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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 | ||
7a292a7a SS |
59 | /* This is used to keep the bfd arch_info in sync with the disassembly flavor. */ |
60 | static void set_disassembly_flavor_sfunc PARAMS ((char *, int, struct cmd_list_element *)); | |
61 | static void set_disassembly_flavor (); | |
62 | ||
63 | void (*disassembly_flavor_hook) PARAMS((char *args, int from_tty)); | |
64 | ||
c906108c SS |
65 | /* Stdio style buffering was used to minimize calls to ptrace, but this |
66 | buffering did not take into account that the code section being accessed | |
67 | may not be an even number of buffers long (even if the buffer is only | |
68 | sizeof(int) long). In cases where the code section size happened to | |
69 | be a non-integral number of buffers long, attempting to read the last | |
70 | buffer would fail. Simply using target_read_memory and ignoring errors, | |
71 | rather than read_memory, is not the correct solution, since legitimate | |
72 | access errors would then be totally ignored. To properly handle this | |
73 | situation and continue to use buffering would require that this code | |
74 | be able to determine the minimum code section size granularity (not the | |
75 | alignment of the section itself, since the actual failing case that | |
76 | pointed out this problem had a section alignment of 4 but was not a | |
77 | multiple of 4 bytes long), on a target by target basis, and then | |
78 | adjust it's buffer size accordingly. This is messy, but potentially | |
79 | feasible. It probably needs the bfd library's help and support. For | |
80 | now, the buffer size is set to 1. (FIXME -fnf) */ | |
81 | ||
82 | #define CODESTREAM_BUFSIZ 1 /* Was sizeof(int), see note above. */ | |
83 | static CORE_ADDR codestream_next_addr; | |
84 | static CORE_ADDR codestream_addr; | |
85 | static unsigned char codestream_buf[CODESTREAM_BUFSIZ]; | |
86 | static int codestream_off; | |
87 | static int codestream_cnt; | |
88 | ||
89 | #define codestream_tell() (codestream_addr + codestream_off) | |
90 | #define codestream_peek() (codestream_cnt == 0 ? \ | |
91 | codestream_fill(1): codestream_buf[codestream_off]) | |
92 | #define codestream_get() (codestream_cnt-- == 0 ? \ | |
93 | codestream_fill(0) : codestream_buf[codestream_off++]) | |
94 | ||
95 | static unsigned char | |
96 | codestream_fill (peek_flag) | |
97 | int peek_flag; | |
98 | { | |
99 | codestream_addr = codestream_next_addr; | |
100 | codestream_next_addr += CODESTREAM_BUFSIZ; | |
101 | codestream_off = 0; | |
102 | codestream_cnt = CODESTREAM_BUFSIZ; | |
103 | read_memory (codestream_addr, (char *) codestream_buf, CODESTREAM_BUFSIZ); | |
104 | ||
105 | if (peek_flag) | |
106 | return (codestream_peek()); | |
107 | else | |
108 | return (codestream_get()); | |
109 | } | |
110 | ||
111 | static void | |
112 | codestream_seek (place) | |
113 | CORE_ADDR place; | |
114 | { | |
115 | codestream_next_addr = place / CODESTREAM_BUFSIZ; | |
116 | codestream_next_addr *= CODESTREAM_BUFSIZ; | |
117 | codestream_cnt = 0; | |
118 | codestream_fill (1); | |
119 | while (codestream_tell() != place) | |
120 | codestream_get (); | |
121 | } | |
122 | ||
123 | static void | |
124 | codestream_read (buf, count) | |
125 | unsigned char *buf; | |
126 | int count; | |
127 | { | |
128 | unsigned char *p; | |
129 | int i; | |
130 | p = buf; | |
131 | for (i = 0; i < count; i++) | |
132 | *p++ = codestream_get (); | |
133 | } | |
134 | ||
135 | /* next instruction is a jump, move to target */ | |
136 | ||
137 | static void | |
138 | i386_follow_jump () | |
139 | { | |
140 | unsigned char buf[4]; | |
141 | long delta; | |
142 | ||
143 | int data16; | |
144 | CORE_ADDR pos; | |
145 | ||
146 | pos = codestream_tell (); | |
147 | ||
148 | data16 = 0; | |
149 | if (codestream_peek () == 0x66) | |
150 | { | |
151 | codestream_get (); | |
152 | data16 = 1; | |
153 | } | |
154 | ||
155 | switch (codestream_get ()) | |
156 | { | |
157 | case 0xe9: | |
158 | /* relative jump: if data16 == 0, disp32, else disp16 */ | |
159 | if (data16) | |
160 | { | |
161 | codestream_read (buf, 2); | |
162 | delta = extract_signed_integer (buf, 2); | |
163 | ||
164 | /* include size of jmp inst (including the 0x66 prefix). */ | |
165 | pos += delta + 4; | |
166 | } | |
167 | else | |
168 | { | |
169 | codestream_read (buf, 4); | |
170 | delta = extract_signed_integer (buf, 4); | |
171 | ||
172 | pos += delta + 5; | |
173 | } | |
174 | break; | |
175 | case 0xeb: | |
176 | /* relative jump, disp8 (ignore data16) */ | |
177 | codestream_read (buf, 1); | |
178 | /* Sign-extend it. */ | |
179 | delta = extract_signed_integer (buf, 1); | |
180 | ||
181 | pos += delta + 2; | |
182 | break; | |
183 | } | |
184 | codestream_seek (pos); | |
185 | } | |
186 | ||
187 | /* | |
188 | * find & return amound a local space allocated, and advance codestream to | |
189 | * first register push (if any) | |
190 | * | |
191 | * if entry sequence doesn't make sense, return -1, and leave | |
192 | * codestream pointer random | |
193 | */ | |
194 | ||
195 | static long | |
196 | i386_get_frame_setup (pc) | |
197 | CORE_ADDR pc; | |
198 | { | |
199 | unsigned char op; | |
200 | ||
201 | codestream_seek (pc); | |
202 | ||
203 | i386_follow_jump (); | |
204 | ||
205 | op = codestream_get (); | |
206 | ||
207 | if (op == 0x58) /* popl %eax */ | |
208 | { | |
209 | /* | |
210 | * this function must start with | |
211 | * | |
212 | * popl %eax 0x58 | |
213 | * xchgl %eax, (%esp) 0x87 0x04 0x24 | |
214 | * or xchgl %eax, 0(%esp) 0x87 0x44 0x24 0x00 | |
215 | * | |
216 | * (the system 5 compiler puts out the second xchg | |
217 | * inst, and the assembler doesn't try to optimize it, | |
218 | * so the 'sib' form gets generated) | |
219 | * | |
220 | * this sequence is used to get the address of the return | |
221 | * buffer for a function that returns a structure | |
222 | */ | |
223 | int pos; | |
224 | unsigned char buf[4]; | |
225 | static unsigned char proto1[3] = { 0x87,0x04,0x24 }; | |
226 | static unsigned char proto2[4] = { 0x87,0x44,0x24,0x00 }; | |
227 | pos = codestream_tell (); | |
228 | codestream_read (buf, 4); | |
229 | if (memcmp (buf, proto1, 3) == 0) | |
230 | pos += 3; | |
231 | else if (memcmp (buf, proto2, 4) == 0) | |
232 | pos += 4; | |
233 | ||
234 | codestream_seek (pos); | |
235 | op = codestream_get (); /* update next opcode */ | |
236 | } | |
237 | ||
238 | if (op == 0x68 || op == 0x6a) | |
239 | { | |
240 | /* | |
241 | * this function may start with | |
242 | * | |
243 | * pushl constant | |
244 | * call _probe | |
245 | * addl $4, %esp | |
246 | * followed by | |
247 | * pushl %ebp | |
248 | * etc. | |
249 | */ | |
250 | int pos; | |
251 | unsigned char buf[8]; | |
252 | ||
253 | /* Skip past the pushl instruction; it has either a one-byte | |
254 | or a four-byte operand, depending on the opcode. */ | |
255 | pos = codestream_tell (); | |
256 | if (op == 0x68) | |
257 | pos += 4; | |
258 | else | |
259 | pos += 1; | |
260 | codestream_seek (pos); | |
261 | ||
262 | /* Read the following 8 bytes, which should be "call _probe" (6 bytes) | |
263 | followed by "addl $4,%esp" (2 bytes). */ | |
264 | codestream_read (buf, sizeof (buf)); | |
265 | if (buf[0] == 0xe8 && buf[6] == 0xc4 && buf[7] == 0x4) | |
266 | pos += sizeof (buf); | |
267 | codestream_seek (pos); | |
268 | op = codestream_get (); /* update next opcode */ | |
269 | } | |
270 | ||
271 | if (op == 0x55) /* pushl %ebp */ | |
272 | { | |
273 | /* check for movl %esp, %ebp - can be written two ways */ | |
274 | switch (codestream_get ()) | |
275 | { | |
276 | case 0x8b: | |
277 | if (codestream_get () != 0xec) | |
278 | return (-1); | |
279 | break; | |
280 | case 0x89: | |
281 | if (codestream_get () != 0xe5) | |
282 | return (-1); | |
283 | break; | |
284 | default: | |
285 | return (-1); | |
286 | } | |
287 | /* check for stack adjustment | |
288 | * | |
289 | * subl $XXX, %esp | |
290 | * | |
291 | * note: you can't subtract a 16 bit immediate | |
292 | * from a 32 bit reg, so we don't have to worry | |
293 | * about a data16 prefix | |
294 | */ | |
295 | op = codestream_peek (); | |
296 | if (op == 0x83) | |
297 | { | |
298 | /* subl with 8 bit immed */ | |
299 | codestream_get (); | |
300 | if (codestream_get () != 0xec) | |
301 | /* Some instruction starting with 0x83 other than subl. */ | |
302 | { | |
303 | codestream_seek (codestream_tell () - 2); | |
304 | return 0; | |
305 | } | |
306 | /* subl with signed byte immediate | |
307 | * (though it wouldn't make sense to be negative) | |
308 | */ | |
309 | return (codestream_get()); | |
310 | } | |
311 | else if (op == 0x81) | |
312 | { | |
313 | char buf[4]; | |
314 | /* Maybe it is subl with 32 bit immedediate. */ | |
315 | codestream_get(); | |
316 | if (codestream_get () != 0xec) | |
317 | /* Some instruction starting with 0x81 other than subl. */ | |
318 | { | |
319 | codestream_seek (codestream_tell () - 2); | |
320 | return 0; | |
321 | } | |
322 | /* It is subl with 32 bit immediate. */ | |
323 | codestream_read ((unsigned char *)buf, 4); | |
324 | return extract_signed_integer (buf, 4); | |
325 | } | |
326 | else | |
327 | { | |
328 | return (0); | |
329 | } | |
330 | } | |
331 | else if (op == 0xc8) | |
332 | { | |
333 | char buf[2]; | |
334 | /* enter instruction: arg is 16 bit unsigned immed */ | |
335 | codestream_read ((unsigned char *)buf, 2); | |
336 | codestream_get (); /* flush final byte of enter instruction */ | |
337 | return extract_unsigned_integer (buf, 2); | |
338 | } | |
339 | return (-1); | |
340 | } | |
341 | ||
342 | /* Return number of args passed to a frame. | |
343 | Can return -1, meaning no way to tell. */ | |
344 | ||
345 | int | |
346 | i386_frame_num_args (fi) | |
347 | struct frame_info *fi; | |
348 | { | |
349 | #if 1 | |
350 | return -1; | |
351 | #else | |
352 | /* This loses because not only might the compiler not be popping the | |
353 | args right after the function call, it might be popping args from both | |
354 | this call and a previous one, and we would say there are more args | |
355 | than there really are. */ | |
356 | ||
357 | int retpc; | |
358 | unsigned char op; | |
359 | struct frame_info *pfi; | |
360 | ||
361 | /* on the 386, the instruction following the call could be: | |
362 | popl %ecx - one arg | |
363 | addl $imm, %esp - imm/4 args; imm may be 8 or 32 bits | |
364 | anything else - zero args */ | |
365 | ||
366 | int frameless; | |
367 | ||
392a587b | 368 | frameless = FRAMELESS_FUNCTION_INVOCATION (fi); |
c906108c SS |
369 | if (frameless) |
370 | /* In the absence of a frame pointer, GDB doesn't get correct values | |
371 | for nameless arguments. Return -1, so it doesn't print any | |
372 | nameless arguments. */ | |
373 | return -1; | |
374 | ||
7a292a7a | 375 | pfi = get_prev_frame (fi); |
c906108c SS |
376 | if (pfi == 0) |
377 | { | |
378 | /* Note: this can happen if we are looking at the frame for | |
379 | main, because FRAME_CHAIN_VALID won't let us go into | |
380 | start. If we have debugging symbols, that's not really | |
381 | a big deal; it just means it will only show as many arguments | |
382 | to main as are declared. */ | |
383 | return -1; | |
384 | } | |
385 | else | |
386 | { | |
387 | retpc = pfi->pc; | |
388 | op = read_memory_integer (retpc, 1); | |
389 | if (op == 0x59) | |
390 | /* pop %ecx */ | |
391 | return 1; | |
392 | else if (op == 0x83) | |
393 | { | |
394 | op = read_memory_integer (retpc+1, 1); | |
395 | if (op == 0xc4) | |
396 | /* addl $<signed imm 8 bits>, %esp */ | |
397 | return (read_memory_integer (retpc+2,1)&0xff)/4; | |
398 | else | |
399 | return 0; | |
400 | } | |
401 | else if (op == 0x81) | |
402 | { /* add with 32 bit immediate */ | |
403 | op = read_memory_integer (retpc+1, 1); | |
404 | if (op == 0xc4) | |
405 | /* addl $<imm 32>, %esp */ | |
406 | return read_memory_integer (retpc+2, 4) / 4; | |
407 | else | |
408 | return 0; | |
409 | } | |
410 | else | |
411 | { | |
412 | return 0; | |
413 | } | |
414 | } | |
415 | #endif | |
416 | } | |
417 | ||
418 | /* | |
419 | * parse the first few instructions of the function to see | |
420 | * what registers were stored. | |
421 | * | |
422 | * We handle these cases: | |
423 | * | |
424 | * The startup sequence can be at the start of the function, | |
425 | * or the function can start with a branch to startup code at the end. | |
426 | * | |
427 | * %ebp can be set up with either the 'enter' instruction, or | |
428 | * 'pushl %ebp, movl %esp, %ebp' (enter is too slow to be useful, | |
429 | * but was once used in the sys5 compiler) | |
430 | * | |
431 | * Local space is allocated just below the saved %ebp by either the | |
432 | * 'enter' instruction, or by 'subl $<size>, %esp'. 'enter' has | |
433 | * a 16 bit unsigned argument for space to allocate, and the | |
434 | * 'addl' instruction could have either a signed byte, or | |
435 | * 32 bit immediate. | |
436 | * | |
437 | * Next, the registers used by this function are pushed. In | |
438 | * the sys5 compiler they will always be in the order: %edi, %esi, %ebx | |
439 | * (and sometimes a harmless bug causes it to also save but not restore %eax); | |
440 | * however, the code below is willing to see the pushes in any order, | |
441 | * and will handle up to 8 of them. | |
442 | * | |
443 | * If the setup sequence is at the end of the function, then the | |
444 | * next instruction will be a branch back to the start. | |
445 | */ | |
446 | ||
447 | void | |
448 | i386_frame_find_saved_regs (fip, fsrp) | |
449 | struct frame_info *fip; | |
450 | struct frame_saved_regs *fsrp; | |
451 | { | |
452 | long locals = -1; | |
453 | unsigned char op; | |
454 | CORE_ADDR dummy_bottom; | |
455 | CORE_ADDR adr; | |
456 | CORE_ADDR pc; | |
457 | int i; | |
458 | ||
459 | memset (fsrp, 0, sizeof *fsrp); | |
460 | ||
461 | /* if frame is the end of a dummy, compute where the | |
462 | * beginning would be | |
463 | */ | |
464 | dummy_bottom = fip->frame - 4 - REGISTER_BYTES - CALL_DUMMY_LENGTH; | |
465 | ||
466 | /* check if the PC is in the stack, in a dummy frame */ | |
467 | if (dummy_bottom <= fip->pc && fip->pc <= fip->frame) | |
468 | { | |
469 | /* all regs were saved by push_call_dummy () */ | |
470 | adr = fip->frame; | |
471 | for (i = 0; i < NUM_REGS; i++) | |
472 | { | |
473 | adr -= REGISTER_RAW_SIZE (i); | |
474 | fsrp->regs[i] = adr; | |
475 | } | |
476 | return; | |
477 | } | |
478 | ||
479 | pc = get_pc_function_start (fip->pc); | |
480 | if (pc != 0) | |
481 | locals = i386_get_frame_setup (pc); | |
482 | ||
483 | if (locals >= 0) | |
484 | { | |
485 | adr = fip->frame - 4 - locals; | |
486 | for (i = 0; i < 8; i++) | |
487 | { | |
488 | op = codestream_get (); | |
489 | if (op < 0x50 || op > 0x57) | |
490 | break; | |
491 | #ifdef I386_REGNO_TO_SYMMETRY | |
492 | /* Dynix uses different internal numbering. Ick. */ | |
493 | fsrp->regs[I386_REGNO_TO_SYMMETRY(op - 0x50)] = adr; | |
494 | #else | |
495 | fsrp->regs[op - 0x50] = adr; | |
496 | #endif | |
497 | adr -= 4; | |
498 | } | |
499 | } | |
500 | ||
501 | fsrp->regs[PC_REGNUM] = fip->frame + 4; | |
502 | fsrp->regs[FP_REGNUM] = fip->frame; | |
503 | } | |
504 | ||
505 | /* return pc of first real instruction */ | |
506 | ||
507 | int | |
508 | i386_skip_prologue (pc) | |
509 | int pc; | |
510 | { | |
511 | unsigned char op; | |
512 | int i; | |
513 | static unsigned char pic_pat[6] = { 0xe8, 0, 0, 0, 0, /* call 0x0 */ | |
514 | 0x5b, /* popl %ebx */ | |
515 | }; | |
516 | CORE_ADDR pos; | |
517 | ||
518 | if (i386_get_frame_setup (pc) < 0) | |
519 | return (pc); | |
520 | ||
521 | /* found valid frame setup - codestream now points to | |
522 | * start of push instructions for saving registers | |
523 | */ | |
524 | ||
525 | /* skip over register saves */ | |
526 | for (i = 0; i < 8; i++) | |
527 | { | |
528 | op = codestream_peek (); | |
529 | /* break if not pushl inst */ | |
530 | if (op < 0x50 || op > 0x57) | |
531 | break; | |
532 | codestream_get (); | |
533 | } | |
534 | ||
535 | /* The native cc on SVR4 in -K PIC mode inserts the following code to get | |
536 | the address of the global offset table (GOT) into register %ebx. | |
537 | call 0x0 | |
538 | popl %ebx | |
539 | movl %ebx,x(%ebp) (optional) | |
540 | addl y,%ebx | |
541 | This code is with the rest of the prologue (at the end of the | |
542 | function), so we have to skip it to get to the first real | |
543 | instruction at the start of the function. */ | |
544 | ||
545 | pos = codestream_tell (); | |
546 | for (i = 0; i < 6; i++) | |
547 | { | |
548 | op = codestream_get (); | |
549 | if (pic_pat [i] != op) | |
550 | break; | |
551 | } | |
552 | if (i == 6) | |
553 | { | |
554 | unsigned char buf[4]; | |
555 | long delta = 6; | |
556 | ||
557 | op = codestream_get (); | |
558 | if (op == 0x89) /* movl %ebx, x(%ebp) */ | |
559 | { | |
560 | op = codestream_get (); | |
561 | if (op == 0x5d) /* one byte offset from %ebp */ | |
562 | { | |
563 | delta += 3; | |
564 | codestream_read (buf, 1); | |
565 | } | |
566 | else if (op == 0x9d) /* four byte offset from %ebp */ | |
567 | { | |
568 | delta += 6; | |
569 | codestream_read (buf, 4); | |
570 | } | |
571 | else /* unexpected instruction */ | |
572 | delta = -1; | |
573 | op = codestream_get (); | |
574 | } | |
575 | /* addl y,%ebx */ | |
576 | if (delta > 0 && op == 0x81 && codestream_get () == 0xc3) | |
577 | { | |
578 | pos += delta + 6; | |
579 | } | |
580 | } | |
581 | codestream_seek (pos); | |
582 | ||
583 | i386_follow_jump (); | |
584 | ||
585 | return (codestream_tell ()); | |
586 | } | |
587 | ||
588 | void | |
589 | i386_push_dummy_frame () | |
590 | { | |
591 | CORE_ADDR sp = read_register (SP_REGNUM); | |
592 | int regnum; | |
593 | char regbuf[MAX_REGISTER_RAW_SIZE]; | |
594 | ||
595 | sp = push_word (sp, read_register (PC_REGNUM)); | |
596 | sp = push_word (sp, read_register (FP_REGNUM)); | |
597 | write_register (FP_REGNUM, sp); | |
598 | for (regnum = 0; regnum < NUM_REGS; regnum++) | |
599 | { | |
600 | read_register_gen (regnum, regbuf); | |
601 | sp = push_bytes (sp, regbuf, REGISTER_RAW_SIZE (regnum)); | |
602 | } | |
603 | write_register (SP_REGNUM, sp); | |
604 | } | |
605 | ||
606 | void | |
607 | i386_pop_frame () | |
608 | { | |
609 | struct frame_info *frame = get_current_frame (); | |
610 | CORE_ADDR fp; | |
611 | int regnum; | |
612 | struct frame_saved_regs fsr; | |
613 | char regbuf[MAX_REGISTER_RAW_SIZE]; | |
614 | ||
615 | fp = FRAME_FP (frame); | |
616 | get_frame_saved_regs (frame, &fsr); | |
617 | for (regnum = 0; regnum < NUM_REGS; regnum++) | |
618 | { | |
619 | CORE_ADDR adr; | |
620 | adr = fsr.regs[regnum]; | |
621 | if (adr) | |
622 | { | |
623 | read_memory (adr, regbuf, REGISTER_RAW_SIZE (regnum)); | |
624 | write_register_bytes (REGISTER_BYTE (regnum), regbuf, | |
625 | REGISTER_RAW_SIZE (regnum)); | |
626 | } | |
627 | } | |
628 | write_register (FP_REGNUM, read_memory_integer (fp, 4)); | |
629 | write_register (PC_REGNUM, read_memory_integer (fp + 4, 4)); | |
630 | write_register (SP_REGNUM, fp + 8); | |
631 | flush_cached_frames (); | |
632 | } | |
633 | ||
634 | #ifdef GET_LONGJMP_TARGET | |
635 | ||
636 | /* Figure out where the longjmp will land. Slurp the args out of the stack. | |
637 | We expect the first arg to be a pointer to the jmp_buf structure from which | |
638 | we extract the pc (JB_PC) that we will land at. The pc is copied into PC. | |
639 | This routine returns true on success. */ | |
640 | ||
641 | int | |
642 | get_longjmp_target(pc) | |
643 | CORE_ADDR *pc; | |
644 | { | |
645 | char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT]; | |
646 | CORE_ADDR sp, jb_addr; | |
647 | ||
648 | sp = read_register (SP_REGNUM); | |
649 | ||
650 | if (target_read_memory (sp + SP_ARG0, /* Offset of first arg on stack */ | |
651 | buf, | |
652 | TARGET_PTR_BIT / TARGET_CHAR_BIT)) | |
653 | return 0; | |
654 | ||
655 | jb_addr = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT); | |
656 | ||
657 | if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf, | |
658 | TARGET_PTR_BIT / TARGET_CHAR_BIT)) | |
659 | return 0; | |
660 | ||
661 | *pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT); | |
662 | ||
663 | return 1; | |
664 | } | |
665 | ||
666 | #endif /* GET_LONGJMP_TARGET */ | |
667 | ||
668 | void | |
669 | i386_extract_return_value(type, regbuf, valbuf) | |
670 | struct type *type; | |
671 | char regbuf[REGISTER_BYTES]; | |
672 | char *valbuf; | |
673 | { | |
674 | /* On AIX, floating point values are returned in floating point registers. */ | |
675 | #ifdef I386_AIX_TARGET | |
676 | if (TYPE_CODE_FLT == TYPE_CODE(type)) | |
677 | { | |
678 | double d; | |
679 | /* 387 %st(0), gcc uses this */ | |
680 | floatformat_to_double (&floatformat_i387_ext, | |
681 | ®buf[REGISTER_BYTE(FP0_REGNUM)], | |
682 | &d); | |
683 | store_floating (valbuf, TYPE_LENGTH (type), d); | |
684 | } | |
685 | else | |
686 | #endif /* I386_AIX_TARGET */ | |
687 | { | |
688 | memcpy (valbuf, regbuf, TYPE_LENGTH (type)); | |
689 | } | |
690 | } | |
691 | ||
692 | #ifdef I386V4_SIGTRAMP_SAVED_PC | |
693 | /* Get saved user PC for sigtramp from the pushed ucontext on the stack | |
694 | for all three variants of SVR4 sigtramps. */ | |
695 | ||
696 | CORE_ADDR | |
697 | i386v4_sigtramp_saved_pc (frame) | |
698 | struct frame_info *frame; | |
699 | { | |
700 | CORE_ADDR saved_pc_offset = 4; | |
701 | char *name = NULL; | |
702 | ||
703 | find_pc_partial_function (frame->pc, &name, NULL, NULL); | |
704 | if (name) | |
705 | { | |
706 | if (STREQ (name, "_sigreturn")) | |
707 | saved_pc_offset = 132 + 14 * 4; | |
708 | else if (STREQ (name, "_sigacthandler")) | |
709 | saved_pc_offset = 80 + 14 * 4; | |
710 | else if (STREQ (name, "sigvechandler")) | |
711 | saved_pc_offset = 120 + 14 * 4; | |
712 | } | |
713 | ||
714 | if (frame->next) | |
715 | return read_memory_integer (frame->next->frame + saved_pc_offset, 4); | |
716 | return read_memory_integer (read_register (SP_REGNUM) + saved_pc_offset, 4); | |
717 | } | |
718 | #endif /* I386V4_SIGTRAMP_SAVED_PC */ | |
719 | ||
720 | #ifdef STATIC_TRANSFORM_NAME | |
721 | /* SunPRO encodes the static variables. This is not related to C++ mangling, | |
722 | it is done for C too. */ | |
723 | ||
724 | char * | |
725 | sunpro_static_transform_name (name) | |
726 | char *name; | |
727 | { | |
728 | char *p; | |
729 | if (IS_STATIC_TRANSFORM_NAME (name)) | |
730 | { | |
731 | /* For file-local statics there will be a period, a bunch | |
732 | of junk (the contents of which match a string given in the | |
733 | N_OPT), a period and the name. For function-local statics | |
734 | there will be a bunch of junk (which seems to change the | |
735 | second character from 'A' to 'B'), a period, the name of the | |
736 | function, and the name. So just skip everything before the | |
737 | last period. */ | |
738 | p = strrchr (name, '.'); | |
739 | if (p != NULL) | |
740 | name = p + 1; | |
741 | } | |
742 | return name; | |
743 | } | |
744 | #endif /* STATIC_TRANSFORM_NAME */ | |
745 | ||
746 | ||
747 | ||
748 | /* Stuff for WIN32 PE style DLL's but is pretty generic really. */ | |
749 | ||
750 | CORE_ADDR | |
751 | skip_trampoline_code (pc, name) | |
752 | CORE_ADDR pc; | |
753 | char *name; | |
754 | { | |
755 | if (pc && read_memory_unsigned_integer (pc, 2) == 0x25ff) /* jmp *(dest) */ | |
756 | { | |
757 | unsigned long indirect = read_memory_unsigned_integer (pc+2, 4); | |
758 | struct minimal_symbol *indsym = | |
759 | indirect ? lookup_minimal_symbol_by_pc (indirect) : 0; | |
760 | char *symname = indsym ? SYMBOL_NAME(indsym) : 0; | |
761 | ||
762 | if (symname) | |
763 | { | |
764 | if (strncmp (symname,"__imp_", 6) == 0 | |
765 | || strncmp (symname,"_imp_", 5) == 0) | |
766 | return name ? 1 : read_memory_unsigned_integer (indirect, 4); | |
767 | } | |
768 | } | |
769 | return 0; /* not a trampoline */ | |
770 | } | |
771 | ||
772 | static int | |
773 | gdb_print_insn_i386 (memaddr, info) | |
774 | bfd_vma memaddr; | |
775 | disassemble_info * info; | |
776 | { | |
777 | if (disassembly_flavor == att_flavor) | |
778 | return print_insn_i386_att (memaddr, info); | |
779 | else if (disassembly_flavor == intel_flavor) | |
780 | return print_insn_i386_intel (memaddr, info); | |
7a292a7a SS |
781 | /* Never reached - disassembly_flavour is always either att_flavor |
782 | or intel_flavor */ | |
783 | abort (); | |
784 | } | |
785 | ||
786 | /* If the disassembly mode is intel, we have to also switch the | |
787 | bfd mach_type. This function is run in the set disassembly_flavor | |
788 | command, and does that. */ | |
789 | ||
790 | static void | |
791 | set_disassembly_flavor_sfunc (args, from_tty, c) | |
792 | char *args; | |
793 | int from_tty; | |
794 | struct cmd_list_element *c; | |
795 | { | |
796 | set_disassembly_flavor (); | |
797 | ||
798 | if (disassembly_flavor_hook != NULL) | |
799 | disassembly_flavor_hook(args, from_tty); | |
800 | } | |
801 | ||
802 | static void | |
803 | set_disassembly_flavor () | |
804 | { | |
805 | if (disassembly_flavor == att_flavor) | |
806 | set_architecture_from_arch_mach (bfd_arch_i386, bfd_mach_i386_i386); | |
807 | else if (disassembly_flavor == intel_flavor) | |
808 | set_architecture_from_arch_mach (bfd_arch_i386, bfd_mach_i386_i386_intel_syntax); | |
c906108c SS |
809 | } |
810 | ||
811 | void | |
812 | _initialize_i386_tdep () | |
813 | { | |
7a292a7a SS |
814 | struct cmd_list_element *new_cmd; |
815 | ||
c906108c SS |
816 | tm_print_insn = gdb_print_insn_i386; |
817 | tm_print_insn_info.mach = bfd_lookup_arch (bfd_arch_i386, 0)->mach; | |
818 | ||
819 | /* Add the variable that controls the disassembly flavor */ | |
7a292a7a SS |
820 | |
821 | new_cmd = add_set_enum_cmd ("disassembly-flavor", no_class, | |
c906108c SS |
822 | valid_flavors, |
823 | (char *) &disassembly_flavor, | |
824 | "Set the disassembly flavor, the valid values are \"att\" and \"intel\", \ | |
825 | and the default value is \"att\".", | |
7a292a7a SS |
826 | &setlist); |
827 | new_cmd->function.sfunc = set_disassembly_flavor_sfunc; | |
828 | add_show_from_set(new_cmd, &showlist); | |
829 | ||
830 | /* Finally, initialize the disassembly flavor to the default given | |
831 | in the disassembly_flavor variable */ | |
c906108c | 832 | |
7a292a7a | 833 | set_disassembly_flavor (); |
c906108c SS |
834 | |
835 | } |