1 /****************************************************************************
3 * GNAT COMPILER COMPONENTS *
7 * C Implementation File *
9 * Copyright (C) 1992-2010, 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"
33 #include "tree-inline.h"
50 static tree find_common_type (tree, tree);
51 static tree compare_arrays (tree, tree, tree);
52 static tree nonbinary_modular_operation (enum tree_code, tree, tree, tree);
53 static tree build_simple_component_ref (tree, tree, tree, bool);
55 /* Return the base type of TYPE. */
58 get_base_type (tree type)
60 if (TREE_CODE (type) == RECORD_TYPE
61 && TYPE_JUSTIFIED_MODULAR_P (type))
62 type = TREE_TYPE (TYPE_FIELDS (type));
64 while (TREE_TYPE (type)
65 && (TREE_CODE (type) == INTEGER_TYPE
66 || TREE_CODE (type) == REAL_TYPE))
67 type = TREE_TYPE (type);
72 /* EXP is a GCC tree representing an address. See if we can find how
73 strictly the object at that address is aligned. Return that alignment
74 in bits. If we don't know anything about the alignment, return 0. */
77 known_alignment (tree exp)
79 unsigned int this_alignment;
80 unsigned int lhs, rhs;
82 switch (TREE_CODE (exp))
85 case VIEW_CONVERT_EXPR:
87 /* Conversions between pointers and integers don't change the alignment
88 of the underlying object. */
89 this_alignment = known_alignment (TREE_OPERAND (exp, 0));
93 /* The value of a COMPOUND_EXPR is that of it's second operand. */
94 this_alignment = known_alignment (TREE_OPERAND (exp, 1));
99 /* If two address are added, the alignment of the result is the
100 minimum of the two alignments. */
101 lhs = known_alignment (TREE_OPERAND (exp, 0));
102 rhs = known_alignment (TREE_OPERAND (exp, 1));
103 this_alignment = MIN (lhs, rhs);
106 case POINTER_PLUS_EXPR:
107 lhs = known_alignment (TREE_OPERAND (exp, 0));
108 rhs = known_alignment (TREE_OPERAND (exp, 1));
109 /* If we don't know the alignment of the offset, we assume that
112 this_alignment = lhs;
114 this_alignment = MIN (lhs, rhs);
118 /* If there is a choice between two values, use the smallest one. */
119 lhs = known_alignment (TREE_OPERAND (exp, 1));
120 rhs = known_alignment (TREE_OPERAND (exp, 2));
121 this_alignment = MIN (lhs, rhs);
126 unsigned HOST_WIDE_INT c = TREE_INT_CST_LOW (exp);
127 /* The first part of this represents the lowest bit in the constant,
128 but it is originally in bytes, not bits. */
129 this_alignment = MIN (BITS_PER_UNIT * (c & -c), BIGGEST_ALIGNMENT);
134 /* If we know the alignment of just one side, use it. Otherwise,
135 use the product of the alignments. */
136 lhs = known_alignment (TREE_OPERAND (exp, 0));
137 rhs = known_alignment (TREE_OPERAND (exp, 1));
140 this_alignment = rhs;
142 this_alignment = lhs;
144 this_alignment = MIN (lhs * rhs, BIGGEST_ALIGNMENT);
148 /* A bit-and expression is as aligned as the maximum alignment of the
149 operands. We typically get here for a complex lhs and a constant
150 negative power of two on the rhs to force an explicit alignment, so
151 don't bother looking at the lhs. */
152 this_alignment = known_alignment (TREE_OPERAND (exp, 1));
156 this_alignment = expr_align (TREE_OPERAND (exp, 0));
161 tree t = maybe_inline_call_in_expr (exp);
163 return known_alignment (t);
166 /* Fall through... */
169 /* For other pointer expressions, we assume that the pointed-to object
170 is at least as aligned as the pointed-to type. Beware that we can
171 have a dummy type here (e.g. a Taft Amendment type), for which the
172 alignment is meaningless and should be ignored. */
173 if (POINTER_TYPE_P (TREE_TYPE (exp))
174 && !TYPE_IS_DUMMY_P (TREE_TYPE (TREE_TYPE (exp))))
175 this_alignment = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp)));
181 return this_alignment;
184 /* We have a comparison or assignment operation on two types, T1 and T2, which
185 are either both array types or both record types. T1 is assumed to be for
186 the left hand side operand, and T2 for the right hand side. Return the
187 type that both operands should be converted to for the operation, if any.
188 Otherwise return zero. */
191 find_common_type (tree t1, tree t2)
193 /* ??? As of today, various constructs lead here with types of different
194 sizes even when both constants (e.g. tagged types, packable vs regular
195 component types, padded vs unpadded types, ...). While some of these
196 would better be handled upstream (types should be made consistent before
197 calling into build_binary_op), some others are really expected and we
198 have to be careful. */
200 /* We must prevent writing more than what the target may hold if this is for
201 an assignment and the case of tagged types is handled in build_binary_op
202 so use the lhs type if it is known to be smaller, or of constant size and
203 the rhs type is not, whatever the modes. We also force t1 in case of
204 constant size equality to minimize occurrences of view conversions on the
205 lhs of assignments. */
206 if (TREE_CONSTANT (TYPE_SIZE (t1))
207 && (!TREE_CONSTANT (TYPE_SIZE (t2))
208 || !tree_int_cst_lt (TYPE_SIZE (t2), TYPE_SIZE (t1))))
211 /* Otherwise, if the lhs type is non-BLKmode, use it. Note that we know
212 that we will not have any alignment problems since, if we did, the
213 non-BLKmode type could not have been used. */
214 if (TYPE_MODE (t1) != BLKmode)
217 /* If the rhs type is of constant size, use it whatever the modes. At
218 this point it is known to be smaller, or of constant size and the
220 if (TREE_CONSTANT (TYPE_SIZE (t2)))
223 /* Otherwise, if the rhs type is non-BLKmode, use it. */
224 if (TYPE_MODE (t2) != BLKmode)
227 /* In this case, both types have variable size and BLKmode. It's
228 probably best to leave the "type mismatch" because changing it
229 could cause a bad self-referential reference. */
233 /* Return an expression tree representing an equality comparison of A1 and A2,
234 two objects of type ARRAY_TYPE. The result should be of type RESULT_TYPE.
236 Two arrays are equal in one of two ways: (1) if both have zero length in
237 some dimension (not necessarily the same dimension) or (2) if the lengths
238 in each dimension are equal and the data is equal. We perform the length
239 tests in as efficient a manner as possible. */
242 compare_arrays (tree result_type, tree a1, tree a2)
244 tree result = convert (result_type, boolean_true_node);
245 tree a1_is_null = convert (result_type, boolean_false_node);
246 tree a2_is_null = convert (result_type, boolean_false_node);
247 tree t1 = TREE_TYPE (a1);
248 tree t2 = TREE_TYPE (a2);
249 bool a1_side_effects_p = TREE_SIDE_EFFECTS (a1);
250 bool a2_side_effects_p = TREE_SIDE_EFFECTS (a2);
251 bool length_zero_p = false;
253 /* If either operand has side-effects, they have to be evaluated only once
254 in spite of the multiple references to the operand in the comparison. */
255 if (a1_side_effects_p)
256 a1 = gnat_protect_expr (a1);
258 if (a2_side_effects_p)
259 a2 = gnat_protect_expr (a2);
261 /* Process each dimension separately and compare the lengths. If any
262 dimension has a length known to be zero, set LENGTH_ZERO_P to true
263 in order to suppress the comparison of the data at the end. */
264 while (TREE_CODE (t1) == ARRAY_TYPE && TREE_CODE (t2) == ARRAY_TYPE)
266 tree lb1 = TYPE_MIN_VALUE (TYPE_DOMAIN (t1));
267 tree ub1 = TYPE_MAX_VALUE (TYPE_DOMAIN (t1));
268 tree lb2 = TYPE_MIN_VALUE (TYPE_DOMAIN (t2));
269 tree ub2 = TYPE_MAX_VALUE (TYPE_DOMAIN (t2));
270 tree length1 = size_binop (PLUS_EXPR, size_binop (MINUS_EXPR, ub1, lb1),
272 tree length2 = size_binop (PLUS_EXPR, size_binop (MINUS_EXPR, ub2, lb2),
274 tree comparison, this_a1_is_null, this_a2_is_null;
276 /* If the length of the first array is a constant, swap our operands
277 unless the length of the second array is the constant zero. */
278 if (TREE_CODE (length1) == INTEGER_CST && !integer_zerop (length2))
283 tem = a1, a1 = a2, a2 = tem;
284 tem = t1, t1 = t2, t2 = tem;
285 tem = lb1, lb1 = lb2, lb2 = tem;
286 tem = ub1, ub1 = ub2, ub2 = tem;
287 tem = length1, length1 = length2, length2 = tem;
288 tem = a1_is_null, a1_is_null = a2_is_null, a2_is_null = tem;
289 btem = a1_side_effects_p, a1_side_effects_p = a2_side_effects_p,
290 a2_side_effects_p = btem;
293 /* If the length of the second array is the constant zero, we can just
294 use the original stored bounds for the first array and see whether
295 last < first holds. */
296 if (integer_zerop (length2))
298 length_zero_p = true;
300 ub1 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
301 lb1 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
303 comparison = build_binary_op (LT_EXPR, result_type, ub1, lb1);
304 comparison = SUBSTITUTE_PLACEHOLDER_IN_EXPR (comparison, a1);
305 if (EXPR_P (comparison))
306 SET_EXPR_LOCATION (comparison, input_location);
308 this_a1_is_null = comparison;
309 this_a2_is_null = convert (result_type, boolean_true_node);
312 /* Otherwise, if the length is some other constant value, we know that
313 this dimension in the second array cannot be superflat, so we can
314 just use its length computed from the actual stored bounds. */
315 else if (TREE_CODE (length2) == INTEGER_CST)
319 ub1 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
320 lb1 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
321 /* Note that we know that UB2 and LB2 are constant and hence
322 cannot contain a PLACEHOLDER_EXPR. */
323 ub2 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t2)));
324 lb2 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t2)));
325 bt = get_base_type (TREE_TYPE (ub1));
328 = build_binary_op (EQ_EXPR, result_type,
329 build_binary_op (MINUS_EXPR, bt, ub1, lb1),
330 build_binary_op (MINUS_EXPR, bt, ub2, lb2));
331 comparison = SUBSTITUTE_PLACEHOLDER_IN_EXPR (comparison, a1);
332 if (EXPR_P (comparison))
333 SET_EXPR_LOCATION (comparison, input_location);
335 this_a1_is_null = build_binary_op (LT_EXPR, result_type, ub1, lb1);
336 if (EXPR_P (this_a1_is_null))
337 SET_EXPR_LOCATION (this_a1_is_null, input_location);
339 this_a2_is_null = convert (result_type, boolean_false_node);
342 /* Otherwise, compare the computed lengths. */
345 length1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length1, a1);
346 length2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length2, a2);
349 = build_binary_op (EQ_EXPR, result_type, length1, length2);
350 if (EXPR_P (comparison))
351 SET_EXPR_LOCATION (comparison, input_location);
353 /* If the length expression is of the form (cond ? val : 0), assume
354 that cond is equivalent to (length != 0). That's guaranteed by
355 construction of the array types in gnat_to_gnu_entity. */
356 if (TREE_CODE (length1) == COND_EXPR
357 && integer_zerop (TREE_OPERAND (length1, 2)))
358 this_a1_is_null = invert_truthvalue (TREE_OPERAND (length1, 0));
360 this_a1_is_null = build_binary_op (EQ_EXPR, result_type, length1,
362 if (EXPR_P (this_a1_is_null))
363 SET_EXPR_LOCATION (this_a1_is_null, input_location);
365 /* Likewise for the second array. */
366 if (TREE_CODE (length2) == COND_EXPR
367 && integer_zerop (TREE_OPERAND (length2, 2)))
368 this_a2_is_null = invert_truthvalue (TREE_OPERAND (length2, 0));
370 this_a2_is_null = build_binary_op (EQ_EXPR, result_type, length2,
372 if (EXPR_P (this_a2_is_null))
373 SET_EXPR_LOCATION (this_a2_is_null, input_location);
376 /* Append expressions for this dimension to the final expressions. */
377 result = build_binary_op (TRUTH_ANDIF_EXPR, result_type,
380 a1_is_null = build_binary_op (TRUTH_ORIF_EXPR, result_type,
381 this_a1_is_null, a1_is_null);
383 a2_is_null = build_binary_op (TRUTH_ORIF_EXPR, result_type,
384 this_a2_is_null, a2_is_null);
390 /* Unless the length of some dimension is known to be zero, compare the
391 data in the array. */
394 tree type = find_common_type (TREE_TYPE (a1), TREE_TYPE (a2));
399 a1 = convert (type, a1),
400 a2 = convert (type, a2);
403 comparison = fold_build2 (EQ_EXPR, result_type, a1, a2);
404 if (EXPR_P (comparison))
405 SET_EXPR_LOCATION (comparison, input_location);
408 = build_binary_op (TRUTH_ANDIF_EXPR, result_type, result, comparison);
411 /* The result is also true if both sizes are zero. */
412 result = build_binary_op (TRUTH_ORIF_EXPR, result_type,
413 build_binary_op (TRUTH_ANDIF_EXPR, result_type,
414 a1_is_null, a2_is_null),
417 /* If either operand has side-effects, they have to be evaluated before
418 starting the comparison above since the place they would be otherwise
419 evaluated could be wrong. */
420 if (a1_side_effects_p)
421 result = build2 (COMPOUND_EXPR, result_type, a1, result);
423 if (a2_side_effects_p)
424 result = build2 (COMPOUND_EXPR, result_type, a2, result);
429 /* Compute the result of applying OP_CODE to LHS and RHS, where both are of
430 type TYPE. We know that TYPE is a modular type with a nonbinary
434 nonbinary_modular_operation (enum tree_code op_code, tree type, tree lhs,
437 tree modulus = TYPE_MODULUS (type);
438 unsigned int needed_precision = tree_floor_log2 (modulus) + 1;
439 unsigned int precision;
440 bool unsignedp = true;
444 /* If this is an addition of a constant, convert it to a subtraction
445 of a constant since we can do that faster. */
446 if (op_code == PLUS_EXPR && TREE_CODE (rhs) == INTEGER_CST)
448 rhs = fold_build2 (MINUS_EXPR, type, modulus, rhs);
449 op_code = MINUS_EXPR;
452 /* For the logical operations, we only need PRECISION bits. For
453 addition and subtraction, we need one more and for multiplication we
454 need twice as many. But we never want to make a size smaller than
456 if (op_code == PLUS_EXPR || op_code == MINUS_EXPR)
457 needed_precision += 1;
458 else if (op_code == MULT_EXPR)
459 needed_precision *= 2;
461 precision = MAX (needed_precision, TYPE_PRECISION (op_type));
463 /* Unsigned will do for everything but subtraction. */
464 if (op_code == MINUS_EXPR)
467 /* If our type is the wrong signedness or isn't wide enough, make a new
468 type and convert both our operands to it. */
469 if (TYPE_PRECISION (op_type) < precision
470 || TYPE_UNSIGNED (op_type) != unsignedp)
472 /* Copy the node so we ensure it can be modified to make it modular. */
473 op_type = copy_node (gnat_type_for_size (precision, unsignedp));
474 modulus = convert (op_type, modulus);
475 SET_TYPE_MODULUS (op_type, modulus);
476 TYPE_MODULAR_P (op_type) = 1;
477 lhs = convert (op_type, lhs);
478 rhs = convert (op_type, rhs);
481 /* Do the operation, then we'll fix it up. */
482 result = fold_build2 (op_code, op_type, lhs, rhs);
484 /* For multiplication, we have no choice but to do a full modulus
485 operation. However, we want to do this in the narrowest
487 if (op_code == MULT_EXPR)
489 tree div_type = copy_node (gnat_type_for_size (needed_precision, 1));
490 modulus = convert (div_type, modulus);
491 SET_TYPE_MODULUS (div_type, modulus);
492 TYPE_MODULAR_P (div_type) = 1;
493 result = convert (op_type,
494 fold_build2 (TRUNC_MOD_EXPR, div_type,
495 convert (div_type, result), modulus));
498 /* For subtraction, add the modulus back if we are negative. */
499 else if (op_code == MINUS_EXPR)
501 result = gnat_protect_expr (result);
502 result = fold_build3 (COND_EXPR, op_type,
503 fold_build2 (LT_EXPR, boolean_type_node, result,
504 convert (op_type, integer_zero_node)),
505 fold_build2 (PLUS_EXPR, op_type, result, modulus),
509 /* For the other operations, subtract the modulus if we are >= it. */
512 result = gnat_protect_expr (result);
513 result = fold_build3 (COND_EXPR, op_type,
514 fold_build2 (GE_EXPR, boolean_type_node,
516 fold_build2 (MINUS_EXPR, op_type,
521 return convert (type, result);
524 /* Make a binary operation of kind OP_CODE. RESULT_TYPE is the type
525 desired for the result. Usually the operation is to be performed
526 in that type. For MODIFY_EXPR and ARRAY_REF, RESULT_TYPE may be 0
527 in which case the type to be used will be derived from the operands.
529 This function is very much unlike the ones for C and C++ since we
530 have already done any type conversion and matching required. All we
531 have to do here is validate the work done by SEM and handle subtypes. */
534 build_binary_op (enum tree_code op_code, tree result_type,
535 tree left_operand, tree right_operand)
537 tree left_type = TREE_TYPE (left_operand);
538 tree right_type = TREE_TYPE (right_operand);
539 tree left_base_type = get_base_type (left_type);
540 tree right_base_type = get_base_type (right_type);
541 tree operation_type = result_type;
542 tree best_type = NULL_TREE;
543 tree modulus, result;
544 bool has_side_effects = false;
547 && TREE_CODE (operation_type) == RECORD_TYPE
548 && TYPE_JUSTIFIED_MODULAR_P (operation_type))
549 operation_type = TREE_TYPE (TYPE_FIELDS (operation_type));
552 && !AGGREGATE_TYPE_P (operation_type)
553 && TYPE_EXTRA_SUBTYPE_P (operation_type))
554 operation_type = get_base_type (operation_type);
556 modulus = (operation_type
557 && TREE_CODE (operation_type) == INTEGER_TYPE
558 && TYPE_MODULAR_P (operation_type)
559 ? TYPE_MODULUS (operation_type) : NULL_TREE);
565 /* If there were integral or pointer conversions on the LHS, remove
566 them; we'll be putting them back below if needed. Likewise for
567 conversions between array and record types, except for justified
568 modular types. But don't do this if the right operand is not
569 BLKmode (for packed arrays) unless we are not changing the mode. */
570 while ((CONVERT_EXPR_P (left_operand)
571 || TREE_CODE (left_operand) == VIEW_CONVERT_EXPR)
572 && (((INTEGRAL_TYPE_P (left_type)
573 || POINTER_TYPE_P (left_type))
574 && (INTEGRAL_TYPE_P (TREE_TYPE
575 (TREE_OPERAND (left_operand, 0)))
576 || POINTER_TYPE_P (TREE_TYPE
577 (TREE_OPERAND (left_operand, 0)))))
578 || (((TREE_CODE (left_type) == RECORD_TYPE
579 && !TYPE_JUSTIFIED_MODULAR_P (left_type))
580 || TREE_CODE (left_type) == ARRAY_TYPE)
581 && ((TREE_CODE (TREE_TYPE
582 (TREE_OPERAND (left_operand, 0)))
584 || (TREE_CODE (TREE_TYPE
585 (TREE_OPERAND (left_operand, 0)))
587 && (TYPE_MODE (right_type) == BLKmode
588 || (TYPE_MODE (left_type)
589 == TYPE_MODE (TREE_TYPE
591 (left_operand, 0))))))))
593 left_operand = TREE_OPERAND (left_operand, 0);
594 left_type = TREE_TYPE (left_operand);
597 /* If a class-wide type may be involved, force use of the RHS type. */
598 if ((TREE_CODE (right_type) == RECORD_TYPE
599 || TREE_CODE (right_type) == UNION_TYPE)
600 && TYPE_ALIGN_OK (right_type))
601 operation_type = right_type;
603 /* If we are copying between padded objects with compatible types, use
604 the padded view of the objects, this is very likely more efficient.
605 Likewise for a padded object that is assigned a constructor, if we
606 can convert the constructor to the inner type, to avoid putting a
607 VIEW_CONVERT_EXPR on the LHS. But don't do so if we wouldn't have
608 actually copied anything. */
609 else if (TYPE_IS_PADDING_P (left_type)
610 && TREE_CONSTANT (TYPE_SIZE (left_type))
611 && ((TREE_CODE (right_operand) == COMPONENT_REF
613 (TREE_TYPE (TREE_OPERAND (right_operand, 0)))
614 && gnat_types_compatible_p
616 TREE_TYPE (TREE_OPERAND (right_operand, 0))))
617 || (TREE_CODE (right_operand) == CONSTRUCTOR
618 && !CONTAINS_PLACEHOLDER_P
619 (DECL_SIZE (TYPE_FIELDS (left_type)))))
620 && !integer_zerop (TYPE_SIZE (right_type)))
621 operation_type = left_type;
623 /* Find the best type to use for copying between aggregate types. */
624 else if (((TREE_CODE (left_type) == ARRAY_TYPE
625 && TREE_CODE (right_type) == ARRAY_TYPE)
626 || (TREE_CODE (left_type) == RECORD_TYPE
627 && TREE_CODE (right_type) == RECORD_TYPE))
628 && (best_type = find_common_type (left_type, right_type)))
629 operation_type = best_type;
631 /* Otherwise use the LHS type. */
632 else if (!operation_type)
633 operation_type = left_type;
635 /* Ensure everything on the LHS is valid. If we have a field reference,
636 strip anything that get_inner_reference can handle. Then remove any
637 conversions between types having the same code and mode. And mark
638 VIEW_CONVERT_EXPRs with TREE_ADDRESSABLE. When done, we must have
639 either an INDIRECT_REF, a NULL_EXPR or a DECL node. */
640 result = left_operand;
643 tree restype = TREE_TYPE (result);
645 if (TREE_CODE (result) == COMPONENT_REF
646 || TREE_CODE (result) == ARRAY_REF
647 || TREE_CODE (result) == ARRAY_RANGE_REF)
648 while (handled_component_p (result))
649 result = TREE_OPERAND (result, 0);
650 else if (TREE_CODE (result) == REALPART_EXPR
651 || TREE_CODE (result) == IMAGPART_EXPR
652 || (CONVERT_EXPR_P (result)
653 && (((TREE_CODE (restype)
654 == TREE_CODE (TREE_TYPE
655 (TREE_OPERAND (result, 0))))
656 && (TYPE_MODE (TREE_TYPE
657 (TREE_OPERAND (result, 0)))
658 == TYPE_MODE (restype)))
659 || TYPE_ALIGN_OK (restype))))
660 result = TREE_OPERAND (result, 0);
661 else if (TREE_CODE (result) == VIEW_CONVERT_EXPR)
663 TREE_ADDRESSABLE (result) = 1;
664 result = TREE_OPERAND (result, 0);
670 gcc_assert (TREE_CODE (result) == INDIRECT_REF
671 || TREE_CODE (result) == NULL_EXPR
674 /* Convert the right operand to the operation type unless it is
675 either already of the correct type or if the type involves a
676 placeholder, since the RHS may not have the same record type. */
677 if (operation_type != right_type
678 && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (operation_type)))
680 right_operand = convert (operation_type, right_operand);
681 right_type = operation_type;
684 /* If the left operand is not of the same type as the operation
685 type, wrap it up in a VIEW_CONVERT_EXPR. */
686 if (left_type != operation_type)
687 left_operand = unchecked_convert (operation_type, left_operand, false);
689 has_side_effects = true;
695 operation_type = TREE_TYPE (left_type);
697 /* ... fall through ... */
699 case ARRAY_RANGE_REF:
700 /* First look through conversion between type variants. Note that
701 this changes neither the operation type nor the type domain. */
702 if (TREE_CODE (left_operand) == VIEW_CONVERT_EXPR
703 && TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (left_operand, 0)))
704 == TYPE_MAIN_VARIANT (left_type))
706 left_operand = TREE_OPERAND (left_operand, 0);
707 left_type = TREE_TYPE (left_operand);
710 /* For a range, make sure the element type is consistent. */
711 if (op_code == ARRAY_RANGE_REF
712 && TREE_TYPE (operation_type) != TREE_TYPE (left_type))
713 operation_type = build_array_type (TREE_TYPE (left_type),
714 TYPE_DOMAIN (operation_type));
716 /* Then convert the right operand to its base type. This will prevent
717 unneeded sign conversions when sizetype is wider than integer. */
718 right_operand = convert (right_base_type, right_operand);
719 right_operand = convert (sizetype, right_operand);
721 if (!TREE_CONSTANT (right_operand)
722 || !TREE_CONSTANT (TYPE_MIN_VALUE (right_type)))
723 gnat_mark_addressable (left_operand);
728 case TRUTH_ANDIF_EXPR:
729 case TRUTH_ORIF_EXPR:
733 #ifdef ENABLE_CHECKING
734 gcc_assert (TREE_CODE (get_base_type (result_type)) == BOOLEAN_TYPE);
736 operation_type = left_base_type;
737 left_operand = convert (operation_type, left_operand);
738 right_operand = convert (operation_type, right_operand);
747 #ifdef ENABLE_CHECKING
748 gcc_assert (TREE_CODE (get_base_type (result_type)) == BOOLEAN_TYPE);
750 /* If either operand is a NULL_EXPR, just return a new one. */
751 if (TREE_CODE (left_operand) == NULL_EXPR)
752 return build2 (op_code, result_type,
753 build1 (NULL_EXPR, integer_type_node,
754 TREE_OPERAND (left_operand, 0)),
757 else if (TREE_CODE (right_operand) == NULL_EXPR)
758 return build2 (op_code, result_type,
759 build1 (NULL_EXPR, integer_type_node,
760 TREE_OPERAND (right_operand, 0)),
763 /* If either object is a justified modular types, get the
764 fields from within. */
765 if (TREE_CODE (left_type) == RECORD_TYPE
766 && TYPE_JUSTIFIED_MODULAR_P (left_type))
768 left_operand = convert (TREE_TYPE (TYPE_FIELDS (left_type)),
770 left_type = TREE_TYPE (left_operand);
771 left_base_type = get_base_type (left_type);
774 if (TREE_CODE (right_type) == RECORD_TYPE
775 && TYPE_JUSTIFIED_MODULAR_P (right_type))
777 right_operand = convert (TREE_TYPE (TYPE_FIELDS (right_type)),
779 right_type = TREE_TYPE (right_operand);
780 right_base_type = get_base_type (right_type);
783 /* If both objects are arrays, compare them specially. */
784 if ((TREE_CODE (left_type) == ARRAY_TYPE
785 || (TREE_CODE (left_type) == INTEGER_TYPE
786 && TYPE_HAS_ACTUAL_BOUNDS_P (left_type)))
787 && (TREE_CODE (right_type) == ARRAY_TYPE
788 || (TREE_CODE (right_type) == INTEGER_TYPE
789 && TYPE_HAS_ACTUAL_BOUNDS_P (right_type))))
791 result = compare_arrays (result_type, left_operand, right_operand);
793 if (op_code == NE_EXPR)
794 result = invert_truthvalue_loc (EXPR_LOCATION (result), result);
796 gcc_assert (op_code == EQ_EXPR);
801 /* Otherwise, the base types must be the same, unless they are both fat
802 pointer types or record types. In the latter case, use the best type
803 and convert both operands to that type. */
804 if (left_base_type != right_base_type)
806 if (TYPE_IS_FAT_POINTER_P (left_base_type)
807 && TYPE_IS_FAT_POINTER_P (right_base_type))
809 gcc_assert (TYPE_MAIN_VARIANT (left_base_type)
810 == TYPE_MAIN_VARIANT (right_base_type));
811 best_type = left_base_type;
814 else if (TREE_CODE (left_base_type) == RECORD_TYPE
815 && TREE_CODE (right_base_type) == RECORD_TYPE)
817 /* The only way this is permitted is if both types have the same
818 name. In that case, one of them must not be self-referential.
819 Use it as the best type. Even better with a fixed size. */
820 gcc_assert (TYPE_NAME (left_base_type)
821 && TYPE_NAME (left_base_type)
822 == TYPE_NAME (right_base_type));
824 if (TREE_CONSTANT (TYPE_SIZE (left_base_type)))
825 best_type = left_base_type;
826 else if (TREE_CONSTANT (TYPE_SIZE (right_base_type)))
827 best_type = right_base_type;
828 else if (!CONTAINS_PLACEHOLDER_P (TYPE_SIZE (left_base_type)))
829 best_type = left_base_type;
830 else if (!CONTAINS_PLACEHOLDER_P (TYPE_SIZE (right_base_type)))
831 best_type = right_base_type;
839 left_operand = convert (best_type, left_operand);
840 right_operand = convert (best_type, right_operand);
844 left_operand = convert (left_base_type, left_operand);
845 right_operand = convert (right_base_type, right_operand);
848 /* If we are comparing a fat pointer against zero, we just need to
849 compare the data pointer. */
850 if (TYPE_IS_FAT_POINTER_P (left_base_type)
851 && TREE_CODE (right_operand) == CONSTRUCTOR
852 && integer_zerop (VEC_index (constructor_elt,
853 CONSTRUCTOR_ELTS (right_operand),
857 = build_component_ref (left_operand, NULL_TREE,
858 TYPE_FIELDS (left_base_type), false);
860 = convert (TREE_TYPE (left_operand), integer_zero_node);
870 /* The RHS of a shift can be any type. Also, ignore any modulus
871 (we used to abort, but this is needed for unchecked conversion
872 to modular types). Otherwise, processing is the same as normal. */
873 gcc_assert (operation_type == left_base_type);
875 left_operand = convert (operation_type, left_operand);
881 /* For binary modulus, if the inputs are in range, so are the
883 if (modulus && integer_pow2p (modulus))
888 gcc_assert (TREE_TYPE (result_type) == left_base_type
889 && TREE_TYPE (result_type) == right_base_type);
890 left_operand = convert (left_base_type, left_operand);
891 right_operand = convert (right_base_type, right_operand);
894 case TRUNC_DIV_EXPR: case TRUNC_MOD_EXPR:
895 case CEIL_DIV_EXPR: case CEIL_MOD_EXPR:
896 case FLOOR_DIV_EXPR: case FLOOR_MOD_EXPR:
897 case ROUND_DIV_EXPR: case ROUND_MOD_EXPR:
898 /* These always produce results lower than either operand. */
902 case POINTER_PLUS_EXPR:
903 gcc_assert (operation_type == left_base_type
904 && sizetype == right_base_type);
905 left_operand = convert (operation_type, left_operand);
906 right_operand = convert (sizetype, right_operand);
909 case PLUS_NOMOD_EXPR:
910 case MINUS_NOMOD_EXPR:
911 if (op_code == PLUS_NOMOD_EXPR)
914 op_code = MINUS_EXPR;
917 /* ... fall through ... */
921 /* Avoid doing arithmetics in ENUMERAL_TYPE or BOOLEAN_TYPE like the
922 other compilers. Contrary to C, Ada doesn't allow arithmetics in
923 these types but can generate addition/subtraction for Succ/Pred. */
925 && (TREE_CODE (operation_type) == ENUMERAL_TYPE
926 || TREE_CODE (operation_type) == BOOLEAN_TYPE))
927 operation_type = left_base_type = right_base_type
928 = gnat_type_for_mode (TYPE_MODE (operation_type),
929 TYPE_UNSIGNED (operation_type));
931 /* ... fall through ... */
935 /* The result type should be the same as the base types of the
936 both operands (and they should be the same). Convert
937 everything to the result type. */
939 gcc_assert (operation_type == left_base_type
940 && left_base_type == right_base_type);
941 left_operand = convert (operation_type, left_operand);
942 right_operand = convert (operation_type, right_operand);
945 if (modulus && !integer_pow2p (modulus))
947 result = nonbinary_modular_operation (op_code, operation_type,
948 left_operand, right_operand);
951 /* If either operand is a NULL_EXPR, just return a new one. */
952 else if (TREE_CODE (left_operand) == NULL_EXPR)
953 return build1 (NULL_EXPR, operation_type, TREE_OPERAND (left_operand, 0));
954 else if (TREE_CODE (right_operand) == NULL_EXPR)
955 return build1 (NULL_EXPR, operation_type, TREE_OPERAND (right_operand, 0));
956 else if (op_code == ARRAY_REF || op_code == ARRAY_RANGE_REF)
957 result = fold (build4 (op_code, operation_type, left_operand,
958 right_operand, NULL_TREE, NULL_TREE));
961 = fold_build2 (op_code, operation_type, left_operand, right_operand);
963 if (TREE_CONSTANT (result))
965 else if (op_code == ARRAY_REF || op_code == ARRAY_RANGE_REF)
967 TREE_THIS_NOTRAP (result) = 1;
968 if (TYPE_VOLATILE (operation_type))
969 TREE_THIS_VOLATILE (result) = 1;
972 TREE_CONSTANT (result)
973 |= (TREE_CONSTANT (left_operand) && TREE_CONSTANT (right_operand));
975 TREE_SIDE_EFFECTS (result) |= has_side_effects;
977 /* If we are working with modular types, perform the MOD operation
978 if something above hasn't eliminated the need for it. */
980 result = fold_build2 (FLOOR_MOD_EXPR, operation_type, result,
981 convert (operation_type, modulus));
983 if (result_type && result_type != operation_type)
984 result = convert (result_type, result);
989 /* Similar, but for unary operations. */
992 build_unary_op (enum tree_code op_code, tree result_type, tree operand)
994 tree type = TREE_TYPE (operand);
995 tree base_type = get_base_type (type);
996 tree operation_type = result_type;
998 bool side_effects = false;
1001 && TREE_CODE (operation_type) == RECORD_TYPE
1002 && TYPE_JUSTIFIED_MODULAR_P (operation_type))
1003 operation_type = TREE_TYPE (TYPE_FIELDS (operation_type));
1006 && !AGGREGATE_TYPE_P (operation_type)
1007 && TYPE_EXTRA_SUBTYPE_P (operation_type))
1008 operation_type = get_base_type (operation_type);
1014 if (!operation_type)
1015 result_type = operation_type = TREE_TYPE (type);
1017 gcc_assert (result_type == TREE_TYPE (type));
1019 result = fold_build1 (op_code, operation_type, operand);
1022 case TRUTH_NOT_EXPR:
1023 #ifdef ENABLE_CHECKING
1024 gcc_assert (TREE_CODE (get_base_type (result_type)) == BOOLEAN_TYPE);
1026 result = invert_truthvalue_loc (EXPR_LOCATION (operand), operand);
1029 case ATTR_ADDR_EXPR:
1031 switch (TREE_CODE (operand))
1034 case UNCONSTRAINED_ARRAY_REF:
1035 result = TREE_OPERAND (operand, 0);
1037 /* Make sure the type here is a pointer, not a reference.
1038 GCC wants pointer types for function addresses. */
1040 result_type = build_pointer_type (type);
1042 /* If the underlying object can alias everything, propagate the
1043 property since we are effectively retrieving the object. */
1044 if (POINTER_TYPE_P (TREE_TYPE (result))
1045 && TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (result)))
1047 if (TREE_CODE (result_type) == POINTER_TYPE
1048 && !TYPE_REF_CAN_ALIAS_ALL (result_type))
1050 = build_pointer_type_for_mode (TREE_TYPE (result_type),
1051 TYPE_MODE (result_type),
1053 else if (TREE_CODE (result_type) == REFERENCE_TYPE
1054 && !TYPE_REF_CAN_ALIAS_ALL (result_type))
1056 = build_reference_type_for_mode (TREE_TYPE (result_type),
1057 TYPE_MODE (result_type),
1064 TREE_TYPE (result) = type = build_pointer_type (type);
1068 /* Fold a compound expression if it has unconstrained array type
1069 since the middle-end cannot handle it. But we don't it in the
1070 general case because it may introduce aliasing issues if the
1071 first operand is an indirect assignment and the second operand
1072 the corresponding address, e.g. for an allocator. */
1073 if (TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
1075 result = build_unary_op (ADDR_EXPR, result_type,
1076 TREE_OPERAND (operand, 1));
1077 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1078 TREE_OPERAND (operand, 0), result);
1084 case ARRAY_RANGE_REF:
1087 /* If this is for 'Address, find the address of the prefix and add
1088 the offset to the field. Otherwise, do this the normal way. */
1089 if (op_code == ATTR_ADDR_EXPR)
1091 HOST_WIDE_INT bitsize;
1092 HOST_WIDE_INT bitpos;
1094 enum machine_mode mode;
1095 int unsignedp, volatilep;
1097 inner = get_inner_reference (operand, &bitsize, &bitpos, &offset,
1098 &mode, &unsignedp, &volatilep,
1101 /* If INNER is a padding type whose field has a self-referential
1102 size, convert to that inner type. We know the offset is zero
1103 and we need to have that type visible. */
1104 if (TYPE_IS_PADDING_P (TREE_TYPE (inner))
1105 && CONTAINS_PLACEHOLDER_P
1106 (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS
1107 (TREE_TYPE (inner))))))
1108 inner = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (inner))),
1111 /* Compute the offset as a byte offset from INNER. */
1113 offset = size_zero_node;
1115 offset = size_binop (PLUS_EXPR, offset,
1116 size_int (bitpos / BITS_PER_UNIT));
1118 /* Take the address of INNER, convert the offset to void *, and
1119 add then. It will later be converted to the desired result
1121 inner = build_unary_op (ADDR_EXPR, NULL_TREE, inner);
1122 inner = convert (ptr_void_type_node, inner);
1123 result = build_binary_op (POINTER_PLUS_EXPR, ptr_void_type_node,
1125 result = convert (build_pointer_type (TREE_TYPE (operand)),
1132 /* If this is just a constructor for a padded record, we can
1133 just take the address of the single field and convert it to
1134 a pointer to our type. */
1135 if (TYPE_IS_PADDING_P (type))
1137 result = VEC_index (constructor_elt,
1138 CONSTRUCTOR_ELTS (operand),
1140 result = convert (build_pointer_type (TREE_TYPE (operand)),
1141 build_unary_op (ADDR_EXPR, NULL_TREE, result));
1148 if (AGGREGATE_TYPE_P (type)
1149 && AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (operand, 0))))
1150 return build_unary_op (ADDR_EXPR, result_type,
1151 TREE_OPERAND (operand, 0));
1153 /* ... fallthru ... */
1155 case VIEW_CONVERT_EXPR:
1156 /* If this just a variant conversion or if the conversion doesn't
1157 change the mode, get the result type from this type and go down.
1158 This is needed for conversions of CONST_DECLs, to eventually get
1159 to the address of their CORRESPONDING_VARs. */
1160 if ((TYPE_MAIN_VARIANT (type)
1161 == TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (operand, 0))))
1162 || (TYPE_MODE (type) != BLKmode
1163 && (TYPE_MODE (type)
1164 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (operand, 0))))))
1165 return build_unary_op (ADDR_EXPR,
1166 (result_type ? result_type
1167 : build_pointer_type (type)),
1168 TREE_OPERAND (operand, 0));
1172 operand = DECL_CONST_CORRESPONDING_VAR (operand);
1174 /* ... fall through ... */
1179 /* If we are taking the address of a padded record whose field is
1180 contains a template, take the address of the template. */
1181 if (TYPE_IS_PADDING_P (type)
1182 && TREE_CODE (TREE_TYPE (TYPE_FIELDS (type))) == RECORD_TYPE
1183 && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (TYPE_FIELDS (type))))
1185 type = TREE_TYPE (TYPE_FIELDS (type));
1186 operand = convert (type, operand);
1189 gnat_mark_addressable (operand);
1190 result = build_fold_addr_expr (operand);
1193 TREE_CONSTANT (result) = staticp (operand) || TREE_CONSTANT (operand);
1197 /* If we want to refer to an unconstrained array, use the appropriate
1198 expression to do so. This will never survive down to the back-end.
1199 But if TYPE is a thin pointer, first convert to a fat pointer. */
1200 if (TYPE_IS_THIN_POINTER_P (type)
1201 && TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type)))
1204 = convert (TREE_TYPE (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type))),
1206 type = TREE_TYPE (operand);
1209 if (TYPE_IS_FAT_POINTER_P (type))
1211 result = build1 (UNCONSTRAINED_ARRAY_REF,
1212 TYPE_UNCONSTRAINED_ARRAY (type), operand);
1213 TREE_READONLY (result)
1214 = TYPE_READONLY (TYPE_UNCONSTRAINED_ARRAY (type));
1217 /* If we are dereferencing an ADDR_EXPR, return its operand. */
1218 else if (TREE_CODE (operand) == ADDR_EXPR)
1219 result = TREE_OPERAND (operand, 0);
1221 /* Otherwise, build and fold the indirect reference. */
1224 result = build_fold_indirect_ref (operand);
1225 TREE_READONLY (result) = TYPE_READONLY (TREE_TYPE (type));
1229 = (!TYPE_IS_FAT_POINTER_P (type) && TYPE_VOLATILE (TREE_TYPE (type)));
1235 tree modulus = ((operation_type
1236 && TREE_CODE (operation_type) == INTEGER_TYPE
1237 && TYPE_MODULAR_P (operation_type))
1238 ? TYPE_MODULUS (operation_type) : NULL_TREE);
1239 int mod_pow2 = modulus && integer_pow2p (modulus);
1241 /* If this is a modular type, there are various possibilities
1242 depending on the operation and whether the modulus is a
1243 power of two or not. */
1247 gcc_assert (operation_type == base_type);
1248 operand = convert (operation_type, operand);
1250 /* The fastest in the negate case for binary modulus is
1251 the straightforward code; the TRUNC_MOD_EXPR below
1252 is an AND operation. */
1253 if (op_code == NEGATE_EXPR && mod_pow2)
1254 result = fold_build2 (TRUNC_MOD_EXPR, operation_type,
1255 fold_build1 (NEGATE_EXPR, operation_type,
1259 /* For nonbinary negate case, return zero for zero operand,
1260 else return the modulus minus the operand. If the modulus
1261 is a power of two minus one, we can do the subtraction
1262 as an XOR since it is equivalent and faster on most machines. */
1263 else if (op_code == NEGATE_EXPR && !mod_pow2)
1265 if (integer_pow2p (fold_build2 (PLUS_EXPR, operation_type,
1267 convert (operation_type,
1268 integer_one_node))))
1269 result = fold_build2 (BIT_XOR_EXPR, operation_type,
1272 result = fold_build2 (MINUS_EXPR, operation_type,
1275 result = fold_build3 (COND_EXPR, operation_type,
1276 fold_build2 (NE_EXPR,
1281 integer_zero_node)),
1286 /* For the NOT cases, we need a constant equal to
1287 the modulus minus one. For a binary modulus, we
1288 XOR against the constant and subtract the operand from
1289 that constant for nonbinary modulus. */
1291 tree cnst = fold_build2 (MINUS_EXPR, operation_type, modulus,
1292 convert (operation_type,
1296 result = fold_build2 (BIT_XOR_EXPR, operation_type,
1299 result = fold_build2 (MINUS_EXPR, operation_type,
1307 /* ... fall through ... */
1310 gcc_assert (operation_type == base_type);
1311 result = fold_build1 (op_code, operation_type,
1312 convert (operation_type, operand));
1317 TREE_SIDE_EFFECTS (result) = 1;
1318 if (TREE_CODE (result) == INDIRECT_REF)
1319 TREE_THIS_VOLATILE (result) = TYPE_VOLATILE (TREE_TYPE (result));
1322 if (result_type && TREE_TYPE (result) != result_type)
1323 result = convert (result_type, result);
1328 /* Similar, but for COND_EXPR. */
1331 build_cond_expr (tree result_type, tree condition_operand,
1332 tree true_operand, tree false_operand)
1334 bool addr_p = false;
1337 /* The front-end verified that result, true and false operands have
1338 same base type. Convert everything to the result type. */
1339 true_operand = convert (result_type, true_operand);
1340 false_operand = convert (result_type, false_operand);
1342 /* If the result type is unconstrained, take the address of the operands and
1343 then dereference the result. Likewise if the result type is passed by
1344 reference, but this is natively handled in the gimplifier. */
1345 if (TREE_CODE (result_type) == UNCONSTRAINED_ARRAY_TYPE
1346 || CONTAINS_PLACEHOLDER_P (TYPE_SIZE (result_type)))
1348 result_type = build_pointer_type (result_type);
1349 true_operand = build_unary_op (ADDR_EXPR, result_type, true_operand);
1350 false_operand = build_unary_op (ADDR_EXPR, result_type, false_operand);
1354 result = fold_build3 (COND_EXPR, result_type, condition_operand,
1355 true_operand, false_operand);
1357 /* If we have a common SAVE_EXPR (possibly surrounded by arithmetics)
1358 in both arms, make sure it gets evaluated by moving it ahead of the
1359 conditional expression. This is necessary because it is evaluated
1360 in only one place at run time and would otherwise be uninitialized
1361 in one of the arms. */
1362 true_operand = skip_simple_arithmetic (true_operand);
1363 false_operand = skip_simple_arithmetic (false_operand);
1365 if (true_operand == false_operand && TREE_CODE (true_operand) == SAVE_EXPR)
1366 result = build2 (COMPOUND_EXPR, result_type, true_operand, result);
1369 result = build_unary_op (INDIRECT_REF, NULL_TREE, result);
1374 /* Similar, but for RETURN_EXPR. If RET_VAL is non-null, build a RETURN_EXPR
1375 around the assignment of RET_VAL to RET_OBJ. Otherwise just build a bare
1376 RETURN_EXPR around RESULT_OBJ, which may be null in this case. */
1379 build_return_expr (tree ret_obj, tree ret_val)
1385 /* The gimplifier explicitly enforces the following invariant:
1394 As a consequence, type consistency dictates that we use the type
1395 of the RET_OBJ as the operation type. */
1396 tree operation_type = TREE_TYPE (ret_obj);
1398 /* Convert the right operand to the operation type. Note that it's the
1399 same transformation as in the MODIFY_EXPR case of build_binary_op,
1400 with the assumption that the type cannot involve a placeholder. */
1401 if (operation_type != TREE_TYPE (ret_val))
1402 ret_val = convert (operation_type, ret_val);
1404 result_expr = build2 (MODIFY_EXPR, operation_type, ret_obj, ret_val);
1407 result_expr = ret_obj;
1409 return build1 (RETURN_EXPR, void_type_node, result_expr);
1412 /* Build a CALL_EXPR to call FUNDECL with one argument, ARG. Return
1416 build_call_1_expr (tree fundecl, tree arg)
1418 tree call = build_call_nary (TREE_TYPE (TREE_TYPE (fundecl)),
1419 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1421 TREE_SIDE_EFFECTS (call) = 1;
1425 /* Build a CALL_EXPR to call FUNDECL with two arguments, ARG1 & ARG2. Return
1429 build_call_2_expr (tree fundecl, tree arg1, tree arg2)
1431 tree call = build_call_nary (TREE_TYPE (TREE_TYPE (fundecl)),
1432 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1434 TREE_SIDE_EFFECTS (call) = 1;
1438 /* Likewise to call FUNDECL with no arguments. */
1441 build_call_0_expr (tree fundecl)
1443 /* We rely on build_call_nary to compute TREE_SIDE_EFFECTS. This makes
1444 it possible to propagate DECL_IS_PURE on parameterless functions. */
1445 tree call = build_call_nary (TREE_TYPE (TREE_TYPE (fundecl)),
1446 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1451 /* Call a function that raises an exception and pass the line number and file
1452 name, if requested. MSG says which exception function to call.
1454 GNAT_NODE is the gnat node conveying the source location for which the
1455 error should be signaled, or Empty in which case the error is signaled on
1456 the current ref_file_name/input_line.
1458 KIND says which kind of exception this is for
1459 (N_Raise_{Constraint,Storage,Program}_Error). */
1462 build_call_raise (int msg, Node_Id gnat_node, char kind)
1464 tree fndecl = gnat_raise_decls[msg];
1465 tree label = get_exception_label (kind);
1471 /* If this is to be done as a goto, handle that case. */
1474 Entity_Id local_raise = Get_Local_Raise_Call_Entity ();
1475 tree gnu_result = build1 (GOTO_EXPR, void_type_node, label);
1477 /* If Local_Raise is present, generate
1478 Local_Raise (exception'Identity); */
1479 if (Present (local_raise))
1481 tree gnu_local_raise
1482 = gnat_to_gnu_entity (local_raise, NULL_TREE, 0);
1483 tree gnu_exception_entity
1484 = gnat_to_gnu_entity (Get_RT_Exception_Entity (msg), NULL_TREE, 0);
1486 = build_call_1_expr (gnu_local_raise,
1487 build_unary_op (ADDR_EXPR, NULL_TREE,
1488 gnu_exception_entity));
1490 gnu_result = build2 (COMPOUND_EXPR, void_type_node,
1491 gnu_call, gnu_result);}
1497 = (Debug_Flag_NN || Exception_Locations_Suppressed)
1499 : (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1500 ? IDENTIFIER_POINTER
1501 (get_identifier (Get_Name_String
1503 (Get_Source_File_Index (Sloc (gnat_node))))))
1507 filename = build_string (len, str);
1509 = (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1510 ? Get_Logical_Line_Number (Sloc(gnat_node)) : input_line;
1512 TREE_TYPE (filename) = build_array_type (unsigned_char_type_node,
1513 build_index_type (size_int (len)));
1516 build_call_2_expr (fndecl,
1518 build_pointer_type (unsigned_char_type_node),
1520 build_int_cst (NULL_TREE, line_number));
1523 /* qsort comparer for the bit positions of two constructor elements
1524 for record components. */
1527 compare_elmt_bitpos (const PTR rt1, const PTR rt2)
1529 const constructor_elt * const elmt1 = (const constructor_elt const *) rt1;
1530 const constructor_elt * const elmt2 = (const constructor_elt const *) rt2;
1531 const_tree const field1 = elmt1->index;
1532 const_tree const field2 = elmt2->index;
1534 = tree_int_cst_compare (bit_position (field1), bit_position (field2));
1536 return ret ? ret : (int) (DECL_UID (field1) - DECL_UID (field2));
1539 /* Return a CONSTRUCTOR of TYPE whose elements are V. */
1542 gnat_build_constructor (tree type, VEC(constructor_elt,gc) *v)
1544 bool allconstant = (TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST);
1545 bool side_effects = false;
1546 tree result, obj, val;
1547 unsigned int n_elmts;
1549 /* Scan the elements to see if they are all constant or if any has side
1550 effects, to let us set global flags on the resulting constructor. Count
1551 the elements along the way for possible sorting purposes below. */
1552 FOR_EACH_CONSTRUCTOR_ELT (v, n_elmts, obj, val)
1554 /* The predicate must be in keeping with output_constructor. */
1555 if (!TREE_CONSTANT (val)
1556 || (TREE_CODE (type) == RECORD_TYPE
1557 && CONSTRUCTOR_BITFIELD_P (obj)
1558 && !initializer_constant_valid_for_bitfield_p (val))
1559 || !initializer_constant_valid_p (val, TREE_TYPE (val)))
1560 allconstant = false;
1562 if (TREE_SIDE_EFFECTS (val))
1563 side_effects = true;
1566 /* For record types with constant components only, sort field list
1567 by increasing bit position. This is necessary to ensure the
1568 constructor can be output as static data. */
1569 if (allconstant && TREE_CODE (type) == RECORD_TYPE && n_elmts > 1)
1570 VEC_qsort (constructor_elt, v, compare_elmt_bitpos);
1572 result = build_constructor (type, v);
1573 TREE_CONSTANT (result) = TREE_STATIC (result) = allconstant;
1574 TREE_SIDE_EFFECTS (result) = side_effects;
1575 TREE_READONLY (result) = TYPE_READONLY (type) || allconstant;
1579 /* Return a COMPONENT_REF to access a field that is given by COMPONENT,
1580 an IDENTIFIER_NODE giving the name of the field, or FIELD, a FIELD_DECL,
1581 for the field. Don't fold the result if NO_FOLD_P is true.
1583 We also handle the fact that we might have been passed a pointer to the
1584 actual record and know how to look for fields in variant parts. */
1587 build_simple_component_ref (tree record_variable, tree component,
1588 tree field, bool no_fold_p)
1590 tree record_type = TYPE_MAIN_VARIANT (TREE_TYPE (record_variable));
1591 tree ref, inner_variable;
1593 gcc_assert ((TREE_CODE (record_type) == RECORD_TYPE
1594 || TREE_CODE (record_type) == UNION_TYPE
1595 || TREE_CODE (record_type) == QUAL_UNION_TYPE)
1596 && TYPE_SIZE (record_type)
1597 && (component != 0) != (field != 0));
1599 /* If no field was specified, look for a field with the specified name
1600 in the current record only. */
1602 for (field = TYPE_FIELDS (record_type); field;
1603 field = TREE_CHAIN (field))
1604 if (DECL_NAME (field) == component)
1610 /* If this field is not in the specified record, see if we can find a field
1611 in the specified record whose original field is the same as this one. */
1612 if (DECL_CONTEXT (field) != record_type)
1616 /* First loop thru normal components. */
1617 for (new_field = TYPE_FIELDS (record_type); new_field;
1618 new_field = DECL_CHAIN (new_field))
1619 if (SAME_FIELD_P (field, new_field))
1622 /* Next, see if we're looking for an inherited component in an extension.
1623 If so, look thru the extension directly. */
1625 && TREE_CODE (record_variable) == VIEW_CONVERT_EXPR
1626 && TYPE_ALIGN_OK (record_type)
1627 && TREE_CODE (TREE_TYPE (TREE_OPERAND (record_variable, 0)))
1629 && TYPE_ALIGN_OK (TREE_TYPE (TREE_OPERAND (record_variable, 0))))
1631 ref = build_simple_component_ref (TREE_OPERAND (record_variable, 0),
1632 NULL_TREE, field, no_fold_p);
1637 /* Next, loop thru DECL_INTERNAL_P components if we haven't found
1638 the component in the first search. Doing this search in 2 steps
1639 is required to avoiding hidden homonymous fields in the
1642 for (new_field = TYPE_FIELDS (record_type); new_field;
1643 new_field = DECL_CHAIN (new_field))
1644 if (DECL_INTERNAL_P (new_field))
1647 = build_simple_component_ref (record_variable,
1648 NULL_TREE, new_field, no_fold_p);
1649 ref = build_simple_component_ref (field_ref, NULL_TREE, field,
1662 /* If the field's offset has overflowed, do not attempt to access it
1663 as doing so may trigger sanity checks deeper in the back-end.
1664 Note that we don't need to warn since this will be done on trying
1665 to declare the object. */
1666 if (TREE_CODE (DECL_FIELD_OFFSET (field)) == INTEGER_CST
1667 && TREE_OVERFLOW (DECL_FIELD_OFFSET (field)))
1670 /* Look through conversion between type variants. Note that this
1671 is transparent as far as the field is concerned. */
1672 if (TREE_CODE (record_variable) == VIEW_CONVERT_EXPR
1673 && TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (record_variable, 0)))
1675 inner_variable = TREE_OPERAND (record_variable, 0);
1677 inner_variable = record_variable;
1679 ref = build3 (COMPONENT_REF, TREE_TYPE (field), inner_variable, field,
1682 if (TREE_READONLY (record_variable) || TREE_READONLY (field))
1683 TREE_READONLY (ref) = 1;
1684 if (TREE_THIS_VOLATILE (record_variable) || TREE_THIS_VOLATILE (field)
1685 || TYPE_VOLATILE (record_type))
1686 TREE_THIS_VOLATILE (ref) = 1;
1691 /* The generic folder may punt in this case because the inner array type
1692 can be self-referential, but folding is in fact not problematic. */
1693 else if (TREE_CODE (record_variable) == CONSTRUCTOR
1694 && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (record_variable)))
1696 VEC(constructor_elt,gc) *elts = CONSTRUCTOR_ELTS (record_variable);
1697 unsigned HOST_WIDE_INT idx;
1699 FOR_EACH_CONSTRUCTOR_ELT (elts, idx, index, value)
1709 /* Like build_simple_component_ref, except that we give an error if the
1710 reference could not be found. */
1713 build_component_ref (tree record_variable, tree component,
1714 tree field, bool no_fold_p)
1716 tree ref = build_simple_component_ref (record_variable, component, field,
1722 /* If FIELD was specified, assume this is an invalid user field so raise
1723 Constraint_Error. Otherwise, we have no type to return so abort. */
1725 return build1 (NULL_EXPR, TREE_TYPE (field),
1726 build_call_raise (CE_Discriminant_Check_Failed, Empty,
1727 N_Raise_Constraint_Error));
1730 /* Helper for build_call_alloc_dealloc, with arguments to be interpreted
1731 identically. Process the case where a GNAT_PROC to call is provided. */
1734 build_call_alloc_dealloc_proc (tree gnu_obj, tree gnu_size, tree gnu_type,
1735 Entity_Id gnat_proc, Entity_Id gnat_pool)
1737 tree gnu_proc = gnat_to_gnu (gnat_proc);
1738 tree gnu_proc_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_proc);
1741 /* The storage pools are obviously always tagged types, but the
1742 secondary stack uses the same mechanism and is not tagged. */
1743 if (Is_Tagged_Type (Etype (gnat_pool)))
1745 /* The size is the third parameter; the alignment is the
1747 Entity_Id gnat_size_type
1748 = Etype (Next_Formal (Next_Formal (First_Formal (gnat_proc))));
1749 tree gnu_size_type = gnat_to_gnu_type (gnat_size_type);
1751 tree gnu_pool = gnat_to_gnu (gnat_pool);
1752 tree gnu_pool_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_pool);
1753 tree gnu_align = size_int (TYPE_ALIGN (gnu_type) / BITS_PER_UNIT);
1755 gnu_size = convert (gnu_size_type, gnu_size);
1756 gnu_align = convert (gnu_size_type, gnu_align);
1758 /* The first arg is always the address of the storage pool; next
1759 comes the address of the object, for a deallocator, then the
1760 size and alignment. */
1762 gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)),
1763 gnu_proc_addr, 4, gnu_pool_addr,
1764 gnu_obj, gnu_size, gnu_align);
1766 gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)),
1767 gnu_proc_addr, 3, gnu_pool_addr,
1768 gnu_size, gnu_align);
1771 /* Secondary stack case. */
1774 /* The size is the second parameter. */
1775 Entity_Id gnat_size_type
1776 = Etype (Next_Formal (First_Formal (gnat_proc)));
1777 tree gnu_size_type = gnat_to_gnu_type (gnat_size_type);
1779 gnu_size = convert (gnu_size_type, gnu_size);
1781 /* The first arg is the address of the object, for a deallocator,
1784 gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)),
1785 gnu_proc_addr, 2, gnu_obj, gnu_size);
1787 gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)),
1788 gnu_proc_addr, 1, gnu_size);
1791 TREE_SIDE_EFFECTS (gnu_call) = 1;
1795 /* Helper for build_call_alloc_dealloc, to build and return an allocator for
1796 DATA_SIZE bytes aimed at containing a DATA_TYPE object, using the default
1797 __gnat_malloc allocator. Honor DATA_TYPE alignments greater than what the
1801 maybe_wrap_malloc (tree data_size, tree data_type, Node_Id gnat_node)
1803 /* When the DATA_TYPE alignment is stricter than what malloc offers
1804 (super-aligned case), we allocate an "aligning" wrapper type and return
1805 the address of its single data field with the malloc's return value
1806 stored just in front. */
1808 unsigned int data_align = TYPE_ALIGN (data_type);
1809 unsigned int default_allocator_alignment
1810 = get_target_default_allocator_alignment () * BITS_PER_UNIT;
1813 = ((data_align > default_allocator_alignment)
1814 ? make_aligning_type (data_type, data_align, data_size,
1815 default_allocator_alignment,
1816 POINTER_SIZE / BITS_PER_UNIT)
1820 = aligning_type ? TYPE_SIZE_UNIT (aligning_type) : data_size;
1824 /* On VMS, if pointers are 64-bit and the allocator size is 32-bit or
1825 Convention C, allocate 32-bit memory. */
1826 if (TARGET_ABI_OPEN_VMS
1827 && POINTER_SIZE == 64
1828 && Nkind (gnat_node) == N_Allocator
1829 && (UI_To_Int (Esize (Etype (gnat_node))) == 32
1830 || Convention (Etype (gnat_node)) == Convention_C))
1831 malloc_ptr = build_call_1_expr (malloc32_decl, size_to_malloc);
1833 malloc_ptr = build_call_1_expr (malloc_decl, size_to_malloc);
1837 /* Latch malloc's return value and get a pointer to the aligning field
1839 tree storage_ptr = gnat_protect_expr (malloc_ptr);
1841 tree aligning_record_addr
1842 = convert (build_pointer_type (aligning_type), storage_ptr);
1844 tree aligning_record
1845 = build_unary_op (INDIRECT_REF, NULL_TREE, aligning_record_addr);
1848 = build_component_ref (aligning_record, NULL_TREE,
1849 TYPE_FIELDS (aligning_type), false);
1851 tree aligning_field_addr
1852 = build_unary_op (ADDR_EXPR, NULL_TREE, aligning_field);
1854 /* Then arrange to store the allocator's return value ahead
1856 tree storage_ptr_slot_addr
1857 = build_binary_op (POINTER_PLUS_EXPR, ptr_void_type_node,
1858 convert (ptr_void_type_node, aligning_field_addr),
1859 size_int (-(HOST_WIDE_INT) POINTER_SIZE
1862 tree storage_ptr_slot
1863 = build_unary_op (INDIRECT_REF, NULL_TREE,
1864 convert (build_pointer_type (ptr_void_type_node),
1865 storage_ptr_slot_addr));
1868 build2 (COMPOUND_EXPR, TREE_TYPE (aligning_field_addr),
1869 build_binary_op (MODIFY_EXPR, NULL_TREE,
1870 storage_ptr_slot, storage_ptr),
1871 aligning_field_addr);
1877 /* Helper for build_call_alloc_dealloc, to release a DATA_TYPE object
1878 designated by DATA_PTR using the __gnat_free entry point. */
1881 maybe_wrap_free (tree data_ptr, tree data_type)
1883 /* In the regular alignment case, we pass the data pointer straight to free.
1884 In the superaligned case, we need to retrieve the initial allocator
1885 return value, stored in front of the data block at allocation time. */
1887 unsigned int data_align = TYPE_ALIGN (data_type);
1888 unsigned int default_allocator_alignment
1889 = get_target_default_allocator_alignment () * BITS_PER_UNIT;
1893 if (data_align > default_allocator_alignment)
1895 /* DATA_FRONT_PTR (void *)
1896 = (void *)DATA_PTR - (void *)sizeof (void *)) */
1899 (POINTER_PLUS_EXPR, ptr_void_type_node,
1900 convert (ptr_void_type_node, data_ptr),
1901 size_int (-(HOST_WIDE_INT) POINTER_SIZE / BITS_PER_UNIT));
1903 /* FREE_PTR (void *) = *(void **)DATA_FRONT_PTR */
1906 (INDIRECT_REF, NULL_TREE,
1907 convert (build_pointer_type (ptr_void_type_node), data_front_ptr));
1910 free_ptr = data_ptr;
1912 return build_call_1_expr (free_decl, free_ptr);
1915 /* Build a GCC tree to call an allocation or deallocation function.
1916 If GNU_OBJ is nonzero, it is an object to deallocate. Otherwise,
1917 generate an allocator.
1919 GNU_SIZE is the number of bytes to allocate and GNU_TYPE is the contained
1920 object type, used to determine the to-be-honored address alignment.
1921 GNAT_PROC, if present, is a procedure to call and GNAT_POOL is the storage
1922 pool to use. If not present, malloc and free are used. GNAT_NODE is used
1923 to provide an error location for restriction violation messages. */
1926 build_call_alloc_dealloc (tree gnu_obj, tree gnu_size, tree gnu_type,
1927 Entity_Id gnat_proc, Entity_Id gnat_pool,
1930 gnu_size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (gnu_size, gnu_obj);
1932 /* Explicit proc to call ? This one is assumed to deal with the type
1933 alignment constraints. */
1934 if (Present (gnat_proc))
1935 return build_call_alloc_dealloc_proc (gnu_obj, gnu_size, gnu_type,
1936 gnat_proc, gnat_pool);
1938 /* Otherwise, object to "free" or "malloc" with possible special processing
1939 for alignments stricter than what the default allocator honors. */
1941 return maybe_wrap_free (gnu_obj, gnu_type);
1944 /* Assert that we no longer can be called with this special pool. */
1945 gcc_assert (gnat_pool != -1);
1947 /* Check that we aren't violating the associated restriction. */
1948 if (!(Nkind (gnat_node) == N_Allocator && Comes_From_Source (gnat_node)))
1949 Check_No_Implicit_Heap_Alloc (gnat_node);
1951 return maybe_wrap_malloc (gnu_size, gnu_type, gnat_node);
1955 /* Build a GCC tree to correspond to allocating an object of TYPE whose
1956 initial value is INIT, if INIT is nonzero. Convert the expression to
1957 RESULT_TYPE, which must be some type of pointer. Return the tree.
1959 GNAT_PROC and GNAT_POOL optionally give the procedure to call and
1960 the storage pool to use. GNAT_NODE is used to provide an error
1961 location for restriction violation messages. If IGNORE_INIT_TYPE is
1962 true, ignore the type of INIT for the purpose of determining the size;
1963 this will cause the maximum size to be allocated if TYPE is of
1964 self-referential size. */
1967 build_allocator (tree type, tree init, tree result_type, Entity_Id gnat_proc,
1968 Entity_Id gnat_pool, Node_Id gnat_node, bool ignore_init_type)
1970 tree size = TYPE_SIZE_UNIT (type);
1973 /* If the initializer, if present, is a NULL_EXPR, just return a new one. */
1974 if (init && TREE_CODE (init) == NULL_EXPR)
1975 return build1 (NULL_EXPR, result_type, TREE_OPERAND (init, 0));
1977 /* If RESULT_TYPE is a fat or thin pointer, set SIZE to be the sum of the
1978 sizes of the object and its template. Allocate the whole thing and
1979 fill in the parts that are known. */
1980 else if (TYPE_IS_FAT_OR_THIN_POINTER_P (result_type))
1983 = build_unc_object_type_from_ptr (result_type, type,
1984 get_identifier ("ALLOC"), false);
1985 tree template_type = TREE_TYPE (TYPE_FIELDS (storage_type));
1986 tree storage_ptr_type = build_pointer_type (storage_type);
1989 size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TYPE_SIZE_UNIT (storage_type),
1992 /* If the size overflows, pass -1 so the allocator will raise
1994 if (TREE_CODE (size) == INTEGER_CST && TREE_OVERFLOW (size))
1995 size = ssize_int (-1);
1997 storage = build_call_alloc_dealloc (NULL_TREE, size, storage_type,
1998 gnat_proc, gnat_pool, gnat_node);
1999 storage = convert (storage_ptr_type, gnat_protect_expr (storage));
2001 if (TYPE_IS_PADDING_P (type))
2003 type = TREE_TYPE (TYPE_FIELDS (type));
2005 init = convert (type, init);
2008 /* If there is an initializing expression, make a constructor for
2009 the entire object including the bounds and copy it into the
2010 object. If there is no initializing expression, just set the
2014 VEC(constructor_elt,gc) *v = VEC_alloc (constructor_elt, gc, 2);
2016 CONSTRUCTOR_APPEND_ELT (v, TYPE_FIELDS (storage_type),
2017 build_template (template_type, type, init));
2018 CONSTRUCTOR_APPEND_ELT (v, DECL_CHAIN (TYPE_FIELDS (storage_type)),
2023 build2 (COMPOUND_EXPR, storage_ptr_type,
2025 (MODIFY_EXPR, storage_type,
2026 build_unary_op (INDIRECT_REF, NULL_TREE,
2027 convert (storage_ptr_type, storage)),
2028 gnat_build_constructor (storage_type, v)),
2029 convert (storage_ptr_type, storage)));
2033 (COMPOUND_EXPR, result_type,
2035 (MODIFY_EXPR, template_type,
2037 (build_unary_op (INDIRECT_REF, NULL_TREE,
2038 convert (storage_ptr_type, storage)),
2039 NULL_TREE, TYPE_FIELDS (storage_type), false),
2040 build_template (template_type, type, NULL_TREE)),
2041 convert (result_type, convert (storage_ptr_type, storage)));
2044 /* If we have an initializing expression, see if its size is simpler
2045 than the size from the type. */
2046 if (!ignore_init_type && init && TYPE_SIZE_UNIT (TREE_TYPE (init))
2047 && (TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (init))) == INTEGER_CST
2048 || CONTAINS_PLACEHOLDER_P (size)))
2049 size = TYPE_SIZE_UNIT (TREE_TYPE (init));
2051 /* If the size is still self-referential, reference the initializing
2052 expression, if it is present. If not, this must have been a
2053 call to allocate a library-level object, in which case we use
2054 the maximum size. */
2055 if (CONTAINS_PLACEHOLDER_P (size))
2057 if (!ignore_init_type && init)
2058 size = substitute_placeholder_in_expr (size, init);
2060 size = max_size (size, true);
2063 /* If the size overflows, pass -1 so the allocator will raise
2065 if (TREE_CODE (size) == INTEGER_CST && TREE_OVERFLOW (size))
2066 size = ssize_int (-1);
2068 result = convert (result_type,
2069 build_call_alloc_dealloc (NULL_TREE, size, type,
2070 gnat_proc, gnat_pool,
2073 /* If we have an initial value, protect the new address, assign the value
2074 and return the address with a COMPOUND_EXPR. */
2077 result = gnat_protect_expr (result);
2079 = build2 (COMPOUND_EXPR, TREE_TYPE (result),
2081 (MODIFY_EXPR, NULL_TREE,
2082 build_unary_op (INDIRECT_REF,
2083 TREE_TYPE (TREE_TYPE (result)), result),
2088 return convert (result_type, result);
2091 /* Fill in a VMS descriptor for EXPR and return a constructor for it.
2092 GNAT_FORMAL is how we find the descriptor record. GNAT_ACTUAL is
2093 how we derive the source location to raise C_E on an out of range
2097 fill_vms_descriptor (tree expr, Entity_Id gnat_formal, Node_Id gnat_actual)
2099 tree parm_decl = get_gnu_tree (gnat_formal);
2100 tree record_type = TREE_TYPE (TREE_TYPE (parm_decl));
2102 const bool do_range_check
2104 IDENTIFIER_POINTER (DECL_NAME (TYPE_FIELDS (record_type))));
2105 VEC(constructor_elt,gc) *v = NULL;
2107 expr = maybe_unconstrained_array (expr);
2108 gnat_mark_addressable (expr);
2110 for (field = TYPE_FIELDS (record_type); field; field = DECL_CHAIN (field))
2112 tree conexpr = convert (TREE_TYPE (field),
2113 SUBSTITUTE_PLACEHOLDER_IN_EXPR
2114 (DECL_INITIAL (field), expr));
2116 /* Check to ensure that only 32-bit pointers are passed in
2117 32-bit descriptors */
2119 && strcmp (IDENTIFIER_POINTER (DECL_NAME (field)), "POINTER") == 0)
2122 = build_pointer_type_for_mode (void_type_node, DImode, false);
2123 tree addr64expr = build_unary_op (ADDR_EXPR, pointer64type, expr);
2125 = build_int_cstu (long_integer_type_node, 0x80000000);
2127 add_stmt (build3 (COND_EXPR, void_type_node,
2128 build_binary_op (GE_EXPR, boolean_type_node,
2129 convert (long_integer_type_node,
2132 build_call_raise (CE_Range_Check_Failed,
2134 N_Raise_Constraint_Error),
2137 CONSTRUCTOR_APPEND_ELT (v, field, conexpr);
2140 return gnat_build_constructor (record_type, v);
2143 /* Indicate that we need to take the address of T and that it therefore
2144 should not be allocated in a register. Returns true if successful. */
2147 gnat_mark_addressable (tree t)
2150 switch (TREE_CODE (t))
2155 case ARRAY_RANGE_REF:
2158 case VIEW_CONVERT_EXPR:
2159 case NON_LVALUE_EXPR:
2161 t = TREE_OPERAND (t, 0);
2165 t = TREE_OPERAND (t, 1);
2169 TREE_ADDRESSABLE (t) = 1;
2175 TREE_ADDRESSABLE (t) = 1;
2179 TREE_ADDRESSABLE (t) = 1;
2183 return DECL_CONST_CORRESPONDING_VAR (t)
2184 && gnat_mark_addressable (DECL_CONST_CORRESPONDING_VAR (t));
2191 /* Save EXP for later use or reuse. This is equivalent to save_expr in tree.c
2192 but we know how to handle our own nodes. */
2195 gnat_save_expr (tree exp)
2197 tree type = TREE_TYPE (exp);
2198 enum tree_code code = TREE_CODE (exp);
2200 if (TREE_CONSTANT (exp) || code == SAVE_EXPR || code == NULL_EXPR)
2203 if (code == UNCONSTRAINED_ARRAY_REF)
2205 tree t = build1 (code, type, gnat_save_expr (TREE_OPERAND (exp, 0)));
2206 TREE_READONLY (t) = TYPE_READONLY (type);
2210 /* If this is a COMPONENT_REF of a fat pointer, save the entire fat pointer.
2211 This may be more efficient, but will also allow us to more easily find
2212 the match for the PLACEHOLDER_EXPR. */
2213 if (code == COMPONENT_REF
2214 && TYPE_IS_FAT_POINTER_P (TREE_TYPE (TREE_OPERAND (exp, 0))))
2215 return build3 (code, type, gnat_save_expr (TREE_OPERAND (exp, 0)),
2216 TREE_OPERAND (exp, 1), TREE_OPERAND (exp, 2));
2218 return save_expr (exp);
2221 /* Protect EXP for immediate reuse. This is a variant of gnat_save_expr that
2222 is optimized under the assumption that EXP's value doesn't change before
2223 its subsequent reuse(s) except through its potential reevaluation. */
2226 gnat_protect_expr (tree exp)
2228 tree type = TREE_TYPE (exp);
2229 enum tree_code code = TREE_CODE (exp);
2231 if (TREE_CONSTANT (exp) || code == SAVE_EXPR || code == NULL_EXPR)
2234 /* If EXP has no side effects, we theoritically don't need to do anything.
2235 However, we may be recursively passed more and more complex expressions
2236 involving checks which will be reused multiple times and eventually be
2237 unshared for gimplification; in order to avoid a complexity explosion
2238 at that point, we protect any expressions more complex than a simple
2239 arithmetic expression. */
2240 if (!TREE_SIDE_EFFECTS (exp))
2242 tree inner = skip_simple_arithmetic (exp);
2243 if (!EXPR_P (inner) || REFERENCE_CLASS_P (inner))
2247 /* If this is a conversion, protect what's inside the conversion. */
2248 if (code == NON_LVALUE_EXPR
2249 || CONVERT_EXPR_CODE_P (code)
2250 || code == VIEW_CONVERT_EXPR)
2251 return build1 (code, type, gnat_protect_expr (TREE_OPERAND (exp, 0)));
2253 /* If we're indirectly referencing something, we only need to protect the
2254 address since the data itself can't change in these situations. */
2255 if (code == INDIRECT_REF || code == UNCONSTRAINED_ARRAY_REF)
2257 tree t = build1 (code, type, gnat_protect_expr (TREE_OPERAND (exp, 0)));
2258 TREE_READONLY (t) = TYPE_READONLY (type);
2262 /* If this is a COMPONENT_REF of a fat pointer, save the entire fat pointer.
2263 This may be more efficient, but will also allow us to more easily find
2264 the match for the PLACEHOLDER_EXPR. */
2265 if (code == COMPONENT_REF
2266 && TYPE_IS_FAT_POINTER_P (TREE_TYPE (TREE_OPERAND (exp, 0))))
2267 return build3 (code, type, gnat_protect_expr (TREE_OPERAND (exp, 0)),
2268 TREE_OPERAND (exp, 1), TREE_OPERAND (exp, 2));
2270 /* If this is a fat pointer or something that can be placed in a register,
2271 just make a SAVE_EXPR. Likewise for a CALL_EXPR as large objects are
2272 returned via invisible reference in most ABIs so the temporary will
2273 directly be filled by the callee. */
2274 if (TYPE_IS_FAT_POINTER_P (type)
2275 || TYPE_MODE (type) != BLKmode
2276 || code == CALL_EXPR)
2277 return save_expr (exp);
2279 /* Otherwise reference, protect the address and dereference. */
2281 build_unary_op (INDIRECT_REF, type,
2282 save_expr (build_unary_op (ADDR_EXPR,
2283 build_reference_type (type),
2287 /* This is equivalent to stabilize_reference_1 in tree.c but we take an extra
2288 argument to force evaluation of everything. */
2291 gnat_stabilize_reference_1 (tree e, bool force)
2293 enum tree_code code = TREE_CODE (e);
2294 tree type = TREE_TYPE (e);
2297 /* We cannot ignore const expressions because it might be a reference
2298 to a const array but whose index contains side-effects. But we can
2299 ignore things that are actual constant or that already have been
2300 handled by this function. */
2301 if (TREE_CONSTANT (e) || code == SAVE_EXPR)
2304 switch (TREE_CODE_CLASS (code))
2306 case tcc_exceptional:
2307 case tcc_declaration:
2308 case tcc_comparison:
2309 case tcc_expression:
2312 /* If this is a COMPONENT_REF of a fat pointer, save the entire
2313 fat pointer. This may be more efficient, but will also allow
2314 us to more easily find the match for the PLACEHOLDER_EXPR. */
2315 if (code == COMPONENT_REF
2316 && TYPE_IS_FAT_POINTER_P (TREE_TYPE (TREE_OPERAND (e, 0))))
2318 = build3 (code, type,
2319 gnat_stabilize_reference_1 (TREE_OPERAND (e, 0), force),
2320 TREE_OPERAND (e, 1), TREE_OPERAND (e, 2));
2321 /* If the expression has side-effects, then encase it in a SAVE_EXPR
2322 so that it will only be evaluated once. */
2323 /* The tcc_reference and tcc_comparison classes could be handled as
2324 below, but it is generally faster to only evaluate them once. */
2325 else if (TREE_SIDE_EFFECTS (e) || force)
2326 return save_expr (e);
2332 /* Recursively stabilize each operand. */
2334 = build2 (code, type,
2335 gnat_stabilize_reference_1 (TREE_OPERAND (e, 0), force),
2336 gnat_stabilize_reference_1 (TREE_OPERAND (e, 1), force));
2340 /* Recursively stabilize each operand. */
2342 = build1 (code, type,
2343 gnat_stabilize_reference_1 (TREE_OPERAND (e, 0), force));
2350 /* See similar handling in gnat_stabilize_reference. */
2351 TREE_READONLY (result) = TREE_READONLY (e);
2352 TREE_SIDE_EFFECTS (result) |= TREE_SIDE_EFFECTS (e);
2353 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
2355 if (code == INDIRECT_REF || code == ARRAY_REF || code == ARRAY_RANGE_REF)
2356 TREE_THIS_NOTRAP (result) = TREE_THIS_NOTRAP (e);
2361 /* This is equivalent to stabilize_reference in tree.c but we know how to
2362 handle our own nodes and we take extra arguments. FORCE says whether to
2363 force evaluation of everything. We set SUCCESS to true unless we walk
2364 through something we don't know how to stabilize. */
2367 gnat_stabilize_reference (tree ref, bool force, bool *success)
2369 tree type = TREE_TYPE (ref);
2370 enum tree_code code = TREE_CODE (ref);
2373 /* Assume we'll success unless proven otherwise. */
2383 /* No action is needed in this case. */
2389 case FIX_TRUNC_EXPR:
2390 case VIEW_CONVERT_EXPR:
2392 = build1 (code, type,
2393 gnat_stabilize_reference (TREE_OPERAND (ref, 0), force,
2398 case UNCONSTRAINED_ARRAY_REF:
2399 result = build1 (code, type,
2400 gnat_stabilize_reference_1 (TREE_OPERAND (ref, 0),
2405 result = build3 (COMPONENT_REF, type,
2406 gnat_stabilize_reference (TREE_OPERAND (ref, 0), force,
2408 TREE_OPERAND (ref, 1), NULL_TREE);
2412 result = build3 (BIT_FIELD_REF, type,
2413 gnat_stabilize_reference (TREE_OPERAND (ref, 0), force,
2415 gnat_stabilize_reference_1 (TREE_OPERAND (ref, 1),
2417 gnat_stabilize_reference_1 (TREE_OPERAND (ref, 2),
2422 case ARRAY_RANGE_REF:
2423 result = build4 (code, type,
2424 gnat_stabilize_reference (TREE_OPERAND (ref, 0), force,
2426 gnat_stabilize_reference_1 (TREE_OPERAND (ref, 1),
2428 NULL_TREE, NULL_TREE);
2432 result = gnat_stabilize_reference_1 (ref, force);
2436 result = build2 (COMPOUND_EXPR, type,
2437 gnat_stabilize_reference (TREE_OPERAND (ref, 0), force,
2439 gnat_stabilize_reference_1 (TREE_OPERAND (ref, 1),
2444 /* Constructors with 1 element are used extensively to formally
2445 convert objects to special wrapping types. */
2446 if (TREE_CODE (type) == RECORD_TYPE
2447 && VEC_length (constructor_elt, CONSTRUCTOR_ELTS (ref)) == 1)
2450 = VEC_index (constructor_elt, CONSTRUCTOR_ELTS (ref), 0)->index;
2452 = VEC_index (constructor_elt, CONSTRUCTOR_ELTS (ref), 0)->value;
2454 = build_constructor_single (type, index,
2455 gnat_stabilize_reference_1 (value,
2467 ref = error_mark_node;
2469 /* ... fall through to failure ... */
2471 /* If arg isn't a kind of lvalue we recognize, make no change.
2472 Caller should recognize the error for an invalid lvalue. */
2479 /* TREE_THIS_VOLATILE and TREE_SIDE_EFFECTS set on the initial expression
2480 may not be sustained across some paths, such as the way via build1 for
2481 INDIRECT_REF. We reset those flags here in the general case, which is
2482 consistent with the GCC version of this routine.
2484 Special care should be taken regarding TREE_SIDE_EFFECTS, because some
2485 paths introduce side-effects where there was none initially (e.g. if a
2486 SAVE_EXPR is built) and we also want to keep track of that. */
2487 TREE_READONLY (result) = TREE_READONLY (ref);
2488 TREE_SIDE_EFFECTS (result) |= TREE_SIDE_EFFECTS (ref);
2489 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);