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 prevent writing more than what the target may hold if this is for
197 an assignment and the case of tagged types is handled in build_binary_op
198 so use the lhs type if it is known to be smaller, or of constant size and
199 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 assignments. */
202 if (TREE_CONSTANT (TYPE_SIZE (t1))
203 && (!TREE_CONSTANT (TYPE_SIZE (t2))
204 || !tree_int_cst_lt (TYPE_SIZE (t2), TYPE_SIZE (t1))))
207 /* Otherwise, if the lhs type is non-BLKmode, use it. Note that we know
208 that we will not have any alignment problems since, if we did, the
209 non-BLKmode type could not have been used. */
210 if (TYPE_MODE (t1) != BLKmode)
213 /* If the rhs type is of constant size, use it whatever the modes. At
214 this point it is known to be smaller, or of constant size and the
216 if (TREE_CONSTANT (TYPE_SIZE (t2)))
219 /* Otherwise, if the rhs type is non-BLKmode, use it. */
220 if (TYPE_MODE (t2) != BLKmode)
223 /* In this case, both types have variable size and BLKmode. It's
224 probably best to leave the "type mismatch" because changing it
225 could cause a bad self-referential reference. */
229 /* Return an expression tree representing an equality comparison of A1 and A2,
230 two objects of type ARRAY_TYPE. The result should be of type RESULT_TYPE.
232 Two arrays are equal in one of two ways: (1) if both have zero length in
233 some dimension (not necessarily the same dimension) or (2) if the lengths
234 in each dimension are equal and the data is equal. We perform the length
235 tests in as efficient a manner as possible. */
238 compare_arrays (location_t loc, tree result_type, tree a1, tree a2)
240 tree result = convert (result_type, boolean_true_node);
241 tree a1_is_null = convert (result_type, boolean_false_node);
242 tree a2_is_null = convert (result_type, boolean_false_node);
243 tree t1 = TREE_TYPE (a1);
244 tree t2 = TREE_TYPE (a2);
245 bool a1_side_effects_p = TREE_SIDE_EFFECTS (a1);
246 bool a2_side_effects_p = TREE_SIDE_EFFECTS (a2);
247 bool length_zero_p = false;
249 /* If either operand has side-effects, they have to be evaluated only once
250 in spite of the multiple references to the operand in the comparison. */
251 if (a1_side_effects_p)
252 a1 = gnat_protect_expr (a1);
254 if (a2_side_effects_p)
255 a2 = gnat_protect_expr (a2);
257 /* Process each dimension separately and compare the lengths. If any
258 dimension has a length known to be zero, set LENGTH_ZERO_P to true
259 in order to suppress the comparison of the data at the end. */
260 while (TREE_CODE (t1) == ARRAY_TYPE && TREE_CODE (t2) == ARRAY_TYPE)
262 tree lb1 = TYPE_MIN_VALUE (TYPE_DOMAIN (t1));
263 tree ub1 = TYPE_MAX_VALUE (TYPE_DOMAIN (t1));
264 tree lb2 = TYPE_MIN_VALUE (TYPE_DOMAIN (t2));
265 tree ub2 = TYPE_MAX_VALUE (TYPE_DOMAIN (t2));
266 tree length1 = size_binop (PLUS_EXPR, size_binop (MINUS_EXPR, ub1, lb1),
268 tree length2 = size_binop (PLUS_EXPR, size_binop (MINUS_EXPR, ub2, lb2),
270 tree comparison, this_a1_is_null, this_a2_is_null;
272 /* If the length of the first array is a constant, swap our operands
273 unless the length of the second array is the constant zero. */
274 if (TREE_CODE (length1) == INTEGER_CST && !integer_zerop (length2))
279 tem = a1, a1 = a2, a2 = tem;
280 tem = t1, t1 = t2, t2 = tem;
281 tem = lb1, lb1 = lb2, lb2 = tem;
282 tem = ub1, ub1 = ub2, ub2 = tem;
283 tem = length1, length1 = length2, length2 = tem;
284 tem = a1_is_null, a1_is_null = a2_is_null, a2_is_null = tem;
285 btem = a1_side_effects_p, a1_side_effects_p = a2_side_effects_p,
286 a2_side_effects_p = btem;
289 /* If the length of the second array is the constant zero, we can just
290 use the original stored bounds for the first array and see whether
291 last < first holds. */
292 if (integer_zerop (length2))
294 length_zero_p = true;
296 ub1 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
297 lb1 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
299 comparison = fold_build2_loc (loc, LT_EXPR, result_type, ub1, lb1);
300 comparison = SUBSTITUTE_PLACEHOLDER_IN_EXPR (comparison, a1);
301 if (EXPR_P (comparison))
302 SET_EXPR_LOCATION (comparison, loc);
304 this_a1_is_null = comparison;
305 this_a2_is_null = convert (result_type, boolean_true_node);
308 /* Otherwise, if the length is some other constant value, we know that
309 this dimension in the second array cannot be superflat, so we can
310 just use its length computed from the actual stored bounds. */
311 else if (TREE_CODE (length2) == INTEGER_CST)
315 ub1 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
316 lb1 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
317 /* Note that we know that UB2 and LB2 are constant and hence
318 cannot contain a PLACEHOLDER_EXPR. */
319 ub2 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t2)));
320 lb2 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t2)));
321 bt = get_base_type (TREE_TYPE (ub1));
324 = fold_build2_loc (loc, EQ_EXPR, result_type,
325 build_binary_op (MINUS_EXPR, bt, ub1, lb1),
326 build_binary_op (MINUS_EXPR, bt, ub2, lb2));
327 comparison = SUBSTITUTE_PLACEHOLDER_IN_EXPR (comparison, a1);
328 if (EXPR_P (comparison))
329 SET_EXPR_LOCATION (comparison, loc);
332 = fold_build2_loc (loc, LT_EXPR, result_type, ub1, lb1);
334 this_a2_is_null = convert (result_type, boolean_false_node);
337 /* Otherwise, compare the computed lengths. */
340 length1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length1, a1);
341 length2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length2, a2);
344 = fold_build2_loc (loc, EQ_EXPR, result_type, length1, length2);
346 /* If the length expression is of the form (cond ? val : 0), assume
347 that cond is equivalent to (length != 0). That's guaranteed by
348 construction of the array types in gnat_to_gnu_entity. */
349 if (TREE_CODE (length1) == COND_EXPR
350 && integer_zerop (TREE_OPERAND (length1, 2)))
352 = invert_truthvalue_loc (loc, TREE_OPERAND (length1, 0));
354 this_a1_is_null = fold_build2_loc (loc, EQ_EXPR, result_type,
355 length1, size_zero_node);
357 /* Likewise for the second array. */
358 if (TREE_CODE (length2) == COND_EXPR
359 && integer_zerop (TREE_OPERAND (length2, 2)))
361 = invert_truthvalue_loc (loc, TREE_OPERAND (length2, 0));
363 this_a2_is_null = fold_build2_loc (loc, EQ_EXPR, result_type,
364 length2, size_zero_node);
367 /* Append expressions for this dimension to the final expressions. */
368 result = build_binary_op (TRUTH_ANDIF_EXPR, result_type,
371 a1_is_null = build_binary_op (TRUTH_ORIF_EXPR, result_type,
372 this_a1_is_null, a1_is_null);
374 a2_is_null = build_binary_op (TRUTH_ORIF_EXPR, result_type,
375 this_a2_is_null, a2_is_null);
381 /* Unless the length of some dimension is known to be zero, compare the
382 data in the array. */
385 tree type = find_common_type (TREE_TYPE (a1), TREE_TYPE (a2));
390 a1 = convert (type, a1),
391 a2 = convert (type, a2);
394 comparison = fold_build2_loc (loc, EQ_EXPR, result_type, a1, a2);
397 = build_binary_op (TRUTH_ANDIF_EXPR, result_type, result, comparison);
400 /* The result is also true if both sizes are zero. */
401 result = build_binary_op (TRUTH_ORIF_EXPR, result_type,
402 build_binary_op (TRUTH_ANDIF_EXPR, result_type,
403 a1_is_null, a2_is_null),
406 /* If either operand has side-effects, they have to be evaluated before
407 starting the comparison above since the place they would be otherwise
408 evaluated could be wrong. */
409 if (a1_side_effects_p)
410 result = build2 (COMPOUND_EXPR, result_type, a1, result);
412 if (a2_side_effects_p)
413 result = build2 (COMPOUND_EXPR, result_type, a2, result);
418 /* Compute the result of applying OP_CODE to LHS and RHS, where both are of
419 type TYPE. We know that TYPE is a modular type with a nonbinary
423 nonbinary_modular_operation (enum tree_code op_code, tree type, tree lhs,
426 tree modulus = TYPE_MODULUS (type);
427 unsigned int needed_precision = tree_floor_log2 (modulus) + 1;
428 unsigned int precision;
429 bool unsignedp = true;
433 /* If this is an addition of a constant, convert it to a subtraction
434 of a constant since we can do that faster. */
435 if (op_code == PLUS_EXPR && TREE_CODE (rhs) == INTEGER_CST)
437 rhs = fold_build2 (MINUS_EXPR, type, modulus, rhs);
438 op_code = MINUS_EXPR;
441 /* For the logical operations, we only need PRECISION bits. For
442 addition and subtraction, we need one more and for multiplication we
443 need twice as many. But we never want to make a size smaller than
445 if (op_code == PLUS_EXPR || op_code == MINUS_EXPR)
446 needed_precision += 1;
447 else if (op_code == MULT_EXPR)
448 needed_precision *= 2;
450 precision = MAX (needed_precision, TYPE_PRECISION (op_type));
452 /* Unsigned will do for everything but subtraction. */
453 if (op_code == MINUS_EXPR)
456 /* If our type is the wrong signedness or isn't wide enough, make a new
457 type and convert both our operands to it. */
458 if (TYPE_PRECISION (op_type) < precision
459 || TYPE_UNSIGNED (op_type) != unsignedp)
461 /* Copy the node so we ensure it can be modified to make it modular. */
462 op_type = copy_node (gnat_type_for_size (precision, unsignedp));
463 modulus = convert (op_type, modulus);
464 SET_TYPE_MODULUS (op_type, modulus);
465 TYPE_MODULAR_P (op_type) = 1;
466 lhs = convert (op_type, lhs);
467 rhs = convert (op_type, rhs);
470 /* Do the operation, then we'll fix it up. */
471 result = fold_build2 (op_code, op_type, lhs, rhs);
473 /* For multiplication, we have no choice but to do a full modulus
474 operation. However, we want to do this in the narrowest
476 if (op_code == MULT_EXPR)
478 tree div_type = copy_node (gnat_type_for_size (needed_precision, 1));
479 modulus = convert (div_type, modulus);
480 SET_TYPE_MODULUS (div_type, modulus);
481 TYPE_MODULAR_P (div_type) = 1;
482 result = convert (op_type,
483 fold_build2 (TRUNC_MOD_EXPR, div_type,
484 convert (div_type, result), modulus));
487 /* For subtraction, add the modulus back if we are negative. */
488 else if (op_code == MINUS_EXPR)
490 result = gnat_protect_expr (result);
491 result = fold_build3 (COND_EXPR, op_type,
492 fold_build2 (LT_EXPR, boolean_type_node, result,
493 convert (op_type, integer_zero_node)),
494 fold_build2 (PLUS_EXPR, op_type, result, modulus),
498 /* For the other operations, subtract the modulus if we are >= it. */
501 result = gnat_protect_expr (result);
502 result = fold_build3 (COND_EXPR, op_type,
503 fold_build2 (GE_EXPR, boolean_type_node,
505 fold_build2 (MINUS_EXPR, op_type,
510 return convert (type, result);
513 /* Make a binary operation of kind OP_CODE. RESULT_TYPE is the type
514 desired for the result. Usually the operation is to be performed
515 in that type. For MODIFY_EXPR and ARRAY_REF, RESULT_TYPE may be 0
516 in which case the type to be used will be derived from the operands.
518 This function is very much unlike the ones for C and C++ since we
519 have already done any type conversion and matching required. All we
520 have to do here is validate the work done by SEM and handle subtypes. */
523 build_binary_op (enum tree_code op_code, tree result_type,
524 tree left_operand, tree right_operand)
526 tree left_type = TREE_TYPE (left_operand);
527 tree right_type = TREE_TYPE (right_operand);
528 tree left_base_type = get_base_type (left_type);
529 tree right_base_type = get_base_type (right_type);
530 tree operation_type = result_type;
531 tree best_type = NULL_TREE;
532 tree modulus, result;
533 bool has_side_effects = false;
536 && TREE_CODE (operation_type) == RECORD_TYPE
537 && TYPE_JUSTIFIED_MODULAR_P (operation_type))
538 operation_type = TREE_TYPE (TYPE_FIELDS (operation_type));
541 && !AGGREGATE_TYPE_P (operation_type)
542 && TYPE_EXTRA_SUBTYPE_P (operation_type))
543 operation_type = get_base_type (operation_type);
545 modulus = (operation_type
546 && TREE_CODE (operation_type) == INTEGER_TYPE
547 && TYPE_MODULAR_P (operation_type)
548 ? TYPE_MODULUS (operation_type) : NULL_TREE);
554 /* If there were integral or pointer conversions on the LHS, remove
555 them; we'll be putting them back below if needed. Likewise for
556 conversions between array and record types, except for justified
557 modular types. But don't do this if the right operand is not
558 BLKmode (for packed arrays) unless we are not changing the mode. */
559 while ((CONVERT_EXPR_P (left_operand)
560 || TREE_CODE (left_operand) == VIEW_CONVERT_EXPR)
561 && (((INTEGRAL_TYPE_P (left_type)
562 || POINTER_TYPE_P (left_type))
563 && (INTEGRAL_TYPE_P (TREE_TYPE
564 (TREE_OPERAND (left_operand, 0)))
565 || POINTER_TYPE_P (TREE_TYPE
566 (TREE_OPERAND (left_operand, 0)))))
567 || (((TREE_CODE (left_type) == RECORD_TYPE
568 && !TYPE_JUSTIFIED_MODULAR_P (left_type))
569 || TREE_CODE (left_type) == ARRAY_TYPE)
570 && ((TREE_CODE (TREE_TYPE
571 (TREE_OPERAND (left_operand, 0)))
573 || (TREE_CODE (TREE_TYPE
574 (TREE_OPERAND (left_operand, 0)))
576 && (TYPE_MODE (right_type) == BLKmode
577 || (TYPE_MODE (left_type)
578 == TYPE_MODE (TREE_TYPE
580 (left_operand, 0))))))))
582 left_operand = TREE_OPERAND (left_operand, 0);
583 left_type = TREE_TYPE (left_operand);
586 /* If a class-wide type may be involved, force use of the RHS type. */
587 if ((TREE_CODE (right_type) == RECORD_TYPE
588 || TREE_CODE (right_type) == UNION_TYPE)
589 && TYPE_ALIGN_OK (right_type))
590 operation_type = right_type;
592 /* If we are copying between padded objects with compatible types, use
593 the padded view of the objects, this is very likely more efficient.
594 Likewise for a padded object that is assigned a constructor, if we
595 can convert the constructor to the inner type, to avoid putting a
596 VIEW_CONVERT_EXPR on the LHS. But don't do so if we wouldn't have
597 actually copied anything. */
598 else if (TYPE_IS_PADDING_P (left_type)
599 && TREE_CONSTANT (TYPE_SIZE (left_type))
600 && ((TREE_CODE (right_operand) == COMPONENT_REF
602 (TREE_TYPE (TREE_OPERAND (right_operand, 0)))
603 && gnat_types_compatible_p
605 TREE_TYPE (TREE_OPERAND (right_operand, 0))))
606 || (TREE_CODE (right_operand) == CONSTRUCTOR
607 && !CONTAINS_PLACEHOLDER_P
608 (DECL_SIZE (TYPE_FIELDS (left_type)))))
609 && !integer_zerop (TYPE_SIZE (right_type)))
610 operation_type = left_type;
612 /* If we have a call to a function that returns an unconstrained type
613 with default discriminant on the RHS, use the RHS type (which is
614 padded) as we cannot compute the size of the actual assignment. */
615 else if (TREE_CODE (right_operand) == CALL_EXPR
616 && TYPE_IS_PADDING_P (right_type)
617 && CONTAINS_PLACEHOLDER_P
618 (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS (right_type)))))
619 operation_type = right_type;
621 /* Find the best type to use for copying between aggregate types. */
622 else if (((TREE_CODE (left_type) == ARRAY_TYPE
623 && TREE_CODE (right_type) == ARRAY_TYPE)
624 || (TREE_CODE (left_type) == RECORD_TYPE
625 && TREE_CODE (right_type) == RECORD_TYPE))
626 && (best_type = find_common_type (left_type, right_type)))
627 operation_type = best_type;
629 /* Otherwise use the LHS type. */
630 else if (!operation_type)
631 operation_type = left_type;
633 /* Ensure everything on the LHS is valid. If we have a field reference,
634 strip anything that get_inner_reference can handle. Then remove any
635 conversions between types having the same code and mode. And mark
636 VIEW_CONVERT_EXPRs with TREE_ADDRESSABLE. When done, we must have
637 either an INDIRECT_REF, a NULL_EXPR or a DECL node. */
638 result = left_operand;
641 tree restype = TREE_TYPE (result);
643 if (TREE_CODE (result) == COMPONENT_REF
644 || TREE_CODE (result) == ARRAY_REF
645 || TREE_CODE (result) == ARRAY_RANGE_REF)
646 while (handled_component_p (result))
647 result = TREE_OPERAND (result, 0);
648 else if (TREE_CODE (result) == REALPART_EXPR
649 || TREE_CODE (result) == IMAGPART_EXPR
650 || (CONVERT_EXPR_P (result)
651 && (((TREE_CODE (restype)
652 == TREE_CODE (TREE_TYPE
653 (TREE_OPERAND (result, 0))))
654 && (TYPE_MODE (TREE_TYPE
655 (TREE_OPERAND (result, 0)))
656 == TYPE_MODE (restype)))
657 || TYPE_ALIGN_OK (restype))))
658 result = TREE_OPERAND (result, 0);
659 else if (TREE_CODE (result) == VIEW_CONVERT_EXPR)
661 TREE_ADDRESSABLE (result) = 1;
662 result = TREE_OPERAND (result, 0);
668 gcc_assert (TREE_CODE (result) == INDIRECT_REF
669 || TREE_CODE (result) == NULL_EXPR
672 /* Convert the right operand to the operation type unless it is
673 either already of the correct type or if the type involves a
674 placeholder, since the RHS may not have the same record type. */
675 if (operation_type != right_type
676 && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (operation_type)))
678 right_operand = convert (operation_type, right_operand);
679 right_type = operation_type;
682 /* If the left operand is not of the same type as the operation
683 type, wrap it up in a VIEW_CONVERT_EXPR. */
684 if (left_type != operation_type)
685 left_operand = unchecked_convert (operation_type, left_operand, false);
687 has_side_effects = true;
693 operation_type = TREE_TYPE (left_type);
695 /* ... fall through ... */
697 case ARRAY_RANGE_REF:
698 /* First look through conversion between type variants. Note that
699 this changes neither the operation type nor the type domain. */
700 if (TREE_CODE (left_operand) == VIEW_CONVERT_EXPR
701 && TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (left_operand, 0)))
702 == TYPE_MAIN_VARIANT (left_type))
704 left_operand = TREE_OPERAND (left_operand, 0);
705 left_type = TREE_TYPE (left_operand);
708 /* For a range, make sure the element type is consistent. */
709 if (op_code == ARRAY_RANGE_REF
710 && TREE_TYPE (operation_type) != TREE_TYPE (left_type))
711 operation_type = build_array_type (TREE_TYPE (left_type),
712 TYPE_DOMAIN (operation_type));
714 /* Then convert the right operand to its base type. This will prevent
715 unneeded sign conversions when sizetype is wider than integer. */
716 right_operand = convert (right_base_type, right_operand);
717 right_operand = convert (sizetype, right_operand);
719 if (!TREE_CONSTANT (right_operand)
720 || !TREE_CONSTANT (TYPE_MIN_VALUE (right_type)))
721 gnat_mark_addressable (left_operand);
726 case TRUTH_ANDIF_EXPR:
727 case TRUTH_ORIF_EXPR:
731 #ifdef ENABLE_CHECKING
732 gcc_assert (TREE_CODE (get_base_type (result_type)) == BOOLEAN_TYPE);
734 operation_type = left_base_type;
735 left_operand = convert (operation_type, left_operand);
736 right_operand = convert (operation_type, right_operand);
745 #ifdef ENABLE_CHECKING
746 gcc_assert (TREE_CODE (get_base_type (result_type)) == BOOLEAN_TYPE);
748 /* If either operand is a NULL_EXPR, just return a new one. */
749 if (TREE_CODE (left_operand) == NULL_EXPR)
750 return build2 (op_code, result_type,
751 build1 (NULL_EXPR, integer_type_node,
752 TREE_OPERAND (left_operand, 0)),
755 else if (TREE_CODE (right_operand) == NULL_EXPR)
756 return build2 (op_code, result_type,
757 build1 (NULL_EXPR, integer_type_node,
758 TREE_OPERAND (right_operand, 0)),
761 /* If either object is a justified modular types, get the
762 fields from within. */
763 if (TREE_CODE (left_type) == RECORD_TYPE
764 && TYPE_JUSTIFIED_MODULAR_P (left_type))
766 left_operand = convert (TREE_TYPE (TYPE_FIELDS (left_type)),
768 left_type = TREE_TYPE (left_operand);
769 left_base_type = get_base_type (left_type);
772 if (TREE_CODE (right_type) == RECORD_TYPE
773 && TYPE_JUSTIFIED_MODULAR_P (right_type))
775 right_operand = convert (TREE_TYPE (TYPE_FIELDS (right_type)),
777 right_type = TREE_TYPE (right_operand);
778 right_base_type = get_base_type (right_type);
781 /* If both objects are arrays, compare them specially. */
782 if ((TREE_CODE (left_type) == ARRAY_TYPE
783 || (TREE_CODE (left_type) == INTEGER_TYPE
784 && TYPE_HAS_ACTUAL_BOUNDS_P (left_type)))
785 && (TREE_CODE (right_type) == ARRAY_TYPE
786 || (TREE_CODE (right_type) == INTEGER_TYPE
787 && TYPE_HAS_ACTUAL_BOUNDS_P (right_type))))
789 result = compare_arrays (input_location,
790 result_type, left_operand, right_operand);
791 if (op_code == NE_EXPR)
792 result = invert_truthvalue_loc (EXPR_LOCATION (result), result);
794 gcc_assert (op_code == EQ_EXPR);
799 /* Otherwise, the base types must be the same, unless they are both fat
800 pointer types or record types. In the latter case, use the best type
801 and convert both operands to that type. */
802 if (left_base_type != right_base_type)
804 if (TYPE_IS_FAT_POINTER_P (left_base_type)
805 && TYPE_IS_FAT_POINTER_P (right_base_type))
807 gcc_assert (TYPE_MAIN_VARIANT (left_base_type)
808 == TYPE_MAIN_VARIANT (right_base_type));
809 best_type = left_base_type;
812 else if (TREE_CODE (left_base_type) == RECORD_TYPE
813 && TREE_CODE (right_base_type) == RECORD_TYPE)
815 /* The only way this is permitted is if both types have the same
816 name. In that case, one of them must not be self-referential.
817 Use it as the best type. Even better with a fixed size. */
818 gcc_assert (TYPE_NAME (left_base_type)
819 && TYPE_NAME (left_base_type)
820 == TYPE_NAME (right_base_type));
822 if (TREE_CONSTANT (TYPE_SIZE (left_base_type)))
823 best_type = left_base_type;
824 else if (TREE_CONSTANT (TYPE_SIZE (right_base_type)))
825 best_type = right_base_type;
826 else if (!CONTAINS_PLACEHOLDER_P (TYPE_SIZE (left_base_type)))
827 best_type = left_base_type;
828 else if (!CONTAINS_PLACEHOLDER_P (TYPE_SIZE (right_base_type)))
829 best_type = right_base_type;
837 left_operand = convert (best_type, left_operand);
838 right_operand = convert (best_type, right_operand);
842 left_operand = convert (left_base_type, left_operand);
843 right_operand = convert (right_base_type, right_operand);
846 /* If we are comparing a fat pointer against zero, we just need to
847 compare the data pointer. */
848 if (TYPE_IS_FAT_POINTER_P (left_base_type)
849 && TREE_CODE (right_operand) == CONSTRUCTOR
850 && integer_zerop (VEC_index (constructor_elt,
851 CONSTRUCTOR_ELTS (right_operand),
855 = build_component_ref (left_operand, NULL_TREE,
856 TYPE_FIELDS (left_base_type), false);
858 = convert (TREE_TYPE (left_operand), integer_zero_node);
868 /* The RHS of a shift can be any type. Also, ignore any modulus
869 (we used to abort, but this is needed for unchecked conversion
870 to modular types). Otherwise, processing is the same as normal. */
871 gcc_assert (operation_type == left_base_type);
873 left_operand = convert (operation_type, left_operand);
879 /* For binary modulus, if the inputs are in range, so are the
881 if (modulus && integer_pow2p (modulus))
886 gcc_assert (TREE_TYPE (result_type) == left_base_type
887 && TREE_TYPE (result_type) == right_base_type);
888 left_operand = convert (left_base_type, left_operand);
889 right_operand = convert (right_base_type, right_operand);
892 case TRUNC_DIV_EXPR: case TRUNC_MOD_EXPR:
893 case CEIL_DIV_EXPR: case CEIL_MOD_EXPR:
894 case FLOOR_DIV_EXPR: case FLOOR_MOD_EXPR:
895 case ROUND_DIV_EXPR: case ROUND_MOD_EXPR:
896 /* These always produce results lower than either operand. */
900 case POINTER_PLUS_EXPR:
901 gcc_assert (operation_type == left_base_type
902 && sizetype == right_base_type);
903 left_operand = convert (operation_type, left_operand);
904 right_operand = convert (sizetype, right_operand);
907 case PLUS_NOMOD_EXPR:
908 case MINUS_NOMOD_EXPR:
909 if (op_code == PLUS_NOMOD_EXPR)
912 op_code = MINUS_EXPR;
915 /* ... fall through ... */
919 /* Avoid doing arithmetics in ENUMERAL_TYPE or BOOLEAN_TYPE like the
920 other compilers. Contrary to C, Ada doesn't allow arithmetics in
921 these types but can generate addition/subtraction for Succ/Pred. */
923 && (TREE_CODE (operation_type) == ENUMERAL_TYPE
924 || TREE_CODE (operation_type) == BOOLEAN_TYPE))
925 operation_type = left_base_type = right_base_type
926 = gnat_type_for_mode (TYPE_MODE (operation_type),
927 TYPE_UNSIGNED (operation_type));
929 /* ... fall through ... */
933 /* The result type should be the same as the base types of the
934 both operands (and they should be the same). Convert
935 everything to the result type. */
937 gcc_assert (operation_type == left_base_type
938 && left_base_type == right_base_type);
939 left_operand = convert (operation_type, left_operand);
940 right_operand = convert (operation_type, right_operand);
943 if (modulus && !integer_pow2p (modulus))
945 result = nonbinary_modular_operation (op_code, operation_type,
946 left_operand, right_operand);
949 /* If either operand is a NULL_EXPR, just return a new one. */
950 else if (TREE_CODE (left_operand) == NULL_EXPR)
951 return build1 (NULL_EXPR, operation_type, TREE_OPERAND (left_operand, 0));
952 else if (TREE_CODE (right_operand) == NULL_EXPR)
953 return build1 (NULL_EXPR, operation_type, TREE_OPERAND (right_operand, 0));
954 else if (op_code == ARRAY_REF || op_code == ARRAY_RANGE_REF)
955 result = fold (build4 (op_code, operation_type, left_operand,
956 right_operand, NULL_TREE, NULL_TREE));
959 = fold_build2 (op_code, operation_type, left_operand, right_operand);
961 if (TREE_CONSTANT (result))
963 else if (op_code == ARRAY_REF || op_code == ARRAY_RANGE_REF)
965 TREE_THIS_NOTRAP (result) = 1;
966 if (TYPE_VOLATILE (operation_type))
967 TREE_THIS_VOLATILE (result) = 1;
970 TREE_CONSTANT (result)
971 |= (TREE_CONSTANT (left_operand) && TREE_CONSTANT (right_operand));
973 TREE_SIDE_EFFECTS (result) |= has_side_effects;
975 /* If we are working with modular types, perform the MOD operation
976 if something above hasn't eliminated the need for it. */
978 result = fold_build2 (FLOOR_MOD_EXPR, operation_type, result,
979 convert (operation_type, modulus));
981 if (result_type && result_type != operation_type)
982 result = convert (result_type, result);
987 /* Similar, but for unary operations. */
990 build_unary_op (enum tree_code op_code, tree result_type, tree operand)
992 tree type = TREE_TYPE (operand);
993 tree base_type = get_base_type (type);
994 tree operation_type = result_type;
996 bool side_effects = false;
999 && TREE_CODE (operation_type) == RECORD_TYPE
1000 && TYPE_JUSTIFIED_MODULAR_P (operation_type))
1001 operation_type = TREE_TYPE (TYPE_FIELDS (operation_type));
1004 && !AGGREGATE_TYPE_P (operation_type)
1005 && TYPE_EXTRA_SUBTYPE_P (operation_type))
1006 operation_type = get_base_type (operation_type);
1012 if (!operation_type)
1013 result_type = operation_type = TREE_TYPE (type);
1015 gcc_assert (result_type == TREE_TYPE (type));
1017 result = fold_build1 (op_code, operation_type, operand);
1020 case TRUTH_NOT_EXPR:
1021 #ifdef ENABLE_CHECKING
1022 gcc_assert (TREE_CODE (get_base_type (result_type)) == BOOLEAN_TYPE);
1024 result = invert_truthvalue_loc (EXPR_LOCATION (operand), operand);
1025 /* When not optimizing, fold the result as invert_truthvalue_loc
1026 doesn't fold the result of comparisons. This is intended to undo
1027 the trick used for boolean rvalues in gnat_to_gnu. */
1029 result = fold (result);
1032 case ATTR_ADDR_EXPR:
1034 switch (TREE_CODE (operand))
1037 case UNCONSTRAINED_ARRAY_REF:
1038 result = TREE_OPERAND (operand, 0);
1040 /* Make sure the type here is a pointer, not a reference.
1041 GCC wants pointer types for function addresses. */
1043 result_type = build_pointer_type (type);
1045 /* If the underlying object can alias everything, propagate the
1046 property since we are effectively retrieving the object. */
1047 if (POINTER_TYPE_P (TREE_TYPE (result))
1048 && TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (result)))
1050 if (TREE_CODE (result_type) == POINTER_TYPE
1051 && !TYPE_REF_CAN_ALIAS_ALL (result_type))
1053 = build_pointer_type_for_mode (TREE_TYPE (result_type),
1054 TYPE_MODE (result_type),
1056 else if (TREE_CODE (result_type) == REFERENCE_TYPE
1057 && !TYPE_REF_CAN_ALIAS_ALL (result_type))
1059 = build_reference_type_for_mode (TREE_TYPE (result_type),
1060 TYPE_MODE (result_type),
1067 TREE_TYPE (result) = type = build_pointer_type (type);
1071 /* Fold a compound expression if it has unconstrained array type
1072 since the middle-end cannot handle it. But we don't it in the
1073 general case because it may introduce aliasing issues if the
1074 first operand is an indirect assignment and the second operand
1075 the corresponding address, e.g. for an allocator. */
1076 if (TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
1078 result = build_unary_op (ADDR_EXPR, result_type,
1079 TREE_OPERAND (operand, 1));
1080 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1081 TREE_OPERAND (operand, 0), result);
1087 case ARRAY_RANGE_REF:
1090 /* If this is for 'Address, find the address of the prefix and add
1091 the offset to the field. Otherwise, do this the normal way. */
1092 if (op_code == ATTR_ADDR_EXPR)
1094 HOST_WIDE_INT bitsize;
1095 HOST_WIDE_INT bitpos;
1097 enum machine_mode mode;
1098 int unsignedp, volatilep;
1100 inner = get_inner_reference (operand, &bitsize, &bitpos, &offset,
1101 &mode, &unsignedp, &volatilep,
1104 /* If INNER is a padding type whose field has a self-referential
1105 size, convert to that inner type. We know the offset is zero
1106 and we need to have that type visible. */
1107 if (TYPE_IS_PADDING_P (TREE_TYPE (inner))
1108 && CONTAINS_PLACEHOLDER_P
1109 (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS
1110 (TREE_TYPE (inner))))))
1111 inner = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (inner))),
1114 /* Compute the offset as a byte offset from INNER. */
1116 offset = size_zero_node;
1118 offset = size_binop (PLUS_EXPR, offset,
1119 size_int (bitpos / BITS_PER_UNIT));
1121 /* Take the address of INNER, convert the offset to void *, and
1122 add then. It will later be converted to the desired result
1124 inner = build_unary_op (ADDR_EXPR, NULL_TREE, inner);
1125 inner = convert (ptr_void_type_node, inner);
1126 result = build_binary_op (POINTER_PLUS_EXPR, ptr_void_type_node,
1128 result = convert (build_pointer_type (TREE_TYPE (operand)),
1135 /* If this is just a constructor for a padded record, we can
1136 just take the address of the single field and convert it to
1137 a pointer to our type. */
1138 if (TYPE_IS_PADDING_P (type))
1140 result = VEC_index (constructor_elt,
1141 CONSTRUCTOR_ELTS (operand),
1143 result = convert (build_pointer_type (TREE_TYPE (operand)),
1144 build_unary_op (ADDR_EXPR, NULL_TREE, result));
1151 if (AGGREGATE_TYPE_P (type)
1152 && AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (operand, 0))))
1153 return build_unary_op (ADDR_EXPR, result_type,
1154 TREE_OPERAND (operand, 0));
1156 /* ... fallthru ... */
1158 case VIEW_CONVERT_EXPR:
1159 /* If this just a variant conversion or if the conversion doesn't
1160 change the mode, get the result type from this type and go down.
1161 This is needed for conversions of CONST_DECLs, to eventually get
1162 to the address of their CORRESPONDING_VARs. */
1163 if ((TYPE_MAIN_VARIANT (type)
1164 == TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (operand, 0))))
1165 || (TYPE_MODE (type) != BLKmode
1166 && (TYPE_MODE (type)
1167 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (operand, 0))))))
1168 return build_unary_op (ADDR_EXPR,
1169 (result_type ? result_type
1170 : build_pointer_type (type)),
1171 TREE_OPERAND (operand, 0));
1175 operand = DECL_CONST_CORRESPONDING_VAR (operand);
1177 /* ... fall through ... */
1182 /* If we are taking the address of a padded record whose field is
1183 contains a template, take the address of the template. */
1184 if (TYPE_IS_PADDING_P (type)
1185 && TREE_CODE (TREE_TYPE (TYPE_FIELDS (type))) == RECORD_TYPE
1186 && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (TYPE_FIELDS (type))))
1188 type = TREE_TYPE (TYPE_FIELDS (type));
1189 operand = convert (type, operand);
1192 gnat_mark_addressable (operand);
1193 result = build_fold_addr_expr (operand);
1196 TREE_CONSTANT (result) = staticp (operand) || TREE_CONSTANT (operand);
1200 /* If we want to refer to an unconstrained array, use the appropriate
1201 expression to do so. This will never survive down to the back-end.
1202 But if TYPE is a thin pointer, first convert to a fat pointer. */
1203 if (TYPE_IS_THIN_POINTER_P (type)
1204 && TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type)))
1207 = convert (TREE_TYPE (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type))),
1209 type = TREE_TYPE (operand);
1212 if (TYPE_IS_FAT_POINTER_P (type))
1214 result = build1 (UNCONSTRAINED_ARRAY_REF,
1215 TYPE_UNCONSTRAINED_ARRAY (type), operand);
1216 TREE_READONLY (result)
1217 = TYPE_READONLY (TYPE_UNCONSTRAINED_ARRAY (type));
1220 /* If we are dereferencing an ADDR_EXPR, return its operand. */
1221 else if (TREE_CODE (operand) == ADDR_EXPR)
1222 result = TREE_OPERAND (operand, 0);
1224 /* Otherwise, build and fold the indirect reference. */
1227 result = build_fold_indirect_ref (operand);
1228 TREE_READONLY (result) = TYPE_READONLY (TREE_TYPE (type));
1232 = (!TYPE_IS_FAT_POINTER_P (type) && TYPE_VOLATILE (TREE_TYPE (type)));
1238 tree modulus = ((operation_type
1239 && TREE_CODE (operation_type) == INTEGER_TYPE
1240 && TYPE_MODULAR_P (operation_type))
1241 ? TYPE_MODULUS (operation_type) : NULL_TREE);
1242 int mod_pow2 = modulus && integer_pow2p (modulus);
1244 /* If this is a modular type, there are various possibilities
1245 depending on the operation and whether the modulus is a
1246 power of two or not. */
1250 gcc_assert (operation_type == base_type);
1251 operand = convert (operation_type, operand);
1253 /* The fastest in the negate case for binary modulus is
1254 the straightforward code; the TRUNC_MOD_EXPR below
1255 is an AND operation. */
1256 if (op_code == NEGATE_EXPR && mod_pow2)
1257 result = fold_build2 (TRUNC_MOD_EXPR, operation_type,
1258 fold_build1 (NEGATE_EXPR, operation_type,
1262 /* For nonbinary negate case, return zero for zero operand,
1263 else return the modulus minus the operand. If the modulus
1264 is a power of two minus one, we can do the subtraction
1265 as an XOR since it is equivalent and faster on most machines. */
1266 else if (op_code == NEGATE_EXPR && !mod_pow2)
1268 if (integer_pow2p (fold_build2 (PLUS_EXPR, operation_type,
1270 convert (operation_type,
1271 integer_one_node))))
1272 result = fold_build2 (BIT_XOR_EXPR, operation_type,
1275 result = fold_build2 (MINUS_EXPR, operation_type,
1278 result = fold_build3 (COND_EXPR, operation_type,
1279 fold_build2 (NE_EXPR,
1284 integer_zero_node)),
1289 /* For the NOT cases, we need a constant equal to
1290 the modulus minus one. For a binary modulus, we
1291 XOR against the constant and subtract the operand from
1292 that constant for nonbinary modulus. */
1294 tree cnst = fold_build2 (MINUS_EXPR, operation_type, modulus,
1295 convert (operation_type,
1299 result = fold_build2 (BIT_XOR_EXPR, operation_type,
1302 result = fold_build2 (MINUS_EXPR, operation_type,
1310 /* ... fall through ... */
1313 gcc_assert (operation_type == base_type);
1314 result = fold_build1 (op_code, operation_type,
1315 convert (operation_type, operand));
1320 TREE_SIDE_EFFECTS (result) = 1;
1321 if (TREE_CODE (result) == INDIRECT_REF)
1322 TREE_THIS_VOLATILE (result) = TYPE_VOLATILE (TREE_TYPE (result));
1325 if (result_type && TREE_TYPE (result) != result_type)
1326 result = convert (result_type, result);
1331 /* Similar, but for COND_EXPR. */
1334 build_cond_expr (tree result_type, tree condition_operand,
1335 tree true_operand, tree false_operand)
1337 bool addr_p = false;
1340 /* The front-end verified that result, true and false operands have
1341 same base type. Convert everything to the result type. */
1342 true_operand = convert (result_type, true_operand);
1343 false_operand = convert (result_type, false_operand);
1345 /* If the result type is unconstrained, take the address of the operands and
1346 then dereference the result. Likewise if the result type is passed by
1347 reference, but this is natively handled in the gimplifier. */
1348 if (TREE_CODE (result_type) == UNCONSTRAINED_ARRAY_TYPE
1349 || CONTAINS_PLACEHOLDER_P (TYPE_SIZE (result_type)))
1351 result_type = build_pointer_type (result_type);
1352 true_operand = build_unary_op (ADDR_EXPR, result_type, true_operand);
1353 false_operand = build_unary_op (ADDR_EXPR, result_type, false_operand);
1357 result = fold_build3 (COND_EXPR, result_type, condition_operand,
1358 true_operand, false_operand);
1360 /* If we have a common SAVE_EXPR (possibly surrounded by arithmetics)
1361 in both arms, make sure it gets evaluated by moving it ahead of the
1362 conditional expression. This is necessary because it is evaluated
1363 in only one place at run time and would otherwise be uninitialized
1364 in one of the arms. */
1365 true_operand = skip_simple_arithmetic (true_operand);
1366 false_operand = skip_simple_arithmetic (false_operand);
1368 if (true_operand == false_operand && TREE_CODE (true_operand) == SAVE_EXPR)
1369 result = build2 (COMPOUND_EXPR, result_type, true_operand, result);
1372 result = build_unary_op (INDIRECT_REF, NULL_TREE, result);
1377 /* Similar, but for COMPOUND_EXPR. */
1380 build_compound_expr (tree result_type, tree stmt_operand, tree expr_operand)
1382 bool addr_p = false;
1385 /* If the result type is unconstrained, take the address of the operand and
1386 then dereference the result. Likewise if the result type is passed by
1387 reference, but this is natively handled in the gimplifier. */
1388 if (TREE_CODE (result_type) == UNCONSTRAINED_ARRAY_TYPE
1389 || CONTAINS_PLACEHOLDER_P (TYPE_SIZE (result_type)))
1391 result_type = build_pointer_type (result_type);
1392 expr_operand = build_unary_op (ADDR_EXPR, result_type, expr_operand);
1396 result = fold_build2 (COMPOUND_EXPR, result_type, stmt_operand,
1400 result = build_unary_op (INDIRECT_REF, NULL_TREE, result);
1404 /* Similar, but for RETURN_EXPR. If RET_VAL is non-null, build a RETURN_EXPR
1405 around the assignment of RET_VAL to RET_OBJ. Otherwise just build a bare
1406 RETURN_EXPR around RESULT_OBJ, which may be null in this case. */
1409 build_return_expr (tree ret_obj, tree ret_val)
1415 /* The gimplifier explicitly enforces the following invariant:
1424 As a consequence, type consistency dictates that we use the type
1425 of the RET_OBJ as the operation type. */
1426 tree operation_type = TREE_TYPE (ret_obj);
1428 /* Convert the right operand to the operation type. Note that it's the
1429 same transformation as in the MODIFY_EXPR case of build_binary_op,
1430 with the assumption that the type cannot involve a placeholder. */
1431 if (operation_type != TREE_TYPE (ret_val))
1432 ret_val = convert (operation_type, ret_val);
1434 result_expr = build2 (MODIFY_EXPR, operation_type, ret_obj, ret_val);
1437 result_expr = ret_obj;
1439 return build1 (RETURN_EXPR, void_type_node, result_expr);
1442 /* Build a CALL_EXPR to call FUNDECL with one argument, ARG. Return
1446 build_call_1_expr (tree fundecl, tree arg)
1448 tree call = build_call_nary (TREE_TYPE (TREE_TYPE (fundecl)),
1449 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1451 TREE_SIDE_EFFECTS (call) = 1;
1455 /* Build a CALL_EXPR to call FUNDECL with two arguments, ARG1 & ARG2. Return
1459 build_call_2_expr (tree fundecl, tree arg1, tree arg2)
1461 tree call = build_call_nary (TREE_TYPE (TREE_TYPE (fundecl)),
1462 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1464 TREE_SIDE_EFFECTS (call) = 1;
1468 /* Likewise to call FUNDECL with no arguments. */
1471 build_call_0_expr (tree fundecl)
1473 /* We rely on build_call_nary to compute TREE_SIDE_EFFECTS. This makes
1474 it possible to propagate DECL_IS_PURE on parameterless functions. */
1475 tree call = build_call_nary (TREE_TYPE (TREE_TYPE (fundecl)),
1476 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1481 /* Call a function that raises an exception and pass the line number and file
1482 name, if requested. MSG says which exception function to call.
1484 GNAT_NODE is the gnat node conveying the source location for which the
1485 error should be signaled, or Empty in which case the error is signaled on
1486 the current ref_file_name/input_line.
1488 KIND says which kind of exception this is for
1489 (N_Raise_{Constraint,Storage,Program}_Error). */
1492 build_call_raise (int msg, Node_Id gnat_node, char kind)
1494 tree fndecl = gnat_raise_decls[msg];
1495 tree label = get_exception_label (kind);
1501 /* If this is to be done as a goto, handle that case. */
1504 Entity_Id local_raise = Get_Local_Raise_Call_Entity ();
1505 tree gnu_result = build1 (GOTO_EXPR, void_type_node, label);
1507 /* If Local_Raise is present, generate
1508 Local_Raise (exception'Identity); */
1509 if (Present (local_raise))
1511 tree gnu_local_raise
1512 = gnat_to_gnu_entity (local_raise, NULL_TREE, 0);
1513 tree gnu_exception_entity
1514 = gnat_to_gnu_entity (Get_RT_Exception_Entity (msg), NULL_TREE, 0);
1516 = build_call_1_expr (gnu_local_raise,
1517 build_unary_op (ADDR_EXPR, NULL_TREE,
1518 gnu_exception_entity));
1520 gnu_result = build2 (COMPOUND_EXPR, void_type_node,
1521 gnu_call, gnu_result);}
1527 = (Debug_Flag_NN || Exception_Locations_Suppressed)
1529 : (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1530 ? IDENTIFIER_POINTER
1531 (get_identifier (Get_Name_String
1533 (Get_Source_File_Index (Sloc (gnat_node))))))
1537 filename = build_string (len, str);
1539 = (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1540 ? Get_Logical_Line_Number (Sloc(gnat_node)) : input_line;
1542 TREE_TYPE (filename) = build_array_type (unsigned_char_type_node,
1543 build_index_type (size_int (len)));
1546 build_call_2_expr (fndecl,
1548 build_pointer_type (unsigned_char_type_node),
1550 build_int_cst (NULL_TREE, line_number));
1553 /* Similar to build_call_raise, for an index or range check exception as
1554 determined by MSG, with extra information generated of the form
1555 "INDEX out of range FIRST..LAST". */
1558 build_call_raise_range (int msg, Node_Id gnat_node,
1559 tree index, tree first, tree last)
1562 tree fndecl = gnat_raise_decls_ext[msg];
1564 int line_number, column_number;
1569 = (Debug_Flag_NN || Exception_Locations_Suppressed)
1571 : (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1572 ? IDENTIFIER_POINTER
1573 (get_identifier (Get_Name_String
1575 (Get_Source_File_Index (Sloc (gnat_node))))))
1579 filename = build_string (len, str);
1580 if (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1582 line_number = Get_Logical_Line_Number (Sloc (gnat_node));
1583 column_number = Get_Column_Number (Sloc (gnat_node));
1587 line_number = input_line;
1591 TREE_TYPE (filename) = build_array_type (unsigned_char_type_node,
1592 build_index_type (size_int (len)));
1594 call = build_call_nary (TREE_TYPE (TREE_TYPE (fndecl)),
1595 build_unary_op (ADDR_EXPR, NULL_TREE, fndecl),
1598 build_pointer_type (unsigned_char_type_node),
1600 build_int_cst (NULL_TREE, line_number),
1601 build_int_cst (NULL_TREE, column_number),
1602 convert (integer_type_node, index),
1603 convert (integer_type_node, first),
1604 convert (integer_type_node, last));
1605 TREE_SIDE_EFFECTS (call) = 1;
1609 /* Similar to build_call_raise, with extra information about the column
1610 where the check failed. */
1613 build_call_raise_column (int msg, Node_Id gnat_node)
1615 tree fndecl = gnat_raise_decls_ext[msg];
1618 int line_number, column_number;
1623 = (Debug_Flag_NN || Exception_Locations_Suppressed)
1625 : (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1626 ? IDENTIFIER_POINTER
1627 (get_identifier (Get_Name_String
1629 (Get_Source_File_Index (Sloc (gnat_node))))))
1633 filename = build_string (len, str);
1634 if (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1636 line_number = Get_Logical_Line_Number (Sloc (gnat_node));
1637 column_number = Get_Column_Number (Sloc (gnat_node));
1641 line_number = input_line;
1645 TREE_TYPE (filename) = build_array_type (unsigned_char_type_node,
1646 build_index_type (size_int (len)));
1648 call = build_call_nary (TREE_TYPE (TREE_TYPE (fndecl)),
1649 build_unary_op (ADDR_EXPR, NULL_TREE, fndecl),
1652 build_pointer_type (unsigned_char_type_node),
1654 build_int_cst (NULL_TREE, line_number),
1655 build_int_cst (NULL_TREE, column_number));
1656 TREE_SIDE_EFFECTS (call) = 1;
1660 /* qsort comparer for the bit positions of two constructor elements
1661 for record components. */
1664 compare_elmt_bitpos (const PTR rt1, const PTR rt2)
1666 const constructor_elt * const elmt1 = (const constructor_elt * const) rt1;
1667 const constructor_elt * const elmt2 = (const constructor_elt * const) rt2;
1668 const_tree const field1 = elmt1->index;
1669 const_tree const field2 = elmt2->index;
1671 = tree_int_cst_compare (bit_position (field1), bit_position (field2));
1673 return ret ? ret : (int) (DECL_UID (field1) - DECL_UID (field2));
1676 /* Return a CONSTRUCTOR of TYPE whose elements are V. */
1679 gnat_build_constructor (tree type, VEC(constructor_elt,gc) *v)
1681 bool allconstant = (TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST);
1682 bool side_effects = false;
1683 tree result, obj, val;
1684 unsigned int n_elmts;
1686 /* Scan the elements to see if they are all constant or if any has side
1687 effects, to let us set global flags on the resulting constructor. Count
1688 the elements along the way for possible sorting purposes below. */
1689 FOR_EACH_CONSTRUCTOR_ELT (v, n_elmts, obj, val)
1691 /* The predicate must be in keeping with output_constructor. */
1692 if (!TREE_CONSTANT (val)
1693 || (TREE_CODE (type) == RECORD_TYPE
1694 && CONSTRUCTOR_BITFIELD_P (obj)
1695 && !initializer_constant_valid_for_bitfield_p (val))
1696 || !initializer_constant_valid_p (val, TREE_TYPE (val)))
1697 allconstant = false;
1699 if (TREE_SIDE_EFFECTS (val))
1700 side_effects = true;
1703 /* For record types with constant components only, sort field list
1704 by increasing bit position. This is necessary to ensure the
1705 constructor can be output as static data. */
1706 if (allconstant && TREE_CODE (type) == RECORD_TYPE && n_elmts > 1)
1707 VEC_qsort (constructor_elt, v, compare_elmt_bitpos);
1709 result = build_constructor (type, v);
1710 TREE_CONSTANT (result) = TREE_STATIC (result) = allconstant;
1711 TREE_SIDE_EFFECTS (result) = side_effects;
1712 TREE_READONLY (result) = TYPE_READONLY (type) || allconstant;
1716 /* Return a COMPONENT_REF to access a field that is given by COMPONENT,
1717 an IDENTIFIER_NODE giving the name of the field, or FIELD, a FIELD_DECL,
1718 for the field. Don't fold the result if NO_FOLD_P is true.
1720 We also handle the fact that we might have been passed a pointer to the
1721 actual record and know how to look for fields in variant parts. */
1724 build_simple_component_ref (tree record_variable, tree component,
1725 tree field, bool no_fold_p)
1727 tree record_type = TYPE_MAIN_VARIANT (TREE_TYPE (record_variable));
1728 tree ref, inner_variable;
1730 gcc_assert ((TREE_CODE (record_type) == RECORD_TYPE
1731 || TREE_CODE (record_type) == UNION_TYPE
1732 || TREE_CODE (record_type) == QUAL_UNION_TYPE)
1733 && TYPE_SIZE (record_type)
1734 && (component != 0) != (field != 0));
1736 /* If no field was specified, look for a field with the specified name
1737 in the current record only. */
1739 for (field = TYPE_FIELDS (record_type); field;
1740 field = TREE_CHAIN (field))
1741 if (DECL_NAME (field) == component)
1747 /* If this field is not in the specified record, see if we can find a field
1748 in the specified record whose original field is the same as this one. */
1749 if (DECL_CONTEXT (field) != record_type)
1753 /* First loop thru normal components. */
1754 for (new_field = TYPE_FIELDS (record_type); new_field;
1755 new_field = DECL_CHAIN (new_field))
1756 if (SAME_FIELD_P (field, new_field))
1759 /* Next, see if we're looking for an inherited component in an extension.
1760 If so, look thru the extension directly. */
1762 && TREE_CODE (record_variable) == VIEW_CONVERT_EXPR
1763 && TYPE_ALIGN_OK (record_type)
1764 && TREE_CODE (TREE_TYPE (TREE_OPERAND (record_variable, 0)))
1766 && TYPE_ALIGN_OK (TREE_TYPE (TREE_OPERAND (record_variable, 0))))
1768 ref = build_simple_component_ref (TREE_OPERAND (record_variable, 0),
1769 NULL_TREE, field, no_fold_p);
1774 /* Next, loop thru DECL_INTERNAL_P components if we haven't found
1775 the component in the first search. Doing this search in 2 steps
1776 is required to avoiding hidden homonymous fields in the
1779 for (new_field = TYPE_FIELDS (record_type); new_field;
1780 new_field = DECL_CHAIN (new_field))
1781 if (DECL_INTERNAL_P (new_field))
1784 = build_simple_component_ref (record_variable,
1785 NULL_TREE, new_field, no_fold_p);
1786 ref = build_simple_component_ref (field_ref, NULL_TREE, field,
1799 /* If the field's offset has overflowed, do not attempt to access it
1800 as doing so may trigger sanity checks deeper in the back-end.
1801 Note that we don't need to warn since this will be done on trying
1802 to declare the object. */
1803 if (TREE_CODE (DECL_FIELD_OFFSET (field)) == INTEGER_CST
1804 && TREE_OVERFLOW (DECL_FIELD_OFFSET (field)))
1807 /* Look through conversion between type variants. Note that this
1808 is transparent as far as the field is concerned. */
1809 if (TREE_CODE (record_variable) == VIEW_CONVERT_EXPR
1810 && TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (record_variable, 0)))
1812 inner_variable = TREE_OPERAND (record_variable, 0);
1814 inner_variable = record_variable;
1816 ref = build3 (COMPONENT_REF, TREE_TYPE (field), inner_variable, field,
1819 if (TREE_READONLY (record_variable) || TREE_READONLY (field))
1820 TREE_READONLY (ref) = 1;
1821 if (TREE_THIS_VOLATILE (record_variable) || TREE_THIS_VOLATILE (field)
1822 || TYPE_VOLATILE (record_type))
1823 TREE_THIS_VOLATILE (ref) = 1;
1828 /* The generic folder may punt in this case because the inner array type
1829 can be self-referential, but folding is in fact not problematic. */
1830 else if (TREE_CODE (record_variable) == CONSTRUCTOR
1831 && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (record_variable)))
1833 VEC(constructor_elt,gc) *elts = CONSTRUCTOR_ELTS (record_variable);
1834 unsigned HOST_WIDE_INT idx;
1836 FOR_EACH_CONSTRUCTOR_ELT (elts, idx, index, value)
1846 /* Like build_simple_component_ref, except that we give an error if the
1847 reference could not be found. */
1850 build_component_ref (tree record_variable, tree component,
1851 tree field, bool no_fold_p)
1853 tree ref = build_simple_component_ref (record_variable, component, field,
1859 /* If FIELD was specified, assume this is an invalid user field so raise
1860 Constraint_Error. Otherwise, we have no type to return so abort. */
1862 return build1 (NULL_EXPR, TREE_TYPE (field),
1863 build_call_raise (CE_Discriminant_Check_Failed, Empty,
1864 N_Raise_Constraint_Error));
1867 /* Helper for build_call_alloc_dealloc, with arguments to be interpreted
1868 identically. Process the case where a GNAT_PROC to call is provided. */
1871 build_call_alloc_dealloc_proc (tree gnu_obj, tree gnu_size, tree gnu_type,
1872 Entity_Id gnat_proc, Entity_Id gnat_pool)
1874 tree gnu_proc = gnat_to_gnu (gnat_proc);
1875 tree gnu_proc_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_proc);
1878 /* The storage pools are obviously always tagged types, but the
1879 secondary stack uses the same mechanism and is not tagged. */
1880 if (Is_Tagged_Type (Etype (gnat_pool)))
1882 /* The size is the third parameter; the alignment is the
1884 Entity_Id gnat_size_type
1885 = Etype (Next_Formal (Next_Formal (First_Formal (gnat_proc))));
1886 tree gnu_size_type = gnat_to_gnu_type (gnat_size_type);
1888 tree gnu_pool = gnat_to_gnu (gnat_pool);
1889 tree gnu_pool_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_pool);
1890 tree gnu_align = size_int (TYPE_ALIGN (gnu_type) / BITS_PER_UNIT);
1892 gnu_size = convert (gnu_size_type, gnu_size);
1893 gnu_align = convert (gnu_size_type, gnu_align);
1895 /* The first arg is always the address of the storage pool; next
1896 comes the address of the object, for a deallocator, then the
1897 size and alignment. */
1899 gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)),
1900 gnu_proc_addr, 4, gnu_pool_addr,
1901 gnu_obj, gnu_size, gnu_align);
1903 gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)),
1904 gnu_proc_addr, 3, gnu_pool_addr,
1905 gnu_size, gnu_align);
1908 /* Secondary stack case. */
1911 /* The size is the second parameter. */
1912 Entity_Id gnat_size_type
1913 = Etype (Next_Formal (First_Formal (gnat_proc)));
1914 tree gnu_size_type = gnat_to_gnu_type (gnat_size_type);
1916 gnu_size = convert (gnu_size_type, gnu_size);
1918 /* The first arg is the address of the object, for a deallocator,
1921 gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)),
1922 gnu_proc_addr, 2, gnu_obj, gnu_size);
1924 gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)),
1925 gnu_proc_addr, 1, gnu_size);
1928 TREE_SIDE_EFFECTS (gnu_call) = 1;
1932 /* Helper for build_call_alloc_dealloc, to build and return an allocator for
1933 DATA_SIZE bytes aimed at containing a DATA_TYPE object, using the default
1934 __gnat_malloc allocator. Honor DATA_TYPE alignments greater than what the
1938 maybe_wrap_malloc (tree data_size, tree data_type, Node_Id gnat_node)
1940 /* When the DATA_TYPE alignment is stricter than what malloc offers
1941 (super-aligned case), we allocate an "aligning" wrapper type and return
1942 the address of its single data field with the malloc's return value
1943 stored just in front. */
1945 unsigned int data_align = TYPE_ALIGN (data_type);
1946 unsigned int default_allocator_alignment
1947 = get_target_default_allocator_alignment () * BITS_PER_UNIT;
1950 = ((data_align > default_allocator_alignment)
1951 ? make_aligning_type (data_type, data_align, data_size,
1952 default_allocator_alignment,
1953 POINTER_SIZE / BITS_PER_UNIT)
1957 = aligning_type ? TYPE_SIZE_UNIT (aligning_type) : data_size;
1961 /* On VMS, if pointers are 64-bit and the allocator size is 32-bit or
1962 Convention C, allocate 32-bit memory. */
1963 if (TARGET_ABI_OPEN_VMS
1964 && POINTER_SIZE == 64
1965 && Nkind (gnat_node) == N_Allocator
1966 && (UI_To_Int (Esize (Etype (gnat_node))) == 32
1967 || Convention (Etype (gnat_node)) == Convention_C))
1968 malloc_ptr = build_call_1_expr (malloc32_decl, size_to_malloc);
1970 malloc_ptr = build_call_1_expr (malloc_decl, size_to_malloc);
1974 /* Latch malloc's return value and get a pointer to the aligning field
1976 tree storage_ptr = gnat_protect_expr (malloc_ptr);
1978 tree aligning_record_addr
1979 = convert (build_pointer_type (aligning_type), storage_ptr);
1981 tree aligning_record
1982 = build_unary_op (INDIRECT_REF, NULL_TREE, aligning_record_addr);
1985 = build_component_ref (aligning_record, NULL_TREE,
1986 TYPE_FIELDS (aligning_type), false);
1988 tree aligning_field_addr
1989 = build_unary_op (ADDR_EXPR, NULL_TREE, aligning_field);
1991 /* Then arrange to store the allocator's return value ahead
1993 tree storage_ptr_slot_addr
1994 = build_binary_op (POINTER_PLUS_EXPR, ptr_void_type_node,
1995 convert (ptr_void_type_node, aligning_field_addr),
1996 size_int (-(HOST_WIDE_INT) POINTER_SIZE
1999 tree storage_ptr_slot
2000 = build_unary_op (INDIRECT_REF, NULL_TREE,
2001 convert (build_pointer_type (ptr_void_type_node),
2002 storage_ptr_slot_addr));
2005 build2 (COMPOUND_EXPR, TREE_TYPE (aligning_field_addr),
2006 build_binary_op (MODIFY_EXPR, NULL_TREE,
2007 storage_ptr_slot, storage_ptr),
2008 aligning_field_addr);
2014 /* Helper for build_call_alloc_dealloc, to release a DATA_TYPE object
2015 designated by DATA_PTR using the __gnat_free entry point. */
2018 maybe_wrap_free (tree data_ptr, tree data_type)
2020 /* In the regular alignment case, we pass the data pointer straight to free.
2021 In the superaligned case, we need to retrieve the initial allocator
2022 return value, stored in front of the data block at allocation time. */
2024 unsigned int data_align = TYPE_ALIGN (data_type);
2025 unsigned int default_allocator_alignment
2026 = get_target_default_allocator_alignment () * BITS_PER_UNIT;
2030 if (data_align > default_allocator_alignment)
2032 /* DATA_FRONT_PTR (void *)
2033 = (void *)DATA_PTR - (void *)sizeof (void *)) */
2036 (POINTER_PLUS_EXPR, ptr_void_type_node,
2037 convert (ptr_void_type_node, data_ptr),
2038 size_int (-(HOST_WIDE_INT) POINTER_SIZE / BITS_PER_UNIT));
2040 /* FREE_PTR (void *) = *(void **)DATA_FRONT_PTR */
2043 (INDIRECT_REF, NULL_TREE,
2044 convert (build_pointer_type (ptr_void_type_node), data_front_ptr));
2047 free_ptr = data_ptr;
2049 return build_call_1_expr (free_decl, free_ptr);
2052 /* Build a GCC tree to call an allocation or deallocation function.
2053 If GNU_OBJ is nonzero, it is an object to deallocate. Otherwise,
2054 generate an allocator.
2056 GNU_SIZE is the number of bytes to allocate and GNU_TYPE is the contained
2057 object type, used to determine the to-be-honored address alignment.
2058 GNAT_PROC, if present, is a procedure to call and GNAT_POOL is the storage
2059 pool to use. If not present, malloc and free are used. GNAT_NODE is used
2060 to provide an error location for restriction violation messages. */
2063 build_call_alloc_dealloc (tree gnu_obj, tree gnu_size, tree gnu_type,
2064 Entity_Id gnat_proc, Entity_Id gnat_pool,
2067 gnu_size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (gnu_size, gnu_obj);
2069 /* Explicit proc to call ? This one is assumed to deal with the type
2070 alignment constraints. */
2071 if (Present (gnat_proc))
2072 return build_call_alloc_dealloc_proc (gnu_obj, gnu_size, gnu_type,
2073 gnat_proc, gnat_pool);
2075 /* Otherwise, object to "free" or "malloc" with possible special processing
2076 for alignments stricter than what the default allocator honors. */
2078 return maybe_wrap_free (gnu_obj, gnu_type);
2081 /* Assert that we no longer can be called with this special pool. */
2082 gcc_assert (gnat_pool != -1);
2084 /* Check that we aren't violating the associated restriction. */
2085 if (!(Nkind (gnat_node) == N_Allocator && Comes_From_Source (gnat_node)))
2086 Check_No_Implicit_Heap_Alloc (gnat_node);
2088 return maybe_wrap_malloc (gnu_size, gnu_type, gnat_node);
2092 /* Build a GCC tree to correspond to allocating an object of TYPE whose
2093 initial value is INIT, if INIT is nonzero. Convert the expression to
2094 RESULT_TYPE, which must be some type of pointer. Return the tree.
2096 GNAT_PROC and GNAT_POOL optionally give the procedure to call and
2097 the storage pool to use. GNAT_NODE is used to provide an error
2098 location for restriction violation messages. If IGNORE_INIT_TYPE is
2099 true, ignore the type of INIT for the purpose of determining the size;
2100 this will cause the maximum size to be allocated if TYPE is of
2101 self-referential size. */
2104 build_allocator (tree type, tree init, tree result_type, Entity_Id gnat_proc,
2105 Entity_Id gnat_pool, Node_Id gnat_node, bool ignore_init_type)
2107 tree size = TYPE_SIZE_UNIT (type);
2110 /* If the initializer, if present, is a NULL_EXPR, just return a new one. */
2111 if (init && TREE_CODE (init) == NULL_EXPR)
2112 return build1 (NULL_EXPR, result_type, TREE_OPERAND (init, 0));
2114 /* If RESULT_TYPE is a fat or thin pointer, set SIZE to be the sum of the
2115 sizes of the object and its template. Allocate the whole thing and
2116 fill in the parts that are known. */
2117 else if (TYPE_IS_FAT_OR_THIN_POINTER_P (result_type))
2120 = build_unc_object_type_from_ptr (result_type, type,
2121 get_identifier ("ALLOC"), false);
2122 tree template_type = TREE_TYPE (TYPE_FIELDS (storage_type));
2123 tree storage_ptr_type = build_pointer_type (storage_type);
2126 size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TYPE_SIZE_UNIT (storage_type),
2129 /* If the size overflows, pass -1 so the allocator will raise
2131 if (TREE_CODE (size) == INTEGER_CST && TREE_OVERFLOW (size))
2132 size = ssize_int (-1);
2134 storage = build_call_alloc_dealloc (NULL_TREE, size, storage_type,
2135 gnat_proc, gnat_pool, gnat_node);
2136 storage = convert (storage_ptr_type, gnat_protect_expr (storage));
2138 /* If there is an initializing expression, then make a constructor for
2139 the entire object including the bounds and copy it into the object.
2140 If there is no initializing expression, just set the bounds. */
2143 VEC(constructor_elt,gc) *v = VEC_alloc (constructor_elt, gc, 2);
2145 CONSTRUCTOR_APPEND_ELT (v, TYPE_FIELDS (storage_type),
2146 build_template (template_type, type, init));
2147 CONSTRUCTOR_APPEND_ELT (v, DECL_CHAIN (TYPE_FIELDS (storage_type)),
2151 build2 (COMPOUND_EXPR, storage_ptr_type,
2153 (MODIFY_EXPR, storage_type,
2154 build_unary_op (INDIRECT_REF, NULL_TREE,
2155 convert (storage_ptr_type, storage)),
2156 gnat_build_constructor (storage_type, v)),
2157 convert (storage_ptr_type, storage)));
2161 (COMPOUND_EXPR, result_type,
2163 (MODIFY_EXPR, template_type,
2165 (build_unary_op (INDIRECT_REF, NULL_TREE,
2166 convert (storage_ptr_type, storage)),
2167 NULL_TREE, TYPE_FIELDS (storage_type), false),
2168 build_template (template_type, type, NULL_TREE)),
2169 convert (result_type, convert (storage_ptr_type, storage)));
2172 /* If we have an initializing expression, see if its size is simpler
2173 than the size from the type. */
2174 if (!ignore_init_type && init && TYPE_SIZE_UNIT (TREE_TYPE (init))
2175 && (TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (init))) == INTEGER_CST
2176 || CONTAINS_PLACEHOLDER_P (size)))
2177 size = TYPE_SIZE_UNIT (TREE_TYPE (init));
2179 /* If the size is still self-referential, reference the initializing
2180 expression, if it is present. If not, this must have been a
2181 call to allocate a library-level object, in which case we use
2182 the maximum size. */
2183 if (CONTAINS_PLACEHOLDER_P (size))
2185 if (!ignore_init_type && init)
2186 size = substitute_placeholder_in_expr (size, init);
2188 size = max_size (size, true);
2191 /* If the size overflows, pass -1 so the allocator will raise
2193 if (TREE_CODE (size) == INTEGER_CST && TREE_OVERFLOW (size))
2194 size = ssize_int (-1);
2196 result = convert (result_type,
2197 build_call_alloc_dealloc (NULL_TREE, size, type,
2198 gnat_proc, gnat_pool,
2201 /* If we have an initial value, protect the new address, assign the value
2202 and return the address with a COMPOUND_EXPR. */
2205 result = gnat_protect_expr (result);
2207 = build2 (COMPOUND_EXPR, TREE_TYPE (result),
2209 (MODIFY_EXPR, NULL_TREE,
2210 build_unary_op (INDIRECT_REF,
2211 TREE_TYPE (TREE_TYPE (result)), result),
2216 return convert (result_type, result);
2219 /* Indicate that we need to take the address of T and that it therefore
2220 should not be allocated in a register. Returns true if successful. */
2223 gnat_mark_addressable (tree t)
2226 switch (TREE_CODE (t))
2231 case ARRAY_RANGE_REF:
2234 case VIEW_CONVERT_EXPR:
2235 case NON_LVALUE_EXPR:
2237 t = TREE_OPERAND (t, 0);
2241 t = TREE_OPERAND (t, 1);
2245 TREE_ADDRESSABLE (t) = 1;
2251 TREE_ADDRESSABLE (t) = 1;
2255 TREE_ADDRESSABLE (t) = 1;
2259 return DECL_CONST_CORRESPONDING_VAR (t)
2260 && gnat_mark_addressable (DECL_CONST_CORRESPONDING_VAR (t));
2267 /* Save EXP for later use or reuse. This is equivalent to save_expr in tree.c
2268 but we know how to handle our own nodes. */
2271 gnat_save_expr (tree exp)
2273 tree type = TREE_TYPE (exp);
2274 enum tree_code code = TREE_CODE (exp);
2276 if (TREE_CONSTANT (exp) || code == SAVE_EXPR || code == NULL_EXPR)
2279 if (code == UNCONSTRAINED_ARRAY_REF)
2281 tree t = build1 (code, type, gnat_save_expr (TREE_OPERAND (exp, 0)));
2282 TREE_READONLY (t) = TYPE_READONLY (type);
2286 /* If this is a COMPONENT_REF of a fat pointer, save the entire fat pointer.
2287 This may be more efficient, but will also allow us to more easily find
2288 the match for the PLACEHOLDER_EXPR. */
2289 if (code == COMPONENT_REF
2290 && TYPE_IS_FAT_POINTER_P (TREE_TYPE (TREE_OPERAND (exp, 0))))
2291 return build3 (code, type, gnat_save_expr (TREE_OPERAND (exp, 0)),
2292 TREE_OPERAND (exp, 1), TREE_OPERAND (exp, 2));
2294 return save_expr (exp);
2297 /* Protect EXP for immediate reuse. This is a variant of gnat_save_expr that
2298 is optimized under the assumption that EXP's value doesn't change before
2299 its subsequent reuse(s) except through its potential reevaluation. */
2302 gnat_protect_expr (tree exp)
2304 tree type = TREE_TYPE (exp);
2305 enum tree_code code = TREE_CODE (exp);
2307 if (TREE_CONSTANT (exp) || code == SAVE_EXPR || code == NULL_EXPR)
2310 /* If EXP has no side effects, we theoretically don't need to do anything.
2311 However, we may be recursively passed more and more complex expressions
2312 involving checks which will be reused multiple times and eventually be
2313 unshared for gimplification; in order to avoid a complexity explosion
2314 at that point, we protect any expressions more complex than a simple
2315 arithmetic expression. */
2316 if (!TREE_SIDE_EFFECTS (exp))
2318 tree inner = skip_simple_arithmetic (exp);
2319 if (!EXPR_P (inner) || REFERENCE_CLASS_P (inner))
2323 /* If this is a conversion, protect what's inside the conversion. */
2324 if (code == NON_LVALUE_EXPR
2325 || CONVERT_EXPR_CODE_P (code)
2326 || code == VIEW_CONVERT_EXPR)
2327 return build1 (code, type, gnat_protect_expr (TREE_OPERAND (exp, 0)));
2329 /* If we're indirectly referencing something, we only need to protect the
2330 address since the data itself can't change in these situations. */
2331 if (code == INDIRECT_REF || code == UNCONSTRAINED_ARRAY_REF)
2333 tree t = build1 (code, type, gnat_protect_expr (TREE_OPERAND (exp, 0)));
2334 TREE_READONLY (t) = TYPE_READONLY (type);
2338 /* If this is a COMPONENT_REF of a fat pointer, save the entire fat pointer.
2339 This may be more efficient, but will also allow us to more easily find
2340 the match for the PLACEHOLDER_EXPR. */
2341 if (code == COMPONENT_REF
2342 && TYPE_IS_FAT_POINTER_P (TREE_TYPE (TREE_OPERAND (exp, 0))))
2343 return build3 (code, type, gnat_protect_expr (TREE_OPERAND (exp, 0)),
2344 TREE_OPERAND (exp, 1), TREE_OPERAND (exp, 2));
2346 /* If this is a fat pointer or something that can be placed in a register,
2347 just make a SAVE_EXPR. Likewise for a CALL_EXPR as large objects are
2348 returned via invisible reference in most ABIs so the temporary will
2349 directly be filled by the callee. */
2350 if (TYPE_IS_FAT_POINTER_P (type)
2351 || TYPE_MODE (type) != BLKmode
2352 || code == CALL_EXPR)
2353 return save_expr (exp);
2355 /* Otherwise reference, protect the address and dereference. */
2357 build_unary_op (INDIRECT_REF, type,
2358 save_expr (build_unary_op (ADDR_EXPR,
2359 build_reference_type (type),
2363 /* This is equivalent to stabilize_reference_1 in tree.c but we take an extra
2364 argument to force evaluation of everything. */
2367 gnat_stabilize_reference_1 (tree e, bool force)
2369 enum tree_code code = TREE_CODE (e);
2370 tree type = TREE_TYPE (e);
2373 /* We cannot ignore const expressions because it might be a reference
2374 to a const array but whose index contains side-effects. But we can
2375 ignore things that are actual constant or that already have been
2376 handled by this function. */
2377 if (TREE_CONSTANT (e) || code == SAVE_EXPR)
2380 switch (TREE_CODE_CLASS (code))
2382 case tcc_exceptional:
2383 case tcc_declaration:
2384 case tcc_comparison:
2385 case tcc_expression:
2388 /* If this is a COMPONENT_REF of a fat pointer, save the entire
2389 fat pointer. This may be more efficient, but will also allow
2390 us to more easily find the match for the PLACEHOLDER_EXPR. */
2391 if (code == COMPONENT_REF
2392 && TYPE_IS_FAT_POINTER_P (TREE_TYPE (TREE_OPERAND (e, 0))))
2394 = build3 (code, type,
2395 gnat_stabilize_reference_1 (TREE_OPERAND (e, 0), force),
2396 TREE_OPERAND (e, 1), TREE_OPERAND (e, 2));
2397 /* If the expression has side-effects, then encase it in a SAVE_EXPR
2398 so that it will only be evaluated once. */
2399 /* The tcc_reference and tcc_comparison classes could be handled as
2400 below, but it is generally faster to only evaluate them once. */
2401 else if (TREE_SIDE_EFFECTS (e) || force)
2402 return save_expr (e);
2408 /* Recursively stabilize each operand. */
2410 = build2 (code, type,
2411 gnat_stabilize_reference_1 (TREE_OPERAND (e, 0), force),
2412 gnat_stabilize_reference_1 (TREE_OPERAND (e, 1), force));
2416 /* Recursively stabilize each operand. */
2418 = build1 (code, type,
2419 gnat_stabilize_reference_1 (TREE_OPERAND (e, 0), force));
2426 /* See similar handling in gnat_stabilize_reference. */
2427 TREE_READONLY (result) = TREE_READONLY (e);
2428 TREE_SIDE_EFFECTS (result) |= TREE_SIDE_EFFECTS (e);
2429 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
2431 if (code == INDIRECT_REF || code == ARRAY_REF || code == ARRAY_RANGE_REF)
2432 TREE_THIS_NOTRAP (result) = TREE_THIS_NOTRAP (e);
2437 /* This is equivalent to stabilize_reference in tree.c but we know how to
2438 handle our own nodes and we take extra arguments. FORCE says whether to
2439 force evaluation of everything. We set SUCCESS to true unless we walk
2440 through something we don't know how to stabilize. */
2443 gnat_stabilize_reference (tree ref, bool force, bool *success)
2445 tree type = TREE_TYPE (ref);
2446 enum tree_code code = TREE_CODE (ref);
2449 /* Assume we'll success unless proven otherwise. */
2459 /* No action is needed in this case. */
2465 case FIX_TRUNC_EXPR:
2466 case VIEW_CONVERT_EXPR:
2468 = build1 (code, type,
2469 gnat_stabilize_reference (TREE_OPERAND (ref, 0), force,
2474 case UNCONSTRAINED_ARRAY_REF:
2475 result = build1 (code, type,
2476 gnat_stabilize_reference_1 (TREE_OPERAND (ref, 0),
2481 result = build3 (COMPONENT_REF, type,
2482 gnat_stabilize_reference (TREE_OPERAND (ref, 0), force,
2484 TREE_OPERAND (ref, 1), NULL_TREE);
2488 result = build3 (BIT_FIELD_REF, type,
2489 gnat_stabilize_reference (TREE_OPERAND (ref, 0), force,
2491 gnat_stabilize_reference_1 (TREE_OPERAND (ref, 1),
2493 gnat_stabilize_reference_1 (TREE_OPERAND (ref, 2),
2498 case ARRAY_RANGE_REF:
2499 result = build4 (code, type,
2500 gnat_stabilize_reference (TREE_OPERAND (ref, 0), force,
2502 gnat_stabilize_reference_1 (TREE_OPERAND (ref, 1),
2504 NULL_TREE, NULL_TREE);
2508 result = gnat_stabilize_reference_1 (ref, force);
2512 result = build2 (COMPOUND_EXPR, type,
2513 gnat_stabilize_reference (TREE_OPERAND (ref, 0), force,
2515 gnat_stabilize_reference_1 (TREE_OPERAND (ref, 1),
2520 /* Constructors with 1 element are used extensively to formally
2521 convert objects to special wrapping types. */
2522 if (TREE_CODE (type) == RECORD_TYPE
2523 && VEC_length (constructor_elt, CONSTRUCTOR_ELTS (ref)) == 1)
2526 = VEC_index (constructor_elt, CONSTRUCTOR_ELTS (ref), 0)->index;
2528 = VEC_index (constructor_elt, CONSTRUCTOR_ELTS (ref), 0)->value;
2530 = build_constructor_single (type, index,
2531 gnat_stabilize_reference_1 (value,
2543 ref = error_mark_node;
2545 /* ... fall through to failure ... */
2547 /* If arg isn't a kind of lvalue we recognize, make no change.
2548 Caller should recognize the error for an invalid lvalue. */
2555 /* TREE_THIS_VOLATILE and TREE_SIDE_EFFECTS set on the initial expression
2556 may not be sustained across some paths, such as the way via build1 for
2557 INDIRECT_REF. We reset those flags here in the general case, which is
2558 consistent with the GCC version of this routine.
2560 Special care should be taken regarding TREE_SIDE_EFFECTS, because some
2561 paths introduce side-effects where there was none initially (e.g. if a
2562 SAVE_EXPR is built) and we also want to keep track of that. */
2563 TREE_READONLY (result) = TREE_READONLY (ref);
2564 TREE_SIDE_EFFECTS (result) |= TREE_SIDE_EFFECTS (ref);
2565 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);