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annotate lwlink/link.c @ 426:652eee8f0c82
Fixed lw_expr_destroy() to not crash on NULL
| author | lost@l-w.ca |
|---|---|
| date | Sun, 19 Sep 2010 10:40:37 -0600 |
| parents | 54499b799779 |
| children |
| rev | line source |
|---|---|
| 339 | 1 /* |
| 2 link.c | |
| 3 Copyright © 2009 William Astle | |
| 4 | |
| 5 This file is part of LWLINK. | |
| 6 | |
| 7 LWLINK is free software: you can redistribute it and/or modify it under the | |
| 8 terms of the GNU General Public License as published by the Free Software | |
| 9 Foundation, either version 3 of the License, or (at your option) any later | |
| 10 version. | |
| 11 | |
| 12 This program is distributed in the hope that it will be useful, but WITHOUT | |
| 13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
| 15 more details. | |
| 16 | |
| 17 You should have received a copy of the GNU General Public License along with | |
| 18 this program. If not, see <http://www.gnu.org/licenses/>. | |
| 19 | |
| 20 | |
| 21 Resolve section and symbol addresses; handle incomplete references | |
| 22 */ | |
| 23 | |
| 24 #include <config.h> | |
| 25 | |
| 26 #include <stdio.h> | |
| 27 #include <stdlib.h> | |
| 28 | |
| 29 #include "expr.h" | |
| 30 #include "lwlink.h" | |
| 31 #include "util.h" | |
| 32 | |
| 33 struct section_list *sectlist = NULL; | |
| 34 int nsects = 0; | |
| 35 static int nforced = 0; | |
| 36 | |
| 37 void check_section_name(char *name, int *base, fileinfo_t *fn) | |
| 38 { | |
| 39 int sn; | |
| 40 | |
| 41 if (fn -> forced == 0) | |
| 42 return; | |
| 43 | |
| 44 for (sn = 0; sn < fn -> nsections; sn++) | |
| 45 { | |
| 46 if (!strcmp(name, fn -> sections[sn].name)) | |
| 47 { | |
| 48 // we have a match | |
| 49 sectlist = lw_realloc(sectlist, sizeof(struct section_list) * (nsects + 1)); | |
| 50 sectlist[nsects].ptr = &(fn -> sections[sn]); | |
| 51 | |
| 52 fn -> sections[sn].processed = 1; | |
| 53 fn -> sections[sn].loadaddress = *base; | |
| 54 *base += fn -> sections[sn].codesize; | |
| 55 nsects++; | |
| 56 } | |
| 57 } | |
| 58 for (sn = 0; sn < fn -> nsubs; sn++) | |
| 59 { | |
| 60 check_section_name(name, base, fn -> subs[sn]); | |
| 61 } | |
| 62 } | |
| 63 | |
| 64 void add_matching_sections(char *name, int yesflags, int noflags, int *base); | |
| 65 void check_section_flags(int yesflags, int noflags, int *base, fileinfo_t *fn) | |
| 66 { | |
| 67 int sn; | |
| 68 | |
| 69 if (fn -> forced == 0) | |
| 70 return; | |
| 71 | |
| 72 for (sn = 0; sn < fn -> nsections; sn++) | |
| 73 { | |
| 74 // ignore if the noflags tell us to | |
| 75 if (noflags && (fn -> sections[sn].flags & noflags)) | |
| 76 continue; | |
| 77 // ignore unless the yesflags tell us not to | |
| 78 if (yesflags && (fn -> sections[sn].flags & yesflags == 0)) | |
| 79 continue; | |
| 80 // ignore it if already processed | |
| 81 if (fn -> sections[sn].processed) | |
| 82 continue; | |
| 83 | |
| 84 // we have a match - now collect *all* sections of the same name! | |
| 85 add_matching_sections(fn -> sections[sn].name, 0, 0, base); | |
| 86 | |
| 87 // and then continue looking for sections | |
| 88 } | |
| 89 for (sn = 0; sn < fn -> nsubs; sn++) | |
| 90 { | |
| 91 check_section_flags(yesflags, noflags, base, fn -> subs[sn]); | |
| 92 } | |
| 93 } | |
| 94 | |
| 95 | |
| 96 | |
| 97 void add_matching_sections(char *name, int yesflags, int noflags, int *base) | |
| 98 { | |
| 99 int fn; | |
| 100 if (name) | |
| 101 { | |
| 102 // named section | |
| 103 // look for all instances of a section by the specified name | |
| 104 // and resolve base addresses and add to the list | |
| 105 for (fn = 0; fn < ninputfiles; fn++) | |
| 106 { | |
| 107 check_section_name(name, base, inputfiles[fn]); | |
| 108 } | |
| 109 } | |
| 110 else | |
| 111 { | |
| 112 // wildcard section | |
| 113 // named section | |
| 114 // look for all instances of a section by the specified name | |
| 115 // and resolve base addresses and add to the list | |
| 116 for (fn = 0; fn < ninputfiles; fn++) | |
| 117 { | |
| 118 check_section_flags(yesflags, noflags, base, inputfiles[fn]); | |
| 119 } | |
| 120 } | |
| 121 } | |
| 122 | |
| 123 // work out section load order and resolve base addresses for each section | |
| 124 // make a list of sections to load in order | |
| 125 void resolve_sections(void) | |
| 126 { | |
| 127 int laddr = 0; | |
| 128 int ln, sn, fn; | |
| 129 | |
| 130 for (ln = 0; ln < linkscript.nlines; ln++) | |
| 131 { | |
| 132 if (linkscript.lines[ln].loadat >= 0) | |
| 133 laddr = linkscript.lines[ln].loadat; | |
| 134 add_matching_sections(linkscript.lines[ln].sectname, linkscript.lines[ln].yesflags, linkscript.lines[ln].noflags, &laddr); | |
| 135 | |
| 136 if (linkscript.lines[ln].sectname) | |
| 137 { | |
| 138 } | |
| 139 else | |
| 140 { | |
| 141 // wildcard section | |
| 142 // look for all sections not yet processed that match flags | |
| 143 | |
| 144 int f = 0; | |
| 145 int fn0, sn0; | |
| 146 char *sname; | |
| 147 | |
| 148 // named section | |
| 149 // look for all instances of a section by the specified name | |
| 150 // and resolve base addresses and add to the list | |
| 151 for (fn0 = 0; fn0 < ninputfiles; fn0++) | |
| 152 { | |
| 153 for (sn0 = 0; sn0 < inputfiles[fn0] -> nsections; sn0++) | |
| 154 { | |
| 155 // ignore if the "no flags" bit says to | |
| 156 if (linkscript.lines[ln].noflags && (inputfiles[fn0] -> sections[sn0].flags & linkscript.lines[ln].noflags)) | |
| 157 continue; | |
| 158 // ignore unless the yes flags tell us not to | |
| 159 if (linkscript.lines[ln].yesflags && (inputfiles[fn0] -> sections[sn0].flags & linkscript.lines[ln].yesflags == 0)) | |
| 160 continue; | |
| 161 if (inputfiles[fn0] -> sections[sn0].processed == 0) | |
| 162 { | |
| 163 sname = inputfiles[fn0] -> sections[sn0].name; | |
| 164 for (fn = 0; fn < ninputfiles; fn++) | |
| 165 { | |
| 166 for (sn = 0; sn < inputfiles[fn] -> nsections; sn++) | |
| 167 { | |
| 168 if (!strcmp(sname, inputfiles[fn] -> sections[sn].name)) | |
| 169 { | |
| 170 // we have a match | |
| 171 sectlist = lw_realloc(sectlist, sizeof(struct section_list) * (nsects + 1)); | |
| 172 sectlist[nsects].ptr = &(inputfiles[fn] -> sections[sn]); | |
| 173 | |
| 174 inputfiles[fn] -> sections[sn].processed = 1; | |
| 175 if (!f && linkscript.lines[ln].loadat >= 0) | |
| 176 { | |
| 177 f = 1; | |
| 178 sectlist[nsects].forceaddr = 1; | |
| 179 laddr = linkscript.lines[ln].loadat; | |
| 180 } | |
| 181 else | |
| 182 { | |
| 183 sectlist[nsects].forceaddr = 0; | |
| 184 } | |
| 185 inputfiles[fn] -> sections[sn].loadaddress = laddr; | |
| 186 laddr += inputfiles[fn] -> sections[sn].codesize; | |
| 187 nsects++; | |
| 188 } | |
| 189 } | |
| 190 } | |
| 191 } | |
| 192 } | |
| 193 } | |
| 194 } | |
| 195 } | |
| 196 | |
| 197 // theoretically, all the base addresses are set now | |
| 198 } | |
| 199 | |
| 200 lw_expr_stack_t *find_external_sym_recurse(char *sym, fileinfo_t *fn) | |
| 201 { | |
| 202 int sn; | |
| 203 lw_expr_stack_t *r; | |
| 204 lw_expr_term_t *term; | |
| 205 symtab_t *se; | |
| 206 int val; | |
| 207 | |
| 208 for (sn = 0; sn < fn -> nsections; sn++) | |
| 209 { | |
| 210 for (se = fn -> sections[sn].exportedsyms; se; se = se -> next) | |
| 211 { | |
| 212 if (!strcmp(sym, se -> sym)) | |
| 213 { | |
| 214 if (!(fn -> forced)) | |
| 215 { | |
| 216 fn -> forced = 1; | |
| 217 nforced = 1; | |
| 218 } | |
| 219 val = se -> offset + fn -> sections[sn].loadaddress; | |
| 220 r = lw_expr_stack_create(); | |
| 221 term = lw_expr_term_create_int(val & 0xffff); | |
| 222 lw_expr_stack_push(r, term); | |
| 223 lw_expr_term_free(term); | |
| 224 return r; | |
| 225 } | |
| 226 } | |
| 227 } | |
| 228 | |
| 229 for (sn = 0; sn < fn -> nsubs; sn++) | |
| 230 { | |
| 231 r = find_external_sym_recurse(sym, fn -> subs[sn]); | |
| 232 if (r) | |
| 233 { | |
| 234 if (!(fn -> forced)) | |
| 235 { | |
| 236 nforced = 1; | |
| 237 fn -> forced = 1; | |
| 238 } | |
| 239 return r; | |
| 240 } | |
| 241 } | |
| 242 return NULL; | |
| 243 } | |
| 244 | |
| 245 // resolve all incomplete references now | |
| 246 // anything that is unresolvable at this stage will throw an error | |
| 247 // because we know the load address of every section now | |
| 248 lw_expr_stack_t *resolve_sym(char *sym, int symtype, void *state) | |
| 249 { | |
| 250 section_t *sect = state; | |
| 251 lw_expr_term_t *term; | |
| 252 int val = 0, i, fn; | |
| 253 lw_expr_stack_t *s; | |
| 254 symtab_t *se; | |
| 255 fileinfo_t *fp; | |
| 256 | |
| 257 if (symtype == 1) | |
| 258 { | |
| 259 // local symbol | |
| 260 if (!sym) | |
| 261 { | |
| 262 val = sect -> loadaddress; | |
| 263 goto out; | |
| 264 } | |
| 265 | |
| 266 // start with this section | |
| 267 for (se = sect -> localsyms; se; se = se -> next) | |
| 268 { | |
| 269 if (!strcmp(se -> sym, sym)) | |
| 270 { | |
| 271 val = se -> offset + sect -> loadaddress; | |
| 272 goto out; | |
| 273 } | |
| 274 } | |
| 275 // not in this section - check all sections in this file | |
| 276 for (i = 0; i < sect -> file -> nsections; i++) | |
| 277 { | |
| 278 for (se = sect -> file -> sections[i].localsyms; se; se = se -> next) | |
| 279 { | |
| 280 if (!strcmp(se -> sym, sym)) | |
| 281 { | |
| 282 val = se -> offset + sect -> file -> sections[i].loadaddress; | |
| 283 goto out; | |
| 284 } | |
| 285 } | |
| 286 } | |
| 287 // not found | |
| 288 symerr = 1; | |
|
395
54499b799779
Q&D sanitization of symbols in map files and error messages in lwlink
lost@l-w.ca
parents:
378
diff
changeset
|
289 fprintf(stderr, "Local symbol %s not found in %s:%s\n", sanitize_symbol(sym), sect -> file -> filename, sect -> name); |
| 339 | 290 goto outerr; |
| 291 } | |
| 292 else | |
| 293 { | |
| 294 // external symbol | |
| 295 // read all files in order until found (or not found) | |
| 296 if (sect) | |
| 297 { | |
| 298 for (fp = sect -> file; fp; fp = fp -> parent) | |
| 299 { | |
| 300 s = find_external_sym_recurse(sym, fp); | |
| 301 if (s) | |
| 302 return s; | |
| 303 } | |
| 304 } | |
| 305 | |
| 306 for (fn = 0; fn < ninputfiles; fn++) | |
| 307 { | |
| 308 s = find_external_sym_recurse(sym, inputfiles[fn]); | |
| 309 if (s) | |
| 310 return s; | |
| 311 } | |
| 312 if (sect) | |
| 313 { | |
|
395
54499b799779
Q&D sanitization of symbols in map files and error messages in lwlink
lost@l-w.ca
parents:
378
diff
changeset
|
314 fprintf(stderr, "External symbol %s not found in %s:%s\n", sanitize_symbol(sym), sect -> file -> filename, sect -> name); |
| 339 | 315 } |
| 316 else | |
| 317 { | |
| 318 fprintf(stderr, "External symbol %s not found\n", sym); | |
| 319 } | |
| 320 symerr = 1; | |
| 321 goto outerr; | |
| 322 } | |
| 323 fprintf(stderr, "Shouldn't ever get here!!!\n"); | |
| 324 exit(88); | |
| 325 out: | |
| 326 s = lw_expr_stack_create(); | |
| 327 term = lw_expr_term_create_int(val & 0xffff); | |
| 328 lw_expr_stack_push(s, term); | |
| 329 lw_expr_term_free(term); | |
| 330 return s; | |
| 331 outerr: | |
| 332 return NULL; | |
| 333 } | |
| 334 | |
| 335 void resolve_references(void) | |
| 336 { | |
| 337 int sn; | |
| 338 reloc_t *rl; | |
| 339 int rval; | |
| 340 | |
| 341 // resolve entry point if required | |
| 342 // this must resolve to an *exported* symbol and will resolve to the | |
| 343 // first instance of that symbol | |
| 344 if (linkscript.execsym) | |
| 345 { | |
| 346 lw_expr_stack_t *s; | |
| 347 | |
| 348 s = resolve_sym(linkscript.execsym, 0, NULL); | |
| 349 if (!s) | |
| 350 { | |
| 351 fprintf(stderr, "Cannot resolve exec address '%s'\n", linkscript.execsym); | |
| 352 symerr = 1; | |
| 353 } | |
| 354 else | |
| 355 { | |
| 356 linkscript.execaddr = lw_expr_get_value(s); | |
| 357 lw_expr_stack_free(s); | |
| 358 } | |
| 359 } | |
| 360 | |
| 361 for (sn = 0; sn < nsects; sn++) | |
| 362 { | |
| 363 for (rl = sectlist[sn].ptr -> incompletes; rl; rl = rl -> next) | |
| 364 { | |
| 365 // do a "simplify" on the expression | |
| 366 rval = lw_expr_reval(rl -> expr, resolve_sym, sectlist[sn].ptr); | |
| 367 | |
| 368 // is it constant? error out if not | |
| 369 if (rval != 0 || !lw_expr_is_constant(rl -> expr)) | |
| 370 { | |
| 371 fprintf(stderr, "Incomplete reference at %s:%s+%02X\n", sectlist[sn].ptr -> file -> filename, sectlist[sn].ptr -> name, rl -> offset); | |
| 372 symerr = 1; | |
| 373 } | |
| 374 else | |
| 375 { | |
| 376 // put the value into the relocation address | |
| 377 rval = lw_expr_get_value(rl -> expr); | |
| 378 if (rl -> flags & RELOC_8BIT) | |
| 379 { | |
| 380 sectlist[sn].ptr -> code[rl -> offset] = rval & 0xff; | |
| 381 } | |
| 382 else | |
| 383 { | |
| 384 sectlist[sn].ptr -> code[rl -> offset] = (rval >> 8) & 0xff; | |
| 385 sectlist[sn].ptr -> code[rl -> offset + 1] = rval & 0xff; | |
| 386 } | |
| 387 } | |
| 388 } | |
| 389 } | |
| 390 | |
| 391 if (symerr) | |
| 392 exit(1); | |
| 393 } | |
| 394 | |
| 395 /* | |
| 396 This is just a pared down version of the algo for resolving references. | |
| 397 */ | |
| 398 void resolve_files(void) | |
| 399 { | |
| 400 int sn; | |
| 401 int fn; | |
| 402 reloc_t *rl; | |
| 403 lw_expr_stack_t *te; | |
| 404 | |
| 405 int rval; | |
| 406 | |
| 407 // resolve entry point if required | |
| 408 // this must resolve to an *exported* symbol and will resolve to the | |
| 409 // first instance of that symbol | |
| 410 if (linkscript.execsym) | |
| 411 { | |
| 412 lw_expr_stack_t *s; | |
| 413 | |
| 414 s = resolve_sym(linkscript.execsym, 0, NULL); | |
| 415 if (!s) | |
| 416 { | |
|
395
54499b799779
Q&D sanitization of symbols in map files and error messages in lwlink
lost@l-w.ca
parents:
378
diff
changeset
|
417 fprintf(stderr, "Cannot resolve exec address '%s'\n", sanitize_symbol(linkscript.execsym)); |
| 339 | 418 symerr = 1; |
| 419 } | |
| 420 } | |
| 421 | |
| 422 do | |
| 423 { | |
| 424 nforced = 0; | |
| 425 for (fn = 0; fn < ninputfiles; fn++) | |
| 426 { | |
| 427 if (inputfiles[fn] -> forced == 0) | |
| 428 continue; | |
| 429 | |
| 430 for (sn = 0; sn < inputfiles[fn] -> nsections; sn++) | |
| 431 { | |
| 432 for (rl = inputfiles[fn] -> sections[sn].incompletes; rl; rl = rl -> next) | |
| 433 { | |
| 434 // do a "simplify" on the expression | |
| 435 te = lw_expr_stack_dup(rl -> expr); | |
| 436 rval = lw_expr_reval(te, resolve_sym, &(inputfiles[fn] -> sections[sn])); | |
| 437 | |
| 438 // is it constant? error out if not | |
| 439 if (rval != 0 || !lw_expr_is_constant(te)) | |
| 440 { | |
| 441 fprintf(stderr, "Incomplete reference at %s:%s+%02X\n", inputfiles[fn] -> filename, inputfiles[fn] -> sections[sn].name, rl -> offset); | |
| 442 symerr = 1; | |
| 443 } | |
| 444 lw_expr_stack_free(te); | |
| 445 } | |
| 446 } | |
| 447 } | |
| 448 } | |
| 449 while (nforced == 1); | |
| 450 | |
| 451 if (symerr) | |
| 452 exit(1); | |
| 453 | |
| 454 // theoretically, all files referenced by other files now have "forced" set to 1 | |
| 455 for (fn = 0; fn < ninputfiles; fn++) | |
| 456 { | |
| 457 if (inputfiles[fn] -> forced == 1) | |
| 458 continue; | |
| 459 | |
| 460 fprintf(stderr, "Warning: %s (%d) does not resolve any symbols\n", inputfiles[fn] -> filename, fn); | |
| 461 } | |
| 462 } |