| 1 | /* This module handles expression trees. |
| 2 | Copyright (C) 1991-2016 Free Software Foundation, Inc. |
| 3 | Written by Steve Chamberlain of Cygnus Support <sac@cygnus.com>. |
| 4 | |
| 5 | This file is part of the GNU Binutils. |
| 6 | |
| 7 | This program 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 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program 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 this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| 20 | MA 02110-1301, USA. */ |
| 21 | |
| 22 | |
| 23 | /* This module is in charge of working out the contents of expressions. |
| 24 | |
| 25 | It has to keep track of the relative/absness of a symbol etc. This |
| 26 | is done by keeping all values in a struct (an etree_value_type) |
| 27 | which contains a value, a section to which it is relative and a |
| 28 | valid bit. */ |
| 29 | |
| 30 | #include "sysdep.h" |
| 31 | #include "bfd.h" |
| 32 | #include "bfdlink.h" |
| 33 | |
| 34 | #include "ld.h" |
| 35 | #include "ldmain.h" |
| 36 | #include "ldmisc.h" |
| 37 | #include "ldexp.h" |
| 38 | #include "ldlex.h" |
| 39 | #include <ldgram.h> |
| 40 | #include "ldlang.h" |
| 41 | #include "libiberty.h" |
| 42 | #include "safe-ctype.h" |
| 43 | |
| 44 | static void exp_fold_tree_1 (etree_type *); |
| 45 | static bfd_vma align_n (bfd_vma, bfd_vma); |
| 46 | |
| 47 | segment_type *segments; |
| 48 | |
| 49 | struct ldexp_control expld; |
| 50 | |
| 51 | /* This structure records symbols for which we need to keep track of |
| 52 | definedness for use in the DEFINED () test. It is also used in |
| 53 | making absolute symbols section relative late in the link. */ |
| 54 | |
| 55 | struct definedness_hash_entry |
| 56 | { |
| 57 | struct bfd_hash_entry root; |
| 58 | |
| 59 | /* If this symbol was assigned from "dot" outside of an output |
| 60 | section statement, the section we'd like it relative to. */ |
| 61 | asection *final_sec; |
| 62 | |
| 63 | /* Symbol was defined by an object file. */ |
| 64 | unsigned int by_object : 1; |
| 65 | |
| 66 | /* Symbols was defined by a script. */ |
| 67 | unsigned int by_script : 1; |
| 68 | |
| 69 | /* Low bit of iteration count. Symbols with matching iteration have |
| 70 | been defined in this pass over the script. */ |
| 71 | unsigned int iteration : 1; |
| 72 | }; |
| 73 | |
| 74 | static struct bfd_hash_table definedness_table; |
| 75 | |
| 76 | /* Print the string representation of the given token. Surround it |
| 77 | with spaces if INFIX_P is TRUE. */ |
| 78 | |
| 79 | static void |
| 80 | exp_print_token (token_code_type code, int infix_p) |
| 81 | { |
| 82 | static const struct |
| 83 | { |
| 84 | token_code_type code; |
| 85 | const char *name; |
| 86 | } |
| 87 | table[] = |
| 88 | { |
| 89 | { INT, "int" }, |
| 90 | { NAME, "NAME" }, |
| 91 | { PLUSEQ, "+=" }, |
| 92 | { MINUSEQ, "-=" }, |
| 93 | { MULTEQ, "*=" }, |
| 94 | { DIVEQ, "/=" }, |
| 95 | { LSHIFTEQ, "<<=" }, |
| 96 | { RSHIFTEQ, ">>=" }, |
| 97 | { ANDEQ, "&=" }, |
| 98 | { OREQ, "|=" }, |
| 99 | { OROR, "||" }, |
| 100 | { ANDAND, "&&" }, |
| 101 | { EQ, "==" }, |
| 102 | { NE, "!=" }, |
| 103 | { LE, "<=" }, |
| 104 | { GE, ">=" }, |
| 105 | { LSHIFT, "<<" }, |
| 106 | { RSHIFT, ">>" }, |
| 107 | { LOG2CEIL, "LOG2CEIL" }, |
| 108 | { ALIGN_K, "ALIGN" }, |
| 109 | { BLOCK, "BLOCK" }, |
| 110 | { QUAD, "QUAD" }, |
| 111 | { SQUAD, "SQUAD" }, |
| 112 | { LONG, "LONG" }, |
| 113 | { SHORT, "SHORT" }, |
| 114 | { BYTE, "BYTE" }, |
| 115 | { SECTIONS, "SECTIONS" }, |
| 116 | { SIZEOF_HEADERS, "SIZEOF_HEADERS" }, |
| 117 | { MEMORY, "MEMORY" }, |
| 118 | { DEFINED, "DEFINED" }, |
| 119 | { TARGET_K, "TARGET" }, |
| 120 | { SEARCH_DIR, "SEARCH_DIR" }, |
| 121 | { MAP, "MAP" }, |
| 122 | { ENTRY, "ENTRY" }, |
| 123 | { NEXT, "NEXT" }, |
| 124 | { ALIGNOF, "ALIGNOF" }, |
| 125 | { SIZEOF, "SIZEOF" }, |
| 126 | { ADDR, "ADDR" }, |
| 127 | { LOADADDR, "LOADADDR" }, |
| 128 | { CONSTANT, "CONSTANT" }, |
| 129 | { ABSOLUTE, "ABSOLUTE" }, |
| 130 | { MAX_K, "MAX" }, |
| 131 | { MIN_K, "MIN" }, |
| 132 | { ASSERT_K, "ASSERT" }, |
| 133 | { REL, "relocatable" }, |
| 134 | { DATA_SEGMENT_ALIGN, "DATA_SEGMENT_ALIGN" }, |
| 135 | { DATA_SEGMENT_RELRO_END, "DATA_SEGMENT_RELRO_END" }, |
| 136 | { DATA_SEGMENT_END, "DATA_SEGMENT_END" }, |
| 137 | { ORIGIN, "ORIGIN" }, |
| 138 | { LENGTH, "LENGTH" }, |
| 139 | { SEGMENT_START, "SEGMENT_START" } |
| 140 | }; |
| 141 | unsigned int idx; |
| 142 | |
| 143 | for (idx = 0; idx < ARRAY_SIZE (table); idx++) |
| 144 | if (table[idx].code == code) |
| 145 | break; |
| 146 | |
| 147 | if (infix_p) |
| 148 | fputc (' ', config.map_file); |
| 149 | |
| 150 | if (idx < ARRAY_SIZE (table)) |
| 151 | fputs (table[idx].name, config.map_file); |
| 152 | else if (code < 127) |
| 153 | fputc (code, config.map_file); |
| 154 | else |
| 155 | fprintf (config.map_file, "<code %d>", code); |
| 156 | |
| 157 | if (infix_p) |
| 158 | fputc (' ', config.map_file); |
| 159 | } |
| 160 | |
| 161 | static void |
| 162 | make_log2ceil (void) |
| 163 | { |
| 164 | bfd_vma value = expld.result.value; |
| 165 | bfd_vma result = -1; |
| 166 | bfd_boolean round_up = FALSE; |
| 167 | |
| 168 | do |
| 169 | { |
| 170 | result++; |
| 171 | /* If more than one bit is set in the value we will need to round up. */ |
| 172 | if ((value > 1) && (value & 1)) |
| 173 | round_up = TRUE; |
| 174 | } |
| 175 | while (value >>= 1); |
| 176 | |
| 177 | if (round_up) |
| 178 | result += 1; |
| 179 | expld.result.section = NULL; |
| 180 | expld.result.value = result; |
| 181 | } |
| 182 | |
| 183 | static void |
| 184 | make_abs (void) |
| 185 | { |
| 186 | if (expld.result.section != NULL) |
| 187 | expld.result.value += expld.result.section->vma; |
| 188 | expld.result.section = bfd_abs_section_ptr; |
| 189 | expld.rel_from_abs = FALSE; |
| 190 | } |
| 191 | |
| 192 | static void |
| 193 | new_abs (bfd_vma value) |
| 194 | { |
| 195 | expld.result.valid_p = TRUE; |
| 196 | expld.result.section = bfd_abs_section_ptr; |
| 197 | expld.result.value = value; |
| 198 | expld.result.str = NULL; |
| 199 | } |
| 200 | |
| 201 | etree_type * |
| 202 | exp_intop (bfd_vma value) |
| 203 | { |
| 204 | etree_type *new_e = (etree_type *) stat_alloc (sizeof (new_e->value)); |
| 205 | new_e->type.node_code = INT; |
| 206 | new_e->type.filename = ldlex_filename (); |
| 207 | new_e->type.lineno = lineno; |
| 208 | new_e->value.value = value; |
| 209 | new_e->value.str = NULL; |
| 210 | new_e->type.node_class = etree_value; |
| 211 | return new_e; |
| 212 | } |
| 213 | |
| 214 | etree_type * |
| 215 | exp_bigintop (bfd_vma value, char *str) |
| 216 | { |
| 217 | etree_type *new_e = (etree_type *) stat_alloc (sizeof (new_e->value)); |
| 218 | new_e->type.node_code = INT; |
| 219 | new_e->type.filename = ldlex_filename (); |
| 220 | new_e->type.lineno = lineno; |
| 221 | new_e->value.value = value; |
| 222 | new_e->value.str = str; |
| 223 | new_e->type.node_class = etree_value; |
| 224 | return new_e; |
| 225 | } |
| 226 | |
| 227 | /* Build an expression representing an unnamed relocatable value. */ |
| 228 | |
| 229 | etree_type * |
| 230 | exp_relop (asection *section, bfd_vma value) |
| 231 | { |
| 232 | etree_type *new_e = (etree_type *) stat_alloc (sizeof (new_e->rel)); |
| 233 | new_e->type.node_code = REL; |
| 234 | new_e->type.filename = ldlex_filename (); |
| 235 | new_e->type.lineno = lineno; |
| 236 | new_e->type.node_class = etree_rel; |
| 237 | new_e->rel.section = section; |
| 238 | new_e->rel.value = value; |
| 239 | return new_e; |
| 240 | } |
| 241 | |
| 242 | static void |
| 243 | new_number (bfd_vma value) |
| 244 | { |
| 245 | expld.result.valid_p = TRUE; |
| 246 | expld.result.value = value; |
| 247 | expld.result.str = NULL; |
| 248 | expld.result.section = NULL; |
| 249 | } |
| 250 | |
| 251 | static void |
| 252 | new_rel (bfd_vma value, asection *section) |
| 253 | { |
| 254 | expld.result.valid_p = TRUE; |
| 255 | expld.result.value = value; |
| 256 | expld.result.str = NULL; |
| 257 | expld.result.section = section; |
| 258 | } |
| 259 | |
| 260 | static void |
| 261 | new_rel_from_abs (bfd_vma value) |
| 262 | { |
| 263 | asection *s = expld.section; |
| 264 | |
| 265 | expld.rel_from_abs = TRUE; |
| 266 | expld.result.valid_p = TRUE; |
| 267 | expld.result.value = value - s->vma; |
| 268 | expld.result.str = NULL; |
| 269 | expld.result.section = s; |
| 270 | } |
| 271 | |
| 272 | /* New-function for the definedness hash table. */ |
| 273 | |
| 274 | static struct bfd_hash_entry * |
| 275 | definedness_newfunc (struct bfd_hash_entry *entry, |
| 276 | struct bfd_hash_table *table ATTRIBUTE_UNUSED, |
| 277 | const char *name ATTRIBUTE_UNUSED) |
| 278 | { |
| 279 | struct definedness_hash_entry *ret = (struct definedness_hash_entry *) entry; |
| 280 | |
| 281 | if (ret == NULL) |
| 282 | ret = (struct definedness_hash_entry *) |
| 283 | bfd_hash_allocate (table, sizeof (struct definedness_hash_entry)); |
| 284 | |
| 285 | if (ret == NULL) |
| 286 | einfo (_("%P%F: bfd_hash_allocate failed creating symbol %s\n"), name); |
| 287 | |
| 288 | ret->by_object = 0; |
| 289 | ret->by_script = 0; |
| 290 | ret->iteration = 0; |
| 291 | return &ret->root; |
| 292 | } |
| 293 | |
| 294 | /* Called during processing of linker script script expressions. |
| 295 | For symbols assigned in a linker script, return a struct describing |
| 296 | where the symbol is defined relative to the current expression, |
| 297 | otherwise return NULL. */ |
| 298 | |
| 299 | static struct definedness_hash_entry * |
| 300 | symbol_defined (const char *name) |
| 301 | { |
| 302 | return ((struct definedness_hash_entry *) |
| 303 | bfd_hash_lookup (&definedness_table, name, FALSE, FALSE)); |
| 304 | } |
| 305 | |
| 306 | /* Update the definedness state of NAME. Return FALSE if script symbol |
| 307 | is multiply defining a strong symbol in an object. */ |
| 308 | |
| 309 | static bfd_boolean |
| 310 | update_definedness (const char *name, struct bfd_link_hash_entry *h) |
| 311 | { |
| 312 | bfd_boolean ret; |
| 313 | struct definedness_hash_entry *defentry |
| 314 | = (struct definedness_hash_entry *) |
| 315 | bfd_hash_lookup (&definedness_table, name, TRUE, FALSE); |
| 316 | |
| 317 | if (defentry == NULL) |
| 318 | einfo (_("%P%F: bfd_hash_lookup failed creating symbol %s\n"), name); |
| 319 | |
| 320 | /* If the symbol was already defined, and not by a script, then it |
| 321 | must be defined by an object file or by the linker target code. */ |
| 322 | ret = TRUE; |
| 323 | if (!defentry->by_script |
| 324 | && (h->type == bfd_link_hash_defined |
| 325 | || h->type == bfd_link_hash_defweak |
| 326 | || h->type == bfd_link_hash_common)) |
| 327 | { |
| 328 | defentry->by_object = 1; |
| 329 | if (h->type == bfd_link_hash_defined |
| 330 | && h->u.def.section->output_section != NULL |
| 331 | && !h->linker_def) |
| 332 | ret = FALSE; |
| 333 | } |
| 334 | |
| 335 | defentry->by_script = 1; |
| 336 | defentry->iteration = lang_statement_iteration; |
| 337 | defentry->final_sec = bfd_abs_section_ptr; |
| 338 | if (expld.phase == lang_final_phase_enum |
| 339 | && expld.rel_from_abs |
| 340 | && expld.result.section == bfd_abs_section_ptr) |
| 341 | defentry->final_sec = section_for_dot (); |
| 342 | return ret; |
| 343 | } |
| 344 | |
| 345 | static void |
| 346 | fold_unary (etree_type *tree) |
| 347 | { |
| 348 | exp_fold_tree_1 (tree->unary.child); |
| 349 | if (expld.result.valid_p) |
| 350 | { |
| 351 | switch (tree->type.node_code) |
| 352 | { |
| 353 | case ALIGN_K: |
| 354 | if (expld.phase != lang_first_phase_enum) |
| 355 | new_rel_from_abs (align_n (expld.dot, expld.result.value)); |
| 356 | else |
| 357 | expld.result.valid_p = FALSE; |
| 358 | break; |
| 359 | |
| 360 | case ABSOLUTE: |
| 361 | make_abs (); |
| 362 | break; |
| 363 | |
| 364 | case LOG2CEIL: |
| 365 | make_log2ceil (); |
| 366 | break; |
| 367 | |
| 368 | case '~': |
| 369 | expld.result.value = ~expld.result.value; |
| 370 | break; |
| 371 | |
| 372 | case '!': |
| 373 | expld.result.value = !expld.result.value; |
| 374 | break; |
| 375 | |
| 376 | case '-': |
| 377 | expld.result.value = -expld.result.value; |
| 378 | break; |
| 379 | |
| 380 | case NEXT: |
| 381 | /* Return next place aligned to value. */ |
| 382 | if (expld.phase != lang_first_phase_enum) |
| 383 | { |
| 384 | make_abs (); |
| 385 | expld.result.value = align_n (expld.dot, expld.result.value); |
| 386 | } |
| 387 | else |
| 388 | expld.result.valid_p = FALSE; |
| 389 | break; |
| 390 | |
| 391 | case DATA_SEGMENT_END: |
| 392 | if (expld.phase == lang_first_phase_enum |
| 393 | || expld.section != bfd_abs_section_ptr) |
| 394 | { |
| 395 | expld.result.valid_p = FALSE; |
| 396 | } |
| 397 | else if (expld.dataseg.phase == exp_dataseg_align_seen |
| 398 | || expld.dataseg.phase == exp_dataseg_relro_seen) |
| 399 | { |
| 400 | expld.dataseg.phase = exp_dataseg_end_seen; |
| 401 | expld.dataseg.end = expld.result.value; |
| 402 | } |
| 403 | else if (expld.dataseg.phase == exp_dataseg_done |
| 404 | || expld.dataseg.phase == exp_dataseg_adjust |
| 405 | || expld.dataseg.phase == exp_dataseg_relro_adjust) |
| 406 | { |
| 407 | /* OK. */ |
| 408 | } |
| 409 | else |
| 410 | expld.result.valid_p = FALSE; |
| 411 | break; |
| 412 | |
| 413 | default: |
| 414 | FAIL (); |
| 415 | break; |
| 416 | } |
| 417 | } |
| 418 | } |
| 419 | |
| 420 | static void |
| 421 | fold_binary (etree_type *tree) |
| 422 | { |
| 423 | etree_value_type lhs; |
| 424 | exp_fold_tree_1 (tree->binary.lhs); |
| 425 | |
| 426 | /* The SEGMENT_START operator is special because its first |
| 427 | operand is a string, not the name of a symbol. Note that the |
| 428 | operands have been swapped, so binary.lhs is second (default) |
| 429 | operand, binary.rhs is first operand. */ |
| 430 | if (expld.result.valid_p && tree->type.node_code == SEGMENT_START) |
| 431 | { |
| 432 | const char *segment_name; |
| 433 | segment_type *seg; |
| 434 | |
| 435 | /* Check to see if the user has overridden the default |
| 436 | value. */ |
| 437 | segment_name = tree->binary.rhs->name.name; |
| 438 | for (seg = segments; seg; seg = seg->next) |
| 439 | if (strcmp (seg->name, segment_name) == 0) |
| 440 | { |
| 441 | if (!seg->used |
| 442 | && config.magic_demand_paged |
| 443 | && (seg->value % config.maxpagesize) != 0) |
| 444 | einfo (_("%P: warning: address of `%s' " |
| 445 | "isn't multiple of maximum page size\n"), |
| 446 | segment_name); |
| 447 | seg->used = TRUE; |
| 448 | new_rel_from_abs (seg->value); |
| 449 | break; |
| 450 | } |
| 451 | return; |
| 452 | } |
| 453 | |
| 454 | lhs = expld.result; |
| 455 | exp_fold_tree_1 (tree->binary.rhs); |
| 456 | expld.result.valid_p &= lhs.valid_p; |
| 457 | |
| 458 | if (expld.result.valid_p) |
| 459 | { |
| 460 | if (lhs.section != expld.result.section) |
| 461 | { |
| 462 | /* If the values are from different sections, and neither is |
| 463 | just a number, make both the source arguments absolute. */ |
| 464 | if (expld.result.section != NULL |
| 465 | && lhs.section != NULL) |
| 466 | { |
| 467 | make_abs (); |
| 468 | lhs.value += lhs.section->vma; |
| 469 | lhs.section = bfd_abs_section_ptr; |
| 470 | } |
| 471 | |
| 472 | /* If the rhs is just a number, keep the lhs section. */ |
| 473 | else if (expld.result.section == NULL) |
| 474 | { |
| 475 | expld.result.section = lhs.section; |
| 476 | /* Make this NULL so that we know one of the operands |
| 477 | was just a number, for later tests. */ |
| 478 | lhs.section = NULL; |
| 479 | } |
| 480 | } |
| 481 | /* At this point we know that both operands have the same |
| 482 | section, or at least one of them is a plain number. */ |
| 483 | |
| 484 | switch (tree->type.node_code) |
| 485 | { |
| 486 | /* Arithmetic operators, bitwise AND, bitwise OR and XOR |
| 487 | keep the section of one of their operands only when the |
| 488 | other operand is a plain number. Losing the section when |
| 489 | operating on two symbols, ie. a result of a plain number, |
| 490 | is required for subtraction and XOR. It's justifiable |
| 491 | for the other operations on the grounds that adding, |
| 492 | multiplying etc. two section relative values does not |
| 493 | really make sense unless they are just treated as |
| 494 | numbers. |
| 495 | The same argument could be made for many expressions |
| 496 | involving one symbol and a number. For example, |
| 497 | "1 << x" and "100 / x" probably should not be given the |
| 498 | section of x. The trouble is that if we fuss about such |
| 499 | things the rules become complex and it is onerous to |
| 500 | document ld expression evaluation. */ |
| 501 | #define BOP(x, y) \ |
| 502 | case x: \ |
| 503 | expld.result.value = lhs.value y expld.result.value; \ |
| 504 | if (expld.result.section == lhs.section) \ |
| 505 | expld.result.section = NULL; \ |
| 506 | break; |
| 507 | |
| 508 | /* Comparison operators, logical AND, and logical OR always |
| 509 | return a plain number. */ |
| 510 | #define BOPN(x, y) \ |
| 511 | case x: \ |
| 512 | expld.result.value = lhs.value y expld.result.value; \ |
| 513 | expld.result.section = NULL; \ |
| 514 | break; |
| 515 | |
| 516 | BOP ('+', +); |
| 517 | BOP ('*', *); |
| 518 | BOP ('-', -); |
| 519 | BOP (LSHIFT, <<); |
| 520 | BOP (RSHIFT, >>); |
| 521 | BOP ('&', &); |
| 522 | BOP ('^', ^); |
| 523 | BOP ('|', |); |
| 524 | BOPN (EQ, ==); |
| 525 | BOPN (NE, !=); |
| 526 | BOPN ('<', <); |
| 527 | BOPN ('>', >); |
| 528 | BOPN (LE, <=); |
| 529 | BOPN (GE, >=); |
| 530 | BOPN (ANDAND, &&); |
| 531 | BOPN (OROR, ||); |
| 532 | |
| 533 | case '%': |
| 534 | if (expld.result.value != 0) |
| 535 | expld.result.value = ((bfd_signed_vma) lhs.value |
| 536 | % (bfd_signed_vma) expld.result.value); |
| 537 | else if (expld.phase != lang_mark_phase_enum) |
| 538 | einfo (_("%F%S %% by zero\n"), tree->binary.rhs); |
| 539 | if (expld.result.section == lhs.section) |
| 540 | expld.result.section = NULL; |
| 541 | break; |
| 542 | |
| 543 | case '/': |
| 544 | if (expld.result.value != 0) |
| 545 | expld.result.value = ((bfd_signed_vma) lhs.value |
| 546 | / (bfd_signed_vma) expld.result.value); |
| 547 | else if (expld.phase != lang_mark_phase_enum) |
| 548 | einfo (_("%F%S / by zero\n"), tree->binary.rhs); |
| 549 | if (expld.result.section == lhs.section) |
| 550 | expld.result.section = NULL; |
| 551 | break; |
| 552 | |
| 553 | case MAX_K: |
| 554 | if (lhs.value > expld.result.value) |
| 555 | expld.result.value = lhs.value; |
| 556 | break; |
| 557 | |
| 558 | case MIN_K: |
| 559 | if (lhs.value < expld.result.value) |
| 560 | expld.result.value = lhs.value; |
| 561 | break; |
| 562 | |
| 563 | case ALIGN_K: |
| 564 | expld.result.value = align_n (lhs.value, expld.result.value); |
| 565 | break; |
| 566 | |
| 567 | case DATA_SEGMENT_ALIGN: |
| 568 | expld.dataseg.relro = exp_dataseg_relro_start; |
| 569 | if (expld.phase == lang_first_phase_enum |
| 570 | || expld.section != bfd_abs_section_ptr) |
| 571 | expld.result.valid_p = FALSE; |
| 572 | else |
| 573 | { |
| 574 | bfd_vma maxpage = lhs.value; |
| 575 | bfd_vma commonpage = expld.result.value; |
| 576 | |
| 577 | expld.result.value = align_n (expld.dot, maxpage); |
| 578 | if (expld.dataseg.phase == exp_dataseg_relro_adjust) |
| 579 | expld.result.value = expld.dataseg.base; |
| 580 | else if (expld.dataseg.phase == exp_dataseg_adjust) |
| 581 | { |
| 582 | if (commonpage < maxpage) |
| 583 | expld.result.value += ((expld.dot + commonpage - 1) |
| 584 | & (maxpage - commonpage)); |
| 585 | } |
| 586 | else |
| 587 | { |
| 588 | expld.result.value += expld.dot & (maxpage - 1); |
| 589 | if (expld.dataseg.phase == exp_dataseg_done) |
| 590 | { |
| 591 | /* OK. */ |
| 592 | } |
| 593 | else if (expld.dataseg.phase == exp_dataseg_none) |
| 594 | { |
| 595 | expld.dataseg.phase = exp_dataseg_align_seen; |
| 596 | expld.dataseg.base = expld.result.value; |
| 597 | expld.dataseg.pagesize = commonpage; |
| 598 | expld.dataseg.maxpagesize = maxpage; |
| 599 | expld.dataseg.relro_end = 0; |
| 600 | } |
| 601 | else |
| 602 | expld.result.valid_p = FALSE; |
| 603 | } |
| 604 | } |
| 605 | break; |
| 606 | |
| 607 | case DATA_SEGMENT_RELRO_END: |
| 608 | /* Operands swapped! DATA_SEGMENT_RELRO_END(offset,exp) |
| 609 | has offset in expld.result and exp in lhs. */ |
| 610 | expld.dataseg.relro = exp_dataseg_relro_end; |
| 611 | expld.dataseg.relro_offset = expld.result.value; |
| 612 | if (expld.phase == lang_first_phase_enum |
| 613 | || expld.section != bfd_abs_section_ptr) |
| 614 | expld.result.valid_p = FALSE; |
| 615 | else if (expld.dataseg.phase == exp_dataseg_align_seen |
| 616 | || expld.dataseg.phase == exp_dataseg_adjust |
| 617 | || expld.dataseg.phase == exp_dataseg_relro_adjust |
| 618 | || expld.dataseg.phase == exp_dataseg_done) |
| 619 | { |
| 620 | if (expld.dataseg.phase == exp_dataseg_align_seen |
| 621 | || expld.dataseg.phase == exp_dataseg_relro_adjust) |
| 622 | expld.dataseg.relro_end = lhs.value + expld.result.value; |
| 623 | |
| 624 | if (expld.dataseg.phase == exp_dataseg_relro_adjust |
| 625 | && (expld.dataseg.relro_end |
| 626 | & (expld.dataseg.pagesize - 1))) |
| 627 | { |
| 628 | expld.dataseg.relro_end += expld.dataseg.pagesize - 1; |
| 629 | expld.dataseg.relro_end &= ~(expld.dataseg.pagesize - 1); |
| 630 | expld.result.value = (expld.dataseg.relro_end |
| 631 | - expld.result.value); |
| 632 | } |
| 633 | else |
| 634 | expld.result.value = lhs.value; |
| 635 | |
| 636 | if (expld.dataseg.phase == exp_dataseg_align_seen) |
| 637 | expld.dataseg.phase = exp_dataseg_relro_seen; |
| 638 | } |
| 639 | else |
| 640 | expld.result.valid_p = FALSE; |
| 641 | break; |
| 642 | |
| 643 | default: |
| 644 | FAIL (); |
| 645 | } |
| 646 | } |
| 647 | } |
| 648 | |
| 649 | static void |
| 650 | fold_trinary (etree_type *tree) |
| 651 | { |
| 652 | exp_fold_tree_1 (tree->trinary.cond); |
| 653 | if (expld.result.valid_p) |
| 654 | exp_fold_tree_1 (expld.result.value |
| 655 | ? tree->trinary.lhs |
| 656 | : tree->trinary.rhs); |
| 657 | } |
| 658 | |
| 659 | static void |
| 660 | fold_name (etree_type *tree) |
| 661 | { |
| 662 | memset (&expld.result, 0, sizeof (expld.result)); |
| 663 | |
| 664 | switch (tree->type.node_code) |
| 665 | { |
| 666 | case SIZEOF_HEADERS: |
| 667 | if (expld.phase != lang_first_phase_enum) |
| 668 | { |
| 669 | bfd_vma hdr_size = 0; |
| 670 | /* Don't find the real header size if only marking sections; |
| 671 | The bfd function may cache incorrect data. */ |
| 672 | if (expld.phase != lang_mark_phase_enum) |
| 673 | hdr_size = bfd_sizeof_headers (link_info.output_bfd, &link_info); |
| 674 | new_number (hdr_size); |
| 675 | } |
| 676 | break; |
| 677 | |
| 678 | case DEFINED: |
| 679 | if (expld.phase != lang_first_phase_enum) |
| 680 | { |
| 681 | struct bfd_link_hash_entry *h; |
| 682 | struct definedness_hash_entry *def; |
| 683 | |
| 684 | h = bfd_wrapped_link_hash_lookup (link_info.output_bfd, |
| 685 | &link_info, |
| 686 | tree->name.name, |
| 687 | FALSE, FALSE, TRUE); |
| 688 | new_number (h != NULL |
| 689 | && (h->type == bfd_link_hash_defined |
| 690 | || h->type == bfd_link_hash_defweak |
| 691 | || h->type == bfd_link_hash_common) |
| 692 | && ((def = symbol_defined (tree->name.name)) == NULL |
| 693 | || def->by_object |
| 694 | || def->iteration == (lang_statement_iteration & 1))); |
| 695 | } |
| 696 | break; |
| 697 | |
| 698 | case NAME: |
| 699 | if (expld.assign_name != NULL |
| 700 | && strcmp (expld.assign_name, tree->name.name) == 0) |
| 701 | { |
| 702 | /* Self-assignment is only allowed for absolute symbols |
| 703 | defined in a linker script. */ |
| 704 | struct bfd_link_hash_entry *h; |
| 705 | struct definedness_hash_entry *def; |
| 706 | |
| 707 | h = bfd_wrapped_link_hash_lookup (link_info.output_bfd, |
| 708 | &link_info, |
| 709 | tree->name.name, |
| 710 | FALSE, FALSE, TRUE); |
| 711 | if (!(h != NULL |
| 712 | && (h->type == bfd_link_hash_defined |
| 713 | || h->type == bfd_link_hash_defweak) |
| 714 | && h->u.def.section == bfd_abs_section_ptr |
| 715 | && (def = symbol_defined (tree->name.name)) != NULL |
| 716 | && def->iteration == (lang_statement_iteration & 1))) |
| 717 | expld.assign_name = NULL; |
| 718 | } |
| 719 | if (expld.phase == lang_first_phase_enum) |
| 720 | ; |
| 721 | else if (tree->name.name[0] == '.' && tree->name.name[1] == 0) |
| 722 | new_rel_from_abs (expld.dot); |
| 723 | else |
| 724 | { |
| 725 | struct bfd_link_hash_entry *h; |
| 726 | |
| 727 | h = bfd_wrapped_link_hash_lookup (link_info.output_bfd, |
| 728 | &link_info, |
| 729 | tree->name.name, |
| 730 | TRUE, FALSE, TRUE); |
| 731 | if (!h) |
| 732 | einfo (_("%P%F: bfd_link_hash_lookup failed: %E\n")); |
| 733 | else if (h->type == bfd_link_hash_defined |
| 734 | || h->type == bfd_link_hash_defweak) |
| 735 | { |
| 736 | asection *output_section; |
| 737 | |
| 738 | output_section = h->u.def.section->output_section; |
| 739 | if (output_section == NULL) |
| 740 | { |
| 741 | if (expld.phase == lang_mark_phase_enum) |
| 742 | new_rel (h->u.def.value, h->u.def.section); |
| 743 | else |
| 744 | einfo (_("%X%S: unresolvable symbol `%s'" |
| 745 | " referenced in expression\n"), |
| 746 | tree, tree->name.name); |
| 747 | } |
| 748 | else if (output_section == bfd_abs_section_ptr |
| 749 | && (expld.section != bfd_abs_section_ptr |
| 750 | || config.sane_expr)) |
| 751 | new_number (h->u.def.value + h->u.def.section->output_offset); |
| 752 | else |
| 753 | new_rel (h->u.def.value + h->u.def.section->output_offset, |
| 754 | output_section); |
| 755 | } |
| 756 | else if (expld.phase == lang_final_phase_enum |
| 757 | || (expld.phase != lang_mark_phase_enum |
| 758 | && expld.assigning_to_dot)) |
| 759 | einfo (_("%F%S: undefined symbol `%s'" |
| 760 | " referenced in expression\n"), |
| 761 | tree, tree->name.name); |
| 762 | else if (h->type == bfd_link_hash_new) |
| 763 | { |
| 764 | h->type = bfd_link_hash_undefined; |
| 765 | h->u.undef.abfd = NULL; |
| 766 | if (h->u.undef.next == NULL && h != link_info.hash->undefs_tail) |
| 767 | bfd_link_add_undef (link_info.hash, h); |
| 768 | } |
| 769 | } |
| 770 | break; |
| 771 | |
| 772 | case ADDR: |
| 773 | if (expld.phase != lang_first_phase_enum) |
| 774 | { |
| 775 | lang_output_section_statement_type *os; |
| 776 | |
| 777 | os = lang_output_section_find (tree->name.name); |
| 778 | if (os == NULL) |
| 779 | { |
| 780 | if (expld.phase == lang_final_phase_enum) |
| 781 | einfo (_("%F%S: undefined section `%s'" |
| 782 | " referenced in expression\n"), |
| 783 | tree, tree->name.name); |
| 784 | } |
| 785 | else if (os->processed_vma) |
| 786 | new_rel (0, os->bfd_section); |
| 787 | } |
| 788 | break; |
| 789 | |
| 790 | case LOADADDR: |
| 791 | if (expld.phase != lang_first_phase_enum) |
| 792 | { |
| 793 | lang_output_section_statement_type *os; |
| 794 | |
| 795 | os = lang_output_section_find (tree->name.name); |
| 796 | if (os == NULL) |
| 797 | { |
| 798 | if (expld.phase == lang_final_phase_enum) |
| 799 | einfo (_("%F%S: undefined section `%s'" |
| 800 | " referenced in expression\n"), |
| 801 | tree, tree->name.name); |
| 802 | } |
| 803 | else if (os->processed_lma) |
| 804 | { |
| 805 | if (os->load_base == NULL) |
| 806 | new_abs (os->bfd_section->lma); |
| 807 | else |
| 808 | { |
| 809 | exp_fold_tree_1 (os->load_base); |
| 810 | if (expld.result.valid_p) |
| 811 | make_abs (); |
| 812 | } |
| 813 | } |
| 814 | } |
| 815 | break; |
| 816 | |
| 817 | case SIZEOF: |
| 818 | case ALIGNOF: |
| 819 | if (expld.phase != lang_first_phase_enum) |
| 820 | { |
| 821 | lang_output_section_statement_type *os; |
| 822 | |
| 823 | os = lang_output_section_find (tree->name.name); |
| 824 | if (os == NULL) |
| 825 | { |
| 826 | if (expld.phase == lang_final_phase_enum) |
| 827 | einfo (_("%F%S: undefined section `%s'" |
| 828 | " referenced in expression\n"), |
| 829 | tree, tree->name.name); |
| 830 | new_number (0); |
| 831 | } |
| 832 | else if (os->bfd_section != NULL) |
| 833 | { |
| 834 | bfd_vma val; |
| 835 | |
| 836 | if (tree->type.node_code == SIZEOF) |
| 837 | val = (os->bfd_section->size |
| 838 | / bfd_octets_per_byte (link_info.output_bfd)); |
| 839 | else |
| 840 | val = (bfd_vma)1 << os->bfd_section->alignment_power; |
| 841 | |
| 842 | new_number (val); |
| 843 | } |
| 844 | else |
| 845 | new_number (0); |
| 846 | } |
| 847 | break; |
| 848 | |
| 849 | case LENGTH: |
| 850 | { |
| 851 | if (expld.phase != lang_first_phase_enum) |
| 852 | { |
| 853 | lang_memory_region_type *mem; |
| 854 | |
| 855 | mem = lang_memory_region_lookup (tree->name.name, FALSE); |
| 856 | if (mem != NULL) |
| 857 | new_number (mem->length); |
| 858 | else |
| 859 | einfo (_("%F%S: undefined MEMORY region `%s'" |
| 860 | " referenced in expression\n"), |
| 861 | tree, tree->name.name); |
| 862 | } |
| 863 | } |
| 864 | break; |
| 865 | |
| 866 | case ORIGIN: |
| 867 | if (expld.phase != lang_first_phase_enum) |
| 868 | { |
| 869 | lang_memory_region_type *mem; |
| 870 | |
| 871 | mem = lang_memory_region_lookup (tree->name.name, FALSE); |
| 872 | if (mem != NULL) |
| 873 | new_rel_from_abs (mem->origin); |
| 874 | else |
| 875 | einfo (_("%F%S: undefined MEMORY region `%s'" |
| 876 | " referenced in expression\n"), |
| 877 | tree, tree->name.name); |
| 878 | } |
| 879 | break; |
| 880 | |
| 881 | case CONSTANT: |
| 882 | if (strcmp (tree->name.name, "MAXPAGESIZE") == 0) |
| 883 | new_number (config.maxpagesize); |
| 884 | else if (strcmp (tree->name.name, "COMMONPAGESIZE") == 0) |
| 885 | new_number (config.commonpagesize); |
| 886 | else |
| 887 | einfo (_("%F%S: unknown constant `%s' referenced in expression\n"), |
| 888 | tree, tree->name.name); |
| 889 | break; |
| 890 | |
| 891 | default: |
| 892 | FAIL (); |
| 893 | break; |
| 894 | } |
| 895 | } |
| 896 | |
| 897 | /* Return true if TREE is '.'. */ |
| 898 | |
| 899 | static bfd_boolean |
| 900 | is_dot (const etree_type *tree) |
| 901 | { |
| 902 | return (tree->type.node_class == etree_name |
| 903 | && tree->type.node_code == NAME |
| 904 | && tree->name.name[0] == '.' |
| 905 | && tree->name.name[1] == 0); |
| 906 | } |
| 907 | |
| 908 | /* Return true if TREE is a constant equal to VAL. */ |
| 909 | |
| 910 | static bfd_boolean |
| 911 | is_value (const etree_type *tree, bfd_vma val) |
| 912 | { |
| 913 | return (tree->type.node_class == etree_value |
| 914 | && tree->value.value == val); |
| 915 | } |
| 916 | |
| 917 | /* Return true if TREE is an absolute symbol equal to VAL defined in |
| 918 | a linker script. */ |
| 919 | |
| 920 | static bfd_boolean |
| 921 | is_sym_value (const etree_type *tree, bfd_vma val) |
| 922 | { |
| 923 | struct bfd_link_hash_entry *h; |
| 924 | struct definedness_hash_entry *def; |
| 925 | |
| 926 | return (tree->type.node_class == etree_name |
| 927 | && tree->type.node_code == NAME |
| 928 | && (def = symbol_defined (tree->name.name)) != NULL |
| 929 | && def->by_script |
| 930 | && def->iteration == (lang_statement_iteration & 1) |
| 931 | && (h = bfd_wrapped_link_hash_lookup (link_info.output_bfd, |
| 932 | &link_info, |
| 933 | tree->name.name, |
| 934 | FALSE, FALSE, TRUE)) != NULL |
| 935 | && h->type == bfd_link_hash_defined |
| 936 | && h->u.def.section == bfd_abs_section_ptr |
| 937 | && h->u.def.value == val); |
| 938 | } |
| 939 | |
| 940 | /* Return true if TREE is ". != 0". */ |
| 941 | |
| 942 | static bfd_boolean |
| 943 | is_dot_ne_0 (const etree_type *tree) |
| 944 | { |
| 945 | return (tree->type.node_class == etree_binary |
| 946 | && tree->type.node_code == NE |
| 947 | && is_dot (tree->binary.lhs) |
| 948 | && is_value (tree->binary.rhs, 0)); |
| 949 | } |
| 950 | |
| 951 | /* Return true if TREE is ". = . + 0" or ". = . + sym" where sym is an |
| 952 | absolute constant with value 0 defined in a linker script. */ |
| 953 | |
| 954 | static bfd_boolean |
| 955 | is_dot_plus_0 (const etree_type *tree) |
| 956 | { |
| 957 | return (tree->type.node_class == etree_binary |
| 958 | && tree->type.node_code == '+' |
| 959 | && is_dot (tree->binary.lhs) |
| 960 | && (is_value (tree->binary.rhs, 0) |
| 961 | || is_sym_value (tree->binary.rhs, 0))); |
| 962 | } |
| 963 | |
| 964 | /* Return true if TREE is "ALIGN (. != 0 ? some_expression : 1)". */ |
| 965 | |
| 966 | static bfd_boolean |
| 967 | is_align_conditional (const etree_type *tree) |
| 968 | { |
| 969 | if (tree->type.node_class == etree_unary |
| 970 | && tree->type.node_code == ALIGN_K) |
| 971 | { |
| 972 | tree = tree->unary.child; |
| 973 | return (tree->type.node_class == etree_trinary |
| 974 | && is_dot_ne_0 (tree->trinary.cond) |
| 975 | && is_value (tree->trinary.rhs, 1)); |
| 976 | } |
| 977 | return FALSE; |
| 978 | } |
| 979 | |
| 980 | /* Subroutine of exp_fold_tree_1 for copying a symbol type. */ |
| 981 | |
| 982 | static void |
| 983 | try_copy_symbol_type (struct bfd_link_hash_entry *h, etree_type *src) |
| 984 | { |
| 985 | if (src->type.node_class == etree_name) |
| 986 | { |
| 987 | struct bfd_link_hash_entry *hsrc; |
| 988 | |
| 989 | hsrc = bfd_link_hash_lookup (link_info.hash, src->name.name, |
| 990 | FALSE, FALSE, TRUE); |
| 991 | if (hsrc) |
| 992 | bfd_copy_link_hash_symbol_type (link_info.output_bfd, h, |
| 993 | hsrc); |
| 994 | } |
| 995 | } |
| 996 | |
| 997 | static void |
| 998 | exp_fold_tree_1 (etree_type *tree) |
| 999 | { |
| 1000 | if (tree == NULL) |
| 1001 | { |
| 1002 | memset (&expld.result, 0, sizeof (expld.result)); |
| 1003 | return; |
| 1004 | } |
| 1005 | |
| 1006 | switch (tree->type.node_class) |
| 1007 | { |
| 1008 | case etree_value: |
| 1009 | if (expld.section == bfd_abs_section_ptr |
| 1010 | && !config.sane_expr) |
| 1011 | new_abs (tree->value.value); |
| 1012 | else |
| 1013 | new_number (tree->value.value); |
| 1014 | expld.result.str = tree->value.str; |
| 1015 | break; |
| 1016 | |
| 1017 | case etree_rel: |
| 1018 | if (expld.phase != lang_first_phase_enum) |
| 1019 | { |
| 1020 | asection *output_section = tree->rel.section->output_section; |
| 1021 | new_rel (tree->rel.value + tree->rel.section->output_offset, |
| 1022 | output_section); |
| 1023 | } |
| 1024 | else |
| 1025 | memset (&expld.result, 0, sizeof (expld.result)); |
| 1026 | break; |
| 1027 | |
| 1028 | case etree_assert: |
| 1029 | exp_fold_tree_1 (tree->assert_s.child); |
| 1030 | if (expld.phase == lang_final_phase_enum && !expld.result.value) |
| 1031 | einfo ("%X%P: %s\n", tree->assert_s.message); |
| 1032 | break; |
| 1033 | |
| 1034 | case etree_unary: |
| 1035 | fold_unary (tree); |
| 1036 | break; |
| 1037 | |
| 1038 | case etree_binary: |
| 1039 | fold_binary (tree); |
| 1040 | break; |
| 1041 | |
| 1042 | case etree_trinary: |
| 1043 | fold_trinary (tree); |
| 1044 | break; |
| 1045 | |
| 1046 | case etree_assign: |
| 1047 | case etree_provide: |
| 1048 | case etree_provided: |
| 1049 | if (tree->assign.dst[0] == '.' && tree->assign.dst[1] == 0) |
| 1050 | { |
| 1051 | if (tree->type.node_class != etree_assign) |
| 1052 | einfo (_("%F%S can not PROVIDE assignment to" |
| 1053 | " location counter\n"), tree); |
| 1054 | if (expld.phase != lang_first_phase_enum) |
| 1055 | { |
| 1056 | /* Notify the folder that this is an assignment to dot. */ |
| 1057 | expld.assigning_to_dot = TRUE; |
| 1058 | exp_fold_tree_1 (tree->assign.src); |
| 1059 | expld.assigning_to_dot = FALSE; |
| 1060 | |
| 1061 | /* If we are assigning to dot inside an output section |
| 1062 | arrange to keep the section, except for certain |
| 1063 | expressions that evaluate to zero. We ignore . = 0, |
| 1064 | . = . + 0, and . = ALIGN (. != 0 ? expr : 1). |
| 1065 | We can't ignore all expressions that evaluate to zero |
| 1066 | because an otherwise empty section might have padding |
| 1067 | added by an alignment expression that changes with |
| 1068 | relaxation. Such a section might have zero size |
| 1069 | before relaxation and so be stripped incorrectly. */ |
| 1070 | if (expld.phase == lang_mark_phase_enum |
| 1071 | && expld.section != bfd_abs_section_ptr |
| 1072 | && !(expld.result.valid_p |
| 1073 | && expld.result.value == 0 |
| 1074 | && (is_value (tree->assign.src, 0) |
| 1075 | || is_sym_value (tree->assign.src, 0) |
| 1076 | || is_dot_plus_0 (tree->assign.src) |
| 1077 | || is_align_conditional (tree->assign.src)))) |
| 1078 | expld.section->flags |= SEC_KEEP; |
| 1079 | |
| 1080 | if (!expld.result.valid_p) |
| 1081 | { |
| 1082 | if (expld.phase != lang_mark_phase_enum) |
| 1083 | einfo (_("%F%S invalid assignment to" |
| 1084 | " location counter\n"), tree); |
| 1085 | } |
| 1086 | else if (expld.dotp == NULL) |
| 1087 | einfo (_("%F%S assignment to location counter" |
| 1088 | " invalid outside of SECTIONS\n"), tree); |
| 1089 | |
| 1090 | /* After allocation, assignment to dot should not be |
| 1091 | done inside an output section since allocation adds a |
| 1092 | padding statement that effectively duplicates the |
| 1093 | assignment. */ |
| 1094 | else if (expld.phase <= lang_allocating_phase_enum |
| 1095 | || expld.section == bfd_abs_section_ptr) |
| 1096 | { |
| 1097 | bfd_vma nextdot; |
| 1098 | |
| 1099 | nextdot = expld.result.value; |
| 1100 | if (expld.result.section != NULL) |
| 1101 | nextdot += expld.result.section->vma; |
| 1102 | else |
| 1103 | nextdot += expld.section->vma; |
| 1104 | if (nextdot < expld.dot |
| 1105 | && expld.section != bfd_abs_section_ptr) |
| 1106 | einfo (_("%F%S cannot move location counter backwards" |
| 1107 | " (from %V to %V)\n"), |
| 1108 | tree, expld.dot, nextdot); |
| 1109 | else |
| 1110 | { |
| 1111 | expld.dot = nextdot; |
| 1112 | *expld.dotp = nextdot; |
| 1113 | } |
| 1114 | } |
| 1115 | } |
| 1116 | else |
| 1117 | memset (&expld.result, 0, sizeof (expld.result)); |
| 1118 | } |
| 1119 | else |
| 1120 | { |
| 1121 | struct bfd_link_hash_entry *h = NULL; |
| 1122 | |
| 1123 | if (tree->type.node_class == etree_provide) |
| 1124 | { |
| 1125 | h = bfd_link_hash_lookup (link_info.hash, tree->assign.dst, |
| 1126 | FALSE, FALSE, TRUE); |
| 1127 | if (h == NULL |
| 1128 | || !(h->type == bfd_link_hash_new |
| 1129 | || h->type == bfd_link_hash_undefined |
| 1130 | || h->type == bfd_link_hash_undefweak |
| 1131 | || h->linker_def)) |
| 1132 | { |
| 1133 | /* Do nothing. The symbol was never referenced, or |
| 1134 | was defined in some object file. Note that |
| 1135 | undefweak symbols are defined by PROVIDE. This |
| 1136 | is to support glibc use of __rela_iplt_start and |
| 1137 | similar weak references. */ |
| 1138 | break; |
| 1139 | } |
| 1140 | } |
| 1141 | |
| 1142 | expld.assign_name = tree->assign.dst; |
| 1143 | exp_fold_tree_1 (tree->assign.src); |
| 1144 | /* expld.assign_name remaining equal to tree->assign.dst |
| 1145 | below indicates the evaluation of tree->assign.src did |
| 1146 | not use the value of tree->assign.dst. We don't allow |
| 1147 | self assignment until the final phase for two reasons: |
| 1148 | 1) Expressions are evaluated multiple times. With |
| 1149 | relaxation, the number of times may vary. |
| 1150 | 2) Section relative symbol values cannot be correctly |
| 1151 | converted to absolute values, as is required by many |
| 1152 | expressions, until final section sizing is complete. */ |
| 1153 | if ((expld.result.valid_p |
| 1154 | && (expld.phase == lang_final_phase_enum |
| 1155 | || expld.assign_name != NULL)) |
| 1156 | || (expld.phase <= lang_mark_phase_enum |
| 1157 | && tree->type.node_class == etree_assign |
| 1158 | && tree->assign.defsym)) |
| 1159 | { |
| 1160 | if (h == NULL) |
| 1161 | { |
| 1162 | h = bfd_link_hash_lookup (link_info.hash, tree->assign.dst, |
| 1163 | TRUE, FALSE, TRUE); |
| 1164 | if (h == NULL) |
| 1165 | einfo (_("%P%F:%s: hash creation failed\n"), |
| 1166 | tree->assign.dst); |
| 1167 | } |
| 1168 | |
| 1169 | if (expld.result.section == NULL) |
| 1170 | expld.result.section = expld.section; |
| 1171 | if (!update_definedness (tree->assign.dst, h) && 0) |
| 1172 | { |
| 1173 | /* Symbol was already defined. For now this error |
| 1174 | is disabled because it causes failures in the ld |
| 1175 | testsuite: ld-elf/var1, ld-scripts/defined5, and |
| 1176 | ld-scripts/pr14962. Some of these no doubt |
| 1177 | reflect scripts used in the wild. */ |
| 1178 | (*link_info.callbacks->multiple_definition) |
| 1179 | (&link_info, h, link_info.output_bfd, |
| 1180 | expld.result.section, expld.result.value); |
| 1181 | } |
| 1182 | h->type = bfd_link_hash_defined; |
| 1183 | h->u.def.value = expld.result.value; |
| 1184 | h->u.def.section = expld.result.section; |
| 1185 | h->linker_def = 0; |
| 1186 | if (tree->type.node_class == etree_provide) |
| 1187 | tree->type.node_class = etree_provided; |
| 1188 | |
| 1189 | /* Copy the symbol type if this is a simple assignment of |
| 1190 | one symbol to another. Also, handle the case of a foldable |
| 1191 | ternary conditional with names on either side. */ |
| 1192 | if (tree->assign.src->type.node_class == etree_name) |
| 1193 | try_copy_symbol_type (h, tree->assign.src); |
| 1194 | else if (tree->assign.src->type.node_class == etree_trinary) |
| 1195 | { |
| 1196 | exp_fold_tree_1 (tree->assign.src->trinary.cond); |
| 1197 | if (expld.result.valid_p) |
| 1198 | { |
| 1199 | if (expld.result.value |
| 1200 | && tree->assign.src->trinary.lhs->type.node_class |
| 1201 | == etree_name) |
| 1202 | try_copy_symbol_type (h, tree->assign.src->trinary.lhs); |
| 1203 | |
| 1204 | if (!expld.result.value |
| 1205 | && tree->assign.src->trinary.rhs->type.node_class |
| 1206 | == etree_name) |
| 1207 | try_copy_symbol_type (h, tree->assign.src->trinary.rhs); |
| 1208 | } |
| 1209 | } |
| 1210 | } |
| 1211 | else if (expld.phase == lang_final_phase_enum) |
| 1212 | { |
| 1213 | h = bfd_link_hash_lookup (link_info.hash, tree->assign.dst, |
| 1214 | FALSE, FALSE, TRUE); |
| 1215 | if (h != NULL |
| 1216 | && h->type == bfd_link_hash_new) |
| 1217 | h->type = bfd_link_hash_undefined; |
| 1218 | } |
| 1219 | expld.assign_name = NULL; |
| 1220 | } |
| 1221 | break; |
| 1222 | |
| 1223 | case etree_name: |
| 1224 | fold_name (tree); |
| 1225 | break; |
| 1226 | |
| 1227 | default: |
| 1228 | FAIL (); |
| 1229 | memset (&expld.result, 0, sizeof (expld.result)); |
| 1230 | break; |
| 1231 | } |
| 1232 | } |
| 1233 | |
| 1234 | void |
| 1235 | exp_fold_tree (etree_type *tree, asection *current_section, bfd_vma *dotp) |
| 1236 | { |
| 1237 | expld.rel_from_abs = FALSE; |
| 1238 | expld.dot = *dotp; |
| 1239 | expld.dotp = dotp; |
| 1240 | expld.section = current_section; |
| 1241 | exp_fold_tree_1 (tree); |
| 1242 | } |
| 1243 | |
| 1244 | void |
| 1245 | exp_fold_tree_no_dot (etree_type *tree) |
| 1246 | { |
| 1247 | expld.rel_from_abs = FALSE; |
| 1248 | expld.dot = 0; |
| 1249 | expld.dotp = NULL; |
| 1250 | expld.section = bfd_abs_section_ptr; |
| 1251 | exp_fold_tree_1 (tree); |
| 1252 | } |
| 1253 | |
| 1254 | etree_type * |
| 1255 | exp_binop (int code, etree_type *lhs, etree_type *rhs) |
| 1256 | { |
| 1257 | etree_type value, *new_e; |
| 1258 | |
| 1259 | value.type.node_code = code; |
| 1260 | value.type.filename = lhs->type.filename; |
| 1261 | value.type.lineno = lhs->type.lineno; |
| 1262 | value.binary.lhs = lhs; |
| 1263 | value.binary.rhs = rhs; |
| 1264 | value.type.node_class = etree_binary; |
| 1265 | exp_fold_tree_no_dot (&value); |
| 1266 | if (expld.result.valid_p) |
| 1267 | return exp_intop (expld.result.value); |
| 1268 | |
| 1269 | new_e = (etree_type *) stat_alloc (sizeof (new_e->binary)); |
| 1270 | memcpy (new_e, &value, sizeof (new_e->binary)); |
| 1271 | return new_e; |
| 1272 | } |
| 1273 | |
| 1274 | etree_type * |
| 1275 | exp_trinop (int code, etree_type *cond, etree_type *lhs, etree_type *rhs) |
| 1276 | { |
| 1277 | etree_type value, *new_e; |
| 1278 | |
| 1279 | value.type.node_code = code; |
| 1280 | value.type.filename = cond->type.filename; |
| 1281 | value.type.lineno = cond->type.lineno; |
| 1282 | value.trinary.lhs = lhs; |
| 1283 | value.trinary.cond = cond; |
| 1284 | value.trinary.rhs = rhs; |
| 1285 | value.type.node_class = etree_trinary; |
| 1286 | exp_fold_tree_no_dot (&value); |
| 1287 | if (expld.result.valid_p) |
| 1288 | return exp_intop (expld.result.value); |
| 1289 | |
| 1290 | new_e = (etree_type *) stat_alloc (sizeof (new_e->trinary)); |
| 1291 | memcpy (new_e, &value, sizeof (new_e->trinary)); |
| 1292 | return new_e; |
| 1293 | } |
| 1294 | |
| 1295 | etree_type * |
| 1296 | exp_unop (int code, etree_type *child) |
| 1297 | { |
| 1298 | etree_type value, *new_e; |
| 1299 | |
| 1300 | value.unary.type.node_code = code; |
| 1301 | value.unary.type.filename = child->type.filename; |
| 1302 | value.unary.type.lineno = child->type.lineno; |
| 1303 | value.unary.child = child; |
| 1304 | value.unary.type.node_class = etree_unary; |
| 1305 | exp_fold_tree_no_dot (&value); |
| 1306 | if (expld.result.valid_p) |
| 1307 | return exp_intop (expld.result.value); |
| 1308 | |
| 1309 | new_e = (etree_type *) stat_alloc (sizeof (new_e->unary)); |
| 1310 | memcpy (new_e, &value, sizeof (new_e->unary)); |
| 1311 | return new_e; |
| 1312 | } |
| 1313 | |
| 1314 | etree_type * |
| 1315 | exp_nameop (int code, const char *name) |
| 1316 | { |
| 1317 | etree_type value, *new_e; |
| 1318 | |
| 1319 | value.name.type.node_code = code; |
| 1320 | value.name.type.filename = ldlex_filename (); |
| 1321 | value.name.type.lineno = lineno; |
| 1322 | value.name.name = name; |
| 1323 | value.name.type.node_class = etree_name; |
| 1324 | |
| 1325 | exp_fold_tree_no_dot (&value); |
| 1326 | if (expld.result.valid_p) |
| 1327 | return exp_intop (expld.result.value); |
| 1328 | |
| 1329 | new_e = (etree_type *) stat_alloc (sizeof (new_e->name)); |
| 1330 | memcpy (new_e, &value, sizeof (new_e->name)); |
| 1331 | return new_e; |
| 1332 | |
| 1333 | } |
| 1334 | |
| 1335 | static etree_type * |
| 1336 | exp_assop (const char *dst, |
| 1337 | etree_type *src, |
| 1338 | enum node_tree_enum class, |
| 1339 | bfd_boolean defsym, |
| 1340 | bfd_boolean hidden) |
| 1341 | { |
| 1342 | etree_type *n; |
| 1343 | |
| 1344 | n = (etree_type *) stat_alloc (sizeof (n->assign)); |
| 1345 | n->assign.type.node_code = '='; |
| 1346 | n->assign.type.filename = src->type.filename; |
| 1347 | n->assign.type.lineno = src->type.lineno; |
| 1348 | n->assign.type.node_class = class; |
| 1349 | n->assign.src = src; |
| 1350 | n->assign.dst = dst; |
| 1351 | n->assign.defsym = defsym; |
| 1352 | n->assign.hidden = hidden; |
| 1353 | return n; |
| 1354 | } |
| 1355 | |
| 1356 | /* Handle linker script assignments and HIDDEN. */ |
| 1357 | |
| 1358 | etree_type * |
| 1359 | exp_assign (const char *dst, etree_type *src, bfd_boolean hidden) |
| 1360 | { |
| 1361 | return exp_assop (dst, src, etree_assign, FALSE, hidden); |
| 1362 | } |
| 1363 | |
| 1364 | /* Handle --defsym command-line option. */ |
| 1365 | |
| 1366 | etree_type * |
| 1367 | exp_defsym (const char *dst, etree_type *src) |
| 1368 | { |
| 1369 | return exp_assop (dst, src, etree_assign, TRUE, FALSE); |
| 1370 | } |
| 1371 | |
| 1372 | /* Handle PROVIDE. */ |
| 1373 | |
| 1374 | etree_type * |
| 1375 | exp_provide (const char *dst, etree_type *src, bfd_boolean hidden) |
| 1376 | { |
| 1377 | return exp_assop (dst, src, etree_provide, FALSE, hidden); |
| 1378 | } |
| 1379 | |
| 1380 | /* Handle ASSERT. */ |
| 1381 | |
| 1382 | etree_type * |
| 1383 | exp_assert (etree_type *exp, const char *message) |
| 1384 | { |
| 1385 | etree_type *n; |
| 1386 | |
| 1387 | n = (etree_type *) stat_alloc (sizeof (n->assert_s)); |
| 1388 | n->assert_s.type.node_code = '!'; |
| 1389 | n->assert_s.type.filename = exp->type.filename; |
| 1390 | n->assert_s.type.lineno = exp->type.lineno; |
| 1391 | n->assert_s.type.node_class = etree_assert; |
| 1392 | n->assert_s.child = exp; |
| 1393 | n->assert_s.message = message; |
| 1394 | return n; |
| 1395 | } |
| 1396 | |
| 1397 | void |
| 1398 | exp_print_tree (etree_type *tree) |
| 1399 | { |
| 1400 | bfd_boolean function_like; |
| 1401 | |
| 1402 | if (config.map_file == NULL) |
| 1403 | config.map_file = stderr; |
| 1404 | |
| 1405 | if (tree == NULL) |
| 1406 | { |
| 1407 | minfo ("NULL TREE\n"); |
| 1408 | return; |
| 1409 | } |
| 1410 | |
| 1411 | switch (tree->type.node_class) |
| 1412 | { |
| 1413 | case etree_value: |
| 1414 | minfo ("0x%v", tree->value.value); |
| 1415 | return; |
| 1416 | case etree_rel: |
| 1417 | if (tree->rel.section->owner != NULL) |
| 1418 | minfo ("%B:", tree->rel.section->owner); |
| 1419 | minfo ("%s+0x%v", tree->rel.section->name, tree->rel.value); |
| 1420 | return; |
| 1421 | case etree_assign: |
| 1422 | fputs (tree->assign.dst, config.map_file); |
| 1423 | exp_print_token (tree->type.node_code, TRUE); |
| 1424 | exp_print_tree (tree->assign.src); |
| 1425 | break; |
| 1426 | case etree_provide: |
| 1427 | case etree_provided: |
| 1428 | fprintf (config.map_file, "PROVIDE (%s, ", tree->assign.dst); |
| 1429 | exp_print_tree (tree->assign.src); |
| 1430 | fputc (')', config.map_file); |
| 1431 | break; |
| 1432 | case etree_binary: |
| 1433 | function_like = FALSE; |
| 1434 | switch (tree->type.node_code) |
| 1435 | { |
| 1436 | case MAX_K: |
| 1437 | case MIN_K: |
| 1438 | case ALIGN_K: |
| 1439 | case DATA_SEGMENT_ALIGN: |
| 1440 | case DATA_SEGMENT_RELRO_END: |
| 1441 | function_like = TRUE; |
| 1442 | break; |
| 1443 | case SEGMENT_START: |
| 1444 | /* Special handling because arguments are in reverse order and |
| 1445 | the segment name is quoted. */ |
| 1446 | exp_print_token (tree->type.node_code, FALSE); |
| 1447 | fputs (" (\"", config.map_file); |
| 1448 | exp_print_tree (tree->binary.rhs); |
| 1449 | fputs ("\", ", config.map_file); |
| 1450 | exp_print_tree (tree->binary.lhs); |
| 1451 | fputc (')', config.map_file); |
| 1452 | return; |
| 1453 | } |
| 1454 | if (function_like) |
| 1455 | { |
| 1456 | exp_print_token (tree->type.node_code, FALSE); |
| 1457 | fputc (' ', config.map_file); |
| 1458 | } |
| 1459 | fputc ('(', config.map_file); |
| 1460 | exp_print_tree (tree->binary.lhs); |
| 1461 | if (function_like) |
| 1462 | fprintf (config.map_file, ", "); |
| 1463 | else |
| 1464 | exp_print_token (tree->type.node_code, TRUE); |
| 1465 | exp_print_tree (tree->binary.rhs); |
| 1466 | fputc (')', config.map_file); |
| 1467 | break; |
| 1468 | case etree_trinary: |
| 1469 | exp_print_tree (tree->trinary.cond); |
| 1470 | fputc ('?', config.map_file); |
| 1471 | exp_print_tree (tree->trinary.lhs); |
| 1472 | fputc (':', config.map_file); |
| 1473 | exp_print_tree (tree->trinary.rhs); |
| 1474 | break; |
| 1475 | case etree_unary: |
| 1476 | exp_print_token (tree->unary.type.node_code, FALSE); |
| 1477 | if (tree->unary.child) |
| 1478 | { |
| 1479 | fprintf (config.map_file, " ("); |
| 1480 | exp_print_tree (tree->unary.child); |
| 1481 | fputc (')', config.map_file); |
| 1482 | } |
| 1483 | break; |
| 1484 | |
| 1485 | case etree_assert: |
| 1486 | fprintf (config.map_file, "ASSERT ("); |
| 1487 | exp_print_tree (tree->assert_s.child); |
| 1488 | fprintf (config.map_file, ", %s)", tree->assert_s.message); |
| 1489 | break; |
| 1490 | |
| 1491 | case etree_name: |
| 1492 | if (tree->type.node_code == NAME) |
| 1493 | fputs (tree->name.name, config.map_file); |
| 1494 | else |
| 1495 | { |
| 1496 | exp_print_token (tree->type.node_code, FALSE); |
| 1497 | if (tree->name.name) |
| 1498 | fprintf (config.map_file, " (%s)", tree->name.name); |
| 1499 | } |
| 1500 | break; |
| 1501 | default: |
| 1502 | FAIL (); |
| 1503 | break; |
| 1504 | } |
| 1505 | } |
| 1506 | |
| 1507 | bfd_vma |
| 1508 | exp_get_vma (etree_type *tree, bfd_vma def, char *name) |
| 1509 | { |
| 1510 | if (tree != NULL) |
| 1511 | { |
| 1512 | exp_fold_tree_no_dot (tree); |
| 1513 | if (expld.result.valid_p) |
| 1514 | return expld.result.value; |
| 1515 | else if (name != NULL && expld.phase != lang_mark_phase_enum) |
| 1516 | einfo (_("%F%S: nonconstant expression for %s\n"), |
| 1517 | tree, name); |
| 1518 | } |
| 1519 | return def; |
| 1520 | } |
| 1521 | |
| 1522 | int |
| 1523 | exp_get_value_int (etree_type *tree, int def, char *name) |
| 1524 | { |
| 1525 | return exp_get_vma (tree, def, name); |
| 1526 | } |
| 1527 | |
| 1528 | fill_type * |
| 1529 | exp_get_fill (etree_type *tree, fill_type *def, char *name) |
| 1530 | { |
| 1531 | fill_type *fill; |
| 1532 | size_t len; |
| 1533 | unsigned int val; |
| 1534 | |
| 1535 | if (tree == NULL) |
| 1536 | return def; |
| 1537 | |
| 1538 | exp_fold_tree_no_dot (tree); |
| 1539 | if (!expld.result.valid_p) |
| 1540 | { |
| 1541 | if (name != NULL && expld.phase != lang_mark_phase_enum) |
| 1542 | einfo (_("%F%S: nonconstant expression for %s\n"), |
| 1543 | tree, name); |
| 1544 | return def; |
| 1545 | } |
| 1546 | |
| 1547 | if (expld.result.str != NULL && (len = strlen (expld.result.str)) != 0) |
| 1548 | { |
| 1549 | unsigned char *dst; |
| 1550 | unsigned char *s; |
| 1551 | fill = (fill_type *) xmalloc ((len + 1) / 2 + sizeof (*fill) - 1); |
| 1552 | fill->size = (len + 1) / 2; |
| 1553 | dst = fill->data; |
| 1554 | s = (unsigned char *) expld.result.str; |
| 1555 | val = 0; |
| 1556 | do |
| 1557 | { |
| 1558 | unsigned int digit; |
| 1559 | |
| 1560 | digit = *s++ - '0'; |
| 1561 | if (digit > 9) |
| 1562 | digit = (digit - 'A' + '0' + 10) & 0xf; |
| 1563 | val <<= 4; |
| 1564 | val += digit; |
| 1565 | --len; |
| 1566 | if ((len & 1) == 0) |
| 1567 | { |
| 1568 | *dst++ = val; |
| 1569 | val = 0; |
| 1570 | } |
| 1571 | } |
| 1572 | while (len != 0); |
| 1573 | } |
| 1574 | else |
| 1575 | { |
| 1576 | fill = (fill_type *) xmalloc (4 + sizeof (*fill) - 1); |
| 1577 | val = expld.result.value; |
| 1578 | fill->data[0] = (val >> 24) & 0xff; |
| 1579 | fill->data[1] = (val >> 16) & 0xff; |
| 1580 | fill->data[2] = (val >> 8) & 0xff; |
| 1581 | fill->data[3] = (val >> 0) & 0xff; |
| 1582 | fill->size = 4; |
| 1583 | } |
| 1584 | return fill; |
| 1585 | } |
| 1586 | |
| 1587 | bfd_vma |
| 1588 | exp_get_abs_int (etree_type *tree, int def, char *name) |
| 1589 | { |
| 1590 | if (tree != NULL) |
| 1591 | { |
| 1592 | exp_fold_tree_no_dot (tree); |
| 1593 | |
| 1594 | if (expld.result.valid_p) |
| 1595 | { |
| 1596 | if (expld.result.section != NULL) |
| 1597 | expld.result.value += expld.result.section->vma; |
| 1598 | return expld.result.value; |
| 1599 | } |
| 1600 | else if (name != NULL && expld.phase != lang_mark_phase_enum) |
| 1601 | { |
| 1602 | einfo (_("%F%S: nonconstant expression for %s\n"), |
| 1603 | tree, name); |
| 1604 | } |
| 1605 | } |
| 1606 | return def; |
| 1607 | } |
| 1608 | |
| 1609 | static bfd_vma |
| 1610 | align_n (bfd_vma value, bfd_vma align) |
| 1611 | { |
| 1612 | if (align <= 1) |
| 1613 | return value; |
| 1614 | |
| 1615 | value = (value + align - 1) / align; |
| 1616 | return value * align; |
| 1617 | } |
| 1618 | |
| 1619 | void |
| 1620 | ldexp_init (void) |
| 1621 | { |
| 1622 | /* The value "13" is ad-hoc, somewhat related to the expected number of |
| 1623 | assignments in a linker script. */ |
| 1624 | if (!bfd_hash_table_init_n (&definedness_table, |
| 1625 | definedness_newfunc, |
| 1626 | sizeof (struct definedness_hash_entry), |
| 1627 | 13)) |
| 1628 | einfo (_("%P%F: can not create hash table: %E\n")); |
| 1629 | } |
| 1630 | |
| 1631 | /* Convert absolute symbols defined by a script from "dot" (also |
| 1632 | SEGMENT_START or ORIGIN) outside of an output section statement, |
| 1633 | to section relative. */ |
| 1634 | |
| 1635 | static bfd_boolean |
| 1636 | set_sym_sections (struct bfd_hash_entry *bh, void *inf ATTRIBUTE_UNUSED) |
| 1637 | { |
| 1638 | struct definedness_hash_entry *def = (struct definedness_hash_entry *) bh; |
| 1639 | if (def->final_sec != bfd_abs_section_ptr) |
| 1640 | { |
| 1641 | struct bfd_link_hash_entry *h; |
| 1642 | h = bfd_link_hash_lookup (link_info.hash, bh->string, |
| 1643 | FALSE, FALSE, TRUE); |
| 1644 | if (h != NULL |
| 1645 | && h->type == bfd_link_hash_defined |
| 1646 | && h->u.def.section == bfd_abs_section_ptr) |
| 1647 | { |
| 1648 | h->u.def.value -= def->final_sec->vma; |
| 1649 | h->u.def.section = def->final_sec; |
| 1650 | } |
| 1651 | } |
| 1652 | return TRUE; |
| 1653 | } |
| 1654 | |
| 1655 | void |
| 1656 | ldexp_finalize_syms (void) |
| 1657 | { |
| 1658 | bfd_hash_traverse (&definedness_table, set_sym_sections, NULL); |
| 1659 | } |
| 1660 | |
| 1661 | void |
| 1662 | ldexp_finish (void) |
| 1663 | { |
| 1664 | bfd_hash_table_free (&definedness_table); |
| 1665 | } |