ld/ldexp.c

   1 /* Copyright (C) 1991 Free Software Foundation, Inc.
   2
   3 This file is part of GLD, the Gnu Linker.
   4
   5 GLD is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation; either version 1, or (at your option)
   8 any later version.
   9
  10 GLD is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with GLD; see the file COPYING.  If not, write to
  17 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  18
  19 /*
  20    $Id$
  21 */
  22
  23 /*
  24  * Written by Steve Chamberlain
  25  * steve@cygnus.com
  26  *
  27  * This module handles expression trees.
  28  */
  29
  30
  31 #include "sysdep.h"
  32 #include "bfd.h"
  33
  34 #include "ld.h"
  35 #include "ldmain.h"
  36 #include "ldmisc.h"
  37 #include "ldexp.h"
  38 #include "ldgram.tab.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 size_t 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
  54 extern bfd_vma print_dot;
  55
  56
  57 static void
  58 exp_print_token(outfile, code)
  59 FILE *outfile;
  60 token_code_type code;
  61 {
  62   static struct  {
  63     token_code_type code;
  64     char *name;
  65   } table[] =
  66     {
  67       INT,      "int",
  68       CHAR,"char",
  69       NAME,"NAME",
  70       PLUSEQ,"+=",
  71       MINUSEQ,"-=",
  72       MULTEQ,"*=",
  73       DIVEQ,"/=",
  74       LSHIFTEQ,"<<=",
  75       RSHIFTEQ,">>=",
  76       ANDEQ,"&=",
  77       OREQ,"|=",
  78       OROR,"||",
  79       ANDAND,"&&",
  80       EQ,"==",
  81       NE,"!=",
  82       LE,"<=",
  83       GE,">=",
  84       LSHIFT,"<<",
  85       RSHIFT,">>=",
  86       ALIGN_K,"ALIGN",
  87       BLOCK,"BLOCK",
  88       SECTIONS,"SECTIONS",
  89       ALIGNMENT,"ALIGNMENT",
  90       SIZEOF_HEADERS,"SIZEOF_HEADERS",
  91       NEXT,"NEXT",
  92       SIZEOF,"SIZEOF",
  93       ADDR,"ADDR",
  94       MEMORY,"MEMORY",
  95       DSECT,"DSECT",
  96       NOLOAD,"NOLOAD",
  97       COPY,"COPY",
  98       INFO,"INFO",
  99       OVERLAY,"OVERLAY",
 100       DEFINED,"DEFINED",
 101       TARGET_K,"TARGET",
 102       SEARCH_DIR,"SEARCH_DIR",
 103       MAP,"MAP",
 104       LONG,"LONG",
 105       SHORT,"SHORT",
 106       BYTE,"BYTE",
 107       ENTRY,"ENTRY",
 108     0,(char *)NULL} ;
 109
 110
 111
 112   unsigned int idx;
 113   for (idx = 0; table[idx].name != (char*)NULL; idx++) {
 114     if (table[idx].code == code) {
 115       fprintf(outfile, "%s", table[idx].name);
 116       return;
 117     }
 118   }
 119   /* Not in table, just print it alone */
 120   fprintf(outfile, "%c",code);
 121 }
 122
 123 static void
 124 make_abs(ptr)
 125 etree_value_type *ptr;
 126 {
 127   if (ptr->section != (lang_output_section_statement_type *)NULL) {
 128     asection *s = ptr->section->bfd_section;
 129     ptr->value += s->vma;
 130     ptr->section = (lang_output_section_statement_type *)NULL;
 131   }
 132
 133 }
 134 static
 135 etree_value_type new_abs(value)
 136 bfd_vma value;
 137 {
 138   etree_value_type new;
 139   new.valid = true;
 140   new.section = (lang_output_section_statement_type *)NULL;
 141   new.value = value;
 142   return new;
 143 }
 144
 145 static void
 146 DEFUN(check, (os, name, op),
 147       lang_output_section_statement_type *os AND
 148       CONST char *name AND
 149       CONST char *op)
 150 {
 151   if (os == (lang_output_section_statement_type *)NULL) {
 152     info("%F%P %s uses undefined section %s\n", op, name);
 153   }
 154   if (os->processed == false) {
 155     info("%F%P %s forward reference of section %s\n",op, name);
 156   }
 157 }
 158
 159 etree_type *exp_intop(value)
 160 bfd_vma value;
 161 {
 162   etree_type *new = (etree_type *)ldmalloc(sizeof(new->value));
 163   new->type.node_code = INT;
 164   new->value.value = value;
 165   new->type.node_class = etree_value;
 166   return new;
 167
 168 }
 169
 170
 171 static
 172 etree_value_type new_rel(value, section)
 173 bfd_vma value;
 174 lang_output_section_statement_type *section;
 175 {
 176   etree_value_type new;
 177   new.valid = true;
 178   new.value = value;
 179   new.section = section;
 180   return new;
 181 }
 182
 183 static
 184 etree_value_type new_rel_from_section(value, section)
 185 bfd_vma value;
 186 lang_output_section_statement_type *section;
 187 {
 188   etree_value_type new;
 189   new.valid = true;
 190   new.value = value;
 191   new.section = section;
 192   if (new.section != (lang_output_section_statement_type *)NULL) {
 193     new.value -= section->bfd_section->vma;
 194   }
 195   return new;
 196 }
 197
 198 static etree_value_type
 199 fold_binary(tree, current_section, allocation_done, dot, dotp)
 200 etree_type *tree;
 201 lang_output_section_statement_type *current_section;
 202 lang_phase_type  allocation_done;
 203 bfd_vma dot;
 204 bfd_vma *dotp;
 205 {
 206   etree_value_type result;
 207
 208   result =  exp_fold_tree(tree->binary.lhs,  current_section,
 209                           allocation_done, dot, dotp);
 210   if (result.valid) {
 211     etree_value_type other;
 212     other = exp_fold_tree(tree->binary.rhs,
 213                           current_section,
 214                           allocation_done, dot,dotp) ;
 215     if (other.valid) {
 216         /* If values are from different sections, or this is an */
 217         /* absolute expression, make both source args absolute */
 218       if (result.section !=  other.section ||
 219           current_section == (lang_output_section_statement_type *)NULL) {
 220
 221         make_abs(&result);
 222         make_abs(&other);
 223       }
 224
 225       switch (tree->type.node_code)
 226         {
 227         case '%':
 228           /* Mod,  both absolule*/
 229
 230           if (other.value == 0) {
 231             info("%F%S % by zero\n");
 232           }
 233           result.value %= other.value;
 234           break;
 235         case '/':
 236           if (other.value == 0) {
 237             info("%F%S / by zero\n");
 238           }
 239           result.value /= other.value;
 240           break;
 241 #define BOP(x,y) case x : result.value = result.value y other.value;break;
 242           BOP('+',+);
 243           BOP('*',*);
 244           BOP('-',-);
 245           BOP(LSHIFT,<<);
 246           BOP(RSHIFT,>>);
 247           BOP(EQ,==);
 248           BOP(NE,!=);
 249           BOP('<',<);
 250           BOP('>',>);
 251           BOP(LE,<=);
 252           BOP(GE,>=);
 253           BOP('&',&);
 254           BOP('^',^);
 255           BOP('|',|);
 256           BOP(ANDAND,&&);
 257           BOP(OROR,||);
 258         default:
 259           FAIL();
 260         }
 261     }
 262     else {
 263       result.valid = false;
 264     }
 265   }
 266   return result;
 267 }
 268 etree_value_type invalid()
 269 {
 270   etree_value_type new;
 271   new.valid = false;
 272   return new;
 273 }
 274
 275 etree_value_type fold_name(tree, current_section, allocation_done, dot)
 276 etree_type *tree;
 277 lang_output_section_statement_type *current_section;
 278 lang_phase_type  allocation_done;
 279 bfd_vma dot;
 280
 281 {
 282   etree_value_type result;
 283   switch (tree->type.node_code)
 284       {
 285       case DEFINED:
 286         result.value =
 287           ldsym_get_soft(tree->name.name) != (ldsym_type *)NULL;
 288         result.section = 0;
 289         result.valid = true;
 290         break;
 291       case NAME:
 292         result.valid = false;
 293         if (tree->name.name[0] == '.' && tree->name.name[1] == 0) {
 294
 295           if (allocation_done != lang_first_phase_enum) {
 296             result = new_rel_from_section(dot, current_section);
 297           }
 298           else {
 299             result = invalid();
 300           }
 301         }
 302         else {
 303           if (allocation_done == lang_final_phase_enum) {
 304             ldsym_type *sy = ldsym_get_soft(tree->name.name);
 305
 306             if (sy) {
 307               asymbol **sdefp = sy->sdefs_chain;
 308
 309               if (sdefp) {
 310                 asymbol *sdef = *sdefp;
 311                 if (sdef->section == (asection *)NULL) {
 312                   /* This is an absolute symbol */
 313                   result = new_abs(sdef->value);
 314                 }
 315                 else {
 316                   lang_output_section_statement_type *os =
 317                     lang_output_section_statement_lookup(
 318                                                          sdef->section->output_section->name);
 319                   /* If the symbol is from a file which we are not
 320                      relocating (-R) then return an absolute for its
 321                      value */
 322                   if (sdef->the_bfd->usrdata &&
 323                       ((lang_input_statement_type*)(sdef->the_bfd->usrdata))->just_syms_flag == true)
 324                       {
 325                         result = new_abs(sdef->value + (sdef->section ?
 326                                          sdef->section->vma : 0));
 327                       }
 328                   else {
 329                     result = new_rel(sdef->value + sdef->section->output_offset, os);
 330                   }
 331                 }
 332               }
 333             }
 334             if (result.valid == false) {
 335               info("%F%S: undefined symbol `%s' referenced in expression.\n",
 336                    tree->name.name);
 337             }
 338
 339           }
 340         }
 341
 342         break;
 343
 344       case ADDR:
 345
 346         if (allocation_done != lang_first_phase_enum) {
 347           lang_output_section_statement_type *os =
 348             lang_output_section_find(tree->name.name);
 349           check(os,tree->name.name,"ADDR");
 350           result =    new_rel((bfd_vma)0,  os);
 351         }
 352         else {
 353           result = invalid();
 354         }
 355         break;
 356       case SIZEOF:
 357         if(allocation_done != lang_first_phase_enum) {
 358           lang_output_section_statement_type *os =
 359             lang_output_section_find(tree->name.name);
 360           check(os,tree->name.name,"SIZEOF");
 361           result = new_abs((bfd_vma)(os->bfd_section->size));
 362         }
 363         else {
 364           result = invalid();
 365         }
 366         break;
 367
 368       default:
 369         FAIL();
 370         break;
 371       }
 372
 373   return result;
 374 }
 375 etree_value_type exp_fold_tree(tree, current_section, allocation_done,
 376                                dot, dotp)
 377 etree_type *tree;
 378 lang_output_section_statement_type *current_section;
 379 lang_phase_type  allocation_done;
 380 bfd_vma dot;
 381 bfd_vma *dotp;
 382 {
 383   etree_value_type result;
 384
 385   if (tree == (etree_type *)NULL) {
 386     result.valid = false;
 387   }
 388   else {
 389     switch (tree->type.node_class)
 390         {
 391         case etree_value:
 392           result = new_rel(tree->value.value, current_section);
 393           break;
 394         case etree_unary:
 395           result = exp_fold_tree(tree->unary.child,
 396                                  current_section,
 397                                  allocation_done, dot, dotp);
 398           if (result.valid == true)
 399               {
 400                 switch(tree->type.node_code)
 401                     {
 402                     case ALIGN_K:
 403                       if (allocation_done != lang_first_phase_enum) {
 404                         result = new_rel_from_section(ALIGN(dot,
 405                                                             result.value) ,
 406                                                       current_section);
 407
 408                       }
 409                       else {
 410                         result.valid = false;
 411                       }
 412                       break;
 413                     case '~':
 414                       make_abs(&result);
 415                       result.value = ~result.value;
 416                       break;
 417                     case '!':
 418                       make_abs(&result);
 419                       result.value = !result.value;
 420                       break;
 421                     case '-':
 422                       make_abs(&result);
 423                       result.value = -result.value;
 424                       break;
 425                     case NEXT:
 426                       result.valid = false;
 427                       break;
 428                     default:
 429                       FAIL();
 430                     }
 431               }
 432
 433           break;
 434         case etree_trinary:
 435
 436           result = exp_fold_tree(tree->trinary.cond,
 437                                  current_section,
 438                                  allocation_done, dot, dotp);
 439           if (result.valid) {
 440             result = exp_fold_tree(result.value ?
 441                                    tree->trinary.lhs:tree->trinary.rhs,
 442                                    current_section,
 443                                    allocation_done, dot, dotp);
 444           }
 445
 446           break;
 447         case etree_binary:
 448           result = fold_binary(tree, current_section, allocation_done,
 449                                dot, dotp);
 450           break;
 451         case etree_assign:
 452           if (tree->assign.dst[0] == '.' && tree->assign.dst[1] == 0) {
 453             /* Assignment to dot can only be done during allocation */
 454             if (allocation_done == lang_allocating_phase_enum) {
 455               result = exp_fold_tree(tree->assign.src,
 456                                      current_section,
 457                                      lang_allocating_phase_enum, dot, dotp);
 458               if (result.valid == false) {
 459                 info("%F%S invalid assignment to location counter\n");
 460               }
 461               else {
 462                 if (current_section ==
 463                     (lang_output_section_statement_type  *)NULL) {
 464                   info("%F%S assignment to location counter invalid outside of SECTION\n");
 465                 }
 466                 else {
 467                   unsigned long nextdot =result.value +
 468                     current_section->bfd_section->vma;
 469                   if (nextdot < dot) {
 470                     info("%F%S cannot move location counter backwards");
 471                   }
 472                   else {
 473                     *dotp = nextdot;
 474                   }
 475                 }
 476               }
 477             }
 478           }
 479           else {
 480             ldsym_type *sy = ldsym_get(tree->assign.dst);
 481
 482             /* If this symbol has just been created then we'll place it into
 483              * a section of our choice
 484              */
 485             result = exp_fold_tree(tree->assign.src,
 486                                    current_section, allocation_done,
 487                                    dot, dotp);
 488             if (result.valid)
 489                 {
 490                   asymbol *def;
 491                   asymbol **def_ptr = (asymbol **)ldmalloc(sizeof(asymbol **));
 492                   /* Add this definition to script file */
 493                   def = (asymbol *)bfd_make_empty_symbol(script_file->the_bfd);
 494                   *def_ptr = def;
 495
 496
 497                   def->value = result.value;
 498                   if (result.section !=
 499                       (lang_output_section_statement_type  *)NULL) {
 500                     if (current_section !=
 501                         (lang_output_section_statement_type *)NULL) {
 502
 503                       def->section = result.section->bfd_section;
 504                       def->flags = BSF_GLOBAL | BSF_EXPORT;
 505                     }
 506                     else {
 507                       /* Force to absolute */
 508                       def->value += result.section->bfd_section->vma;
 509                       def->section = (asection *)NULL;
 510                       def->flags = BSF_GLOBAL | BSF_EXPORT | BSF_ABSOLUTE;
 511                     }
 512
 513
 514                   }
 515                   else {
 516                     def->section = (asection *)NULL;
 517                     def->flags = BSF_GLOBAL | BSF_EXPORT | BSF_ABSOLUTE;
 518                   }
 519
 520
 521                   def->udata = (PTR)NULL;
 522                   def->name = sy->name;
 523                   Q_enter_global_ref(def_ptr);
 524                 }
 525
 526           }
 527
 528
 529           break;
 530         case etree_name:
 531           result = fold_name(tree, current_section, allocation_done, dot);
 532           break;
 533         default:
 534           info("%F%S Need more of these %d",tree->type.node_class );
 535
 536         }
 537   }
 538
 539   return result;
 540 }
 541
 542
 543 etree_value_type exp_fold_tree_no_dot(tree, current_section, allocation_done)
 544 etree_type *tree;
 545 lang_output_section_statement_type *current_section;
 546 lang_phase_type  allocation_done;
 547 {
 548 return exp_fold_tree(tree, current_section, allocation_done, (bfd_vma)
 549                      0, (bfd_vma *)NULL);
 550 }
 551
 552 etree_type *
 553 exp_binop(code, lhs, rhs)
 554 int code;
 555 etree_type *lhs;
 556 etree_type *rhs;
 557 {
 558   etree_type value, *new;
 559   etree_value_type r;
 560
 561   value.type.node_code = code;
 562   value.binary.lhs = lhs;
 563   value.binary.rhs = rhs;
 564   value.type.node_class = etree_binary;
 565   r = exp_fold_tree_no_dot(&value,  (lang_output_section_statement_type *)NULL,
 566                            lang_first_phase_enum );
 567   if (r.valid)
 568     {
 569       return exp_intop(r.value);
 570     }
 571   new = (etree_type *)ldmalloc(sizeof(new->binary));
 572   memcpy((char *)new, (char *)&value, sizeof(new->binary));
 573   return new;
 574 }
 575
 576 etree_type *
 577 exp_trinop(code, cond, lhs, rhs)
 578 int code;
 579 etree_type *cond;
 580 etree_type *lhs;
 581 etree_type *rhs;
 582 {
 583   etree_type value, *new;
 584   etree_value_type r;
 585   value.type.node_code = code;
 586   value.trinary.lhs = lhs;
 587   value.trinary.cond = cond;
 588   value.trinary.rhs = rhs;
 589   value.type.node_class = etree_trinary;
 590   r= exp_fold_tree_no_dot(&value,  (lang_output_section_statement_type
 591                                     *)NULL,lang_first_phase_enum);
 592   if (r.valid) {
 593     return exp_intop(r.value);
 594   }
 595   new = (etree_type *)ldmalloc(sizeof(new->trinary));
 596   memcpy((char *)new,(char *) &value, sizeof(new->trinary));
 597   return new;
 598 }
 599
 600
 601 etree_type *
 602 exp_unop(code, child)
 603 int code;
 604 etree_type *child;
 605 {
 606   etree_type value, *new;
 607
 608   etree_value_type r;
 609   value.unary.type.node_code = code;
 610   value.unary.child = child;
 611   value.unary.type.node_class = etree_unary;
 612 r = exp_fold_tree_no_dot(&value,(lang_output_section_statement_type *)NULL,
 613               lang_first_phase_enum);
 614 if (r.valid) {
 615     return exp_intop(r.value);
 616   }
 617   new = (etree_type *)ldmalloc(sizeof(new->unary));
 618   memcpy((char *)new, (char *)&value, sizeof(new->unary));
 619   return new;
 620 }
 621
 622
 623 etree_type *
 624 exp_nameop(code, name)
 625 int code;
 626 char *name;
 627 {
 628
 629   etree_type value, *new;
 630
 631   etree_value_type r;
 632   value.name.type.node_code = code;
 633   value.name.name = name;
 634   value.name.type.node_class = etree_name;
 635
 636
 637   r = exp_fold_tree_no_dot(&value,(lang_output_section_statement_type *)NULL,
 638                 lang_first_phase_enum);
 639   if (r.valid) {
 640     return exp_intop(r.value);
 641   }
 642   new = (etree_type *)ldmalloc(sizeof(new->name));
 643   memcpy((char *)new, (char *)&value, sizeof(new->name));
 644   return new;
 645
 646 }
 647
 648
 649
 650
 651 etree_type *
 652 exp_assop(code, dst, src)
 653 int code;
 654 char *dst;
 655 etree_type *src;
 656 {
 657   etree_type value, *new;
 658
 659   value.assign.type.node_code = code;
 660
 661
 662   value.assign.src = src;
 663   value.assign.dst = dst;
 664   value.assign.type.node_class = etree_assign;
 665
 666 #if 0
 667   if (exp_fold_tree_no_dot(&value, &result)) {
 668     return exp_intop(result);
 669   }
 670 #endif
 671   new = (etree_type*)ldmalloc(sizeof(new->assign));
 672   memcpy((char *)new, (char *)&value, sizeof(new->assign));
 673   return new;
 674 }
 675
 676 void
 677 exp_print_tree(outfile, tree)
 678 FILE *outfile;
 679 etree_type *tree;
 680 {
 681   switch (tree->type.node_class) {
 682   case etree_value:
 683     fprintf(outfile,"0x%08lx",(bfd_vma)(tree->value.value));
 684     return;
 685   case etree_assign:
 686 #if 0
 687     if (tree->assign.dst->sdefs != (asymbol *)NULL){
 688       fprintf(outfile,"%s (%x) ",tree->assign.dst->name,
 689               tree->assign.dst->sdefs->value);
 690     }
 691     else {
 692       fprintf(outfile,"%s (UNDEFINED)",tree->assign.dst->name);
 693     }
 694 #endif
 695     fprintf(outfile,"%s ",tree->assign.dst);
 696     exp_print_token(outfile,tree->type.node_code);
 697     exp_print_tree(outfile,tree->assign.src);
 698     break;
 699   case etree_binary:
 700     exp_print_tree(outfile,tree->binary.lhs);
 701     exp_print_token(outfile,tree->type.node_code);
 702     exp_print_tree(outfile,tree->binary.rhs);
 703     break;
 704   case etree_trinary:
 705     exp_print_tree(outfile,tree->trinary.cond);
 706     fprintf(outfile,"?");
 707     exp_print_tree(outfile,tree->trinary.lhs);
 708     fprintf(outfile,":");
 709     exp_print_tree(outfile,tree->trinary.rhs);
 710     break;
 711   case etree_unary:
 712     exp_print_token(outfile,tree->unary.type.node_code);
 713     fprintf(outfile,"(");
 714     exp_print_tree(outfile,tree->unary.child);
 715     fprintf(outfile,")");
 716     break;
 717   case etree_undef:
 718     fprintf(outfile,"????????");
 719     break;
 720   case etree_name:
 721     if (tree->type.node_code == NAME) {
 722       fprintf(outfile,"%s", tree->name.name);
 723     }
 724     else {
 725       exp_print_token(outfile,tree->type.node_code);
 726       fprintf(outfile,"(%s)", tree->name.name);
 727     }
 728     break;
 729   default:
 730     FAIL();
 731     break;
 732   }
 733 }
 734
 735
 736
 737
 738 bfd_vma
 739 exp_get_vma(tree, def, name, allocation_done)
 740 etree_type *tree;
 741 bfd_vma def;
 742 char *name;
 743 lang_phase_type allocation_done;
 744 {
 745   etree_value_type r;
 746
 747   if (tree != (etree_type *)NULL) {
 748     r = exp_fold_tree_no_dot(tree,
 749                       (lang_output_section_statement_type *)NULL,
 750                       allocation_done);
 751     if (r.valid == false && name) {
 752       info("%F%S Nonconstant expression for %s\n",name);
 753     }
 754     return r.value;
 755   }
 756   else {
 757     return def;
 758   }
 759 }
 760
 761 int
 762 exp_get_value_int(tree,def,name, allocation_done)
 763 etree_type *tree;
 764 int def;
 765 char *name;
 766 lang_phase_type allocation_done;
 767 {
 768   return (int)exp_get_vma(tree,(bfd_vma)def,name, allocation_done);
 769 }