ld/ldexp.c

   1 /* This module handles expression trees.
   2    Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
   3    2001, 2002, 2003, 2004, 2005
   4    Free Software Foundation, Inc.
   5    Written by Steve Chamberlain of Cygnus Support <sac@cygnus.com>.
   6
   7    This file is part of GLD, the Gnu Linker.
   8
   9    GLD is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2, or (at your option)
  12    any later version.
  13
  14    GLD is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with GLD; see the file COPYING.  If not, write to the Free
  21    Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
  22    02110-1301, USA.  */
  23
  24 /* This module is in charge of working out the contents of expressions.
  25
  26    It has to keep track of the relative/absness of a symbol etc. This
  27    is done by keeping all values in a struct (an etree_value_type)
  28    which contains a value, a section to which it is relative and a
  29    valid bit.  */
  30
  31 #include "bfd.h"
  32 #include "sysdep.h"
  33 #include "bfdlink.h"
  34
  35 #include "ld.h"
  36 #include "ldmain.h"
  37 #include "ldmisc.h"
  38 #include "ldexp.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 void exp_fold_tree_no_dot (etree_type *);
  46 static bfd_vma align_n (bfd_vma, bfd_vma);
  47
  48 segment_type *segments;
  49
  50 struct ldexp_control expld;
  51
  52 /* Print the string representation of the given token.  Surround it
  53    with spaces if INFIX_P is TRUE.  */
  54
  55 static void
  56 exp_print_token (token_code_type code, int infix_p)
  57 {
  58   static const struct
  59   {
  60     token_code_type code;
  61     char * name;
  62   }
  63   table[] =
  64   {
  65     { INT, "int" },
  66     { NAME, "NAME" },
  67     { PLUSEQ, "+=" },
  68     { MINUSEQ, "-=" },
  69     { MULTEQ, "*=" },
  70     { DIVEQ, "/=" },
  71     { LSHIFTEQ, "<<=" },
  72     { RSHIFTEQ, ">>=" },
  73     { ANDEQ, "&=" },
  74     { OREQ, "|=" },
  75     { OROR, "||" },
  76     { ANDAND, "&&" },
  77     { EQ, "==" },
  78     { NE, "!=" },
  79     { LE, "<=" },
  80     { GE, ">=" },
  81     { LSHIFT, "<<" },
  82     { RSHIFT, ">>" },
  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     { SIZEOF, "SIZEOF" },
 100     { ADDR, "ADDR" },
 101     { LOADADDR, "LOADADDR" },
 102     { MAX_K, "MAX_K" },
 103     { REL, "relocatable" },
 104     { DATA_SEGMENT_ALIGN, "DATA_SEGMENT_ALIGN" },
 105     { DATA_SEGMENT_RELRO_END, "DATA_SEGMENT_RELRO_END" },
 106     { DATA_SEGMENT_END, "DATA_SEGMENT_END" },
 107     { ORIGIN, "ORIGIN" },
 108     { LENGTH, "LENGTH" },
 109     { SEGMENT_START, "SEGMENT_START" }
 110   };
 111   unsigned int idx;
 112
 113   for (idx = 0; idx < ARRAY_SIZE (table); idx++)
 114     if (table[idx].code == code)
 115       break;
 116
 117   if (infix_p)
 118     fputc (' ', config.map_file);
 119
 120   if (idx < ARRAY_SIZE (table))
 121     fputs (table[idx].name, config.map_file);
 122   else if (code < 127)
 123     fputc (code, config.map_file);
 124   else
 125     fprintf (config.map_file, "<code %d>", code);
 126
 127   if (infix_p)
 128     fputc (' ', config.map_file);
 129 }
 130
 131 static void
 132 make_abs (void)
 133 {
 134   expld.result.value += expld.result.section->vma;
 135   expld.result.section = bfd_abs_section_ptr;
 136 }
 137
 138 static void
 139 new_abs (bfd_vma value)
 140 {
 141   expld.result.valid_p = TRUE;
 142   expld.result.section = bfd_abs_section_ptr;
 143   expld.result.value = value;
 144   expld.result.str = NULL;
 145 }
 146
 147 etree_type *
 148 exp_intop (bfd_vma value)
 149 {
 150   etree_type *new = stat_alloc (sizeof (new->value));
 151   new->type.node_code = INT;
 152   new->value.value = value;
 153   new->value.str = NULL;
 154   new->type.node_class = etree_value;
 155   return new;
 156 }
 157
 158 etree_type *
 159 exp_bigintop (bfd_vma value, char *str)
 160 {
 161   etree_type *new = stat_alloc (sizeof (new->value));
 162   new->type.node_code = INT;
 163   new->value.value = value;
 164   new->value.str = str;
 165   new->type.node_class = etree_value;
 166   return new;
 167 }
 168
 169 /* Build an expression representing an unnamed relocatable value.  */
 170
 171 etree_type *
 172 exp_relop (asection *section, bfd_vma value)
 173 {
 174   etree_type *new = stat_alloc (sizeof (new->rel));
 175   new->type.node_code = REL;
 176   new->type.node_class = etree_rel;
 177   new->rel.section = section;
 178   new->rel.value = value;
 179   return new;
 180 }
 181
 182 static void
 183 new_rel (bfd_vma value, char *str, asection *section)
 184 {
 185   expld.result.valid_p = TRUE;
 186   expld.result.value = value;
 187   expld.result.str = str;
 188   expld.result.section = section;
 189 }
 190
 191 static void
 192 new_rel_from_abs (bfd_vma value)
 193 {
 194   expld.result.valid_p = TRUE;
 195   expld.result.value = value - expld.section->vma;
 196   expld.result.str = NULL;
 197   expld.result.section = expld.section;
 198 }
 199
 200 static void
 201 fold_unary (etree_type *tree)
 202 {
 203   exp_fold_tree_1 (tree->unary.child);
 204   if (expld.result.valid_p)
 205     {
 206       switch (tree->type.node_code)
 207         {
 208         case ALIGN_K:
 209           if (expld.phase != lang_first_phase_enum)
 210             new_rel_from_abs (align_n (expld.dot, expld.result.value));
 211           else
 212             expld.result.valid_p = FALSE;
 213           break;
 214
 215         case ABSOLUTE:
 216           make_abs ();
 217           break;
 218
 219         case '~':
 220           make_abs ();
 221           expld.result.value = ~expld.result.value;
 222           break;
 223
 224         case '!':
 225           make_abs ();
 226           expld.result.value = !expld.result.value;
 227           break;
 228
 229         case '-':
 230           make_abs ();
 231           expld.result.value = -expld.result.value;
 232           break;
 233
 234         case NEXT:
 235           /* Return next place aligned to value.  */
 236           if (expld.phase != lang_first_phase_enum)
 237             {
 238               make_abs ();
 239               expld.result.value = align_n (expld.dot, expld.result.value);
 240             }
 241           else
 242             expld.result.valid_p = FALSE;
 243           break;
 244
 245         case DATA_SEGMENT_END:
 246           if (expld.phase != lang_first_phase_enum
 247               && expld.section == bfd_abs_section_ptr
 248               && (expld.dataseg.phase == exp_dataseg_align_seen
 249                   || expld.dataseg.phase == exp_dataseg_relro_seen
 250                   || expld.dataseg.phase == exp_dataseg_adjust
 251                   || expld.dataseg.phase == exp_dataseg_relro_adjust
 252                   || expld.phase == lang_final_phase_enum))
 253             {
 254               if (expld.dataseg.phase == exp_dataseg_align_seen
 255                   || expld.dataseg.phase == exp_dataseg_relro_seen)
 256                 {
 257                   expld.dataseg.phase = exp_dataseg_end_seen;
 258                   expld.dataseg.end = expld.result.value;
 259                 }
 260             }
 261           else
 262             expld.result.valid_p = FALSE;
 263           break;
 264
 265         default:
 266           FAIL ();
 267           break;
 268         }
 269     }
 270 }
 271
 272 static void
 273 fold_binary (etree_type *tree)
 274 {
 275   exp_fold_tree_1 (tree->binary.lhs);
 276
 277   /* The SEGMENT_START operator is special because its first
 278      operand is a string, not the name of a symbol.  */
 279   if (expld.result.valid_p && tree->type.node_code == SEGMENT_START)
 280     {
 281       const char *segment_name;
 282       segment_type *seg;
 283       /* Check to see if the user has overridden the default
 284          value.  */
 285       segment_name = tree->binary.rhs->name.name;
 286       for (seg = segments; seg; seg = seg->next)
 287         if (strcmp (seg->name, segment_name) == 0)
 288           {
 289             seg->used = TRUE;
 290             expld.result.value = seg->value;
 291             expld.result.str = NULL;
 292             expld.result.section = NULL;
 293             break;
 294           }
 295     }
 296   else if (expld.result.valid_p)
 297     {
 298       etree_value_type lhs = expld.result;
 299
 300       exp_fold_tree_1 (tree->binary.rhs);
 301       if (expld.result.valid_p)
 302         {
 303           /* If the values are from different sections, or this is an
 304              absolute expression, make both the source arguments
 305              absolute.  However, adding or subtracting an absolute
 306              value from a relative value is meaningful, and is an
 307              exception.  */
 308           if (expld.section != bfd_abs_section_ptr
 309               && lhs.section == bfd_abs_section_ptr
 310               && tree->type.node_code == '+')
 311             {
 312               /* Keep the section of the rhs term.  */
 313               expld.result.value = lhs.value + expld.result.value;
 314               return;
 315             }
 316           else if (expld.section != bfd_abs_section_ptr
 317               && expld.result.section == bfd_abs_section_ptr
 318               && (tree->type.node_code == '+'
 319                   || tree->type.node_code == '-'))
 320             {
 321               /* Keep the section of the lhs term.  */
 322               expld.result.section = lhs.section;
 323             }
 324           else if (expld.result.section != lhs.section
 325                    || expld.section == bfd_abs_section_ptr)
 326             {
 327               make_abs ();
 328               lhs.value += lhs.section->vma;
 329             }
 330
 331           switch (tree->type.node_code)
 332             {
 333             case '%':
 334               if (expld.result.value != 0)
 335                 expld.result.value = ((bfd_signed_vma) lhs.value
 336                                       % (bfd_signed_vma) expld.result.value);
 337               else if (expld.phase != lang_mark_phase_enum)
 338                 einfo (_("%F%S %% by zero\n"));
 339               break;
 340
 341             case '/':
 342               if (expld.result.value != 0)
 343                 expld.result.value = ((bfd_signed_vma) lhs.value
 344                                       / (bfd_signed_vma) expld.result.value);
 345               else if (expld.phase != lang_mark_phase_enum)
 346                 einfo (_("%F%S / by zero\n"));
 347               break;
 348
 349 #define BOP(x, y) \
 350             case x:                                                     \
 351               expld.result.value = lhs.value y expld.result.value;      \
 352               break;
 353
 354               BOP ('+', +);
 355               BOP ('*', *);
 356               BOP ('-', -);
 357               BOP (LSHIFT, <<);
 358               BOP (RSHIFT, >>);
 359               BOP (EQ, ==);
 360               BOP (NE, !=);
 361               BOP ('<', <);
 362               BOP ('>', >);
 363               BOP (LE, <=);
 364               BOP (GE, >=);
 365               BOP ('&', &);
 366               BOP ('^', ^);
 367               BOP ('|', |);
 368               BOP (ANDAND, &&);
 369               BOP (OROR, ||);
 370
 371             case MAX_K:
 372               if (lhs.value > expld.result.value)
 373                 expld.result.value = lhs.value;
 374               break;
 375
 376             case MIN_K:
 377               if (lhs.value < expld.result.value)
 378                 expld.result.value = lhs.value;
 379               break;
 380
 381             case ALIGN_K:
 382               expld.result.value = align_n (lhs.value, expld.result.value);
 383               break;
 384
 385             case DATA_SEGMENT_ALIGN:
 386               if (expld.phase != lang_first_phase_enum
 387                   && expld.section == bfd_abs_section_ptr
 388                   && (expld.dataseg.phase == exp_dataseg_none
 389                       || expld.dataseg.phase == exp_dataseg_adjust
 390                       || expld.dataseg.phase == exp_dataseg_relro_adjust
 391                       || expld.phase == lang_final_phase_enum))
 392                 {
 393                   bfd_vma maxpage = lhs.value;
 394                   bfd_vma commonpage = expld.result.value;
 395
 396                   expld.result.value = align_n (expld.dot, maxpage);
 397                   if (expld.dataseg.phase == exp_dataseg_relro_adjust)
 398                     expld.result.value = expld.dataseg.base;
 399                   else if (expld.dataseg.phase != exp_dataseg_adjust)
 400                     {
 401                       expld.result.value += expld.dot & (maxpage - 1);
 402                       if (expld.phase == lang_allocating_phase_enum)
 403                         {
 404                           expld.dataseg.phase = exp_dataseg_align_seen;
 405                           expld.dataseg.min_base = align_n (expld.dot, maxpage);
 406                           expld.dataseg.base = expld.result.value;
 407                           expld.dataseg.pagesize = commonpage;
 408                           expld.dataseg.maxpagesize = maxpage;
 409                           expld.dataseg.relro_end = 0;
 410                         }
 411                     }
 412                   else if (commonpage < maxpage)
 413                     expld.result.value += ((expld.dot + commonpage - 1)
 414                                            & (maxpage - commonpage));
 415                 }
 416               else
 417                 expld.result.valid_p = FALSE;
 418               break;
 419
 420             case DATA_SEGMENT_RELRO_END:
 421               if (expld.phase != lang_first_phase_enum
 422                   && (expld.dataseg.phase == exp_dataseg_align_seen
 423                       || expld.dataseg.phase == exp_dataseg_adjust
 424                       || expld.dataseg.phase == exp_dataseg_relro_adjust
 425                       || expld.phase == lang_final_phase_enum))
 426                 {
 427                   if (expld.dataseg.phase == exp_dataseg_align_seen
 428                       || expld.dataseg.phase == exp_dataseg_relro_adjust)
 429                     expld.dataseg.relro_end = lhs.value + expld.result.value;
 430
 431                   if (expld.dataseg.phase == exp_dataseg_relro_adjust
 432                       && (expld.dataseg.relro_end
 433                           & (expld.dataseg.pagesize - 1)))
 434                     {
 435                       expld.dataseg.relro_end += expld.dataseg.pagesize - 1;
 436                       expld.dataseg.relro_end &= ~(expld.dataseg.pagesize - 1);
 437                       expld.result.value = (expld.dataseg.relro_end
 438                                             - expld.result.value);
 439                     }
 440                   else
 441                     expld.result.value = lhs.value;
 442
 443                   if (expld.dataseg.phase == exp_dataseg_align_seen)
 444                     expld.dataseg.phase = exp_dataseg_relro_seen;
 445                 }
 446               else
 447                 expld.result.valid_p = FALSE;
 448               break;
 449
 450             default:
 451               FAIL ();
 452             }
 453         }
 454       else
 455         expld.result.valid_p = FALSE;
 456     }
 457 }
 458
 459 static void
 460 fold_trinary (etree_type *tree)
 461 {
 462   exp_fold_tree_1 (tree->trinary.cond);
 463   if (expld.result.valid_p)
 464     exp_fold_tree_1 (expld.result.value
 465                      ? tree->trinary.lhs
 466                      : tree->trinary.rhs);
 467 }
 468
 469 static void
 470 fold_name (etree_type *tree)
 471 {
 472   memset (&expld.result, 0, sizeof (expld.result));
 473
 474   switch (tree->type.node_code)
 475     {
 476     case SIZEOF_HEADERS:
 477       if (expld.phase != lang_first_phase_enum)
 478         {
 479           bfd_vma hdr_size = 0;
 480           /* Don't find the real header size if only marking sections;
 481              The bfd function may cache incorrect data.  */
 482           if (expld.phase != lang_mark_phase_enum)
 483             hdr_size = bfd_sizeof_headers (output_bfd, link_info.relocatable);
 484           new_abs (hdr_size);
 485         }
 486       break;
 487     case DEFINED:
 488       if (expld.phase == lang_first_phase_enum)
 489         lang_track_definedness (tree->name.name);
 490       else
 491         {
 492           struct bfd_link_hash_entry *h;
 493           int def_iteration
 494             = lang_symbol_definition_iteration (tree->name.name);
 495
 496           h = bfd_wrapped_link_hash_lookup (output_bfd, &link_info,
 497                                             tree->name.name,
 498                                             FALSE, FALSE, TRUE);
 499           expld.result.value = (h != NULL
 500                                 && (h->type == bfd_link_hash_defined
 501                                     || h->type == bfd_link_hash_defweak
 502                                     || h->type == bfd_link_hash_common)
 503                                 && (def_iteration == lang_statement_iteration
 504                                     || def_iteration == -1));
 505           expld.result.section = bfd_abs_section_ptr;
 506           expld.result.valid_p = TRUE;
 507         }
 508       break;
 509     case NAME:
 510       if (expld.phase == lang_first_phase_enum)
 511         ;
 512       else if (tree->name.name[0] == '.' && tree->name.name[1] == 0)
 513         new_rel_from_abs (expld.dot);
 514       else
 515         {
 516           struct bfd_link_hash_entry *h;
 517
 518           h = bfd_wrapped_link_hash_lookup (output_bfd, &link_info,
 519                                             tree->name.name,
 520                                             TRUE, FALSE, TRUE);
 521           if (!h)
 522             einfo (_("%P%F: bfd_link_hash_lookup failed: %E\n"));
 523           else if (h->type == bfd_link_hash_defined
 524                    || h->type == bfd_link_hash_defweak)
 525             {
 526               if (bfd_is_abs_section (h->u.def.section))
 527                 new_abs (h->u.def.value);
 528               else
 529                 {
 530                   asection *output_section;
 531
 532                   output_section = h->u.def.section->output_section;
 533                   if (output_section == NULL)
 534                     {
 535                       if (expld.phase != lang_mark_phase_enum)
 536                         einfo (_("%X%S: unresolvable symbol `%s'"
 537                                  " referenced in expression\n"),
 538                                tree->name.name);
 539                     }
 540                   else
 541                     new_rel (h->u.def.value + h->u.def.section->output_offset,
 542                              NULL, output_section);
 543                 }
 544             }
 545           else if (expld.phase == lang_final_phase_enum
 546                    || expld.assigning_to_dot)
 547             einfo (_("%F%S: undefined symbol `%s' referenced in expression\n"),
 548                    tree->name.name);
 549           else if (h->type == bfd_link_hash_new)
 550             {
 551               h->type = bfd_link_hash_undefined;
 552               h->u.undef.abfd = NULL;
 553               if (h->u.undef.next == NULL && h != link_info.hash->undefs_tail)
 554                 bfd_link_add_undef (link_info.hash, h);
 555             }
 556         }
 557       break;
 558
 559     case ADDR:
 560       if (expld.phase != lang_first_phase_enum)
 561         {
 562           lang_output_section_statement_type *os;
 563
 564           os = lang_output_section_find (tree->name.name);
 565           if (os != NULL && os->processed)
 566             new_rel (0, NULL, os->bfd_section);
 567         }
 568       break;
 569
 570     case LOADADDR:
 571       if (expld.phase != lang_first_phase_enum)
 572         {
 573           lang_output_section_statement_type *os;
 574
 575           os = lang_output_section_find (tree->name.name);
 576           if (os != NULL && os->processed)
 577             {
 578               if (os->load_base == NULL)
 579                 new_rel (0, NULL, os->bfd_section);
 580               else
 581                 exp_fold_tree_1 (os->load_base);
 582             }
 583         }
 584       break;
 585
 586     case SIZEOF:
 587       if (expld.phase != lang_first_phase_enum)
 588         {
 589           int opb = bfd_octets_per_byte (output_bfd);
 590           lang_output_section_statement_type *os;
 591
 592           os = lang_output_section_find (tree->name.name);
 593           if (os == NULL)
 594             new_abs (0);
 595           else if (os->processed)
 596             new_abs (os->bfd_section->size / opb);
 597         }
 598       break;
 599
 600     case LENGTH:
 601       {
 602         lang_memory_region_type *mem;
 603
 604         mem = lang_memory_region_lookup (tree->name.name, FALSE);
 605         if (mem != NULL)
 606           new_abs (mem->length);
 607         else
 608           einfo (_("%F%S: undefined MEMORY region `%s'"
 609                    " referenced in expression\n"), tree->name.name);
 610       }
 611       break;
 612
 613     case ORIGIN:
 614       {
 615         lang_memory_region_type *mem;
 616
 617         mem = lang_memory_region_lookup (tree->name.name, FALSE);
 618         if (mem != NULL)
 619           new_abs (mem->origin);
 620         else
 621           einfo (_("%F%S: undefined MEMORY region `%s'"
 622                    " referenced in expression\n"), tree->name.name);
 623       }
 624       break;
 625
 626     default:
 627       FAIL ();
 628       break;
 629     }
 630 }
 631
 632 static void
 633 exp_fold_tree_1 (etree_type *tree)
 634 {
 635   if (tree == NULL)
 636     {
 637       memset (&expld.result, 0, sizeof (expld.result));
 638       return;
 639     }
 640
 641   switch (tree->type.node_class)
 642     {
 643     case etree_value:
 644       new_rel (tree->value.value, tree->value.str, expld.section);
 645       break;
 646
 647     case etree_rel:
 648       if (expld.phase != lang_first_phase_enum)
 649         {
 650           asection *output_section = tree->rel.section->output_section;
 651           new_rel (tree->rel.value + tree->rel.section->output_offset,
 652                    NULL, output_section);
 653         }
 654       else
 655         memset (&expld.result, 0, sizeof (expld.result));
 656       break;
 657
 658     case etree_assert:
 659       exp_fold_tree_1 (tree->assert_s.child);
 660       if (expld.phase == lang_final_phase_enum && !expld.result.value)
 661         einfo ("%X%P: %s\n", tree->assert_s.message);
 662       break;
 663
 664     case etree_unary:
 665       fold_unary (tree);
 666       break;
 667
 668     case etree_binary:
 669       fold_binary (tree);
 670       break;
 671
 672     case etree_trinary:
 673       fold_trinary (tree);
 674       break;
 675
 676     case etree_assign:
 677     case etree_provide:
 678     case etree_provided:
 679       if (tree->assign.dst[0] == '.' && tree->assign.dst[1] == 0)
 680         {
 681           /* Assignment to dot can only be done during allocation.  */
 682           if (tree->type.node_class != etree_assign)
 683             einfo (_("%F%S can not PROVIDE assignment to location counter\n"));
 684           if (expld.phase == lang_mark_phase_enum
 685               || expld.phase == lang_allocating_phase_enum
 686               || (expld.phase == lang_final_phase_enum
 687                   && expld.section == bfd_abs_section_ptr))
 688             {
 689               /* Notify the folder that this is an assignment to dot.  */
 690               expld.assigning_to_dot = TRUE;
 691               exp_fold_tree_1 (tree->assign.src);
 692               expld.assigning_to_dot = FALSE;
 693
 694               if (!expld.result.valid_p)
 695                 {
 696                   if (expld.phase != lang_mark_phase_enum)
 697                     einfo (_("%F%S invalid assignment to location counter\n"));
 698                 }
 699               else if (expld.dotp == NULL)
 700                 einfo (_("%F%S assignment to location counter"
 701                          " invalid outside of SECTION\n"));
 702               else
 703                 {
 704                   bfd_vma nextdot;
 705
 706                   nextdot = expld.result.value + expld.section->vma;
 707                   if (nextdot < expld.dot
 708                       && expld.section != bfd_abs_section_ptr)
 709                     einfo (_("%F%S cannot move location counter backwards"
 710                              " (from %V to %V)\n"), expld.dot, nextdot);
 711                   else
 712                     {
 713                       expld.dot = nextdot;
 714                       *expld.dotp = nextdot;
 715                     }
 716                 }
 717             }
 718           else
 719             memset (&expld.result, 0, sizeof (expld.result));
 720         }
 721       else
 722         {
 723           struct bfd_link_hash_entry *h = NULL;
 724
 725           if (tree->type.node_class == etree_provide)
 726             {
 727               h = bfd_link_hash_lookup (link_info.hash, tree->assign.dst,
 728                                         FALSE, FALSE, TRUE);
 729               if (h == NULL
 730                   || (h->type != bfd_link_hash_new
 731                       && h->type != bfd_link_hash_undefined
 732                       && h->type != bfd_link_hash_common))
 733                 {
 734                   /* Do nothing.  The symbol was never referenced, or was
 735                      defined by some object.  */
 736                   break;
 737                 }
 738               if (tree->assign.hidden)
 739                 bfd_hide_symbol (output_bfd, &link_info, h, TRUE);
 740             }
 741
 742           exp_fold_tree_1 (tree->assign.src);
 743           if (expld.result.valid_p)
 744             {
 745               if (h == NULL)
 746                 {
 747                   h = bfd_link_hash_lookup (link_info.hash, tree->assign.dst,
 748                                             TRUE, FALSE, TRUE);
 749                   if (h == NULL)
 750                     einfo (_("%P%F:%s: hash creation failed\n"),
 751                            tree->assign.dst);
 752                 }
 753
 754               /* FIXME: Should we worry if the symbol is already
 755                  defined?  */
 756               lang_update_definedness (tree->assign.dst, h);
 757               h->type = bfd_link_hash_defined;
 758               h->u.def.value = expld.result.value;
 759               h->u.def.section = expld.result.section;
 760               if (tree->type.node_class == etree_provide)
 761                 tree->type.node_class = etree_provided;
 762             }
 763         }
 764       break;
 765
 766     case etree_name:
 767       fold_name (tree);
 768       break;
 769
 770     default:
 771       FAIL ();
 772       memset (&expld.result, 0, sizeof (expld.result));
 773       break;
 774     }
 775 }
 776
 777 void
 778 exp_fold_tree (etree_type *tree, asection *current_section, bfd_vma *dotp)
 779 {
 780   expld.dot = *dotp;
 781   expld.dotp = dotp;
 782   expld.section = current_section;
 783   exp_fold_tree_1 (tree);
 784 }
 785
 786 static void
 787 exp_fold_tree_no_dot (etree_type *tree)
 788 {
 789   expld.dot = 0;
 790   expld.dotp = NULL;
 791   expld.section = bfd_abs_section_ptr;
 792   exp_fold_tree_1 (tree);
 793 }
 794
 795 etree_type *
 796 exp_binop (int code, etree_type *lhs, etree_type *rhs)
 797 {
 798   etree_type value, *new;
 799
 800   value.type.node_code = code;
 801   value.binary.lhs = lhs;
 802   value.binary.rhs = rhs;
 803   value.type.node_class = etree_binary;
 804   exp_fold_tree_no_dot (&value);
 805   if (expld.result.valid_p)
 806     return exp_intop (expld.result.value);
 807
 808   new = stat_alloc (sizeof (new->binary));
 809   memcpy (new, &value, sizeof (new->binary));
 810   return new;
 811 }
 812
 813 etree_type *
 814 exp_trinop (int code, etree_type *cond, etree_type *lhs, etree_type *rhs)
 815 {
 816   etree_type value, *new;
 817
 818   value.type.node_code = code;
 819   value.trinary.lhs = lhs;
 820   value.trinary.cond = cond;
 821   value.trinary.rhs = rhs;
 822   value.type.node_class = etree_trinary;
 823   exp_fold_tree_no_dot (&value);
 824   if (expld.result.valid_p)
 825     return exp_intop (expld.result.value);
 826
 827   new = stat_alloc (sizeof (new->trinary));
 828   memcpy (new, &value, sizeof (new->trinary));
 829   return new;
 830 }
 831
 832 etree_type *
 833 exp_unop (int code, etree_type *child)
 834 {
 835   etree_type value, *new;
 836
 837   value.unary.type.node_code = code;
 838   value.unary.child = child;
 839   value.unary.type.node_class = etree_unary;
 840   exp_fold_tree_no_dot (&value);
 841   if (expld.result.valid_p)
 842     return exp_intop (expld.result.value);
 843
 844   new = stat_alloc (sizeof (new->unary));
 845   memcpy (new, &value, sizeof (new->unary));
 846   return new;
 847 }
 848
 849 etree_type *
 850 exp_nameop (int code, const char *name)
 851 {
 852   etree_type value, *new;
 853
 854   value.name.type.node_code = code;
 855   value.name.name = name;
 856   value.name.type.node_class = etree_name;
 857
 858   exp_fold_tree_no_dot (&value);
 859   if (expld.result.valid_p)
 860     return exp_intop (expld.result.value);
 861
 862   new = stat_alloc (sizeof (new->name));
 863   memcpy (new, &value, sizeof (new->name));
 864   return new;
 865
 866 }
 867
 868 etree_type *
 869 exp_assop (int code, const char *dst, etree_type *src)
 870 {
 871   etree_type *new;
 872
 873   new = stat_alloc (sizeof (new->assign));
 874   new->type.node_code = code;
 875   new->type.node_class = etree_assign;
 876   new->assign.src = src;
 877   new->assign.dst = dst;
 878   return new;
 879 }
 880
 881 /* Handle PROVIDE.  */
 882
 883 etree_type *
 884 exp_provide (const char *dst, etree_type *src, bfd_boolean hidden)
 885 {
 886   etree_type *n;
 887
 888   n = stat_alloc (sizeof (n->assign));
 889   n->assign.type.node_code = '=';
 890   n->assign.type.node_class = etree_provide;
 891   n->assign.src = src;
 892   n->assign.dst = dst;
 893   n->assign.hidden = hidden;
 894   return n;
 895 }
 896
 897 /* Handle ASSERT.  */
 898
 899 etree_type *
 900 exp_assert (etree_type *exp, const char *message)
 901 {
 902   etree_type *n;
 903
 904   n = stat_alloc (sizeof (n->assert_s));
 905   n->assert_s.type.node_code = '!';
 906   n->assert_s.type.node_class = etree_assert;
 907   n->assert_s.child = exp;
 908   n->assert_s.message = message;
 909   return n;
 910 }
 911
 912 void
 913 exp_print_tree (etree_type *tree)
 914 {
 915   if (config.map_file == NULL)
 916     config.map_file = stderr;
 917
 918   if (tree == NULL)
 919     {
 920       minfo ("NULL TREE\n");
 921       return;
 922     }
 923
 924   switch (tree->type.node_class)
 925     {
 926     case etree_value:
 927       minfo ("0x%v", tree->value.value);
 928       return;
 929     case etree_rel:
 930       if (tree->rel.section->owner != NULL)
 931         minfo ("%B:", tree->rel.section->owner);
 932       minfo ("%s+0x%v", tree->rel.section->name, tree->rel.value);
 933       return;
 934     case etree_assign:
 935       fprintf (config.map_file, "%s", tree->assign.dst);
 936       exp_print_token (tree->type.node_code, TRUE);
 937       exp_print_tree (tree->assign.src);
 938       break;
 939     case etree_provide:
 940     case etree_provided:
 941       fprintf (config.map_file, "PROVIDE (%s, ", tree->assign.dst);
 942       exp_print_tree (tree->assign.src);
 943       fprintf (config.map_file, ")");
 944       break;
 945     case etree_binary:
 946       fprintf (config.map_file, "(");
 947       exp_print_tree (tree->binary.lhs);
 948       exp_print_token (tree->type.node_code, TRUE);
 949       exp_print_tree (tree->binary.rhs);
 950       fprintf (config.map_file, ")");
 951       break;
 952     case etree_trinary:
 953       exp_print_tree (tree->trinary.cond);
 954       fprintf (config.map_file, "?");
 955       exp_print_tree (tree->trinary.lhs);
 956       fprintf (config.map_file, ":");
 957       exp_print_tree (tree->trinary.rhs);
 958       break;
 959     case etree_unary:
 960       exp_print_token (tree->unary.type.node_code, FALSE);
 961       if (tree->unary.child)
 962         {
 963           fprintf (config.map_file, " (");
 964           exp_print_tree (tree->unary.child);
 965           fprintf (config.map_file, ")");
 966         }
 967       break;
 968
 969     case etree_assert:
 970       fprintf (config.map_file, "ASSERT (");
 971       exp_print_tree (tree->assert_s.child);
 972       fprintf (config.map_file, ", %s)", tree->assert_s.message);
 973       break;
 974
 975     case etree_name:
 976       if (tree->type.node_code == NAME)
 977         {
 978           fprintf (config.map_file, "%s", tree->name.name);
 979         }
 980       else
 981         {
 982           exp_print_token (tree->type.node_code, FALSE);
 983           if (tree->name.name)
 984             fprintf (config.map_file, " (%s)", tree->name.name);
 985         }
 986       break;
 987     default:
 988       FAIL ();
 989       break;
 990     }
 991 }
 992
 993 bfd_vma
 994 exp_get_vma (etree_type *tree, bfd_vma def, char *name)
 995 {
 996   if (tree != NULL)
 997     {
 998       exp_fold_tree_no_dot (tree);
 999       if (expld.result.valid_p)
1000         return expld.result.value;
1001       else if (name != NULL && expld.phase != lang_mark_phase_enum)
1002         einfo (_("%F%S nonconstant expression for %s\n"), name);
1003     }
1004   return def;
1005 }
1006
1007 int
1008 exp_get_value_int (etree_type *tree, int def, char *name)
1009 {
1010   return exp_get_vma (tree, def, name);
1011 }
1012
1013 fill_type *
1014 exp_get_fill (etree_type *tree, fill_type *def, char *name)
1015 {
1016   fill_type *fill;
1017   size_t len;
1018   unsigned int val;
1019
1020   if (tree == NULL)
1021     return def;
1022
1023   exp_fold_tree_no_dot (tree);
1024   if (!expld.result.valid_p)
1025     {
1026       if (name != NULL && expld.phase != lang_mark_phase_enum)
1027         einfo (_("%F%S nonconstant expression for %s\n"), name);
1028       return def;
1029     }
1030
1031   if (expld.result.str != NULL && (len = strlen (expld.result.str)) != 0)
1032     {
1033       unsigned char *dst;
1034       unsigned char *s;
1035       fill = xmalloc ((len + 1) / 2 + sizeof (*fill) - 1);
1036       fill->size = (len + 1) / 2;
1037       dst = fill->data;
1038       s = (unsigned char *) expld.result.str;
1039       val = 0;
1040       do
1041         {
1042           unsigned int digit;
1043
1044           digit = *s++ - '0';
1045           if (digit > 9)
1046             digit = (digit - 'A' + '0' + 10) & 0xf;
1047           val <<= 4;
1048           val += digit;
1049           --len;
1050           if ((len & 1) == 0)
1051             {
1052               *dst++ = val;
1053               val = 0;
1054             }
1055         }
1056       while (len != 0);
1057     }
1058   else
1059     {
1060       fill = xmalloc (4 + sizeof (*fill) - 1);
1061       val = expld.result.value;
1062       fill->data[0] = (val >> 24) & 0xff;
1063       fill->data[1] = (val >> 16) & 0xff;
1064       fill->data[2] = (val >>  8) & 0xff;
1065       fill->data[3] = (val >>  0) & 0xff;
1066       fill->size = 4;
1067     }
1068   return fill;
1069 }
1070
1071 bfd_vma
1072 exp_get_abs_int (etree_type *tree, int def, char *name)
1073 {
1074   if (tree != NULL)
1075     {
1076       exp_fold_tree_no_dot (tree);
1077
1078       if (expld.result.valid_p)
1079         {
1080           expld.result.value += expld.result.section->vma;
1081           return expld.result.value;
1082         }
1083       else if (name != NULL && expld.phase != lang_mark_phase_enum)
1084         einfo (_("%F%S non constant expression for %s\n"), name);
1085     }
1086   return def;
1087 }
1088
1089 static bfd_vma
1090 align_n (bfd_vma value, bfd_vma align)
1091 {
1092   if (align <= 1)
1093     return value;
1094
1095   value = (value + align - 1) / align;
1096   return value * align;
1097 }