| 1 | // expression.cc -- expressions in linker scripts for gold |
| 2 | |
| 3 | // Copyright 2006, 2007, 2008 Free Software Foundation, Inc. |
| 4 | // Written by Ian Lance Taylor <iant@google.com>. |
| 5 | |
| 6 | // This file is part of gold. |
| 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 3 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., 51 Franklin Street - Fifth Floor, Boston, |
| 21 | // MA 02110-1301, USA. |
| 22 | |
| 23 | #include "gold.h" |
| 24 | |
| 25 | #include <string> |
| 26 | |
| 27 | #include "elfcpp.h" |
| 28 | #include "parameters.h" |
| 29 | #include "symtab.h" |
| 30 | #include "layout.h" |
| 31 | #include "output.h" |
| 32 | #include "script.h" |
| 33 | #include "script-c.h" |
| 34 | |
| 35 | namespace gold |
| 36 | { |
| 37 | |
| 38 | // This file holds the code which handles linker expressions. |
| 39 | |
| 40 | // The dot symbol, which linker scripts refer to simply as ".", |
| 41 | // requires special treatment. The dot symbol is set several times, |
| 42 | // section addresses will refer to it, output sections will change it, |
| 43 | // and it can be set based on the value of other symbols. We simplify |
| 44 | // the handling by prohibiting setting the dot symbol to the value of |
| 45 | // a non-absolute symbol. |
| 46 | |
| 47 | // When evaluating the value of an expression, we pass in a pointer to |
| 48 | // this struct, so that the expression evaluation can find the |
| 49 | // information it needs. |
| 50 | |
| 51 | struct Expression::Expression_eval_info |
| 52 | { |
| 53 | // The symbol table. |
| 54 | const Symbol_table* symtab; |
| 55 | // The layout--we use this to get section information. |
| 56 | const Layout* layout; |
| 57 | // Whether to check assertions. |
| 58 | bool check_assertions; |
| 59 | // Whether expressions can refer to the dot symbol. The dot symbol |
| 60 | // is only available within a SECTIONS clause. |
| 61 | bool is_dot_available; |
| 62 | // The current value of the dot symbol. |
| 63 | uint64_t dot_value; |
| 64 | // The section in which the dot symbol is defined; this is NULL if |
| 65 | // it is absolute. |
| 66 | Output_section* dot_section; |
| 67 | // Points to where the section of the result should be stored. |
| 68 | Output_section** result_section_pointer; |
| 69 | }; |
| 70 | |
| 71 | // Evaluate an expression. |
| 72 | |
| 73 | uint64_t |
| 74 | Expression::eval(const Symbol_table* symtab, const Layout* layout, |
| 75 | bool check_assertions) |
| 76 | { |
| 77 | Output_section* dummy; |
| 78 | return this->eval_maybe_dot(symtab, layout, check_assertions, |
| 79 | false, 0, NULL, &dummy); |
| 80 | } |
| 81 | |
| 82 | // Evaluate an expression which may refer to the dot symbol. |
| 83 | |
| 84 | uint64_t |
| 85 | Expression::eval_with_dot(const Symbol_table* symtab, const Layout* layout, |
| 86 | bool check_assertions, uint64_t dot_value, |
| 87 | Output_section* dot_section, |
| 88 | Output_section** result_section_pointer) |
| 89 | { |
| 90 | return this->eval_maybe_dot(symtab, layout, check_assertions, true, |
| 91 | dot_value, dot_section, result_section_pointer); |
| 92 | } |
| 93 | |
| 94 | // Evaluate an expression which may or may not refer to the dot |
| 95 | // symbol. |
| 96 | |
| 97 | uint64_t |
| 98 | Expression::eval_maybe_dot(const Symbol_table* symtab, const Layout* layout, |
| 99 | bool check_assertions, bool is_dot_available, |
| 100 | uint64_t dot_value, Output_section* dot_section, |
| 101 | Output_section** result_section_pointer) |
| 102 | { |
| 103 | Expression_eval_info eei; |
| 104 | eei.symtab = symtab; |
| 105 | eei.layout = layout; |
| 106 | eei.check_assertions = check_assertions; |
| 107 | eei.is_dot_available = is_dot_available; |
| 108 | eei.dot_value = dot_value; |
| 109 | eei.dot_section = dot_section; |
| 110 | |
| 111 | // We assume the value is absolute, and only set this to a section |
| 112 | // if we find a section relative reference. |
| 113 | *result_section_pointer = NULL; |
| 114 | eei.result_section_pointer = result_section_pointer; |
| 115 | |
| 116 | return this->value(&eei); |
| 117 | } |
| 118 | |
| 119 | // A number. |
| 120 | |
| 121 | class Integer_expression : public Expression |
| 122 | { |
| 123 | public: |
| 124 | Integer_expression(uint64_t val) |
| 125 | : val_(val) |
| 126 | { } |
| 127 | |
| 128 | uint64_t |
| 129 | value(const Expression_eval_info*) |
| 130 | { return this->val_; } |
| 131 | |
| 132 | void |
| 133 | print(FILE* f) const |
| 134 | { fprintf(f, "0x%llx", static_cast<unsigned long long>(this->val_)); } |
| 135 | |
| 136 | private: |
| 137 | uint64_t val_; |
| 138 | }; |
| 139 | |
| 140 | extern "C" Expression* |
| 141 | script_exp_integer(uint64_t val) |
| 142 | { |
| 143 | return new Integer_expression(val); |
| 144 | } |
| 145 | |
| 146 | // An expression whose value is the value of a symbol. |
| 147 | |
| 148 | class Symbol_expression : public Expression |
| 149 | { |
| 150 | public: |
| 151 | Symbol_expression(const char* name, size_t length) |
| 152 | : name_(name, length) |
| 153 | { } |
| 154 | |
| 155 | uint64_t |
| 156 | value(const Expression_eval_info*); |
| 157 | |
| 158 | void |
| 159 | print(FILE* f) const |
| 160 | { fprintf(f, "%s", this->name_.c_str()); } |
| 161 | |
| 162 | private: |
| 163 | std::string name_; |
| 164 | }; |
| 165 | |
| 166 | uint64_t |
| 167 | Symbol_expression::value(const Expression_eval_info* eei) |
| 168 | { |
| 169 | Symbol* sym = eei->symtab->lookup(this->name_.c_str()); |
| 170 | if (sym == NULL || !sym->is_defined()) |
| 171 | { |
| 172 | gold_error(_("undefined symbol '%s' referenced in expression"), |
| 173 | this->name_.c_str()); |
| 174 | return 0; |
| 175 | } |
| 176 | |
| 177 | *eei->result_section_pointer = sym->output_section(); |
| 178 | |
| 179 | if (parameters->target().get_size() == 32) |
| 180 | return eei->symtab->get_sized_symbol<32>(sym)->value(); |
| 181 | else if (parameters->target().get_size() == 64) |
| 182 | return eei->symtab->get_sized_symbol<64>(sym)->value(); |
| 183 | else |
| 184 | gold_unreachable(); |
| 185 | } |
| 186 | |
| 187 | // An expression whose value is the value of the special symbol ".". |
| 188 | // This is only valid within a SECTIONS clause. |
| 189 | |
| 190 | class Dot_expression : public Expression |
| 191 | { |
| 192 | public: |
| 193 | Dot_expression() |
| 194 | { } |
| 195 | |
| 196 | uint64_t |
| 197 | value(const Expression_eval_info*); |
| 198 | |
| 199 | void |
| 200 | print(FILE* f) const |
| 201 | { fprintf(f, "."); } |
| 202 | }; |
| 203 | |
| 204 | uint64_t |
| 205 | Dot_expression::value(const Expression_eval_info* eei) |
| 206 | { |
| 207 | if (!eei->is_dot_available) |
| 208 | { |
| 209 | gold_error(_("invalid reference to dot symbol outside of " |
| 210 | "SECTIONS clause")); |
| 211 | return 0; |
| 212 | } |
| 213 | *eei->result_section_pointer = eei->dot_section; |
| 214 | return eei->dot_value; |
| 215 | } |
| 216 | |
| 217 | // A string. This is either the name of a symbol, or ".". |
| 218 | |
| 219 | extern "C" Expression* |
| 220 | script_exp_string(const char* name, size_t length) |
| 221 | { |
| 222 | if (length == 1 && name[0] == '.') |
| 223 | return new Dot_expression(); |
| 224 | else |
| 225 | return new Symbol_expression(name, length); |
| 226 | } |
| 227 | |
| 228 | // A unary expression. |
| 229 | |
| 230 | class Unary_expression : public Expression |
| 231 | { |
| 232 | public: |
| 233 | Unary_expression(Expression* arg) |
| 234 | : arg_(arg) |
| 235 | { } |
| 236 | |
| 237 | ~Unary_expression() |
| 238 | { delete this->arg_; } |
| 239 | |
| 240 | protected: |
| 241 | uint64_t |
| 242 | arg_value(const Expression_eval_info* eei, |
| 243 | Output_section** arg_section_pointer) const |
| 244 | { |
| 245 | return this->arg_->eval_maybe_dot(eei->symtab, eei->layout, |
| 246 | eei->check_assertions, |
| 247 | eei->is_dot_available, |
| 248 | eei->dot_value, |
| 249 | eei->dot_section, |
| 250 | arg_section_pointer); |
| 251 | } |
| 252 | |
| 253 | void |
| 254 | arg_print(FILE* f) const |
| 255 | { this->arg_->print(f); } |
| 256 | |
| 257 | private: |
| 258 | Expression* arg_; |
| 259 | }; |
| 260 | |
| 261 | // Handle unary operators. We use a preprocessor macro as a hack to |
| 262 | // capture the C operator. |
| 263 | |
| 264 | #define UNARY_EXPRESSION(NAME, OPERATOR) \ |
| 265 | class Unary_ ## NAME : public Unary_expression \ |
| 266 | { \ |
| 267 | public: \ |
| 268 | Unary_ ## NAME(Expression* arg) \ |
| 269 | : Unary_expression(arg) \ |
| 270 | { } \ |
| 271 | \ |
| 272 | uint64_t \ |
| 273 | value(const Expression_eval_info* eei) \ |
| 274 | { \ |
| 275 | Output_section* arg_section; \ |
| 276 | uint64_t ret = OPERATOR this->arg_value(eei, &arg_section); \ |
| 277 | if (arg_section != NULL && parameters->options().relocatable()) \ |
| 278 | gold_warning(_("unary " #NAME " applied to section " \ |
| 279 | "relative value")); \ |
| 280 | return ret; \ |
| 281 | } \ |
| 282 | \ |
| 283 | void \ |
| 284 | print(FILE* f) const \ |
| 285 | { \ |
| 286 | fprintf(f, "(%s ", #OPERATOR); \ |
| 287 | this->arg_print(f); \ |
| 288 | fprintf(f, ")"); \ |
| 289 | } \ |
| 290 | }; \ |
| 291 | \ |
| 292 | extern "C" Expression* \ |
| 293 | script_exp_unary_ ## NAME(Expression* arg) \ |
| 294 | { \ |
| 295 | return new Unary_ ## NAME(arg); \ |
| 296 | } |
| 297 | |
| 298 | UNARY_EXPRESSION(minus, -) |
| 299 | UNARY_EXPRESSION(logical_not, !) |
| 300 | UNARY_EXPRESSION(bitwise_not, ~) |
| 301 | |
| 302 | // A binary expression. |
| 303 | |
| 304 | class Binary_expression : public Expression |
| 305 | { |
| 306 | public: |
| 307 | Binary_expression(Expression* left, Expression* right) |
| 308 | : left_(left), right_(right) |
| 309 | { } |
| 310 | |
| 311 | ~Binary_expression() |
| 312 | { |
| 313 | delete this->left_; |
| 314 | delete this->right_; |
| 315 | } |
| 316 | |
| 317 | protected: |
| 318 | uint64_t |
| 319 | left_value(const Expression_eval_info* eei, |
| 320 | Output_section** section_pointer) const |
| 321 | { |
| 322 | return this->left_->eval_maybe_dot(eei->symtab, eei->layout, |
| 323 | eei->check_assertions, |
| 324 | eei->is_dot_available, |
| 325 | eei->dot_value, |
| 326 | eei->dot_section, |
| 327 | section_pointer); |
| 328 | } |
| 329 | |
| 330 | uint64_t |
| 331 | right_value(const Expression_eval_info* eei, |
| 332 | Output_section** section_pointer) const |
| 333 | { |
| 334 | return this->right_->eval_maybe_dot(eei->symtab, eei->layout, |
| 335 | eei->check_assertions, |
| 336 | eei->is_dot_available, |
| 337 | eei->dot_value, |
| 338 | eei->dot_section, |
| 339 | section_pointer); |
| 340 | } |
| 341 | |
| 342 | void |
| 343 | left_print(FILE* f) const |
| 344 | { this->left_->print(f); } |
| 345 | |
| 346 | void |
| 347 | right_print(FILE* f) const |
| 348 | { this->right_->print(f); } |
| 349 | |
| 350 | // This is a call to function FUNCTION_NAME. Print it. This is for |
| 351 | // debugging. |
| 352 | void |
| 353 | print_function(FILE* f, const char *function_name) const |
| 354 | { |
| 355 | fprintf(f, "%s(", function_name); |
| 356 | this->left_print(f); |
| 357 | fprintf(f, ", "); |
| 358 | this->right_print(f); |
| 359 | fprintf(f, ")"); |
| 360 | } |
| 361 | |
| 362 | private: |
| 363 | Expression* left_; |
| 364 | Expression* right_; |
| 365 | }; |
| 366 | |
| 367 | // Handle binary operators. We use a preprocessor macro as a hack to |
| 368 | // capture the C operator. KEEP_LEFT means that if the left operand |
| 369 | // is section relative and the right operand is not, the result uses |
| 370 | // the same section as the left operand. KEEP_RIGHT is the same with |
| 371 | // left and right swapped. IS_DIV means that we need to give an error |
| 372 | // if the right operand is zero. WARN means that we should warn if |
| 373 | // used on section relative values in a relocatable link. We always |
| 374 | // warn if used on values in different sections in a relocatable link. |
| 375 | |
| 376 | #define BINARY_EXPRESSION(NAME, OPERATOR, KEEP_LEFT, KEEP_RIGHT, IS_DIV, WARN) \ |
| 377 | class Binary_ ## NAME : public Binary_expression \ |
| 378 | { \ |
| 379 | public: \ |
| 380 | Binary_ ## NAME(Expression* left, Expression* right) \ |
| 381 | : Binary_expression(left, right) \ |
| 382 | { } \ |
| 383 | \ |
| 384 | uint64_t \ |
| 385 | value(const Expression_eval_info* eei) \ |
| 386 | { \ |
| 387 | Output_section* left_section; \ |
| 388 | uint64_t left = this->left_value(eei, &left_section); \ |
| 389 | Output_section* right_section; \ |
| 390 | uint64_t right = this->right_value(eei, &right_section); \ |
| 391 | if (KEEP_RIGHT && left_section == NULL && right_section != NULL) \ |
| 392 | *eei->result_section_pointer = right_section; \ |
| 393 | else if (KEEP_LEFT \ |
| 394 | && left_section != NULL \ |
| 395 | && right_section == NULL) \ |
| 396 | *eei->result_section_pointer = left_section; \ |
| 397 | else if ((WARN || left_section != right_section) \ |
| 398 | && (left_section != NULL || right_section != NULL) \ |
| 399 | && parameters->options().relocatable()) \ |
| 400 | gold_warning(_("binary " #NAME " applied to section " \ |
| 401 | "relative value")); \ |
| 402 | if (IS_DIV && right == 0) \ |
| 403 | { \ |
| 404 | gold_error(_(#NAME " by zero")); \ |
| 405 | return 0; \ |
| 406 | } \ |
| 407 | return left OPERATOR right; \ |
| 408 | } \ |
| 409 | \ |
| 410 | void \ |
| 411 | print(FILE* f) const \ |
| 412 | { \ |
| 413 | fprintf(f, "("); \ |
| 414 | this->left_print(f); \ |
| 415 | fprintf(f, " %s ", #OPERATOR); \ |
| 416 | this->right_print(f); \ |
| 417 | fprintf(f, ")"); \ |
| 418 | } \ |
| 419 | }; \ |
| 420 | \ |
| 421 | extern "C" Expression* \ |
| 422 | script_exp_binary_ ## NAME(Expression* left, Expression* right) \ |
| 423 | { \ |
| 424 | return new Binary_ ## NAME(left, right); \ |
| 425 | } |
| 426 | |
| 427 | BINARY_EXPRESSION(mult, *, false, false, false, true) |
| 428 | BINARY_EXPRESSION(div, /, false, false, true, true) |
| 429 | BINARY_EXPRESSION(mod, %, false, false, true, true) |
| 430 | BINARY_EXPRESSION(add, +, true, true, false, true) |
| 431 | BINARY_EXPRESSION(sub, -, true, false, false, false) |
| 432 | BINARY_EXPRESSION(lshift, <<, false, false, false, true) |
| 433 | BINARY_EXPRESSION(rshift, >>, false, false, false, true) |
| 434 | BINARY_EXPRESSION(eq, ==, false, false, false, false) |
| 435 | BINARY_EXPRESSION(ne, !=, false, false, false, false) |
| 436 | BINARY_EXPRESSION(le, <=, false, false, false, false) |
| 437 | BINARY_EXPRESSION(ge, >=, false, false, false, false) |
| 438 | BINARY_EXPRESSION(lt, <, false, false, false, false) |
| 439 | BINARY_EXPRESSION(gt, >, false, false, false, false) |
| 440 | BINARY_EXPRESSION(bitwise_and, &, true, true, false, true) |
| 441 | BINARY_EXPRESSION(bitwise_xor, ^, true, true, false, true) |
| 442 | BINARY_EXPRESSION(bitwise_or, |, true, true, false, true) |
| 443 | BINARY_EXPRESSION(logical_and, &&, false, false, false, true) |
| 444 | BINARY_EXPRESSION(logical_or, ||, false, false, false, true) |
| 445 | |
| 446 | // A trinary expression. |
| 447 | |
| 448 | class Trinary_expression : public Expression |
| 449 | { |
| 450 | public: |
| 451 | Trinary_expression(Expression* arg1, Expression* arg2, Expression* arg3) |
| 452 | : arg1_(arg1), arg2_(arg2), arg3_(arg3) |
| 453 | { } |
| 454 | |
| 455 | ~Trinary_expression() |
| 456 | { |
| 457 | delete this->arg1_; |
| 458 | delete this->arg2_; |
| 459 | delete this->arg3_; |
| 460 | } |
| 461 | |
| 462 | protected: |
| 463 | uint64_t |
| 464 | arg1_value(const Expression_eval_info* eei, |
| 465 | Output_section** section_pointer) const |
| 466 | { |
| 467 | return this->arg1_->eval_maybe_dot(eei->symtab, eei->layout, |
| 468 | eei->check_assertions, |
| 469 | eei->is_dot_available, |
| 470 | eei->dot_value, |
| 471 | eei->dot_section, |
| 472 | section_pointer); |
| 473 | } |
| 474 | |
| 475 | uint64_t |
| 476 | arg2_value(const Expression_eval_info* eei, |
| 477 | Output_section** section_pointer) const |
| 478 | { |
| 479 | return this->arg1_->eval_maybe_dot(eei->symtab, eei->layout, |
| 480 | eei->check_assertions, |
| 481 | eei->is_dot_available, |
| 482 | eei->dot_value, |
| 483 | eei->dot_section, |
| 484 | section_pointer); |
| 485 | } |
| 486 | |
| 487 | uint64_t |
| 488 | arg3_value(const Expression_eval_info* eei, |
| 489 | Output_section** section_pointer) const |
| 490 | { |
| 491 | return this->arg1_->eval_maybe_dot(eei->symtab, eei->layout, |
| 492 | eei->check_assertions, |
| 493 | eei->is_dot_available, |
| 494 | eei->dot_value, |
| 495 | eei->dot_section, |
| 496 | section_pointer); |
| 497 | } |
| 498 | |
| 499 | void |
| 500 | arg1_print(FILE* f) const |
| 501 | { this->arg1_->print(f); } |
| 502 | |
| 503 | void |
| 504 | arg2_print(FILE* f) const |
| 505 | { this->arg2_->print(f); } |
| 506 | |
| 507 | void |
| 508 | arg3_print(FILE* f) const |
| 509 | { this->arg3_->print(f); } |
| 510 | |
| 511 | private: |
| 512 | Expression* arg1_; |
| 513 | Expression* arg2_; |
| 514 | Expression* arg3_; |
| 515 | }; |
| 516 | |
| 517 | // The conditional operator. |
| 518 | |
| 519 | class Trinary_cond : public Trinary_expression |
| 520 | { |
| 521 | public: |
| 522 | Trinary_cond(Expression* arg1, Expression* arg2, Expression* arg3) |
| 523 | : Trinary_expression(arg1, arg2, arg3) |
| 524 | { } |
| 525 | |
| 526 | uint64_t |
| 527 | value(const Expression_eval_info* eei) |
| 528 | { |
| 529 | Output_section* arg1_section; |
| 530 | uint64_t arg1 = this->arg1_value(eei, &arg1_section); |
| 531 | return (arg1 |
| 532 | ? this->arg2_value(eei, eei->result_section_pointer) |
| 533 | : this->arg3_value(eei, eei->result_section_pointer)); |
| 534 | } |
| 535 | |
| 536 | void |
| 537 | print(FILE* f) const |
| 538 | { |
| 539 | fprintf(f, "("); |
| 540 | this->arg1_print(f); |
| 541 | fprintf(f, " ? "); |
| 542 | this->arg2_print(f); |
| 543 | fprintf(f, " : "); |
| 544 | this->arg3_print(f); |
| 545 | fprintf(f, ")"); |
| 546 | } |
| 547 | }; |
| 548 | |
| 549 | extern "C" Expression* |
| 550 | script_exp_trinary_cond(Expression* arg1, Expression* arg2, Expression* arg3) |
| 551 | { |
| 552 | return new Trinary_cond(arg1, arg2, arg3); |
| 553 | } |
| 554 | |
| 555 | // Max function. |
| 556 | |
| 557 | class Max_expression : public Binary_expression |
| 558 | { |
| 559 | public: |
| 560 | Max_expression(Expression* left, Expression* right) |
| 561 | : Binary_expression(left, right) |
| 562 | { } |
| 563 | |
| 564 | uint64_t |
| 565 | value(const Expression_eval_info* eei) |
| 566 | { |
| 567 | Output_section* left_section; |
| 568 | uint64_t left = this->left_value(eei, &left_section); |
| 569 | Output_section* right_section; |
| 570 | uint64_t right = this->right_value(eei, &right_section); |
| 571 | if (left_section == right_section) |
| 572 | *eei->result_section_pointer = left_section; |
| 573 | else if ((left_section != NULL || right_section != NULL) |
| 574 | && parameters->options().relocatable()) |
| 575 | gold_warning(_("max applied to section relative value")); |
| 576 | return std::max(left, right); |
| 577 | } |
| 578 | |
| 579 | void |
| 580 | print(FILE* f) const |
| 581 | { this->print_function(f, "MAX"); } |
| 582 | }; |
| 583 | |
| 584 | extern "C" Expression* |
| 585 | script_exp_function_max(Expression* left, Expression* right) |
| 586 | { |
| 587 | return new Max_expression(left, right); |
| 588 | } |
| 589 | |
| 590 | // Min function. |
| 591 | |
| 592 | class Min_expression : public Binary_expression |
| 593 | { |
| 594 | public: |
| 595 | Min_expression(Expression* left, Expression* right) |
| 596 | : Binary_expression(left, right) |
| 597 | { } |
| 598 | |
| 599 | uint64_t |
| 600 | value(const Expression_eval_info* eei) |
| 601 | { |
| 602 | Output_section* left_section; |
| 603 | uint64_t left = this->left_value(eei, &left_section); |
| 604 | Output_section* right_section; |
| 605 | uint64_t right = this->right_value(eei, &right_section); |
| 606 | if (left_section == right_section) |
| 607 | *eei->result_section_pointer = left_section; |
| 608 | else if ((left_section != NULL || right_section != NULL) |
| 609 | && parameters->options().relocatable()) |
| 610 | gold_warning(_("min applied to section relative value")); |
| 611 | return std::min(left, right); |
| 612 | } |
| 613 | |
| 614 | void |
| 615 | print(FILE* f) const |
| 616 | { this->print_function(f, "MIN"); } |
| 617 | }; |
| 618 | |
| 619 | extern "C" Expression* |
| 620 | script_exp_function_min(Expression* left, Expression* right) |
| 621 | { |
| 622 | return new Min_expression(left, right); |
| 623 | } |
| 624 | |
| 625 | // Class Section_expression. This is a parent class used for |
| 626 | // functions which take the name of an output section. |
| 627 | |
| 628 | class Section_expression : public Expression |
| 629 | { |
| 630 | public: |
| 631 | Section_expression(const char* section_name, size_t section_name_len) |
| 632 | : section_name_(section_name, section_name_len) |
| 633 | { } |
| 634 | |
| 635 | uint64_t |
| 636 | value(const Expression_eval_info*); |
| 637 | |
| 638 | void |
| 639 | print(FILE* f) const |
| 640 | { fprintf(f, "%s(%s)", this->function_name(), this->section_name_.c_str()); } |
| 641 | |
| 642 | protected: |
| 643 | // The child class must implement this. |
| 644 | virtual uint64_t |
| 645 | value_from_output_section(const Expression_eval_info*, |
| 646 | Output_section*) = 0; |
| 647 | |
| 648 | // The child class must implement this. |
| 649 | virtual uint64_t |
| 650 | value_from_script_output_section(uint64_t address, uint64_t load_address, |
| 651 | uint64_t addralign, uint64_t size) = 0; |
| 652 | |
| 653 | // The child class must implement this. |
| 654 | virtual const char* |
| 655 | function_name() const = 0; |
| 656 | |
| 657 | private: |
| 658 | std::string section_name_; |
| 659 | }; |
| 660 | |
| 661 | uint64_t |
| 662 | Section_expression::value(const Expression_eval_info* eei) |
| 663 | { |
| 664 | const char* section_name = this->section_name_.c_str(); |
| 665 | Output_section* os = eei->layout->find_output_section(section_name); |
| 666 | if (os != NULL) |
| 667 | return this->value_from_output_section(eei, os); |
| 668 | |
| 669 | uint64_t address; |
| 670 | uint64_t load_address; |
| 671 | uint64_t addralign; |
| 672 | uint64_t size; |
| 673 | const Script_options* ss = eei->layout->script_options(); |
| 674 | if (ss->saw_sections_clause()) |
| 675 | { |
| 676 | if (ss->script_sections()->get_output_section_info(section_name, |
| 677 | &address, |
| 678 | &load_address, |
| 679 | &addralign, |
| 680 | &size)) |
| 681 | return this->value_from_script_output_section(address, load_address, |
| 682 | addralign, size); |
| 683 | } |
| 684 | |
| 685 | gold_error("%s called on nonexistent output section '%s'", |
| 686 | this->function_name(), section_name); |
| 687 | return 0; |
| 688 | } |
| 689 | |
| 690 | // ABSOLUTE function. |
| 691 | |
| 692 | class Absolute_expression : public Unary_expression |
| 693 | { |
| 694 | public: |
| 695 | Absolute_expression(Expression* arg) |
| 696 | : Unary_expression(arg) |
| 697 | { } |
| 698 | |
| 699 | uint64_t |
| 700 | value(const Expression_eval_info* eei) |
| 701 | { |
| 702 | Output_section* dummy; |
| 703 | uint64_t ret = this->arg_value(eei, &dummy); |
| 704 | // Force the value to be absolute. |
| 705 | *eei->result_section_pointer = NULL; |
| 706 | return ret; |
| 707 | } |
| 708 | |
| 709 | void |
| 710 | print(FILE* f) const |
| 711 | { |
| 712 | fprintf(f, "ABSOLUTE("); |
| 713 | this->arg_print(f); |
| 714 | fprintf(f, ")"); |
| 715 | } |
| 716 | }; |
| 717 | |
| 718 | extern "C" Expression* |
| 719 | script_exp_function_absolute(Expression* arg) |
| 720 | { |
| 721 | return new Absolute_expression(arg); |
| 722 | } |
| 723 | |
| 724 | // ALIGN function. |
| 725 | |
| 726 | class Align_expression : public Binary_expression |
| 727 | { |
| 728 | public: |
| 729 | Align_expression(Expression* left, Expression* right) |
| 730 | : Binary_expression(left, right) |
| 731 | { } |
| 732 | |
| 733 | uint64_t |
| 734 | value(const Expression_eval_info* eei) |
| 735 | { |
| 736 | Output_section* align_section; |
| 737 | uint64_t align = this->right_value(eei, &align_section); |
| 738 | if (align_section != NULL |
| 739 | && parameters->options().relocatable()) |
| 740 | gold_warning(_("aligning to section relative value")); |
| 741 | |
| 742 | uint64_t value = this->left_value(eei, eei->result_section_pointer); |
| 743 | if (align <= 1) |
| 744 | return value; |
| 745 | return ((value + align - 1) / align) * align; |
| 746 | } |
| 747 | |
| 748 | void |
| 749 | print(FILE* f) const |
| 750 | { this->print_function(f, "ALIGN"); } |
| 751 | }; |
| 752 | |
| 753 | extern "C" Expression* |
| 754 | script_exp_function_align(Expression* left, Expression* right) |
| 755 | { |
| 756 | return new Align_expression(left, right); |
| 757 | } |
| 758 | |
| 759 | // ASSERT function. |
| 760 | |
| 761 | class Assert_expression : public Unary_expression |
| 762 | { |
| 763 | public: |
| 764 | Assert_expression(Expression* arg, const char* message, size_t length) |
| 765 | : Unary_expression(arg), message_(message, length) |
| 766 | { } |
| 767 | |
| 768 | uint64_t |
| 769 | value(const Expression_eval_info* eei) |
| 770 | { |
| 771 | uint64_t value = this->arg_value(eei, eei->result_section_pointer); |
| 772 | if (!value && eei->check_assertions) |
| 773 | gold_error("%s", this->message_.c_str()); |
| 774 | return value; |
| 775 | } |
| 776 | |
| 777 | void |
| 778 | print(FILE* f) const |
| 779 | { |
| 780 | fprintf(f, "ASSERT("); |
| 781 | this->arg_print(f); |
| 782 | fprintf(f, ", %s)", this->message_.c_str()); |
| 783 | } |
| 784 | |
| 785 | private: |
| 786 | std::string message_; |
| 787 | }; |
| 788 | |
| 789 | extern "C" Expression* |
| 790 | script_exp_function_assert(Expression* expr, const char* message, |
| 791 | size_t length) |
| 792 | { |
| 793 | return new Assert_expression(expr, message, length); |
| 794 | } |
| 795 | |
| 796 | // ADDR function. |
| 797 | |
| 798 | class Addr_expression : public Section_expression |
| 799 | { |
| 800 | public: |
| 801 | Addr_expression(const char* section_name, size_t section_name_len) |
| 802 | : Section_expression(section_name, section_name_len) |
| 803 | { } |
| 804 | |
| 805 | protected: |
| 806 | uint64_t |
| 807 | value_from_output_section(const Expression_eval_info* eei, |
| 808 | Output_section* os) |
| 809 | { |
| 810 | *eei->result_section_pointer = os; |
| 811 | return os->address(); |
| 812 | } |
| 813 | |
| 814 | uint64_t |
| 815 | value_from_script_output_section(uint64_t address, uint64_t, uint64_t, |
| 816 | uint64_t) |
| 817 | { return address; } |
| 818 | |
| 819 | const char* |
| 820 | function_name() const |
| 821 | { return "ADDR"; } |
| 822 | }; |
| 823 | |
| 824 | extern "C" Expression* |
| 825 | script_exp_function_addr(const char* section_name, size_t section_name_len) |
| 826 | { |
| 827 | return new Addr_expression(section_name, section_name_len); |
| 828 | } |
| 829 | |
| 830 | // ALIGNOF. |
| 831 | |
| 832 | class Alignof_expression : public Section_expression |
| 833 | { |
| 834 | public: |
| 835 | Alignof_expression(const char* section_name, size_t section_name_len) |
| 836 | : Section_expression(section_name, section_name_len) |
| 837 | { } |
| 838 | |
| 839 | protected: |
| 840 | uint64_t |
| 841 | value_from_output_section(const Expression_eval_info*, |
| 842 | Output_section* os) |
| 843 | { return os->addralign(); } |
| 844 | |
| 845 | uint64_t |
| 846 | value_from_script_output_section(uint64_t, uint64_t, uint64_t addralign, |
| 847 | uint64_t) |
| 848 | { return addralign; } |
| 849 | |
| 850 | const char* |
| 851 | function_name() const |
| 852 | { return "ALIGNOF"; } |
| 853 | }; |
| 854 | |
| 855 | extern "C" Expression* |
| 856 | script_exp_function_alignof(const char* section_name, size_t section_name_len) |
| 857 | { |
| 858 | return new Alignof_expression(section_name, section_name_len); |
| 859 | } |
| 860 | |
| 861 | // CONSTANT. It would be nice if we could simply evaluate this |
| 862 | // immediately and return an Integer_expression, but unfortunately we |
| 863 | // don't know the target. |
| 864 | |
| 865 | class Constant_expression : public Expression |
| 866 | { |
| 867 | public: |
| 868 | Constant_expression(const char* name, size_t length); |
| 869 | |
| 870 | uint64_t |
| 871 | value(const Expression_eval_info*); |
| 872 | |
| 873 | void |
| 874 | print(FILE* f) const; |
| 875 | |
| 876 | private: |
| 877 | enum Constant_function |
| 878 | { |
| 879 | CONSTANT_MAXPAGESIZE, |
| 880 | CONSTANT_COMMONPAGESIZE |
| 881 | }; |
| 882 | |
| 883 | Constant_function function_; |
| 884 | }; |
| 885 | |
| 886 | Constant_expression::Constant_expression(const char* name, size_t length) |
| 887 | { |
| 888 | if (length == 11 && strncmp(name, "MAXPAGESIZE", length) == 0) |
| 889 | this->function_ = CONSTANT_MAXPAGESIZE; |
| 890 | else if (length == 14 && strncmp(name, "COMMONPAGESIZE", length) == 0) |
| 891 | this->function_ = CONSTANT_COMMONPAGESIZE; |
| 892 | else |
| 893 | { |
| 894 | std::string s(name, length); |
| 895 | gold_error(_("unknown constant %s"), s.c_str()); |
| 896 | this->function_ = CONSTANT_MAXPAGESIZE; |
| 897 | } |
| 898 | } |
| 899 | |
| 900 | uint64_t |
| 901 | Constant_expression::value(const Expression_eval_info*) |
| 902 | { |
| 903 | switch (this->function_) |
| 904 | { |
| 905 | case CONSTANT_MAXPAGESIZE: |
| 906 | return parameters->target().abi_pagesize(); |
| 907 | case CONSTANT_COMMONPAGESIZE: |
| 908 | return parameters->target().common_pagesize(); |
| 909 | default: |
| 910 | gold_unreachable(); |
| 911 | } |
| 912 | } |
| 913 | |
| 914 | void |
| 915 | Constant_expression::print(FILE* f) const |
| 916 | { |
| 917 | const char* name; |
| 918 | switch (this->function_) |
| 919 | { |
| 920 | case CONSTANT_MAXPAGESIZE: |
| 921 | name = "MAXPAGESIZE"; |
| 922 | break; |
| 923 | case CONSTANT_COMMONPAGESIZE: |
| 924 | name = "COMMONPAGESIZE"; |
| 925 | break; |
| 926 | default: |
| 927 | gold_unreachable(); |
| 928 | } |
| 929 | fprintf(f, "CONSTANT(%s)", name); |
| 930 | } |
| 931 | |
| 932 | extern "C" Expression* |
| 933 | script_exp_function_constant(const char* name, size_t length) |
| 934 | { |
| 935 | return new Constant_expression(name, length); |
| 936 | } |
| 937 | |
| 938 | // DATA_SEGMENT_ALIGN. FIXME: we don't implement this; we always fall |
| 939 | // back to the general case. |
| 940 | |
| 941 | extern "C" Expression* |
| 942 | script_exp_function_data_segment_align(Expression* left, Expression*) |
| 943 | { |
| 944 | Expression* e1 = script_exp_function_align(script_exp_string(".", 1), left); |
| 945 | Expression* e2 = script_exp_binary_sub(left, script_exp_integer(1)); |
| 946 | Expression* e3 = script_exp_binary_bitwise_and(script_exp_string(".", 1), |
| 947 | e2); |
| 948 | return script_exp_binary_add(e1, e3); |
| 949 | } |
| 950 | |
| 951 | // DATA_SEGMENT_RELRO. FIXME: This is not implemented. |
| 952 | |
| 953 | extern "C" Expression* |
| 954 | script_exp_function_data_segment_relro_end(Expression*, Expression* right) |
| 955 | { |
| 956 | return right; |
| 957 | } |
| 958 | |
| 959 | // DATA_SEGMENT_END. FIXME: This is not implemented. |
| 960 | |
| 961 | extern "C" Expression* |
| 962 | script_exp_function_data_segment_end(Expression* val) |
| 963 | { |
| 964 | return val; |
| 965 | } |
| 966 | |
| 967 | // DEFINED function. |
| 968 | |
| 969 | class Defined_expression : public Expression |
| 970 | { |
| 971 | public: |
| 972 | Defined_expression(const char* symbol_name, size_t symbol_name_len) |
| 973 | : symbol_name_(symbol_name, symbol_name_len) |
| 974 | { } |
| 975 | |
| 976 | uint64_t |
| 977 | value(const Expression_eval_info* eei) |
| 978 | { |
| 979 | Symbol* sym = eei->symtab->lookup(this->symbol_name_.c_str()); |
| 980 | return sym != NULL && sym->is_defined(); |
| 981 | } |
| 982 | |
| 983 | void |
| 984 | print(FILE* f) const |
| 985 | { fprintf(f, "DEFINED(%s)", this->symbol_name_.c_str()); } |
| 986 | |
| 987 | private: |
| 988 | std::string symbol_name_; |
| 989 | }; |
| 990 | |
| 991 | extern "C" Expression* |
| 992 | script_exp_function_defined(const char* symbol_name, size_t symbol_name_len) |
| 993 | { |
| 994 | return new Defined_expression(symbol_name, symbol_name_len); |
| 995 | } |
| 996 | |
| 997 | // LOADADDR function |
| 998 | |
| 999 | class Loadaddr_expression : public Section_expression |
| 1000 | { |
| 1001 | public: |
| 1002 | Loadaddr_expression(const char* section_name, size_t section_name_len) |
| 1003 | : Section_expression(section_name, section_name_len) |
| 1004 | { } |
| 1005 | |
| 1006 | protected: |
| 1007 | uint64_t |
| 1008 | value_from_output_section(const Expression_eval_info* eei, |
| 1009 | Output_section* os) |
| 1010 | { |
| 1011 | if (os->has_load_address()) |
| 1012 | return os->load_address(); |
| 1013 | else |
| 1014 | { |
| 1015 | *eei->result_section_pointer = os; |
| 1016 | return os->address(); |
| 1017 | } |
| 1018 | } |
| 1019 | |
| 1020 | uint64_t |
| 1021 | value_from_script_output_section(uint64_t, uint64_t load_address, uint64_t, |
| 1022 | uint64_t) |
| 1023 | { return load_address; } |
| 1024 | |
| 1025 | const char* |
| 1026 | function_name() const |
| 1027 | { return "LOADADDR"; } |
| 1028 | }; |
| 1029 | |
| 1030 | extern "C" Expression* |
| 1031 | script_exp_function_loadaddr(const char* section_name, size_t section_name_len) |
| 1032 | { |
| 1033 | return new Loadaddr_expression(section_name, section_name_len); |
| 1034 | } |
| 1035 | |
| 1036 | // SIZEOF function |
| 1037 | |
| 1038 | class Sizeof_expression : public Section_expression |
| 1039 | { |
| 1040 | public: |
| 1041 | Sizeof_expression(const char* section_name, size_t section_name_len) |
| 1042 | : Section_expression(section_name, section_name_len) |
| 1043 | { } |
| 1044 | |
| 1045 | protected: |
| 1046 | uint64_t |
| 1047 | value_from_output_section(const Expression_eval_info*, |
| 1048 | Output_section* os) |
| 1049 | { |
| 1050 | // We can not use data_size here, as the size of the section may |
| 1051 | // not have been finalized. Instead we get whatever the current |
| 1052 | // size is. This will work correctly for backward references in |
| 1053 | // linker scripts. |
| 1054 | return os->current_data_size(); |
| 1055 | } |
| 1056 | |
| 1057 | uint64_t |
| 1058 | value_from_script_output_section(uint64_t, uint64_t, uint64_t, |
| 1059 | uint64_t size) |
| 1060 | { return size; } |
| 1061 | |
| 1062 | const char* |
| 1063 | function_name() const |
| 1064 | { return "SIZEOF"; } |
| 1065 | }; |
| 1066 | |
| 1067 | extern "C" Expression* |
| 1068 | script_exp_function_sizeof(const char* section_name, size_t section_name_len) |
| 1069 | { |
| 1070 | return new Sizeof_expression(section_name, section_name_len); |
| 1071 | } |
| 1072 | |
| 1073 | // SIZEOF_HEADERS. |
| 1074 | |
| 1075 | class Sizeof_headers_expression : public Expression |
| 1076 | { |
| 1077 | public: |
| 1078 | Sizeof_headers_expression() |
| 1079 | { } |
| 1080 | |
| 1081 | uint64_t |
| 1082 | value(const Expression_eval_info*); |
| 1083 | |
| 1084 | void |
| 1085 | print(FILE* f) const |
| 1086 | { fprintf(f, "SIZEOF_HEADERS"); } |
| 1087 | }; |
| 1088 | |
| 1089 | uint64_t |
| 1090 | Sizeof_headers_expression::value(const Expression_eval_info* eei) |
| 1091 | { |
| 1092 | unsigned int ehdr_size; |
| 1093 | unsigned int phdr_size; |
| 1094 | if (parameters->target().get_size() == 32) |
| 1095 | { |
| 1096 | ehdr_size = elfcpp::Elf_sizes<32>::ehdr_size; |
| 1097 | phdr_size = elfcpp::Elf_sizes<32>::phdr_size; |
| 1098 | } |
| 1099 | else if (parameters->target().get_size() == 64) |
| 1100 | { |
| 1101 | ehdr_size = elfcpp::Elf_sizes<64>::ehdr_size; |
| 1102 | phdr_size = elfcpp::Elf_sizes<64>::phdr_size; |
| 1103 | } |
| 1104 | else |
| 1105 | gold_unreachable(); |
| 1106 | |
| 1107 | return ehdr_size + phdr_size * eei->layout->expected_segment_count(); |
| 1108 | } |
| 1109 | |
| 1110 | extern "C" Expression* |
| 1111 | script_exp_function_sizeof_headers() |
| 1112 | { |
| 1113 | return new Sizeof_headers_expression(); |
| 1114 | } |
| 1115 | |
| 1116 | // In the GNU linker SEGMENT_START basically returns the value for |
| 1117 | // -Ttext, -Tdata, or -Tbss. We could implement this by copying the |
| 1118 | // values from General_options to Parameters. But I doubt that |
| 1119 | // anybody actually uses it. The point of it for the GNU linker was |
| 1120 | // because -Ttext set the address of the .text section rather than the |
| 1121 | // text segment. In gold -Ttext sets the text segment address anyhow. |
| 1122 | |
| 1123 | extern "C" Expression* |
| 1124 | script_exp_function_segment_start(const char*, size_t, Expression*) |
| 1125 | { |
| 1126 | gold_fatal(_("SEGMENT_START not implemented")); |
| 1127 | } |
| 1128 | |
| 1129 | // Functions for memory regions. These can not be implemented unless |
| 1130 | // and until we implement memory regions. |
| 1131 | |
| 1132 | extern "C" Expression* |
| 1133 | script_exp_function_origin(const char*, size_t) |
| 1134 | { |
| 1135 | gold_fatal(_("ORIGIN not implemented")); |
| 1136 | } |
| 1137 | |
| 1138 | extern "C" Expression* |
| 1139 | script_exp_function_length(const char*, size_t) |
| 1140 | { |
| 1141 | gold_fatal(_("LENGTH not implemented")); |
| 1142 | } |
| 1143 | |
| 1144 | } // End namespace gold. |