| 1 | /* Intel 386 target-dependent stuff. |
| 2 | Copyright (C) 1988, 1989, 1991, 1994, 1995, 1996, 1998 |
| 3 | Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 59 Temple Place - Suite 330, |
| 20 | Boston, MA 02111-1307, USA. */ |
| 21 | |
| 22 | #include "defs.h" |
| 23 | #include "gdb_string.h" |
| 24 | #include "frame.h" |
| 25 | #include "inferior.h" |
| 26 | #include "gdbcore.h" |
| 27 | #include "target.h" |
| 28 | #include "floatformat.h" |
| 29 | #include "symtab.h" |
| 30 | #include "gdbcmd.h" |
| 31 | #include "command.h" |
| 32 | #include "arch-utils.h" |
| 33 | |
| 34 | static long i386_get_frame_setup (CORE_ADDR); |
| 35 | |
| 36 | static void i386_follow_jump (void); |
| 37 | |
| 38 | static void codestream_read (unsigned char *, int); |
| 39 | |
| 40 | static void codestream_seek (CORE_ADDR); |
| 41 | |
| 42 | static unsigned char codestream_fill (int); |
| 43 | |
| 44 | CORE_ADDR skip_trampoline_code (CORE_ADDR, char *); |
| 45 | |
| 46 | static int gdb_print_insn_i386 (bfd_vma, disassemble_info *); |
| 47 | |
| 48 | void _initialize_i386_tdep (void); |
| 49 | |
| 50 | /* i386_register_byte[i] is the offset into the register file of the |
| 51 | start of register number i. We initialize this from |
| 52 | i386_register_raw_size. */ |
| 53 | int i386_register_byte[MAX_NUM_REGS]; |
| 54 | |
| 55 | /* i386_register_raw_size[i] is the number of bytes of storage in |
| 56 | GDB's register array occupied by register i. */ |
| 57 | int i386_register_raw_size[MAX_NUM_REGS] = { |
| 58 | 4, 4, 4, 4, |
| 59 | 4, 4, 4, 4, |
| 60 | 4, 4, 4, 4, |
| 61 | 4, 4, 4, 4, |
| 62 | 10, 10, 10, 10, |
| 63 | 10, 10, 10, 10, |
| 64 | 4, 4, 4, 4, |
| 65 | 4, 4, 4, 4, |
| 66 | 16, 16, 16, 16, |
| 67 | 16, 16, 16, 16, |
| 68 | 4 |
| 69 | }; |
| 70 | |
| 71 | /* i386_register_virtual_size[i] is the size in bytes of the virtual |
| 72 | type of register i. */ |
| 73 | int i386_register_virtual_size[MAX_NUM_REGS]; |
| 74 | |
| 75 | |
| 76 | /* This is the variable the is set with "set disassembly-flavor", |
| 77 | and its legitimate values. */ |
| 78 | static const char att_flavor[] = "att"; |
| 79 | static const char intel_flavor[] = "intel"; |
| 80 | static const char *valid_flavors[] = |
| 81 | { |
| 82 | att_flavor, |
| 83 | intel_flavor, |
| 84 | NULL |
| 85 | }; |
| 86 | static const char *disassembly_flavor = att_flavor; |
| 87 | |
| 88 | static void i386_print_register (char *, int, int); |
| 89 | |
| 90 | /* This is used to keep the bfd arch_info in sync with the disassembly flavor. */ |
| 91 | static void set_disassembly_flavor_sfunc (char *, int, |
| 92 | struct cmd_list_element *); |
| 93 | static void set_disassembly_flavor (void); |
| 94 | |
| 95 | /* Stdio style buffering was used to minimize calls to ptrace, but this |
| 96 | buffering did not take into account that the code section being accessed |
| 97 | may not be an even number of buffers long (even if the buffer is only |
| 98 | sizeof(int) long). In cases where the code section size happened to |
| 99 | be a non-integral number of buffers long, attempting to read the last |
| 100 | buffer would fail. Simply using target_read_memory and ignoring errors, |
| 101 | rather than read_memory, is not the correct solution, since legitimate |
| 102 | access errors would then be totally ignored. To properly handle this |
| 103 | situation and continue to use buffering would require that this code |
| 104 | be able to determine the minimum code section size granularity (not the |
| 105 | alignment of the section itself, since the actual failing case that |
| 106 | pointed out this problem had a section alignment of 4 but was not a |
| 107 | multiple of 4 bytes long), on a target by target basis, and then |
| 108 | adjust it's buffer size accordingly. This is messy, but potentially |
| 109 | feasible. It probably needs the bfd library's help and support. For |
| 110 | now, the buffer size is set to 1. (FIXME -fnf) */ |
| 111 | |
| 112 | #define CODESTREAM_BUFSIZ 1 /* Was sizeof(int), see note above. */ |
| 113 | static CORE_ADDR codestream_next_addr; |
| 114 | static CORE_ADDR codestream_addr; |
| 115 | static unsigned char codestream_buf[CODESTREAM_BUFSIZ]; |
| 116 | static int codestream_off; |
| 117 | static int codestream_cnt; |
| 118 | |
| 119 | #define codestream_tell() (codestream_addr + codestream_off) |
| 120 | #define codestream_peek() (codestream_cnt == 0 ? \ |
| 121 | codestream_fill(1): codestream_buf[codestream_off]) |
| 122 | #define codestream_get() (codestream_cnt-- == 0 ? \ |
| 123 | codestream_fill(0) : codestream_buf[codestream_off++]) |
| 124 | |
| 125 | static unsigned char |
| 126 | codestream_fill (int peek_flag) |
| 127 | { |
| 128 | codestream_addr = codestream_next_addr; |
| 129 | codestream_next_addr += CODESTREAM_BUFSIZ; |
| 130 | codestream_off = 0; |
| 131 | codestream_cnt = CODESTREAM_BUFSIZ; |
| 132 | read_memory (codestream_addr, (char *) codestream_buf, CODESTREAM_BUFSIZ); |
| 133 | |
| 134 | if (peek_flag) |
| 135 | return (codestream_peek ()); |
| 136 | else |
| 137 | return (codestream_get ()); |
| 138 | } |
| 139 | |
| 140 | static void |
| 141 | codestream_seek (CORE_ADDR place) |
| 142 | { |
| 143 | codestream_next_addr = place / CODESTREAM_BUFSIZ; |
| 144 | codestream_next_addr *= CODESTREAM_BUFSIZ; |
| 145 | codestream_cnt = 0; |
| 146 | codestream_fill (1); |
| 147 | while (codestream_tell () != place) |
| 148 | codestream_get (); |
| 149 | } |
| 150 | |
| 151 | static void |
| 152 | codestream_read (unsigned char *buf, int count) |
| 153 | { |
| 154 | unsigned char *p; |
| 155 | int i; |
| 156 | p = buf; |
| 157 | for (i = 0; i < count; i++) |
| 158 | *p++ = codestream_get (); |
| 159 | } |
| 160 | |
| 161 | /* next instruction is a jump, move to target */ |
| 162 | |
| 163 | static void |
| 164 | i386_follow_jump (void) |
| 165 | { |
| 166 | unsigned char buf[4]; |
| 167 | long delta; |
| 168 | |
| 169 | int data16; |
| 170 | CORE_ADDR pos; |
| 171 | |
| 172 | pos = codestream_tell (); |
| 173 | |
| 174 | data16 = 0; |
| 175 | if (codestream_peek () == 0x66) |
| 176 | { |
| 177 | codestream_get (); |
| 178 | data16 = 1; |
| 179 | } |
| 180 | |
| 181 | switch (codestream_get ()) |
| 182 | { |
| 183 | case 0xe9: |
| 184 | /* relative jump: if data16 == 0, disp32, else disp16 */ |
| 185 | if (data16) |
| 186 | { |
| 187 | codestream_read (buf, 2); |
| 188 | delta = extract_signed_integer (buf, 2); |
| 189 | |
| 190 | /* include size of jmp inst (including the 0x66 prefix). */ |
| 191 | pos += delta + 4; |
| 192 | } |
| 193 | else |
| 194 | { |
| 195 | codestream_read (buf, 4); |
| 196 | delta = extract_signed_integer (buf, 4); |
| 197 | |
| 198 | pos += delta + 5; |
| 199 | } |
| 200 | break; |
| 201 | case 0xeb: |
| 202 | /* relative jump, disp8 (ignore data16) */ |
| 203 | codestream_read (buf, 1); |
| 204 | /* Sign-extend it. */ |
| 205 | delta = extract_signed_integer (buf, 1); |
| 206 | |
| 207 | pos += delta + 2; |
| 208 | break; |
| 209 | } |
| 210 | codestream_seek (pos); |
| 211 | } |
| 212 | |
| 213 | /* |
| 214 | * find & return amound a local space allocated, and advance codestream to |
| 215 | * first register push (if any) |
| 216 | * |
| 217 | * if entry sequence doesn't make sense, return -1, and leave |
| 218 | * codestream pointer random |
| 219 | */ |
| 220 | |
| 221 | static long |
| 222 | i386_get_frame_setup (CORE_ADDR pc) |
| 223 | { |
| 224 | unsigned char op; |
| 225 | |
| 226 | codestream_seek (pc); |
| 227 | |
| 228 | i386_follow_jump (); |
| 229 | |
| 230 | op = codestream_get (); |
| 231 | |
| 232 | if (op == 0x58) /* popl %eax */ |
| 233 | { |
| 234 | /* |
| 235 | * this function must start with |
| 236 | * |
| 237 | * popl %eax 0x58 |
| 238 | * xchgl %eax, (%esp) 0x87 0x04 0x24 |
| 239 | * or xchgl %eax, 0(%esp) 0x87 0x44 0x24 0x00 |
| 240 | * |
| 241 | * (the system 5 compiler puts out the second xchg |
| 242 | * inst, and the assembler doesn't try to optimize it, |
| 243 | * so the 'sib' form gets generated) |
| 244 | * |
| 245 | * this sequence is used to get the address of the return |
| 246 | * buffer for a function that returns a structure |
| 247 | */ |
| 248 | int pos; |
| 249 | unsigned char buf[4]; |
| 250 | static unsigned char proto1[3] = |
| 251 | {0x87, 0x04, 0x24}; |
| 252 | static unsigned char proto2[4] = |
| 253 | {0x87, 0x44, 0x24, 0x00}; |
| 254 | pos = codestream_tell (); |
| 255 | codestream_read (buf, 4); |
| 256 | if (memcmp (buf, proto1, 3) == 0) |
| 257 | pos += 3; |
| 258 | else if (memcmp (buf, proto2, 4) == 0) |
| 259 | pos += 4; |
| 260 | |
| 261 | codestream_seek (pos); |
| 262 | op = codestream_get (); /* update next opcode */ |
| 263 | } |
| 264 | |
| 265 | if (op == 0x68 || op == 0x6a) |
| 266 | { |
| 267 | /* |
| 268 | * this function may start with |
| 269 | * |
| 270 | * pushl constant |
| 271 | * call _probe |
| 272 | * addl $4, %esp |
| 273 | * followed by |
| 274 | * pushl %ebp |
| 275 | * etc. |
| 276 | */ |
| 277 | int pos; |
| 278 | unsigned char buf[8]; |
| 279 | |
| 280 | /* Skip past the pushl instruction; it has either a one-byte |
| 281 | or a four-byte operand, depending on the opcode. */ |
| 282 | pos = codestream_tell (); |
| 283 | if (op == 0x68) |
| 284 | pos += 4; |
| 285 | else |
| 286 | pos += 1; |
| 287 | codestream_seek (pos); |
| 288 | |
| 289 | /* Read the following 8 bytes, which should be "call _probe" (6 bytes) |
| 290 | followed by "addl $4,%esp" (2 bytes). */ |
| 291 | codestream_read (buf, sizeof (buf)); |
| 292 | if (buf[0] == 0xe8 && buf[6] == 0xc4 && buf[7] == 0x4) |
| 293 | pos += sizeof (buf); |
| 294 | codestream_seek (pos); |
| 295 | op = codestream_get (); /* update next opcode */ |
| 296 | } |
| 297 | |
| 298 | if (op == 0x55) /* pushl %ebp */ |
| 299 | { |
| 300 | /* check for movl %esp, %ebp - can be written two ways */ |
| 301 | switch (codestream_get ()) |
| 302 | { |
| 303 | case 0x8b: |
| 304 | if (codestream_get () != 0xec) |
| 305 | return (-1); |
| 306 | break; |
| 307 | case 0x89: |
| 308 | if (codestream_get () != 0xe5) |
| 309 | return (-1); |
| 310 | break; |
| 311 | default: |
| 312 | return (-1); |
| 313 | } |
| 314 | /* check for stack adjustment |
| 315 | |
| 316 | * subl $XXX, %esp |
| 317 | * |
| 318 | * note: you can't subtract a 16 bit immediate |
| 319 | * from a 32 bit reg, so we don't have to worry |
| 320 | * about a data16 prefix |
| 321 | */ |
| 322 | op = codestream_peek (); |
| 323 | if (op == 0x83) |
| 324 | { |
| 325 | /* subl with 8 bit immed */ |
| 326 | codestream_get (); |
| 327 | if (codestream_get () != 0xec) |
| 328 | /* Some instruction starting with 0x83 other than subl. */ |
| 329 | { |
| 330 | codestream_seek (codestream_tell () - 2); |
| 331 | return 0; |
| 332 | } |
| 333 | /* subl with signed byte immediate |
| 334 | * (though it wouldn't make sense to be negative) |
| 335 | */ |
| 336 | return (codestream_get ()); |
| 337 | } |
| 338 | else if (op == 0x81) |
| 339 | { |
| 340 | char buf[4]; |
| 341 | /* Maybe it is subl with 32 bit immedediate. */ |
| 342 | codestream_get (); |
| 343 | if (codestream_get () != 0xec) |
| 344 | /* Some instruction starting with 0x81 other than subl. */ |
| 345 | { |
| 346 | codestream_seek (codestream_tell () - 2); |
| 347 | return 0; |
| 348 | } |
| 349 | /* It is subl with 32 bit immediate. */ |
| 350 | codestream_read ((unsigned char *) buf, 4); |
| 351 | return extract_signed_integer (buf, 4); |
| 352 | } |
| 353 | else |
| 354 | { |
| 355 | return (0); |
| 356 | } |
| 357 | } |
| 358 | else if (op == 0xc8) |
| 359 | { |
| 360 | char buf[2]; |
| 361 | /* enter instruction: arg is 16 bit unsigned immed */ |
| 362 | codestream_read ((unsigned char *) buf, 2); |
| 363 | codestream_get (); /* flush final byte of enter instruction */ |
| 364 | return extract_unsigned_integer (buf, 2); |
| 365 | } |
| 366 | return (-1); |
| 367 | } |
| 368 | |
| 369 | /* Return number of args passed to a frame. |
| 370 | Can return -1, meaning no way to tell. */ |
| 371 | |
| 372 | int |
| 373 | i386_frame_num_args (struct frame_info *fi) |
| 374 | { |
| 375 | #if 1 |
| 376 | return -1; |
| 377 | #else |
| 378 | /* This loses because not only might the compiler not be popping the |
| 379 | args right after the function call, it might be popping args from both |
| 380 | this call and a previous one, and we would say there are more args |
| 381 | than there really are. */ |
| 382 | |
| 383 | int retpc; |
| 384 | unsigned char op; |
| 385 | struct frame_info *pfi; |
| 386 | |
| 387 | /* on the 386, the instruction following the call could be: |
| 388 | popl %ecx - one arg |
| 389 | addl $imm, %esp - imm/4 args; imm may be 8 or 32 bits |
| 390 | anything else - zero args */ |
| 391 | |
| 392 | int frameless; |
| 393 | |
| 394 | frameless = FRAMELESS_FUNCTION_INVOCATION (fi); |
| 395 | if (frameless) |
| 396 | /* In the absence of a frame pointer, GDB doesn't get correct values |
| 397 | for nameless arguments. Return -1, so it doesn't print any |
| 398 | nameless arguments. */ |
| 399 | return -1; |
| 400 | |
| 401 | pfi = get_prev_frame (fi); |
| 402 | if (pfi == 0) |
| 403 | { |
| 404 | /* Note: this can happen if we are looking at the frame for |
| 405 | main, because FRAME_CHAIN_VALID won't let us go into |
| 406 | start. If we have debugging symbols, that's not really |
| 407 | a big deal; it just means it will only show as many arguments |
| 408 | to main as are declared. */ |
| 409 | return -1; |
| 410 | } |
| 411 | else |
| 412 | { |
| 413 | retpc = pfi->pc; |
| 414 | op = read_memory_integer (retpc, 1); |
| 415 | if (op == 0x59) |
| 416 | /* pop %ecx */ |
| 417 | return 1; |
| 418 | else if (op == 0x83) |
| 419 | { |
| 420 | op = read_memory_integer (retpc + 1, 1); |
| 421 | if (op == 0xc4) |
| 422 | /* addl $<signed imm 8 bits>, %esp */ |
| 423 | return (read_memory_integer (retpc + 2, 1) & 0xff) / 4; |
| 424 | else |
| 425 | return 0; |
| 426 | } |
| 427 | else if (op == 0x81) |
| 428 | { /* add with 32 bit immediate */ |
| 429 | op = read_memory_integer (retpc + 1, 1); |
| 430 | if (op == 0xc4) |
| 431 | /* addl $<imm 32>, %esp */ |
| 432 | return read_memory_integer (retpc + 2, 4) / 4; |
| 433 | else |
| 434 | return 0; |
| 435 | } |
| 436 | else |
| 437 | { |
| 438 | return 0; |
| 439 | } |
| 440 | } |
| 441 | #endif |
| 442 | } |
| 443 | |
| 444 | /* |
| 445 | * parse the first few instructions of the function to see |
| 446 | * what registers were stored. |
| 447 | * |
| 448 | * We handle these cases: |
| 449 | * |
| 450 | * The startup sequence can be at the start of the function, |
| 451 | * or the function can start with a branch to startup code at the end. |
| 452 | * |
| 453 | * %ebp can be set up with either the 'enter' instruction, or |
| 454 | * 'pushl %ebp, movl %esp, %ebp' (enter is too slow to be useful, |
| 455 | * but was once used in the sys5 compiler) |
| 456 | * |
| 457 | * Local space is allocated just below the saved %ebp by either the |
| 458 | * 'enter' instruction, or by 'subl $<size>, %esp'. 'enter' has |
| 459 | * a 16 bit unsigned argument for space to allocate, and the |
| 460 | * 'addl' instruction could have either a signed byte, or |
| 461 | * 32 bit immediate. |
| 462 | * |
| 463 | * Next, the registers used by this function are pushed. In |
| 464 | * the sys5 compiler they will always be in the order: %edi, %esi, %ebx |
| 465 | * (and sometimes a harmless bug causes it to also save but not restore %eax); |
| 466 | * however, the code below is willing to see the pushes in any order, |
| 467 | * and will handle up to 8 of them. |
| 468 | * |
| 469 | * If the setup sequence is at the end of the function, then the |
| 470 | * next instruction will be a branch back to the start. |
| 471 | */ |
| 472 | |
| 473 | void |
| 474 | i386_frame_init_saved_regs (struct frame_info *fip) |
| 475 | { |
| 476 | long locals = -1; |
| 477 | unsigned char op; |
| 478 | CORE_ADDR dummy_bottom; |
| 479 | CORE_ADDR adr; |
| 480 | CORE_ADDR pc; |
| 481 | int i; |
| 482 | |
| 483 | if (fip->saved_regs) |
| 484 | return; |
| 485 | |
| 486 | frame_saved_regs_zalloc (fip); |
| 487 | |
| 488 | /* if frame is the end of a dummy, compute where the |
| 489 | * beginning would be |
| 490 | */ |
| 491 | dummy_bottom = fip->frame - 4 - REGISTER_BYTES - CALL_DUMMY_LENGTH; |
| 492 | |
| 493 | /* check if the PC is in the stack, in a dummy frame */ |
| 494 | if (dummy_bottom <= fip->pc && fip->pc <= fip->frame) |
| 495 | { |
| 496 | /* all regs were saved by push_call_dummy () */ |
| 497 | adr = fip->frame; |
| 498 | for (i = 0; i < NUM_REGS; i++) |
| 499 | { |
| 500 | adr -= REGISTER_RAW_SIZE (i); |
| 501 | fip->saved_regs[i] = adr; |
| 502 | } |
| 503 | return; |
| 504 | } |
| 505 | |
| 506 | pc = get_pc_function_start (fip->pc); |
| 507 | if (pc != 0) |
| 508 | locals = i386_get_frame_setup (pc); |
| 509 | |
| 510 | if (locals >= 0) |
| 511 | { |
| 512 | adr = fip->frame - 4 - locals; |
| 513 | for (i = 0; i < 8; i++) |
| 514 | { |
| 515 | op = codestream_get (); |
| 516 | if (op < 0x50 || op > 0x57) |
| 517 | break; |
| 518 | #ifdef I386_REGNO_TO_SYMMETRY |
| 519 | /* Dynix uses different internal numbering. Ick. */ |
| 520 | fip->saved_regs[I386_REGNO_TO_SYMMETRY (op - 0x50)] = adr; |
| 521 | #else |
| 522 | fip->saved_regs[op - 0x50] = adr; |
| 523 | #endif |
| 524 | adr -= 4; |
| 525 | } |
| 526 | } |
| 527 | |
| 528 | fip->saved_regs[PC_REGNUM] = fip->frame + 4; |
| 529 | fip->saved_regs[FP_REGNUM] = fip->frame; |
| 530 | } |
| 531 | |
| 532 | /* return pc of first real instruction */ |
| 533 | |
| 534 | int |
| 535 | i386_skip_prologue (int pc) |
| 536 | { |
| 537 | unsigned char op; |
| 538 | int i; |
| 539 | static unsigned char pic_pat[6] = |
| 540 | {0xe8, 0, 0, 0, 0, /* call 0x0 */ |
| 541 | 0x5b, /* popl %ebx */ |
| 542 | }; |
| 543 | CORE_ADDR pos; |
| 544 | |
| 545 | if (i386_get_frame_setup (pc) < 0) |
| 546 | return (pc); |
| 547 | |
| 548 | /* found valid frame setup - codestream now points to |
| 549 | * start of push instructions for saving registers |
| 550 | */ |
| 551 | |
| 552 | /* skip over register saves */ |
| 553 | for (i = 0; i < 8; i++) |
| 554 | { |
| 555 | op = codestream_peek (); |
| 556 | /* break if not pushl inst */ |
| 557 | if (op < 0x50 || op > 0x57) |
| 558 | break; |
| 559 | codestream_get (); |
| 560 | } |
| 561 | |
| 562 | /* The native cc on SVR4 in -K PIC mode inserts the following code to get |
| 563 | the address of the global offset table (GOT) into register %ebx. |
| 564 | call 0x0 |
| 565 | popl %ebx |
| 566 | movl %ebx,x(%ebp) (optional) |
| 567 | addl y,%ebx |
| 568 | This code is with the rest of the prologue (at the end of the |
| 569 | function), so we have to skip it to get to the first real |
| 570 | instruction at the start of the function. */ |
| 571 | |
| 572 | pos = codestream_tell (); |
| 573 | for (i = 0; i < 6; i++) |
| 574 | { |
| 575 | op = codestream_get (); |
| 576 | if (pic_pat[i] != op) |
| 577 | break; |
| 578 | } |
| 579 | if (i == 6) |
| 580 | { |
| 581 | unsigned char buf[4]; |
| 582 | long delta = 6; |
| 583 | |
| 584 | op = codestream_get (); |
| 585 | if (op == 0x89) /* movl %ebx, x(%ebp) */ |
| 586 | { |
| 587 | op = codestream_get (); |
| 588 | if (op == 0x5d) /* one byte offset from %ebp */ |
| 589 | { |
| 590 | delta += 3; |
| 591 | codestream_read (buf, 1); |
| 592 | } |
| 593 | else if (op == 0x9d) /* four byte offset from %ebp */ |
| 594 | { |
| 595 | delta += 6; |
| 596 | codestream_read (buf, 4); |
| 597 | } |
| 598 | else /* unexpected instruction */ |
| 599 | delta = -1; |
| 600 | op = codestream_get (); |
| 601 | } |
| 602 | /* addl y,%ebx */ |
| 603 | if (delta > 0 && op == 0x81 && codestream_get () == 0xc3) |
| 604 | { |
| 605 | pos += delta + 6; |
| 606 | } |
| 607 | } |
| 608 | codestream_seek (pos); |
| 609 | |
| 610 | i386_follow_jump (); |
| 611 | |
| 612 | return (codestream_tell ()); |
| 613 | } |
| 614 | |
| 615 | void |
| 616 | i386_push_dummy_frame (void) |
| 617 | { |
| 618 | CORE_ADDR sp = read_register (SP_REGNUM); |
| 619 | int regnum; |
| 620 | char regbuf[MAX_REGISTER_RAW_SIZE]; |
| 621 | |
| 622 | sp = push_word (sp, read_register (PC_REGNUM)); |
| 623 | sp = push_word (sp, read_register (FP_REGNUM)); |
| 624 | write_register (FP_REGNUM, sp); |
| 625 | for (regnum = 0; regnum < NUM_REGS; regnum++) |
| 626 | { |
| 627 | read_register_gen (regnum, regbuf); |
| 628 | sp = push_bytes (sp, regbuf, REGISTER_RAW_SIZE (regnum)); |
| 629 | } |
| 630 | write_register (SP_REGNUM, sp); |
| 631 | } |
| 632 | |
| 633 | /* Insert the (relative) function address into the call sequence |
| 634 | stored at DYMMY. */ |
| 635 | |
| 636 | void |
| 637 | i386_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs, |
| 638 | value_ptr *args, struct type *type, int gcc_p) |
| 639 | { |
| 640 | int from, to, delta, loc; |
| 641 | |
| 642 | loc = (int)(read_register (SP_REGNUM) - CALL_DUMMY_LENGTH); |
| 643 | from = loc + 5; |
| 644 | to = (int)(fun); |
| 645 | delta = to - from; |
| 646 | |
| 647 | *((char *)(dummy) + 1) = (delta & 0xff); |
| 648 | *((char *)(dummy) + 2) = ((delta >> 8) & 0xff); |
| 649 | *((char *)(dummy) + 3) = ((delta >> 16) & 0xff); |
| 650 | *((char *)(dummy) + 4) = ((delta >> 24) & 0xff); |
| 651 | } |
| 652 | |
| 653 | void |
| 654 | i386_pop_frame (void) |
| 655 | { |
| 656 | struct frame_info *frame = get_current_frame (); |
| 657 | CORE_ADDR fp; |
| 658 | int regnum; |
| 659 | char regbuf[MAX_REGISTER_RAW_SIZE]; |
| 660 | |
| 661 | fp = FRAME_FP (frame); |
| 662 | i386_frame_init_saved_regs (frame); |
| 663 | |
| 664 | for (regnum = 0; regnum < NUM_REGS; regnum++) |
| 665 | { |
| 666 | CORE_ADDR adr; |
| 667 | adr = frame->saved_regs[regnum]; |
| 668 | if (adr) |
| 669 | { |
| 670 | read_memory (adr, regbuf, REGISTER_RAW_SIZE (regnum)); |
| 671 | write_register_bytes (REGISTER_BYTE (regnum), regbuf, |
| 672 | REGISTER_RAW_SIZE (regnum)); |
| 673 | } |
| 674 | } |
| 675 | write_register (FP_REGNUM, read_memory_integer (fp, 4)); |
| 676 | write_register (PC_REGNUM, read_memory_integer (fp + 4, 4)); |
| 677 | write_register (SP_REGNUM, fp + 8); |
| 678 | flush_cached_frames (); |
| 679 | } |
| 680 | |
| 681 | #ifdef GET_LONGJMP_TARGET |
| 682 | |
| 683 | /* Figure out where the longjmp will land. Slurp the args out of the stack. |
| 684 | We expect the first arg to be a pointer to the jmp_buf structure from which |
| 685 | we extract the pc (JB_PC) that we will land at. The pc is copied into PC. |
| 686 | This routine returns true on success. */ |
| 687 | |
| 688 | int |
| 689 | get_longjmp_target (CORE_ADDR *pc) |
| 690 | { |
| 691 | char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT]; |
| 692 | CORE_ADDR sp, jb_addr; |
| 693 | |
| 694 | sp = read_register (SP_REGNUM); |
| 695 | |
| 696 | if (target_read_memory (sp + SP_ARG0, /* Offset of first arg on stack */ |
| 697 | buf, |
| 698 | TARGET_PTR_BIT / TARGET_CHAR_BIT)) |
| 699 | return 0; |
| 700 | |
| 701 | jb_addr = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT); |
| 702 | |
| 703 | if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf, |
| 704 | TARGET_PTR_BIT / TARGET_CHAR_BIT)) |
| 705 | return 0; |
| 706 | |
| 707 | *pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT); |
| 708 | |
| 709 | return 1; |
| 710 | } |
| 711 | |
| 712 | #endif /* GET_LONGJMP_TARGET */ |
| 713 | |
| 714 | /* These registers are used for returning integers (and on some |
| 715 | targets also for returning `struct' and `union' values when their |
| 716 | size and alignment match an integer type). */ |
| 717 | #define LOW_RETURN_REGNUM 0 /* %eax */ |
| 718 | #define HIGH_RETURN_REGNUM 2 /* %edx */ |
| 719 | |
| 720 | /* Extract from an array REGBUF containing the (raw) register state, a |
| 721 | function return value of TYPE, and copy that, in virtual format, |
| 722 | into VALBUF. */ |
| 723 | |
| 724 | void |
| 725 | i386_extract_return_value (struct type *type, char *regbuf, char *valbuf) |
| 726 | { |
| 727 | int len = TYPE_LENGTH (type); |
| 728 | |
| 729 | if (TYPE_CODE_FLT == TYPE_CODE (type)) |
| 730 | { |
| 731 | if (NUM_FREGS == 0) |
| 732 | { |
| 733 | warning ("Cannot find floating-point return value."); |
| 734 | memset (valbuf, 0, len); |
| 735 | return; |
| 736 | } |
| 737 | |
| 738 | /* Floating-point return values can be found in %st(0). */ |
| 739 | if (len == TARGET_LONG_DOUBLE_BIT / TARGET_CHAR_BIT |
| 740 | && TARGET_LONG_DOUBLE_FORMAT == &floatformat_i387_ext) |
| 741 | { |
| 742 | /* Copy straight over, but take care of the padding. */ |
| 743 | memcpy (valbuf, ®buf[REGISTER_BYTE (FP0_REGNUM)], |
| 744 | FPU_REG_RAW_SIZE); |
| 745 | memset (valbuf + FPU_REG_RAW_SIZE, 0, len - FPU_REG_RAW_SIZE); |
| 746 | } |
| 747 | else |
| 748 | { |
| 749 | /* Convert the extended floating-point number found in |
| 750 | %st(0) to the desired type. This is probably not exactly |
| 751 | how it would happen on the target itself, but it is the |
| 752 | best we can do. */ |
| 753 | DOUBLEST val; |
| 754 | floatformat_to_doublest (&floatformat_i387_ext, |
| 755 | ®buf[REGISTER_BYTE (FP0_REGNUM)], &val); |
| 756 | store_floating (valbuf, TYPE_LENGTH (type), val); |
| 757 | } |
| 758 | } |
| 759 | else |
| 760 | { |
| 761 | int low_size = REGISTER_RAW_SIZE (LOW_RETURN_REGNUM); |
| 762 | int high_size = REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM); |
| 763 | |
| 764 | if (len <= low_size) |
| 765 | memcpy (valbuf, ®buf[REGISTER_BYTE (LOW_RETURN_REGNUM)], len); |
| 766 | else if (len <= (low_size + high_size)) |
| 767 | { |
| 768 | memcpy (valbuf, |
| 769 | ®buf[REGISTER_BYTE (LOW_RETURN_REGNUM)], low_size); |
| 770 | memcpy (valbuf + low_size, |
| 771 | ®buf[REGISTER_BYTE (HIGH_RETURN_REGNUM)], len - low_size); |
| 772 | } |
| 773 | else |
| 774 | internal_error ("Cannot extract return value of %d bytes long.", len); |
| 775 | } |
| 776 | } |
| 777 | |
| 778 | /* Write into the appropriate registers a function return value stored |
| 779 | in VALBUF of type TYPE, given in virtual format. */ |
| 780 | |
| 781 | void |
| 782 | i386_store_return_value (struct type *type, char *valbuf) |
| 783 | { |
| 784 | int len = TYPE_LENGTH (type); |
| 785 | |
| 786 | if (TYPE_CODE_FLT == TYPE_CODE (type)) |
| 787 | { |
| 788 | if (NUM_FREGS == 0) |
| 789 | { |
| 790 | warning ("Cannot set floating-point return value."); |
| 791 | return; |
| 792 | } |
| 793 | |
| 794 | /* Floating-point return values can be found in %st(0). */ |
| 795 | if (len == TARGET_LONG_DOUBLE_BIT / TARGET_CHAR_BIT |
| 796 | && TARGET_LONG_DOUBLE_FORMAT == &floatformat_i387_ext) |
| 797 | { |
| 798 | /* Copy straight over. */ |
| 799 | write_register_bytes (REGISTER_BYTE (FP0_REGNUM), valbuf, |
| 800 | FPU_REG_RAW_SIZE); |
| 801 | } |
| 802 | else |
| 803 | { |
| 804 | char buf[FPU_REG_RAW_SIZE]; |
| 805 | DOUBLEST val; |
| 806 | |
| 807 | /* Convert the value found in VALBUF to the extended |
| 808 | floating point format used by the FPU. This is probably |
| 809 | not exactly how it would happen on the target itself, but |
| 810 | it is the best we can do. */ |
| 811 | val = extract_floating (valbuf, TYPE_LENGTH (type)); |
| 812 | floatformat_from_doublest (&floatformat_i387_ext, &val, buf); |
| 813 | write_register_bytes (REGISTER_BYTE (FP0_REGNUM), buf, |
| 814 | FPU_REG_RAW_SIZE); |
| 815 | } |
| 816 | } |
| 817 | else |
| 818 | { |
| 819 | int low_size = REGISTER_RAW_SIZE (LOW_RETURN_REGNUM); |
| 820 | int high_size = REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM); |
| 821 | |
| 822 | if (len <= low_size) |
| 823 | write_register_bytes (REGISTER_BYTE (LOW_RETURN_REGNUM), valbuf, len); |
| 824 | else if (len <= (low_size + high_size)) |
| 825 | { |
| 826 | write_register_bytes (REGISTER_BYTE (LOW_RETURN_REGNUM), |
| 827 | valbuf, low_size); |
| 828 | write_register_bytes (REGISTER_BYTE (HIGH_RETURN_REGNUM), |
| 829 | valbuf + low_size, len - low_size); |
| 830 | } |
| 831 | else |
| 832 | internal_error ("Cannot store return value of %d bytes long.", len); |
| 833 | } |
| 834 | } |
| 835 | |
| 836 | /* Convert data from raw format for register REGNUM in buffer FROM to |
| 837 | virtual format with type TYPE in buffer TO. In principle both |
| 838 | formats are identical except that the virtual format has two extra |
| 839 | bytes appended that aren't used. We set these to zero. */ |
| 840 | |
| 841 | void |
| 842 | i386_register_convert_to_virtual (int regnum, struct type *type, |
| 843 | char *from, char *to) |
| 844 | { |
| 845 | /* Copy straight over, but take care of the padding. */ |
| 846 | memcpy (to, from, FPU_REG_RAW_SIZE); |
| 847 | memset (to + FPU_REG_RAW_SIZE, 0, TYPE_LENGTH (type) - FPU_REG_RAW_SIZE); |
| 848 | } |
| 849 | |
| 850 | /* Convert data from virtual format with type TYPE in buffer FROM to |
| 851 | raw format for register REGNUM in buffer TO. Simply omit the two |
| 852 | unused bytes. */ |
| 853 | |
| 854 | void |
| 855 | i386_register_convert_to_raw (struct type *type, int regnum, |
| 856 | char *from, char *to) |
| 857 | { |
| 858 | memcpy (to, from, FPU_REG_RAW_SIZE); |
| 859 | } |
| 860 | |
| 861 | \f |
| 862 | #ifdef I386V4_SIGTRAMP_SAVED_PC |
| 863 | /* Get saved user PC for sigtramp from the pushed ucontext on the stack |
| 864 | for all three variants of SVR4 sigtramps. */ |
| 865 | |
| 866 | CORE_ADDR |
| 867 | i386v4_sigtramp_saved_pc (struct frame_info *frame) |
| 868 | { |
| 869 | CORE_ADDR saved_pc_offset = 4; |
| 870 | char *name = NULL; |
| 871 | |
| 872 | find_pc_partial_function (frame->pc, &name, NULL, NULL); |
| 873 | if (name) |
| 874 | { |
| 875 | if (STREQ (name, "_sigreturn")) |
| 876 | saved_pc_offset = 132 + 14 * 4; |
| 877 | else if (STREQ (name, "_sigacthandler")) |
| 878 | saved_pc_offset = 80 + 14 * 4; |
| 879 | else if (STREQ (name, "sigvechandler")) |
| 880 | saved_pc_offset = 120 + 14 * 4; |
| 881 | } |
| 882 | |
| 883 | if (frame->next) |
| 884 | return read_memory_integer (frame->next->frame + saved_pc_offset, 4); |
| 885 | return read_memory_integer (read_register (SP_REGNUM) + saved_pc_offset, 4); |
| 886 | } |
| 887 | #endif /* I386V4_SIGTRAMP_SAVED_PC */ |
| 888 | |
| 889 | |
| 890 | #ifdef STATIC_TRANSFORM_NAME |
| 891 | /* SunPRO encodes the static variables. This is not related to C++ mangling, |
| 892 | it is done for C too. */ |
| 893 | |
| 894 | char * |
| 895 | sunpro_static_transform_name (char *name) |
| 896 | { |
| 897 | char *p; |
| 898 | if (IS_STATIC_TRANSFORM_NAME (name)) |
| 899 | { |
| 900 | /* For file-local statics there will be a period, a bunch |
| 901 | of junk (the contents of which match a string given in the |
| 902 | N_OPT), a period and the name. For function-local statics |
| 903 | there will be a bunch of junk (which seems to change the |
| 904 | second character from 'A' to 'B'), a period, the name of the |
| 905 | function, and the name. So just skip everything before the |
| 906 | last period. */ |
| 907 | p = strrchr (name, '.'); |
| 908 | if (p != NULL) |
| 909 | name = p + 1; |
| 910 | } |
| 911 | return name; |
| 912 | } |
| 913 | #endif /* STATIC_TRANSFORM_NAME */ |
| 914 | |
| 915 | |
| 916 | |
| 917 | /* Stuff for WIN32 PE style DLL's but is pretty generic really. */ |
| 918 | |
| 919 | CORE_ADDR |
| 920 | skip_trampoline_code (CORE_ADDR pc, char *name) |
| 921 | { |
| 922 | if (pc && read_memory_unsigned_integer (pc, 2) == 0x25ff) /* jmp *(dest) */ |
| 923 | { |
| 924 | unsigned long indirect = read_memory_unsigned_integer (pc + 2, 4); |
| 925 | struct minimal_symbol *indsym = |
| 926 | indirect ? lookup_minimal_symbol_by_pc (indirect) : 0; |
| 927 | char *symname = indsym ? SYMBOL_NAME (indsym) : 0; |
| 928 | |
| 929 | if (symname) |
| 930 | { |
| 931 | if (strncmp (symname, "__imp_", 6) == 0 |
| 932 | || strncmp (symname, "_imp_", 5) == 0) |
| 933 | return name ? 1 : read_memory_unsigned_integer (indirect, 4); |
| 934 | } |
| 935 | } |
| 936 | return 0; /* not a trampoline */ |
| 937 | } |
| 938 | |
| 939 | static int |
| 940 | gdb_print_insn_i386 (bfd_vma memaddr, disassemble_info *info) |
| 941 | { |
| 942 | if (disassembly_flavor == att_flavor) |
| 943 | return print_insn_i386_att (memaddr, info); |
| 944 | else if (disassembly_flavor == intel_flavor) |
| 945 | return print_insn_i386_intel (memaddr, info); |
| 946 | /* Never reached - disassembly_flavour is always either att_flavor |
| 947 | or intel_flavor */ |
| 948 | abort (); |
| 949 | } |
| 950 | |
| 951 | /* If the disassembly mode is intel, we have to also switch the |
| 952 | bfd mach_type. This function is run in the set disassembly_flavor |
| 953 | command, and does that. */ |
| 954 | |
| 955 | static void |
| 956 | set_disassembly_flavor_sfunc (char *args, int from_tty, |
| 957 | struct cmd_list_element *c) |
| 958 | { |
| 959 | set_disassembly_flavor (); |
| 960 | } |
| 961 | |
| 962 | static void |
| 963 | set_disassembly_flavor (void) |
| 964 | { |
| 965 | if (disassembly_flavor == att_flavor) |
| 966 | set_architecture_from_arch_mach (bfd_arch_i386, bfd_mach_i386_i386); |
| 967 | else if (disassembly_flavor == intel_flavor) |
| 968 | set_architecture_from_arch_mach (bfd_arch_i386, bfd_mach_i386_i386_intel_syntax); |
| 969 | } |
| 970 | |
| 971 | |
| 972 | void |
| 973 | _initialize_i386_tdep (void) |
| 974 | { |
| 975 | /* Initialize the table saying where each register starts in the |
| 976 | register file. */ |
| 977 | { |
| 978 | int i, offset; |
| 979 | |
| 980 | offset = 0; |
| 981 | for (i = 0; i < MAX_NUM_REGS; i++) |
| 982 | { |
| 983 | i386_register_byte[i] = offset; |
| 984 | offset += i386_register_raw_size[i]; |
| 985 | } |
| 986 | } |
| 987 | |
| 988 | /* Initialize the table of virtual register sizes. */ |
| 989 | { |
| 990 | int i; |
| 991 | |
| 992 | for (i = 0; i < MAX_NUM_REGS; i++) |
| 993 | i386_register_virtual_size[i] = TYPE_LENGTH (REGISTER_VIRTUAL_TYPE (i)); |
| 994 | } |
| 995 | |
| 996 | tm_print_insn = gdb_print_insn_i386; |
| 997 | tm_print_insn_info.mach = bfd_lookup_arch (bfd_arch_i386, 0)->mach; |
| 998 | |
| 999 | /* Add the variable that controls the disassembly flavor */ |
| 1000 | { |
| 1001 | struct cmd_list_element *new_cmd; |
| 1002 | |
| 1003 | new_cmd = add_set_enum_cmd ("disassembly-flavor", no_class, |
| 1004 | valid_flavors, |
| 1005 | &disassembly_flavor, |
| 1006 | "Set the disassembly flavor, the valid values are \"att\" and \"intel\", \ |
| 1007 | and the default value is \"att\".", |
| 1008 | &setlist); |
| 1009 | new_cmd->function.sfunc = set_disassembly_flavor_sfunc; |
| 1010 | add_show_from_set (new_cmd, &showlist); |
| 1011 | } |
| 1012 | |
| 1013 | /* Finally, initialize the disassembly flavor to the default given |
| 1014 | in the disassembly_flavor variable */ |
| 1015 | |
| 1016 | set_disassembly_flavor (); |
| 1017 | } |