| 1 | /* seh pdata/xdata coff object file format |
| 2 | Copyright (C) 2009-2015 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GAS. |
| 5 | |
| 6 | GAS is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 3, or (at your option) |
| 9 | any later version. |
| 10 | |
| 11 | GAS is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with GAS; see the file COPYING. If not, write to the Free |
| 18 | Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA |
| 19 | 02110-1301, USA. */ |
| 20 | |
| 21 | #include "obj-coff-seh.h" |
| 22 | |
| 23 | |
| 24 | /* Private segment collection list. */ |
| 25 | struct seh_seg_list { |
| 26 | segT seg; |
| 27 | int subseg; |
| 28 | char *seg_name; |
| 29 | }; |
| 30 | |
| 31 | /* Local data. */ |
| 32 | static seh_context *seh_ctx_cur = NULL; |
| 33 | |
| 34 | static struct hash_control *seh_hash; |
| 35 | |
| 36 | static struct seh_seg_list *x_segcur = NULL; |
| 37 | static struct seh_seg_list *p_segcur = NULL; |
| 38 | |
| 39 | static void write_function_xdata (seh_context *); |
| 40 | static void write_function_pdata (seh_context *); |
| 41 | |
| 42 | \f |
| 43 | /* Build based on segment the derived .pdata/.xdata |
| 44 | segment name containing origin segment's postfix name part. */ |
| 45 | static char * |
| 46 | get_pxdata_name (segT seg, const char *base_name) |
| 47 | { |
| 48 | const char *name,*dollar, *dot; |
| 49 | char *sname; |
| 50 | |
| 51 | name = bfd_get_section_name (stdoutput, seg); |
| 52 | |
| 53 | dollar = strchr (name, '$'); |
| 54 | dot = strchr (name + 1, '.'); |
| 55 | |
| 56 | if (!dollar && !dot) |
| 57 | name = ""; |
| 58 | else if (!dollar) |
| 59 | name = dot; |
| 60 | else if (!dot) |
| 61 | name = dollar; |
| 62 | else if (dot < dollar) |
| 63 | name = dot; |
| 64 | else |
| 65 | name = dollar; |
| 66 | |
| 67 | sname = concat (base_name, name, NULL); |
| 68 | |
| 69 | return sname; |
| 70 | } |
| 71 | |
| 72 | /* Allocate a seh_seg_list structure. */ |
| 73 | static struct seh_seg_list * |
| 74 | alloc_pxdata_item (segT seg, int subseg, char *name) |
| 75 | { |
| 76 | struct seh_seg_list *r; |
| 77 | |
| 78 | r = (struct seh_seg_list *) |
| 79 | xmalloc (sizeof (struct seh_seg_list) + strlen (name)); |
| 80 | r->seg = seg; |
| 81 | r->subseg = subseg; |
| 82 | r->seg_name = name; |
| 83 | return r; |
| 84 | } |
| 85 | |
| 86 | /* Generate pdata/xdata segment with same linkonce properties |
| 87 | of based segment. */ |
| 88 | static segT |
| 89 | make_pxdata_seg (segT cseg, char *name) |
| 90 | { |
| 91 | segT save_seg = now_seg; |
| 92 | int save_subseg = now_subseg; |
| 93 | segT r; |
| 94 | flagword flags; |
| 95 | |
| 96 | r = subseg_new (name, 0); |
| 97 | /* Check if code segment is marked as linked once. */ |
| 98 | flags = bfd_get_section_flags (stdoutput, cseg) |
| 99 | & (SEC_LINK_ONCE | SEC_LINK_DUPLICATES_DISCARD |
| 100 | | SEC_LINK_DUPLICATES_ONE_ONLY | SEC_LINK_DUPLICATES_SAME_SIZE |
| 101 | | SEC_LINK_DUPLICATES_SAME_CONTENTS); |
| 102 | |
| 103 | /* Add standard section flags. */ |
| 104 | flags |= SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_DATA; |
| 105 | |
| 106 | /* Apply possibly linked once flags to new generated segment, too. */ |
| 107 | if (!bfd_set_section_flags (stdoutput, r, flags)) |
| 108 | as_bad (_("bfd_set_section_flags: %s"), |
| 109 | bfd_errmsg (bfd_get_error ())); |
| 110 | |
| 111 | /* Restore to previous segment. */ |
| 112 | subseg_set (save_seg, save_subseg); |
| 113 | return r; |
| 114 | } |
| 115 | |
| 116 | static void |
| 117 | seh_hash_insert (const char *name, struct seh_seg_list *item) |
| 118 | { |
| 119 | const char *error_string; |
| 120 | |
| 121 | if ((error_string = hash_jam (seh_hash, name, (char *) item))) |
| 122 | as_fatal (_("Inserting \"%s\" into structure table failed: %s"), |
| 123 | name, error_string); |
| 124 | } |
| 125 | |
| 126 | static struct seh_seg_list * |
| 127 | seh_hash_find (char *name) |
| 128 | { |
| 129 | return (struct seh_seg_list *) hash_find (seh_hash, name); |
| 130 | } |
| 131 | |
| 132 | static struct seh_seg_list * |
| 133 | seh_hash_find_or_make (segT cseg, const char *base_name) |
| 134 | { |
| 135 | struct seh_seg_list *item; |
| 136 | char *name; |
| 137 | |
| 138 | /* Initialize seh_hash once. */ |
| 139 | if (!seh_hash) |
| 140 | seh_hash = hash_new (); |
| 141 | |
| 142 | name = get_pxdata_name (cseg, base_name); |
| 143 | |
| 144 | item = seh_hash_find (name); |
| 145 | if (!item) |
| 146 | { |
| 147 | item = alloc_pxdata_item (make_pxdata_seg (cseg, name), 0, name); |
| 148 | |
| 149 | seh_hash_insert (item->seg_name, item); |
| 150 | } |
| 151 | else |
| 152 | free (name); |
| 153 | |
| 154 | return item; |
| 155 | } |
| 156 | |
| 157 | /* Check if current segment has same name. */ |
| 158 | static int |
| 159 | seh_validate_seg (const char *directive) |
| 160 | { |
| 161 | const char *cseg_name, *nseg_name; |
| 162 | if (seh_ctx_cur->code_seg == now_seg) |
| 163 | return 1; |
| 164 | cseg_name = bfd_get_section_name (stdoutput, seh_ctx_cur->code_seg); |
| 165 | nseg_name = bfd_get_section_name (stdoutput, now_seg); |
| 166 | as_bad (_("%s used in segment '%s' instead of expected '%s'"), |
| 167 | directive, nseg_name, cseg_name); |
| 168 | ignore_rest_of_line (); |
| 169 | return 0; |
| 170 | } |
| 171 | |
| 172 | /* Switch back to the code section, whatever that may be. */ |
| 173 | static void |
| 174 | obj_coff_seh_code (int ignored ATTRIBUTE_UNUSED) |
| 175 | { |
| 176 | subseg_set (seh_ctx_cur->code_seg, 0); |
| 177 | } |
| 178 | |
| 179 | static void |
| 180 | switch_xdata (int subseg, segT code_seg) |
| 181 | { |
| 182 | x_segcur = seh_hash_find_or_make (code_seg, ".xdata"); |
| 183 | |
| 184 | subseg_set (x_segcur->seg, subseg); |
| 185 | } |
| 186 | |
| 187 | static void |
| 188 | switch_pdata (segT code_seg) |
| 189 | { |
| 190 | p_segcur = seh_hash_find_or_make (code_seg, ".pdata"); |
| 191 | |
| 192 | subseg_set (p_segcur->seg, p_segcur->subseg); |
| 193 | } |
| 194 | \f |
| 195 | /* Parsing routines. */ |
| 196 | |
| 197 | /* Return the style of SEH unwind info to generate. */ |
| 198 | |
| 199 | static seh_kind |
| 200 | seh_get_target_kind (void) |
| 201 | { |
| 202 | if (!stdoutput) |
| 203 | return seh_kind_unknown; |
| 204 | switch (bfd_get_arch (stdoutput)) |
| 205 | { |
| 206 | case bfd_arch_arm: |
| 207 | case bfd_arch_powerpc: |
| 208 | case bfd_arch_sh: |
| 209 | return seh_kind_arm; |
| 210 | case bfd_arch_i386: |
| 211 | switch (bfd_get_mach (stdoutput)) |
| 212 | { |
| 213 | case bfd_mach_x86_64: |
| 214 | case bfd_mach_x86_64_intel_syntax: |
| 215 | return seh_kind_x64; |
| 216 | default: |
| 217 | break; |
| 218 | } |
| 219 | /* FALL THROUGH. */ |
| 220 | case bfd_arch_mips: |
| 221 | return seh_kind_mips; |
| 222 | case bfd_arch_ia64: |
| 223 | /* Should return seh_kind_x64. But not implemented yet. */ |
| 224 | return seh_kind_unknown; |
| 225 | default: |
| 226 | break; |
| 227 | } |
| 228 | return seh_kind_unknown; |
| 229 | } |
| 230 | |
| 231 | /* Verify that we're in the context of a seh_proc. */ |
| 232 | |
| 233 | static int |
| 234 | verify_context (const char *directive) |
| 235 | { |
| 236 | if (seh_ctx_cur == NULL) |
| 237 | { |
| 238 | as_bad (_("%s used outside of .seh_proc block"), directive); |
| 239 | ignore_rest_of_line (); |
| 240 | return 0; |
| 241 | } |
| 242 | return 1; |
| 243 | } |
| 244 | |
| 245 | /* Similar, except we also verify the appropriate target. */ |
| 246 | |
| 247 | static int |
| 248 | verify_context_and_target (const char *directive, seh_kind target) |
| 249 | { |
| 250 | if (seh_get_target_kind () != target) |
| 251 | { |
| 252 | as_warn (_("%s ignored for this target"), directive); |
| 253 | ignore_rest_of_line (); |
| 254 | return 0; |
| 255 | } |
| 256 | return verify_context (directive); |
| 257 | } |
| 258 | |
| 259 | /* Skip whitespace and a comma. Error if the comma is not seen. */ |
| 260 | |
| 261 | static int |
| 262 | skip_whitespace_and_comma (int required) |
| 263 | { |
| 264 | SKIP_WHITESPACE (); |
| 265 | if (*input_line_pointer == ',') |
| 266 | { |
| 267 | input_line_pointer++; |
| 268 | SKIP_WHITESPACE (); |
| 269 | return 1; |
| 270 | } |
| 271 | else if (required) |
| 272 | { |
| 273 | as_bad (_("missing separator")); |
| 274 | ignore_rest_of_line (); |
| 275 | } |
| 276 | else |
| 277 | demand_empty_rest_of_line (); |
| 278 | return 0; |
| 279 | } |
| 280 | |
| 281 | /* Mark current context to use 32-bit instruction (arm). */ |
| 282 | |
| 283 | static void |
| 284 | obj_coff_seh_32 (int what) |
| 285 | { |
| 286 | if (!verify_context_and_target ((what ? ".seh_32" : ".seh_no32"), |
| 287 | seh_kind_arm)) |
| 288 | return; |
| 289 | |
| 290 | seh_ctx_cur->use_instruction_32 = (what ? 1 : 0); |
| 291 | demand_empty_rest_of_line (); |
| 292 | } |
| 293 | |
| 294 | /* Set for current context the handler and optional data (arm). */ |
| 295 | |
| 296 | static void |
| 297 | obj_coff_seh_eh (int what ATTRIBUTE_UNUSED) |
| 298 | { |
| 299 | if (!verify_context_and_target (".seh_eh", seh_kind_arm)) |
| 300 | return; |
| 301 | |
| 302 | /* Write block to .text if exception handler is set. */ |
| 303 | seh_ctx_cur->handler_written = 1; |
| 304 | emit_expr (&seh_ctx_cur->handler, 4); |
| 305 | emit_expr (&seh_ctx_cur->handler_data, 4); |
| 306 | |
| 307 | demand_empty_rest_of_line (); |
| 308 | } |
| 309 | |
| 310 | /* Set for current context the default handler (x64). */ |
| 311 | |
| 312 | static void |
| 313 | obj_coff_seh_handler (int what ATTRIBUTE_UNUSED) |
| 314 | { |
| 315 | char *symbol_name; |
| 316 | char name_end; |
| 317 | |
| 318 | if (!verify_context (".seh_handler")) |
| 319 | return; |
| 320 | |
| 321 | if (*input_line_pointer == 0 || *input_line_pointer == '\n') |
| 322 | { |
| 323 | as_bad (_(".seh_handler requires a handler")); |
| 324 | demand_empty_rest_of_line (); |
| 325 | return; |
| 326 | } |
| 327 | |
| 328 | SKIP_WHITESPACE (); |
| 329 | |
| 330 | if (*input_line_pointer == '@') |
| 331 | { |
| 332 | symbol_name = input_line_pointer; |
| 333 | name_end = get_symbol_end (); |
| 334 | |
| 335 | seh_ctx_cur->handler.X_op = O_constant; |
| 336 | seh_ctx_cur->handler.X_add_number = 0; |
| 337 | |
| 338 | if (strcasecmp (symbol_name, "@0") == 0 |
| 339 | || strcasecmp (symbol_name, "@null") == 0) |
| 340 | ; |
| 341 | else if (strcasecmp (symbol_name, "@1") == 0) |
| 342 | seh_ctx_cur->handler.X_add_number = 1; |
| 343 | else |
| 344 | as_bad (_("unknown constant value '%s' for handler"), symbol_name); |
| 345 | |
| 346 | *input_line_pointer = name_end; |
| 347 | } |
| 348 | else |
| 349 | expression (&seh_ctx_cur->handler); |
| 350 | |
| 351 | seh_ctx_cur->handler_data.X_op = O_constant; |
| 352 | seh_ctx_cur->handler_data.X_add_number = 0; |
| 353 | seh_ctx_cur->handler_flags = 0; |
| 354 | |
| 355 | if (!skip_whitespace_and_comma (0)) |
| 356 | return; |
| 357 | |
| 358 | if (seh_get_target_kind () == seh_kind_x64) |
| 359 | { |
| 360 | do |
| 361 | { |
| 362 | symbol_name = input_line_pointer; |
| 363 | name_end = get_symbol_end (); |
| 364 | |
| 365 | if (strcasecmp (symbol_name, "@unwind") == 0) |
| 366 | seh_ctx_cur->handler_flags |= UNW_FLAG_UHANDLER; |
| 367 | else if (strcasecmp (symbol_name, "@except") == 0) |
| 368 | seh_ctx_cur->handler_flags |= UNW_FLAG_EHANDLER; |
| 369 | else |
| 370 | as_bad (_(".seh_handler constant '%s' unknown"), symbol_name); |
| 371 | |
| 372 | *input_line_pointer = name_end; |
| 373 | } |
| 374 | while (skip_whitespace_and_comma (0)); |
| 375 | } |
| 376 | else |
| 377 | { |
| 378 | expression (&seh_ctx_cur->handler_data); |
| 379 | demand_empty_rest_of_line (); |
| 380 | |
| 381 | if (seh_ctx_cur->handler_written) |
| 382 | as_warn (_(".seh_handler after .seh_eh is ignored")); |
| 383 | } |
| 384 | } |
| 385 | |
| 386 | /* Switch to subsection for handler data for exception region (x64). */ |
| 387 | |
| 388 | static void |
| 389 | obj_coff_seh_handlerdata (int what ATTRIBUTE_UNUSED) |
| 390 | { |
| 391 | if (!verify_context_and_target (".seh_handlerdata", seh_kind_x64)) |
| 392 | return; |
| 393 | demand_empty_rest_of_line (); |
| 394 | |
| 395 | switch_xdata (seh_ctx_cur->subsection + 1, seh_ctx_cur->code_seg); |
| 396 | } |
| 397 | |
| 398 | /* Mark end of current context. */ |
| 399 | |
| 400 | static void |
| 401 | do_seh_endproc (void) |
| 402 | { |
| 403 | seh_ctx_cur->end_addr = symbol_temp_new_now (); |
| 404 | |
| 405 | write_function_xdata (seh_ctx_cur); |
| 406 | write_function_pdata (seh_ctx_cur); |
| 407 | seh_ctx_cur = NULL; |
| 408 | } |
| 409 | |
| 410 | static void |
| 411 | obj_coff_seh_endproc (int what ATTRIBUTE_UNUSED) |
| 412 | { |
| 413 | demand_empty_rest_of_line (); |
| 414 | if (seh_ctx_cur == NULL) |
| 415 | { |
| 416 | as_bad (_(".seh_endproc used without .seh_proc")); |
| 417 | return; |
| 418 | } |
| 419 | seh_validate_seg (".seh_endproc"); |
| 420 | do_seh_endproc (); |
| 421 | } |
| 422 | |
| 423 | /* Mark begin of new context. */ |
| 424 | |
| 425 | static void |
| 426 | obj_coff_seh_proc (int what ATTRIBUTE_UNUSED) |
| 427 | { |
| 428 | char *symbol_name; |
| 429 | char name_end; |
| 430 | |
| 431 | if (seh_ctx_cur != NULL) |
| 432 | { |
| 433 | as_bad (_("previous SEH entry not closed (missing .seh_endproc)")); |
| 434 | do_seh_endproc (); |
| 435 | } |
| 436 | |
| 437 | if (*input_line_pointer == 0 || *input_line_pointer == '\n') |
| 438 | { |
| 439 | as_bad (_(".seh_proc requires function label name")); |
| 440 | demand_empty_rest_of_line (); |
| 441 | return; |
| 442 | } |
| 443 | |
| 444 | seh_ctx_cur = XCNEW (seh_context); |
| 445 | |
| 446 | seh_ctx_cur->code_seg = now_seg; |
| 447 | |
| 448 | if (seh_get_target_kind () == seh_kind_x64) |
| 449 | { |
| 450 | x_segcur = seh_hash_find_or_make (seh_ctx_cur->code_seg, ".xdata"); |
| 451 | seh_ctx_cur->subsection = x_segcur->subseg; |
| 452 | x_segcur->subseg += 2; |
| 453 | } |
| 454 | |
| 455 | SKIP_WHITESPACE (); |
| 456 | |
| 457 | symbol_name = input_line_pointer; |
| 458 | name_end = get_symbol_end (); |
| 459 | seh_ctx_cur->func_name = xstrdup (symbol_name); |
| 460 | *input_line_pointer = name_end; |
| 461 | |
| 462 | demand_empty_rest_of_line (); |
| 463 | |
| 464 | seh_ctx_cur->start_addr = symbol_temp_new_now (); |
| 465 | } |
| 466 | |
| 467 | /* Mark end of prologue for current context. */ |
| 468 | |
| 469 | static void |
| 470 | obj_coff_seh_endprologue (int what ATTRIBUTE_UNUSED) |
| 471 | { |
| 472 | if (!verify_context (".seh_endprologue") |
| 473 | || !seh_validate_seg (".seh_endprologue")) |
| 474 | return; |
| 475 | demand_empty_rest_of_line (); |
| 476 | |
| 477 | if (seh_ctx_cur->endprologue_addr != NULL) |
| 478 | as_warn (_("duplicate .seh_endprologue in .seh_proc block")); |
| 479 | else |
| 480 | seh_ctx_cur->endprologue_addr = symbol_temp_new_now (); |
| 481 | } |
| 482 | |
| 483 | /* End-of-file hook. */ |
| 484 | |
| 485 | void |
| 486 | obj_coff_seh_do_final (void) |
| 487 | { |
| 488 | if (seh_ctx_cur != NULL) |
| 489 | { |
| 490 | as_bad (_("open SEH entry at end of file (missing .cfi_endproc)")); |
| 491 | do_seh_endproc (); |
| 492 | } |
| 493 | } |
| 494 | |
| 495 | /* Enter a prologue element into current context (x64). */ |
| 496 | |
| 497 | static void |
| 498 | seh_x64_make_prologue_element (int code, int info, offsetT off) |
| 499 | { |
| 500 | seh_prologue_element *n; |
| 501 | |
| 502 | if (seh_ctx_cur == NULL) |
| 503 | return; |
| 504 | if (seh_ctx_cur->elems_count == seh_ctx_cur->elems_max) |
| 505 | { |
| 506 | seh_ctx_cur->elems_max += 8; |
| 507 | seh_ctx_cur->elems = XRESIZEVEC (seh_prologue_element, |
| 508 | seh_ctx_cur->elems, |
| 509 | seh_ctx_cur->elems_max); |
| 510 | } |
| 511 | |
| 512 | n = &seh_ctx_cur->elems[seh_ctx_cur->elems_count++]; |
| 513 | n->code = code; |
| 514 | n->info = info; |
| 515 | n->off = off; |
| 516 | n->pc_addr = symbol_temp_new_now (); |
| 517 | } |
| 518 | |
| 519 | /* Helper to read a register name from input stream (x64). */ |
| 520 | |
| 521 | static int |
| 522 | seh_x64_read_reg (const char *directive, int kind) |
| 523 | { |
| 524 | static const char * const int_regs[16] = |
| 525 | { "rax", "rcx", "rdx", "rbx", "rsp", "rbp","rsi","rdi", |
| 526 | "r8","r9","r10","r11","r12","r13","r14","r15" }; |
| 527 | static const char * const xmm_regs[16] = |
| 528 | { "xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5", "xmm6", "xmm7", |
| 529 | "xmm8", "xmm9", "xmm10","xmm11","xmm12","xmm13","xmm14","xmm15" }; |
| 530 | |
| 531 | const char * const *regs = NULL; |
| 532 | char name_end; |
| 533 | char *symbol_name = NULL; |
| 534 | int i; |
| 535 | |
| 536 | switch (kind) |
| 537 | { |
| 538 | case 0: |
| 539 | case 1: |
| 540 | regs = int_regs; |
| 541 | break; |
| 542 | case 2: |
| 543 | regs = xmm_regs; |
| 544 | break; |
| 545 | default: |
| 546 | abort (); |
| 547 | } |
| 548 | |
| 549 | SKIP_WHITESPACE (); |
| 550 | if (*input_line_pointer == '%') |
| 551 | ++input_line_pointer; |
| 552 | symbol_name = input_line_pointer; |
| 553 | name_end = get_symbol_end (); |
| 554 | |
| 555 | for (i = 0; i < 16; i++) |
| 556 | if (! strcasecmp (regs[i], symbol_name)) |
| 557 | break; |
| 558 | |
| 559 | *input_line_pointer = name_end; |
| 560 | |
| 561 | /* Error if register not found, or EAX used as a frame pointer. */ |
| 562 | if (i == 16 || (kind == 0 && i == 0)) |
| 563 | { |
| 564 | as_bad (_("invalid register for %s"), directive); |
| 565 | return -1; |
| 566 | } |
| 567 | |
| 568 | return i; |
| 569 | } |
| 570 | |
| 571 | /* Add a register push-unwind token to the current context. */ |
| 572 | |
| 573 | static void |
| 574 | obj_coff_seh_pushreg (int what ATTRIBUTE_UNUSED) |
| 575 | { |
| 576 | int reg; |
| 577 | |
| 578 | if (!verify_context_and_target (".seh_pushreg", seh_kind_x64) |
| 579 | || !seh_validate_seg (".seh_pushreg")) |
| 580 | return; |
| 581 | |
| 582 | reg = seh_x64_read_reg (".seh_pushreg", 1); |
| 583 | demand_empty_rest_of_line (); |
| 584 | |
| 585 | if (reg < 0) |
| 586 | return; |
| 587 | |
| 588 | seh_x64_make_prologue_element (UWOP_PUSH_NONVOL, reg, 0); |
| 589 | } |
| 590 | |
| 591 | /* Add a register frame-unwind token to the current context. */ |
| 592 | |
| 593 | static void |
| 594 | obj_coff_seh_pushframe (int what ATTRIBUTE_UNUSED) |
| 595 | { |
| 596 | if (!verify_context_and_target (".seh_pushframe", seh_kind_x64) |
| 597 | || !seh_validate_seg (".seh_pushframe")) |
| 598 | return; |
| 599 | demand_empty_rest_of_line (); |
| 600 | |
| 601 | seh_x64_make_prologue_element (UWOP_PUSH_MACHFRAME, 0, 0); |
| 602 | } |
| 603 | |
| 604 | /* Add a register save-unwind token to current context. */ |
| 605 | |
| 606 | static void |
| 607 | obj_coff_seh_save (int what) |
| 608 | { |
| 609 | const char *directive = (what == 1 ? ".seh_savereg" : ".seh_savexmm"); |
| 610 | int code, reg, scale; |
| 611 | offsetT off; |
| 612 | |
| 613 | if (!verify_context_and_target (directive, seh_kind_x64) |
| 614 | || !seh_validate_seg (directive)) |
| 615 | return; |
| 616 | |
| 617 | reg = seh_x64_read_reg (directive, what); |
| 618 | |
| 619 | if (!skip_whitespace_and_comma (1)) |
| 620 | return; |
| 621 | |
| 622 | off = get_absolute_expression (); |
| 623 | demand_empty_rest_of_line (); |
| 624 | |
| 625 | if (reg < 0) |
| 626 | return; |
| 627 | if (off < 0) |
| 628 | { |
| 629 | as_bad (_("%s offset is negative"), directive); |
| 630 | return; |
| 631 | } |
| 632 | |
| 633 | scale = (what == 1 ? 8 : 16); |
| 634 | |
| 635 | if ((off & (scale - 1)) == 0 && off <= (offsetT) (0xffff * scale)) |
| 636 | { |
| 637 | code = (what == 1 ? UWOP_SAVE_NONVOL : UWOP_SAVE_XMM128); |
| 638 | off /= scale; |
| 639 | } |
| 640 | else if (off < (offsetT) 0xffffffff) |
| 641 | code = (what == 1 ? UWOP_SAVE_NONVOL_FAR : UWOP_SAVE_XMM128_FAR); |
| 642 | else |
| 643 | { |
| 644 | as_bad (_("%s offset out of range"), directive); |
| 645 | return; |
| 646 | } |
| 647 | |
| 648 | seh_x64_make_prologue_element (code, reg, off); |
| 649 | } |
| 650 | |
| 651 | /* Add a stack-allocation token to current context. */ |
| 652 | |
| 653 | static void |
| 654 | obj_coff_seh_stackalloc (int what ATTRIBUTE_UNUSED) |
| 655 | { |
| 656 | offsetT off; |
| 657 | int code, info; |
| 658 | |
| 659 | if (!verify_context_and_target (".seh_stackalloc", seh_kind_x64) |
| 660 | || !seh_validate_seg (".seh_stackalloc")) |
| 661 | return; |
| 662 | |
| 663 | off = get_absolute_expression (); |
| 664 | demand_empty_rest_of_line (); |
| 665 | |
| 666 | if (off == 0) |
| 667 | return; |
| 668 | if (off < 0) |
| 669 | { |
| 670 | as_bad (_(".seh_stackalloc offset is negative")); |
| 671 | return; |
| 672 | } |
| 673 | |
| 674 | if ((off & 7) == 0 && off <= 128) |
| 675 | code = UWOP_ALLOC_SMALL, info = (off - 8) >> 3, off = 0; |
| 676 | else if ((off & 7) == 0 && off <= (offsetT) (0xffff * 8)) |
| 677 | code = UWOP_ALLOC_LARGE, info = 0, off >>= 3; |
| 678 | else if (off <= (offsetT) 0xffffffff) |
| 679 | code = UWOP_ALLOC_LARGE, info = 1; |
| 680 | else |
| 681 | { |
| 682 | as_bad (_(".seh_stackalloc offset out of range")); |
| 683 | return; |
| 684 | } |
| 685 | |
| 686 | seh_x64_make_prologue_element (code, info, off); |
| 687 | } |
| 688 | |
| 689 | /* Add a frame-pointer token to current context. */ |
| 690 | |
| 691 | static void |
| 692 | obj_coff_seh_setframe (int what ATTRIBUTE_UNUSED) |
| 693 | { |
| 694 | offsetT off; |
| 695 | int reg; |
| 696 | |
| 697 | if (!verify_context_and_target (".seh_setframe", seh_kind_x64) |
| 698 | || !seh_validate_seg (".seh_setframe")) |
| 699 | return; |
| 700 | |
| 701 | reg = seh_x64_read_reg (".seh_setframe", 0); |
| 702 | |
| 703 | if (!skip_whitespace_and_comma (1)) |
| 704 | return; |
| 705 | |
| 706 | off = get_absolute_expression (); |
| 707 | demand_empty_rest_of_line (); |
| 708 | |
| 709 | if (reg < 0) |
| 710 | return; |
| 711 | if (off < 0) |
| 712 | as_bad (_(".seh_setframe offset is negative")); |
| 713 | else if (off > 240) |
| 714 | as_bad (_(".seh_setframe offset out of range")); |
| 715 | else if (off & 15) |
| 716 | as_bad (_(".seh_setframe offset not a multiple of 16")); |
| 717 | else if (seh_ctx_cur->framereg != 0) |
| 718 | as_bad (_("duplicate .seh_setframe in current .seh_proc")); |
| 719 | else |
| 720 | { |
| 721 | seh_ctx_cur->framereg = reg; |
| 722 | seh_ctx_cur->frameoff = off; |
| 723 | seh_x64_make_prologue_element (UWOP_SET_FPREG, 0, 0); |
| 724 | } |
| 725 | } |
| 726 | \f |
| 727 | /* Data writing routines. */ |
| 728 | |
| 729 | /* Output raw integers in 1, 2, or 4 bytes. */ |
| 730 | |
| 731 | static inline void |
| 732 | out_one (int byte) |
| 733 | { |
| 734 | FRAG_APPEND_1_CHAR (byte); |
| 735 | } |
| 736 | |
| 737 | static inline void |
| 738 | out_two (int data) |
| 739 | { |
| 740 | md_number_to_chars (frag_more (2), data, 2); |
| 741 | } |
| 742 | |
| 743 | static inline void |
| 744 | out_four (int data) |
| 745 | { |
| 746 | md_number_to_chars (frag_more (4), data, 4); |
| 747 | } |
| 748 | |
| 749 | /* Write out prologue data for x64. */ |
| 750 | |
| 751 | static void |
| 752 | seh_x64_write_prologue_data (const seh_context *c) |
| 753 | { |
| 754 | int i; |
| 755 | |
| 756 | /* We have to store in reverse order. */ |
| 757 | for (i = c->elems_count - 1; i >= 0; --i) |
| 758 | { |
| 759 | const seh_prologue_element *e = c->elems + i; |
| 760 | expressionS exp; |
| 761 | |
| 762 | /* First comes byte offset in code. */ |
| 763 | exp.X_op = O_subtract; |
| 764 | exp.X_add_symbol = e->pc_addr; |
| 765 | exp.X_op_symbol = c->start_addr; |
| 766 | exp.X_add_number = 0; |
| 767 | emit_expr (&exp, 1); |
| 768 | |
| 769 | /* Second comes code+info packed into a byte. */ |
| 770 | out_one ((e->info << 4) | e->code); |
| 771 | |
| 772 | switch (e->code) |
| 773 | { |
| 774 | case UWOP_PUSH_NONVOL: |
| 775 | case UWOP_ALLOC_SMALL: |
| 776 | case UWOP_SET_FPREG: |
| 777 | case UWOP_PUSH_MACHFRAME: |
| 778 | /* These have no extra data. */ |
| 779 | break; |
| 780 | |
| 781 | case UWOP_ALLOC_LARGE: |
| 782 | if (e->info) |
| 783 | { |
| 784 | case UWOP_SAVE_NONVOL_FAR: |
| 785 | case UWOP_SAVE_XMM128_FAR: |
| 786 | /* An unscaled 4 byte offset. */ |
| 787 | out_four (e->off); |
| 788 | break; |
| 789 | } |
| 790 | /* FALLTHRU */ |
| 791 | |
| 792 | case UWOP_SAVE_NONVOL: |
| 793 | case UWOP_SAVE_XMM128: |
| 794 | /* A scaled 2 byte offset. */ |
| 795 | out_two (e->off); |
| 796 | break; |
| 797 | |
| 798 | default: |
| 799 | abort (); |
| 800 | } |
| 801 | } |
| 802 | } |
| 803 | |
| 804 | static int |
| 805 | seh_x64_size_prologue_data (const seh_context *c) |
| 806 | { |
| 807 | int i, ret = 0; |
| 808 | |
| 809 | for (i = c->elems_count - 1; i >= 0; --i) |
| 810 | switch (c->elems[i].code) |
| 811 | { |
| 812 | case UWOP_PUSH_NONVOL: |
| 813 | case UWOP_ALLOC_SMALL: |
| 814 | case UWOP_SET_FPREG: |
| 815 | case UWOP_PUSH_MACHFRAME: |
| 816 | ret += 1; |
| 817 | break; |
| 818 | |
| 819 | case UWOP_SAVE_NONVOL: |
| 820 | case UWOP_SAVE_XMM128: |
| 821 | ret += 2; |
| 822 | break; |
| 823 | |
| 824 | case UWOP_SAVE_NONVOL_FAR: |
| 825 | case UWOP_SAVE_XMM128_FAR: |
| 826 | ret += 3; |
| 827 | break; |
| 828 | |
| 829 | case UWOP_ALLOC_LARGE: |
| 830 | ret += (c->elems[i].info ? 3 : 2); |
| 831 | break; |
| 832 | |
| 833 | default: |
| 834 | abort (); |
| 835 | } |
| 836 | |
| 837 | return ret; |
| 838 | } |
| 839 | |
| 840 | /* Write out the xdata information for one function (x64). */ |
| 841 | |
| 842 | static void |
| 843 | seh_x64_write_function_xdata (seh_context *c) |
| 844 | { |
| 845 | int flags, count_unwind_codes; |
| 846 | expressionS exp; |
| 847 | |
| 848 | /* Set 4-byte alignment. */ |
| 849 | frag_align (2, 0, 0); |
| 850 | |
| 851 | c->xdata_addr = symbol_temp_new_now (); |
| 852 | flags = c->handler_flags; |
| 853 | count_unwind_codes = seh_x64_size_prologue_data (c); |
| 854 | |
| 855 | /* ubyte:3 version, ubyte:5 flags. */ |
| 856 | out_one ((flags << 3) | 1); |
| 857 | |
| 858 | /* Size of prologue. */ |
| 859 | if (c->endprologue_addr) |
| 860 | { |
| 861 | exp.X_op = O_subtract; |
| 862 | exp.X_add_symbol = c->endprologue_addr; |
| 863 | exp.X_op_symbol = c->start_addr; |
| 864 | exp.X_add_number = 0; |
| 865 | emit_expr (&exp, 1); |
| 866 | } |
| 867 | else |
| 868 | out_one (0); |
| 869 | |
| 870 | /* Number of slots (i.e. shorts) in the unwind codes array. */ |
| 871 | if (count_unwind_codes > 255) |
| 872 | as_fatal (_("too much unwind data in this .seh_proc")); |
| 873 | out_one (count_unwind_codes); |
| 874 | |
| 875 | /* ubyte:4 frame-reg, ubyte:4 frame-reg-offset. */ |
| 876 | /* Note that frameoff is already a multiple of 16, and therefore |
| 877 | the offset is already both scaled and shifted into place. */ |
| 878 | out_one (c->frameoff | c->framereg); |
| 879 | |
| 880 | seh_x64_write_prologue_data (c); |
| 881 | |
| 882 | /* We need to align prologue data. */ |
| 883 | if (count_unwind_codes & 1) |
| 884 | out_two (0); |
| 885 | |
| 886 | if (flags & (UNW_FLAG_EHANDLER | UNW_FLAG_UHANDLER)) |
| 887 | { |
| 888 | /* Force the use of segment-relative relocations instead of absolute |
| 889 | valued expressions. Don't adjust for constants (e.g. NULL). */ |
| 890 | if (c->handler.X_op == O_symbol) |
| 891 | c->handler.X_op = O_symbol_rva; |
| 892 | emit_expr (&c->handler, 4); |
| 893 | } |
| 894 | |
| 895 | /* Handler data will be tacked in here by subsections. */ |
| 896 | } |
| 897 | |
| 898 | /* Write out xdata for one function. */ |
| 899 | |
| 900 | static void |
| 901 | write_function_xdata (seh_context *c) |
| 902 | { |
| 903 | segT save_seg = now_seg; |
| 904 | int save_subseg = now_subseg; |
| 905 | |
| 906 | /* MIPS, SH, ARM don't have xdata. */ |
| 907 | if (seh_get_target_kind () != seh_kind_x64) |
| 908 | return; |
| 909 | |
| 910 | switch_xdata (c->subsection, c->code_seg); |
| 911 | |
| 912 | seh_x64_write_function_xdata (c); |
| 913 | |
| 914 | subseg_set (save_seg, save_subseg); |
| 915 | } |
| 916 | |
| 917 | /* Write pdata section data for one function (arm). */ |
| 918 | |
| 919 | static void |
| 920 | seh_arm_write_function_pdata (seh_context *c) |
| 921 | { |
| 922 | expressionS exp; |
| 923 | unsigned int prol_len = 0, func_len = 0; |
| 924 | unsigned int val; |
| 925 | |
| 926 | /* Start address of the function. */ |
| 927 | exp.X_op = O_symbol; |
| 928 | exp.X_add_symbol = c->start_addr; |
| 929 | exp.X_add_number = 0; |
| 930 | emit_expr (&exp, 4); |
| 931 | |
| 932 | exp.X_op = O_subtract; |
| 933 | exp.X_add_symbol = c->end_addr; |
| 934 | exp.X_op_symbol = c->start_addr; |
| 935 | exp.X_add_number = 0; |
| 936 | if (resolve_expression (&exp) && exp.X_op == O_constant) |
| 937 | func_len = exp.X_add_number; |
| 938 | else |
| 939 | as_bad (_(".seh_endproc in a different section from .seh_proc")); |
| 940 | |
| 941 | if (c->endprologue_addr) |
| 942 | { |
| 943 | exp.X_op = O_subtract; |
| 944 | exp.X_add_symbol = c->endprologue_addr; |
| 945 | exp.X_op_symbol = c->start_addr; |
| 946 | exp.X_add_number = 0; |
| 947 | |
| 948 | if (resolve_expression (&exp) && exp.X_op == O_constant) |
| 949 | prol_len = exp.X_add_number; |
| 950 | else |
| 951 | as_bad (_(".seh_endprologue in a different section from .seh_proc")); |
| 952 | } |
| 953 | |
| 954 | /* Both function and prologue are in units of instructions. */ |
| 955 | func_len >>= (c->use_instruction_32 ? 2 : 1); |
| 956 | prol_len >>= (c->use_instruction_32 ? 2 : 1); |
| 957 | |
| 958 | /* Assemble the second word of the pdata. */ |
| 959 | val = prol_len & 0xff; |
| 960 | val |= (func_len & 0x3fffff) << 8; |
| 961 | if (c->use_instruction_32) |
| 962 | val |= 0x40000000U; |
| 963 | if (c->handler_written) |
| 964 | val |= 0x80000000U; |
| 965 | out_four (val); |
| 966 | } |
| 967 | |
| 968 | /* Write out pdata for one function. */ |
| 969 | |
| 970 | static void |
| 971 | write_function_pdata (seh_context *c) |
| 972 | { |
| 973 | expressionS exp; |
| 974 | segT save_seg = now_seg; |
| 975 | int save_subseg = now_subseg; |
| 976 | memset (&exp, 0, sizeof (expressionS)); |
| 977 | switch_pdata (c->code_seg); |
| 978 | |
| 979 | switch (seh_get_target_kind ()) |
| 980 | { |
| 981 | case seh_kind_x64: |
| 982 | exp.X_op = O_symbol_rva; |
| 983 | exp.X_add_number = 0; |
| 984 | |
| 985 | exp.X_add_symbol = c->start_addr; |
| 986 | emit_expr (&exp, 4); |
| 987 | exp.X_op = O_symbol_rva; |
| 988 | exp.X_add_number = 0; |
| 989 | exp.X_add_symbol = c->end_addr; |
| 990 | emit_expr (&exp, 4); |
| 991 | exp.X_op = O_symbol_rva; |
| 992 | exp.X_add_number = 0; |
| 993 | exp.X_add_symbol = c->xdata_addr; |
| 994 | emit_expr (&exp, 4); |
| 995 | break; |
| 996 | |
| 997 | case seh_kind_mips: |
| 998 | exp.X_op = O_symbol; |
| 999 | exp.X_add_number = 0; |
| 1000 | |
| 1001 | exp.X_add_symbol = c->start_addr; |
| 1002 | emit_expr (&exp, 4); |
| 1003 | exp.X_add_symbol = c->end_addr; |
| 1004 | emit_expr (&exp, 4); |
| 1005 | |
| 1006 | emit_expr (&c->handler, 4); |
| 1007 | emit_expr (&c->handler_data, 4); |
| 1008 | |
| 1009 | exp.X_add_symbol = (c->endprologue_addr |
| 1010 | ? c->endprologue_addr |
| 1011 | : c->start_addr); |
| 1012 | emit_expr (&exp, 4); |
| 1013 | break; |
| 1014 | |
| 1015 | case seh_kind_arm: |
| 1016 | seh_arm_write_function_pdata (c); |
| 1017 | break; |
| 1018 | |
| 1019 | default: |
| 1020 | abort (); |
| 1021 | } |
| 1022 | |
| 1023 | subseg_set (save_seg, save_subseg); |
| 1024 | } |