1 /****************************************************************************
3 * GNAT COMPILER COMPONENTS *
7 * C Implementation File *
9 * Copyright (C) 1992-2008, 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"
49 static tree find_common_type (tree, tree);
50 static bool contains_save_expr_p (tree);
51 static tree contains_null_expr (tree);
52 static tree compare_arrays (tree, tree, tree);
53 static tree nonbinary_modular_operation (enum tree_code, tree, tree, tree);
54 static tree build_simple_component_ref (tree, tree, tree, bool);
56 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical
59 This preparation consists of taking the ordinary representation of
60 an expression expr and producing a valid tree boolean expression
61 describing whether expr is nonzero. We could simply always do
63 build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
65 but we optimize comparisons, &&, ||, and !.
67 The resulting type should always be the same as the input type.
68 This function is simpler than the corresponding C version since
69 the only possible operands will be things of Boolean type. */
72 gnat_truthvalue_conversion (tree expr)
74 tree type = TREE_TYPE (expr);
76 switch (TREE_CODE (expr))
78 case EQ_EXPR: case NE_EXPR: case LE_EXPR: case GE_EXPR:
79 case LT_EXPR: case GT_EXPR:
80 case TRUTH_ANDIF_EXPR:
89 return (integer_zerop (expr)
90 ? build_int_cst (type, 0)
91 : build_int_cst (type, 1));
94 return (real_zerop (expr)
95 ? fold_convert (type, integer_zero_node)
96 : fold_convert (type, integer_one_node));
99 /* Distribute the conversion into the arms of a COND_EXPR. */
101 tree arg1 = gnat_truthvalue_conversion (TREE_OPERAND (expr, 1));
102 tree arg2 = gnat_truthvalue_conversion (TREE_OPERAND (expr, 2));
103 return fold_build3 (COND_EXPR, type, TREE_OPERAND (expr, 0),
108 return build_binary_op (NE_EXPR, type, expr,
109 fold_convert (type, integer_zero_node));
113 /* Return the base type of TYPE. */
116 get_base_type (tree type)
118 if (TREE_CODE (type) == RECORD_TYPE
119 && TYPE_JUSTIFIED_MODULAR_P (type))
120 type = TREE_TYPE (TYPE_FIELDS (type));
122 while (TREE_TYPE (type)
123 && (TREE_CODE (type) == INTEGER_TYPE
124 || TREE_CODE (type) == REAL_TYPE))
125 type = TREE_TYPE (type);
130 /* EXP is a GCC tree representing an address. See if we can find how
131 strictly the object at that address is aligned. Return that alignment
132 in bits. If we don't know anything about the alignment, return 0. */
135 known_alignment (tree exp)
137 unsigned int this_alignment;
138 unsigned int lhs, rhs;
139 unsigned int type_alignment;
141 /* For pointer expressions, we know that the designated object is always at
142 least as strictly aligned as the designated subtype, so we account for
143 both type and expression information in this case.
145 Beware that we can still get a dummy designated subtype here (e.g. Taft
146 Amendement types), in which the alignment information is meaningless and
149 We always compute a type_alignment value and return the MAX of it
150 compared with what we get from the expression tree. Just set the
151 type_alignment value to 0 when the type information is to be ignored. */
153 = ((POINTER_TYPE_P (TREE_TYPE (exp))
154 && !TYPE_IS_DUMMY_P (TREE_TYPE (TREE_TYPE (exp))))
155 ? TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))) : 0);
157 switch (TREE_CODE (exp))
160 case VIEW_CONVERT_EXPR:
162 case NON_LVALUE_EXPR:
163 /* Conversions between pointers and integers don't change the alignment
164 of the underlying object. */
165 this_alignment = known_alignment (TREE_OPERAND (exp, 0));
169 /* The value of a COMPOUND_EXPR is that of it's second operand. */
170 this_alignment = known_alignment (TREE_OPERAND (exp, 1));
174 case POINTER_PLUS_EXPR:
176 /* If two address are added, the alignment of the result is the
177 minimum of the two alignments. */
178 lhs = known_alignment (TREE_OPERAND (exp, 0));
179 rhs = known_alignment (TREE_OPERAND (exp, 1));
180 this_alignment = MIN (lhs, rhs);
184 /* If there is a choice between two values, use the smallest one. */
185 lhs = known_alignment (TREE_OPERAND (exp, 1));
186 rhs = known_alignment (TREE_OPERAND (exp, 2));
187 this_alignment = MIN (lhs, rhs);
191 /* The first part of this represents the lowest bit in the constant,
192 but is it in bytes, not bits. */
195 * (TREE_INT_CST_LOW (exp) & - TREE_INT_CST_LOW (exp)),
200 /* If we know the alignment of just one side, use it. Otherwise,
201 use the product of the alignments. */
202 lhs = known_alignment (TREE_OPERAND (exp, 0));
203 rhs = known_alignment (TREE_OPERAND (exp, 1));
205 if (lhs == 0 || rhs == 0)
206 this_alignment = MIN (BIGGEST_ALIGNMENT, MAX (lhs, rhs));
208 this_alignment = MIN (BIGGEST_ALIGNMENT, lhs * rhs);
212 /* A bit-and expression is as aligned as the maximum alignment of the
213 operands. We typically get here for a complex lhs and a constant
214 negative power of two on the rhs to force an explicit alignment, so
215 don't bother looking at the lhs. */
216 this_alignment = known_alignment (TREE_OPERAND (exp, 1));
220 this_alignment = expr_align (TREE_OPERAND (exp, 0));
228 return MAX (type_alignment, this_alignment);
231 /* We have a comparison or assignment operation on two types, T1 and T2, which
232 are either both array types or both record types. T1 is assumed to be for
233 the left hand side operand, and T2 for the right hand side. Return the
234 type that both operands should be converted to for the operation, if any.
235 Otherwise return zero. */
238 find_common_type (tree t1, tree t2)
240 /* ??? As of today, various constructs lead here with types of different
241 sizes even when both constants (e.g. tagged types, packable vs regular
242 component types, padded vs unpadded types, ...). While some of these
243 would better be handled upstream (types should be made consistent before
244 calling into build_binary_op), some others are really expected and we
245 have to be careful. */
247 /* We must prevent writing more than what the target may hold if this is for
248 an assignment and the case of tagged types is handled in build_binary_op
249 so use the lhs type if it is known to be smaller, or of constant size and
250 the rhs type is not, whatever the modes. We also force t1 in case of
251 constant size equality to minimize occurrences of view conversions on the
252 lhs of assignments. */
253 if (TREE_CONSTANT (TYPE_SIZE (t1))
254 && (!TREE_CONSTANT (TYPE_SIZE (t2))
255 || !tree_int_cst_lt (TYPE_SIZE (t2), TYPE_SIZE (t1))))
258 /* Otherwise, if the lhs type is non-BLKmode, use it. Note that we know
259 that we will not have any alignment problems since, if we did, the
260 non-BLKmode type could not have been used. */
261 if (TYPE_MODE (t1) != BLKmode)
264 /* If the rhs type is of constant size, use it whatever the modes. At
265 this point it is known to be smaller, or of constant size and the
267 if (TREE_CONSTANT (TYPE_SIZE (t2)))
270 /* Otherwise, if the rhs type is non-BLKmode, use it. */
271 if (TYPE_MODE (t2) != BLKmode)
274 /* In this case, both types have variable size and BLKmode. It's
275 probably best to leave the "type mismatch" because changing it
276 could cause a bad self-referential reference. */
280 /* See if EXP contains a SAVE_EXPR in a position where we would
283 ??? This is a real kludge, but is probably the best approach short
284 of some very general solution. */
287 contains_save_expr_p (tree exp)
289 switch (TREE_CODE (exp))
294 case ADDR_EXPR: case INDIRECT_REF:
296 case NOP_EXPR: case CONVERT_EXPR: case VIEW_CONVERT_EXPR:
297 return contains_save_expr_p (TREE_OPERAND (exp, 0));
302 unsigned HOST_WIDE_INT ix;
304 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), ix, value)
305 if (contains_save_expr_p (value))
315 /* See if EXP contains a NULL_EXPR in an expression we use for sizes. Return
316 it if so. This is used to detect types whose sizes involve computations
317 that are known to raise Constraint_Error. */
320 contains_null_expr (tree exp)
324 if (TREE_CODE (exp) == NULL_EXPR)
327 switch (TREE_CODE_CLASS (TREE_CODE (exp)))
330 return contains_null_expr (TREE_OPERAND (exp, 0));
334 tem = contains_null_expr (TREE_OPERAND (exp, 0));
338 return contains_null_expr (TREE_OPERAND (exp, 1));
341 switch (TREE_CODE (exp))
344 return contains_null_expr (TREE_OPERAND (exp, 0));
347 tem = contains_null_expr (TREE_OPERAND (exp, 0));
351 tem = contains_null_expr (TREE_OPERAND (exp, 1));
355 return contains_null_expr (TREE_OPERAND (exp, 2));
366 /* Return an expression tree representing an equality comparison of
367 A1 and A2, two objects of ARRAY_TYPE. The returned expression should
368 be of type RESULT_TYPE
370 Two arrays are equal in one of two ways: (1) if both have zero length
371 in some dimension (not necessarily the same dimension) or (2) if the
372 lengths in each dimension are equal and the data is equal. We perform the
373 length tests in as efficient a manner as possible. */
376 compare_arrays (tree result_type, tree a1, tree a2)
378 tree t1 = TREE_TYPE (a1);
379 tree t2 = TREE_TYPE (a2);
380 tree result = convert (result_type, integer_one_node);
381 tree a1_is_null = convert (result_type, integer_zero_node);
382 tree a2_is_null = convert (result_type, integer_zero_node);
383 bool length_zero_p = false;
385 /* Process each dimension separately and compare the lengths. If any
386 dimension has a size known to be zero, set SIZE_ZERO_P to 1 to
387 suppress the comparison of the data. */
388 while (TREE_CODE (t1) == ARRAY_TYPE && TREE_CODE (t2) == ARRAY_TYPE)
390 tree lb1 = TYPE_MIN_VALUE (TYPE_DOMAIN (t1));
391 tree ub1 = TYPE_MAX_VALUE (TYPE_DOMAIN (t1));
392 tree lb2 = TYPE_MIN_VALUE (TYPE_DOMAIN (t2));
393 tree ub2 = TYPE_MAX_VALUE (TYPE_DOMAIN (t2));
394 tree bt = get_base_type (TREE_TYPE (lb1));
395 tree length1 = fold_build2 (MINUS_EXPR, bt, ub1, lb1);
396 tree length2 = fold_build2 (MINUS_EXPR, bt, ub2, lb2);
399 tree comparison, this_a1_is_null, this_a2_is_null;
401 /* If the length of the first array is a constant, swap our operands
402 unless the length of the second array is the constant zero.
403 Note that we have set the `length' values to the length - 1. */
404 if (TREE_CODE (length1) == INTEGER_CST
405 && !integer_zerop (fold_build2 (PLUS_EXPR, bt, length2,
406 convert (bt, integer_one_node))))
408 tem = a1, a1 = a2, a2 = tem;
409 tem = t1, t1 = t2, t2 = tem;
410 tem = lb1, lb1 = lb2, lb2 = tem;
411 tem = ub1, ub1 = ub2, ub2 = tem;
412 tem = length1, length1 = length2, length2 = tem;
413 tem = a1_is_null, a1_is_null = a2_is_null, a2_is_null = tem;
416 /* If the length of this dimension in the second array is the constant
417 zero, we can just go inside the original bounds for the first
418 array and see if last < first. */
419 if (integer_zerop (fold_build2 (PLUS_EXPR, bt, length2,
420 convert (bt, integer_one_node))))
422 tree ub = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
423 tree lb = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
425 comparison = build_binary_op (LT_EXPR, result_type, ub, lb);
426 comparison = SUBSTITUTE_PLACEHOLDER_IN_EXPR (comparison, a1);
427 length1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length1, a1);
429 length_zero_p = true;
430 this_a1_is_null = comparison;
431 this_a2_is_null = convert (result_type, integer_one_node);
434 /* If the length is some other constant value, we know that the
435 this dimension in the first array cannot be superflat, so we
436 can just use its length from the actual stored bounds. */
437 else if (TREE_CODE (length2) == INTEGER_CST)
439 ub1 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
440 lb1 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
441 ub2 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t2)));
442 lb2 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t2)));
443 nbt = get_base_type (TREE_TYPE (ub1));
446 = build_binary_op (EQ_EXPR, result_type,
447 build_binary_op (MINUS_EXPR, nbt, ub1, lb1),
448 build_binary_op (MINUS_EXPR, nbt, ub2, lb2));
450 /* Note that we know that UB2 and LB2 are constant and hence
451 cannot contain a PLACEHOLDER_EXPR. */
453 comparison = SUBSTITUTE_PLACEHOLDER_IN_EXPR (comparison, a1);
454 length1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length1, a1);
456 this_a1_is_null = build_binary_op (LT_EXPR, result_type, ub1, lb1);
457 this_a2_is_null = convert (result_type, integer_zero_node);
460 /* Otherwise compare the computed lengths. */
463 length1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length1, a1);
464 length2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length2, a2);
467 = build_binary_op (EQ_EXPR, result_type, length1, length2);
470 = build_binary_op (LT_EXPR, result_type, length1,
471 convert (bt, integer_zero_node));
473 = build_binary_op (LT_EXPR, result_type, length2,
474 convert (bt, integer_zero_node));
477 result = build_binary_op (TRUTH_ANDIF_EXPR, result_type,
480 a1_is_null = build_binary_op (TRUTH_ORIF_EXPR, result_type,
481 this_a1_is_null, a1_is_null);
482 a2_is_null = build_binary_op (TRUTH_ORIF_EXPR, result_type,
483 this_a2_is_null, a2_is_null);
489 /* Unless the size of some bound is known to be zero, compare the
490 data in the array. */
493 tree type = find_common_type (TREE_TYPE (a1), TREE_TYPE (a2));
496 a1 = convert (type, a1), a2 = convert (type, a2);
498 result = build_binary_op (TRUTH_ANDIF_EXPR, result_type, result,
499 fold_build2 (EQ_EXPR, result_type, a1, a2));
503 /* The result is also true if both sizes are zero. */
504 result = build_binary_op (TRUTH_ORIF_EXPR, result_type,
505 build_binary_op (TRUTH_ANDIF_EXPR, result_type,
506 a1_is_null, a2_is_null),
509 /* If either operand contains SAVE_EXPRs, they have to be evaluated before
510 starting the comparison above since the place it would be otherwise
511 evaluated would be wrong. */
513 if (contains_save_expr_p (a1))
514 result = build2 (COMPOUND_EXPR, result_type, a1, result);
516 if (contains_save_expr_p (a2))
517 result = build2 (COMPOUND_EXPR, result_type, a2, result);
522 /* Compute the result of applying OP_CODE to LHS and RHS, where both are of
523 type TYPE. We know that TYPE is a modular type with a nonbinary
527 nonbinary_modular_operation (enum tree_code op_code, tree type, tree lhs,
530 tree modulus = TYPE_MODULUS (type);
531 unsigned int needed_precision = tree_floor_log2 (modulus) + 1;
532 unsigned int precision;
533 bool unsignedp = true;
537 /* If this is an addition of a constant, convert it to a subtraction
538 of a constant since we can do that faster. */
539 if (op_code == PLUS_EXPR && TREE_CODE (rhs) == INTEGER_CST)
541 rhs = fold_build2 (MINUS_EXPR, type, modulus, rhs);
542 op_code = MINUS_EXPR;
545 /* For the logical operations, we only need PRECISION bits. For
546 addition and subtraction, we need one more and for multiplication we
547 need twice as many. But we never want to make a size smaller than
549 if (op_code == PLUS_EXPR || op_code == MINUS_EXPR)
550 needed_precision += 1;
551 else if (op_code == MULT_EXPR)
552 needed_precision *= 2;
554 precision = MAX (needed_precision, TYPE_PRECISION (op_type));
556 /* Unsigned will do for everything but subtraction. */
557 if (op_code == MINUS_EXPR)
560 /* If our type is the wrong signedness or isn't wide enough, make a new
561 type and convert both our operands to it. */
562 if (TYPE_PRECISION (op_type) < precision
563 || TYPE_UNSIGNED (op_type) != unsignedp)
565 /* Copy the node so we ensure it can be modified to make it modular. */
566 op_type = copy_node (gnat_type_for_size (precision, unsignedp));
567 modulus = convert (op_type, modulus);
568 SET_TYPE_MODULUS (op_type, modulus);
569 TYPE_MODULAR_P (op_type) = 1;
570 lhs = convert (op_type, lhs);
571 rhs = convert (op_type, rhs);
574 /* Do the operation, then we'll fix it up. */
575 result = fold_build2 (op_code, op_type, lhs, rhs);
577 /* For multiplication, we have no choice but to do a full modulus
578 operation. However, we want to do this in the narrowest
580 if (op_code == MULT_EXPR)
582 tree div_type = copy_node (gnat_type_for_size (needed_precision, 1));
583 modulus = convert (div_type, modulus);
584 SET_TYPE_MODULUS (div_type, modulus);
585 TYPE_MODULAR_P (div_type) = 1;
586 result = convert (op_type,
587 fold_build2 (TRUNC_MOD_EXPR, div_type,
588 convert (div_type, result), modulus));
591 /* For subtraction, add the modulus back if we are negative. */
592 else if (op_code == MINUS_EXPR)
594 result = save_expr (result);
595 result = fold_build3 (COND_EXPR, op_type,
596 fold_build2 (LT_EXPR, integer_type_node, result,
597 convert (op_type, integer_zero_node)),
598 fold_build2 (PLUS_EXPR, op_type, result, modulus),
602 /* For the other operations, subtract the modulus if we are >= it. */
605 result = save_expr (result);
606 result = fold_build3 (COND_EXPR, op_type,
607 fold_build2 (GE_EXPR, integer_type_node,
609 fold_build2 (MINUS_EXPR, op_type,
614 return convert (type, result);
617 /* Make a binary operation of kind OP_CODE. RESULT_TYPE is the type
618 desired for the result. Usually the operation is to be performed
619 in that type. For MODIFY_EXPR and ARRAY_REF, RESULT_TYPE may be 0
620 in which case the type to be used will be derived from the operands.
622 This function is very much unlike the ones for C and C++ since we
623 have already done any type conversion and matching required. All we
624 have to do here is validate the work done by SEM and handle subtypes. */
627 build_binary_op (enum tree_code op_code, tree result_type,
628 tree left_operand, tree right_operand)
630 tree left_type = TREE_TYPE (left_operand);
631 tree right_type = TREE_TYPE (right_operand);
632 tree left_base_type = get_base_type (left_type);
633 tree right_base_type = get_base_type (right_type);
634 tree operation_type = result_type;
635 tree best_type = NULL_TREE;
638 bool has_side_effects = false;
641 && TREE_CODE (operation_type) == RECORD_TYPE
642 && TYPE_JUSTIFIED_MODULAR_P (operation_type))
643 operation_type = TREE_TYPE (TYPE_FIELDS (operation_type));
646 && !AGGREGATE_TYPE_P (operation_type)
647 && TYPE_EXTRA_SUBTYPE_P (operation_type))
648 operation_type = get_base_type (operation_type);
650 modulus = (operation_type && TREE_CODE (operation_type) == INTEGER_TYPE
651 && TYPE_MODULAR_P (operation_type)
652 ? TYPE_MODULUS (operation_type) : 0);
657 /* If there were any integral or pointer conversions on LHS, remove
658 them; we'll be putting them back below if needed. Likewise for
659 conversions between array and record types. But don't do this if
660 the right operand is not BLKmode (for packed arrays)
661 unless we are not changing the mode. */
662 while ((TREE_CODE (left_operand) == CONVERT_EXPR
663 || TREE_CODE (left_operand) == NOP_EXPR
664 || TREE_CODE (left_operand) == VIEW_CONVERT_EXPR)
665 && (((INTEGRAL_TYPE_P (left_type)
666 || POINTER_TYPE_P (left_type))
667 && (INTEGRAL_TYPE_P (TREE_TYPE
668 (TREE_OPERAND (left_operand, 0)))
669 || POINTER_TYPE_P (TREE_TYPE
670 (TREE_OPERAND (left_operand, 0)))))
671 || (((TREE_CODE (left_type) == RECORD_TYPE
672 /* Don't remove conversions to justified modular
674 && !TYPE_JUSTIFIED_MODULAR_P (left_type))
675 || TREE_CODE (left_type) == ARRAY_TYPE)
676 && ((TREE_CODE (TREE_TYPE
677 (TREE_OPERAND (left_operand, 0)))
679 || (TREE_CODE (TREE_TYPE
680 (TREE_OPERAND (left_operand, 0)))
682 && (TYPE_MODE (right_type) == BLKmode
683 || (TYPE_MODE (left_type)
684 == TYPE_MODE (TREE_TYPE
686 (left_operand, 0))))))))
688 left_operand = TREE_OPERAND (left_operand, 0);
689 left_type = TREE_TYPE (left_operand);
693 operation_type = left_type;
695 /* If we are copying one array or record to another, find the best type
697 if (((TREE_CODE (left_type) == ARRAY_TYPE
698 && TREE_CODE (right_type) == ARRAY_TYPE)
699 || (TREE_CODE (left_type) == RECORD_TYPE
700 && TREE_CODE (right_type) == RECORD_TYPE))
701 && (best_type = find_common_type (left_type, right_type)))
702 operation_type = best_type;
704 /* If a class-wide type may be involved, force use of the RHS type. */
705 if ((TREE_CODE (right_type) == RECORD_TYPE
706 || TREE_CODE (right_type) == UNION_TYPE)
707 && TYPE_ALIGN_OK (right_type))
708 operation_type = right_type;
710 /* Ensure everything on the LHS is valid. If we have a field reference,
711 strip anything that get_inner_reference can handle. Then remove any
712 conversions with type types having the same code and mode. Mark
713 VIEW_CONVERT_EXPRs with TREE_ADDRESSABLE. When done, we must have
714 either an INDIRECT_REF or a decl. */
715 result = left_operand;
718 tree restype = TREE_TYPE (result);
720 if (TREE_CODE (result) == COMPONENT_REF
721 || TREE_CODE (result) == ARRAY_REF
722 || TREE_CODE (result) == ARRAY_RANGE_REF)
723 while (handled_component_p (result))
724 result = TREE_OPERAND (result, 0);
725 else if (TREE_CODE (result) == REALPART_EXPR
726 || TREE_CODE (result) == IMAGPART_EXPR
727 || ((TREE_CODE (result) == NOP_EXPR
728 || TREE_CODE (result) == CONVERT_EXPR)
729 && (((TREE_CODE (restype)
730 == TREE_CODE (TREE_TYPE
731 (TREE_OPERAND (result, 0))))
732 && (TYPE_MODE (TREE_TYPE
733 (TREE_OPERAND (result, 0)))
734 == TYPE_MODE (restype)))
735 || TYPE_ALIGN_OK (restype))))
736 result = TREE_OPERAND (result, 0);
737 else if (TREE_CODE (result) == VIEW_CONVERT_EXPR)
739 TREE_ADDRESSABLE (result) = 1;
740 result = TREE_OPERAND (result, 0);
746 gcc_assert (TREE_CODE (result) == INDIRECT_REF
747 || TREE_CODE (result) == NULL_EXPR || DECL_P (result));
749 /* Convert the right operand to the operation type unless
750 it is either already of the correct type or if the type
751 involves a placeholder, since the RHS may not have the same
753 if (operation_type != right_type
754 && (!CONTAINS_PLACEHOLDER_P (TYPE_SIZE (operation_type))))
756 right_operand = convert (operation_type, right_operand);
757 right_type = operation_type;
760 /* If the left operand is not the same type as the operation type,
761 surround it in a VIEW_CONVERT_EXPR. */
762 if (left_type != operation_type)
763 left_operand = unchecked_convert (operation_type, left_operand, false);
765 has_side_effects = true;
771 operation_type = TREE_TYPE (left_type);
773 /* ... fall through ... */
775 case ARRAY_RANGE_REF:
776 /* First look through conversion between type variants. Note that
777 this changes neither the operation type nor the type domain. */
778 if (TREE_CODE (left_operand) == VIEW_CONVERT_EXPR
779 && TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (left_operand, 0)))
780 == TYPE_MAIN_VARIANT (left_type))
782 left_operand = TREE_OPERAND (left_operand, 0);
783 left_type = TREE_TYPE (left_operand);
786 /* Then convert the right operand to its base type. This will
787 prevent unneeded signedness conversions when sizetype is wider than
789 right_operand = convert (right_base_type, right_operand);
790 right_operand = convert (TYPE_DOMAIN (left_type), right_operand);
792 if (!TREE_CONSTANT (right_operand)
793 || !TREE_CONSTANT (TYPE_MIN_VALUE (right_type)))
794 gnat_mark_addressable (left_operand);
803 gcc_assert (!POINTER_TYPE_P (left_type));
805 /* ... fall through ... */
809 /* If either operand is a NULL_EXPR, just return a new one. */
810 if (TREE_CODE (left_operand) == NULL_EXPR)
811 return build2 (op_code, result_type,
812 build1 (NULL_EXPR, integer_type_node,
813 TREE_OPERAND (left_operand, 0)),
816 else if (TREE_CODE (right_operand) == NULL_EXPR)
817 return build2 (op_code, result_type,
818 build1 (NULL_EXPR, integer_type_node,
819 TREE_OPERAND (right_operand, 0)),
822 /* If either object is a justified modular types, get the
823 fields from within. */
824 if (TREE_CODE (left_type) == RECORD_TYPE
825 && TYPE_JUSTIFIED_MODULAR_P (left_type))
827 left_operand = convert (TREE_TYPE (TYPE_FIELDS (left_type)),
829 left_type = TREE_TYPE (left_operand);
830 left_base_type = get_base_type (left_type);
833 if (TREE_CODE (right_type) == RECORD_TYPE
834 && TYPE_JUSTIFIED_MODULAR_P (right_type))
836 right_operand = convert (TREE_TYPE (TYPE_FIELDS (right_type)),
838 right_type = TREE_TYPE (right_operand);
839 right_base_type = get_base_type (right_type);
842 /* If both objects are arrays, compare them specially. */
843 if ((TREE_CODE (left_type) == ARRAY_TYPE
844 || (TREE_CODE (left_type) == INTEGER_TYPE
845 && TYPE_HAS_ACTUAL_BOUNDS_P (left_type)))
846 && (TREE_CODE (right_type) == ARRAY_TYPE
847 || (TREE_CODE (right_type) == INTEGER_TYPE
848 && TYPE_HAS_ACTUAL_BOUNDS_P (right_type))))
850 result = compare_arrays (result_type, left_operand, right_operand);
852 if (op_code == NE_EXPR)
853 result = invert_truthvalue (result);
855 gcc_assert (op_code == EQ_EXPR);
860 /* Otherwise, the base types must be the same unless the objects are
861 fat pointers or records. If we have records, use the best type and
862 convert both operands to that type. */
863 if (left_base_type != right_base_type)
865 if (TYPE_FAT_POINTER_P (left_base_type)
866 && TYPE_FAT_POINTER_P (right_base_type)
867 && TYPE_MAIN_VARIANT (left_base_type)
868 == TYPE_MAIN_VARIANT (right_base_type))
869 best_type = left_base_type;
870 else if (TREE_CODE (left_base_type) == RECORD_TYPE
871 && TREE_CODE (right_base_type) == RECORD_TYPE)
873 /* The only way these are permitted to be the same is if both
874 types have the same name. In that case, one of them must
875 not be self-referential. Use that one as the best type.
876 Even better is if one is of fixed size. */
877 gcc_assert (TYPE_NAME (left_base_type)
878 && (TYPE_NAME (left_base_type)
879 == TYPE_NAME (right_base_type)));
881 if (TREE_CONSTANT (TYPE_SIZE (left_base_type)))
882 best_type = left_base_type;
883 else if (TREE_CONSTANT (TYPE_SIZE (right_base_type)))
884 best_type = right_base_type;
885 else if (!CONTAINS_PLACEHOLDER_P (TYPE_SIZE (left_base_type)))
886 best_type = left_base_type;
887 else if (!CONTAINS_PLACEHOLDER_P (TYPE_SIZE (right_base_type)))
888 best_type = right_base_type;
895 left_operand = convert (best_type, left_operand);
896 right_operand = convert (best_type, right_operand);
899 /* If we are comparing a fat pointer against zero, we need to
900 just compare the data pointer. */
901 else if (TYPE_FAT_POINTER_P (left_base_type)
902 && TREE_CODE (right_operand) == CONSTRUCTOR
903 && integer_zerop (VEC_index (constructor_elt,
904 CONSTRUCTOR_ELTS (right_operand),
908 right_operand = build_component_ref (left_operand, NULL_TREE,
909 TYPE_FIELDS (left_base_type),
911 left_operand = convert (TREE_TYPE (right_operand),
916 left_operand = convert (left_base_type, left_operand);
917 right_operand = convert (right_base_type, right_operand);
923 case PREINCREMENT_EXPR:
924 case PREDECREMENT_EXPR:
925 case POSTINCREMENT_EXPR:
926 case POSTDECREMENT_EXPR:
927 /* In these, the result type and the left operand type should be the
928 same. Do the operation in the base type of those and convert the
929 right operand (which is an integer) to that type.
931 Note that these operations are only used in loop control where
932 we guarantee that no overflow can occur. So nothing special need
933 be done for modular types. */
935 gcc_assert (left_type == result_type);
936 operation_type = get_base_type (result_type);
937 left_operand = convert (operation_type, left_operand);
938 right_operand = convert (operation_type, right_operand);
939 has_side_effects = true;
947 /* The RHS of a shift can be any type. Also, ignore any modulus
948 (we used to abort, but this is needed for unchecked conversion
949 to modular types). Otherwise, processing is the same as normal. */
950 gcc_assert (operation_type == left_base_type);
952 left_operand = convert (operation_type, left_operand);
955 case TRUTH_ANDIF_EXPR:
956 case TRUTH_ORIF_EXPR:
960 left_operand = gnat_truthvalue_conversion (left_operand);
961 right_operand = gnat_truthvalue_conversion (right_operand);
967 /* For binary modulus, if the inputs are in range, so are the
969 if (modulus && integer_pow2p (modulus))
975 gcc_assert (TREE_TYPE (result_type) == left_base_type
976 && TREE_TYPE (result_type) == right_base_type);
977 left_operand = convert (left_base_type, left_operand);
978 right_operand = convert (right_base_type, right_operand);
981 case TRUNC_DIV_EXPR: case TRUNC_MOD_EXPR:
982 case CEIL_DIV_EXPR: case CEIL_MOD_EXPR:
983 case FLOOR_DIV_EXPR: case FLOOR_MOD_EXPR:
984 case ROUND_DIV_EXPR: case ROUND_MOD_EXPR:
985 /* These always produce results lower than either operand. */
989 case POINTER_PLUS_EXPR:
990 gcc_assert (operation_type == left_base_type
991 && sizetype == right_base_type);
992 left_operand = convert (operation_type, left_operand);
993 right_operand = convert (sizetype, right_operand);
998 /* The result type should be the same as the base types of the
999 both operands (and they should be the same). Convert
1000 everything to the result type. */
1002 gcc_assert (operation_type == left_base_type
1003 && left_base_type == right_base_type);
1004 left_operand = convert (operation_type, left_operand);
1005 right_operand = convert (operation_type, right_operand);
1008 if (modulus && !integer_pow2p (modulus))
1010 result = nonbinary_modular_operation (op_code, operation_type,
1011 left_operand, right_operand);
1012 modulus = NULL_TREE;
1014 /* If either operand is a NULL_EXPR, just return a new one. */
1015 else if (TREE_CODE (left_operand) == NULL_EXPR)
1016 return build1 (NULL_EXPR, operation_type, TREE_OPERAND (left_operand, 0));
1017 else if (TREE_CODE (right_operand) == NULL_EXPR)
1018 return build1 (NULL_EXPR, operation_type, TREE_OPERAND (right_operand, 0));
1019 else if (op_code == ARRAY_REF || op_code == ARRAY_RANGE_REF)
1020 result = fold (build4 (op_code, operation_type, left_operand,
1021 right_operand, NULL_TREE, NULL_TREE));
1024 = fold_build2 (op_code, operation_type, left_operand, right_operand);
1026 TREE_SIDE_EFFECTS (result) |= has_side_effects;
1027 TREE_CONSTANT (result)
1028 |= (TREE_CONSTANT (left_operand) & TREE_CONSTANT (right_operand)
1029 && op_code != ARRAY_REF && op_code != ARRAY_RANGE_REF);
1031 if ((op_code == ARRAY_REF || op_code == ARRAY_RANGE_REF)
1032 && TYPE_VOLATILE (operation_type))
1033 TREE_THIS_VOLATILE (result) = 1;
1035 /* If we are working with modular types, perform the MOD operation
1036 if something above hasn't eliminated the need for it. */
1038 result = fold_build2 (FLOOR_MOD_EXPR, operation_type, result,
1039 convert (operation_type, modulus));
1041 if (result_type && result_type != operation_type)
1042 result = convert (result_type, result);
1047 /* Similar, but for unary operations. */
1050 build_unary_op (enum tree_code op_code, tree result_type, tree operand)
1052 tree type = TREE_TYPE (operand);
1053 tree base_type = get_base_type (type);
1054 tree operation_type = result_type;
1056 bool side_effects = false;
1059 && TREE_CODE (operation_type) == RECORD_TYPE
1060 && TYPE_JUSTIFIED_MODULAR_P (operation_type))
1061 operation_type = TREE_TYPE (TYPE_FIELDS (operation_type));
1064 && !AGGREGATE_TYPE_P (operation_type)
1065 && TYPE_EXTRA_SUBTYPE_P (operation_type))
1066 operation_type = get_base_type (operation_type);
1072 if (!operation_type)
1073 result_type = operation_type = TREE_TYPE (type);
1075 gcc_assert (result_type == TREE_TYPE (type));
1077 result = fold_build1 (op_code, operation_type, operand);
1080 case TRUTH_NOT_EXPR:
1081 gcc_assert (result_type == base_type);
1082 result = invert_truthvalue (gnat_truthvalue_conversion (operand));
1085 case ATTR_ADDR_EXPR:
1087 switch (TREE_CODE (operand))
1090 case UNCONSTRAINED_ARRAY_REF:
1091 result = TREE_OPERAND (operand, 0);
1093 /* Make sure the type here is a pointer, not a reference.
1094 GCC wants pointer types for function addresses. */
1096 result_type = build_pointer_type (type);
1098 /* If the underlying object can alias everything, propagate the
1099 property since we are effectively retrieving the object. */
1100 if (POINTER_TYPE_P (TREE_TYPE (result))
1101 && TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (result)))
1103 if (TREE_CODE (result_type) == POINTER_TYPE
1104 && !TYPE_REF_CAN_ALIAS_ALL (result_type))
1106 = build_pointer_type_for_mode (TREE_TYPE (result_type),
1107 TYPE_MODE (result_type),
1109 else if (TREE_CODE (result_type) == REFERENCE_TYPE
1110 && !TYPE_REF_CAN_ALIAS_ALL (result_type))
1112 = build_reference_type_for_mode (TREE_TYPE (result_type),
1113 TYPE_MODE (result_type),
1120 TREE_TYPE (result) = type = build_pointer_type (type);
1124 case ARRAY_RANGE_REF:
1127 /* If this is for 'Address, find the address of the prefix and
1128 add the offset to the field. Otherwise, do this the normal
1130 if (op_code == ATTR_ADDR_EXPR)
1132 HOST_WIDE_INT bitsize;
1133 HOST_WIDE_INT bitpos;
1135 enum machine_mode mode;
1136 int unsignedp, volatilep;
1138 inner = get_inner_reference (operand, &bitsize, &bitpos, &offset,
1139 &mode, &unsignedp, &volatilep,
1142 /* If INNER is a padding type whose field has a self-referential
1143 size, convert to that inner type. We know the offset is zero
1144 and we need to have that type visible. */
1145 if (TREE_CODE (TREE_TYPE (inner)) == RECORD_TYPE
1146 && TYPE_IS_PADDING_P (TREE_TYPE (inner))
1147 && (CONTAINS_PLACEHOLDER_P
1148 (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS
1149 (TREE_TYPE (inner)))))))
1150 inner = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (inner))),
1153 /* Compute the offset as a byte offset from INNER. */
1155 offset = size_zero_node;
1157 if (bitpos % BITS_PER_UNIT != 0)
1159 ("taking address of object not aligned on storage unit?",
1162 offset = size_binop (PLUS_EXPR, offset,
1163 size_int (bitpos / BITS_PER_UNIT));
1165 /* Take the address of INNER, convert the offset to void *, and
1166 add then. It will later be converted to the desired result
1168 inner = build_unary_op (ADDR_EXPR, NULL_TREE, inner);
1169 inner = convert (ptr_void_type_node, inner);
1170 result = build_binary_op (POINTER_PLUS_EXPR, ptr_void_type_node,
1172 result = convert (build_pointer_type (TREE_TYPE (operand)),
1179 /* If this is just a constructor for a padded record, we can
1180 just take the address of the single field and convert it to
1181 a pointer to our type. */
1182 if (TREE_CODE (type) == RECORD_TYPE && TYPE_IS_PADDING_P (type))
1184 result = (VEC_index (constructor_elt,
1185 CONSTRUCTOR_ELTS (operand),
1189 result = convert (build_pointer_type (TREE_TYPE (operand)),
1190 build_unary_op (ADDR_EXPR, NULL_TREE, result));
1197 if (AGGREGATE_TYPE_P (type)
1198 && AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (operand, 0))))
1199 return build_unary_op (ADDR_EXPR, result_type,
1200 TREE_OPERAND (operand, 0));
1202 /* ... fallthru ... */
1204 case VIEW_CONVERT_EXPR:
1205 /* If this just a variant conversion or if the conversion doesn't
1206 change the mode, get the result type from this type and go down.
1207 This is needed for conversions of CONST_DECLs, to eventually get
1208 to the address of their CORRESPONDING_VARs. */
1209 if ((TYPE_MAIN_VARIANT (type)
1210 == TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (operand, 0))))
1211 || (TYPE_MODE (type) != BLKmode
1212 && (TYPE_MODE (type)
1213 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (operand, 0))))))
1214 return build_unary_op (ADDR_EXPR,
1215 (result_type ? result_type
1216 : build_pointer_type (type)),
1217 TREE_OPERAND (operand, 0));
1221 operand = DECL_CONST_CORRESPONDING_VAR (operand);
1223 /* ... fall through ... */
1228 /* If we are taking the address of a padded record whose field is
1229 contains a template, take the address of the template. */
1230 if (TREE_CODE (type) == RECORD_TYPE
1231 && TYPE_IS_PADDING_P (type)
1232 && TREE_CODE (TREE_TYPE (TYPE_FIELDS (type))) == RECORD_TYPE
1233 && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (TYPE_FIELDS (type))))
1235 type = TREE_TYPE (TYPE_FIELDS (type));
1236 operand = convert (type, operand);
1239 if (type != error_mark_node)
1240 operation_type = build_pointer_type (type);
1242 gnat_mark_addressable (operand);
1243 result = fold_build1 (ADDR_EXPR, operation_type, operand);
1246 TREE_CONSTANT (result) = staticp (operand) || TREE_CONSTANT (operand);
1250 /* If we want to refer to an entire unconstrained array,
1251 make up an expression to do so. This will never survive to
1252 the backend. If TYPE is a thin pointer, first convert the
1253 operand to a fat pointer. */
1254 if (TYPE_THIN_POINTER_P (type)
1255 && TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type)))
1258 = convert (TREE_TYPE (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type))),
1260 type = TREE_TYPE (operand);
1263 if (TYPE_FAT_POINTER_P (type))
1265 result = build1 (UNCONSTRAINED_ARRAY_REF,
1266 TYPE_UNCONSTRAINED_ARRAY (type), operand);
1267 TREE_READONLY (result) = TREE_STATIC (result)
1268 = TYPE_READONLY (TYPE_UNCONSTRAINED_ARRAY (type));
1270 else if (TREE_CODE (operand) == ADDR_EXPR)
1271 result = TREE_OPERAND (operand, 0);
1275 result = fold_build1 (op_code, TREE_TYPE (type), operand);
1276 TREE_READONLY (result) = TYPE_READONLY (TREE_TYPE (type));
1280 = (!TYPE_FAT_POINTER_P (type) && TYPE_VOLATILE (TREE_TYPE (type)));
1286 tree modulus = ((operation_type
1287 && TREE_CODE (operation_type) == INTEGER_TYPE
1288 && TYPE_MODULAR_P (operation_type))
1289 ? TYPE_MODULUS (operation_type) : 0);
1290 int mod_pow2 = modulus && integer_pow2p (modulus);
1292 /* If this is a modular type, there are various possibilities
1293 depending on the operation and whether the modulus is a
1294 power of two or not. */
1298 gcc_assert (operation_type == base_type);
1299 operand = convert (operation_type, operand);
1301 /* The fastest in the negate case for binary modulus is
1302 the straightforward code; the TRUNC_MOD_EXPR below
1303 is an AND operation. */
1304 if (op_code == NEGATE_EXPR && mod_pow2)
1305 result = fold_build2 (TRUNC_MOD_EXPR, operation_type,
1306 fold_build1 (NEGATE_EXPR, operation_type,
1310 /* For nonbinary negate case, return zero for zero operand,
1311 else return the modulus minus the operand. If the modulus
1312 is a power of two minus one, we can do the subtraction
1313 as an XOR since it is equivalent and faster on most machines. */
1314 else if (op_code == NEGATE_EXPR && !mod_pow2)
1316 if (integer_pow2p (fold_build2 (PLUS_EXPR, operation_type,
1318 convert (operation_type,
1319 integer_one_node))))
1320 result = fold_build2 (BIT_XOR_EXPR, operation_type,
1323 result = fold_build2 (MINUS_EXPR, operation_type,
1326 result = fold_build3 (COND_EXPR, operation_type,
1327 fold_build2 (NE_EXPR,
1332 integer_zero_node)),
1337 /* For the NOT cases, we need a constant equal to
1338 the modulus minus one. For a binary modulus, we
1339 XOR against the constant and subtract the operand from
1340 that constant for nonbinary modulus. */
1342 tree cnst = fold_build2 (MINUS_EXPR, operation_type, modulus,
1343 convert (operation_type,
1347 result = fold_build2 (BIT_XOR_EXPR, operation_type,
1350 result = fold_build2 (MINUS_EXPR, operation_type,
1358 /* ... fall through ... */
1361 gcc_assert (operation_type == base_type);
1362 result = fold_build1 (op_code, operation_type,
1363 convert (operation_type, operand));
1368 TREE_SIDE_EFFECTS (result) = 1;
1369 if (TREE_CODE (result) == INDIRECT_REF)
1370 TREE_THIS_VOLATILE (result) = TYPE_VOLATILE (TREE_TYPE (result));
1373 if (result_type && TREE_TYPE (result) != result_type)
1374 result = convert (result_type, result);
1379 /* Similar, but for COND_EXPR. */
1382 build_cond_expr (tree result_type, tree condition_operand,
1383 tree true_operand, tree false_operand)
1386 bool addr_p = false;
1388 /* The front-end verifies that result, true and false operands have same base
1389 type. Convert everything to the result type. */
1391 true_operand = convert (result_type, true_operand);
1392 false_operand = convert (result_type, false_operand);
1394 /* If the result type is unconstrained, take the address of
1395 the operands and then dereference our result. */
1396 if (TREE_CODE (result_type) == UNCONSTRAINED_ARRAY_TYPE
1397 || CONTAINS_PLACEHOLDER_P (TYPE_SIZE (result_type)))
1400 result_type = build_pointer_type (result_type);
1401 true_operand = build_unary_op (ADDR_EXPR, result_type, true_operand);
1402 false_operand = build_unary_op (ADDR_EXPR, result_type, false_operand);
1405 result = fold_build3 (COND_EXPR, result_type, condition_operand,
1406 true_operand, false_operand);
1408 /* If either operand is a SAVE_EXPR (possibly surrounded by
1409 arithmetic, make sure it gets done. */
1410 true_operand = skip_simple_arithmetic (true_operand);
1411 false_operand = skip_simple_arithmetic (false_operand);
1413 if (TREE_CODE (true_operand) == SAVE_EXPR)
1414 result = build2 (COMPOUND_EXPR, result_type, true_operand, result);
1416 if (TREE_CODE (false_operand) == SAVE_EXPR)
1417 result = build2 (COMPOUND_EXPR, result_type, false_operand, result);
1419 /* ??? Seems the code above is wrong, as it may move ahead of the COND
1420 SAVE_EXPRs with side effects and not shared by both arms. */
1423 result = build_unary_op (INDIRECT_REF, NULL_TREE, result);
1428 /* Similar, but for RETURN_EXPR. If RESULT_DECL is non-zero, build
1429 a RETURN_EXPR around the assignment of RET_VAL to RESULT_DECL.
1430 If RESULT_DECL is zero, build a bare RETURN_EXPR. */
1433 build_return_expr (tree result_decl, tree ret_val)
1439 /* The gimplifier explicitly enforces the following invariant:
1448 As a consequence, type-homogeneity dictates that we use the type
1449 of the RESULT_DECL as the operation type. */
1451 tree operation_type = TREE_TYPE (result_decl);
1453 /* Convert the right operand to the operation type. Note that
1454 it's the same transformation as in the MODIFY_EXPR case of
1455 build_binary_op with the additional guarantee that the type
1456 cannot involve a placeholder, since otherwise the function
1457 would use the "target pointer" return mechanism. */
1459 if (operation_type != TREE_TYPE (ret_val))
1460 ret_val = convert (operation_type, ret_val);
1463 = build2 (MODIFY_EXPR, operation_type, result_decl, ret_val);
1466 result_expr = NULL_TREE;
1468 return build1 (RETURN_EXPR, void_type_node, result_expr);
1471 /* Build a CALL_EXPR to call FUNDECL with one argument, ARG. Return
1475 build_call_1_expr (tree fundecl, tree arg)
1477 tree call = build_call_nary (TREE_TYPE (TREE_TYPE (fundecl)),
1478 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1480 TREE_SIDE_EFFECTS (call) = 1;
1484 /* Build a CALL_EXPR to call FUNDECL with two arguments, ARG1 & ARG2. Return
1488 build_call_2_expr (tree fundecl, tree arg1, tree arg2)
1490 tree call = build_call_nary (TREE_TYPE (TREE_TYPE (fundecl)),
1491 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1493 TREE_SIDE_EFFECTS (call) = 1;
1497 /* Likewise to call FUNDECL with no arguments. */
1500 build_call_0_expr (tree fundecl)
1502 /* We rely on build_call_nary to compute TREE_SIDE_EFFECTS. This makes
1503 it possible to propagate DECL_IS_PURE on parameterless functions. */
1504 tree call = build_call_nary (TREE_TYPE (TREE_TYPE (fundecl)),
1505 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1510 /* Call a function that raises an exception and pass the line number and file
1511 name, if requested. MSG says which exception function to call.
1513 GNAT_NODE is the gnat node conveying the source location for which the
1514 error should be signaled, or Empty in which case the error is signaled on
1515 the current ref_file_name/input_line.
1517 KIND says which kind of exception this is for
1518 (N_Raise_{Constraint,Storage,Program}_Error). */
1521 build_call_raise (int msg, Node_Id gnat_node, char kind)
1523 tree fndecl = gnat_raise_decls[msg];
1524 tree label = get_exception_label (kind);
1530 /* If this is to be done as a goto, handle that case. */
1533 Entity_Id local_raise = Get_Local_Raise_Call_Entity ();
1534 tree gnu_result = build1 (GOTO_EXPR, void_type_node, label);
1536 /* If Local_Raise is present, generate
1537 Local_Raise (exception'Identity); */
1538 if (Present (local_raise))
1540 tree gnu_local_raise
1541 = gnat_to_gnu_entity (local_raise, NULL_TREE, 0);
1542 tree gnu_exception_entity
1543 = gnat_to_gnu_entity (Get_RT_Exception_Entity (msg), NULL_TREE, 0);
1545 = build_call_1_expr (gnu_local_raise,
1546 build_unary_op (ADDR_EXPR, NULL_TREE,
1547 gnu_exception_entity));
1549 gnu_result = build2 (COMPOUND_EXPR, void_type_node,
1550 gnu_call, gnu_result);}
1556 = (Debug_Flag_NN || Exception_Locations_Suppressed)
1558 : (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1559 ? IDENTIFIER_POINTER
1560 (get_identifier (Get_Name_String
1562 (Get_Source_File_Index (Sloc (gnat_node))))))
1565 len = strlen (str) + 1;
1566 filename = build_string (len, str);
1568 = (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1569 ? Get_Logical_Line_Number (Sloc(gnat_node)) : input_line;
1571 TREE_TYPE (filename)
1572 = build_array_type (char_type_node,
1573 build_index_type (build_int_cst (NULL_TREE, len)));
1576 build_call_2_expr (fndecl,
1577 build1 (ADDR_EXPR, build_pointer_type (char_type_node),
1579 build_int_cst (NULL_TREE, line_number));
1582 /* qsort comparer for the bit positions of two constructor elements
1583 for record components. */
1586 compare_elmt_bitpos (const PTR rt1, const PTR rt2)
1588 const_tree const elmt1 = * (const_tree const *) rt1;
1589 const_tree const elmt2 = * (const_tree const *) rt2;
1590 const_tree const field1 = TREE_PURPOSE (elmt1);
1591 const_tree const field2 = TREE_PURPOSE (elmt2);
1593 = tree_int_cst_compare (bit_position (field1), bit_position (field2));
1595 return ret ? ret : (int) (DECL_UID (field1) - DECL_UID (field2));
1598 /* Return a CONSTRUCTOR of TYPE whose list is LIST. */
1601 gnat_build_constructor (tree type, tree list)
1605 bool allconstant = (TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST);
1606 bool side_effects = false;
1609 /* Scan the elements to see if they are all constant or if any has side
1610 effects, to let us set global flags on the resulting constructor. Count
1611 the elements along the way for possible sorting purposes below. */
1612 for (n_elmts = 0, elmt = list; elmt; elmt = TREE_CHAIN (elmt), n_elmts ++)
1614 if (!TREE_CONSTANT (TREE_VALUE (elmt))
1615 || (TREE_CODE (type) == RECORD_TYPE
1616 && DECL_BIT_FIELD (TREE_PURPOSE (elmt))
1617 && TREE_CODE (TREE_VALUE (elmt)) != INTEGER_CST)
1618 || !initializer_constant_valid_p (TREE_VALUE (elmt),
1619 TREE_TYPE (TREE_VALUE (elmt))))
1620 allconstant = false;
1622 if (TREE_SIDE_EFFECTS (TREE_VALUE (elmt)))
1623 side_effects = true;
1625 /* Propagate an NULL_EXPR from the size of the type. We won't ever
1626 be executing the code we generate here in that case, but handle it
1627 specially to avoid the compiler blowing up. */
1628 if (TREE_CODE (type) == RECORD_TYPE
1630 = contains_null_expr (DECL_SIZE (TREE_PURPOSE (elmt))))))
1631 return build1 (NULL_EXPR, type, TREE_OPERAND (result, 0));
1634 /* For record types with constant components only, sort field list
1635 by increasing bit position. This is necessary to ensure the
1636 constructor can be output as static data. */
1637 if (allconstant && TREE_CODE (type) == RECORD_TYPE && n_elmts > 1)
1639 /* Fill an array with an element tree per index, and ask qsort to order
1640 them according to what a bitpos comparison function says. */
1641 tree *gnu_arr = (tree *) alloca (sizeof (tree) * n_elmts);
1644 for (i = 0, elmt = list; elmt; elmt = TREE_CHAIN (elmt), i++)
1647 qsort (gnu_arr, n_elmts, sizeof (tree), compare_elmt_bitpos);
1649 /* Then reconstruct the list from the sorted array contents. */
1651 for (i = n_elmts - 1; i >= 0; i--)
1653 TREE_CHAIN (gnu_arr[i]) = list;
1658 result = build_constructor_from_list (type, list);
1659 TREE_CONSTANT (result) = TREE_INVARIANT (result)
1660 = TREE_STATIC (result) = allconstant;
1661 TREE_SIDE_EFFECTS (result) = side_effects;
1662 TREE_READONLY (result) = TYPE_READONLY (type) || allconstant;
1666 /* Return a COMPONENT_REF to access a field that is given by COMPONENT,
1667 an IDENTIFIER_NODE giving the name of the field, or FIELD, a FIELD_DECL,
1668 for the field. Don't fold the result if NO_FOLD_P is true.
1670 We also handle the fact that we might have been passed a pointer to the
1671 actual record and know how to look for fields in variant parts. */
1674 build_simple_component_ref (tree record_variable, tree component,
1675 tree field, bool no_fold_p)
1677 tree record_type = TYPE_MAIN_VARIANT (TREE_TYPE (record_variable));
1678 tree ref, inner_variable;
1680 gcc_assert ((TREE_CODE (record_type) == RECORD_TYPE
1681 || TREE_CODE (record_type) == UNION_TYPE
1682 || TREE_CODE (record_type) == QUAL_UNION_TYPE)
1683 && TYPE_SIZE (record_type)
1684 && (component != 0) != (field != 0));
1686 /* If no field was specified, look for a field with the specified name
1687 in the current record only. */
1689 for (field = TYPE_FIELDS (record_type); field;
1690 field = TREE_CHAIN (field))
1691 if (DECL_NAME (field) == component)
1697 /* If this field is not in the specified record, see if we can find
1698 something in the record whose original field is the same as this one. */
1699 if (DECL_CONTEXT (field) != record_type)
1700 /* Check if there is a field with name COMPONENT in the record. */
1704 /* First loop thru normal components. */
1706 for (new_field = TYPE_FIELDS (record_type); new_field;
1707 new_field = TREE_CHAIN (new_field))
1708 if (field == new_field
1709 || DECL_ORIGINAL_FIELD (new_field) == field
1710 || new_field == DECL_ORIGINAL_FIELD (field)
1711 || (DECL_ORIGINAL_FIELD (field)
1712 && (DECL_ORIGINAL_FIELD (field)
1713 == DECL_ORIGINAL_FIELD (new_field))))
1716 /* Next, loop thru DECL_INTERNAL_P components if we haven't found
1717 the component in the first search. Doing this search in 2 steps
1718 is required to avoiding hidden homonymous fields in the
1722 for (new_field = TYPE_FIELDS (record_type); new_field;
1723 new_field = TREE_CHAIN (new_field))
1724 if (DECL_INTERNAL_P (new_field))
1727 = build_simple_component_ref (record_variable,
1728 NULL_TREE, new_field, no_fold_p);
1729 ref = build_simple_component_ref (field_ref, NULL_TREE, field,
1742 /* If the field's offset has overflowed, do not attempt to access it
1743 as doing so may trigger sanity checks deeper in the back-end.
1744 Note that we don't need to warn since this will be done on trying
1745 to declare the object. */
1746 if (TREE_CODE (DECL_FIELD_OFFSET (field)) == INTEGER_CST
1747 && TREE_OVERFLOW (DECL_FIELD_OFFSET (field)))
1750 /* Look through conversion between type variants. Note that this
1751 is transparent as far as the field is concerned. */
1752 if (TREE_CODE (record_variable) == VIEW_CONVERT_EXPR
1753 && TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (record_variable, 0)))
1755 inner_variable = TREE_OPERAND (record_variable, 0);
1757 inner_variable = record_variable;
1759 ref = build3 (COMPONENT_REF, TREE_TYPE (field), inner_variable, field,
1762 if (TREE_READONLY (record_variable) || TREE_READONLY (field))
1763 TREE_READONLY (ref) = 1;
1764 if (TREE_THIS_VOLATILE (record_variable) || TREE_THIS_VOLATILE (field)
1765 || TYPE_VOLATILE (record_type))
1766 TREE_THIS_VOLATILE (ref) = 1;
1771 /* The generic folder may punt in this case because the inner array type
1772 can be self-referential, but folding is in fact not problematic. */
1773 else if (TREE_CODE (record_variable) == CONSTRUCTOR
1774 && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (record_variable)))
1776 VEC(constructor_elt,gc) *elts = CONSTRUCTOR_ELTS (record_variable);
1777 unsigned HOST_WIDE_INT idx;
1779 FOR_EACH_CONSTRUCTOR_ELT (elts, idx, index, value)
1789 /* Like build_simple_component_ref, except that we give an error if the
1790 reference could not be found. */
1793 build_component_ref (tree record_variable, tree component,
1794 tree field, bool no_fold_p)
1796 tree ref = build_simple_component_ref (record_variable, component, field,
1802 /* If FIELD was specified, assume this is an invalid user field so
1803 raise constraint error. Otherwise, we can't find the type to return, so
1806 return build1 (NULL_EXPR, TREE_TYPE (field),
1807 build_call_raise (CE_Discriminant_Check_Failed, Empty,
1808 N_Raise_Constraint_Error));
1811 /* Build a GCC tree to call an allocation or deallocation function.
1812 If GNU_OBJ is nonzero, it is an object to deallocate. Otherwise,
1813 generate an allocator.
1815 GNU_SIZE is the size of the object in bytes and ALIGN is the alignment in
1816 bits. GNAT_PROC, if present, is a procedure to call and GNAT_POOL is the
1817 storage pool to use. If not preset, malloc and free will be used except
1818 if GNAT_PROC is the "fake" value of -1, in which case we allocate the
1819 object dynamically on the stack frame. */
1822 build_call_alloc_dealloc (tree gnu_obj, tree gnu_size, unsigned align,
1823 Entity_Id gnat_proc, Entity_Id gnat_pool,
1826 tree gnu_align = size_int (align / BITS_PER_UNIT);
1828 gnu_size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (gnu_size, gnu_obj);
1830 if (Present (gnat_proc))
1832 /* The storage pools are obviously always tagged types, but the
1833 secondary stack uses the same mechanism and is not tagged */
1834 if (Is_Tagged_Type (Etype (gnat_pool)))
1836 /* The size is the third parameter; the alignment is the
1838 Entity_Id gnat_size_type
1839 = Etype (Next_Formal (Next_Formal (First_Formal (gnat_proc))));
1840 tree gnu_size_type = gnat_to_gnu_type (gnat_size_type);
1841 tree gnu_proc = gnat_to_gnu (gnat_proc);
1842 tree gnu_proc_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_proc);
1843 tree gnu_pool = gnat_to_gnu (gnat_pool);
1844 tree gnu_pool_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_pool);
1847 gnu_size = convert (gnu_size_type, gnu_size);
1848 gnu_align = convert (gnu_size_type, gnu_align);
1850 /* The first arg is always the address of the storage pool; next
1851 comes the address of the object, for a deallocator, then the
1852 size and alignment. */
1854 gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)),
1855 gnu_proc_addr, 4, gnu_pool_addr,
1856 gnu_obj, gnu_size, gnu_align);
1858 gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)),
1859 gnu_proc_addr, 3, gnu_pool_addr,
1860 gnu_size, gnu_align);
1861 TREE_SIDE_EFFECTS (gnu_call) = 1;
1865 /* Secondary stack case. */
1868 /* The size is the second parameter */
1869 Entity_Id gnat_size_type
1870 = Etype (Next_Formal (First_Formal (gnat_proc)));
1871 tree gnu_size_type = gnat_to_gnu_type (gnat_size_type);
1872 tree gnu_proc = gnat_to_gnu (gnat_proc);
1873 tree gnu_proc_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_proc);
1876 gnu_size = convert (gnu_size_type, gnu_size);
1878 /* The first arg is the address of the object, for a
1879 deallocator, then the size */
1881 gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)),
1882 gnu_proc_addr, 2, gnu_obj, gnu_size);
1884 gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)),
1885 gnu_proc_addr, 1, gnu_size);
1886 TREE_SIDE_EFFECTS (gnu_call) = 1;
1892 return build_call_1_expr (free_decl, gnu_obj);
1894 /* ??? For now, disable variable-sized allocators in the stack since
1895 we can't yet gimplify an ALLOCATE_EXPR. */
1896 else if (gnat_pool == -1
1897 && TREE_CODE (gnu_size) == INTEGER_CST && !flag_stack_check)
1899 /* If the size is a constant, we can put it in the fixed portion of
1900 the stack frame to avoid the need to adjust the stack pointer. */
1901 if (TREE_CODE (gnu_size) == INTEGER_CST && !flag_stack_check)
1904 = build_range_type (NULL_TREE, size_one_node, gnu_size);
1905 tree gnu_array_type = build_array_type (char_type_node, gnu_range);
1907 = create_var_decl (get_identifier ("RETVAL"), NULL_TREE,
1908 gnu_array_type, NULL_TREE, false, false, false,
1909 false, NULL, gnat_node);
1911 return convert (ptr_void_type_node,
1912 build_unary_op (ADDR_EXPR, NULL_TREE, gnu_decl));
1917 return build2 (ALLOCATE_EXPR, ptr_void_type_node, gnu_size, gnu_align);
1922 if (Nkind (gnat_node) != N_Allocator || !Comes_From_Source (gnat_node))
1923 Check_No_Implicit_Heap_Alloc (gnat_node);
1924 return build_call_1_expr (malloc_decl, gnu_size);
1928 /* Build a GCC tree to correspond to allocating an object of TYPE whose
1929 initial value is INIT, if INIT is nonzero. Convert the expression to
1930 RESULT_TYPE, which must be some type of pointer. Return the tree.
1931 GNAT_PROC and GNAT_POOL optionally give the procedure to call and
1932 the storage pool to use. GNAT_NODE is used to provide an error
1933 location for restriction violations messages. If IGNORE_INIT_TYPE is
1934 true, ignore the type of INIT for the purpose of determining the size;
1935 this will cause the maximum size to be allocated if TYPE is of
1936 self-referential size. */
1939 build_allocator (tree type, tree init, tree result_type, Entity_Id gnat_proc,
1940 Entity_Id gnat_pool, Node_Id gnat_node, bool ignore_init_type)
1942 tree size = TYPE_SIZE_UNIT (type);
1944 unsigned int default_allocator_alignment
1945 = get_target_default_allocator_alignment () * BITS_PER_UNIT;
1947 /* If the initializer, if present, is a NULL_EXPR, just return a new one. */
1948 if (init && TREE_CODE (init) == NULL_EXPR)
1949 return build1 (NULL_EXPR, result_type, TREE_OPERAND (init, 0));
1951 /* If RESULT_TYPE is a fat or thin pointer, set SIZE to be the sum of the
1952 sizes of the object and its template. Allocate the whole thing and
1953 fill in the parts that are known. */
1954 else if (TYPE_FAT_OR_THIN_POINTER_P (result_type))
1957 = build_unc_object_type_from_ptr (result_type, type,
1958 get_identifier ("ALLOC"));
1959 tree template_type = TREE_TYPE (TYPE_FIELDS (storage_type));
1960 tree storage_ptr_type = build_pointer_type (storage_type);
1962 tree template_cons = NULL_TREE;
1964 size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TYPE_SIZE_UNIT (storage_type),
1967 /* If the size overflows, pass -1 so the allocator will raise
1969 if (TREE_CODE (size) == INTEGER_CST && TREE_OVERFLOW (size))
1970 size = ssize_int (-1);
1972 storage = build_call_alloc_dealloc (NULL_TREE, size,
1973 TYPE_ALIGN (storage_type),
1974 gnat_proc, gnat_pool, gnat_node);
1975 storage = convert (storage_ptr_type, protect_multiple_eval (storage));
1977 if (TREE_CODE (type) == RECORD_TYPE && TYPE_IS_PADDING_P (type))
1979 type = TREE_TYPE (TYPE_FIELDS (type));
1982 init = convert (type, init);
1985 /* If there is an initializing expression, make a constructor for
1986 the entire object including the bounds and copy it into the
1987 object. If there is no initializing expression, just set the
1991 template_cons = tree_cons (TREE_CHAIN (TYPE_FIELDS (storage_type)),
1993 template_cons = tree_cons (TYPE_FIELDS (storage_type),
1994 build_template (template_type, type,
2000 build2 (COMPOUND_EXPR, storage_ptr_type,
2002 (MODIFY_EXPR, storage_type,
2003 build_unary_op (INDIRECT_REF, NULL_TREE,
2004 convert (storage_ptr_type, storage)),
2005 gnat_build_constructor (storage_type, template_cons)),
2006 convert (storage_ptr_type, storage)));
2010 (COMPOUND_EXPR, result_type,
2012 (MODIFY_EXPR, template_type,
2014 (build_unary_op (INDIRECT_REF, NULL_TREE,
2015 convert (storage_ptr_type, storage)),
2016 NULL_TREE, TYPE_FIELDS (storage_type), 0),
2017 build_template (template_type, type, NULL_TREE)),
2018 convert (result_type, convert (storage_ptr_type, storage)));
2021 /* If we have an initializing expression, see if its size is simpler
2022 than the size from the type. */
2023 if (!ignore_init_type && init && TYPE_SIZE_UNIT (TREE_TYPE (init))
2024 && (TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (init))) == INTEGER_CST
2025 || CONTAINS_PLACEHOLDER_P (size)))
2026 size = TYPE_SIZE_UNIT (TREE_TYPE (init));
2028 /* If the size is still self-referential, reference the initializing
2029 expression, if it is present. If not, this must have been a
2030 call to allocate a library-level object, in which case we use
2031 the maximum size. */
2032 if (CONTAINS_PLACEHOLDER_P (size))
2034 if (!ignore_init_type && init)
2035 size = substitute_placeholder_in_expr (size, init);
2037 size = max_size (size, true);
2040 /* If the size overflows, pass -1 so the allocator will raise
2042 if (TREE_CODE (size) == INTEGER_CST && TREE_OVERFLOW (size))
2043 size = ssize_int (-1);
2045 /* If this is in the default storage pool and the type alignment is larger
2046 than what the default allocator supports, make an "aligning" record type
2047 with room to store a pointer before the field, allocate an object of that
2048 type, store the system's allocator return value just in front of the
2049 field and return the field's address. */
2051 if (No (gnat_proc) && TYPE_ALIGN (type) > default_allocator_alignment)
2053 /* Construct the aligning type with enough room for a pointer ahead
2054 of the field, then allocate. */
2056 = make_aligning_type (type, TYPE_ALIGN (type), size,
2057 default_allocator_alignment,
2058 POINTER_SIZE / BITS_PER_UNIT);
2060 tree record, record_addr;
2063 = build_call_alloc_dealloc (NULL_TREE, TYPE_SIZE_UNIT (record_type),
2064 default_allocator_alignment, Empty, Empty,
2068 = convert (build_pointer_type (record_type),
2069 save_expr (record_addr));
2071 record = build_unary_op (INDIRECT_REF, NULL_TREE, record_addr);
2073 /* Our RESULT (the Ada allocator's value) is the super-aligned address
2074 of the internal record field ... */
2076 = build_unary_op (ADDR_EXPR, NULL_TREE,
2078 (record, NULL_TREE, TYPE_FIELDS (record_type), 0));
2079 result = convert (result_type, result);
2081 /* ... with the system allocator's return value stored just in
2085 = build_binary_op (POINTER_PLUS_EXPR, ptr_void_type_node,
2086 convert (ptr_void_type_node, result),
2087 size_int (-POINTER_SIZE/BITS_PER_UNIT));
2090 = convert (build_pointer_type (ptr_void_type_node), ptr_addr);
2093 = build2 (COMPOUND_EXPR, TREE_TYPE (result),
2094 build_binary_op (MODIFY_EXPR, NULL_TREE,
2095 build_unary_op (INDIRECT_REF, NULL_TREE,
2097 convert (ptr_void_type_node,
2103 result = convert (result_type,
2104 build_call_alloc_dealloc (NULL_TREE, size,
2110 /* If we have an initial value, put the new address into a SAVE_EXPR, assign
2111 the value, and return the address. Do this with a COMPOUND_EXPR. */
2115 result = save_expr (result);
2117 = build2 (COMPOUND_EXPR, TREE_TYPE (result),
2119 (MODIFY_EXPR, NULL_TREE,
2120 build_unary_op (INDIRECT_REF,
2121 TREE_TYPE (TREE_TYPE (result)), result),
2126 return convert (result_type, result);
2129 /* Fill in a VMS descriptor for EXPR and return a constructor for it.
2130 GNAT_FORMAL is how we find the descriptor record. */
2133 fill_vms_descriptor (tree expr, Entity_Id gnat_formal)
2135 tree record_type = TREE_TYPE (TREE_TYPE (get_gnu_tree (gnat_formal)));
2137 tree const_list = NULL_TREE;
2139 expr = maybe_unconstrained_array (expr);
2140 gnat_mark_addressable (expr);
2142 for (field = TYPE_FIELDS (record_type); field; field = TREE_CHAIN (field))
2145 convert (TREE_TYPE (field),
2146 SUBSTITUTE_PLACEHOLDER_IN_EXPR
2147 (DECL_INITIAL (field), expr)),
2150 return gnat_build_constructor (record_type, nreverse (const_list));
2153 /* Indicate that we need to make the address of EXPR_NODE and it therefore
2154 should not be allocated in a register. Returns true if successful. */
2157 gnat_mark_addressable (tree expr_node)
2160 switch (TREE_CODE (expr_node))
2165 case ARRAY_RANGE_REF:
2168 case VIEW_CONVERT_EXPR:
2170 case NON_LVALUE_EXPR:
2172 expr_node = TREE_OPERAND (expr_node, 0);
2176 TREE_ADDRESSABLE (expr_node) = 1;
2182 TREE_ADDRESSABLE (expr_node) = 1;
2186 TREE_ADDRESSABLE (expr_node) = 1;
2190 return (DECL_CONST_CORRESPONDING_VAR (expr_node)
2191 && (gnat_mark_addressable
2192 (DECL_CONST_CORRESPONDING_VAR (expr_node))));