gcc/fortran/data.c

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