ld/ldexp.c

   1 /* This module handles expression trees.
   2 Copyright (C) 1991 Free Software Foundation, Inc.
   3 Written by Steve Chamberlain of Cygnus Support (sac@cygnus.com).
   4
   5 This file is part of GLD, the Gnu Linker.
   6
   7 GLD 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 2, or (at your option)
  10 any later version.
  11
  12 GLD 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 GLD; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  20
  21 /*
  22 This module is in charge of working out the contents of expressions.
  23
  24 It has to keep track of the relative/absness of a symbol etc. This is
  25 done by keeping all values in a struct (an etree_value_type) which
  26 contains a value, a section to which it is relative and a valid bit.
  27
  28 */
  29
  30
  31 #include "bfd.h"
  32 #include "sysdep.h"
  33
  34 #include "ld.h"
  35 #include "ldmain.h"
  36 #include "ldmisc.h"
  37 #include "ldexp.h"
  38 #include "ldgram.h"
  39 #include "ldsym.h"
  40 #include "ldlang.h"
  41
  42 extern char *output_filename;
  43 extern unsigned int undefined_global_sym_count;
  44 extern unsigned int defined_global_sym_count;
  45 extern bfd *output_bfd;
  46 extern bfd_size_type largest_section;
  47 extern lang_statement_list_type file_chain;
  48 extern args_type command_line;
  49 extern ld_config_type config;
  50
  51 extern lang_input_statement_type *script_file;
  52 extern unsigned int defined_global_sym_count;
  53   extern lang_output_section_statement_type *abs_output_section;
  54 extern bfd_vma print_dot;
  55
  56
  57 static void
  58 DEFUN(exp_print_token,( code),
  59       token_code_type code)
  60 {
  61   static struct  {
  62     token_code_type code;
  63     char *name;
  64   } table[] =
  65       {
  66         INT,    "int",
  67         NAME,"NAME",
  68         PLUSEQ,"+=",
  69         MINUSEQ,"-=",
  70         MULTEQ,"*=",
  71         DIVEQ,"/=",
  72         LSHIFTEQ,"<<=",
  73         RSHIFTEQ,">>=",
  74         ANDEQ,"&=",
  75         OREQ,"|=",
  76         OROR,"||",
  77         ANDAND,"&&",
  78         EQ,"==",
  79         NE,"!=",
  80         LE,"<=",
  81         GE,">=",
  82         LSHIFT,"<<",
  83         RSHIFT,">>=",
  84         ALIGN_K,"ALIGN",
  85         BLOCK,"BLOCK",
  86         SECTIONS,"SECTIONS",
  87         SIZEOF_HEADERS,"SIZEOF_HEADERS",
  88         NEXT,"NEXT",
  89         SIZEOF,"SIZEOF",
  90         ADDR,"ADDR",
  91         MEMORY,"MEMORY",
  92
  93
  94
  95
  96
  97         DEFINED,"DEFINED",
  98         TARGET_K,"TARGET",
  99         SEARCH_DIR,"SEARCH_DIR",
 100         MAP,"MAP",
 101         LONG,"LONG",
 102         SHORT,"SHORT",
 103         BYTE,"BYTE",
 104         ENTRY,"ENTRY",
 105         0,(char *)NULL} ;
 106
 107
 108
 109   unsigned int idx;
 110   for (idx = 0; table[idx].name != (char*)NULL; idx++) {
 111     if (table[idx].code == code) {
 112       fprintf(config.map_file, "%s", table[idx].name);
 113       return;
 114     }
 115   }
 116   /* Not in table, just print it alone */
 117   fprintf(config.map_file, "%c",code);
 118 }
 119
 120 static void
 121 DEFUN(make_abs,(ptr),
 122       etree_value_type *ptr)
 123 {
 124     asection *s = ptr->section->bfd_section;
 125     ptr->value += s->vma;
 126     ptr->section = abs_output_section;
 127 }
 128
 129 static
 130 DEFUN(etree_value_type new_abs,(value),
 131       bfd_vma value)
 132 {
 133
 134
 135   etree_value_type new;
 136   new.valid = true;
 137   new.section = abs_output_section;
 138   new.value = value;
 139   return new;
 140 }
 141
 142 static void
 143 DEFUN(check, (os, name, op),
 144       lang_output_section_statement_type *os AND
 145       CONST char *name AND
 146       CONST char *op)
 147 {
 148   if (os == (lang_output_section_statement_type *)NULL) {
 149     einfo("%F%P %s uses undefined section %s\n", op, name);
 150   }
 151   if (os->processed == false) {
 152     einfo("%F%P %s forward reference of section %s\n",op, name);
 153   }
 154 }
 155
 156 etree_type *
 157 DEFUN(exp_intop,(value),
 158       bfd_vma value)
 159 {
 160   etree_type *new = (etree_type *)stat_alloc((bfd_size_type)(sizeof(new->value)));
 161   new->type.node_code = INT;
 162   new->value.value = value;
 163   new->type.node_class = etree_value;
 164   return new;
 165
 166 }
 167
 168
 169 static
 170 DEFUN(etree_value_type new_rel,(value, section),
 171       bfd_vma value AND
 172       lang_output_section_statement_type *section)
 173 {
 174   etree_value_type new;
 175   new.valid = true;
 176   new.value = value;
 177   new.section = section;
 178   return new;
 179 }
 180
 181 static
 182 DEFUN(etree_value_type
 183       new_rel_from_section, (value, section),
 184       bfd_vma value AND
 185       lang_output_section_statement_type *section)
 186 {
 187   etree_value_type new;
 188   new.valid = true;
 189   new.value = value;
 190   new.section = section;
 191
 192     new.value -= section->bfd_section->vma;
 193
 194   return new;
 195 }
 196
 197 static etree_value_type
 198 DEFUN(fold_binary,(tree, current_section, allocation_done, dot, dotp),
 199       etree_type *tree AND
 200       lang_output_section_statement_type *current_section AND
 201       lang_phase_type  allocation_done AND
 202       bfd_vma dot AND
 203       bfd_vma *dotp)
 204 {
 205   etree_value_type result;
 206
 207   result =  exp_fold_tree(tree->binary.lhs,  current_section,
 208                           allocation_done, dot, dotp);
 209   if (result.valid) {
 210     etree_value_type other;
 211     other = exp_fold_tree(tree->binary.rhs,
 212                           current_section,
 213                           allocation_done, dot,dotp) ;
 214     if (other.valid) {
 215         /* If values are from different sections, or this is an */
 216         /* absolute expression, make both source args absolute */
 217       if (result.section !=  other.section ||
 218           current_section == abs_output_section)
 219       {
 220         make_abs(&result);
 221         make_abs(&other);
 222       }
 223
 224       switch (tree->type.node_code)
 225         {
 226         case '%':
 227           /* Mod,  both absolule*/
 228
 229           if (other.value == 0) {
 230             einfo("%F%S % by zero\n");
 231           }
 232           result.value = (int)result.value % (int)other.value;
 233           break;
 234         case '/':
 235           if (other.value == 0) {
 236             einfo("%F%S / by zero\n");
 237           }
 238           result.value = (int)result.value / (int) other.value;
 239           break;
 240 #define BOP(x,y) case x : result.value = result.value y other.value;break;
 241           BOP('+',+);
 242           BOP('*',*);
 243           BOP('-',-);
 244           BOP(LSHIFT,<<);
 245           BOP(RSHIFT,>>);
 246           BOP(EQ,==);
 247           BOP(NE,!=);
 248           BOP('<',<);
 249           BOP('>',>);
 250           BOP(LE,<=);
 251           BOP(GE,>=);
 252           BOP('&',&);
 253           BOP('^',^);
 254           BOP('|',|);
 255           BOP(ANDAND,&&);
 256           BOP(OROR,||);
 257         default:
 258           FAIL();
 259         }
 260     }
 261     else {
 262       result.valid = false;
 263     }
 264   }
 265   return result;
 266 }
 267 etree_value_type
 268 DEFUN_VOID(invalid)
 269 {
 270   etree_value_type new;
 271   new.valid = false;
 272   return new;
 273 }
 274
 275 etree_value_type
 276 DEFUN(fold_name, (tree, current_section, allocation_done, dot),
 277       etree_type *tree AND
 278       lang_output_section_statement_type *current_section AND
 279       lang_phase_type  allocation_done AND
 280       bfd_vma dot)
 281 {
 282   etree_value_type result;
 283   switch (tree->type.node_code)
 284       {
 285       case SIZEOF_HEADERS:
 286         if (allocation_done != lang_first_phase_enum)
 287             {
 288               result = new_abs(bfd_sizeof_headers(output_bfd,
 289                                                 config.relocateable_output));
 290
 291             }
 292         else {
 293           result.valid = false;
 294         }
 295         break;
 296       case DEFINED:
 297         result.value =
 298           ldsym_get_soft(tree->name.name) != (ldsym_type *)NULL;
 299         result.section = 0;
 300         result.valid = true;
 301         break;
 302       case NAME:
 303         result.valid = false;
 304         if (tree->name.name[0] == '.' && tree->name.name[1] == 0) {
 305
 306           if (allocation_done != lang_first_phase_enum) {
 307             result = new_rel_from_section(dot, current_section);
 308           }
 309           else {
 310             result = invalid();
 311           }
 312         }
 313         else {
 314           if (allocation_done == lang_final_phase_enum) {
 315             ldsym_type *sy = ldsym_get_soft(tree->name.name);
 316
 317             if (sy) {
 318               asymbol **sdefp = sy->sdefs_chain;
 319
 320               if (sdefp) {
 321                 asymbol *sdef = *sdefp;
 322 #if 0
 323                 if (sdef->section == (asection *)NULL) {
 324                   /* This is an absolute symbol */
 325                   result = new_abs(sdef->value);
 326                 }
 327                 else
 328 #endif
 329  {
 330                   lang_output_section_statement_type *os =
 331                     lang_output_section_statement_lookup(
 332                                                          sdef->section->output_section->name);
 333                   /* If the symbol is from a file which we are not
 334                      relocating (-R) then return an absolute for its
 335                      value */
 336                   if (sdef->the_bfd->usrdata &&
 337                       ((lang_input_statement_type*)(sdef->the_bfd->usrdata))->just_syms_flag == true)
 338                       {
 339                         result = new_abs(sdef->value +sdef->section->vma);
 340
 341                       }
 342                   else {
 343                     result = new_rel(sdef->value + sdef->section->output_offset, os);
 344                   }
 345                 }
 346               }
 347             }
 348             if (result.valid == false) {
 349               einfo("%F%S: undefined symbol `%s' referenced in expression.\n",
 350                    tree->name.name);
 351             }
 352
 353           }
 354         }
 355
 356         break;
 357
 358       case ADDR:
 359
 360         if (allocation_done != lang_first_phase_enum) {
 361           lang_output_section_statement_type *os =
 362             lang_output_section_find(tree->name.name);
 363           check(os,tree->name.name,"ADDR");
 364           result =    new_rel((bfd_vma)0,  os);
 365         }
 366         else {
 367           result = invalid();
 368         }
 369         break;
 370       case SIZEOF:
 371         if(allocation_done != lang_first_phase_enum) {
 372           lang_output_section_statement_type *os =
 373             lang_output_section_find(tree->name.name);
 374           check(os,tree->name.name,"SIZEOF");
 375           result = new_abs((bfd_vma)(os->bfd_section->_raw_size));
 376         }
 377         else {
 378           result = invalid();
 379         }
 380         break;
 381
 382       default:
 383         FAIL();
 384         break;
 385       }
 386
 387   return result;
 388 }
 389 etree_value_type
 390 DEFUN(exp_fold_tree,(tree, current_section, allocation_done,
 391                     dot, dotp),
 392       etree_type *tree AND
 393       lang_output_section_statement_type *current_section AND
 394       lang_phase_type  allocation_done AND
 395       bfd_vma dot AND
 396       bfd_vma *dotp)
 397 {
 398   etree_value_type result;
 399
 400   if (tree == (etree_type *)NULL) {
 401       result.valid = false;
 402     }
 403   else {
 404       switch (tree->type.node_class)
 405       {
 406       case etree_value:
 407         result = new_rel(tree->value.value, current_section);
 408         break;
 409       case etree_unary:
 410         result = exp_fold_tree(tree->unary.child,
 411                                current_section,
 412                                allocation_done, dot, dotp);
 413         if (result.valid == true)
 414         {
 415           switch(tree->type.node_code)
 416           {
 417           case ALIGN_K:
 418             if (allocation_done != lang_first_phase_enum) {
 419                 result = new_rel_from_section(ALIGN(dot,
 420                                                     result.value) ,
 421                                               current_section);
 422
 423               }
 424             else {
 425                 result.valid = false;
 426               }
 427             break;
 428           case '~':
 429             make_abs(&result);
 430             result.value = ~result.value;
 431             break;
 432           case '!':
 433             make_abs(&result);
 434             result.value = !result.value;
 435             break;
 436           case '-':
 437             make_abs(&result);
 438             result.value = -result.value;
 439             break;
 440           case NEXT:
 441             if (allocation_done ==lang_allocating_phase_enum) {
 442                 make_abs(&result);
 443                 result.value = ALIGN(dot, result.value);
 444               }
 445             else {
 446                 /* Return next place aligned to value */
 447                 result.valid = false;
 448               }
 449             break;
 450           default:
 451             FAIL();
 452           }
 453         }
 454
 455         break;
 456       case etree_trinary:
 457
 458         result = exp_fold_tree(tree->trinary.cond,
 459                                current_section,
 460                                allocation_done, dot, dotp);
 461         if (result.valid) {
 462             result = exp_fold_tree(result.value ?
 463                                    tree->trinary.lhs:tree->trinary.rhs,
 464                                    current_section,
 465                                    allocation_done, dot, dotp);
 466           }
 467
 468         break;
 469       case etree_binary:
 470         result = fold_binary(tree, current_section, allocation_done,
 471                              dot, dotp);
 472         break;
 473       case etree_assign:
 474         if (tree->assign.dst[0] == '.' && tree->assign.dst[1] == 0) {
 475             /* Assignment to dot can only be done during allocation */
 476             if (allocation_done == lang_allocating_phase_enum) {
 477                 result = exp_fold_tree(tree->assign.src,
 478                                        current_section,
 479                                        lang_allocating_phase_enum, dot, dotp);
 480                 if (result.valid == false) {
 481                     einfo("%F%S invalid assignment to location counter\n");
 482                   }
 483                 else {
 484                     if (current_section ==
 485                         (lang_output_section_statement_type  *)NULL) {
 486                         einfo("%F%S assignment to location counter invalid outside of SECTION\n");
 487                       }
 488                     else {
 489                         unsigned long nextdot =result.value +
 490                          current_section->bfd_section->vma;
 491                         if (nextdot < dot) {
 492                             einfo("%F%S cannot move location counter backwards");
 493                           }
 494                         else {
 495                             *dotp = nextdot;
 496                           }
 497                       }
 498                   }
 499               }
 500           }
 501         else {
 502             ldsym_type *sy = ldsym_get(tree->assign.dst);
 503
 504             /* If this symbol has just been created then we'll place it into
 505              * a section of our choice
 506              */
 507             result = exp_fold_tree(tree->assign.src,
 508                                    current_section, allocation_done,
 509                                    dot, dotp);
 510             if (result.valid)
 511             {
 512               asymbol *def;
 513               asymbol **def_ptr ;
 514               /* Add this definition to script file */
 515               if (sy->sdefs_chain)
 516               {
 517                 def_ptr = sy->sdefs_chain;
 518                 def = *def_ptr;
 519
 520               }
 521               else
 522               {
 523                 def_ptr = (asymbol **)stat_alloc((bfd_size_type)(sizeof(asymbol **)));
 524                 def = (asymbol   *)bfd_make_empty_symbol(script_file->the_bfd);
 525
 526
 527                 def->flags = 0;
 528
 529                 sy->sdefs_chain = def_ptr;
 530                 *def_ptr = def;
 531               }
 532
 533               def->value = result.value;
 534
 535                       def->section = result.section->bfd_section;
 536                       def->flags = BSF_GLOBAL | BSF_EXPORT;
 537
 538
 539               def->udata = (PTR)NULL;
 540               def->name = sy->name;
 541
 542               if (sy->sdefs_chain == 0)           Q_enter_global_ref(def_ptr);
 543             }
 544
 545           }
 546
 547
 548         break;
 549       case etree_name:
 550         result = fold_name(tree, current_section, allocation_done, dot);
 551         break;
 552       default:
 553         einfo("%F%S Need more of these %d",tree->type.node_class );
 554
 555       }
 556     }
 557
 558   return result;
 559 }
 560
 561
 562 etree_value_type
 563 DEFUN(exp_fold_tree_no_dot,(tree, current_section, allocation_done),
 564       etree_type *tree AND
 565       lang_output_section_statement_type *current_section AND
 566       lang_phase_type  allocation_done)
 567 {
 568 return exp_fold_tree(tree, current_section, allocation_done, (bfd_vma)
 569                      0, (bfd_vma *)NULL);
 570 }
 571
 572 etree_type *
 573 DEFUN(exp_binop,(code, lhs, rhs),
 574       int code AND
 575       etree_type *lhs AND
 576       etree_type *rhs)
 577 {
 578   etree_type value, *new;
 579   etree_value_type r;
 580
 581   value.type.node_code = code;
 582   value.binary.lhs = lhs;
 583   value.binary.rhs = rhs;
 584   value.type.node_class = etree_binary;
 585   r = exp_fold_tree_no_dot(&value,
 586                            abs_output_section,
 587                            lang_first_phase_enum );
 588   if (r.valid)
 589     {
 590       return exp_intop(r.value);
 591     }
 592   new = (etree_type *)stat_alloc((bfd_size_type)(sizeof(new->binary)));
 593   memcpy((char *)new, (char *)&value, sizeof(new->binary));
 594   return new;
 595 }
 596
 597 etree_type *
 598 DEFUN(exp_trinop,(code, cond, lhs, rhs),
 599       int code AND
 600       etree_type *cond AND
 601       etree_type *lhs AND
 602       etree_type *rhs)
 603 {
 604   etree_type value, *new;
 605   etree_value_type r;
 606   value.type.node_code = code;
 607   value.trinary.lhs = lhs;
 608   value.trinary.cond = cond;
 609   value.trinary.rhs = rhs;
 610   value.type.node_class = etree_trinary;
 611   r= exp_fold_tree_no_dot(&value,  (lang_output_section_statement_type
 612                                     *)NULL,lang_first_phase_enum);
 613   if (r.valid) {
 614     return exp_intop(r.value);
 615   }
 616   new = (etree_type *)stat_alloc((bfd_size_type)(sizeof(new->trinary)));
 617   memcpy((char *)new,(char *) &value, sizeof(new->trinary));
 618   return new;
 619 }
 620
 621
 622 etree_type *
 623 DEFUN(exp_unop,(code, child),
 624       int code AND
 625       etree_type *child)
 626 {
 627   etree_type value, *new;
 628
 629   etree_value_type r;
 630   value.unary.type.node_code = code;
 631   value.unary.child = child;
 632   value.unary.type.node_class = etree_unary;
 633   r = exp_fold_tree_no_dot(&value,(lang_output_section_statement_type *)NULL,
 634                            lang_first_phase_enum);
 635   if (r.valid) {
 636     return exp_intop(r.value);
 637   }
 638   new = (etree_type *)stat_alloc((bfd_size_type)(sizeof(new->unary)));
 639   memcpy((char *)new, (char *)&value, sizeof(new->unary));
 640   return new;
 641 }
 642
 643
 644 etree_type *
 645 DEFUN(exp_nameop,(code, name),
 646       int code AND
 647       CONST char *name)
 648 {
 649
 650   etree_type value, *new;
 651   etree_value_type r;
 652   value.name.type.node_code = code;
 653   value.name.name = name;
 654   value.name.type.node_class = etree_name;
 655
 656
 657   r = exp_fold_tree_no_dot(&value,
 658                            (lang_output_section_statement_type *)NULL,
 659                            lang_first_phase_enum);
 660   if (r.valid) {
 661     return exp_intop(r.value);
 662   }
 663   new = (etree_type *)stat_alloc((bfd_size_type)(sizeof(new->name)));
 664   memcpy((char *)new, (char *)&value, sizeof(new->name));
 665   return new;
 666
 667 }
 668
 669
 670
 671
 672 etree_type *
 673 DEFUN(exp_assop,(code, dst, src),
 674       int code AND
 675       CONST char *dst AND
 676       etree_type *src)
 677 {
 678   etree_type value, *new;
 679
 680   value.assign.type.node_code = code;
 681
 682
 683   value.assign.src = src;
 684   value.assign.dst = dst;
 685   value.assign.type.node_class = etree_assign;
 686
 687 #if 0
 688   if (exp_fold_tree_no_dot(&value, &result)) {
 689     return exp_intop(result);
 690   }
 691 #endif
 692   new = (etree_type*)stat_alloc((bfd_size_type)(sizeof(new->assign)));
 693   memcpy((char *)new, (char *)&value, sizeof(new->assign));
 694   return new;
 695 }
 696
 697 void
 698 DEFUN(exp_print_tree,(tree),
 699       etree_type *tree)
 700 {
 701   switch (tree->type.node_class) {
 702   case etree_value:
 703     print_address(tree->value.value);
 704     return;
 705
 706   case etree_assign:
 707 #if 0
 708     if (tree->assign.dst->sdefs != (asymbol *)NULL){
 709       fprintf(config.map_file,"%s (%x) ",tree->assign.dst->name,
 710               tree->assign.dst->sdefs->value);
 711     }
 712     else {
 713       fprintf(config.map_file,"%s (UNDEFINED)",tree->assign.dst->name);
 714     }
 715 #endif
 716     fprintf(config.map_file,"%s ",tree->assign.dst);
 717     exp_print_token(tree->type.node_code);
 718     exp_print_tree(tree->assign.src);
 719     break;
 720   case etree_binary:
 721     fprintf(config.map_file,"(");
 722     exp_print_tree(tree->binary.lhs);
 723     exp_print_token(tree->type.node_code);
 724     exp_print_tree(tree->binary.rhs);
 725     fprintf(config.map_file,")");
 726     break;
 727   case etree_trinary:
 728     exp_print_tree(tree->trinary.cond);
 729     fprintf(config.map_file,"?");
 730     exp_print_tree(tree->trinary.lhs);
 731     fprintf(config.map_file,":");
 732     exp_print_tree(tree->trinary.rhs);
 733     break;
 734   case etree_unary:
 735     exp_print_token(tree->unary.type.node_code);
 736     if (tree->unary.child)
 737     {
 738
 739     fprintf(config.map_file,"(");
 740     exp_print_tree(tree->unary.child);
 741     fprintf(config.map_file,")");
 742   }
 743
 744     break;
 745   case etree_undef:
 746     fprintf(config.map_file,"????????");
 747     break;
 748   case etree_name:
 749     if (tree->type.node_code == NAME) {
 750       fprintf(config.map_file,"%s", tree->name.name);
 751     }
 752     else {
 753       exp_print_token(tree->type.node_code);
 754       if (tree->name.name)
 755       fprintf(config.map_file,"(%s)", tree->name.name);
 756     }
 757     break;
 758   default:
 759     FAIL();
 760     break;
 761   }
 762 }
 763
 764
 765
 766
 767 bfd_vma
 768 DEFUN(exp_get_vma,(tree, def, name, allocation_done),
 769       etree_type *tree AND
 770       bfd_vma def AND
 771       char *name AND
 772       lang_phase_type allocation_done)
 773 {
 774   etree_value_type r;
 775
 776   if (tree != (etree_type *)NULL) {
 777     r = exp_fold_tree_no_dot(tree,
 778                  abs_output_section,
 779                       allocation_done);
 780     if (r.valid == false && name) {
 781       einfo("%F%S Nonconstant expression for %s\n",name);
 782     }
 783     return r.value;
 784   }
 785   else {
 786     return def;
 787   }
 788 }
 789
 790 int
 791 DEFUN(exp_get_value_int,(tree,def,name, allocation_done),
 792       etree_type *tree AND
 793       int def AND
 794       char *name AND
 795       lang_phase_type allocation_done)
 796 {
 797   return (int)exp_get_vma(tree,(bfd_vma)def,name, allocation_done);
 798 }
 799