gcc/fortran/data.c

   1 /* Supporting functions for resolving DATA statement.
   2    Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
   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 resolving 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   mpz_t delta;
  50   mpz_t tmp;
  51
  52   mpz_init (tmp);
  53   mpz_set_si (*offset, 0);
  54   mpz_init_set_si (delta, 1);
  55   for (i = 0; i < ar->dimen; i++)
  56     {
  57       e = gfc_copy_expr (ar->start[i]);
  58       gfc_simplify_expr (e, 1);
  59
  60       if ((gfc_is_constant_expr (ar->as->lower[i]) == 0)
  61           || (gfc_is_constant_expr (ar->as->upper[i]) == 0)
  62           || (gfc_is_constant_expr (e) == 0))
  63         gfc_error ("non-constant array in DATA statement %L", &ar->where);
  64
  65       mpz_set (tmp, e->value.integer);
  66       mpz_sub (tmp, tmp, ar->as->lower[i]->value.integer);
  67       mpz_mul (tmp, tmp, delta);
  68       mpz_add (*offset, tmp, *offset);
  69
  70       mpz_sub (tmp, ar->as->upper[i]->value.integer,
  71                ar->as->lower[i]->value.integer);
  72       mpz_add_ui (tmp, tmp, 1);
  73       mpz_mul (delta, tmp, delta);
  74     }
  75   mpz_clear (delta);
  76   mpz_clear (tmp);
  77 }
  78
  79
  80 /* Find if there is a constructor which offset is equal to OFFSET.  */
  81
  82 static gfc_constructor *
  83 find_con_by_offset (splay_tree spt, mpz_t offset)
  84 {
  85   mpz_t tmp;
  86   gfc_constructor *ret = NULL;
  87   gfc_constructor *con;
  88   splay_tree_node sptn;
  89
  90   /* The complexity is due to needing quick access to the linked list of
  91      constructors.  Both a linked list and a splay tree are used, and both
  92      are kept up to date if they are array elements (which is the only time
  93      that a specific constructor has to be found).  */
  94
  95   gcc_assert (spt != NULL);
  96   mpz_init (tmp);
  97
  98   sptn = splay_tree_lookup (spt, (splay_tree_key) mpz_get_si (offset));
  99
 100   if (sptn)
 101     ret = (gfc_constructor*) sptn->value;
 102   else
 103     {
 104        /* Need to check and see if we match a range, so we will pull
 105           the next lowest index and see if the range matches.  */
 106        sptn = splay_tree_predecessor (spt,
 107                                       (splay_tree_key) mpz_get_si (offset));
 108        if (sptn)
 109          {
 110             con = (gfc_constructor*) sptn->value;
 111             if (mpz_cmp_ui (con->repeat, 1) > 0)
 112               {
 113                  mpz_init (tmp);
 114                  mpz_add (tmp, con->n.offset, con->repeat);
 115                  if (mpz_cmp (offset, tmp) < 0)
 116                    ret = con;
 117                  mpz_clear (tmp);
 118               }
 119             else
 120               ret = NULL; /* The range did not match.  */
 121          }
 122       else
 123         ret = NULL; /* No pred, so no match.  */
 124     }
 125
 126   return ret;
 127 }
 128
 129
 130 /* Find if there is a constructor which component is equal to COM.  */
 131
 132 static gfc_constructor *
 133 find_con_by_component (gfc_component *com, gfc_constructor *con)
 134 {
 135   for (; con; con = con->next)
 136     {
 137       if (com == con->n.component)
 138         return con;
 139     }
 140   return NULL;
 141 }
 142
 143
 144 /* Create a character type initialization expression from RVALUE.
 145    TS [and REF] describe [the substring of] the variable being initialized.
 146    INIT is the existing initializer, not NULL.  Initialization is performed
 147    according to normal assignment rules.  */
 148
 149 static gfc_expr *
 150 create_character_intializer (gfc_expr *init, gfc_typespec *ts,
 151                              gfc_ref *ref, gfc_expr *rvalue)
 152 {
 153   int len, start, end;
 154   gfc_char_t *dest;
 155
 156   gfc_extract_int (ts->u.cl->length, &len);
 157
 158   if (init == NULL)
 159     {
 160       /* Create a new initializer.  */
 161       init = gfc_get_expr ();
 162       init->expr_type = EXPR_CONSTANT;
 163       init->ts = *ts;
 164
 165       dest = gfc_get_wide_string (len + 1);
 166       dest[len] = '\0';
 167       init->value.character.length = len;
 168       init->value.character.string = dest;
 169       /* Blank the string if we're only setting a substring.  */
 170       if (ref != NULL)
 171         gfc_wide_memset (dest, ' ', len);
 172     }
 173   else
 174     dest = init->value.character.string;
 175
 176   if (ref)
 177     {
 178       gfc_expr *start_expr, *end_expr;
 179
 180       gcc_assert (ref->type == REF_SUBSTRING);
 181
 182       /* Only set a substring of the destination.  Fortran substring bounds
 183          are one-based [start, end], we want zero based [start, end).  */
 184       start_expr = gfc_copy_expr (ref->u.ss.start);
 185       end_expr = gfc_copy_expr (ref->u.ss.end);
 186
 187       if ((gfc_simplify_expr (start_expr, 1) == FAILURE)
 188           || (gfc_simplify_expr (end_expr, 1)) == FAILURE)
 189         {
 190           gfc_error ("failure to simplify substring reference in DATA "
 191                      "statement at %L", &ref->u.ss.start->where);
 192           return NULL;
 193         }
 194
 195       gfc_extract_int (start_expr, &start);
 196       start--;
 197       gfc_extract_int (end_expr, &end);
 198     }
 199   else
 200     {
 201       /* Set the whole string.  */
 202       start = 0;
 203       end = len;
 204     }
 205
 206   /* Copy the initial value.  */
 207   if (rvalue->ts.type == BT_HOLLERITH)
 208     len = rvalue->representation.length;
 209   else
 210     len = rvalue->value.character.length;
 211
 212   if (len > end - start)
 213     {
 214       len = end - start;
 215       gfc_warning_now ("initialization string truncated to match variable "
 216                        "at %L", &rvalue->where);
 217     }
 218
 219   if (rvalue->ts.type == BT_HOLLERITH)
 220     {
 221       int i;
 222       for (i = 0; i < len; i++)
 223         dest[start+i] = rvalue->representation.string[i];
 224     }
 225   else
 226     memcpy (&dest[start], rvalue->value.character.string,
 227             len * sizeof (gfc_char_t));
 228
 229   /* Pad with spaces.  Substrings will already be blanked.  */
 230   if (len < end - start && ref == NULL)
 231     gfc_wide_memset (&dest[start + len], ' ', end - (start + len));
 232
 233   if (rvalue->ts.type == BT_HOLLERITH)
 234     {
 235       init->representation.length = init->value.character.length;
 236       init->representation.string
 237         = gfc_widechar_to_char (init->value.character.string,
 238                                 init->value.character.length);
 239     }
 240
 241   return init;
 242 }
 243
 244
 245 /* Assign the initial value RVALUE to  LVALUE's symbol->value. If the
 246    LVALUE already has an initialization, we extend this, otherwise we
 247    create a new one.  */
 248
 249 gfc_try
 250 gfc_assign_data_value (gfc_expr *lvalue, gfc_expr *rvalue, mpz_t index)
 251 {
 252   gfc_ref *ref;
 253   gfc_expr *init;
 254   gfc_expr *expr;
 255   gfc_constructor *con;
 256   gfc_constructor *last_con;
 257   gfc_constructor *pred;
 258   gfc_symbol *symbol;
 259   gfc_typespec *last_ts;
 260   mpz_t offset;
 261   splay_tree spt;
 262   splay_tree_node sptn;
 263
 264   symbol = lvalue->symtree->n.sym;
 265   init = symbol->value;
 266   last_ts = &symbol->ts;
 267   last_con = NULL;
 268   mpz_init_set_si (offset, 0);
 269
 270   /* Find/create the parent expressions for subobject references.  */
 271   for (ref = lvalue->ref; ref; ref = ref->next)
 272     {
 273       /* Break out of the loop if we find a substring.  */
 274       if (ref->type == REF_SUBSTRING)
 275         {
 276           /* A substring should always be the last subobject reference.  */
 277           gcc_assert (ref->next == NULL);
 278           break;
 279         }
 280
 281       /* Use the existing initializer expression if it exists.  Otherwise
 282          create a new one.  */
 283       if (init == NULL)
 284         expr = gfc_get_expr ();
 285       else
 286         expr = init;
 287
 288       /* Find or create this element.  */
 289       switch (ref->type)
 290         {
 291         case REF_ARRAY:
 292           if (init && expr->expr_type != EXPR_ARRAY)
 293             {
 294               gfc_error ("'%s' at %L already is initialized at %L",
 295                          lvalue->symtree->n.sym->name, &lvalue->where,
 296                          &init->where);
 297               return FAILURE;
 298             }
 299
 300           if (init == NULL)
 301             {
 302               /* The element typespec will be the same as the array
 303                  typespec.  */
 304               expr->ts = *last_ts;
 305               /* Setup the expression to hold the constructor.  */
 306               expr->expr_type = EXPR_ARRAY;
 307               expr->rank = ref->u.ar.as->rank;
 308             }
 309
 310           if (ref->u.ar.type == AR_ELEMENT)
 311             get_array_index (&ref->u.ar, &offset);
 312           else
 313             mpz_set (offset, index);
 314
 315           /* Check the bounds.  */
 316           if (mpz_cmp_si (offset, 0) < 0)
 317             {
 318               gfc_error ("Data element below array lower bound at %L",
 319                          &lvalue->where);
 320               return FAILURE;
 321             }
 322           else
 323             {
 324               mpz_t size;
 325               if (spec_size (ref->u.ar.as, &size) == SUCCESS)
 326                 {
 327                   if (mpz_cmp (offset, size) >= 0)
 328                   {
 329                     mpz_clear (size);
 330                     gfc_error ("Data element above array upper bound at %L",
 331                                &lvalue->where);
 332                     return FAILURE;
 333                   }
 334                   mpz_clear (size);
 335                 }
 336             }
 337
 338           /* Splay tree containing offset and gfc_constructor.  */
 339           spt = expr->con_by_offset;
 340
 341           if (spt == NULL)
 342             {
 343                spt = splay_tree_new (splay_tree_compare_ints, NULL, NULL);
 344                expr->con_by_offset = spt;
 345                con = NULL;
 346             }
 347          else
 348           con = find_con_by_offset (spt, offset);
 349
 350           if (con == NULL)
 351             {
 352               splay_tree_key j;
 353
 354               /* Create a new constructor.  */
 355               con = gfc_get_constructor ();
 356               mpz_set (con->n.offset, offset);
 357               j = (splay_tree_key) mpz_get_si (offset);
 358               sptn = splay_tree_insert (spt, j, (splay_tree_value) con);
 359               /* Fix up the linked list.  */
 360               sptn = splay_tree_predecessor (spt, j);
 361               if (sptn == NULL)
 362                 {  /* Insert at the head.  */
 363                    con->next = expr->value.constructor;
 364                    expr->value.constructor = con;
 365                 }
 366               else
 367                 {  /* Insert in the chain.  */
 368                    pred = (gfc_constructor*) sptn->value;
 369                    con->next = pred->next;
 370                    pred->next = con;
 371                 }
 372             }
 373           break;
 374
 375         case REF_COMPONENT:
 376           if (init == NULL)
 377             {
 378               /* Setup the expression to hold the constructor.  */
 379               expr->expr_type = EXPR_STRUCTURE;
 380               expr->ts.type = BT_DERIVED;
 381               expr->ts.u.derived = ref->u.c.sym;
 382             }
 383           else
 384             gcc_assert (expr->expr_type == EXPR_STRUCTURE);
 385           last_ts = &ref->u.c.component->ts;
 386
 387           /* Find the same element in the existing constructor.  */
 388           con = expr->value.constructor;
 389           con = find_con_by_component (ref->u.c.component, con);
 390
 391           if (con == NULL)
 392             {
 393               /* Create a new constructor.  */
 394               con = gfc_get_constructor ();
 395               con->n.component = ref->u.c.component;
 396               con->next = expr->value.constructor;
 397               expr->value.constructor = con;
 398             }
 399           break;
 400
 401         default:
 402           gcc_unreachable ();
 403         }
 404
 405       if (init == NULL)
 406         {
 407           /* Point the container at the new expression.  */
 408           if (last_con == NULL)
 409             symbol->value = expr;
 410           else
 411             last_con->expr = expr;
 412         }
 413       init = con->expr;
 414       last_con = con;
 415     }
 416
 417   if (ref || last_ts->type == BT_CHARACTER)
 418     {
 419       if (lvalue->ts.u.cl->length == NULL && !(ref && ref->u.ss.length != NULL))
 420         return FAILURE;
 421       expr = create_character_intializer (init, last_ts, ref, rvalue);
 422     }
 423   else
 424     {
 425       /* Overwriting an existing initializer is non-standard but usually only
 426          provokes a warning from other compilers.  */
 427       if (init != NULL)
 428         {
 429           /* Order in which the expressions arrive here depends on whether
 430              they are from data statements or F95 style declarations.
 431              Therefore, check which is the most recent.  */
 432           expr = (LOCATION_LINE (init->where.lb->location)
 433                   > LOCATION_LINE (rvalue->where.lb->location))
 434                ? init : rvalue;
 435           gfc_notify_std (GFC_STD_GNU, "Extension: re-initialization "
 436                           "of '%s' at %L", symbol->name, &expr->where);
 437         }
 438
 439       expr = gfc_copy_expr (rvalue);
 440       if (!gfc_compare_types (&lvalue->ts, &expr->ts))
 441         gfc_convert_type (expr, &lvalue->ts, 0);
 442     }
 443
 444   if (last_con == NULL)
 445     symbol->value = expr;
 446   else
 447     last_con->expr = expr;
 448
 449   return SUCCESS;
 450 }
 451
 452
 453 /* Similarly, but initialize REPEAT consecutive values in LVALUE the same
 454    value in RVALUE.  For the nonce, LVALUE must refer to a full array, not
 455    an array section.  */
 456
 457 void
 458 gfc_assign_data_value_range (gfc_expr *lvalue, gfc_expr *rvalue,
 459                              mpz_t index, mpz_t repeat)
 460 {
 461   gfc_ref *ref;
 462   gfc_expr *init, *expr;
 463   gfc_constructor *con, *last_con;
 464   gfc_constructor *pred;
 465   gfc_symbol *symbol;
 466   gfc_typespec *last_ts;
 467   mpz_t offset;
 468   splay_tree spt;
 469   splay_tree_node sptn;
 470
 471   symbol = lvalue->symtree->n.sym;
 472   init = symbol->value;
 473   last_ts = &symbol->ts;
 474   last_con = NULL;
 475   mpz_init_set_si (offset, 0);
 476
 477   /* Find/create the parent expressions for subobject references.  */
 478   for (ref = lvalue->ref; ref; ref = ref->next)
 479     {
 480       /* Use the existing initializer expression if it exists.
 481          Otherwise create a new one.  */
 482       if (init == NULL)
 483         expr = gfc_get_expr ();
 484       else
 485         expr = init;
 486
 487       /* Find or create this element.  */
 488       switch (ref->type)
 489         {
 490         case REF_ARRAY:
 491           if (init == NULL)
 492             {
 493               /* The element typespec will be the same as the array
 494                  typespec.  */
 495               expr->ts = *last_ts;
 496               /* Setup the expression to hold the constructor.  */
 497               expr->expr_type = EXPR_ARRAY;
 498               expr->rank = ref->u.ar.as->rank;
 499             }
 500           else
 501             gcc_assert (expr->expr_type == EXPR_ARRAY);
 502
 503           if (ref->u.ar.type == AR_ELEMENT)
 504             {
 505               get_array_index (&ref->u.ar, &offset);
 506
 507               /* This had better not be the bottom of the reference.
 508                  We can still get to a full array via a component.  */
 509               gcc_assert (ref->next != NULL);
 510             }
 511           else
 512             {
 513               mpz_set (offset, index);
 514
 515               /* We're at a full array or an array section.  This means
 516                  that we've better have found a full array, and that we're
 517                  at the bottom of the reference.  */
 518               gcc_assert (ref->u.ar.type == AR_FULL);
 519               gcc_assert (ref->next == NULL);
 520             }
 521
 522           /* Find the same element in the existing constructor.  */
 523
 524           /* Splay tree containing offset and gfc_constructor.  */
 525           spt = expr->con_by_offset;
 526
 527           if (spt == NULL)
 528             {
 529                spt = splay_tree_new (splay_tree_compare_ints, NULL, NULL);
 530                expr->con_by_offset = spt;
 531                con = NULL;
 532             }
 533           else
 534             con = find_con_by_offset (spt, offset);
 535
 536           if (con == NULL)
 537             {
 538               splay_tree_key j;
 539               /* Create a new constructor.  */
 540               con = gfc_get_constructor ();
 541               mpz_set (con->n.offset, offset);
 542               j = (splay_tree_key) mpz_get_si (offset);
 543
 544               if (ref->next == NULL)
 545                 mpz_set (con->repeat, repeat);
 546               sptn = splay_tree_insert (spt, j, (splay_tree_value) con);
 547               /* Fix up the linked list.  */
 548               sptn = splay_tree_predecessor (spt, j);
 549               if (sptn == NULL)
 550                 {  /* Insert at the head.  */
 551                    con->next = expr->value.constructor;
 552                    expr->value.constructor = con;
 553                 }
 554               else
 555                 {  /* Insert in the chain.  */
 556                    pred = (gfc_constructor*) sptn->value;
 557                    con->next = pred->next;
 558                    pred->next = con;
 559                 }
 560             }
 561           else
 562             gcc_assert (ref->next != NULL);
 563           break;
 564
 565         case REF_COMPONENT:
 566           if (init == NULL)
 567             {
 568               /* Setup the expression to hold the constructor.  */
 569               expr->expr_type = EXPR_STRUCTURE;
 570               expr->ts.type = BT_DERIVED;
 571               expr->ts.u.derived = ref->u.c.sym;
 572             }
 573           else
 574             gcc_assert (expr->expr_type == EXPR_STRUCTURE);
 575           last_ts = &ref->u.c.component->ts;
 576
 577           /* Find the same element in the existing constructor.  */
 578           con = expr->value.constructor;
 579           con = find_con_by_component (ref->u.c.component, con);
 580
 581           if (con == NULL)
 582             {
 583               /* Create a new constructor.  */
 584               con = gfc_get_constructor ();
 585               con->n.component = ref->u.c.component;
 586               con->next = expr->value.constructor;
 587               expr->value.constructor = con;
 588             }
 589
 590           /* Since we're only intending to initialize arrays here,
 591              there better be an inner reference.  */
 592           gcc_assert (ref->next != NULL);
 593           break;
 594
 595         case REF_SUBSTRING:
 596         default:
 597           gcc_unreachable ();
 598         }
 599
 600       if (init == NULL)
 601         {
 602           /* Point the container at the new expression.  */
 603           if (last_con == NULL)
 604             symbol->value = expr;
 605           else
 606             last_con->expr = expr;
 607         }
 608       init = con->expr;
 609       last_con = con;
 610     }
 611
 612   if (last_ts->type == BT_CHARACTER)
 613     expr = create_character_intializer (init, last_ts, NULL, rvalue);
 614   else
 615     {
 616       /* We should never be overwriting an existing initializer.  */
 617       gcc_assert (!init);
 618
 619       expr = gfc_copy_expr (rvalue);
 620       if (!gfc_compare_types (&lvalue->ts, &expr->ts))
 621         gfc_convert_type (expr, &lvalue->ts, 0);
 622     }
 623
 624   if (last_con == NULL)
 625     symbol->value = expr;
 626   else
 627     last_con->expr = expr;
 628 }
 629
 630 /* Modify the index of array section and re-calculate the array offset.  */
 631
 632 void
 633 gfc_advance_section (mpz_t *section_index, gfc_array_ref *ar,
 634                      mpz_t *offset_ret)
 635 {
 636   int i;
 637   mpz_t delta;
 638   mpz_t tmp;
 639   bool forwards;
 640   int cmp;
 641
 642   for (i = 0; i < ar->dimen; i++)
 643     {
 644       if (ar->dimen_type[i] != DIMEN_RANGE)
 645         continue;
 646
 647       if (ar->stride[i])
 648         {
 649           mpz_add (section_index[i], section_index[i],
 650                    ar->stride[i]->value.integer);
 651         if (mpz_cmp_si (ar->stride[i]->value.integer, 0) >= 0)
 652           forwards = true;
 653         else
 654           forwards = false;
 655         }
 656       else
 657         {
 658           mpz_add_ui (section_index[i], section_index[i], 1);
 659           forwards = true;
 660         }
 661
 662       if (ar->end[i])
 663         cmp = mpz_cmp (section_index[i], ar->end[i]->value.integer);
 664       else
 665         cmp = mpz_cmp (section_index[i], ar->as->upper[i]->value.integer);
 666
 667       if ((cmp > 0 && forwards) || (cmp < 0 && !forwards))
 668         {
 669           /* Reset index to start, then loop to advance the next index.  */
 670           if (ar->start[i])
 671             mpz_set (section_index[i], ar->start[i]->value.integer);
 672           else
 673             mpz_set (section_index[i], ar->as->lower[i]->value.integer);
 674         }
 675       else
 676         break;
 677     }
 678
 679   mpz_set_si (*offset_ret, 0);
 680   mpz_init_set_si (delta, 1);
 681   mpz_init (tmp);
 682   for (i = 0; i < ar->dimen; i++)
 683     {
 684       mpz_sub (tmp, section_index[i], ar->as->lower[i]->value.integer);
 685       mpz_mul (tmp, tmp, delta);
 686       mpz_add (*offset_ret, tmp, *offset_ret);
 687
 688       mpz_sub (tmp, ar->as->upper[i]->value.integer,
 689                ar->as->lower[i]->value.integer);
 690       mpz_add_ui (tmp, tmp, 1);
 691       mpz_mul (delta, tmp, delta);
 692     }
 693   mpz_clear (tmp);
 694   mpz_clear (delta);
 695 }
 696
 697
 698 /* Rearrange a structure constructor so the elements are in the specified
 699    order.  Also insert NULL entries if necessary.  */
 700
 701 static void
 702 formalize_structure_cons (gfc_expr *expr)
 703 {
 704   gfc_constructor *head;
 705   gfc_constructor *tail;
 706   gfc_constructor *cur;
 707   gfc_constructor *last;
 708   gfc_constructor *c;
 709   gfc_component *order;
 710
 711   c = expr->value.constructor;
 712
 713   /* Constructor is already formalized.  */
 714   if (!c || c->n.component == NULL)
 715     return;
 716
 717   head = tail = NULL;
 718   for (order = expr->ts.u.derived->components; order; order = order->next)
 719     {
 720       /* Find the next component.  */
 721       last = NULL;
 722       cur = c;
 723       while (cur != NULL && cur->n.component != order)
 724         {
 725           last = cur;
 726           cur = cur->next;
 727         }
 728
 729       if (cur == NULL)
 730         {
 731           /* Create a new one.  */
 732           cur = gfc_get_constructor ();
 733         }
 734       else
 735         {
 736           /* Remove it from the chain.  */
 737           if (last == NULL)
 738             c = cur->next;
 739           else
 740             last->next = cur->next;
 741           cur->next = NULL;
 742
 743           formalize_init_expr (cur->expr);
 744         }
 745
 746       /* Add it to the new constructor.  */
 747       if (head == NULL)
 748         head = tail = cur;
 749       else
 750         {
 751           tail->next = cur;
 752           tail = tail->next;
 753         }
 754     }
 755   gcc_assert (c == NULL);
 756   expr->value.constructor = head;
 757 }
 758
 759
 760 /* Make sure an initialization expression is in normalized form, i.e., all
 761    elements of the constructors are in the correct order.  */
 762
 763 static void
 764 formalize_init_expr (gfc_expr *expr)
 765 {
 766   expr_t type;
 767   gfc_constructor *c;
 768
 769   if (expr == NULL)
 770     return;
 771
 772   type = expr->expr_type;
 773   switch (type)
 774     {
 775     case EXPR_ARRAY:
 776       c = expr->value.constructor;
 777       while (c)
 778         {
 779           formalize_init_expr (c->expr);
 780           c = c->next;
 781         }
 782       break;
 783
 784     case EXPR_STRUCTURE:
 785       formalize_structure_cons (expr);
 786       break;
 787
 788     default:
 789       break;
 790     }
 791 }
 792
 793
 794 /* Resolve symbol's initial value after all data statement.  */
 795
 796 void
 797 gfc_formalize_init_value (gfc_symbol *sym)
 798 {
 799   formalize_init_expr (sym->value);
 800 }
 801
 802
 803 /* Get the integer value into RET_AS and SECTION from AS and AR, and return
 804    offset.  */
 805
 806 void
 807 gfc_get_section_index (gfc_array_ref *ar, mpz_t *section_index, mpz_t *offset)
 808 {
 809   int i;
 810   mpz_t delta;
 811   mpz_t tmp;
 812
 813   mpz_set_si (*offset, 0);
 814   mpz_init (tmp);
 815   mpz_init_set_si (delta, 1);
 816   for (i = 0; i < ar->dimen; i++)
 817     {
 818       mpz_init (section_index[i]);
 819       switch (ar->dimen_type[i])
 820         {
 821         case DIMEN_ELEMENT:
 822         case DIMEN_RANGE:
 823           if (ar->start[i])
 824             {
 825               mpz_sub (tmp, ar->start[i]->value.integer,
 826                        ar->as->lower[i]->value.integer);
 827               mpz_mul (tmp, tmp, delta);
 828               mpz_add (*offset, tmp, *offset);
 829               mpz_set (section_index[i], ar->start[i]->value.integer);
 830             }
 831           else
 832               mpz_set (section_index[i], ar->as->lower[i]->value.integer);
 833           break;
 834
 835         case DIMEN_VECTOR:
 836           gfc_internal_error ("TODO: Vector sections in data statements");
 837
 838         default:
 839           gcc_unreachable ();
 840         }
 841
 842       mpz_sub (tmp, ar->as->upper[i]->value.integer,
 843                ar->as->lower[i]->value.integer);
 844       mpz_add_ui (tmp, tmp, 1);
 845       mpz_mul (delta, tmp, delta);
 846     }
 847
 848   mpz_clear (tmp);
 849   mpz_clear (delta);
 850 }
 851