2015-12-18 Paul Thomas <pault@gcc.gnu.org>
[official-gcc.git] / gcc / fortran / data.c
blob07ca6ad8d32b008aa15eb7c3eebc065e8b1dc7bd
1 /* Supporting functions for resolving DATA statement.
2 Copyright (C) 2002-2015 Free Software Foundation, Inc.
3 Contributed by Lifang Zeng <zlf605@hotmail.com>
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
22 /* Notes for DATA statement implementation:
24 We first assign initial value to each symbol by gfc_assign_data_value
25 during resolving DATA statement. Refer to check_data_variable and
26 traverse_data_list in resolve.c.
28 The complexity exists in the handling of array section, implied do
29 and array of struct appeared in DATA statement.
31 We call gfc_conv_structure, gfc_con_array_array_initializer,
32 etc., to convert the initial value. Refer to trans-expr.c and
33 trans-array.c. */
35 #include "config.h"
36 #include "system.h"
37 #include "coretypes.h"
38 #include "gfortran.h"
39 #include "data.h"
40 #include "constructor.h"
42 static void formalize_init_expr (gfc_expr *);
44 /* Calculate the array element offset. */
46 static void
47 get_array_index (gfc_array_ref *ar, mpz_t *offset)
49 gfc_expr *e;
50 int i;
51 mpz_t delta;
52 mpz_t tmp;
54 mpz_init (tmp);
55 mpz_set_si (*offset, 0);
56 mpz_init_set_si (delta, 1);
57 for (i = 0; i < ar->dimen; i++)
59 e = gfc_copy_expr (ar->start[i]);
60 gfc_simplify_expr (e, 1);
62 if ((gfc_is_constant_expr (ar->as->lower[i]) == 0)
63 || (gfc_is_constant_expr (ar->as->upper[i]) == 0)
64 || (gfc_is_constant_expr (e) == 0))
65 gfc_error ("non-constant array in DATA statement %L", &ar->where);
67 mpz_set (tmp, e->value.integer);
68 gfc_free_expr (e);
69 mpz_sub (tmp, tmp, ar->as->lower[i]->value.integer);
70 mpz_mul (tmp, tmp, delta);
71 mpz_add (*offset, tmp, *offset);
73 mpz_sub (tmp, ar->as->upper[i]->value.integer,
74 ar->as->lower[i]->value.integer);
75 mpz_add_ui (tmp, tmp, 1);
76 mpz_mul (delta, tmp, delta);
78 mpz_clear (delta);
79 mpz_clear (tmp);
82 /* Find if there is a constructor which component is equal to COM.
83 TODO: remove this, use symbol.c(gfc_find_component) instead. */
85 static gfc_constructor *
86 find_con_by_component (gfc_component *com, gfc_constructor_base base)
88 gfc_constructor *c;
90 for (c = gfc_constructor_first (base); c; c = gfc_constructor_next (c))
91 if (com == c->n.component)
92 return c;
94 return NULL;
98 /* Create a character type initialization expression from RVALUE.
99 TS [and REF] describe [the substring of] the variable being initialized.
100 INIT is the existing initializer, not NULL. Initialization is performed
101 according to normal assignment rules. */
103 static gfc_expr *
104 create_character_initializer (gfc_expr *init, gfc_typespec *ts,
105 gfc_ref *ref, gfc_expr *rvalue)
107 int len, start, end, tlen;
108 gfc_char_t *dest;
109 bool alloced_init = false;
111 gfc_extract_int (ts->u.cl->length, &len);
113 if (init == NULL)
115 /* Create a new initializer. */
116 init = gfc_get_character_expr (ts->kind, NULL, NULL, len);
117 init->ts = *ts;
118 alloced_init = true;
121 dest = init->value.character.string;
123 if (ref)
125 gfc_expr *start_expr, *end_expr;
127 gcc_assert (ref->type == REF_SUBSTRING);
129 /* Only set a substring of the destination. Fortran substring bounds
130 are one-based [start, end], we want zero based [start, end). */
131 start_expr = gfc_copy_expr (ref->u.ss.start);
132 end_expr = gfc_copy_expr (ref->u.ss.end);
134 if ((!gfc_simplify_expr(start_expr, 1))
135 || !(gfc_simplify_expr(end_expr, 1)))
137 gfc_error ("failure to simplify substring reference in DATA "
138 "statement at %L", &ref->u.ss.start->where);
139 gfc_free_expr (start_expr);
140 gfc_free_expr (end_expr);
141 if (alloced_init)
142 gfc_free_expr (init);
143 return NULL;
146 gfc_extract_int (start_expr, &start);
147 gfc_free_expr (start_expr);
148 start--;
149 gfc_extract_int (end_expr, &end);
150 gfc_free_expr (end_expr);
152 else
154 /* Set the whole string. */
155 start = 0;
156 end = len;
159 /* Copy the initial value. */
160 if (rvalue->ts.type == BT_HOLLERITH)
161 len = rvalue->representation.length - rvalue->ts.u.pad;
162 else
163 len = rvalue->value.character.length;
165 tlen = end - start;
166 if (len > tlen)
168 if (tlen < 0)
170 gfc_warning_now (0, "Unused initialization string at %L because "
171 "variable has zero length", &rvalue->where);
172 len = 0;
174 else
176 gfc_warning_now (0, "Initialization string at %L was truncated to "
177 "fit the variable (%d/%d)", &rvalue->where,
178 tlen, len);
179 len = tlen;
183 if (rvalue->ts.type == BT_HOLLERITH)
185 int i;
186 for (i = 0; i < len; i++)
187 dest[start+i] = rvalue->representation.string[i];
189 else
190 memcpy (&dest[start], rvalue->value.character.string,
191 len * sizeof (gfc_char_t));
193 /* Pad with spaces. Substrings will already be blanked. */
194 if (len < tlen && ref == NULL)
195 gfc_wide_memset (&dest[start + len], ' ', end - (start + len));
197 if (rvalue->ts.type == BT_HOLLERITH)
199 init->representation.length = init->value.character.length;
200 init->representation.string
201 = gfc_widechar_to_char (init->value.character.string,
202 init->value.character.length);
205 return init;
209 /* Assign the initial value RVALUE to LVALUE's symbol->value. If the
210 LVALUE already has an initialization, we extend this, otherwise we
211 create a new one. If REPEAT is non-NULL, initialize *REPEAT
212 consecutive values in LVALUE the same value in RVALUE. In that case,
213 LVALUE must refer to a full array, not an array section. */
215 bool
216 gfc_assign_data_value (gfc_expr *lvalue, gfc_expr *rvalue, mpz_t index,
217 mpz_t *repeat)
219 gfc_ref *ref;
220 gfc_expr *init;
221 gfc_expr *expr = NULL;
222 gfc_constructor *con;
223 gfc_constructor *last_con;
224 gfc_symbol *symbol;
225 gfc_typespec *last_ts;
226 mpz_t offset;
228 symbol = lvalue->symtree->n.sym;
229 init = symbol->value;
230 last_ts = &symbol->ts;
231 last_con = NULL;
232 mpz_init_set_si (offset, 0);
234 /* Find/create the parent expressions for subobject references. */
235 for (ref = lvalue->ref; ref; ref = ref->next)
237 /* Break out of the loop if we find a substring. */
238 if (ref->type == REF_SUBSTRING)
240 /* A substring should always be the last subobject reference. */
241 gcc_assert (ref->next == NULL);
242 break;
245 /* Use the existing initializer expression if it exists. Otherwise
246 create a new one. */
247 if (init == NULL)
248 expr = gfc_get_expr ();
249 else
250 expr = init;
252 /* Find or create this element. */
253 switch (ref->type)
255 case REF_ARRAY:
256 if (ref->u.ar.as->rank == 0)
258 gcc_assert (ref->u.ar.as->corank > 0);
259 if (init == NULL)
260 free (expr);
261 continue;
264 if (init && expr->expr_type != EXPR_ARRAY)
266 gfc_error ("%qs at %L already is initialized at %L",
267 lvalue->symtree->n.sym->name, &lvalue->where,
268 &init->where);
269 goto abort;
272 if (init == NULL)
274 /* The element typespec will be the same as the array
275 typespec. */
276 expr->ts = *last_ts;
277 /* Setup the expression to hold the constructor. */
278 expr->expr_type = EXPR_ARRAY;
279 expr->rank = ref->u.ar.as->rank;
282 if (ref->u.ar.type == AR_ELEMENT)
283 get_array_index (&ref->u.ar, &offset);
284 else
285 mpz_set (offset, index);
287 /* Check the bounds. */
288 if (mpz_cmp_si (offset, 0) < 0)
290 gfc_error ("Data element below array lower bound at %L",
291 &lvalue->where);
292 goto abort;
294 else if (repeat != NULL
295 && ref->u.ar.type != AR_ELEMENT)
297 mpz_t size, end;
298 gcc_assert (ref->u.ar.type == AR_FULL
299 && ref->next == NULL);
300 mpz_init_set (end, offset);
301 mpz_add (end, end, *repeat);
302 if (spec_size (ref->u.ar.as, &size))
304 if (mpz_cmp (end, size) > 0)
306 mpz_clear (size);
307 gfc_error ("Data element above array upper bound at %L",
308 &lvalue->where);
309 goto abort;
311 mpz_clear (size);
314 con = gfc_constructor_lookup (expr->value.constructor,
315 mpz_get_si (offset));
316 if (!con)
318 con = gfc_constructor_lookup_next (expr->value.constructor,
319 mpz_get_si (offset));
320 if (con != NULL && mpz_cmp (con->offset, end) >= 0)
321 con = NULL;
324 /* Overwriting an existing initializer is non-standard but
325 usually only provokes a warning from other compilers. */
326 if (con != NULL && con->expr != NULL)
328 /* Order in which the expressions arrive here depends on
329 whether they are from data statements or F95 style
330 declarations. Therefore, check which is the most
331 recent. */
332 gfc_expr *exprd;
333 exprd = (LOCATION_LINE (con->expr->where.lb->location)
334 > LOCATION_LINE (rvalue->where.lb->location))
335 ? con->expr : rvalue;
336 if (gfc_notify_std (GFC_STD_GNU,
337 "re-initialization of %qs at %L",
338 symbol->name, &exprd->where) == false)
339 return false;
342 while (con != NULL)
344 gfc_constructor *next_con = gfc_constructor_next (con);
346 if (mpz_cmp (con->offset, end) >= 0)
347 break;
348 if (mpz_cmp (con->offset, offset) < 0)
350 gcc_assert (mpz_cmp_si (con->repeat, 1) > 0);
351 mpz_sub (con->repeat, offset, con->offset);
353 else if (mpz_cmp_si (con->repeat, 1) > 0
354 && mpz_get_si (con->offset)
355 + mpz_get_si (con->repeat) > mpz_get_si (end))
357 int endi;
358 splay_tree_node node
359 = splay_tree_lookup (con->base,
360 mpz_get_si (con->offset));
361 gcc_assert (node
362 && con == (gfc_constructor *) node->value
363 && node->key == (splay_tree_key)
364 mpz_get_si (con->offset));
365 endi = mpz_get_si (con->offset)
366 + mpz_get_si (con->repeat);
367 if (endi > mpz_get_si (end) + 1)
368 mpz_set_si (con->repeat, endi - mpz_get_si (end));
369 else
370 mpz_set_si (con->repeat, 1);
371 mpz_set (con->offset, end);
372 node->key = (splay_tree_key) mpz_get_si (end);
373 break;
375 else
376 gfc_constructor_remove (con);
377 con = next_con;
380 con = gfc_constructor_insert_expr (&expr->value.constructor,
381 NULL, &rvalue->where,
382 mpz_get_si (offset));
383 mpz_set (con->repeat, *repeat);
384 repeat = NULL;
385 mpz_clear (end);
386 break;
388 else
390 mpz_t size;
391 if (spec_size (ref->u.ar.as, &size))
393 if (mpz_cmp (offset, size) >= 0)
395 mpz_clear (size);
396 gfc_error ("Data element above array upper bound at %L",
397 &lvalue->where);
398 goto abort;
400 mpz_clear (size);
404 con = gfc_constructor_lookup (expr->value.constructor,
405 mpz_get_si (offset));
406 if (!con)
408 con = gfc_constructor_insert_expr (&expr->value.constructor,
409 NULL, &rvalue->where,
410 mpz_get_si (offset));
412 else if (mpz_cmp_si (con->repeat, 1) > 0)
414 /* Need to split a range. */
415 if (mpz_cmp (con->offset, offset) < 0)
417 gfc_constructor *pred_con = con;
418 con = gfc_constructor_insert_expr (&expr->value.constructor,
419 NULL, &con->where,
420 mpz_get_si (offset));
421 con->expr = gfc_copy_expr (pred_con->expr);
422 mpz_add (con->repeat, pred_con->offset, pred_con->repeat);
423 mpz_sub (con->repeat, con->repeat, offset);
424 mpz_sub (pred_con->repeat, offset, pred_con->offset);
426 if (mpz_cmp_si (con->repeat, 1) > 0)
428 gfc_constructor *succ_con;
429 succ_con
430 = gfc_constructor_insert_expr (&expr->value.constructor,
431 NULL, &con->where,
432 mpz_get_si (offset) + 1);
433 succ_con->expr = gfc_copy_expr (con->expr);
434 mpz_sub_ui (succ_con->repeat, con->repeat, 1);
435 mpz_set_si (con->repeat, 1);
438 break;
440 case REF_COMPONENT:
441 if (init == NULL)
443 /* Setup the expression to hold the constructor. */
444 expr->expr_type = EXPR_STRUCTURE;
445 expr->ts.type = BT_DERIVED;
446 expr->ts.u.derived = ref->u.c.sym;
448 else
449 gcc_assert (expr->expr_type == EXPR_STRUCTURE);
450 last_ts = &ref->u.c.component->ts;
452 /* Find the same element in the existing constructor. */
453 con = find_con_by_component (ref->u.c.component,
454 expr->value.constructor);
456 if (con == NULL)
458 /* Create a new constructor. */
459 con = gfc_constructor_append_expr (&expr->value.constructor,
460 NULL, NULL);
461 con->n.component = ref->u.c.component;
463 break;
465 default:
466 gcc_unreachable ();
469 if (init == NULL)
471 /* Point the container at the new expression. */
472 if (last_con == NULL)
473 symbol->value = expr;
474 else
475 last_con->expr = expr;
477 init = con->expr;
478 last_con = con;
481 mpz_clear (offset);
482 gcc_assert (repeat == NULL);
484 if (ref || last_ts->type == BT_CHARACTER)
486 if (lvalue->ts.u.cl->length == NULL && !(ref && ref->u.ss.length != NULL))
487 return false;
488 expr = create_character_initializer (init, last_ts, ref, rvalue);
490 else
492 /* Overwriting an existing initializer is non-standard but usually only
493 provokes a warning from other compilers. */
494 if (init != NULL)
496 /* Order in which the expressions arrive here depends on whether
497 they are from data statements or F95 style declarations.
498 Therefore, check which is the most recent. */
499 expr = (LOCATION_LINE (init->where.lb->location)
500 > LOCATION_LINE (rvalue->where.lb->location))
501 ? init : rvalue;
502 if (gfc_notify_std (GFC_STD_GNU,
503 "re-initialization of %qs at %L",
504 symbol->name, &expr->where) == false)
505 return false;
508 expr = gfc_copy_expr (rvalue);
509 if (!gfc_compare_types (&lvalue->ts, &expr->ts))
510 gfc_convert_type (expr, &lvalue->ts, 0);
513 if (last_con == NULL)
514 symbol->value = expr;
515 else
516 last_con->expr = expr;
518 return true;
520 abort:
521 if (!init)
522 gfc_free_expr (expr);
523 mpz_clear (offset);
524 return false;
528 /* Modify the index of array section and re-calculate the array offset. */
530 void
531 gfc_advance_section (mpz_t *section_index, gfc_array_ref *ar,
532 mpz_t *offset_ret)
534 int i;
535 mpz_t delta;
536 mpz_t tmp;
537 bool forwards;
538 int cmp;
540 for (i = 0; i < ar->dimen; i++)
542 if (ar->dimen_type[i] != DIMEN_RANGE)
543 continue;
545 if (ar->stride[i])
547 mpz_add (section_index[i], section_index[i],
548 ar->stride[i]->value.integer);
549 if (mpz_cmp_si (ar->stride[i]->value.integer, 0) >= 0)
550 forwards = true;
551 else
552 forwards = false;
554 else
556 mpz_add_ui (section_index[i], section_index[i], 1);
557 forwards = true;
560 if (ar->end[i])
561 cmp = mpz_cmp (section_index[i], ar->end[i]->value.integer);
562 else
563 cmp = mpz_cmp (section_index[i], ar->as->upper[i]->value.integer);
565 if ((cmp > 0 && forwards) || (cmp < 0 && !forwards))
567 /* Reset index to start, then loop to advance the next index. */
568 if (ar->start[i])
569 mpz_set (section_index[i], ar->start[i]->value.integer);
570 else
571 mpz_set (section_index[i], ar->as->lower[i]->value.integer);
573 else
574 break;
577 mpz_set_si (*offset_ret, 0);
578 mpz_init_set_si (delta, 1);
579 mpz_init (tmp);
580 for (i = 0; i < ar->dimen; i++)
582 mpz_sub (tmp, section_index[i], ar->as->lower[i]->value.integer);
583 mpz_mul (tmp, tmp, delta);
584 mpz_add (*offset_ret, tmp, *offset_ret);
586 mpz_sub (tmp, ar->as->upper[i]->value.integer,
587 ar->as->lower[i]->value.integer);
588 mpz_add_ui (tmp, tmp, 1);
589 mpz_mul (delta, tmp, delta);
591 mpz_clear (tmp);
592 mpz_clear (delta);
596 /* Rearrange a structure constructor so the elements are in the specified
597 order. Also insert NULL entries if necessary. */
599 static void
600 formalize_structure_cons (gfc_expr *expr)
602 gfc_constructor_base base = NULL;
603 gfc_constructor *cur;
604 gfc_component *order;
606 /* Constructor is already formalized. */
607 cur = gfc_constructor_first (expr->value.constructor);
608 if (!cur || cur->n.component == NULL)
609 return;
611 for (order = expr->ts.u.derived->components; order; order = order->next)
613 cur = find_con_by_component (order, expr->value.constructor);
614 if (cur)
615 gfc_constructor_append_expr (&base, cur->expr, &cur->expr->where);
616 else
617 gfc_constructor_append_expr (&base, NULL, NULL);
620 /* For all what it's worth, one would expect
621 gfc_constructor_free (expr->value.constructor);
622 here. However, if the constructor is actually free'd,
623 hell breaks loose in the testsuite?! */
625 expr->value.constructor = base;
629 /* Make sure an initialization expression is in normalized form, i.e., all
630 elements of the constructors are in the correct order. */
632 static void
633 formalize_init_expr (gfc_expr *expr)
635 expr_t type;
636 gfc_constructor *c;
638 if (expr == NULL)
639 return;
641 type = expr->expr_type;
642 switch (type)
644 case EXPR_ARRAY:
645 for (c = gfc_constructor_first (expr->value.constructor);
646 c; c = gfc_constructor_next (c))
647 formalize_init_expr (c->expr);
649 break;
651 case EXPR_STRUCTURE:
652 formalize_structure_cons (expr);
653 break;
655 default:
656 break;
661 /* Resolve symbol's initial value after all data statement. */
663 void
664 gfc_formalize_init_value (gfc_symbol *sym)
666 formalize_init_expr (sym->value);
670 /* Get the integer value into RET_AS and SECTION from AS and AR, and return
671 offset. */
673 void
674 gfc_get_section_index (gfc_array_ref *ar, mpz_t *section_index, mpz_t *offset)
676 int i;
677 mpz_t delta;
678 mpz_t tmp;
680 mpz_set_si (*offset, 0);
681 mpz_init (tmp);
682 mpz_init_set_si (delta, 1);
683 for (i = 0; i < ar->dimen; i++)
685 mpz_init (section_index[i]);
686 switch (ar->dimen_type[i])
688 case DIMEN_ELEMENT:
689 case DIMEN_RANGE:
690 if (ar->start[i])
692 mpz_sub (tmp, ar->start[i]->value.integer,
693 ar->as->lower[i]->value.integer);
694 mpz_mul (tmp, tmp, delta);
695 mpz_add (*offset, tmp, *offset);
696 mpz_set (section_index[i], ar->start[i]->value.integer);
698 else
699 mpz_set (section_index[i], ar->as->lower[i]->value.integer);
700 break;
702 case DIMEN_VECTOR:
703 gfc_internal_error ("TODO: Vector sections in data statements");
705 default:
706 gcc_unreachable ();
709 mpz_sub (tmp, ar->as->upper[i]->value.integer,
710 ar->as->lower[i]->value.integer);
711 mpz_add_ui (tmp, tmp, 1);
712 mpz_mul (delta, tmp, delta);
715 mpz_clear (tmp);
716 mpz_clear (delta);