1 /****************************************************************************
3 * GNAT COMPILER COMPONENTS *
7 * C Implementation File *
9 * Copyright (C) 1992-2004, 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 2, 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 distributed with GNAT; see file COPYING. If not, write *
19 * to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, *
20 * MA 02111-1307, USA. *
22 * GNAT was originally developed by the GNAT team at New York University. *
23 * Extensive contributions were provided by Ada Core Technologies Inc. *
25 ****************************************************************************/
29 #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) ? convert (type, integer_zero_node)
90 : convert (type, integer_one_node));
93 return (real_zerop (expr) ? convert (type, integer_zero_node)
94 : convert (type, integer_one_node));
97 /* Distribute the conversion into the arms of a COND_EXPR. */
99 (build3 (COND_EXPR, type, TREE_OPERAND (expr, 0),
100 gnat_truthvalue_conversion (TREE_OPERAND (expr, 1)),
101 gnat_truthvalue_conversion (TREE_OPERAND (expr, 2))));
104 return build_binary_op (NE_EXPR, type, expr,
105 convert (type, integer_zero_node));
109 /* Return the base type of TYPE. */
112 get_base_type (tree type)
114 if (TREE_CODE (type) == RECORD_TYPE
115 && TYPE_JUSTIFIED_MODULAR_P (type))
116 type = TREE_TYPE (TYPE_FIELDS (type));
118 while (TREE_TYPE (type)
119 && (TREE_CODE (type) == INTEGER_TYPE
120 || TREE_CODE (type) == REAL_TYPE))
121 type = TREE_TYPE (type);
126 /* Likewise, but only return types known to the Ada source. */
128 get_ada_base_type (tree type)
130 while (TREE_TYPE (type)
131 && (TREE_CODE (type) == INTEGER_TYPE
132 || TREE_CODE (type) == REAL_TYPE)
133 && !TYPE_EXTRA_SUBTYPE_P (type))
134 type = TREE_TYPE (type);
139 /* EXP is a GCC tree representing an address. See if we can find how
140 strictly the object at that address is aligned. Return that alignment
141 in bits. If we don't know anything about the alignment, return 0. */
144 known_alignment (tree exp)
146 unsigned int this_alignment;
147 unsigned int lhs, rhs;
148 unsigned int type_alignment;
150 /* For pointer expressions, we know that the designated object is always at
151 least as strictly aligned as the designated subtype, so we account for
152 both type and expression information in this case.
154 Beware that we can still get a dummy designated subtype here (e.g. Taft
155 Amendement types), in which the alignment information is meaningless and
158 We always compute a type_alignment value and return the MAX of it
159 compared with what we get from the expression tree. Just set the
160 type_alignment value to 0 when the type information is to be ignored. */
162 = ((POINTER_TYPE_P (TREE_TYPE (exp))
163 && !TYPE_IS_DUMMY_P (TREE_TYPE (TREE_TYPE (exp))))
164 ? TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))) : 0);
166 switch (TREE_CODE (exp))
170 case NON_LVALUE_EXPR:
171 /* Conversions between pointers and integers don't change the alignment
172 of the underlying object. */
173 this_alignment = known_alignment (TREE_OPERAND (exp, 0));
178 /* If two address are added, the alignment of the result is the
179 minimum of the two aligments. */
180 lhs = known_alignment (TREE_OPERAND (exp, 0));
181 rhs = known_alignment (TREE_OPERAND (exp, 1));
182 this_alignment = MIN (lhs, rhs);
186 /* The first part of this represents the lowest bit in the constant,
187 but is it in bytes, not bits. */
190 * (TREE_INT_CST_LOW (exp) & - TREE_INT_CST_LOW (exp)),
195 /* If we know the alignment of just one side, use it. Otherwise,
196 use the product of the alignments. */
197 lhs = known_alignment (TREE_OPERAND (exp, 0));
198 rhs = known_alignment (TREE_OPERAND (exp, 1));
200 if (lhs == 0 || rhs == 0)
201 this_alignment = MIN (BIGGEST_ALIGNMENT, MAX (lhs, rhs));
203 this_alignment = MIN (BIGGEST_ALIGNMENT, lhs * rhs);
207 this_alignment = expr_align (TREE_OPERAND (exp, 0));
215 return MAX (type_alignment, this_alignment);
218 /* We have a comparison or assignment operation on two types, T1 and T2,
219 which are both either array types or both record types.
220 Return the type that both operands should be converted to, if any.
221 Otherwise return zero. */
224 find_common_type (tree t1, tree t2)
226 /* If either type is non-BLKmode, use it. Note that we know that we will
227 not have any alignment problems since if we did the non-BLKmode
228 type could not have been used. */
229 if (TYPE_MODE (t1) != BLKmode)
231 else if (TYPE_MODE (t2) != BLKmode)
234 /* Otherwise, return the type that has a constant size. */
235 if (TREE_CONSTANT (TYPE_SIZE (t1)))
237 else if (TREE_CONSTANT (TYPE_SIZE (t2)))
240 /* In this case, both types have variable size. It's probably
241 best to leave the "type mismatch" because changing it could
242 case a bad self-referential reference. */
246 /* See if EXP contains a SAVE_EXPR in a position where we would
249 ??? This is a real kludge, but is probably the best approach short
250 of some very general solution. */
253 contains_save_expr_p (tree exp)
255 switch (TREE_CODE (exp))
260 case ADDR_EXPR: case INDIRECT_REF:
262 case NOP_EXPR: case CONVERT_EXPR: case VIEW_CONVERT_EXPR:
263 return contains_save_expr_p (TREE_OPERAND (exp, 0));
266 return (CONSTRUCTOR_ELTS (exp)
267 && contains_save_expr_p (CONSTRUCTOR_ELTS (exp)));
270 return (contains_save_expr_p (TREE_VALUE (exp))
272 && contains_save_expr_p (TREE_CHAIN (exp))));
279 /* See if EXP contains a NULL_EXPR in an expression we use for sizes. Return
280 it if so. This is used to detect types whose sizes involve computations
281 that are known to raise Constraint_Error. */
284 contains_null_expr (tree exp)
288 if (TREE_CODE (exp) == NULL_EXPR)
291 switch (TREE_CODE_CLASS (TREE_CODE (exp)))
294 return contains_null_expr (TREE_OPERAND (exp, 0));
298 tem = contains_null_expr (TREE_OPERAND (exp, 0));
302 return contains_null_expr (TREE_OPERAND (exp, 1));
305 switch (TREE_CODE (exp))
308 return contains_null_expr (TREE_OPERAND (exp, 0));
311 tem = contains_null_expr (TREE_OPERAND (exp, 0));
315 tem = contains_null_expr (TREE_OPERAND (exp, 1));
319 return contains_null_expr (TREE_OPERAND (exp, 2));
330 /* Return an expression tree representing an equality comparison of
331 A1 and A2, two objects of ARRAY_TYPE. The returned expression should
332 be of type RESULT_TYPE
334 Two arrays are equal in one of two ways: (1) if both have zero length
335 in some dimension (not necessarily the same dimension) or (2) if the
336 lengths in each dimension are equal and the data is equal. We perform the
337 length tests in as efficient a manner as possible. */
340 compare_arrays (tree result_type, tree a1, tree a2)
342 tree t1 = TREE_TYPE (a1);
343 tree t2 = TREE_TYPE (a2);
344 tree result = convert (result_type, integer_one_node);
345 tree a1_is_null = convert (result_type, integer_zero_node);
346 tree a2_is_null = convert (result_type, integer_zero_node);
347 bool length_zero_p = false;
349 /* Process each dimension separately and compare the lengths. If any
350 dimension has a size known to be zero, set SIZE_ZERO_P to 1 to
351 suppress the comparison of the data. */
352 while (TREE_CODE (t1) == ARRAY_TYPE && TREE_CODE (t2) == ARRAY_TYPE)
354 tree lb1 = TYPE_MIN_VALUE (TYPE_DOMAIN (t1));
355 tree ub1 = TYPE_MAX_VALUE (TYPE_DOMAIN (t1));
356 tree lb2 = TYPE_MIN_VALUE (TYPE_DOMAIN (t2));
357 tree ub2 = TYPE_MAX_VALUE (TYPE_DOMAIN (t2));
358 tree bt = get_base_type (TREE_TYPE (lb1));
359 tree length1 = fold (build2 (MINUS_EXPR, bt, ub1, lb1));
360 tree length2 = fold (build2 (MINUS_EXPR, bt, ub2, lb2));
363 tree comparison, this_a1_is_null, this_a2_is_null;
365 /* If the length of the first array is a constant, swap our operands
366 unless the length of the second array is the constant zero.
367 Note that we have set the `length' values to the length - 1. */
368 if (TREE_CODE (length1) == INTEGER_CST
369 && !integer_zerop (fold (build2 (PLUS_EXPR, bt, length2,
370 convert (bt, integer_one_node)))))
372 tem = a1, a1 = a2, a2 = tem;
373 tem = t1, t1 = t2, t2 = tem;
374 tem = lb1, lb1 = lb2, lb2 = tem;
375 tem = ub1, ub1 = ub2, ub2 = tem;
376 tem = length1, length1 = length2, length2 = tem;
377 tem = a1_is_null, a1_is_null = a2_is_null, a2_is_null = tem;
380 /* If the length of this dimension in the second array is the constant
381 zero, we can just go inside the original bounds for the first
382 array and see if last < first. */
383 if (integer_zerop (fold (build2 (PLUS_EXPR, bt, length2,
384 convert (bt, integer_one_node)))))
386 tree ub = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
387 tree lb = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
389 comparison = build_binary_op (LT_EXPR, result_type, ub, lb);
390 comparison = SUBSTITUTE_PLACEHOLDER_IN_EXPR (comparison, a1);
391 length1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length1, a1);
393 length_zero_p = true;
394 this_a1_is_null = comparison;
395 this_a2_is_null = convert (result_type, integer_one_node);
398 /* If the length is some other constant value, we know that the
399 this dimension in the first array cannot be superflat, so we
400 can just use its length from the actual stored bounds. */
401 else if (TREE_CODE (length2) == INTEGER_CST)
403 ub1 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
404 lb1 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
405 ub2 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t2)));
406 lb2 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t2)));
407 nbt = get_base_type (TREE_TYPE (ub1));
410 = build_binary_op (EQ_EXPR, result_type,
411 build_binary_op (MINUS_EXPR, nbt, ub1, lb1),
412 build_binary_op (MINUS_EXPR, nbt, ub2, lb2));
414 /* Note that we know that UB2 and LB2 are constant and hence
415 cannot contain a PLACEHOLDER_EXPR. */
417 comparison = SUBSTITUTE_PLACEHOLDER_IN_EXPR (comparison, a1);
418 length1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length1, a1);
420 this_a1_is_null = build_binary_op (LT_EXPR, result_type, ub1, lb1);
421 this_a2_is_null = convert (result_type, integer_zero_node);
424 /* Otherwise compare the computed lengths. */
427 length1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length1, a1);
428 length2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length2, a2);
431 = build_binary_op (EQ_EXPR, result_type, length1, length2);
434 = build_binary_op (LT_EXPR, result_type, length1,
435 convert (bt, integer_zero_node));
437 = build_binary_op (LT_EXPR, result_type, length2,
438 convert (bt, integer_zero_node));
441 result = build_binary_op (TRUTH_ANDIF_EXPR, result_type,
444 a1_is_null = build_binary_op (TRUTH_ORIF_EXPR, result_type,
445 this_a1_is_null, a1_is_null);
446 a2_is_null = build_binary_op (TRUTH_ORIF_EXPR, result_type,
447 this_a2_is_null, a2_is_null);
453 /* Unless the size of some bound is known to be zero, compare the
454 data in the array. */
457 tree type = find_common_type (TREE_TYPE (a1), TREE_TYPE (a2));
460 a1 = convert (type, a1), a2 = convert (type, a2);
462 result = build_binary_op (TRUTH_ANDIF_EXPR, result_type, result,
463 fold (build2 (EQ_EXPR, result_type, a1, a2)));
467 /* The result is also true if both sizes are zero. */
468 result = build_binary_op (TRUTH_ORIF_EXPR, result_type,
469 build_binary_op (TRUTH_ANDIF_EXPR, result_type,
470 a1_is_null, a2_is_null),
473 /* If either operand contains SAVE_EXPRs, they have to be evaluated before
474 starting the comparison above since the place it would be otherwise
475 evaluated would be wrong. */
477 if (contains_save_expr_p (a1))
478 result = build2 (COMPOUND_EXPR, result_type, a1, result);
480 if (contains_save_expr_p (a2))
481 result = build2 (COMPOUND_EXPR, result_type, a2, result);
486 /* Compute the result of applying OP_CODE to LHS and RHS, where both are of
487 type TYPE. We know that TYPE is a modular type with a nonbinary
491 nonbinary_modular_operation (enum tree_code op_code, tree type, tree lhs,
494 tree modulus = TYPE_MODULUS (type);
495 unsigned int needed_precision = tree_floor_log2 (modulus) + 1;
496 unsigned int precision;
497 bool unsignedp = true;
501 /* If this is an addition of a constant, convert it to a subtraction
502 of a constant since we can do that faster. */
503 if (op_code == PLUS_EXPR && TREE_CODE (rhs) == INTEGER_CST)
504 rhs = fold (build2 (MINUS_EXPR, type, modulus, rhs)), op_code = MINUS_EXPR;
506 /* For the logical operations, we only need PRECISION bits. For
507 addition and subraction, we need one more and for multiplication we
508 need twice as many. But we never want to make a size smaller than
510 if (op_code == PLUS_EXPR || op_code == MINUS_EXPR)
511 needed_precision += 1;
512 else if (op_code == MULT_EXPR)
513 needed_precision *= 2;
515 precision = MAX (needed_precision, TYPE_PRECISION (op_type));
517 /* Unsigned will do for everything but subtraction. */
518 if (op_code == MINUS_EXPR)
521 /* If our type is the wrong signedness or isn't wide enough, make a new
522 type and convert both our operands to it. */
523 if (TYPE_PRECISION (op_type) < precision
524 || TYPE_UNSIGNED (op_type) != unsignedp)
526 /* Copy the node so we ensure it can be modified to make it modular. */
527 op_type = copy_node (gnat_type_for_size (precision, unsignedp));
528 modulus = convert (op_type, modulus);
529 SET_TYPE_MODULUS (op_type, modulus);
530 TYPE_MODULAR_P (op_type) = 1;
531 lhs = convert (op_type, lhs);
532 rhs = convert (op_type, rhs);
535 /* Do the operation, then we'll fix it up. */
536 result = fold (build2 (op_code, op_type, lhs, rhs));
538 /* For multiplication, we have no choice but to do a full modulus
539 operation. However, we want to do this in the narrowest
541 if (op_code == MULT_EXPR)
543 tree div_type = copy_node (gnat_type_for_size (needed_precision, 1));
544 modulus = convert (div_type, modulus);
545 SET_TYPE_MODULUS (div_type, modulus);
546 TYPE_MODULAR_P (div_type) = 1;
547 result = convert (op_type,
548 fold (build2 (TRUNC_MOD_EXPR, div_type,
549 convert (div_type, result), modulus)));
552 /* For subtraction, add the modulus back if we are negative. */
553 else if (op_code == MINUS_EXPR)
555 result = save_expr (result);
556 result = fold (build3 (COND_EXPR, op_type,
557 build2 (LT_EXPR, integer_type_node, result,
558 convert (op_type, integer_zero_node)),
559 fold (build2 (PLUS_EXPR, op_type,
564 /* For the other operations, subtract the modulus if we are >= it. */
567 result = save_expr (result);
568 result = fold (build3 (COND_EXPR, op_type,
569 build2 (GE_EXPR, integer_type_node,
571 fold (build2 (MINUS_EXPR, op_type,
576 return convert (type, result);
579 /* Make a binary operation of kind OP_CODE. RESULT_TYPE is the type
580 desired for the result. Usually the operation is to be performed
581 in that type. For MODIFY_EXPR and ARRAY_REF, RESULT_TYPE may be 0
582 in which case the type to be used will be derived from the operands.
584 This function is very much unlike the ones for C and C++ since we
585 have already done any type conversion and matching required. All we
586 have to do here is validate the work done by SEM and handle subtypes. */
589 build_binary_op (enum tree_code op_code, tree result_type,
590 tree left_operand, tree right_operand)
592 tree left_type = TREE_TYPE (left_operand);
593 tree right_type = TREE_TYPE (right_operand);
594 tree left_base_type = get_base_type (left_type);
595 tree right_base_type = get_base_type (right_type);
596 tree operation_type = result_type;
597 tree best_type = NULL_TREE;
600 bool has_side_effects = false;
603 && TREE_CODE (operation_type) == RECORD_TYPE
604 && TYPE_JUSTIFIED_MODULAR_P (operation_type))
605 operation_type = TREE_TYPE (TYPE_FIELDS (operation_type));
608 && !AGGREGATE_TYPE_P (operation_type)
609 && TYPE_EXTRA_SUBTYPE_P (operation_type))
610 operation_type = get_base_type (operation_type);
612 modulus = (operation_type && TREE_CODE (operation_type) == INTEGER_TYPE
613 && TYPE_MODULAR_P (operation_type)
614 ? TYPE_MODULUS (operation_type) : 0);
619 /* If there were any integral or pointer conversions on LHS, remove
620 them; we'll be putting them back below if needed. Likewise for
621 conversions between array and record types. But don't do this if
622 the right operand is not BLKmode (for packed arrays)
623 unless we are not changing the mode. */
624 while ((TREE_CODE (left_operand) == CONVERT_EXPR
625 || TREE_CODE (left_operand) == NOP_EXPR
626 || TREE_CODE (left_operand) == VIEW_CONVERT_EXPR)
627 && (((INTEGRAL_TYPE_P (left_type)
628 || POINTER_TYPE_P (left_type))
629 && (INTEGRAL_TYPE_P (TREE_TYPE
630 (TREE_OPERAND (left_operand, 0)))
631 || POINTER_TYPE_P (TREE_TYPE
632 (TREE_OPERAND (left_operand, 0)))))
633 || (((TREE_CODE (left_type) == RECORD_TYPE
634 /* Don't remove conversions to justified modular
636 && !TYPE_JUSTIFIED_MODULAR_P (left_type))
637 || TREE_CODE (left_type) == ARRAY_TYPE)
638 && ((TREE_CODE (TREE_TYPE
639 (TREE_OPERAND (left_operand, 0)))
641 || (TREE_CODE (TREE_TYPE
642 (TREE_OPERAND (left_operand, 0)))
644 && (TYPE_MODE (right_type) == BLKmode
645 || (TYPE_MODE (left_type)
646 == TYPE_MODE (TREE_TYPE
648 (left_operand, 0))))))))
650 left_operand = TREE_OPERAND (left_operand, 0);
651 left_type = TREE_TYPE (left_operand);
655 operation_type = left_type;
657 /* If the RHS has a conversion between record and array types and
658 an inner type is no worse, use it. Note we cannot do this for
659 modular types or types with TYPE_ALIGN_OK, since the latter
660 might indicate a conversion between a root type and a class-wide
661 type, which we must not remove. */
662 while (TREE_CODE (right_operand) == VIEW_CONVERT_EXPR
663 && ((TREE_CODE (right_type) == RECORD_TYPE
664 && !TYPE_JUSTIFIED_MODULAR_P (right_type)
665 && !TYPE_ALIGN_OK (right_type)
666 && !TYPE_IS_FAT_POINTER_P (right_type))
667 || TREE_CODE (right_type) == ARRAY_TYPE)
668 && (((TREE_CODE (TREE_TYPE (TREE_OPERAND (right_operand, 0)))
670 && !(TYPE_JUSTIFIED_MODULAR_P
671 (TREE_TYPE (TREE_OPERAND (right_operand, 0))))
673 (TREE_TYPE (TREE_OPERAND (right_operand, 0))))
674 && !(TYPE_IS_FAT_POINTER_P
675 (TREE_TYPE (TREE_OPERAND (right_operand, 0)))))
676 || (TREE_CODE (TREE_TYPE (TREE_OPERAND (right_operand, 0)))
679 == find_common_type (right_type,
680 TREE_TYPE (TREE_OPERAND
681 (right_operand, 0))))
682 || right_type != best_type))
684 right_operand = TREE_OPERAND (right_operand, 0);
685 right_type = TREE_TYPE (right_operand);
688 /* If we are copying one array or record to another, find the best type
690 if (((TREE_CODE (left_type) == ARRAY_TYPE
691 && TREE_CODE (right_type) == ARRAY_TYPE)
692 || (TREE_CODE (left_type) == RECORD_TYPE
693 && TREE_CODE (right_type) == RECORD_TYPE))
694 && (best_type = find_common_type (left_type, right_type)))
695 operation_type = best_type;
697 /* If a class-wide type may be involved, force use of the RHS type. */
698 if (TREE_CODE (right_type) == RECORD_TYPE && TYPE_ALIGN_OK (right_type))
699 operation_type = right_type;
701 /* Ensure everything on the LHS is valid. If we have a field reference,
702 strip anything that get_inner_reference can handle. Then remove any
703 conversions with type types having the same code and mode. Mark
704 VIEW_CONVERT_EXPRs with TREE_ADDRESSABLE. When done, we must have
705 either an INDIRECT_REF or a decl. */
706 result = left_operand;
709 tree restype = TREE_TYPE (result);
711 if (TREE_CODE (result) == COMPONENT_REF
712 || TREE_CODE (result) == ARRAY_REF
713 || TREE_CODE (result) == ARRAY_RANGE_REF)
714 while (handled_component_p (result))
715 result = TREE_OPERAND (result, 0);
716 else if (TREE_CODE (result) == REALPART_EXPR
717 || TREE_CODE (result) == IMAGPART_EXPR
718 || ((TREE_CODE (result) == NOP_EXPR
719 || TREE_CODE (result) == CONVERT_EXPR)
720 && (((TREE_CODE (restype)
721 == TREE_CODE (TREE_TYPE
722 (TREE_OPERAND (result, 0))))
723 && (TYPE_MODE (TREE_TYPE
724 (TREE_OPERAND (result, 0)))
725 == TYPE_MODE (restype)))
726 || TYPE_ALIGN_OK (restype))))
727 result = TREE_OPERAND (result, 0);
728 else if (TREE_CODE (result) == VIEW_CONVERT_EXPR)
730 TREE_ADDRESSABLE (result) = 1;
731 result = TREE_OPERAND (result, 0);
737 if (TREE_CODE (result) != INDIRECT_REF && TREE_CODE (result) != NULL_EXPR
741 /* Convert the right operand to the operation type unless
742 it is either already of the correct type or if the type
743 involves a placeholder, since the RHS may not have the same
745 if (operation_type != right_type
746 && (!CONTAINS_PLACEHOLDER_P (TYPE_SIZE (operation_type))))
748 right_operand = convert (operation_type, right_operand);
749 right_type = operation_type;
752 /* If the left operand is not the same type as the operation type,
753 surround it in a VIEW_CONVERT_EXPR. */
754 if (left_type != operation_type)
755 left_operand = unchecked_convert (operation_type, left_operand, false);
757 has_side_effects = true;
763 operation_type = TREE_TYPE (left_type);
765 /* ... fall through ... */
767 case ARRAY_RANGE_REF:
769 /* First convert the right operand to its base type. This will
770 prevent unneeded signedness conversions when sizetype is wider than
772 right_operand = convert (right_base_type, right_operand);
773 right_operand = convert (TYPE_DOMAIN (left_type), right_operand);
775 if (!TREE_CONSTANT (right_operand)
776 || !TREE_CONSTANT (TYPE_MIN_VALUE (right_type)))
777 gnat_mark_addressable (left_operand);
786 if (POINTER_TYPE_P (left_type))
789 /* ... fall through ... */
793 /* If either operand is a NULL_EXPR, just return a new one. */
794 if (TREE_CODE (left_operand) == NULL_EXPR)
795 return build2 (op_code, result_type,
796 build1 (NULL_EXPR, integer_type_node,
797 TREE_OPERAND (left_operand, 0)),
800 else if (TREE_CODE (right_operand) == NULL_EXPR)
801 return build2 (op_code, result_type,
802 build1 (NULL_EXPR, integer_type_node,
803 TREE_OPERAND (right_operand, 0)),
806 /* If either object is a justified modular types, get the
807 fields from within. */
808 if (TREE_CODE (left_type) == RECORD_TYPE
809 && TYPE_JUSTIFIED_MODULAR_P (left_type))
811 left_operand = convert (TREE_TYPE (TYPE_FIELDS (left_type)),
813 left_type = TREE_TYPE (left_operand);
814 left_base_type = get_base_type (left_type);
817 if (TREE_CODE (right_type) == RECORD_TYPE
818 && TYPE_JUSTIFIED_MODULAR_P (right_type))
820 right_operand = convert (TREE_TYPE (TYPE_FIELDS (right_type)),
822 right_type = TREE_TYPE (right_operand);
823 right_base_type = get_base_type (right_type);
826 /* If both objects are arrays, compare them specially. */
827 if ((TREE_CODE (left_type) == ARRAY_TYPE
828 || (TREE_CODE (left_type) == INTEGER_TYPE
829 && TYPE_HAS_ACTUAL_BOUNDS_P (left_type)))
830 && (TREE_CODE (right_type) == ARRAY_TYPE
831 || (TREE_CODE (right_type) == INTEGER_TYPE
832 && TYPE_HAS_ACTUAL_BOUNDS_P (right_type))))
834 result = compare_arrays (result_type, left_operand, right_operand);
836 if (op_code == EQ_EXPR)
838 else if (op_code == NE_EXPR)
839 result = invert_truthvalue (result);
846 /* Otherwise, the base types must be the same unless the objects are
847 records. If we have records, use the best type and convert both
848 operands to that type. */
849 if (left_base_type != right_base_type)
851 if (TREE_CODE (left_base_type) == RECORD_TYPE
852 && TREE_CODE (right_base_type) == RECORD_TYPE)
854 /* The only way these are permitted to be the same is if both
855 types have the same name. In that case, one of them must
856 not be self-referential. Use that one as the best type.
857 Even better is if one is of fixed size. */
858 best_type = NULL_TREE;
860 if (!TYPE_NAME (left_base_type)
861 || TYPE_NAME (left_base_type) != TYPE_NAME (right_base_type))
864 if (TREE_CONSTANT (TYPE_SIZE (left_base_type)))
865 best_type = left_base_type;
866 else if (TREE_CONSTANT (TYPE_SIZE (right_base_type)))
867 best_type = right_base_type;
868 else if (!CONTAINS_PLACEHOLDER_P (TYPE_SIZE (left_base_type)))
869 best_type = left_base_type;
870 else if (!CONTAINS_PLACEHOLDER_P (TYPE_SIZE (right_base_type)))
871 best_type = right_base_type;
875 left_operand = convert (best_type, left_operand);
876 right_operand = convert (best_type, right_operand);
882 /* If we are comparing a fat pointer against zero, we need to
883 just compare the data pointer. */
884 else if (TYPE_FAT_POINTER_P (left_base_type)
885 && TREE_CODE (right_operand) == CONSTRUCTOR
886 && integer_zerop (TREE_VALUE
887 (CONSTRUCTOR_ELTS (right_operand))))
889 right_operand = build_component_ref (left_operand, NULL_TREE,
890 TYPE_FIELDS (left_base_type),
892 left_operand = convert (TREE_TYPE (right_operand),
897 left_operand = convert (left_base_type, left_operand);
898 right_operand = convert (right_base_type, right_operand);
904 case PREINCREMENT_EXPR:
905 case PREDECREMENT_EXPR:
906 case POSTINCREMENT_EXPR:
907 case POSTDECREMENT_EXPR:
908 /* In these, the result type and the left operand type should be the
909 same. Do the operation in the base type of those and convert the
910 right operand (which is an integer) to that type.
912 Note that these operations are only used in loop control where
913 we guarantee that no overflow can occur. So nothing special need
914 be done for modular types. */
916 if (left_type != result_type)
919 operation_type = get_base_type (result_type);
920 left_operand = convert (operation_type, left_operand);
921 right_operand = convert (operation_type, right_operand);
922 has_side_effects = true;
930 /* The RHS of a shift can be any type. Also, ignore any modulus
931 (we used to abort, but this is needed for unchecked conversion
932 to modular types). Otherwise, processing is the same as normal. */
933 if (operation_type != left_base_type)
937 left_operand = convert (operation_type, left_operand);
940 case TRUTH_ANDIF_EXPR:
941 case TRUTH_ORIF_EXPR:
945 left_operand = gnat_truthvalue_conversion (left_operand);
946 right_operand = gnat_truthvalue_conversion (right_operand);
952 /* For binary modulus, if the inputs are in range, so are the
954 if (modulus && integer_pow2p (modulus))
960 if (TREE_TYPE (result_type) != left_base_type
961 || TREE_TYPE (result_type) != right_base_type)
964 left_operand = convert (left_base_type, left_operand);
965 right_operand = convert (right_base_type, right_operand);
968 case TRUNC_DIV_EXPR: case TRUNC_MOD_EXPR:
969 case CEIL_DIV_EXPR: case CEIL_MOD_EXPR:
970 case FLOOR_DIV_EXPR: case FLOOR_MOD_EXPR:
971 case ROUND_DIV_EXPR: case ROUND_MOD_EXPR:
972 /* These always produce results lower than either operand. */
978 /* The result type should be the same as the base types of the
979 both operands (and they should be the same). Convert
980 everything to the result type. */
982 if (operation_type != left_base_type
983 || left_base_type != right_base_type)
986 left_operand = convert (operation_type, left_operand);
987 right_operand = convert (operation_type, right_operand);
990 if (modulus && !integer_pow2p (modulus))
992 result = nonbinary_modular_operation (op_code, operation_type,
993 left_operand, right_operand);
996 /* If either operand is a NULL_EXPR, just return a new one. */
997 else if (TREE_CODE (left_operand) == NULL_EXPR)
998 return build1 (NULL_EXPR, operation_type, TREE_OPERAND (left_operand, 0));
999 else if (TREE_CODE (right_operand) == NULL_EXPR)
1000 return build1 (NULL_EXPR, operation_type, TREE_OPERAND (right_operand, 0));
1001 else if (op_code == ARRAY_REF || op_code == ARRAY_RANGE_REF)
1002 result = fold (build4 (op_code, operation_type, left_operand,
1003 right_operand, NULL_TREE, NULL_TREE));
1006 = fold (build2 (op_code, operation_type, left_operand, right_operand));
1008 TREE_SIDE_EFFECTS (result) |= has_side_effects;
1009 TREE_CONSTANT (result)
1010 |= (TREE_CONSTANT (left_operand) & TREE_CONSTANT (right_operand)
1011 && op_code != ARRAY_REF && op_code != ARRAY_RANGE_REF);
1013 if ((op_code == ARRAY_REF || op_code == ARRAY_RANGE_REF)
1014 && TYPE_VOLATILE (operation_type))
1015 TREE_THIS_VOLATILE (result) = 1;
1017 /* If we are working with modular types, perform the MOD operation
1018 if something above hasn't eliminated the need for it. */
1020 result = fold (build2 (FLOOR_MOD_EXPR, operation_type, result,
1021 convert (operation_type, modulus)));
1023 if (result_type && result_type != operation_type)
1024 result = convert (result_type, result);
1029 /* Similar, but for unary operations. */
1032 build_unary_op (enum tree_code op_code, tree result_type, tree operand)
1034 tree type = TREE_TYPE (operand);
1035 tree base_type = get_base_type (type);
1036 tree operation_type = result_type;
1038 bool side_effects = false;
1041 && TREE_CODE (operation_type) == RECORD_TYPE
1042 && TYPE_JUSTIFIED_MODULAR_P (operation_type))
1043 operation_type = TREE_TYPE (TYPE_FIELDS (operation_type));
1046 && !AGGREGATE_TYPE_P (operation_type)
1047 && TYPE_EXTRA_SUBTYPE_P (operation_type))
1048 operation_type = get_base_type (operation_type);
1054 if (!operation_type)
1055 result_type = operation_type = TREE_TYPE (type);
1056 else if (result_type != TREE_TYPE (type))
1059 result = fold (build1 (op_code, operation_type, operand));
1062 case TRUTH_NOT_EXPR:
1063 if (result_type != base_type)
1066 result = invert_truthvalue (gnat_truthvalue_conversion (operand));
1069 case ATTR_ADDR_EXPR:
1071 switch (TREE_CODE (operand))
1074 case UNCONSTRAINED_ARRAY_REF:
1075 result = TREE_OPERAND (operand, 0);
1077 /* Make sure the type here is a pointer, not a reference.
1078 GCC wants pointer types for function addresses. */
1080 result_type = build_pointer_type (type);
1085 TREE_TYPE (result) = type = build_pointer_type (type);
1089 case ARRAY_RANGE_REF:
1092 /* If this is for 'Address, find the address of the prefix and
1093 add the offset to the field. Otherwise, do this the normal
1095 if (op_code == ATTR_ADDR_EXPR)
1097 HOST_WIDE_INT bitsize;
1098 HOST_WIDE_INT bitpos;
1100 enum machine_mode mode;
1101 int unsignedp, volatilep;
1103 inner = get_inner_reference (operand, &bitsize, &bitpos, &offset,
1104 &mode, &unsignedp, &volatilep);
1106 /* If INNER is a padding type whose field has a self-referential
1107 size, convert to that inner type. We know the offset is zero
1108 and we need to have that type visible. */
1109 if (TREE_CODE (TREE_TYPE (inner)) == RECORD_TYPE
1110 && TYPE_IS_PADDING_P (TREE_TYPE (inner))
1111 && (CONTAINS_PLACEHOLDER_P
1112 (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS
1113 (TREE_TYPE (inner)))))))
1114 inner = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (inner))),
1117 /* Compute the offset as a byte offset from INNER. */
1119 offset = size_zero_node;
1121 if (bitpos % BITS_PER_UNIT != 0)
1123 ("taking address of object not aligned on storage unit?",
1126 offset = size_binop (PLUS_EXPR, offset,
1127 size_int (bitpos / BITS_PER_UNIT));
1129 /* Take the address of INNER, convert the offset to void *, and
1130 add then. It will later be converted to the desired result
1132 inner = build_unary_op (ADDR_EXPR, NULL_TREE, inner);
1133 inner = convert (ptr_void_type_node, inner);
1134 offset = convert (ptr_void_type_node, offset);
1135 result = build_binary_op (PLUS_EXPR, ptr_void_type_node,
1137 result = convert (build_pointer_type (TREE_TYPE (operand)),
1144 /* If this is just a constructor for a padded record, we can
1145 just take the address of the single field and convert it to
1146 a pointer to our type. */
1147 if (TREE_CODE (type) == RECORD_TYPE && TYPE_IS_PADDING_P (type))
1150 = build_unary_op (ADDR_EXPR, NULL_TREE,
1151 TREE_VALUE (CONSTRUCTOR_ELTS (operand)));
1152 result = convert (build_pointer_type (TREE_TYPE (operand)),
1160 if (AGGREGATE_TYPE_P (type)
1161 && AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (operand, 0))))
1162 return build_unary_op (ADDR_EXPR, result_type,
1163 TREE_OPERAND (operand, 0));
1165 /* If this NOP_EXPR doesn't change the mode, get the result type
1166 from this type and go down. We need to do this in case
1167 this is a conversion of a CONST_DECL. */
1168 if (TYPE_MODE (type) != BLKmode
1169 && (TYPE_MODE (type)
1170 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (operand, 0)))))
1171 return build_unary_op (ADDR_EXPR,
1172 (result_type ? result_type
1173 : build_pointer_type (type)),
1174 TREE_OPERAND (operand, 0));
1178 operand = DECL_CONST_CORRESPONDING_VAR (operand);
1180 /* ... fall through ... */
1185 /* If we are taking the address of a padded record whose field is
1186 contains a template, take the address of the template. */
1187 if (TREE_CODE (type) == RECORD_TYPE
1188 && TYPE_IS_PADDING_P (type)
1189 && TREE_CODE (TREE_TYPE (TYPE_FIELDS (type))) == RECORD_TYPE
1190 && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (TYPE_FIELDS (type))))
1192 type = TREE_TYPE (TYPE_FIELDS (type));
1193 operand = convert (type, operand);
1196 if (type != error_mark_node)
1197 operation_type = build_pointer_type (type);
1199 gnat_mark_addressable (operand);
1200 result = fold (build1 (ADDR_EXPR, operation_type, operand));
1203 TREE_CONSTANT (result) = staticp (operand) || TREE_CONSTANT (operand);
1207 /* If we want to refer to an entire unconstrained array,
1208 make up an expression to do so. This will never survive to
1209 the backend. If TYPE is a thin pointer, first convert the
1210 operand to a fat pointer. */
1211 if (TYPE_THIN_POINTER_P (type)
1212 && TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type)))
1215 = convert (TREE_TYPE (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type))),
1217 type = TREE_TYPE (operand);
1220 if (TYPE_FAT_POINTER_P (type))
1222 result = build1 (UNCONSTRAINED_ARRAY_REF,
1223 TYPE_UNCONSTRAINED_ARRAY (type), operand);
1224 TREE_READONLY (result) = TREE_STATIC (result)
1225 = TYPE_READONLY (TYPE_UNCONSTRAINED_ARRAY (type));
1227 else if (TREE_CODE (operand) == ADDR_EXPR)
1228 result = TREE_OPERAND (operand, 0);
1232 result = fold (build1 (op_code, TREE_TYPE (type), operand));
1233 TREE_READONLY (result) = TYPE_READONLY (TREE_TYPE (type));
1237 = (!TYPE_FAT_POINTER_P (type) && TYPE_VOLATILE (TREE_TYPE (type)));
1243 tree modulus = ((operation_type
1244 && TREE_CODE (operation_type) == INTEGER_TYPE
1245 && TYPE_MODULAR_P (operation_type))
1246 ? TYPE_MODULUS (operation_type) : 0);
1247 int mod_pow2 = modulus && integer_pow2p (modulus);
1249 /* If this is a modular type, there are various possibilities
1250 depending on the operation and whether the modulus is a
1251 power of two or not. */
1255 if (operation_type != base_type)
1258 operand = convert (operation_type, operand);
1260 /* The fastest in the negate case for binary modulus is
1261 the straightforward code; the TRUNC_MOD_EXPR below
1262 is an AND operation. */
1263 if (op_code == NEGATE_EXPR && mod_pow2)
1264 result = fold (build2 (TRUNC_MOD_EXPR, operation_type,
1265 fold (build1 (NEGATE_EXPR, operation_type,
1269 /* For nonbinary negate case, return zero for zero operand,
1270 else return the modulus minus the operand. If the modulus
1271 is a power of two minus one, we can do the subtraction
1272 as an XOR since it is equivalent and faster on most machines. */
1273 else if (op_code == NEGATE_EXPR && !mod_pow2)
1275 if (integer_pow2p (fold (build2 (PLUS_EXPR, operation_type,
1277 convert (operation_type,
1278 integer_one_node)))))
1279 result = fold (build2 (BIT_XOR_EXPR, operation_type,
1282 result = fold (build2 (MINUS_EXPR, operation_type,
1285 result = fold (build3 (COND_EXPR, operation_type,
1286 fold (build2 (NE_EXPR,
1291 integer_zero_node))),
1296 /* For the NOT cases, we need a constant equal to
1297 the modulus minus one. For a binary modulus, we
1298 XOR against the constant and subtract the operand from
1299 that constant for nonbinary modulus. */
1301 tree cnst = fold (build2 (MINUS_EXPR, operation_type, modulus,
1302 convert (operation_type,
1303 integer_one_node)));
1306 result = fold (build2 (BIT_XOR_EXPR, operation_type,
1309 result = fold (build2 (MINUS_EXPR, operation_type,
1317 /* ... fall through ... */
1320 if (operation_type != base_type)
1323 result = fold (build1 (op_code, operation_type, convert (operation_type,
1329 TREE_SIDE_EFFECTS (result) = 1;
1330 if (TREE_CODE (result) == INDIRECT_REF)
1331 TREE_THIS_VOLATILE (result) = TYPE_VOLATILE (TREE_TYPE (result));
1334 if (result_type && TREE_TYPE (result) != result_type)
1335 result = convert (result_type, result);
1340 /* Similar, but for COND_EXPR. */
1343 build_cond_expr (tree result_type, tree condition_operand,
1344 tree true_operand, tree false_operand)
1347 bool addr_p = false;
1349 /* The front-end verifies that result, true and false operands have same base
1350 type. Convert everything to the result type. */
1352 true_operand = convert (result_type, true_operand);
1353 false_operand = convert (result_type, false_operand);
1355 /* If the result type is unconstrained, take the address of
1356 the operands and then dereference our result. */
1357 if (TREE_CODE (result_type) == UNCONSTRAINED_ARRAY_TYPE
1358 || CONTAINS_PLACEHOLDER_P (TYPE_SIZE (result_type)))
1361 result_type = build_pointer_type (result_type);
1362 true_operand = build_unary_op (ADDR_EXPR, result_type, true_operand);
1363 false_operand = build_unary_op (ADDR_EXPR, result_type, false_operand);
1366 result = fold (build3 (COND_EXPR, result_type, condition_operand,
1367 true_operand, false_operand));
1369 /* If either operand is a SAVE_EXPR (possibly surrounded by
1370 arithmetic, make sure it gets done. */
1371 true_operand = skip_simple_arithmetic (true_operand);
1372 false_operand = skip_simple_arithmetic (false_operand);
1374 if (TREE_CODE (true_operand) == SAVE_EXPR)
1375 result = build2 (COMPOUND_EXPR, result_type, true_operand, result);
1377 if (TREE_CODE (false_operand) == SAVE_EXPR)
1378 result = build2 (COMPOUND_EXPR, result_type, false_operand, result);
1380 /* ??? Seems the code above is wrong, as it may move ahead of the COND
1381 SAVE_EXPRs with side effects and not shared by both arms. */
1384 result = build_unary_op (INDIRECT_REF, NULL_TREE, result);
1390 /* Build a CALL_EXPR to call FUNDECL with one argument, ARG. Return
1394 build_call_1_expr (tree fundecl, tree arg)
1396 tree call = build3 (CALL_EXPR, TREE_TYPE (TREE_TYPE (fundecl)),
1397 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1398 chainon (NULL_TREE, build_tree_list (NULL_TREE, arg)),
1401 TREE_SIDE_EFFECTS (call) = 1;
1406 /* Build a CALL_EXPR to call FUNDECL with two arguments, ARG1 & ARG2. Return
1410 build_call_2_expr (tree fundecl, tree arg1, tree arg2)
1412 tree call = build3 (CALL_EXPR, TREE_TYPE (TREE_TYPE (fundecl)),
1413 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1414 chainon (chainon (NULL_TREE,
1415 build_tree_list (NULL_TREE, arg1)),
1416 build_tree_list (NULL_TREE, arg2)),
1419 TREE_SIDE_EFFECTS (call) = 1;
1424 /* Likewise to call FUNDECL with no arguments. */
1427 build_call_0_expr (tree fundecl)
1429 tree call = build3 (CALL_EXPR, TREE_TYPE (TREE_TYPE (fundecl)),
1430 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1431 NULL_TREE, NULL_TREE);
1433 TREE_SIDE_EFFECTS (call) = 1;
1438 /* Call a function that raises an exception and pass the line number and file
1439 name, if requested. MSG says which exception function to call. */
1442 build_call_raise (int msg)
1444 tree fndecl = gnat_raise_decls[msg];
1445 const char *str = Debug_Flag_NN ? "" : ref_filename;
1446 int len = strlen (str) + 1;
1447 tree filename = build_string (len, str);
1449 TREE_TYPE (filename)
1450 = build_array_type (char_type_node,
1451 build_index_type (build_int_cst (NULL_TREE, len)));
1454 build_call_2_expr (fndecl,
1455 build1 (ADDR_EXPR, build_pointer_type (char_type_node),
1457 build_int_cst (NULL_TREE, input_line));
1460 /* Return a CONSTRUCTOR of TYPE whose list is LIST. */
1463 gnat_build_constructor (tree type, tree list)
1466 bool allconstant = (TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST);
1467 bool side_effects = false;
1470 for (elmt = list; elmt; elmt = TREE_CHAIN (elmt))
1472 if (!TREE_CONSTANT (TREE_VALUE (elmt))
1473 || (TREE_CODE (type) == RECORD_TYPE
1474 && DECL_BIT_FIELD (TREE_PURPOSE (elmt))
1475 && TREE_CODE (TREE_VALUE (elmt)) != INTEGER_CST)
1476 || !initializer_constant_valid_p (TREE_VALUE (elmt),
1477 TREE_TYPE (TREE_VALUE (elmt))))
1478 allconstant = false;
1480 if (TREE_SIDE_EFFECTS (TREE_VALUE (elmt)))
1481 side_effects = true;
1483 /* Propagate an NULL_EXPR from the size of the type. We won't ever
1484 be executing the code we generate here in that case, but handle it
1485 specially to avoid the cmpiler blowing up. */
1486 if (TREE_CODE (type) == RECORD_TYPE
1488 = contains_null_expr (DECL_SIZE (TREE_PURPOSE (elmt))))))
1489 return build1 (NULL_EXPR, type, TREE_OPERAND (result, 0));
1492 /* If TYPE is a RECORD_TYPE and the fields are not in the
1493 same order as their bit position, don't treat this as constant
1494 since varasm.c can't handle it. */
1495 if (allconstant && TREE_CODE (type) == RECORD_TYPE)
1497 tree last_pos = bitsize_zero_node;
1500 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
1502 tree this_pos = bit_position (field);
1504 if (TREE_CODE (this_pos) != INTEGER_CST
1505 || tree_int_cst_lt (this_pos, last_pos))
1507 allconstant = false;
1511 last_pos = this_pos;
1515 result = build_constructor (type, list);
1516 TREE_CONSTANT (result) = TREE_INVARIANT (result)
1517 = TREE_STATIC (result) = allconstant;
1518 TREE_SIDE_EFFECTS (result) = side_effects;
1519 TREE_READONLY (result) = TYPE_READONLY (type) || allconstant;
1523 /* Return a COMPONENT_REF to access a field that is given by COMPONENT,
1524 an IDENTIFIER_NODE giving the name of the field, or FIELD, a FIELD_DECL,
1525 for the field. Don't fold the result if NO_FOLD_P is true.
1527 We also handle the fact that we might have been passed a pointer to the
1528 actual record and know how to look for fields in variant parts. */
1531 build_simple_component_ref (tree record_variable, tree component,
1532 tree field, bool no_fold_p)
1534 tree record_type = TYPE_MAIN_VARIANT (TREE_TYPE (record_variable));
1537 if ((TREE_CODE (record_type) != RECORD_TYPE
1538 && TREE_CODE (record_type) != UNION_TYPE
1539 && TREE_CODE (record_type) != QUAL_UNION_TYPE)
1540 || !TYPE_SIZE (record_type)
1541 || (component != 0) == (field != 0))
1544 /* If no field was specified, look for a field with the specified name
1545 in the current record only. */
1547 for (field = TYPE_FIELDS (record_type); field;
1548 field = TREE_CHAIN (field))
1549 if (DECL_NAME (field) == component)
1555 /* If this field is not in the specified record, see if we can find
1556 something in the record whose original field is the same as this one. */
1557 if (DECL_CONTEXT (field) != record_type)
1558 /* Check if there is a field with name COMPONENT in the record. */
1562 /* First loop thru normal components. */
1564 for (new_field = TYPE_FIELDS (record_type); new_field;
1565 new_field = TREE_CHAIN (new_field))
1566 if (DECL_ORIGINAL_FIELD (new_field) == field
1567 || new_field == DECL_ORIGINAL_FIELD (field)
1568 || (DECL_ORIGINAL_FIELD (field)
1569 && (DECL_ORIGINAL_FIELD (field)
1570 == DECL_ORIGINAL_FIELD (new_field))))
1573 /* Next, loop thru DECL_INTERNAL_P components if we haven't found
1574 the component in the first search. Doing this search in 2 steps
1575 is required to avoiding hidden homonymous fields in the
1579 for (new_field = TYPE_FIELDS (record_type); new_field;
1580 new_field = TREE_CHAIN (new_field))
1581 if (DECL_INTERNAL_P (new_field))
1584 = build_simple_component_ref (record_variable,
1585 NULL_TREE, new_field, no_fold_p);
1586 ref = build_simple_component_ref (field_ref, NULL_TREE, field,
1599 /* It would be nice to call "fold" here, but that can lose a type
1600 we need to tag a PLACEHOLDER_EXPR with, so we can't do it. */
1601 ref = build3 (COMPONENT_REF, TREE_TYPE (field), record_variable, field,
1604 if (TREE_READONLY (record_variable) || TREE_READONLY (field))
1605 TREE_READONLY (ref) = 1;
1606 if (TREE_THIS_VOLATILE (record_variable) || TREE_THIS_VOLATILE (field)
1607 || TYPE_VOLATILE (record_type))
1608 TREE_THIS_VOLATILE (ref) = 1;
1610 return no_fold_p ? ref : fold (ref);
1613 /* Like build_simple_component_ref, except that we give an error if the
1614 reference could not be found. */
1617 build_component_ref (tree record_variable, tree component,
1618 tree field, bool no_fold_p)
1620 tree ref = build_simple_component_ref (record_variable, component, field,
1626 /* If FIELD was specified, assume this is an invalid user field so
1627 raise constraint error. Otherwise, we can't find the type to return, so
1631 return build1 (NULL_EXPR, TREE_TYPE (field),
1632 build_call_raise (CE_Discriminant_Check_Failed));
1637 /* Build a GCC tree to call an allocation or deallocation function.
1638 If GNU_OBJ is nonzero, it is an object to deallocate. Otherwise,
1639 generate an allocator.
1641 GNU_SIZE is the size of the object in bytes and ALIGN is the alignment in
1642 bits. GNAT_PROC, if present, is a procedure to call and GNAT_POOL is the
1643 storage pool to use. If not preset, malloc and free will be used except
1644 if GNAT_PROC is the "fake" value of -1, in which case we allocate the
1645 object dynamically on the stack frame. */
1648 build_call_alloc_dealloc (tree gnu_obj, tree gnu_size, unsigned align,
1649 Entity_Id gnat_proc, Entity_Id gnat_pool,
1652 tree gnu_align = size_int (align / BITS_PER_UNIT);
1654 gnu_size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (gnu_size, gnu_obj);
1656 if (Present (gnat_proc))
1658 /* The storage pools are obviously always tagged types, but the
1659 secondary stack uses the same mechanism and is not tagged */
1660 if (Is_Tagged_Type (Etype (gnat_pool)))
1662 /* The size is the third parameter; the alignment is the
1664 Entity_Id gnat_size_type
1665 = Etype (Next_Formal (Next_Formal (First_Formal (gnat_proc))));
1666 tree gnu_size_type = gnat_to_gnu_type (gnat_size_type);
1667 tree gnu_proc = gnat_to_gnu (gnat_proc);
1668 tree gnu_proc_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_proc);
1669 tree gnu_pool = gnat_to_gnu (gnat_pool);
1670 tree gnu_pool_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_pool);
1671 tree gnu_args = NULL_TREE;
1674 /* The first arg is always the address of the storage pool; next
1675 comes the address of the object, for a deallocator, then the
1676 size and alignment. */
1678 = chainon (gnu_args, build_tree_list (NULL_TREE, gnu_pool_addr));
1682 = chainon (gnu_args, build_tree_list (NULL_TREE, gnu_obj));
1685 = chainon (gnu_args,
1686 build_tree_list (NULL_TREE,
1687 convert (gnu_size_type, gnu_size)));
1689 = chainon (gnu_args,
1690 build_tree_list (NULL_TREE,
1691 convert (gnu_size_type, gnu_align)));
1693 gnu_call = build3 (CALL_EXPR, TREE_TYPE (TREE_TYPE (gnu_proc)),
1694 gnu_proc_addr, gnu_args, NULL_TREE);
1695 TREE_SIDE_EFFECTS (gnu_call) = 1;
1699 /* Secondary stack case. */
1702 /* The size is the second parameter */
1703 Entity_Id gnat_size_type
1704 = Etype (Next_Formal (First_Formal (gnat_proc)));
1705 tree gnu_size_type = gnat_to_gnu_type (gnat_size_type);
1706 tree gnu_proc = gnat_to_gnu (gnat_proc);
1707 tree gnu_proc_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_proc);
1708 tree gnu_args = NULL_TREE;
1711 /* The first arg is the address of the object, for a
1712 deallocator, then the size */
1715 = chainon (gnu_args, build_tree_list (NULL_TREE, gnu_obj));
1718 = chainon (gnu_args,
1719 build_tree_list (NULL_TREE,
1720 convert (gnu_size_type, gnu_size)));
1722 gnu_call = build3 (CALL_EXPR, TREE_TYPE (TREE_TYPE (gnu_proc)),
1723 gnu_proc_addr, gnu_args, NULL_TREE);
1724 TREE_SIDE_EFFECTS (gnu_call) = 1;
1730 return build_call_1_expr (free_decl, gnu_obj);
1732 /* ??? For now, disable variable-sized allocators in the stack since
1733 we can't yet gimplify an ALLOCATE_EXPR. */
1734 else if (gnat_pool == -1
1735 && TREE_CODE (gnu_size) == INTEGER_CST && !flag_stack_check)
1737 /* If the size is a constant, we can put it in the fixed portion of
1738 the stack frame to avoid the need to adjust the stack pointer. */
1739 if (TREE_CODE (gnu_size) == INTEGER_CST && !flag_stack_check)
1742 = build_range_type (NULL_TREE, size_one_node, gnu_size);
1743 tree gnu_array_type = build_array_type (char_type_node, gnu_range);
1745 = create_var_decl (get_identifier ("RETVAL"), NULL_TREE,
1746 gnu_array_type, NULL_TREE, false, false, false,
1747 false, NULL, gnat_node);
1749 return convert (ptr_void_type_node,
1750 build_unary_op (ADDR_EXPR, NULL_TREE, gnu_decl));
1755 return build2 (ALLOCATE_EXPR, ptr_void_type_node, gnu_size, gnu_align);
1760 if (Nkind (gnat_node) != N_Allocator || !Comes_From_Source (gnat_node))
1761 Check_No_Implicit_Heap_Alloc (gnat_node);
1762 return build_call_1_expr (malloc_decl, gnu_size);
1766 /* Build a GCC tree to correspond to allocating an object of TYPE whose
1767 initial value is INIT, if INIT is nonzero. Convert the expression to
1768 RESULT_TYPE, which must be some type of pointer. Return the tree.
1769 GNAT_PROC and GNAT_POOL optionally give the procedure to call and
1770 the storage pool to use. */
1773 build_allocator (tree type, tree init, tree result_type, Entity_Id gnat_proc,
1774 Entity_Id gnat_pool, Node_Id gnat_node)
1776 tree size = TYPE_SIZE_UNIT (type);
1779 /* If the initializer, if present, is a NULL_EXPR, just return a new one. */
1780 if (init && TREE_CODE (init) == NULL_EXPR)
1781 return build1 (NULL_EXPR, result_type, TREE_OPERAND (init, 0));
1783 /* If RESULT_TYPE is a fat or thin pointer, set SIZE to be the sum of the
1784 sizes of the object and its template. Allocate the whole thing and
1785 fill in the parts that are known. */
1786 else if (TYPE_FAT_OR_THIN_POINTER_P (result_type))
1789 = (TYPE_FAT_POINTER_P (result_type)
1790 ? TREE_TYPE (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (result_type))))
1791 : TREE_TYPE (TYPE_FIELDS (TREE_TYPE (result_type))));
1793 = build_unc_object_type (template_type, type,
1794 get_identifier ("ALLOC"));
1795 tree storage_ptr_type = build_pointer_type (storage_type);
1797 tree template_cons = NULL_TREE;
1799 size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TYPE_SIZE_UNIT (storage_type),
1802 /* If the size overflows, pass -1 so the allocator will raise
1804 if (TREE_CODE (size) == INTEGER_CST && TREE_OVERFLOW (size))
1805 size = ssize_int (-1);
1807 storage = build_call_alloc_dealloc (NULL_TREE, size,
1808 TYPE_ALIGN (storage_type),
1809 gnat_proc, gnat_pool, gnat_node);
1810 storage = convert (storage_ptr_type, protect_multiple_eval (storage));
1812 if (TREE_CODE (type) == RECORD_TYPE && TYPE_IS_PADDING_P (type))
1814 type = TREE_TYPE (TYPE_FIELDS (type));
1817 init = convert (type, init);
1820 /* If there is an initializing expression, make a constructor for
1821 the entire object including the bounds and copy it into the
1822 object. If there is no initializing expression, just set the
1826 template_cons = tree_cons (TREE_CHAIN (TYPE_FIELDS (storage_type)),
1828 template_cons = tree_cons (TYPE_FIELDS (storage_type),
1829 build_template (template_type, type,
1835 build2 (COMPOUND_EXPR, storage_ptr_type,
1837 (MODIFY_EXPR, storage_type,
1838 build_unary_op (INDIRECT_REF, NULL_TREE,
1839 convert (storage_ptr_type, storage)),
1840 gnat_build_constructor (storage_type, template_cons)),
1841 convert (storage_ptr_type, storage)));
1845 (COMPOUND_EXPR, result_type,
1847 (MODIFY_EXPR, template_type,
1849 (build_unary_op (INDIRECT_REF, NULL_TREE,
1850 convert (storage_ptr_type, storage)),
1851 NULL_TREE, TYPE_FIELDS (storage_type), 0),
1852 build_template (template_type, type, NULL_TREE)),
1853 convert (result_type, convert (storage_ptr_type, storage)));
1856 /* If we have an initializing expression, see if its size is simpler
1857 than the size from the type. */
1858 if (init && TYPE_SIZE_UNIT (TREE_TYPE (init))
1859 && (TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (init))) == INTEGER_CST
1860 || CONTAINS_PLACEHOLDER_P (size)))
1861 size = TYPE_SIZE_UNIT (TREE_TYPE (init));
1863 /* If the size is still self-referential, reference the initializing
1864 expression, if it is present. If not, this must have been a
1865 call to allocate a library-level object, in which case we use
1866 the maximum size. */
1867 if (CONTAINS_PLACEHOLDER_P (size))
1870 size = substitute_placeholder_in_expr (size, init);
1872 size = max_size (size, true);
1875 /* If the size overflows, pass -1 so the allocator will raise
1877 if (TREE_CODE (size) == INTEGER_CST && TREE_OVERFLOW (size))
1878 size = ssize_int (-1);
1880 /* If this is a type whose alignment is larger than the
1881 biggest we support in normal alignment and this is in
1882 the default storage pool, make an "aligning type", allocate
1883 it, point to the field we need, and return that. */
1884 if (TYPE_ALIGN (type) > BIGGEST_ALIGNMENT
1887 tree new_type = make_aligning_type (type, TYPE_ALIGN (type), size);
1889 result = build_call_alloc_dealloc (NULL_TREE, TYPE_SIZE_UNIT (new_type),
1890 BIGGEST_ALIGNMENT, Empty,
1892 result = save_expr (result);
1893 result = convert (build_pointer_type (new_type), result);
1894 result = build_unary_op (INDIRECT_REF, NULL_TREE, result);
1895 result = build_component_ref (result, NULL_TREE,
1896 TYPE_FIELDS (new_type), 0);
1897 result = convert (result_type,
1898 build_unary_op (ADDR_EXPR, NULL_TREE, result));
1901 result = convert (result_type,
1902 build_call_alloc_dealloc (NULL_TREE, size,
1908 /* If we have an initial value, put the new address into a SAVE_EXPR, assign
1909 the value, and return the address. Do this with a COMPOUND_EXPR. */
1913 result = save_expr (result);
1915 = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1917 (MODIFY_EXPR, NULL_TREE,
1918 build_unary_op (INDIRECT_REF,
1919 TREE_TYPE (TREE_TYPE (result)), result),
1924 return convert (result_type, result);
1927 /* Fill in a VMS descriptor for EXPR and return a constructor for it.
1928 GNAT_FORMAL is how we find the descriptor record. */
1931 fill_vms_descriptor (tree expr, Entity_Id gnat_formal)
1933 tree record_type = TREE_TYPE (TREE_TYPE (get_gnu_tree (gnat_formal)));
1935 tree const_list = NULL_TREE;
1937 expr = maybe_unconstrained_array (expr);
1938 gnat_mark_addressable (expr);
1940 for (field = TYPE_FIELDS (record_type); field; field = TREE_CHAIN (field))
1943 convert (TREE_TYPE (field),
1944 SUBSTITUTE_PLACEHOLDER_IN_EXPR
1945 (DECL_INITIAL (field), expr)),
1948 return gnat_build_constructor (record_type, nreverse (const_list));
1951 /* Indicate that we need to make the address of EXPR_NODE and it therefore
1952 should not be allocated in a register. Returns true if successful. */
1955 gnat_mark_addressable (tree expr_node)
1958 switch (TREE_CODE (expr_node))
1963 case ARRAY_RANGE_REF:
1966 case VIEW_CONVERT_EXPR:
1968 case NON_LVALUE_EXPR:
1970 expr_node = TREE_OPERAND (expr_node, 0);
1974 TREE_ADDRESSABLE (expr_node) = 1;
1980 TREE_ADDRESSABLE (expr_node) = 1;
1984 TREE_ADDRESSABLE (expr_node) = 1;
1988 return (DECL_CONST_CORRESPONDING_VAR (expr_node)
1989 && (gnat_mark_addressable
1990 (DECL_CONST_CORRESPONDING_VAR (expr_node))));