ld/ldexp.c

   1 /* This module handles expression trees.
   2    Copyright (C) 1991-2014 Free Software Foundation, Inc.
   3    Written by Steve Chamberlain of Cygnus Support <sac@cygnus.com>.
   4
   5    This file is part of the GNU Binutils.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  20    MA 02110-1301, USA.  */
  21
  22
  23 /* This module is in charge of working out the contents of expressions.
  24
  25    It has to keep track of the relative/absness of a symbol etc. This
  26    is done by keeping all values in a struct (an etree_value_type)
  27    which contains a value, a section to which it is relative and a
  28    valid bit.  */
  29
  30 #include "sysdep.h"
  31 #include "bfd.h"
  32 #include "bfdlink.h"
  33
  34 #include "ld.h"
  35 #include "ldmain.h"
  36 #include "ldmisc.h"
  37 #include "ldexp.h"
  38 #include "ldlex.h"
  39 #include <ldgram.h>
  40 #include "ldlang.h"
  41 #include "libiberty.h"
  42 #include "safe-ctype.h"
  43
  44 static void exp_fold_tree_1 (etree_type *);
  45 static bfd_vma align_n (bfd_vma, bfd_vma);
  46
  47 segment_type *segments;
  48
  49 struct ldexp_control expld;
  50
  51 /* Print the string representation of the given token.  Surround it
  52    with spaces if INFIX_P is TRUE.  */
  53
  54 static void
  55 exp_print_token (token_code_type code, int infix_p)
  56 {
  57   static const struct
  58   {
  59     token_code_type code;
  60     const char * name;
  61   }
  62   table[] =
  63   {
  64     { INT, "int" },
  65     { NAME, "NAME" },
  66     { PLUSEQ, "+=" },
  67     { MINUSEQ, "-=" },
  68     { MULTEQ, "*=" },
  69     { DIVEQ, "/=" },
  70     { LSHIFTEQ, "<<=" },
  71     { RSHIFTEQ, ">>=" },
  72     { ANDEQ, "&=" },
  73     { OREQ, "|=" },
  74     { OROR, "||" },
  75     { ANDAND, "&&" },
  76     { EQ, "==" },
  77     { NE, "!=" },
  78     { LE, "<=" },
  79     { GE, ">=" },
  80     { LSHIFT, "<<" },
  81     { RSHIFT, ">>" },
  82     { LOG2CEIL, "LOG2CEIL" },
  83     { ALIGN_K, "ALIGN" },
  84     { BLOCK, "BLOCK" },
  85     { QUAD, "QUAD" },
  86     { SQUAD, "SQUAD" },
  87     { LONG, "LONG" },
  88     { SHORT, "SHORT" },
  89     { BYTE, "BYTE" },
  90     { SECTIONS, "SECTIONS" },
  91     { SIZEOF_HEADERS, "SIZEOF_HEADERS" },
  92     { MEMORY, "MEMORY" },
  93     { DEFINED, "DEFINED" },
  94     { TARGET_K, "TARGET" },
  95     { SEARCH_DIR, "SEARCH_DIR" },
  96     { MAP, "MAP" },
  97     { ENTRY, "ENTRY" },
  98     { NEXT, "NEXT" },
  99     { ALIGNOF, "ALIGNOF" },
 100     { SIZEOF, "SIZEOF" },
 101     { ADDR, "ADDR" },
 102     { LOADADDR, "LOADADDR" },
 103     { CONSTANT, "CONSTANT" },
 104     { ABSOLUTE, "ABSOLUTE" },
 105     { MAX_K, "MAX" },
 106     { MIN_K, "MIN" },
 107     { ASSERT_K, "ASSERT" },
 108     { REL, "relocatable" },
 109     { DATA_SEGMENT_ALIGN, "DATA_SEGMENT_ALIGN" },
 110     { DATA_SEGMENT_RELRO_END, "DATA_SEGMENT_RELRO_END" },
 111     { DATA_SEGMENT_END, "DATA_SEGMENT_END" },
 112     { ORIGIN, "ORIGIN" },
 113     { LENGTH, "LENGTH" },
 114     { SEGMENT_START, "SEGMENT_START" }
 115   };
 116   unsigned int idx;
 117
 118   for (idx = 0; idx < ARRAY_SIZE (table); idx++)
 119     if (table[idx].code == code)
 120       break;
 121
 122   if (infix_p)
 123     fputc (' ', config.map_file);
 124
 125   if (idx < ARRAY_SIZE (table))
 126     fputs (table[idx].name, config.map_file);
 127   else if (code < 127)
 128     fputc (code, config.map_file);
 129   else
 130     fprintf (config.map_file, "<code %d>", code);
 131
 132   if (infix_p)
 133     fputc (' ', config.map_file);
 134 }
 135
 136 static void
 137 make_log2ceil (void)
 138 {
 139   bfd_vma value = expld.result.value;
 140   bfd_vma result = -1;
 141   bfd_boolean round_up = FALSE;
 142
 143   do
 144     {
 145       result++;
 146       /* If more than one bit is set in the value we will need to round up.  */
 147       if ((value > 1) && (value & 1))
 148         round_up = TRUE;
 149     }
 150   while (value >>= 1);
 151
 152   if (round_up)
 153     result += 1;
 154   expld.result.section = NULL;
 155   expld.result.value = result;
 156 }
 157
 158 static void
 159 make_abs (void)
 160 {
 161   if (expld.result.section != NULL)
 162     expld.result.value += expld.result.section->vma;
 163   expld.result.section = bfd_abs_section_ptr;
 164 }
 165
 166 static void
 167 new_abs (bfd_vma value)
 168 {
 169   expld.result.valid_p = TRUE;
 170   expld.result.section = bfd_abs_section_ptr;
 171   expld.result.value = value;
 172   expld.result.str = NULL;
 173 }
 174
 175 etree_type *
 176 exp_intop (bfd_vma value)
 177 {
 178   etree_type *new_e = (etree_type *) stat_alloc (sizeof (new_e->value));
 179   new_e->type.node_code = INT;
 180   new_e->type.filename = ldlex_filename ();
 181   new_e->type.lineno = lineno;
 182   new_e->value.value = value;
 183   new_e->value.str = NULL;
 184   new_e->type.node_class = etree_value;
 185   return new_e;
 186 }
 187
 188 etree_type *
 189 exp_bigintop (bfd_vma value, char *str)
 190 {
 191   etree_type *new_e = (etree_type *) stat_alloc (sizeof (new_e->value));
 192   new_e->type.node_code = INT;
 193   new_e->type.filename = ldlex_filename ();
 194   new_e->type.lineno = lineno;
 195   new_e->value.value = value;
 196   new_e->value.str = str;
 197   new_e->type.node_class = etree_value;
 198   return new_e;
 199 }
 200
 201 /* Build an expression representing an unnamed relocatable value.  */
 202
 203 etree_type *
 204 exp_relop (asection *section, bfd_vma value)
 205 {
 206   etree_type *new_e = (etree_type *) stat_alloc (sizeof (new_e->rel));
 207   new_e->type.node_code = REL;
 208   new_e->type.filename = ldlex_filename ();
 209   new_e->type.lineno = lineno;
 210   new_e->type.node_class = etree_rel;
 211   new_e->rel.section = section;
 212   new_e->rel.value = value;
 213   return new_e;
 214 }
 215
 216 static void
 217 new_number (bfd_vma value)
 218 {
 219   expld.result.valid_p = TRUE;
 220   expld.result.value = value;
 221   expld.result.str = NULL;
 222   expld.result.section = NULL;
 223 }
 224
 225 static void
 226 new_rel (bfd_vma value, asection *section)
 227 {
 228   expld.result.valid_p = TRUE;
 229   expld.result.value = value;
 230   expld.result.str = NULL;
 231   expld.result.section = section;
 232 }
 233
 234 static void
 235 new_rel_from_abs (bfd_vma value)
 236 {
 237   asection *s = expld.section;
 238
 239   if (s == bfd_abs_section_ptr && expld.phase == lang_final_phase_enum)
 240     s = section_for_dot ();
 241   expld.result.valid_p = TRUE;
 242   expld.result.value = value - s->vma;
 243   expld.result.str = NULL;
 244   expld.result.section = s;
 245 }
 246
 247 static void
 248 fold_unary (etree_type *tree)
 249 {
 250   exp_fold_tree_1 (tree->unary.child);
 251   if (expld.result.valid_p)
 252     {
 253       switch (tree->type.node_code)
 254         {
 255         case ALIGN_K:
 256           if (expld.phase != lang_first_phase_enum)
 257             new_rel_from_abs (align_n (expld.dot, expld.result.value));
 258           else
 259             expld.result.valid_p = FALSE;
 260           break;
 261
 262         case ABSOLUTE:
 263           make_abs ();
 264           break;
 265
 266         case LOG2CEIL:
 267           make_log2ceil ();
 268           break;
 269
 270         case '~':
 271           expld.result.value = ~expld.result.value;
 272           break;
 273
 274         case '!':
 275           expld.result.value = !expld.result.value;
 276           break;
 277
 278         case '-':
 279           expld.result.value = -expld.result.value;
 280           break;
 281
 282         case NEXT:
 283           /* Return next place aligned to value.  */
 284           if (expld.phase != lang_first_phase_enum)
 285             {
 286               make_abs ();
 287               expld.result.value = align_n (expld.dot, expld.result.value);
 288             }
 289           else
 290             expld.result.valid_p = FALSE;
 291           break;
 292
 293         case DATA_SEGMENT_END:
 294           if (expld.phase == lang_first_phase_enum
 295               || expld.section != bfd_abs_section_ptr)
 296             {
 297               expld.result.valid_p = FALSE;
 298             }
 299           else if (expld.dataseg.phase == exp_dataseg_align_seen
 300                    || expld.dataseg.phase == exp_dataseg_relro_seen)
 301             {
 302               expld.dataseg.phase = exp_dataseg_end_seen;
 303               expld.dataseg.end = expld.result.value;
 304             }
 305           else if (expld.dataseg.phase == exp_dataseg_done
 306                    || expld.dataseg.phase == exp_dataseg_adjust
 307                    || expld.dataseg.phase == exp_dataseg_relro_adjust)
 308             {
 309               /* OK.  */
 310             }
 311           else
 312             expld.result.valid_p = FALSE;
 313           break;
 314
 315         default:
 316           FAIL ();
 317           break;
 318         }
 319     }
 320 }
 321
 322 static void
 323 fold_binary (etree_type *tree)
 324 {
 325   etree_value_type lhs;
 326   exp_fold_tree_1 (tree->binary.lhs);
 327
 328   /* The SEGMENT_START operator is special because its first
 329      operand is a string, not the name of a symbol.  Note that the
 330      operands have been swapped, so binary.lhs is second (default)
 331      operand, binary.rhs is first operand.  */
 332   if (expld.result.valid_p && tree->type.node_code == SEGMENT_START)
 333     {
 334       const char *segment_name;
 335       segment_type *seg;
 336
 337       /* Check to see if the user has overridden the default
 338          value.  */
 339       segment_name = tree->binary.rhs->name.name;
 340       for (seg = segments; seg; seg = seg->next)
 341         if (strcmp (seg->name, segment_name) == 0)
 342           {
 343             if (!seg->used
 344                 && config.magic_demand_paged
 345                 && (seg->value % config.maxpagesize) != 0)
 346               einfo (_("%P: warning: address of `%s' isn't multiple of maximum page size\n"),
 347                      segment_name);
 348             seg->used = TRUE;
 349             new_rel_from_abs (seg->value);
 350             break;
 351           }
 352       return;
 353     }
 354
 355   lhs = expld.result;
 356   exp_fold_tree_1 (tree->binary.rhs);
 357   expld.result.valid_p &= lhs.valid_p;
 358
 359   if (expld.result.valid_p)
 360     {
 361       if (lhs.section != expld.result.section)
 362         {
 363           /* If the values are from different sections, and neither is
 364              just a number, make both the source arguments absolute.  */
 365           if (expld.result.section != NULL
 366               && lhs.section != NULL)
 367             {
 368               make_abs ();
 369               lhs.value += lhs.section->vma;
 370               lhs.section = bfd_abs_section_ptr;
 371             }
 372
 373           /* If the rhs is just a number, keep the lhs section.  */
 374           else if (expld.result.section == NULL)
 375             {
 376               expld.result.section = lhs.section;
 377               /* Make this NULL so that we know one of the operands
 378                  was just a number, for later tests.  */
 379               lhs.section = NULL;
 380             }
 381         }
 382       /* At this point we know that both operands have the same
 383          section, or at least one of them is a plain number.  */
 384
 385       switch (tree->type.node_code)
 386         {
 387           /* Arithmetic operators, bitwise AND, bitwise OR and XOR
 388              keep the section of one of their operands only when the
 389              other operand is a plain number.  Losing the section when
 390              operating on two symbols, ie. a result of a plain number,
 391              is required for subtraction and XOR.  It's justifiable
 392              for the other operations on the grounds that adding,
 393              multiplying etc. two section relative values does not
 394              really make sense unless they are just treated as
 395              numbers.
 396              The same argument could be made for many expressions
 397              involving one symbol and a number.  For example,
 398              "1 << x" and "100 / x" probably should not be given the
 399              section of x.  The trouble is that if we fuss about such
 400              things the rules become complex and it is onerous to
 401              document ld expression evaluation.  */
 402 #define BOP(x, y) \
 403         case x:                                                 \
 404           expld.result.value = lhs.value y expld.result.value;  \
 405           if (expld.result.section == lhs.section)              \
 406             expld.result.section = NULL;                        \
 407           break;
 408
 409           /* Comparison operators, logical AND, and logical OR always
 410              return a plain number.  */
 411 #define BOPN(x, y) \
 412         case x:                                                 \
 413           expld.result.value = lhs.value y expld.result.value;  \
 414           expld.result.section = NULL;                          \
 415           break;
 416
 417           BOP ('+', +);
 418           BOP ('*', *);
 419           BOP ('-', -);
 420           BOP (LSHIFT, <<);
 421           BOP (RSHIFT, >>);
 422           BOP ('&', &);
 423           BOP ('^', ^);
 424           BOP ('|', |);
 425           BOPN (EQ, ==);
 426           BOPN (NE, !=);
 427           BOPN ('<', <);
 428           BOPN ('>', >);
 429           BOPN (LE, <=);
 430           BOPN (GE, >=);
 431           BOPN (ANDAND, &&);
 432           BOPN (OROR, ||);
 433
 434         case '%':
 435           if (expld.result.value != 0)
 436             expld.result.value = ((bfd_signed_vma) lhs.value
 437                                   % (bfd_signed_vma) expld.result.value);
 438           else if (expld.phase != lang_mark_phase_enum)
 439             einfo (_("%F%S %% by zero\n"), tree->binary.rhs);
 440           if (expld.result.section == lhs.section)
 441             expld.result.section = NULL;
 442           break;
 443
 444         case '/':
 445           if (expld.result.value != 0)
 446             expld.result.value = ((bfd_signed_vma) lhs.value
 447                                   / (bfd_signed_vma) expld.result.value);
 448           else if (expld.phase != lang_mark_phase_enum)
 449             einfo (_("%F%S / by zero\n"), tree->binary.rhs);
 450           if (expld.result.section == lhs.section)
 451             expld.result.section = NULL;
 452           break;
 453
 454         case MAX_K:
 455           if (lhs.value > expld.result.value)
 456             expld.result.value = lhs.value;
 457           break;
 458
 459         case MIN_K:
 460           if (lhs.value < expld.result.value)
 461             expld.result.value = lhs.value;
 462           break;
 463
 464         case ALIGN_K:
 465           expld.result.value = align_n (lhs.value, expld.result.value);
 466           break;
 467
 468         case DATA_SEGMENT_ALIGN:
 469           expld.dataseg.relro = exp_dataseg_relro_start;
 470           if (expld.phase == lang_first_phase_enum
 471               || expld.section != bfd_abs_section_ptr)
 472             expld.result.valid_p = FALSE;
 473           else
 474             {
 475               bfd_vma maxpage = lhs.value;
 476               bfd_vma commonpage = expld.result.value;
 477
 478               expld.result.value = align_n (expld.dot, maxpage);
 479               if (expld.dataseg.phase == exp_dataseg_relro_adjust)
 480                 expld.result.value = expld.dataseg.base;
 481               else if (expld.dataseg.phase == exp_dataseg_adjust)
 482                 {
 483                   if (commonpage < maxpage)
 484                     expld.result.value += ((expld.dot + commonpage - 1)
 485                                            & (maxpage - commonpage));
 486                 }
 487               else
 488                 {
 489                   expld.result.value += expld.dot & (maxpage - 1);
 490                   if (expld.dataseg.phase == exp_dataseg_done)
 491                     {
 492                       /* OK.  */
 493                     }
 494                   else if (expld.dataseg.phase == exp_dataseg_none)
 495                     {
 496                       expld.dataseg.phase = exp_dataseg_align_seen;
 497                       expld.dataseg.min_base = expld.dot;
 498                       expld.dataseg.base = expld.result.value;
 499                       expld.dataseg.pagesize = commonpage;
 500                       expld.dataseg.maxpagesize = maxpage;
 501                       expld.dataseg.relro_end = 0;
 502                     }
 503                   else
 504                     expld.result.valid_p = FALSE;
 505                 }
 506             }
 507           break;
 508
 509         case DATA_SEGMENT_RELRO_END:
 510           expld.dataseg.relro = exp_dataseg_relro_end;
 511           if (expld.phase == lang_first_phase_enum
 512               || expld.section != bfd_abs_section_ptr)
 513             expld.result.valid_p = FALSE;
 514           else if (expld.dataseg.phase == exp_dataseg_align_seen
 515                    || expld.dataseg.phase == exp_dataseg_adjust
 516                    || expld.dataseg.phase == exp_dataseg_relro_adjust
 517                    || expld.dataseg.phase == exp_dataseg_done)
 518             {
 519               if (expld.dataseg.phase == exp_dataseg_align_seen
 520                   || expld.dataseg.phase == exp_dataseg_relro_adjust)
 521                 expld.dataseg.relro_end = lhs.value + expld.result.value;
 522
 523               if (expld.dataseg.phase == exp_dataseg_relro_adjust
 524                   && (expld.dataseg.relro_end
 525                       & (expld.dataseg.pagesize - 1)))
 526                 {
 527                   expld.dataseg.relro_end += expld.dataseg.pagesize - 1;
 528                   expld.dataseg.relro_end &= ~(expld.dataseg.pagesize - 1);
 529                   expld.result.value = (expld.dataseg.relro_end
 530                                         - expld.result.value);
 531                 }
 532               else
 533                 expld.result.value = lhs.value;
 534
 535               if (expld.dataseg.phase == exp_dataseg_align_seen)
 536                 expld.dataseg.phase = exp_dataseg_relro_seen;
 537             }
 538           else
 539             expld.result.valid_p = FALSE;
 540           break;
 541
 542         default:
 543           FAIL ();
 544         }
 545     }
 546 }
 547
 548 static void
 549 fold_trinary (etree_type *tree)
 550 {
 551   exp_fold_tree_1 (tree->trinary.cond);
 552   if (expld.result.valid_p)
 553     exp_fold_tree_1 (expld.result.value
 554                      ? tree->trinary.lhs
 555                      : tree->trinary.rhs);
 556 }
 557
 558 static void
 559 fold_name (etree_type *tree)
 560 {
 561   memset (&expld.result, 0, sizeof (expld.result));
 562
 563   switch (tree->type.node_code)
 564     {
 565     case SIZEOF_HEADERS:
 566       if (expld.phase != lang_first_phase_enum)
 567         {
 568           bfd_vma hdr_size = 0;
 569           /* Don't find the real header size if only marking sections;
 570              The bfd function may cache incorrect data.  */
 571           if (expld.phase != lang_mark_phase_enum)
 572             hdr_size = bfd_sizeof_headers (link_info.output_bfd, &link_info);
 573           new_number (hdr_size);
 574         }
 575       break;
 576
 577     case DEFINED:
 578       if (expld.phase != lang_first_phase_enum)
 579         {
 580           struct bfd_link_hash_entry *h;
 581           struct lang_definedness_hash_entry *def;
 582
 583           h = bfd_wrapped_link_hash_lookup (link_info.output_bfd,
 584                                             &link_info,
 585                                             tree->name.name,
 586                                             FALSE, FALSE, TRUE);
 587           new_number (h != NULL
 588                       && (h->type == bfd_link_hash_defined
 589                           || h->type == bfd_link_hash_defweak
 590                           || h->type == bfd_link_hash_common)
 591                       && ((def = lang_symbol_defined (tree->name.name)) == NULL
 592                           || def->by_object
 593                           || def->iteration == (lang_statement_iteration & 1)));
 594         }
 595       break;
 596
 597     case NAME:
 598       if (expld.assign_name != NULL
 599           && strcmp (expld.assign_name, tree->name.name) == 0)
 600         {
 601           /* Self-assignment is only allowed for absolute symbols
 602              defined in a linker script.  */
 603           struct bfd_link_hash_entry *h;
 604           struct lang_definedness_hash_entry *def;
 605
 606           h = bfd_wrapped_link_hash_lookup (link_info.output_bfd,
 607                                             &link_info,
 608                                             tree->name.name,
 609                                             FALSE, FALSE, TRUE);
 610           if (!(h != NULL
 611                 && (h->type == bfd_link_hash_defined
 612                     || h->type == bfd_link_hash_defweak)
 613                 && h->u.def.section == bfd_abs_section_ptr
 614                 && (def = lang_symbol_defined (tree->name.name)) != NULL
 615                 && def->iteration == (lang_statement_iteration & 1)))
 616             expld.assign_name = NULL;
 617         }
 618       if (expld.phase == lang_first_phase_enum)
 619         ;
 620       else if (tree->name.name[0] == '.' && tree->name.name[1] == 0)
 621         new_rel_from_abs (expld.dot);
 622       else
 623         {
 624           struct bfd_link_hash_entry *h;
 625
 626           h = bfd_wrapped_link_hash_lookup (link_info.output_bfd,
 627                                             &link_info,
 628                                             tree->name.name,
 629                                             TRUE, FALSE, TRUE);
 630           if (!h)
 631             einfo (_("%P%F: bfd_link_hash_lookup failed: %E\n"));
 632           else if (h->type == bfd_link_hash_defined
 633                    || h->type == bfd_link_hash_defweak)
 634             {
 635               asection *output_section;
 636
 637               output_section = h->u.def.section->output_section;
 638               if (output_section == NULL)
 639                 {
 640                   if (expld.phase == lang_mark_phase_enum)
 641                     new_rel (h->u.def.value, h->u.def.section);
 642                   else
 643                     einfo (_("%X%S: unresolvable symbol `%s'"
 644                              " referenced in expression\n"),
 645                            tree, tree->name.name);
 646                 }
 647               else if (output_section == bfd_abs_section_ptr
 648                        && (expld.section != bfd_abs_section_ptr
 649                            || config.sane_expr))
 650                 new_number (h->u.def.value + h->u.def.section->output_offset);
 651               else
 652                 new_rel (h->u.def.value + h->u.def.section->output_offset,
 653                          output_section);
 654             }
 655           else if (expld.phase == lang_final_phase_enum
 656                    || (expld.phase != lang_mark_phase_enum
 657                        && expld.assigning_to_dot))
 658             einfo (_("%F%S: undefined symbol `%s'"
 659                      " referenced in expression\n"),
 660                    tree, tree->name.name);
 661           else if (h->type == bfd_link_hash_new)
 662             {
 663               h->type = bfd_link_hash_undefined;
 664               h->u.undef.abfd = NULL;
 665               if (h->u.undef.next == NULL && h != link_info.hash->undefs_tail)
 666                 bfd_link_add_undef (link_info.hash, h);
 667             }
 668         }
 669       break;
 670
 671     case ADDR:
 672       if (expld.phase != lang_first_phase_enum)
 673         {
 674           lang_output_section_statement_type *os;
 675
 676           os = lang_output_section_find (tree->name.name);
 677           if (os == NULL)
 678             {
 679               if (expld.phase == lang_final_phase_enum)
 680                 einfo (_("%F%S: undefined section `%s'"
 681                          " referenced in expression\n"),
 682                        tree, tree->name.name);
 683             }
 684           else if (os->processed_vma)
 685             new_rel (0, os->bfd_section);
 686         }
 687       break;
 688
 689     case LOADADDR:
 690       if (expld.phase != lang_first_phase_enum)
 691         {
 692           lang_output_section_statement_type *os;
 693
 694           os = lang_output_section_find (tree->name.name);
 695           if (os == NULL)
 696             {
 697               if (expld.phase == lang_final_phase_enum)
 698                 einfo (_("%F%S: undefined section `%s'"
 699                          " referenced in expression\n"),
 700                        tree, tree->name.name);
 701             }
 702           else if (os->processed_lma)
 703             {
 704               if (os->load_base == NULL)
 705                 new_abs (os->bfd_section->lma);
 706               else
 707                 {
 708                   exp_fold_tree_1 (os->load_base);
 709                   if (expld.result.valid_p)
 710                     make_abs ();
 711                 }
 712             }
 713         }
 714       break;
 715
 716     case SIZEOF:
 717     case ALIGNOF:
 718       if (expld.phase != lang_first_phase_enum)
 719         {
 720           lang_output_section_statement_type *os;
 721
 722           os = lang_output_section_find (tree->name.name);
 723           if (os == NULL)
 724             {
 725               if (expld.phase == lang_final_phase_enum)
 726                 einfo (_("%F%S: undefined section `%s'"
 727                          " referenced in expression\n"),
 728                        tree, tree->name.name);
 729               new_number (0);
 730             }
 731           else if (os->bfd_section != NULL)
 732             {
 733               bfd_vma val;
 734
 735               if (tree->type.node_code == SIZEOF)
 736                 val = (os->bfd_section->size
 737                        / bfd_octets_per_byte (link_info.output_bfd));
 738               else
 739                 val = (bfd_vma)1 << os->bfd_section->alignment_power;
 740
 741               new_number (val);
 742             }
 743           else
 744             new_number (0);
 745         }
 746       break;
 747
 748     case LENGTH:
 749       {
 750         lang_memory_region_type *mem;
 751
 752         mem = lang_memory_region_lookup (tree->name.name, FALSE);
 753         if (mem != NULL)
 754           new_number (mem->length);
 755         else
 756           einfo (_("%F%S: undefined MEMORY region `%s'"
 757                    " referenced in expression\n"),
 758                  tree, tree->name.name);
 759       }
 760       break;
 761
 762     case ORIGIN:
 763       if (expld.phase != lang_first_phase_enum)
 764         {
 765           lang_memory_region_type *mem;
 766
 767           mem = lang_memory_region_lookup (tree->name.name, FALSE);
 768           if (mem != NULL)
 769             new_rel_from_abs (mem->origin);
 770           else
 771             einfo (_("%F%S: undefined MEMORY region `%s'"
 772                      " referenced in expression\n"),
 773                    tree, tree->name.name);
 774         }
 775       break;
 776
 777     case CONSTANT:
 778       if (strcmp (tree->name.name, "MAXPAGESIZE") == 0)
 779         new_number (config.maxpagesize);
 780       else if (strcmp (tree->name.name, "COMMONPAGESIZE") == 0)
 781         new_number (config.commonpagesize);
 782       else
 783         einfo (_("%F%S: unknown constant `%s' referenced in expression\n"),
 784                tree, tree->name.name);
 785       break;
 786
 787     default:
 788       FAIL ();
 789       break;
 790     }
 791 }
 792
 793 /* Return true if TREE is '.'.  */
 794
 795 static bfd_boolean
 796 is_dot (const etree_type *tree)
 797 {
 798   return (tree->type.node_class == etree_name
 799           && tree->type.node_code == NAME
 800           && tree->name.name[0] == '.'
 801           && tree->name.name[1] == 0);
 802 }
 803
 804 /* Return true if TREE is a constant equal to VAL.  */
 805
 806 static bfd_boolean
 807 is_value (const etree_type *tree, bfd_vma val)
 808 {
 809   return (tree->type.node_class == etree_value
 810           && tree->value.value == val);
 811 }
 812
 813 /* Return true if TREE is an absolute symbol equal to VAL defined in
 814    a linker script.  */
 815
 816 static bfd_boolean
 817 is_sym_value (const etree_type *tree, bfd_vma val)
 818 {
 819   struct bfd_link_hash_entry *h;
 820   struct lang_definedness_hash_entry *def;
 821
 822   return (tree->type.node_class == etree_name
 823           && tree->type.node_code == NAME
 824           && (def = lang_symbol_defined (tree->name.name)) != NULL
 825           && def->by_script
 826           && def->iteration == (lang_statement_iteration & 1)
 827           && (h = bfd_wrapped_link_hash_lookup (link_info.output_bfd,
 828                                                 &link_info,
 829                                                 tree->name.name,
 830                                                 FALSE, FALSE, TRUE)) != NULL
 831           && h->type == bfd_link_hash_defined
 832           && h->u.def.section == bfd_abs_section_ptr
 833           && h->u.def.value == val);
 834 }
 835
 836 /* Return true if TREE is ". != 0".  */
 837
 838 static bfd_boolean
 839 is_dot_ne_0 (const etree_type *tree)
 840 {
 841   return (tree->type.node_class == etree_binary
 842           && tree->type.node_code == NE
 843           && is_dot (tree->binary.lhs)
 844           && is_value (tree->binary.rhs, 0));
 845 }
 846
 847 /* Return true if TREE is ". = . + 0" or ". = . + sym" where sym is an
 848    absolute constant with value 0 defined in a linker script.  */
 849
 850 static bfd_boolean
 851 is_dot_plus_0 (const etree_type *tree)
 852 {
 853   return (tree->type.node_class == etree_binary
 854           && tree->type.node_code == '+'
 855           && is_dot (tree->binary.lhs)
 856           && (is_value (tree->binary.rhs, 0)
 857               || is_sym_value (tree->binary.rhs, 0)));
 858 }
 859
 860 /* Return true if TREE is "ALIGN (. != 0 ? some_expression : 1)".  */
 861
 862 static bfd_boolean
 863 is_align_conditional (const etree_type *tree)
 864 {
 865   if (tree->type.node_class == etree_unary
 866       && tree->type.node_code == ALIGN_K)
 867     {
 868       tree = tree->unary.child;
 869       return (tree->type.node_class == etree_trinary
 870               && is_dot_ne_0 (tree->trinary.cond)
 871               && is_value (tree->trinary.rhs, 1));
 872     }
 873   return 0;
 874 }
 875
 876 static void
 877 exp_fold_tree_1 (etree_type *tree)
 878 {
 879   if (tree == NULL)
 880     {
 881       memset (&expld.result, 0, sizeof (expld.result));
 882       return;
 883     }
 884
 885   switch (tree->type.node_class)
 886     {
 887     case etree_value:
 888       if (expld.section == bfd_abs_section_ptr
 889           && !config.sane_expr)
 890         new_abs (tree->value.value);
 891       else
 892         new_number (tree->value.value);
 893       expld.result.str = tree->value.str;
 894       break;
 895
 896     case etree_rel:
 897       if (expld.phase != lang_first_phase_enum)
 898         {
 899           asection *output_section = tree->rel.section->output_section;
 900           new_rel (tree->rel.value + tree->rel.section->output_offset,
 901                    output_section);
 902         }
 903       else
 904         memset (&expld.result, 0, sizeof (expld.result));
 905       break;
 906
 907     case etree_assert:
 908       exp_fold_tree_1 (tree->assert_s.child);
 909       if (expld.phase == lang_final_phase_enum && !expld.result.value)
 910         einfo ("%X%P: %s\n", tree->assert_s.message);
 911       break;
 912
 913     case etree_unary:
 914       fold_unary (tree);
 915       break;
 916
 917     case etree_binary:
 918       fold_binary (tree);
 919       break;
 920
 921     case etree_trinary:
 922       fold_trinary (tree);
 923       break;
 924
 925     case etree_assign:
 926     case etree_provide:
 927     case etree_provided:
 928       if (tree->assign.dst[0] == '.' && tree->assign.dst[1] == 0)
 929         {
 930           if (tree->type.node_class != etree_assign)
 931             einfo (_("%F%S can not PROVIDE assignment to"
 932                      " location counter\n"), tree);
 933           if (expld.phase != lang_first_phase_enum)
 934             {
 935               /* Notify the folder that this is an assignment to dot.  */
 936               expld.assigning_to_dot = TRUE;
 937               exp_fold_tree_1 (tree->assign.src);
 938               expld.assigning_to_dot = FALSE;
 939
 940               /* If we are assigning to dot inside an output section
 941                  arrange to keep the section, except for certain
 942                  expressions that evaluate to zero.  We ignore . = 0,
 943                  . = . + 0, and . = ALIGN (. != 0 ? expr : 1).  */
 944               if (expld.phase == lang_mark_phase_enum
 945                   && expld.section != bfd_abs_section_ptr
 946                   && !(expld.result.valid_p
 947                        && expld.result.value == 0
 948                        && (is_value (tree->assign.src, 0)
 949                            || is_sym_value (tree->assign.src, 0)
 950                            || is_dot_plus_0 (tree->assign.src)
 951                            || is_align_conditional (tree->assign.src))))
 952                 expld.section->flags |= SEC_KEEP;
 953
 954               if (!expld.result.valid_p)
 955                 {
 956                   if (expld.phase != lang_mark_phase_enum)
 957                     einfo (_("%F%S invalid assignment to"
 958                              " location counter\n"), tree);
 959                 }
 960               else if (expld.dotp == NULL)
 961                 einfo (_("%F%S assignment to location counter"
 962                          " invalid outside of SECTIONS\n"), tree);
 963
 964               /* After allocation, assignment to dot should not be
 965                  done inside an output section since allocation adds a
 966                  padding statement that effectively duplicates the
 967                  assignment.  */
 968               else if (expld.phase <= lang_allocating_phase_enum
 969                        || expld.section == bfd_abs_section_ptr)
 970                 {
 971                   bfd_vma nextdot;
 972
 973                   nextdot = expld.result.value;
 974                   if (expld.result.section != NULL)
 975                     nextdot += expld.result.section->vma;
 976                   else
 977                     nextdot += expld.section->vma;
 978                   if (nextdot < expld.dot
 979                       && expld.section != bfd_abs_section_ptr)
 980                     einfo (_("%F%S cannot move location counter backwards"
 981                              " (from %V to %V)\n"),
 982                            tree, expld.dot, nextdot);
 983                   else
 984                     {
 985                       expld.dot = nextdot;
 986                       *expld.dotp = nextdot;
 987                     }
 988                 }
 989             }
 990           else
 991             memset (&expld.result, 0, sizeof (expld.result));
 992         }
 993       else
 994         {
 995           struct bfd_link_hash_entry *h = NULL;
 996
 997           if (tree->type.node_class == etree_provide)
 998             {
 999               h = bfd_link_hash_lookup (link_info.hash, tree->assign.dst,
1000                                         FALSE, FALSE, TRUE);
1001               if (h == NULL
1002                   || (h->type != bfd_link_hash_new
1003                       && h->type != bfd_link_hash_undefined
1004                       && h->type != bfd_link_hash_common
1005                       && !(h->type == bfd_link_hash_defined
1006                            && (h->u.def.section->flags
1007                                & SEC_LINKER_CREATED) != 0)))
1008                 {
1009                   /* Do nothing.  The symbol was never referenced, or was
1010                      defined by some object.  */
1011                   break;
1012                 }
1013             }
1014
1015           expld.assign_name = tree->assign.dst;
1016           exp_fold_tree_1 (tree->assign.src);
1017           /* expld.assign_name remaining equal to tree->assign.dst
1018              below indicates the evaluation of tree->assign.src did
1019              not use the value of tree->assign.dst.  We don't allow
1020              self assignment until the final phase for two reasons:
1021              1) Expressions are evaluated multiple times.  With
1022              relaxation, the number of times may vary.
1023              2) Section relative symbol values cannot be correctly
1024              converted to absolute values, as is required by many
1025              expressions, until final section sizing is complete.  */
1026           if ((expld.result.valid_p
1027                && (expld.phase == lang_final_phase_enum
1028                    || expld.assign_name != NULL))
1029               || (expld.phase <= lang_mark_phase_enum
1030                   && tree->type.node_class == etree_assign
1031                   && tree->assign.defsym))
1032             {
1033               if (h == NULL)
1034                 {
1035                   h = bfd_link_hash_lookup (link_info.hash, tree->assign.dst,
1036                                             TRUE, FALSE, TRUE);
1037                   if (h == NULL)
1038                     einfo (_("%P%F:%s: hash creation failed\n"),
1039                            tree->assign.dst);
1040                 }
1041
1042               /* FIXME: Should we worry if the symbol is already
1043                  defined?  */
1044               lang_update_definedness (tree->assign.dst, h);
1045               h->type = bfd_link_hash_defined;
1046               h->u.def.value = expld.result.value;
1047               if (expld.result.section == NULL)
1048                 expld.result.section = expld.section;
1049               h->u.def.section = expld.result.section;
1050               if (tree->type.node_class == etree_provide)
1051                 tree->type.node_class = etree_provided;
1052
1053               /* Copy the symbol type if this is a simple assignment of
1054                  one symbol to another.  This could be more general
1055                  (e.g. a ?: operator with NAMEs in each branch).  */
1056               if (tree->assign.src->type.node_class == etree_name)
1057                 {
1058                   struct bfd_link_hash_entry *hsrc;
1059
1060                   hsrc = bfd_link_hash_lookup (link_info.hash,
1061                                                tree->assign.src->name.name,
1062                                                FALSE, FALSE, TRUE);
1063                   if (hsrc)
1064                     bfd_copy_link_hash_symbol_type (link_info.output_bfd, h,
1065                                                     hsrc);
1066                 }
1067             }
1068           else if (expld.phase == lang_final_phase_enum)
1069             {
1070               h = bfd_link_hash_lookup (link_info.hash, tree->assign.dst,
1071                                         FALSE, FALSE, TRUE);
1072               if (h != NULL
1073                   && h->type == bfd_link_hash_new)
1074                 h->type = bfd_link_hash_undefined;
1075             }
1076           expld.assign_name = NULL;
1077         }
1078       break;
1079
1080     case etree_name:
1081       fold_name (tree);
1082       break;
1083
1084     default:
1085       FAIL ();
1086       memset (&expld.result, 0, sizeof (expld.result));
1087       break;
1088     }
1089 }
1090
1091 void
1092 exp_fold_tree (etree_type *tree, asection *current_section, bfd_vma *dotp)
1093 {
1094   expld.dot = *dotp;
1095   expld.dotp = dotp;
1096   expld.section = current_section;
1097   exp_fold_tree_1 (tree);
1098 }
1099
1100 void
1101 exp_fold_tree_no_dot (etree_type *tree)
1102 {
1103   expld.dot = 0;
1104   expld.dotp = NULL;
1105   expld.section = bfd_abs_section_ptr;
1106   exp_fold_tree_1 (tree);
1107 }
1108
1109 etree_type *
1110 exp_binop (int code, etree_type *lhs, etree_type *rhs)
1111 {
1112   etree_type value, *new_e;
1113
1114   value.type.node_code = code;
1115   value.type.filename = lhs->type.filename;
1116   value.type.lineno = lhs->type.lineno;
1117   value.binary.lhs = lhs;
1118   value.binary.rhs = rhs;
1119   value.type.node_class = etree_binary;
1120   exp_fold_tree_no_dot (&value);
1121   if (expld.result.valid_p)
1122     return exp_intop (expld.result.value);
1123
1124   new_e = (etree_type *) stat_alloc (sizeof (new_e->binary));
1125   memcpy (new_e, &value, sizeof (new_e->binary));
1126   return new_e;
1127 }
1128
1129 etree_type *
1130 exp_trinop (int code, etree_type *cond, etree_type *lhs, etree_type *rhs)
1131 {
1132   etree_type value, *new_e;
1133
1134   value.type.node_code = code;
1135   value.type.filename = cond->type.filename;
1136   value.type.lineno = cond->type.lineno;
1137   value.trinary.lhs = lhs;
1138   value.trinary.cond = cond;
1139   value.trinary.rhs = rhs;
1140   value.type.node_class = etree_trinary;
1141   exp_fold_tree_no_dot (&value);
1142   if (expld.result.valid_p)
1143     return exp_intop (expld.result.value);
1144
1145   new_e = (etree_type *) stat_alloc (sizeof (new_e->trinary));
1146   memcpy (new_e, &value, sizeof (new_e->trinary));
1147   return new_e;
1148 }
1149
1150 etree_type *
1151 exp_unop (int code, etree_type *child)
1152 {
1153   etree_type value, *new_e;
1154
1155   value.unary.type.node_code = code;
1156   value.unary.type.filename = child->type.filename;
1157   value.unary.type.lineno = child->type.lineno;
1158   value.unary.child = child;
1159   value.unary.type.node_class = etree_unary;
1160   exp_fold_tree_no_dot (&value);
1161   if (expld.result.valid_p)
1162     return exp_intop (expld.result.value);
1163
1164   new_e = (etree_type *) stat_alloc (sizeof (new_e->unary));
1165   memcpy (new_e, &value, sizeof (new_e->unary));
1166   return new_e;
1167 }
1168
1169 etree_type *
1170 exp_nameop (int code, const char *name)
1171 {
1172   etree_type value, *new_e;
1173
1174   value.name.type.node_code = code;
1175   value.name.type.filename = ldlex_filename ();
1176   value.name.type.lineno = lineno;
1177   value.name.name = name;
1178   value.name.type.node_class = etree_name;
1179
1180   exp_fold_tree_no_dot (&value);
1181   if (expld.result.valid_p)
1182     return exp_intop (expld.result.value);
1183
1184   new_e = (etree_type *) stat_alloc (sizeof (new_e->name));
1185   memcpy (new_e, &value, sizeof (new_e->name));
1186   return new_e;
1187
1188 }
1189
1190 static etree_type *
1191 exp_assop (const char *dst,
1192            etree_type *src,
1193            enum node_tree_enum class,
1194            bfd_boolean defsym,
1195            bfd_boolean hidden)
1196 {
1197   etree_type *n;
1198
1199   n = (etree_type *) stat_alloc (sizeof (n->assign));
1200   n->assign.type.node_code = '=';
1201   n->assign.type.filename = src->type.filename;
1202   n->assign.type.lineno = src->type.lineno;
1203   n->assign.type.node_class = class;
1204   n->assign.src = src;
1205   n->assign.dst = dst;
1206   n->assign.defsym = defsym;
1207   n->assign.hidden = hidden;
1208   return n;
1209 }
1210
1211 /* Handle linker script assignments and HIDDEN.  */
1212
1213 etree_type *
1214 exp_assign (const char *dst, etree_type *src, bfd_boolean hidden)
1215 {
1216   return exp_assop (dst, src, etree_assign, FALSE, hidden);
1217 }
1218
1219 /* Handle --defsym command-line option.  */
1220
1221 etree_type *
1222 exp_defsym (const char *dst, etree_type *src)
1223 {
1224   return exp_assop (dst, src, etree_assign, TRUE, FALSE);
1225 }
1226
1227 /* Handle PROVIDE.  */
1228
1229 etree_type *
1230 exp_provide (const char *dst, etree_type *src, bfd_boolean hidden)
1231 {
1232   return exp_assop (dst, src, etree_provide, FALSE, hidden);
1233 }
1234
1235 /* Handle ASSERT.  */
1236
1237 etree_type *
1238 exp_assert (etree_type *exp, const char *message)
1239 {
1240   etree_type *n;
1241
1242   n = (etree_type *) stat_alloc (sizeof (n->assert_s));
1243   n->assert_s.type.node_code = '!';
1244   n->assert_s.type.filename = exp->type.filename;
1245   n->assert_s.type.lineno = exp->type.lineno;
1246   n->assert_s.type.node_class = etree_assert;
1247   n->assert_s.child = exp;
1248   n->assert_s.message = message;
1249   return n;
1250 }
1251
1252 void
1253 exp_print_tree (etree_type *tree)
1254 {
1255   bfd_boolean function_like;
1256
1257   if (config.map_file == NULL)
1258     config.map_file = stderr;
1259
1260   if (tree == NULL)
1261     {
1262       minfo ("NULL TREE\n");
1263       return;
1264     }
1265
1266   switch (tree->type.node_class)
1267     {
1268     case etree_value:
1269       minfo ("0x%v", tree->value.value);
1270       return;
1271     case etree_rel:
1272       if (tree->rel.section->owner != NULL)
1273         minfo ("%B:", tree->rel.section->owner);
1274       minfo ("%s+0x%v", tree->rel.section->name, tree->rel.value);
1275       return;
1276     case etree_assign:
1277       fputs (tree->assign.dst, config.map_file);
1278       exp_print_token (tree->type.node_code, TRUE);
1279       exp_print_tree (tree->assign.src);
1280       break;
1281     case etree_provide:
1282     case etree_provided:
1283       fprintf (config.map_file, "PROVIDE (%s, ", tree->assign.dst);
1284       exp_print_tree (tree->assign.src);
1285       fputc (')', config.map_file);
1286       break;
1287     case etree_binary:
1288       function_like = FALSE;
1289       switch (tree->type.node_code)
1290         {
1291         case MAX_K:
1292         case MIN_K:
1293         case ALIGN_K:
1294         case DATA_SEGMENT_ALIGN:
1295         case DATA_SEGMENT_RELRO_END:
1296           function_like = TRUE;
1297           break;
1298         case SEGMENT_START:
1299           /* Special handling because arguments are in reverse order and
1300              the segment name is quoted.  */
1301           exp_print_token (tree->type.node_code, FALSE);
1302           fputs (" (\"", config.map_file);
1303           exp_print_tree (tree->binary.rhs);
1304           fputs ("\", ", config.map_file);
1305           exp_print_tree (tree->binary.lhs);
1306           fputc (')', config.map_file);
1307           return;
1308         }
1309       if (function_like)
1310         {
1311           exp_print_token (tree->type.node_code, FALSE);
1312           fputc (' ', config.map_file);
1313         }
1314       fputc ('(', config.map_file);
1315       exp_print_tree (tree->binary.lhs);
1316       if (function_like)
1317         fprintf (config.map_file, ", ");
1318       else
1319         exp_print_token (tree->type.node_code, TRUE);
1320       exp_print_tree (tree->binary.rhs);
1321       fputc (')', config.map_file);
1322       break;
1323     case etree_trinary:
1324       exp_print_tree (tree->trinary.cond);
1325       fputc ('?', config.map_file);
1326       exp_print_tree (tree->trinary.lhs);
1327       fputc (':', config.map_file);
1328       exp_print_tree (tree->trinary.rhs);
1329       break;
1330     case etree_unary:
1331       exp_print_token (tree->unary.type.node_code, FALSE);
1332       if (tree->unary.child)
1333         {
1334           fprintf (config.map_file, " (");
1335           exp_print_tree (tree->unary.child);
1336           fputc (')', config.map_file);
1337         }
1338       break;
1339
1340     case etree_assert:
1341       fprintf (config.map_file, "ASSERT (");
1342       exp_print_tree (tree->assert_s.child);
1343       fprintf (config.map_file, ", %s)", tree->assert_s.message);
1344       break;
1345
1346     case etree_name:
1347       if (tree->type.node_code == NAME)
1348         fputs (tree->name.name, config.map_file);
1349       else
1350         {
1351           exp_print_token (tree->type.node_code, FALSE);
1352           if (tree->name.name)
1353             fprintf (config.map_file, " (%s)", tree->name.name);
1354         }
1355       break;
1356     default:
1357       FAIL ();
1358       break;
1359     }
1360 }
1361
1362 bfd_vma
1363 exp_get_vma (etree_type *tree, bfd_vma def, char *name)
1364 {
1365   if (tree != NULL)
1366     {
1367       exp_fold_tree_no_dot (tree);
1368       if (expld.result.valid_p)
1369         return expld.result.value;
1370       else if (name != NULL && expld.phase != lang_mark_phase_enum)
1371         einfo (_("%F%S: nonconstant expression for %s\n"),
1372                tree, name);
1373     }
1374   return def;
1375 }
1376
1377 int
1378 exp_get_value_int (etree_type *tree, int def, char *name)
1379 {
1380   return exp_get_vma (tree, def, name);
1381 }
1382
1383 fill_type *
1384 exp_get_fill (etree_type *tree, fill_type *def, char *name)
1385 {
1386   fill_type *fill;
1387   size_t len;
1388   unsigned int val;
1389
1390   if (tree == NULL)
1391     return def;
1392
1393   exp_fold_tree_no_dot (tree);
1394   if (!expld.result.valid_p)
1395     {
1396       if (name != NULL && expld.phase != lang_mark_phase_enum)
1397         einfo (_("%F%S: nonconstant expression for %s\n"),
1398                tree, name);
1399       return def;
1400     }
1401
1402   if (expld.result.str != NULL && (len = strlen (expld.result.str)) != 0)
1403     {
1404       unsigned char *dst;
1405       unsigned char *s;
1406       fill = (fill_type *) xmalloc ((len + 1) / 2 + sizeof (*fill) - 1);
1407       fill->size = (len + 1) / 2;
1408       dst = fill->data;
1409       s = (unsigned char *) expld.result.str;
1410       val = 0;
1411       do
1412         {
1413           unsigned int digit;
1414
1415           digit = *s++ - '0';
1416           if (digit > 9)
1417             digit = (digit - 'A' + '0' + 10) & 0xf;
1418           val <<= 4;
1419           val += digit;
1420           --len;
1421           if ((len & 1) == 0)
1422             {
1423               *dst++ = val;
1424               val = 0;
1425             }
1426         }
1427       while (len != 0);
1428     }
1429   else
1430     {
1431       fill = (fill_type *) xmalloc (4 + sizeof (*fill) - 1);
1432       val = expld.result.value;
1433       fill->data[0] = (val >> 24) & 0xff;
1434       fill->data[1] = (val >> 16) & 0xff;
1435       fill->data[2] = (val >>  8) & 0xff;
1436       fill->data[3] = (val >>  0) & 0xff;
1437       fill->size = 4;
1438     }
1439   return fill;
1440 }
1441
1442 bfd_vma
1443 exp_get_abs_int (etree_type *tree, int def, char *name)
1444 {
1445   if (tree != NULL)
1446     {
1447       exp_fold_tree_no_dot (tree);
1448
1449       if (expld.result.valid_p)
1450         {
1451           if (expld.result.section != NULL)
1452             expld.result.value += expld.result.section->vma;
1453           return expld.result.value;
1454         }
1455       else if (name != NULL && expld.phase != lang_mark_phase_enum)
1456         {
1457           einfo (_("%F%S: nonconstant expression for %s\n"),
1458                  tree, name);
1459         }
1460     }
1461   return def;
1462 }
1463
1464 static bfd_vma
1465 align_n (bfd_vma value, bfd_vma align)
1466 {
1467   if (align <= 1)
1468     return value;
1469
1470   value = (value + align - 1) / align;
1471   return value * align;
1472 }