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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 | ||
c5aa993b | 5 | This file is part of GDB. |
c906108c | 6 | |
c5aa993b JM |
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. | |
c906108c | 11 | |
c5aa993b JM |
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. | |
c906108c | 16 | |
c5aa993b JM |
17 | You should have received a copy of the GNU General Public License |
18 | along with this program; if not, write to the Free Software | |
19 | Foundation, Inc., 59 Temple Place - Suite 330, | |
20 | Boston, MA 02111-1307, USA. */ | |
c906108c SS |
21 | |
22 | #include "defs.h" | |
23 | #include "gdb_string.h" | |
24 | #include "frame.h" | |
25 | #include "inferior.h" | |
26 | #include "gdbcore.h" | |
27 | #include "target.h" | |
28 | #include "floatformat.h" | |
29 | #include "symtab.h" | |
30 | #include "gdbcmd.h" | |
31 | #include "command.h" | |
32 | ||
33 | static long i386_get_frame_setup PARAMS ((CORE_ADDR)); | |
34 | ||
35 | static void i386_follow_jump PARAMS ((void)); | |
36 | ||
37 | static void codestream_read PARAMS ((unsigned char *, int)); | |
38 | ||
39 | static void codestream_seek PARAMS ((CORE_ADDR)); | |
40 | ||
41 | static unsigned char codestream_fill PARAMS ((int)); | |
42 | ||
43 | CORE_ADDR skip_trampoline_code PARAMS ((CORE_ADDR, char *)); | |
44 | ||
45 | static int gdb_print_insn_i386 (bfd_vma, disassemble_info *); | |
46 | ||
47 | void _initialize_i386_tdep PARAMS ((void)); | |
48 | ||
917317f4 JM |
49 | /* i386_register_byte[i] is the offset into the register file of the |
50 | start of register number i. We initialize this from | |
51 | i386_register_raw_size. */ | |
52 | int i386_register_byte[MAX_NUM_REGS]; | |
53 | ||
ceb4951f JB |
54 | /* i386_register_raw_size[i] is the number of bytes of storage in |
55 | GDB's register array occupied by register i. */ | |
917317f4 JM |
56 | int i386_register_raw_size[MAX_NUM_REGS] = { |
57 | 4, 4, 4, 4, | |
58 | 4, 4, 4, 4, | |
59 | 4, 4, 4, 4, | |
60 | 4, 4, 4, 4, | |
61 | 10, 10, 10, 10, | |
62 | 10, 10, 10, 10, | |
63 | 4, 4, 4, 4, | |
64 | 4, 4, 4, 4, | |
65 | 16, 16, 16, 16, | |
66 | 16, 16, 16, 16, | |
67 | 4 | |
68 | }; | |
69 | ||
70 | /* i386_register_virtual_size[i] is the size in bytes of the virtual | |
71 | type of register i. */ | |
72 | int i386_register_virtual_size[MAX_NUM_REGS]; | |
73 | ||
74 | ||
c906108c | 75 | /* This is the variable the is set with "set disassembly-flavor", |
c5aa993b | 76 | and its legitimate values. */ |
c906108c SS |
77 | static char att_flavor[] = "att"; |
78 | static char intel_flavor[] = "intel"; | |
c5aa993b JM |
79 | static char *valid_flavors[] = |
80 | { | |
c906108c SS |
81 | att_flavor, |
82 | intel_flavor, | |
83 | NULL | |
84 | }; | |
85 | static char *disassembly_flavor = att_flavor; | |
86 | ||
d4f3574e SS |
87 | static void i386_print_register PARAMS ((char *, int, int)); |
88 | ||
7a292a7a SS |
89 | /* This is used to keep the bfd arch_info in sync with the disassembly flavor. */ |
90 | static void set_disassembly_flavor_sfunc PARAMS ((char *, int, struct cmd_list_element *)); | |
d4f3574e | 91 | static void set_disassembly_flavor PARAMS ((void)); |
7a292a7a | 92 | |
c906108c SS |
93 | /* Stdio style buffering was used to minimize calls to ptrace, but this |
94 | buffering did not take into account that the code section being accessed | |
95 | may not be an even number of buffers long (even if the buffer is only | |
96 | sizeof(int) long). In cases where the code section size happened to | |
97 | be a non-integral number of buffers long, attempting to read the last | |
98 | buffer would fail. Simply using target_read_memory and ignoring errors, | |
99 | rather than read_memory, is not the correct solution, since legitimate | |
100 | access errors would then be totally ignored. To properly handle this | |
101 | situation and continue to use buffering would require that this code | |
102 | be able to determine the minimum code section size granularity (not the | |
103 | alignment of the section itself, since the actual failing case that | |
104 | pointed out this problem had a section alignment of 4 but was not a | |
105 | multiple of 4 bytes long), on a target by target basis, and then | |
106 | adjust it's buffer size accordingly. This is messy, but potentially | |
107 | feasible. It probably needs the bfd library's help and support. For | |
108 | now, the buffer size is set to 1. (FIXME -fnf) */ | |
109 | ||
110 | #define CODESTREAM_BUFSIZ 1 /* Was sizeof(int), see note above. */ | |
111 | static CORE_ADDR codestream_next_addr; | |
112 | static CORE_ADDR codestream_addr; | |
113 | static unsigned char codestream_buf[CODESTREAM_BUFSIZ]; | |
114 | static int codestream_off; | |
115 | static int codestream_cnt; | |
116 | ||
117 | #define codestream_tell() (codestream_addr + codestream_off) | |
118 | #define codestream_peek() (codestream_cnt == 0 ? \ | |
119 | codestream_fill(1): codestream_buf[codestream_off]) | |
120 | #define codestream_get() (codestream_cnt-- == 0 ? \ | |
121 | codestream_fill(0) : codestream_buf[codestream_off++]) | |
122 | ||
c5aa993b | 123 | static unsigned char |
c906108c | 124 | codestream_fill (peek_flag) |
c5aa993b | 125 | int peek_flag; |
c906108c SS |
126 | { |
127 | codestream_addr = codestream_next_addr; | |
128 | codestream_next_addr += CODESTREAM_BUFSIZ; | |
129 | codestream_off = 0; | |
130 | codestream_cnt = CODESTREAM_BUFSIZ; | |
131 | read_memory (codestream_addr, (char *) codestream_buf, CODESTREAM_BUFSIZ); | |
c5aa993b | 132 | |
c906108c | 133 | if (peek_flag) |
c5aa993b | 134 | return (codestream_peek ()); |
c906108c | 135 | else |
c5aa993b | 136 | return (codestream_get ()); |
c906108c SS |
137 | } |
138 | ||
139 | static void | |
140 | codestream_seek (place) | |
c5aa993b | 141 | CORE_ADDR place; |
c906108c SS |
142 | { |
143 | codestream_next_addr = place / CODESTREAM_BUFSIZ; | |
144 | codestream_next_addr *= CODESTREAM_BUFSIZ; | |
145 | codestream_cnt = 0; | |
146 | codestream_fill (1); | |
c5aa993b | 147 | while (codestream_tell () != place) |
c906108c SS |
148 | codestream_get (); |
149 | } | |
150 | ||
151 | static void | |
152 | codestream_read (buf, count) | |
153 | unsigned char *buf; | |
154 | int count; | |
155 | { | |
156 | unsigned char *p; | |
157 | int i; | |
158 | p = buf; | |
159 | for (i = 0; i < count; i++) | |
160 | *p++ = codestream_get (); | |
161 | } | |
162 | ||
163 | /* next instruction is a jump, move to target */ | |
164 | ||
165 | static void | |
166 | i386_follow_jump () | |
167 | { | |
168 | unsigned char buf[4]; | |
169 | long delta; | |
170 | ||
171 | int data16; | |
172 | CORE_ADDR pos; | |
173 | ||
174 | pos = codestream_tell (); | |
175 | ||
176 | data16 = 0; | |
177 | if (codestream_peek () == 0x66) | |
178 | { | |
179 | codestream_get (); | |
180 | data16 = 1; | |
181 | } | |
182 | ||
183 | switch (codestream_get ()) | |
184 | { | |
185 | case 0xe9: | |
186 | /* relative jump: if data16 == 0, disp32, else disp16 */ | |
187 | if (data16) | |
188 | { | |
189 | codestream_read (buf, 2); | |
190 | delta = extract_signed_integer (buf, 2); | |
191 | ||
192 | /* include size of jmp inst (including the 0x66 prefix). */ | |
c5aa993b | 193 | pos += delta + 4; |
c906108c SS |
194 | } |
195 | else | |
196 | { | |
197 | codestream_read (buf, 4); | |
198 | delta = extract_signed_integer (buf, 4); | |
199 | ||
200 | pos += delta + 5; | |
201 | } | |
202 | break; | |
203 | case 0xeb: | |
204 | /* relative jump, disp8 (ignore data16) */ | |
205 | codestream_read (buf, 1); | |
206 | /* Sign-extend it. */ | |
207 | delta = extract_signed_integer (buf, 1); | |
208 | ||
209 | pos += delta + 2; | |
210 | break; | |
211 | } | |
212 | codestream_seek (pos); | |
213 | } | |
214 | ||
215 | /* | |
216 | * find & return amound a local space allocated, and advance codestream to | |
217 | * first register push (if any) | |
218 | * | |
219 | * if entry sequence doesn't make sense, return -1, and leave | |
220 | * codestream pointer random | |
221 | */ | |
222 | ||
223 | static long | |
224 | i386_get_frame_setup (pc) | |
225 | CORE_ADDR pc; | |
226 | { | |
227 | unsigned char op; | |
228 | ||
229 | codestream_seek (pc); | |
230 | ||
231 | i386_follow_jump (); | |
232 | ||
233 | op = codestream_get (); | |
234 | ||
235 | if (op == 0x58) /* popl %eax */ | |
236 | { | |
237 | /* | |
238 | * this function must start with | |
239 | * | |
c5aa993b | 240 | * popl %eax 0x58 |
c906108c SS |
241 | * xchgl %eax, (%esp) 0x87 0x04 0x24 |
242 | * or xchgl %eax, 0(%esp) 0x87 0x44 0x24 0x00 | |
243 | * | |
244 | * (the system 5 compiler puts out the second xchg | |
245 | * inst, and the assembler doesn't try to optimize it, | |
246 | * so the 'sib' form gets generated) | |
247 | * | |
248 | * this sequence is used to get the address of the return | |
249 | * buffer for a function that returns a structure | |
250 | */ | |
251 | int pos; | |
252 | unsigned char buf[4]; | |
c5aa993b JM |
253 | static unsigned char proto1[3] = |
254 | {0x87, 0x04, 0x24}; | |
255 | static unsigned char proto2[4] = | |
256 | {0x87, 0x44, 0x24, 0x00}; | |
c906108c SS |
257 | pos = codestream_tell (); |
258 | codestream_read (buf, 4); | |
259 | if (memcmp (buf, proto1, 3) == 0) | |
260 | pos += 3; | |
261 | else if (memcmp (buf, proto2, 4) == 0) | |
262 | pos += 4; | |
263 | ||
264 | codestream_seek (pos); | |
c5aa993b | 265 | op = codestream_get (); /* update next opcode */ |
c906108c SS |
266 | } |
267 | ||
268 | if (op == 0x68 || op == 0x6a) | |
269 | { | |
270 | /* | |
271 | * this function may start with | |
272 | * | |
273 | * pushl constant | |
274 | * call _probe | |
275 | * addl $4, %esp | |
276 | * followed by | |
277 | * pushl %ebp | |
278 | * etc. | |
279 | */ | |
280 | int pos; | |
281 | unsigned char buf[8]; | |
282 | ||
283 | /* Skip past the pushl instruction; it has either a one-byte | |
284 | or a four-byte operand, depending on the opcode. */ | |
285 | pos = codestream_tell (); | |
286 | if (op == 0x68) | |
287 | pos += 4; | |
288 | else | |
289 | pos += 1; | |
290 | codestream_seek (pos); | |
291 | ||
292 | /* Read the following 8 bytes, which should be "call _probe" (6 bytes) | |
293 | followed by "addl $4,%esp" (2 bytes). */ | |
294 | codestream_read (buf, sizeof (buf)); | |
295 | if (buf[0] == 0xe8 && buf[6] == 0xc4 && buf[7] == 0x4) | |
296 | pos += sizeof (buf); | |
297 | codestream_seek (pos); | |
c5aa993b | 298 | op = codestream_get (); /* update next opcode */ |
c906108c SS |
299 | } |
300 | ||
301 | if (op == 0x55) /* pushl %ebp */ | |
c5aa993b | 302 | { |
c906108c SS |
303 | /* check for movl %esp, %ebp - can be written two ways */ |
304 | switch (codestream_get ()) | |
305 | { | |
306 | case 0x8b: | |
307 | if (codestream_get () != 0xec) | |
308 | return (-1); | |
309 | break; | |
310 | case 0x89: | |
311 | if (codestream_get () != 0xe5) | |
312 | return (-1); | |
313 | break; | |
314 | default: | |
315 | return (-1); | |
316 | } | |
317 | /* check for stack adjustment | |
c5aa993b | 318 | |
c906108c SS |
319 | * subl $XXX, %esp |
320 | * | |
321 | * note: you can't subtract a 16 bit immediate | |
322 | * from a 32 bit reg, so we don't have to worry | |
323 | * about a data16 prefix | |
324 | */ | |
325 | op = codestream_peek (); | |
326 | if (op == 0x83) | |
327 | { | |
328 | /* subl with 8 bit immed */ | |
329 | codestream_get (); | |
330 | if (codestream_get () != 0xec) | |
331 | /* Some instruction starting with 0x83 other than subl. */ | |
332 | { | |
333 | codestream_seek (codestream_tell () - 2); | |
334 | return 0; | |
335 | } | |
336 | /* subl with signed byte immediate | |
337 | * (though it wouldn't make sense to be negative) | |
338 | */ | |
c5aa993b | 339 | return (codestream_get ()); |
c906108c SS |
340 | } |
341 | else if (op == 0x81) | |
342 | { | |
343 | char buf[4]; | |
344 | /* Maybe it is subl with 32 bit immedediate. */ | |
c5aa993b | 345 | codestream_get (); |
c906108c SS |
346 | if (codestream_get () != 0xec) |
347 | /* Some instruction starting with 0x81 other than subl. */ | |
348 | { | |
349 | codestream_seek (codestream_tell () - 2); | |
350 | return 0; | |
351 | } | |
352 | /* It is subl with 32 bit immediate. */ | |
c5aa993b | 353 | codestream_read ((unsigned char *) buf, 4); |
c906108c SS |
354 | return extract_signed_integer (buf, 4); |
355 | } | |
356 | else | |
357 | { | |
358 | return (0); | |
359 | } | |
360 | } | |
361 | else if (op == 0xc8) | |
362 | { | |
363 | char buf[2]; | |
364 | /* enter instruction: arg is 16 bit unsigned immed */ | |
c5aa993b JM |
365 | codestream_read ((unsigned char *) buf, 2); |
366 | codestream_get (); /* flush final byte of enter instruction */ | |
c906108c SS |
367 | return extract_unsigned_integer (buf, 2); |
368 | } | |
369 | return (-1); | |
370 | } | |
371 | ||
372 | /* Return number of args passed to a frame. | |
373 | Can return -1, meaning no way to tell. */ | |
374 | ||
375 | int | |
376 | i386_frame_num_args (fi) | |
377 | struct frame_info *fi; | |
378 | { | |
379 | #if 1 | |
380 | return -1; | |
381 | #else | |
382 | /* This loses because not only might the compiler not be popping the | |
383 | args right after the function call, it might be popping args from both | |
384 | this call and a previous one, and we would say there are more args | |
385 | than there really are. */ | |
386 | ||
c5aa993b JM |
387 | int retpc; |
388 | unsigned char op; | |
c906108c SS |
389 | struct frame_info *pfi; |
390 | ||
391 | /* on the 386, the instruction following the call could be: | |
392 | popl %ecx - one arg | |
393 | addl $imm, %esp - imm/4 args; imm may be 8 or 32 bits | |
394 | anything else - zero args */ | |
395 | ||
396 | int frameless; | |
397 | ||
392a587b | 398 | frameless = FRAMELESS_FUNCTION_INVOCATION (fi); |
c906108c SS |
399 | if (frameless) |
400 | /* In the absence of a frame pointer, GDB doesn't get correct values | |
401 | for nameless arguments. Return -1, so it doesn't print any | |
402 | nameless arguments. */ | |
403 | return -1; | |
404 | ||
c5aa993b | 405 | pfi = get_prev_frame (fi); |
c906108c SS |
406 | if (pfi == 0) |
407 | { | |
408 | /* Note: this can happen if we are looking at the frame for | |
c5aa993b JM |
409 | main, because FRAME_CHAIN_VALID won't let us go into |
410 | start. If we have debugging symbols, that's not really | |
411 | a big deal; it just means it will only show as many arguments | |
412 | to main as are declared. */ | |
c906108c SS |
413 | return -1; |
414 | } | |
415 | else | |
416 | { | |
c5aa993b JM |
417 | retpc = pfi->pc; |
418 | op = read_memory_integer (retpc, 1); | |
419 | if (op == 0x59) | |
420 | /* pop %ecx */ | |
421 | return 1; | |
c906108c SS |
422 | else if (op == 0x83) |
423 | { | |
c5aa993b JM |
424 | op = read_memory_integer (retpc + 1, 1); |
425 | if (op == 0xc4) | |
426 | /* addl $<signed imm 8 bits>, %esp */ | |
427 | return (read_memory_integer (retpc + 2, 1) & 0xff) / 4; | |
c906108c SS |
428 | else |
429 | return 0; | |
430 | } | |
431 | else if (op == 0x81) | |
c5aa993b JM |
432 | { /* add with 32 bit immediate */ |
433 | op = read_memory_integer (retpc + 1, 1); | |
434 | if (op == 0xc4) | |
435 | /* addl $<imm 32>, %esp */ | |
436 | return read_memory_integer (retpc + 2, 4) / 4; | |
c906108c SS |
437 | else |
438 | return 0; | |
439 | } | |
440 | else | |
441 | { | |
442 | return 0; | |
443 | } | |
444 | } | |
445 | #endif | |
446 | } | |
447 | ||
448 | /* | |
449 | * parse the first few instructions of the function to see | |
450 | * what registers were stored. | |
451 | * | |
452 | * We handle these cases: | |
453 | * | |
454 | * The startup sequence can be at the start of the function, | |
455 | * or the function can start with a branch to startup code at the end. | |
456 | * | |
457 | * %ebp can be set up with either the 'enter' instruction, or | |
458 | * 'pushl %ebp, movl %esp, %ebp' (enter is too slow to be useful, | |
459 | * but was once used in the sys5 compiler) | |
460 | * | |
461 | * Local space is allocated just below the saved %ebp by either the | |
462 | * 'enter' instruction, or by 'subl $<size>, %esp'. 'enter' has | |
463 | * a 16 bit unsigned argument for space to allocate, and the | |
464 | * 'addl' instruction could have either a signed byte, or | |
465 | * 32 bit immediate. | |
466 | * | |
467 | * Next, the registers used by this function are pushed. In | |
468 | * the sys5 compiler they will always be in the order: %edi, %esi, %ebx | |
469 | * (and sometimes a harmless bug causes it to also save but not restore %eax); | |
470 | * however, the code below is willing to see the pushes in any order, | |
471 | * and will handle up to 8 of them. | |
472 | * | |
473 | * If the setup sequence is at the end of the function, then the | |
474 | * next instruction will be a branch back to the start. | |
475 | */ | |
476 | ||
477 | void | |
1211c4e4 | 478 | i386_frame_init_saved_regs (fip) |
c906108c | 479 | struct frame_info *fip; |
c906108c SS |
480 | { |
481 | long locals = -1; | |
482 | unsigned char op; | |
483 | CORE_ADDR dummy_bottom; | |
484 | CORE_ADDR adr; | |
485 | CORE_ADDR pc; | |
486 | int i; | |
c5aa993b | 487 | |
1211c4e4 AC |
488 | if (fip->saved_regs) |
489 | return; | |
490 | ||
491 | frame_saved_regs_zalloc (fip); | |
c5aa993b | 492 | |
c906108c SS |
493 | /* if frame is the end of a dummy, compute where the |
494 | * beginning would be | |
495 | */ | |
496 | dummy_bottom = fip->frame - 4 - REGISTER_BYTES - CALL_DUMMY_LENGTH; | |
c5aa993b | 497 | |
c906108c | 498 | /* check if the PC is in the stack, in a dummy frame */ |
c5aa993b | 499 | if (dummy_bottom <= fip->pc && fip->pc <= fip->frame) |
c906108c SS |
500 | { |
501 | /* all regs were saved by push_call_dummy () */ | |
502 | adr = fip->frame; | |
c5aa993b | 503 | for (i = 0; i < NUM_REGS; i++) |
c906108c SS |
504 | { |
505 | adr -= REGISTER_RAW_SIZE (i); | |
1211c4e4 | 506 | fip->saved_regs[i] = adr; |
c906108c SS |
507 | } |
508 | return; | |
509 | } | |
c5aa993b | 510 | |
c906108c SS |
511 | pc = get_pc_function_start (fip->pc); |
512 | if (pc != 0) | |
513 | locals = i386_get_frame_setup (pc); | |
c5aa993b JM |
514 | |
515 | if (locals >= 0) | |
c906108c SS |
516 | { |
517 | adr = fip->frame - 4 - locals; | |
c5aa993b | 518 | for (i = 0; i < 8; i++) |
c906108c SS |
519 | { |
520 | op = codestream_get (); | |
521 | if (op < 0x50 || op > 0x57) | |
522 | break; | |
523 | #ifdef I386_REGNO_TO_SYMMETRY | |
524 | /* Dynix uses different internal numbering. Ick. */ | |
1211c4e4 | 525 | fip->saved_regs[I386_REGNO_TO_SYMMETRY (op - 0x50)] = adr; |
c906108c | 526 | #else |
1211c4e4 | 527 | fip->saved_regs[op - 0x50] = adr; |
c906108c SS |
528 | #endif |
529 | adr -= 4; | |
530 | } | |
531 | } | |
c5aa993b | 532 | |
1211c4e4 AC |
533 | fip->saved_regs[PC_REGNUM] = fip->frame + 4; |
534 | fip->saved_regs[FP_REGNUM] = fip->frame; | |
c906108c SS |
535 | } |
536 | ||
537 | /* return pc of first real instruction */ | |
538 | ||
539 | int | |
540 | i386_skip_prologue (pc) | |
541 | int pc; | |
542 | { | |
543 | unsigned char op; | |
544 | int i; | |
c5aa993b JM |
545 | static unsigned char pic_pat[6] = |
546 | {0xe8, 0, 0, 0, 0, /* call 0x0 */ | |
547 | 0x5b, /* popl %ebx */ | |
548 | }; | |
c906108c | 549 | CORE_ADDR pos; |
c5aa993b | 550 | |
c906108c SS |
551 | if (i386_get_frame_setup (pc) < 0) |
552 | return (pc); | |
c5aa993b | 553 | |
c906108c SS |
554 | /* found valid frame setup - codestream now points to |
555 | * start of push instructions for saving registers | |
556 | */ | |
c5aa993b | 557 | |
c906108c SS |
558 | /* skip over register saves */ |
559 | for (i = 0; i < 8; i++) | |
560 | { | |
561 | op = codestream_peek (); | |
562 | /* break if not pushl inst */ | |
c5aa993b | 563 | if (op < 0x50 || op > 0x57) |
c906108c SS |
564 | break; |
565 | codestream_get (); | |
566 | } | |
567 | ||
568 | /* The native cc on SVR4 in -K PIC mode inserts the following code to get | |
569 | the address of the global offset table (GOT) into register %ebx. | |
c5aa993b JM |
570 | call 0x0 |
571 | popl %ebx | |
572 | movl %ebx,x(%ebp) (optional) | |
573 | addl y,%ebx | |
c906108c SS |
574 | This code is with the rest of the prologue (at the end of the |
575 | function), so we have to skip it to get to the first real | |
576 | instruction at the start of the function. */ | |
c5aa993b | 577 | |
c906108c SS |
578 | pos = codestream_tell (); |
579 | for (i = 0; i < 6; i++) | |
580 | { | |
581 | op = codestream_get (); | |
c5aa993b | 582 | if (pic_pat[i] != op) |
c906108c SS |
583 | break; |
584 | } | |
585 | if (i == 6) | |
586 | { | |
587 | unsigned char buf[4]; | |
588 | long delta = 6; | |
589 | ||
590 | op = codestream_get (); | |
c5aa993b | 591 | if (op == 0x89) /* movl %ebx, x(%ebp) */ |
c906108c SS |
592 | { |
593 | op = codestream_get (); | |
c5aa993b | 594 | if (op == 0x5d) /* one byte offset from %ebp */ |
c906108c SS |
595 | { |
596 | delta += 3; | |
597 | codestream_read (buf, 1); | |
598 | } | |
c5aa993b | 599 | else if (op == 0x9d) /* four byte offset from %ebp */ |
c906108c SS |
600 | { |
601 | delta += 6; | |
602 | codestream_read (buf, 4); | |
603 | } | |
c5aa993b JM |
604 | else /* unexpected instruction */ |
605 | delta = -1; | |
606 | op = codestream_get (); | |
c906108c | 607 | } |
c5aa993b JM |
608 | /* addl y,%ebx */ |
609 | if (delta > 0 && op == 0x81 && codestream_get () == 0xc3) | |
c906108c | 610 | { |
c5aa993b | 611 | pos += delta + 6; |
c906108c SS |
612 | } |
613 | } | |
614 | codestream_seek (pos); | |
c5aa993b | 615 | |
c906108c | 616 | i386_follow_jump (); |
c5aa993b | 617 | |
c906108c SS |
618 | return (codestream_tell ()); |
619 | } | |
620 | ||
621 | void | |
622 | i386_push_dummy_frame () | |
623 | { | |
624 | CORE_ADDR sp = read_register (SP_REGNUM); | |
625 | int regnum; | |
626 | char regbuf[MAX_REGISTER_RAW_SIZE]; | |
c5aa993b | 627 | |
c906108c SS |
628 | sp = push_word (sp, read_register (PC_REGNUM)); |
629 | sp = push_word (sp, read_register (FP_REGNUM)); | |
630 | write_register (FP_REGNUM, sp); | |
631 | for (regnum = 0; regnum < NUM_REGS; regnum++) | |
632 | { | |
633 | read_register_gen (regnum, regbuf); | |
634 | sp = push_bytes (sp, regbuf, REGISTER_RAW_SIZE (regnum)); | |
635 | } | |
636 | write_register (SP_REGNUM, sp); | |
637 | } | |
638 | ||
639 | void | |
640 | i386_pop_frame () | |
641 | { | |
642 | struct frame_info *frame = get_current_frame (); | |
643 | CORE_ADDR fp; | |
644 | int regnum; | |
c906108c | 645 | char regbuf[MAX_REGISTER_RAW_SIZE]; |
c5aa993b | 646 | |
c906108c | 647 | fp = FRAME_FP (frame); |
1211c4e4 AC |
648 | i386_frame_init_saved_regs (frame); |
649 | ||
c5aa993b | 650 | for (regnum = 0; regnum < NUM_REGS; regnum++) |
c906108c SS |
651 | { |
652 | CORE_ADDR adr; | |
1211c4e4 | 653 | adr = frame->saved_regs[regnum]; |
c906108c SS |
654 | if (adr) |
655 | { | |
656 | read_memory (adr, regbuf, REGISTER_RAW_SIZE (regnum)); | |
657 | write_register_bytes (REGISTER_BYTE (regnum), regbuf, | |
658 | REGISTER_RAW_SIZE (regnum)); | |
659 | } | |
660 | } | |
661 | write_register (FP_REGNUM, read_memory_integer (fp, 4)); | |
662 | write_register (PC_REGNUM, read_memory_integer (fp + 4, 4)); | |
663 | write_register (SP_REGNUM, fp + 8); | |
664 | flush_cached_frames (); | |
665 | } | |
666 | ||
667 | #ifdef GET_LONGJMP_TARGET | |
668 | ||
669 | /* Figure out where the longjmp will land. Slurp the args out of the stack. | |
670 | We expect the first arg to be a pointer to the jmp_buf structure from which | |
671 | we extract the pc (JB_PC) that we will land at. The pc is copied into PC. | |
672 | This routine returns true on success. */ | |
673 | ||
674 | int | |
c5aa993b | 675 | get_longjmp_target (pc) |
c906108c SS |
676 | CORE_ADDR *pc; |
677 | { | |
678 | char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT]; | |
679 | CORE_ADDR sp, jb_addr; | |
680 | ||
681 | sp = read_register (SP_REGNUM); | |
682 | ||
c5aa993b | 683 | if (target_read_memory (sp + SP_ARG0, /* Offset of first arg on stack */ |
c906108c SS |
684 | buf, |
685 | TARGET_PTR_BIT / TARGET_CHAR_BIT)) | |
686 | return 0; | |
687 | ||
688 | jb_addr = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT); | |
689 | ||
690 | if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf, | |
691 | TARGET_PTR_BIT / TARGET_CHAR_BIT)) | |
692 | return 0; | |
693 | ||
694 | *pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT); | |
695 | ||
696 | return 1; | |
697 | } | |
698 | ||
699 | #endif /* GET_LONGJMP_TARGET */ | |
700 | ||
1a309862 MK |
701 | /* These registers are used for returning integers (and on some |
702 | targets also for returning `struct' and `union' values when their | |
703 | size and alignment match an integer type. */ | |
704 | #define LOW_RETURN_REGNUM 0 /* %eax */ | |
705 | #define HIGH_RETURN_REGNUM 2 /* %edx */ | |
706 | ||
707 | /* Extract from an array REGBUF containing the (raw) register state, a | |
708 | function return value of TYPE, and copy that, in virtual format, | |
709 | into VALBUF. */ | |
710 | ||
c906108c | 711 | void |
1a309862 | 712 | i386_extract_return_value (struct type *type, char *regbuf, char *valbuf) |
c906108c | 713 | { |
1a309862 MK |
714 | int len = TYPE_LENGTH (type); |
715 | ||
c5aa993b | 716 | if (TYPE_CODE_FLT == TYPE_CODE (type)) |
c906108c | 717 | { |
1a309862 MK |
718 | if (NUM_FREGS == 0) |
719 | { | |
720 | warning ("Cannot find floating-point return value."); | |
721 | memset (valbuf, 0, len); | |
722 | } | |
723 | ||
724 | /* Floating-point return values can be found in %st(0). */ | |
725 | if (len == TARGET_LONG_DOUBLE_BIT / TARGET_CHAR_BIT | |
726 | && TARGET_LONG_DOUBLE_FORMAT == &floatformat_i387_ext) | |
727 | { | |
728 | /* Copy straight over, but take care of the padding. */ | |
729 | memcpy (valbuf, ®buf[REGISTER_BYTE (FP0_REGNUM)], | |
730 | FPU_REG_RAW_SIZE); | |
731 | memset (valbuf + FPU_REG_RAW_SIZE, 0, len - FPU_REG_RAW_SIZE); | |
732 | } | |
733 | else | |
734 | { | |
735 | /* Convert the extended floating-point number found in | |
736 | %st(0) to the desired type. This is probably not exactly | |
737 | how it would happen on the target itself, but it is the | |
738 | best we can do. */ | |
739 | DOUBLEST val; | |
740 | floatformat_to_doublest (&floatformat_i387_ext, | |
741 | ®buf[REGISTER_BYTE (FP0_REGNUM)], &val); | |
742 | store_floating (valbuf, TYPE_LENGTH (type), val); | |
743 | } | |
c906108c SS |
744 | } |
745 | else | |
c5aa993b | 746 | { |
d4f3574e SS |
747 | int low_size = REGISTER_RAW_SIZE (LOW_RETURN_REGNUM); |
748 | int high_size = REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM); | |
749 | ||
750 | if (len <= low_size) | |
1a309862 | 751 | memcpy (valbuf, ®buf[REGISTER_BYTE (LOW_RETURN_REGNUM)], len); |
d4f3574e SS |
752 | else if (len <= (low_size + high_size)) |
753 | { | |
754 | memcpy (valbuf, | |
1a309862 | 755 | ®buf[REGISTER_BYTE (LOW_RETURN_REGNUM)], low_size); |
d4f3574e | 756 | memcpy (valbuf + low_size, |
1a309862 | 757 | ®buf[REGISTER_BYTE (HIGH_RETURN_REGNUM)], len - low_size); |
d4f3574e SS |
758 | } |
759 | else | |
1a309862 | 760 | internal_error ("Cannot extract return value of %d bytes long.", len); |
c906108c SS |
761 | } |
762 | } | |
763 | ||
ac27f131 MK |
764 | /* Convert data from raw format for register REGNUM in buffer FROM to |
765 | virtual format with type TYPE in buffer TO. In principle both | |
766 | formats are identical except that the virtual format has two extra | |
767 | bytes appended that aren't used. We set these to zero. */ | |
768 | ||
769 | void | |
770 | i386_register_convert_to_virtual (int regnum, struct type *type, | |
771 | char *from, char *to) | |
772 | { | |
773 | /* Copy straight over, but take care of the padding. */ | |
774 | memcpy (to, from, FPU_REG_RAW_SIZE); | |
775 | memset (to + FPU_REG_RAW_SIZE, 0, TYPE_LENGTH (type) - FPU_REG_RAW_SIZE); | |
776 | } | |
777 | ||
778 | /* Convert data from virtual format with type TYPE in buffer FROM to | |
779 | raw format for register REGNUM in buffer TO. Simply omit the two | |
780 | unused bytes. */ | |
781 | ||
782 | void | |
783 | i386_register_convert_to_raw (struct type *type, int regnum, | |
784 | char *from, char *to) | |
785 | { | |
786 | memcpy (to, from, FPU_REG_RAW_SIZE); | |
787 | } | |
788 | ||
789 | \f | |
c906108c SS |
790 | #ifdef I386V4_SIGTRAMP_SAVED_PC |
791 | /* Get saved user PC for sigtramp from the pushed ucontext on the stack | |
792 | for all three variants of SVR4 sigtramps. */ | |
793 | ||
794 | CORE_ADDR | |
795 | i386v4_sigtramp_saved_pc (frame) | |
796 | struct frame_info *frame; | |
797 | { | |
798 | CORE_ADDR saved_pc_offset = 4; | |
799 | char *name = NULL; | |
800 | ||
801 | find_pc_partial_function (frame->pc, &name, NULL, NULL); | |
802 | if (name) | |
803 | { | |
804 | if (STREQ (name, "_sigreturn")) | |
805 | saved_pc_offset = 132 + 14 * 4; | |
806 | else if (STREQ (name, "_sigacthandler")) | |
807 | saved_pc_offset = 80 + 14 * 4; | |
808 | else if (STREQ (name, "sigvechandler")) | |
809 | saved_pc_offset = 120 + 14 * 4; | |
810 | } | |
811 | ||
812 | if (frame->next) | |
813 | return read_memory_integer (frame->next->frame + saved_pc_offset, 4); | |
814 | return read_memory_integer (read_register (SP_REGNUM) + saved_pc_offset, 4); | |
815 | } | |
816 | #endif /* I386V4_SIGTRAMP_SAVED_PC */ | |
817 | ||
a0b3c4fd | 818 | |
c906108c SS |
819 | #ifdef STATIC_TRANSFORM_NAME |
820 | /* SunPRO encodes the static variables. This is not related to C++ mangling, | |
821 | it is done for C too. */ | |
822 | ||
823 | char * | |
824 | sunpro_static_transform_name (name) | |
825 | char *name; | |
826 | { | |
827 | char *p; | |
828 | if (IS_STATIC_TRANSFORM_NAME (name)) | |
829 | { | |
830 | /* For file-local statics there will be a period, a bunch | |
c5aa993b JM |
831 | of junk (the contents of which match a string given in the |
832 | N_OPT), a period and the name. For function-local statics | |
833 | there will be a bunch of junk (which seems to change the | |
834 | second character from 'A' to 'B'), a period, the name of the | |
835 | function, and the name. So just skip everything before the | |
836 | last period. */ | |
c906108c SS |
837 | p = strrchr (name, '.'); |
838 | if (p != NULL) | |
839 | name = p + 1; | |
840 | } | |
841 | return name; | |
842 | } | |
843 | #endif /* STATIC_TRANSFORM_NAME */ | |
844 | ||
845 | ||
846 | ||
847 | /* Stuff for WIN32 PE style DLL's but is pretty generic really. */ | |
848 | ||
849 | CORE_ADDR | |
850 | skip_trampoline_code (pc, name) | |
851 | CORE_ADDR pc; | |
852 | char *name; | |
853 | { | |
c5aa993b | 854 | if (pc && read_memory_unsigned_integer (pc, 2) == 0x25ff) /* jmp *(dest) */ |
c906108c | 855 | { |
c5aa993b | 856 | unsigned long indirect = read_memory_unsigned_integer (pc + 2, 4); |
c906108c | 857 | struct minimal_symbol *indsym = |
c5aa993b JM |
858 | indirect ? lookup_minimal_symbol_by_pc (indirect) : 0; |
859 | char *symname = indsym ? SYMBOL_NAME (indsym) : 0; | |
c906108c | 860 | |
c5aa993b | 861 | if (symname) |
c906108c | 862 | { |
c5aa993b JM |
863 | if (strncmp (symname, "__imp_", 6) == 0 |
864 | || strncmp (symname, "_imp_", 5) == 0) | |
c906108c SS |
865 | return name ? 1 : read_memory_unsigned_integer (indirect, 4); |
866 | } | |
867 | } | |
868 | return 0; /* not a trampoline */ | |
869 | } | |
870 | ||
871 | static int | |
872 | gdb_print_insn_i386 (memaddr, info) | |
873 | bfd_vma memaddr; | |
c5aa993b | 874 | disassemble_info *info; |
c906108c SS |
875 | { |
876 | if (disassembly_flavor == att_flavor) | |
877 | return print_insn_i386_att (memaddr, info); | |
878 | else if (disassembly_flavor == intel_flavor) | |
879 | return print_insn_i386_intel (memaddr, info); | |
7a292a7a SS |
880 | /* Never reached - disassembly_flavour is always either att_flavor |
881 | or intel_flavor */ | |
882 | abort (); | |
883 | } | |
884 | ||
885 | /* If the disassembly mode is intel, we have to also switch the | |
886 | bfd mach_type. This function is run in the set disassembly_flavor | |
887 | command, and does that. */ | |
888 | ||
889 | static void | |
890 | set_disassembly_flavor_sfunc (args, from_tty, c) | |
891 | char *args; | |
892 | int from_tty; | |
893 | struct cmd_list_element *c; | |
894 | { | |
895 | set_disassembly_flavor (); | |
7a292a7a SS |
896 | } |
897 | ||
898 | static void | |
899 | set_disassembly_flavor () | |
900 | { | |
901 | if (disassembly_flavor == att_flavor) | |
902 | set_architecture_from_arch_mach (bfd_arch_i386, bfd_mach_i386_i386); | |
903 | else if (disassembly_flavor == intel_flavor) | |
904 | set_architecture_from_arch_mach (bfd_arch_i386, bfd_mach_i386_i386_intel_syntax); | |
c906108c SS |
905 | } |
906 | ||
2acceee2 | 907 | |
c906108c SS |
908 | void |
909 | _initialize_i386_tdep () | |
910 | { | |
917317f4 JM |
911 | /* Initialize the table saying where each register starts in the |
912 | register file. */ | |
913 | { | |
914 | int i, offset; | |
915 | ||
916 | offset = 0; | |
917 | for (i = 0; i < MAX_NUM_REGS; i++) | |
918 | { | |
919 | i386_register_byte[i] = offset; | |
920 | offset += i386_register_raw_size[i]; | |
921 | } | |
922 | } | |
923 | ||
924 | /* Initialize the table of virtual register sizes. */ | |
925 | { | |
926 | int i; | |
927 | ||
928 | for (i = 0; i < MAX_NUM_REGS; i++) | |
929 | i386_register_virtual_size[i] = TYPE_LENGTH (REGISTER_VIRTUAL_TYPE (i)); | |
930 | } | |
c5aa993b | 931 | |
c906108c SS |
932 | tm_print_insn = gdb_print_insn_i386; |
933 | tm_print_insn_info.mach = bfd_lookup_arch (bfd_arch_i386, 0)->mach; | |
934 | ||
935 | /* Add the variable that controls the disassembly flavor */ | |
917317f4 JM |
936 | { |
937 | struct cmd_list_element *new_cmd; | |
7a292a7a | 938 | |
917317f4 JM |
939 | new_cmd = add_set_enum_cmd ("disassembly-flavor", no_class, |
940 | valid_flavors, | |
1ed2a135 | 941 | &disassembly_flavor, |
917317f4 | 942 | "Set the disassembly flavor, the valid values are \"att\" and \"intel\", \ |
c906108c | 943 | and the default value is \"att\".", |
917317f4 JM |
944 | &setlist); |
945 | new_cmd->function.sfunc = set_disassembly_flavor_sfunc; | |
946 | add_show_from_set (new_cmd, &showlist); | |
947 | } | |
c5aa993b | 948 | |
7a292a7a SS |
949 | /* Finally, initialize the disassembly flavor to the default given |
950 | in the disassembly_flavor variable */ | |
c906108c | 951 | |
7a292a7a | 952 | set_disassembly_flavor (); |
c906108c | 953 | } |