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"
47 static tree find_common_type (tree, tree);
48 static int contains_save_expr_p (tree);
49 static tree contains_null_expr (tree);
50 static tree compare_arrays (tree, tree, tree);
51 static tree nonbinary_modular_operation (enum tree_code, tree, tree, tree);
52 static tree build_simple_component_ref (tree, tree, tree, int);
54 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical
57 This preparation consists of taking the ordinary representation of
58 an expression expr and producing a valid tree boolean expression
59 describing whether expr is nonzero. We could simply always do
61 build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
63 but we optimize comparisons, &&, ||, and !.
65 The resulting type should always be the same as the input type.
66 This function is simpler than the corresponding C version since
67 the only possible operands will be things of Boolean type. */
70 gnat_truthvalue_conversion (tree expr)
72 tree type = TREE_TYPE (expr);
74 switch (TREE_CODE (expr))
76 case EQ_EXPR: case NE_EXPR: case LE_EXPR: case GE_EXPR:
77 case LT_EXPR: case GT_EXPR:
78 case TRUTH_ANDIF_EXPR:
87 /* Distribute the conversion into the arms of a COND_EXPR. */
89 (build (COND_EXPR, type, TREE_OPERAND (expr, 0),
90 gnat_truthvalue_conversion (TREE_OPERAND (expr, 1)),
91 gnat_truthvalue_conversion (TREE_OPERAND (expr, 2))));
94 return build_binary_op (NE_EXPR, type, expr,
95 convert (type, integer_zero_node));
99 /* Return the base type of TYPE. */
102 get_base_type (tree type)
104 if (TREE_CODE (type) == RECORD_TYPE
105 && TYPE_LEFT_JUSTIFIED_MODULAR_P (type))
106 type = TREE_TYPE (TYPE_FIELDS (type));
108 while (TREE_TYPE (type) != 0
109 && (TREE_CODE (type) == INTEGER_TYPE
110 || TREE_CODE (type) == REAL_TYPE))
111 type = TREE_TYPE (type);
116 /* Likewise, but only return types known to the Ada source. */
118 get_ada_base_type (tree type)
120 while (TREE_TYPE (type) != 0
121 && (TREE_CODE (type) == INTEGER_TYPE
122 || TREE_CODE (type) == REAL_TYPE)
123 && ! TYPE_EXTRA_SUBTYPE_P (type))
124 type = TREE_TYPE (type);
129 /* EXP is a GCC tree representing an address. See if we can find how
130 strictly the object at that address is aligned. Return that alignment
131 in bits. If we don't know anything about the alignment, return 0. */
134 known_alignment (tree exp)
136 unsigned int this_alignment;
137 unsigned int lhs, rhs;
138 unsigned int type_alignment;
140 /* For pointer expressions, we know that the designated object is always at
141 least as strictly aligned as the designated subtype, so we account for
142 both type and expression information in this case.
144 Beware that we can still get a dummy designated subtype here (e.g. Taft
145 Amendement types), in which the alignment information is meaningless and
148 We always compute a type_alignment value and return the MAX of it
149 compared with what we get from the expression tree. Just set the
150 type_alignment value to 0 when the type information is to be ignored. */
152 = ((POINTER_TYPE_P (TREE_TYPE (exp))
153 && ! TYPE_IS_DUMMY_P (TREE_TYPE (TREE_TYPE (exp))))
154 ? TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))) : 0);
156 switch (TREE_CODE (exp))
160 case NON_LVALUE_EXPR:
161 /* Conversions between pointers and integers don't change the alignment
162 of the underlying object. */
163 this_alignment = known_alignment (TREE_OPERAND (exp, 0));
168 /* If two address are added, the alignment of the result is the
169 minimum of the two aligments. */
170 lhs = known_alignment (TREE_OPERAND (exp, 0));
171 rhs = known_alignment (TREE_OPERAND (exp, 1));
172 this_alignment = MIN (lhs, rhs);
176 /* The first part of this represents the lowest bit in the constant,
177 but is it in bytes, not bits. */
180 * (TREE_INT_CST_LOW (exp) & - TREE_INT_CST_LOW (exp)),
185 /* If we know the alignment of just one side, use it. Otherwise,
186 use the product of the alignments. */
187 lhs = known_alignment (TREE_OPERAND (exp, 0));
188 rhs = known_alignment (TREE_OPERAND (exp, 1));
190 if (lhs == 0 || rhs == 0)
191 this_alignment = MIN (BIGGEST_ALIGNMENT, MAX (lhs, rhs));
193 this_alignment = MIN (BIGGEST_ALIGNMENT, lhs * rhs);
197 this_alignment = expr_align (TREE_OPERAND (exp, 0));
205 return MAX (type_alignment, this_alignment);
208 /* We have a comparison or assignment operation on two types, T1 and T2,
209 which are both either array types or both record types.
210 Return the type that both operands should be converted to, if any.
211 Otherwise return zero. */
214 find_common_type (tree t1, tree t2)
216 /* If either type is non-BLKmode, use it. Note that we know that we will
217 not have any alignment problems since if we did the non-BLKmode
218 type could not have been used. */
219 if (TYPE_MODE (t1) != BLKmode)
221 else if (TYPE_MODE (t2) != BLKmode)
224 /* Otherwise, return the type that has a constant size. */
225 if (TREE_CONSTANT (TYPE_SIZE (t1)))
227 else if (TREE_CONSTANT (TYPE_SIZE (t2)))
230 /* In this case, both types have variable size. It's probably
231 best to leave the "type mismatch" because changing it could
232 case a bad self-referential reference. */
236 /* See if EXP contains a SAVE_EXPR in a position where we would
239 ??? This is a real kludge, but is probably the best approach short
240 of some very general solution. */
243 contains_save_expr_p (tree exp)
245 switch (TREE_CODE (exp))
250 case ADDR_EXPR: case INDIRECT_REF:
252 case NOP_EXPR: case CONVERT_EXPR: case VIEW_CONVERT_EXPR:
253 return contains_save_expr_p (TREE_OPERAND (exp, 0));
256 return (CONSTRUCTOR_ELTS (exp) != 0
257 && contains_save_expr_p (CONSTRUCTOR_ELTS (exp)));
260 return (contains_save_expr_p (TREE_VALUE (exp))
261 || (TREE_CHAIN (exp) != 0
262 && contains_save_expr_p (TREE_CHAIN (exp))));
269 /* See if EXP contains a NULL_EXPR in an expression we use for sizes. Return
270 it if so. This is used to detect types whose sizes involve computations
271 that are known to raise Constraint_Error. */
274 contains_null_expr (tree exp)
278 if (TREE_CODE (exp) == NULL_EXPR)
281 switch (TREE_CODE_CLASS (TREE_CODE (exp)))
284 return contains_null_expr (TREE_OPERAND (exp, 0));
287 tem = contains_null_expr (TREE_OPERAND (exp, 0));
291 return contains_null_expr (TREE_OPERAND (exp, 1));
294 switch (TREE_CODE (exp))
297 return contains_null_expr (TREE_OPERAND (exp, 0));
300 tem = contains_null_expr (TREE_OPERAND (exp, 0));
304 tem = contains_null_expr (TREE_OPERAND (exp, 1));
308 return contains_null_expr (TREE_OPERAND (exp, 2));
319 /* Return an expression tree representing an equality comparison of
320 A1 and A2, two objects of ARRAY_TYPE. The returned expression should
321 be of type RESULT_TYPE
323 Two arrays are equal in one of two ways: (1) if both have zero length
324 in some dimension (not necessarily the same dimension) or (2) if the
325 lengths in each dimension are equal and the data is equal. We perform the
326 length tests in as efficient a manner as possible. */
329 compare_arrays (tree result_type, tree a1, tree a2)
331 tree t1 = TREE_TYPE (a1);
332 tree t2 = TREE_TYPE (a2);
333 tree result = convert (result_type, integer_one_node);
334 tree a1_is_null = convert (result_type, integer_zero_node);
335 tree a2_is_null = convert (result_type, integer_zero_node);
336 int length_zero_p = 0;
338 /* Process each dimension separately and compare the lengths. If any
339 dimension has a size known to be zero, set SIZE_ZERO_P to 1 to
340 suppress the comparison of the data. */
341 while (TREE_CODE (t1) == ARRAY_TYPE && TREE_CODE (t2) == ARRAY_TYPE)
343 tree lb1 = TYPE_MIN_VALUE (TYPE_DOMAIN (t1));
344 tree ub1 = TYPE_MAX_VALUE (TYPE_DOMAIN (t1));
345 tree lb2 = TYPE_MIN_VALUE (TYPE_DOMAIN (t2));
346 tree ub2 = TYPE_MAX_VALUE (TYPE_DOMAIN (t2));
347 tree bt = get_base_type (TREE_TYPE (lb1));
348 tree length1 = fold (build (MINUS_EXPR, bt, ub1, lb1));
349 tree length2 = fold (build (MINUS_EXPR, bt, ub2, lb2));
352 tree comparison, this_a1_is_null, this_a2_is_null;
354 /* If the length of the first array is a constant, swap our operands
355 unless the length of the second array is the constant zero.
356 Note that we have set the `length' values to the length - 1. */
357 if (TREE_CODE (length1) == INTEGER_CST
358 && ! integer_zerop (fold (build (PLUS_EXPR, bt, length2,
359 convert (bt, integer_one_node)))))
361 tem = a1, a1 = a2, a2 = tem;
362 tem = t1, t1 = t2, t2 = tem;
363 tem = lb1, lb1 = lb2, lb2 = tem;
364 tem = ub1, ub1 = ub2, ub2 = tem;
365 tem = length1, length1 = length2, length2 = tem;
366 tem = a1_is_null, a1_is_null = a2_is_null, a2_is_null = tem;
369 /* If the length of this dimension in the second array is the constant
370 zero, we can just go inside the original bounds for the first
371 array and see if last < first. */
372 if (integer_zerop (fold (build (PLUS_EXPR, bt, length2,
373 convert (bt, integer_one_node)))))
375 tree ub = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
376 tree lb = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
378 comparison = build_binary_op (LT_EXPR, result_type, ub, lb);
379 comparison = SUBSTITUTE_PLACEHOLDER_IN_EXPR (comparison, a1);
380 length1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length1, a1);
383 this_a1_is_null = comparison;
384 this_a2_is_null = convert (result_type, integer_one_node);
387 /* If the length is some other constant value, we know that the
388 this dimension in the first array cannot be superflat, so we
389 can just use its length from the actual stored bounds. */
390 else if (TREE_CODE (length2) == INTEGER_CST)
392 ub1 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
393 lb1 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
394 ub2 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t2)));
395 lb2 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t2)));
396 nbt = get_base_type (TREE_TYPE (ub1));
399 = build_binary_op (EQ_EXPR, result_type,
400 build_binary_op (MINUS_EXPR, nbt, ub1, lb1),
401 build_binary_op (MINUS_EXPR, nbt, ub2, lb2));
403 /* Note that we know that UB2 and LB2 are constant and hence
404 cannot contain a PLACEHOLDER_EXPR. */
406 comparison = SUBSTITUTE_PLACEHOLDER_IN_EXPR (comparison, a1);
407 length1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length1, a1);
409 this_a1_is_null = build_binary_op (LT_EXPR, result_type, ub1, lb1);
410 this_a2_is_null = convert (result_type, integer_zero_node);
413 /* Otherwise compare the computed lengths. */
416 length1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length1, a1);
417 length2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length2, a2);
420 = build_binary_op (EQ_EXPR, result_type, length1, length2);
423 = build_binary_op (LT_EXPR, result_type, length1,
424 convert (bt, integer_zero_node));
426 = build_binary_op (LT_EXPR, result_type, length2,
427 convert (bt, integer_zero_node));
430 result = build_binary_op (TRUTH_ANDIF_EXPR, result_type,
433 a1_is_null = build_binary_op (TRUTH_ORIF_EXPR, result_type,
434 this_a1_is_null, a1_is_null);
435 a2_is_null = build_binary_op (TRUTH_ORIF_EXPR, result_type,
436 this_a2_is_null, a2_is_null);
442 /* Unless the size of some bound is known to be zero, compare the
443 data in the array. */
446 tree type = find_common_type (TREE_TYPE (a1), TREE_TYPE (a2));
449 a1 = convert (type, a1), a2 = convert (type, a2);
451 result = build_binary_op (TRUTH_ANDIF_EXPR, result_type, result,
452 fold (build (EQ_EXPR, result_type, a1, a2)));
456 /* The result is also true if both sizes are zero. */
457 result = build_binary_op (TRUTH_ORIF_EXPR, result_type,
458 build_binary_op (TRUTH_ANDIF_EXPR, result_type,
459 a1_is_null, a2_is_null),
462 /* If either operand contains SAVE_EXPRs, they have to be evaluated before
463 starting the comparison above since the place it would be otherwise
464 evaluated would be wrong. */
466 if (contains_save_expr_p (a1))
467 result = build (COMPOUND_EXPR, result_type, a1, result);
469 if (contains_save_expr_p (a2))
470 result = build (COMPOUND_EXPR, result_type, a2, result);
475 /* Compute the result of applying OP_CODE to LHS and RHS, where both are of
476 type TYPE. We know that TYPE is a modular type with a nonbinary
480 nonbinary_modular_operation (enum tree_code op_code,
485 tree modulus = TYPE_MODULUS (type);
486 unsigned int needed_precision = tree_floor_log2 (modulus) + 1;
487 unsigned int precision;
492 /* If this is an addition of a constant, convert it to a subtraction
493 of a constant since we can do that faster. */
494 if (op_code == PLUS_EXPR && TREE_CODE (rhs) == INTEGER_CST)
495 rhs = fold (build (MINUS_EXPR, type, modulus, rhs)), op_code = MINUS_EXPR;
497 /* For the logical operations, we only need PRECISION bits. For
498 addition and subraction, we need one more and for multiplication we
499 need twice as many. But we never want to make a size smaller than
501 if (op_code == PLUS_EXPR || op_code == MINUS_EXPR)
502 needed_precision += 1;
503 else if (op_code == MULT_EXPR)
504 needed_precision *= 2;
506 precision = MAX (needed_precision, TYPE_PRECISION (op_type));
508 /* Unsigned will do for everything but subtraction. */
509 if (op_code == MINUS_EXPR)
512 /* If our type is the wrong signedness or isn't wide enough, make a new
513 type and convert both our operands to it. */
514 if (TYPE_PRECISION (op_type) < precision
515 || TYPE_UNSIGNED (op_type) != unsignedp)
517 /* Copy the node so we ensure it can be modified to make it modular. */
518 op_type = copy_node (gnat_type_for_size (precision, unsignedp));
519 modulus = convert (op_type, modulus);
520 SET_TYPE_MODULUS (op_type, modulus);
521 TYPE_MODULAR_P (op_type) = 1;
522 lhs = convert (op_type, lhs);
523 rhs = convert (op_type, rhs);
526 /* Do the operation, then we'll fix it up. */
527 result = fold (build (op_code, op_type, lhs, rhs));
529 /* For multiplication, we have no choice but to do a full modulus
530 operation. However, we want to do this in the narrowest
532 if (op_code == MULT_EXPR)
534 tree div_type = copy_node (gnat_type_for_size (needed_precision, 1));
535 modulus = convert (div_type, modulus);
536 SET_TYPE_MODULUS (div_type, modulus);
537 TYPE_MODULAR_P (div_type) = 1;
538 result = convert (op_type,
539 fold (build (TRUNC_MOD_EXPR, div_type,
540 convert (div_type, result), modulus)));
543 /* For subtraction, add the modulus back if we are negative. */
544 else if (op_code == MINUS_EXPR)
546 result = save_expr (result);
547 result = fold (build (COND_EXPR, op_type,
548 build (LT_EXPR, integer_type_node, result,
549 convert (op_type, integer_zero_node)),
550 fold (build (PLUS_EXPR, op_type,
555 /* For the other operations, subtract the modulus if we are >= it. */
558 result = save_expr (result);
559 result = fold (build (COND_EXPR, op_type,
560 build (GE_EXPR, integer_type_node,
562 fold (build (MINUS_EXPR, op_type,
567 return convert (type, result);
570 /* Make a binary operation of kind OP_CODE. RESULT_TYPE is the type
571 desired for the result. Usually the operation is to be performed
572 in that type. For MODIFY_EXPR and ARRAY_REF, RESULT_TYPE may be 0
573 in which case the type to be used will be derived from the operands.
575 This function is very much unlike the ones for C and C++ since we
576 have already done any type conversion and matching required. All we
577 have to do here is validate the work done by SEM and handle subtypes. */
580 build_binary_op (enum tree_code op_code,
585 tree left_type = TREE_TYPE (left_operand);
586 tree right_type = TREE_TYPE (right_operand);
587 tree left_base_type = get_base_type (left_type);
588 tree right_base_type = get_base_type (right_type);
589 tree operation_type = result_type;
593 int has_side_effects = 0;
595 if (operation_type != 0
596 && TREE_CODE (operation_type) == RECORD_TYPE
597 && TYPE_LEFT_JUSTIFIED_MODULAR_P (operation_type))
598 operation_type = TREE_TYPE (TYPE_FIELDS (operation_type));
600 if (operation_type != 0
601 && ! AGGREGATE_TYPE_P (operation_type)
602 && TYPE_EXTRA_SUBTYPE_P (operation_type))
603 operation_type = get_base_type (operation_type);
605 modulus = (operation_type != 0 && TREE_CODE (operation_type) == INTEGER_TYPE
606 && TYPE_MODULAR_P (operation_type)
607 ? TYPE_MODULUS (operation_type) : 0);
612 /* If there were any integral or pointer conversions on LHS, remove
613 them; we'll be putting them back below if needed. Likewise for
614 conversions between array and record types. But don't do this if
615 the right operand is not BLKmode (for packed arrays)
616 unless we are not changing the mode. */
617 while ((TREE_CODE (left_operand) == CONVERT_EXPR
618 || TREE_CODE (left_operand) == NOP_EXPR
619 || TREE_CODE (left_operand) == VIEW_CONVERT_EXPR)
620 && (((INTEGRAL_TYPE_P (left_type)
621 || POINTER_TYPE_P (left_type))
622 && (INTEGRAL_TYPE_P (TREE_TYPE
623 (TREE_OPERAND (left_operand, 0)))
624 || POINTER_TYPE_P (TREE_TYPE
625 (TREE_OPERAND (left_operand, 0)))))
626 || (((TREE_CODE (left_type) == RECORD_TYPE
627 /* Don't remove conversions to left-justified modular
629 && ! TYPE_LEFT_JUSTIFIED_MODULAR_P (left_type))
630 || TREE_CODE (left_type) == ARRAY_TYPE)
631 && ((TREE_CODE (TREE_TYPE
632 (TREE_OPERAND (left_operand, 0)))
634 || (TREE_CODE (TREE_TYPE
635 (TREE_OPERAND (left_operand, 0)))
637 && (TYPE_MODE (right_type) == BLKmode
638 || (TYPE_MODE (left_type)
639 == TYPE_MODE (TREE_TYPE
641 (left_operand, 0))))))))
643 left_operand = TREE_OPERAND (left_operand, 0);
644 left_type = TREE_TYPE (left_operand);
647 if (operation_type == 0)
648 operation_type = left_type;
650 /* If the RHS has a conversion between record and array types and
651 an inner type is no worse, use it. Note we cannot do this for
652 modular types or types with TYPE_ALIGN_OK, since the latter
653 might indicate a conversion between a root type and a class-wide
654 type, which we must not remove. */
655 while (TREE_CODE (right_operand) == VIEW_CONVERT_EXPR
656 && ((TREE_CODE (right_type) == RECORD_TYPE
657 && ! TYPE_LEFT_JUSTIFIED_MODULAR_P (right_type)
658 && ! TYPE_ALIGN_OK (right_type)
659 && ! TYPE_IS_FAT_POINTER_P (right_type))
660 || TREE_CODE (right_type) == ARRAY_TYPE)
661 && (((TREE_CODE (TREE_TYPE (TREE_OPERAND (right_operand, 0)))
663 && ! (TYPE_LEFT_JUSTIFIED_MODULAR_P
664 (TREE_TYPE (TREE_OPERAND (right_operand, 0))))
666 (TREE_TYPE (TREE_OPERAND (right_operand, 0))))
667 && ! (TYPE_IS_FAT_POINTER_P
668 (TREE_TYPE (TREE_OPERAND (right_operand, 0)))))
669 || (TREE_CODE (TREE_TYPE (TREE_OPERAND (right_operand, 0)))
672 == find_common_type (right_type,
673 TREE_TYPE (TREE_OPERAND
674 (right_operand, 0))))
675 || right_type != best_type))
677 right_operand = TREE_OPERAND (right_operand, 0);
678 right_type = TREE_TYPE (right_operand);
681 /* If we are copying one array or record to another, find the best type
683 if (((TREE_CODE (left_type) == ARRAY_TYPE
684 && TREE_CODE (right_type) == ARRAY_TYPE)
685 || (TREE_CODE (left_type) == RECORD_TYPE
686 && TREE_CODE (right_type) == RECORD_TYPE))
687 && (best_type = find_common_type (left_type, right_type)) != 0)
688 operation_type = best_type;
690 /* If a class-wide type may be involved, force use of the RHS type. */
691 if (TREE_CODE (right_type) == RECORD_TYPE && TYPE_ALIGN_OK (right_type))
692 operation_type = right_type;
694 /* Ensure everything on the LHS is valid. If we have a field reference,
695 strip anything that get_inner_reference can handle. Then remove any
696 conversions with type types having the same code and mode. Mark
697 VIEW_CONVERT_EXPRs with TREE_ADDRESSABLE. When done, we must have
698 either an INDIRECT_REF or a decl. */
699 result = left_operand;
702 tree restype = TREE_TYPE (result);
704 if (TREE_CODE (result) == COMPONENT_REF
705 || TREE_CODE (result) == ARRAY_REF
706 || TREE_CODE (result) == ARRAY_RANGE_REF)
707 while (handled_component_p (result))
708 result = TREE_OPERAND (result, 0);
709 else if (TREE_CODE (result) == REALPART_EXPR
710 || TREE_CODE (result) == IMAGPART_EXPR
711 || ((TREE_CODE (result) == NOP_EXPR
712 || TREE_CODE (result) == CONVERT_EXPR)
713 && (((TREE_CODE (restype)
714 == TREE_CODE (TREE_TYPE
715 (TREE_OPERAND (result, 0))))
716 && (TYPE_MODE (TREE_TYPE
717 (TREE_OPERAND (result, 0)))
718 == TYPE_MODE (restype)))
719 || TYPE_ALIGN_OK (restype))))
720 result = TREE_OPERAND (result, 0);
721 else if (TREE_CODE (result) == VIEW_CONVERT_EXPR)
723 TREE_ADDRESSABLE (result) = 1;
724 result = TREE_OPERAND (result, 0);
730 if (TREE_CODE (result) != INDIRECT_REF && TREE_CODE (result) != NULL_EXPR
731 && ! DECL_P (result))
734 /* Convert the right operand to the operation type unless
735 it is either already of the correct type or if the type
736 involves a placeholder, since the RHS may not have the same
738 if (operation_type != right_type
739 && (! CONTAINS_PLACEHOLDER_P (TYPE_SIZE (operation_type))))
741 /* For a variable-size type, with both BLKmode, convert using
742 CONVERT_EXPR instead of an unchecked conversion since we don't
743 need to make a temporary (and can't anyway). */
744 if (TREE_CODE (TYPE_SIZE (operation_type)) != INTEGER_CST
745 && TYPE_MODE (TREE_TYPE (right_operand)) == BLKmode
746 && TREE_CODE (right_operand) != UNCONSTRAINED_ARRAY_REF)
747 right_operand = build1 (CONVERT_EXPR, operation_type,
750 right_operand = convert (operation_type, right_operand);
752 right_type = operation_type;
755 /* If the modes differ, make up a bogus type and convert the RHS to
756 it. This can happen with packed types. */
757 if (TYPE_MODE (left_type) != TYPE_MODE (right_type))
759 tree new_type = copy_node (left_type);
761 TYPE_SIZE (new_type) = TYPE_SIZE (right_type);
762 TYPE_SIZE_UNIT (new_type) = TYPE_SIZE_UNIT (right_type);
763 TYPE_MAIN_VARIANT (new_type) = new_type;
764 right_operand = convert (new_type, right_operand);
767 has_side_effects = 1;
772 if (operation_type == 0)
773 operation_type = TREE_TYPE (left_type);
775 /* ... fall through ... */
777 case ARRAY_RANGE_REF:
779 /* First convert the right operand to its base type. This will
780 prevent unneed signedness conversions when sizetype is wider than
782 right_operand = convert (right_base_type, right_operand);
783 right_operand = convert (TYPE_DOMAIN (left_type), right_operand);
785 if (! TREE_CONSTANT (right_operand)
786 || ! TREE_CONSTANT (TYPE_MIN_VALUE (right_type)))
787 gnat_mark_addressable (left_operand);
796 if (POINTER_TYPE_P (left_type))
799 /* ... fall through ... */
803 /* If either operand is a NULL_EXPR, just return a new one. */
804 if (TREE_CODE (left_operand) == NULL_EXPR)
805 return build (op_code, result_type,
806 build1 (NULL_EXPR, integer_type_node,
807 TREE_OPERAND (left_operand, 0)),
810 else if (TREE_CODE (right_operand) == NULL_EXPR)
811 return build (op_code, result_type,
812 build1 (NULL_EXPR, integer_type_node,
813 TREE_OPERAND (right_operand, 0)),
816 /* If either object is a left-justified modular types, get the
817 fields from within. */
818 if (TREE_CODE (left_type) == RECORD_TYPE
819 && TYPE_LEFT_JUSTIFIED_MODULAR_P (left_type))
821 left_operand = convert (TREE_TYPE (TYPE_FIELDS (left_type)),
823 left_type = TREE_TYPE (left_operand);
824 left_base_type = get_base_type (left_type);
827 if (TREE_CODE (right_type) == RECORD_TYPE
828 && TYPE_LEFT_JUSTIFIED_MODULAR_P (right_type))
830 right_operand = convert (TREE_TYPE (TYPE_FIELDS (right_type)),
832 right_type = TREE_TYPE (right_operand);
833 right_base_type = get_base_type (right_type);
836 /* If both objects are arrays, compare them specially. */
837 if ((TREE_CODE (left_type) == ARRAY_TYPE
838 || (TREE_CODE (left_type) == INTEGER_TYPE
839 && TYPE_HAS_ACTUAL_BOUNDS_P (left_type)))
840 && (TREE_CODE (right_type) == ARRAY_TYPE
841 || (TREE_CODE (right_type) == INTEGER_TYPE
842 && TYPE_HAS_ACTUAL_BOUNDS_P (right_type))))
844 result = compare_arrays (result_type, left_operand, right_operand);
846 if (op_code == EQ_EXPR)
848 else if (op_code == NE_EXPR)
849 result = invert_truthvalue (result);
856 /* Otherwise, the base types must be the same unless the objects are
857 records. If we have records, use the best type and convert both
858 operands to that type. */
859 if (left_base_type != right_base_type)
861 if (TREE_CODE (left_base_type) == RECORD_TYPE
862 && TREE_CODE (right_base_type) == RECORD_TYPE)
864 /* The only way these are permitted to be the same is if both
865 types have the same name. In that case, one of them must
866 not be self-referential. Use that one as the best type.
867 Even better is if one is of fixed size. */
870 if (TYPE_NAME (left_base_type) == 0
871 || TYPE_NAME (left_base_type) != TYPE_NAME (right_base_type))
874 if (TREE_CONSTANT (TYPE_SIZE (left_base_type)))
875 best_type = left_base_type;
876 else if (TREE_CONSTANT (TYPE_SIZE (right_base_type)))
877 best_type = right_base_type;
878 else if (! CONTAINS_PLACEHOLDER_P (TYPE_SIZE (left_base_type)))
879 best_type = left_base_type;
880 else if (! CONTAINS_PLACEHOLDER_P (TYPE_SIZE (right_base_type)))
881 best_type = right_base_type;
885 left_operand = convert (best_type, left_operand);
886 right_operand = convert (best_type, right_operand);
892 /* If we are comparing a fat pointer against zero, we need to
893 just compare the data pointer. */
894 else if (TYPE_FAT_POINTER_P (left_base_type)
895 && TREE_CODE (right_operand) == CONSTRUCTOR
896 && integer_zerop (TREE_VALUE (CONSTRUCTOR_ELTS (right_operand))))
898 right_operand = build_component_ref (left_operand, NULL_TREE,
899 TYPE_FIELDS (left_base_type),
901 left_operand = convert (TREE_TYPE (right_operand),
906 left_operand = convert (left_base_type, left_operand);
907 right_operand = convert (right_base_type, right_operand);
913 case PREINCREMENT_EXPR:
914 case PREDECREMENT_EXPR:
915 case POSTINCREMENT_EXPR:
916 case POSTDECREMENT_EXPR:
917 /* In these, the result type and the left operand type should be the
918 same. Do the operation in the base type of those and convert the
919 right operand (which is an integer) to that type.
921 Note that these operations are only used in loop control where
922 we guarantee that no overflow can occur. So nothing special need
923 be done for modular types. */
925 if (left_type != result_type)
928 operation_type = get_base_type (result_type);
929 left_operand = convert (operation_type, left_operand);
930 right_operand = convert (operation_type, right_operand);
931 has_side_effects = 1;
939 /* The RHS of a shift can be any type. Also, ignore any modulus
940 (we used to abort, but this is needed for unchecked conversion
941 to modular types). Otherwise, processing is the same as normal. */
942 if (operation_type != left_base_type)
946 left_operand = convert (operation_type, left_operand);
949 case TRUTH_ANDIF_EXPR:
950 case TRUTH_ORIF_EXPR:
954 left_operand = gnat_truthvalue_conversion (left_operand);
955 right_operand = gnat_truthvalue_conversion (right_operand);
961 /* For binary modulus, if the inputs are in range, so are the
963 if (modulus != 0 && integer_pow2p (modulus))
969 if (TREE_TYPE (result_type) != left_base_type
970 || TREE_TYPE (result_type) != right_base_type)
973 left_operand = convert (left_base_type, left_operand);
974 right_operand = convert (right_base_type, right_operand);
977 case TRUNC_DIV_EXPR: case TRUNC_MOD_EXPR:
978 case CEIL_DIV_EXPR: case CEIL_MOD_EXPR:
979 case FLOOR_DIV_EXPR: case FLOOR_MOD_EXPR:
980 case ROUND_DIV_EXPR: case ROUND_MOD_EXPR:
981 /* These always produce results lower than either operand. */
987 /* The result type should be the same as the base types of the
988 both operands (and they should be the same). Convert
989 everything to the result type. */
991 if (operation_type != left_base_type
992 || left_base_type != right_base_type)
995 left_operand = convert (operation_type, left_operand);
996 right_operand = convert (operation_type, right_operand);
999 if (modulus != 0 && ! integer_pow2p (modulus))
1001 result = nonbinary_modular_operation (op_code, operation_type,
1002 left_operand, right_operand);
1005 /* If either operand is a NULL_EXPR, just return a new one. */
1006 else if (TREE_CODE (left_operand) == NULL_EXPR)
1007 return build1 (NULL_EXPR, operation_type, TREE_OPERAND (left_operand, 0));
1008 else if (TREE_CODE (right_operand) == NULL_EXPR)
1009 return build1 (NULL_EXPR, operation_type, TREE_OPERAND (right_operand, 0));
1011 result = fold (build (op_code, operation_type,
1012 left_operand, right_operand));
1014 TREE_SIDE_EFFECTS (result) |= has_side_effects;
1015 TREE_CONSTANT (result)
1016 |= (TREE_CONSTANT (left_operand) & TREE_CONSTANT (right_operand)
1017 && op_code != ARRAY_REF && op_code != ARRAY_RANGE_REF);
1019 if ((op_code == ARRAY_REF || op_code == ARRAY_RANGE_REF)
1020 && TYPE_VOLATILE (operation_type))
1021 TREE_THIS_VOLATILE (result) = 1;
1023 /* If we are working with modular types, perform the MOD operation
1024 if something above hasn't eliminated the need for it. */
1026 result = fold (build (FLOOR_MOD_EXPR, operation_type, result,
1027 convert (operation_type, modulus)));
1029 if (result_type != 0 && result_type != operation_type)
1030 result = convert (result_type, result);
1035 /* Similar, but for unary operations. */
1038 build_unary_op (enum tree_code op_code, tree result_type, tree operand)
1040 tree type = TREE_TYPE (operand);
1041 tree base_type = get_base_type (type);
1042 tree operation_type = result_type;
1044 int side_effects = 0;
1046 if (operation_type != 0
1047 && TREE_CODE (operation_type) == RECORD_TYPE
1048 && TYPE_LEFT_JUSTIFIED_MODULAR_P (operation_type))
1049 operation_type = TREE_TYPE (TYPE_FIELDS (operation_type));
1051 if (operation_type != 0
1052 && ! AGGREGATE_TYPE_P (operation_type)
1053 && TYPE_EXTRA_SUBTYPE_P (operation_type))
1054 operation_type = get_base_type (operation_type);
1060 if (operation_type == 0)
1061 result_type = operation_type = TREE_TYPE (type);
1062 else if (result_type != TREE_TYPE (type))
1065 result = fold (build1 (op_code, operation_type, operand));
1068 case TRUTH_NOT_EXPR:
1069 if (result_type != base_type)
1072 result = invert_truthvalue (gnat_truthvalue_conversion (operand));
1075 case ATTR_ADDR_EXPR:
1077 switch (TREE_CODE (operand))
1080 case UNCONSTRAINED_ARRAY_REF:
1081 result = TREE_OPERAND (operand, 0);
1083 /* Make sure the type here is a pointer, not a reference.
1084 GCC wants pointer types for function addresses. */
1085 if (result_type == 0)
1086 result_type = build_pointer_type (type);
1091 TREE_TYPE (result) = type = build_pointer_type (type);
1095 case ARRAY_RANGE_REF:
1098 /* If this is for 'Address, find the address of the prefix and
1099 add the offset to the field. Otherwise, do this the normal
1101 if (op_code == ATTR_ADDR_EXPR)
1103 HOST_WIDE_INT bitsize;
1104 HOST_WIDE_INT bitpos;
1106 enum machine_mode mode;
1107 int unsignedp, volatilep;
1109 inner = get_inner_reference (operand, &bitsize, &bitpos, &offset,
1110 &mode, &unsignedp, &volatilep);
1112 /* If INNER is a padding type whose field has a self-referential
1113 size, convert to that inner type. We know the offset is zero
1114 and we need to have that type visible. */
1115 if (TREE_CODE (TREE_TYPE (inner)) == RECORD_TYPE
1116 && TYPE_IS_PADDING_P (TREE_TYPE (inner))
1117 && (CONTAINS_PLACEHOLDER_P
1118 (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS
1119 (TREE_TYPE (inner)))))))
1120 inner = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (inner))),
1123 /* Compute the offset as a byte offset from INNER. */
1125 offset = size_zero_node;
1127 if (bitpos % BITS_PER_UNIT != 0)
1129 ("taking address of object not aligned on storage unit?",
1132 offset = size_binop (PLUS_EXPR, offset,
1133 size_int (bitpos / BITS_PER_UNIT));
1135 /* Take the address of INNER, convert the offset to void *, and
1136 add then. It will later be converted to the desired result
1138 inner = build_unary_op (ADDR_EXPR, NULL_TREE, inner);
1139 inner = convert (ptr_void_type_node, inner);
1140 offset = convert (ptr_void_type_node, offset);
1141 result = build_binary_op (PLUS_EXPR, ptr_void_type_node,
1143 result = convert (build_pointer_type (TREE_TYPE (operand)),
1150 /* If this is just a constructor for a padded record, we can
1151 just take the address of the single field and convert it to
1152 a pointer to our type. */
1153 if (TREE_CODE (type) == RECORD_TYPE && TYPE_IS_PADDING_P (type))
1156 = build_unary_op (ADDR_EXPR, NULL_TREE,
1157 TREE_VALUE (CONSTRUCTOR_ELTS (operand)));
1158 result = convert (build_pointer_type (TREE_TYPE (operand)),
1166 if (AGGREGATE_TYPE_P (type)
1167 && AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (operand, 0))))
1168 return build_unary_op (ADDR_EXPR, result_type,
1169 TREE_OPERAND (operand, 0));
1171 /* If this NOP_EXPR doesn't change the mode, get the result type
1172 from this type and go down. We need to do this in case
1173 this is a conversion of a CONST_DECL. */
1174 if (TYPE_MODE (type) != BLKmode
1175 && (TYPE_MODE (type)
1176 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (operand, 0)))))
1177 return build_unary_op (ADDR_EXPR,
1179 ? build_pointer_type (type)
1181 TREE_OPERAND (operand, 0));
1185 operand = DECL_CONST_CORRESPONDING_VAR (operand);
1187 /* ... fall through ... */
1192 /* If we are taking the address of a padded record whose field is
1193 contains a template, take the address of the template. */
1194 if (TREE_CODE (type) == RECORD_TYPE
1195 && TYPE_IS_PADDING_P (type)
1196 && TREE_CODE (TREE_TYPE (TYPE_FIELDS (type))) == RECORD_TYPE
1197 && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (TYPE_FIELDS (type))))
1199 type = TREE_TYPE (TYPE_FIELDS (type));
1200 operand = convert (type, operand);
1203 if (type != error_mark_node)
1204 operation_type = build_pointer_type (type);
1206 gnat_mark_addressable (operand);
1207 result = fold (build1 (ADDR_EXPR, operation_type, operand));
1210 TREE_CONSTANT (result) = staticp (operand) || TREE_CONSTANT (operand);
1214 /* If we want to refer to an entire unconstrained array,
1215 make up an expression to do so. This will never survive to
1216 the backend. If TYPE is a thin pointer, first convert the
1217 operand to a fat pointer. */
1218 if (TYPE_THIN_POINTER_P (type)
1219 && TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type)) != 0)
1222 = convert (TREE_TYPE (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type))),
1224 type = TREE_TYPE (operand);
1227 if (TYPE_FAT_POINTER_P (type))
1228 result = build1 (UNCONSTRAINED_ARRAY_REF,
1229 TYPE_UNCONSTRAINED_ARRAY (type), operand);
1231 else if (TREE_CODE (operand) == ADDR_EXPR)
1232 result = TREE_OPERAND (operand, 0);
1236 result = fold (build1 (op_code, TREE_TYPE (type), operand));
1237 TREE_READONLY (result) = TYPE_READONLY (TREE_TYPE (type));
1241 = (! TYPE_FAT_POINTER_P (type) && TYPE_VOLATILE (TREE_TYPE (type)));
1247 tree modulus = ((operation_type != 0
1248 && TREE_CODE (operation_type) == INTEGER_TYPE
1249 && TYPE_MODULAR_P (operation_type))
1250 ? TYPE_MODULUS (operation_type) : 0);
1251 int mod_pow2 = modulus != 0 && integer_pow2p (modulus);
1253 /* If this is a modular type, there are various possibilities
1254 depending on the operation and whether the modulus is a
1255 power of two or not. */
1259 if (operation_type != base_type)
1262 operand = convert (operation_type, operand);
1264 /* The fastest in the negate case for binary modulus is
1265 the straightforward code; the TRUNC_MOD_EXPR below
1266 is an AND operation. */
1267 if (op_code == NEGATE_EXPR && mod_pow2)
1268 result = fold (build (TRUNC_MOD_EXPR, operation_type,
1269 fold (build1 (NEGATE_EXPR, operation_type,
1273 /* For nonbinary negate case, return zero for zero operand,
1274 else return the modulus minus the operand. If the modulus
1275 is a power of two minus one, we can do the subtraction
1276 as an XOR since it is equivalent and faster on most machines. */
1277 else if (op_code == NEGATE_EXPR && ! mod_pow2)
1279 if (integer_pow2p (fold (build (PLUS_EXPR, operation_type,
1281 convert (operation_type,
1282 integer_one_node)))))
1283 result = fold (build (BIT_XOR_EXPR, operation_type,
1286 result = fold (build (MINUS_EXPR, operation_type,
1289 result = fold (build (COND_EXPR, operation_type,
1290 fold (build (NE_EXPR, integer_type_node,
1292 convert (operation_type,
1293 integer_zero_node))),
1298 /* For the NOT cases, we need a constant equal to
1299 the modulus minus one. For a binary modulus, we
1300 XOR against the constant and subtract the operand from
1301 that constant for nonbinary modulus. */
1303 tree cnst = fold (build (MINUS_EXPR, operation_type, modulus,
1304 convert (operation_type,
1305 integer_one_node)));
1308 result = fold (build (BIT_XOR_EXPR, operation_type,
1311 result = fold (build (MINUS_EXPR, operation_type,
1319 /* ... fall through ... */
1322 if (operation_type != base_type)
1325 result = fold (build1 (op_code, operation_type, convert (operation_type,
1331 TREE_SIDE_EFFECTS (result) = 1;
1332 if (TREE_CODE (result) == INDIRECT_REF)
1333 TREE_THIS_VOLATILE (result) = TYPE_VOLATILE (TREE_TYPE (result));
1336 if (result_type != 0 && TREE_TYPE (result) != result_type)
1337 result = convert (result_type, result);
1342 /* Similar, but for COND_EXPR. */
1345 build_cond_expr (tree result_type,
1346 tree condition_operand,
1353 /* Front-end verifies that result, true and false operands have same base
1354 type. Convert everything to the result type. */
1356 true_operand = convert (result_type, true_operand);
1357 false_operand = convert (result_type, false_operand);
1359 /* If the result type is unconstrained, take the address of
1360 the operands and then dereference our result. */
1362 if (TREE_CODE (result_type) == UNCONSTRAINED_ARRAY_TYPE
1363 || CONTAINS_PLACEHOLDER_P (TYPE_SIZE (result_type)))
1366 result_type = build_pointer_type (result_type);
1367 true_operand = build_unary_op (ADDR_EXPR, result_type, true_operand);
1368 false_operand = build_unary_op (ADDR_EXPR, result_type, false_operand);
1371 result = fold (build (COND_EXPR, result_type, condition_operand,
1372 true_operand, false_operand));
1374 /* If either operand is a SAVE_EXPR (possibly surrounded by
1375 arithmetic, make sure it gets done. */
1376 true_operand = skip_simple_arithmetic (true_operand);
1377 false_operand = skip_simple_arithmetic (false_operand);
1379 if (TREE_CODE (true_operand) == SAVE_EXPR)
1380 result = build (COMPOUND_EXPR, result_type, true_operand, result);
1382 if (TREE_CODE (false_operand) == SAVE_EXPR)
1383 result = build (COMPOUND_EXPR, result_type, false_operand, result);
1385 /* ??? Seems the code above is wrong, as it may move ahead of the COND
1386 SAVE_EXPRs with side effects and not shared by both arms. */
1389 result = build_unary_op (INDIRECT_REF, NULL_TREE, result);
1395 /* Build a CALL_EXPR to call FUNDECL with one argument, ARG. Return
1399 build_call_1_expr (tree fundecl, tree arg)
1401 tree call = build (CALL_EXPR, TREE_TYPE (TREE_TYPE (fundecl)),
1402 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1403 chainon (NULL_TREE, build_tree_list (NULL_TREE, arg)),
1406 TREE_SIDE_EFFECTS (call) = 1;
1411 /* Build a CALL_EXPR to call FUNDECL with two arguments, ARG1 & ARG2. Return
1415 build_call_2_expr (tree fundecl, tree arg1, tree arg2)
1417 tree call = build (CALL_EXPR, TREE_TYPE (TREE_TYPE (fundecl)),
1418 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1419 chainon (chainon (NULL_TREE,
1420 build_tree_list (NULL_TREE, arg1)),
1421 build_tree_list (NULL_TREE, arg2)),
1424 TREE_SIDE_EFFECTS (call) = 1;
1429 /* Likewise to call FUNDECL with no arguments. */
1432 build_call_0_expr (tree fundecl)
1434 tree call = build (CALL_EXPR, TREE_TYPE (TREE_TYPE (fundecl)),
1435 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1436 NULL_TREE, NULL_TREE);
1438 TREE_SIDE_EFFECTS (call) = 1;
1443 /* Call a function that raises an exception and pass the line number and file
1444 name, if requested. MSG says which exception function to call. */
1447 build_call_raise (int msg)
1449 tree fndecl = gnat_raise_decls[msg];
1450 const char *str = discard_file_names ? "" : ref_filename;
1451 int len = strlen (str) + 1;
1452 tree filename = build_string (len, str);
1454 TREE_TYPE (filename)
1455 = build_array_type (char_type_node,
1456 build_index_type (build_int_2 (len, 0)));
1459 build_call_2_expr (fndecl,
1460 build1 (ADDR_EXPR, build_pointer_type (char_type_node),
1462 build_int_2 (input_line, 0));
1465 /* Return a CONSTRUCTOR of TYPE whose list is LIST. */
1468 gnat_build_constructor (tree type, tree list)
1471 int allconstant = (TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST);
1472 int side_effects = 0;
1475 for (elmt = list; elmt; elmt = TREE_CHAIN (elmt))
1477 if (! TREE_CONSTANT (TREE_VALUE (elmt))
1478 || (TREE_CODE (type) == RECORD_TYPE
1479 && DECL_BIT_FIELD (TREE_PURPOSE (elmt))
1480 && TREE_CODE (TREE_VALUE (elmt)) != INTEGER_CST)
1481 || ! initializer_constant_valid_p (TREE_VALUE (elmt),
1482 TREE_TYPE (TREE_VALUE (elmt))))
1485 if (TREE_SIDE_EFFECTS (TREE_VALUE (elmt)))
1488 /* Propagate an NULL_EXPR from the size of the type. We won't ever
1489 be executing the code we generate here in that case, but handle it
1490 specially to avoid the cmpiler blowing up. */
1491 if (TREE_CODE (type) == RECORD_TYPE
1493 = contains_null_expr (DECL_SIZE (TREE_PURPOSE (elmt))))))
1494 return build1 (NULL_EXPR, type, TREE_OPERAND (result, 0));
1497 /* If TYPE is a RECORD_TYPE and the fields are not in the
1498 same order as their bit position, don't treat this as constant
1499 since varasm.c can't handle it. */
1500 if (allconstant && TREE_CODE (type) == RECORD_TYPE)
1502 tree last_pos = bitsize_zero_node;
1505 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
1507 tree this_pos = bit_position (field);
1509 if (TREE_CODE (this_pos) != INTEGER_CST
1510 || tree_int_cst_lt (this_pos, last_pos))
1516 last_pos = this_pos;
1520 result = build_constructor (type, list);
1521 TREE_CONSTANT (result) = allconstant;
1522 TREE_STATIC (result) = allconstant;
1523 TREE_SIDE_EFFECTS (result) = side_effects;
1524 TREE_READONLY (result) = TYPE_READONLY (type);
1529 /* Return a COMPONENT_REF to access a field that is given by COMPONENT,
1530 an IDENTIFIER_NODE giving the name of the field, or FIELD, a FIELD_DECL,
1531 for the field. Don't fold the result if NO_FOLD_P is nonzero.
1533 We also handle the fact that we might have been passed a pointer to the
1534 actual record and know how to look for fields in variant parts. */
1537 build_simple_component_ref (tree record_variable,
1542 tree record_type = TYPE_MAIN_VARIANT (TREE_TYPE (record_variable));
1545 if ((TREE_CODE (record_type) != RECORD_TYPE
1546 && TREE_CODE (record_type) != UNION_TYPE
1547 && TREE_CODE (record_type) != QUAL_UNION_TYPE)
1548 || TYPE_SIZE (record_type) == 0)
1551 /* Either COMPONENT or FIELD must be specified, but not both. */
1552 if ((component != 0) == (field != 0))
1555 /* If no field was specified, look for a field with the specified name
1556 in the current record only. */
1558 for (field = TYPE_FIELDS (record_type); field;
1559 field = TREE_CHAIN (field))
1560 if (DECL_NAME (field) == component)
1566 /* If this field is not in the specified record, see if we can find
1567 something in the record whose original field is the same as this one. */
1568 if (DECL_CONTEXT (field) != record_type)
1569 /* Check if there is a field with name COMPONENT in the record. */
1573 /* First loop thru normal components. */
1575 for (new_field = TYPE_FIELDS (record_type); new_field != 0;
1576 new_field = TREE_CHAIN (new_field))
1577 if (DECL_ORIGINAL_FIELD (new_field) == field
1578 || new_field == DECL_ORIGINAL_FIELD (field)
1579 || (DECL_ORIGINAL_FIELD (field) != 0
1580 && (DECL_ORIGINAL_FIELD (field)
1581 == DECL_ORIGINAL_FIELD (new_field))))
1584 /* Next, loop thru DECL_INTERNAL_P components if we haven't found
1585 the component in the first search. Doing this search in 2 steps
1586 is required to avoiding hidden homonymous fields in the
1590 for (new_field = TYPE_FIELDS (record_type); new_field != 0;
1591 new_field = TREE_CHAIN (new_field))
1592 if (DECL_INTERNAL_P (new_field))
1595 = build_simple_component_ref (record_variable,
1596 NULL_TREE, new_field, no_fold_p);
1597 ref = build_simple_component_ref (field_ref, NULL_TREE, field,
1610 /* It would be nice to call "fold" here, but that can lose a type
1611 we need to tag a PLACEHOLDER_EXPR with, so we can't do it. */
1612 ref = build (COMPONENT_REF, TREE_TYPE (field), record_variable, field);
1614 if (TREE_READONLY (record_variable) || TREE_READONLY (field))
1615 TREE_READONLY (ref) = 1;
1616 if (TREE_THIS_VOLATILE (record_variable) || TREE_THIS_VOLATILE (field)
1617 || TYPE_VOLATILE (record_type))
1618 TREE_THIS_VOLATILE (ref) = 1;
1620 return no_fold_p ? ref : fold (ref);
1623 /* Like build_simple_component_ref, except that we give an error if the
1624 reference could not be found. */
1627 build_component_ref (tree record_variable,
1632 tree ref = build_simple_component_ref (record_variable, component, field,
1638 /* If FIELD was specified, assume this is an invalid user field so
1639 raise constraint error. Otherwise, we can't find the type to return, so
1642 else if (field != 0)
1643 return build1 (NULL_EXPR, TREE_TYPE (field),
1644 build_call_raise (CE_Discriminant_Check_Failed));
1649 /* Build a GCC tree to call an allocation or deallocation function.
1650 If GNU_OBJ is nonzero, it is an object to deallocate. Otherwise,
1651 generate an allocator.
1653 GNU_SIZE is the size of the object in bytes and ALIGN is the alignment in
1654 bits. GNAT_PROC, if present, is a procedure to call and GNAT_POOL is the
1655 storage pool to use. If not preset, malloc and free will be used except
1656 if GNAT_PROC is the "fake" value of -1, in which case we allocate the
1657 object dynamically on the stack frame. */
1660 build_call_alloc_dealloc (tree gnu_obj, tree gnu_size, unsigned align,
1661 Entity_Id gnat_proc, Entity_Id gnat_pool,
1664 tree gnu_align = size_int (align / BITS_PER_UNIT);
1666 gnu_size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (gnu_size, gnu_obj);
1668 if (Present (gnat_proc))
1670 /* The storage pools are obviously always tagged types, but the
1671 secondary stack uses the same mechanism and is not tagged */
1672 if (Is_Tagged_Type (Etype (gnat_pool)))
1674 /* The size is the third parameter; the alignment is the
1676 Entity_Id gnat_size_type
1677 = Etype (Next_Formal (Next_Formal (First_Formal (gnat_proc))));
1678 tree gnu_size_type = gnat_to_gnu_type (gnat_size_type);
1679 tree gnu_proc = gnat_to_gnu (gnat_proc);
1680 tree gnu_proc_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_proc);
1681 tree gnu_pool = gnat_to_gnu (gnat_pool);
1682 tree gnu_pool_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_pool);
1683 tree gnu_args = NULL_TREE;
1686 /* The first arg is always the address of the storage pool; next
1687 comes the address of the object, for a deallocator, then the
1688 size and alignment. */
1690 = chainon (gnu_args, build_tree_list (NULL_TREE, gnu_pool_addr));
1694 = chainon (gnu_args, build_tree_list (NULL_TREE, gnu_obj));
1697 = chainon (gnu_args,
1698 build_tree_list (NULL_TREE,
1699 convert (gnu_size_type, gnu_size)));
1701 = chainon (gnu_args,
1702 build_tree_list (NULL_TREE,
1703 convert (gnu_size_type, gnu_align)));
1705 gnu_call = build (CALL_EXPR, TREE_TYPE (TREE_TYPE (gnu_proc)),
1706 gnu_proc_addr, gnu_args, NULL_TREE);
1707 TREE_SIDE_EFFECTS (gnu_call) = 1;
1711 /* Secondary stack case. */
1714 /* The size is the second parameter */
1715 Entity_Id gnat_size_type
1716 = Etype (Next_Formal (First_Formal (gnat_proc)));
1717 tree gnu_size_type = gnat_to_gnu_type (gnat_size_type);
1718 tree gnu_proc = gnat_to_gnu (gnat_proc);
1719 tree gnu_proc_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_proc);
1720 tree gnu_args = NULL_TREE;
1723 /* The first arg is the address of the object, for a
1724 deallocator, then the size */
1727 = chainon (gnu_args, build_tree_list (NULL_TREE, gnu_obj));
1730 = chainon (gnu_args,
1731 build_tree_list (NULL_TREE,
1732 convert (gnu_size_type, gnu_size)));
1734 gnu_call = build (CALL_EXPR, TREE_TYPE (TREE_TYPE (gnu_proc)),
1735 gnu_proc_addr, gnu_args, NULL_TREE);
1736 TREE_SIDE_EFFECTS (gnu_call) = 1;
1742 return build_call_1_expr (free_decl, gnu_obj);
1743 else if (gnat_pool == -1)
1745 /* If the size is a constant, we can put it in the fixed portion of
1746 the stack frame to avoid the need to adjust the stack pointer. */
1747 if (TREE_CODE (gnu_size) == INTEGER_CST && ! flag_stack_check)
1750 = build_range_type (NULL_TREE, size_one_node, gnu_size);
1751 tree gnu_array_type = build_array_type (char_type_node, gnu_range);
1753 create_var_decl (get_identifier ("RETVAL"), NULL_TREE,
1754 gnu_array_type, NULL_TREE, 0, 0, 0, 0, 0);
1756 return convert (ptr_void_type_node,
1757 build_unary_op (ADDR_EXPR, NULL_TREE, gnu_decl));
1760 return build (ALLOCATE_EXPR, ptr_void_type_node, gnu_size, gnu_align);
1764 if (Nkind (gnat_node) != N_Allocator || !Comes_From_Source (gnat_node))
1765 Check_No_Implicit_Heap_Alloc (gnat_node);
1766 return build_call_1_expr (malloc_decl, gnu_size);
1770 /* Build a GCC tree to correspond to allocating an object of TYPE whose
1771 initial value is INIT, if INIT is nonzero. Convert the expression to
1772 RESULT_TYPE, which must be some type of pointer. Return the tree.
1773 GNAT_PROC and GNAT_POOL optionally give the procedure to call and
1774 the storage pool to use. */
1777 build_allocator (tree type,
1780 Entity_Id gnat_proc,
1781 Entity_Id gnat_pool,
1784 tree size = TYPE_SIZE_UNIT (type);
1787 /* If the initializer, if present, is a NULL_EXPR, just return a new one. */
1788 if (init != 0 && TREE_CODE (init) == NULL_EXPR)
1789 return build1 (NULL_EXPR, result_type, TREE_OPERAND (init, 0));
1791 /* If RESULT_TYPE is a fat or thin pointer, set SIZE to be the sum of the
1792 sizes of the object and its template. Allocate the whole thing and
1793 fill in the parts that are known. */
1794 else if (TYPE_FAT_OR_THIN_POINTER_P (result_type))
1797 = (TYPE_FAT_POINTER_P (result_type)
1798 ? TREE_TYPE (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (result_type))))
1799 : TREE_TYPE (TYPE_FIELDS (TREE_TYPE (result_type))));
1801 = build_unc_object_type (template_type, type,
1802 get_identifier ("ALLOC"));
1803 tree storage_ptr_type = build_pointer_type (storage_type);
1805 tree template_cons = NULL_TREE;
1807 size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TYPE_SIZE_UNIT (storage_type),
1810 /* If the size overflows, pass -1 so the allocator will raise
1812 if (TREE_CODE (size) == INTEGER_CST && TREE_OVERFLOW (size))
1813 size = ssize_int (-1);
1815 storage = build_call_alloc_dealloc (NULL_TREE, size,
1816 TYPE_ALIGN (storage_type),
1817 gnat_proc, gnat_pool, gnat_node);
1818 storage = convert (storage_ptr_type, protect_multiple_eval (storage));
1820 if (TREE_CODE (type) == RECORD_TYPE && TYPE_IS_PADDING_P (type))
1822 type = TREE_TYPE (TYPE_FIELDS (type));
1825 init = convert (type, init);
1828 /* If there is an initializing expression, make a constructor for
1829 the entire object including the bounds and copy it into the
1830 object. If there is no initializing expression, just set the
1834 template_cons = tree_cons (TREE_CHAIN (TYPE_FIELDS (storage_type)),
1836 template_cons = tree_cons (TYPE_FIELDS (storage_type),
1837 build_template (template_type, type,
1843 build (COMPOUND_EXPR, storage_ptr_type,
1845 (MODIFY_EXPR, storage_type,
1846 build_unary_op (INDIRECT_REF, NULL_TREE,
1847 convert (storage_ptr_type, storage)),
1848 gnat_build_constructor (storage_type, template_cons)),
1849 convert (storage_ptr_type, storage)));
1853 (COMPOUND_EXPR, result_type,
1855 (MODIFY_EXPR, template_type,
1857 (build_unary_op (INDIRECT_REF, NULL_TREE,
1858 convert (storage_ptr_type, storage)),
1859 NULL_TREE, TYPE_FIELDS (storage_type), 0),
1860 build_template (template_type, type, NULL_TREE)),
1861 convert (result_type, convert (storage_ptr_type, storage)));
1864 /* If we have an initializing expression, see if its size is simpler
1865 than the size from the type. */
1866 if (init != 0 && TYPE_SIZE_UNIT (TREE_TYPE (init)) != 0
1867 && (TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (init))) == INTEGER_CST
1868 || CONTAINS_PLACEHOLDER_P (size)))
1869 size = TYPE_SIZE_UNIT (TREE_TYPE (init));
1871 /* If the size is still self-referential, reference the initializing
1872 expression, if it is present. If not, this must have been a
1873 call to allocate a library-level object, in which case we use
1874 the maximum size. */
1875 if (CONTAINS_PLACEHOLDER_P (size))
1878 size = max_size (size, 1);
1880 size = substitute_placeholder_in_expr (size, init);
1883 /* If the size overflows, pass -1 so the allocator will raise
1885 if (TREE_CODE (size) == INTEGER_CST && TREE_OVERFLOW (size))
1886 size = ssize_int (-1);
1888 /* If this is a type whose alignment is larger than the
1889 biggest we support in normal alignment and this is in
1890 the default storage pool, make an "aligning type", allocate
1891 it, point to the field we need, and return that. */
1892 if (TYPE_ALIGN (type) > BIGGEST_ALIGNMENT
1895 tree new_type = make_aligning_type (type, TYPE_ALIGN (type), size);
1897 result = build_call_alloc_dealloc (NULL_TREE, TYPE_SIZE_UNIT (new_type),
1898 BIGGEST_ALIGNMENT, Empty,
1900 result = save_expr (result);
1901 result = convert (build_pointer_type (new_type), result);
1902 result = build_unary_op (INDIRECT_REF, NULL_TREE, result);
1903 result = build_component_ref (result, NULL_TREE,
1904 TYPE_FIELDS (new_type), 0);
1905 result = convert (result_type,
1906 build_unary_op (ADDR_EXPR, NULL_TREE, result));
1909 result = convert (result_type,
1910 build_call_alloc_dealloc (NULL_TREE, size,
1916 /* If we have an initial value, put the new address into a SAVE_EXPR, assign
1917 the value, and return the address. Do this with a COMPOUND_EXPR. */
1921 result = save_expr (result);
1923 = build (COMPOUND_EXPR, TREE_TYPE (result),
1925 (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (result)),
1926 build_unary_op (INDIRECT_REF, TREE_TYPE (TREE_TYPE (result)),
1932 return convert (result_type, result);
1935 /* Fill in a VMS descriptor for EXPR and return a constructor for it.
1936 GNAT_FORMAL is how we find the descriptor record. */
1939 fill_vms_descriptor (tree expr, Entity_Id gnat_formal)
1941 tree record_type = TREE_TYPE (TREE_TYPE (get_gnu_tree (gnat_formal)));
1943 tree const_list = 0;
1945 expr = maybe_unconstrained_array (expr);
1946 gnat_mark_addressable (expr);
1948 for (field = TYPE_FIELDS (record_type); field; field = TREE_CHAIN (field))
1951 convert (TREE_TYPE (field),
1952 SUBSTITUTE_PLACEHOLDER_IN_EXPR
1953 (DECL_INITIAL (field), expr)),
1956 return gnat_build_constructor (record_type, nreverse (const_list));
1959 /* Indicate that we need to make the address of EXPR_NODE and it therefore
1960 should not be allocated in a register. Returns true if successful. */
1963 gnat_mark_addressable (tree expr_node)
1966 switch (TREE_CODE (expr_node))
1971 case ARRAY_RANGE_REF:
1974 case VIEW_CONVERT_EXPR:
1976 case NON_LVALUE_EXPR:
1979 expr_node = TREE_OPERAND (expr_node, 0);
1983 TREE_ADDRESSABLE (expr_node) = 1;
1989 put_var_into_stack (expr_node, true);
1990 TREE_ADDRESSABLE (expr_node) = 1;
1994 TREE_ADDRESSABLE (expr_node) = 1;
1998 return (DECL_CONST_CORRESPONDING_VAR (expr_node) != 0
1999 && (gnat_mark_addressable
2000 (DECL_CONST_CORRESPONDING_VAR (expr_node))));