| 1 | /* Intel 386 target-dependent stuff. |
| 2 | |
| 3 | Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, |
| 4 | 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 |
| 5 | Free Software Foundation, Inc. |
| 6 | |
| 7 | This file is part of GDB. |
| 8 | |
| 9 | This program is free software; you can redistribute it and/or modify |
| 10 | it under the terms of the GNU General Public License as published by |
| 11 | the Free Software Foundation; either version 3 of the License, or |
| 12 | (at your option) any later version. |
| 13 | |
| 14 | This program is distributed in the hope that it will be useful, |
| 15 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | GNU General Public License for more details. |
| 18 | |
| 19 | You should have received a copy of the GNU General Public License |
| 20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 21 | |
| 22 | #include "defs.h" |
| 23 | #include "arch-utils.h" |
| 24 | #include "command.h" |
| 25 | #include "dummy-frame.h" |
| 26 | #include "dwarf2-frame.h" |
| 27 | #include "doublest.h" |
| 28 | #include "frame.h" |
| 29 | #include "frame-base.h" |
| 30 | #include "frame-unwind.h" |
| 31 | #include "inferior.h" |
| 32 | #include "gdbcmd.h" |
| 33 | #include "gdbcore.h" |
| 34 | #include "gdbtypes.h" |
| 35 | #include "objfiles.h" |
| 36 | #include "osabi.h" |
| 37 | #include "regcache.h" |
| 38 | #include "reggroups.h" |
| 39 | #include "regset.h" |
| 40 | #include "symfile.h" |
| 41 | #include "symtab.h" |
| 42 | #include "target.h" |
| 43 | #include "value.h" |
| 44 | #include "dis-asm.h" |
| 45 | |
| 46 | #include "gdb_assert.h" |
| 47 | #include "gdb_string.h" |
| 48 | |
| 49 | #include "i386-tdep.h" |
| 50 | #include "i387-tdep.h" |
| 51 | |
| 52 | /* Register names. */ |
| 53 | |
| 54 | static char *i386_register_names[] = |
| 55 | { |
| 56 | "eax", "ecx", "edx", "ebx", |
| 57 | "esp", "ebp", "esi", "edi", |
| 58 | "eip", "eflags", "cs", "ss", |
| 59 | "ds", "es", "fs", "gs", |
| 60 | "st0", "st1", "st2", "st3", |
| 61 | "st4", "st5", "st6", "st7", |
| 62 | "fctrl", "fstat", "ftag", "fiseg", |
| 63 | "fioff", "foseg", "fooff", "fop", |
| 64 | "xmm0", "xmm1", "xmm2", "xmm3", |
| 65 | "xmm4", "xmm5", "xmm6", "xmm7", |
| 66 | "mxcsr" |
| 67 | }; |
| 68 | |
| 69 | static const int i386_num_register_names = ARRAY_SIZE (i386_register_names); |
| 70 | |
| 71 | /* Register names for MMX pseudo-registers. */ |
| 72 | |
| 73 | static char *i386_mmx_names[] = |
| 74 | { |
| 75 | "mm0", "mm1", "mm2", "mm3", |
| 76 | "mm4", "mm5", "mm6", "mm7" |
| 77 | }; |
| 78 | |
| 79 | static const int i386_num_mmx_regs = ARRAY_SIZE (i386_mmx_names); |
| 80 | |
| 81 | static int |
| 82 | i386_mmx_regnum_p (struct gdbarch *gdbarch, int regnum) |
| 83 | { |
| 84 | int mm0_regnum = gdbarch_tdep (gdbarch)->mm0_regnum; |
| 85 | |
| 86 | if (mm0_regnum < 0) |
| 87 | return 0; |
| 88 | |
| 89 | return (regnum >= mm0_regnum && regnum < mm0_regnum + i386_num_mmx_regs); |
| 90 | } |
| 91 | |
| 92 | /* SSE register? */ |
| 93 | |
| 94 | static int |
| 95 | i386_sse_regnum_p (struct gdbarch *gdbarch, int regnum) |
| 96 | { |
| 97 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 98 | |
| 99 | if (I387_NUM_XMM_REGS (tdep) == 0) |
| 100 | return 0; |
| 101 | |
| 102 | return (I387_XMM0_REGNUM (tdep) <= regnum |
| 103 | && regnum < I387_MXCSR_REGNUM (tdep)); |
| 104 | } |
| 105 | |
| 106 | static int |
| 107 | i386_mxcsr_regnum_p (struct gdbarch *gdbarch, int regnum) |
| 108 | { |
| 109 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 110 | |
| 111 | if (I387_NUM_XMM_REGS (tdep) == 0) |
| 112 | return 0; |
| 113 | |
| 114 | return (regnum == I387_MXCSR_REGNUM (tdep)); |
| 115 | } |
| 116 | |
| 117 | /* FP register? */ |
| 118 | |
| 119 | int |
| 120 | i386_fp_regnum_p (struct gdbarch *gdbarch, int regnum) |
| 121 | { |
| 122 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 123 | |
| 124 | if (I387_ST0_REGNUM (tdep) < 0) |
| 125 | return 0; |
| 126 | |
| 127 | return (I387_ST0_REGNUM (tdep) <= regnum |
| 128 | && regnum < I387_FCTRL_REGNUM (tdep)); |
| 129 | } |
| 130 | |
| 131 | int |
| 132 | i386_fpc_regnum_p (struct gdbarch *gdbarch, int regnum) |
| 133 | { |
| 134 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 135 | |
| 136 | if (I387_ST0_REGNUM (tdep) < 0) |
| 137 | return 0; |
| 138 | |
| 139 | return (I387_FCTRL_REGNUM (tdep) <= regnum |
| 140 | && regnum < I387_XMM0_REGNUM (tdep)); |
| 141 | } |
| 142 | |
| 143 | /* Return the name of register REGNUM. */ |
| 144 | |
| 145 | const char * |
| 146 | i386_register_name (struct gdbarch *gdbarch, int regnum) |
| 147 | { |
| 148 | if (i386_mmx_regnum_p (gdbarch, regnum)) |
| 149 | return i386_mmx_names[regnum - I387_MM0_REGNUM (gdbarch_tdep (gdbarch))]; |
| 150 | |
| 151 | if (regnum >= 0 && regnum < i386_num_register_names) |
| 152 | return i386_register_names[regnum]; |
| 153 | |
| 154 | return NULL; |
| 155 | } |
| 156 | |
| 157 | /* Convert a dbx register number REG to the appropriate register |
| 158 | number used by GDB. */ |
| 159 | |
| 160 | static int |
| 161 | i386_dbx_reg_to_regnum (struct gdbarch *gdbarch, int reg) |
| 162 | { |
| 163 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 164 | |
| 165 | /* This implements what GCC calls the "default" register map |
| 166 | (dbx_register_map[]). */ |
| 167 | |
| 168 | if (reg >= 0 && reg <= 7) |
| 169 | { |
| 170 | /* General-purpose registers. The debug info calls %ebp |
| 171 | register 4, and %esp register 5. */ |
| 172 | if (reg == 4) |
| 173 | return 5; |
| 174 | else if (reg == 5) |
| 175 | return 4; |
| 176 | else return reg; |
| 177 | } |
| 178 | else if (reg >= 12 && reg <= 19) |
| 179 | { |
| 180 | /* Floating-point registers. */ |
| 181 | return reg - 12 + I387_ST0_REGNUM (tdep); |
| 182 | } |
| 183 | else if (reg >= 21 && reg <= 28) |
| 184 | { |
| 185 | /* SSE registers. */ |
| 186 | return reg - 21 + I387_XMM0_REGNUM (tdep); |
| 187 | } |
| 188 | else if (reg >= 29 && reg <= 36) |
| 189 | { |
| 190 | /* MMX registers. */ |
| 191 | return reg - 29 + I387_MM0_REGNUM (tdep); |
| 192 | } |
| 193 | |
| 194 | /* This will hopefully provoke a warning. */ |
| 195 | return gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs (gdbarch); |
| 196 | } |
| 197 | |
| 198 | /* Convert SVR4 register number REG to the appropriate register number |
| 199 | used by GDB. */ |
| 200 | |
| 201 | static int |
| 202 | i386_svr4_reg_to_regnum (struct gdbarch *gdbarch, int reg) |
| 203 | { |
| 204 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 205 | |
| 206 | /* This implements the GCC register map that tries to be compatible |
| 207 | with the SVR4 C compiler for DWARF (svr4_dbx_register_map[]). */ |
| 208 | |
| 209 | /* The SVR4 register numbering includes %eip and %eflags, and |
| 210 | numbers the floating point registers differently. */ |
| 211 | if (reg >= 0 && reg <= 9) |
| 212 | { |
| 213 | /* General-purpose registers. */ |
| 214 | return reg; |
| 215 | } |
| 216 | else if (reg >= 11 && reg <= 18) |
| 217 | { |
| 218 | /* Floating-point registers. */ |
| 219 | return reg - 11 + I387_ST0_REGNUM (tdep); |
| 220 | } |
| 221 | else if (reg >= 21 && reg <= 36) |
| 222 | { |
| 223 | /* The SSE and MMX registers have the same numbers as with dbx. */ |
| 224 | return i386_dbx_reg_to_regnum (gdbarch, reg); |
| 225 | } |
| 226 | |
| 227 | switch (reg) |
| 228 | { |
| 229 | case 37: return I387_FCTRL_REGNUM (tdep); |
| 230 | case 38: return I387_FSTAT_REGNUM (tdep); |
| 231 | case 39: return I387_MXCSR_REGNUM (tdep); |
| 232 | case 40: return I386_ES_REGNUM; |
| 233 | case 41: return I386_CS_REGNUM; |
| 234 | case 42: return I386_SS_REGNUM; |
| 235 | case 43: return I386_DS_REGNUM; |
| 236 | case 44: return I386_FS_REGNUM; |
| 237 | case 45: return I386_GS_REGNUM; |
| 238 | } |
| 239 | |
| 240 | /* This will hopefully provoke a warning. */ |
| 241 | return gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs (gdbarch); |
| 242 | } |
| 243 | |
| 244 | \f |
| 245 | |
| 246 | /* This is the variable that is set with "set disassembly-flavor", and |
| 247 | its legitimate values. */ |
| 248 | static const char att_flavor[] = "att"; |
| 249 | static const char intel_flavor[] = "intel"; |
| 250 | static const char *valid_flavors[] = |
| 251 | { |
| 252 | att_flavor, |
| 253 | intel_flavor, |
| 254 | NULL |
| 255 | }; |
| 256 | static const char *disassembly_flavor = att_flavor; |
| 257 | \f |
| 258 | |
| 259 | /* Use the program counter to determine the contents and size of a |
| 260 | breakpoint instruction. Return a pointer to a string of bytes that |
| 261 | encode a breakpoint instruction, store the length of the string in |
| 262 | *LEN and optionally adjust *PC to point to the correct memory |
| 263 | location for inserting the breakpoint. |
| 264 | |
| 265 | On the i386 we have a single breakpoint that fits in a single byte |
| 266 | and can be inserted anywhere. |
| 267 | |
| 268 | This function is 64-bit safe. */ |
| 269 | |
| 270 | static const gdb_byte * |
| 271 | i386_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pc, int *len) |
| 272 | { |
| 273 | static gdb_byte break_insn[] = { 0xcc }; /* int 3 */ |
| 274 | |
| 275 | *len = sizeof (break_insn); |
| 276 | return break_insn; |
| 277 | } |
| 278 | \f |
| 279 | /* Displaced instruction handling. */ |
| 280 | |
| 281 | |
| 282 | static int |
| 283 | i386_absolute_jmp_p (gdb_byte *insn) |
| 284 | { |
| 285 | /* jmp far (absolute address in operand) */ |
| 286 | if (insn[0] == 0xea) |
| 287 | return 1; |
| 288 | |
| 289 | if (insn[0] == 0xff) |
| 290 | { |
| 291 | /* jump near, absolute indirect (/4) */ |
| 292 | if ((insn[1] & 0x38) == 0x20) |
| 293 | return 1; |
| 294 | |
| 295 | /* jump far, absolute indirect (/5) */ |
| 296 | if ((insn[1] & 0x38) == 0x28) |
| 297 | return 1; |
| 298 | } |
| 299 | |
| 300 | return 0; |
| 301 | } |
| 302 | |
| 303 | static int |
| 304 | i386_absolute_call_p (gdb_byte *insn) |
| 305 | { |
| 306 | /* call far, absolute */ |
| 307 | if (insn[0] == 0x9a) |
| 308 | return 1; |
| 309 | |
| 310 | if (insn[0] == 0xff) |
| 311 | { |
| 312 | /* Call near, absolute indirect (/2) */ |
| 313 | if ((insn[1] & 0x38) == 0x10) |
| 314 | return 1; |
| 315 | |
| 316 | /* Call far, absolute indirect (/3) */ |
| 317 | if ((insn[1] & 0x38) == 0x18) |
| 318 | return 1; |
| 319 | } |
| 320 | |
| 321 | return 0; |
| 322 | } |
| 323 | |
| 324 | static int |
| 325 | i386_ret_p (gdb_byte *insn) |
| 326 | { |
| 327 | switch (insn[0]) |
| 328 | { |
| 329 | case 0xc2: /* ret near, pop N bytes */ |
| 330 | case 0xc3: /* ret near */ |
| 331 | case 0xca: /* ret far, pop N bytes */ |
| 332 | case 0xcb: /* ret far */ |
| 333 | case 0xcf: /* iret */ |
| 334 | return 1; |
| 335 | |
| 336 | default: |
| 337 | return 0; |
| 338 | } |
| 339 | } |
| 340 | |
| 341 | static int |
| 342 | i386_call_p (gdb_byte *insn) |
| 343 | { |
| 344 | if (i386_absolute_call_p (insn)) |
| 345 | return 1; |
| 346 | |
| 347 | /* call near, relative */ |
| 348 | if (insn[0] == 0xe8) |
| 349 | return 1; |
| 350 | |
| 351 | return 0; |
| 352 | } |
| 353 | |
| 354 | static int |
| 355 | i386_breakpoint_p (gdb_byte *insn) |
| 356 | { |
| 357 | return insn[0] == 0xcc; /* int 3 */ |
| 358 | } |
| 359 | |
| 360 | /* Return non-zero if INSN is a system call, and set *LENGTHP to its |
| 361 | length in bytes. Otherwise, return zero. */ |
| 362 | static int |
| 363 | i386_syscall_p (gdb_byte *insn, ULONGEST *lengthp) |
| 364 | { |
| 365 | if (insn[0] == 0xcd) |
| 366 | { |
| 367 | *lengthp = 2; |
| 368 | return 1; |
| 369 | } |
| 370 | |
| 371 | return 0; |
| 372 | } |
| 373 | |
| 374 | /* Fix up the state of registers and memory after having single-stepped |
| 375 | a displaced instruction. */ |
| 376 | void |
| 377 | i386_displaced_step_fixup (struct gdbarch *gdbarch, |
| 378 | struct displaced_step_closure *closure, |
| 379 | CORE_ADDR from, CORE_ADDR to, |
| 380 | struct regcache *regs) |
| 381 | { |
| 382 | /* The offset we applied to the instruction's address. |
| 383 | This could well be negative (when viewed as a signed 32-bit |
| 384 | value), but ULONGEST won't reflect that, so take care when |
| 385 | applying it. */ |
| 386 | ULONGEST insn_offset = to - from; |
| 387 | |
| 388 | /* Since we use simple_displaced_step_copy_insn, our closure is a |
| 389 | copy of the instruction. */ |
| 390 | gdb_byte *insn = (gdb_byte *) closure; |
| 391 | |
| 392 | if (debug_displaced) |
| 393 | fprintf_unfiltered (gdb_stdlog, |
| 394 | "displaced: fixup (0x%s, 0x%s), " |
| 395 | "insn = 0x%02x 0x%02x ...\n", |
| 396 | paddr_nz (from), paddr_nz (to), insn[0], insn[1]); |
| 397 | |
| 398 | /* The list of issues to contend with here is taken from |
| 399 | resume_execution in arch/i386/kernel/kprobes.c, Linux 2.6.20. |
| 400 | Yay for Free Software! */ |
| 401 | |
| 402 | /* Relocate the %eip, if necessary. */ |
| 403 | |
| 404 | /* Except in the case of absolute or indirect jump or call |
| 405 | instructions, or a return instruction, the new eip is relative to |
| 406 | the displaced instruction; make it relative. Well, signal |
| 407 | handler returns don't need relocation either, but we use the |
| 408 | value of %eip to recognize those; see below. */ |
| 409 | if (! i386_absolute_jmp_p (insn) |
| 410 | && ! i386_absolute_call_p (insn) |
| 411 | && ! i386_ret_p (insn)) |
| 412 | { |
| 413 | ULONGEST orig_eip; |
| 414 | ULONGEST insn_len; |
| 415 | |
| 416 | regcache_cooked_read_unsigned (regs, I386_EIP_REGNUM, &orig_eip); |
| 417 | |
| 418 | /* A signal trampoline system call changes the %eip, resuming |
| 419 | execution of the main program after the signal handler has |
| 420 | returned. That makes them like 'return' instructions; we |
| 421 | shouldn't relocate %eip. |
| 422 | |
| 423 | But most system calls don't, and we do need to relocate %eip. |
| 424 | |
| 425 | Our heuristic for distinguishing these cases: if stepping |
| 426 | over the system call instruction left control directly after |
| 427 | the instruction, the we relocate --- control almost certainly |
| 428 | doesn't belong in the displaced copy. Otherwise, we assume |
| 429 | the instruction has put control where it belongs, and leave |
| 430 | it unrelocated. Goodness help us if there are PC-relative |
| 431 | system calls. */ |
| 432 | if (i386_syscall_p (insn, &insn_len) |
| 433 | && orig_eip != to + insn_len) |
| 434 | { |
| 435 | if (debug_displaced) |
| 436 | fprintf_unfiltered (gdb_stdlog, |
| 437 | "displaced: syscall changed %%eip; " |
| 438 | "not relocating\n"); |
| 439 | } |
| 440 | else |
| 441 | { |
| 442 | ULONGEST eip = (orig_eip - insn_offset) & 0xffffffffUL; |
| 443 | |
| 444 | /* If we have stepped over a breakpoint, set the %eip to |
| 445 | point at the breakpoint instruction itself. |
| 446 | |
| 447 | (gdbarch_decr_pc_after_break was never something the core |
| 448 | of GDB should have been concerned with; arch-specific |
| 449 | code should be making PC values consistent before |
| 450 | presenting them to GDB.) */ |
| 451 | if (i386_breakpoint_p (insn)) |
| 452 | { |
| 453 | if (debug_displaced) |
| 454 | fprintf_unfiltered (gdb_stdlog, |
| 455 | "displaced: stepped breakpoint\n"); |
| 456 | eip--; |
| 457 | } |
| 458 | |
| 459 | regcache_cooked_write_unsigned (regs, I386_EIP_REGNUM, eip); |
| 460 | |
| 461 | if (debug_displaced) |
| 462 | fprintf_unfiltered (gdb_stdlog, |
| 463 | "displaced: " |
| 464 | "relocated %%eip from 0x%s to 0x%s\n", |
| 465 | paddr_nz (orig_eip), paddr_nz (eip)); |
| 466 | } |
| 467 | } |
| 468 | |
| 469 | /* If the instruction was PUSHFL, then the TF bit will be set in the |
| 470 | pushed value, and should be cleared. We'll leave this for later, |
| 471 | since GDB already messes up the TF flag when stepping over a |
| 472 | pushfl. */ |
| 473 | |
| 474 | /* If the instruction was a call, the return address now atop the |
| 475 | stack is the address following the copied instruction. We need |
| 476 | to make it the address following the original instruction. */ |
| 477 | if (i386_call_p (insn)) |
| 478 | { |
| 479 | ULONGEST esp; |
| 480 | ULONGEST retaddr; |
| 481 | const ULONGEST retaddr_len = 4; |
| 482 | |
| 483 | regcache_cooked_read_unsigned (regs, I386_ESP_REGNUM, &esp); |
| 484 | retaddr = read_memory_unsigned_integer (esp, retaddr_len); |
| 485 | retaddr = (retaddr - insn_offset) & 0xffffffffUL; |
| 486 | write_memory_unsigned_integer (esp, retaddr_len, retaddr); |
| 487 | |
| 488 | if (debug_displaced) |
| 489 | fprintf_unfiltered (gdb_stdlog, |
| 490 | "displaced: relocated return addr at 0x%s " |
| 491 | "to 0x%s\n", |
| 492 | paddr_nz (esp), |
| 493 | paddr_nz (retaddr)); |
| 494 | } |
| 495 | } |
| 496 | |
| 497 | |
| 498 | \f |
| 499 | #ifdef I386_REGNO_TO_SYMMETRY |
| 500 | #error "The Sequent Symmetry is no longer supported." |
| 501 | #endif |
| 502 | |
| 503 | /* According to the System V ABI, the registers %ebp, %ebx, %edi, %esi |
| 504 | and %esp "belong" to the calling function. Therefore these |
| 505 | registers should be saved if they're going to be modified. */ |
| 506 | |
| 507 | /* The maximum number of saved registers. This should include all |
| 508 | registers mentioned above, and %eip. */ |
| 509 | #define I386_NUM_SAVED_REGS I386_NUM_GREGS |
| 510 | |
| 511 | struct i386_frame_cache |
| 512 | { |
| 513 | /* Base address. */ |
| 514 | CORE_ADDR base; |
| 515 | LONGEST sp_offset; |
| 516 | CORE_ADDR pc; |
| 517 | |
| 518 | /* Saved registers. */ |
| 519 | CORE_ADDR saved_regs[I386_NUM_SAVED_REGS]; |
| 520 | CORE_ADDR saved_sp; |
| 521 | int saved_sp_reg; |
| 522 | int pc_in_eax; |
| 523 | |
| 524 | /* Stack space reserved for local variables. */ |
| 525 | long locals; |
| 526 | }; |
| 527 | |
| 528 | /* Allocate and initialize a frame cache. */ |
| 529 | |
| 530 | static struct i386_frame_cache * |
| 531 | i386_alloc_frame_cache (void) |
| 532 | { |
| 533 | struct i386_frame_cache *cache; |
| 534 | int i; |
| 535 | |
| 536 | cache = FRAME_OBSTACK_ZALLOC (struct i386_frame_cache); |
| 537 | |
| 538 | /* Base address. */ |
| 539 | cache->base = 0; |
| 540 | cache->sp_offset = -4; |
| 541 | cache->pc = 0; |
| 542 | |
| 543 | /* Saved registers. We initialize these to -1 since zero is a valid |
| 544 | offset (that's where %ebp is supposed to be stored). */ |
| 545 | for (i = 0; i < I386_NUM_SAVED_REGS; i++) |
| 546 | cache->saved_regs[i] = -1; |
| 547 | cache->saved_sp = 0; |
| 548 | cache->saved_sp_reg = -1; |
| 549 | cache->pc_in_eax = 0; |
| 550 | |
| 551 | /* Frameless until proven otherwise. */ |
| 552 | cache->locals = -1; |
| 553 | |
| 554 | return cache; |
| 555 | } |
| 556 | |
| 557 | /* If the instruction at PC is a jump, return the address of its |
| 558 | target. Otherwise, return PC. */ |
| 559 | |
| 560 | static CORE_ADDR |
| 561 | i386_follow_jump (CORE_ADDR pc) |
| 562 | { |
| 563 | gdb_byte op; |
| 564 | long delta = 0; |
| 565 | int data16 = 0; |
| 566 | |
| 567 | target_read_memory (pc, &op, 1); |
| 568 | if (op == 0x66) |
| 569 | { |
| 570 | data16 = 1; |
| 571 | op = read_memory_unsigned_integer (pc + 1, 1); |
| 572 | } |
| 573 | |
| 574 | switch (op) |
| 575 | { |
| 576 | case 0xe9: |
| 577 | /* Relative jump: if data16 == 0, disp32, else disp16. */ |
| 578 | if (data16) |
| 579 | { |
| 580 | delta = read_memory_integer (pc + 2, 2); |
| 581 | |
| 582 | /* Include the size of the jmp instruction (including the |
| 583 | 0x66 prefix). */ |
| 584 | delta += 4; |
| 585 | } |
| 586 | else |
| 587 | { |
| 588 | delta = read_memory_integer (pc + 1, 4); |
| 589 | |
| 590 | /* Include the size of the jmp instruction. */ |
| 591 | delta += 5; |
| 592 | } |
| 593 | break; |
| 594 | case 0xeb: |
| 595 | /* Relative jump, disp8 (ignore data16). */ |
| 596 | delta = read_memory_integer (pc + data16 + 1, 1); |
| 597 | |
| 598 | delta += data16 + 2; |
| 599 | break; |
| 600 | } |
| 601 | |
| 602 | return pc + delta; |
| 603 | } |
| 604 | |
| 605 | /* Check whether PC points at a prologue for a function returning a |
| 606 | structure or union. If so, it updates CACHE and returns the |
| 607 | address of the first instruction after the code sequence that |
| 608 | removes the "hidden" argument from the stack or CURRENT_PC, |
| 609 | whichever is smaller. Otherwise, return PC. */ |
| 610 | |
| 611 | static CORE_ADDR |
| 612 | i386_analyze_struct_return (CORE_ADDR pc, CORE_ADDR current_pc, |
| 613 | struct i386_frame_cache *cache) |
| 614 | { |
| 615 | /* Functions that return a structure or union start with: |
| 616 | |
| 617 | popl %eax 0x58 |
| 618 | xchgl %eax, (%esp) 0x87 0x04 0x24 |
| 619 | or xchgl %eax, 0(%esp) 0x87 0x44 0x24 0x00 |
| 620 | |
| 621 | (the System V compiler puts out the second `xchg' instruction, |
| 622 | and the assembler doesn't try to optimize it, so the 'sib' form |
| 623 | gets generated). This sequence is used to get the address of the |
| 624 | return buffer for a function that returns a structure. */ |
| 625 | static gdb_byte proto1[3] = { 0x87, 0x04, 0x24 }; |
| 626 | static gdb_byte proto2[4] = { 0x87, 0x44, 0x24, 0x00 }; |
| 627 | gdb_byte buf[4]; |
| 628 | gdb_byte op; |
| 629 | |
| 630 | if (current_pc <= pc) |
| 631 | return pc; |
| 632 | |
| 633 | target_read_memory (pc, &op, 1); |
| 634 | |
| 635 | if (op != 0x58) /* popl %eax */ |
| 636 | return pc; |
| 637 | |
| 638 | target_read_memory (pc + 1, buf, 4); |
| 639 | if (memcmp (buf, proto1, 3) != 0 && memcmp (buf, proto2, 4) != 0) |
| 640 | return pc; |
| 641 | |
| 642 | if (current_pc == pc) |
| 643 | { |
| 644 | cache->sp_offset += 4; |
| 645 | return current_pc; |
| 646 | } |
| 647 | |
| 648 | if (current_pc == pc + 1) |
| 649 | { |
| 650 | cache->pc_in_eax = 1; |
| 651 | return current_pc; |
| 652 | } |
| 653 | |
| 654 | if (buf[1] == proto1[1]) |
| 655 | return pc + 4; |
| 656 | else |
| 657 | return pc + 5; |
| 658 | } |
| 659 | |
| 660 | static CORE_ADDR |
| 661 | i386_skip_probe (CORE_ADDR pc) |
| 662 | { |
| 663 | /* A function may start with |
| 664 | |
| 665 | pushl constant |
| 666 | call _probe |
| 667 | addl $4, %esp |
| 668 | |
| 669 | followed by |
| 670 | |
| 671 | pushl %ebp |
| 672 | |
| 673 | etc. */ |
| 674 | gdb_byte buf[8]; |
| 675 | gdb_byte op; |
| 676 | |
| 677 | target_read_memory (pc, &op, 1); |
| 678 | |
| 679 | if (op == 0x68 || op == 0x6a) |
| 680 | { |
| 681 | int delta; |
| 682 | |
| 683 | /* Skip past the `pushl' instruction; it has either a one-byte or a |
| 684 | four-byte operand, depending on the opcode. */ |
| 685 | if (op == 0x68) |
| 686 | delta = 5; |
| 687 | else |
| 688 | delta = 2; |
| 689 | |
| 690 | /* Read the following 8 bytes, which should be `call _probe' (6 |
| 691 | bytes) followed by `addl $4,%esp' (2 bytes). */ |
| 692 | read_memory (pc + delta, buf, sizeof (buf)); |
| 693 | if (buf[0] == 0xe8 && buf[6] == 0xc4 && buf[7] == 0x4) |
| 694 | pc += delta + sizeof (buf); |
| 695 | } |
| 696 | |
| 697 | return pc; |
| 698 | } |
| 699 | |
| 700 | /* GCC 4.1 and later, can put code in the prologue to realign the |
| 701 | stack pointer. Check whether PC points to such code, and update |
| 702 | CACHE accordingly. Return the first instruction after the code |
| 703 | sequence or CURRENT_PC, whichever is smaller. If we don't |
| 704 | recognize the code, return PC. */ |
| 705 | |
| 706 | static CORE_ADDR |
| 707 | i386_analyze_stack_align (CORE_ADDR pc, CORE_ADDR current_pc, |
| 708 | struct i386_frame_cache *cache) |
| 709 | { |
| 710 | /* There are 2 code sequences to re-align stack before the frame |
| 711 | gets set up: |
| 712 | |
| 713 | 1. Use a caller-saved saved register: |
| 714 | |
| 715 | leal 4(%esp), %reg |
| 716 | andl $-XXX, %esp |
| 717 | pushl -4(%reg) |
| 718 | |
| 719 | 2. Use a callee-saved saved register: |
| 720 | |
| 721 | pushl %reg |
| 722 | leal 8(%esp), %reg |
| 723 | andl $-XXX, %esp |
| 724 | pushl -4(%reg) |
| 725 | |
| 726 | "andl $-XXX, %esp" can be either 3 bytes or 6 bytes: |
| 727 | |
| 728 | 0x83 0xe4 0xf0 andl $-16, %esp |
| 729 | 0x81 0xe4 0x00 0xff 0xff 0xff andl $-256, %esp |
| 730 | */ |
| 731 | |
| 732 | gdb_byte buf[14]; |
| 733 | int reg; |
| 734 | int offset, offset_and; |
| 735 | static int regnums[8] = { |
| 736 | I386_EAX_REGNUM, /* %eax */ |
| 737 | I386_ECX_REGNUM, /* %ecx */ |
| 738 | I386_EDX_REGNUM, /* %edx */ |
| 739 | I386_EBX_REGNUM, /* %ebx */ |
| 740 | I386_ESP_REGNUM, /* %esp */ |
| 741 | I386_EBP_REGNUM, /* %ebp */ |
| 742 | I386_ESI_REGNUM, /* %esi */ |
| 743 | I386_EDI_REGNUM /* %edi */ |
| 744 | }; |
| 745 | |
| 746 | if (target_read_memory (pc, buf, sizeof buf)) |
| 747 | return pc; |
| 748 | |
| 749 | /* Check caller-saved saved register. The first instruction has |
| 750 | to be "leal 4(%esp), %reg". */ |
| 751 | if (buf[0] == 0x8d && buf[2] == 0x24 && buf[3] == 0x4) |
| 752 | { |
| 753 | /* MOD must be binary 10 and R/M must be binary 100. */ |
| 754 | if ((buf[1] & 0xc7) != 0x44) |
| 755 | return pc; |
| 756 | |
| 757 | /* REG has register number. */ |
| 758 | reg = (buf[1] >> 3) & 7; |
| 759 | offset = 4; |
| 760 | } |
| 761 | else |
| 762 | { |
| 763 | /* Check callee-saved saved register. The first instruction |
| 764 | has to be "pushl %reg". */ |
| 765 | if ((buf[0] & 0xf8) != 0x50) |
| 766 | return pc; |
| 767 | |
| 768 | /* Get register. */ |
| 769 | reg = buf[0] & 0x7; |
| 770 | |
| 771 | /* The next instruction has to be "leal 8(%esp), %reg". */ |
| 772 | if (buf[1] != 0x8d || buf[3] != 0x24 || buf[4] != 0x8) |
| 773 | return pc; |
| 774 | |
| 775 | /* MOD must be binary 10 and R/M must be binary 100. */ |
| 776 | if ((buf[2] & 0xc7) != 0x44) |
| 777 | return pc; |
| 778 | |
| 779 | /* REG has register number. Registers in pushl and leal have to |
| 780 | be the same. */ |
| 781 | if (reg != ((buf[2] >> 3) & 7)) |
| 782 | return pc; |
| 783 | |
| 784 | offset = 5; |
| 785 | } |
| 786 | |
| 787 | /* Rigister can't be %esp nor %ebp. */ |
| 788 | if (reg == 4 || reg == 5) |
| 789 | return pc; |
| 790 | |
| 791 | /* The next instruction has to be "andl $-XXX, %esp". */ |
| 792 | if (buf[offset + 1] != 0xe4 |
| 793 | || (buf[offset] != 0x81 && buf[offset] != 0x83)) |
| 794 | return pc; |
| 795 | |
| 796 | offset_and = offset; |
| 797 | offset += buf[offset] == 0x81 ? 6 : 3; |
| 798 | |
| 799 | /* The next instruction has to be "pushl -4(%reg)". 8bit -4 is |
| 800 | 0xfc. REG must be binary 110 and MOD must be binary 01. */ |
| 801 | if (buf[offset] != 0xff |
| 802 | || buf[offset + 2] != 0xfc |
| 803 | || (buf[offset + 1] & 0xf8) != 0x70) |
| 804 | return pc; |
| 805 | |
| 806 | /* R/M has register. Registers in leal and pushl have to be the |
| 807 | same. */ |
| 808 | if (reg != (buf[offset + 1] & 7)) |
| 809 | return pc; |
| 810 | |
| 811 | if (current_pc > pc + offset_and) |
| 812 | cache->saved_sp_reg = regnums[reg]; |
| 813 | |
| 814 | return min (pc + offset + 3, current_pc); |
| 815 | } |
| 816 | |
| 817 | /* Maximum instruction length we need to handle. */ |
| 818 | #define I386_MAX_MATCHED_INSN_LEN 6 |
| 819 | |
| 820 | /* Instruction description. */ |
| 821 | struct i386_insn |
| 822 | { |
| 823 | size_t len; |
| 824 | gdb_byte insn[I386_MAX_MATCHED_INSN_LEN]; |
| 825 | gdb_byte mask[I386_MAX_MATCHED_INSN_LEN]; |
| 826 | }; |
| 827 | |
| 828 | /* Search for the instruction at PC in the list SKIP_INSNS. Return |
| 829 | the first instruction description that matches. Otherwise, return |
| 830 | NULL. */ |
| 831 | |
| 832 | static struct i386_insn * |
| 833 | i386_match_insn (CORE_ADDR pc, struct i386_insn *skip_insns) |
| 834 | { |
| 835 | struct i386_insn *insn; |
| 836 | gdb_byte op; |
| 837 | |
| 838 | target_read_memory (pc, &op, 1); |
| 839 | |
| 840 | for (insn = skip_insns; insn->len > 0; insn++) |
| 841 | { |
| 842 | if ((op & insn->mask[0]) == insn->insn[0]) |
| 843 | { |
| 844 | gdb_byte buf[I386_MAX_MATCHED_INSN_LEN - 1]; |
| 845 | int insn_matched = 1; |
| 846 | size_t i; |
| 847 | |
| 848 | gdb_assert (insn->len > 1); |
| 849 | gdb_assert (insn->len <= I386_MAX_MATCHED_INSN_LEN); |
| 850 | |
| 851 | target_read_memory (pc + 1, buf, insn->len - 1); |
| 852 | for (i = 1; i < insn->len; i++) |
| 853 | { |
| 854 | if ((buf[i - 1] & insn->mask[i]) != insn->insn[i]) |
| 855 | insn_matched = 0; |
| 856 | } |
| 857 | |
| 858 | if (insn_matched) |
| 859 | return insn; |
| 860 | } |
| 861 | } |
| 862 | |
| 863 | return NULL; |
| 864 | } |
| 865 | |
| 866 | /* Some special instructions that might be migrated by GCC into the |
| 867 | part of the prologue that sets up the new stack frame. Because the |
| 868 | stack frame hasn't been setup yet, no registers have been saved |
| 869 | yet, and only the scratch registers %eax, %ecx and %edx can be |
| 870 | touched. */ |
| 871 | |
| 872 | struct i386_insn i386_frame_setup_skip_insns[] = |
| 873 | { |
| 874 | /* Check for `movb imm8, r' and `movl imm32, r'. |
| 875 | |
| 876 | ??? Should we handle 16-bit operand-sizes here? */ |
| 877 | |
| 878 | /* `movb imm8, %al' and `movb imm8, %ah' */ |
| 879 | /* `movb imm8, %cl' and `movb imm8, %ch' */ |
| 880 | { 2, { 0xb0, 0x00 }, { 0xfa, 0x00 } }, |
| 881 | /* `movb imm8, %dl' and `movb imm8, %dh' */ |
| 882 | { 2, { 0xb2, 0x00 }, { 0xfb, 0x00 } }, |
| 883 | /* `movl imm32, %eax' and `movl imm32, %ecx' */ |
| 884 | { 5, { 0xb8 }, { 0xfe } }, |
| 885 | /* `movl imm32, %edx' */ |
| 886 | { 5, { 0xba }, { 0xff } }, |
| 887 | |
| 888 | /* Check for `mov imm32, r32'. Note that there is an alternative |
| 889 | encoding for `mov m32, %eax'. |
| 890 | |
| 891 | ??? Should we handle SIB adressing here? |
| 892 | ??? Should we handle 16-bit operand-sizes here? */ |
| 893 | |
| 894 | /* `movl m32, %eax' */ |
| 895 | { 5, { 0xa1 }, { 0xff } }, |
| 896 | /* `movl m32, %eax' and `mov; m32, %ecx' */ |
| 897 | { 6, { 0x89, 0x05 }, {0xff, 0xf7 } }, |
| 898 | /* `movl m32, %edx' */ |
| 899 | { 6, { 0x89, 0x15 }, {0xff, 0xff } }, |
| 900 | |
| 901 | /* Check for `xorl r32, r32' and the equivalent `subl r32, r32'. |
| 902 | Because of the symmetry, there are actually two ways to encode |
| 903 | these instructions; opcode bytes 0x29 and 0x2b for `subl' and |
| 904 | opcode bytes 0x31 and 0x33 for `xorl'. */ |
| 905 | |
| 906 | /* `subl %eax, %eax' */ |
| 907 | { 2, { 0x29, 0xc0 }, { 0xfd, 0xff } }, |
| 908 | /* `subl %ecx, %ecx' */ |
| 909 | { 2, { 0x29, 0xc9 }, { 0xfd, 0xff } }, |
| 910 | /* `subl %edx, %edx' */ |
| 911 | { 2, { 0x29, 0xd2 }, { 0xfd, 0xff } }, |
| 912 | /* `xorl %eax, %eax' */ |
| 913 | { 2, { 0x31, 0xc0 }, { 0xfd, 0xff } }, |
| 914 | /* `xorl %ecx, %ecx' */ |
| 915 | { 2, { 0x31, 0xc9 }, { 0xfd, 0xff } }, |
| 916 | /* `xorl %edx, %edx' */ |
| 917 | { 2, { 0x31, 0xd2 }, { 0xfd, 0xff } }, |
| 918 | { 0 } |
| 919 | }; |
| 920 | |
| 921 | |
| 922 | /* Check whether PC points to a no-op instruction. */ |
| 923 | static CORE_ADDR |
| 924 | i386_skip_noop (CORE_ADDR pc) |
| 925 | { |
| 926 | gdb_byte op; |
| 927 | int check = 1; |
| 928 | |
| 929 | target_read_memory (pc, &op, 1); |
| 930 | |
| 931 | while (check) |
| 932 | { |
| 933 | check = 0; |
| 934 | /* Ignore `nop' instruction. */ |
| 935 | if (op == 0x90) |
| 936 | { |
| 937 | pc += 1; |
| 938 | target_read_memory (pc, &op, 1); |
| 939 | check = 1; |
| 940 | } |
| 941 | /* Ignore no-op instruction `mov %edi, %edi'. |
| 942 | Microsoft system dlls often start with |
| 943 | a `mov %edi,%edi' instruction. |
| 944 | The 5 bytes before the function start are |
| 945 | filled with `nop' instructions. |
| 946 | This pattern can be used for hot-patching: |
| 947 | The `mov %edi, %edi' instruction can be replaced by a |
| 948 | near jump to the location of the 5 `nop' instructions |
| 949 | which can be replaced by a 32-bit jump to anywhere |
| 950 | in the 32-bit address space. */ |
| 951 | |
| 952 | else if (op == 0x8b) |
| 953 | { |
| 954 | target_read_memory (pc + 1, &op, 1); |
| 955 | if (op == 0xff) |
| 956 | { |
| 957 | pc += 2; |
| 958 | target_read_memory (pc, &op, 1); |
| 959 | check = 1; |
| 960 | } |
| 961 | } |
| 962 | } |
| 963 | return pc; |
| 964 | } |
| 965 | |
| 966 | /* Check whether PC points at a code that sets up a new stack frame. |
| 967 | If so, it updates CACHE and returns the address of the first |
| 968 | instruction after the sequence that sets up the frame or LIMIT, |
| 969 | whichever is smaller. If we don't recognize the code, return PC. */ |
| 970 | |
| 971 | static CORE_ADDR |
| 972 | i386_analyze_frame_setup (CORE_ADDR pc, CORE_ADDR limit, |
| 973 | struct i386_frame_cache *cache) |
| 974 | { |
| 975 | struct i386_insn *insn; |
| 976 | gdb_byte op; |
| 977 | int skip = 0; |
| 978 | |
| 979 | if (limit <= pc) |
| 980 | return limit; |
| 981 | |
| 982 | target_read_memory (pc, &op, 1); |
| 983 | |
| 984 | if (op == 0x55) /* pushl %ebp */ |
| 985 | { |
| 986 | /* Take into account that we've executed the `pushl %ebp' that |
| 987 | starts this instruction sequence. */ |
| 988 | cache->saved_regs[I386_EBP_REGNUM] = 0; |
| 989 | cache->sp_offset += 4; |
| 990 | pc++; |
| 991 | |
| 992 | /* If that's all, return now. */ |
| 993 | if (limit <= pc) |
| 994 | return limit; |
| 995 | |
| 996 | /* Check for some special instructions that might be migrated by |
| 997 | GCC into the prologue and skip them. At this point in the |
| 998 | prologue, code should only touch the scratch registers %eax, |
| 999 | %ecx and %edx, so while the number of posibilities is sheer, |
| 1000 | it is limited. |
| 1001 | |
| 1002 | Make sure we only skip these instructions if we later see the |
| 1003 | `movl %esp, %ebp' that actually sets up the frame. */ |
| 1004 | while (pc + skip < limit) |
| 1005 | { |
| 1006 | insn = i386_match_insn (pc + skip, i386_frame_setup_skip_insns); |
| 1007 | if (insn == NULL) |
| 1008 | break; |
| 1009 | |
| 1010 | skip += insn->len; |
| 1011 | } |
| 1012 | |
| 1013 | /* If that's all, return now. */ |
| 1014 | if (limit <= pc + skip) |
| 1015 | return limit; |
| 1016 | |
| 1017 | target_read_memory (pc + skip, &op, 1); |
| 1018 | |
| 1019 | /* Check for `movl %esp, %ebp' -- can be written in two ways. */ |
| 1020 | switch (op) |
| 1021 | { |
| 1022 | case 0x8b: |
| 1023 | if (read_memory_unsigned_integer (pc + skip + 1, 1) != 0xec) |
| 1024 | return pc; |
| 1025 | break; |
| 1026 | case 0x89: |
| 1027 | if (read_memory_unsigned_integer (pc + skip + 1, 1) != 0xe5) |
| 1028 | return pc; |
| 1029 | break; |
| 1030 | default: |
| 1031 | return pc; |
| 1032 | } |
| 1033 | |
| 1034 | /* OK, we actually have a frame. We just don't know how large |
| 1035 | it is yet. Set its size to zero. We'll adjust it if |
| 1036 | necessary. We also now commit to skipping the special |
| 1037 | instructions mentioned before. */ |
| 1038 | cache->locals = 0; |
| 1039 | pc += (skip + 2); |
| 1040 | |
| 1041 | /* If that's all, return now. */ |
| 1042 | if (limit <= pc) |
| 1043 | return limit; |
| 1044 | |
| 1045 | /* Check for stack adjustment |
| 1046 | |
| 1047 | subl $XXX, %esp |
| 1048 | |
| 1049 | NOTE: You can't subtract a 16-bit immediate from a 32-bit |
| 1050 | reg, so we don't have to worry about a data16 prefix. */ |
| 1051 | target_read_memory (pc, &op, 1); |
| 1052 | if (op == 0x83) |
| 1053 | { |
| 1054 | /* `subl' with 8-bit immediate. */ |
| 1055 | if (read_memory_unsigned_integer (pc + 1, 1) != 0xec) |
| 1056 | /* Some instruction starting with 0x83 other than `subl'. */ |
| 1057 | return pc; |
| 1058 | |
| 1059 | /* `subl' with signed 8-bit immediate (though it wouldn't |
| 1060 | make sense to be negative). */ |
| 1061 | cache->locals = read_memory_integer (pc + 2, 1); |
| 1062 | return pc + 3; |
| 1063 | } |
| 1064 | else if (op == 0x81) |
| 1065 | { |
| 1066 | /* Maybe it is `subl' with a 32-bit immediate. */ |
| 1067 | if (read_memory_unsigned_integer (pc + 1, 1) != 0xec) |
| 1068 | /* Some instruction starting with 0x81 other than `subl'. */ |
| 1069 | return pc; |
| 1070 | |
| 1071 | /* It is `subl' with a 32-bit immediate. */ |
| 1072 | cache->locals = read_memory_integer (pc + 2, 4); |
| 1073 | return pc + 6; |
| 1074 | } |
| 1075 | else |
| 1076 | { |
| 1077 | /* Some instruction other than `subl'. */ |
| 1078 | return pc; |
| 1079 | } |
| 1080 | } |
| 1081 | else if (op == 0xc8) /* enter */ |
| 1082 | { |
| 1083 | cache->locals = read_memory_unsigned_integer (pc + 1, 2); |
| 1084 | return pc + 4; |
| 1085 | } |
| 1086 | |
| 1087 | return pc; |
| 1088 | } |
| 1089 | |
| 1090 | /* Check whether PC points at code that saves registers on the stack. |
| 1091 | If so, it updates CACHE and returns the address of the first |
| 1092 | instruction after the register saves or CURRENT_PC, whichever is |
| 1093 | smaller. Otherwise, return PC. */ |
| 1094 | |
| 1095 | static CORE_ADDR |
| 1096 | i386_analyze_register_saves (CORE_ADDR pc, CORE_ADDR current_pc, |
| 1097 | struct i386_frame_cache *cache) |
| 1098 | { |
| 1099 | CORE_ADDR offset = 0; |
| 1100 | gdb_byte op; |
| 1101 | int i; |
| 1102 | |
| 1103 | if (cache->locals > 0) |
| 1104 | offset -= cache->locals; |
| 1105 | for (i = 0; i < 8 && pc < current_pc; i++) |
| 1106 | { |
| 1107 | target_read_memory (pc, &op, 1); |
| 1108 | if (op < 0x50 || op > 0x57) |
| 1109 | break; |
| 1110 | |
| 1111 | offset -= 4; |
| 1112 | cache->saved_regs[op - 0x50] = offset; |
| 1113 | cache->sp_offset += 4; |
| 1114 | pc++; |
| 1115 | } |
| 1116 | |
| 1117 | return pc; |
| 1118 | } |
| 1119 | |
| 1120 | /* Do a full analysis of the prologue at PC and update CACHE |
| 1121 | accordingly. Bail out early if CURRENT_PC is reached. Return the |
| 1122 | address where the analysis stopped. |
| 1123 | |
| 1124 | We handle these cases: |
| 1125 | |
| 1126 | The startup sequence can be at the start of the function, or the |
| 1127 | function can start with a branch to startup code at the end. |
| 1128 | |
| 1129 | %ebp can be set up with either the 'enter' instruction, or "pushl |
| 1130 | %ebp, movl %esp, %ebp" (`enter' is too slow to be useful, but was |
| 1131 | once used in the System V compiler). |
| 1132 | |
| 1133 | Local space is allocated just below the saved %ebp by either the |
| 1134 | 'enter' instruction, or by "subl $<size>, %esp". 'enter' has a |
| 1135 | 16-bit unsigned argument for space to allocate, and the 'addl' |
| 1136 | instruction could have either a signed byte, or 32-bit immediate. |
| 1137 | |
| 1138 | Next, the registers used by this function are pushed. With the |
| 1139 | System V compiler they will always be in the order: %edi, %esi, |
| 1140 | %ebx (and sometimes a harmless bug causes it to also save but not |
| 1141 | restore %eax); however, the code below is willing to see the pushes |
| 1142 | in any order, and will handle up to 8 of them. |
| 1143 | |
| 1144 | If the setup sequence is at the end of the function, then the next |
| 1145 | instruction will be a branch back to the start. */ |
| 1146 | |
| 1147 | static CORE_ADDR |
| 1148 | i386_analyze_prologue (CORE_ADDR pc, CORE_ADDR current_pc, |
| 1149 | struct i386_frame_cache *cache) |
| 1150 | { |
| 1151 | pc = i386_skip_noop (pc); |
| 1152 | pc = i386_follow_jump (pc); |
| 1153 | pc = i386_analyze_struct_return (pc, current_pc, cache); |
| 1154 | pc = i386_skip_probe (pc); |
| 1155 | pc = i386_analyze_stack_align (pc, current_pc, cache); |
| 1156 | pc = i386_analyze_frame_setup (pc, current_pc, cache); |
| 1157 | return i386_analyze_register_saves (pc, current_pc, cache); |
| 1158 | } |
| 1159 | |
| 1160 | /* Return PC of first real instruction. */ |
| 1161 | |
| 1162 | static CORE_ADDR |
| 1163 | i386_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR start_pc) |
| 1164 | { |
| 1165 | static gdb_byte pic_pat[6] = |
| 1166 | { |
| 1167 | 0xe8, 0, 0, 0, 0, /* call 0x0 */ |
| 1168 | 0x5b, /* popl %ebx */ |
| 1169 | }; |
| 1170 | struct i386_frame_cache cache; |
| 1171 | CORE_ADDR pc; |
| 1172 | gdb_byte op; |
| 1173 | int i; |
| 1174 | |
| 1175 | cache.locals = -1; |
| 1176 | pc = i386_analyze_prologue (start_pc, 0xffffffff, &cache); |
| 1177 | if (cache.locals < 0) |
| 1178 | return start_pc; |
| 1179 | |
| 1180 | /* Found valid frame setup. */ |
| 1181 | |
| 1182 | /* The native cc on SVR4 in -K PIC mode inserts the following code |
| 1183 | to get the address of the global offset table (GOT) into register |
| 1184 | %ebx: |
| 1185 | |
| 1186 | call 0x0 |
| 1187 | popl %ebx |
| 1188 | movl %ebx,x(%ebp) (optional) |
| 1189 | addl y,%ebx |
| 1190 | |
| 1191 | This code is with the rest of the prologue (at the end of the |
| 1192 | function), so we have to skip it to get to the first real |
| 1193 | instruction at the start of the function. */ |
| 1194 | |
| 1195 | for (i = 0; i < 6; i++) |
| 1196 | { |
| 1197 | target_read_memory (pc + i, &op, 1); |
| 1198 | if (pic_pat[i] != op) |
| 1199 | break; |
| 1200 | } |
| 1201 | if (i == 6) |
| 1202 | { |
| 1203 | int delta = 6; |
| 1204 | |
| 1205 | target_read_memory (pc + delta, &op, 1); |
| 1206 | |
| 1207 | if (op == 0x89) /* movl %ebx, x(%ebp) */ |
| 1208 | { |
| 1209 | op = read_memory_unsigned_integer (pc + delta + 1, 1); |
| 1210 | |
| 1211 | if (op == 0x5d) /* One byte offset from %ebp. */ |
| 1212 | delta += 3; |
| 1213 | else if (op == 0x9d) /* Four byte offset from %ebp. */ |
| 1214 | delta += 6; |
| 1215 | else /* Unexpected instruction. */ |
| 1216 | delta = 0; |
| 1217 | |
| 1218 | target_read_memory (pc + delta, &op, 1); |
| 1219 | } |
| 1220 | |
| 1221 | /* addl y,%ebx */ |
| 1222 | if (delta > 0 && op == 0x81 |
| 1223 | && read_memory_unsigned_integer (pc + delta + 1, 1) == 0xc3) |
| 1224 | { |
| 1225 | pc += delta + 6; |
| 1226 | } |
| 1227 | } |
| 1228 | |
| 1229 | /* If the function starts with a branch (to startup code at the end) |
| 1230 | the last instruction should bring us back to the first |
| 1231 | instruction of the real code. */ |
| 1232 | if (i386_follow_jump (start_pc) != start_pc) |
| 1233 | pc = i386_follow_jump (pc); |
| 1234 | |
| 1235 | return pc; |
| 1236 | } |
| 1237 | |
| 1238 | /* Check that the code pointed to by PC corresponds to a call to |
| 1239 | __main, skip it if so. Return PC otherwise. */ |
| 1240 | |
| 1241 | CORE_ADDR |
| 1242 | i386_skip_main_prologue (struct gdbarch *gdbarch, CORE_ADDR pc) |
| 1243 | { |
| 1244 | gdb_byte op; |
| 1245 | |
| 1246 | target_read_memory (pc, &op, 1); |
| 1247 | if (op == 0xe8) |
| 1248 | { |
| 1249 | gdb_byte buf[4]; |
| 1250 | |
| 1251 | if (target_read_memory (pc + 1, buf, sizeof buf) == 0) |
| 1252 | { |
| 1253 | /* Make sure address is computed correctly as a 32bit |
| 1254 | integer even if CORE_ADDR is 64 bit wide. */ |
| 1255 | struct minimal_symbol *s; |
| 1256 | CORE_ADDR call_dest = pc + 5 + extract_signed_integer (buf, 4); |
| 1257 | |
| 1258 | call_dest = call_dest & 0xffffffffU; |
| 1259 | s = lookup_minimal_symbol_by_pc (call_dest); |
| 1260 | if (s != NULL |
| 1261 | && SYMBOL_LINKAGE_NAME (s) != NULL |
| 1262 | && strcmp (SYMBOL_LINKAGE_NAME (s), "__main") == 0) |
| 1263 | pc += 5; |
| 1264 | } |
| 1265 | } |
| 1266 | |
| 1267 | return pc; |
| 1268 | } |
| 1269 | |
| 1270 | /* This function is 64-bit safe. */ |
| 1271 | |
| 1272 | static CORE_ADDR |
| 1273 | i386_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame) |
| 1274 | { |
| 1275 | gdb_byte buf[8]; |
| 1276 | |
| 1277 | frame_unwind_register (next_frame, gdbarch_pc_regnum (gdbarch), buf); |
| 1278 | return extract_typed_address (buf, builtin_type (gdbarch)->builtin_func_ptr); |
| 1279 | } |
| 1280 | \f |
| 1281 | |
| 1282 | /* Normal frames. */ |
| 1283 | |
| 1284 | static struct i386_frame_cache * |
| 1285 | i386_frame_cache (struct frame_info *this_frame, void **this_cache) |
| 1286 | { |
| 1287 | struct i386_frame_cache *cache; |
| 1288 | gdb_byte buf[4]; |
| 1289 | int i; |
| 1290 | |
| 1291 | if (*this_cache) |
| 1292 | return *this_cache; |
| 1293 | |
| 1294 | cache = i386_alloc_frame_cache (); |
| 1295 | *this_cache = cache; |
| 1296 | |
| 1297 | /* In principle, for normal frames, %ebp holds the frame pointer, |
| 1298 | which holds the base address for the current stack frame. |
| 1299 | However, for functions that don't need it, the frame pointer is |
| 1300 | optional. For these "frameless" functions the frame pointer is |
| 1301 | actually the frame pointer of the calling frame. Signal |
| 1302 | trampolines are just a special case of a "frameless" function. |
| 1303 | They (usually) share their frame pointer with the frame that was |
| 1304 | in progress when the signal occurred. */ |
| 1305 | |
| 1306 | get_frame_register (this_frame, I386_EBP_REGNUM, buf); |
| 1307 | cache->base = extract_unsigned_integer (buf, 4); |
| 1308 | if (cache->base == 0) |
| 1309 | return cache; |
| 1310 | |
| 1311 | /* For normal frames, %eip is stored at 4(%ebp). */ |
| 1312 | cache->saved_regs[I386_EIP_REGNUM] = 4; |
| 1313 | |
| 1314 | cache->pc = get_frame_func (this_frame); |
| 1315 | if (cache->pc != 0) |
| 1316 | i386_analyze_prologue (cache->pc, get_frame_pc (this_frame), cache); |
| 1317 | |
| 1318 | if (cache->saved_sp_reg != -1) |
| 1319 | { |
| 1320 | /* Saved stack pointer has been saved. */ |
| 1321 | get_frame_register (this_frame, cache->saved_sp_reg, buf); |
| 1322 | cache->saved_sp = extract_unsigned_integer(buf, 4); |
| 1323 | } |
| 1324 | |
| 1325 | if (cache->locals < 0) |
| 1326 | { |
| 1327 | /* We didn't find a valid frame, which means that CACHE->base |
| 1328 | currently holds the frame pointer for our calling frame. If |
| 1329 | we're at the start of a function, or somewhere half-way its |
| 1330 | prologue, the function's frame probably hasn't been fully |
| 1331 | setup yet. Try to reconstruct the base address for the stack |
| 1332 | frame by looking at the stack pointer. For truly "frameless" |
| 1333 | functions this might work too. */ |
| 1334 | |
| 1335 | if (cache->saved_sp_reg != -1) |
| 1336 | { |
| 1337 | /* We're halfway aligning the stack. */ |
| 1338 | cache->base = ((cache->saved_sp - 4) & 0xfffffff0) - 4; |
| 1339 | cache->saved_regs[I386_EIP_REGNUM] = cache->saved_sp - 4; |
| 1340 | |
| 1341 | /* This will be added back below. */ |
| 1342 | cache->saved_regs[I386_EIP_REGNUM] -= cache->base; |
| 1343 | } |
| 1344 | else |
| 1345 | { |
| 1346 | get_frame_register (this_frame, I386_ESP_REGNUM, buf); |
| 1347 | cache->base = extract_unsigned_integer (buf, 4) + cache->sp_offset; |
| 1348 | } |
| 1349 | } |
| 1350 | |
| 1351 | /* Now that we have the base address for the stack frame we can |
| 1352 | calculate the value of %esp in the calling frame. */ |
| 1353 | if (cache->saved_sp == 0) |
| 1354 | cache->saved_sp = cache->base + 8; |
| 1355 | |
| 1356 | /* Adjust all the saved registers such that they contain addresses |
| 1357 | instead of offsets. */ |
| 1358 | for (i = 0; i < I386_NUM_SAVED_REGS; i++) |
| 1359 | if (cache->saved_regs[i] != -1) |
| 1360 | cache->saved_regs[i] += cache->base; |
| 1361 | |
| 1362 | return cache; |
| 1363 | } |
| 1364 | |
| 1365 | static void |
| 1366 | i386_frame_this_id (struct frame_info *this_frame, void **this_cache, |
| 1367 | struct frame_id *this_id) |
| 1368 | { |
| 1369 | struct i386_frame_cache *cache = i386_frame_cache (this_frame, this_cache); |
| 1370 | |
| 1371 | /* This marks the outermost frame. */ |
| 1372 | if (cache->base == 0) |
| 1373 | return; |
| 1374 | |
| 1375 | /* See the end of i386_push_dummy_call. */ |
| 1376 | (*this_id) = frame_id_build (cache->base + 8, cache->pc); |
| 1377 | } |
| 1378 | |
| 1379 | static struct value * |
| 1380 | i386_frame_prev_register (struct frame_info *this_frame, void **this_cache, |
| 1381 | int regnum) |
| 1382 | { |
| 1383 | struct i386_frame_cache *cache = i386_frame_cache (this_frame, this_cache); |
| 1384 | |
| 1385 | gdb_assert (regnum >= 0); |
| 1386 | |
| 1387 | /* The System V ABI says that: |
| 1388 | |
| 1389 | "The flags register contains the system flags, such as the |
| 1390 | direction flag and the carry flag. The direction flag must be |
| 1391 | set to the forward (that is, zero) direction before entry and |
| 1392 | upon exit from a function. Other user flags have no specified |
| 1393 | role in the standard calling sequence and are not preserved." |
| 1394 | |
| 1395 | To guarantee the "upon exit" part of that statement we fake a |
| 1396 | saved flags register that has its direction flag cleared. |
| 1397 | |
| 1398 | Note that GCC doesn't seem to rely on the fact that the direction |
| 1399 | flag is cleared after a function return; it always explicitly |
| 1400 | clears the flag before operations where it matters. |
| 1401 | |
| 1402 | FIXME: kettenis/20030316: I'm not quite sure whether this is the |
| 1403 | right thing to do. The way we fake the flags register here makes |
| 1404 | it impossible to change it. */ |
| 1405 | |
| 1406 | if (regnum == I386_EFLAGS_REGNUM) |
| 1407 | { |
| 1408 | ULONGEST val; |
| 1409 | |
| 1410 | val = get_frame_register_unsigned (this_frame, regnum); |
| 1411 | val &= ~(1 << 10); |
| 1412 | return frame_unwind_got_constant (this_frame, regnum, val); |
| 1413 | } |
| 1414 | |
| 1415 | if (regnum == I386_EIP_REGNUM && cache->pc_in_eax) |
| 1416 | return frame_unwind_got_register (this_frame, regnum, I386_EAX_REGNUM); |
| 1417 | |
| 1418 | if (regnum == I386_ESP_REGNUM && cache->saved_sp) |
| 1419 | return frame_unwind_got_constant (this_frame, regnum, cache->saved_sp); |
| 1420 | |
| 1421 | if (regnum < I386_NUM_SAVED_REGS && cache->saved_regs[regnum] != -1) |
| 1422 | return frame_unwind_got_memory (this_frame, regnum, |
| 1423 | cache->saved_regs[regnum]); |
| 1424 | |
| 1425 | return frame_unwind_got_register (this_frame, regnum, regnum); |
| 1426 | } |
| 1427 | |
| 1428 | static const struct frame_unwind i386_frame_unwind = |
| 1429 | { |
| 1430 | NORMAL_FRAME, |
| 1431 | i386_frame_this_id, |
| 1432 | i386_frame_prev_register, |
| 1433 | NULL, |
| 1434 | default_frame_sniffer |
| 1435 | }; |
| 1436 | \f |
| 1437 | |
| 1438 | /* Signal trampolines. */ |
| 1439 | |
| 1440 | static struct i386_frame_cache * |
| 1441 | i386_sigtramp_frame_cache (struct frame_info *this_frame, void **this_cache) |
| 1442 | { |
| 1443 | struct i386_frame_cache *cache; |
| 1444 | struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame)); |
| 1445 | CORE_ADDR addr; |
| 1446 | gdb_byte buf[4]; |
| 1447 | |
| 1448 | if (*this_cache) |
| 1449 | return *this_cache; |
| 1450 | |
| 1451 | cache = i386_alloc_frame_cache (); |
| 1452 | |
| 1453 | get_frame_register (this_frame, I386_ESP_REGNUM, buf); |
| 1454 | cache->base = extract_unsigned_integer (buf, 4) - 4; |
| 1455 | |
| 1456 | addr = tdep->sigcontext_addr (this_frame); |
| 1457 | if (tdep->sc_reg_offset) |
| 1458 | { |
| 1459 | int i; |
| 1460 | |
| 1461 | gdb_assert (tdep->sc_num_regs <= I386_NUM_SAVED_REGS); |
| 1462 | |
| 1463 | for (i = 0; i < tdep->sc_num_regs; i++) |
| 1464 | if (tdep->sc_reg_offset[i] != -1) |
| 1465 | cache->saved_regs[i] = addr + tdep->sc_reg_offset[i]; |
| 1466 | } |
| 1467 | else |
| 1468 | { |
| 1469 | cache->saved_regs[I386_EIP_REGNUM] = addr + tdep->sc_pc_offset; |
| 1470 | cache->saved_regs[I386_ESP_REGNUM] = addr + tdep->sc_sp_offset; |
| 1471 | } |
| 1472 | |
| 1473 | *this_cache = cache; |
| 1474 | return cache; |
| 1475 | } |
| 1476 | |
| 1477 | static void |
| 1478 | i386_sigtramp_frame_this_id (struct frame_info *this_frame, void **this_cache, |
| 1479 | struct frame_id *this_id) |
| 1480 | { |
| 1481 | struct i386_frame_cache *cache = |
| 1482 | i386_sigtramp_frame_cache (this_frame, this_cache); |
| 1483 | |
| 1484 | /* See the end of i386_push_dummy_call. */ |
| 1485 | (*this_id) = frame_id_build (cache->base + 8, get_frame_pc (this_frame)); |
| 1486 | } |
| 1487 | |
| 1488 | static struct value * |
| 1489 | i386_sigtramp_frame_prev_register (struct frame_info *this_frame, |
| 1490 | void **this_cache, int regnum) |
| 1491 | { |
| 1492 | /* Make sure we've initialized the cache. */ |
| 1493 | i386_sigtramp_frame_cache (this_frame, this_cache); |
| 1494 | |
| 1495 | return i386_frame_prev_register (this_frame, this_cache, regnum); |
| 1496 | } |
| 1497 | |
| 1498 | static int |
| 1499 | i386_sigtramp_frame_sniffer (const struct frame_unwind *self, |
| 1500 | struct frame_info *this_frame, |
| 1501 | void **this_prologue_cache) |
| 1502 | { |
| 1503 | struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame)); |
| 1504 | |
| 1505 | /* We shouldn't even bother if we don't have a sigcontext_addr |
| 1506 | handler. */ |
| 1507 | if (tdep->sigcontext_addr == NULL) |
| 1508 | return 0; |
| 1509 | |
| 1510 | if (tdep->sigtramp_p != NULL) |
| 1511 | { |
| 1512 | if (tdep->sigtramp_p (this_frame)) |
| 1513 | return 1; |
| 1514 | } |
| 1515 | |
| 1516 | if (tdep->sigtramp_start != 0) |
| 1517 | { |
| 1518 | CORE_ADDR pc = get_frame_pc (this_frame); |
| 1519 | |
| 1520 | gdb_assert (tdep->sigtramp_end != 0); |
| 1521 | if (pc >= tdep->sigtramp_start && pc < tdep->sigtramp_end) |
| 1522 | return 1; |
| 1523 | } |
| 1524 | |
| 1525 | return 0; |
| 1526 | } |
| 1527 | |
| 1528 | static const struct frame_unwind i386_sigtramp_frame_unwind = |
| 1529 | { |
| 1530 | SIGTRAMP_FRAME, |
| 1531 | i386_sigtramp_frame_this_id, |
| 1532 | i386_sigtramp_frame_prev_register, |
| 1533 | NULL, |
| 1534 | i386_sigtramp_frame_sniffer |
| 1535 | }; |
| 1536 | \f |
| 1537 | |
| 1538 | static CORE_ADDR |
| 1539 | i386_frame_base_address (struct frame_info *this_frame, void **this_cache) |
| 1540 | { |
| 1541 | struct i386_frame_cache *cache = i386_frame_cache (this_frame, this_cache); |
| 1542 | |
| 1543 | return cache->base; |
| 1544 | } |
| 1545 | |
| 1546 | static const struct frame_base i386_frame_base = |
| 1547 | { |
| 1548 | &i386_frame_unwind, |
| 1549 | i386_frame_base_address, |
| 1550 | i386_frame_base_address, |
| 1551 | i386_frame_base_address |
| 1552 | }; |
| 1553 | |
| 1554 | static struct frame_id |
| 1555 | i386_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame) |
| 1556 | { |
| 1557 | CORE_ADDR fp; |
| 1558 | |
| 1559 | fp = get_frame_register_unsigned (this_frame, I386_EBP_REGNUM); |
| 1560 | |
| 1561 | /* See the end of i386_push_dummy_call. */ |
| 1562 | return frame_id_build (fp + 8, get_frame_pc (this_frame)); |
| 1563 | } |
| 1564 | \f |
| 1565 | |
| 1566 | /* Figure out where the longjmp will land. Slurp the args out of the |
| 1567 | stack. We expect the first arg to be a pointer to the jmp_buf |
| 1568 | structure from which we extract the address that we will land at. |
| 1569 | This address is copied into PC. This routine returns non-zero on |
| 1570 | success. */ |
| 1571 | |
| 1572 | static int |
| 1573 | i386_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc) |
| 1574 | { |
| 1575 | gdb_byte buf[4]; |
| 1576 | CORE_ADDR sp, jb_addr; |
| 1577 | struct gdbarch *gdbarch = get_frame_arch (frame); |
| 1578 | int jb_pc_offset = gdbarch_tdep (gdbarch)->jb_pc_offset; |
| 1579 | |
| 1580 | /* If JB_PC_OFFSET is -1, we have no way to find out where the |
| 1581 | longjmp will land. */ |
| 1582 | if (jb_pc_offset == -1) |
| 1583 | return 0; |
| 1584 | |
| 1585 | get_frame_register (frame, I386_ESP_REGNUM, buf); |
| 1586 | sp = extract_unsigned_integer (buf, 4); |
| 1587 | if (target_read_memory (sp + 4, buf, 4)) |
| 1588 | return 0; |
| 1589 | |
| 1590 | jb_addr = extract_unsigned_integer (buf, 4); |
| 1591 | if (target_read_memory (jb_addr + jb_pc_offset, buf, 4)) |
| 1592 | return 0; |
| 1593 | |
| 1594 | *pc = extract_unsigned_integer (buf, 4); |
| 1595 | return 1; |
| 1596 | } |
| 1597 | \f |
| 1598 | |
| 1599 | /* Check whether TYPE must be 16-byte-aligned when passed as a |
| 1600 | function argument. 16-byte vectors, _Decimal128 and structures or |
| 1601 | unions containing such types must be 16-byte-aligned; other |
| 1602 | arguments are 4-byte-aligned. */ |
| 1603 | |
| 1604 | static int |
| 1605 | i386_16_byte_align_p (struct type *type) |
| 1606 | { |
| 1607 | type = check_typedef (type); |
| 1608 | if ((TYPE_CODE (type) == TYPE_CODE_DECFLOAT |
| 1609 | || (TYPE_CODE (type) == TYPE_CODE_ARRAY && TYPE_VECTOR (type))) |
| 1610 | && TYPE_LENGTH (type) == 16) |
| 1611 | return 1; |
| 1612 | if (TYPE_CODE (type) == TYPE_CODE_ARRAY) |
| 1613 | return i386_16_byte_align_p (TYPE_TARGET_TYPE (type)); |
| 1614 | if (TYPE_CODE (type) == TYPE_CODE_STRUCT |
| 1615 | || TYPE_CODE (type) == TYPE_CODE_UNION) |
| 1616 | { |
| 1617 | int i; |
| 1618 | for (i = 0; i < TYPE_NFIELDS (type); i++) |
| 1619 | { |
| 1620 | if (i386_16_byte_align_p (TYPE_FIELD_TYPE (type, i))) |
| 1621 | return 1; |
| 1622 | } |
| 1623 | } |
| 1624 | return 0; |
| 1625 | } |
| 1626 | |
| 1627 | static CORE_ADDR |
| 1628 | i386_push_dummy_call (struct gdbarch *gdbarch, struct value *function, |
| 1629 | struct regcache *regcache, CORE_ADDR bp_addr, int nargs, |
| 1630 | struct value **args, CORE_ADDR sp, int struct_return, |
| 1631 | CORE_ADDR struct_addr) |
| 1632 | { |
| 1633 | gdb_byte buf[4]; |
| 1634 | int i; |
| 1635 | int write_pass; |
| 1636 | int args_space = 0; |
| 1637 | |
| 1638 | /* Determine the total space required for arguments and struct |
| 1639 | return address in a first pass (allowing for 16-byte-aligned |
| 1640 | arguments), then push arguments in a second pass. */ |
| 1641 | |
| 1642 | for (write_pass = 0; write_pass < 2; write_pass++) |
| 1643 | { |
| 1644 | int args_space_used = 0; |
| 1645 | int have_16_byte_aligned_arg = 0; |
| 1646 | |
| 1647 | if (struct_return) |
| 1648 | { |
| 1649 | if (write_pass) |
| 1650 | { |
| 1651 | /* Push value address. */ |
| 1652 | store_unsigned_integer (buf, 4, struct_addr); |
| 1653 | write_memory (sp, buf, 4); |
| 1654 | args_space_used += 4; |
| 1655 | } |
| 1656 | else |
| 1657 | args_space += 4; |
| 1658 | } |
| 1659 | |
| 1660 | for (i = 0; i < nargs; i++) |
| 1661 | { |
| 1662 | int len = TYPE_LENGTH (value_enclosing_type (args[i])); |
| 1663 | |
| 1664 | if (write_pass) |
| 1665 | { |
| 1666 | if (i386_16_byte_align_p (value_enclosing_type (args[i]))) |
| 1667 | args_space_used = align_up (args_space_used, 16); |
| 1668 | |
| 1669 | write_memory (sp + args_space_used, |
| 1670 | value_contents_all (args[i]), len); |
| 1671 | /* The System V ABI says that: |
| 1672 | |
| 1673 | "An argument's size is increased, if necessary, to make it a |
| 1674 | multiple of [32-bit] words. This may require tail padding, |
| 1675 | depending on the size of the argument." |
| 1676 | |
| 1677 | This makes sure the stack stays word-aligned. */ |
| 1678 | args_space_used += align_up (len, 4); |
| 1679 | } |
| 1680 | else |
| 1681 | { |
| 1682 | if (i386_16_byte_align_p (value_enclosing_type (args[i]))) |
| 1683 | { |
| 1684 | args_space = align_up (args_space, 16); |
| 1685 | have_16_byte_aligned_arg = 1; |
| 1686 | } |
| 1687 | args_space += align_up (len, 4); |
| 1688 | } |
| 1689 | } |
| 1690 | |
| 1691 | if (!write_pass) |
| 1692 | { |
| 1693 | if (have_16_byte_aligned_arg) |
| 1694 | args_space = align_up (args_space, 16); |
| 1695 | sp -= args_space; |
| 1696 | } |
| 1697 | } |
| 1698 | |
| 1699 | /* Store return address. */ |
| 1700 | sp -= 4; |
| 1701 | store_unsigned_integer (buf, 4, bp_addr); |
| 1702 | write_memory (sp, buf, 4); |
| 1703 | |
| 1704 | /* Finally, update the stack pointer... */ |
| 1705 | store_unsigned_integer (buf, 4, sp); |
| 1706 | regcache_cooked_write (regcache, I386_ESP_REGNUM, buf); |
| 1707 | |
| 1708 | /* ...and fake a frame pointer. */ |
| 1709 | regcache_cooked_write (regcache, I386_EBP_REGNUM, buf); |
| 1710 | |
| 1711 | /* MarkK wrote: This "+ 8" is all over the place: |
| 1712 | (i386_frame_this_id, i386_sigtramp_frame_this_id, |
| 1713 | i386_dummy_id). It's there, since all frame unwinders for |
| 1714 | a given target have to agree (within a certain margin) on the |
| 1715 | definition of the stack address of a frame. Otherwise frame id |
| 1716 | comparison might not work correctly. Since DWARF2/GCC uses the |
| 1717 | stack address *before* the function call as a frame's CFA. On |
| 1718 | the i386, when %ebp is used as a frame pointer, the offset |
| 1719 | between the contents %ebp and the CFA as defined by GCC. */ |
| 1720 | return sp + 8; |
| 1721 | } |
| 1722 | |
| 1723 | /* These registers are used for returning integers (and on some |
| 1724 | targets also for returning `struct' and `union' values when their |
| 1725 | size and alignment match an integer type). */ |
| 1726 | #define LOW_RETURN_REGNUM I386_EAX_REGNUM /* %eax */ |
| 1727 | #define HIGH_RETURN_REGNUM I386_EDX_REGNUM /* %edx */ |
| 1728 | |
| 1729 | /* Read, for architecture GDBARCH, a function return value of TYPE |
| 1730 | from REGCACHE, and copy that into VALBUF. */ |
| 1731 | |
| 1732 | static void |
| 1733 | i386_extract_return_value (struct gdbarch *gdbarch, struct type *type, |
| 1734 | struct regcache *regcache, gdb_byte *valbuf) |
| 1735 | { |
| 1736 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 1737 | int len = TYPE_LENGTH (type); |
| 1738 | gdb_byte buf[I386_MAX_REGISTER_SIZE]; |
| 1739 | |
| 1740 | if (TYPE_CODE (type) == TYPE_CODE_FLT) |
| 1741 | { |
| 1742 | if (tdep->st0_regnum < 0) |
| 1743 | { |
| 1744 | warning (_("Cannot find floating-point return value.")); |
| 1745 | memset (valbuf, 0, len); |
| 1746 | return; |
| 1747 | } |
| 1748 | |
| 1749 | /* Floating-point return values can be found in %st(0). Convert |
| 1750 | its contents to the desired type. This is probably not |
| 1751 | exactly how it would happen on the target itself, but it is |
| 1752 | the best we can do. */ |
| 1753 | regcache_raw_read (regcache, I386_ST0_REGNUM, buf); |
| 1754 | convert_typed_floating (buf, builtin_type_i387_ext, valbuf, type); |
| 1755 | } |
| 1756 | else |
| 1757 | { |
| 1758 | int low_size = register_size (gdbarch, LOW_RETURN_REGNUM); |
| 1759 | int high_size = register_size (gdbarch, HIGH_RETURN_REGNUM); |
| 1760 | |
| 1761 | if (len <= low_size) |
| 1762 | { |
| 1763 | regcache_raw_read (regcache, LOW_RETURN_REGNUM, buf); |
| 1764 | memcpy (valbuf, buf, len); |
| 1765 | } |
| 1766 | else if (len <= (low_size + high_size)) |
| 1767 | { |
| 1768 | regcache_raw_read (regcache, LOW_RETURN_REGNUM, buf); |
| 1769 | memcpy (valbuf, buf, low_size); |
| 1770 | regcache_raw_read (regcache, HIGH_RETURN_REGNUM, buf); |
| 1771 | memcpy (valbuf + low_size, buf, len - low_size); |
| 1772 | } |
| 1773 | else |
| 1774 | internal_error (__FILE__, __LINE__, |
| 1775 | _("Cannot extract return value of %d bytes long."), len); |
| 1776 | } |
| 1777 | } |
| 1778 | |
| 1779 | /* Write, for architecture GDBARCH, a function return value of TYPE |
| 1780 | from VALBUF into REGCACHE. */ |
| 1781 | |
| 1782 | static void |
| 1783 | i386_store_return_value (struct gdbarch *gdbarch, struct type *type, |
| 1784 | struct regcache *regcache, const gdb_byte *valbuf) |
| 1785 | { |
| 1786 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 1787 | int len = TYPE_LENGTH (type); |
| 1788 | |
| 1789 | if (TYPE_CODE (type) == TYPE_CODE_FLT) |
| 1790 | { |
| 1791 | ULONGEST fstat; |
| 1792 | gdb_byte buf[I386_MAX_REGISTER_SIZE]; |
| 1793 | |
| 1794 | if (tdep->st0_regnum < 0) |
| 1795 | { |
| 1796 | warning (_("Cannot set floating-point return value.")); |
| 1797 | return; |
| 1798 | } |
| 1799 | |
| 1800 | /* Returning floating-point values is a bit tricky. Apart from |
| 1801 | storing the return value in %st(0), we have to simulate the |
| 1802 | state of the FPU at function return point. */ |
| 1803 | |
| 1804 | /* Convert the value found in VALBUF to the extended |
| 1805 | floating-point format used by the FPU. This is probably |
| 1806 | not exactly how it would happen on the target itself, but |
| 1807 | it is the best we can do. */ |
| 1808 | convert_typed_floating (valbuf, type, buf, builtin_type_i387_ext); |
| 1809 | regcache_raw_write (regcache, I386_ST0_REGNUM, buf); |
| 1810 | |
| 1811 | /* Set the top of the floating-point register stack to 7. The |
| 1812 | actual value doesn't really matter, but 7 is what a normal |
| 1813 | function return would end up with if the program started out |
| 1814 | with a freshly initialized FPU. */ |
| 1815 | regcache_raw_read_unsigned (regcache, I387_FSTAT_REGNUM (tdep), &fstat); |
| 1816 | fstat |= (7 << 11); |
| 1817 | regcache_raw_write_unsigned (regcache, I387_FSTAT_REGNUM (tdep), fstat); |
| 1818 | |
| 1819 | /* Mark %st(1) through %st(7) as empty. Since we set the top of |
| 1820 | the floating-point register stack to 7, the appropriate value |
| 1821 | for the tag word is 0x3fff. */ |
| 1822 | regcache_raw_write_unsigned (regcache, I387_FTAG_REGNUM (tdep), 0x3fff); |
| 1823 | } |
| 1824 | else |
| 1825 | { |
| 1826 | int low_size = register_size (gdbarch, LOW_RETURN_REGNUM); |
| 1827 | int high_size = register_size (gdbarch, HIGH_RETURN_REGNUM); |
| 1828 | |
| 1829 | if (len <= low_size) |
| 1830 | regcache_raw_write_part (regcache, LOW_RETURN_REGNUM, 0, len, valbuf); |
| 1831 | else if (len <= (low_size + high_size)) |
| 1832 | { |
| 1833 | regcache_raw_write (regcache, LOW_RETURN_REGNUM, valbuf); |
| 1834 | regcache_raw_write_part (regcache, HIGH_RETURN_REGNUM, 0, |
| 1835 | len - low_size, valbuf + low_size); |
| 1836 | } |
| 1837 | else |
| 1838 | internal_error (__FILE__, __LINE__, |
| 1839 | _("Cannot store return value of %d bytes long."), len); |
| 1840 | } |
| 1841 | } |
| 1842 | \f |
| 1843 | |
| 1844 | /* This is the variable that is set with "set struct-convention", and |
| 1845 | its legitimate values. */ |
| 1846 | static const char default_struct_convention[] = "default"; |
| 1847 | static const char pcc_struct_convention[] = "pcc"; |
| 1848 | static const char reg_struct_convention[] = "reg"; |
| 1849 | static const char *valid_conventions[] = |
| 1850 | { |
| 1851 | default_struct_convention, |
| 1852 | pcc_struct_convention, |
| 1853 | reg_struct_convention, |
| 1854 | NULL |
| 1855 | }; |
| 1856 | static const char *struct_convention = default_struct_convention; |
| 1857 | |
| 1858 | /* Return non-zero if TYPE, which is assumed to be a structure, |
| 1859 | a union type, or an array type, should be returned in registers |
| 1860 | for architecture GDBARCH. */ |
| 1861 | |
| 1862 | static int |
| 1863 | i386_reg_struct_return_p (struct gdbarch *gdbarch, struct type *type) |
| 1864 | { |
| 1865 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 1866 | enum type_code code = TYPE_CODE (type); |
| 1867 | int len = TYPE_LENGTH (type); |
| 1868 | |
| 1869 | gdb_assert (code == TYPE_CODE_STRUCT |
| 1870 | || code == TYPE_CODE_UNION |
| 1871 | || code == TYPE_CODE_ARRAY); |
| 1872 | |
| 1873 | if (struct_convention == pcc_struct_convention |
| 1874 | || (struct_convention == default_struct_convention |
| 1875 | && tdep->struct_return == pcc_struct_return)) |
| 1876 | return 0; |
| 1877 | |
| 1878 | /* Structures consisting of a single `float', `double' or 'long |
| 1879 | double' member are returned in %st(0). */ |
| 1880 | if (code == TYPE_CODE_STRUCT && TYPE_NFIELDS (type) == 1) |
| 1881 | { |
| 1882 | type = check_typedef (TYPE_FIELD_TYPE (type, 0)); |
| 1883 | if (TYPE_CODE (type) == TYPE_CODE_FLT) |
| 1884 | return (len == 4 || len == 8 || len == 12); |
| 1885 | } |
| 1886 | |
| 1887 | return (len == 1 || len == 2 || len == 4 || len == 8); |
| 1888 | } |
| 1889 | |
| 1890 | /* Determine, for architecture GDBARCH, how a return value of TYPE |
| 1891 | should be returned. If it is supposed to be returned in registers, |
| 1892 | and READBUF is non-zero, read the appropriate value from REGCACHE, |
| 1893 | and copy it into READBUF. If WRITEBUF is non-zero, write the value |
| 1894 | from WRITEBUF into REGCACHE. */ |
| 1895 | |
| 1896 | static enum return_value_convention |
| 1897 | i386_return_value (struct gdbarch *gdbarch, struct type *func_type, |
| 1898 | struct type *type, struct regcache *regcache, |
| 1899 | gdb_byte *readbuf, const gdb_byte *writebuf) |
| 1900 | { |
| 1901 | enum type_code code = TYPE_CODE (type); |
| 1902 | |
| 1903 | if (((code == TYPE_CODE_STRUCT |
| 1904 | || code == TYPE_CODE_UNION |
| 1905 | || code == TYPE_CODE_ARRAY) |
| 1906 | && !i386_reg_struct_return_p (gdbarch, type)) |
| 1907 | /* 128-bit decimal float uses the struct return convention. */ |
| 1908 | || (code == TYPE_CODE_DECFLOAT && TYPE_LENGTH (type) == 16)) |
| 1909 | { |
| 1910 | /* The System V ABI says that: |
| 1911 | |
| 1912 | "A function that returns a structure or union also sets %eax |
| 1913 | to the value of the original address of the caller's area |
| 1914 | before it returns. Thus when the caller receives control |
| 1915 | again, the address of the returned object resides in register |
| 1916 | %eax and can be used to access the object." |
| 1917 | |
| 1918 | So the ABI guarantees that we can always find the return |
| 1919 | value just after the function has returned. */ |
| 1920 | |
| 1921 | /* Note that the ABI doesn't mention functions returning arrays, |
| 1922 | which is something possible in certain languages such as Ada. |
| 1923 | In this case, the value is returned as if it was wrapped in |
| 1924 | a record, so the convention applied to records also applies |
| 1925 | to arrays. */ |
| 1926 | |
| 1927 | if (readbuf) |
| 1928 | { |
| 1929 | ULONGEST addr; |
| 1930 | |
| 1931 | regcache_raw_read_unsigned (regcache, I386_EAX_REGNUM, &addr); |
| 1932 | read_memory (addr, readbuf, TYPE_LENGTH (type)); |
| 1933 | } |
| 1934 | |
| 1935 | return RETURN_VALUE_ABI_RETURNS_ADDRESS; |
| 1936 | } |
| 1937 | |
| 1938 | /* This special case is for structures consisting of a single |
| 1939 | `float', `double' or 'long double' member. These structures are |
| 1940 | returned in %st(0). For these structures, we call ourselves |
| 1941 | recursively, changing TYPE into the type of the first member of |
| 1942 | the structure. Since that should work for all structures that |
| 1943 | have only one member, we don't bother to check the member's type |
| 1944 | here. */ |
| 1945 | if (code == TYPE_CODE_STRUCT && TYPE_NFIELDS (type) == 1) |
| 1946 | { |
| 1947 | type = check_typedef (TYPE_FIELD_TYPE (type, 0)); |
| 1948 | return i386_return_value (gdbarch, func_type, type, regcache, |
| 1949 | readbuf, writebuf); |
| 1950 | } |
| 1951 | |
| 1952 | if (readbuf) |
| 1953 | i386_extract_return_value (gdbarch, type, regcache, readbuf); |
| 1954 | if (writebuf) |
| 1955 | i386_store_return_value (gdbarch, type, regcache, writebuf); |
| 1956 | |
| 1957 | return RETURN_VALUE_REGISTER_CONVENTION; |
| 1958 | } |
| 1959 | \f |
| 1960 | |
| 1961 | /* Type for %eflags. */ |
| 1962 | struct type *i386_eflags_type; |
| 1963 | |
| 1964 | /* Type for %mxcsr. */ |
| 1965 | struct type *i386_mxcsr_type; |
| 1966 | |
| 1967 | /* Construct types for ISA-specific registers. */ |
| 1968 | static void |
| 1969 | i386_init_types (void) |
| 1970 | { |
| 1971 | struct type *type; |
| 1972 | |
| 1973 | type = init_flags_type ("builtin_type_i386_eflags", 4); |
| 1974 | append_flags_type_flag (type, 0, "CF"); |
| 1975 | append_flags_type_flag (type, 1, NULL); |
| 1976 | append_flags_type_flag (type, 2, "PF"); |
| 1977 | append_flags_type_flag (type, 4, "AF"); |
| 1978 | append_flags_type_flag (type, 6, "ZF"); |
| 1979 | append_flags_type_flag (type, 7, "SF"); |
| 1980 | append_flags_type_flag (type, 8, "TF"); |
| 1981 | append_flags_type_flag (type, 9, "IF"); |
| 1982 | append_flags_type_flag (type, 10, "DF"); |
| 1983 | append_flags_type_flag (type, 11, "OF"); |
| 1984 | append_flags_type_flag (type, 14, "NT"); |
| 1985 | append_flags_type_flag (type, 16, "RF"); |
| 1986 | append_flags_type_flag (type, 17, "VM"); |
| 1987 | append_flags_type_flag (type, 18, "AC"); |
| 1988 | append_flags_type_flag (type, 19, "VIF"); |
| 1989 | append_flags_type_flag (type, 20, "VIP"); |
| 1990 | append_flags_type_flag (type, 21, "ID"); |
| 1991 | i386_eflags_type = type; |
| 1992 | |
| 1993 | type = init_flags_type ("builtin_type_i386_mxcsr", 4); |
| 1994 | append_flags_type_flag (type, 0, "IE"); |
| 1995 | append_flags_type_flag (type, 1, "DE"); |
| 1996 | append_flags_type_flag (type, 2, "ZE"); |
| 1997 | append_flags_type_flag (type, 3, "OE"); |
| 1998 | append_flags_type_flag (type, 4, "UE"); |
| 1999 | append_flags_type_flag (type, 5, "PE"); |
| 2000 | append_flags_type_flag (type, 6, "DAZ"); |
| 2001 | append_flags_type_flag (type, 7, "IM"); |
| 2002 | append_flags_type_flag (type, 8, "DM"); |
| 2003 | append_flags_type_flag (type, 9, "ZM"); |
| 2004 | append_flags_type_flag (type, 10, "OM"); |
| 2005 | append_flags_type_flag (type, 11, "UM"); |
| 2006 | append_flags_type_flag (type, 12, "PM"); |
| 2007 | append_flags_type_flag (type, 15, "FZ"); |
| 2008 | i386_mxcsr_type = type; |
| 2009 | } |
| 2010 | |
| 2011 | /* Construct vector type for MMX registers. */ |
| 2012 | struct type * |
| 2013 | i386_mmx_type (struct gdbarch *gdbarch) |
| 2014 | { |
| 2015 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 2016 | |
| 2017 | if (!tdep->i386_mmx_type) |
| 2018 | { |
| 2019 | /* The type we're building is this: */ |
| 2020 | #if 0 |
| 2021 | union __gdb_builtin_type_vec64i |
| 2022 | { |
| 2023 | int64_t uint64; |
| 2024 | int32_t v2_int32[2]; |
| 2025 | int16_t v4_int16[4]; |
| 2026 | int8_t v8_int8[8]; |
| 2027 | }; |
| 2028 | #endif |
| 2029 | |
| 2030 | struct type *t; |
| 2031 | |
| 2032 | t = init_composite_type ("__gdb_builtin_type_vec64i", TYPE_CODE_UNION); |
| 2033 | append_composite_type_field (t, "uint64", builtin_type_int64); |
| 2034 | append_composite_type_field (t, "v2_int32", |
| 2035 | init_vector_type (builtin_type_int32, 2)); |
| 2036 | append_composite_type_field (t, "v4_int16", |
| 2037 | init_vector_type (builtin_type_int16, 4)); |
| 2038 | append_composite_type_field (t, "v8_int8", |
| 2039 | init_vector_type (builtin_type_int8, 8)); |
| 2040 | |
| 2041 | TYPE_VECTOR (t) = 1; |
| 2042 | TYPE_NAME (t) = "builtin_type_vec64i"; |
| 2043 | tdep->i386_mmx_type = t; |
| 2044 | } |
| 2045 | |
| 2046 | return tdep->i386_mmx_type; |
| 2047 | } |
| 2048 | |
| 2049 | struct type * |
| 2050 | i386_sse_type (struct gdbarch *gdbarch) |
| 2051 | { |
| 2052 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 2053 | |
| 2054 | if (!tdep->i386_sse_type) |
| 2055 | { |
| 2056 | /* The type we're building is this: */ |
| 2057 | #if 0 |
| 2058 | union __gdb_builtin_type_vec128i |
| 2059 | { |
| 2060 | int128_t uint128; |
| 2061 | int64_t v2_int64[2]; |
| 2062 | int32_t v4_int32[4]; |
| 2063 | int16_t v8_int16[8]; |
| 2064 | int8_t v16_int8[16]; |
| 2065 | double v2_double[2]; |
| 2066 | float v4_float[4]; |
| 2067 | }; |
| 2068 | #endif |
| 2069 | |
| 2070 | struct type *t; |
| 2071 | |
| 2072 | t = init_composite_type ("__gdb_builtin_type_vec128i", TYPE_CODE_UNION); |
| 2073 | append_composite_type_field (t, "v4_float", |
| 2074 | init_vector_type (builtin_type (gdbarch) |
| 2075 | ->builtin_float, 4)); |
| 2076 | append_composite_type_field (t, "v2_double", |
| 2077 | init_vector_type (builtin_type (gdbarch) |
| 2078 | ->builtin_double, 2)); |
| 2079 | append_composite_type_field (t, "v16_int8", |
| 2080 | init_vector_type (builtin_type_int8, 16)); |
| 2081 | append_composite_type_field (t, "v8_int16", |
| 2082 | init_vector_type (builtin_type_int16, 8)); |
| 2083 | append_composite_type_field (t, "v4_int32", |
| 2084 | init_vector_type (builtin_type_int32, 4)); |
| 2085 | append_composite_type_field (t, "v2_int64", |
| 2086 | init_vector_type (builtin_type_int64, 2)); |
| 2087 | append_composite_type_field (t, "uint128", builtin_type_int128); |
| 2088 | |
| 2089 | TYPE_VECTOR (t) = 1; |
| 2090 | TYPE_NAME (t) = "builtin_type_vec128i"; |
| 2091 | tdep->i386_sse_type = t; |
| 2092 | } |
| 2093 | |
| 2094 | return tdep->i386_sse_type; |
| 2095 | } |
| 2096 | |
| 2097 | /* Return the GDB type object for the "standard" data type of data in |
| 2098 | register REGNUM. Perhaps %esi and %edi should go here, but |
| 2099 | potentially they could be used for things other than address. */ |
| 2100 | |
| 2101 | static struct type * |
| 2102 | i386_register_type (struct gdbarch *gdbarch, int regnum) |
| 2103 | { |
| 2104 | if (regnum == I386_EIP_REGNUM) |
| 2105 | return builtin_type (gdbarch)->builtin_func_ptr; |
| 2106 | |
| 2107 | if (regnum == I386_EFLAGS_REGNUM) |
| 2108 | return i386_eflags_type; |
| 2109 | |
| 2110 | if (regnum == I386_EBP_REGNUM || regnum == I386_ESP_REGNUM) |
| 2111 | return builtin_type (gdbarch)->builtin_data_ptr; |
| 2112 | |
| 2113 | if (i386_fp_regnum_p (gdbarch, regnum)) |
| 2114 | return builtin_type_i387_ext; |
| 2115 | |
| 2116 | if (i386_mmx_regnum_p (gdbarch, regnum)) |
| 2117 | return i386_mmx_type (gdbarch); |
| 2118 | |
| 2119 | if (i386_sse_regnum_p (gdbarch, regnum)) |
| 2120 | return i386_sse_type (gdbarch); |
| 2121 | |
| 2122 | if (regnum == I387_MXCSR_REGNUM (gdbarch_tdep (gdbarch))) |
| 2123 | return i386_mxcsr_type; |
| 2124 | |
| 2125 | return builtin_type (gdbarch)->builtin_int; |
| 2126 | } |
| 2127 | |
| 2128 | /* Map a cooked register onto a raw register or memory. For the i386, |
| 2129 | the MMX registers need to be mapped onto floating point registers. */ |
| 2130 | |
| 2131 | static int |
| 2132 | i386_mmx_regnum_to_fp_regnum (struct regcache *regcache, int regnum) |
| 2133 | { |
| 2134 | struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache)); |
| 2135 | int mmxreg, fpreg; |
| 2136 | ULONGEST fstat; |
| 2137 | int tos; |
| 2138 | |
| 2139 | mmxreg = regnum - tdep->mm0_regnum; |
| 2140 | regcache_raw_read_unsigned (regcache, I387_FSTAT_REGNUM (tdep), &fstat); |
| 2141 | tos = (fstat >> 11) & 0x7; |
| 2142 | fpreg = (mmxreg + tos) % 8; |
| 2143 | |
| 2144 | return (I387_ST0_REGNUM (tdep) + fpreg); |
| 2145 | } |
| 2146 | |
| 2147 | static void |
| 2148 | i386_pseudo_register_read (struct gdbarch *gdbarch, struct regcache *regcache, |
| 2149 | int regnum, gdb_byte *buf) |
| 2150 | { |
| 2151 | if (i386_mmx_regnum_p (gdbarch, regnum)) |
| 2152 | { |
| 2153 | gdb_byte mmx_buf[MAX_REGISTER_SIZE]; |
| 2154 | int fpnum = i386_mmx_regnum_to_fp_regnum (regcache, regnum); |
| 2155 | |
| 2156 | /* Extract (always little endian). */ |
| 2157 | regcache_raw_read (regcache, fpnum, mmx_buf); |
| 2158 | memcpy (buf, mmx_buf, register_size (gdbarch, regnum)); |
| 2159 | } |
| 2160 | else |
| 2161 | regcache_raw_read (regcache, regnum, buf); |
| 2162 | } |
| 2163 | |
| 2164 | static void |
| 2165 | i386_pseudo_register_write (struct gdbarch *gdbarch, struct regcache *regcache, |
| 2166 | int regnum, const gdb_byte *buf) |
| 2167 | { |
| 2168 | if (i386_mmx_regnum_p (gdbarch, regnum)) |
| 2169 | { |
| 2170 | gdb_byte mmx_buf[MAX_REGISTER_SIZE]; |
| 2171 | int fpnum = i386_mmx_regnum_to_fp_regnum (regcache, regnum); |
| 2172 | |
| 2173 | /* Read ... */ |
| 2174 | regcache_raw_read (regcache, fpnum, mmx_buf); |
| 2175 | /* ... Modify ... (always little endian). */ |
| 2176 | memcpy (mmx_buf, buf, register_size (gdbarch, regnum)); |
| 2177 | /* ... Write. */ |
| 2178 | regcache_raw_write (regcache, fpnum, mmx_buf); |
| 2179 | } |
| 2180 | else |
| 2181 | regcache_raw_write (regcache, regnum, buf); |
| 2182 | } |
| 2183 | \f |
| 2184 | |
| 2185 | /* Return the register number of the register allocated by GCC after |
| 2186 | REGNUM, or -1 if there is no such register. */ |
| 2187 | |
| 2188 | static int |
| 2189 | i386_next_regnum (int regnum) |
| 2190 | { |
| 2191 | /* GCC allocates the registers in the order: |
| 2192 | |
| 2193 | %eax, %edx, %ecx, %ebx, %esi, %edi, %ebp, %esp, ... |
| 2194 | |
| 2195 | Since storing a variable in %esp doesn't make any sense we return |
| 2196 | -1 for %ebp and for %esp itself. */ |
| 2197 | static int next_regnum[] = |
| 2198 | { |
| 2199 | I386_EDX_REGNUM, /* Slot for %eax. */ |
| 2200 | I386_EBX_REGNUM, /* Slot for %ecx. */ |
| 2201 | I386_ECX_REGNUM, /* Slot for %edx. */ |
| 2202 | I386_ESI_REGNUM, /* Slot for %ebx. */ |
| 2203 | -1, -1, /* Slots for %esp and %ebp. */ |
| 2204 | I386_EDI_REGNUM, /* Slot for %esi. */ |
| 2205 | I386_EBP_REGNUM /* Slot for %edi. */ |
| 2206 | }; |
| 2207 | |
| 2208 | if (regnum >= 0 && regnum < sizeof (next_regnum) / sizeof (next_regnum[0])) |
| 2209 | return next_regnum[regnum]; |
| 2210 | |
| 2211 | return -1; |
| 2212 | } |
| 2213 | |
| 2214 | /* Return nonzero if a value of type TYPE stored in register REGNUM |
| 2215 | needs any special handling. */ |
| 2216 | |
| 2217 | static int |
| 2218 | i386_convert_register_p (struct gdbarch *gdbarch, int regnum, struct type *type) |
| 2219 | { |
| 2220 | int len = TYPE_LENGTH (type); |
| 2221 | |
| 2222 | /* Values may be spread across multiple registers. Most debugging |
| 2223 | formats aren't expressive enough to specify the locations, so |
| 2224 | some heuristics is involved. Right now we only handle types that |
| 2225 | have a length that is a multiple of the word size, since GCC |
| 2226 | doesn't seem to put any other types into registers. */ |
| 2227 | if (len > 4 && len % 4 == 0) |
| 2228 | { |
| 2229 | int last_regnum = regnum; |
| 2230 | |
| 2231 | while (len > 4) |
| 2232 | { |
| 2233 | last_regnum = i386_next_regnum (last_regnum); |
| 2234 | len -= 4; |
| 2235 | } |
| 2236 | |
| 2237 | if (last_regnum != -1) |
| 2238 | return 1; |
| 2239 | } |
| 2240 | |
| 2241 | return i387_convert_register_p (gdbarch, regnum, type); |
| 2242 | } |
| 2243 | |
| 2244 | /* Read a value of type TYPE from register REGNUM in frame FRAME, and |
| 2245 | return its contents in TO. */ |
| 2246 | |
| 2247 | static void |
| 2248 | i386_register_to_value (struct frame_info *frame, int regnum, |
| 2249 | struct type *type, gdb_byte *to) |
| 2250 | { |
| 2251 | struct gdbarch *gdbarch = get_frame_arch (frame); |
| 2252 | int len = TYPE_LENGTH (type); |
| 2253 | |
| 2254 | /* FIXME: kettenis/20030609: What should we do if REGNUM isn't |
| 2255 | available in FRAME (i.e. if it wasn't saved)? */ |
| 2256 | |
| 2257 | if (i386_fp_regnum_p (gdbarch, regnum)) |
| 2258 | { |
| 2259 | i387_register_to_value (frame, regnum, type, to); |
| 2260 | return; |
| 2261 | } |
| 2262 | |
| 2263 | /* Read a value spread across multiple registers. */ |
| 2264 | |
| 2265 | gdb_assert (len > 4 && len % 4 == 0); |
| 2266 | |
| 2267 | while (len > 0) |
| 2268 | { |
| 2269 | gdb_assert (regnum != -1); |
| 2270 | gdb_assert (register_size (gdbarch, regnum) == 4); |
| 2271 | |
| 2272 | get_frame_register (frame, regnum, to); |
| 2273 | regnum = i386_next_regnum (regnum); |
| 2274 | len -= 4; |
| 2275 | to += 4; |
| 2276 | } |
| 2277 | } |
| 2278 | |
| 2279 | /* Write the contents FROM of a value of type TYPE into register |
| 2280 | REGNUM in frame FRAME. */ |
| 2281 | |
| 2282 | static void |
| 2283 | i386_value_to_register (struct frame_info *frame, int regnum, |
| 2284 | struct type *type, const gdb_byte *from) |
| 2285 | { |
| 2286 | int len = TYPE_LENGTH (type); |
| 2287 | |
| 2288 | if (i386_fp_regnum_p (get_frame_arch (frame), regnum)) |
| 2289 | { |
| 2290 | i387_value_to_register (frame, regnum, type, from); |
| 2291 | return; |
| 2292 | } |
| 2293 | |
| 2294 | /* Write a value spread across multiple registers. */ |
| 2295 | |
| 2296 | gdb_assert (len > 4 && len % 4 == 0); |
| 2297 | |
| 2298 | while (len > 0) |
| 2299 | { |
| 2300 | gdb_assert (regnum != -1); |
| 2301 | gdb_assert (register_size (get_frame_arch (frame), regnum) == 4); |
| 2302 | |
| 2303 | put_frame_register (frame, regnum, from); |
| 2304 | regnum = i386_next_regnum (regnum); |
| 2305 | len -= 4; |
| 2306 | from += 4; |
| 2307 | } |
| 2308 | } |
| 2309 | \f |
| 2310 | /* Supply register REGNUM from the buffer specified by GREGS and LEN |
| 2311 | in the general-purpose register set REGSET to register cache |
| 2312 | REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */ |
| 2313 | |
| 2314 | void |
| 2315 | i386_supply_gregset (const struct regset *regset, struct regcache *regcache, |
| 2316 | int regnum, const void *gregs, size_t len) |
| 2317 | { |
| 2318 | const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch); |
| 2319 | const gdb_byte *regs = gregs; |
| 2320 | int i; |
| 2321 | |
| 2322 | gdb_assert (len == tdep->sizeof_gregset); |
| 2323 | |
| 2324 | for (i = 0; i < tdep->gregset_num_regs; i++) |
| 2325 | { |
| 2326 | if ((regnum == i || regnum == -1) |
| 2327 | && tdep->gregset_reg_offset[i] != -1) |
| 2328 | regcache_raw_supply (regcache, i, regs + tdep->gregset_reg_offset[i]); |
| 2329 | } |
| 2330 | } |
| 2331 | |
| 2332 | /* Collect register REGNUM from the register cache REGCACHE and store |
| 2333 | it in the buffer specified by GREGS and LEN as described by the |
| 2334 | general-purpose register set REGSET. If REGNUM is -1, do this for |
| 2335 | all registers in REGSET. */ |
| 2336 | |
| 2337 | void |
| 2338 | i386_collect_gregset (const struct regset *regset, |
| 2339 | const struct regcache *regcache, |
| 2340 | int regnum, void *gregs, size_t len) |
| 2341 | { |
| 2342 | const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch); |
| 2343 | gdb_byte *regs = gregs; |
| 2344 | int i; |
| 2345 | |
| 2346 | gdb_assert (len == tdep->sizeof_gregset); |
| 2347 | |
| 2348 | for (i = 0; i < tdep->gregset_num_regs; i++) |
| 2349 | { |
| 2350 | if ((regnum == i || regnum == -1) |
| 2351 | && tdep->gregset_reg_offset[i] != -1) |
| 2352 | regcache_raw_collect (regcache, i, regs + tdep->gregset_reg_offset[i]); |
| 2353 | } |
| 2354 | } |
| 2355 | |
| 2356 | /* Supply register REGNUM from the buffer specified by FPREGS and LEN |
| 2357 | in the floating-point register set REGSET to register cache |
| 2358 | REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */ |
| 2359 | |
| 2360 | static void |
| 2361 | i386_supply_fpregset (const struct regset *regset, struct regcache *regcache, |
| 2362 | int regnum, const void *fpregs, size_t len) |
| 2363 | { |
| 2364 | const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch); |
| 2365 | |
| 2366 | if (len == I387_SIZEOF_FXSAVE) |
| 2367 | { |
| 2368 | i387_supply_fxsave (regcache, regnum, fpregs); |
| 2369 | return; |
| 2370 | } |
| 2371 | |
| 2372 | gdb_assert (len == tdep->sizeof_fpregset); |
| 2373 | i387_supply_fsave (regcache, regnum, fpregs); |
| 2374 | } |
| 2375 | |
| 2376 | /* Collect register REGNUM from the register cache REGCACHE and store |
| 2377 | it in the buffer specified by FPREGS and LEN as described by the |
| 2378 | floating-point register set REGSET. If REGNUM is -1, do this for |
| 2379 | all registers in REGSET. */ |
| 2380 | |
| 2381 | static void |
| 2382 | i386_collect_fpregset (const struct regset *regset, |
| 2383 | const struct regcache *regcache, |
| 2384 | int regnum, void *fpregs, size_t len) |
| 2385 | { |
| 2386 | const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch); |
| 2387 | |
| 2388 | if (len == I387_SIZEOF_FXSAVE) |
| 2389 | { |
| 2390 | i387_collect_fxsave (regcache, regnum, fpregs); |
| 2391 | return; |
| 2392 | } |
| 2393 | |
| 2394 | gdb_assert (len == tdep->sizeof_fpregset); |
| 2395 | i387_collect_fsave (regcache, regnum, fpregs); |
| 2396 | } |
| 2397 | |
| 2398 | /* Return the appropriate register set for the core section identified |
| 2399 | by SECT_NAME and SECT_SIZE. */ |
| 2400 | |
| 2401 | const struct regset * |
| 2402 | i386_regset_from_core_section (struct gdbarch *gdbarch, |
| 2403 | const char *sect_name, size_t sect_size) |
| 2404 | { |
| 2405 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 2406 | |
| 2407 | if (strcmp (sect_name, ".reg") == 0 && sect_size == tdep->sizeof_gregset) |
| 2408 | { |
| 2409 | if (tdep->gregset == NULL) |
| 2410 | tdep->gregset = regset_alloc (gdbarch, i386_supply_gregset, |
| 2411 | i386_collect_gregset); |
| 2412 | return tdep->gregset; |
| 2413 | } |
| 2414 | |
| 2415 | if ((strcmp (sect_name, ".reg2") == 0 && sect_size == tdep->sizeof_fpregset) |
| 2416 | || (strcmp (sect_name, ".reg-xfp") == 0 |
| 2417 | && sect_size == I387_SIZEOF_FXSAVE)) |
| 2418 | { |
| 2419 | if (tdep->fpregset == NULL) |
| 2420 | tdep->fpregset = regset_alloc (gdbarch, i386_supply_fpregset, |
| 2421 | i386_collect_fpregset); |
| 2422 | return tdep->fpregset; |
| 2423 | } |
| 2424 | |
| 2425 | return NULL; |
| 2426 | } |
| 2427 | \f |
| 2428 | |
| 2429 | /* Stuff for WIN32 PE style DLL's but is pretty generic really. */ |
| 2430 | |
| 2431 | CORE_ADDR |
| 2432 | i386_pe_skip_trampoline_code (CORE_ADDR pc, char *name) |
| 2433 | { |
| 2434 | if (pc && read_memory_unsigned_integer (pc, 2) == 0x25ff) /* jmp *(dest) */ |
| 2435 | { |
| 2436 | unsigned long indirect = read_memory_unsigned_integer (pc + 2, 4); |
| 2437 | struct minimal_symbol *indsym = |
| 2438 | indirect ? lookup_minimal_symbol_by_pc (indirect) : 0; |
| 2439 | char *symname = indsym ? SYMBOL_LINKAGE_NAME (indsym) : 0; |
| 2440 | |
| 2441 | if (symname) |
| 2442 | { |
| 2443 | if (strncmp (symname, "__imp_", 6) == 0 |
| 2444 | || strncmp (symname, "_imp_", 5) == 0) |
| 2445 | return name ? 1 : read_memory_unsigned_integer (indirect, 4); |
| 2446 | } |
| 2447 | } |
| 2448 | return 0; /* Not a trampoline. */ |
| 2449 | } |
| 2450 | \f |
| 2451 | |
| 2452 | /* Return whether the THIS_FRAME corresponds to a sigtramp |
| 2453 | routine. */ |
| 2454 | |
| 2455 | int |
| 2456 | i386_sigtramp_p (struct frame_info *this_frame) |
| 2457 | { |
| 2458 | CORE_ADDR pc = get_frame_pc (this_frame); |
| 2459 | char *name; |
| 2460 | |
| 2461 | find_pc_partial_function (pc, &name, NULL, NULL); |
| 2462 | return (name && strcmp ("_sigtramp", name) == 0); |
| 2463 | } |
| 2464 | \f |
| 2465 | |
| 2466 | /* We have two flavours of disassembly. The machinery on this page |
| 2467 | deals with switching between those. */ |
| 2468 | |
| 2469 | static int |
| 2470 | i386_print_insn (bfd_vma pc, struct disassemble_info *info) |
| 2471 | { |
| 2472 | gdb_assert (disassembly_flavor == att_flavor |
| 2473 | || disassembly_flavor == intel_flavor); |
| 2474 | |
| 2475 | /* FIXME: kettenis/20020915: Until disassembler_options is properly |
| 2476 | constified, cast to prevent a compiler warning. */ |
| 2477 | info->disassembler_options = (char *) disassembly_flavor; |
| 2478 | |
| 2479 | return print_insn_i386 (pc, info); |
| 2480 | } |
| 2481 | \f |
| 2482 | |
| 2483 | /* There are a few i386 architecture variants that differ only |
| 2484 | slightly from the generic i386 target. For now, we don't give them |
| 2485 | their own source file, but include them here. As a consequence, |
| 2486 | they'll always be included. */ |
| 2487 | |
| 2488 | /* System V Release 4 (SVR4). */ |
| 2489 | |
| 2490 | /* Return whether THIS_FRAME corresponds to a SVR4 sigtramp |
| 2491 | routine. */ |
| 2492 | |
| 2493 | static int |
| 2494 | i386_svr4_sigtramp_p (struct frame_info *this_frame) |
| 2495 | { |
| 2496 | CORE_ADDR pc = get_frame_pc (this_frame); |
| 2497 | char *name; |
| 2498 | |
| 2499 | /* UnixWare uses _sigacthandler. The origin of the other symbols is |
| 2500 | currently unknown. */ |
| 2501 | find_pc_partial_function (pc, &name, NULL, NULL); |
| 2502 | return (name && (strcmp ("_sigreturn", name) == 0 |
| 2503 | || strcmp ("_sigacthandler", name) == 0 |
| 2504 | || strcmp ("sigvechandler", name) == 0)); |
| 2505 | } |
| 2506 | |
| 2507 | /* Assuming THIS_FRAME is for a SVR4 sigtramp routine, return the |
| 2508 | address of the associated sigcontext (ucontext) structure. */ |
| 2509 | |
| 2510 | static CORE_ADDR |
| 2511 | i386_svr4_sigcontext_addr (struct frame_info *this_frame) |
| 2512 | { |
| 2513 | gdb_byte buf[4]; |
| 2514 | CORE_ADDR sp; |
| 2515 | |
| 2516 | get_frame_register (this_frame, I386_ESP_REGNUM, buf); |
| 2517 | sp = extract_unsigned_integer (buf, 4); |
| 2518 | |
| 2519 | return read_memory_unsigned_integer (sp + 8, 4); |
| 2520 | } |
| 2521 | \f |
| 2522 | |
| 2523 | /* Generic ELF. */ |
| 2524 | |
| 2525 | void |
| 2526 | i386_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 2527 | { |
| 2528 | /* We typically use stabs-in-ELF with the SVR4 register numbering. */ |
| 2529 | set_gdbarch_stab_reg_to_regnum (gdbarch, i386_svr4_reg_to_regnum); |
| 2530 | } |
| 2531 | |
| 2532 | /* System V Release 4 (SVR4). */ |
| 2533 | |
| 2534 | void |
| 2535 | i386_svr4_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 2536 | { |
| 2537 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 2538 | |
| 2539 | /* System V Release 4 uses ELF. */ |
| 2540 | i386_elf_init_abi (info, gdbarch); |
| 2541 | |
| 2542 | /* System V Release 4 has shared libraries. */ |
| 2543 | set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); |
| 2544 | |
| 2545 | tdep->sigtramp_p = i386_svr4_sigtramp_p; |
| 2546 | tdep->sigcontext_addr = i386_svr4_sigcontext_addr; |
| 2547 | tdep->sc_pc_offset = 36 + 14 * 4; |
| 2548 | tdep->sc_sp_offset = 36 + 17 * 4; |
| 2549 | |
| 2550 | tdep->jb_pc_offset = 20; |
| 2551 | } |
| 2552 | |
| 2553 | /* DJGPP. */ |
| 2554 | |
| 2555 | static void |
| 2556 | i386_go32_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 2557 | { |
| 2558 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 2559 | |
| 2560 | /* DJGPP doesn't have any special frames for signal handlers. */ |
| 2561 | tdep->sigtramp_p = NULL; |
| 2562 | |
| 2563 | tdep->jb_pc_offset = 36; |
| 2564 | } |
| 2565 | \f |
| 2566 | |
| 2567 | /* i386 register groups. In addition to the normal groups, add "mmx" |
| 2568 | and "sse". */ |
| 2569 | |
| 2570 | static struct reggroup *i386_sse_reggroup; |
| 2571 | static struct reggroup *i386_mmx_reggroup; |
| 2572 | |
| 2573 | static void |
| 2574 | i386_init_reggroups (void) |
| 2575 | { |
| 2576 | i386_sse_reggroup = reggroup_new ("sse", USER_REGGROUP); |
| 2577 | i386_mmx_reggroup = reggroup_new ("mmx", USER_REGGROUP); |
| 2578 | } |
| 2579 | |
| 2580 | static void |
| 2581 | i386_add_reggroups (struct gdbarch *gdbarch) |
| 2582 | { |
| 2583 | reggroup_add (gdbarch, i386_sse_reggroup); |
| 2584 | reggroup_add (gdbarch, i386_mmx_reggroup); |
| 2585 | reggroup_add (gdbarch, general_reggroup); |
| 2586 | reggroup_add (gdbarch, float_reggroup); |
| 2587 | reggroup_add (gdbarch, all_reggroup); |
| 2588 | reggroup_add (gdbarch, save_reggroup); |
| 2589 | reggroup_add (gdbarch, restore_reggroup); |
| 2590 | reggroup_add (gdbarch, vector_reggroup); |
| 2591 | reggroup_add (gdbarch, system_reggroup); |
| 2592 | } |
| 2593 | |
| 2594 | int |
| 2595 | i386_register_reggroup_p (struct gdbarch *gdbarch, int regnum, |
| 2596 | struct reggroup *group) |
| 2597 | { |
| 2598 | int sse_regnum_p = (i386_sse_regnum_p (gdbarch, regnum) |
| 2599 | || i386_mxcsr_regnum_p (gdbarch, regnum)); |
| 2600 | int fp_regnum_p = (i386_fp_regnum_p (gdbarch, regnum) |
| 2601 | || i386_fpc_regnum_p (gdbarch, regnum)); |
| 2602 | int mmx_regnum_p = (i386_mmx_regnum_p (gdbarch, regnum)); |
| 2603 | |
| 2604 | if (group == i386_mmx_reggroup) |
| 2605 | return mmx_regnum_p; |
| 2606 | if (group == i386_sse_reggroup) |
| 2607 | return sse_regnum_p; |
| 2608 | if (group == vector_reggroup) |
| 2609 | return (mmx_regnum_p || sse_regnum_p); |
| 2610 | if (group == float_reggroup) |
| 2611 | return fp_regnum_p; |
| 2612 | if (group == general_reggroup) |
| 2613 | return (!fp_regnum_p && !mmx_regnum_p && !sse_regnum_p); |
| 2614 | |
| 2615 | return default_register_reggroup_p (gdbarch, regnum, group); |
| 2616 | } |
| 2617 | \f |
| 2618 | |
| 2619 | /* Get the ARGIth function argument for the current function. */ |
| 2620 | |
| 2621 | static CORE_ADDR |
| 2622 | i386_fetch_pointer_argument (struct frame_info *frame, int argi, |
| 2623 | struct type *type) |
| 2624 | { |
| 2625 | CORE_ADDR sp = get_frame_register_unsigned (frame, I386_ESP_REGNUM); |
| 2626 | return read_memory_unsigned_integer (sp + (4 * (argi + 1)), 4); |
| 2627 | } |
| 2628 | |
| 2629 | static void |
| 2630 | i386_skip_permanent_breakpoint (struct regcache *regcache) |
| 2631 | { |
| 2632 | CORE_ADDR current_pc = regcache_read_pc (regcache); |
| 2633 | |
| 2634 | /* On i386, breakpoint is exactly 1 byte long, so we just |
| 2635 | adjust the PC in the regcache. */ |
| 2636 | current_pc += 1; |
| 2637 | regcache_write_pc (regcache, current_pc); |
| 2638 | } |
| 2639 | |
| 2640 | |
| 2641 | \f |
| 2642 | static struct gdbarch * |
| 2643 | i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) |
| 2644 | { |
| 2645 | struct gdbarch_tdep *tdep; |
| 2646 | struct gdbarch *gdbarch; |
| 2647 | |
| 2648 | /* If there is already a candidate, use it. */ |
| 2649 | arches = gdbarch_list_lookup_by_info (arches, &info); |
| 2650 | if (arches != NULL) |
| 2651 | return arches->gdbarch; |
| 2652 | |
| 2653 | /* Allocate space for the new architecture. */ |
| 2654 | tdep = XCALLOC (1, struct gdbarch_tdep); |
| 2655 | gdbarch = gdbarch_alloc (&info, tdep); |
| 2656 | |
| 2657 | /* General-purpose registers. */ |
| 2658 | tdep->gregset = NULL; |
| 2659 | tdep->gregset_reg_offset = NULL; |
| 2660 | tdep->gregset_num_regs = I386_NUM_GREGS; |
| 2661 | tdep->sizeof_gregset = 0; |
| 2662 | |
| 2663 | /* Floating-point registers. */ |
| 2664 | tdep->fpregset = NULL; |
| 2665 | tdep->sizeof_fpregset = I387_SIZEOF_FSAVE; |
| 2666 | |
| 2667 | /* The default settings include the FPU registers, the MMX registers |
| 2668 | and the SSE registers. This can be overridden for a specific ABI |
| 2669 | by adjusting the members `st0_regnum', `mm0_regnum' and |
| 2670 | `num_xmm_regs' of `struct gdbarch_tdep', otherwise the registers |
| 2671 | will show up in the output of "info all-registers". Ideally we |
| 2672 | should try to autodetect whether they are available, such that we |
| 2673 | can prevent "info all-registers" from displaying registers that |
| 2674 | aren't available. |
| 2675 | |
| 2676 | NOTE: kevinb/2003-07-13: ... if it's a choice between printing |
| 2677 | [the SSE registers] always (even when they don't exist) or never |
| 2678 | showing them to the user (even when they do exist), I prefer the |
| 2679 | former over the latter. */ |
| 2680 | |
| 2681 | tdep->st0_regnum = I386_ST0_REGNUM; |
| 2682 | |
| 2683 | /* The MMX registers are implemented as pseudo-registers. Put off |
| 2684 | calculating the register number for %mm0 until we know the number |
| 2685 | of raw registers. */ |
| 2686 | tdep->mm0_regnum = 0; |
| 2687 | |
| 2688 | /* I386_NUM_XREGS includes %mxcsr, so substract one. */ |
| 2689 | tdep->num_xmm_regs = I386_NUM_XREGS - 1; |
| 2690 | |
| 2691 | tdep->jb_pc_offset = -1; |
| 2692 | tdep->struct_return = pcc_struct_return; |
| 2693 | tdep->sigtramp_start = 0; |
| 2694 | tdep->sigtramp_end = 0; |
| 2695 | tdep->sigtramp_p = i386_sigtramp_p; |
| 2696 | tdep->sigcontext_addr = NULL; |
| 2697 | tdep->sc_reg_offset = NULL; |
| 2698 | tdep->sc_pc_offset = -1; |
| 2699 | tdep->sc_sp_offset = -1; |
| 2700 | |
| 2701 | /* The format used for `long double' on almost all i386 targets is |
| 2702 | the i387 extended floating-point format. In fact, of all targets |
| 2703 | in the GCC 2.95 tree, only OSF/1 does it different, and insists |
| 2704 | on having a `long double' that's not `long' at all. */ |
| 2705 | set_gdbarch_long_double_format (gdbarch, floatformats_i387_ext); |
| 2706 | |
| 2707 | /* Although the i387 extended floating-point has only 80 significant |
| 2708 | bits, a `long double' actually takes up 96, probably to enforce |
| 2709 | alignment. */ |
| 2710 | set_gdbarch_long_double_bit (gdbarch, 96); |
| 2711 | |
| 2712 | /* The default ABI includes general-purpose registers, |
| 2713 | floating-point registers, and the SSE registers. */ |
| 2714 | set_gdbarch_num_regs (gdbarch, I386_SSE_NUM_REGS); |
| 2715 | set_gdbarch_register_name (gdbarch, i386_register_name); |
| 2716 | set_gdbarch_register_type (gdbarch, i386_register_type); |
| 2717 | |
| 2718 | /* Register numbers of various important registers. */ |
| 2719 | set_gdbarch_sp_regnum (gdbarch, I386_ESP_REGNUM); /* %esp */ |
| 2720 | set_gdbarch_pc_regnum (gdbarch, I386_EIP_REGNUM); /* %eip */ |
| 2721 | set_gdbarch_ps_regnum (gdbarch, I386_EFLAGS_REGNUM); /* %eflags */ |
| 2722 | set_gdbarch_fp0_regnum (gdbarch, I386_ST0_REGNUM); /* %st(0) */ |
| 2723 | |
| 2724 | /* NOTE: kettenis/20040418: GCC does have two possible register |
| 2725 | numbering schemes on the i386: dbx and SVR4. These schemes |
| 2726 | differ in how they number %ebp, %esp, %eflags, and the |
| 2727 | floating-point registers, and are implemented by the arrays |
| 2728 | dbx_register_map[] and svr4_dbx_register_map in |
| 2729 | gcc/config/i386.c. GCC also defines a third numbering scheme in |
| 2730 | gcc/config/i386.c, which it designates as the "default" register |
| 2731 | map used in 64bit mode. This last register numbering scheme is |
| 2732 | implemented in dbx64_register_map, and is used for AMD64; see |
| 2733 | amd64-tdep.c. |
| 2734 | |
| 2735 | Currently, each GCC i386 target always uses the same register |
| 2736 | numbering scheme across all its supported debugging formats |
| 2737 | i.e. SDB (COFF), stabs and DWARF 2. This is because |
| 2738 | gcc/sdbout.c, gcc/dbxout.c and gcc/dwarf2out.c all use the |
| 2739 | DBX_REGISTER_NUMBER macro which is defined by each target's |
| 2740 | respective config header in a manner independent of the requested |
| 2741 | output debugging format. |
| 2742 | |
| 2743 | This does not match the arrangement below, which presumes that |
| 2744 | the SDB and stabs numbering schemes differ from the DWARF and |
| 2745 | DWARF 2 ones. The reason for this arrangement is that it is |
| 2746 | likely to get the numbering scheme for the target's |
| 2747 | default/native debug format right. For targets where GCC is the |
| 2748 | native compiler (FreeBSD, NetBSD, OpenBSD, GNU/Linux) or for |
| 2749 | targets where the native toolchain uses a different numbering |
| 2750 | scheme for a particular debug format (stabs-in-ELF on Solaris) |
| 2751 | the defaults below will have to be overridden, like |
| 2752 | i386_elf_init_abi() does. */ |
| 2753 | |
| 2754 | /* Use the dbx register numbering scheme for stabs and COFF. */ |
| 2755 | set_gdbarch_stab_reg_to_regnum (gdbarch, i386_dbx_reg_to_regnum); |
| 2756 | set_gdbarch_sdb_reg_to_regnum (gdbarch, i386_dbx_reg_to_regnum); |
| 2757 | |
| 2758 | /* Use the SVR4 register numbering scheme for DWARF 2. */ |
| 2759 | set_gdbarch_dwarf2_reg_to_regnum (gdbarch, i386_svr4_reg_to_regnum); |
| 2760 | |
| 2761 | /* We don't set gdbarch_stab_reg_to_regnum, since ECOFF doesn't seem to |
| 2762 | be in use on any of the supported i386 targets. */ |
| 2763 | |
| 2764 | set_gdbarch_print_float_info (gdbarch, i387_print_float_info); |
| 2765 | |
| 2766 | set_gdbarch_get_longjmp_target (gdbarch, i386_get_longjmp_target); |
| 2767 | |
| 2768 | /* Call dummy code. */ |
| 2769 | set_gdbarch_push_dummy_call (gdbarch, i386_push_dummy_call); |
| 2770 | |
| 2771 | set_gdbarch_convert_register_p (gdbarch, i386_convert_register_p); |
| 2772 | set_gdbarch_register_to_value (gdbarch, i386_register_to_value); |
| 2773 | set_gdbarch_value_to_register (gdbarch, i386_value_to_register); |
| 2774 | |
| 2775 | set_gdbarch_return_value (gdbarch, i386_return_value); |
| 2776 | |
| 2777 | set_gdbarch_skip_prologue (gdbarch, i386_skip_prologue); |
| 2778 | |
| 2779 | /* Stack grows downward. */ |
| 2780 | set_gdbarch_inner_than (gdbarch, core_addr_lessthan); |
| 2781 | |
| 2782 | set_gdbarch_breakpoint_from_pc (gdbarch, i386_breakpoint_from_pc); |
| 2783 | set_gdbarch_decr_pc_after_break (gdbarch, 1); |
| 2784 | set_gdbarch_max_insn_length (gdbarch, I386_MAX_INSN_LEN); |
| 2785 | |
| 2786 | set_gdbarch_frame_args_skip (gdbarch, 8); |
| 2787 | |
| 2788 | /* Wire in the MMX registers. */ |
| 2789 | set_gdbarch_num_pseudo_regs (gdbarch, i386_num_mmx_regs); |
| 2790 | set_gdbarch_pseudo_register_read (gdbarch, i386_pseudo_register_read); |
| 2791 | set_gdbarch_pseudo_register_write (gdbarch, i386_pseudo_register_write); |
| 2792 | |
| 2793 | set_gdbarch_print_insn (gdbarch, i386_print_insn); |
| 2794 | |
| 2795 | set_gdbarch_dummy_id (gdbarch, i386_dummy_id); |
| 2796 | |
| 2797 | set_gdbarch_unwind_pc (gdbarch, i386_unwind_pc); |
| 2798 | |
| 2799 | /* Add the i386 register groups. */ |
| 2800 | i386_add_reggroups (gdbarch); |
| 2801 | set_gdbarch_register_reggroup_p (gdbarch, i386_register_reggroup_p); |
| 2802 | |
| 2803 | /* Helper for function argument information. */ |
| 2804 | set_gdbarch_fetch_pointer_argument (gdbarch, i386_fetch_pointer_argument); |
| 2805 | |
| 2806 | /* Hook in the DWARF CFI frame unwinder. */ |
| 2807 | dwarf2_append_unwinders (gdbarch); |
| 2808 | |
| 2809 | frame_base_set_default (gdbarch, &i386_frame_base); |
| 2810 | |
| 2811 | /* Hook in ABI-specific overrides, if they have been registered. */ |
| 2812 | gdbarch_init_osabi (info, gdbarch); |
| 2813 | |
| 2814 | frame_unwind_append_unwinder (gdbarch, &i386_sigtramp_frame_unwind); |
| 2815 | frame_unwind_append_unwinder (gdbarch, &i386_frame_unwind); |
| 2816 | |
| 2817 | /* If we have a register mapping, enable the generic core file |
| 2818 | support, unless it has already been enabled. */ |
| 2819 | if (tdep->gregset_reg_offset |
| 2820 | && !gdbarch_regset_from_core_section_p (gdbarch)) |
| 2821 | set_gdbarch_regset_from_core_section (gdbarch, |
| 2822 | i386_regset_from_core_section); |
| 2823 | |
| 2824 | /* Unless support for MMX has been disabled, make %mm0 the first |
| 2825 | pseudo-register. */ |
| 2826 | if (tdep->mm0_regnum == 0) |
| 2827 | tdep->mm0_regnum = gdbarch_num_regs (gdbarch); |
| 2828 | |
| 2829 | set_gdbarch_skip_permanent_breakpoint (gdbarch, |
| 2830 | i386_skip_permanent_breakpoint); |
| 2831 | |
| 2832 | return gdbarch; |
| 2833 | } |
| 2834 | |
| 2835 | static enum gdb_osabi |
| 2836 | i386_coff_osabi_sniffer (bfd *abfd) |
| 2837 | { |
| 2838 | if (strcmp (bfd_get_target (abfd), "coff-go32-exe") == 0 |
| 2839 | || strcmp (bfd_get_target (abfd), "coff-go32") == 0) |
| 2840 | return GDB_OSABI_GO32; |
| 2841 | |
| 2842 | return GDB_OSABI_UNKNOWN; |
| 2843 | } |
| 2844 | \f |
| 2845 | |
| 2846 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
| 2847 | void _initialize_i386_tdep (void); |
| 2848 | |
| 2849 | void |
| 2850 | _initialize_i386_tdep (void) |
| 2851 | { |
| 2852 | register_gdbarch_init (bfd_arch_i386, i386_gdbarch_init); |
| 2853 | |
| 2854 | /* Add the variable that controls the disassembly flavor. */ |
| 2855 | add_setshow_enum_cmd ("disassembly-flavor", no_class, valid_flavors, |
| 2856 | &disassembly_flavor, _("\ |
| 2857 | Set the disassembly flavor."), _("\ |
| 2858 | Show the disassembly flavor."), _("\ |
| 2859 | The valid values are \"att\" and \"intel\", and the default value is \"att\"."), |
| 2860 | NULL, |
| 2861 | NULL, /* FIXME: i18n: */ |
| 2862 | &setlist, &showlist); |
| 2863 | |
| 2864 | /* Add the variable that controls the convention for returning |
| 2865 | structs. */ |
| 2866 | add_setshow_enum_cmd ("struct-convention", no_class, valid_conventions, |
| 2867 | &struct_convention, _("\ |
| 2868 | Set the convention for returning small structs."), _("\ |
| 2869 | Show the convention for returning small structs."), _("\ |
| 2870 | Valid values are \"default\", \"pcc\" and \"reg\", and the default value\n\ |
| 2871 | is \"default\"."), |
| 2872 | NULL, |
| 2873 | NULL, /* FIXME: i18n: */ |
| 2874 | &setlist, &showlist); |
| 2875 | |
| 2876 | gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_coff_flavour, |
| 2877 | i386_coff_osabi_sniffer); |
| 2878 | |
| 2879 | gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_SVR4, |
| 2880 | i386_svr4_init_abi); |
| 2881 | gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_GO32, |
| 2882 | i386_go32_init_abi); |
| 2883 | |
| 2884 | /* Initialize the i386-specific register groups & types. */ |
| 2885 | i386_init_reggroups (); |
| 2886 | i386_init_types(); |
| 2887 | } |