700 = build_constructor_single (type, index,
2701 gnat_stabilize_reference_1 (value,
2713 ref = error_mark_node;
2715 /* ... fall through to failure ... */
2717 /* If arg isn't a kind of lvalue we recognize, make no change.
2718 Caller should recognize the error for an invalid lvalue. */
2725 /* TREE_THIS_VOLATILE and TREE_SIDE_EFFECTS set on the initial expression
2726 may not be sustained across some paths, such as the way via build1 for
2727 INDIRECT_REF. We reset those flags here in the general case, which is
2728 consistent with the GCC version of this routine.
2730 Special care should be taken regarding TREE_SIDE_EFFECTS, because some
2731 paths introduce side-effects where there was none initially (e.g. if a
2732 SAVE_EXPR is built) and we also want to keep track of that. */
2733 TREE_READONLY (result) = TREE_READONLY (ref);
2734 TREE_SIDE_EFFECTS (result) |= TREE_SIDE_EFFECTS (ref);
2735 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
2737 if (code == INDIRECT_REF
2738 || code == UNCONSTRAINED_ARRAY_REF
2739 || code == ARRAY_REF
2740 || code == ARRAY_RANGE_REF)
2741 TREE_THIS_NOTRAP (result) = TREE_THIS_NOTRAP (ref);
2746 /* If EXPR is an expression that is invariant in the current function, in the
2747 sense that it can be evaluated anywhere in the function and any number of
2748 times, return EXPR or an equivalent expression. Otherwise return NULL. */
2751 gnat_invariant_expr (tree expr)
2753 tree type = TREE_TYPE (expr), t;
2755 expr = remove_conversions (expr, false);
2757 while ((TREE_CODE (expr) == CONST_DECL
2758 || (TREE_CODE (expr) == VAR_DECL && TREE_READONLY (expr)))
2759 && decl_function_context (expr) == current_function_decl
2760 && DECL_INITIAL (expr))
2761 expr = remove_conversions (DECL_INITIAL (expr), false);
2763 if (TREE_CONSTANT (expr))
2764 return fold_convert (type, expr);
2770 switch (TREE_CODE (t))
2773 if (TREE_OPERAND (t, 2) != NULL_TREE)
2778 case ARRAY_RANGE_REF:
2779 if (!TREE_CONSTANT (TREE_OPERAND (t, 1))
2780 || TREE_OPERAND (t, 2) != NULL_TREE
2781 || TREE_OPERAND (t, 3) != NULL_TREE)
2786 case VIEW_CONVERT_EXPR:
2792 if (!TREE_READONLY (t)
2793 || TREE_SIDE_EFFECTS (t)
2794 || !TREE_THIS_NOTRAP (t))
2802 t = TREE_OPERAND (t, 0);
2806 if (TREE_SIDE_EFFECTS (t))
2809 if (TREE_CODE (t) == CONST_DECL
2810 && (DECL_EXTERNAL (t)
2811 || decl_function_context (t) != current_function_decl))
2812 return fold_convert (type, expr);
2814 if (!TREE_READONLY (t))
2817 if (TREE_CODE (t) == PARM_DECL)
2818 return fold_convert (type, expr);
2820 if (TREE_CODE (t) == VAR_DECL
2821 && (DECL_EXTERNAL (t)
2822 || decl_function_context (t) != current_function_decl))
2823 return fold_convert (type, expr);