| 1 | /* ldwrite.c -- write out the linked file |
| 2 | Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 1998 |
| 3 | Free Software Foundation, Inc. |
| 4 | Written by Steve Chamberlain sac@cygnus.com |
| 5 | |
| 6 | This file is part of GLD, the Gnu Linker. |
| 7 | |
| 8 | This program is free software; you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation; either version 2 of the License, or |
| 11 | (at your option) any later version. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program; if not, write to the Free Software |
| 20 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| 21 | |
| 22 | #include "bfd.h" |
| 23 | #include "sysdep.h" |
| 24 | #include "bfdlink.h" |
| 25 | #include "libiberty.h" |
| 26 | |
| 27 | #include "ld.h" |
| 28 | #include "ldexp.h" |
| 29 | #include "ldlang.h" |
| 30 | #include "ldwrite.h" |
| 31 | #include "ldmisc.h" |
| 32 | #include "ldgram.h" |
| 33 | #include "ldmain.h" |
| 34 | |
| 35 | static void build_link_order PARAMS ((lang_statement_union_type *)); |
| 36 | static asection *clone_section PARAMS ((bfd *, asection *, int *)); |
| 37 | static void split_sections PARAMS ((bfd *, struct bfd_link_info *)); |
| 38 | |
| 39 | /* Build link_order structures for the BFD linker. */ |
| 40 | |
| 41 | static void |
| 42 | build_link_order (statement) |
| 43 | lang_statement_union_type *statement; |
| 44 | { |
| 45 | switch (statement->header.type) |
| 46 | { |
| 47 | case lang_data_statement_enum: |
| 48 | { |
| 49 | asection *output_section; |
| 50 | struct bfd_link_order *link_order; |
| 51 | bfd_vma value; |
| 52 | boolean big_endian = false; |
| 53 | |
| 54 | output_section = statement->data_statement.output_section; |
| 55 | ASSERT (output_section->owner == output_bfd); |
| 56 | |
| 57 | link_order = bfd_new_link_order (output_bfd, output_section); |
| 58 | if (link_order == NULL) |
| 59 | einfo (_("%P%F: bfd_new_link_order failed\n")); |
| 60 | |
| 61 | link_order->type = bfd_data_link_order; |
| 62 | link_order->offset = statement->data_statement.output_vma; |
| 63 | link_order->u.data.contents = (bfd_byte *) xmalloc (QUAD_SIZE); |
| 64 | |
| 65 | value = statement->data_statement.value; |
| 66 | |
| 67 | /* If the endianness of the output BFD is not known, then we |
| 68 | base the endianness of the data on the first input file. |
| 69 | By convention, the bfd_put routines for an unknown |
| 70 | endianness are big endian, so we must swap here if the |
| 71 | input file is little endian. */ |
| 72 | if (bfd_big_endian (output_bfd)) |
| 73 | big_endian = true; |
| 74 | else if (bfd_little_endian (output_bfd)) |
| 75 | big_endian = false; |
| 76 | else |
| 77 | { |
| 78 | boolean swap; |
| 79 | |
| 80 | swap = false; |
| 81 | if (command_line.endian == ENDIAN_BIG) |
| 82 | big_endian = true; |
| 83 | else if (command_line.endian == ENDIAN_LITTLE) |
| 84 | { |
| 85 | big_endian = false; |
| 86 | swap = true; |
| 87 | } |
| 88 | else if (command_line.endian == ENDIAN_UNSET) |
| 89 | { |
| 90 | big_endian = true; |
| 91 | { |
| 92 | LANG_FOR_EACH_INPUT_STATEMENT (s) |
| 93 | { |
| 94 | if (s->the_bfd != NULL) |
| 95 | { |
| 96 | if (bfd_little_endian (s->the_bfd)) |
| 97 | { |
| 98 | big_endian = false; |
| 99 | swap = true; |
| 100 | } |
| 101 | break; |
| 102 | } |
| 103 | } |
| 104 | } |
| 105 | } |
| 106 | |
| 107 | if (swap) |
| 108 | { |
| 109 | bfd_byte buffer[8]; |
| 110 | |
| 111 | switch (statement->data_statement.type) |
| 112 | { |
| 113 | case QUAD: |
| 114 | case SQUAD: |
| 115 | if (sizeof (bfd_vma) >= QUAD_SIZE) |
| 116 | { |
| 117 | bfd_putl64 (value, buffer); |
| 118 | value = bfd_getb64 (buffer); |
| 119 | break; |
| 120 | } |
| 121 | /* Fall through. */ |
| 122 | case LONG: |
| 123 | bfd_putl32 (value, buffer); |
| 124 | value = bfd_getb32 (buffer); |
| 125 | break; |
| 126 | case SHORT: |
| 127 | bfd_putl16 (value, buffer); |
| 128 | value = bfd_getb16 (buffer); |
| 129 | break; |
| 130 | case BYTE: |
| 131 | break; |
| 132 | default: |
| 133 | abort (); |
| 134 | } |
| 135 | } |
| 136 | } |
| 137 | |
| 138 | ASSERT (output_section->owner == output_bfd); |
| 139 | switch (statement->data_statement.type) |
| 140 | { |
| 141 | case QUAD: |
| 142 | case SQUAD: |
| 143 | if (sizeof (bfd_vma) >= QUAD_SIZE) |
| 144 | bfd_put_64 (output_bfd, value, link_order->u.data.contents); |
| 145 | else |
| 146 | { |
| 147 | bfd_vma high; |
| 148 | |
| 149 | if (statement->data_statement.type == QUAD) |
| 150 | high = 0; |
| 151 | else if ((value & 0x80000000) == 0) |
| 152 | high = 0; |
| 153 | else |
| 154 | high = (bfd_vma) -1; |
| 155 | bfd_put_32 (output_bfd, high, |
| 156 | (link_order->u.data.contents |
| 157 | + (big_endian ? 0 : 4))); |
| 158 | bfd_put_32 (output_bfd, value, |
| 159 | (link_order->u.data.contents |
| 160 | + (big_endian ? 4 : 0))); |
| 161 | } |
| 162 | link_order->size = QUAD_SIZE; |
| 163 | break; |
| 164 | case LONG: |
| 165 | bfd_put_32 (output_bfd, value, link_order->u.data.contents); |
| 166 | link_order->size = LONG_SIZE; |
| 167 | break; |
| 168 | case SHORT: |
| 169 | bfd_put_16 (output_bfd, value, link_order->u.data.contents); |
| 170 | link_order->size = SHORT_SIZE; |
| 171 | break; |
| 172 | case BYTE: |
| 173 | bfd_put_8 (output_bfd, value, link_order->u.data.contents); |
| 174 | link_order->size = BYTE_SIZE; |
| 175 | break; |
| 176 | default: |
| 177 | abort (); |
| 178 | } |
| 179 | } |
| 180 | break; |
| 181 | |
| 182 | case lang_reloc_statement_enum: |
| 183 | { |
| 184 | lang_reloc_statement_type *rs; |
| 185 | asection *output_section; |
| 186 | struct bfd_link_order *link_order; |
| 187 | |
| 188 | rs = &statement->reloc_statement; |
| 189 | |
| 190 | output_section = rs->output_section; |
| 191 | ASSERT (output_section->owner == output_bfd); |
| 192 | |
| 193 | link_order = bfd_new_link_order (output_bfd, output_section); |
| 194 | if (link_order == NULL) |
| 195 | einfo (_("%P%F: bfd_new_link_order failed\n")); |
| 196 | |
| 197 | link_order->offset = rs->output_vma; |
| 198 | link_order->size = bfd_get_reloc_size (rs->howto); |
| 199 | |
| 200 | link_order->u.reloc.p = |
| 201 | ((struct bfd_link_order_reloc *) |
| 202 | xmalloc (sizeof (struct bfd_link_order_reloc))); |
| 203 | |
| 204 | link_order->u.reloc.p->reloc = rs->reloc; |
| 205 | link_order->u.reloc.p->addend = rs->addend_value; |
| 206 | |
| 207 | if (rs->name == NULL) |
| 208 | { |
| 209 | link_order->type = bfd_section_reloc_link_order; |
| 210 | if (rs->section->owner == output_bfd) |
| 211 | link_order->u.reloc.p->u.section = rs->section; |
| 212 | else |
| 213 | { |
| 214 | link_order->u.reloc.p->u.section = rs->section->output_section; |
| 215 | link_order->u.reloc.p->addend += rs->section->output_offset; |
| 216 | } |
| 217 | } |
| 218 | else |
| 219 | { |
| 220 | link_order->type = bfd_symbol_reloc_link_order; |
| 221 | link_order->u.reloc.p->u.name = rs->name; |
| 222 | } |
| 223 | } |
| 224 | break; |
| 225 | |
| 226 | case lang_input_section_enum: |
| 227 | /* Create a new link_order in the output section with this |
| 228 | attached */ |
| 229 | if (statement->input_section.ifile->just_syms_flag == false) |
| 230 | { |
| 231 | asection *i = statement->input_section.section; |
| 232 | asection *output_section = i->output_section; |
| 233 | |
| 234 | ASSERT (output_section->owner == output_bfd); |
| 235 | |
| 236 | if ((output_section->flags & SEC_HAS_CONTENTS) != 0) |
| 237 | { |
| 238 | struct bfd_link_order *link_order; |
| 239 | |
| 240 | link_order = bfd_new_link_order (output_bfd, output_section); |
| 241 | |
| 242 | if (i->flags & SEC_NEVER_LOAD) |
| 243 | { |
| 244 | /* We've got a never load section inside one which |
| 245 | is going to be output, we'll change it into a |
| 246 | fill link_order */ |
| 247 | link_order->type = bfd_fill_link_order; |
| 248 | link_order->u.fill.value = 0; |
| 249 | } |
| 250 | else |
| 251 | { |
| 252 | link_order->type = bfd_indirect_link_order; |
| 253 | link_order->u.indirect.section = i; |
| 254 | ASSERT (i->output_section == output_section); |
| 255 | } |
| 256 | if (i->_cooked_size) |
| 257 | link_order->size = i->_cooked_size; |
| 258 | else |
| 259 | link_order->size = bfd_get_section_size_before_reloc (i); |
| 260 | link_order->offset = i->output_offset; |
| 261 | } |
| 262 | } |
| 263 | break; |
| 264 | |
| 265 | case lang_padding_statement_enum: |
| 266 | /* Make a new link_order with the right filler */ |
| 267 | { |
| 268 | asection *output_section; |
| 269 | struct bfd_link_order *link_order; |
| 270 | |
| 271 | output_section = statement->padding_statement.output_section; |
| 272 | ASSERT (statement->padding_statement.output_section->owner |
| 273 | == output_bfd); |
| 274 | if ((output_section->flags & SEC_HAS_CONTENTS) != 0) |
| 275 | { |
| 276 | link_order = bfd_new_link_order (output_bfd, output_section); |
| 277 | link_order->type = bfd_fill_link_order; |
| 278 | link_order->size = statement->padding_statement.size; |
| 279 | link_order->offset = statement->padding_statement.output_offset; |
| 280 | link_order->u.fill.value = statement->padding_statement.fill; |
| 281 | } |
| 282 | } |
| 283 | break; |
| 284 | |
| 285 | default: |
| 286 | /* All the other ones fall through */ |
| 287 | break; |
| 288 | } |
| 289 | } |
| 290 | |
| 291 | /* Call BFD to write out the linked file. */ |
| 292 | |
| 293 | |
| 294 | /**********************************************************************/ |
| 295 | |
| 296 | |
| 297 | /* Wander around the input sections, make sure that |
| 298 | we'll never try and create an output section with more relocs |
| 299 | than will fit.. Do this by always assuming the worst case, and |
| 300 | creating new output sections with all the right bits */ |
| 301 | #define TESTIT 1 |
| 302 | static asection * |
| 303 | clone_section (abfd, s, count) |
| 304 | bfd *abfd; |
| 305 | asection *s; |
| 306 | int *count; |
| 307 | { |
| 308 | #define SSIZE 8 |
| 309 | char sname[SSIZE]; /* ?? find the name for this size */ |
| 310 | asection *n; |
| 311 | struct bfd_link_hash_entry *h; |
| 312 | /* Invent a section name - use first five |
| 313 | chars of base section name and a digit suffix */ |
| 314 | do |
| 315 | { |
| 316 | unsigned int i; |
| 317 | char b[6]; |
| 318 | for (i = 0; i < sizeof (b) - 1 && s->name[i]; i++) |
| 319 | b[i] = s->name[i]; |
| 320 | b[i] = 0; |
| 321 | sprintf (sname, "%s%d", b, (*count)++); |
| 322 | } |
| 323 | while (bfd_get_section_by_name (abfd, sname)); |
| 324 | |
| 325 | n = bfd_make_section_anyway (abfd, xstrdup (sname)); |
| 326 | |
| 327 | /* Create a symbol of the same name */ |
| 328 | |
| 329 | h = bfd_link_hash_lookup (link_info.hash, |
| 330 | sname, true, true, false); |
| 331 | h->type = bfd_link_hash_defined; |
| 332 | h->u.def.value = 0; |
| 333 | h->u.def.section = n ; |
| 334 | |
| 335 | |
| 336 | n->flags = s->flags; |
| 337 | n->vma = s->vma; |
| 338 | n->user_set_vma = s->user_set_vma; |
| 339 | n->lma = s->lma; |
| 340 | n->_cooked_size = 0; |
| 341 | n->_raw_size = 0; |
| 342 | n->output_offset = s->output_offset; |
| 343 | n->output_section = n; |
| 344 | n->orelocation = 0; |
| 345 | n->reloc_count = 0; |
| 346 | n->alignment_power = s->alignment_power; |
| 347 | return n; |
| 348 | } |
| 349 | |
| 350 | #if TESTING |
| 351 | static void |
| 352 | ds (s) |
| 353 | asection *s; |
| 354 | { |
| 355 | struct bfd_link_order *l = s->link_order_head; |
| 356 | printf ("vma %x size %x\n", s->vma, s->_raw_size); |
| 357 | while (l) |
| 358 | { |
| 359 | if (l->type == bfd_indirect_link_order) |
| 360 | { |
| 361 | printf ("%8x %s\n", l->offset, l->u.indirect.section->owner->filename); |
| 362 | } |
| 363 | else |
| 364 | { |
| 365 | printf (_("%8x something else\n"), l->offset); |
| 366 | } |
| 367 | l = l->next; |
| 368 | } |
| 369 | printf ("\n"); |
| 370 | } |
| 371 | dump (s, a1, a2) |
| 372 | char *s; |
| 373 | asection *a1; |
| 374 | asection *a2; |
| 375 | { |
| 376 | printf ("%s\n", s); |
| 377 | ds (a1); |
| 378 | ds (a2); |
| 379 | } |
| 380 | |
| 381 | static void |
| 382 | sanity_check (abfd) |
| 383 | bfd *abfd; |
| 384 | { |
| 385 | asection *s; |
| 386 | for (s = abfd->sections; s; s = s->next) |
| 387 | { |
| 388 | struct bfd_link_order *p; |
| 389 | bfd_vma prev = 0; |
| 390 | for (p = s->link_order_head; p; p = p->next) |
| 391 | { |
| 392 | if (p->offset > 100000) |
| 393 | abort (); |
| 394 | if (p->offset < prev) |
| 395 | abort (); |
| 396 | prev = p->offset; |
| 397 | } |
| 398 | } |
| 399 | } |
| 400 | #else |
| 401 | #define sanity_check(a) |
| 402 | #define dump(a, b, c) |
| 403 | #endif |
| 404 | |
| 405 | static void |
| 406 | split_sections (abfd, info) |
| 407 | bfd *abfd; |
| 408 | struct bfd_link_info *info; |
| 409 | { |
| 410 | asection *original_sec; |
| 411 | int nsecs = abfd->section_count; |
| 412 | sanity_check (abfd); |
| 413 | /* look through all the original sections */ |
| 414 | for (original_sec = abfd->sections; |
| 415 | original_sec && nsecs; |
| 416 | original_sec = original_sec->next, nsecs--) |
| 417 | { |
| 418 | boolean first = true; |
| 419 | int count = 0; |
| 420 | int lines = 0; |
| 421 | int relocs = 0; |
| 422 | struct bfd_link_order **pp; |
| 423 | bfd_vma vma = original_sec->vma; |
| 424 | bfd_vma shift_offset = 0; |
| 425 | asection *cursor = original_sec; |
| 426 | |
| 427 | /* count up the relocations and line entries to see if |
| 428 | anything would be too big to fit */ |
| 429 | for (pp = &(cursor->link_order_head); *pp; pp = &((*pp)->next)) |
| 430 | { |
| 431 | struct bfd_link_order *p = *pp; |
| 432 | int thislines = 0; |
| 433 | int thisrelocs = 0; |
| 434 | if (p->type == bfd_indirect_link_order) |
| 435 | { |
| 436 | asection *sec; |
| 437 | |
| 438 | sec = p->u.indirect.section; |
| 439 | |
| 440 | if (info->strip == strip_none |
| 441 | || info->strip == strip_some) |
| 442 | thislines = sec->lineno_count; |
| 443 | |
| 444 | if (info->relocateable) |
| 445 | thisrelocs = sec->reloc_count; |
| 446 | |
| 447 | } |
| 448 | else if (info->relocateable |
| 449 | && (p->type == bfd_section_reloc_link_order |
| 450 | || p->type == bfd_symbol_reloc_link_order)) |
| 451 | thisrelocs++; |
| 452 | |
| 453 | if (! first |
| 454 | && (thisrelocs + relocs > config.split_by_reloc |
| 455 | || thislines + lines > config.split_by_reloc |
| 456 | || config.split_by_file)) |
| 457 | { |
| 458 | /* create a new section and put this link order and the |
| 459 | following link orders into it */ |
| 460 | struct bfd_link_order *l = p; |
| 461 | asection *n = clone_section (abfd, cursor, &count); |
| 462 | *pp = NULL; /* Snip off link orders from old section */ |
| 463 | n->link_order_head = l; /* attach to new section */ |
| 464 | pp = &n->link_order_head; |
| 465 | |
| 466 | /* change the size of the original section and |
| 467 | update the vma of the new one */ |
| 468 | |
| 469 | dump ("before snip", cursor, n); |
| 470 | |
| 471 | n->_raw_size = cursor->_raw_size - l->offset; |
| 472 | cursor->_raw_size = l->offset; |
| 473 | |
| 474 | vma += cursor->_raw_size; |
| 475 | n->lma = n->vma = vma; |
| 476 | |
| 477 | shift_offset = l->offset; |
| 478 | |
| 479 | /* run down the chain and change the output section to |
| 480 | the right one, update the offsets too */ |
| 481 | |
| 482 | while (l) |
| 483 | { |
| 484 | l->offset -= shift_offset; |
| 485 | if (l->type == bfd_indirect_link_order) |
| 486 | { |
| 487 | l->u.indirect.section->output_section = n; |
| 488 | l->u.indirect.section->output_offset = l->offset; |
| 489 | } |
| 490 | l = l->next; |
| 491 | } |
| 492 | dump ("after snip", cursor, n); |
| 493 | cursor = n; |
| 494 | relocs = thisrelocs; |
| 495 | lines = thislines; |
| 496 | } |
| 497 | else |
| 498 | { |
| 499 | relocs += thisrelocs; |
| 500 | lines += thislines; |
| 501 | } |
| 502 | |
| 503 | first = false; |
| 504 | } |
| 505 | } |
| 506 | sanity_check (abfd); |
| 507 | } |
| 508 | /**********************************************************************/ |
| 509 | void |
| 510 | ldwrite () |
| 511 | { |
| 512 | /* Reset error indicator, which can typically something like invalid |
| 513 | format from openning up the .o files */ |
| 514 | bfd_set_error (bfd_error_no_error); |
| 515 | lang_for_each_statement (build_link_order); |
| 516 | |
| 517 | if (config.split_by_reloc || config.split_by_file) |
| 518 | split_sections (output_bfd, &link_info); |
| 519 | if (!bfd_final_link (output_bfd, &link_info)) |
| 520 | { |
| 521 | /* If there was an error recorded, print it out. Otherwise assume |
| 522 | an appropriate error message like unknown symbol was printed |
| 523 | out. */ |
| 524 | |
| 525 | if (bfd_get_error () != bfd_error_no_error) |
| 526 | einfo (_("%F%P: final link failed: %E\n"), output_bfd); |
| 527 | else |
| 528 | xexit(1); |
| 529 | } |
| 530 | } |