| 1 | /* dw2gencfi.c - Support for generating Dwarf2 CFI information. |
| 2 | Copyright 2003 Free Software Foundation, Inc. |
| 3 | Contributed by Michal Ludvig <mludvig@suse.cz> |
| 4 | |
| 5 | This file is part of GAS, the GNU Assembler. |
| 6 | |
| 7 | GAS 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 2, or (at your option) |
| 10 | any later version. |
| 11 | |
| 12 | GAS 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 GAS; see the file COPYING. If not, write to the Free |
| 19 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA |
| 20 | 02111-1307, USA. */ |
| 21 | |
| 22 | #include "as.h" |
| 23 | #include "dw2gencfi.h" |
| 24 | |
| 25 | |
| 26 | /* We re-use DWARF2_LINE_MIN_INSN_LENGTH for the code alignment field |
| 27 | of the CIE. Default to 1 if not otherwise specified. */ |
| 28 | #ifndef DWARF2_LINE_MIN_INSN_LENGTH |
| 29 | # define DWARF2_LINE_MIN_INSN_LENGTH 1 |
| 30 | #endif |
| 31 | |
| 32 | /* If TARGET_USE_CFIPOP is defined, it is required that the target |
| 33 | provide the following definitions. Otherwise provide them to |
| 34 | allow compilation to continue. */ |
| 35 | #ifndef TARGET_USE_CFIPOP |
| 36 | # ifndef DWARF2_DEFAULT_RETURN_COLUMN |
| 37 | # define DWARF2_DEFAULT_RETURN_COLUMN 0 |
| 38 | # endif |
| 39 | # ifndef DWARF2_CIE_DATA_ALIGNMENT |
| 40 | # define DWARF2_CIE_DATA_ALIGNMENT 1 |
| 41 | # endif |
| 42 | #endif |
| 43 | |
| 44 | #ifndef EH_FRAME_ALIGNMENT |
| 45 | # ifdef BFD_ASSEMBLER |
| 46 | # define EH_FRAME_ALIGNMENT (bfd_get_arch_size (stdoutput) == 64 ? 3 : 2) |
| 47 | # else |
| 48 | # define EH_FRAME_ALIGNMENT 2 |
| 49 | # endif |
| 50 | #endif |
| 51 | |
| 52 | #ifndef tc_cfi_frame_initial_instructions |
| 53 | # define tc_cfi_frame_initial_instructions() ((void)0) |
| 54 | #endif |
| 55 | |
| 56 | |
| 57 | struct cfi_insn_data |
| 58 | { |
| 59 | struct cfi_insn_data *next; |
| 60 | int insn; |
| 61 | union { |
| 62 | struct { |
| 63 | unsigned reg; |
| 64 | offsetT offset; |
| 65 | } ri; |
| 66 | |
| 67 | struct { |
| 68 | unsigned reg1; |
| 69 | unsigned reg2; |
| 70 | } rr; |
| 71 | |
| 72 | unsigned r; |
| 73 | offsetT i; |
| 74 | |
| 75 | struct { |
| 76 | symbolS *lab1; |
| 77 | symbolS *lab2; |
| 78 | } ll; |
| 79 | |
| 80 | struct cfi_escape_data { |
| 81 | struct cfi_escape_data *next; |
| 82 | expressionS exp; |
| 83 | } *esc; |
| 84 | } u; |
| 85 | }; |
| 86 | |
| 87 | struct fde_entry |
| 88 | { |
| 89 | struct fde_entry *next; |
| 90 | symbolS *start_address; |
| 91 | symbolS *end_address; |
| 92 | struct cfi_insn_data *data; |
| 93 | struct cfi_insn_data **last; |
| 94 | unsigned int return_column; |
| 95 | }; |
| 96 | |
| 97 | struct cie_entry |
| 98 | { |
| 99 | struct cie_entry *next; |
| 100 | symbolS *start_address; |
| 101 | unsigned int return_column; |
| 102 | struct cfi_insn_data *first, *last; |
| 103 | }; |
| 104 | |
| 105 | |
| 106 | /* Current open FDE entry. */ |
| 107 | static struct fde_entry *cur_fde_data; |
| 108 | static symbolS *last_address; |
| 109 | static offsetT cur_cfa_offset; |
| 110 | |
| 111 | /* List of FDE entries. */ |
| 112 | static struct fde_entry *all_fde_data; |
| 113 | static struct fde_entry **last_fde_data = &all_fde_data; |
| 114 | |
| 115 | /* List of CIEs so that they could be reused. */ |
| 116 | static struct cie_entry *cie_root; |
| 117 | |
| 118 | /* Stack of old CFI data, for save/restore. */ |
| 119 | struct cfa_save_data |
| 120 | { |
| 121 | struct cfa_save_data *next; |
| 122 | offsetT cfa_offset; |
| 123 | }; |
| 124 | |
| 125 | static struct cfa_save_data *cfa_save_stack; |
| 126 | \f |
| 127 | /* Construct a new FDE structure and add it to the end of the fde list. */ |
| 128 | |
| 129 | static struct fde_entry * |
| 130 | alloc_fde_entry (void) |
| 131 | { |
| 132 | struct fde_entry *fde = xcalloc (1, sizeof (struct fde_entry)); |
| 133 | |
| 134 | cur_fde_data = fde; |
| 135 | *last_fde_data = fde; |
| 136 | last_fde_data = &fde->next; |
| 137 | |
| 138 | fde->last = &fde->data; |
| 139 | fde->return_column = DWARF2_DEFAULT_RETURN_COLUMN; |
| 140 | |
| 141 | return fde; |
| 142 | } |
| 143 | |
| 144 | /* The following functions are available for a backend to construct its |
| 145 | own unwind information, usually from legacy unwind directives. */ |
| 146 | |
| 147 | /* Construct a new INSN structure and add it to the end of the insn list |
| 148 | for the currently active FDE. */ |
| 149 | |
| 150 | static struct cfi_insn_data * |
| 151 | alloc_cfi_insn_data (void) |
| 152 | { |
| 153 | struct cfi_insn_data *insn = xcalloc (1, sizeof (struct cfi_insn_data)); |
| 154 | |
| 155 | *cur_fde_data->last = insn; |
| 156 | cur_fde_data->last = &insn->next; |
| 157 | |
| 158 | return insn; |
| 159 | } |
| 160 | |
| 161 | /* Construct a new FDE structure that begins at LABEL. */ |
| 162 | |
| 163 | void |
| 164 | cfi_new_fde (symbolS *label) |
| 165 | { |
| 166 | struct fde_entry *fde = alloc_fde_entry (); |
| 167 | fde->start_address = label; |
| 168 | last_address = label; |
| 169 | } |
| 170 | |
| 171 | /* End the currently open FDE. */ |
| 172 | |
| 173 | void |
| 174 | cfi_end_fde (symbolS *label) |
| 175 | { |
| 176 | cur_fde_data->end_address = label; |
| 177 | cur_fde_data = NULL; |
| 178 | } |
| 179 | |
| 180 | /* Set the return column for the current FDE. */ |
| 181 | |
| 182 | void |
| 183 | cfi_set_return_column (unsigned regno) |
| 184 | { |
| 185 | cur_fde_data->return_column = regno; |
| 186 | } |
| 187 | |
| 188 | /* Universal functions to store new instructions. */ |
| 189 | |
| 190 | static void |
| 191 | cfi_add_CFA_insn(int insn) |
| 192 | { |
| 193 | struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data (); |
| 194 | |
| 195 | insn_ptr->insn = insn; |
| 196 | } |
| 197 | |
| 198 | static void |
| 199 | cfi_add_CFA_insn_reg (int insn, unsigned regno) |
| 200 | { |
| 201 | struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data (); |
| 202 | |
| 203 | insn_ptr->insn = insn; |
| 204 | insn_ptr->u.r = regno; |
| 205 | } |
| 206 | |
| 207 | static void |
| 208 | cfi_add_CFA_insn_offset (int insn, offsetT offset) |
| 209 | { |
| 210 | struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data (); |
| 211 | |
| 212 | insn_ptr->insn = insn; |
| 213 | insn_ptr->u.i = offset; |
| 214 | } |
| 215 | |
| 216 | static void |
| 217 | cfi_add_CFA_insn_reg_reg (int insn, unsigned reg1, unsigned reg2) |
| 218 | { |
| 219 | struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data (); |
| 220 | |
| 221 | insn_ptr->insn = insn; |
| 222 | insn_ptr->u.rr.reg1 = reg1; |
| 223 | insn_ptr->u.rr.reg2 = reg2; |
| 224 | } |
| 225 | |
| 226 | static void |
| 227 | cfi_add_CFA_insn_reg_offset (int insn, unsigned regno, offsetT offset) |
| 228 | { |
| 229 | struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data (); |
| 230 | |
| 231 | insn_ptr->insn = insn; |
| 232 | insn_ptr->u.ri.reg = regno; |
| 233 | insn_ptr->u.ri.offset = offset; |
| 234 | } |
| 235 | |
| 236 | /* Add a CFI insn to advance the PC from the last address to LABEL. */ |
| 237 | |
| 238 | void |
| 239 | cfi_add_advance_loc (symbolS *label) |
| 240 | { |
| 241 | struct cfi_insn_data *insn = alloc_cfi_insn_data (); |
| 242 | |
| 243 | insn->insn = DW_CFA_advance_loc; |
| 244 | insn->u.ll.lab1 = last_address; |
| 245 | insn->u.ll.lab2 = label; |
| 246 | |
| 247 | last_address = label; |
| 248 | } |
| 249 | |
| 250 | /* Add a DW_CFA_offset record to the CFI data. */ |
| 251 | |
| 252 | void |
| 253 | cfi_add_CFA_offset (unsigned regno, offsetT offset) |
| 254 | { |
| 255 | unsigned int abs_data_align; |
| 256 | |
| 257 | cfi_add_CFA_insn_reg_offset (DW_CFA_offset, regno, offset); |
| 258 | |
| 259 | abs_data_align = (DWARF2_CIE_DATA_ALIGNMENT < 0 |
| 260 | ? -DWARF2_CIE_DATA_ALIGNMENT : DWARF2_CIE_DATA_ALIGNMENT); |
| 261 | if (offset % abs_data_align) |
| 262 | as_bad (_("register save offset not a multiple of %u"), abs_data_align); |
| 263 | } |
| 264 | |
| 265 | /* Add a DW_CFA_def_cfa record to the CFI data. */ |
| 266 | |
| 267 | void |
| 268 | cfi_add_CFA_def_cfa (unsigned regno, offsetT offset) |
| 269 | { |
| 270 | cfi_add_CFA_insn_reg_offset (DW_CFA_def_cfa, regno, offset); |
| 271 | cur_cfa_offset = offset; |
| 272 | } |
| 273 | |
| 274 | /* Add a DW_CFA_register record to the CFI data. */ |
| 275 | |
| 276 | void |
| 277 | cfi_add_CFA_register (unsigned reg1, unsigned reg2) |
| 278 | { |
| 279 | cfi_add_CFA_insn_reg_reg (DW_CFA_register, reg1, reg2); |
| 280 | } |
| 281 | |
| 282 | /* Add a DW_CFA_def_cfa_register record to the CFI data. */ |
| 283 | |
| 284 | void |
| 285 | cfi_add_CFA_def_cfa_register (unsigned regno) |
| 286 | { |
| 287 | cfi_add_CFA_insn_reg (DW_CFA_def_cfa_register, regno); |
| 288 | } |
| 289 | |
| 290 | /* Add a DW_CFA_def_cfa_offset record to the CFI data. */ |
| 291 | |
| 292 | void |
| 293 | cfi_add_CFA_def_cfa_offset (offsetT offset) |
| 294 | { |
| 295 | cfi_add_CFA_insn_offset (DW_CFA_def_cfa_offset, offset); |
| 296 | cur_cfa_offset = offset; |
| 297 | } |
| 298 | |
| 299 | void |
| 300 | cfi_add_CFA_restore (unsigned regno) |
| 301 | { |
| 302 | cfi_add_CFA_insn_reg (DW_CFA_restore, regno); |
| 303 | } |
| 304 | |
| 305 | void |
| 306 | cfi_add_CFA_undefined (unsigned regno) |
| 307 | { |
| 308 | cfi_add_CFA_insn_reg (DW_CFA_undefined, regno); |
| 309 | } |
| 310 | |
| 311 | void |
| 312 | cfi_add_CFA_same_value (unsigned regno) |
| 313 | { |
| 314 | cfi_add_CFA_insn_reg (DW_CFA_same_value, regno); |
| 315 | } |
| 316 | |
| 317 | void |
| 318 | cfi_add_CFA_remember_state (void) |
| 319 | { |
| 320 | struct cfa_save_data *p; |
| 321 | |
| 322 | cfi_add_CFA_insn (DW_CFA_remember_state); |
| 323 | |
| 324 | p = xmalloc (sizeof (*p)); |
| 325 | p->cfa_offset = cur_cfa_offset; |
| 326 | p->next = cfa_save_stack; |
| 327 | cfa_save_stack = p; |
| 328 | } |
| 329 | |
| 330 | void |
| 331 | cfi_add_CFA_restore_state (void) |
| 332 | { |
| 333 | struct cfa_save_data *p; |
| 334 | |
| 335 | cfi_add_CFA_insn (DW_CFA_restore_state); |
| 336 | |
| 337 | p = cfa_save_stack; |
| 338 | if (p) |
| 339 | { |
| 340 | cur_cfa_offset = p->cfa_offset; |
| 341 | cfa_save_stack = p->next; |
| 342 | free (p); |
| 343 | } |
| 344 | } |
| 345 | |
| 346 | \f |
| 347 | /* Parse CFI assembler directives. */ |
| 348 | |
| 349 | static void dot_cfi (int); |
| 350 | static void dot_cfi_escape (int); |
| 351 | static void dot_cfi_startproc (int); |
| 352 | static void dot_cfi_endproc (int); |
| 353 | |
| 354 | /* Fake CFI type; outside the byte range of any real CFI insn. */ |
| 355 | #define CFI_adjust_cfa_offset 0x100 |
| 356 | #define CFI_return_column 0x101 |
| 357 | #define CFI_rel_offset 0x102 |
| 358 | #define CFI_escape 0x103 |
| 359 | |
| 360 | const pseudo_typeS cfi_pseudo_table[] = |
| 361 | { |
| 362 | { "cfi_startproc", dot_cfi_startproc, 0 }, |
| 363 | { "cfi_endproc", dot_cfi_endproc, 0 }, |
| 364 | { "cfi_def_cfa", dot_cfi, DW_CFA_def_cfa }, |
| 365 | { "cfi_def_cfa_register", dot_cfi, DW_CFA_def_cfa_register }, |
| 366 | { "cfi_def_cfa_offset", dot_cfi, DW_CFA_def_cfa_offset }, |
| 367 | { "cfi_adjust_cfa_offset", dot_cfi, CFI_adjust_cfa_offset }, |
| 368 | { "cfi_offset", dot_cfi, DW_CFA_offset }, |
| 369 | { "cfi_rel_offset", dot_cfi, CFI_rel_offset }, |
| 370 | { "cfi_register", dot_cfi, DW_CFA_register }, |
| 371 | { "cfi_return_column", dot_cfi, CFI_return_column }, |
| 372 | { "cfi_restore", dot_cfi, DW_CFA_restore }, |
| 373 | { "cfi_undefined", dot_cfi, DW_CFA_undefined }, |
| 374 | { "cfi_same_value", dot_cfi, DW_CFA_same_value }, |
| 375 | { "cfi_remember_state", dot_cfi, DW_CFA_remember_state }, |
| 376 | { "cfi_restore_state", dot_cfi, DW_CFA_restore_state }, |
| 377 | { "cfi_window_save", dot_cfi, DW_CFA_GNU_window_save }, |
| 378 | { "cfi_escape", dot_cfi_escape, 0 }, |
| 379 | { NULL, NULL, 0 } |
| 380 | }; |
| 381 | |
| 382 | static void |
| 383 | cfi_parse_separator (void) |
| 384 | { |
| 385 | SKIP_WHITESPACE (); |
| 386 | if (*input_line_pointer == ',') |
| 387 | input_line_pointer++; |
| 388 | else |
| 389 | as_bad (_("missing separator")); |
| 390 | } |
| 391 | |
| 392 | static unsigned |
| 393 | cfi_parse_reg (void) |
| 394 | { |
| 395 | int regno; |
| 396 | expressionS exp; |
| 397 | |
| 398 | #ifdef tc_regname_to_dw2regnum |
| 399 | SKIP_WHITESPACE (); |
| 400 | if (is_name_beginner (*input_line_pointer) |
| 401 | || (*input_line_pointer == '%' |
| 402 | && is_name_beginner (*++input_line_pointer))) |
| 403 | { |
| 404 | char *name, c; |
| 405 | |
| 406 | name = input_line_pointer; |
| 407 | c = get_symbol_end (); |
| 408 | |
| 409 | if ((regno = tc_regname_to_dw2regnum (name)) < 0) |
| 410 | { |
| 411 | as_bad (_("bad register expression")); |
| 412 | regno = 0; |
| 413 | } |
| 414 | |
| 415 | *input_line_pointer = c; |
| 416 | return regno; |
| 417 | } |
| 418 | #endif |
| 419 | |
| 420 | expression (&exp); |
| 421 | switch (exp.X_op) |
| 422 | { |
| 423 | case O_register: |
| 424 | case O_constant: |
| 425 | regno = exp.X_add_number; |
| 426 | break; |
| 427 | |
| 428 | default: |
| 429 | as_bad (_("bad register expression")); |
| 430 | regno = 0; |
| 431 | break; |
| 432 | } |
| 433 | |
| 434 | return regno; |
| 435 | } |
| 436 | |
| 437 | static offsetT |
| 438 | cfi_parse_const (void) |
| 439 | { |
| 440 | return get_absolute_expression (); |
| 441 | } |
| 442 | |
| 443 | static void |
| 444 | dot_cfi (int arg) |
| 445 | { |
| 446 | offsetT offset; |
| 447 | unsigned reg1, reg2; |
| 448 | |
| 449 | if (!cur_fde_data) |
| 450 | { |
| 451 | as_bad (_("CFI instruction used without previous .cfi_startproc")); |
| 452 | return; |
| 453 | } |
| 454 | |
| 455 | /* If the last address was not at the current PC, advance to current. */ |
| 456 | if (symbol_get_frag (last_address) != frag_now |
| 457 | || S_GET_VALUE (last_address) != frag_now_fix ()) |
| 458 | cfi_add_advance_loc (symbol_temp_new_now ()); |
| 459 | |
| 460 | switch (arg) |
| 461 | { |
| 462 | case DW_CFA_offset: |
| 463 | reg1 = cfi_parse_reg (); |
| 464 | cfi_parse_separator (); |
| 465 | offset = cfi_parse_const (); |
| 466 | cfi_add_CFA_offset (reg1, offset); |
| 467 | break; |
| 468 | |
| 469 | case CFI_rel_offset: |
| 470 | reg1 = cfi_parse_reg (); |
| 471 | cfi_parse_separator (); |
| 472 | offset = cfi_parse_const (); |
| 473 | cfi_add_CFA_offset (reg1, offset - cur_cfa_offset); |
| 474 | break; |
| 475 | |
| 476 | case DW_CFA_def_cfa: |
| 477 | reg1 = cfi_parse_reg (); |
| 478 | cfi_parse_separator (); |
| 479 | offset = cfi_parse_const (); |
| 480 | cfi_add_CFA_def_cfa (reg1, offset); |
| 481 | break; |
| 482 | |
| 483 | case DW_CFA_register: |
| 484 | reg1 = cfi_parse_reg (); |
| 485 | cfi_parse_separator (); |
| 486 | reg2 = cfi_parse_reg (); |
| 487 | cfi_add_CFA_register (reg1, reg2); |
| 488 | break; |
| 489 | |
| 490 | case DW_CFA_def_cfa_register: |
| 491 | reg1 = cfi_parse_reg (); |
| 492 | cfi_add_CFA_def_cfa_register (reg1); |
| 493 | break; |
| 494 | |
| 495 | case DW_CFA_def_cfa_offset: |
| 496 | offset = cfi_parse_const (); |
| 497 | cfi_add_CFA_def_cfa_offset (offset); |
| 498 | break; |
| 499 | |
| 500 | case CFI_adjust_cfa_offset: |
| 501 | offset = cfi_parse_const (); |
| 502 | cfi_add_CFA_def_cfa_offset (cur_cfa_offset + offset); |
| 503 | break; |
| 504 | |
| 505 | case DW_CFA_restore: |
| 506 | reg1 = cfi_parse_reg (); |
| 507 | cfi_add_CFA_restore (reg1); |
| 508 | break; |
| 509 | |
| 510 | case DW_CFA_undefined: |
| 511 | reg1 = cfi_parse_reg (); |
| 512 | cfi_add_CFA_undefined (reg1); |
| 513 | break; |
| 514 | |
| 515 | case DW_CFA_same_value: |
| 516 | reg1 = cfi_parse_reg (); |
| 517 | cfi_add_CFA_same_value (reg1); |
| 518 | break; |
| 519 | |
| 520 | case CFI_return_column: |
| 521 | reg1 = cfi_parse_reg (); |
| 522 | cfi_set_return_column (reg1); |
| 523 | break; |
| 524 | |
| 525 | case DW_CFA_remember_state: |
| 526 | cfi_add_CFA_remember_state (); |
| 527 | break; |
| 528 | |
| 529 | case DW_CFA_restore_state: |
| 530 | cfi_add_CFA_restore_state (); |
| 531 | break; |
| 532 | |
| 533 | case DW_CFA_GNU_window_save: |
| 534 | cfi_add_CFA_insn (DW_CFA_GNU_window_save); |
| 535 | break; |
| 536 | |
| 537 | default: |
| 538 | abort (); |
| 539 | } |
| 540 | |
| 541 | demand_empty_rest_of_line (); |
| 542 | } |
| 543 | |
| 544 | static void |
| 545 | dot_cfi_escape (int ignored ATTRIBUTE_UNUSED) |
| 546 | { |
| 547 | struct cfi_escape_data *head, **tail, *e; |
| 548 | struct cfi_insn_data *insn; |
| 549 | |
| 550 | if (!cur_fde_data) |
| 551 | { |
| 552 | as_bad (_("CFI instruction used without previous .cfi_startproc")); |
| 553 | return; |
| 554 | } |
| 555 | |
| 556 | /* If the last address was not at the current PC, advance to current. */ |
| 557 | if (symbol_get_frag (last_address) != frag_now |
| 558 | || S_GET_VALUE (last_address) != frag_now_fix ()) |
| 559 | cfi_add_advance_loc (symbol_temp_new_now ()); |
| 560 | |
| 561 | tail = &head; |
| 562 | do |
| 563 | { |
| 564 | e = xmalloc (sizeof (*e)); |
| 565 | do_parse_cons_expression (&e->exp, 1); |
| 566 | *tail = e; |
| 567 | tail = &e->next; |
| 568 | } |
| 569 | while (*input_line_pointer++ == ','); |
| 570 | *tail = NULL; |
| 571 | |
| 572 | insn = alloc_cfi_insn_data (); |
| 573 | insn->insn = CFI_escape; |
| 574 | insn->u.esc = head; |
| 575 | } |
| 576 | |
| 577 | static void |
| 578 | dot_cfi_startproc (int ignored ATTRIBUTE_UNUSED) |
| 579 | { |
| 580 | int simple = 0; |
| 581 | |
| 582 | if (cur_fde_data) |
| 583 | { |
| 584 | as_bad (_("previous CFI entry not closed (missing .cfi_endproc)")); |
| 585 | return; |
| 586 | } |
| 587 | |
| 588 | cfi_new_fde (symbol_temp_new_now ()); |
| 589 | |
| 590 | SKIP_WHITESPACE (); |
| 591 | if (is_name_beginner (*input_line_pointer)) |
| 592 | { |
| 593 | char *name, c; |
| 594 | |
| 595 | name = input_line_pointer; |
| 596 | c = get_symbol_end (); |
| 597 | |
| 598 | if (strcmp (name, "simple") == 0) |
| 599 | { |
| 600 | simple = 1; |
| 601 | *input_line_pointer = c; |
| 602 | } |
| 603 | else |
| 604 | input_line_pointer = name; |
| 605 | } |
| 606 | demand_empty_rest_of_line (); |
| 607 | |
| 608 | if (!simple) |
| 609 | tc_cfi_frame_initial_instructions (); |
| 610 | } |
| 611 | |
| 612 | static void |
| 613 | dot_cfi_endproc (int ignored ATTRIBUTE_UNUSED) |
| 614 | { |
| 615 | if (! cur_fde_data) |
| 616 | { |
| 617 | as_bad (_(".cfi_endproc without corresponding .cfi_startproc")); |
| 618 | return; |
| 619 | } |
| 620 | |
| 621 | cfi_end_fde (symbol_temp_new_now ()); |
| 622 | } |
| 623 | |
| 624 | \f |
| 625 | /* Emit a single byte into the current segment. */ |
| 626 | |
| 627 | static inline void |
| 628 | out_one (int byte) |
| 629 | { |
| 630 | FRAG_APPEND_1_CHAR (byte); |
| 631 | } |
| 632 | |
| 633 | /* Emit a two-byte word into the current segment. */ |
| 634 | |
| 635 | static inline void |
| 636 | out_two (int data) |
| 637 | { |
| 638 | md_number_to_chars (frag_more (2), data, 2); |
| 639 | } |
| 640 | |
| 641 | /* Emit a four byte word into the current segment. */ |
| 642 | |
| 643 | static inline void |
| 644 | out_four (int data) |
| 645 | { |
| 646 | md_number_to_chars (frag_more (4), data, 4); |
| 647 | } |
| 648 | |
| 649 | /* Emit an unsigned "little-endian base 128" number. */ |
| 650 | |
| 651 | static void |
| 652 | out_uleb128 (addressT value) |
| 653 | { |
| 654 | output_leb128 (frag_more (sizeof_leb128 (value, 0)), value, 0); |
| 655 | } |
| 656 | |
| 657 | /* Emit an unsigned "little-endian base 128" number. */ |
| 658 | |
| 659 | static void |
| 660 | out_sleb128 (offsetT value) |
| 661 | { |
| 662 | output_leb128 (frag_more (sizeof_leb128 (value, 1)), value, 1); |
| 663 | } |
| 664 | |
| 665 | static void |
| 666 | output_cfi_insn (struct cfi_insn_data *insn) |
| 667 | { |
| 668 | offsetT offset; |
| 669 | unsigned int regno; |
| 670 | |
| 671 | switch (insn->insn) |
| 672 | { |
| 673 | case DW_CFA_advance_loc: |
| 674 | { |
| 675 | symbolS *from = insn->u.ll.lab1; |
| 676 | symbolS *to = insn->u.ll.lab2; |
| 677 | |
| 678 | if (symbol_get_frag (to) == symbol_get_frag (from)) |
| 679 | { |
| 680 | addressT delta = S_GET_VALUE (to) - S_GET_VALUE (from); |
| 681 | addressT scaled = delta / DWARF2_LINE_MIN_INSN_LENGTH; |
| 682 | |
| 683 | if (scaled <= 0x3F) |
| 684 | out_one (DW_CFA_advance_loc + scaled); |
| 685 | else if (delta <= 0xFF) |
| 686 | { |
| 687 | out_one (DW_CFA_advance_loc1); |
| 688 | out_one (delta); |
| 689 | } |
| 690 | else if (delta <= 0xFFFF) |
| 691 | { |
| 692 | out_one (DW_CFA_advance_loc2); |
| 693 | out_two (delta); |
| 694 | } |
| 695 | else |
| 696 | { |
| 697 | out_one (DW_CFA_advance_loc4); |
| 698 | out_four (delta); |
| 699 | } |
| 700 | } |
| 701 | else |
| 702 | { |
| 703 | expressionS exp; |
| 704 | |
| 705 | exp.X_op = O_subtract; |
| 706 | exp.X_add_symbol = to; |
| 707 | exp.X_op_symbol = from; |
| 708 | exp.X_add_number = 0; |
| 709 | |
| 710 | /* The code in ehopt.c expects that one byte of the encoding |
| 711 | is already allocated to the frag. This comes from the way |
| 712 | that it scans the .eh_frame section looking first for the |
| 713 | .byte DW_CFA_advance_loc4. */ |
| 714 | frag_more (1); |
| 715 | |
| 716 | frag_var (rs_cfa, 4, 0, DWARF2_LINE_MIN_INSN_LENGTH << 3, |
| 717 | make_expr_symbol (&exp), frag_now_fix () - 1, |
| 718 | (char *) frag_now); |
| 719 | } |
| 720 | } |
| 721 | break; |
| 722 | |
| 723 | case DW_CFA_def_cfa: |
| 724 | offset = insn->u.ri.offset; |
| 725 | if (offset < 0) |
| 726 | { |
| 727 | out_one (DW_CFA_def_cfa_sf); |
| 728 | out_uleb128 (insn->u.ri.reg); |
| 729 | out_uleb128 (offset); |
| 730 | } |
| 731 | else |
| 732 | { |
| 733 | out_one (DW_CFA_def_cfa); |
| 734 | out_uleb128 (insn->u.ri.reg); |
| 735 | out_uleb128 (offset); |
| 736 | } |
| 737 | break; |
| 738 | |
| 739 | case DW_CFA_def_cfa_register: |
| 740 | case DW_CFA_undefined: |
| 741 | case DW_CFA_same_value: |
| 742 | out_one (insn->insn); |
| 743 | out_uleb128 (insn->u.r); |
| 744 | break; |
| 745 | |
| 746 | case DW_CFA_def_cfa_offset: |
| 747 | offset = insn->u.i; |
| 748 | if (offset < 0) |
| 749 | { |
| 750 | out_one (DW_CFA_def_cfa_offset_sf); |
| 751 | out_sleb128 (offset); |
| 752 | } |
| 753 | else |
| 754 | { |
| 755 | out_one (DW_CFA_def_cfa_offset); |
| 756 | out_uleb128 (offset); |
| 757 | } |
| 758 | break; |
| 759 | |
| 760 | case DW_CFA_restore: |
| 761 | regno = insn->u.r; |
| 762 | if (regno <= 0x3F) |
| 763 | { |
| 764 | out_one (DW_CFA_restore + regno); |
| 765 | } |
| 766 | else |
| 767 | { |
| 768 | out_one (DW_CFA_restore_extended); |
| 769 | out_uleb128 (regno); |
| 770 | } |
| 771 | break; |
| 772 | |
| 773 | case DW_CFA_offset: |
| 774 | regno = insn->u.ri.reg; |
| 775 | offset = insn->u.ri.offset / DWARF2_CIE_DATA_ALIGNMENT; |
| 776 | if (offset < 0) |
| 777 | { |
| 778 | out_one (DW_CFA_offset_extended_sf); |
| 779 | out_uleb128 (regno); |
| 780 | out_sleb128 (offset); |
| 781 | } |
| 782 | else if (regno <= 0x3F) |
| 783 | { |
| 784 | out_one (DW_CFA_offset + regno); |
| 785 | out_uleb128 (offset); |
| 786 | } |
| 787 | else |
| 788 | { |
| 789 | out_one (DW_CFA_offset_extended); |
| 790 | out_uleb128 (regno); |
| 791 | out_uleb128 (offset); |
| 792 | } |
| 793 | break; |
| 794 | |
| 795 | case DW_CFA_register: |
| 796 | out_one (DW_CFA_register); |
| 797 | out_uleb128 (insn->u.rr.reg1); |
| 798 | out_uleb128 (insn->u.rr.reg2); |
| 799 | break; |
| 800 | |
| 801 | case DW_CFA_remember_state: |
| 802 | case DW_CFA_restore_state: |
| 803 | out_one (insn->insn); |
| 804 | break; |
| 805 | |
| 806 | case DW_CFA_GNU_window_save: |
| 807 | out_one (DW_CFA_GNU_window_save); |
| 808 | break; |
| 809 | |
| 810 | case CFI_escape: |
| 811 | { |
| 812 | struct cfi_escape_data *e; |
| 813 | for (e = insn->u.esc; e ; e = e->next) |
| 814 | emit_expr (&e->exp, 1); |
| 815 | break; |
| 816 | } |
| 817 | |
| 818 | default: |
| 819 | abort (); |
| 820 | } |
| 821 | } |
| 822 | |
| 823 | static void |
| 824 | output_cie (struct cie_entry *cie) |
| 825 | { |
| 826 | symbolS *after_size_address, *end_address; |
| 827 | expressionS exp; |
| 828 | struct cfi_insn_data *i; |
| 829 | |
| 830 | cie->start_address = symbol_temp_new_now (); |
| 831 | after_size_address = symbol_temp_make (); |
| 832 | end_address = symbol_temp_make (); |
| 833 | |
| 834 | exp.X_op = O_subtract; |
| 835 | exp.X_add_symbol = end_address; |
| 836 | exp.X_op_symbol = after_size_address; |
| 837 | exp.X_add_number = 0; |
| 838 | |
| 839 | emit_expr (&exp, 4); /* Length */ |
| 840 | symbol_set_value_now (after_size_address); |
| 841 | out_four (0); /* CIE id */ |
| 842 | out_one (DW_CIE_VERSION); /* Version */ |
| 843 | out_one ('z'); /* Augmentation */ |
| 844 | out_one ('R'); |
| 845 | out_one (0); |
| 846 | out_uleb128 (DWARF2_LINE_MIN_INSN_LENGTH); /* Code alignment */ |
| 847 | out_sleb128 (DWARF2_CIE_DATA_ALIGNMENT); /* Data alignment */ |
| 848 | if (DW_CIE_VERSION == 1) /* Return column. */ |
| 849 | out_one (cie->return_column); |
| 850 | else |
| 851 | out_uleb128 (cie->return_column); |
| 852 | out_uleb128 (1); /* Augmentation size */ |
| 853 | #if defined DIFF_EXPR_OK || defined tc_cfi_emit_pcrel_expr |
| 854 | out_one (DW_EH_PE_pcrel | DW_EH_PE_sdata4); |
| 855 | #else |
| 856 | out_one (DW_EH_PE_sdata4); |
| 857 | #endif |
| 858 | |
| 859 | if (cie->first) |
| 860 | for (i = cie->first; i != cie->last; i = i->next) |
| 861 | output_cfi_insn (i); |
| 862 | |
| 863 | frag_align (2, 0, 0); |
| 864 | symbol_set_value_now (end_address); |
| 865 | } |
| 866 | |
| 867 | static void |
| 868 | output_fde (struct fde_entry *fde, struct cie_entry *cie, |
| 869 | struct cfi_insn_data *first, int align) |
| 870 | { |
| 871 | symbolS *after_size_address, *end_address; |
| 872 | expressionS exp; |
| 873 | |
| 874 | after_size_address = symbol_temp_make (); |
| 875 | end_address = symbol_temp_make (); |
| 876 | |
| 877 | exp.X_op = O_subtract; |
| 878 | exp.X_add_symbol = end_address; |
| 879 | exp.X_op_symbol = after_size_address; |
| 880 | exp.X_add_number = 0; |
| 881 | emit_expr (&exp, 4); /* Length */ |
| 882 | symbol_set_value_now (after_size_address); |
| 883 | |
| 884 | exp.X_add_symbol = after_size_address; |
| 885 | exp.X_op_symbol = cie->start_address; |
| 886 | emit_expr (&exp, 4); /* CIE offset */ |
| 887 | |
| 888 | #ifdef DIFF_EXPR_OK |
| 889 | exp.X_add_symbol = fde->start_address; |
| 890 | exp.X_op_symbol = symbol_temp_new_now (); |
| 891 | emit_expr (&exp, 4); /* Code offset */ |
| 892 | #else |
| 893 | exp.X_op = O_symbol; |
| 894 | exp.X_add_symbol = fde->start_address; |
| 895 | exp.X_op_symbol = NULL; |
| 896 | #ifdef tc_cfi_emit_pcrel_expr |
| 897 | tc_cfi_emit_pcrel_expr (&exp, 4); /* Code offset */ |
| 898 | #else |
| 899 | emit_expr (&exp, 4); /* Code offset */ |
| 900 | #endif |
| 901 | exp.X_op = O_subtract; |
| 902 | #endif |
| 903 | |
| 904 | exp.X_add_symbol = fde->end_address; |
| 905 | exp.X_op_symbol = fde->start_address; /* Code length */ |
| 906 | emit_expr (&exp, 4); |
| 907 | |
| 908 | out_uleb128 (0); /* Augmentation size */ |
| 909 | |
| 910 | for (; first; first = first->next) |
| 911 | output_cfi_insn (first); |
| 912 | |
| 913 | frag_align (align, 0, 0); |
| 914 | symbol_set_value_now (end_address); |
| 915 | } |
| 916 | |
| 917 | static struct cie_entry * |
| 918 | select_cie_for_fde (struct fde_entry *fde, struct cfi_insn_data **pfirst) |
| 919 | { |
| 920 | struct cfi_insn_data *i, *j; |
| 921 | struct cie_entry *cie; |
| 922 | |
| 923 | for (cie = cie_root; cie; cie = cie->next) |
| 924 | { |
| 925 | if (cie->return_column != fde->return_column) |
| 926 | continue; |
| 927 | for (i = cie->first, j = fde->data; |
| 928 | i != cie->last && j != NULL; |
| 929 | i = i->next, j = j->next) |
| 930 | { |
| 931 | if (i->insn != j->insn) |
| 932 | goto fail; |
| 933 | switch (i->insn) |
| 934 | { |
| 935 | case DW_CFA_advance_loc: |
| 936 | /* We reached the first advance in the FDE, but did not |
| 937 | reach the end of the CIE list. */ |
| 938 | goto fail; |
| 939 | |
| 940 | case DW_CFA_offset: |
| 941 | case DW_CFA_def_cfa: |
| 942 | if (i->u.ri.reg != j->u.ri.reg) |
| 943 | goto fail; |
| 944 | if (i->u.ri.offset != j->u.ri.offset) |
| 945 | goto fail; |
| 946 | break; |
| 947 | |
| 948 | case DW_CFA_register: |
| 949 | if (i->u.rr.reg1 != j->u.rr.reg1) |
| 950 | goto fail; |
| 951 | if (i->u.rr.reg2 != j->u.rr.reg2) |
| 952 | goto fail; |
| 953 | break; |
| 954 | |
| 955 | case DW_CFA_def_cfa_register: |
| 956 | case DW_CFA_restore: |
| 957 | case DW_CFA_undefined: |
| 958 | case DW_CFA_same_value: |
| 959 | if (i->u.r != j->u.r) |
| 960 | goto fail; |
| 961 | break; |
| 962 | |
| 963 | case DW_CFA_def_cfa_offset: |
| 964 | if (i->u.i != j->u.i) |
| 965 | goto fail; |
| 966 | break; |
| 967 | |
| 968 | case CFI_escape: |
| 969 | /* Don't bother matching these for now. */ |
| 970 | goto fail; |
| 971 | |
| 972 | default: |
| 973 | abort (); |
| 974 | } |
| 975 | } |
| 976 | |
| 977 | /* Success if we reached the end of the CIE list, and we've either |
| 978 | run out of FDE entries or we've encountered an advance or |
| 979 | escape. */ |
| 980 | if (i == cie->last |
| 981 | && (!j |
| 982 | || j->insn == DW_CFA_advance_loc |
| 983 | || j->insn == CFI_escape)) |
| 984 | { |
| 985 | *pfirst = j; |
| 986 | return cie; |
| 987 | } |
| 988 | |
| 989 | fail:; |
| 990 | } |
| 991 | |
| 992 | cie = xmalloc (sizeof (struct cie_entry)); |
| 993 | cie->next = cie_root; |
| 994 | cie_root = cie; |
| 995 | cie->return_column = fde->return_column; |
| 996 | cie->first = fde->data; |
| 997 | |
| 998 | for (i = cie->first; i ; i = i->next) |
| 999 | if (i->insn == DW_CFA_advance_loc |
| 1000 | || i->insn == CFI_escape) |
| 1001 | break; |
| 1002 | |
| 1003 | cie->last = i; |
| 1004 | *pfirst = i; |
| 1005 | |
| 1006 | output_cie (cie); |
| 1007 | |
| 1008 | return cie; |
| 1009 | } |
| 1010 | |
| 1011 | void |
| 1012 | cfi_finish (void) |
| 1013 | { |
| 1014 | segT cfi_seg; |
| 1015 | struct fde_entry *fde; |
| 1016 | int save_flag_traditional_format; |
| 1017 | |
| 1018 | if (cur_fde_data) |
| 1019 | { |
| 1020 | as_bad (_("open CFI at the end of file; missing .cfi_endproc directive")); |
| 1021 | cur_fde_data->end_address = cur_fde_data->start_address; |
| 1022 | } |
| 1023 | |
| 1024 | if (all_fde_data == 0) |
| 1025 | return; |
| 1026 | |
| 1027 | /* Open .eh_frame section. */ |
| 1028 | cfi_seg = subseg_new (".eh_frame", 0); |
| 1029 | #ifdef BFD_ASSEMBLER |
| 1030 | bfd_set_section_flags (stdoutput, cfi_seg, |
| 1031 | SEC_ALLOC | SEC_LOAD | SEC_DATA | SEC_READONLY); |
| 1032 | #endif |
| 1033 | subseg_set (cfi_seg, 0); |
| 1034 | record_alignment (cfi_seg, EH_FRAME_ALIGNMENT); |
| 1035 | |
| 1036 | /* Make sure check_eh_frame doesn't do anything with our output. */ |
| 1037 | save_flag_traditional_format = flag_traditional_format; |
| 1038 | flag_traditional_format = 1; |
| 1039 | |
| 1040 | for (fde = all_fde_data; fde ; fde = fde->next) |
| 1041 | { |
| 1042 | struct cfi_insn_data *first; |
| 1043 | struct cie_entry *cie; |
| 1044 | |
| 1045 | cie = select_cie_for_fde (fde, &first); |
| 1046 | output_fde (fde, cie, first, fde->next == NULL ? EH_FRAME_ALIGNMENT : 2); |
| 1047 | } |
| 1048 | |
| 1049 | flag_traditional_format = save_flag_traditional_format; |
| 1050 | } |