| 1 | /* Intel 386 target-dependent stuff. |
| 2 | |
| 3 | Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, |
| 4 | 1997, 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc. |
| 5 | |
| 6 | This file is part of GDB. |
| 7 | |
| 8 | This program is free software; you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation; either version 2 of the License, or |
| 11 | (at your option) any later version. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program; if not, write to the Free Software |
| 20 | Foundation, Inc., 59 Temple Place - Suite 330, |
| 21 | Boston, MA 02111-1307, USA. */ |
| 22 | |
| 23 | #include "defs.h" |
| 24 | #include "gdb_string.h" |
| 25 | #include "frame.h" |
| 26 | #include "inferior.h" |
| 27 | #include "gdbcore.h" |
| 28 | #include "target.h" |
| 29 | #include "floatformat.h" |
| 30 | #include "symtab.h" |
| 31 | #include "gdbcmd.h" |
| 32 | #include "command.h" |
| 33 | #include "arch-utils.h" |
| 34 | #include "regcache.h" |
| 35 | #include "doublest.h" |
| 36 | #include "value.h" |
| 37 | #include "gdb_assert.h" |
| 38 | |
| 39 | #include "i386-tdep.h" |
| 40 | |
| 41 | /* Names of the registers. The first 10 registers match the register |
| 42 | numbering scheme used by GCC for stabs and DWARF. */ |
| 43 | static char *i386_register_names[] = |
| 44 | { |
| 45 | "eax", "ecx", "edx", "ebx", |
| 46 | "esp", "ebp", "esi", "edi", |
| 47 | "eip", "eflags", "cs", "ss", |
| 48 | "ds", "es", "fs", "gs", |
| 49 | "st0", "st1", "st2", "st3", |
| 50 | "st4", "st5", "st6", "st7", |
| 51 | "fctrl", "fstat", "ftag", "fiseg", |
| 52 | "fioff", "foseg", "fooff", "fop", |
| 53 | "xmm0", "xmm1", "xmm2", "xmm3", |
| 54 | "xmm4", "xmm5", "xmm6", "xmm7", |
| 55 | "mxcsr" |
| 56 | }; |
| 57 | |
| 58 | /* i386_register_offset[i] is the offset into the register file of the |
| 59 | start of register number i. We initialize this from |
| 60 | i386_register_size. */ |
| 61 | static int i386_register_offset[I386_SSE_NUM_REGS]; |
| 62 | |
| 63 | /* i386_register_size[i] is the number of bytes of storage in GDB's |
| 64 | register array occupied by register i. */ |
| 65 | static int i386_register_size[I386_SSE_NUM_REGS] = { |
| 66 | 4, 4, 4, 4, |
| 67 | 4, 4, 4, 4, |
| 68 | 4, 4, 4, 4, |
| 69 | 4, 4, 4, 4, |
| 70 | 10, 10, 10, 10, |
| 71 | 10, 10, 10, 10, |
| 72 | 4, 4, 4, 4, |
| 73 | 4, 4, 4, 4, |
| 74 | 16, 16, 16, 16, |
| 75 | 16, 16, 16, 16, |
| 76 | 4 |
| 77 | }; |
| 78 | |
| 79 | /* Return the name of register REG. */ |
| 80 | |
| 81 | const char * |
| 82 | i386_register_name (int reg) |
| 83 | { |
| 84 | if (reg < 0) |
| 85 | return NULL; |
| 86 | if (reg >= sizeof (i386_register_names) / sizeof (*i386_register_names)) |
| 87 | return NULL; |
| 88 | |
| 89 | return i386_register_names[reg]; |
| 90 | } |
| 91 | |
| 92 | /* Return the offset into the register array of the start of register |
| 93 | number REG. */ |
| 94 | int |
| 95 | i386_register_byte (int reg) |
| 96 | { |
| 97 | return i386_register_offset[reg]; |
| 98 | } |
| 99 | |
| 100 | /* Return the number of bytes of storage in GDB's register array |
| 101 | occupied by register REG. */ |
| 102 | |
| 103 | int |
| 104 | i386_register_raw_size (int reg) |
| 105 | { |
| 106 | return i386_register_size[reg]; |
| 107 | } |
| 108 | |
| 109 | /* Convert stabs register number REG to the appropriate register |
| 110 | number used by GDB. */ |
| 111 | |
| 112 | static int |
| 113 | i386_stab_reg_to_regnum (int reg) |
| 114 | { |
| 115 | /* This implements what GCC calls the "default" register map. */ |
| 116 | if (reg >= 0 && reg <= 7) |
| 117 | { |
| 118 | /* General registers. */ |
| 119 | return reg; |
| 120 | } |
| 121 | else if (reg >= 12 && reg <= 19) |
| 122 | { |
| 123 | /* Floating-point registers. */ |
| 124 | return reg - 12 + FP0_REGNUM; |
| 125 | } |
| 126 | else if (reg >= 21 && reg <= 28) |
| 127 | { |
| 128 | /* SSE registers. */ |
| 129 | return reg - 21 + XMM0_REGNUM; |
| 130 | } |
| 131 | else if (reg >= 29 && reg <= 36) |
| 132 | { |
| 133 | /* MMX registers. */ |
| 134 | /* FIXME: kettenis/2001-07-28: Should we have the MMX registers |
| 135 | as pseudo-registers? */ |
| 136 | return reg - 29 + FP0_REGNUM; |
| 137 | } |
| 138 | |
| 139 | /* This will hopefully provoke a warning. */ |
| 140 | return NUM_REGS + NUM_PSEUDO_REGS; |
| 141 | } |
| 142 | |
| 143 | /* Convert DWARF register number REG to the appropriate register |
| 144 | number used by GDB. */ |
| 145 | |
| 146 | static int |
| 147 | i386_dwarf_reg_to_regnum (int reg) |
| 148 | { |
| 149 | /* The DWARF register numbering includes %eip and %eflags, and |
| 150 | numbers the floating point registers differently. */ |
| 151 | if (reg >= 0 && reg <= 9) |
| 152 | { |
| 153 | /* General registers. */ |
| 154 | return reg; |
| 155 | } |
| 156 | else if (reg >= 11 && reg <= 18) |
| 157 | { |
| 158 | /* Floating-point registers. */ |
| 159 | return reg - 11 + FP0_REGNUM; |
| 160 | } |
| 161 | else if (reg >= 21) |
| 162 | { |
| 163 | /* The SSE and MMX registers have identical numbers as in stabs. */ |
| 164 | return i386_stab_reg_to_regnum (reg); |
| 165 | } |
| 166 | |
| 167 | /* This will hopefully provoke a warning. */ |
| 168 | return NUM_REGS + NUM_PSEUDO_REGS; |
| 169 | } |
| 170 | \f |
| 171 | |
| 172 | /* This is the variable that is set with "set disassembly-flavor", and |
| 173 | its legitimate values. */ |
| 174 | static const char att_flavor[] = "att"; |
| 175 | static const char intel_flavor[] = "intel"; |
| 176 | static const char *valid_flavors[] = |
| 177 | { |
| 178 | att_flavor, |
| 179 | intel_flavor, |
| 180 | NULL |
| 181 | }; |
| 182 | static const char *disassembly_flavor = att_flavor; |
| 183 | |
| 184 | /* Stdio style buffering was used to minimize calls to ptrace, but |
| 185 | this buffering did not take into account that the code section |
| 186 | being accessed may not be an even number of buffers long (even if |
| 187 | the buffer is only sizeof(int) long). In cases where the code |
| 188 | section size happened to be a non-integral number of buffers long, |
| 189 | attempting to read the last buffer would fail. Simply using |
| 190 | target_read_memory and ignoring errors, rather than read_memory, is |
| 191 | not the correct solution, since legitimate access errors would then |
| 192 | be totally ignored. To properly handle this situation and continue |
| 193 | to use buffering would require that this code be able to determine |
| 194 | the minimum code section size granularity (not the alignment of the |
| 195 | section itself, since the actual failing case that pointed out this |
| 196 | problem had a section alignment of 4 but was not a multiple of 4 |
| 197 | bytes long), on a target by target basis, and then adjust it's |
| 198 | buffer size accordingly. This is messy, but potentially feasible. |
| 199 | It probably needs the bfd library's help and support. For now, the |
| 200 | buffer size is set to 1. (FIXME -fnf) */ |
| 201 | |
| 202 | #define CODESTREAM_BUFSIZ 1 /* Was sizeof(int), see note above. */ |
| 203 | static CORE_ADDR codestream_next_addr; |
| 204 | static CORE_ADDR codestream_addr; |
| 205 | static unsigned char codestream_buf[CODESTREAM_BUFSIZ]; |
| 206 | static int codestream_off; |
| 207 | static int codestream_cnt; |
| 208 | |
| 209 | #define codestream_tell() (codestream_addr + codestream_off) |
| 210 | #define codestream_peek() \ |
| 211 | (codestream_cnt == 0 ? \ |
| 212 | codestream_fill(1) : codestream_buf[codestream_off]) |
| 213 | #define codestream_get() \ |
| 214 | (codestream_cnt-- == 0 ? \ |
| 215 | codestream_fill(0) : codestream_buf[codestream_off++]) |
| 216 | |
| 217 | static unsigned char |
| 218 | codestream_fill (int peek_flag) |
| 219 | { |
| 220 | codestream_addr = codestream_next_addr; |
| 221 | codestream_next_addr += CODESTREAM_BUFSIZ; |
| 222 | codestream_off = 0; |
| 223 | codestream_cnt = CODESTREAM_BUFSIZ; |
| 224 | read_memory (codestream_addr, (char *) codestream_buf, CODESTREAM_BUFSIZ); |
| 225 | |
| 226 | if (peek_flag) |
| 227 | return (codestream_peek ()); |
| 228 | else |
| 229 | return (codestream_get ()); |
| 230 | } |
| 231 | |
| 232 | static void |
| 233 | codestream_seek (CORE_ADDR place) |
| 234 | { |
| 235 | codestream_next_addr = place / CODESTREAM_BUFSIZ; |
| 236 | codestream_next_addr *= CODESTREAM_BUFSIZ; |
| 237 | codestream_cnt = 0; |
| 238 | codestream_fill (1); |
| 239 | while (codestream_tell () != place) |
| 240 | codestream_get (); |
| 241 | } |
| 242 | |
| 243 | static void |
| 244 | codestream_read (unsigned char *buf, int count) |
| 245 | { |
| 246 | unsigned char *p; |
| 247 | int i; |
| 248 | p = buf; |
| 249 | for (i = 0; i < count; i++) |
| 250 | *p++ = codestream_get (); |
| 251 | } |
| 252 | \f |
| 253 | |
| 254 | /* If the next instruction is a jump, move to its target. */ |
| 255 | |
| 256 | static void |
| 257 | i386_follow_jump (void) |
| 258 | { |
| 259 | unsigned char buf[4]; |
| 260 | long delta; |
| 261 | |
| 262 | int data16; |
| 263 | CORE_ADDR pos; |
| 264 | |
| 265 | pos = codestream_tell (); |
| 266 | |
| 267 | data16 = 0; |
| 268 | if (codestream_peek () == 0x66) |
| 269 | { |
| 270 | codestream_get (); |
| 271 | data16 = 1; |
| 272 | } |
| 273 | |
| 274 | switch (codestream_get ()) |
| 275 | { |
| 276 | case 0xe9: |
| 277 | /* Relative jump: if data16 == 0, disp32, else disp16. */ |
| 278 | if (data16) |
| 279 | { |
| 280 | codestream_read (buf, 2); |
| 281 | delta = extract_signed_integer (buf, 2); |
| 282 | |
| 283 | /* Include the size of the jmp instruction (including the |
| 284 | 0x66 prefix). */ |
| 285 | pos += delta + 4; |
| 286 | } |
| 287 | else |
| 288 | { |
| 289 | codestream_read (buf, 4); |
| 290 | delta = extract_signed_integer (buf, 4); |
| 291 | |
| 292 | pos += delta + 5; |
| 293 | } |
| 294 | break; |
| 295 | case 0xeb: |
| 296 | /* Relative jump, disp8 (ignore data16). */ |
| 297 | codestream_read (buf, 1); |
| 298 | /* Sign-extend it. */ |
| 299 | delta = extract_signed_integer (buf, 1); |
| 300 | |
| 301 | pos += delta + 2; |
| 302 | break; |
| 303 | } |
| 304 | codestream_seek (pos); |
| 305 | } |
| 306 | |
| 307 | /* Find & return the amount a local space allocated, and advance the |
| 308 | codestream to the first register push (if any). |
| 309 | |
| 310 | If the entry sequence doesn't make sense, return -1, and leave |
| 311 | codestream pointer at a random spot. */ |
| 312 | |
| 313 | static long |
| 314 | i386_get_frame_setup (CORE_ADDR pc) |
| 315 | { |
| 316 | unsigned char op; |
| 317 | |
| 318 | codestream_seek (pc); |
| 319 | |
| 320 | i386_follow_jump (); |
| 321 | |
| 322 | op = codestream_get (); |
| 323 | |
| 324 | if (op == 0x58) /* popl %eax */ |
| 325 | { |
| 326 | /* This function must start with |
| 327 | |
| 328 | popl %eax 0x58 |
| 329 | xchgl %eax, (%esp) 0x87 0x04 0x24 |
| 330 | or xchgl %eax, 0(%esp) 0x87 0x44 0x24 0x00 |
| 331 | |
| 332 | (the System V compiler puts out the second `xchg' |
| 333 | instruction, and the assembler doesn't try to optimize it, so |
| 334 | the 'sib' form gets generated). This sequence is used to get |
| 335 | the address of the return buffer for a function that returns |
| 336 | a structure. */ |
| 337 | int pos; |
| 338 | unsigned char buf[4]; |
| 339 | static unsigned char proto1[3] = { 0x87, 0x04, 0x24 }; |
| 340 | static unsigned char proto2[4] = { 0x87, 0x44, 0x24, 0x00 }; |
| 341 | |
| 342 | pos = codestream_tell (); |
| 343 | codestream_read (buf, 4); |
| 344 | if (memcmp (buf, proto1, 3) == 0) |
| 345 | pos += 3; |
| 346 | else if (memcmp (buf, proto2, 4) == 0) |
| 347 | pos += 4; |
| 348 | |
| 349 | codestream_seek (pos); |
| 350 | op = codestream_get (); /* Update next opcode. */ |
| 351 | } |
| 352 | |
| 353 | if (op == 0x68 || op == 0x6a) |
| 354 | { |
| 355 | /* This function may start with |
| 356 | |
| 357 | pushl constant |
| 358 | call _probe |
| 359 | addl $4, %esp |
| 360 | |
| 361 | followed by |
| 362 | |
| 363 | pushl %ebp |
| 364 | |
| 365 | etc. */ |
| 366 | int pos; |
| 367 | unsigned char buf[8]; |
| 368 | |
| 369 | /* Skip past the `pushl' instruction; it has either a one-byte |
| 370 | or a four-byte operand, depending on the opcode. */ |
| 371 | pos = codestream_tell (); |
| 372 | if (op == 0x68) |
| 373 | pos += 4; |
| 374 | else |
| 375 | pos += 1; |
| 376 | codestream_seek (pos); |
| 377 | |
| 378 | /* Read the following 8 bytes, which should be "call _probe" (6 |
| 379 | bytes) followed by "addl $4,%esp" (2 bytes). */ |
| 380 | codestream_read (buf, sizeof (buf)); |
| 381 | if (buf[0] == 0xe8 && buf[6] == 0xc4 && buf[7] == 0x4) |
| 382 | pos += sizeof (buf); |
| 383 | codestream_seek (pos); |
| 384 | op = codestream_get (); /* Update next opcode. */ |
| 385 | } |
| 386 | |
| 387 | if (op == 0x55) /* pushl %ebp */ |
| 388 | { |
| 389 | /* Check for "movl %esp, %ebp" -- can be written in two ways. */ |
| 390 | switch (codestream_get ()) |
| 391 | { |
| 392 | case 0x8b: |
| 393 | if (codestream_get () != 0xec) |
| 394 | return -1; |
| 395 | break; |
| 396 | case 0x89: |
| 397 | if (codestream_get () != 0xe5) |
| 398 | return -1; |
| 399 | break; |
| 400 | default: |
| 401 | return -1; |
| 402 | } |
| 403 | /* Check for stack adjustment |
| 404 | |
| 405 | subl $XXX, %esp |
| 406 | |
| 407 | NOTE: You can't subtract a 16 bit immediate from a 32 bit |
| 408 | reg, so we don't have to worry about a data16 prefix. */ |
| 409 | op = codestream_peek (); |
| 410 | if (op == 0x83) |
| 411 | { |
| 412 | /* `subl' with 8 bit immediate. */ |
| 413 | codestream_get (); |
| 414 | if (codestream_get () != 0xec) |
| 415 | /* Some instruction starting with 0x83 other than `subl'. */ |
| 416 | { |
| 417 | codestream_seek (codestream_tell () - 2); |
| 418 | return 0; |
| 419 | } |
| 420 | /* `subl' with signed byte immediate (though it wouldn't |
| 421 | make sense to be negative). */ |
| 422 | return (codestream_get ()); |
| 423 | } |
| 424 | else if (op == 0x81) |
| 425 | { |
| 426 | char buf[4]; |
| 427 | /* Maybe it is `subl' with a 32 bit immedediate. */ |
| 428 | codestream_get (); |
| 429 | if (codestream_get () != 0xec) |
| 430 | /* Some instruction starting with 0x81 other than `subl'. */ |
| 431 | { |
| 432 | codestream_seek (codestream_tell () - 2); |
| 433 | return 0; |
| 434 | } |
| 435 | /* It is `subl' with a 32 bit immediate. */ |
| 436 | codestream_read ((unsigned char *) buf, 4); |
| 437 | return extract_signed_integer (buf, 4); |
| 438 | } |
| 439 | else |
| 440 | { |
| 441 | return 0; |
| 442 | } |
| 443 | } |
| 444 | else if (op == 0xc8) |
| 445 | { |
| 446 | char buf[2]; |
| 447 | /* `enter' with 16 bit unsigned immediate. */ |
| 448 | codestream_read ((unsigned char *) buf, 2); |
| 449 | codestream_get (); /* Flush final byte of enter instruction. */ |
| 450 | return extract_unsigned_integer (buf, 2); |
| 451 | } |
| 452 | return (-1); |
| 453 | } |
| 454 | |
| 455 | /* Return the chain-pointer for FRAME. In the case of the i386, the |
| 456 | frame's nominal address is the address of a 4-byte word containing |
| 457 | the calling frame's address. */ |
| 458 | |
| 459 | static CORE_ADDR |
| 460 | i386_frame_chain (struct frame_info *frame) |
| 461 | { |
| 462 | if (frame->signal_handler_caller) |
| 463 | return frame->frame; |
| 464 | |
| 465 | if (! inside_entry_file (frame->pc)) |
| 466 | return read_memory_unsigned_integer (frame->frame, 4); |
| 467 | |
| 468 | return 0; |
| 469 | } |
| 470 | |
| 471 | /* Determine whether the function invocation represented by FRAME does |
| 472 | not have a from on the stack associated with it. If it does not, |
| 473 | return non-zero, otherwise return zero. */ |
| 474 | |
| 475 | static int |
| 476 | i386_frameless_function_invocation (struct frame_info *frame) |
| 477 | { |
| 478 | if (frame->signal_handler_caller) |
| 479 | return 0; |
| 480 | |
| 481 | return frameless_look_for_prologue (frame); |
| 482 | } |
| 483 | |
| 484 | /* Assuming FRAME is for a sigtramp routine, return the saved program |
| 485 | counter. */ |
| 486 | |
| 487 | static CORE_ADDR |
| 488 | i386_sigtramp_saved_pc (struct frame_info *frame) |
| 489 | { |
| 490 | struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); |
| 491 | CORE_ADDR addr; |
| 492 | |
| 493 | addr = tdep->sigcontext_addr (frame); |
| 494 | return read_memory_unsigned_integer (addr + tdep->sc_pc_offset, 4); |
| 495 | } |
| 496 | |
| 497 | /* Return the saved program counter for FRAME. */ |
| 498 | |
| 499 | static CORE_ADDR |
| 500 | i386_frame_saved_pc (struct frame_info *frame) |
| 501 | { |
| 502 | if (frame->signal_handler_caller) |
| 503 | return i386_sigtramp_saved_pc (frame); |
| 504 | |
| 505 | return read_memory_unsigned_integer (frame->frame + 4, 4); |
| 506 | } |
| 507 | |
| 508 | /* Immediately after a function call, return the saved pc. */ |
| 509 | |
| 510 | static CORE_ADDR |
| 511 | i386_saved_pc_after_call (struct frame_info *frame) |
| 512 | { |
| 513 | return read_memory_unsigned_integer (read_register (SP_REGNUM), 4); |
| 514 | } |
| 515 | |
| 516 | /* Return number of args passed to a frame. |
| 517 | Can return -1, meaning no way to tell. */ |
| 518 | |
| 519 | static int |
| 520 | i386_frame_num_args (struct frame_info *fi) |
| 521 | { |
| 522 | #if 1 |
| 523 | return -1; |
| 524 | #else |
| 525 | /* This loses because not only might the compiler not be popping the |
| 526 | args right after the function call, it might be popping args from |
| 527 | both this call and a previous one, and we would say there are |
| 528 | more args than there really are. */ |
| 529 | |
| 530 | int retpc; |
| 531 | unsigned char op; |
| 532 | struct frame_info *pfi; |
| 533 | |
| 534 | /* On the i386, the instruction following the call could be: |
| 535 | popl %ecx - one arg |
| 536 | addl $imm, %esp - imm/4 args; imm may be 8 or 32 bits |
| 537 | anything else - zero args. */ |
| 538 | |
| 539 | int frameless; |
| 540 | |
| 541 | frameless = FRAMELESS_FUNCTION_INVOCATION (fi); |
| 542 | if (frameless) |
| 543 | /* In the absence of a frame pointer, GDB doesn't get correct |
| 544 | values for nameless arguments. Return -1, so it doesn't print |
| 545 | any nameless arguments. */ |
| 546 | return -1; |
| 547 | |
| 548 | pfi = get_prev_frame (fi); |
| 549 | if (pfi == 0) |
| 550 | { |
| 551 | /* NOTE: This can happen if we are looking at the frame for |
| 552 | main, because FRAME_CHAIN_VALID won't let us go into start. |
| 553 | If we have debugging symbols, that's not really a big deal; |
| 554 | it just means it will only show as many arguments to main as |
| 555 | are declared. */ |
| 556 | return -1; |
| 557 | } |
| 558 | else |
| 559 | { |
| 560 | retpc = pfi->pc; |
| 561 | op = read_memory_integer (retpc, 1); |
| 562 | if (op == 0x59) /* pop %ecx */ |
| 563 | return 1; |
| 564 | else if (op == 0x83) |
| 565 | { |
| 566 | op = read_memory_integer (retpc + 1, 1); |
| 567 | if (op == 0xc4) |
| 568 | /* addl $<signed imm 8 bits>, %esp */ |
| 569 | return (read_memory_integer (retpc + 2, 1) & 0xff) / 4; |
| 570 | else |
| 571 | return 0; |
| 572 | } |
| 573 | else if (op == 0x81) /* `add' with 32 bit immediate. */ |
| 574 | { |
| 575 | op = read_memory_integer (retpc + 1, 1); |
| 576 | if (op == 0xc4) |
| 577 | /* addl $<imm 32>, %esp */ |
| 578 | return read_memory_integer (retpc + 2, 4) / 4; |
| 579 | else |
| 580 | return 0; |
| 581 | } |
| 582 | else |
| 583 | { |
| 584 | return 0; |
| 585 | } |
| 586 | } |
| 587 | #endif |
| 588 | } |
| 589 | |
| 590 | /* Parse the first few instructions the function to see what registers |
| 591 | were stored. |
| 592 | |
| 593 | We handle these cases: |
| 594 | |
| 595 | The startup sequence can be at the start of the function, or the |
| 596 | function can start with a branch to startup code at the end. |
| 597 | |
| 598 | %ebp can be set up with either the 'enter' instruction, or "pushl |
| 599 | %ebp, movl %esp, %ebp" (`enter' is too slow to be useful, but was |
| 600 | once used in the System V compiler). |
| 601 | |
| 602 | Local space is allocated just below the saved %ebp by either the |
| 603 | 'enter' instruction, or by "subl $<size>, %esp". 'enter' has a 16 |
| 604 | bit unsigned argument for space to allocate, and the 'addl' |
| 605 | instruction could have either a signed byte, or 32 bit immediate. |
| 606 | |
| 607 | Next, the registers used by this function are pushed. With the |
| 608 | System V compiler they will always be in the order: %edi, %esi, |
| 609 | %ebx (and sometimes a harmless bug causes it to also save but not |
| 610 | restore %eax); however, the code below is willing to see the pushes |
| 611 | in any order, and will handle up to 8 of them. |
| 612 | |
| 613 | If the setup sequence is at the end of the function, then the next |
| 614 | instruction will be a branch back to the start. */ |
| 615 | |
| 616 | static void |
| 617 | i386_frame_init_saved_regs (struct frame_info *fip) |
| 618 | { |
| 619 | long locals = -1; |
| 620 | unsigned char op; |
| 621 | CORE_ADDR dummy_bottom; |
| 622 | CORE_ADDR addr; |
| 623 | CORE_ADDR pc; |
| 624 | int i; |
| 625 | |
| 626 | if (fip->saved_regs) |
| 627 | return; |
| 628 | |
| 629 | frame_saved_regs_zalloc (fip); |
| 630 | |
| 631 | /* If the frame is the end of a dummy, compute where the beginning |
| 632 | would be. */ |
| 633 | dummy_bottom = fip->frame - 4 - REGISTER_BYTES - CALL_DUMMY_LENGTH; |
| 634 | |
| 635 | /* Check if the PC points in the stack, in a dummy frame. */ |
| 636 | if (dummy_bottom <= fip->pc && fip->pc <= fip->frame) |
| 637 | { |
| 638 | /* All registers were saved by push_call_dummy. */ |
| 639 | addr = fip->frame; |
| 640 | for (i = 0; i < NUM_REGS; i++) |
| 641 | { |
| 642 | addr -= REGISTER_RAW_SIZE (i); |
| 643 | fip->saved_regs[i] = addr; |
| 644 | } |
| 645 | return; |
| 646 | } |
| 647 | |
| 648 | pc = get_pc_function_start (fip->pc); |
| 649 | if (pc != 0) |
| 650 | locals = i386_get_frame_setup (pc); |
| 651 | |
| 652 | if (locals >= 0) |
| 653 | { |
| 654 | addr = fip->frame - 4 - locals; |
| 655 | for (i = 0; i < 8; i++) |
| 656 | { |
| 657 | op = codestream_get (); |
| 658 | if (op < 0x50 || op > 0x57) |
| 659 | break; |
| 660 | #ifdef I386_REGNO_TO_SYMMETRY |
| 661 | /* Dynix uses different internal numbering. Ick. */ |
| 662 | fip->saved_regs[I386_REGNO_TO_SYMMETRY (op - 0x50)] = addr; |
| 663 | #else |
| 664 | fip->saved_regs[op - 0x50] = addr; |
| 665 | #endif |
| 666 | addr -= 4; |
| 667 | } |
| 668 | } |
| 669 | |
| 670 | fip->saved_regs[PC_REGNUM] = fip->frame + 4; |
| 671 | fip->saved_regs[FP_REGNUM] = fip->frame; |
| 672 | } |
| 673 | |
| 674 | /* Return PC of first real instruction. */ |
| 675 | |
| 676 | static CORE_ADDR |
| 677 | i386_skip_prologue (CORE_ADDR pc) |
| 678 | { |
| 679 | unsigned char op; |
| 680 | int i; |
| 681 | static unsigned char pic_pat[6] = |
| 682 | { 0xe8, 0, 0, 0, 0, /* call 0x0 */ |
| 683 | 0x5b, /* popl %ebx */ |
| 684 | }; |
| 685 | CORE_ADDR pos; |
| 686 | |
| 687 | if (i386_get_frame_setup (pc) < 0) |
| 688 | return (pc); |
| 689 | |
| 690 | /* Found valid frame setup -- codestream now points to start of push |
| 691 | instructions for saving registers. */ |
| 692 | |
| 693 | /* Skip over register saves. */ |
| 694 | for (i = 0; i < 8; i++) |
| 695 | { |
| 696 | op = codestream_peek (); |
| 697 | /* Break if not `pushl' instrunction. */ |
| 698 | if (op < 0x50 || op > 0x57) |
| 699 | break; |
| 700 | codestream_get (); |
| 701 | } |
| 702 | |
| 703 | /* The native cc on SVR4 in -K PIC mode inserts the following code |
| 704 | to get the address of the global offset table (GOT) into register |
| 705 | %ebx |
| 706 | |
| 707 | call 0x0 |
| 708 | popl %ebx |
| 709 | movl %ebx,x(%ebp) (optional) |
| 710 | addl y,%ebx |
| 711 | |
| 712 | This code is with the rest of the prologue (at the end of the |
| 713 | function), so we have to skip it to get to the first real |
| 714 | instruction at the start of the function. */ |
| 715 | |
| 716 | pos = codestream_tell (); |
| 717 | for (i = 0; i < 6; i++) |
| 718 | { |
| 719 | op = codestream_get (); |
| 720 | if (pic_pat[i] != op) |
| 721 | break; |
| 722 | } |
| 723 | if (i == 6) |
| 724 | { |
| 725 | unsigned char buf[4]; |
| 726 | long delta = 6; |
| 727 | |
| 728 | op = codestream_get (); |
| 729 | if (op == 0x89) /* movl %ebx, x(%ebp) */ |
| 730 | { |
| 731 | op = codestream_get (); |
| 732 | if (op == 0x5d) /* One byte offset from %ebp. */ |
| 733 | { |
| 734 | delta += 3; |
| 735 | codestream_read (buf, 1); |
| 736 | } |
| 737 | else if (op == 0x9d) /* Four byte offset from %ebp. */ |
| 738 | { |
| 739 | delta += 6; |
| 740 | codestream_read (buf, 4); |
| 741 | } |
| 742 | else /* Unexpected instruction. */ |
| 743 | delta = -1; |
| 744 | op = codestream_get (); |
| 745 | } |
| 746 | /* addl y,%ebx */ |
| 747 | if (delta > 0 && op == 0x81 && codestream_get () == 0xc3) |
| 748 | { |
| 749 | pos += delta + 6; |
| 750 | } |
| 751 | } |
| 752 | codestream_seek (pos); |
| 753 | |
| 754 | i386_follow_jump (); |
| 755 | |
| 756 | return (codestream_tell ()); |
| 757 | } |
| 758 | |
| 759 | /* Use the program counter to determine the contents and size of a |
| 760 | breakpoint instruction. Return a pointer to a string of bytes that |
| 761 | encode a breakpoint instruction, store the length of the string in |
| 762 | *LEN and optionally adjust *PC to point to the correct memory |
| 763 | location for inserting the breakpoint. |
| 764 | |
| 765 | On the i386 we have a single breakpoint that fits in a single byte |
| 766 | and can be inserted anywhere. */ |
| 767 | |
| 768 | static const unsigned char * |
| 769 | i386_breakpoint_from_pc (CORE_ADDR *pc, int *len) |
| 770 | { |
| 771 | static unsigned char break_insn[] = { 0xcc }; /* int 3 */ |
| 772 | |
| 773 | *len = sizeof (break_insn); |
| 774 | return break_insn; |
| 775 | } |
| 776 | |
| 777 | static void |
| 778 | i386_push_dummy_frame (void) |
| 779 | { |
| 780 | CORE_ADDR sp = read_register (SP_REGNUM); |
| 781 | CORE_ADDR fp; |
| 782 | int regnum; |
| 783 | char regbuf[MAX_REGISTER_RAW_SIZE]; |
| 784 | |
| 785 | sp = push_word (sp, read_register (PC_REGNUM)); |
| 786 | sp = push_word (sp, read_register (FP_REGNUM)); |
| 787 | fp = sp; |
| 788 | for (regnum = 0; regnum < NUM_REGS; regnum++) |
| 789 | { |
| 790 | read_register_gen (regnum, regbuf); |
| 791 | sp = push_bytes (sp, regbuf, REGISTER_RAW_SIZE (regnum)); |
| 792 | } |
| 793 | write_register (SP_REGNUM, sp); |
| 794 | write_register (FP_REGNUM, fp); |
| 795 | } |
| 796 | |
| 797 | /* The i386 call dummy sequence: |
| 798 | |
| 799 | call 11223344 (32-bit relative) |
| 800 | int 3 |
| 801 | |
| 802 | It is 8 bytes long. */ |
| 803 | |
| 804 | static LONGEST i386_call_dummy_words[] = |
| 805 | { |
| 806 | 0x223344e8, |
| 807 | 0xcc11 |
| 808 | }; |
| 809 | |
| 810 | /* Insert the (relative) function address into the call sequence |
| 811 | stored at DYMMY. */ |
| 812 | |
| 813 | static void |
| 814 | i386_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs, |
| 815 | struct value **args, struct type *type, int gcc_p) |
| 816 | { |
| 817 | int from, to, delta, loc; |
| 818 | |
| 819 | loc = (int)(read_register (SP_REGNUM) - CALL_DUMMY_LENGTH); |
| 820 | from = loc + 5; |
| 821 | to = (int)(fun); |
| 822 | delta = to - from; |
| 823 | |
| 824 | *((char *)(dummy) + 1) = (delta & 0xff); |
| 825 | *((char *)(dummy) + 2) = ((delta >> 8) & 0xff); |
| 826 | *((char *)(dummy) + 3) = ((delta >> 16) & 0xff); |
| 827 | *((char *)(dummy) + 4) = ((delta >> 24) & 0xff); |
| 828 | } |
| 829 | |
| 830 | static void |
| 831 | i386_pop_frame (void) |
| 832 | { |
| 833 | struct frame_info *frame = get_current_frame (); |
| 834 | CORE_ADDR fp; |
| 835 | int regnum; |
| 836 | char regbuf[MAX_REGISTER_RAW_SIZE]; |
| 837 | |
| 838 | fp = FRAME_FP (frame); |
| 839 | i386_frame_init_saved_regs (frame); |
| 840 | |
| 841 | for (regnum = 0; regnum < NUM_REGS; regnum++) |
| 842 | { |
| 843 | CORE_ADDR addr; |
| 844 | addr = frame->saved_regs[regnum]; |
| 845 | if (addr) |
| 846 | { |
| 847 | read_memory (addr, regbuf, REGISTER_RAW_SIZE (regnum)); |
| 848 | write_register_bytes (REGISTER_BYTE (regnum), regbuf, |
| 849 | REGISTER_RAW_SIZE (regnum)); |
| 850 | } |
| 851 | } |
| 852 | write_register (FP_REGNUM, read_memory_integer (fp, 4)); |
| 853 | write_register (PC_REGNUM, read_memory_integer (fp + 4, 4)); |
| 854 | write_register (SP_REGNUM, fp + 8); |
| 855 | flush_cached_frames (); |
| 856 | } |
| 857 | \f |
| 858 | |
| 859 | /* Figure out where the longjmp will land. Slurp the args out of the |
| 860 | stack. We expect the first arg to be a pointer to the jmp_buf |
| 861 | structure from which we extract the address that we will land at. |
| 862 | This address is copied into PC. This routine returns true on |
| 863 | success. */ |
| 864 | |
| 865 | static int |
| 866 | i386_get_longjmp_target (CORE_ADDR *pc) |
| 867 | { |
| 868 | char buf[4]; |
| 869 | CORE_ADDR sp, jb_addr; |
| 870 | int jb_pc_offset = gdbarch_tdep (current_gdbarch)->jb_pc_offset; |
| 871 | |
| 872 | /* If JB_PC_OFFSET is -1, we have no way to find out where the |
| 873 | longjmp will land. */ |
| 874 | if (jb_pc_offset == -1) |
| 875 | return 0; |
| 876 | |
| 877 | sp = read_register (SP_REGNUM); |
| 878 | if (target_read_memory (sp + 4, buf, 4)) |
| 879 | return 0; |
| 880 | |
| 881 | jb_addr = extract_address (buf, 4); |
| 882 | if (target_read_memory (jb_addr + jb_pc_offset, buf, 4)) |
| 883 | return 0; |
| 884 | |
| 885 | *pc = extract_address (buf, 4); |
| 886 | return 1; |
| 887 | } |
| 888 | \f |
| 889 | |
| 890 | static CORE_ADDR |
| 891 | i386_push_arguments (int nargs, struct value **args, CORE_ADDR sp, |
| 892 | int struct_return, CORE_ADDR struct_addr) |
| 893 | { |
| 894 | sp = default_push_arguments (nargs, args, sp, struct_return, struct_addr); |
| 895 | |
| 896 | if (struct_return) |
| 897 | { |
| 898 | char buf[4]; |
| 899 | |
| 900 | sp -= 4; |
| 901 | store_address (buf, 4, struct_addr); |
| 902 | write_memory (sp, buf, 4); |
| 903 | } |
| 904 | |
| 905 | return sp; |
| 906 | } |
| 907 | |
| 908 | static void |
| 909 | i386_store_struct_return (CORE_ADDR addr, CORE_ADDR sp) |
| 910 | { |
| 911 | /* Do nothing. Everything was already done by i386_push_arguments. */ |
| 912 | } |
| 913 | |
| 914 | /* These registers are used for returning integers (and on some |
| 915 | targets also for returning `struct' and `union' values when their |
| 916 | size and alignment match an integer type). */ |
| 917 | #define LOW_RETURN_REGNUM 0 /* %eax */ |
| 918 | #define HIGH_RETURN_REGNUM 2 /* %edx */ |
| 919 | |
| 920 | /* Extract from an array REGBUF containing the (raw) register state, a |
| 921 | function return value of TYPE, and copy that, in virtual format, |
| 922 | into VALBUF. */ |
| 923 | |
| 924 | static void |
| 925 | i386_extract_return_value (struct type *type, char *regbuf, char *valbuf) |
| 926 | { |
| 927 | int len = TYPE_LENGTH (type); |
| 928 | |
| 929 | if (TYPE_CODE (type) == TYPE_CODE_STRUCT |
| 930 | && TYPE_NFIELDS (type) == 1) |
| 931 | { |
| 932 | i386_extract_return_value (TYPE_FIELD_TYPE (type, 0), regbuf, valbuf); |
| 933 | return; |
| 934 | } |
| 935 | |
| 936 | if (TYPE_CODE (type) == TYPE_CODE_FLT) |
| 937 | { |
| 938 | if (FP0_REGNUM == 0) |
| 939 | { |
| 940 | warning ("Cannot find floating-point return value."); |
| 941 | memset (valbuf, 0, len); |
| 942 | return; |
| 943 | } |
| 944 | |
| 945 | /* Floating-point return values can be found in %st(0). Convert |
| 946 | its contents to the desired type. This is probably not |
| 947 | exactly how it would happen on the target itself, but it is |
| 948 | the best we can do. */ |
| 949 | convert_typed_floating (®buf[REGISTER_BYTE (FP0_REGNUM)], |
| 950 | builtin_type_i387_ext, valbuf, type); |
| 951 | } |
| 952 | else |
| 953 | { |
| 954 | int low_size = REGISTER_RAW_SIZE (LOW_RETURN_REGNUM); |
| 955 | int high_size = REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM); |
| 956 | |
| 957 | if (len <= low_size) |
| 958 | memcpy (valbuf, ®buf[REGISTER_BYTE (LOW_RETURN_REGNUM)], len); |
| 959 | else if (len <= (low_size + high_size)) |
| 960 | { |
| 961 | memcpy (valbuf, |
| 962 | ®buf[REGISTER_BYTE (LOW_RETURN_REGNUM)], low_size); |
| 963 | memcpy (valbuf + low_size, |
| 964 | ®buf[REGISTER_BYTE (HIGH_RETURN_REGNUM)], len - low_size); |
| 965 | } |
| 966 | else |
| 967 | internal_error (__FILE__, __LINE__, |
| 968 | "Cannot extract return value of %d bytes long.", len); |
| 969 | } |
| 970 | } |
| 971 | |
| 972 | /* Write into the appropriate registers a function return value stored |
| 973 | in VALBUF of type TYPE, given in virtual format. */ |
| 974 | |
| 975 | static void |
| 976 | i386_store_return_value (struct type *type, char *valbuf) |
| 977 | { |
| 978 | int len = TYPE_LENGTH (type); |
| 979 | |
| 980 | if (TYPE_CODE (type) == TYPE_CODE_STRUCT |
| 981 | && TYPE_NFIELDS (type) == 1) |
| 982 | { |
| 983 | i386_store_return_value (TYPE_FIELD_TYPE (type, 0), valbuf); |
| 984 | return; |
| 985 | } |
| 986 | |
| 987 | if (TYPE_CODE (type) == TYPE_CODE_FLT) |
| 988 | { |
| 989 | unsigned int fstat; |
| 990 | char buf[FPU_REG_RAW_SIZE]; |
| 991 | |
| 992 | if (FP0_REGNUM == 0) |
| 993 | { |
| 994 | warning ("Cannot set floating-point return value."); |
| 995 | return; |
| 996 | } |
| 997 | |
| 998 | /* Returning floating-point values is a bit tricky. Apart from |
| 999 | storing the return value in %st(0), we have to simulate the |
| 1000 | state of the FPU at function return point. */ |
| 1001 | |
| 1002 | /* Convert the value found in VALBUF to the extended |
| 1003 | floating-point format used by the FPU. This is probably |
| 1004 | not exactly how it would happen on the target itself, but |
| 1005 | it is the best we can do. */ |
| 1006 | convert_typed_floating (valbuf, type, buf, builtin_type_i387_ext); |
| 1007 | write_register_bytes (REGISTER_BYTE (FP0_REGNUM), buf, |
| 1008 | FPU_REG_RAW_SIZE); |
| 1009 | |
| 1010 | /* Set the top of the floating-point register stack to 7. The |
| 1011 | actual value doesn't really matter, but 7 is what a normal |
| 1012 | function return would end up with if the program started out |
| 1013 | with a freshly initialized FPU. */ |
| 1014 | fstat = read_register (FSTAT_REGNUM); |
| 1015 | fstat |= (7 << 11); |
| 1016 | write_register (FSTAT_REGNUM, fstat); |
| 1017 | |
| 1018 | /* Mark %st(1) through %st(7) as empty. Since we set the top of |
| 1019 | the floating-point register stack to 7, the appropriate value |
| 1020 | for the tag word is 0x3fff. */ |
| 1021 | write_register (FTAG_REGNUM, 0x3fff); |
| 1022 | } |
| 1023 | else |
| 1024 | { |
| 1025 | int low_size = REGISTER_RAW_SIZE (LOW_RETURN_REGNUM); |
| 1026 | int high_size = REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM); |
| 1027 | |
| 1028 | if (len <= low_size) |
| 1029 | write_register_bytes (REGISTER_BYTE (LOW_RETURN_REGNUM), valbuf, len); |
| 1030 | else if (len <= (low_size + high_size)) |
| 1031 | { |
| 1032 | write_register_bytes (REGISTER_BYTE (LOW_RETURN_REGNUM), |
| 1033 | valbuf, low_size); |
| 1034 | write_register_bytes (REGISTER_BYTE (HIGH_RETURN_REGNUM), |
| 1035 | valbuf + low_size, len - low_size); |
| 1036 | } |
| 1037 | else |
| 1038 | internal_error (__FILE__, __LINE__, |
| 1039 | "Cannot store return value of %d bytes long.", len); |
| 1040 | } |
| 1041 | } |
| 1042 | |
| 1043 | /* Extract from an array REGBUF containing the (raw) register state |
| 1044 | the address in which a function should return its structure value, |
| 1045 | as a CORE_ADDR. */ |
| 1046 | |
| 1047 | static CORE_ADDR |
| 1048 | i386_extract_struct_value_address (char *regbuf) |
| 1049 | { |
| 1050 | return extract_address (®buf[REGISTER_BYTE (LOW_RETURN_REGNUM)], |
| 1051 | REGISTER_RAW_SIZE (LOW_RETURN_REGNUM)); |
| 1052 | } |
| 1053 | \f |
| 1054 | |
| 1055 | /* This is the variable that is set with "set struct-convention", and |
| 1056 | its legitimate values. */ |
| 1057 | static const char default_struct_convention[] = "default"; |
| 1058 | static const char pcc_struct_convention[] = "pcc"; |
| 1059 | static const char reg_struct_convention[] = "reg"; |
| 1060 | static const char *valid_conventions[] = |
| 1061 | { |
| 1062 | default_struct_convention, |
| 1063 | pcc_struct_convention, |
| 1064 | reg_struct_convention, |
| 1065 | NULL |
| 1066 | }; |
| 1067 | static const char *struct_convention = default_struct_convention; |
| 1068 | |
| 1069 | static int |
| 1070 | i386_use_struct_convention (int gcc_p, struct type *type) |
| 1071 | { |
| 1072 | enum struct_return struct_return; |
| 1073 | |
| 1074 | if (struct_convention == default_struct_convention) |
| 1075 | struct_return = gdbarch_tdep (current_gdbarch)->struct_return; |
| 1076 | else if (struct_convention == pcc_struct_convention) |
| 1077 | struct_return = pcc_struct_return; |
| 1078 | else |
| 1079 | struct_return = reg_struct_return; |
| 1080 | |
| 1081 | return generic_use_struct_convention (struct_return == reg_struct_return, |
| 1082 | type); |
| 1083 | } |
| 1084 | \f |
| 1085 | |
| 1086 | /* Return the GDB type object for the "standard" data type of data in |
| 1087 | register REGNUM. Perhaps %esi and %edi should go here, but |
| 1088 | potentially they could be used for things other than address. */ |
| 1089 | |
| 1090 | static struct type * |
| 1091 | i386_register_virtual_type (int regnum) |
| 1092 | { |
| 1093 | if (regnum == PC_REGNUM || regnum == FP_REGNUM || regnum == SP_REGNUM) |
| 1094 | return lookup_pointer_type (builtin_type_void); |
| 1095 | |
| 1096 | if (IS_FP_REGNUM (regnum)) |
| 1097 | return builtin_type_i387_ext; |
| 1098 | |
| 1099 | if (IS_SSE_REGNUM (regnum)) |
| 1100 | return builtin_type_vec128i; |
| 1101 | |
| 1102 | return builtin_type_int; |
| 1103 | } |
| 1104 | |
| 1105 | /* Return true iff register REGNUM's virtual format is different from |
| 1106 | its raw format. Note that this definition assumes that the host |
| 1107 | supports IEEE 32-bit floats, since it doesn't say that SSE |
| 1108 | registers need conversion. Even if we can't find a counterexample, |
| 1109 | this is still sloppy. */ |
| 1110 | |
| 1111 | static int |
| 1112 | i386_register_convertible (int regnum) |
| 1113 | { |
| 1114 | return IS_FP_REGNUM (regnum); |
| 1115 | } |
| 1116 | |
| 1117 | /* Convert data from raw format for register REGNUM in buffer FROM to |
| 1118 | virtual format with type TYPE in buffer TO. */ |
| 1119 | |
| 1120 | static void |
| 1121 | i386_register_convert_to_virtual (int regnum, struct type *type, |
| 1122 | char *from, char *to) |
| 1123 | { |
| 1124 | gdb_assert (IS_FP_REGNUM (regnum)); |
| 1125 | |
| 1126 | /* We only support floating-point values. */ |
| 1127 | if (TYPE_CODE (type) != TYPE_CODE_FLT) |
| 1128 | { |
| 1129 | warning ("Cannot convert floating-point register value " |
| 1130 | "to non-floating-point type."); |
| 1131 | memset (to, 0, TYPE_LENGTH (type)); |
| 1132 | return; |
| 1133 | } |
| 1134 | |
| 1135 | /* Convert to TYPE. This should be a no-op if TYPE is equivalent to |
| 1136 | the extended floating-point format used by the FPU. */ |
| 1137 | convert_typed_floating (from, builtin_type_i387_ext, to, type); |
| 1138 | } |
| 1139 | |
| 1140 | /* Convert data from virtual format with type TYPE in buffer FROM to |
| 1141 | raw format for register REGNUM in buffer TO. */ |
| 1142 | |
| 1143 | static void |
| 1144 | i386_register_convert_to_raw (struct type *type, int regnum, |
| 1145 | char *from, char *to) |
| 1146 | { |
| 1147 | gdb_assert (IS_FP_REGNUM (regnum)); |
| 1148 | |
| 1149 | /* We only support floating-point values. */ |
| 1150 | if (TYPE_CODE (type) != TYPE_CODE_FLT) |
| 1151 | { |
| 1152 | warning ("Cannot convert non-floating-point type " |
| 1153 | "to floating-point register value."); |
| 1154 | memset (to, 0, TYPE_LENGTH (type)); |
| 1155 | return; |
| 1156 | } |
| 1157 | |
| 1158 | /* Convert from TYPE. This should be a no-op if TYPE is equivalent |
| 1159 | to the extended floating-point format used by the FPU. */ |
| 1160 | convert_typed_floating (from, type, to, builtin_type_i387_ext); |
| 1161 | } |
| 1162 | \f |
| 1163 | |
| 1164 | #ifdef STATIC_TRANSFORM_NAME |
| 1165 | /* SunPRO encodes the static variables. This is not related to C++ |
| 1166 | mangling, it is done for C too. */ |
| 1167 | |
| 1168 | char * |
| 1169 | sunpro_static_transform_name (char *name) |
| 1170 | { |
| 1171 | char *p; |
| 1172 | if (IS_STATIC_TRANSFORM_NAME (name)) |
| 1173 | { |
| 1174 | /* For file-local statics there will be a period, a bunch of |
| 1175 | junk (the contents of which match a string given in the |
| 1176 | N_OPT), a period and the name. For function-local statics |
| 1177 | there will be a bunch of junk (which seems to change the |
| 1178 | second character from 'A' to 'B'), a period, the name of the |
| 1179 | function, and the name. So just skip everything before the |
| 1180 | last period. */ |
| 1181 | p = strrchr (name, '.'); |
| 1182 | if (p != NULL) |
| 1183 | name = p + 1; |
| 1184 | } |
| 1185 | return name; |
| 1186 | } |
| 1187 | #endif /* STATIC_TRANSFORM_NAME */ |
| 1188 | \f |
| 1189 | |
| 1190 | /* Stuff for WIN32 PE style DLL's but is pretty generic really. */ |
| 1191 | |
| 1192 | CORE_ADDR |
| 1193 | skip_trampoline_code (CORE_ADDR pc, char *name) |
| 1194 | { |
| 1195 | if (pc && read_memory_unsigned_integer (pc, 2) == 0x25ff) /* jmp *(dest) */ |
| 1196 | { |
| 1197 | unsigned long indirect = read_memory_unsigned_integer (pc + 2, 4); |
| 1198 | struct minimal_symbol *indsym = |
| 1199 | indirect ? lookup_minimal_symbol_by_pc (indirect) : 0; |
| 1200 | char *symname = indsym ? SYMBOL_NAME (indsym) : 0; |
| 1201 | |
| 1202 | if (symname) |
| 1203 | { |
| 1204 | if (strncmp (symname, "__imp_", 6) == 0 |
| 1205 | || strncmp (symname, "_imp_", 5) == 0) |
| 1206 | return name ? 1 : read_memory_unsigned_integer (indirect, 4); |
| 1207 | } |
| 1208 | } |
| 1209 | return 0; /* Not a trampoline. */ |
| 1210 | } |
| 1211 | \f |
| 1212 | |
| 1213 | /* Return non-zero if PC and NAME show that we are in a signal |
| 1214 | trampoline. */ |
| 1215 | |
| 1216 | static int |
| 1217 | i386_pc_in_sigtramp (CORE_ADDR pc, char *name) |
| 1218 | { |
| 1219 | return (name && strcmp ("_sigtramp", name) == 0); |
| 1220 | } |
| 1221 | \f |
| 1222 | |
| 1223 | /* We have two flavours of disassembly. The machinery on this page |
| 1224 | deals with switching between those. */ |
| 1225 | |
| 1226 | static int |
| 1227 | gdb_print_insn_i386 (bfd_vma memaddr, disassemble_info *info) |
| 1228 | { |
| 1229 | if (disassembly_flavor == att_flavor) |
| 1230 | return print_insn_i386_att (memaddr, info); |
| 1231 | else if (disassembly_flavor == intel_flavor) |
| 1232 | return print_insn_i386_intel (memaddr, info); |
| 1233 | /* Never reached -- disassembly_flavour is always either att_flavor |
| 1234 | or intel_flavor. */ |
| 1235 | internal_error (__FILE__, __LINE__, "failed internal consistency check"); |
| 1236 | } |
| 1237 | \f |
| 1238 | |
| 1239 | /* There are a few i386 architecture variants that differ only |
| 1240 | slightly from the generic i386 target. For now, we don't give them |
| 1241 | their own source file, but include them here. As a consequence, |
| 1242 | they'll always be included. */ |
| 1243 | |
| 1244 | /* System V Release 4 (SVR4). */ |
| 1245 | |
| 1246 | static int |
| 1247 | i386_svr4_pc_in_sigtramp (CORE_ADDR pc, char *name) |
| 1248 | { |
| 1249 | return (name && (strcmp ("_sigreturn", name) == 0 |
| 1250 | || strcmp ("_sigacthandler", name) == 0 |
| 1251 | || strcmp ("sigvechandler", name) == 0)); |
| 1252 | } |
| 1253 | |
| 1254 | /* Get address of the pushed ucontext (sigcontext) on the stack for |
| 1255 | all three variants of SVR4 sigtramps. */ |
| 1256 | |
| 1257 | static CORE_ADDR |
| 1258 | i386_svr4_sigcontext_addr (struct frame_info *frame) |
| 1259 | { |
| 1260 | int sigcontext_offset = -1; |
| 1261 | char *name = NULL; |
| 1262 | |
| 1263 | find_pc_partial_function (frame->pc, &name, NULL, NULL); |
| 1264 | if (name) |
| 1265 | { |
| 1266 | if (strcmp (name, "_sigreturn") == 0) |
| 1267 | sigcontext_offset = 132; |
| 1268 | else if (strcmp (name, "_sigacthandler") == 0) |
| 1269 | sigcontext_offset = 80; |
| 1270 | else if (strcmp (name, "sigvechandler") == 0) |
| 1271 | sigcontext_offset = 120; |
| 1272 | } |
| 1273 | |
| 1274 | gdb_assert (sigcontext_offset != -1); |
| 1275 | |
| 1276 | if (frame->next) |
| 1277 | return frame->next->frame + sigcontext_offset; |
| 1278 | return read_register (SP_REGNUM) + sigcontext_offset; |
| 1279 | } |
| 1280 | \f |
| 1281 | |
| 1282 | /* DJGPP. */ |
| 1283 | |
| 1284 | static int |
| 1285 | i386_go32_pc_in_sigtramp (CORE_ADDR pc, char *name) |
| 1286 | { |
| 1287 | /* DJGPP doesn't have any special frames for signal handlers. */ |
| 1288 | return 0; |
| 1289 | } |
| 1290 | \f |
| 1291 | |
| 1292 | /* Generic ELF. */ |
| 1293 | |
| 1294 | void |
| 1295 | i386_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 1296 | { |
| 1297 | /* We typically use stabs-in-ELF with the DWARF register numbering. */ |
| 1298 | set_gdbarch_stab_reg_to_regnum (gdbarch, i386_dwarf_reg_to_regnum); |
| 1299 | } |
| 1300 | |
| 1301 | /* System V Release 4 (SVR4). */ |
| 1302 | |
| 1303 | void |
| 1304 | i386_svr4_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 1305 | { |
| 1306 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 1307 | |
| 1308 | /* System V Release 4 uses ELF. */ |
| 1309 | i386_elf_init_abi (info, gdbarch); |
| 1310 | |
| 1311 | /* FIXME: kettenis/20020511: Why do we override this function here? */ |
| 1312 | set_gdbarch_frame_chain_valid (gdbarch, func_frame_chain_valid); |
| 1313 | |
| 1314 | set_gdbarch_pc_in_sigtramp (gdbarch, i386_svr4_pc_in_sigtramp); |
| 1315 | tdep->sigcontext_addr = i386_svr4_sigcontext_addr; |
| 1316 | tdep->sc_pc_offset = 14 * 4; |
| 1317 | tdep->sc_sp_offset = 7 * 4; |
| 1318 | |
| 1319 | tdep->jb_pc_offset = 20; |
| 1320 | } |
| 1321 | |
| 1322 | /* DJGPP. */ |
| 1323 | |
| 1324 | static void |
| 1325 | i386_go32_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 1326 | { |
| 1327 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 1328 | |
| 1329 | set_gdbarch_pc_in_sigtramp (gdbarch, i386_go32_pc_in_sigtramp); |
| 1330 | |
| 1331 | tdep->jb_pc_offset = 36; |
| 1332 | } |
| 1333 | |
| 1334 | /* NetWare. */ |
| 1335 | |
| 1336 | static void |
| 1337 | i386_nw_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 1338 | { |
| 1339 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 1340 | |
| 1341 | /* FIXME: kettenis/20020511: Why do we override this function here? */ |
| 1342 | set_gdbarch_frame_chain_valid (gdbarch, func_frame_chain_valid); |
| 1343 | |
| 1344 | tdep->jb_pc_offset = 24; |
| 1345 | } |
| 1346 | \f |
| 1347 | |
| 1348 | static struct gdbarch * |
| 1349 | i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) |
| 1350 | { |
| 1351 | struct gdbarch_tdep *tdep; |
| 1352 | struct gdbarch *gdbarch; |
| 1353 | enum gdb_osabi osabi = GDB_OSABI_UNKNOWN; |
| 1354 | |
| 1355 | /* Try to determine the OS ABI of the object we're loading. */ |
| 1356 | if (info.abfd != NULL) |
| 1357 | osabi = gdbarch_lookup_osabi (info.abfd); |
| 1358 | |
| 1359 | /* Find a candidate among extant architectures. */ |
| 1360 | for (arches = gdbarch_list_lookup_by_info (arches, &info); |
| 1361 | arches != NULL; |
| 1362 | arches = gdbarch_list_lookup_by_info (arches->next, &info)) |
| 1363 | { |
| 1364 | /* Make sure the OS ABI selection matches. */ |
| 1365 | tdep = gdbarch_tdep (arches->gdbarch); |
| 1366 | if (tdep && tdep->osabi == osabi) |
| 1367 | return arches->gdbarch; |
| 1368 | } |
| 1369 | |
| 1370 | /* Allocate space for the new architecture. */ |
| 1371 | tdep = XMALLOC (struct gdbarch_tdep); |
| 1372 | gdbarch = gdbarch_alloc (&info, tdep); |
| 1373 | |
| 1374 | tdep->osabi = osabi; |
| 1375 | |
| 1376 | /* The i386 default settings don't include the SSE registers. |
| 1377 | FIXME: kettenis/20020614: They do include the FPU registers for |
| 1378 | now, which probably is not quite right. */ |
| 1379 | tdep->num_xmm_regs = 0; |
| 1380 | |
| 1381 | tdep->jb_pc_offset = -1; |
| 1382 | tdep->struct_return = pcc_struct_return; |
| 1383 | tdep->sigtramp_start = 0; |
| 1384 | tdep->sigtramp_end = 0; |
| 1385 | tdep->sigcontext_addr = NULL; |
| 1386 | tdep->sc_pc_offset = -1; |
| 1387 | tdep->sc_sp_offset = -1; |
| 1388 | |
| 1389 | /* The format used for `long double' on almost all i386 targets is |
| 1390 | the i387 extended floating-point format. In fact, of all targets |
| 1391 | in the GCC 2.95 tree, only OSF/1 does it different, and insists |
| 1392 | on having a `long double' that's not `long' at all. */ |
| 1393 | set_gdbarch_long_double_format (gdbarch, &floatformat_i387_ext); |
| 1394 | |
| 1395 | /* Although the i386 extended floating-point has only 80 significant |
| 1396 | bits, a `long double' actually takes up 96, probably to enforce |
| 1397 | alignment. */ |
| 1398 | set_gdbarch_long_double_bit (gdbarch, 96); |
| 1399 | |
| 1400 | /* NOTE: tm-i386aix.h, tm-i386bsd.h, tm-i386os9k.h, tm-ptx.h, |
| 1401 | tm-symmetry.h currently override this. Sigh. */ |
| 1402 | set_gdbarch_num_regs (gdbarch, I386_NUM_GREGS + I386_NUM_FREGS); |
| 1403 | |
| 1404 | set_gdbarch_sp_regnum (gdbarch, 4); |
| 1405 | set_gdbarch_fp_regnum (gdbarch, 5); |
| 1406 | set_gdbarch_pc_regnum (gdbarch, 8); |
| 1407 | set_gdbarch_ps_regnum (gdbarch, 9); |
| 1408 | set_gdbarch_fp0_regnum (gdbarch, 16); |
| 1409 | |
| 1410 | /* Use the "default" register numbering scheme for stabs and COFF. */ |
| 1411 | set_gdbarch_stab_reg_to_regnum (gdbarch, i386_stab_reg_to_regnum); |
| 1412 | set_gdbarch_sdb_reg_to_regnum (gdbarch, i386_stab_reg_to_regnum); |
| 1413 | |
| 1414 | /* Use the DWARF register numbering scheme for DWARF and DWARF 2. */ |
| 1415 | set_gdbarch_dwarf_reg_to_regnum (gdbarch, i386_dwarf_reg_to_regnum); |
| 1416 | set_gdbarch_dwarf2_reg_to_regnum (gdbarch, i386_dwarf_reg_to_regnum); |
| 1417 | |
| 1418 | /* We don't define ECOFF_REG_TO_REGNUM, since ECOFF doesn't seem to |
| 1419 | be in use on any of the supported i386 targets. */ |
| 1420 | |
| 1421 | set_gdbarch_register_name (gdbarch, i386_register_name); |
| 1422 | set_gdbarch_register_size (gdbarch, 4); |
| 1423 | set_gdbarch_register_bytes (gdbarch, I386_SIZEOF_GREGS + I386_SIZEOF_FREGS); |
| 1424 | set_gdbarch_register_byte (gdbarch, i386_register_byte); |
| 1425 | set_gdbarch_register_raw_size (gdbarch, i386_register_raw_size); |
| 1426 | set_gdbarch_max_register_raw_size (gdbarch, 16); |
| 1427 | set_gdbarch_max_register_virtual_size (gdbarch, 16); |
| 1428 | set_gdbarch_register_virtual_type (gdbarch, i386_register_virtual_type); |
| 1429 | |
| 1430 | set_gdbarch_get_longjmp_target (gdbarch, i386_get_longjmp_target); |
| 1431 | |
| 1432 | set_gdbarch_use_generic_dummy_frames (gdbarch, 0); |
| 1433 | |
| 1434 | /* Call dummy code. */ |
| 1435 | set_gdbarch_call_dummy_location (gdbarch, ON_STACK); |
| 1436 | set_gdbarch_call_dummy_start_offset (gdbarch, 0); |
| 1437 | set_gdbarch_call_dummy_breakpoint_offset (gdbarch, 5); |
| 1438 | set_gdbarch_call_dummy_breakpoint_offset_p (gdbarch, 1); |
| 1439 | set_gdbarch_call_dummy_length (gdbarch, 8); |
| 1440 | set_gdbarch_call_dummy_p (gdbarch, 1); |
| 1441 | set_gdbarch_call_dummy_words (gdbarch, i386_call_dummy_words); |
| 1442 | set_gdbarch_sizeof_call_dummy_words (gdbarch, |
| 1443 | sizeof (i386_call_dummy_words)); |
| 1444 | set_gdbarch_call_dummy_stack_adjust_p (gdbarch, 0); |
| 1445 | set_gdbarch_fix_call_dummy (gdbarch, i386_fix_call_dummy); |
| 1446 | |
| 1447 | set_gdbarch_register_convertible (gdbarch, i386_register_convertible); |
| 1448 | set_gdbarch_register_convert_to_virtual (gdbarch, |
| 1449 | i386_register_convert_to_virtual); |
| 1450 | set_gdbarch_register_convert_to_raw (gdbarch, i386_register_convert_to_raw); |
| 1451 | |
| 1452 | set_gdbarch_get_saved_register (gdbarch, generic_get_saved_register); |
| 1453 | set_gdbarch_push_arguments (gdbarch, i386_push_arguments); |
| 1454 | |
| 1455 | set_gdbarch_pc_in_call_dummy (gdbarch, pc_in_call_dummy_on_stack); |
| 1456 | |
| 1457 | /* "An argument's size is increased, if necessary, to make it a |
| 1458 | multiple of [32-bit] words. This may require tail padding, |
| 1459 | depending on the size of the argument" -- from the x86 ABI. */ |
| 1460 | set_gdbarch_parm_boundary (gdbarch, 32); |
| 1461 | |
| 1462 | set_gdbarch_deprecated_extract_return_value (gdbarch, |
| 1463 | i386_extract_return_value); |
| 1464 | set_gdbarch_push_arguments (gdbarch, i386_push_arguments); |
| 1465 | set_gdbarch_push_dummy_frame (gdbarch, i386_push_dummy_frame); |
| 1466 | set_gdbarch_pop_frame (gdbarch, i386_pop_frame); |
| 1467 | set_gdbarch_store_struct_return (gdbarch, i386_store_struct_return); |
| 1468 | set_gdbarch_store_return_value (gdbarch, i386_store_return_value); |
| 1469 | set_gdbarch_deprecated_extract_struct_value_address (gdbarch, |
| 1470 | i386_extract_struct_value_address); |
| 1471 | set_gdbarch_use_struct_convention (gdbarch, i386_use_struct_convention); |
| 1472 | |
| 1473 | set_gdbarch_frame_init_saved_regs (gdbarch, i386_frame_init_saved_regs); |
| 1474 | set_gdbarch_skip_prologue (gdbarch, i386_skip_prologue); |
| 1475 | |
| 1476 | /* Stack grows downward. */ |
| 1477 | set_gdbarch_inner_than (gdbarch, core_addr_lessthan); |
| 1478 | |
| 1479 | set_gdbarch_breakpoint_from_pc (gdbarch, i386_breakpoint_from_pc); |
| 1480 | set_gdbarch_decr_pc_after_break (gdbarch, 1); |
| 1481 | set_gdbarch_function_start_offset (gdbarch, 0); |
| 1482 | |
| 1483 | /* The following redefines make backtracing through sigtramp work. |
| 1484 | They manufacture a fake sigtramp frame and obtain the saved pc in |
| 1485 | sigtramp from the sigcontext structure which is pushed by the |
| 1486 | kernel on the user stack, along with a pointer to it. */ |
| 1487 | |
| 1488 | set_gdbarch_frame_args_skip (gdbarch, 8); |
| 1489 | set_gdbarch_frameless_function_invocation (gdbarch, |
| 1490 | i386_frameless_function_invocation); |
| 1491 | set_gdbarch_frame_chain (gdbarch, i386_frame_chain); |
| 1492 | set_gdbarch_frame_chain_valid (gdbarch, file_frame_chain_valid); |
| 1493 | set_gdbarch_frame_saved_pc (gdbarch, i386_frame_saved_pc); |
| 1494 | set_gdbarch_frame_args_address (gdbarch, default_frame_address); |
| 1495 | set_gdbarch_frame_locals_address (gdbarch, default_frame_address); |
| 1496 | set_gdbarch_saved_pc_after_call (gdbarch, i386_saved_pc_after_call); |
| 1497 | set_gdbarch_frame_num_args (gdbarch, i386_frame_num_args); |
| 1498 | set_gdbarch_pc_in_sigtramp (gdbarch, i386_pc_in_sigtramp); |
| 1499 | |
| 1500 | /* Hook in ABI-specific overrides, if they have been registered. */ |
| 1501 | gdbarch_init_osabi (info, gdbarch, osabi); |
| 1502 | |
| 1503 | return gdbarch; |
| 1504 | } |
| 1505 | |
| 1506 | static enum gdb_osabi |
| 1507 | i386_coff_osabi_sniffer (bfd *abfd) |
| 1508 | { |
| 1509 | if (strcmp (bfd_get_target (abfd), "coff-go32-exe") == 0 |
| 1510 | || strcmp (bfd_get_target (abfd), "coff-go32") == 0) |
| 1511 | return GDB_OSABI_GO32; |
| 1512 | |
| 1513 | return GDB_OSABI_UNKNOWN; |
| 1514 | } |
| 1515 | |
| 1516 | static enum gdb_osabi |
| 1517 | i386_nlm_osabi_sniffer (bfd *abfd) |
| 1518 | { |
| 1519 | return GDB_OSABI_NETWARE; |
| 1520 | } |
| 1521 | \f |
| 1522 | |
| 1523 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
| 1524 | void _initialize_i386_tdep (void); |
| 1525 | |
| 1526 | void |
| 1527 | _initialize_i386_tdep (void) |
| 1528 | { |
| 1529 | register_gdbarch_init (bfd_arch_i386, i386_gdbarch_init); |
| 1530 | |
| 1531 | /* Initialize the table saying where each register starts in the |
| 1532 | register file. */ |
| 1533 | { |
| 1534 | int i, offset; |
| 1535 | |
| 1536 | offset = 0; |
| 1537 | for (i = 0; i < I386_SSE_NUM_REGS; i++) |
| 1538 | { |
| 1539 | i386_register_offset[i] = offset; |
| 1540 | offset += i386_register_size[i]; |
| 1541 | } |
| 1542 | } |
| 1543 | |
| 1544 | tm_print_insn = gdb_print_insn_i386; |
| 1545 | tm_print_insn_info.mach = bfd_lookup_arch (bfd_arch_i386, 0)->mach; |
| 1546 | |
| 1547 | /* Add the variable that controls the disassembly flavor. */ |
| 1548 | { |
| 1549 | struct cmd_list_element *new_cmd; |
| 1550 | |
| 1551 | new_cmd = add_set_enum_cmd ("disassembly-flavor", no_class, |
| 1552 | valid_flavors, |
| 1553 | &disassembly_flavor, |
| 1554 | "\ |
| 1555 | Set the disassembly flavor, the valid values are \"att\" and \"intel\", \ |
| 1556 | and the default value is \"att\".", |
| 1557 | &setlist); |
| 1558 | add_show_from_set (new_cmd, &showlist); |
| 1559 | } |
| 1560 | |
| 1561 | /* Add the variable that controls the convention for returning |
| 1562 | structs. */ |
| 1563 | { |
| 1564 | struct cmd_list_element *new_cmd; |
| 1565 | |
| 1566 | new_cmd = add_set_enum_cmd ("struct-convention", no_class, |
| 1567 | valid_conventions, |
| 1568 | &struct_convention, "\ |
| 1569 | Set the convention for returning small structs, valid values \ |
| 1570 | are \"default\", \"pcc\" and \"reg\", and the default value is \"default\".", |
| 1571 | &setlist); |
| 1572 | add_show_from_set (new_cmd, &showlist); |
| 1573 | } |
| 1574 | |
| 1575 | gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_coff_flavour, |
| 1576 | i386_coff_osabi_sniffer); |
| 1577 | gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_nlm_flavour, |
| 1578 | i386_nlm_osabi_sniffer); |
| 1579 | |
| 1580 | gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_SVR4, |
| 1581 | i386_svr4_init_abi); |
| 1582 | gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_GO32, |
| 1583 | i386_go32_init_abi); |
| 1584 | gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_NETWARE, |
| 1585 | i386_nw_init_abi); |
| 1586 | } |