gcc/fortran/data.c

   1 /* Supporting functions for resolving DATA statement.
   2    Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008
   3    Free Software Foundation, Inc.
   4    Contributed by Lifang Zeng <zlf605@hotmail.com>
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22
  23 /* Notes for DATA statement implementation:
  24
  25    We first assign initial value to each symbol by gfc_assign_data_value
  26    during resolveing DATA statement. Refer to check_data_variable and
  27    traverse_data_list in resolve.c.
  28
  29    The complexity exists in the handling of array section, implied do
  30    and array of struct appeared in DATA statement.
  31
  32    We call gfc_conv_structure, gfc_con_array_array_initializer,
  33    etc., to convert the initial value. Refer to trans-expr.c and
  34    trans-array.c.  */
  35
  36 #include "config.h"
  37 #include "gfortran.h"
  38 #include "data.h"
  39
  40 static void formalize_init_expr (gfc_expr *);
  41
  42 /* Calculate the array element offset.  */
  43
  44 static void
  45 get_array_index (gfc_array_ref *ar, mpz_t *offset)
  46 {
  47   gfc_expr *e;
  48   int i;
  49   try re;
  50   mpz_t delta;
  51   mpz_t tmp;
  52
  53   mpz_init (tmp);
  54   mpz_set_si (*offset, 0);
  55   mpz_init_set_si (delta, 1);
  56   for (i = 0; i < ar->dimen; i++)
  57     {
  58       e = gfc_copy_expr (ar->start[i]);
  59       re = gfc_simplify_expr (e, 1);
  60
  61       if ((gfc_is_constant_expr (ar->as->lower[i]) == 0)
  62           || (gfc_is_constant_expr (ar->as->upper[i]) == 0)
  63           || (gfc_is_constant_expr (e) == 0))
  64         gfc_error ("non-constant array in DATA statement %L", &ar->where);
  65
  66       mpz_set (tmp, e->value.integer);
  67       mpz_sub (tmp, tmp, ar->as->lower[i]->value.integer);
  68       mpz_mul (tmp, tmp, delta);
  69       mpz_add (*offset, tmp, *offset);
  70
  71       mpz_sub (tmp, ar->as->upper[i]->value.integer,
  72                ar->as->lower[i]->value.integer);
  73       mpz_add_ui (tmp, tmp, 1);
  74       mpz_mul (delta, tmp, delta);
  75     }
  76   mpz_clear (delta);
  77   mpz_clear (tmp);
  78 }
  79
  80
  81 /* Find if there is a constructor which offset is equal to OFFSET.  */
  82
  83 static gfc_constructor *
  84 find_con_by_offset (splay_tree spt, mpz_t offset)
  85 {
  86   mpz_t tmp;
  87   gfc_constructor *ret = NULL;
  88   gfc_constructor *con;
  89   splay_tree_node sptn;
  90
  91   /* The complexity is due to needing quick access to the linked list of
  92      constructors.  Both a linked list and a splay tree are used, and both
  93      are kept up to date if they are array elements (which is the only time
  94      that a specific constructor has to be found).  */
  95
  96   gcc_assert (spt != NULL);
  97   mpz_init (tmp);
  98
  99   sptn = splay_tree_lookup (spt, (splay_tree_key) mpz_get_si (offset));
 100
 101   if (sptn)
 102     ret = (gfc_constructor*) sptn->value;
 103   else
 104     {
 105        /* Need to check and see if we match a range, so we will pull
 106           the next lowest index and see if the range matches.  */
 107        sptn = splay_tree_predecessor (spt,
 108                                       (splay_tree_key) mpz_get_si (offset));
 109        if (sptn)
 110          {
 111             con = (gfc_constructor*) sptn->value;
 112             if (mpz_cmp_ui (con->repeat, 1) > 0)
 113               {
 114                  mpz_init (tmp);
 115                  mpz_add (tmp, con->n.offset, con->repeat);
 116                  if (mpz_cmp (offset, tmp) < 0)
 117                    ret = con;
 118                  mpz_clear (tmp);
 119               }
 120             else
 121               ret = NULL; /* The range did not match.  */
 122          }
 123       else
 124         ret = NULL; /* No pred, so no match.  */
 125     }
 126
 127   return ret;
 128 }
 129
 130
 131 /* Find if there is a constructor which component is equal to COM.  */
 132
 133 static gfc_constructor *
 134 find_con_by_component (gfc_component *com, gfc_constructor *con)
 135 {
 136   for (; con; con = con->next)
 137     {
 138       if (com == con->n.component)
 139         return con;
 140     }
 141   return NULL;
 142 }
 143
 144
 145 /* Create a character type initialization expression from RVALUE.
 146    TS [and REF] describe [the substring of] the variable being initialized.
 147    INIT is thh existing initializer, not NULL.  Initialization is performed
 148    according to normal assignment rules.  */
 149
 150 static gfc_expr *
 151 create_character_intializer (gfc_expr *init, gfc_typespec *ts,
 152                              gfc_ref *ref, gfc_expr *rvalue)
 153 {
 154   int len, start, end;
 155   gfc_char_t *dest;
 156
 157   gfc_extract_int (ts->cl->length, &len);
 158
 159   if (init == NULL)
 160     {
 161       /* Create a new initializer.  */
 162       init = gfc_get_expr ();
 163       init->expr_type = EXPR_CONSTANT;
 164       init->ts = *ts;
 165
 166       dest = gfc_get_wide_string (len + 1);
 167       dest[len] = '\0';
 168       init->value.character.length = len;
 169       init->value.character.string = dest;
 170       /* Blank the string if we're only setting a substring.  */
 171       if (ref != NULL)
 172         gfc_wide_memset (dest, ' ', len);
 173     }
 174   else
 175     dest = init->value.character.string;
 176
 177   if (ref)
 178     {
 179       gfc_expr *start_expr, *end_expr;
 180
 181       gcc_assert (ref->type == REF_SUBSTRING);
 182
 183       /* Only set a substring of the destination.  Fortran substring bounds
 184          are one-based [start, end], we want zero based [start, end).  */
 185       start_expr = gfc_copy_expr (ref->u.ss.start);
 186       end_expr = gfc_copy_expr (ref->u.ss.end);
 187
 188       if ((gfc_simplify_expr (start_expr, 1) == FAILURE)
 189           || (gfc_simplify_expr (end_expr, 1)) == FAILURE)
 190         {
 191           gfc_error ("failure to simplify substring reference in DATA "
 192                      "statement at %L", &ref->u.ss.start->where);
 193           return NULL;
 194         }
 195
 196       gfc_extract_int (start_expr, &start);
 197       start--;
 198       gfc_extract_int (end_expr, &end);
 199     }
 200   else
 201     {
 202       /* Set the whole string.  */
 203       start = 0;
 204       end = len;
 205     }
 206
 207   /* Copy the initial value.  */
 208   if (rvalue->ts.type == BT_HOLLERITH)
 209     len = rvalue->representation.length;
 210   else
 211     len = rvalue->value.character.length;
 212
 213   if (len > end - start)
 214     {
 215       len = end - start;
 216       gfc_warning_now ("initialization string truncated to match variable "
 217                        "at %L", &rvalue->where);
 218     }
 219
 220   if (rvalue->ts.type == BT_HOLLERITH)
 221     {
 222       int i;
 223       for (i = 0; i < len; i++)
 224         dest[start+i] = rvalue->representation.string[i];
 225     }
 226   else
 227     memcpy (&dest[start], rvalue->value.character.string,
 228             len * sizeof (gfc_char_t));
 229
 230   /* Pad with spaces.  Substrings will already be blanked.  */
 231   if (len < end - start && ref == NULL)
 232     gfc_wide_memset (&dest[start + len], ' ', end - (start + len));
 233
 234   if (rvalue->ts.type == BT_HOLLERITH)
 235     {
 236       init->representation.length = init->value.character.length;
 237       init->representation.string
 238         = gfc_widechar_to_char (init->value.character.string,
 239                                 init->value.character.length);
 240     }
 241
 242   return init;
 243 }
 244
 245
 246 /* Assign the initial value RVALUE to  LVALUE's symbol->value. If the
 247    LVALUE already has an initialization, we extend this, otherwise we
 248    create a new one.  */
 249
 250 try
 251 gfc_assign_data_value (gfc_expr *lvalue, gfc_expr *rvalue, mpz_t index)
 252 {
 253   gfc_ref *ref;
 254   gfc_expr *init;
 255   gfc_expr *expr;
 256   gfc_constructor *con;
 257   gfc_constructor *last_con;
 258   gfc_constructor *pred;
 259   gfc_symbol *symbol;
 260   gfc_typespec *last_ts;
 261   mpz_t offset;
 262   splay_tree spt;
 263   splay_tree_node sptn;
 264
 265   symbol = lvalue->symtree->n.sym;
 266   init = symbol->value;
 267   last_ts = &symbol->ts;
 268   last_con = NULL;
 269   mpz_init_set_si (offset, 0);
 270
 271   /* Find/create the parent expressions for subobject references.  */
 272   for (ref = lvalue->ref; ref; ref = ref->next)
 273     {
 274       /* Break out of the loop if we find a substring.  */
 275       if (ref->type == REF_SUBSTRING)
 276         {
 277           /* A substring should always be the last subobject reference.  */
 278           gcc_assert (ref->next == NULL);
 279           break;
 280         }
 281
 282       /* Use the existing initializer expression if it exists.  Otherwise
 283          create a new one.  */
 284       if (init == NULL)
 285         expr = gfc_get_expr ();
 286       else
 287         expr = init;
 288
 289       /* Find or create this element.  */
 290       switch (ref->type)
 291         {
 292         case REF_ARRAY:
 293           if (init && expr->expr_type != EXPR_ARRAY)
 294             {
 295               gfc_error ("'%s' at %L already is initialized at %L",
 296                          lvalue->symtree->n.sym->name, &lvalue->where,
 297                          &init->where);
 298               return FAILURE;
 299             }
 300
 301           if (init == NULL)
 302             {
 303               /* The element typespec will be the same as the array
 304                  typespec.  */
 305               expr->ts = *last_ts;
 306               /* Setup the expression to hold the constructor.  */
 307               expr->expr_type = EXPR_ARRAY;
 308               expr->rank = ref->u.ar.as->rank;
 309             }
 310
 311           if (ref->u.ar.type == AR_ELEMENT)
 312             get_array_index (&ref->u.ar, &offset);
 313           else
 314             mpz_set (offset, index);
 315
 316           /* Check the bounds.  */
 317           if (mpz_cmp_si (offset, 0) < 0)
 318             {
 319               gfc_error ("Data element below array lower bound at %L",
 320                          &lvalue->where);
 321               return FAILURE;
 322             }
 323           else
 324             {
 325               mpz_t size;
 326               if (spec_size (ref->u.ar.as, &size) == SUCCESS)
 327                 {
 328                   if (mpz_cmp (offset, size) >= 0)
 329                   {
 330                     mpz_clear (size);
 331                     gfc_error ("Data element above array upper bound at %L",
 332                                &lvalue->where);
 333                     return FAILURE;
 334                   }
 335                   mpz_clear (size);
 336                 }
 337             }
 338
 339           /* Splay tree containing offset and gfc_constructor.  */
 340           spt = expr->con_by_offset;
 341
 342           if (spt == NULL)
 343             {
 344                spt = splay_tree_new (splay_tree_compare_ints, NULL, NULL);
 345                expr->con_by_offset = spt;
 346                con = NULL;
 347             }
 348          else
 349           con = find_con_by_offset (spt, offset);
 350
 351           if (con == NULL)
 352             {
 353               splay_tree_key j;
 354
 355               /* Create a new constructor.  */
 356               con = gfc_get_constructor ();
 357               mpz_set (con->n.offset, offset);
 358               j = (splay_tree_key) mpz_get_si (offset);
 359               sptn = splay_tree_insert (spt, j, (splay_tree_value) con);
 360               /* Fix up the linked list.  */
 361               sptn = splay_tree_predecessor (spt, j);
 362               if (sptn == NULL)
 363                 {  /* Insert at the head.  */
 364                    con->next = expr->value.constructor;
 365                    expr->value.constructor = con;
 366                 }
 367               else
 368                 {  /* Insert in the chain.  */
 369                    pred = (gfc_constructor*) sptn->value;
 370                    con->next = pred->next;
 371                    pred->next = con;
 372                 }
 373             }
 374           break;
 375
 376         case REF_COMPONENT:
 377           if (init == NULL)
 378             {
 379               /* Setup the expression to hold the constructor.  */
 380               expr->expr_type = EXPR_STRUCTURE;
 381               expr->ts.type = BT_DERIVED;
 382               expr->ts.derived = ref->u.c.sym;
 383             }
 384           else
 385             gcc_assert (expr->expr_type == EXPR_STRUCTURE);
 386           last_ts = &ref->u.c.component->ts;
 387
 388           /* Find the same element in the existing constructor.  */
 389           con = expr->value.constructor;
 390           con = find_con_by_component (ref->u.c.component, con);
 391
 392           if (con == NULL)
 393             {
 394               /* Create a new constructor.  */
 395               con = gfc_get_constructor ();
 396               con->n.component = ref->u.c.component;
 397               con->next = expr->value.constructor;
 398               expr->value.constructor = con;
 399             }
 400           break;
 401
 402         default:
 403           gcc_unreachable ();
 404         }
 405
 406       if (init == NULL)
 407         {
 408           /* Point the container at the new expression.  */
 409           if (last_con == NULL)
 410             symbol->value = expr;
 411           else
 412             last_con->expr = expr;
 413         }
 414       init = con->expr;
 415       last_con = con;
 416     }
 417
 418   if (ref || last_ts->type == BT_CHARACTER)
 419     expr = create_character_intializer (init, last_ts, ref, rvalue);
 420   else
 421     {
 422       /* Overwriting an existing initializer is non-standard but usually only
 423          provokes a warning from other compilers.  */
 424       if (init != NULL)
 425         {
 426           /* Order in which the expressions arrive here depends on whether
 427              they are from data statements or F95 style declarations.
 428              Therefore, check which is the most recent.  */
 429           expr = (LOCATION_LINE (init->where.lb->location)
 430                   > LOCATION_LINE (rvalue->where.lb->location))
 431                ? init : rvalue;
 432           gfc_notify_std (GFC_STD_GNU, "Extension: re-initialization "
 433                           "of '%s' at %L", symbol->name, &expr->where);
 434         }
 435
 436       expr = gfc_copy_expr (rvalue);
 437       if (!gfc_compare_types (&lvalue->ts, &expr->ts))
 438         gfc_convert_type (expr, &lvalue->ts, 0);
 439     }
 440
 441   if (last_con == NULL)
 442     symbol->value = expr;
 443   else
 444     last_con->expr = expr;
 445
 446   return SUCCESS;
 447 }
 448
 449
 450 /* Similarly, but initialize REPEAT consecutive values in LVALUE the same
 451    value in RVALUE.  For the nonce, LVALUE must refer to a full array, not
 452    an array section.  */
 453
 454 void
 455 gfc_assign_data_value_range (gfc_expr *lvalue, gfc_expr *rvalue,
 456                              mpz_t index, mpz_t repeat)
 457 {
 458   gfc_ref *ref;
 459   gfc_expr *init, *expr;
 460   gfc_constructor *con, *last_con;
 461   gfc_constructor *pred;
 462   gfc_symbol *symbol;
 463   gfc_typespec *last_ts;
 464   mpz_t offset;
 465   splay_tree spt;
 466   splay_tree_node sptn;
 467
 468   symbol = lvalue->symtree->n.sym;
 469   init = symbol->value;
 470   last_ts = &symbol->ts;
 471   last_con = NULL;
 472   mpz_init_set_si (offset, 0);
 473
 474   /* Find/create the parent expressions for subobject references.  */
 475   for (ref = lvalue->ref; ref; ref = ref->next)
 476     {
 477       /* Use the existing initializer expression if it exists.
 478          Otherwise create a new one.  */
 479       if (init == NULL)
 480         expr = gfc_get_expr ();
 481       else
 482         expr = init;
 483
 484       /* Find or create this element.  */
 485       switch (ref->type)
 486         {
 487         case REF_ARRAY:
 488           if (init == NULL)
 489             {
 490               /* The element typespec will be the same as the array
 491                  typespec.  */
 492               expr->ts = *last_ts;
 493               /* Setup the expression to hold the constructor.  */
 494               expr->expr_type = EXPR_ARRAY;
 495               expr->rank = ref->u.ar.as->rank;
 496             }
 497           else
 498             gcc_assert (expr->expr_type == EXPR_ARRAY);
 499
 500           if (ref->u.ar.type == AR_ELEMENT)
 501             {
 502               get_array_index (&ref->u.ar, &offset);
 503
 504               /* This had better not be the bottom of the reference.
 505                  We can still get to a full array via a component.  */
 506               gcc_assert (ref->next != NULL);
 507             }
 508           else
 509             {
 510               mpz_set (offset, index);
 511
 512               /* We're at a full array or an array section.  This means
 513                  that we've better have found a full array, and that we're
 514                  at the bottom of the reference.  */
 515               gcc_assert (ref->u.ar.type == AR_FULL);
 516               gcc_assert (ref->next == NULL);
 517             }
 518
 519           /* Find the same element in the existing constructor.  */
 520
 521           /* Splay tree containing offset and gfc_constructor.  */
 522           spt = expr->con_by_offset;
 523
 524           if (spt == NULL)
 525             {
 526                spt = splay_tree_new (splay_tree_compare_ints, NULL, NULL);
 527                expr->con_by_offset = spt;
 528                con = NULL;
 529             }
 530           else
 531             con = find_con_by_offset (spt, offset);
 532
 533           if (con == NULL)
 534             {
 535               splay_tree_key j;
 536               /* Create a new constructor.  */
 537               con = gfc_get_constructor ();
 538               mpz_set (con->n.offset, offset);
 539               j = (splay_tree_key) mpz_get_si (offset);
 540
 541               if (ref->next == NULL)
 542                 mpz_set (con->repeat, repeat);
 543               sptn = splay_tree_insert (spt, j, (splay_tree_value) con);
 544               /* Fix up the linked list.  */
 545               sptn = splay_tree_predecessor (spt, j);
 546               if (sptn == NULL)
 547                 {  /* Insert at the head.  */
 548                    con->next = expr->value.constructor;
 549                    expr->value.constructor = con;
 550                 }
 551               else
 552                 {  /* Insert in the chain.  */
 553                    pred = (gfc_constructor*) sptn->value;
 554                    con->next = pred->next;
 555                    pred->next = con;
 556                 }
 557             }
 558           else
 559             gcc_assert (ref->next != NULL);
 560           break;
 561
 562         case REF_COMPONENT:
 563           if (init == NULL)
 564             {
 565               /* Setup the expression to hold the constructor.  */
 566               expr->expr_type = EXPR_STRUCTURE;
 567               expr->ts.type = BT_DERIVED;
 568               expr->ts.derived = ref->u.c.sym;
 569             }
 570           else
 571             gcc_assert (expr->expr_type == EXPR_STRUCTURE);
 572           last_ts = &ref->u.c.component->ts;
 573
 574           /* Find the same element in the existing constructor.  */
 575           con = expr->value.constructor;
 576           con = find_con_by_component (ref->u.c.component, con);
 577
 578           if (con == NULL)
 579             {
 580               /* Create a new constructor.  */
 581               con = gfc_get_constructor ();
 582               con->n.component = ref->u.c.component;
 583               con->next = expr->value.constructor;
 584               expr->value.constructor = con;
 585             }
 586
 587           /* Since we're only intending to initialize arrays here,
 588              there better be an inner reference.  */
 589           gcc_assert (ref->next != NULL);
 590           break;
 591
 592         case REF_SUBSTRING:
 593         default:
 594           gcc_unreachable ();
 595         }
 596
 597       if (init == NULL)
 598         {
 599           /* Point the container at the new expression.  */
 600           if (last_con == NULL)
 601             symbol->value = expr;
 602           else
 603             last_con->expr = expr;
 604         }
 605       init = con->expr;
 606       last_con = con;
 607     }
 608
 609   if (last_ts->type == BT_CHARACTER)
 610     expr = create_character_intializer (init, last_ts, NULL, rvalue);
 611   else
 612     {
 613       /* We should never be overwriting an existing initializer.  */
 614       gcc_assert (!init);
 615
 616       expr = gfc_copy_expr (rvalue);
 617       if (!gfc_compare_types (&lvalue->ts, &expr->ts))
 618         gfc_convert_type (expr, &lvalue->ts, 0);
 619     }
 620
 621   if (last_con == NULL)
 622     symbol->value = expr;
 623   else
 624     last_con->expr = expr;
 625 }
 626
 627 /* Modify the index of array section and re-calculate the array offset.  */
 628
 629 void
 630 gfc_advance_section (mpz_t *section_index, gfc_array_ref *ar,
 631                      mpz_t *offset_ret)
 632 {
 633   int i;
 634   mpz_t delta;
 635   mpz_t tmp;
 636   bool forwards;
 637   int cmp;
 638
 639   for (i = 0; i < ar->dimen; i++)
 640     {
 641       if (ar->dimen_type[i] != DIMEN_RANGE)
 642         continue;
 643
 644       if (ar->stride[i])
 645         {
 646           mpz_add (section_index[i], section_index[i],
 647                    ar->stride[i]->value.integer);
 648         if (mpz_cmp_si (ar->stride[i]->value.integer, 0) >= 0)
 649           forwards = true;
 650         else
 651           forwards = false;
 652         }
 653       else
 654         {
 655           mpz_add_ui (section_index[i], section_index[i], 1);
 656           forwards = true;
 657         }
 658
 659       if (ar->end[i])
 660         cmp = mpz_cmp (section_index[i], ar->end[i]->value.integer);
 661       else
 662         cmp = mpz_cmp (section_index[i], ar->as->upper[i]->value.integer);
 663
 664       if ((cmp > 0 && forwards) || (cmp < 0 && !forwards))
 665         {
 666           /* Reset index to start, then loop to advance the next index.  */
 667           if (ar->start[i])
 668             mpz_set (section_index[i], ar->start[i]->value.integer);
 669           else
 670             mpz_set (section_index[i], ar->as->lower[i]->value.integer);
 671         }
 672       else
 673         break;
 674     }
 675
 676   mpz_set_si (*offset_ret, 0);
 677   mpz_init_set_si (delta, 1);
 678   mpz_init (tmp);
 679   for (i = 0; i < ar->dimen; i++)
 680     {
 681       mpz_sub (tmp, section_index[i], ar->as->lower[i]->value.integer);
 682       mpz_mul (tmp, tmp, delta);
 683       mpz_add (*offset_ret, tmp, *offset_ret);
 684
 685       mpz_sub (tmp, ar->as->upper[i]->value.integer,
 686                ar->as->lower[i]->value.integer);
 687       mpz_add_ui (tmp, tmp, 1);
 688       mpz_mul (delta, tmp, delta);
 689     }
 690   mpz_clear (tmp);
 691   mpz_clear (delta);
 692 }
 693
 694
 695 /* Rearrange a structure constructor so the elements are in the specified
 696    order.  Also insert NULL entries if necessary.  */
 697
 698 static void
 699 formalize_structure_cons (gfc_expr *expr)
 700 {
 701   gfc_constructor *head;
 702   gfc_constructor *tail;
 703   gfc_constructor *cur;
 704   gfc_constructor *last;
 705   gfc_constructor *c;
 706   gfc_component *order;
 707
 708   c = expr->value.constructor;
 709
 710   /* Constructor is already formalized.  */
 711   if (!c || c->n.component == NULL)
 712     return;
 713
 714   head = tail = NULL;
 715   for (order = expr->ts.derived->components; order; order = order->next)
 716     {
 717       /* Find the next component.  */
 718       last = NULL;
 719       cur = c;
 720       while (cur != NULL && cur->n.component != order)
 721         {
 722           last = cur;
 723           cur = cur->next;
 724         }
 725
 726       if (cur == NULL)
 727         {
 728           /* Create a new one.  */
 729           cur = gfc_get_constructor ();
 730         }
 731       else
 732         {
 733           /* Remove it from the chain.  */
 734           if (last == NULL)
 735             c = cur->next;
 736           else
 737             last->next = cur->next;
 738           cur->next = NULL;
 739
 740           formalize_init_expr (cur->expr);
 741         }
 742
 743       /* Add it to the new constructor.  */
 744       if (head == NULL)
 745         head = tail = cur;
 746       else
 747         {
 748           tail->next = cur;
 749           tail = tail->next;
 750         }
 751     }
 752   gcc_assert (c == NULL);
 753   expr->value.constructor = head;
 754 }
 755
 756
 757 /* Make sure an initialization expression is in normalized form.  Ie. all
 758    elements of the constructors are in the correct order.  */
 759
 760 static void
 761 formalize_init_expr (gfc_expr *expr)
 762 {
 763   expr_t type;
 764   gfc_constructor *c;
 765
 766   if (expr == NULL)
 767     return;
 768
 769   type = expr->expr_type;
 770   switch (type)
 771     {
 772     case EXPR_ARRAY:
 773       c = expr->value.constructor;
 774       while (c)
 775         {
 776           formalize_init_expr (c->expr);
 777           c = c->next;
 778         }
 779       break;
 780
 781     case EXPR_STRUCTURE:
 782       formalize_structure_cons (expr);
 783       break;
 784
 785     default:
 786       break;
 787     }
 788 }
 789
 790
 791 /* Resolve symbol's initial value after all data statement.  */
 792
 793 void
 794 gfc_formalize_init_value (gfc_symbol *sym)
 795 {
 796   formalize_init_expr (sym->value);
 797 }
 798
 799
 800 /* Get the integer value into RET_AS and SECTION from AS and AR, and return
 801    offset.  */
 802
 803 void
 804 gfc_get_section_index (gfc_array_ref *ar, mpz_t *section_index, mpz_t *offset)
 805 {
 806   int i;
 807   mpz_t delta;
 808   mpz_t tmp;
 809
 810   mpz_set_si (*offset, 0);
 811   mpz_init (tmp);
 812   mpz_init_set_si (delta, 1);
 813   for (i = 0; i < ar->dimen; i++)
 814     {
 815       mpz_init (section_index[i]);
 816       switch (ar->dimen_type[i])
 817         {
 818         case DIMEN_ELEMENT:
 819         case DIMEN_RANGE:
 820           if (ar->start[i])
 821             {
 822               mpz_sub (tmp, ar->start[i]->value.integer,
 823                        ar->as->lower[i]->value.integer);
 824               mpz_mul (tmp, tmp, delta);
 825               mpz_add (*offset, tmp, *offset);
 826               mpz_set (section_index[i], ar->start[i]->value.integer);
 827             }
 828           else
 829               mpz_set (section_index[i], ar->as->lower[i]->value.integer);
 830           break;
 831
 832         case DIMEN_VECTOR:
 833           gfc_internal_error ("TODO: Vector sections in data statements");
 834
 835         default:
 836           gcc_unreachable ();
 837         }
 838
 839       mpz_sub (tmp, ar->as->upper[i]->value.integer,
 840                ar->as->lower[i]->value.integer);
 841       mpz_add_ui (tmp, tmp, 1);
 842       mpz_mul (delta, tmp, delta);
 843     }
 844
 845   mpz_clear (tmp);
 846   mpz_clear (delta);
 847 }
 848