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gigi.h (fill_vms_descriptor): Add third parameter gnat_actual
[gcc.git] / gcc / ada / gcc-interface / utils2.c
1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * U T I L S 2 *
6 * *
7 * C Implementation File *
8 * *
9 * Copyright (C) 1992-2008, Free Software Foundation, Inc. *
10 * *
11 * GNAT is free software; you can redistribute it and/or modify it under *
12 * terms of the GNU General Public License as published by the Free Soft- *
13 * ware Foundation; either version 3, or (at your option) any later ver- *
14 * sion. GNAT is distributed in the hope that it will be useful, but WITH- *
15 * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY *
16 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License *
17 * for more details. You should have received a copy of the GNU General *
18 * Public License along with GCC; see the file COPYING3. If not see *
19 * <http://www.gnu.org/licenses/>. *
20 * *
21 * GNAT was originally developed by the GNAT team at New York University. *
22 * Extensive contributions were provided by Ada Core Technologies Inc. *
23 * *
24 ****************************************************************************/
25
26 #include "config.h"
27 #include "system.h"
28 #include "coretypes.h"
29 #include "tm.h"
30 #include "tree.h"
31 #include "rtl.h"
32 #include "ggc.h"
33 #include "flags.h"
34 #include "output.h"
35 #include "ada.h"
36 #include "types.h"
37 #include "atree.h"
38 #include "stringt.h"
39 #include "namet.h"
40 #include "uintp.h"
41 #include "fe.h"
42 #include "elists.h"
43 #include "nlists.h"
44 #include "sinfo.h"
45 #include "einfo.h"
46 #include "ada-tree.h"
47 #include "gigi.h"
48
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);
55 \f
56 /* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical
57 operation.
58
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
62
63 build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
64
65 but we optimize comparisons, &&, ||, and !.
66
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. */
70
71 tree
72 gnat_truthvalue_conversion (tree expr)
73 {
74 tree type = TREE_TYPE (expr);
75
76 switch (TREE_CODE (expr))
77 {
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:
81 case TRUTH_ORIF_EXPR:
82 case TRUTH_AND_EXPR:
83 case TRUTH_OR_EXPR:
84 case TRUTH_XOR_EXPR:
85 case ERROR_MARK:
86 return expr;
87
88 case INTEGER_CST:
89 return (integer_zerop (expr)
90 ? build_int_cst (type, 0)
91 : build_int_cst (type, 1));
92
93 case REAL_CST:
94 return (real_zerop (expr)
95 ? fold_convert (type, integer_zero_node)
96 : fold_convert (type, integer_one_node));
97
98 case COND_EXPR:
99 /* Distribute the conversion into the arms of a COND_EXPR. */
100 {
101 tree arg1 = gnat_truthvalue_conversion (TREE_OPERAND (expr, 1));
102 tree arg2 = gnat_truthvalue_conversion (TREE_OPERAND (expr, 2));
103 return fold_build3 (COND_EXPR, type, TREE_OPERAND (expr, 0),
104 arg1, arg2);
105 }
106
107 default:
108 return build_binary_op (NE_EXPR, type, expr,
109 fold_convert (type, integer_zero_node));
110 }
111 }
112 \f
113 /* Return the base type of TYPE. */
114
115 tree
116 get_base_type (tree type)
117 {
118 if (TREE_CODE (type) == RECORD_TYPE
119 && TYPE_JUSTIFIED_MODULAR_P (type))
120 type = TREE_TYPE (TYPE_FIELDS (type));
121
122 while (TREE_TYPE (type)
123 && (TREE_CODE (type) == INTEGER_TYPE
124 || TREE_CODE (type) == REAL_TYPE))
125 type = TREE_TYPE (type);
126
127 return type;
128 }
129 \f
130 /* EXP is a GCC tree representing an address. See if we can find how
131 strictly the object at that address is aligned. Return that alignment
132 in bits. If we don't know anything about the alignment, return 0. */
133
134 unsigned int
135 known_alignment (tree exp)
136 {
137 unsigned int this_alignment;
138 unsigned int lhs, rhs;
139
140 switch (TREE_CODE (exp))
141 {
142 CASE_CONVERT:
143 case VIEW_CONVERT_EXPR:
144 case NON_LVALUE_EXPR:
145 /* Conversions between pointers and integers don't change the alignment
146 of the underlying object. */
147 this_alignment = known_alignment (TREE_OPERAND (exp, 0));
148 break;
149
150 case COMPOUND_EXPR:
151 /* The value of a COMPOUND_EXPR is that of it's second operand. */
152 this_alignment = known_alignment (TREE_OPERAND (exp, 1));
153 break;
154
155 case PLUS_EXPR:
156 case MINUS_EXPR:
157 /* If two address are added, the alignment of the result is the
158 minimum of the two alignments. */
159 lhs = known_alignment (TREE_OPERAND (exp, 0));
160 rhs = known_alignment (TREE_OPERAND (exp, 1));
161 this_alignment = MIN (lhs, rhs);
162 break;
163
164 case POINTER_PLUS_EXPR:
165 lhs = known_alignment (TREE_OPERAND (exp, 0));
166 rhs = known_alignment (TREE_OPERAND (exp, 1));
167 /* If we don't know the alignment of the offset, we assume that
168 of the base. */
169 if (rhs == 0)
170 this_alignment = lhs;
171 else
172 this_alignment = MIN (lhs, rhs);
173 break;
174
175 case COND_EXPR:
176 /* If there is a choice between two values, use the smallest one. */
177 lhs = known_alignment (TREE_OPERAND (exp, 1));
178 rhs = known_alignment (TREE_OPERAND (exp, 2));
179 this_alignment = MIN (lhs, rhs);
180 break;
181
182 case INTEGER_CST:
183 {
184 unsigned HOST_WIDE_INT c = TREE_INT_CST_LOW (exp);
185 /* The first part of this represents the lowest bit in the constant,
186 but it is originally in bytes, not bits. */
187 this_alignment = MIN (BITS_PER_UNIT * (c & -c), BIGGEST_ALIGNMENT);
188 }
189 break;
190
191 case MULT_EXPR:
192 /* If we know the alignment of just one side, use it. Otherwise,
193 use the product of the alignments. */
194 lhs = known_alignment (TREE_OPERAND (exp, 0));
195 rhs = known_alignment (TREE_OPERAND (exp, 1));
196
197 if (lhs == 0)
198 this_alignment = rhs;
199 else if (rhs == 0)
200 this_alignment = lhs;
201 else
202 this_alignment = MIN (lhs * rhs, BIGGEST_ALIGNMENT);
203 break;
204
205 case BIT_AND_EXPR:
206 /* A bit-and expression is as aligned as the maximum alignment of the
207 operands. We typically get here for a complex lhs and a constant
208 negative power of two on the rhs to force an explicit alignment, so
209 don't bother looking at the lhs. */
210 this_alignment = known_alignment (TREE_OPERAND (exp, 1));
211 break;
212
213 case ADDR_EXPR:
214 this_alignment = expr_align (TREE_OPERAND (exp, 0));
215 break;
216
217 default:
218 /* For other pointer expressions, we assume that the pointed-to object
219 is at least as aligned as the pointed-to type. Beware that we can
220 have a dummy type here (e.g. a Taft Amendment type), for which the
221 alignment is meaningless and should be ignored. */
222 if (POINTER_TYPE_P (TREE_TYPE (exp))
223 && !TYPE_IS_DUMMY_P (TREE_TYPE (TREE_TYPE (exp))))
224 this_alignment = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp)));
225 else
226 this_alignment = 0;
227 break;
228 }
229
230 return this_alignment;
231 }
232 \f
233 /* We have a comparison or assignment operation on two types, T1 and T2, which
234 are either both array types or both record types. T1 is assumed to be for
235 the left hand side operand, and T2 for the right hand side. Return the
236 type that both operands should be converted to for the operation, if any.
237 Otherwise return zero. */
238
239 static tree
240 find_common_type (tree t1, tree t2)
241 {
242 /* ??? As of today, various constructs lead here with types of different
243 sizes even when both constants (e.g. tagged types, packable vs regular
244 component types, padded vs unpadded types, ...). While some of these
245 would better be handled upstream (types should be made consistent before
246 calling into build_binary_op), some others are really expected and we
247 have to be careful. */
248
249 /* We must prevent writing more than what the target may hold if this is for
250 an assignment and the case of tagged types is handled in build_binary_op
251 so use the lhs type if it is known to be smaller, or of constant size and
252 the rhs type is not, whatever the modes. We also force t1 in case of
253 constant size equality to minimize occurrences of view conversions on the
254 lhs of assignments. */
255 if (TREE_CONSTANT (TYPE_SIZE (t1))
256 && (!TREE_CONSTANT (TYPE_SIZE (t2))
257 || !tree_int_cst_lt (TYPE_SIZE (t2), TYPE_SIZE (t1))))
258 return t1;
259
260 /* Otherwise, if the lhs type is non-BLKmode, use it. Note that we know
261 that we will not have any alignment problems since, if we did, the
262 non-BLKmode type could not have been used. */
263 if (TYPE_MODE (t1) != BLKmode)
264 return t1;
265
266 /* If the rhs type is of constant size, use it whatever the modes. At
267 this point it is known to be smaller, or of constant size and the
268 lhs type is not. */
269 if (TREE_CONSTANT (TYPE_SIZE (t2)))
270 return t2;
271
272 /* Otherwise, if the rhs type is non-BLKmode, use it. */
273 if (TYPE_MODE (t2) != BLKmode)
274 return t2;
275
276 /* In this case, both types have variable size and BLKmode. It's
277 probably best to leave the "type mismatch" because changing it
278 could cause a bad self-referential reference. */
279 return NULL_TREE;
280 }
281 \f
282 /* See if EXP contains a SAVE_EXPR in a position where we would
283 normally put it.
284
285 ??? This is a real kludge, but is probably the best approach short
286 of some very general solution. */
287
288 static bool
289 contains_save_expr_p (tree exp)
290 {
291 switch (TREE_CODE (exp))
292 {
293 case SAVE_EXPR:
294 return true;
295
296 case ADDR_EXPR: case INDIRECT_REF:
297 case COMPONENT_REF:
298 CASE_CONVERT: case VIEW_CONVERT_EXPR:
299 return contains_save_expr_p (TREE_OPERAND (exp, 0));
300
301 case CONSTRUCTOR:
302 {
303 tree value;
304 unsigned HOST_WIDE_INT ix;
305
306 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), ix, value)
307 if (contains_save_expr_p (value))
308 return true;
309 return false;
310 }
311
312 default:
313 return false;
314 }
315 }
316 \f
317 /* See if EXP contains a NULL_EXPR in an expression we use for sizes. Return
318 it if so. This is used to detect types whose sizes involve computations
319 that are known to raise Constraint_Error. */
320
321 static tree
322 contains_null_expr (tree exp)
323 {
324 tree tem;
325
326 if (TREE_CODE (exp) == NULL_EXPR)
327 return exp;
328
329 switch (TREE_CODE_CLASS (TREE_CODE (exp)))
330 {
331 case tcc_unary:
332 return contains_null_expr (TREE_OPERAND (exp, 0));
333
334 case tcc_comparison:
335 case tcc_binary:
336 tem = contains_null_expr (TREE_OPERAND (exp, 0));
337 if (tem)
338 return tem;
339
340 return contains_null_expr (TREE_OPERAND (exp, 1));
341
342 case tcc_expression:
343 switch (TREE_CODE (exp))
344 {
345 case SAVE_EXPR:
346 return contains_null_expr (TREE_OPERAND (exp, 0));
347
348 case COND_EXPR:
349 tem = contains_null_expr (TREE_OPERAND (exp, 0));
350 if (tem)
351 return tem;
352
353 tem = contains_null_expr (TREE_OPERAND (exp, 1));
354 if (tem)
355 return tem;
356
357 return contains_null_expr (TREE_OPERAND (exp, 2));
358
359 default:
360 return 0;
361 }
362
363 default:
364 return 0;
365 }
366 }
367 \f
368 /* Return an expression tree representing an equality comparison of
369 A1 and A2, two objects of ARRAY_TYPE. The returned expression should
370 be of type RESULT_TYPE
371
372 Two arrays are equal in one of two ways: (1) if both have zero length
373 in some dimension (not necessarily the same dimension) or (2) if the
374 lengths in each dimension are equal and the data is equal. We perform the
375 length tests in as efficient a manner as possible. */
376
377 static tree
378 compare_arrays (tree result_type, tree a1, tree a2)
379 {
380 tree t1 = TREE_TYPE (a1);
381 tree t2 = TREE_TYPE (a2);
382 tree result = convert (result_type, integer_one_node);
383 tree a1_is_null = convert (result_type, integer_zero_node);
384 tree a2_is_null = convert (result_type, integer_zero_node);
385 bool length_zero_p = false;
386
387 /* Process each dimension separately and compare the lengths. If any
388 dimension has a size known to be zero, set SIZE_ZERO_P to 1 to
389 suppress the comparison of the data. */
390 while (TREE_CODE (t1) == ARRAY_TYPE && TREE_CODE (t2) == ARRAY_TYPE)
391 {
392 tree lb1 = TYPE_MIN_VALUE (TYPE_DOMAIN (t1));
393 tree ub1 = TYPE_MAX_VALUE (TYPE_DOMAIN (t1));
394 tree lb2 = TYPE_MIN_VALUE (TYPE_DOMAIN (t2));
395 tree ub2 = TYPE_MAX_VALUE (TYPE_DOMAIN (t2));
396 tree bt = get_base_type (TREE_TYPE (lb1));
397 tree length1 = fold_build2 (MINUS_EXPR, bt, ub1, lb1);
398 tree length2 = fold_build2 (MINUS_EXPR, bt, ub2, lb2);
399 tree nbt;
400 tree tem;
401 tree comparison, this_a1_is_null, this_a2_is_null;
402
403 /* If the length of the first array is a constant, swap our operands
404 unless the length of the second array is the constant zero.
405 Note that we have set the `length' values to the length - 1. */
406 if (TREE_CODE (length1) == INTEGER_CST
407 && !integer_zerop (fold_build2 (PLUS_EXPR, bt, length2,
408 convert (bt, integer_one_node))))
409 {
410 tem = a1, a1 = a2, a2 = tem;
411 tem = t1, t1 = t2, t2 = tem;
412 tem = lb1, lb1 = lb2, lb2 = tem;
413 tem = ub1, ub1 = ub2, ub2 = tem;
414 tem = length1, length1 = length2, length2 = tem;
415 tem = a1_is_null, a1_is_null = a2_is_null, a2_is_null = tem;
416 }
417
418 /* If the length of this dimension in the second array is the constant
419 zero, we can just go inside the original bounds for the first
420 array and see if last < first. */
421 if (integer_zerop (fold_build2 (PLUS_EXPR, bt, length2,
422 convert (bt, integer_one_node))))
423 {
424 tree ub = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
425 tree lb = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
426
427 comparison = build_binary_op (LT_EXPR, result_type, ub, lb);
428 comparison = SUBSTITUTE_PLACEHOLDER_IN_EXPR (comparison, a1);
429 length1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length1, a1);
430
431 length_zero_p = true;
432 this_a1_is_null = comparison;
433 this_a2_is_null = convert (result_type, integer_one_node);
434 }
435
436 /* If the length is some other constant value, we know that the
437 this dimension in the first array cannot be superflat, so we
438 can just use its length from the actual stored bounds. */
439 else if (TREE_CODE (length2) == INTEGER_CST)
440 {
441 ub1 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
442 lb1 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t1)));
443 ub2 = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t2)));
444 lb2 = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (t2)));
445 nbt = get_base_type (TREE_TYPE (ub1));
446
447 comparison
448 = build_binary_op (EQ_EXPR, result_type,
449 build_binary_op (MINUS_EXPR, nbt, ub1, lb1),
450 build_binary_op (MINUS_EXPR, nbt, ub2, lb2));
451
452 /* Note that we know that UB2 and LB2 are constant and hence
453 cannot contain a PLACEHOLDER_EXPR. */
454
455 comparison = SUBSTITUTE_PLACEHOLDER_IN_EXPR (comparison, a1);
456 length1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length1, a1);
457
458 this_a1_is_null = build_binary_op (LT_EXPR, result_type, ub1, lb1);
459 this_a2_is_null = convert (result_type, integer_zero_node);
460 }
461
462 /* Otherwise compare the computed lengths. */
463 else
464 {
465 length1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length1, a1);
466 length2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (length2, a2);
467
468 comparison
469 = build_binary_op (EQ_EXPR, result_type, length1, length2);
470
471 this_a1_is_null
472 = build_binary_op (LT_EXPR, result_type, length1,
473 convert (bt, integer_zero_node));
474 this_a2_is_null
475 = build_binary_op (LT_EXPR, result_type, length2,
476 convert (bt, integer_zero_node));
477 }
478
479 result = build_binary_op (TRUTH_ANDIF_EXPR, result_type,
480 result, comparison);
481
482 a1_is_null = build_binary_op (TRUTH_ORIF_EXPR, result_type,
483 this_a1_is_null, a1_is_null);
484 a2_is_null = build_binary_op (TRUTH_ORIF_EXPR, result_type,
485 this_a2_is_null, a2_is_null);
486
487 t1 = TREE_TYPE (t1);
488 t2 = TREE_TYPE (t2);
489 }
490
491 /* Unless the size of some bound is known to be zero, compare the
492 data in the array. */
493 if (!length_zero_p)
494 {
495 tree type = find_common_type (TREE_TYPE (a1), TREE_TYPE (a2));
496
497 if (type)
498 a1 = convert (type, a1), a2 = convert (type, a2);
499
500 result = build_binary_op (TRUTH_ANDIF_EXPR, result_type, result,
501 fold_build2 (EQ_EXPR, result_type, a1, a2));
502
503 }
504
505 /* The result is also true if both sizes are zero. */
506 result = build_binary_op (TRUTH_ORIF_EXPR, result_type,
507 build_binary_op (TRUTH_ANDIF_EXPR, result_type,
508 a1_is_null, a2_is_null),
509 result);
510
511 /* If either operand contains SAVE_EXPRs, they have to be evaluated before
512 starting the comparison above since the place it would be otherwise
513 evaluated would be wrong. */
514
515 if (contains_save_expr_p (a1))
516 result = build2 (COMPOUND_EXPR, result_type, a1, result);
517
518 if (contains_save_expr_p (a2))
519 result = build2 (COMPOUND_EXPR, result_type, a2, result);
520
521 return result;
522 }
523 \f
524 /* Compute the result of applying OP_CODE to LHS and RHS, where both are of
525 type TYPE. We know that TYPE is a modular type with a nonbinary
526 modulus. */
527
528 static tree
529 nonbinary_modular_operation (enum tree_code op_code, tree type, tree lhs,
530 tree rhs)
531 {
532 tree modulus = TYPE_MODULUS (type);
533 unsigned int needed_precision = tree_floor_log2 (modulus) + 1;
534 unsigned int precision;
535 bool unsignedp = true;
536 tree op_type = type;
537 tree result;
538
539 /* If this is an addition of a constant, convert it to a subtraction
540 of a constant since we can do that faster. */
541 if (op_code == PLUS_EXPR && TREE_CODE (rhs) == INTEGER_CST)
542 {
543 rhs = fold_build2 (MINUS_EXPR, type, modulus, rhs);
544 op_code = MINUS_EXPR;
545 }
546
547 /* For the logical operations, we only need PRECISION bits. For
548 addition and subtraction, we need one more and for multiplication we
549 need twice as many. But we never want to make a size smaller than
550 our size. */
551 if (op_code == PLUS_EXPR || op_code == MINUS_EXPR)
552 needed_precision += 1;
553 else if (op_code == MULT_EXPR)
554 needed_precision *= 2;
555
556 precision = MAX (needed_precision, TYPE_PRECISION (op_type));
557
558 /* Unsigned will do for everything but subtraction. */
559 if (op_code == MINUS_EXPR)
560 unsignedp = false;
561
562 /* If our type is the wrong signedness or isn't wide enough, make a new
563 type and convert both our operands to it. */
564 if (TYPE_PRECISION (op_type) < precision
565 || TYPE_UNSIGNED (op_type) != unsignedp)
566 {
567 /* Copy the node so we ensure it can be modified to make it modular. */
568 op_type = copy_node (gnat_type_for_size (precision, unsignedp));
569 modulus = convert (op_type, modulus);
570 SET_TYPE_MODULUS (op_type, modulus);
571 TYPE_MODULAR_P (op_type) = 1;
572 lhs = convert (op_type, lhs);
573 rhs = convert (op_type, rhs);
574 }
575
576 /* Do the operation, then we'll fix it up. */
577 result = fold_build2 (op_code, op_type, lhs, rhs);
578
579 /* For multiplication, we have no choice but to do a full modulus
580 operation. However, we want to do this in the narrowest
581 possible size. */
582 if (op_code == MULT_EXPR)
583 {
584 tree div_type = copy_node (gnat_type_for_size (needed_precision, 1));
585 modulus = convert (div_type, modulus);
586 SET_TYPE_MODULUS (div_type, modulus);
587 TYPE_MODULAR_P (div_type) = 1;
588 result = convert (op_type,
589 fold_build2 (TRUNC_MOD_EXPR, div_type,
590 convert (div_type, result), modulus));
591 }
592
593 /* For subtraction, add the modulus back if we are negative. */
594 else if (op_code == MINUS_EXPR)
595 {
596 result = save_expr (result);
597 result = fold_build3 (COND_EXPR, op_type,
598 fold_build2 (LT_EXPR, integer_type_node, result,
599 convert (op_type, integer_zero_node)),
600 fold_build2 (PLUS_EXPR, op_type, result, modulus),
601 result);
602 }
603
604 /* For the other operations, subtract the modulus if we are >= it. */
605 else
606 {
607 result = save_expr (result);
608 result = fold_build3 (COND_EXPR, op_type,
609 fold_build2 (GE_EXPR, integer_type_node,
610 result, modulus),
611 fold_build2 (MINUS_EXPR, op_type,
612 result, modulus),
613 result);
614 }
615
616 return convert (type, result);
617 }
618 \f
619 /* Make a binary operation of kind OP_CODE. RESULT_TYPE is the type
620 desired for the result. Usually the operation is to be performed
621 in that type. For MODIFY_EXPR and ARRAY_REF, RESULT_TYPE may be 0
622 in which case the type to be used will be derived from the operands.
623
624 This function is very much unlike the ones for C and C++ since we
625 have already done any type conversion and matching required. All we
626 have to do here is validate the work done by SEM and handle subtypes. */
627
628 tree
629 build_binary_op (enum tree_code op_code, tree result_type,
630 tree left_operand, tree right_operand)
631 {
632 tree left_type = TREE_TYPE (left_operand);
633 tree right_type = TREE_TYPE (right_operand);
634 tree left_base_type = get_base_type (left_type);
635 tree right_base_type = get_base_type (right_type);
636 tree operation_type = result_type;
637 tree best_type = NULL_TREE;
638 tree modulus, result;
639 bool has_side_effects = false;
640
641 if (operation_type
642 && TREE_CODE (operation_type) == RECORD_TYPE
643 && TYPE_JUSTIFIED_MODULAR_P (operation_type))
644 operation_type = TREE_TYPE (TYPE_FIELDS (operation_type));
645
646 if (operation_type
647 && !AGGREGATE_TYPE_P (operation_type)
648 && TYPE_EXTRA_SUBTYPE_P (operation_type))
649 operation_type = get_base_type (operation_type);
650
651 modulus = (operation_type
652 && TREE_CODE (operation_type) == INTEGER_TYPE
653 && TYPE_MODULAR_P (operation_type)
654 ? TYPE_MODULUS (operation_type) : NULL_TREE);
655
656 switch (op_code)
657 {
658 case MODIFY_EXPR:
659 /* If there were integral or pointer conversions on the LHS, remove
660 them; we'll be putting them back below if needed. Likewise for
661 conversions between array and record types, except for justified
662 modular types. But don't do this if the right operand is not
663 BLKmode (for packed arrays) unless we are not changing the mode. */
664 while ((CONVERT_EXPR_P (left_operand)
665 || TREE_CODE (left_operand) == VIEW_CONVERT_EXPR)
666 && (((INTEGRAL_TYPE_P (left_type)
667 || POINTER_TYPE_P (left_type))
668 && (INTEGRAL_TYPE_P (TREE_TYPE
669 (TREE_OPERAND (left_operand, 0)))
670 || POINTER_TYPE_P (TREE_TYPE
671 (TREE_OPERAND (left_operand, 0)))))
672 || (((TREE_CODE (left_type) == RECORD_TYPE
673 && !TYPE_JUSTIFIED_MODULAR_P (left_type))
674 || TREE_CODE (left_type) == ARRAY_TYPE)
675 && ((TREE_CODE (TREE_TYPE
676 (TREE_OPERAND (left_operand, 0)))
677 == RECORD_TYPE)
678 || (TREE_CODE (TREE_TYPE
679 (TREE_OPERAND (left_operand, 0)))
680 == ARRAY_TYPE))
681 && (TYPE_MODE (right_type) == BLKmode
682 || (TYPE_MODE (left_type)
683 == TYPE_MODE (TREE_TYPE
684 (TREE_OPERAND
685 (left_operand, 0))))))))
686 {
687 left_operand = TREE_OPERAND (left_operand, 0);
688 left_type = TREE_TYPE (left_operand);
689 }
690
691 /* If a class-wide type may be involved, force use of the RHS type. */
692 if ((TREE_CODE (right_type) == RECORD_TYPE
693 || TREE_CODE (right_type) == UNION_TYPE)
694 && TYPE_ALIGN_OK (right_type))
695 operation_type = right_type;
696
697 /* If we are copying between padded objects with compatible types, use
698 the padded view of the objects, this is very likely more efficient.
699 Likewise for a padded that is assigned a constructor, in order to
700 avoid putting a VIEW_CONVERT_EXPR on the LHS. But don't do this if
701 we wouldn't have actually copied anything. */
702 else if (TREE_CODE (left_type) == RECORD_TYPE
703 && TYPE_IS_PADDING_P (left_type)
704 && TREE_CONSTANT (TYPE_SIZE (left_type))
705 && ((TREE_CODE (right_operand) == COMPONENT_REF
706 && TREE_CODE (TREE_TYPE (TREE_OPERAND (right_operand, 0)))
707 == RECORD_TYPE
708 && TYPE_IS_PADDING_P
709 (TREE_TYPE (TREE_OPERAND (right_operand, 0)))
710 && gnat_types_compatible_p
711 (left_type,
712 TREE_TYPE (TREE_OPERAND (right_operand, 0))))
713 || TREE_CODE (right_operand) == CONSTRUCTOR)
714 && !integer_zerop (TYPE_SIZE (right_type)))
715 operation_type = left_type;
716
717 /* Find the best type to use for copying between aggregate types. */
718 else if (((TREE_CODE (left_type) == ARRAY_TYPE
719 && TREE_CODE (right_type) == ARRAY_TYPE)
720 || (TREE_CODE (left_type) == RECORD_TYPE
721 && TREE_CODE (right_type) == RECORD_TYPE))
722 && (best_type = find_common_type (left_type, right_type)))
723 operation_type = best_type;
724
725 /* Otherwise use the LHS type. */
726 else if (!operation_type)
727 operation_type = left_type;
728
729 /* Ensure everything on the LHS is valid. If we have a field reference,
730 strip anything that get_inner_reference can handle. Then remove any
731 conversions between types having the same code and mode. And mark
732 VIEW_CONVERT_EXPRs with TREE_ADDRESSABLE. When done, we must have
733 either an INDIRECT_REF, a NULL_EXPR or a DECL node. */
734 result = left_operand;
735 while (true)
736 {
737 tree restype = TREE_TYPE (result);
738
739 if (TREE_CODE (result) == COMPONENT_REF
740 || TREE_CODE (result) == ARRAY_REF
741 || TREE_CODE (result) == ARRAY_RANGE_REF)
742 while (handled_component_p (result))
743 result = TREE_OPERAND (result, 0);
744 else if (TREE_CODE (result) == REALPART_EXPR
745 || TREE_CODE (result) == IMAGPART_EXPR
746 || (CONVERT_EXPR_P (result)
747 && (((TREE_CODE (restype)
748 == TREE_CODE (TREE_TYPE
749 (TREE_OPERAND (result, 0))))
750 && (TYPE_MODE (TREE_TYPE
751 (TREE_OPERAND (result, 0)))
752 == TYPE_MODE (restype)))
753 || TYPE_ALIGN_OK (restype))))
754 result = TREE_OPERAND (result, 0);
755 else if (TREE_CODE (result) == VIEW_CONVERT_EXPR)
756 {
757 TREE_ADDRESSABLE (result) = 1;
758 result = TREE_OPERAND (result, 0);
759 }
760 else
761 break;
762 }
763
764 gcc_assert (TREE_CODE (result) == INDIRECT_REF
765 || TREE_CODE (result) == NULL_EXPR
766 || DECL_P (result));
767
768 /* Convert the right operand to the operation type unless it is
769 either already of the correct type or if the type involves a
770 placeholder, since the RHS may not have the same record type. */
771 if (operation_type != right_type
772 && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (operation_type)))
773 {
774 right_operand = convert (operation_type, right_operand);
775 right_type = operation_type;
776 }
777
778 /* If the left operand is not of the same type as the operation
779 type, wrap it up in a VIEW_CONVERT_EXPR. */
780 if (left_type != operation_type)
781 left_operand = unchecked_convert (operation_type, left_operand, false);
782
783 has_side_effects = true;
784 modulus = NULL_TREE;
785 break;
786
787 case ARRAY_REF:
788 if (!operation_type)
789 operation_type = TREE_TYPE (left_type);
790
791 /* ... fall through ... */
792
793 case ARRAY_RANGE_REF:
794 /* First look through conversion between type variants. Note that
795 this changes neither the operation type nor the type domain. */
796 if (TREE_CODE (left_operand) == VIEW_CONVERT_EXPR
797 && TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (left_operand, 0)))
798 == TYPE_MAIN_VARIANT (left_type))
799 {
800 left_operand = TREE_OPERAND (left_operand, 0);
801 left_type = TREE_TYPE (left_operand);
802 }
803
804 /* Then convert the right operand to its base type. This will
805 prevent unneeded signedness conversions when sizetype is wider than
806 integer. */
807 right_operand = convert (right_base_type, right_operand);
808 right_operand = convert (TYPE_DOMAIN (left_type), right_operand);
809
810 if (!TREE_CONSTANT (right_operand)
811 || !TREE_CONSTANT (TYPE_MIN_VALUE (right_type)))
812 gnat_mark_addressable (left_operand);
813
814 modulus = NULL_TREE;
815 break;
816
817 case GE_EXPR:
818 case LE_EXPR:
819 case GT_EXPR:
820 case LT_EXPR:
821 gcc_assert (!POINTER_TYPE_P (left_type));
822
823 /* ... fall through ... */
824
825 case EQ_EXPR:
826 case NE_EXPR:
827 /* If either operand is a NULL_EXPR, just return a new one. */
828 if (TREE_CODE (left_operand) == NULL_EXPR)
829 return build2 (op_code, result_type,
830 build1 (NULL_EXPR, integer_type_node,
831 TREE_OPERAND (left_operand, 0)),
832 integer_zero_node);
833
834 else if (TREE_CODE (right_operand) == NULL_EXPR)
835 return build2 (op_code, result_type,
836 build1 (NULL_EXPR, integer_type_node,
837 TREE_OPERAND (right_operand, 0)),
838 integer_zero_node);
839
840 /* If either object is a justified modular types, get the
841 fields from within. */
842 if (TREE_CODE (left_type) == RECORD_TYPE
843 && TYPE_JUSTIFIED_MODULAR_P (left_type))
844 {
845 left_operand = convert (TREE_TYPE (TYPE_FIELDS (left_type)),
846 left_operand);
847 left_type = TREE_TYPE (left_operand);
848 left_base_type = get_base_type (left_type);
849 }
850
851 if (TREE_CODE (right_type) == RECORD_TYPE
852 && TYPE_JUSTIFIED_MODULAR_P (right_type))
853 {
854 right_operand = convert (TREE_TYPE (TYPE_FIELDS (right_type)),
855 right_operand);
856 right_type = TREE_TYPE (right_operand);
857 right_base_type = get_base_type (right_type);
858 }
859
860 /* If both objects are arrays, compare them specially. */
861 if ((TREE_CODE (left_type) == ARRAY_TYPE
862 || (TREE_CODE (left_type) == INTEGER_TYPE
863 && TYPE_HAS_ACTUAL_BOUNDS_P (left_type)))
864 && (TREE_CODE (right_type) == ARRAY_TYPE
865 || (TREE_CODE (right_type) == INTEGER_TYPE
866 && TYPE_HAS_ACTUAL_BOUNDS_P (right_type))))
867 {
868 result = compare_arrays (result_type, left_operand, right_operand);
869
870 if (op_code == NE_EXPR)
871 result = invert_truthvalue (result);
872 else
873 gcc_assert (op_code == EQ_EXPR);
874
875 return result;
876 }
877
878 /* Otherwise, the base types must be the same unless the objects are
879 fat pointers or records. If we have records, use the best type and
880 convert both operands to that type. */
881 if (left_base_type != right_base_type)
882 {
883 if (TYPE_FAT_POINTER_P (left_base_type)
884 && TYPE_FAT_POINTER_P (right_base_type)
885 && TYPE_MAIN_VARIANT (left_base_type)
886 == TYPE_MAIN_VARIANT (right_base_type))
887 best_type = left_base_type;
888 else if (TREE_CODE (left_base_type) == RECORD_TYPE
889 && TREE_CODE (right_base_type) == RECORD_TYPE)
890 {
891 /* The only way these are permitted to be the same is if both
892 types have the same name. In that case, one of them must
893 not be self-referential. Use that one as the best type.
894 Even better is if one is of fixed size. */
895 gcc_assert (TYPE_NAME (left_base_type)
896 && (TYPE_NAME (left_base_type)
897 == TYPE_NAME (right_base_type)));
898
899 if (TREE_CONSTANT (TYPE_SIZE (left_base_type)))
900 best_type = left_base_type;
901 else if (TREE_CONSTANT (TYPE_SIZE (right_base_type)))
902 best_type = right_base_type;
903 else if (!CONTAINS_PLACEHOLDER_P (TYPE_SIZE (left_base_type)))
904 best_type = left_base_type;
905 else if (!CONTAINS_PLACEHOLDER_P (TYPE_SIZE (right_base_type)))
906 best_type = right_base_type;
907 else
908 gcc_unreachable ();
909 }
910 else
911 gcc_unreachable ();
912
913 left_operand = convert (best_type, left_operand);
914 right_operand = convert (best_type, right_operand);
915 }
916
917 /* If we are comparing a fat pointer against zero, we need to
918 just compare the data pointer. */
919 else if (TYPE_FAT_POINTER_P (left_base_type)
920 && TREE_CODE (right_operand) == CONSTRUCTOR
921 && integer_zerop (VEC_index (constructor_elt,
922 CONSTRUCTOR_ELTS (right_operand),
923 0)
924 ->value))
925 {
926 right_operand = build_component_ref (left_operand, NULL_TREE,
927 TYPE_FIELDS (left_base_type),
928 false);
929 left_operand = convert (TREE_TYPE (right_operand),
930 integer_zero_node);
931 }
932 else
933 {
934 left_operand = convert (left_base_type, left_operand);
935 right_operand = convert (right_base_type, right_operand);
936 }
937
938 modulus = NULL_TREE;
939 break;
940
941 case PREINCREMENT_EXPR:
942 case PREDECREMENT_EXPR:
943 case POSTINCREMENT_EXPR:
944 case POSTDECREMENT_EXPR:
945 /* In these, the result type and the left operand type should be the
946 same. Do the operation in the base type of those and convert the
947 right operand (which is an integer) to that type.
948
949 Note that these operations are only used in loop control where
950 we guarantee that no overflow can occur. So nothing special need
951 be done for modular types. */
952
953 gcc_assert (left_type == result_type);
954 operation_type = get_base_type (result_type);
955 left_operand = convert (operation_type, left_operand);
956 right_operand = convert (operation_type, right_operand);
957 has_side_effects = true;
958 modulus = NULL_TREE;
959 break;
960
961 case LSHIFT_EXPR:
962 case RSHIFT_EXPR:
963 case LROTATE_EXPR:
964 case RROTATE_EXPR:
965 /* The RHS of a shift can be any type. Also, ignore any modulus
966 (we used to abort, but this is needed for unchecked conversion
967 to modular types). Otherwise, processing is the same as normal. */
968 gcc_assert (operation_type == left_base_type);
969 modulus = NULL_TREE;
970 left_operand = convert (operation_type, left_operand);
971 break;
972
973 case TRUTH_ANDIF_EXPR:
974 case TRUTH_ORIF_EXPR:
975 case TRUTH_AND_EXPR:
976 case TRUTH_OR_EXPR:
977 case TRUTH_XOR_EXPR:
978 left_operand = gnat_truthvalue_conversion (left_operand);
979 right_operand = gnat_truthvalue_conversion (right_operand);
980 goto common;
981
982 case BIT_AND_EXPR:
983 case BIT_IOR_EXPR:
984 case BIT_XOR_EXPR:
985 /* For binary modulus, if the inputs are in range, so are the
986 outputs. */
987 if (modulus && integer_pow2p (modulus))
988 modulus = NULL_TREE;
989 goto common;
990
991 case COMPLEX_EXPR:
992 gcc_assert (TREE_TYPE (result_type) == left_base_type
993 && TREE_TYPE (result_type) == right_base_type);
994 left_operand = convert (left_base_type, left_operand);
995 right_operand = convert (right_base_type, right_operand);
996 break;
997
998 case TRUNC_DIV_EXPR: case TRUNC_MOD_EXPR:
999 case CEIL_DIV_EXPR: case CEIL_MOD_EXPR:
1000 case FLOOR_DIV_EXPR: case FLOOR_MOD_EXPR:
1001 case ROUND_DIV_EXPR: case ROUND_MOD_EXPR:
1002 /* These always produce results lower than either operand. */
1003 modulus = NULL_TREE;
1004 goto common;
1005
1006 case POINTER_PLUS_EXPR:
1007 gcc_assert (operation_type == left_base_type
1008 && sizetype == right_base_type);
1009 left_operand = convert (operation_type, left_operand);
1010 right_operand = convert (sizetype, right_operand);
1011 break;
1012
1013 case PLUS_EXPR:
1014 case MINUS_EXPR:
1015 /* Avoid doing arithmetics in BOOLEAN_TYPE like the other compilers.
1016 Contrary to C, Ada doesn't allow arithmetics in Standard.Boolean
1017 but we can generate addition or subtraction for 'Succ and 'Pred. */
1018 if (operation_type && TREE_CODE (operation_type) == BOOLEAN_TYPE)
1019 operation_type = left_base_type = right_base_type = integer_type_node;
1020 goto common;
1021
1022 default:
1023 common:
1024 /* The result type should be the same as the base types of the
1025 both operands (and they should be the same). Convert
1026 everything to the result type. */
1027
1028 gcc_assert (operation_type == left_base_type
1029 && left_base_type == right_base_type);
1030 left_operand = convert (operation_type, left_operand);
1031 right_operand = convert (operation_type, right_operand);
1032 }
1033
1034 if (modulus && !integer_pow2p (modulus))
1035 {
1036 result = nonbinary_modular_operation (op_code, operation_type,
1037 left_operand, right_operand);
1038 modulus = NULL_TREE;
1039 }
1040 /* If either operand is a NULL_EXPR, just return a new one. */
1041 else if (TREE_CODE (left_operand) == NULL_EXPR)
1042 return build1 (NULL_EXPR, operation_type, TREE_OPERAND (left_operand, 0));
1043 else if (TREE_CODE (right_operand) == NULL_EXPR)
1044 return build1 (NULL_EXPR, operation_type, TREE_OPERAND (right_operand, 0));
1045 else if (op_code == ARRAY_REF || op_code == ARRAY_RANGE_REF)
1046 result = fold (build4 (op_code, operation_type, left_operand,
1047 right_operand, NULL_TREE, NULL_TREE));
1048 else
1049 result
1050 = fold_build2 (op_code, operation_type, left_operand, right_operand);
1051
1052 TREE_SIDE_EFFECTS (result) |= has_side_effects;
1053 TREE_CONSTANT (result)
1054 |= (TREE_CONSTANT (left_operand) & TREE_CONSTANT (right_operand)
1055 && op_code != ARRAY_REF && op_code != ARRAY_RANGE_REF);
1056
1057 if ((op_code == ARRAY_REF || op_code == ARRAY_RANGE_REF)
1058 && TYPE_VOLATILE (operation_type))
1059 TREE_THIS_VOLATILE (result) = 1;
1060
1061 /* If we are working with modular types, perform the MOD operation
1062 if something above hasn't eliminated the need for it. */
1063 if (modulus)
1064 result = fold_build2 (FLOOR_MOD_EXPR, operation_type, result,
1065 convert (operation_type, modulus));
1066
1067 if (result_type && result_type != operation_type)
1068 result = convert (result_type, result);
1069
1070 return result;
1071 }
1072 \f
1073 /* Similar, but for unary operations. */
1074
1075 tree
1076 build_unary_op (enum tree_code op_code, tree result_type, tree operand)
1077 {
1078 tree type = TREE_TYPE (operand);
1079 tree base_type = get_base_type (type);
1080 tree operation_type = result_type;
1081 tree result;
1082 bool side_effects = false;
1083
1084 if (operation_type
1085 && TREE_CODE (operation_type) == RECORD_TYPE
1086 && TYPE_JUSTIFIED_MODULAR_P (operation_type))
1087 operation_type = TREE_TYPE (TYPE_FIELDS (operation_type));
1088
1089 if (operation_type
1090 && !AGGREGATE_TYPE_P (operation_type)
1091 && TYPE_EXTRA_SUBTYPE_P (operation_type))
1092 operation_type = get_base_type (operation_type);
1093
1094 switch (op_code)
1095 {
1096 case REALPART_EXPR:
1097 case IMAGPART_EXPR:
1098 if (!operation_type)
1099 result_type = operation_type = TREE_TYPE (type);
1100 else
1101 gcc_assert (result_type == TREE_TYPE (type));
1102
1103 result = fold_build1 (op_code, operation_type, operand);
1104 break;
1105
1106 case TRUTH_NOT_EXPR:
1107 gcc_assert (result_type == base_type);
1108 result = invert_truthvalue (gnat_truthvalue_conversion (operand));
1109 break;
1110
1111 case ATTR_ADDR_EXPR:
1112 case ADDR_EXPR:
1113 switch (TREE_CODE (operand))
1114 {
1115 case INDIRECT_REF:
1116 case UNCONSTRAINED_ARRAY_REF:
1117 result = TREE_OPERAND (operand, 0);
1118
1119 /* Make sure the type here is a pointer, not a reference.
1120 GCC wants pointer types for function addresses. */
1121 if (!result_type)
1122 result_type = build_pointer_type (type);
1123
1124 /* If the underlying object can alias everything, propagate the
1125 property since we are effectively retrieving the object. */
1126 if (POINTER_TYPE_P (TREE_TYPE (result))
1127 && TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (result)))
1128 {
1129 if (TREE_CODE (result_type) == POINTER_TYPE
1130 && !TYPE_REF_CAN_ALIAS_ALL (result_type))
1131 result_type
1132 = build_pointer_type_for_mode (TREE_TYPE (result_type),
1133 TYPE_MODE (result_type),
1134 true);
1135 else if (TREE_CODE (result_type) == REFERENCE_TYPE
1136 && !TYPE_REF_CAN_ALIAS_ALL (result_type))
1137 result_type
1138 = build_reference_type_for_mode (TREE_TYPE (result_type),
1139 TYPE_MODE (result_type),
1140 true);
1141 }
1142 break;
1143
1144 case NULL_EXPR:
1145 result = operand;
1146 TREE_TYPE (result) = type = build_pointer_type (type);
1147 break;
1148
1149 case ARRAY_REF:
1150 case ARRAY_RANGE_REF:
1151 case COMPONENT_REF:
1152 case BIT_FIELD_REF:
1153 /* If this is for 'Address, find the address of the prefix and
1154 add the offset to the field. Otherwise, do this the normal
1155 way. */
1156 if (op_code == ATTR_ADDR_EXPR)
1157 {
1158 HOST_WIDE_INT bitsize;
1159 HOST_WIDE_INT bitpos;
1160 tree offset, inner;
1161 enum machine_mode mode;
1162 int unsignedp, volatilep;
1163
1164 inner = get_inner_reference (operand, &bitsize, &bitpos, &offset,
1165 &mode, &unsignedp, &volatilep,
1166 false);
1167
1168 /* If INNER is a padding type whose field has a self-referential
1169 size, convert to that inner type. We know the offset is zero
1170 and we need to have that type visible. */
1171 if (TREE_CODE (TREE_TYPE (inner)) == RECORD_TYPE
1172 && TYPE_IS_PADDING_P (TREE_TYPE (inner))
1173 && (CONTAINS_PLACEHOLDER_P
1174 (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS
1175 (TREE_TYPE (inner)))))))
1176 inner = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (inner))),
1177 inner);
1178
1179 /* Compute the offset as a byte offset from INNER. */
1180 if (!offset)
1181 offset = size_zero_node;
1182
1183 if (bitpos % BITS_PER_UNIT != 0)
1184 post_error
1185 ("taking address of object not aligned on storage unit?",
1186 error_gnat_node);
1187
1188 offset = size_binop (PLUS_EXPR, offset,
1189 size_int (bitpos / BITS_PER_UNIT));
1190
1191 /* Take the address of INNER, convert the offset to void *, and
1192 add then. It will later be converted to the desired result
1193 type, if any. */
1194 inner = build_unary_op (ADDR_EXPR, NULL_TREE, inner);
1195 inner = convert (ptr_void_type_node, inner);
1196 result = build_binary_op (POINTER_PLUS_EXPR, ptr_void_type_node,
1197 inner, offset);
1198 result = convert (build_pointer_type (TREE_TYPE (operand)),
1199 result);
1200 break;
1201 }
1202 goto common;
1203
1204 case CONSTRUCTOR:
1205 /* If this is just a constructor for a padded record, we can
1206 just take the address of the single field and convert it to
1207 a pointer to our type. */
1208 if (TREE_CODE (type) == RECORD_TYPE && TYPE_IS_PADDING_P (type))
1209 {
1210 result = (VEC_index (constructor_elt,
1211 CONSTRUCTOR_ELTS (operand),
1212 0)
1213 ->value);
1214
1215 result = convert (build_pointer_type (TREE_TYPE (operand)),
1216 build_unary_op (ADDR_EXPR, NULL_TREE, result));
1217 break;
1218 }
1219
1220 goto common;
1221
1222 case NOP_EXPR:
1223 if (AGGREGATE_TYPE_P (type)
1224 && AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (operand, 0))))
1225 return build_unary_op (ADDR_EXPR, result_type,
1226 TREE_OPERAND (operand, 0));
1227
1228 /* ... fallthru ... */
1229
1230 case VIEW_CONVERT_EXPR:
1231 /* If this just a variant conversion or if the conversion doesn't
1232 change the mode, get the result type from this type and go down.
1233 This is needed for conversions of CONST_DECLs, to eventually get
1234 to the address of their CORRESPONDING_VARs. */
1235 if ((TYPE_MAIN_VARIANT (type)
1236 == TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (operand, 0))))
1237 || (TYPE_MODE (type) != BLKmode
1238 && (TYPE_MODE (type)
1239 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (operand, 0))))))
1240 return build_unary_op (ADDR_EXPR,
1241 (result_type ? result_type
1242 : build_pointer_type (type)),
1243 TREE_OPERAND (operand, 0));
1244 goto common;
1245
1246 case CONST_DECL:
1247 operand = DECL_CONST_CORRESPONDING_VAR (operand);
1248
1249 /* ... fall through ... */
1250
1251 default:
1252 common:
1253
1254 /* If we are taking the address of a padded record whose field is
1255 contains a template, take the address of the template. */
1256 if (TREE_CODE (type) == RECORD_TYPE
1257 && TYPE_IS_PADDING_P (type)
1258 && TREE_CODE (TREE_TYPE (TYPE_FIELDS (type))) == RECORD_TYPE
1259 && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (TYPE_FIELDS (type))))
1260 {
1261 type = TREE_TYPE (TYPE_FIELDS (type));
1262 operand = convert (type, operand);
1263 }
1264
1265 if (type != error_mark_node)
1266 operation_type = build_pointer_type (type);
1267
1268 gnat_mark_addressable (operand);
1269 result = fold_build1 (ADDR_EXPR, operation_type, operand);
1270 }
1271
1272 TREE_CONSTANT (result) = staticp (operand) || TREE_CONSTANT (operand);
1273 break;
1274
1275 case INDIRECT_REF:
1276 /* If we want to refer to an entire unconstrained array,
1277 make up an expression to do so. This will never survive to
1278 the backend. If TYPE is a thin pointer, first convert the
1279 operand to a fat pointer. */
1280 if (TYPE_THIN_POINTER_P (type)
1281 && TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type)))
1282 {
1283 operand
1284 = convert (TREE_TYPE (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type))),
1285 operand);
1286 type = TREE_TYPE (operand);
1287 }
1288
1289 if (TYPE_FAT_POINTER_P (type))
1290 {
1291 result = build1 (UNCONSTRAINED_ARRAY_REF,
1292 TYPE_UNCONSTRAINED_ARRAY (type), operand);
1293 TREE_READONLY (result) = TREE_STATIC (result)
1294 = TYPE_READONLY (TYPE_UNCONSTRAINED_ARRAY (type));
1295 }
1296 else if (TREE_CODE (operand) == ADDR_EXPR)
1297 result = TREE_OPERAND (operand, 0);
1298
1299 else
1300 {
1301 result = fold_build1 (op_code, TREE_TYPE (type), operand);
1302 TREE_READONLY (result) = TYPE_READONLY (TREE_TYPE (type));
1303 }
1304
1305 side_effects
1306 = (!TYPE_FAT_POINTER_P (type) && TYPE_VOLATILE (TREE_TYPE (type)));
1307 break;
1308
1309 case NEGATE_EXPR:
1310 case BIT_NOT_EXPR:
1311 {
1312 tree modulus = ((operation_type
1313 && TREE_CODE (operation_type) == INTEGER_TYPE
1314 && TYPE_MODULAR_P (operation_type))
1315 ? TYPE_MODULUS (operation_type) : NULL_TREE);
1316 int mod_pow2 = modulus && integer_pow2p (modulus);
1317
1318 /* If this is a modular type, there are various possibilities
1319 depending on the operation and whether the modulus is a
1320 power of two or not. */
1321
1322 if (modulus)
1323 {
1324 gcc_assert (operation_type == base_type);
1325 operand = convert (operation_type, operand);
1326
1327 /* The fastest in the negate case for binary modulus is
1328 the straightforward code; the TRUNC_MOD_EXPR below
1329 is an AND operation. */
1330 if (op_code == NEGATE_EXPR && mod_pow2)
1331 result = fold_build2 (TRUNC_MOD_EXPR, operation_type,
1332 fold_build1 (NEGATE_EXPR, operation_type,
1333 operand),
1334 modulus);
1335
1336 /* For nonbinary negate case, return zero for zero operand,
1337 else return the modulus minus the operand. If the modulus
1338 is a power of two minus one, we can do the subtraction
1339 as an XOR since it is equivalent and faster on most machines. */
1340 else if (op_code == NEGATE_EXPR && !mod_pow2)
1341 {
1342 if (integer_pow2p (fold_build2 (PLUS_EXPR, operation_type,
1343 modulus,
1344 convert (operation_type,
1345 integer_one_node))))
1346 result = fold_build2 (BIT_XOR_EXPR, operation_type,
1347 operand, modulus);
1348 else
1349 result = fold_build2 (MINUS_EXPR, operation_type,
1350 modulus, operand);
1351
1352 result = fold_build3 (COND_EXPR, operation_type,
1353 fold_build2 (NE_EXPR,
1354 integer_type_node,
1355 operand,
1356 convert
1357 (operation_type,
1358 integer_zero_node)),
1359 result, operand);
1360 }
1361 else
1362 {
1363 /* For the NOT cases, we need a constant equal to
1364 the modulus minus one. For a binary modulus, we
1365 XOR against the constant and subtract the operand from
1366 that constant for nonbinary modulus. */
1367
1368 tree cnst = fold_build2 (MINUS_EXPR, operation_type, modulus,
1369 convert (operation_type,
1370 integer_one_node));
1371
1372 if (mod_pow2)
1373 result = fold_build2 (BIT_XOR_EXPR, operation_type,
1374 operand, cnst);
1375 else
1376 result = fold_build2 (MINUS_EXPR, operation_type,
1377 cnst, operand);
1378 }
1379
1380 break;
1381 }
1382 }
1383
1384 /* ... fall through ... */
1385
1386 default:
1387 gcc_assert (operation_type == base_type);
1388 result = fold_build1 (op_code, operation_type,
1389 convert (operation_type, operand));
1390 }
1391
1392 if (side_effects)
1393 {
1394 TREE_SIDE_EFFECTS (result) = 1;
1395 if (TREE_CODE (result) == INDIRECT_REF)
1396 TREE_THIS_VOLATILE (result) = TYPE_VOLATILE (TREE_TYPE (result));
1397 }
1398
1399 if (result_type && TREE_TYPE (result) != result_type)
1400 result = convert (result_type, result);
1401
1402 return result;
1403 }
1404 \f
1405 /* Similar, but for COND_EXPR. */
1406
1407 tree
1408 build_cond_expr (tree result_type, tree condition_operand,
1409 tree true_operand, tree false_operand)
1410 {
1411 tree result;
1412 bool addr_p = false;
1413
1414 /* The front-end verifies that result, true and false operands have same base
1415 type. Convert everything to the result type. */
1416
1417 true_operand = convert (result_type, true_operand);
1418 false_operand = convert (result_type, false_operand);
1419
1420 /* If the result type is unconstrained, take the address of
1421 the operands and then dereference our result. */
1422 if (TREE_CODE (result_type) == UNCONSTRAINED_ARRAY_TYPE
1423 || CONTAINS_PLACEHOLDER_P (TYPE_SIZE (result_type)))
1424 {
1425 addr_p = true;
1426 result_type = build_pointer_type (result_type);
1427 true_operand = build_unary_op (ADDR_EXPR, result_type, true_operand);
1428 false_operand = build_unary_op (ADDR_EXPR, result_type, false_operand);
1429 }
1430
1431 result = fold_build3 (COND_EXPR, result_type, condition_operand,
1432 true_operand, false_operand);
1433
1434 /* If either operand is a SAVE_EXPR (possibly surrounded by
1435 arithmetic, make sure it gets done. */
1436 true_operand = skip_simple_arithmetic (true_operand);
1437 false_operand = skip_simple_arithmetic (false_operand);
1438
1439 if (TREE_CODE (true_operand) == SAVE_EXPR)
1440 result = build2 (COMPOUND_EXPR, result_type, true_operand, result);
1441
1442 if (TREE_CODE (false_operand) == SAVE_EXPR)
1443 result = build2 (COMPOUND_EXPR, result_type, false_operand, result);
1444
1445 /* ??? Seems the code above is wrong, as it may move ahead of the COND
1446 SAVE_EXPRs with side effects and not shared by both arms. */
1447
1448 if (addr_p)
1449 result = build_unary_op (INDIRECT_REF, NULL_TREE, result);
1450
1451 return result;
1452 }
1453
1454 /* Similar, but for RETURN_EXPR. If RESULT_DECL is non-zero, build
1455 a RETURN_EXPR around the assignment of RET_VAL to RESULT_DECL.
1456 If RESULT_DECL is zero, build a bare RETURN_EXPR. */
1457
1458 tree
1459 build_return_expr (tree result_decl, tree ret_val)
1460 {
1461 tree result_expr;
1462
1463 if (result_decl)
1464 {
1465 /* The gimplifier explicitly enforces the following invariant:
1466
1467 RETURN_EXPR
1468 |
1469 MODIFY_EXPR
1470 / \
1471 / \
1472 RESULT_DECL ...
1473
1474 As a consequence, type-homogeneity dictates that we use the type
1475 of the RESULT_DECL as the operation type. */
1476
1477 tree operation_type = TREE_TYPE (result_decl);
1478
1479 /* Convert the right operand to the operation type. Note that
1480 it's the same transformation as in the MODIFY_EXPR case of
1481 build_binary_op with the additional guarantee that the type
1482 cannot involve a placeholder, since otherwise the function
1483 would use the "target pointer" return mechanism. */
1484
1485 if (operation_type != TREE_TYPE (ret_val))
1486 ret_val = convert (operation_type, ret_val);
1487
1488 result_expr
1489 = build2 (MODIFY_EXPR, operation_type, result_decl, ret_val);
1490 }
1491 else
1492 result_expr = NULL_TREE;
1493
1494 return build1 (RETURN_EXPR, void_type_node, result_expr);
1495 }
1496 \f
1497 /* Build a CALL_EXPR to call FUNDECL with one argument, ARG. Return
1498 the CALL_EXPR. */
1499
1500 tree
1501 build_call_1_expr (tree fundecl, tree arg)
1502 {
1503 tree call = build_call_nary (TREE_TYPE (TREE_TYPE (fundecl)),
1504 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1505 1, arg);
1506 TREE_SIDE_EFFECTS (call) = 1;
1507 return call;
1508 }
1509
1510 /* Build a CALL_EXPR to call FUNDECL with two arguments, ARG1 & ARG2. Return
1511 the CALL_EXPR. */
1512
1513 tree
1514 build_call_2_expr (tree fundecl, tree arg1, tree arg2)
1515 {
1516 tree call = build_call_nary (TREE_TYPE (TREE_TYPE (fundecl)),
1517 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1518 2, arg1, arg2);
1519 TREE_SIDE_EFFECTS (call) = 1;
1520 return call;
1521 }
1522
1523 /* Likewise to call FUNDECL with no arguments. */
1524
1525 tree
1526 build_call_0_expr (tree fundecl)
1527 {
1528 /* We rely on build_call_nary to compute TREE_SIDE_EFFECTS. This makes
1529 it possible to propagate DECL_IS_PURE on parameterless functions. */
1530 tree call = build_call_nary (TREE_TYPE (TREE_TYPE (fundecl)),
1531 build_unary_op (ADDR_EXPR, NULL_TREE, fundecl),
1532 0);
1533 return call;
1534 }
1535 \f
1536 /* Call a function that raises an exception and pass the line number and file
1537 name, if requested. MSG says which exception function to call.
1538
1539 GNAT_NODE is the gnat node conveying the source location for which the
1540 error should be signaled, or Empty in which case the error is signaled on
1541 the current ref_file_name/input_line.
1542
1543 KIND says which kind of exception this is for
1544 (N_Raise_{Constraint,Storage,Program}_Error). */
1545
1546 tree
1547 build_call_raise (int msg, Node_Id gnat_node, char kind)
1548 {
1549 tree fndecl = gnat_raise_decls[msg];
1550 tree label = get_exception_label (kind);
1551 tree filename;
1552 int line_number;
1553 const char *str;
1554 int len;
1555
1556 /* If this is to be done as a goto, handle that case. */
1557 if (label)
1558 {
1559 Entity_Id local_raise = Get_Local_Raise_Call_Entity ();
1560 tree gnu_result = build1 (GOTO_EXPR, void_type_node, label);
1561
1562 /* If Local_Raise is present, generate
1563 Local_Raise (exception'Identity); */
1564 if (Present (local_raise))
1565 {
1566 tree gnu_local_raise
1567 = gnat_to_gnu_entity (local_raise, NULL_TREE, 0);
1568 tree gnu_exception_entity
1569 = gnat_to_gnu_entity (Get_RT_Exception_Entity (msg), NULL_TREE, 0);
1570 tree gnu_call
1571 = build_call_1_expr (gnu_local_raise,
1572 build_unary_op (ADDR_EXPR, NULL_TREE,
1573 gnu_exception_entity));
1574
1575 gnu_result = build2 (COMPOUND_EXPR, void_type_node,
1576 gnu_call, gnu_result);}
1577
1578 return gnu_result;
1579 }
1580
1581 str
1582 = (Debug_Flag_NN || Exception_Locations_Suppressed)
1583 ? ""
1584 : (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1585 ? IDENTIFIER_POINTER
1586 (get_identifier (Get_Name_String
1587 (Debug_Source_Name
1588 (Get_Source_File_Index (Sloc (gnat_node))))))
1589 : ref_filename;
1590
1591 len = strlen (str) + 1;
1592 filename = build_string (len, str);
1593 line_number
1594 = (gnat_node != Empty && Sloc (gnat_node) != No_Location)
1595 ? Get_Logical_Line_Number (Sloc(gnat_node)) : input_line;
1596
1597 TREE_TYPE (filename)
1598 = build_array_type (char_type_node,
1599 build_index_type (build_int_cst (NULL_TREE, len)));
1600
1601 return
1602 build_call_2_expr (fndecl,
1603 build1 (ADDR_EXPR, build_pointer_type (char_type_node),
1604 filename),
1605 build_int_cst (NULL_TREE, line_number));
1606 }
1607 \f
1608 /* qsort comparer for the bit positions of two constructor elements
1609 for record components. */
1610
1611 static int
1612 compare_elmt_bitpos (const PTR rt1, const PTR rt2)
1613 {
1614 const_tree const elmt1 = * (const_tree const *) rt1;
1615 const_tree const elmt2 = * (const_tree const *) rt2;
1616 const_tree const field1 = TREE_PURPOSE (elmt1);
1617 const_tree const field2 = TREE_PURPOSE (elmt2);
1618 const int ret
1619 = tree_int_cst_compare (bit_position (field1), bit_position (field2));
1620
1621 return ret ? ret : (int) (DECL_UID (field1) - DECL_UID (field2));
1622 }
1623
1624 /* Return a CONSTRUCTOR of TYPE whose list is LIST. */
1625
1626 tree
1627 gnat_build_constructor (tree type, tree list)
1628 {
1629 tree elmt;
1630 int n_elmts;
1631 bool allconstant = (TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST);
1632 bool side_effects = false;
1633 tree result;
1634
1635 /* Scan the elements to see if they are all constant or if any has side
1636 effects, to let us set global flags on the resulting constructor. Count
1637 the elements along the way for possible sorting purposes below. */
1638 for (n_elmts = 0, elmt = list; elmt; elmt = TREE_CHAIN (elmt), n_elmts ++)
1639 {
1640 if (!TREE_CONSTANT (TREE_VALUE (elmt))
1641 || (TREE_CODE (type) == RECORD_TYPE
1642 && DECL_BIT_FIELD (TREE_PURPOSE (elmt))
1643 && TREE_CODE (TREE_VALUE (elmt)) != INTEGER_CST)
1644 || !initializer_constant_valid_p (TREE_VALUE (elmt),
1645 TREE_TYPE (TREE_VALUE (elmt))))
1646 allconstant = false;
1647
1648 if (TREE_SIDE_EFFECTS (TREE_VALUE (elmt)))
1649 side_effects = true;
1650
1651 /* Propagate an NULL_EXPR from the size of the type. We won't ever
1652 be executing the code we generate here in that case, but handle it
1653 specially to avoid the compiler blowing up. */
1654 if (TREE_CODE (type) == RECORD_TYPE
1655 && (0 != (result
1656 = contains_null_expr (DECL_SIZE (TREE_PURPOSE (elmt))))))
1657 return build1 (NULL_EXPR, type, TREE_OPERAND (result, 0));
1658 }
1659
1660 /* For record types with constant components only, sort field list
1661 by increasing bit position. This is necessary to ensure the
1662 constructor can be output as static data. */
1663 if (allconstant && TREE_CODE (type) == RECORD_TYPE && n_elmts > 1)
1664 {
1665 /* Fill an array with an element tree per index, and ask qsort to order
1666 them according to what a bitpos comparison function says. */
1667 tree *gnu_arr = (tree *) alloca (sizeof (tree) * n_elmts);
1668 int i;
1669
1670 for (i = 0, elmt = list; elmt; elmt = TREE_CHAIN (elmt), i++)
1671 gnu_arr[i] = elmt;
1672
1673 qsort (gnu_arr, n_elmts, sizeof (tree), compare_elmt_bitpos);
1674
1675 /* Then reconstruct the list from the sorted array contents. */
1676 list = NULL_TREE;
1677 for (i = n_elmts - 1; i >= 0; i--)
1678 {
1679 TREE_CHAIN (gnu_arr[i]) = list;
1680 list = gnu_arr[i];
1681 }
1682 }
1683
1684 result = build_constructor_from_list (type, list);
1685 TREE_CONSTANT (result) = TREE_STATIC (result) = allconstant;
1686 TREE_SIDE_EFFECTS (result) = side_effects;
1687 TREE_READONLY (result) = TYPE_READONLY (type) || allconstant;
1688 return result;
1689 }
1690 \f
1691 /* Return a COMPONENT_REF to access a field that is given by COMPONENT,
1692 an IDENTIFIER_NODE giving the name of the field, or FIELD, a FIELD_DECL,
1693 for the field. Don't fold the result if NO_FOLD_P is true.
1694
1695 We also handle the fact that we might have been passed a pointer to the
1696 actual record and know how to look for fields in variant parts. */
1697
1698 static tree
1699 build_simple_component_ref (tree record_variable, tree component,
1700 tree field, bool no_fold_p)
1701 {
1702 tree record_type = TYPE_MAIN_VARIANT (TREE_TYPE (record_variable));
1703 tree ref, inner_variable;
1704
1705 gcc_assert ((TREE_CODE (record_type) == RECORD_TYPE
1706 || TREE_CODE (record_type) == UNION_TYPE
1707 || TREE_CODE (record_type) == QUAL_UNION_TYPE)
1708 && TYPE_SIZE (record_type)
1709 && (component != 0) != (field != 0));
1710
1711 /* If no field was specified, look for a field with the specified name
1712 in the current record only. */
1713 if (!field)
1714 for (field = TYPE_FIELDS (record_type); field;
1715 field = TREE_CHAIN (field))
1716 if (DECL_NAME (field) == component)
1717 break;
1718
1719 if (!field)
1720 return NULL_TREE;
1721
1722 /* If this field is not in the specified record, see if we can find
1723 something in the record whose original field is the same as this one. */
1724 if (DECL_CONTEXT (field) != record_type)
1725 /* Check if there is a field with name COMPONENT in the record. */
1726 {
1727 tree new_field;
1728
1729 /* First loop thru normal components. */
1730
1731 for (new_field = TYPE_FIELDS (record_type); new_field;
1732 new_field = TREE_CHAIN (new_field))
1733 if (field == new_field
1734 || DECL_ORIGINAL_FIELD (new_field) == field
1735 || new_field == DECL_ORIGINAL_FIELD (field)
1736 || (DECL_ORIGINAL_FIELD (field)
1737 && (DECL_ORIGINAL_FIELD (field)
1738 == DECL_ORIGINAL_FIELD (new_field))))
1739 break;
1740
1741 /* Next, loop thru DECL_INTERNAL_P components if we haven't found
1742 the component in the first search. Doing this search in 2 steps
1743 is required to avoiding hidden homonymous fields in the
1744 _Parent field. */
1745
1746 if (!new_field)
1747 for (new_field = TYPE_FIELDS (record_type); new_field;
1748 new_field = TREE_CHAIN (new_field))
1749 if (DECL_INTERNAL_P (new_field))
1750 {
1751 tree field_ref
1752 = build_simple_component_ref (record_variable,
1753 NULL_TREE, new_field, no_fold_p);
1754 ref = build_simple_component_ref (field_ref, NULL_TREE, field,
1755 no_fold_p);
1756
1757 if (ref)
1758 return ref;
1759 }
1760
1761 field = new_field;
1762 }
1763
1764 if (!field)
1765 return NULL_TREE;
1766
1767 /* If the field's offset has overflowed, do not attempt to access it
1768 as doing so may trigger sanity checks deeper in the back-end.
1769 Note that we don't need to warn since this will be done on trying
1770 to declare the object. */
1771 if (TREE_CODE (DECL_FIELD_OFFSET (field)) == INTEGER_CST
1772 && TREE_OVERFLOW (DECL_FIELD_OFFSET (field)))
1773 return NULL_TREE;
1774
1775 /* Look through conversion between type variants. Note that this
1776 is transparent as far as the field is concerned. */
1777 if (TREE_CODE (record_variable) == VIEW_CONVERT_EXPR
1778 && TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (record_variable, 0)))
1779 == record_type)
1780 inner_variable = TREE_OPERAND (record_variable, 0);
1781 else
1782 inner_variable = record_variable;
1783
1784 ref = build3 (COMPONENT_REF, TREE_TYPE (field), inner_variable, field,
1785 NULL_TREE);
1786
1787 if (TREE_READONLY (record_variable) || TREE_READONLY (field))
1788 TREE_READONLY (ref) = 1;
1789 if (TREE_THIS_VOLATILE (record_variable) || TREE_THIS_VOLATILE (field)
1790 || TYPE_VOLATILE (record_type))
1791 TREE_THIS_VOLATILE (ref) = 1;
1792
1793 if (no_fold_p)
1794 return ref;
1795
1796 /* The generic folder may punt in this case because the inner array type
1797 can be self-referential, but folding is in fact not problematic. */
1798 else if (TREE_CODE (record_variable) == CONSTRUCTOR
1799 && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (record_variable)))
1800 {
1801 VEC(constructor_elt,gc) *elts = CONSTRUCTOR_ELTS (record_variable);
1802 unsigned HOST_WIDE_INT idx;
1803 tree index, value;
1804 FOR_EACH_CONSTRUCTOR_ELT (elts, idx, index, value)
1805 if (index == field)
1806 return value;
1807 return ref;
1808 }
1809
1810 else
1811 return fold (ref);
1812 }
1813 \f
1814 /* Like build_simple_component_ref, except that we give an error if the
1815 reference could not be found. */
1816
1817 tree
1818 build_component_ref (tree record_variable, tree component,
1819 tree field, bool no_fold_p)
1820 {
1821 tree ref = build_simple_component_ref (record_variable, component, field,
1822 no_fold_p);
1823
1824 if (ref)
1825 return ref;
1826
1827 /* If FIELD was specified, assume this is an invalid user field so
1828 raise constraint error. Otherwise, we can't find the type to return, so
1829 abort. */
1830 gcc_assert (field);
1831 return build1 (NULL_EXPR, TREE_TYPE (field),
1832 build_call_raise (CE_Discriminant_Check_Failed, Empty,
1833 N_Raise_Constraint_Error));
1834 }
1835 \f
1836 /* Build a GCC tree to call an allocation or deallocation function.
1837 If GNU_OBJ is nonzero, it is an object to deallocate. Otherwise,
1838 generate an allocator.
1839
1840 GNU_SIZE is the size of the object in bytes and ALIGN is the alignment in
1841 bits. GNAT_PROC, if present, is a procedure to call and GNAT_POOL is the
1842 storage pool to use. If not preset, malloc and free will be used except
1843 if GNAT_PROC is the "fake" value of -1, in which case we allocate the
1844 object dynamically on the stack frame. */
1845
1846 tree
1847 build_call_alloc_dealloc (tree gnu_obj, tree gnu_size, unsigned align,
1848 Entity_Id gnat_proc, Entity_Id gnat_pool,
1849 Node_Id gnat_node)
1850 {
1851 tree gnu_align = size_int (align / BITS_PER_UNIT);
1852
1853 gnu_size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (gnu_size, gnu_obj);
1854
1855 if (Present (gnat_proc))
1856 {
1857 /* The storage pools are obviously always tagged types, but the
1858 secondary stack uses the same mechanism and is not tagged */
1859 if (Is_Tagged_Type (Etype (gnat_pool)))
1860 {
1861 /* The size is the third parameter; the alignment is the
1862 same type. */
1863 Entity_Id gnat_size_type
1864 = Etype (Next_Formal (Next_Formal (First_Formal (gnat_proc))));
1865 tree gnu_size_type = gnat_to_gnu_type (gnat_size_type);
1866 tree gnu_proc = gnat_to_gnu (gnat_proc);
1867 tree gnu_proc_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_proc);
1868 tree gnu_pool = gnat_to_gnu (gnat_pool);
1869 tree gnu_pool_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_pool);
1870 tree gnu_call;
1871
1872 gnu_size = convert (gnu_size_type, gnu_size);
1873 gnu_align = convert (gnu_size_type, gnu_align);
1874
1875 /* The first arg is always the address of the storage pool; next
1876 comes the address of the object, for a deallocator, then the
1877 size and alignment. */
1878 if (gnu_obj)
1879 gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)),
1880 gnu_proc_addr, 4, gnu_pool_addr,
1881 gnu_obj, gnu_size, gnu_align);
1882 else
1883 gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)),
1884 gnu_proc_addr, 3, gnu_pool_addr,
1885 gnu_size, gnu_align);
1886 TREE_SIDE_EFFECTS (gnu_call) = 1;
1887 return gnu_call;
1888 }
1889
1890 /* Secondary stack case. */
1891 else
1892 {
1893 /* The size is the second parameter */
1894 Entity_Id gnat_size_type
1895 = Etype (Next_Formal (First_Formal (gnat_proc)));
1896 tree gnu_size_type = gnat_to_gnu_type (gnat_size_type);
1897 tree gnu_proc = gnat_to_gnu (gnat_proc);
1898 tree gnu_proc_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_proc);
1899 tree gnu_call;
1900
1901 gnu_size = convert (gnu_size_type, gnu_size);
1902
1903 /* The first arg is the address of the object, for a
1904 deallocator, then the size */
1905 if (gnu_obj)
1906 gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)),
1907 gnu_proc_addr, 2, gnu_obj, gnu_size);
1908 else
1909 gnu_call = build_call_nary (TREE_TYPE (TREE_TYPE (gnu_proc)),
1910 gnu_proc_addr, 1, gnu_size);
1911 TREE_SIDE_EFFECTS (gnu_call) = 1;
1912 return gnu_call;
1913 }
1914 }
1915
1916 else if (gnu_obj)
1917 return build_call_1_expr (free_decl, gnu_obj);
1918
1919 /* ??? For now, disable variable-sized allocators in the stack since
1920 we can't yet gimplify an ALLOCATE_EXPR. */
1921 else if (gnat_pool == -1
1922 && TREE_CODE (gnu_size) == INTEGER_CST && !flag_stack_check)
1923 {
1924 /* If the size is a constant, we can put it in the fixed portion of
1925 the stack frame to avoid the need to adjust the stack pointer. */
1926 if (TREE_CODE (gnu_size) == INTEGER_CST && !flag_stack_check)
1927 {
1928 tree gnu_range
1929 = build_range_type (NULL_TREE, size_one_node, gnu_size);
1930 tree gnu_array_type = build_array_type (char_type_node, gnu_range);
1931 tree gnu_decl
1932 = create_var_decl (get_identifier ("RETVAL"), NULL_TREE,
1933 gnu_array_type, NULL_TREE, false, false, false,
1934 false, NULL, gnat_node);
1935
1936 return convert (ptr_void_type_node,
1937 build_unary_op (ADDR_EXPR, NULL_TREE, gnu_decl));
1938 }
1939 else
1940 gcc_unreachable ();
1941 #if 0
1942 return build2 (ALLOCATE_EXPR, ptr_void_type_node, gnu_size, gnu_align);
1943 #endif
1944 }
1945 else
1946 {
1947 if (Nkind (gnat_node) != N_Allocator || !Comes_From_Source (gnat_node))
1948 Check_No_Implicit_Heap_Alloc (gnat_node);
1949
1950 /* If the allocator size is 32bits but the pointer size is 64bits then
1951 allocate 32bit memory (sometimes necessary on 64bit VMS). Otherwise
1952 default to standard malloc. */
1953 if (UI_To_Int (Esize (Etype (gnat_node))) == 32 && POINTER_SIZE == 64)
1954 return build_call_1_expr (malloc32_decl, gnu_size);
1955 else
1956 return build_call_1_expr (malloc_decl, gnu_size);
1957 }
1958 }
1959 \f
1960 /* Build a GCC tree to correspond to allocating an object of TYPE whose
1961 initial value is INIT, if INIT is nonzero. Convert the expression to
1962 RESULT_TYPE, which must be some type of pointer. Return the tree.
1963 GNAT_PROC and GNAT_POOL optionally give the procedure to call and
1964 the storage pool to use. GNAT_NODE is used to provide an error
1965 location for restriction violations messages. If IGNORE_INIT_TYPE is
1966 true, ignore the type of INIT for the purpose of determining the size;
1967 this will cause the maximum size to be allocated if TYPE is of
1968 self-referential size. */
1969
1970 tree
1971 build_allocator (tree type, tree init, tree result_type, Entity_Id gnat_proc,
1972 Entity_Id gnat_pool, Node_Id gnat_node, bool ignore_init_type)
1973 {
1974 tree size = TYPE_SIZE_UNIT (type);
1975 tree result;
1976 unsigned int default_allocator_alignment
1977 = get_target_default_allocator_alignment () * BITS_PER_UNIT;
1978
1979 /* If the initializer, if present, is a NULL_EXPR, just return a new one. */
1980 if (init && TREE_CODE (init) == NULL_EXPR)
1981 return build1 (NULL_EXPR, result_type, TREE_OPERAND (init, 0));
1982
1983 /* If RESULT_TYPE is a fat or thin pointer, set SIZE to be the sum of the
1984 sizes of the object and its template. Allocate the whole thing and
1985 fill in the parts that are known. */
1986 else if (TYPE_FAT_OR_THIN_POINTER_P (result_type))
1987 {
1988 tree storage_type
1989 = build_unc_object_type_from_ptr (result_type, type,
1990 get_identifier ("ALLOC"));
1991 tree template_type = TREE_TYPE (TYPE_FIELDS (storage_type));
1992 tree storage_ptr_type = build_pointer_type (storage_type);
1993 tree storage;
1994 tree template_cons = NULL_TREE;
1995
1996 size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TYPE_SIZE_UNIT (storage_type),
1997 init);
1998
1999 /* If the size overflows, pass -1 so the allocator will raise
2000 storage error. */
2001 if (TREE_CODE (size) == INTEGER_CST && TREE_OVERFLOW (size))
2002 size = ssize_int (-1);
2003
2004 storage = build_call_alloc_dealloc (NULL_TREE, size,
2005 TYPE_ALIGN (storage_type),
2006 gnat_proc, gnat_pool, gnat_node);
2007 storage = convert (storage_ptr_type, protect_multiple_eval (storage));
2008
2009 if (TREE_CODE (type) == RECORD_TYPE && TYPE_IS_PADDING_P (type))
2010 {
2011 type = TREE_TYPE (TYPE_FIELDS (type));
2012
2013 if (init)
2014 init = convert (type, init);
2015 }
2016
2017 /* If there is an initializing expression, make a constructor for
2018 the entire object including the bounds and copy it into the
2019 object. If there is no initializing expression, just set the
2020 bounds. */
2021 if (init)
2022 {
2023 template_cons = tree_cons (TREE_CHAIN (TYPE_FIELDS (storage_type)),
2024 init, NULL_TREE);
2025 template_cons = tree_cons (TYPE_FIELDS (storage_type),
2026 build_template (template_type, type,
2027 init),
2028 template_cons);
2029
2030 return convert
2031 (result_type,
2032 build2 (COMPOUND_EXPR, storage_ptr_type,
2033 build_binary_op
2034 (MODIFY_EXPR, storage_type,
2035 build_unary_op (INDIRECT_REF, NULL_TREE,
2036 convert (storage_ptr_type, storage)),
2037 gnat_build_constructor (storage_type, template_cons)),
2038 convert (storage_ptr_type, storage)));
2039 }
2040 else
2041 return build2
2042 (COMPOUND_EXPR, result_type,
2043 build_binary_op
2044 (MODIFY_EXPR, template_type,
2045 build_component_ref
2046 (build_unary_op (INDIRECT_REF, NULL_TREE,
2047 convert (storage_ptr_type, storage)),
2048 NULL_TREE, TYPE_FIELDS (storage_type), 0),
2049 build_template (template_type, type, NULL_TREE)),
2050 convert (result_type, convert (storage_ptr_type, storage)));
2051 }
2052
2053 /* If we have an initializing expression, see if its size is simpler
2054 than the size from the type. */
2055 if (!ignore_init_type && init && TYPE_SIZE_UNIT (TREE_TYPE (init))
2056 && (TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (init))) == INTEGER_CST
2057 || CONTAINS_PLACEHOLDER_P (size)))
2058 size = TYPE_SIZE_UNIT (TREE_TYPE (init));
2059
2060 /* If the size is still self-referential, reference the initializing
2061 expression, if it is present. If not, this must have been a
2062 call to allocate a library-level object, in which case we use
2063 the maximum size. */
2064 if (CONTAINS_PLACEHOLDER_P (size))
2065 {
2066 if (!ignore_init_type && init)
2067 size = substitute_placeholder_in_expr (size, init);
2068 else
2069 size = max_size (size, true);
2070 }
2071
2072 /* If the size overflows, pass -1 so the allocator will raise
2073 storage error. */
2074 if (TREE_CODE (size) == INTEGER_CST && TREE_OVERFLOW (size))
2075 size = ssize_int (-1);
2076
2077 /* If this is in the default storage pool and the type alignment is larger
2078 than what the default allocator supports, make an "aligning" record type
2079 with room to store a pointer before the field, allocate an object of that
2080 type, store the system's allocator return value just in front of the
2081 field and return the field's address. */
2082
2083 if (No (gnat_proc) && TYPE_ALIGN (type) > default_allocator_alignment)
2084 {
2085 /* Construct the aligning type with enough room for a pointer ahead
2086 of the field, then allocate. */
2087 tree record_type
2088 = make_aligning_type (type, TYPE_ALIGN (type), size,
2089 default_allocator_alignment,
2090 POINTER_SIZE / BITS_PER_UNIT);
2091
2092 tree record, record_addr;
2093
2094 record_addr
2095 = build_call_alloc_dealloc (NULL_TREE, TYPE_SIZE_UNIT (record_type),
2096 default_allocator_alignment, Empty, Empty,
2097 gnat_node);
2098
2099 record_addr
2100 = convert (build_pointer_type (record_type),
2101 save_expr (record_addr));
2102
2103 record = build_unary_op (INDIRECT_REF, NULL_TREE, record_addr);
2104
2105 /* Our RESULT (the Ada allocator's value) is the super-aligned address
2106 of the internal record field ... */
2107 result
2108 = build_unary_op (ADDR_EXPR, NULL_TREE,
2109 build_component_ref
2110 (record, NULL_TREE, TYPE_FIELDS (record_type), 0));
2111 result = convert (result_type, result);
2112
2113 /* ... with the system allocator's return value stored just in
2114 front. */
2115 {
2116 tree ptr_addr
2117 = build_binary_op (POINTER_PLUS_EXPR, ptr_void_type_node,
2118 convert (ptr_void_type_node, result),
2119 size_int (-POINTER_SIZE/BITS_PER_UNIT));
2120
2121 tree ptr_ref
2122 = convert (build_pointer_type (ptr_void_type_node), ptr_addr);
2123
2124 result
2125 = build2 (COMPOUND_EXPR, TREE_TYPE (result),
2126 build_binary_op (MODIFY_EXPR, NULL_TREE,
2127 build_unary_op (INDIRECT_REF, NULL_TREE,
2128 ptr_ref),
2129 convert (ptr_void_type_node,
2130 record_addr)),
2131 result);
2132 }
2133 }
2134 else
2135 result = convert (result_type,
2136 build_call_alloc_dealloc (NULL_TREE, size,
2137 TYPE_ALIGN (type),
2138 gnat_proc,
2139 gnat_pool,
2140 gnat_node));
2141
2142 /* If we have an initial value, put the new address into a SAVE_EXPR, assign
2143 the value, and return the address. Do this with a COMPOUND_EXPR. */
2144
2145 if (init)
2146 {
2147 result = save_expr (result);
2148 result
2149 = build2 (COMPOUND_EXPR, TREE_TYPE (result),
2150 build_binary_op
2151 (MODIFY_EXPR, NULL_TREE,
2152 build_unary_op (INDIRECT_REF,
2153 TREE_TYPE (TREE_TYPE (result)), result),
2154 init),
2155 result);
2156 }
2157
2158 return convert (result_type, result);
2159 }
2160 \f
2161 /* Fill in a VMS descriptor for EXPR and return a constructor for it.
2162 GNAT_FORMAL is how we find the descriptor record. GNAT_ACTUAL is
2163 how we derive the source location to raise C_E on an out of range
2164 pointer. */
2165
2166 tree
2167 fill_vms_descriptor (tree expr, Entity_Id gnat_formal, Node_Id gnat_actual)
2168 {
2169 tree field;
2170 tree parm_decl = get_gnu_tree (gnat_formal);
2171 tree const_list = NULL_TREE;
2172 tree record_type = TREE_TYPE (TREE_TYPE (parm_decl));
2173 int do_range_check =
2174 strcmp ("MBO",
2175 IDENTIFIER_POINTER (DECL_NAME (TYPE_FIELDS (record_type))));
2176
2177 expr = maybe_unconstrained_array (expr);
2178 gnat_mark_addressable (expr);
2179
2180 for (field = TYPE_FIELDS (record_type); field; field = TREE_CHAIN (field))
2181 {
2182 tree conexpr = convert (TREE_TYPE (field),
2183 SUBSTITUTE_PLACEHOLDER_IN_EXPR
2184 (DECL_INITIAL (field), expr));
2185
2186 /* Check to ensure that only 32bit pointers are passed in
2187 32bit descriptors */
2188 if (do_range_check &&
2189 strcmp (IDENTIFIER_POINTER (DECL_NAME (field)), "POINTER") == 0)
2190 {
2191 tree pointer64type =
2192 build_pointer_type_for_mode (void_type_node, DImode, false);
2193 tree addr64expr = build_unary_op (ADDR_EXPR, pointer64type, expr);
2194 tree malloc64low =
2195 build_int_cstu (long_integer_type_node, 0x80000000);
2196
2197 add_stmt (build3 (COND_EXPR, void_type_node,
2198 build_binary_op (GE_EXPR, long_integer_type_node,
2199 convert (long_integer_type_node,
2200 addr64expr),
2201 malloc64low),
2202 build_call_raise (CE_Range_Check_Failed, gnat_actual,
2203 N_Raise_Constraint_Error),
2204 NULL_TREE));
2205 }
2206 const_list = tree_cons (field, conexpr, const_list);
2207 }
2208
2209 return gnat_build_constructor (record_type, nreverse (const_list));
2210 }
2211
2212 /* Indicate that we need to make the address of EXPR_NODE and it therefore
2213 should not be allocated in a register. Returns true if successful. */
2214
2215 bool
2216 gnat_mark_addressable (tree expr_node)
2217 {
2218 while (1)
2219 switch (TREE_CODE (expr_node))
2220 {
2221 case ADDR_EXPR:
2222 case COMPONENT_REF:
2223 case ARRAY_REF:
2224 case ARRAY_RANGE_REF:
2225 case REALPART_EXPR:
2226 case IMAGPART_EXPR:
2227 case VIEW_CONVERT_EXPR:
2228 case NON_LVALUE_EXPR:
2229 CASE_CONVERT:
2230 expr_node = TREE_OPERAND (expr_node, 0);
2231 break;
2232
2233 case CONSTRUCTOR:
2234 TREE_ADDRESSABLE (expr_node) = 1;
2235 return true;
2236
2237 case VAR_DECL:
2238 case PARM_DECL:
2239 case RESULT_DECL:
2240 TREE_ADDRESSABLE (expr_node) = 1;
2241 return true;
2242
2243 case FUNCTION_DECL:
2244 TREE_ADDRESSABLE (expr_node) = 1;
2245 return true;
2246
2247 case CONST_DECL:
2248 return (DECL_CONST_CORRESPONDING_VAR (expr_node)
2249 && (gnat_mark_addressable
2250 (DECL_CONST_CORRESPONDING_VAR (expr_node))));
2251 default:
2252 return true;
2253 }
2254 }