1 /****************************************************************************
3 * GNAT COMPILER COMPONENTS *
7 * C Implementation File *
9 * Copyright (C) 1992-2011, 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"
34 #include "tree-inline.h"
51 /* Return the base type of TYPE. */
54 get_base_type (tree type)
56 if (TREE_CODE (type) == RECORD_TYPE
57 && TYPE_JUSTIFIED_MODULAR_P (type))
58 type = TREE_TYPE (TYPE_FIELDS (type));
60 while (TREE_TYPE (type)
61 && (TREE_CODE (type) == INTEGER_TYPE
62 || TREE_CODE (type) == REAL_TYPE))
63 type = TREE_TYPE (type);
68 /* EXP is a GCC tree representing an address. See if we can find how
69 strictly the object at that address is aligned. Return that alignment
70 in bits. If we don't know anything about the alignment, return 0. */
73 known_alignment (tree exp)
75 unsigned int this_alignment;
76 unsigned int lhs, rhs;
78 switch (TREE_CODE (exp))
81 case VIEW_CONVERT_EXPR:
83 /* Conversions between pointers and integers don't change the alignment
84 of the underlying object. */
85 this_alignment = known_alignment (TREE_OPERAND (exp, 0));
89 /* The value of a COMPOUND_EXPR is that of it's second operand. */
90 this_alignment = known_alignment (TREE_OPERAND (exp, 1));
95 /* If two address are added, the alignment of the result is the
96 minimum of the two alignments. */
97 lhs = known_alignment (TREE_OPERAND (exp, 0));
98 rhs = known_alignment (TREE_OPERAND (exp, 1));
99 this_alignment = MIN (lhs, rhs);
102 case POINTER_PLUS_EXPR:
103 lhs = known_alignment (TREE_OPERAND (exp, 0));
104 rhs = known_alignment (TREE_OPERAND (exp, 1));
105 /* If we don't know the alignment of the offset, we assume that
108 this_alignment = lhs;
110 this_alignment = MIN (lhs, rhs);
114 /* If there is a choice between two values, use the smallest one. */
115 lhs = known_alignment (TREE_OPERAND (exp, 1));
116 rhs = known_alignment (TREE_OPERAND (exp, 2));
117 this_alignment = MIN (lhs, rhs);
122 unsigned HOST_WIDE_INT c = TREE_INT_CST_LOW (exp);
123 /* The first part of this represents the lowest bit in the constant,
124 but it is originally in bytes, not bits. */
125 this_alignment = MIN (BITS_PER_UNIT * (c & -c), BIGGEST_ALIGNMENT);
130 /* If we know the alignment of just one side, use it. Otherwise,
131 use the product of the alignments. */
132 lhs = known_alignment (TREE_OPERAND (exp, 0));
133 rhs = known_alignment (TREE_OPERAND (exp, 1));
136 this_alignment = rhs;
138 this_alignment = lhs;
140 this_alignment = MIN (lhs * rhs, BIGGEST_ALIGNMENT);
144 /* A bit-and expression is as aligned as the maximum alignment of the
145 operands. We typically get here for a complex lhs and a constant
146 negative power of two on the rhs to force an explicit alignment, so
147 don't bother looking at the lhs. */
148 this_alignment = known_alignment (TREE_OPERAND (exp, 1));
152 this_alignment = expr_align (TREE_OPERAND (exp, 0));
157 tree t = maybe_inline_call_in_expr (exp);
159 return known_alignment (t);
162 /* Fall through... */
165 /* For other pointer expressions, we assume that the pointed-to object
166 is at least as aligned as the pointed-to type. Beware that we can
167 have a dummy type here (e.g. a Taft Amendment type), for which the
168 alignment is meaningless and should be ignored. */
169 if (POINTER_TYPE_P (TREE_TYPE (exp))
170 && !TYPE_IS_DUMMY_P (TREE_TYPE (TREE_TYPE (exp))))
171 this_alignment = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp)));
177 return this_alignment;
180 /* We have a comparison or assignment operation on two types, T1 and T2, which
181 are either both array types or both record types. T1 is assumed to be for
182 the left hand side operand, and T2 for the right hand side. Return the
183 type that both operands should be converted to for the operation, if any.
184 Otherwise return zero. */
187 find_common_type (tree t1, tree t2)
189 /* ??? As of today, various constructs lead to here with types of different
190 sizes even when both constants (e.g. tagged types, packable vs regular
191 component types, padded vs unpadded types, ...). While some of these
192 would better be handled upstream (types should be made consistent before
193 calling into build_binary_op), some others are really expected and we
194 have to be careful. */
196 /* We must avoid writing more than what the target can hold if this is for
197 an assignment and the case of tagged types is handled in build_binary_op
198 so we use the lhs type if it is known to be smaller or of constant size
199 and the rhs type is not, whatever the modes. We also force t1 in case of
200 constant size equality to minimize occurrences of view conversions on the
201 lhs of an assignment, except for the case of record types with a variant
202 part on the lhs but not on the rhs to make the conversion simpler. */
203 if (TREE_CONSTANT (TYPE_SIZE (t1))
204 && (!TREE_CONSTANT (TYPE_SIZE (t2))
205 || tree_int_cst_lt (TYPE_SIZE (t1), TYPE_SIZE (t2))
206 || (TYPE_SIZE (t1) == TYPE_SIZE (t2)
207 && !(TREE_CODE (t1) == RECORD_TYPE
208 && TREE_CODE (t2) == RECORD_TYPE
209 && get_variant_part (t1) != NULL_TREE
210 && get_variant_part (t2) == NULL_TREE))))
213 /* Otherwise, if the lhs type is non-BLKmode, use it. Note that we know
214 that we will not have any alignment problems since, if we did, the
215 non-BLKmode type could not have been used. */
216 if (TYPE_MODE (t1) != BLKmode)
219 /* If the rhs type is of constant size, use it whatever the modes. At
220 this point it is known to be smaller, or of constant size and the
222 if (TREE_CONSTANT (TYPE_SIZE (t2)))
225 /* Otherwise, if the rhs type is non-BLKmode, use it. */
226 if (TYPE_MODE (t2) != BLKmode)
229 /* In this case, both types have variable size and BLKmode. It's
230 probably best to leave the "type mismatch" because changing it
231 could cause a bad self-referential reference. */
235 /* Return an expression tree representing an equality comparison of A1 and A2,
236 two objects of type ARRAY_TYPE. The result should be of type RESULT_TYPE.
238 Two arrays are equal in one of two ways: (1) if both have zero length in
239 some dimension (not necessarily the same dimension) or (2) if the lengths
240 in each dimension are equal and the data is equal. We perform the length
241 tests in as efficient a manner as possible. */
244 compare_arrays (location_t loc, tree result_type, tree a1, tree a2)
246 tree result = convert (result_type, boolean_true_node);
247 tree a1_is_null = convert (result_type, boolean_false_node);
248 tree a2_is_null = convert (result_type, boolean_false_node);
249 tree t1 = TREE_TYPE (a1);
250 tree t2 = TREE_TYPE (a2);
251 bool a1_side_effects_p = TREE_SIDE_EFFECTS (a1);
252 bool a2_side_effects_p = TREE_SIDE_EFFECTS (a2);
253 bool length_zero_p = false;
255 /* If either operand has side-effects, they have to be evaluated only once
256 in spite of the multiple references to the operand in the comparison. */
257 if (a1_side_effects_p)
258 a1 = gnat_protect_expr (a1);
260 if (a2_side_effects_p)
261 a2 = gnat_protect_expr (a2);
263 /* Process each dimension separately and compare the lengths. If any
264 dimension has a length known to be zero, set LENGTH_ZERO_P to true
265 in order to suppress the comparison of the data at the end. */
266 while (TREE_CODE (t1) == ARRAY_TYPE && TREE_CODE (t2) == ARRAY_TYPE)
268 tree lb1 = TYPE_MIN_VALUE (TYPE_DOMAIN (t1));
269 tree ub1 = TYPE_MAX_VALUE (TYPE_DOMAIN (t1));
270 tree lb2 = TYPE_MIN_VALUE (TYPE_DOMAIN (t2));
271 tree ub2 = TYPE_MAX_VALUE (TYPE_DOMAIN (t2));
272 tree length1 = size_binop (PLUS_EXPR, size_binop (MINUS_EXPR, ub1, lb1),
274 tree length2 = size_binop (PLUS_EXPR, size_binop (MINUS_EXPR, ub2, lb2),
276 tree comparison, this_a1_is_null, this_a2_is_null;
278 /* If the length of the first array is a constant, swap our operands
279 unless the length of the second array is the constant zero. */
280 if (TREE_CODE (length1) == INTEGER_CST && !integer_zerop (length2))
285 tem = a1, a1 = a2, a2 = tem;
286 tem = t1, t1 = t2, t2 = tem;
287 tem = lb1, lb1 = lb2, lb2 = tem;
288 tem = ub1, ub1 = ub2, ub2 = tem;
289 tem = length1, length1 = length2, length2 = tem;
290 tem = a1_is_null, a1_is_null = a2_is_null, a2_is_null = tem;
291 btem = a1_side_effects_p, a1_side_effects_p = a2_side_effects_p,
292 a2_side_effects_p = btem;
295 /* If the length of the second array is the constant zero, we can just
296 use the original stored bounds for the first array and see whether
297 last < first holds. */
298 if (integer_zerop (length2))
300 length_zero_p = true;
302 ub1 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
303 lb1 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
305 comparison = fold_build2_loc (loc, LT_EXPR, result_type, ub1, lb1);
306 comparison = SUBSTITUTE_PLACEHOLDER_IN_EXPR (comparison, a1);
307 if (EXPR_P (comparison))
308 SET_EXPR_LOCATION (comparison, loc);
310 this_a1_is_null = comparison;
311 this_a2_is_null = convert (result_type, boolean_true_node);
314 /* Otherwise, if the length is some other constant value, we know that
315 this dimension in the second array cannot be superflat, so we can
316 just use its length computed from the actual stored bounds. */
317 else if (TREE_CODE (length2) == INTEGER_CST)
321 ub1 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
322 lb1 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
323 /* Note that we know that UB2 and LB2 are constant and hence
324 cannot contain a PLACEHOLDER_EXPR. */
325 ub2 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t2)));
326 lb2 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t2)));
327 bt = get_base_type (TREE_TYPE (ub1));
330 = fold_build2_loc (loc, EQ_EXPR, result_type,
331 build_binary_op (MINUS_EXPR, bt, ub1, lb1),
332 build_binary_op (MINUS_EXPR, bt, ub2, lb2));
333 comparison = SUBSTITUTE_PLACEHOLDER_IN_EXPR (comparison, a1);
334 if (EXPR_P (comparison))
335 SET_EXPR_LOCATION (comparison, loc);
338 = fold_build2_loc (loc, LT_EXPR, result_type, ub1, lb1);
340 this_a2_is_null = convert (result_type, boolean_false_node);
343 /* Otherwise, compare the computed lengths. */
346 length1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length1, a1);
347 length2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length2, a2);
350 = fold_build2_loc (loc, EQ_EXPR, result_type, length1, length2);
352 /* If the length expression is of the form (cond ? val : 0), assume
353 that cond is equivalent to (length != 0). That's guaranteed by
354 construction of the array types in gnat_to_gnu_entity. */
355 if (TREE_CODE (length1) == COND_EXPR
356 && integer_zerop (TREE_OPERAND (length1, 2)))
358 = invert_truthvalue_loc (loc, TREE_OPERAND (length1, 0));
360 this_a1_is_null = fold_build2_loc (loc, EQ_EXPR, result_type,
361 length1, size_zero_node);
363 /* Likewise for the second array. */
364 if (TREE_CODE (length2) == COND_EXPR
365 && integer_zerop (TREE_OPERAND (length2, 2)))
367 = invert_truthvalue_loc (loc, TREE_OPERAND (length2, 0));
369 this_a2_is_null = fold_build2_loc (loc, EQ_EXPR, result_type,
370 length2, size_zero_node);
373 /* Append expressions for this dimension to the final expressions. */
374 result = build_binary_op (TRUTH_ANDIF_EXPR, result_type,
377 a1_is_null = build_binary_op (TRUTH_ORIF_EXPR, result_type,
378 this_a1_is_null, a1_is_null);
380 a2_is_null = build_binary_op (TRUTH_ORIF_EXPR, result_type,
381 this_a2_is_null, a2_is_null);
387 /* Unless the length of some dimension is known to be zero, compare the
388 data in the array. */
391 tree type = find_common_type (TREE_TYPE (a1), TREE_TYPE (a2));
396 a1 = convert (type, a1),
397 a2 = convert (type, a2);
400 comparison = fold_build2_loc (loc, EQ_EXPR, result_type, a1, a2);
403 = build_binary_op (TRUTH_ANDIF_EXPR, result_type, result, comparison);
406 /* The result is also true if both sizes are zero. */
407 result = build_binary_op (TRUTH_ORIF_EXPR, result_type,
408 build_binary_op (TRUTH_ANDIF_EXPR, result_type,
409 a1_is_null, a2_is_null),
412 /* If either operand has side-effects, they have to be evaluated before
413 starting the comparison above since the place they would be otherwise
414 evaluated could be wrong. */
415 if (a1_side_effects_p)
416 result = build2 (COMPOUND_EXPR, result_type, a1, result);
418 if (a2_side_effects_p)
419 result = build2 (COMPOUND_EXPR, result_type, a2, result);
424 /* Compute the result of applying OP_CODE to LHS and RHS, where both are of
425 type TYPE. We know that TYPE is a modular type with a nonbinary
429 nonbinary_modular_operation (enum tree_code op_code, tree type, tree lhs,
432 tree modulus = TYPE_MODULUS (type);
433 unsigned int needed_precision = tree_floor_log2 (modulus) + 1;
434 unsigned int precision;
435 bool unsignedp = true;
439 /* If this is an addition of a constant, convert it to a subtraction
440 of a constant since we can do that faster. */
441 if (op_code == PLUS_EXPR && TREE_CODE (rhs) == INTEGER_CST)
443 rhs = fold_build2 (MINUS_EXPR, type, modulus, rhs);
444 op_code = MINUS_EXPR;
447 /* For the logical operations, we only need PRECISION bits. For
448 addition and subtraction, we need one more and for multiplication we
449 need twice as many. But we never want to make a size smaller than
451 if (op_code == PLUS_EXPR || op_code == MINUS_EXPR)
452 needed_precision += 1;
453 else if (op_code == MULT_EXPR)
454 needed_precision *= 2;
456 precision = MAX (needed_precision, TYPE_PRECISION (op_type));
458 /* Unsigned will do for everything but subtraction. */
459 if (op_code == MINUS_EXPR)
462 /* If our type is the wrong signedness or isn't wide enough, make a new
463 type and convert both our operands to it. */
464 if (TYPE_PRECISION (op_type) < precision
465 || TYPE_UNSIGNED (op_type) != unsignedp)
467 /* Copy the node so we ensure it can be modified to make it modular. */
468 op_type = copy_node (gnat_type_for_size (precision, unsignedp));
469 modulus = convert (op_type, modulus);
470 SET_TYPE_MODULUS (op_type, modulus);
471 TYPE_MODULAR_P (op_type) = 1;
472 lhs = convert (op_type, lhs);
473 rhs = convert (op_type, rhs);
476 /* Do the operation, then we'll fix it up. */
477 result = fold_build2 (op_code, op_type, lhs, rhs);
479 /* For multiplication, we have no choice but to do a full modulus
480 operation. However, we want to do this in the narrowest
482 if (op_code == MULT_EXPR)
484 tree div_type = copy_node (gnat_type_for_size (needed_precision, 1));
485 modulus = convert (div_type, modulus);
486 SET_TYPE_MODULUS (div_type, modulus);
487 TYPE_MODULAR_P (div_type) = 1;
488 result = convert (op_type,
489 fold_build2 (TRUNC_MOD_EXPR, div_type,
490 convert (div_type, result), modulus));
493 /* For subtraction, add the modulus back if we are negative. */
494 else if (op_code == MINUS_EXPR)
496 result = gnat_protect_expr (result);
497 result = fold_build3 (COND_EXPR, op_type,
498 fold_build2 (LT_EXPR, boolean_type_node, result,
499 convert (op_type, integer_zero_node)),
500 fold_build2 (PLUS_EXPR, op_type, result, modulus),
504 /* For the other operations, subtract the modulus if we are >= it. */
507 result = gnat_protect_expr (result);
508 result = fold_build3 (COND_EXPR, op_type,
509 fold_build2 (GE_EXPR, boolean_type_node,
511 fold_build2 (MINUS_EXPR, op_type,
516 return convert (type, result);
519 /* Make a binary operation of kind OP_CODE. RESULT_TYPE is the type
520 desired for the result. Usually the operation is to be performed
521 in that type. For MODIFY_EXPR and ARRAY_REF, RESULT_TYPE may be 0
522 in which case the type to be used will be derived from the operands.
524 This function is very much unlike the ones for C and C++ since we
525 have already done any type conversion and matching required. All we
526 have to do here is validate the work done by SEM and handle subtypes. */
529 build_binary_op (enum tree_code op_code, tree result_type,
530 tree left_operand, tree right_operand)
532 tree left_type = TREE_TYPE (left_operand);
533 tree right_type = TREE_TYPE (right_operand);
534 tree left_base_type = get_base_type (left_type);
535 tree right_base_type = get_base_type (right_type);
536 tree operation_type = result_type;
537 tree best_type = NULL_TREE;
538 tree modulus, result;
539 bool has_side_effects = false;
542 && TREE_CODE (operation_type) == RECORD_TYPE
543 && TYPE_JUSTIFIED_MODULAR_P (operation_type))
544 operation_type = TREE_TYPE (TYPE_FIELDS (operation_type));
547 && !AGGREGATE_TYPE_P (operation_type)
548 && TYPE_EXTRA_SUBTYPE_P (operation_type))
549 operation_type = get_base_type (operation_type);
551 modulus = (operation_type
552 && TREE_CODE (operation_type) == INTEGER_TYPE
553 && TYPE_MODULAR_P (operation_type)
554 ? TYPE_MODULUS (operation_type) : NULL_TREE);
560 /* If there were integral or pointer conversions on the LHS, remove
561 them; we'll be putting them back below if needed. Likewise for
562 conversions between array and record types, except for justified
563 modular types. But don't do this if the right operand is not
564 BLKmode (for packed arrays) unless we are not changing the mode. */
565 while ((CONVERT_EXPR_P (left_operand)
566 || TREE_CODE (left_operand) == VIEW_CONVERT_EXPR)
567 && (((INTEGRAL_TYPE_P (left_type)
568 || POINTER_TYPE_P (left_type))
569 && (INTEGRAL_TYPE_P (TREE_TYPE
570 (TREE_OPERAND (left_operand, 0)))
571 || POINTER_TYPE_P (TREE_TYPE
572 (TREE_OPERAND (left_operand, 0)))))
573 || (((TREE_CODE (left_type) == RECORD_TYPE
574 && !TYPE_JUSTIFIED_MODULAR_P (left_type))
575 || TREE_CODE (left_type) == ARRAY_TYPE)
576 && ((TREE_CODE (TREE_TYPE
577 (TREE_OPERAND (left_operand, 0)))
579 || (TREE_CODE (TREE_TYPE
580 (TREE_OPERAND (left_operand, 0)))
582 && (TYPE_MODE (right_type) == BLKmode
583 || (TYPE_MODE (left_type)
584 == TYPE_MODE (TREE_TYPE
586 (left_operand, 0))))))))
588 left_operand = TREE_OPERAND (left_operand, 0);
589 left_type = TREE_TYPE (left_operand);
592 /* If a class-wide type may be involved, force use of the RHS type. */
593 if ((TREE_CODE (right_type) == RECORD_TYPE
594 || TREE_CODE (right_type) == UNION_TYPE)
595 && TYPE_ALIGN_OK (right_type))
596 operation_type = right_type;
598 /* If we are copying between padded objects with compatible types, use
599 the padded view of the objects, this is very likely more efficient.
600 Likewise for a padded object that is assigned a constructor, if we
601 can convert the constructor to the inner type, to avoid putting a
602 VIEW_CONVERT_EXPR on the LHS. But don't do so if we wouldn't have
603 actually copied anything. */
604 else if (TYPE_IS_PADDING_P (left_type)
605 && TREE_CONSTANT (TYPE_SIZE (left_type))
606 && ((TREE_CODE (right_operand) == COMPONENT_REF
608 (TREE_TYPE (TREE_OPERAND (right_operand, 0)))
609 && gnat_types_compatible_p
611 TREE_TYPE (TREE_OPERAND (right_operand, 0))))
612 || (TREE_CODE (right_operand) == CONSTRUCTOR
613 && !CONTAINS_PLACEHOLDER_P
614 (DECL_SIZE (TYPE_FIELDS (left_type)))))
615 && !integer_zerop (TYPE_SIZE (right_type)))
616 operation_type = left_type;
618 /* If we have a call to a function that returns an unconstrained type
619 with default discriminant on the RHS, use the RHS type (which is
620 padded) as we cannot compute the size of the actual assignment. */
621 else if (TREE_CODE (right_operand) == CALL_EXPR
622 && TYPE_IS_PADDING_P (right_type)
623 && CONTAINS_PLACEHOLDER_P
624 (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS (right_type)))))
625 operation_type = right_type;
627 /* Find the best type to use for copying between aggregate types. */
628 else if (((TREE_CODE (left_type) == ARRAY_TYPE
629 && TREE_CODE (right_type) == ARRAY_TYPE)
630 || (TREE_CODE (left_type) == RECORD_TYPE
631 && TREE_CODE (right_type) == RECORD_TYPE))
632 && (best_type = find_common_type (left_type, right_type)))
633 operation_type = best_type;
635 /* Otherwise use the LHS type. */
636 else if (!operation_type)
637 operation_type = left_type;
639 /* Ensure everything on the LHS is valid. If we have a field reference,
640 strip anything that get_inner_reference can handle. Then remove any
641 conversions between types having the same code and mode. And mark
642 VIEW_CONVERT_EXPRs with TREE_ADDRESSABLE. When done, we must have
643 either an INDIRECT_REF, a NULL_EXPR or a DECL node. */
644 result = left_operand;
647 tree restype = TREE_TYPE (result);
649 if (TREE_CODE (result) == COMPONENT_REF
650 || TREE_CODE (result) == ARRAY_REF
651 || TREE_CODE (result) == ARRAY_RANGE_REF)
652 while (handled_component_p (result))
653 result = TREE_OPERAND (result, 0);
654 else if (TREE_CODE (result) == REALPART_EXPR
655 || TREE_CODE (result) == IMAGPART_EXPR
656 || (CONVERT_EXPR_P (result)
657 && (((TREE_CODE (restype)
658 == TREE_CODE (TREE_TYPE
659 (TREE_OPERAND (result, 0))))
660 && (TYPE_MODE (TREE_TYPE
661 (TREE_OPERAND (result, 0)))
662 == TYPE_MODE (restype)))
663 || TYPE_ALIGN_OK (restype))))
664 result = TREE_OPERAND (result, 0);
665 else if (TREE_CODE (result) == VIEW_CONVERT_EXPR)
667 TREE_ADDRESSABLE (result) = 1;
668 result = TREE_OPERAND (result, 0);
674 gcc_assert (TREE_CODE (result) == INDIRECT_REF
675 || TREE_CODE (result) == NULL_EXPR
678 /* Convert the right operand to the operation type unless it is
679 either already of the correct type or if the type involves a
680 placeholder, since the RHS may not have the same record type. */
681 if (operation_type != right_type
682 && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (operation_type)))
684 right_operand = convert (operation_type, right_operand);
685 right_type = operation_type;
688 /* If the left operand is not of the same type as the operation
689 type, wrap it up in a VIEW_CONVERT_EXPR. */
690 if (left_type != operation_type)
691 left_operand = unchecked_convert (operation_type, left_operand, false);
693 has_side_effects = true;
699 operation_type = TREE_TYPE (left_type);
701 /* ... fall through ... */
703 case ARRAY_RANGE_REF:
704 /* First look through conversion between type variants. Note that
705 this changes neither the operation type nor the type domain. */
706 if (TREE_CODE (left_operand) == VIEW_CONVERT_EXPR
707 && TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (left_operand, 0)))
708 == TYPE_MAIN_VARIANT (left_type))
710 left_operand = TREE_OPERAND (left_operand, 0);
711 left_type = TREE_TYPE (left_operand);
714 /* For a range, make sure the element type is consistent. */
715 if (op_code == ARRAY_RANGE_REF
716 && TREE_TYPE (operation_type) != TREE_TYPE (left_type))
717 operation_type = build_array_type (TREE_TYPE (left_type),
718 TYPE_DOMAIN (operation_type));
720 /* Then convert the right operand to its base type. This will prevent
721 unneeded sign conversions when sizetype is wider than integer. */
722 right_operand = convert (right_base_type, right_operand);
723 right_operand = convert (sizetype, right_operand);
725 if (!TREE_CONSTANT (right_operand)
726 || !TREE_CONSTANT (TYPE_MIN_VALUE (right_type)))
727 gnat_mark_addressable (left_operand);
732 case TRUTH_ANDIF_EXPR:
733 case TRUTH_ORIF_EXPR:
737 #ifdef ENABLE_CHECKING
738 gcc_assert (TREE_CODE (get_base_type (result_type)) == BOOLEAN_TYPE);
740 operation_type = left_base_type;
741 left_operand = convert (operation_type, left_operand);
742 right_operand = convert (operation_type, right_operand);
751 #ifdef ENABLE_CHECKING
752 gcc_assert (TREE_CODE (get_base_type (result_type)) == BOOLEAN_TYPE);
754 /* If either operand is a NULL_EXPR, just return a new one. */
755 if (TREE_CODE (left_operand) == NULL_EXPR)
756 return build2 (op_code, result_type,
757 build1 (NULL_EXPR, integer_type_node,
758 TREE_OPERAND (left_operand, 0)),
761 else if (TREE_CODE (right_operand) == NULL_EXPR)
762 return build2 (op_code, result_type,
763 build1 (NULL_EXPR, integer_type_node,
764 TREE_OPERAND (right_operand, 0)),
767 /* If either object is a justified modular types, get the
768 fields from within. */
769 if (TREE_CODE (left_type) == RECORD_TYPE
770 && TYPE_JUSTIFIED_MODULAR_P (left_type))
772 left_operand = convert (TREE_TYPE (TYPE_FIELDS (left_type)),
774 left_type = TREE_TYPE (left_operand);
775 left_base_type = get_base_type (left_type);
778 if (TREE_CODE (right_type) == RECORD_TYPE
779 && TYPE_JUSTIFIED_MODULAR_P (right_type))
781 right_operand = convert (TREE_TYPE (TYPE_FIELDS (right_type)),
783 right_type = TREE_TYPE (right_operand);
784 right_base_type = get_base_type (right_type);
787 /* If both objects are arrays, compare them specially. */
788 if ((TREE_CODE (left_type) == ARRAY_TYPE
789 || (TREE_CODE (left_type) == INTEGER_TYPE
790 && TYPE_HAS_ACTUAL_BOUNDS_P (left_type)))
791 && (TREE_CODE (right_type) == ARRAY_TYPE
792 || (TREE_CODE (right_type) == INTEGER_TYPE
793 && TYPE_HAS_ACTUAL_BOUNDS_P (right_type))))
795 result = compare_arrays (input_location,
796 result_type, left_operand, right_operand);
797 if (op_code == NE_EXPR)
798 result = invert_truthvalue_loc (EXPR_LOCATION (result), result);
800 gcc_assert (op_code == EQ_EXPR);
805 /* Otherwise, the base types must be the same, unless they are both fat
806 pointer types or record types. In the latter case, use the best type
807 and convert both operands to that type. */
808 if (left_base_type != right_base_type)
810 if (TYPE_IS_FAT_POINTER_P (left_base_type)
811 && TYPE_IS_FAT_POINTER_P (right_base_type))
813 gcc_assert (TYPE_MAIN_VARIANT (left_base_type)
814 == TYPE_MAIN_VARIANT (right_base_type));
815 best_type = left_base_type;
818 else if (TREE_CODE (left_base_type) == RECORD_TYPE
819 && TREE_CODE (right_base_type) == RECORD_TYPE)
821 /* The only way this is permitted is if both types have the same
822 name. In that case, one of them must not be self-referential.
823 Use it as the best type. Even better with a fixed size. */
824 gcc_assert (TYPE_NAME (left_base_type)
825 && TYPE_NAME (left_base_type)
826 == TYPE_NAME (right_base_type));
828 if (TREE_CONSTANT (TYPE_SIZE (left_base_type)))
829 best_type = left_base_type;
830 else if (TREE_CONSTANT (TYPE_SIZE (right_base_type)))
831 best_type = right_base_type;
832 else if (!CONTAINS_PLACEHOLDER_P (TYPE_SIZE (left_base_type)))
833 best_type = left_base_type;
834 else if (!CONTAINS_PLACEHOLDER_P (TYPE_SIZE (right_base_type)))
835 best_type = right_base_type;
843 left_operand = convert (best_type, left_operand);
844 right_operand = convert (best_type, right_operand);
848 left_operand = convert (left_base_type, left_operand);
849 right_operand = convert (right_base_type, right_operand);
852 /* If we are comparing a fat pointer against zero, we just need to
853 compare the data pointer. */
854 if (TYPE_IS_FAT_POINTER_P (left_base_type)
855 && TREE_CODE (right_operand) == CONSTRUCTOR
856 && integer_zerop (VEC_index (constructor_elt,
857 CONSTRUCTOR_ELTS (right_operand),
861 = build_component_ref (left_operand, NULL_TREE,
862 TYPE_FIELDS (left_base_type), false);
864 = convert (TREE_TYPE (left_operand), integer_zero_node);
874 /* The RHS of a shift can be any type. Also, ignore any modulus
875 (we used to abort, but this is needed for unchecked conversion
876 to modular types). Otherwise, processing is the same as normal. */
877 gcc_assert (operation_type == left_base_type);
879 left_operand = convert (operation_type, left_operand);
885 /* For binary modulus, if the inputs are in range, so are the
887 if (modulus && integer_pow2p (modulus))
892 gcc_assert (TREE_TYPE (result_type) == left_base_type
893 && TREE_TYPE (result_type) == right_base_type);
894 left_operand = convert (left_base_type, left_operand);
895 right_operand = convert (right_base_type, right_operand);
898 case TRUNC_DIV_EXPR: case TRUNC_MOD_EXPR:
899 case CEIL_DIV_EXPR: case CEIL_MOD_EXPR:
900 case FLOOR_DIV_EXPR: case FLOOR_MOD_EXPR:
901 case ROUND_DIV_EXPR: case ROUND_MOD_EXPR:
902 /* These always produce results lower than either operand. */
906 case POINTER_PLUS_EXPR:
907 gcc_assert (operation_type == left_base_type
908 && sizetype == right_base_type);
909 left_operand = convert (operation_type, left_operand);
910 right_operand = convert (sizetype, right_operand);
913 case PLUS_NOMOD_EXPR:
914 case MINUS_NOMOD_EXPR:
915 if (op_code == PLUS_NOMOD_EXPR)
918 op_code = MINUS_EXPR;
921 /* ... fall through ... */
925 /* Avoid doing arithmetics in ENUMERAL_TYPE or BOOLEAN_TYPE like the
926 other compilers. Contrary to C, Ada doesn't allow arithmetics in
927 these types but can generate addition/subtraction for Succ/Pred. */
929 && (TREE_CODE (operation_type) == ENUMERAL_TYPE
930 || TREE_CODE (operation_type) == BOOLEAN_TYPE))
931 operation_type = left_base_type = right_base_type
932 = gnat_type_for_mode (TYPE_MODE (operation_type),
933 TYPE_UNSIGNED (operation_type));
935 /* ... fall through ... */
939 /* The result type should be the same as the base types of the
940 both operands (and they should be the same). Convert
941 everything to the result type. */
943 gcc_assert (operation_type == left_base_type
944 && left_base_type == right_base_type);
945 left_operand = convert (operation_type, left_operand);
946 right_operand = convert (operation_type, right_operand);
949 if (modulus && !integer_pow2p (modulus))
951 result = nonbinary_modular_operation (op_code, operation_type,
952 left_operand, right_operand);
955 /* If either operand is a NULL_EXPR, just return a new one. */
956 else if (TREE_CODE (left_operand) == NULL_EXPR)
957 return build1 (NULL_EXPR, operation_type, TREE_OPERAND (left_operand, 0));
958 else if (TREE_CODE (right_operand) == NULL_EXPR)
959 return build1 (NULL_EXPR, operation_type, TREE_OPERAND (right_operand, 0));
960 else if (op_code == ARRAY_REF || op_code == ARRAY_RANGE_REF)
961 result = fold (build4 (op_code, operation_type, left_operand,
962 right_operand, NULL_TREE, NULL_TREE));
965 = fold_build2 (op_code, operation_type, left_operand, right_operand);
967 if (TREE_CONSTANT (result))
969 else if (op_code == ARRAY_REF || op_code == ARRAY_RANGE_REF)
971 TREE_THIS_NOTRAP (result) = 1;
972 if (TYPE_VOLATILE (operation_type))
973 TREE_THIS_VOLATILE (result) = 1;
976 TREE_CONSTANT (result)
977 |= (TREE_CONSTANT (left_operand) && TREE_CONSTANT (right_operand));
979 TREE_SIDE_EFFECTS (result) |= has_side_effects;
981 /* If we are working with modular types, perform the MOD operation
982 if something above hasn't eliminated the need for it. */
984 result = fold_build2 (FLOOR_MOD_EXPR, operation_type, result,
985 convert (operation_type, modulus));
987 if (result_type && result_type != operation_type)
988 result = convert (result_type, result);
993 /* Similar, but for unary operations. */
996 build_unary_op (enum tree_code op_code, tree result_type, tree operand)
998 tree type = TREE_TYPE (operand);
999 tree base_type = get_base_type (type);
1000 tree operation_type = result_type;
1002 bool side_effects = false;
1005 && TREE_CODE (operation_type) == RECORD_TYPE
1006 && TYPE_JUSTIFIED_MODULAR_P (operation_type))
1007 operation_type = TREE_TYPE (TYPE_FIELDS (operation_type));
1010 && !AGGREGATE_TYPE_P (operation_type)
1011 && TYPE_EXTRA_SUBTYPE_P (operation_type))
1012 operation_type = get_base_type (operation_type);
1018 if (!operation_type)
1019 result_type = operation_type = TREE_TYPE (type);
1021 gcc_assert (result_type == TREE_TYPE (type));
1023 result = fold_build1 (op_code, operation_type, operand);
1026 case TRUTH_NOT_EXPR:
1027 #ifdef ENABLE_CHECKING
1028 gcc_assert (TREE_CODE (get_base_type (result_type)) == BOOLEAN_TYPE);
1030 result = invert_truthvalue_loc (EXPR_LOCATION (operand), operand);
1031 /* When not optimizing, fold the result as invert_truthvalue_loc
1032 doesn't fold the result of comparisons. This is intended to undo
1033 the trick used for boolean rvalues in gnat_to_gnu. */
1035 result = fold (result);
1038 case ATTR_ADDR_EXPR:
1040 switch (TREE_CODE (operand))
1043 case UNCONSTRAINED_ARRAY_REF:
1044 result = TREE_OPERAND (operand, 0);
1046 /* Make sure the type here is a pointer, not a reference.
1047 GCC wants pointer types for function addresses. */
1049 result_type = build_pointer_type (type);
1051 /* If the underlying object can alias everything, propagate the
1052 property since we are effectively retrieving the object. */
1053 if (POINTER_TYPE_P (TREE_TYPE (result))
1054 && TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (result)))
1056 if (TREE_CODE (result_type) == POINTER_TYPE
1057 && !TYPE_REF_CAN_ALIAS_ALL (result_type))
1059 = build_pointer_type_for_mode (TREE_TYPE (result_type),
1060 TYPE_MODE (result_type),
1062 else if (TREE_CODE (result_type) == REFERENCE_TYPE
1063 && !TYPE_REF_CAN_ALIAS_ALL (result_type))
1065 = build_reference_type_for_mode (TREE_TYPE (result_type),
1066 TYPE_MODE (result_type),
1073 TREE_TYPE (result) = type = build_pointer_type (type);
1077 /* Fold a compound expression if it has unconstrained array type
1078 since the middle-end cannot handle it. But we don't it in the
1079 general case because it may introduce aliasing issues if the
1080 first operand is an indirect assignment and the second operand
1081 the corresponding address, e.g. for an allocator. */
1082 if (TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
1084 result = build_unary_op (ADDR_EXPR, result_type,
1085 TREE_OPERAND (operand, 1));
1086 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1087 TREE_OPERAND (operand, 0), result);
1093 case ARRAY_RANGE_REF:
1096 /* If this is for 'Address, find the address of the prefix and add
1097 the offset to the field. Otherwise, do this the normal way. */
1098 if (op_code == ATTR_ADDR_EXPR)
1100 HOST_WIDE_INT bitsize;
1101 HOST_WIDE_INT bitpos;
1103 enum machine_mode mode;
1104 int unsignedp, volatilep;
1106 inner = get_inner_reference (operand, &bitsize, &bitpos, &offset,
1107 &mode, &unsignedp, &volatilep,
1110 /* If INNER is a padding type whose field has a self-referential
1111 size, convert to that inner type. We know the offset is zero
1112 and we need to have that type visible. */
1113 if (TYPE_IS_PADDING_P (TREE_TYPE (inner))
1114 && CONTAINS_PLACEHOLDER_P
1115 (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS
1116 (TREE_TYPE (inner))))))
1117 inner = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (inner))),
1120 /* Compute the offset as a byte offset from INNER. */
1122 offset = size_zero_node;
1124 offset = size_binop (PLUS_EXPR, offset,
1125 size_int (bitpos / BITS_PER_UNIT));
1127 /* Take the address of INNER, convert the offset to void *, and
1128 add then. It will later be converted to the desired result
1130 inner = build_unary_op (ADDR_EXPR, NULL_TREE, inner);
1131 inner = convert (ptr_void_type_node, inner);
1132 result = build_binary_op (POINTER_PLUS_EXPR, ptr_void_type_node,
1134 result = convert (build_pointer_type (TREE_TYPE (operand)),
1141 /* If this is just a constructor for a padded record, we can
1142 just take the address of the single field and convert it to
1143 a pointer to our type. */
1144 if (TYPE_IS_PADDING_P (type))
1146 result = VEC_index (constructor_elt,
1147 CONSTRUCTOR_ELTS (operand),
1149 result = convert (build_pointer_type (TREE_TYPE (operand)),
1150 build_unary_op (ADDR_EXPR, NULL_TREE, result));
1157 if (AGGREGATE_TYPE_P (type)
1158 && AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (operand, 0))))
1159 return build_unary_op (ADDR_EXPR, result_type,
1160 TREE_OPERAND (operand, 0));
1162 /* ... fallthru ... */
1164 case VIEW_CONVERT_EXPR:
1165 /* If this just a variant conversion or if the conversion doesn't
1166 change the mode, get the result type from this type and go down.
1167 This is needed for conversions of CONST_DECLs, to eventually get
1168 to the address of their CORRESPONDING_VARs. */
1169 if ((TYPE_MAIN_VARIANT (type)
1170 == TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (operand, 0))))
1171 || (TYPE_MODE (type) != BLKmode
1172 && (TYPE_MODE (type)
1173 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (operand, 0))))))
1174 return build_unary_op (ADDR_EXPR,
1175 (result_type ? result_type
1176 : build_pointer_type (type)),
1177 TREE_OPERAND (operand, 0));
1181 operand = DECL_CONST_CORRESPONDING_VAR (operand);
1183 /* ... fall through ... */
1188 /* If we are taking the address of a padded record whose field is
1189 contains a template, take the address of the template. */
1190 if (TYPE_IS_PADDING_P (type)
1191 && TREE_CODE (TREE_TYPE (TYPE_FIELDS (type))) == RECORD_TYPE
1192 && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (TYPE_FIELDS (type))))
1194 type = TREE_TYPE (TYPE_FIELDS (type));
1195 operand = convert (type, operand);
1198 gnat_mark_addressable (operand);
1199 result = build_fold_addr_expr (operand);
1202 TREE_CONSTANT (result) = staticp (operand) || TREE_CONSTANT (operand);
1206 /* If we want to refer to an unconstrained array, use the appropriate
1207 expression to do so. This will never survive down to the back-end.
1208 But if TYPE is a thin pointer, first convert to a fat pointer. */
1209 if (TYPE_IS_THIN_POINTER_P (type)
1210 && TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type)))
1213 = convert (TREE_TYPE (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type))),
1215 type = TREE_TYPE (operand);
1218 if (TYPE_IS_FAT_POINTER_P (type))
1220 result = build1 (UNCONSTRAINED_ARRAY_REF,
1221 TYPE_UNCONSTRAINED_ARRAY (type), operand);
1222 TREE_READONLY (result)
1223 = TYPE_READONLY (TYPE_UNCONSTRAINED_ARRAY (type));
1226 /* If we are dereferencing an ADDR_EXPR, return its operand. */
1227 else if (TREE_CODE (operand) == ADDR_EXPR)
1228 result = TREE_OPERAND (operand, 0);
1230 /* Otherwise, build and fold the indirect reference. */
1233 result = build_fold_indirect_ref (operand);
1234 TREE_READONLY (result) = TYPE_READONLY (TREE_TYPE (type));
1238 = (!TYPE_IS_FAT_POINTER_P (type) && TYPE_VOLATILE (TREE_TYPE (type)));
1244 tree modulus = ((operation_type
1245 && TREE_CODE (operation_type) == INTEGER_TYPE
1246 && TYPE_MODULAR_P (operation_type))
1247 ? TYPE_MODULUS (operation_type) : NULL_TREE);
1248 int mod_pow2 = modulus && integer_pow2p (modulus);
1250 /* If this is a modular type, there are various possibilities
1251 depending on the operation and whether the modulus is a
1252 power of two or not. */
1256 gcc_assert (operation_type == base_type);
1257 operand = convert (operation_type, operand);
1259 /* The fastest in the negate case for binary modulus is
1260 the straightforward code; the TRUNC_MOD_EXPR below
1261 is an AND operation. */
1262 if (op_code == NEGATE_EXPR && mod_pow2)
1263 result = fold_build2 (TRUNC_MOD_EXPR, operation_type,
1264 fold_build1 (NEGATE_EXPR, operation_type,
1268 /* For nonbinary negate case, return zero for zero operand,
1269 else return the modulus minus the operand. If the modulus
1270 is a power of two minus one, we can do the subtraction
1271 as an XOR since it is equivalent and faster on most machines. */
1272 else if (op_code == NEGATE_EXPR && !mod_pow2)
1274 if (integer_pow2p (fold_build2 (PLUS_EXPR, operation_type,
1276 convert (operation_type,
1277 integer_one_node))))
1278 result = fold_build2 (BIT_XOR_EXPR, operation_type,
1281 result = fold_build2 (MINUS_EXPR, operation_type,
1284 result = fold_build3 (COND_EXPR, operation_type,
1285 fold_build2 (NE_EXPR,
1290 integer_zero_node)),
1295 /* For the NOT cases, we need a constant equal to
1296 the modulus minus one. For a binary modulus, we
1297 XOR against the constant and subtract the operand from
1298 that constant for nonbinary modulus. */
1300 tree cnst = fold_build2 (MINUS_EXPR, operation_type, modulus,
1301 convert (operation_type,
1305 result = fold_build2 (BIT_XOR_EXPR, operation_type,
1308 result = fold_build2 (MINUS_EXPR, operation_type,
1316 /* ... fall through ... */
1319 gcc_assert (operation_type == base_type);
1320 result = fold_build1 (op_code, operation_type,
1321 convert (operation_type, operand));
1326 TREE_SIDE_EFFECTS (result) = 1;
1327 if (TREE_CODE (result) == INDIRECT_REF)
1328 TREE_THIS_VOLATILE (result) = TYPE_VOLATILE (TREE_TYPE (result));
1331 if (result_type && TREE_TYPE (result) != result_type)
1332 result = convert (result_type, result);
1337 /* Similar, but for COND_EXPR. */
1340 build_cond_expr (tree result_type, tree condition_operand,
1341 tree true_operand, tree false_operand)
1343 bool addr_p = false;
1346 /* The front-end verified that result, true and false operands have
1347 same base type. Convert everything to the result type. */
1348 true_operand = convert (result_type, true_operand);
1349 false_operand = convert (result_type, false_operand);
1351 /* If the result type is unconstrained, take the address of the operands and
1352 then dereference the result. Likewise if the result type is passed by
1353 reference, but this is natively handled in the gimplifier. */
1354 if (TREE_CODE (result_type) == UNCONSTRAINED_ARRAY_TYPE
1355 || CONTAINS_PLACEHOLDER_P (TYPE_SIZE (result_type)))
1357 result_type = build_pointer_type (result_type);
1358 true_operand = build_unary_op (ADDR_EXPR, result_type, true_operand);
1359 false_operand = build_unary_op (ADDR_EXPR, result_type, false_operand);
1363 result = fold_build3 (COND_EXPR, result_type, condition_operand,
1364 true_operand, false_operand);
1366 /* If we have a common SAVE_EXPR (possibly surrounded by arithmetics)
1367 in both arms, make sure it gets evaluated by moving it ahead of the
1368 conditional expression. This is necessary because it is evaluated
1369 in only one place at run time and would otherwise be uninitialized
1370 in one of the arms. */
1371 true_operand = skip_simple_arithmetic (true_operand);
1372 false_operand = skip_simple_arithmetic (false_operand);
1374 if (true_operand == false_operand && TREE_CODE (true_operand) == SAVE_EXPR)
1375 result = build2 (COMPOUND_EXPR, result_type, true_operand, result);
1378 result = build_unary_op (INDIRECT_REF, NULL_TREE, result);
1383 /* Similar, but for COMPOUND_EXPR. */
1386 build_compound_expr (tree result_type, tree stmt_operand, tree expr_operand)
1388 bool addr_p = false;
1391 /* If the result type is unconstrained, take the address of the operand and
1392 then dereference the result. Likewise if the result type is passed by
1393 reference, but this is natively handled in the gimplifier. */
1394 if (TREE_CODE (result_type) == UNCONSTRAINED_ARRAY_TYPE
1395 || CONTAINS_PLACEHOLDER_P (TYPE_SIZE (result_type)))
1397 result_type = build_pointer_type (result_type);
1398 expr_operand = build_unary_op (ADDR_EXPR, result_type, expr_operand);
1402 result = fold_build2 (COMPOUND_EXPR, result_type, stmt_operand,
1406 result = build_unary_op (INDIRECT_REF, NULL_TREE, result);
1410 /* Similar, but for RETURN_EXPR. If RET_VAL is non-null, build a RETURN_EXPR
1411 around the assignment of RET_VAL to RET_OBJ. Otherwise just build a bare
1412 RETURN_EXPR around RESULT_OBJ, which may be null in this case. */
1415 build_return_expr (tree ret_obj, tree ret_val)
1421 /* The gimplifier explicitly enforces the following invariant:
1430 As a consequence, type consistency dictates that we use the type
1431 of the RET_OBJ as the operation type. */
1432 tree operation_type = TREE_TYPE (ret_obj);
1434 /* Convert the right operand to the operation type. Note that it's the
1435 same transformation as in the MODIFY_EXPR case of build_binary_op,
1436 with the assumption that the type cannot involve a placeholder. */
1437 if (operation_type != TREE_TYPE (ret_val))
1438 ret_val = convert (operation_type, ret_val);
1440 result_expr = build2 (MODIFY_EXPR, operation_type, ret_obj, ret_val);
1443 result_expr = ret_obj;
1445 return build1 (RETURN_EXPR, void_type_node, result_expr);
1448 /* Build a CALL_EXPR to call FUNDECL with one argument, ARG. Return
1452 build_call_1_expr (tree fundecl, tree arg)
1454 tree call = build_call_nary (TREE_TYPE (TREE_TYPE (fundecl)),
1455 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1457 TREE_SIDE_EFFECTS (call) = 1;
1461 /* Build a CALL_EXPR to call FUNDECL with two arguments, ARG1 & ARG2. Return
1465 build_call_2_expr (tree fundecl, tree arg1, tree arg2)
1467 tree call = build_call_nary (TREE_TYPE (TREE_TYPE (fundecl)),
1468 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1470 TREE_SIDE_EFFECTS (call) = 1;
1474 /* Likewise to call FUNDECL with no arguments. */
1477 build_call_0_expr (tree fundecl)
1479 /* We rely on build_call_nary to compute TREE_SIDE_EFFECTS. This makes
1480 it possible to propagate DECL_IS_PURE on parameterless functions. */
1481 tree call = build_call_nary (TREE_TYPE (TREE_TYPE (fundecl)),
1482 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1487 /* Call a function that raises an exception and pass the line number and file
1488 name, if requested. MSG says which exception function to call.
1490 GNAT_NODE is the gnat node conveying the source location for which the
1491 error should be signaled, or Empty in which case the error is signaled on
1492 the current ref_file_name/input_line.
1494 KIND says which kind of exception this is for
1495 (N_Raise_{Constraint,Storage,Program}_Error). */
1498 build_call_raise (int msg, Node_Id gnat_node, char kind)
1500 tree fndecl = gnat_raise_decls[msg];
1501 tree label = get_exception_label (kind);
1507 /* If this is to be done as a goto, handle that case. */
1510 Entity_Id local_raise = Get_Local_Raise_Call_Entity ();
1511 tree gnu_result = build1 (GOTO_EXPR, void_type_node, label);
1513 /* If Local_Raise is present, generate
1514 Local_Raise (exception'Identity); */
1515 if (Present (local_raise))
1517 tree gnu_local_raise
1518 = gnat_to_gnu_entity (local_raise, NULL_TREE, 0);
1519 tree gnu_exception_entity
1520 = gnat_to_gnu_entity (Get_RT_Exception_Entity (msg), NULL_TREE, 0);
1522 = build_call_1_expr (gnu_local_raise,
1523 build_unary_op (ADDR_EXPR, NULL_TREE,
1524 gnu_exception_entity));
1526 gnu_result = build2 (COMPOUND_EXPR, void_type_node,
1527 gnu_call, gnu_result);}
1533 = (Debug_Flag_NN || Exception_Locations_Suppressed)
1535 : (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1536 ? IDENTIFIER_POINTER
1537 (get_identifier (Get_Name_String
1539 (Get_Source_File_Index (Sloc (gnat_node))))))
1543 filename = build_string (len, str);
1545 = (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1546 ? Get_Logical_Line_Number (Sloc(gnat_node)) : input_line;
1548 TREE_TYPE (filename) = build_array_type (unsigned_char_type_node,
1549 build_index_type (size_int (len)));
1552 build_call_2_expr (fndecl,
1554 build_pointer_type (unsigned_char_type_node),
1556 build_int_cst (NULL_TREE, line_number));
1559 /* Similar to build_call_raise, for an index or range check exception as
1560 determined by MSG, with extra information generated of the form
1561 "INDEX out of range FIRST..LAST". */
1564 build_call_raise_range (int msg, Node_Id gnat_node,
1565 tree index, tree first, tree last)
1568 tree fndecl = gnat_raise_decls_ext[msg];
1570 int line_number, column_number;
1575 = (Debug_Flag_NN || Exception_Locations_Suppressed)
1577 : (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1578 ? IDENTIFIER_POINTER
1579 (get_identifier (Get_Name_String
1581 (Get_Source_File_Index (Sloc (gnat_node))))))
1585 filename = build_string (len, str);
1586 if (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1588 line_number = Get_Logical_Line_Number (Sloc (gnat_node));
1589 column_number = Get_Column_Number (Sloc (gnat_node));
1593 line_number = input_line;
1597 TREE_TYPE (filename) = build_array_type (unsigned_char_type_node,
1598 build_index_type (size_int (len)));
1600 call = build_call_nary (TREE_TYPE (TREE_TYPE (fndecl)),
1601 build_unary_op (ADDR_EXPR, NULL_TREE, fndecl),
1604 build_pointer_type (unsigned_char_type_node),
1606 build_int_cst (NULL_TREE, line_number),
1607 build_int_cst (NULL_TREE, column_number),
1608 convert (integer_type_node, index),
1609 convert (integer_type_node, first),
1610 convert (integer_type_node, last));
1611 TREE_SIDE_EFFECTS (call) = 1;
1615 /* Similar to build_call_raise, with extra information about the column
1616 where the check failed. */
1619 build_call_raise_column (int msg, Node_Id gnat_node)
1621 tree fndecl = gnat_raise_decls_ext[msg];
1624 int line_number, column_number;
1629 = (Debug_Flag_NN || Exception_Locations_Suppressed)
1631 : (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1632 ? IDENTIFIER_POINTER
1633 (get_identifier (Get_Name_String
1635 (Get_Source_File_Index (Sloc (gnat_node))))))
1639 filename = build_string (len, str);
1640 if (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1642 line_number = Get_Logical_Line_Number (Sloc (gnat_node));
1643 column_number = Get_Column_Number (Sloc (gnat_node));
1647 line_number = input_line;
1651 TREE_TYPE (filename) = build_array_type (unsigned_char_type_node,
1652 build_index_type (size_int (len)));
1654 call = build_call_nary (TREE_TYPE (TREE_TYPE (fndecl)),
1655 build_unary_op (ADDR_EXPR, NULL_TREE, fndecl),
1658 build_pointer_type (unsigned_char_type_node),
1660 build_int_cst (NULL_TREE, line_number),
1661 build_int_cst (NULL_TREE, column_number));
1662 TREE_SIDE_EFFECTS (call) = 1;
1666 /* qsort comparer for the bit positions of two constructor elements
1667 for record components. */
1670 compare_elmt_bitpos (const PTR rt1, const PTR rt2)
1672 const constructor_elt * const elmt1 = (const constructor_elt * const) rt1;
1673 const constructor_elt * const elmt2 = (const constructor_elt * const) rt2;
1674 const_tree const field1 = elmt1->index;
1675 const_tree const field2 = elmt2->index;
1677 = tree_int_cst_compare (bit_position (field1), bit_position (field2));
1679 return ret ? ret : (int) (DECL_UID (field1) - DECL_UID (field2));
1682 /* Return a CONSTRUCTOR of TYPE whose elements are V. */
1685 gnat_build_constructor (tree type, VEC(constructor_elt,gc) *v)
1687 bool allconstant = (TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST);
1688 bool side_effects = false;
1689 tree result, obj, val;
1690 unsigned int n_elmts;
1692 /* Scan the elements to see if they are all constant or if any has side
1693 effects, to let us set global flags on the resulting constructor. Count
1694 the elements along the way for possible sorting purposes below. */
1695 FOR_EACH_CONSTRUCTOR_ELT (v, n_elmts, obj, val)
1697 /* The predicate must be in keeping with output_constructor. */
1698 if (!TREE_CONSTANT (val)
1699 || (TREE_CODE (type) == RECORD_TYPE
1700 && CONSTRUCTOR_BITFIELD_P (obj)
1701 && !initializer_constant_valid_for_bitfield_p (val))
1702 || !initializer_constant_valid_p (val, TREE_TYPE (val)))
1703 allconstant = false;
1705 if (TREE_SIDE_EFFECTS (val))
1706 side_effects = true;
1709 /* For record types with constant components only, sort field list
1710 by increasing bit position. This is necessary to ensure the
1711 constructor can be output as static data. */
1712 if (allconstant && TREE_CODE (type) == RECORD_TYPE && n_elmts > 1)
1713 VEC_qsort (constructor_elt, v, compare_elmt_bitpos);
1715 result = build_constructor (type, v);
1716 TREE_CONSTANT (result) = TREE_STATIC (result) = allconstant;
1717 TREE_SIDE_EFFECTS (result) = side_effects;
1718 TREE_READONLY (result) = TYPE_READONLY (type) || allconstant;
1722 /* Return a COMPONENT_REF to access a field that is given by COMPONENT,
1723 an IDENTIFIER_NODE giving the name of the field, or FIELD, a FIELD_DECL,
1724 for the field. Don't fold the result if NO_FOLD_P is true.
1726 We also handle the fact that we might have been passed a pointer to the
1727 actual record and know how to look for fields in variant parts. */
1730 build_simple_component_ref (tree record_variable, tree component,
1731 tree field, bool no_fold_p)
1733 tree record_type = TYPE_MAIN_VARIANT (TREE_TYPE (record_variable));
1734 tree ref, inner_variable;
1736 gcc_assert ((TREE_CODE (record_type) == RECORD_TYPE
1737 || TREE_CODE (record_type) == UNION_TYPE
1738 || TREE_CODE (record_type) == QUAL_UNION_TYPE)
1739 && TYPE_SIZE (record_type)
1740 && (component != 0) != (field != 0));
1742 /* If no field was specified, look for a field with the specified name
1743 in the current record only. */
1745 for (field = TYPE_FIELDS (record_type); field;
1746 field = TREE_CHAIN (field))
1747 if (DECL_NAME (field) == component)
1753 /* If this field is not in the specified record, see if we can find a field
1754 in the specified record whose original field is the same as this one. */
1755 if (DECL_CONTEXT (field) != record_type)
1759 /* First loop thru normal components. */
1760 for (new_field = TYPE_FIELDS (record_type); new_field;
1761 new_field = DECL_CHAIN (new_field))
1762 if (SAME_FIELD_P (field, new_field))
1765 /* Next, see if we're looking for an inherited component in an extension.
1766 If so, look thru the extension directly. */
1768 && TREE_CODE (record_variable) == VIEW_CONVERT_EXPR
1769 && TYPE_ALIGN_OK (record_type)
1770 && TREE_CODE (TREE_TYPE (TREE_OPERAND (record_variable, 0)))
1772 && TYPE_ALIGN_OK (TREE_TYPE (TREE_OPERAND (record_variable, 0))))
1774 ref = build_simple_component_ref (TREE_OPERAND (record_variable, 0),
1775 NULL_TREE, field, no_fold_p);
1780 /* Next, loop thru DECL_INTERNAL_P components if we haven't found
1781 the component in the first search. Doing this search in 2 steps
1782 is required to avoiding hidden homonymous fields in the
1785 for (new_field = TYPE_FIELDS (record_type); new_field;
1786 new_field = DECL_CHAIN (new_field))
1787 if (DECL_INTERNAL_P (new_field))
1790 = build_simple_component_ref (record_variable,
1791 NULL_TREE, new_field, no_fold_p);
1792 ref = build_simple_component_ref (field_ref, NULL_TREE, field,
1805 /* If the field's offset has overflowed, do not attempt to access it
1806 as doing so may trigger sanity checks deeper in the back-end.
1807 Note that we don't need to warn since this will be done on trying
1808 to declare the object. */
1809 if (TREE_CODE (DECL_FIELD_OFFSET (field)) == INTEGER_CST
1810 && TREE_OVERFLOW (DECL_FIELD_OFFSET (field)))
1813 /* Look through conversion between type variants. Note that this
1814 is transparent as far as the field is concerned. */
1815 if (TREE_CODE (record_variable) == VIEW_CONVERT_EXPR
1816 && TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (record_variable, 0)))
1818 inner_variable = TREE_OPERAND (record_variable, 0);
1820 inner_variable = record_variable;
1822 ref = build3 (COMPONENT_REF, TREE_TYPE (field), inner_variable, field,
1825 if (TREE_READONLY (record_variable) || TREE_READONLY (field))
1826 TREE_READONLY (ref) = 1;
1827 if (TREE_THIS_VOLATILE (record_variable) || TREE_THIS_VOLATILE (field)
1828 || TYPE_VOLATILE (record_type))
1829 TREE_THIS_VOLATILE (ref) = 1;
1834 /* The generic folder may punt in this case because the inner array type
1835 can be self-referential, but folding is in fact not problematic. */
1836 else if (TREE_CODE (record_variable) == CONSTRUCTOR
1837 && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (record_variable)))
1839 VEC(constructor_elt,gc) *elts = CONSTRUCTOR_ELTS (record_variable);
1840 unsigned HOST_WIDE_INT idx;
1842 FOR_EACH_CONSTRUCTOR_ELT (elts, idx, index, value)
1852 /* Like build_simple_component_ref, except that we give an error if the
1853 reference could not be found. */
1856 build_component_ref (tree record_variable, tree component,
1857 tree field, bool no_fold_p)
1859 tree ref = build_simple_component_ref (record_variable, component, field,
1865 /* If FIELD was specified, assume this is an invalid user field so raise
1866 Constraint_Error. Otherwise, we have no type to return so abort. */
1868 return build1 (NULL_EXPR, TREE_TYPE (field),
1869 build_call_raise (CE_Discriminant_Check_Failed, Empty,
1870 N_Raise_Constraint_Error));
1873 /* Helper for build_call_alloc_dealloc, with arguments to be interpreted
1874 identically. Process the case where a GNAT_PROC to call is provided. */
1877 build_call_alloc_dealloc_proc (tree gnu_obj, tree gnu_size, tree gnu_type,
1878 Entity_Id gnat_proc, Entity_Id gnat_pool)
1880 tree gnu_proc = gnat_to_gnu (gnat_proc);
1881 tree gnu_proc_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_proc);
1884 /* The storage pools are obviously always tagged types, but the
1885 secondary stack uses the same mechanism and is not tagged. */
1886 if (Is_Tagged_Type (Etype (gnat_pool)))
1888 /* The size is the third parameter; the alignment is the
1890 Entity_Id gnat_size_type
1891 = Etype (Next_Formal (Next_Formal (First_Formal (gnat_proc))));
1892 tree gnu_size_type = gnat_to_gnu_type (gnat_size_type);
1894 tree gnu_pool = gnat_to_gnu (gnat_pool);
1895 tree gnu_pool_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_pool);
1896 tree gnu_align = size_int (TYPE_ALIGN (gnu_type) / BITS_PER_UNIT);
1898 gnu_size = convert (gnu_size_type, gnu_size);
1899 gnu_align = convert (gnu_size_type, gnu_align);
1901 /* The first arg is always the address of the storage pool; next
1902 comes the address of the object, for a deallocator, then the
1903 size and alignment. */
1905 gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)),
1906 gnu_proc_addr, 4, gnu_pool_addr,
1907 gnu_obj, gnu_size, gnu_align);
1909 gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)),
1910 gnu_proc_addr, 3, gnu_pool_addr,
1911 gnu_size, gnu_align);
1914 /* Secondary stack case. */
1917 /* The size is the second parameter. */
1918 Entity_Id gnat_size_type
1919 = Etype (Next_Formal (First_Formal (gnat_proc)));
1920 tree gnu_size_type = gnat_to_gnu_type (gnat_size_type);
1922 gnu_size = convert (gnu_size_type, gnu_size);
1924 /* The first arg is the address of the object, for a deallocator,
1927 gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)),
1928 gnu_proc_addr, 2, gnu_obj, gnu_size);
1930 gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)),
1931 gnu_proc_addr, 1, gnu_size);
1934 TREE_SIDE_EFFECTS (gnu_call) = 1;
1938 /* Helper for build_call_alloc_dealloc, to build and return an allocator for
1939 DATA_SIZE bytes aimed at containing a DATA_TYPE object, using the default
1940 __gnat_malloc allocator. Honor DATA_TYPE alignments greater than what the
1944 maybe_wrap_malloc (tree data_size, tree data_type, Node_Id gnat_node)
1946 /* When the DATA_TYPE alignment is stricter than what malloc offers
1947 (super-aligned case), we allocate an "aligning" wrapper type and return
1948 the address of its single data field with the malloc's return value
1949 stored just in front. */
1951 unsigned int data_align = TYPE_ALIGN (data_type);
1952 unsigned int default_allocator_alignment
1953 = get_target_default_allocator_alignment () * BITS_PER_UNIT;
1956 = ((data_align > default_allocator_alignment)
1957 ? make_aligning_type (data_type, data_align, data_size,
1958 default_allocator_alignment,
1959 POINTER_SIZE / BITS_PER_UNIT)
1963 = aligning_type ? TYPE_SIZE_UNIT (aligning_type) : data_size;
1967 /* On VMS, if pointers are 64-bit and the allocator size is 32-bit or
1968 Convention C, allocate 32-bit memory. */
1969 if (TARGET_ABI_OPEN_VMS
1970 && POINTER_SIZE == 64
1971 && Nkind (gnat_node) == N_Allocator
1972 && (UI_To_Int (Esize (Etype (gnat_node))) == 32
1973 || Convention (Etype (gnat_node)) == Convention_C))
1974 malloc_ptr = build_call_1_expr (malloc32_decl, size_to_malloc);
1976 malloc_ptr = build_call_1_expr (malloc_decl, size_to_malloc);
1980 /* Latch malloc's return value and get a pointer to the aligning field
1982 tree storage_ptr = gnat_protect_expr (malloc_ptr);
1984 tree aligning_record_addr
1985 = convert (build_pointer_type (aligning_type), storage_ptr);
1987 tree aligning_record
1988 = build_unary_op (INDIRECT_REF, NULL_TREE, aligning_record_addr);
1991 = build_component_ref (aligning_record, NULL_TREE,
1992 TYPE_FIELDS (aligning_type), false);
1994 tree aligning_field_addr
1995 = build_unary_op (ADDR_EXPR, NULL_TREE, aligning_field);
1997 /* Then arrange to store the allocator's return value ahead
1999 tree storage_ptr_slot_addr
2000 = build_binary_op (POINTER_PLUS_EXPR, ptr_void_type_node,
2001 convert (ptr_void_type_node, aligning_field_addr),
2002 size_int (-(HOST_WIDE_INT) POINTER_SIZE
2005 tree storage_ptr_slot
2006 = build_unary_op (INDIRECT_REF, NULL_TREE,
2007 convert (build_pointer_type (ptr_void_type_node),
2008 storage_ptr_slot_addr));
2011 build2 (COMPOUND_EXPR, TREE_TYPE (aligning_field_addr),
2012 build_binary_op (MODIFY_EXPR, NULL_TREE,
2013 storage_ptr_slot, storage_ptr),
2014 aligning_field_addr);
2020 /* Helper for build_call_alloc_dealloc, to release a DATA_TYPE object
2021 designated by DATA_PTR using the __gnat_free entry point. */
2024 maybe_wrap_free (tree data_ptr, tree data_type)
2026 /* In the regular alignment case, we pass the data pointer straight to free.
2027 In the superaligned case, we need to retrieve the initial allocator
2028 return value, stored in front of the data block at allocation time. */
2030 unsigned int data_align = TYPE_ALIGN (data_type);
2031 unsigned int default_allocator_alignment
2032 = get_target_default_allocator_alignment () * BITS_PER_UNIT;
2036 if (data_align > default_allocator_alignment)
2038 /* DATA_FRONT_PTR (void *)
2039 = (void *)DATA_PTR - (void *)sizeof (void *)) */
2042 (POINTER_PLUS_EXPR, ptr_void_type_node,
2043 convert (ptr_void_type_node, data_ptr),
2044 size_int (-(HOST_WIDE_INT) POINTER_SIZE / BITS_PER_UNIT));
2046 /* FREE_PTR (void *) = *(void **)DATA_FRONT_PTR */
2049 (INDIRECT_REF, NULL_TREE,
2050 convert (build_pointer_type (ptr_void_type_node), data_front_ptr));
2053 free_ptr = data_ptr;
2055 return build_call_1_expr (free_decl, free_ptr);
2058 /* Build a GCC tree to call an allocation or deallocation function.
2059 If GNU_OBJ is nonzero, it is an object to deallocate. Otherwise,
2060 generate an allocator.
2062 GNU_SIZE is the number of bytes to allocate and GNU_TYPE is the contained
2063 object type, used to determine the to-be-honored address alignment.
2064 GNAT_PROC, if present, is a procedure to call and GNAT_POOL is the storage
2065 pool to use. If not present, malloc and free are used. GNAT_NODE is used
2066 to provide an error location for restriction violation messages. */
2069 build_call_alloc_dealloc (tree gnu_obj, tree gnu_size, tree gnu_type,
2070 Entity_Id gnat_proc, Entity_Id gnat_pool,
2073 gnu_size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (gnu_size, gnu_obj);
2075 /* Explicit proc to call ? This one is assumed to deal with the type
2076 alignment constraints. */
2077 if (Present (gnat_proc))
2078 return build_call_alloc_dealloc_proc (gnu_obj, gnu_size, gnu_type,
2079 gnat_proc, gnat_pool);
2081 /* Otherwise, object to "free" or "malloc" with possible special processing
2082 for alignments stricter than what the default allocator honors. */
2084 return maybe_wrap_free (gnu_obj, gnu_type);
2087 /* Assert that we no longer can be called with this special pool. */
2088 gcc_assert (gnat_pool != -1);
2090 /* Check that we aren't violating the associated restriction. */
2091 if (!(Nkind (gnat_node) == N_Allocator && Comes_From_Source (gnat_node)))
2092 Check_No_Implicit_Heap_Alloc (gnat_node);
2094 return maybe_wrap_malloc (gnu_size, gnu_type, gnat_node);
2098 /* Build a GCC tree to correspond to allocating an object of TYPE whose
2099 initial value is INIT, if INIT is nonzero. Convert the expression to
2100 RESULT_TYPE, which must be some type of pointer. Return the tree.
2102 GNAT_PROC and GNAT_POOL optionally give the procedure to call and
2103 the storage pool to use. GNAT_NODE is used to provide an error
2104 location for restriction violation messages. If IGNORE_INIT_TYPE is
2105 true, ignore the type of INIT for the purpose of determining the size;
2106 this will cause the maximum size to be allocated if TYPE is of
2107 self-referential size. */
2110 build_allocator (tree type, tree init, tree result_type, Entity_Id gnat_proc,
2111 Entity_Id gnat_pool, Node_Id gnat_node, bool ignore_init_type)
2113 tree size = TYPE_SIZE_UNIT (type);
2116 /* If the initializer, if present, is a NULL_EXPR, just return a new one. */
2117 if (init && TREE_CODE (init) == NULL_EXPR)
2118 return build1 (NULL_EXPR, result_type, TREE_OPERAND (init, 0));
2120 /* If RESULT_TYPE is a fat or thin pointer, set SIZE to be the sum of the
2121 sizes of the object and its template. Allocate the whole thing and
2122 fill in the parts that are known. */
2123 else if (TYPE_IS_FAT_OR_THIN_POINTER_P (result_type))
2126 = build_unc_object_type_from_ptr (result_type, type,
2127 get_identifier ("ALLOC"), false);
2128 tree template_type = TREE_TYPE (TYPE_FIELDS (storage_type));
2129 tree storage_ptr_type = build_pointer_type (storage_type);
2132 size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TYPE_SIZE_UNIT (storage_type),
2135 /* If the size overflows, pass -1 so the allocator will raise
2137 if (TREE_CODE (size) == INTEGER_CST && TREE_OVERFLOW (size))
2138 size = ssize_int (-1);
2140 storage = build_call_alloc_dealloc (NULL_TREE, size, storage_type,
2141 gnat_proc, gnat_pool, gnat_node);
2142 storage = convert (storage_ptr_type, gnat_protect_expr (storage));
2144 /* If there is an initializing expression, then make a constructor for
2145 the entire object including the bounds and copy it into the object.
2146 If there is no initializing expression, just set the bounds. */
2149 VEC(constructor_elt,gc) *v = VEC_alloc (constructor_elt, gc, 2);
2151 CONSTRUCTOR_APPEND_ELT (v, TYPE_FIELDS (storage_type),
2152 build_template (template_type, type, init));
2153 CONSTRUCTOR_APPEND_ELT (v, DECL_CHAIN (TYPE_FIELDS (storage_type)),
2157 build2 (COMPOUND_EXPR, storage_ptr_type,
2159 (MODIFY_EXPR, storage_type,
2160 build_unary_op (INDIRECT_REF, NULL_TREE,
2161 convert (storage_ptr_type, storage)),
2162 gnat_build_constructor (storage_type, v)),
2163 convert (storage_ptr_type, storage)));
2167 (COMPOUND_EXPR, result_type,
2169 (MODIFY_EXPR, template_type,
2171 (build_unary_op (INDIRECT_REF, NULL_TREE,
2172 convert (storage_ptr_type, storage)),
2173 NULL_TREE, TYPE_FIELDS (storage_type), false),
2174 build_template (template_type, type, NULL_TREE)),
2175 convert (result_type, convert (storage_ptr_type, storage)));
2178 /* If we have an initializing expression, see if its size is simpler
2179 than the size from the type. */
2180 if (!ignore_init_type && init && TYPE_SIZE_UNIT (TREE_TYPE (init))
2181 && (TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (init))) == INTEGER_CST
2182 || CONTAINS_PLACEHOLDER_P (size)))
2183 size = TYPE_SIZE_UNIT (TREE_TYPE (init));
2185 /* If the size is still self-referential, reference the initializing
2186 expression, if it is present. If not, this must have been a
2187 call to allocate a library-level object, in which case we use
2188 the maximum size. */
2189 if (CONTAINS_PLACEHOLDER_P (size))
2191 if (!ignore_init_type && init)
2192 size = substitute_placeholder_in_expr (size, init);
2194 size = max_size (size, true);
2197 /* If the size overflows, pass -1 so the allocator will raise
2199 if (TREE_CODE (size) == INTEGER_CST && TREE_OVERFLOW (size))
2200 size = ssize_int (-1);
2202 result = convert (result_type,
2203 build_call_alloc_dealloc (NULL_TREE, size, type,
2204 gnat_proc, gnat_pool,
2207 /* If we have an initial value, protect the new address, assign the value
2208 and return the address with a COMPOUND_EXPR. */
2211 result = gnat_protect_expr (result);
2213 = build2 (COMPOUND_EXPR, TREE_TYPE (result),
2215 (MODIFY_EXPR, NULL_TREE,
2216 build_unary_op (INDIRECT_REF,
2217 TREE_TYPE (TREE_TYPE (result)), result),
2222 return convert (result_type, result);
2225 /* Indicate that we need to take the address of T and that it therefore
2226 should not be allocated in a register. Returns true if successful. */
2229 gnat_mark_addressable (tree t)
2232 switch (TREE_CODE (t))
2237 case ARRAY_RANGE_REF:
2240 case VIEW_CONVERT_EXPR:
2241 case NON_LVALUE_EXPR:
2243 t = TREE_OPERAND (t, 0);
2247 t = TREE_OPERAND (t, 1);
2251 TREE_ADDRESSABLE (t) = 1;
2257 TREE_ADDRESSABLE (t) = 1;
2261 TREE_ADDRESSABLE (t) = 1;
2265 return DECL_CONST_CORRESPONDING_VAR (t)
2266 && gnat_mark_addressable (DECL_CONST_CORRESPONDING_VAR (t));
2273 /* Save EXP for later use or reuse. This is equivalent to save_expr in tree.c
2274 but we know how to handle our own nodes. */
2277 gnat_save_expr (tree exp)
2279 tree type = TREE_TYPE (exp);
2280 enum tree_code code = TREE_CODE (exp);
2282 if (TREE_CONSTANT (exp) || code == SAVE_EXPR || code == NULL_EXPR)
2285 if (code == UNCONSTRAINED_ARRAY_REF)
2287 tree t = build1 (code, type, gnat_save_expr (TREE_OPERAND (exp, 0)));
2288 TREE_READONLY (t) = TYPE_READONLY (type);
2292 /* If this is a COMPONENT_REF of a fat pointer, save the entire fat pointer.
2293 This may be more efficient, but will also allow us to more easily find
2294 the match for the PLACEHOLDER_EXPR. */
2295 if (code == COMPONENT_REF
2296 && TYPE_IS_FAT_POINTER_P (TREE_TYPE (TREE_OPERAND (exp, 0))))
2297 return build3 (code, type, gnat_save_expr (TREE_OPERAND (exp, 0)),
2298 TREE_OPERAND (exp, 1), TREE_OPERAND (exp, 2));
2300 return save_expr (exp);
2303 /* Protect EXP for immediate reuse. This is a variant of gnat_save_expr that
2304 is optimized under the assumption that EXP's value doesn't change before
2305 its subsequent reuse(s) except through its potential reevaluation. */
2308 gnat_protect_expr (tree exp)
2310 tree type = TREE_TYPE (exp);
2311 enum tree_code code = TREE_CODE (exp);
2313 if (TREE_CONSTANT (exp) || code == SAVE_EXPR || code == NULL_EXPR)
2316 /* If EXP has no side effects, we theoretically don't need to do anything.
2317 However, we may be recursively passed more and more complex expressions
2318 involving checks which will be reused multiple times and eventually be
2319 unshared for gimplification; in order to avoid a complexity explosion
2320 at that point, we protect any expressions more complex than a simple
2321 arithmetic expression. */
2322 if (!TREE_SIDE_EFFECTS (exp))
2324 tree inner = skip_simple_arithmetic (exp);
2325 if (!EXPR_P (inner) || REFERENCE_CLASS_P (inner))
2329 /* If this is a conversion, protect what's inside the conversion. */
2330 if (code == NON_LVALUE_EXPR
2331 || CONVERT_EXPR_CODE_P (code)
2332 || code == VIEW_CONVERT_EXPR)
2333 return build1 (code, type, gnat_protect_expr (TREE_OPERAND (exp, 0)));
2335 /* If we're indirectly referencing something, we only need to protect the
2336 address since the data itself can't change in these situations. */
2337 if (code == INDIRECT_REF || code == UNCONSTRAINED_ARRAY_REF)
2339 tree t = build1 (code, type, gnat_protect_expr (TREE_OPERAND (exp, 0)));
2340 TREE_READONLY (t) = TYPE_READONLY (type);
2344 /* If this is a COMPONENT_REF of a fat pointer, save the entire fat pointer.
2345 This may be more efficient, but will also allow us to more easily find
2346 the match for the PLACEHOLDER_EXPR. */
2347 if (code == COMPONENT_REF
2348 && TYPE_IS_FAT_POINTER_P (TREE_TYPE (TREE_OPERAND (exp, 0))))
2349 return build3 (code, type, gnat_protect_expr (TREE_OPERAND (exp, 0)),
2350 TREE_OPERAND (exp, 1), TREE_OPERAND (exp, 2));
2352 /* If this is a fat pointer or something that can be placed in a register,
2353 just make a SAVE_EXPR. Likewise for a CALL_EXPR as large objects are
2354 returned via invisible reference in most ABIs so the temporary will
2355 directly be filled by the callee. */
2356 if (TYPE_IS_FAT_POINTER_P (type)
2357 || TYPE_MODE (type) != BLKmode
2358 || code == CALL_EXPR)
2359 return save_expr (exp);
2361 /* Otherwise reference, protect the address and dereference. */
2363 build_unary_op (INDIRECT_REF, type,
2364 save_expr (build_unary_op (ADDR_EXPR,
2365 build_reference_type (type),
2369 /* This is equivalent to stabilize_reference_1 in tree.c but we take an extra
2370 argument to force evaluation of everything. */
2373 gnat_stabilize_reference_1 (tree e, bool force)
2375 enum tree_code code = TREE_CODE (e);
2376 tree type = TREE_TYPE (e);
2379 /* We cannot ignore const expressions because it might be a reference
2380 to a const array but whose index contains side-effects. But we can
2381 ignore things that are actual constant or that already have been
2382 handled by this function. */
2383 if (TREE_CONSTANT (e) || code == SAVE_EXPR)
2386 switch (TREE_CODE_CLASS (code))
2388 case tcc_exceptional:
2389 case tcc_declaration:
2390 case tcc_comparison:
2391 case tcc_expression:
2394 /* If this is a COMPONENT_REF of a fat pointer, save the entire
2395 fat pointer. This may be more efficient, but will also allow
2396 us to more easily find the match for the PLACEHOLDER_EXPR. */
2397 if (code == COMPONENT_REF
2398 && TYPE_IS_FAT_POINTER_P (TREE_TYPE (TREE_OPERAND (e, 0))))
2400 = build3 (code, type,
2401 gnat_stabilize_reference_1 (TREE_OPERAND (e, 0), force),
2402 TREE_OPERAND (e, 1), TREE_OPERAND (e, 2));
2403 /* If the expression has side-effects, then encase it in a SAVE_EXPR
2404 so that it will only be evaluated once. */
2405 /* The tcc_reference and tcc_comparison classes could be handled as
2406 below, but it is generally faster to only evaluate them once. */
2407 else if (TREE_SIDE_EFFECTS (e) || force)
2408 return save_expr (e);
2414 /* Recursively stabilize each operand. */
2416 = build2 (code, type,
2417 gnat_stabilize_reference_1 (TREE_OPERAND (e, 0), force),
2418 gnat_stabilize_reference_1 (TREE_OPERAND (e, 1), force));
2422 /* Recursively stabilize each operand. */
2424 = build1 (code, type,
2425 gnat_stabilize_reference_1 (TREE_OPERAND (e, 0), force));
2432 /* See similar handling in gnat_stabilize_reference. */
2433 TREE_READONLY (result) = TREE_READONLY (e);
2434 TREE_SIDE_EFFECTS (result) |= TREE_SIDE_EFFECTS (e);
2435 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
2437 if (code == INDIRECT_REF || code == ARRAY_REF || code == ARRAY_RANGE_REF)
2438 TREE_THIS_NOTRAP (result) = TREE_THIS_NOTRAP (e);
2443 /* This is equivalent to stabilize_reference in tree.c but we know how to
2444 handle our own nodes and we take extra arguments. FORCE says whether to
2445 force evaluation of everything. We set SUCCESS to true unless we walk
2446 through something we don't know how to stabilize. */
2449 gnat_stabilize_reference (tree ref, bool force, bool *success)
2451 tree type = TREE_TYPE (ref);
2452 enum tree_code code = TREE_CODE (ref);
2455 /* Assume we'll success unless proven otherwise. */
2465 /* No action is needed in this case. */
2471 case FIX_TRUNC_EXPR:
2472 case VIEW_CONVERT_EXPR:
2474 = build1 (code, type,
2475 gnat_stabilize_reference (TREE_OPERAND (ref, 0), force,
2480 case UNCONSTRAINED_ARRAY_REF:
2481 result = build1 (code, type,
2482 gnat_stabilize_reference_1 (TREE_OPERAND (ref, 0),
2487 result = build3 (COMPONENT_REF, type,
2488 gnat_stabilize_reference (TREE_OPERAND (ref, 0), force,
2490 TREE_OPERAND (ref, 1), NULL_TREE);
2494 result = build3 (BIT_FIELD_REF, type,
2495 gnat_stabilize_reference (TREE_OPERAND (ref, 0), force,
2497 gnat_stabilize_reference_1 (TREE_OPERAND (ref, 1),
2499 gnat_stabilize_reference_1 (TREE_OPERAND (ref, 2),
2504 case ARRAY_RANGE_REF:
2505 result = build4 (code, type,
2506 gnat_stabilize_reference (TREE_OPERAND (ref, 0), force,
2508 gnat_stabilize_reference_1 (TREE_OPERAND (ref, 1),
2510 NULL_TREE, NULL_TREE);
2514 result = gnat_stabilize_reference_1 (ref, force);
2518 result = build2 (COMPOUND_EXPR, type,
2519 gnat_stabilize_reference (TREE_OPERAND (ref, 0), force,
2521 gnat_stabilize_reference_1 (TREE_OPERAND (ref, 1),
2526 /* Constructors with 1 element are used extensively to formally
2527 convert objects to special wrapping types. */
2528 if (TREE_CODE (type) == RECORD_TYPE
2529 && VEC_length (constructor_elt, CONSTRUCTOR_ELTS (ref)) == 1)
2532 = VEC_index (constructor_elt, CONSTRUCTOR_ELTS (ref), 0)->index;
2534 = VEC_index (constructor_elt, CONSTRUCTOR_ELTS (ref), 0)->value;
2536 = build_constructor_single (type, index,
2537 gnat_stabilize_reference_1 (value,
2549 ref = error_mark_node;
2551 /* ... fall through to failure ... */
2553 /* If arg isn't a kind of lvalue we recognize, make no change.
2554 Caller should recognize the error for an invalid lvalue. */
2561 /* TREE_THIS_VOLATILE and TREE_SIDE_EFFECTS set on the initial expression
2562 may not be sustained across some paths, such as the way via build1 for
2563 INDIRECT_REF. We reset those flags here in the general case, which is
2564 consistent with the GCC version of this routine.
2566 Special care should be taken regarding TREE_SIDE_EFFECTS, because some
2567 paths introduce side-effects where there was none initially (e.g. if a
2568 SAVE_EXPR is built) and we also want to keep track of that. */
2569 TREE_READONLY (result) = TREE_READONLY (ref);
2570 TREE_SIDE_EFFECTS (result) |= TREE_SIDE_EFFECTS (ref);
2571 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);