Commit | Line | Data |
---|---|---|
c906108c | 1 | /* Intel 386 target-dependent stuff. |
b6ba6518 KB |
2 | Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, |
3 | 1998, 1999, 2000, 2001 | |
c906108c SS |
4 | Free Software Foundation, Inc. |
5 | ||
c5aa993b | 6 | This file is part of GDB. |
c906108c | 7 | |
c5aa993b JM |
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. | |
c906108c | 12 | |
c5aa993b JM |
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. | |
c906108c | 17 | |
c5aa993b JM |
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. */ | |
c906108c SS |
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" | |
b4a20239 | 33 | #include "arch-utils.h" |
4e052eda | 34 | #include "regcache.h" |
c906108c | 35 | |
917317f4 JM |
36 | /* i386_register_byte[i] is the offset into the register file of the |
37 | start of register number i. We initialize this from | |
38 | i386_register_raw_size. */ | |
39 | int i386_register_byte[MAX_NUM_REGS]; | |
40 | ||
ceb4951f JB |
41 | /* i386_register_raw_size[i] is the number of bytes of storage in |
42 | GDB's register array occupied by register i. */ | |
917317f4 JM |
43 | int i386_register_raw_size[MAX_NUM_REGS] = { |
44 | 4, 4, 4, 4, | |
45 | 4, 4, 4, 4, | |
46 | 4, 4, 4, 4, | |
47 | 4, 4, 4, 4, | |
48 | 10, 10, 10, 10, | |
49 | 10, 10, 10, 10, | |
50 | 4, 4, 4, 4, | |
51 | 4, 4, 4, 4, | |
52 | 16, 16, 16, 16, | |
53 | 16, 16, 16, 16, | |
54 | 4 | |
55 | }; | |
56 | ||
57 | /* i386_register_virtual_size[i] is the size in bytes of the virtual | |
58 | type of register i. */ | |
59 | int i386_register_virtual_size[MAX_NUM_REGS]; | |
fc338970 | 60 | \f |
917317f4 | 61 | |
fc338970 MK |
62 | /* This is the variable that is set with "set disassembly-flavor", and |
63 | its legitimate values. */ | |
53904c9e AC |
64 | static const char att_flavor[] = "att"; |
65 | static const char intel_flavor[] = "intel"; | |
66 | static const char *valid_flavors[] = | |
c5aa993b | 67 | { |
c906108c SS |
68 | att_flavor, |
69 | intel_flavor, | |
70 | NULL | |
71 | }; | |
53904c9e | 72 | static const char *disassembly_flavor = att_flavor; |
c906108c | 73 | |
fc338970 MK |
74 | /* This is used to keep the bfd arch_info in sync with the disassembly |
75 | flavor. */ | |
a14ed312 KB |
76 | static void set_disassembly_flavor_sfunc (char *, int, |
77 | struct cmd_list_element *); | |
78 | static void set_disassembly_flavor (void); | |
fc338970 MK |
79 | \f |
80 | ||
81 | /* Stdio style buffering was used to minimize calls to ptrace, but | |
82 | this buffering did not take into account that the code section | |
83 | being accessed may not be an even number of buffers long (even if | |
84 | the buffer is only sizeof(int) long). In cases where the code | |
85 | section size happened to be a non-integral number of buffers long, | |
86 | attempting to read the last buffer would fail. Simply using | |
87 | target_read_memory and ignoring errors, rather than read_memory, is | |
88 | not the correct solution, since legitimate access errors would then | |
89 | be totally ignored. To properly handle this situation and continue | |
90 | to use buffering would require that this code be able to determine | |
91 | the minimum code section size granularity (not the alignment of the | |
92 | section itself, since the actual failing case that pointed out this | |
93 | problem had a section alignment of 4 but was not a multiple of 4 | |
94 | bytes long), on a target by target basis, and then adjust it's | |
95 | buffer size accordingly. This is messy, but potentially feasible. | |
96 | It probably needs the bfd library's help and support. For now, the | |
97 | buffer size is set to 1. (FIXME -fnf) */ | |
98 | ||
99 | #define CODESTREAM_BUFSIZ 1 /* Was sizeof(int), see note above. */ | |
c906108c SS |
100 | static CORE_ADDR codestream_next_addr; |
101 | static CORE_ADDR codestream_addr; | |
102 | static unsigned char codestream_buf[CODESTREAM_BUFSIZ]; | |
103 | static int codestream_off; | |
104 | static int codestream_cnt; | |
105 | ||
106 | #define codestream_tell() (codestream_addr + codestream_off) | |
fc338970 MK |
107 | #define codestream_peek() \ |
108 | (codestream_cnt == 0 ? \ | |
109 | codestream_fill(1) : codestream_buf[codestream_off]) | |
110 | #define codestream_get() \ | |
111 | (codestream_cnt-- == 0 ? \ | |
112 | codestream_fill(0) : codestream_buf[codestream_off++]) | |
c906108c | 113 | |
c5aa993b | 114 | static unsigned char |
fba45db2 | 115 | codestream_fill (int peek_flag) |
c906108c SS |
116 | { |
117 | codestream_addr = codestream_next_addr; | |
118 | codestream_next_addr += CODESTREAM_BUFSIZ; | |
119 | codestream_off = 0; | |
120 | codestream_cnt = CODESTREAM_BUFSIZ; | |
121 | read_memory (codestream_addr, (char *) codestream_buf, CODESTREAM_BUFSIZ); | |
c5aa993b | 122 | |
c906108c | 123 | if (peek_flag) |
c5aa993b | 124 | return (codestream_peek ()); |
c906108c | 125 | else |
c5aa993b | 126 | return (codestream_get ()); |
c906108c SS |
127 | } |
128 | ||
129 | static void | |
fba45db2 | 130 | codestream_seek (CORE_ADDR place) |
c906108c SS |
131 | { |
132 | codestream_next_addr = place / CODESTREAM_BUFSIZ; | |
133 | codestream_next_addr *= CODESTREAM_BUFSIZ; | |
134 | codestream_cnt = 0; | |
135 | codestream_fill (1); | |
c5aa993b | 136 | while (codestream_tell () != place) |
c906108c SS |
137 | codestream_get (); |
138 | } | |
139 | ||
140 | static void | |
fba45db2 | 141 | codestream_read (unsigned char *buf, int count) |
c906108c SS |
142 | { |
143 | unsigned char *p; | |
144 | int i; | |
145 | p = buf; | |
146 | for (i = 0; i < count; i++) | |
147 | *p++ = codestream_get (); | |
148 | } | |
fc338970 | 149 | \f |
c906108c | 150 | |
fc338970 | 151 | /* If the next instruction is a jump, move to its target. */ |
c906108c SS |
152 | |
153 | static void | |
fba45db2 | 154 | i386_follow_jump (void) |
c906108c SS |
155 | { |
156 | unsigned char buf[4]; | |
157 | long delta; | |
158 | ||
159 | int data16; | |
160 | CORE_ADDR pos; | |
161 | ||
162 | pos = codestream_tell (); | |
163 | ||
164 | data16 = 0; | |
165 | if (codestream_peek () == 0x66) | |
166 | { | |
167 | codestream_get (); | |
168 | data16 = 1; | |
169 | } | |
170 | ||
171 | switch (codestream_get ()) | |
172 | { | |
173 | case 0xe9: | |
fc338970 | 174 | /* Relative jump: if data16 == 0, disp32, else disp16. */ |
c906108c SS |
175 | if (data16) |
176 | { | |
177 | codestream_read (buf, 2); | |
178 | delta = extract_signed_integer (buf, 2); | |
179 | ||
fc338970 MK |
180 | /* Include the size of the jmp instruction (including the |
181 | 0x66 prefix). */ | |
c5aa993b | 182 | pos += delta + 4; |
c906108c SS |
183 | } |
184 | else | |
185 | { | |
186 | codestream_read (buf, 4); | |
187 | delta = extract_signed_integer (buf, 4); | |
188 | ||
189 | pos += delta + 5; | |
190 | } | |
191 | break; | |
192 | case 0xeb: | |
fc338970 | 193 | /* Relative jump, disp8 (ignore data16). */ |
c906108c SS |
194 | codestream_read (buf, 1); |
195 | /* Sign-extend it. */ | |
196 | delta = extract_signed_integer (buf, 1); | |
197 | ||
198 | pos += delta + 2; | |
199 | break; | |
200 | } | |
201 | codestream_seek (pos); | |
202 | } | |
203 | ||
fc338970 MK |
204 | /* Find & return the amount a local space allocated, and advance the |
205 | codestream to the first register push (if any). | |
206 | ||
207 | If the entry sequence doesn't make sense, return -1, and leave | |
208 | codestream pointer at a random spot. */ | |
c906108c SS |
209 | |
210 | static long | |
fba45db2 | 211 | i386_get_frame_setup (CORE_ADDR pc) |
c906108c SS |
212 | { |
213 | unsigned char op; | |
214 | ||
215 | codestream_seek (pc); | |
216 | ||
217 | i386_follow_jump (); | |
218 | ||
219 | op = codestream_get (); | |
220 | ||
221 | if (op == 0x58) /* popl %eax */ | |
222 | { | |
fc338970 MK |
223 | /* This function must start with |
224 | ||
225 | popl %eax 0x58 | |
226 | xchgl %eax, (%esp) 0x87 0x04 0x24 | |
227 | or xchgl %eax, 0(%esp) 0x87 0x44 0x24 0x00 | |
228 | ||
229 | (the System V compiler puts out the second `xchg' | |
230 | instruction, and the assembler doesn't try to optimize it, so | |
231 | the 'sib' form gets generated). This sequence is used to get | |
232 | the address of the return buffer for a function that returns | |
233 | a structure. */ | |
c906108c SS |
234 | int pos; |
235 | unsigned char buf[4]; | |
fc338970 MK |
236 | static unsigned char proto1[3] = { 0x87, 0x04, 0x24 }; |
237 | static unsigned char proto2[4] = { 0x87, 0x44, 0x24, 0x00 }; | |
238 | ||
c906108c SS |
239 | pos = codestream_tell (); |
240 | codestream_read (buf, 4); | |
241 | if (memcmp (buf, proto1, 3) == 0) | |
242 | pos += 3; | |
243 | else if (memcmp (buf, proto2, 4) == 0) | |
244 | pos += 4; | |
245 | ||
246 | codestream_seek (pos); | |
fc338970 | 247 | op = codestream_get (); /* Update next opcode. */ |
c906108c SS |
248 | } |
249 | ||
250 | if (op == 0x68 || op == 0x6a) | |
251 | { | |
fc338970 MK |
252 | /* This function may start with |
253 | ||
254 | pushl constant | |
255 | call _probe | |
256 | addl $4, %esp | |
257 | ||
258 | followed by | |
259 | ||
260 | pushl %ebp | |
261 | ||
262 | etc. */ | |
c906108c SS |
263 | int pos; |
264 | unsigned char buf[8]; | |
265 | ||
fc338970 | 266 | /* Skip past the `pushl' instruction; it has either a one-byte |
c906108c SS |
267 | or a four-byte operand, depending on the opcode. */ |
268 | pos = codestream_tell (); | |
269 | if (op == 0x68) | |
270 | pos += 4; | |
271 | else | |
272 | pos += 1; | |
273 | codestream_seek (pos); | |
274 | ||
fc338970 MK |
275 | /* Read the following 8 bytes, which should be "call _probe" (6 |
276 | bytes) followed by "addl $4,%esp" (2 bytes). */ | |
c906108c SS |
277 | codestream_read (buf, sizeof (buf)); |
278 | if (buf[0] == 0xe8 && buf[6] == 0xc4 && buf[7] == 0x4) | |
279 | pos += sizeof (buf); | |
280 | codestream_seek (pos); | |
fc338970 | 281 | op = codestream_get (); /* Update next opcode. */ |
c906108c SS |
282 | } |
283 | ||
284 | if (op == 0x55) /* pushl %ebp */ | |
c5aa993b | 285 | { |
fc338970 | 286 | /* Check for "movl %esp, %ebp" -- can be written in two ways. */ |
c906108c SS |
287 | switch (codestream_get ()) |
288 | { | |
289 | case 0x8b: | |
290 | if (codestream_get () != 0xec) | |
fc338970 | 291 | return -1; |
c906108c SS |
292 | break; |
293 | case 0x89: | |
294 | if (codestream_get () != 0xe5) | |
fc338970 | 295 | return -1; |
c906108c SS |
296 | break; |
297 | default: | |
fc338970 | 298 | return -1; |
c906108c | 299 | } |
fc338970 MK |
300 | /* Check for stack adjustment |
301 | ||
302 | subl $XXX, %esp | |
303 | ||
304 | NOTE: You can't subtract a 16 bit immediate from a 32 bit | |
305 | reg, so we don't have to worry about a data16 prefix. */ | |
c906108c SS |
306 | op = codestream_peek (); |
307 | if (op == 0x83) | |
308 | { | |
fc338970 | 309 | /* `subl' with 8 bit immediate. */ |
c906108c SS |
310 | codestream_get (); |
311 | if (codestream_get () != 0xec) | |
fc338970 | 312 | /* Some instruction starting with 0x83 other than `subl'. */ |
c906108c SS |
313 | { |
314 | codestream_seek (codestream_tell () - 2); | |
315 | return 0; | |
316 | } | |
fc338970 MK |
317 | /* `subl' with signed byte immediate (though it wouldn't |
318 | make sense to be negative). */ | |
c5aa993b | 319 | return (codestream_get ()); |
c906108c SS |
320 | } |
321 | else if (op == 0x81) | |
322 | { | |
323 | char buf[4]; | |
fc338970 | 324 | /* Maybe it is `subl' with a 32 bit immedediate. */ |
c5aa993b | 325 | codestream_get (); |
c906108c | 326 | if (codestream_get () != 0xec) |
fc338970 | 327 | /* Some instruction starting with 0x81 other than `subl'. */ |
c906108c SS |
328 | { |
329 | codestream_seek (codestream_tell () - 2); | |
330 | return 0; | |
331 | } | |
fc338970 | 332 | /* It is `subl' with a 32 bit immediate. */ |
c5aa993b | 333 | codestream_read ((unsigned char *) buf, 4); |
c906108c SS |
334 | return extract_signed_integer (buf, 4); |
335 | } | |
336 | else | |
337 | { | |
fc338970 | 338 | return 0; |
c906108c SS |
339 | } |
340 | } | |
341 | else if (op == 0xc8) | |
342 | { | |
343 | char buf[2]; | |
fc338970 | 344 | /* `enter' with 16 bit unsigned immediate. */ |
c5aa993b | 345 | codestream_read ((unsigned char *) buf, 2); |
fc338970 | 346 | codestream_get (); /* Flush final byte of enter instruction. */ |
c906108c SS |
347 | return extract_unsigned_integer (buf, 2); |
348 | } | |
349 | return (-1); | |
350 | } | |
351 | ||
352 | /* Return number of args passed to a frame. | |
353 | Can return -1, meaning no way to tell. */ | |
354 | ||
355 | int | |
fba45db2 | 356 | i386_frame_num_args (struct frame_info *fi) |
c906108c SS |
357 | { |
358 | #if 1 | |
359 | return -1; | |
360 | #else | |
361 | /* This loses because not only might the compiler not be popping the | |
fc338970 MK |
362 | args right after the function call, it might be popping args from |
363 | both this call and a previous one, and we would say there are | |
364 | more args than there really are. */ | |
c906108c | 365 | |
c5aa993b JM |
366 | int retpc; |
367 | unsigned char op; | |
c906108c SS |
368 | struct frame_info *pfi; |
369 | ||
fc338970 | 370 | /* On the i386, the instruction following the call could be: |
c906108c SS |
371 | popl %ecx - one arg |
372 | addl $imm, %esp - imm/4 args; imm may be 8 or 32 bits | |
fc338970 | 373 | anything else - zero args. */ |
c906108c SS |
374 | |
375 | int frameless; | |
376 | ||
392a587b | 377 | frameless = FRAMELESS_FUNCTION_INVOCATION (fi); |
c906108c | 378 | if (frameless) |
fc338970 MK |
379 | /* In the absence of a frame pointer, GDB doesn't get correct |
380 | values for nameless arguments. Return -1, so it doesn't print | |
381 | any nameless arguments. */ | |
c906108c SS |
382 | return -1; |
383 | ||
c5aa993b | 384 | pfi = get_prev_frame (fi); |
c906108c SS |
385 | if (pfi == 0) |
386 | { | |
fc338970 MK |
387 | /* NOTE: This can happen if we are looking at the frame for |
388 | main, because FRAME_CHAIN_VALID won't let us go into start. | |
389 | If we have debugging symbols, that's not really a big deal; | |
390 | it just means it will only show as many arguments to main as | |
391 | are declared. */ | |
c906108c SS |
392 | return -1; |
393 | } | |
394 | else | |
395 | { | |
c5aa993b JM |
396 | retpc = pfi->pc; |
397 | op = read_memory_integer (retpc, 1); | |
fc338970 | 398 | if (op == 0x59) /* pop %ecx */ |
c5aa993b | 399 | return 1; |
c906108c SS |
400 | else if (op == 0x83) |
401 | { | |
c5aa993b JM |
402 | op = read_memory_integer (retpc + 1, 1); |
403 | if (op == 0xc4) | |
404 | /* addl $<signed imm 8 bits>, %esp */ | |
405 | return (read_memory_integer (retpc + 2, 1) & 0xff) / 4; | |
c906108c SS |
406 | else |
407 | return 0; | |
408 | } | |
fc338970 MK |
409 | else if (op == 0x81) /* `add' with 32 bit immediate. */ |
410 | { | |
c5aa993b JM |
411 | op = read_memory_integer (retpc + 1, 1); |
412 | if (op == 0xc4) | |
413 | /* addl $<imm 32>, %esp */ | |
414 | return read_memory_integer (retpc + 2, 4) / 4; | |
c906108c SS |
415 | else |
416 | return 0; | |
417 | } | |
418 | else | |
419 | { | |
420 | return 0; | |
421 | } | |
422 | } | |
423 | #endif | |
424 | } | |
425 | ||
fc338970 MK |
426 | /* Parse the first few instructions the function to see what registers |
427 | were stored. | |
428 | ||
429 | We handle these cases: | |
430 | ||
431 | The startup sequence can be at the start of the function, or the | |
432 | function can start with a branch to startup code at the end. | |
433 | ||
434 | %ebp can be set up with either the 'enter' instruction, or "pushl | |
435 | %ebp, movl %esp, %ebp" (`enter' is too slow to be useful, but was | |
436 | once used in the System V compiler). | |
437 | ||
438 | Local space is allocated just below the saved %ebp by either the | |
439 | 'enter' instruction, or by "subl $<size>, %esp". 'enter' has a 16 | |
440 | bit unsigned argument for space to allocate, and the 'addl' | |
441 | instruction could have either a signed byte, or 32 bit immediate. | |
442 | ||
443 | Next, the registers used by this function are pushed. With the | |
444 | System V compiler they will always be in the order: %edi, %esi, | |
445 | %ebx (and sometimes a harmless bug causes it to also save but not | |
446 | restore %eax); however, the code below is willing to see the pushes | |
447 | in any order, and will handle up to 8 of them. | |
448 | ||
449 | If the setup sequence is at the end of the function, then the next | |
450 | instruction will be a branch back to the start. */ | |
c906108c SS |
451 | |
452 | void | |
fba45db2 | 453 | i386_frame_init_saved_regs (struct frame_info *fip) |
c906108c SS |
454 | { |
455 | long locals = -1; | |
456 | unsigned char op; | |
457 | CORE_ADDR dummy_bottom; | |
fc338970 | 458 | CORE_ADDR addr; |
c906108c SS |
459 | CORE_ADDR pc; |
460 | int i; | |
c5aa993b | 461 | |
1211c4e4 AC |
462 | if (fip->saved_regs) |
463 | return; | |
464 | ||
465 | frame_saved_regs_zalloc (fip); | |
c5aa993b | 466 | |
fc338970 MK |
467 | /* If the frame is the end of a dummy, compute where the beginning |
468 | would be. */ | |
c906108c | 469 | dummy_bottom = fip->frame - 4 - REGISTER_BYTES - CALL_DUMMY_LENGTH; |
c5aa993b | 470 | |
fc338970 | 471 | /* Check if the PC points in the stack, in a dummy frame. */ |
c5aa993b | 472 | if (dummy_bottom <= fip->pc && fip->pc <= fip->frame) |
c906108c | 473 | { |
fc338970 MK |
474 | /* All registers were saved by push_call_dummy. */ |
475 | addr = fip->frame; | |
c5aa993b | 476 | for (i = 0; i < NUM_REGS; i++) |
c906108c | 477 | { |
fc338970 MK |
478 | addr -= REGISTER_RAW_SIZE (i); |
479 | fip->saved_regs[i] = addr; | |
c906108c SS |
480 | } |
481 | return; | |
482 | } | |
c5aa993b | 483 | |
c906108c SS |
484 | pc = get_pc_function_start (fip->pc); |
485 | if (pc != 0) | |
486 | locals = i386_get_frame_setup (pc); | |
c5aa993b JM |
487 | |
488 | if (locals >= 0) | |
c906108c | 489 | { |
fc338970 | 490 | addr = fip->frame - 4 - locals; |
c5aa993b | 491 | for (i = 0; i < 8; i++) |
c906108c SS |
492 | { |
493 | op = codestream_get (); | |
494 | if (op < 0x50 || op > 0x57) | |
495 | break; | |
496 | #ifdef I386_REGNO_TO_SYMMETRY | |
497 | /* Dynix uses different internal numbering. Ick. */ | |
fc338970 | 498 | fip->saved_regs[I386_REGNO_TO_SYMMETRY (op - 0x50)] = addr; |
c906108c | 499 | #else |
fc338970 | 500 | fip->saved_regs[op - 0x50] = addr; |
c906108c | 501 | #endif |
fc338970 | 502 | addr -= 4; |
c906108c SS |
503 | } |
504 | } | |
c5aa993b | 505 | |
1211c4e4 AC |
506 | fip->saved_regs[PC_REGNUM] = fip->frame + 4; |
507 | fip->saved_regs[FP_REGNUM] = fip->frame; | |
c906108c SS |
508 | } |
509 | ||
fc338970 | 510 | /* Return PC of first real instruction. */ |
c906108c SS |
511 | |
512 | int | |
fba45db2 | 513 | i386_skip_prologue (int pc) |
c906108c SS |
514 | { |
515 | unsigned char op; | |
516 | int i; | |
c5aa993b | 517 | static unsigned char pic_pat[6] = |
fc338970 MK |
518 | { 0xe8, 0, 0, 0, 0, /* call 0x0 */ |
519 | 0x5b, /* popl %ebx */ | |
c5aa993b | 520 | }; |
c906108c | 521 | CORE_ADDR pos; |
c5aa993b | 522 | |
c906108c SS |
523 | if (i386_get_frame_setup (pc) < 0) |
524 | return (pc); | |
c5aa993b | 525 | |
fc338970 MK |
526 | /* Found valid frame setup -- codestream now points to start of push |
527 | instructions for saving registers. */ | |
c5aa993b | 528 | |
fc338970 | 529 | /* Skip over register saves. */ |
c906108c SS |
530 | for (i = 0; i < 8; i++) |
531 | { | |
532 | op = codestream_peek (); | |
fc338970 | 533 | /* Break if not `pushl' instrunction. */ |
c5aa993b | 534 | if (op < 0x50 || op > 0x57) |
c906108c SS |
535 | break; |
536 | codestream_get (); | |
537 | } | |
538 | ||
fc338970 MK |
539 | /* The native cc on SVR4 in -K PIC mode inserts the following code |
540 | to get the address of the global offset table (GOT) into register | |
541 | %ebx | |
542 | ||
543 | call 0x0 | |
544 | popl %ebx | |
545 | movl %ebx,x(%ebp) (optional) | |
546 | addl y,%ebx | |
547 | ||
c906108c SS |
548 | This code is with the rest of the prologue (at the end of the |
549 | function), so we have to skip it to get to the first real | |
550 | instruction at the start of the function. */ | |
c5aa993b | 551 | |
c906108c SS |
552 | pos = codestream_tell (); |
553 | for (i = 0; i < 6; i++) | |
554 | { | |
555 | op = codestream_get (); | |
c5aa993b | 556 | if (pic_pat[i] != op) |
c906108c SS |
557 | break; |
558 | } | |
559 | if (i == 6) | |
560 | { | |
561 | unsigned char buf[4]; | |
562 | long delta = 6; | |
563 | ||
564 | op = codestream_get (); | |
c5aa993b | 565 | if (op == 0x89) /* movl %ebx, x(%ebp) */ |
c906108c SS |
566 | { |
567 | op = codestream_get (); | |
fc338970 | 568 | if (op == 0x5d) /* One byte offset from %ebp. */ |
c906108c SS |
569 | { |
570 | delta += 3; | |
571 | codestream_read (buf, 1); | |
572 | } | |
fc338970 | 573 | else if (op == 0x9d) /* Four byte offset from %ebp. */ |
c906108c SS |
574 | { |
575 | delta += 6; | |
576 | codestream_read (buf, 4); | |
577 | } | |
fc338970 | 578 | else /* Unexpected instruction. */ |
c5aa993b JM |
579 | delta = -1; |
580 | op = codestream_get (); | |
c906108c | 581 | } |
c5aa993b JM |
582 | /* addl y,%ebx */ |
583 | if (delta > 0 && op == 0x81 && codestream_get () == 0xc3) | |
c906108c | 584 | { |
c5aa993b | 585 | pos += delta + 6; |
c906108c SS |
586 | } |
587 | } | |
588 | codestream_seek (pos); | |
c5aa993b | 589 | |
c906108c | 590 | i386_follow_jump (); |
c5aa993b | 591 | |
c906108c SS |
592 | return (codestream_tell ()); |
593 | } | |
594 | ||
595 | void | |
fba45db2 | 596 | i386_push_dummy_frame (void) |
c906108c SS |
597 | { |
598 | CORE_ADDR sp = read_register (SP_REGNUM); | |
599 | int regnum; | |
600 | char regbuf[MAX_REGISTER_RAW_SIZE]; | |
c5aa993b | 601 | |
c906108c SS |
602 | sp = push_word (sp, read_register (PC_REGNUM)); |
603 | sp = push_word (sp, read_register (FP_REGNUM)); | |
604 | write_register (FP_REGNUM, sp); | |
605 | for (regnum = 0; regnum < NUM_REGS; regnum++) | |
606 | { | |
607 | read_register_gen (regnum, regbuf); | |
608 | sp = push_bytes (sp, regbuf, REGISTER_RAW_SIZE (regnum)); | |
609 | } | |
610 | write_register (SP_REGNUM, sp); | |
611 | } | |
612 | ||
a7769679 MK |
613 | /* Insert the (relative) function address into the call sequence |
614 | stored at DYMMY. */ | |
615 | ||
616 | void | |
617 | i386_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs, | |
618 | value_ptr *args, struct type *type, int gcc_p) | |
619 | { | |
620 | int from, to, delta, loc; | |
621 | ||
622 | loc = (int)(read_register (SP_REGNUM) - CALL_DUMMY_LENGTH); | |
623 | from = loc + 5; | |
624 | to = (int)(fun); | |
625 | delta = to - from; | |
626 | ||
627 | *((char *)(dummy) + 1) = (delta & 0xff); | |
628 | *((char *)(dummy) + 2) = ((delta >> 8) & 0xff); | |
629 | *((char *)(dummy) + 3) = ((delta >> 16) & 0xff); | |
630 | *((char *)(dummy) + 4) = ((delta >> 24) & 0xff); | |
631 | } | |
632 | ||
c906108c | 633 | void |
fba45db2 | 634 | i386_pop_frame (void) |
c906108c SS |
635 | { |
636 | struct frame_info *frame = get_current_frame (); | |
637 | CORE_ADDR fp; | |
638 | int regnum; | |
c906108c | 639 | char regbuf[MAX_REGISTER_RAW_SIZE]; |
c5aa993b | 640 | |
c906108c | 641 | fp = FRAME_FP (frame); |
1211c4e4 AC |
642 | i386_frame_init_saved_regs (frame); |
643 | ||
c5aa993b | 644 | for (regnum = 0; regnum < NUM_REGS; regnum++) |
c906108c | 645 | { |
fc338970 MK |
646 | CORE_ADDR addr; |
647 | addr = frame->saved_regs[regnum]; | |
648 | if (addr) | |
c906108c | 649 | { |
fc338970 | 650 | read_memory (addr, regbuf, REGISTER_RAW_SIZE (regnum)); |
c906108c SS |
651 | write_register_bytes (REGISTER_BYTE (regnum), regbuf, |
652 | REGISTER_RAW_SIZE (regnum)); | |
653 | } | |
654 | } | |
655 | write_register (FP_REGNUM, read_memory_integer (fp, 4)); | |
656 | write_register (PC_REGNUM, read_memory_integer (fp + 4, 4)); | |
657 | write_register (SP_REGNUM, fp + 8); | |
658 | flush_cached_frames (); | |
659 | } | |
fc338970 | 660 | \f |
c906108c SS |
661 | |
662 | #ifdef GET_LONGJMP_TARGET | |
663 | ||
fc338970 MK |
664 | /* Figure out where the longjmp will land. Slurp the args out of the |
665 | stack. We expect the first arg to be a pointer to the jmp_buf | |
666 | structure from which we extract the pc (JB_PC) that we will land | |
667 | at. The pc is copied into PC. This routine returns true on | |
668 | success. */ | |
c906108c SS |
669 | |
670 | int | |
fba45db2 | 671 | get_longjmp_target (CORE_ADDR *pc) |
c906108c SS |
672 | { |
673 | char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT]; | |
674 | CORE_ADDR sp, jb_addr; | |
675 | ||
676 | sp = read_register (SP_REGNUM); | |
677 | ||
fc338970 | 678 | if (target_read_memory (sp + SP_ARG0, /* Offset of first arg on stack. */ |
c906108c SS |
679 | buf, |
680 | TARGET_PTR_BIT / TARGET_CHAR_BIT)) | |
681 | return 0; | |
682 | ||
683 | jb_addr = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT); | |
684 | ||
685 | if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf, | |
686 | TARGET_PTR_BIT / TARGET_CHAR_BIT)) | |
687 | return 0; | |
688 | ||
689 | *pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT); | |
690 | ||
691 | return 1; | |
692 | } | |
693 | ||
694 | #endif /* GET_LONGJMP_TARGET */ | |
fc338970 | 695 | \f |
c906108c | 696 | |
1a309862 MK |
697 | /* These registers are used for returning integers (and on some |
698 | targets also for returning `struct' and `union' values when their | |
ef9dff19 | 699 | size and alignment match an integer type). */ |
1a309862 MK |
700 | #define LOW_RETURN_REGNUM 0 /* %eax */ |
701 | #define HIGH_RETURN_REGNUM 2 /* %edx */ | |
702 | ||
703 | /* Extract from an array REGBUF containing the (raw) register state, a | |
704 | function return value of TYPE, and copy that, in virtual format, | |
705 | into VALBUF. */ | |
706 | ||
c906108c | 707 | void |
1a309862 | 708 | i386_extract_return_value (struct type *type, char *regbuf, char *valbuf) |
c906108c | 709 | { |
1a309862 MK |
710 | int len = TYPE_LENGTH (type); |
711 | ||
c5aa993b | 712 | if (TYPE_CODE_FLT == TYPE_CODE (type)) |
c906108c | 713 | { |
1a309862 MK |
714 | if (NUM_FREGS == 0) |
715 | { | |
716 | warning ("Cannot find floating-point return value."); | |
717 | memset (valbuf, 0, len); | |
ef9dff19 | 718 | return; |
1a309862 MK |
719 | } |
720 | ||
721 | /* Floating-point return values can be found in %st(0). */ | |
722 | if (len == TARGET_LONG_DOUBLE_BIT / TARGET_CHAR_BIT | |
723 | && TARGET_LONG_DOUBLE_FORMAT == &floatformat_i387_ext) | |
724 | { | |
725 | /* Copy straight over, but take care of the padding. */ | |
726 | memcpy (valbuf, ®buf[REGISTER_BYTE (FP0_REGNUM)], | |
727 | FPU_REG_RAW_SIZE); | |
728 | memset (valbuf + FPU_REG_RAW_SIZE, 0, len - FPU_REG_RAW_SIZE); | |
729 | } | |
730 | else | |
731 | { | |
732 | /* Convert the extended floating-point number found in | |
733 | %st(0) to the desired type. This is probably not exactly | |
734 | how it would happen on the target itself, but it is the | |
735 | best we can do. */ | |
736 | DOUBLEST val; | |
737 | floatformat_to_doublest (&floatformat_i387_ext, | |
738 | ®buf[REGISTER_BYTE (FP0_REGNUM)], &val); | |
739 | store_floating (valbuf, TYPE_LENGTH (type), val); | |
740 | } | |
c906108c SS |
741 | } |
742 | else | |
c5aa993b | 743 | { |
d4f3574e SS |
744 | int low_size = REGISTER_RAW_SIZE (LOW_RETURN_REGNUM); |
745 | int high_size = REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM); | |
746 | ||
747 | if (len <= low_size) | |
1a309862 | 748 | memcpy (valbuf, ®buf[REGISTER_BYTE (LOW_RETURN_REGNUM)], len); |
d4f3574e SS |
749 | else if (len <= (low_size + high_size)) |
750 | { | |
751 | memcpy (valbuf, | |
1a309862 | 752 | ®buf[REGISTER_BYTE (LOW_RETURN_REGNUM)], low_size); |
d4f3574e | 753 | memcpy (valbuf + low_size, |
1a309862 | 754 | ®buf[REGISTER_BYTE (HIGH_RETURN_REGNUM)], len - low_size); |
d4f3574e SS |
755 | } |
756 | else | |
8e65ff28 AC |
757 | internal_error (__FILE__, __LINE__, |
758 | "Cannot extract return value of %d bytes long.", len); | |
c906108c SS |
759 | } |
760 | } | |
761 | ||
ef9dff19 MK |
762 | /* Write into the appropriate registers a function return value stored |
763 | in VALBUF of type TYPE, given in virtual format. */ | |
764 | ||
765 | void | |
766 | i386_store_return_value (struct type *type, char *valbuf) | |
767 | { | |
768 | int len = TYPE_LENGTH (type); | |
769 | ||
770 | if (TYPE_CODE_FLT == TYPE_CODE (type)) | |
771 | { | |
772 | if (NUM_FREGS == 0) | |
773 | { | |
774 | warning ("Cannot set floating-point return value."); | |
775 | return; | |
776 | } | |
777 | ||
778 | /* Floating-point return values can be found in %st(0). */ | |
779 | if (len == TARGET_LONG_DOUBLE_BIT / TARGET_CHAR_BIT | |
780 | && TARGET_LONG_DOUBLE_FORMAT == &floatformat_i387_ext) | |
781 | { | |
782 | /* Copy straight over. */ | |
783 | write_register_bytes (REGISTER_BYTE (FP0_REGNUM), valbuf, | |
784 | FPU_REG_RAW_SIZE); | |
785 | } | |
786 | else | |
787 | { | |
788 | char buf[FPU_REG_RAW_SIZE]; | |
789 | DOUBLEST val; | |
790 | ||
791 | /* Convert the value found in VALBUF to the extended | |
792 | floating point format used by the FPU. This is probably | |
793 | not exactly how it would happen on the target itself, but | |
794 | it is the best we can do. */ | |
795 | val = extract_floating (valbuf, TYPE_LENGTH (type)); | |
796 | floatformat_from_doublest (&floatformat_i387_ext, &val, buf); | |
797 | write_register_bytes (REGISTER_BYTE (FP0_REGNUM), buf, | |
798 | FPU_REG_RAW_SIZE); | |
799 | } | |
800 | } | |
801 | else | |
802 | { | |
803 | int low_size = REGISTER_RAW_SIZE (LOW_RETURN_REGNUM); | |
804 | int high_size = REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM); | |
805 | ||
806 | if (len <= low_size) | |
807 | write_register_bytes (REGISTER_BYTE (LOW_RETURN_REGNUM), valbuf, len); | |
808 | else if (len <= (low_size + high_size)) | |
809 | { | |
810 | write_register_bytes (REGISTER_BYTE (LOW_RETURN_REGNUM), | |
811 | valbuf, low_size); | |
812 | write_register_bytes (REGISTER_BYTE (HIGH_RETURN_REGNUM), | |
813 | valbuf + low_size, len - low_size); | |
814 | } | |
815 | else | |
8e65ff28 AC |
816 | internal_error (__FILE__, __LINE__, |
817 | "Cannot store return value of %d bytes long.", len); | |
ef9dff19 MK |
818 | } |
819 | } | |
fc338970 | 820 | \f |
ef9dff19 | 821 | |
ac27f131 MK |
822 | /* Convert data from raw format for register REGNUM in buffer FROM to |
823 | virtual format with type TYPE in buffer TO. In principle both | |
824 | formats are identical except that the virtual format has two extra | |
825 | bytes appended that aren't used. We set these to zero. */ | |
826 | ||
827 | void | |
828 | i386_register_convert_to_virtual (int regnum, struct type *type, | |
829 | char *from, char *to) | |
830 | { | |
831 | /* Copy straight over, but take care of the padding. */ | |
832 | memcpy (to, from, FPU_REG_RAW_SIZE); | |
833 | memset (to + FPU_REG_RAW_SIZE, 0, TYPE_LENGTH (type) - FPU_REG_RAW_SIZE); | |
834 | } | |
835 | ||
836 | /* Convert data from virtual format with type TYPE in buffer FROM to | |
837 | raw format for register REGNUM in buffer TO. Simply omit the two | |
838 | unused bytes. */ | |
839 | ||
840 | void | |
841 | i386_register_convert_to_raw (struct type *type, int regnum, | |
842 | char *from, char *to) | |
843 | { | |
844 | memcpy (to, from, FPU_REG_RAW_SIZE); | |
845 | } | |
ac27f131 | 846 | \f |
fc338970 | 847 | |
c906108c | 848 | #ifdef I386V4_SIGTRAMP_SAVED_PC |
fc338970 MK |
849 | /* Get saved user PC for sigtramp from the pushed ucontext on the |
850 | stack for all three variants of SVR4 sigtramps. */ | |
c906108c SS |
851 | |
852 | CORE_ADDR | |
fba45db2 | 853 | i386v4_sigtramp_saved_pc (struct frame_info *frame) |
c906108c SS |
854 | { |
855 | CORE_ADDR saved_pc_offset = 4; | |
856 | char *name = NULL; | |
857 | ||
858 | find_pc_partial_function (frame->pc, &name, NULL, NULL); | |
859 | if (name) | |
860 | { | |
861 | if (STREQ (name, "_sigreturn")) | |
862 | saved_pc_offset = 132 + 14 * 4; | |
863 | else if (STREQ (name, "_sigacthandler")) | |
864 | saved_pc_offset = 80 + 14 * 4; | |
865 | else if (STREQ (name, "sigvechandler")) | |
866 | saved_pc_offset = 120 + 14 * 4; | |
867 | } | |
868 | ||
869 | if (frame->next) | |
870 | return read_memory_integer (frame->next->frame + saved_pc_offset, 4); | |
871 | return read_memory_integer (read_register (SP_REGNUM) + saved_pc_offset, 4); | |
872 | } | |
873 | #endif /* I386V4_SIGTRAMP_SAVED_PC */ | |
fc338970 | 874 | \f |
a0b3c4fd | 875 | |
c906108c | 876 | #ifdef STATIC_TRANSFORM_NAME |
fc338970 MK |
877 | /* SunPRO encodes the static variables. This is not related to C++ |
878 | mangling, it is done for C too. */ | |
c906108c SS |
879 | |
880 | char * | |
fba45db2 | 881 | sunpro_static_transform_name (char *name) |
c906108c SS |
882 | { |
883 | char *p; | |
884 | if (IS_STATIC_TRANSFORM_NAME (name)) | |
885 | { | |
fc338970 MK |
886 | /* For file-local statics there will be a period, a bunch of |
887 | junk (the contents of which match a string given in the | |
c5aa993b JM |
888 | N_OPT), a period and the name. For function-local statics |
889 | there will be a bunch of junk (which seems to change the | |
890 | second character from 'A' to 'B'), a period, the name of the | |
891 | function, and the name. So just skip everything before the | |
892 | last period. */ | |
c906108c SS |
893 | p = strrchr (name, '.'); |
894 | if (p != NULL) | |
895 | name = p + 1; | |
896 | } | |
897 | return name; | |
898 | } | |
899 | #endif /* STATIC_TRANSFORM_NAME */ | |
fc338970 | 900 | \f |
c906108c | 901 | |
fc338970 | 902 | /* Stuff for WIN32 PE style DLL's but is pretty generic really. */ |
c906108c SS |
903 | |
904 | CORE_ADDR | |
fba45db2 | 905 | skip_trampoline_code (CORE_ADDR pc, char *name) |
c906108c | 906 | { |
fc338970 | 907 | if (pc && read_memory_unsigned_integer (pc, 2) == 0x25ff) /* jmp *(dest) */ |
c906108c | 908 | { |
c5aa993b | 909 | unsigned long indirect = read_memory_unsigned_integer (pc + 2, 4); |
c906108c | 910 | struct minimal_symbol *indsym = |
fc338970 | 911 | indirect ? lookup_minimal_symbol_by_pc (indirect) : 0; |
c5aa993b | 912 | char *symname = indsym ? SYMBOL_NAME (indsym) : 0; |
c906108c | 913 | |
c5aa993b | 914 | if (symname) |
c906108c | 915 | { |
c5aa993b JM |
916 | if (strncmp (symname, "__imp_", 6) == 0 |
917 | || strncmp (symname, "_imp_", 5) == 0) | |
c906108c SS |
918 | return name ? 1 : read_memory_unsigned_integer (indirect, 4); |
919 | } | |
920 | } | |
fc338970 | 921 | return 0; /* Not a trampoline. */ |
c906108c | 922 | } |
fc338970 MK |
923 | \f |
924 | ||
925 | /* We have two flavours of disassembly. The machinery on this page | |
926 | deals with switching between those. */ | |
c906108c SS |
927 | |
928 | static int | |
fba45db2 | 929 | gdb_print_insn_i386 (bfd_vma memaddr, disassemble_info *info) |
c906108c SS |
930 | { |
931 | if (disassembly_flavor == att_flavor) | |
932 | return print_insn_i386_att (memaddr, info); | |
933 | else if (disassembly_flavor == intel_flavor) | |
934 | return print_insn_i386_intel (memaddr, info); | |
fc338970 MK |
935 | /* Never reached -- disassembly_flavour is always either att_flavor |
936 | or intel_flavor. */ | |
e1e9e218 | 937 | internal_error (__FILE__, __LINE__, "failed internal consistency check"); |
7a292a7a SS |
938 | } |
939 | ||
fc338970 MK |
940 | /* If the disassembly mode is intel, we have to also switch the bfd |
941 | mach_type. This function is run in the set disassembly_flavor | |
7a292a7a SS |
942 | command, and does that. */ |
943 | ||
944 | static void | |
fba45db2 KB |
945 | set_disassembly_flavor_sfunc (char *args, int from_tty, |
946 | struct cmd_list_element *c) | |
7a292a7a SS |
947 | { |
948 | set_disassembly_flavor (); | |
7a292a7a SS |
949 | } |
950 | ||
951 | static void | |
fba45db2 | 952 | set_disassembly_flavor (void) |
7a292a7a SS |
953 | { |
954 | if (disassembly_flavor == att_flavor) | |
955 | set_architecture_from_arch_mach (bfd_arch_i386, bfd_mach_i386_i386); | |
956 | else if (disassembly_flavor == intel_flavor) | |
fc338970 MK |
957 | set_architecture_from_arch_mach (bfd_arch_i386, |
958 | bfd_mach_i386_i386_intel_syntax); | |
c906108c | 959 | } |
fc338970 | 960 | \f |
2acceee2 | 961 | |
28e9e0f0 MK |
962 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
963 | void _initialize_i386_tdep (void); | |
964 | ||
c906108c | 965 | void |
fba45db2 | 966 | _initialize_i386_tdep (void) |
c906108c | 967 | { |
917317f4 JM |
968 | /* Initialize the table saying where each register starts in the |
969 | register file. */ | |
970 | { | |
971 | int i, offset; | |
972 | ||
973 | offset = 0; | |
974 | for (i = 0; i < MAX_NUM_REGS; i++) | |
975 | { | |
976 | i386_register_byte[i] = offset; | |
977 | offset += i386_register_raw_size[i]; | |
978 | } | |
979 | } | |
980 | ||
981 | /* Initialize the table of virtual register sizes. */ | |
982 | { | |
983 | int i; | |
984 | ||
985 | for (i = 0; i < MAX_NUM_REGS; i++) | |
986 | i386_register_virtual_size[i] = TYPE_LENGTH (REGISTER_VIRTUAL_TYPE (i)); | |
987 | } | |
c5aa993b | 988 | |
c906108c SS |
989 | tm_print_insn = gdb_print_insn_i386; |
990 | tm_print_insn_info.mach = bfd_lookup_arch (bfd_arch_i386, 0)->mach; | |
991 | ||
fc338970 | 992 | /* Add the variable that controls the disassembly flavor. */ |
917317f4 JM |
993 | { |
994 | struct cmd_list_element *new_cmd; | |
7a292a7a | 995 | |
917317f4 JM |
996 | new_cmd = add_set_enum_cmd ("disassembly-flavor", no_class, |
997 | valid_flavors, | |
1ed2a135 | 998 | &disassembly_flavor, |
fc338970 MK |
999 | "\ |
1000 | Set the disassembly flavor, the valid values are \"att\" and \"intel\", \ | |
c906108c | 1001 | and the default value is \"att\".", |
917317f4 JM |
1002 | &setlist); |
1003 | new_cmd->function.sfunc = set_disassembly_flavor_sfunc; | |
1004 | add_show_from_set (new_cmd, &showlist); | |
1005 | } | |
c5aa993b | 1006 | |
7a292a7a | 1007 | /* Finally, initialize the disassembly flavor to the default given |
fc338970 | 1008 | in the disassembly_flavor variable. */ |
7a292a7a | 1009 | set_disassembly_flavor (); |
c906108c | 1010 | } |