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c906108c SS |
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, Boston, MA 02111-1307, USA. */ | |
20 | ||
21 | #include "defs.h" | |
22 | #include "gdb_string.h" | |
23 | #include "frame.h" | |
24 | #include "inferior.h" | |
25 | #include "gdbcore.h" | |
26 | #include "target.h" | |
27 | #include "floatformat.h" | |
28 | #include "symtab.h" | |
29 | #include "gdbcmd.h" | |
30 | #include "command.h" | |
31 | ||
32 | static long i386_get_frame_setup PARAMS ((CORE_ADDR)); | |
33 | ||
34 | static void i386_follow_jump PARAMS ((void)); | |
35 | ||
36 | static void codestream_read PARAMS ((unsigned char *, int)); | |
37 | ||
38 | static void codestream_seek PARAMS ((CORE_ADDR)); | |
39 | ||
40 | static unsigned char codestream_fill PARAMS ((int)); | |
41 | ||
42 | CORE_ADDR skip_trampoline_code PARAMS ((CORE_ADDR, char *)); | |
43 | ||
44 | static int gdb_print_insn_i386 (bfd_vma, disassemble_info *); | |
45 | ||
46 | void _initialize_i386_tdep PARAMS ((void)); | |
47 | ||
48 | /* This is the variable the is set with "set disassembly-flavor", | |
49 | and its legitimate values. */ | |
50 | static char att_flavor[] = "att"; | |
51 | static char intel_flavor[] = "intel"; | |
52 | static char *valid_flavors[] = { | |
53 | att_flavor, | |
54 | intel_flavor, | |
55 | NULL | |
56 | }; | |
57 | static char *disassembly_flavor = att_flavor; | |
58 | ||
59 | /* Stdio style buffering was used to minimize calls to ptrace, but this | |
60 | buffering did not take into account that the code section being accessed | |
61 | may not be an even number of buffers long (even if the buffer is only | |
62 | sizeof(int) long). In cases where the code section size happened to | |
63 | be a non-integral number of buffers long, attempting to read the last | |
64 | buffer would fail. Simply using target_read_memory and ignoring errors, | |
65 | rather than read_memory, is not the correct solution, since legitimate | |
66 | access errors would then be totally ignored. To properly handle this | |
67 | situation and continue to use buffering would require that this code | |
68 | be able to determine the minimum code section size granularity (not the | |
69 | alignment of the section itself, since the actual failing case that | |
70 | pointed out this problem had a section alignment of 4 but was not a | |
71 | multiple of 4 bytes long), on a target by target basis, and then | |
72 | adjust it's buffer size accordingly. This is messy, but potentially | |
73 | feasible. It probably needs the bfd library's help and support. For | |
74 | now, the buffer size is set to 1. (FIXME -fnf) */ | |
75 | ||
76 | #define CODESTREAM_BUFSIZ 1 /* Was sizeof(int), see note above. */ | |
77 | static CORE_ADDR codestream_next_addr; | |
78 | static CORE_ADDR codestream_addr; | |
79 | static unsigned char codestream_buf[CODESTREAM_BUFSIZ]; | |
80 | static int codestream_off; | |
81 | static int codestream_cnt; | |
82 | ||
83 | #define codestream_tell() (codestream_addr + codestream_off) | |
84 | #define codestream_peek() (codestream_cnt == 0 ? \ | |
85 | codestream_fill(1): codestream_buf[codestream_off]) | |
86 | #define codestream_get() (codestream_cnt-- == 0 ? \ | |
87 | codestream_fill(0) : codestream_buf[codestream_off++]) | |
88 | ||
89 | static unsigned char | |
90 | codestream_fill (peek_flag) | |
91 | int peek_flag; | |
92 | { | |
93 | codestream_addr = codestream_next_addr; | |
94 | codestream_next_addr += CODESTREAM_BUFSIZ; | |
95 | codestream_off = 0; | |
96 | codestream_cnt = CODESTREAM_BUFSIZ; | |
97 | read_memory (codestream_addr, (char *) codestream_buf, CODESTREAM_BUFSIZ); | |
98 | ||
99 | if (peek_flag) | |
100 | return (codestream_peek()); | |
101 | else | |
102 | return (codestream_get()); | |
103 | } | |
104 | ||
105 | static void | |
106 | codestream_seek (place) | |
107 | CORE_ADDR place; | |
108 | { | |
109 | codestream_next_addr = place / CODESTREAM_BUFSIZ; | |
110 | codestream_next_addr *= CODESTREAM_BUFSIZ; | |
111 | codestream_cnt = 0; | |
112 | codestream_fill (1); | |
113 | while (codestream_tell() != place) | |
114 | codestream_get (); | |
115 | } | |
116 | ||
117 | static void | |
118 | codestream_read (buf, count) | |
119 | unsigned char *buf; | |
120 | int count; | |
121 | { | |
122 | unsigned char *p; | |
123 | int i; | |
124 | p = buf; | |
125 | for (i = 0; i < count; i++) | |
126 | *p++ = codestream_get (); | |
127 | } | |
128 | ||
129 | /* next instruction is a jump, move to target */ | |
130 | ||
131 | static void | |
132 | i386_follow_jump () | |
133 | { | |
134 | unsigned char buf[4]; | |
135 | long delta; | |
136 | ||
137 | int data16; | |
138 | CORE_ADDR pos; | |
139 | ||
140 | pos = codestream_tell (); | |
141 | ||
142 | data16 = 0; | |
143 | if (codestream_peek () == 0x66) | |
144 | { | |
145 | codestream_get (); | |
146 | data16 = 1; | |
147 | } | |
148 | ||
149 | switch (codestream_get ()) | |
150 | { | |
151 | case 0xe9: | |
152 | /* relative jump: if data16 == 0, disp32, else disp16 */ | |
153 | if (data16) | |
154 | { | |
155 | codestream_read (buf, 2); | |
156 | delta = extract_signed_integer (buf, 2); | |
157 | ||
158 | /* include size of jmp inst (including the 0x66 prefix). */ | |
159 | pos += delta + 4; | |
160 | } | |
161 | else | |
162 | { | |
163 | codestream_read (buf, 4); | |
164 | delta = extract_signed_integer (buf, 4); | |
165 | ||
166 | pos += delta + 5; | |
167 | } | |
168 | break; | |
169 | case 0xeb: | |
170 | /* relative jump, disp8 (ignore data16) */ | |
171 | codestream_read (buf, 1); | |
172 | /* Sign-extend it. */ | |
173 | delta = extract_signed_integer (buf, 1); | |
174 | ||
175 | pos += delta + 2; | |
176 | break; | |
177 | } | |
178 | codestream_seek (pos); | |
179 | } | |
180 | ||
181 | /* | |
182 | * find & return amound a local space allocated, and advance codestream to | |
183 | * first register push (if any) | |
184 | * | |
185 | * if entry sequence doesn't make sense, return -1, and leave | |
186 | * codestream pointer random | |
187 | */ | |
188 | ||
189 | static long | |
190 | i386_get_frame_setup (pc) | |
191 | CORE_ADDR pc; | |
192 | { | |
193 | unsigned char op; | |
194 | ||
195 | codestream_seek (pc); | |
196 | ||
197 | i386_follow_jump (); | |
198 | ||
199 | op = codestream_get (); | |
200 | ||
201 | if (op == 0x58) /* popl %eax */ | |
202 | { | |
203 | /* | |
204 | * this function must start with | |
205 | * | |
206 | * popl %eax 0x58 | |
207 | * xchgl %eax, (%esp) 0x87 0x04 0x24 | |
208 | * or xchgl %eax, 0(%esp) 0x87 0x44 0x24 0x00 | |
209 | * | |
210 | * (the system 5 compiler puts out the second xchg | |
211 | * inst, and the assembler doesn't try to optimize it, | |
212 | * so the 'sib' form gets generated) | |
213 | * | |
214 | * this sequence is used to get the address of the return | |
215 | * buffer for a function that returns a structure | |
216 | */ | |
217 | int pos; | |
218 | unsigned char buf[4]; | |
219 | static unsigned char proto1[3] = { 0x87,0x04,0x24 }; | |
220 | static unsigned char proto2[4] = { 0x87,0x44,0x24,0x00 }; | |
221 | pos = codestream_tell (); | |
222 | codestream_read (buf, 4); | |
223 | if (memcmp (buf, proto1, 3) == 0) | |
224 | pos += 3; | |
225 | else if (memcmp (buf, proto2, 4) == 0) | |
226 | pos += 4; | |
227 | ||
228 | codestream_seek (pos); | |
229 | op = codestream_get (); /* update next opcode */ | |
230 | } | |
231 | ||
232 | if (op == 0x68 || op == 0x6a) | |
233 | { | |
234 | /* | |
235 | * this function may start with | |
236 | * | |
237 | * pushl constant | |
238 | * call _probe | |
239 | * addl $4, %esp | |
240 | * followed by | |
241 | * pushl %ebp | |
242 | * etc. | |
243 | */ | |
244 | int pos; | |
245 | unsigned char buf[8]; | |
246 | ||
247 | /* Skip past the pushl instruction; it has either a one-byte | |
248 | or a four-byte operand, depending on the opcode. */ | |
249 | pos = codestream_tell (); | |
250 | if (op == 0x68) | |
251 | pos += 4; | |
252 | else | |
253 | pos += 1; | |
254 | codestream_seek (pos); | |
255 | ||
256 | /* Read the following 8 bytes, which should be "call _probe" (6 bytes) | |
257 | followed by "addl $4,%esp" (2 bytes). */ | |
258 | codestream_read (buf, sizeof (buf)); | |
259 | if (buf[0] == 0xe8 && buf[6] == 0xc4 && buf[7] == 0x4) | |
260 | pos += sizeof (buf); | |
261 | codestream_seek (pos); | |
262 | op = codestream_get (); /* update next opcode */ | |
263 | } | |
264 | ||
265 | if (op == 0x55) /* pushl %ebp */ | |
266 | { | |
267 | /* check for movl %esp, %ebp - can be written two ways */ | |
268 | switch (codestream_get ()) | |
269 | { | |
270 | case 0x8b: | |
271 | if (codestream_get () != 0xec) | |
272 | return (-1); | |
273 | break; | |
274 | case 0x89: | |
275 | if (codestream_get () != 0xe5) | |
276 | return (-1); | |
277 | break; | |
278 | default: | |
279 | return (-1); | |
280 | } | |
281 | /* check for stack adjustment | |
282 | * | |
283 | * subl $XXX, %esp | |
284 | * | |
285 | * note: you can't subtract a 16 bit immediate | |
286 | * from a 32 bit reg, so we don't have to worry | |
287 | * about a data16 prefix | |
288 | */ | |
289 | op = codestream_peek (); | |
290 | if (op == 0x83) | |
291 | { | |
292 | /* subl with 8 bit immed */ | |
293 | codestream_get (); | |
294 | if (codestream_get () != 0xec) | |
295 | /* Some instruction starting with 0x83 other than subl. */ | |
296 | { | |
297 | codestream_seek (codestream_tell () - 2); | |
298 | return 0; | |
299 | } | |
300 | /* subl with signed byte immediate | |
301 | * (though it wouldn't make sense to be negative) | |
302 | */ | |
303 | return (codestream_get()); | |
304 | } | |
305 | else if (op == 0x81) | |
306 | { | |
307 | char buf[4]; | |
308 | /* Maybe it is subl with 32 bit immedediate. */ | |
309 | codestream_get(); | |
310 | if (codestream_get () != 0xec) | |
311 | /* Some instruction starting with 0x81 other than subl. */ | |
312 | { | |
313 | codestream_seek (codestream_tell () - 2); | |
314 | return 0; | |
315 | } | |
316 | /* It is subl with 32 bit immediate. */ | |
317 | codestream_read ((unsigned char *)buf, 4); | |
318 | return extract_signed_integer (buf, 4); | |
319 | } | |
320 | else | |
321 | { | |
322 | return (0); | |
323 | } | |
324 | } | |
325 | else if (op == 0xc8) | |
326 | { | |
327 | char buf[2]; | |
328 | /* enter instruction: arg is 16 bit unsigned immed */ | |
329 | codestream_read ((unsigned char *)buf, 2); | |
330 | codestream_get (); /* flush final byte of enter instruction */ | |
331 | return extract_unsigned_integer (buf, 2); | |
332 | } | |
333 | return (-1); | |
334 | } | |
335 | ||
336 | /* Return number of args passed to a frame. | |
337 | Can return -1, meaning no way to tell. */ | |
338 | ||
339 | int | |
340 | i386_frame_num_args (fi) | |
341 | struct frame_info *fi; | |
342 | { | |
343 | #if 1 | |
344 | return -1; | |
345 | #else | |
346 | /* This loses because not only might the compiler not be popping the | |
347 | args right after the function call, it might be popping args from both | |
348 | this call and a previous one, and we would say there are more args | |
349 | than there really are. */ | |
350 | ||
351 | int retpc; | |
352 | unsigned char op; | |
353 | struct frame_info *pfi; | |
354 | ||
355 | /* on the 386, the instruction following the call could be: | |
356 | popl %ecx - one arg | |
357 | addl $imm, %esp - imm/4 args; imm may be 8 or 32 bits | |
358 | anything else - zero args */ | |
359 | ||
360 | int frameless; | |
361 | ||
362 | FRAMELESS_FUNCTION_INVOCATION (fi, frameless); | |
363 | if (frameless) | |
364 | /* In the absence of a frame pointer, GDB doesn't get correct values | |
365 | for nameless arguments. Return -1, so it doesn't print any | |
366 | nameless arguments. */ | |
367 | return -1; | |
368 | ||
369 | pfi = get_prev_frame_info (fi); | |
370 | if (pfi == 0) | |
371 | { | |
372 | /* Note: this can happen if we are looking at the frame for | |
373 | main, because FRAME_CHAIN_VALID won't let us go into | |
374 | start. If we have debugging symbols, that's not really | |
375 | a big deal; it just means it will only show as many arguments | |
376 | to main as are declared. */ | |
377 | return -1; | |
378 | } | |
379 | else | |
380 | { | |
381 | retpc = pfi->pc; | |
382 | op = read_memory_integer (retpc, 1); | |
383 | if (op == 0x59) | |
384 | /* pop %ecx */ | |
385 | return 1; | |
386 | else if (op == 0x83) | |
387 | { | |
388 | op = read_memory_integer (retpc+1, 1); | |
389 | if (op == 0xc4) | |
390 | /* addl $<signed imm 8 bits>, %esp */ | |
391 | return (read_memory_integer (retpc+2,1)&0xff)/4; | |
392 | else | |
393 | return 0; | |
394 | } | |
395 | else if (op == 0x81) | |
396 | { /* add with 32 bit immediate */ | |
397 | op = read_memory_integer (retpc+1, 1); | |
398 | if (op == 0xc4) | |
399 | /* addl $<imm 32>, %esp */ | |
400 | return read_memory_integer (retpc+2, 4) / 4; | |
401 | else | |
402 | return 0; | |
403 | } | |
404 | else | |
405 | { | |
406 | return 0; | |
407 | } | |
408 | } | |
409 | #endif | |
410 | } | |
411 | ||
412 | /* | |
413 | * parse the first few instructions of the function to see | |
414 | * what registers were stored. | |
415 | * | |
416 | * We handle these cases: | |
417 | * | |
418 | * The startup sequence can be at the start of the function, | |
419 | * or the function can start with a branch to startup code at the end. | |
420 | * | |
421 | * %ebp can be set up with either the 'enter' instruction, or | |
422 | * 'pushl %ebp, movl %esp, %ebp' (enter is too slow to be useful, | |
423 | * but was once used in the sys5 compiler) | |
424 | * | |
425 | * Local space is allocated just below the saved %ebp by either the | |
426 | * 'enter' instruction, or by 'subl $<size>, %esp'. 'enter' has | |
427 | * a 16 bit unsigned argument for space to allocate, and the | |
428 | * 'addl' instruction could have either a signed byte, or | |
429 | * 32 bit immediate. | |
430 | * | |
431 | * Next, the registers used by this function are pushed. In | |
432 | * the sys5 compiler they will always be in the order: %edi, %esi, %ebx | |
433 | * (and sometimes a harmless bug causes it to also save but not restore %eax); | |
434 | * however, the code below is willing to see the pushes in any order, | |
435 | * and will handle up to 8 of them. | |
436 | * | |
437 | * If the setup sequence is at the end of the function, then the | |
438 | * next instruction will be a branch back to the start. | |
439 | */ | |
440 | ||
441 | void | |
442 | i386_frame_find_saved_regs (fip, fsrp) | |
443 | struct frame_info *fip; | |
444 | struct frame_saved_regs *fsrp; | |
445 | { | |
446 | long locals = -1; | |
447 | unsigned char op; | |
448 | CORE_ADDR dummy_bottom; | |
449 | CORE_ADDR adr; | |
450 | CORE_ADDR pc; | |
451 | int i; | |
452 | ||
453 | memset (fsrp, 0, sizeof *fsrp); | |
454 | ||
455 | /* if frame is the end of a dummy, compute where the | |
456 | * beginning would be | |
457 | */ | |
458 | dummy_bottom = fip->frame - 4 - REGISTER_BYTES - CALL_DUMMY_LENGTH; | |
459 | ||
460 | /* check if the PC is in the stack, in a dummy frame */ | |
461 | if (dummy_bottom <= fip->pc && fip->pc <= fip->frame) | |
462 | { | |
463 | /* all regs were saved by push_call_dummy () */ | |
464 | adr = fip->frame; | |
465 | for (i = 0; i < NUM_REGS; i++) | |
466 | { | |
467 | adr -= REGISTER_RAW_SIZE (i); | |
468 | fsrp->regs[i] = adr; | |
469 | } | |
470 | return; | |
471 | } | |
472 | ||
473 | pc = get_pc_function_start (fip->pc); | |
474 | if (pc != 0) | |
475 | locals = i386_get_frame_setup (pc); | |
476 | ||
477 | if (locals >= 0) | |
478 | { | |
479 | adr = fip->frame - 4 - locals; | |
480 | for (i = 0; i < 8; i++) | |
481 | { | |
482 | op = codestream_get (); | |
483 | if (op < 0x50 || op > 0x57) | |
484 | break; | |
485 | #ifdef I386_REGNO_TO_SYMMETRY | |
486 | /* Dynix uses different internal numbering. Ick. */ | |
487 | fsrp->regs[I386_REGNO_TO_SYMMETRY(op - 0x50)] = adr; | |
488 | #else | |
489 | fsrp->regs[op - 0x50] = adr; | |
490 | #endif | |
491 | adr -= 4; | |
492 | } | |
493 | } | |
494 | ||
495 | fsrp->regs[PC_REGNUM] = fip->frame + 4; | |
496 | fsrp->regs[FP_REGNUM] = fip->frame; | |
497 | } | |
498 | ||
499 | /* return pc of first real instruction */ | |
500 | ||
501 | int | |
502 | i386_skip_prologue (pc) | |
503 | int pc; | |
504 | { | |
505 | unsigned char op; | |
506 | int i; | |
507 | static unsigned char pic_pat[6] = { 0xe8, 0, 0, 0, 0, /* call 0x0 */ | |
508 | 0x5b, /* popl %ebx */ | |
509 | }; | |
510 | CORE_ADDR pos; | |
511 | ||
512 | if (i386_get_frame_setup (pc) < 0) | |
513 | return (pc); | |
514 | ||
515 | /* found valid frame setup - codestream now points to | |
516 | * start of push instructions for saving registers | |
517 | */ | |
518 | ||
519 | /* skip over register saves */ | |
520 | for (i = 0; i < 8; i++) | |
521 | { | |
522 | op = codestream_peek (); | |
523 | /* break if not pushl inst */ | |
524 | if (op < 0x50 || op > 0x57) | |
525 | break; | |
526 | codestream_get (); | |
527 | } | |
528 | ||
529 | /* The native cc on SVR4 in -K PIC mode inserts the following code to get | |
530 | the address of the global offset table (GOT) into register %ebx. | |
531 | call 0x0 | |
532 | popl %ebx | |
533 | movl %ebx,x(%ebp) (optional) | |
534 | addl y,%ebx | |
535 | This code is with the rest of the prologue (at the end of the | |
536 | function), so we have to skip it to get to the first real | |
537 | instruction at the start of the function. */ | |
538 | ||
539 | pos = codestream_tell (); | |
540 | for (i = 0; i < 6; i++) | |
541 | { | |
542 | op = codestream_get (); | |
543 | if (pic_pat [i] != op) | |
544 | break; | |
545 | } | |
546 | if (i == 6) | |
547 | { | |
548 | unsigned char buf[4]; | |
549 | long delta = 6; | |
550 | ||
551 | op = codestream_get (); | |
552 | if (op == 0x89) /* movl %ebx, x(%ebp) */ | |
553 | { | |
554 | op = codestream_get (); | |
555 | if (op == 0x5d) /* one byte offset from %ebp */ | |
556 | { | |
557 | delta += 3; | |
558 | codestream_read (buf, 1); | |
559 | } | |
560 | else if (op == 0x9d) /* four byte offset from %ebp */ | |
561 | { | |
562 | delta += 6; | |
563 | codestream_read (buf, 4); | |
564 | } | |
565 | else /* unexpected instruction */ | |
566 | delta = -1; | |
567 | op = codestream_get (); | |
568 | } | |
569 | /* addl y,%ebx */ | |
570 | if (delta > 0 && op == 0x81 && codestream_get () == 0xc3) | |
571 | { | |
572 | pos += delta + 6; | |
573 | } | |
574 | } | |
575 | codestream_seek (pos); | |
576 | ||
577 | i386_follow_jump (); | |
578 | ||
579 | return (codestream_tell ()); | |
580 | } | |
581 | ||
582 | void | |
583 | i386_push_dummy_frame () | |
584 | { | |
585 | CORE_ADDR sp = read_register (SP_REGNUM); | |
586 | int regnum; | |
587 | char regbuf[MAX_REGISTER_RAW_SIZE]; | |
588 | ||
589 | sp = push_word (sp, read_register (PC_REGNUM)); | |
590 | sp = push_word (sp, read_register (FP_REGNUM)); | |
591 | write_register (FP_REGNUM, sp); | |
592 | for (regnum = 0; regnum < NUM_REGS; regnum++) | |
593 | { | |
594 | read_register_gen (regnum, regbuf); | |
595 | sp = push_bytes (sp, regbuf, REGISTER_RAW_SIZE (regnum)); | |
596 | } | |
597 | write_register (SP_REGNUM, sp); | |
598 | } | |
599 | ||
600 | void | |
601 | i386_pop_frame () | |
602 | { | |
603 | struct frame_info *frame = get_current_frame (); | |
604 | CORE_ADDR fp; | |
605 | int regnum; | |
606 | struct frame_saved_regs fsr; | |
607 | char regbuf[MAX_REGISTER_RAW_SIZE]; | |
608 | ||
609 | fp = FRAME_FP (frame); | |
610 | get_frame_saved_regs (frame, &fsr); | |
611 | for (regnum = 0; regnum < NUM_REGS; regnum++) | |
612 | { | |
613 | CORE_ADDR adr; | |
614 | adr = fsr.regs[regnum]; | |
615 | if (adr) | |
616 | { | |
617 | read_memory (adr, regbuf, REGISTER_RAW_SIZE (regnum)); | |
618 | write_register_bytes (REGISTER_BYTE (regnum), regbuf, | |
619 | REGISTER_RAW_SIZE (regnum)); | |
620 | } | |
621 | } | |
622 | write_register (FP_REGNUM, read_memory_integer (fp, 4)); | |
623 | write_register (PC_REGNUM, read_memory_integer (fp + 4, 4)); | |
624 | write_register (SP_REGNUM, fp + 8); | |
625 | flush_cached_frames (); | |
626 | } | |
627 | ||
628 | #ifdef GET_LONGJMP_TARGET | |
629 | ||
630 | /* Figure out where the longjmp will land. Slurp the args out of the stack. | |
631 | We expect the first arg to be a pointer to the jmp_buf structure from which | |
632 | we extract the pc (JB_PC) that we will land at. The pc is copied into PC. | |
633 | This routine returns true on success. */ | |
634 | ||
635 | int | |
636 | get_longjmp_target(pc) | |
637 | CORE_ADDR *pc; | |
638 | { | |
639 | char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT]; | |
640 | CORE_ADDR sp, jb_addr; | |
641 | ||
642 | sp = read_register (SP_REGNUM); | |
643 | ||
644 | if (target_read_memory (sp + SP_ARG0, /* Offset of first arg on stack */ | |
645 | buf, | |
646 | TARGET_PTR_BIT / TARGET_CHAR_BIT)) | |
647 | return 0; | |
648 | ||
649 | jb_addr = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT); | |
650 | ||
651 | if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf, | |
652 | TARGET_PTR_BIT / TARGET_CHAR_BIT)) | |
653 | return 0; | |
654 | ||
655 | *pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT); | |
656 | ||
657 | return 1; | |
658 | } | |
659 | ||
660 | #endif /* GET_LONGJMP_TARGET */ | |
661 | ||
662 | void | |
663 | i386_extract_return_value(type, regbuf, valbuf) | |
664 | struct type *type; | |
665 | char regbuf[REGISTER_BYTES]; | |
666 | char *valbuf; | |
667 | { | |
668 | /* On AIX, floating point values are returned in floating point registers. */ | |
669 | #ifdef I386_AIX_TARGET | |
670 | if (TYPE_CODE_FLT == TYPE_CODE(type)) | |
671 | { | |
672 | double d; | |
673 | /* 387 %st(0), gcc uses this */ | |
674 | floatformat_to_double (&floatformat_i387_ext, | |
675 | ®buf[REGISTER_BYTE(FP0_REGNUM)], | |
676 | &d); | |
677 | store_floating (valbuf, TYPE_LENGTH (type), d); | |
678 | } | |
679 | else | |
680 | #endif /* I386_AIX_TARGET */ | |
681 | { | |
682 | memcpy (valbuf, regbuf, TYPE_LENGTH (type)); | |
683 | } | |
684 | } | |
685 | ||
686 | #ifdef I386V4_SIGTRAMP_SAVED_PC | |
687 | /* Get saved user PC for sigtramp from the pushed ucontext on the stack | |
688 | for all three variants of SVR4 sigtramps. */ | |
689 | ||
690 | CORE_ADDR | |
691 | i386v4_sigtramp_saved_pc (frame) | |
692 | struct frame_info *frame; | |
693 | { | |
694 | CORE_ADDR saved_pc_offset = 4; | |
695 | char *name = NULL; | |
696 | ||
697 | find_pc_partial_function (frame->pc, &name, NULL, NULL); | |
698 | if (name) | |
699 | { | |
700 | if (STREQ (name, "_sigreturn")) | |
701 | saved_pc_offset = 132 + 14 * 4; | |
702 | else if (STREQ (name, "_sigacthandler")) | |
703 | saved_pc_offset = 80 + 14 * 4; | |
704 | else if (STREQ (name, "sigvechandler")) | |
705 | saved_pc_offset = 120 + 14 * 4; | |
706 | } | |
707 | ||
708 | if (frame->next) | |
709 | return read_memory_integer (frame->next->frame + saved_pc_offset, 4); | |
710 | return read_memory_integer (read_register (SP_REGNUM) + saved_pc_offset, 4); | |
711 | } | |
712 | #endif /* I386V4_SIGTRAMP_SAVED_PC */ | |
713 | ||
714 | #ifdef STATIC_TRANSFORM_NAME | |
715 | /* SunPRO encodes the static variables. This is not related to C++ mangling, | |
716 | it is done for C too. */ | |
717 | ||
718 | char * | |
719 | sunpro_static_transform_name (name) | |
720 | char *name; | |
721 | { | |
722 | char *p; | |
723 | if (IS_STATIC_TRANSFORM_NAME (name)) | |
724 | { | |
725 | /* For file-local statics there will be a period, a bunch | |
726 | of junk (the contents of which match a string given in the | |
727 | N_OPT), a period and the name. For function-local statics | |
728 | there will be a bunch of junk (which seems to change the | |
729 | second character from 'A' to 'B'), a period, the name of the | |
730 | function, and the name. So just skip everything before the | |
731 | last period. */ | |
732 | p = strrchr (name, '.'); | |
733 | if (p != NULL) | |
734 | name = p + 1; | |
735 | } | |
736 | return name; | |
737 | } | |
738 | #endif /* STATIC_TRANSFORM_NAME */ | |
739 | ||
740 | ||
741 | ||
742 | /* Stuff for WIN32 PE style DLL's but is pretty generic really. */ | |
743 | ||
744 | CORE_ADDR | |
745 | skip_trampoline_code (pc, name) | |
746 | CORE_ADDR pc; | |
747 | char *name; | |
748 | { | |
749 | if (pc && read_memory_unsigned_integer (pc, 2) == 0x25ff) /* jmp *(dest) */ | |
750 | { | |
751 | unsigned long indirect = read_memory_unsigned_integer (pc+2, 4); | |
752 | struct minimal_symbol *indsym = | |
753 | indirect ? lookup_minimal_symbol_by_pc (indirect) : 0; | |
754 | char *symname = indsym ? SYMBOL_NAME(indsym) : 0; | |
755 | ||
756 | if (symname) | |
757 | { | |
758 | if (strncmp (symname,"__imp_", 6) == 0 | |
759 | || strncmp (symname,"_imp_", 5) == 0) | |
760 | return name ? 1 : read_memory_unsigned_integer (indirect, 4); | |
761 | } | |
762 | } | |
763 | return 0; /* not a trampoline */ | |
764 | } | |
765 | ||
766 | static int | |
767 | gdb_print_insn_i386 (memaddr, info) | |
768 | bfd_vma memaddr; | |
769 | disassemble_info * info; | |
770 | { | |
771 | if (disassembly_flavor == att_flavor) | |
772 | return print_insn_i386_att (memaddr, info); | |
773 | else if (disassembly_flavor == intel_flavor) | |
774 | return print_insn_i386_intel (memaddr, info); | |
775 | } | |
776 | ||
777 | void | |
778 | _initialize_i386_tdep () | |
779 | { | |
780 | tm_print_insn = gdb_print_insn_i386; | |
781 | tm_print_insn_info.mach = bfd_lookup_arch (bfd_arch_i386, 0)->mach; | |
782 | ||
783 | /* Add the variable that controls the disassembly flavor */ | |
784 | add_show_from_set( | |
785 | add_set_enum_cmd ("disassembly-flavor", no_class, | |
786 | valid_flavors, | |
787 | (char *) &disassembly_flavor, | |
788 | "Set the disassembly flavor, the valid values are \"att\" and \"intel\", \ | |
789 | and the default value is \"att\".", | |
790 | &setlist), | |
791 | &showlist); | |
792 | ||
793 | ||
794 | } |