| 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 | This module writes out the final image by reading sections from the |
| 25 | input files, relocating them and writing them out |
| 26 | |
| 27 | There are two main paths through this module, one for normal |
| 28 | operation and one for partial linking. |
| 29 | |
| 30 | During normal operation, raw section data is read along with the |
| 31 | associated relocation information, the relocation info applied and |
| 32 | the section data written out on a section by section basis. |
| 33 | |
| 34 | When partially linking, all the relocation records are read to work |
| 35 | out how big the output relocation vector will be. Then raw data is |
| 36 | read, relocated and written section by section. |
| 37 | |
| 38 | Written by Steve Chamberlain steve@cygnus.com |
| 39 | |
| 40 | */ |
| 41 | |
| 42 | |
| 43 | #include "sysdep.h" |
| 44 | #include "bfd.h" |
| 45 | |
| 46 | #include "ldlang.h" |
| 47 | #include "ld.h" |
| 48 | #include "ldwrite.h" |
| 49 | #include "ldmisc.h" |
| 50 | #include "ldsym.h" |
| 51 | #include "ldgram.tab.h" |
| 52 | |
| 53 | |
| 54 | |
| 55 | char *ldmalloc(); |
| 56 | /* Static vars for do_warnings and subroutines of it */ |
| 57 | int list_unresolved_refs; /* List unresolved refs */ |
| 58 | int list_warning_symbols; /* List warning syms */ |
| 59 | int list_multiple_defs; /* List multiple definitions */ |
| 60 | extern int errno; |
| 61 | extern char *sys_errlist[]; |
| 62 | |
| 63 | extern unsigned int undefined_global_sym_count; |
| 64 | |
| 65 | extern bfd *output_bfd; |
| 66 | |
| 67 | extern struct lang_output_section_statement_struct * create_object_symbols; |
| 68 | |
| 69 | extern char lprefix; |
| 70 | |
| 71 | #ifdef __STDC__ |
| 72 | void lang_for_each_statement(void (*func)()); |
| 73 | #else /* __STDC__ */ |
| 74 | void lang_for_each_statement(); |
| 75 | #endif /* __STDC__ */ |
| 76 | |
| 77 | extern size_t largest_section; |
| 78 | ld_config_type config; |
| 79 | |
| 80 | extern unsigned int global_symbol_count; |
| 81 | |
| 82 | boolean trace_files; |
| 83 | |
| 84 | static void perform_relocation(input_bfd, |
| 85 | input_section, |
| 86 | data, |
| 87 | symbols) |
| 88 | bfd *input_bfd; |
| 89 | asection *input_section; |
| 90 | PTR data; |
| 91 | asymbol **symbols; |
| 92 | { |
| 93 | static asymbol *error_symbol = (asymbol *)NULL; |
| 94 | static unsigned int error_count = 0; |
| 95 | #define MAX_ERRORS_IN_A_ROW 5 |
| 96 | size_t reloc_size = get_reloc_upper_bound(input_bfd, input_section); |
| 97 | |
| 98 | arelent **reloc_vector = (arelent **)ldmalloc(reloc_size); |
| 99 | arelent **parent; |
| 100 | bfd *ob = output_bfd; |
| 101 | asection *os = input_section->output_section; |
| 102 | if (config.relocateable_output == false) ob = (bfd *)NULL; |
| 103 | |
| 104 | if (bfd_canonicalize_reloc(input_bfd, |
| 105 | input_section, |
| 106 | reloc_vector, |
| 107 | symbols) ) |
| 108 | { |
| 109 | for (parent = reloc_vector; *parent; parent++) |
| 110 | { |
| 111 | |
| 112 | bfd_reloc_status_enum_type r= |
| 113 | bfd_perform_relocation(input_bfd, |
| 114 | *parent, |
| 115 | data, |
| 116 | input_section, |
| 117 | ob); |
| 118 | |
| 119 | if (r == bfd_reloc_ok) { |
| 120 | if (ob != (bfd *)NULL) { |
| 121 | /* A parital link, so keep the relocs */ |
| 122 | os->orelocation[os->reloc_count] = *parent; |
| 123 | os->reloc_count++; |
| 124 | } |
| 125 | } |
| 126 | else |
| 127 | { |
| 128 | asymbol *s; |
| 129 | arelent *p = *parent; |
| 130 | |
| 131 | if (ob != (bfd *)NULL) { |
| 132 | /* A parital link, so keep the relocs */ |
| 133 | os->orelocation[os->reloc_count] = *parent; |
| 134 | os->reloc_count++; |
| 135 | } |
| 136 | |
| 137 | if (p->sym_ptr_ptr != (asymbol **)NULL) { |
| 138 | s = *(p->sym_ptr_ptr); |
| 139 | } |
| 140 | else { |
| 141 | s = (asymbol *)NULL; |
| 142 | } |
| 143 | switch (r) |
| 144 | { |
| 145 | case bfd_reloc_undefined: |
| 146 | /* We remember the symbol, and never print more than |
| 147 | a reasonable number of them in a row */ |
| 148 | if (s == error_symbol) { |
| 149 | error_count++; |
| 150 | } |
| 151 | else { |
| 152 | error_count = 0; |
| 153 | error_symbol = s; |
| 154 | } |
| 155 | if (error_count < MAX_ERRORS_IN_A_ROW) { |
| 156 | info("%C: undefined reference to `%T'\n", |
| 157 | input_bfd, |
| 158 | input_section, |
| 159 | symbols, |
| 160 | (*parent)->address, |
| 161 | s); |
| 162 | config.make_executable = false; |
| 163 | } |
| 164 | else if (error_count == MAX_ERRORS_IN_A_ROW) { |
| 165 | info("%C: more undefined references to `%T' follow\n", |
| 166 | input_bfd, |
| 167 | input_section, |
| 168 | symbols, |
| 169 | (*parent)->address, |
| 170 | s); |
| 171 | } |
| 172 | else { |
| 173 | /* Don't print any more */ |
| 174 | } |
| 175 | break; |
| 176 | case bfd_reloc_dangerous: |
| 177 | info("%B: relocation may be wrong `%T'\n", |
| 178 | input_bfd, |
| 179 | s); |
| 180 | break; |
| 181 | case bfd_reloc_outofrange: |
| 182 | info("%B:%s relocation address out of range %T (%x)\n", |
| 183 | input_bfd, |
| 184 | input_section->name, |
| 185 | s, |
| 186 | p->address); |
| 187 | break; |
| 188 | case bfd_reloc_overflow: |
| 189 | info("%B:%s relocation overflow in %T reloc type %d\n", |
| 190 | input_bfd, |
| 191 | input_section->name, |
| 192 | s, |
| 193 | p->howto->type); |
| 194 | break; |
| 195 | default: |
| 196 | info("%F%B: relocation error, symbol `%T'\n", |
| 197 | input_bfd, |
| 198 | s); |
| 199 | break; |
| 200 | } |
| 201 | } |
| 202 | } |
| 203 | } |
| 204 | free((char *)reloc_vector); |
| 205 | } |
| 206 | |
| 207 | |
| 208 | |
| 209 | |
| 210 | |
| 211 | |
| 212 | PTR data_area; |
| 213 | |
| 214 | static void |
| 215 | copy_and_relocate(statement) |
| 216 | lang_statement_union_type *statement; |
| 217 | { |
| 218 | switch (statement->header.type) { |
| 219 | case lang_fill_statement_enum: |
| 220 | { |
| 221 | #if 0 |
| 222 | bfd_byte play_area[SHORT_SIZE]; |
| 223 | unsigned int i; |
| 224 | bfd_putshort(output_bfd, statement->fill_statement.fill, play_area); |
| 225 | /* Write out all entire shorts */ |
| 226 | for (i = 0; |
| 227 | i < statement->fill_statement.size - SHORT_SIZE + 1; |
| 228 | i+= SHORT_SIZE) |
| 229 | { |
| 230 | bfd_set_section_contents(output_bfd, |
| 231 | statement->fill_statement.output_section, |
| 232 | play_area, |
| 233 | statement->data_statement.output_offset +i, |
| 234 | SHORT_SIZE); |
| 235 | |
| 236 | } |
| 237 | |
| 238 | /* Now write any remaining byte */ |
| 239 | if (i < statement->fill_statement.size) |
| 240 | { |
| 241 | bfd_set_section_contents(output_bfd, |
| 242 | statement->fill_statement.output_section, |
| 243 | play_area, |
| 244 | statement->data_statement.output_offset +i, |
| 245 | 1); |
| 246 | |
| 247 | } |
| 248 | #endif |
| 249 | } |
| 250 | break; |
| 251 | case lang_data_statement_enum: |
| 252 | { |
| 253 | bfd_vma value = statement->data_statement.value; |
| 254 | bfd_byte play_area[LONG_SIZE]; |
| 255 | unsigned int size; |
| 256 | switch (statement->data_statement.type) { |
| 257 | case LONG: |
| 258 | bfd_putlong(output_bfd, value, play_area); |
| 259 | size = LONG_SIZE; |
| 260 | break; |
| 261 | case SHORT: |
| 262 | bfd_putshort(output_bfd, value, play_area); |
| 263 | size = SHORT_SIZE; |
| 264 | break; |
| 265 | case BYTE: |
| 266 | bfd_putchar(output_bfd, value, play_area); |
| 267 | size = BYTE_SIZE; |
| 268 | break; |
| 269 | } |
| 270 | |
| 271 | bfd_set_section_contents(output_bfd, |
| 272 | statement->data_statement.output_section, |
| 273 | play_area, |
| 274 | statement->data_statement.output_vma, |
| 275 | size); |
| 276 | |
| 277 | |
| 278 | |
| 279 | |
| 280 | } |
| 281 | break; |
| 282 | case lang_input_section_enum: |
| 283 | { |
| 284 | |
| 285 | asection *i = statement->input_section.section; |
| 286 | asection *output_section = i->output_section; |
| 287 | lang_input_statement_type *ifile = |
| 288 | statement->input_section.ifile; |
| 289 | if (ifile->just_syms_flag == false) { |
| 290 | bfd *inbfd = ifile->the_bfd; |
| 291 | |
| 292 | if (output_section->flags & SEC_LOAD && i->size != 0) |
| 293 | { |
| 294 | if(bfd_get_section_contents(inbfd, |
| 295 | i, |
| 296 | data_area, |
| 297 | 0L, |
| 298 | i->size) == false) |
| 299 | { |
| 300 | info("%F%B error reading section contents %E\n", |
| 301 | inbfd); |
| 302 | } |
| 303 | perform_relocation (inbfd, i, data_area, ifile->asymbols); |
| 304 | |
| 305 | |
| 306 | if(bfd_set_section_contents(output_bfd, |
| 307 | output_section, |
| 308 | data_area, |
| 309 | (file_ptr)i->output_offset, |
| 310 | i->size) == false) |
| 311 | { |
| 312 | info("%F%B error writing section contents of %E\n", |
| 313 | output_bfd); |
| 314 | } |
| 315 | |
| 316 | } |
| 317 | } |
| 318 | |
| 319 | } |
| 320 | break; |
| 321 | |
| 322 | default: |
| 323 | /* All the other ones fall through */ |
| 324 | ; |
| 325 | |
| 326 | } |
| 327 | } |
| 328 | |
| 329 | void |
| 330 | write_norel() |
| 331 | { |
| 332 | /* Output the text and data segments, relocating as we go. */ |
| 333 | lang_for_each_statement(copy_and_relocate); |
| 334 | } |
| 335 | |
| 336 | |
| 337 | static void read_relocs(abfd, section, symbols) |
| 338 | bfd *abfd; |
| 339 | asection *section; |
| 340 | asymbol **symbols; |
| 341 | { |
| 342 | /* Work out the output section ascociated with this input section */ |
| 343 | asection *output_section = section->output_section; |
| 344 | |
| 345 | size_t reloc_size = get_reloc_upper_bound(abfd, section); |
| 346 | arelent **reloc_vector = (arelent **)ldmalloc(reloc_size); |
| 347 | |
| 348 | if (bfd_canonicalize_reloc(abfd, |
| 349 | section, |
| 350 | reloc_vector, |
| 351 | symbols)) { |
| 352 | output_section->reloc_count += section->reloc_count; |
| 353 | } |
| 354 | } |
| 355 | |
| 356 | |
| 357 | static void |
| 358 | write_rel() |
| 359 | { |
| 360 | /* |
| 361 | Run through each section of each file and work work out the total |
| 362 | number of relocation records which will finally be in each output |
| 363 | section |
| 364 | */ |
| 365 | |
| 366 | LANG_FOR_EACH_INPUT_SECTION |
| 367 | (statement, abfd, section, |
| 368 | (read_relocs(abfd, section, statement->asymbols))); |
| 369 | |
| 370 | |
| 371 | |
| 372 | /* |
| 373 | Now run though all the output sections and allocate the space for |
| 374 | all the relocations |
| 375 | */ |
| 376 | LANG_FOR_EACH_OUTPUT_SECTION |
| 377 | (section, |
| 378 | (section->orelocation = |
| 379 | (arelent **)ldmalloc((size_t)(sizeof(arelent **)* |
| 380 | section->reloc_count)), |
| 381 | section->reloc_count = 0, |
| 382 | section->flags |= SEC_HAS_CONTENTS)); |
| 383 | |
| 384 | |
| 385 | /* |
| 386 | Copy the data, relocating as we go |
| 387 | */ |
| 388 | lang_for_each_statement(copy_and_relocate); |
| 389 | } |
| 390 | |
| 391 | void |
| 392 | ldwrite () |
| 393 | { |
| 394 | data_area = (PTR) ldmalloc(largest_section); |
| 395 | if (config.relocateable_output == true) |
| 396 | { |
| 397 | write_rel(); |
| 398 | } |
| 399 | else |
| 400 | { |
| 401 | write_norel(); |
| 402 | } |
| 403 | free(data_area); |
| 404 | /* Output the symbol table (both globals and locals). */ |
| 405 | ldsym_write (); |
| 406 | |
| 407 | } |
| 408 | |