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[/] [or1k/] [trunk/] [gdb-5.3/] [gdb/] [i386-tdep.c] - Blame information for rev 1767

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1 1181 sfurman
/* Intel 386 target-dependent stuff.
2
 
3
   Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
4
   1997, 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
5
 
6
   This file is part of GDB.
7
 
8
   This program is free software; you can redistribute it and/or modify
9
   it under the terms of the GNU General Public License as published by
10
   the Free Software Foundation; either version 2 of the License, or
11
   (at your option) any later version.
12
 
13
   This program is distributed in the hope that it will be useful,
14
   but WITHOUT ANY WARRANTY; without even the implied warranty of
15
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16
   GNU General Public License for more details.
17
 
18
   You should have received a copy of the GNU General Public License
19
   along with this program; if not, write to the Free Software
20
   Foundation, Inc., 59 Temple Place - Suite 330,
21
   Boston, MA 02111-1307, USA.  */
22
 
23
#include "defs.h"
24
#include "gdb_string.h"
25
#include "frame.h"
26
#include "inferior.h"
27
#include "gdbcore.h"
28
#include "objfiles.h"
29
#include "target.h"
30
#include "floatformat.h"
31
#include "symfile.h"
32
#include "symtab.h"
33
#include "gdbcmd.h"
34
#include "command.h"
35
#include "arch-utils.h"
36
#include "regcache.h"
37
#include "doublest.h"
38
#include "value.h"
39
#include "gdb_assert.h"
40
 
41
#include "i386-tdep.h"
42
#include "i387-tdep.h"
43
 
44
/* Names of the registers.  The first 10 registers match the register
45
   numbering scheme used by GCC for stabs and DWARF.  */
46
static char *i386_register_names[] =
47
{
48
  "eax",   "ecx",    "edx",   "ebx",
49
  "esp",   "ebp",    "esi",   "edi",
50
  "eip",   "eflags", "cs",    "ss",
51
  "ds",    "es",     "fs",    "gs",
52
  "st0",   "st1",    "st2",   "st3",
53
  "st4",   "st5",    "st6",   "st7",
54
  "fctrl", "fstat",  "ftag",  "fiseg",
55
  "fioff", "foseg",  "fooff", "fop",
56
  "xmm0",  "xmm1",   "xmm2",  "xmm3",
57
  "xmm4",  "xmm5",   "xmm6",  "xmm7",
58
  "mxcsr"
59
};
60
 
61
/* MMX registers.  */
62
 
63
static char *i386_mmx_names[] =
64
{
65
  "mm0", "mm1", "mm2", "mm3",
66
  "mm4", "mm5", "mm6", "mm7"
67
};
68
static const int mmx_num_regs = (sizeof (i386_mmx_names)
69
                                 / sizeof (i386_mmx_names[0]));
70
#define MM0_REGNUM (NUM_REGS)
71
 
72
static int
73
mmx_regnum_p (int reg)
74
{
75
  return (reg >= MM0_REGNUM && reg < MM0_REGNUM + mmx_num_regs);
76
}
77
 
78
/* Return the name of register REG.  */
79
 
80
const char *
81
i386_register_name (int reg)
82
{
83
  if (reg < 0)
84
    return NULL;
85
  if (mmx_regnum_p (reg))
86
    return i386_mmx_names[reg - MM0_REGNUM];
87
  if (reg >= sizeof (i386_register_names) / sizeof (*i386_register_names))
88
    return NULL;
89
 
90
  return i386_register_names[reg];
91
}
92
 
93
/* Convert stabs register number REG to the appropriate register
94
   number used by GDB.  */
95
 
96
static int
97
i386_stab_reg_to_regnum (int reg)
98
{
99
  /* This implements what GCC calls the "default" register map.  */
100
  if (reg >= 0 && reg <= 7)
101
    {
102
      /* General registers.  */
103
      return reg;
104
    }
105
  else if (reg >= 12 && reg <= 19)
106
    {
107
      /* Floating-point registers.  */
108
      return reg - 12 + FP0_REGNUM;
109
    }
110
  else if (reg >= 21 && reg <= 28)
111
    {
112
      /* SSE registers.  */
113
      return reg - 21 + XMM0_REGNUM;
114
    }
115
  else if (reg >= 29 && reg <= 36)
116
    {
117
      /* MMX registers.  */
118
      return reg - 29 + MM0_REGNUM;
119
    }
120
 
121
  /* This will hopefully provoke a warning.  */
122
  return NUM_REGS + NUM_PSEUDO_REGS;
123
}
124
 
125
/* Convert DWARF register number REG to the appropriate register
126
   number used by GDB.  */
127
 
128
static int
129
i386_dwarf_reg_to_regnum (int reg)
130
{
131
  /* The DWARF register numbering includes %eip and %eflags, and
132
     numbers the floating point registers differently.  */
133
  if (reg >= 0 && reg <= 9)
134
    {
135
      /* General registers.  */
136
      return reg;
137
    }
138
  else if (reg >= 11 && reg <= 18)
139
    {
140
      /* Floating-point registers.  */
141
      return reg - 11 + FP0_REGNUM;
142
    }
143
  else if (reg >= 21)
144
    {
145
      /* The SSE and MMX registers have identical numbers as in stabs.  */
146
      return i386_stab_reg_to_regnum (reg);
147
    }
148
 
149
  /* This will hopefully provoke a warning.  */
150
  return NUM_REGS + NUM_PSEUDO_REGS;
151
}
152
 
153
 
154
/* This is the variable that is set with "set disassembly-flavor", and
155
   its legitimate values.  */
156
static const char att_flavor[] = "att";
157
static const char intel_flavor[] = "intel";
158
static const char *valid_flavors[] =
159
{
160
  att_flavor,
161
  intel_flavor,
162
  NULL
163
};
164
static const char *disassembly_flavor = att_flavor;
165
 
166
/* Stdio style buffering was used to minimize calls to ptrace, but
167
   this buffering did not take into account that the code section
168
   being accessed may not be an even number of buffers long (even if
169
   the buffer is only sizeof(int) long).  In cases where the code
170
   section size happened to be a non-integral number of buffers long,
171
   attempting to read the last buffer would fail.  Simply using
172
   target_read_memory and ignoring errors, rather than read_memory, is
173
   not the correct solution, since legitimate access errors would then
174
   be totally ignored.  To properly handle this situation and continue
175
   to use buffering would require that this code be able to determine
176
   the minimum code section size granularity (not the alignment of the
177
   section itself, since the actual failing case that pointed out this
178
   problem had a section alignment of 4 but was not a multiple of 4
179
   bytes long), on a target by target basis, and then adjust it's
180
   buffer size accordingly.  This is messy, but potentially feasible.
181
   It probably needs the bfd library's help and support.  For now, the
182
   buffer size is set to 1.  (FIXME -fnf) */
183
 
184
#define CODESTREAM_BUFSIZ 1     /* Was sizeof(int), see note above.  */
185
static CORE_ADDR codestream_next_addr;
186
static CORE_ADDR codestream_addr;
187
static unsigned char codestream_buf[CODESTREAM_BUFSIZ];
188
static int codestream_off;
189
static int codestream_cnt;
190
 
191
#define codestream_tell() (codestream_addr + codestream_off)
192
#define codestream_peek() \
193
  (codestream_cnt == 0 ? \
194
   codestream_fill(1) : codestream_buf[codestream_off])
195
#define codestream_get() \
196
  (codestream_cnt-- == 0 ? \
197
   codestream_fill(0) : codestream_buf[codestream_off++])
198
 
199
static unsigned char
200
codestream_fill (int peek_flag)
201
{
202
  codestream_addr = codestream_next_addr;
203
  codestream_next_addr += CODESTREAM_BUFSIZ;
204
  codestream_off = 0;
205
  codestream_cnt = CODESTREAM_BUFSIZ;
206
  read_memory (codestream_addr, (char *) codestream_buf, CODESTREAM_BUFSIZ);
207
 
208
  if (peek_flag)
209
    return (codestream_peek ());
210
  else
211
    return (codestream_get ());
212
}
213
 
214
static void
215
codestream_seek (CORE_ADDR place)
216
{
217
  codestream_next_addr = place / CODESTREAM_BUFSIZ;
218
  codestream_next_addr *= CODESTREAM_BUFSIZ;
219
  codestream_cnt = 0;
220
  codestream_fill (1);
221
  while (codestream_tell () != place)
222
    codestream_get ();
223
}
224
 
225
static void
226
codestream_read (unsigned char *buf, int count)
227
{
228
  unsigned char *p;
229
  int i;
230
  p = buf;
231
  for (i = 0; i < count; i++)
232
    *p++ = codestream_get ();
233
}
234
 
235
 
236
/* If the next instruction is a jump, move to its target.  */
237
 
238
static void
239
i386_follow_jump (void)
240
{
241
  unsigned char buf[4];
242
  long delta;
243
 
244
  int data16;
245
  CORE_ADDR pos;
246
 
247
  pos = codestream_tell ();
248
 
249
  data16 = 0;
250
  if (codestream_peek () == 0x66)
251
    {
252
      codestream_get ();
253
      data16 = 1;
254
    }
255
 
256
  switch (codestream_get ())
257
    {
258
    case 0xe9:
259
      /* Relative jump: if data16 == 0, disp32, else disp16.  */
260
      if (data16)
261
        {
262
          codestream_read (buf, 2);
263
          delta = extract_signed_integer (buf, 2);
264
 
265
          /* Include the size of the jmp instruction (including the
266
             0x66 prefix).  */
267
          pos += delta + 4;
268
        }
269
      else
270
        {
271
          codestream_read (buf, 4);
272
          delta = extract_signed_integer (buf, 4);
273
 
274
          pos += delta + 5;
275
        }
276
      break;
277
    case 0xeb:
278
      /* Relative jump, disp8 (ignore data16).  */
279
      codestream_read (buf, 1);
280
      /* Sign-extend it.  */
281
      delta = extract_signed_integer (buf, 1);
282
 
283
      pos += delta + 2;
284
      break;
285
    }
286
  codestream_seek (pos);
287
}
288
 
289
/* Find & return the amount a local space allocated, and advance the
290
   codestream to the first register push (if any).
291
 
292
   If the entry sequence doesn't make sense, return -1, and leave
293
   codestream pointer at a random spot.  */
294
 
295
static long
296
i386_get_frame_setup (CORE_ADDR pc)
297
{
298
  unsigned char op;
299
 
300
  codestream_seek (pc);
301
 
302
  i386_follow_jump ();
303
 
304
  op = codestream_get ();
305
 
306
  if (op == 0x58)               /* popl %eax */
307
    {
308
      /* This function must start with
309
 
310
            popl %eax             0x58
311
            xchgl %eax, (%esp)    0x87 0x04 0x24
312
         or xchgl %eax, 0(%esp)   0x87 0x44 0x24 0x00
313
 
314
         (the System V compiler puts out the second `xchg'
315
         instruction, and the assembler doesn't try to optimize it, so
316
         the 'sib' form gets generated).  This sequence is used to get
317
         the address of the return buffer for a function that returns
318
         a structure.  */
319
      int pos;
320
      unsigned char buf[4];
321
      static unsigned char proto1[3] = { 0x87, 0x04, 0x24 };
322
      static unsigned char proto2[4] = { 0x87, 0x44, 0x24, 0x00 };
323
 
324
      pos = codestream_tell ();
325
      codestream_read (buf, 4);
326
      if (memcmp (buf, proto1, 3) == 0)
327
        pos += 3;
328
      else if (memcmp (buf, proto2, 4) == 0)
329
        pos += 4;
330
 
331
      codestream_seek (pos);
332
      op = codestream_get ();   /* Update next opcode.  */
333
    }
334
 
335
  if (op == 0x68 || op == 0x6a)
336
    {
337
      /* This function may start with
338
 
339
            pushl constant
340
            call _probe
341
            addl $4, %esp
342
 
343
         followed by
344
 
345
            pushl %ebp
346
 
347
         etc.  */
348
      int pos;
349
      unsigned char buf[8];
350
 
351
      /* Skip past the `pushl' instruction; it has either a one-byte
352
         or a four-byte operand, depending on the opcode.  */
353
      pos = codestream_tell ();
354
      if (op == 0x68)
355
        pos += 4;
356
      else
357
        pos += 1;
358
      codestream_seek (pos);
359
 
360
      /* Read the following 8 bytes, which should be "call _probe" (6
361
         bytes) followed by "addl $4,%esp" (2 bytes).  */
362
      codestream_read (buf, sizeof (buf));
363
      if (buf[0] == 0xe8 && buf[6] == 0xc4 && buf[7] == 0x4)
364
        pos += sizeof (buf);
365
      codestream_seek (pos);
366
      op = codestream_get ();   /* Update next opcode.  */
367
    }
368
 
369
  if (op == 0x55)               /* pushl %ebp */
370
    {
371
      /* Check for "movl %esp, %ebp" -- can be written in two ways.  */
372
      switch (codestream_get ())
373
        {
374
        case 0x8b:
375
          if (codestream_get () != 0xec)
376
            return -1;
377
          break;
378
        case 0x89:
379
          if (codestream_get () != 0xe5)
380
            return -1;
381
          break;
382
        default:
383
          return -1;
384
        }
385
      /* Check for stack adjustment
386
 
387
           subl $XXX, %esp
388
 
389
         NOTE: You can't subtract a 16 bit immediate from a 32 bit
390
         reg, so we don't have to worry about a data16 prefix.  */
391
      op = codestream_peek ();
392
      if (op == 0x83)
393
        {
394
          /* `subl' with 8 bit immediate.  */
395
          codestream_get ();
396
          if (codestream_get () != 0xec)
397
            /* Some instruction starting with 0x83 other than `subl'.  */
398
            {
399
              codestream_seek (codestream_tell () - 2);
400
              return 0;
401
            }
402
          /* `subl' with signed byte immediate (though it wouldn't
403
             make sense to be negative).  */
404
          return (codestream_get ());
405
        }
406
      else if (op == 0x81)
407
        {
408
          char buf[4];
409
          /* Maybe it is `subl' with a 32 bit immedediate.  */
410
          codestream_get ();
411
          if (codestream_get () != 0xec)
412
            /* Some instruction starting with 0x81 other than `subl'.  */
413
            {
414
              codestream_seek (codestream_tell () - 2);
415
              return 0;
416
            }
417
          /* It is `subl' with a 32 bit immediate.  */
418
          codestream_read ((unsigned char *) buf, 4);
419
          return extract_signed_integer (buf, 4);
420
        }
421
      else
422
        {
423
          return 0;
424
        }
425
    }
426
  else if (op == 0xc8)
427
    {
428
      char buf[2];
429
      /* `enter' with 16 bit unsigned immediate.  */
430
      codestream_read ((unsigned char *) buf, 2);
431
      codestream_get ();        /* Flush final byte of enter instruction.  */
432
      return extract_unsigned_integer (buf, 2);
433
    }
434
  return (-1);
435
}
436
 
437
/* Signal trampolines don't have a meaningful frame.  The frame
438
   pointer value we use is actually the frame pointer of the calling
439
   frame -- that is, the frame which was in progress when the signal
440
   trampoline was entered.  GDB mostly treats this frame pointer value
441
   as a magic cookie.  We detect the case of a signal trampoline by
442
   looking at the SIGNAL_HANDLER_CALLER field, which is set based on
443
   PC_IN_SIGTRAMP.
444
 
445
   When a signal trampoline is invoked from a frameless function, we
446
   essentially have two frameless functions in a row.  In this case,
447
   we use the same magic cookie for three frames in a row.  We detect
448
   this case by seeing whether the next frame has
449
   SIGNAL_HANDLER_CALLER set, and, if it does, checking whether the
450
   current frame is actually frameless.  In this case, we need to get
451
   the PC by looking at the SP register value stored in the signal
452
   context.
453
 
454
   This should work in most cases except in horrible situations where
455
   a signal occurs just as we enter a function but before the frame
456
   has been set up.  Incidentally, that's just what happens when we
457
   call a function from GDB with a signal pending (there's a test in
458
   the testsuite that makes this happen).  Therefore we pretend that
459
   we have a frameless function if we're stopped at the start of a
460
   function.  */
461
 
462
/* Return non-zero if we're dealing with a frameless signal, that is,
463
   a signal trampoline invoked from a frameless function.  */
464
 
465
static int
466
i386_frameless_signal_p (struct frame_info *frame)
467
{
468
  return (frame->next && frame->next->signal_handler_caller
469
          && (frameless_look_for_prologue (frame)
470
              || frame->pc == get_pc_function_start (frame->pc)));
471
}
472
 
473
/* Return the chain-pointer for FRAME.  In the case of the i386, the
474
   frame's nominal address is the address of a 4-byte word containing
475
   the calling frame's address.  */
476
 
477
static CORE_ADDR
478
i386_frame_chain (struct frame_info *frame)
479
{
480
  if (PC_IN_CALL_DUMMY (frame->pc, 0, 0))
481
    return frame->frame;
482
 
483
  if (frame->signal_handler_caller
484
      || i386_frameless_signal_p (frame))
485
    return frame->frame;
486
 
487
  if (! inside_entry_file (frame->pc))
488
    return read_memory_unsigned_integer (frame->frame, 4);
489
 
490
  return 0;
491
}
492
 
493
/* Determine whether the function invocation represented by FRAME does
494
   not have a from on the stack associated with it.  If it does not,
495
   return non-zero, otherwise return zero.  */
496
 
497
static int
498
i386_frameless_function_invocation (struct frame_info *frame)
499
{
500
  if (frame->signal_handler_caller)
501
    return 0;
502
 
503
  return frameless_look_for_prologue (frame);
504
}
505
 
506
/* Assuming FRAME is for a sigtramp routine, return the saved program
507
   counter.  */
508
 
509
static CORE_ADDR
510
i386_sigtramp_saved_pc (struct frame_info *frame)
511
{
512
  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
513
  CORE_ADDR addr;
514
 
515
  addr = tdep->sigcontext_addr (frame);
516
  return read_memory_unsigned_integer (addr + tdep->sc_pc_offset, 4);
517
}
518
 
519
/* Assuming FRAME is for a sigtramp routine, return the saved stack
520
   pointer.  */
521
 
522
static CORE_ADDR
523
i386_sigtramp_saved_sp (struct frame_info *frame)
524
{
525
  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
526
  CORE_ADDR addr;
527
 
528
  addr = tdep->sigcontext_addr (frame);
529
  return read_memory_unsigned_integer (addr + tdep->sc_sp_offset, 4);
530
}
531
 
532
/* Return the saved program counter for FRAME.  */
533
 
534
static CORE_ADDR
535
i386_frame_saved_pc (struct frame_info *frame)
536
{
537
  if (PC_IN_CALL_DUMMY (frame->pc, 0, 0))
538
    return generic_read_register_dummy (frame->pc, frame->frame,
539
                                        PC_REGNUM);
540
 
541
  if (frame->signal_handler_caller)
542
    return i386_sigtramp_saved_pc (frame);
543
 
544
  if (i386_frameless_signal_p (frame))
545
    {
546
      CORE_ADDR sp = i386_sigtramp_saved_sp (frame->next);
547
      return read_memory_unsigned_integer (sp, 4);
548
    }
549
 
550
  return read_memory_unsigned_integer (frame->frame + 4, 4);
551
}
552
 
553
/* Immediately after a function call, return the saved pc.  */
554
 
555
static CORE_ADDR
556
i386_saved_pc_after_call (struct frame_info *frame)
557
{
558
  if (frame->signal_handler_caller)
559
    return i386_sigtramp_saved_pc (frame);
560
 
561
  return read_memory_unsigned_integer (read_register (SP_REGNUM), 4);
562
}
563
 
564
/* Return number of args passed to a frame.
565
   Can return -1, meaning no way to tell.  */
566
 
567
static int
568
i386_frame_num_args (struct frame_info *fi)
569
{
570
#if 1
571
  return -1;
572
#else
573
  /* This loses because not only might the compiler not be popping the
574
     args right after the function call, it might be popping args from
575
     both this call and a previous one, and we would say there are
576
     more args than there really are.  */
577
 
578
  int retpc;
579
  unsigned char op;
580
  struct frame_info *pfi;
581
 
582
  /* On the i386, the instruction following the call could be:
583
     popl %ecx        -  one arg
584
     addl $imm, %esp  -  imm/4 args; imm may be 8 or 32 bits
585
     anything else    -  zero args.  */
586
 
587
  int frameless;
588
 
589
  frameless = FRAMELESS_FUNCTION_INVOCATION (fi);
590
  if (frameless)
591
    /* In the absence of a frame pointer, GDB doesn't get correct
592
       values for nameless arguments.  Return -1, so it doesn't print
593
       any nameless arguments.  */
594
    return -1;
595
 
596
  pfi = get_prev_frame (fi);
597
  if (pfi == 0)
598
    {
599
      /* NOTE: This can happen if we are looking at the frame for
600
         main, because FRAME_CHAIN_VALID won't let us go into start.
601
         If we have debugging symbols, that's not really a big deal;
602
         it just means it will only show as many arguments to main as
603
         are declared.  */
604
      return -1;
605
    }
606
  else
607
    {
608
      retpc = pfi->pc;
609
      op = read_memory_integer (retpc, 1);
610
      if (op == 0x59)           /* pop %ecx */
611
        return 1;
612
      else if (op == 0x83)
613
        {
614
          op = read_memory_integer (retpc + 1, 1);
615
          if (op == 0xc4)
616
            /* addl $<signed imm 8 bits>, %esp */
617
            return (read_memory_integer (retpc + 2, 1) & 0xff) / 4;
618
          else
619
            return 0;
620
        }
621
      else if (op == 0x81)      /* `add' with 32 bit immediate.  */
622
        {
623
          op = read_memory_integer (retpc + 1, 1);
624
          if (op == 0xc4)
625
            /* addl $<imm 32>, %esp */
626
            return read_memory_integer (retpc + 2, 4) / 4;
627
          else
628
            return 0;
629
        }
630
      else
631
        {
632
          return 0;
633
        }
634
    }
635
#endif
636
}
637
 
638
/* Parse the first few instructions the function to see what registers
639
   were stored.
640
 
641
   We handle these cases:
642
 
643
   The startup sequence can be at the start of the function, or the
644
   function can start with a branch to startup code at the end.
645
 
646
   %ebp can be set up with either the 'enter' instruction, or "pushl
647
   %ebp, movl %esp, %ebp" (`enter' is too slow to be useful, but was
648
   once used in the System V compiler).
649
 
650
   Local space is allocated just below the saved %ebp by either the
651
   'enter' instruction, or by "subl $<size>, %esp".  'enter' has a 16
652
   bit unsigned argument for space to allocate, and the 'addl'
653
   instruction could have either a signed byte, or 32 bit immediate.
654
 
655
   Next, the registers used by this function are pushed.  With the
656
   System V compiler they will always be in the order: %edi, %esi,
657
   %ebx (and sometimes a harmless bug causes it to also save but not
658
   restore %eax); however, the code below is willing to see the pushes
659
   in any order, and will handle up to 8 of them.
660
 
661
   If the setup sequence is at the end of the function, then the next
662
   instruction will be a branch back to the start.  */
663
 
664
static void
665
i386_frame_init_saved_regs (struct frame_info *fip)
666
{
667
  long locals = -1;
668
  unsigned char op;
669
  CORE_ADDR addr;
670
  CORE_ADDR pc;
671
  int i;
672
 
673
  if (fip->saved_regs)
674
    return;
675
 
676
  frame_saved_regs_zalloc (fip);
677
 
678
  pc = get_pc_function_start (fip->pc);
679
  if (pc != 0)
680
    locals = i386_get_frame_setup (pc);
681
 
682
  if (locals >= 0)
683
    {
684
      addr = fip->frame - 4 - locals;
685
      for (i = 0; i < 8; i++)
686
        {
687
          op = codestream_get ();
688
          if (op < 0x50 || op > 0x57)
689
            break;
690
#ifdef I386_REGNO_TO_SYMMETRY
691
          /* Dynix uses different internal numbering.  Ick.  */
692
          fip->saved_regs[I386_REGNO_TO_SYMMETRY (op - 0x50)] = addr;
693
#else
694
          fip->saved_regs[op - 0x50] = addr;
695
#endif
696
          addr -= 4;
697
        }
698
    }
699
 
700
  fip->saved_regs[PC_REGNUM] = fip->frame + 4;
701
  fip->saved_regs[FP_REGNUM] = fip->frame;
702
}
703
 
704
/* Return PC of first real instruction.  */
705
 
706
static CORE_ADDR
707
i386_skip_prologue (CORE_ADDR pc)
708
{
709
  unsigned char op;
710
  int i;
711
  static unsigned char pic_pat[6] =
712
  { 0xe8, 0, 0, 0, 0,               /* call   0x0 */
713
    0x5b,                       /* popl   %ebx */
714
  };
715
  CORE_ADDR pos;
716
 
717
  if (i386_get_frame_setup (pc) < 0)
718
    return (pc);
719
 
720
  /* Found valid frame setup -- codestream now points to start of push
721
     instructions for saving registers.  */
722
 
723
  /* Skip over register saves.  */
724
  for (i = 0; i < 8; i++)
725
    {
726
      op = codestream_peek ();
727
      /* Break if not `pushl' instrunction.  */
728
      if (op < 0x50 || op > 0x57)
729
        break;
730
      codestream_get ();
731
    }
732
 
733
  /* The native cc on SVR4 in -K PIC mode inserts the following code
734
     to get the address of the global offset table (GOT) into register
735
     %ebx
736
 
737
        call    0x0
738
        popl    %ebx
739
        movl    %ebx,x(%ebp)    (optional)
740
        addl    y,%ebx
741
 
742
     This code is with the rest of the prologue (at the end of the
743
     function), so we have to skip it to get to the first real
744
     instruction at the start of the function.  */
745
 
746
  pos = codestream_tell ();
747
  for (i = 0; i < 6; i++)
748
    {
749
      op = codestream_get ();
750
      if (pic_pat[i] != op)
751
        break;
752
    }
753
  if (i == 6)
754
    {
755
      unsigned char buf[4];
756
      long delta = 6;
757
 
758
      op = codestream_get ();
759
      if (op == 0x89)           /* movl %ebx, x(%ebp) */
760
        {
761
          op = codestream_get ();
762
          if (op == 0x5d)       /* One byte offset from %ebp.  */
763
            {
764
              delta += 3;
765
              codestream_read (buf, 1);
766
            }
767
          else if (op == 0x9d)  /* Four byte offset from %ebp.  */
768
            {
769
              delta += 6;
770
              codestream_read (buf, 4);
771
            }
772
          else                  /* Unexpected instruction.  */
773
            delta = -1;
774
          op = codestream_get ();
775
        }
776
      /* addl y,%ebx */
777
      if (delta > 0 && op == 0x81 && codestream_get () == 0xc3)
778
        {
779
          pos += delta + 6;
780
        }
781
    }
782
  codestream_seek (pos);
783
 
784
  i386_follow_jump ();
785
 
786
  return (codestream_tell ());
787
}
788
 
789
/* Use the program counter to determine the contents and size of a
790
   breakpoint instruction.  Return a pointer to a string of bytes that
791
   encode a breakpoint instruction, store the length of the string in
792
   *LEN and optionally adjust *PC to point to the correct memory
793
   location for inserting the breakpoint.
794
 
795
   On the i386 we have a single breakpoint that fits in a single byte
796
   and can be inserted anywhere.  */
797
 
798
static const unsigned char *
799
i386_breakpoint_from_pc (CORE_ADDR *pc, int *len)
800
{
801
  static unsigned char break_insn[] = { 0xcc }; /* int 3 */
802
 
803
  *len = sizeof (break_insn);
804
  return break_insn;
805
}
806
 
807
/* Push the return address (pointing to the call dummy) onto the stack
808
   and return the new value for the stack pointer.  */
809
 
810
static CORE_ADDR
811
i386_push_return_address (CORE_ADDR pc, CORE_ADDR sp)
812
{
813
  char buf[4];
814
 
815
  store_unsigned_integer (buf, 4, CALL_DUMMY_ADDRESS ());
816
  write_memory (sp - 4, buf, 4);
817
  return sp - 4;
818
}
819
 
820
static void
821
i386_do_pop_frame (struct frame_info *frame)
822
{
823
  CORE_ADDR fp;
824
  int regnum;
825
  char regbuf[I386_MAX_REGISTER_SIZE];
826
 
827
  fp = FRAME_FP (frame);
828
  i386_frame_init_saved_regs (frame);
829
 
830
  for (regnum = 0; regnum < NUM_REGS; regnum++)
831
    {
832
      CORE_ADDR addr;
833
      addr = frame->saved_regs[regnum];
834
      if (addr)
835
        {
836
          read_memory (addr, regbuf, REGISTER_RAW_SIZE (regnum));
837
          write_register_gen (regnum, regbuf);
838
        }
839
    }
840
  write_register (FP_REGNUM, read_memory_integer (fp, 4));
841
  write_register (PC_REGNUM, read_memory_integer (fp + 4, 4));
842
  write_register (SP_REGNUM, fp + 8);
843
  flush_cached_frames ();
844
}
845
 
846
static void
847
i386_pop_frame (void)
848
{
849
  generic_pop_current_frame (i386_do_pop_frame);
850
}
851
 
852
 
853
/* Figure out where the longjmp will land.  Slurp the args out of the
854
   stack.  We expect the first arg to be a pointer to the jmp_buf
855
   structure from which we extract the address that we will land at.
856
   This address is copied into PC.  This routine returns true on
857
   success.  */
858
 
859
static int
860
i386_get_longjmp_target (CORE_ADDR *pc)
861
{
862
  char buf[4];
863
  CORE_ADDR sp, jb_addr;
864
  int jb_pc_offset = gdbarch_tdep (current_gdbarch)->jb_pc_offset;
865
 
866
  /* If JB_PC_OFFSET is -1, we have no way to find out where the
867
     longjmp will land.  */
868
  if (jb_pc_offset == -1)
869
    return 0;
870
 
871
  sp = read_register (SP_REGNUM);
872
  if (target_read_memory (sp + 4, buf, 4))
873
    return 0;
874
 
875
  jb_addr = extract_address (buf, 4);
876
  if (target_read_memory (jb_addr + jb_pc_offset, buf, 4))
877
    return 0;
878
 
879
  *pc = extract_address (buf, 4);
880
  return 1;
881
}
882
 
883
 
884
static CORE_ADDR
885
i386_push_arguments (int nargs, struct value **args, CORE_ADDR sp,
886
                     int struct_return, CORE_ADDR struct_addr)
887
{
888
  sp = default_push_arguments (nargs, args, sp, struct_return, struct_addr);
889
 
890
  if (struct_return)
891
    {
892
      char buf[4];
893
 
894
      sp -= 4;
895
      store_address (buf, 4, struct_addr);
896
      write_memory (sp, buf, 4);
897
    }
898
 
899
  return sp;
900
}
901
 
902
static void
903
i386_store_struct_return (CORE_ADDR addr, CORE_ADDR sp)
904
{
905
  /* Do nothing.  Everything was already done by i386_push_arguments.  */
906
}
907
 
908
/* These registers are used for returning integers (and on some
909
   targets also for returning `struct' and `union' values when their
910
   size and alignment match an integer type).  */
911
#define LOW_RETURN_REGNUM 0     /* %eax */
912
#define HIGH_RETURN_REGNUM 2    /* %edx */
913
 
914
/* Extract from an array REGBUF containing the (raw) register state, a
915
   function return value of TYPE, and copy that, in virtual format,
916
   into VALBUF.  */
917
 
918
static void
919
i386_extract_return_value (struct type *type, struct regcache *regcache,
920
                           void *dst)
921
{
922
  bfd_byte *valbuf = dst;
923
  int len = TYPE_LENGTH (type);
924
  char buf[I386_MAX_REGISTER_SIZE];
925
 
926
  if (TYPE_CODE (type) == TYPE_CODE_STRUCT
927
      && TYPE_NFIELDS (type) == 1)
928
    {
929
      i386_extract_return_value (TYPE_FIELD_TYPE (type, 0), regcache, valbuf);
930
      return;
931
    }
932
 
933
  if (TYPE_CODE (type) == TYPE_CODE_FLT)
934
    {
935
      if (FP0_REGNUM == 0)
936
        {
937
          warning ("Cannot find floating-point return value.");
938
          memset (valbuf, 0, len);
939
          return;
940
        }
941
 
942
      /* Floating-point return values can be found in %st(0).  Convert
943
         its contents to the desired type.  This is probably not
944
         exactly how it would happen on the target itself, but it is
945
         the best we can do.  */
946
      regcache_raw_read (regcache, FP0_REGNUM, buf);
947
      convert_typed_floating (buf, builtin_type_i387_ext, valbuf, type);
948
    }
949
  else
950
    {
951
      int low_size = REGISTER_RAW_SIZE (LOW_RETURN_REGNUM);
952
      int high_size = REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM);
953
 
954
      if (len <= low_size)
955
        {
956
          regcache_raw_read (regcache, LOW_RETURN_REGNUM, buf);
957
          memcpy (valbuf, buf, len);
958
        }
959
      else if (len <= (low_size + high_size))
960
        {
961
          regcache_raw_read (regcache, LOW_RETURN_REGNUM, buf);
962
          memcpy (valbuf, buf, low_size);
963
          regcache_raw_read (regcache, HIGH_RETURN_REGNUM, buf);
964
          memcpy (valbuf + low_size, buf, len - low_size);
965
        }
966
      else
967
        internal_error (__FILE__, __LINE__,
968
                        "Cannot extract return value of %d bytes long.", len);
969
    }
970
}
971
 
972
/* Write into the appropriate registers a function return value stored
973
   in VALBUF of type TYPE, given in virtual format.  */
974
 
975
static void
976
i386_store_return_value (struct type *type, struct regcache *regcache,
977
                         const void *valbuf)
978
{
979
  int len = TYPE_LENGTH (type);
980
 
981
  if (TYPE_CODE (type) == TYPE_CODE_STRUCT
982
      && TYPE_NFIELDS (type) == 1)
983
    {
984
      i386_store_return_value (TYPE_FIELD_TYPE (type, 0), regcache, valbuf);
985
      return;
986
    }
987
 
988
  if (TYPE_CODE (type) == TYPE_CODE_FLT)
989
    {
990
      ULONGEST fstat;
991
      char buf[FPU_REG_RAW_SIZE];
992
 
993
      if (FP0_REGNUM == 0)
994
        {
995
          warning ("Cannot set floating-point return value.");
996
          return;
997
        }
998
 
999
      /* Returning floating-point values is a bit tricky.  Apart from
1000
         storing the return value in %st(0), we have to simulate the
1001
         state of the FPU at function return point.  */
1002
 
1003
      /* Convert the value found in VALBUF to the extended
1004
         floating-point format used by the FPU.  This is probably
1005
         not exactly how it would happen on the target itself, but
1006
         it is the best we can do.  */
1007
      convert_typed_floating (valbuf, type, buf, builtin_type_i387_ext);
1008
      regcache_raw_write (regcache, FP0_REGNUM, buf);
1009
 
1010
      /* Set the top of the floating-point register stack to 7.  The
1011
         actual value doesn't really matter, but 7 is what a normal
1012
         function return would end up with if the program started out
1013
         with a freshly initialized FPU.  */
1014
      regcache_raw_read_unsigned (regcache, FSTAT_REGNUM, &fstat);
1015
      fstat |= (7 << 11);
1016
      regcache_raw_write_unsigned (regcache, FSTAT_REGNUM, fstat);
1017
 
1018
      /* Mark %st(1) through %st(7) as empty.  Since we set the top of
1019
         the floating-point register stack to 7, the appropriate value
1020
         for the tag word is 0x3fff.  */
1021
      regcache_raw_write_unsigned (regcache, FTAG_REGNUM, 0x3fff);
1022
    }
1023
  else
1024
    {
1025
      int low_size = REGISTER_RAW_SIZE (LOW_RETURN_REGNUM);
1026
      int high_size = REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM);
1027
 
1028
      if (len <= low_size)
1029
        regcache_raw_write_part (regcache, LOW_RETURN_REGNUM, 0, len, valbuf);
1030
      else if (len <= (low_size + high_size))
1031
        {
1032
          regcache_raw_write (regcache, LOW_RETURN_REGNUM, valbuf);
1033
          regcache_raw_write_part (regcache, HIGH_RETURN_REGNUM, 0,
1034
                                   len - low_size, (char *) valbuf + low_size);
1035
        }
1036
      else
1037
        internal_error (__FILE__, __LINE__,
1038
                        "Cannot store return value of %d bytes long.", len);
1039
    }
1040
}
1041
 
1042
/* Extract from an array REGBUF containing the (raw) register state
1043
   the address in which a function should return its structure value,
1044
   as a CORE_ADDR.  */
1045
 
1046
static CORE_ADDR
1047
i386_extract_struct_value_address (struct regcache *regcache)
1048
{
1049
  /* NOTE: cagney/2002-08-12: Replaced a call to
1050
     regcache_raw_read_as_address() with a call to
1051
     regcache_cooked_read_unsigned().  The old, ...as_address function
1052
     was eventually calling extract_unsigned_integer (via
1053
     extract_address) to unpack the registers value.  The below is
1054
     doing an unsigned extract so that it is functionally equivalent.
1055
     The read needs to be cooked as, otherwise, it will never
1056
     correctly return the value of a register in the [NUM_REGS
1057
     .. NUM_REGS+NUM_PSEUDO_REGS) range.  */
1058
  ULONGEST val;
1059
  regcache_cooked_read_unsigned (regcache, LOW_RETURN_REGNUM, &val);
1060
  return val;
1061
}
1062
 
1063
 
1064
/* This is the variable that is set with "set struct-convention", and
1065
   its legitimate values.  */
1066
static const char default_struct_convention[] = "default";
1067
static const char pcc_struct_convention[] = "pcc";
1068
static const char reg_struct_convention[] = "reg";
1069
static const char *valid_conventions[] =
1070
{
1071
  default_struct_convention,
1072
  pcc_struct_convention,
1073
  reg_struct_convention,
1074
  NULL
1075
};
1076
static const char *struct_convention = default_struct_convention;
1077
 
1078
static int
1079
i386_use_struct_convention (int gcc_p, struct type *type)
1080
{
1081
  enum struct_return struct_return;
1082
 
1083
  if (struct_convention == default_struct_convention)
1084
    struct_return = gdbarch_tdep (current_gdbarch)->struct_return;
1085
  else if (struct_convention == pcc_struct_convention)
1086
    struct_return = pcc_struct_return;
1087
  else
1088
    struct_return = reg_struct_return;
1089
 
1090
  return generic_use_struct_convention (struct_return == reg_struct_return,
1091
                                        type);
1092
}
1093
 
1094
 
1095
/* Return the GDB type object for the "standard" data type of data in
1096
   register REGNUM.  Perhaps %esi and %edi should go here, but
1097
   potentially they could be used for things other than address.  */
1098
 
1099
static struct type *
1100
i386_register_virtual_type (int regnum)
1101
{
1102
  if (regnum == PC_REGNUM || regnum == FP_REGNUM || regnum == SP_REGNUM)
1103
    return lookup_pointer_type (builtin_type_void);
1104
 
1105
  if (IS_FP_REGNUM (regnum))
1106
    return builtin_type_i387_ext;
1107
 
1108
  if (IS_SSE_REGNUM (regnum))
1109
    return builtin_type_vec128i;
1110
 
1111
  if (mmx_regnum_p (regnum))
1112
    return builtin_type_vec64i;
1113
 
1114
  return builtin_type_int;
1115
}
1116
 
1117
/* Map a cooked register onto a raw register or memory.  For the i386,
1118
   the MMX registers need to be mapped onto floating point registers.  */
1119
 
1120
static int
1121
mmx_regnum_to_fp_regnum (struct regcache *regcache, int regnum)
1122
{
1123
  int mmxi;
1124
  ULONGEST fstat;
1125
  int tos;
1126
  int fpi;
1127
  mmxi = regnum - MM0_REGNUM;
1128
  regcache_raw_read_unsigned (regcache, FSTAT_REGNUM, &fstat);
1129
  tos = (fstat >> 11) & 0x7;
1130
  fpi = (mmxi + tos) % 8;
1131
  return (FP0_REGNUM + fpi);
1132
}
1133
 
1134
static void
1135
i386_pseudo_register_read (struct gdbarch *gdbarch, struct regcache *regcache,
1136
                           int regnum, void *buf)
1137
{
1138
  if (mmx_regnum_p (regnum))
1139
    {
1140
      char *mmx_buf = alloca (MAX_REGISTER_RAW_SIZE);
1141
      int fpnum = mmx_regnum_to_fp_regnum (regcache, regnum);
1142
      regcache_raw_read (regcache, fpnum, mmx_buf);
1143
      /* Extract (always little endian).  */
1144
      memcpy (buf, mmx_buf, REGISTER_RAW_SIZE (regnum));
1145
    }
1146
  else
1147
    regcache_raw_read (regcache, regnum, buf);
1148
}
1149
 
1150
static void
1151
i386_pseudo_register_write (struct gdbarch *gdbarch, struct regcache *regcache,
1152
                            int regnum, const void *buf)
1153
{
1154
  if (mmx_regnum_p (regnum))
1155
    {
1156
      char *mmx_buf = alloca (MAX_REGISTER_RAW_SIZE);
1157
      int fpnum = mmx_regnum_to_fp_regnum (regcache, regnum);
1158
      /* Read ...  */
1159
      regcache_raw_read (regcache, fpnum, mmx_buf);
1160
      /* ... Modify ... (always little endian).  */
1161
      memcpy (mmx_buf, buf, REGISTER_RAW_SIZE (regnum));
1162
      /* ... Write.  */
1163
      regcache_raw_write (regcache, fpnum, mmx_buf);
1164
    }
1165
  else
1166
    regcache_raw_write (regcache, regnum, buf);
1167
}
1168
 
1169
/* Return true iff register REGNUM's virtual format is different from
1170
   its raw format.  Note that this definition assumes that the host
1171
   supports IEEE 32-bit floats, since it doesn't say that SSE
1172
   registers need conversion.  Even if we can't find a counterexample,
1173
   this is still sloppy.  */
1174
 
1175
static int
1176
i386_register_convertible (int regnum)
1177
{
1178
  return IS_FP_REGNUM (regnum);
1179
}
1180
 
1181
/* Convert data from raw format for register REGNUM in buffer FROM to
1182
   virtual format with type TYPE in buffer TO.  */
1183
 
1184
static void
1185
i386_register_convert_to_virtual (int regnum, struct type *type,
1186
                                  char *from, char *to)
1187
{
1188
  gdb_assert (IS_FP_REGNUM (regnum));
1189
 
1190
  /* We only support floating-point values.  */
1191
  if (TYPE_CODE (type) != TYPE_CODE_FLT)
1192
    {
1193
      warning ("Cannot convert floating-point register value "
1194
               "to non-floating-point type.");
1195
      memset (to, 0, TYPE_LENGTH (type));
1196
      return;
1197
    }
1198
 
1199
  /* Convert to TYPE.  This should be a no-op if TYPE is equivalent to
1200
     the extended floating-point format used by the FPU.  */
1201
  convert_typed_floating (from, builtin_type_i387_ext, to, type);
1202
}
1203
 
1204
/* Convert data from virtual format with type TYPE in buffer FROM to
1205
   raw format for register REGNUM in buffer TO.  */
1206
 
1207
static void
1208
i386_register_convert_to_raw (struct type *type, int regnum,
1209
                              char *from, char *to)
1210
{
1211
  gdb_assert (IS_FP_REGNUM (regnum));
1212
 
1213
  /* We only support floating-point values.  */
1214
  if (TYPE_CODE (type) != TYPE_CODE_FLT)
1215
    {
1216
      warning ("Cannot convert non-floating-point type "
1217
               "to floating-point register value.");
1218
      memset (to, 0, TYPE_LENGTH (type));
1219
      return;
1220
    }
1221
 
1222
  /* Convert from TYPE.  This should be a no-op if TYPE is equivalent
1223
     to the extended floating-point format used by the FPU.  */
1224
  convert_typed_floating (from, type, to, builtin_type_i387_ext);
1225
}
1226
 
1227
 
1228
#ifdef STATIC_TRANSFORM_NAME
1229
/* SunPRO encodes the static variables.  This is not related to C++
1230
   mangling, it is done for C too.  */
1231
 
1232
char *
1233
sunpro_static_transform_name (char *name)
1234
{
1235
  char *p;
1236
  if (IS_STATIC_TRANSFORM_NAME (name))
1237
    {
1238
      /* For file-local statics there will be a period, a bunch of
1239
         junk (the contents of which match a string given in the
1240
         N_OPT), a period and the name.  For function-local statics
1241
         there will be a bunch of junk (which seems to change the
1242
         second character from 'A' to 'B'), a period, the name of the
1243
         function, and the name.  So just skip everything before the
1244
         last period.  */
1245
      p = strrchr (name, '.');
1246
      if (p != NULL)
1247
        name = p + 1;
1248
    }
1249
  return name;
1250
}
1251
#endif /* STATIC_TRANSFORM_NAME */
1252
 
1253
 
1254
/* Stuff for WIN32 PE style DLL's but is pretty generic really.  */
1255
 
1256
CORE_ADDR
1257
i386_pe_skip_trampoline_code (CORE_ADDR pc, char *name)
1258
{
1259
  if (pc && read_memory_unsigned_integer (pc, 2) == 0x25ff) /* jmp *(dest) */
1260
    {
1261
      unsigned long indirect = read_memory_unsigned_integer (pc + 2, 4);
1262
      struct minimal_symbol *indsym =
1263
        indirect ? lookup_minimal_symbol_by_pc (indirect) : 0;
1264
      char *symname = indsym ? SYMBOL_NAME (indsym) : 0;
1265
 
1266
      if (symname)
1267
        {
1268
          if (strncmp (symname, "__imp_", 6) == 0
1269
              || strncmp (symname, "_imp_", 5) == 0)
1270
            return name ? 1 : read_memory_unsigned_integer (indirect, 4);
1271
        }
1272
    }
1273
  return 0;                      /* Not a trampoline.  */
1274
}
1275
 
1276
 
1277
/* Return non-zero if PC and NAME show that we are in a signal
1278
   trampoline.  */
1279
 
1280
static int
1281
i386_pc_in_sigtramp (CORE_ADDR pc, char *name)
1282
{
1283
  return (name && strcmp ("_sigtramp", name) == 0);
1284
}
1285
 
1286
 
1287
/* We have two flavours of disassembly.  The machinery on this page
1288
   deals with switching between those.  */
1289
 
1290
static int
1291
gdb_print_insn_i386 (bfd_vma memaddr, disassemble_info *info)
1292
{
1293
  if (disassembly_flavor == att_flavor)
1294
    return print_insn_i386_att (memaddr, info);
1295
  else if (disassembly_flavor == intel_flavor)
1296
    return print_insn_i386_intel (memaddr, info);
1297
  /* Never reached -- disassembly_flavour is always either att_flavor
1298
     or intel_flavor.  */
1299
  internal_error (__FILE__, __LINE__, "failed internal consistency check");
1300
}
1301
 
1302
 
1303
/* There are a few i386 architecture variants that differ only
1304
   slightly from the generic i386 target.  For now, we don't give them
1305
   their own source file, but include them here.  As a consequence,
1306
   they'll always be included.  */
1307
 
1308
/* System V Release 4 (SVR4).  */
1309
 
1310
static int
1311
i386_svr4_pc_in_sigtramp (CORE_ADDR pc, char *name)
1312
{
1313
  return (name && (strcmp ("_sigreturn", name) == 0
1314
                   || strcmp ("_sigacthandler", name) == 0
1315
                   || strcmp ("sigvechandler", name) == 0));
1316
}
1317
 
1318
/* Get address of the pushed ucontext (sigcontext) on the stack for
1319
   all three variants of SVR4 sigtramps.  */
1320
 
1321
static CORE_ADDR
1322
i386_svr4_sigcontext_addr (struct frame_info *frame)
1323
{
1324
  int sigcontext_offset = -1;
1325
  char *name = NULL;
1326
 
1327
  find_pc_partial_function (frame->pc, &name, NULL, NULL);
1328
  if (name)
1329
    {
1330
      if (strcmp (name, "_sigreturn") == 0)
1331
        sigcontext_offset = 132;
1332
      else if (strcmp (name, "_sigacthandler") == 0)
1333
        sigcontext_offset = 80;
1334
      else if (strcmp (name, "sigvechandler") == 0)
1335
        sigcontext_offset = 120;
1336
    }
1337
 
1338
  gdb_assert (sigcontext_offset != -1);
1339
 
1340
  if (frame->next)
1341
    return frame->next->frame + sigcontext_offset;
1342
  return read_register (SP_REGNUM) + sigcontext_offset;
1343
}
1344
 
1345
 
1346
/* DJGPP.  */
1347
 
1348
static int
1349
i386_go32_pc_in_sigtramp (CORE_ADDR pc, char *name)
1350
{
1351
  /* DJGPP doesn't have any special frames for signal handlers.  */
1352
  return 0;
1353
}
1354
 
1355
 
1356
/* Generic ELF.  */
1357
 
1358
void
1359
i386_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
1360
{
1361
  /* We typically use stabs-in-ELF with the DWARF register numbering.  */
1362
  set_gdbarch_stab_reg_to_regnum (gdbarch, i386_dwarf_reg_to_regnum);
1363
}
1364
 
1365
/* System V Release 4 (SVR4).  */
1366
 
1367
void
1368
i386_svr4_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
1369
{
1370
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
1371
 
1372
  /* System V Release 4 uses ELF.  */
1373
  i386_elf_init_abi (info, gdbarch);
1374
 
1375
  /* System V Release 4 has shared libraries.  */
1376
  set_gdbarch_in_solib_call_trampoline (gdbarch, in_plt_section);
1377
  set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
1378
 
1379
  /* FIXME: kettenis/20020511: Why do we override this function here?  */
1380
  set_gdbarch_frame_chain_valid (gdbarch, generic_func_frame_chain_valid);
1381
 
1382
  set_gdbarch_pc_in_sigtramp (gdbarch, i386_svr4_pc_in_sigtramp);
1383
  tdep->sigcontext_addr = i386_svr4_sigcontext_addr;
1384
  tdep->sc_pc_offset = 14 * 4;
1385
  tdep->sc_sp_offset = 7 * 4;
1386
 
1387
  tdep->jb_pc_offset = 20;
1388
}
1389
 
1390
/* DJGPP.  */
1391
 
1392
static void
1393
i386_go32_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
1394
{
1395
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
1396
 
1397
  set_gdbarch_pc_in_sigtramp (gdbarch, i386_go32_pc_in_sigtramp);
1398
 
1399
  tdep->jb_pc_offset = 36;
1400
}
1401
 
1402
/* NetWare.  */
1403
 
1404
static void
1405
i386_nw_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
1406
{
1407
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
1408
 
1409
  /* FIXME: kettenis/20020511: Why do we override this function here?  */
1410
  set_gdbarch_frame_chain_valid (gdbarch, generic_func_frame_chain_valid);
1411
 
1412
  tdep->jb_pc_offset = 24;
1413
}
1414
 
1415
 
1416
static struct gdbarch *
1417
i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
1418
{
1419
  struct gdbarch_tdep *tdep;
1420
  struct gdbarch *gdbarch;
1421
  enum gdb_osabi osabi = GDB_OSABI_UNKNOWN;
1422
 
1423
  /* Try to determine the OS ABI of the object we're loading.  */
1424
  if (info.abfd != NULL)
1425
    osabi = gdbarch_lookup_osabi (info.abfd);
1426
 
1427
  /* Find a candidate among extant architectures.  */
1428
  for (arches = gdbarch_list_lookup_by_info (arches, &info);
1429
       arches != NULL;
1430
       arches = gdbarch_list_lookup_by_info (arches->next, &info))
1431
    {
1432
      /* Make sure the OS ABI selection matches.  */
1433
      tdep = gdbarch_tdep (arches->gdbarch);
1434
      if (tdep && tdep->osabi == osabi)
1435
        return arches->gdbarch;
1436
    }
1437
 
1438
  /* Allocate space for the new architecture.  */
1439
  tdep = XMALLOC (struct gdbarch_tdep);
1440
  gdbarch = gdbarch_alloc (&info, tdep);
1441
 
1442
  tdep->osabi = osabi;
1443
 
1444
  /* The i386 default settings don't include the SSE registers.
1445
     FIXME: kettenis/20020614: They do include the FPU registers for
1446
     now, which probably is not quite right.  */
1447
  tdep->num_xmm_regs = 0;
1448
 
1449
  tdep->jb_pc_offset = -1;
1450
  tdep->struct_return = pcc_struct_return;
1451
  tdep->sigtramp_start = 0;
1452
  tdep->sigtramp_end = 0;
1453
  tdep->sigcontext_addr = NULL;
1454
  tdep->sc_pc_offset = -1;
1455
  tdep->sc_sp_offset = -1;
1456
 
1457
  /* The format used for `long double' on almost all i386 targets is
1458
     the i387 extended floating-point format.  In fact, of all targets
1459
     in the GCC 2.95 tree, only OSF/1 does it different, and insists
1460
     on having a `long double' that's not `long' at all.  */
1461
  set_gdbarch_long_double_format (gdbarch, &floatformat_i387_ext);
1462
 
1463
  /* Although the i386 extended floating-point has only 80 significant
1464
     bits, a `long double' actually takes up 96, probably to enforce
1465
     alignment.  */
1466
  set_gdbarch_long_double_bit (gdbarch, 96);
1467
 
1468
  /* NOTE: tm-i386aix.h, tm-i386bsd.h, tm-i386os9k.h, tm-ptx.h,
1469
     tm-symmetry.h currently override this.  Sigh.  */
1470
  set_gdbarch_num_regs (gdbarch, I386_NUM_GREGS + I386_NUM_FREGS);
1471
 
1472
  set_gdbarch_sp_regnum (gdbarch, 4);
1473
  set_gdbarch_fp_regnum (gdbarch, 5);
1474
  set_gdbarch_pc_regnum (gdbarch, 8);
1475
  set_gdbarch_ps_regnum (gdbarch, 9);
1476
  set_gdbarch_fp0_regnum (gdbarch, 16);
1477
 
1478
  /* Use the "default" register numbering scheme for stabs and COFF.  */
1479
  set_gdbarch_stab_reg_to_regnum (gdbarch, i386_stab_reg_to_regnum);
1480
  set_gdbarch_sdb_reg_to_regnum (gdbarch, i386_stab_reg_to_regnum);
1481
 
1482
  /* Use the DWARF register numbering scheme for DWARF and DWARF 2.  */
1483
  set_gdbarch_dwarf_reg_to_regnum (gdbarch, i386_dwarf_reg_to_regnum);
1484
  set_gdbarch_dwarf2_reg_to_regnum (gdbarch, i386_dwarf_reg_to_regnum);
1485
 
1486
  /* We don't define ECOFF_REG_TO_REGNUM, since ECOFF doesn't seem to
1487
     be in use on any of the supported i386 targets.  */
1488
 
1489
  set_gdbarch_register_name (gdbarch, i386_register_name);
1490
  set_gdbarch_register_size (gdbarch, 4);
1491
  set_gdbarch_register_bytes (gdbarch, I386_SIZEOF_GREGS + I386_SIZEOF_FREGS);
1492
  set_gdbarch_max_register_raw_size (gdbarch, I386_MAX_REGISTER_SIZE);
1493
  set_gdbarch_max_register_virtual_size (gdbarch, I386_MAX_REGISTER_SIZE);
1494
  set_gdbarch_register_virtual_type (gdbarch, i386_register_virtual_type);
1495
 
1496
  set_gdbarch_print_float_info (gdbarch, i387_print_float_info);
1497
 
1498
  set_gdbarch_get_longjmp_target (gdbarch, i386_get_longjmp_target);
1499
 
1500
  set_gdbarch_use_generic_dummy_frames (gdbarch, 1);
1501
 
1502
  /* Call dummy code.  */
1503
  set_gdbarch_call_dummy_location (gdbarch, AT_ENTRY_POINT);
1504
  set_gdbarch_call_dummy_address (gdbarch, entry_point_address);
1505
  set_gdbarch_call_dummy_start_offset (gdbarch, 0);
1506
  set_gdbarch_call_dummy_breakpoint_offset (gdbarch, 0);
1507
  set_gdbarch_call_dummy_breakpoint_offset_p (gdbarch, 1);
1508
  set_gdbarch_call_dummy_length (gdbarch, 0);
1509
  set_gdbarch_call_dummy_p (gdbarch, 1);
1510
  set_gdbarch_call_dummy_words (gdbarch, NULL);
1511
  set_gdbarch_sizeof_call_dummy_words (gdbarch, 0);
1512
  set_gdbarch_call_dummy_stack_adjust_p (gdbarch, 0);
1513
  set_gdbarch_fix_call_dummy (gdbarch, generic_fix_call_dummy);
1514
 
1515
  set_gdbarch_register_convertible (gdbarch, i386_register_convertible);
1516
  set_gdbarch_register_convert_to_virtual (gdbarch,
1517
                                           i386_register_convert_to_virtual);
1518
  set_gdbarch_register_convert_to_raw (gdbarch, i386_register_convert_to_raw);
1519
 
1520
  set_gdbarch_get_saved_register (gdbarch, generic_unwind_get_saved_register);
1521
  set_gdbarch_push_arguments (gdbarch, i386_push_arguments);
1522
 
1523
  set_gdbarch_pc_in_call_dummy (gdbarch, pc_in_call_dummy_at_entry_point);
1524
 
1525
  /* "An argument's size is increased, if necessary, to make it a
1526
     multiple of [32-bit] words.  This may require tail padding,
1527
     depending on the size of the argument" -- from the x86 ABI.  */
1528
  set_gdbarch_parm_boundary (gdbarch, 32);
1529
 
1530
  set_gdbarch_extract_return_value (gdbarch, i386_extract_return_value);
1531
  set_gdbarch_push_arguments (gdbarch, i386_push_arguments);
1532
  set_gdbarch_push_dummy_frame (gdbarch, generic_push_dummy_frame);
1533
  set_gdbarch_push_return_address (gdbarch, i386_push_return_address);
1534
  set_gdbarch_pop_frame (gdbarch, i386_pop_frame);
1535
  set_gdbarch_store_struct_return (gdbarch, i386_store_struct_return);
1536
  set_gdbarch_store_return_value (gdbarch, i386_store_return_value);
1537
  set_gdbarch_extract_struct_value_address (gdbarch,
1538
                                            i386_extract_struct_value_address);
1539
  set_gdbarch_use_struct_convention (gdbarch, i386_use_struct_convention);
1540
 
1541
  set_gdbarch_frame_init_saved_regs (gdbarch, i386_frame_init_saved_regs);
1542
  set_gdbarch_skip_prologue (gdbarch, i386_skip_prologue);
1543
 
1544
  /* Stack grows downward.  */
1545
  set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
1546
 
1547
  set_gdbarch_breakpoint_from_pc (gdbarch, i386_breakpoint_from_pc);
1548
  set_gdbarch_decr_pc_after_break (gdbarch, 1);
1549
  set_gdbarch_function_start_offset (gdbarch, 0);
1550
 
1551
  /* The following redefines make backtracing through sigtramp work.
1552
     They manufacture a fake sigtramp frame and obtain the saved pc in
1553
     sigtramp from the sigcontext structure which is pushed by the
1554
     kernel on the user stack, along with a pointer to it.  */
1555
 
1556
  set_gdbarch_frame_args_skip (gdbarch, 8);
1557
  set_gdbarch_frameless_function_invocation (gdbarch,
1558
                                           i386_frameless_function_invocation);
1559
  set_gdbarch_frame_chain (gdbarch, i386_frame_chain);
1560
  set_gdbarch_frame_chain_valid (gdbarch, generic_file_frame_chain_valid);
1561
  set_gdbarch_frame_saved_pc (gdbarch, i386_frame_saved_pc);
1562
  set_gdbarch_frame_args_address (gdbarch, default_frame_address);
1563
  set_gdbarch_frame_locals_address (gdbarch, default_frame_address);
1564
  set_gdbarch_saved_pc_after_call (gdbarch, i386_saved_pc_after_call);
1565
  set_gdbarch_frame_num_args (gdbarch, i386_frame_num_args);
1566
  set_gdbarch_pc_in_sigtramp (gdbarch, i386_pc_in_sigtramp);
1567
 
1568
  /* Wire in the MMX registers.  */
1569
  set_gdbarch_num_pseudo_regs (gdbarch, mmx_num_regs);
1570
  set_gdbarch_pseudo_register_read (gdbarch, i386_pseudo_register_read);
1571
  set_gdbarch_pseudo_register_write (gdbarch, i386_pseudo_register_write);
1572
 
1573
  /* Hook in ABI-specific overrides, if they have been registered.  */
1574
  gdbarch_init_osabi (info, gdbarch, osabi);
1575
 
1576
  return gdbarch;
1577
}
1578
 
1579
static enum gdb_osabi
1580
i386_coff_osabi_sniffer (bfd *abfd)
1581
{
1582
  if (strcmp (bfd_get_target (abfd), "coff-go32-exe") == 0
1583
      || strcmp (bfd_get_target (abfd), "coff-go32") == 0)
1584
    return GDB_OSABI_GO32;
1585
 
1586
  return GDB_OSABI_UNKNOWN;
1587
}
1588
 
1589
static enum gdb_osabi
1590
i386_nlm_osabi_sniffer (bfd *abfd)
1591
{
1592
  return GDB_OSABI_NETWARE;
1593
}
1594
 
1595
 
1596
/* Provide a prototype to silence -Wmissing-prototypes.  */
1597
void _initialize_i386_tdep (void);
1598
 
1599
void
1600
_initialize_i386_tdep (void)
1601
{
1602
  register_gdbarch_init (bfd_arch_i386, i386_gdbarch_init);
1603
 
1604
  tm_print_insn = gdb_print_insn_i386;
1605
  tm_print_insn_info.mach = bfd_lookup_arch (bfd_arch_i386, 0)->mach;
1606
 
1607
  /* Add the variable that controls the disassembly flavor.  */
1608
  {
1609
    struct cmd_list_element *new_cmd;
1610
 
1611
    new_cmd = add_set_enum_cmd ("disassembly-flavor", no_class,
1612
                                valid_flavors,
1613
                                &disassembly_flavor,
1614
                                "\
1615
Set the disassembly flavor, the valid values are \"att\" and \"intel\", \
1616
and the default value is \"att\".",
1617
                                &setlist);
1618
    add_show_from_set (new_cmd, &showlist);
1619
  }
1620
 
1621
  /* Add the variable that controls the convention for returning
1622
     structs.  */
1623
  {
1624
    struct cmd_list_element *new_cmd;
1625
 
1626
    new_cmd = add_set_enum_cmd ("struct-convention", no_class,
1627
                                 valid_conventions,
1628
                                &struct_convention, "\
1629
Set the convention for returning small structs, valid values \
1630
are \"default\", \"pcc\" and \"reg\", and the default value is \"default\".",
1631
                                &setlist);
1632
    add_show_from_set (new_cmd, &showlist);
1633
  }
1634
 
1635
  gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_coff_flavour,
1636
                                  i386_coff_osabi_sniffer);
1637
  gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_nlm_flavour,
1638
                                  i386_nlm_osabi_sniffer);
1639
 
1640
  gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_SVR4,
1641
                          i386_svr4_init_abi);
1642
  gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_GO32,
1643
                          i386_go32_init_abi);
1644
  gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_NETWARE,
1645
                          i386_nw_init_abi);
1646
}

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