aboutsummaryrefslogtreecommitdiff
path: root/gdb/disasm.c
blob: 940592864387c83a71a977398556c18db178807a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
/* Disassemble support for GDB.

   Copyright (C) 2000-2016 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "target.h"
#include "value.h"
#include "ui-out.h"
#include "disasm.h"
#include "gdbcore.h"
#include "dis-asm.h"
#include "source.h"

/* Disassemble functions.
   FIXME: We should get rid of all the duplicate code in gdb that does
   the same thing: disassemble_command() and the gdbtk variation.  */

/* This structure is used to store line number information for the
   deprecated /m option.
   We need a different sort of line table from the normal one cuz we can't
   depend upon implicit line-end pc's for lines to do the
   reordering in this function.  */

struct deprecated_dis_line_entry
{
  int line;
  CORE_ADDR start_pc;
  CORE_ADDR end_pc;
};

/* This Structure is used to store line number information.
   We need a different sort of line table from the normal one cuz we can't
   depend upon implicit line-end pc's for lines to do the
   reordering in this function.  */

struct dis_line_entry
{
  struct symtab *symtab;
  int line;
};

/* Hash function for dis_line_entry.  */

static hashval_t
hash_dis_line_entry (const void *item)
{
  const struct dis_line_entry *dle = (const struct dis_line_entry *) item;

  return htab_hash_pointer (dle->symtab) + dle->line;
}

/* Equal function for dis_line_entry.  */

static int
eq_dis_line_entry (const void *item_lhs, const void *item_rhs)
{
  const struct dis_line_entry *lhs = (const struct dis_line_entry *) item_lhs;
  const struct dis_line_entry *rhs = (const struct dis_line_entry *) item_rhs;

  return (lhs->symtab == rhs->symtab
	  && lhs->line == rhs->line);
}

/* Create the table to manage lines for mixed source/disassembly.  */

static htab_t
allocate_dis_line_table (void)
{
  return htab_create_alloc (41,
			    hash_dis_line_entry, eq_dis_line_entry,
			    xfree, xcalloc, xfree);
}

/* Add DLE to TABLE.
   Returns 1 if added, 0 if already present.  */

static void
maybe_add_dis_line_entry (htab_t table, struct symtab *symtab, int line)
{
  void **slot;
  struct dis_line_entry dle, *dlep;

  dle.symtab = symtab;
  dle.line = line;
  slot = htab_find_slot (table, &dle, INSERT);
  if (*slot == NULL)
    {
      dlep = XNEW (struct dis_line_entry);
      dlep->symtab = symtab;
      dlep->line = line;
      *slot = dlep;
    }
}

/* Return non-zero if SYMTAB, LINE are in TABLE.  */

static int
line_has_code_p (htab_t table, struct symtab *symtab, int line)
{
  struct dis_line_entry dle;

  dle.symtab = symtab;
  dle.line = line;
  return htab_find (table, &dle) != NULL;
}

/* Like target_read_memory, but slightly different parameters.  */
static int
dis_asm_read_memory (bfd_vma memaddr, gdb_byte *myaddr, unsigned int len,
		     struct disassemble_info *info)
{
  return target_read_code (memaddr, myaddr, len);
}

/* Like memory_error with slightly different parameters.  */
static void
dis_asm_memory_error (int err, bfd_vma memaddr,
		      struct disassemble_info *info)
{
  memory_error (TARGET_XFER_E_IO, memaddr);
}

/* Like print_address with slightly different parameters.  */
static void
dis_asm_print_address (bfd_vma addr, struct disassemble_info *info)
{
  struct gdbarch *gdbarch = (struct gdbarch *) info->application_data;

  print_address (gdbarch, addr, (struct ui_file *) info->stream);
}

static int
compare_lines (const void *mle1p, const void *mle2p)
{
  struct deprecated_dis_line_entry *mle1, *mle2;
  int val;

  mle1 = (struct deprecated_dis_line_entry *) mle1p;
  mle2 = (struct deprecated_dis_line_entry *) mle2p;

  /* End of sequence markers have a line number of 0 but don't want to
     be sorted to the head of the list, instead sort by PC.  */
  if (mle1->line == 0 || mle2->line == 0)
    {
      val = mle1->start_pc - mle2->start_pc;
      if (val == 0)
        val = mle1->line - mle2->line;
    }
  else
    {
      val = mle1->line - mle2->line;
      if (val == 0)
        val = mle1->start_pc - mle2->start_pc;
    }
  return val;
}

/* See disasm.h.  */

int
gdb_pretty_print_insn (struct gdbarch *gdbarch, struct ui_out *uiout,
		       struct disassemble_info * di,
		       const struct disasm_insn *insn, int flags,
		       struct ui_file *stb)
{
  /* parts of the symbolic representation of the address */
  int unmapped;
  int offset;
  int line;
  int size;
  struct cleanup *ui_out_chain;
  char *filename = NULL;
  char *name = NULL;
  CORE_ADDR pc;

  ui_out_chain = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
  pc = insn->addr;

  if (insn->number != 0)
    {
      ui_out_field_fmt (uiout, "insn-number", "%u", insn->number);
      ui_out_text (uiout, "\t");
    }

  if ((flags & DISASSEMBLY_SPECULATIVE) != 0)
    {
      if (insn->is_speculative)
	{
	  ui_out_field_string (uiout, "is-speculative", "?");

	  /* The speculative execution indication overwrites the first
	     character of the PC prefix.
	     We assume a PC prefix length of 3 characters.  */
	  if ((flags & DISASSEMBLY_OMIT_PC) == 0)
	    ui_out_text (uiout, pc_prefix (pc) + 1);
	  else
	    ui_out_text (uiout, "  ");
	}
      else if ((flags & DISASSEMBLY_OMIT_PC) == 0)
	ui_out_text (uiout, pc_prefix (pc));
      else
	ui_out_text (uiout, "   ");
    }
  else if ((flags & DISASSEMBLY_OMIT_PC) == 0)
    ui_out_text (uiout, pc_prefix (pc));
  ui_out_field_core_addr (uiout, "address", gdbarch, pc);

  if (!build_address_symbolic (gdbarch, pc, 0, &name, &offset, &filename,
			       &line, &unmapped))
    {
      /* We don't care now about line, filename and unmapped.  But we might in
	 the future.  */
      ui_out_text (uiout, " <");
      if ((flags & DISASSEMBLY_OMIT_FNAME) == 0)
	ui_out_field_string (uiout, "func-name", name);
      ui_out_text (uiout, "+");
      ui_out_field_int (uiout, "offset", offset);
      ui_out_text (uiout, ">:\t");
    }
  else
    ui_out_text (uiout, ":\t");

  if (filename != NULL)
    xfree (filename);
  if (name != NULL)
    xfree (name);

  ui_file_rewind (stb);
  if (flags & DISASSEMBLY_RAW_INSN)
    {
      CORE_ADDR end_pc;
      bfd_byte data;
      int err;
      const char *spacer = "";

      /* Build the opcodes using a temporary stream so we can
	 write them out in a single go for the MI.  */
      struct ui_file *opcode_stream = mem_fileopen ();
      struct cleanup *cleanups =
	make_cleanup_ui_file_delete (opcode_stream);

      size = gdbarch_print_insn (gdbarch, pc, di);
      end_pc = pc + size;

      for (;pc < end_pc; ++pc)
	{
	  err = (*di->read_memory_func) (pc, &data, 1, di);
	  if (err != 0)
	    (*di->memory_error_func) (err, pc, di);
	  fprintf_filtered (opcode_stream, "%s%02x",
			    spacer, (unsigned) data);
	  spacer = " ";
	}

      ui_out_field_stream (uiout, "opcodes", opcode_stream);
      ui_out_text (uiout, "\t");

      do_cleanups (cleanups);
    }
  else
    size = gdbarch_print_insn (gdbarch, pc, di);

  ui_out_field_stream (uiout, "inst", stb);
  ui_file_rewind (stb);
  do_cleanups (ui_out_chain);
  ui_out_text (uiout, "\n");

  return size;
}

static int
dump_insns (struct gdbarch *gdbarch, struct ui_out *uiout,
	    struct disassemble_info * di,
	    CORE_ADDR low, CORE_ADDR high,
	    int how_many, int flags, struct ui_file *stb,
	    CORE_ADDR *end_pc)
{
  struct disasm_insn insn;
  int num_displayed = 0;

  memset (&insn, 0, sizeof (insn));
  insn.addr = low;

  while (insn.addr < high && (how_many < 0 || num_displayed < how_many))
    {
      int size;

      size = gdb_pretty_print_insn (gdbarch, uiout, di, &insn, flags, stb);
      if (size <= 0)
	break;

      ++num_displayed;
      insn.addr += size;

      /* Allow user to bail out with ^C.  */
      QUIT;
    }

  if (end_pc != NULL)
    *end_pc = insn.addr;

  return num_displayed;
}

/* The idea here is to present a source-O-centric view of a
   function to the user.  This means that things are presented
   in source order, with (possibly) out of order assembly
   immediately following.

   N.B. This view is deprecated.  */

static void
do_mixed_source_and_assembly_deprecated
  (struct gdbarch *gdbarch, struct ui_out *uiout,
   struct disassemble_info *di, struct symtab *symtab,
   CORE_ADDR low, CORE_ADDR high,
   int how_many, int flags, struct ui_file *stb)
{
  int newlines = 0;
  int nlines;
  struct linetable_entry *le;
  struct deprecated_dis_line_entry *mle;
  struct symtab_and_line sal;
  int i;
  int out_of_order = 0;
  int next_line = 0;
  int num_displayed = 0;
  print_source_lines_flags psl_flags = 0;
  struct cleanup *ui_out_chain;
  struct cleanup *ui_out_tuple_chain = make_cleanup (null_cleanup, 0);
  struct cleanup *ui_out_list_chain = make_cleanup (null_cleanup, 0);

  gdb_assert (symtab != NULL && SYMTAB_LINETABLE (symtab) != NULL);

  nlines = SYMTAB_LINETABLE (symtab)->nitems;
  le = SYMTAB_LINETABLE (symtab)->item;

  if (flags & DISASSEMBLY_FILENAME)
    psl_flags |= PRINT_SOURCE_LINES_FILENAME;

  mle = (struct deprecated_dis_line_entry *)
    alloca (nlines * sizeof (struct deprecated_dis_line_entry));

  /* Copy linetable entries for this function into our data
     structure, creating end_pc's and setting out_of_order as
     appropriate.  */

  /* First, skip all the preceding functions.  */

  for (i = 0; i < nlines - 1 && le[i].pc < low; i++);

  /* Now, copy all entries before the end of this function.  */

  for (; i < nlines - 1 && le[i].pc < high; i++)
    {
      if (le[i].line == le[i + 1].line && le[i].pc == le[i + 1].pc)
	continue;		/* Ignore duplicates.  */

      /* Skip any end-of-function markers.  */
      if (le[i].line == 0)
	continue;

      mle[newlines].line = le[i].line;
      if (le[i].line > le[i + 1].line)
	out_of_order = 1;
      mle[newlines].start_pc = le[i].pc;
      mle[newlines].end_pc = le[i + 1].pc;
      newlines++;
    }

  /* If we're on the last line, and it's part of the function,
     then we need to get the end pc in a special way.  */

  if (i == nlines - 1 && le[i].pc < high)
    {
      mle[newlines].line = le[i].line;
      mle[newlines].start_pc = le[i].pc;
      sal = find_pc_line (le[i].pc, 0);
      mle[newlines].end_pc = sal.end;
      newlines++;
    }

  /* Now, sort mle by line #s (and, then by addresses within lines).  */

  if (out_of_order)
    qsort (mle, newlines, sizeof (struct deprecated_dis_line_entry),
	   compare_lines);

  /* Now, for each line entry, emit the specified lines (unless
     they have been emitted before), followed by the assembly code
     for that line.  */

  ui_out_chain = make_cleanup_ui_out_list_begin_end (uiout, "asm_insns");

  for (i = 0; i < newlines; i++)
    {
      /* Print out everything from next_line to the current line.  */
      if (mle[i].line >= next_line)
	{
	  if (next_line != 0)
	    {
	      /* Just one line to print.  */
	      if (next_line == mle[i].line)
		{
		  ui_out_tuple_chain
		    = make_cleanup_ui_out_tuple_begin_end (uiout,
							   "src_and_asm_line");
		  print_source_lines (symtab, next_line, mle[i].line + 1, psl_flags);
		}
	      else
		{
		  /* Several source lines w/o asm instructions associated.  */
		  for (; next_line < mle[i].line; next_line++)
		    {
		      struct cleanup *ui_out_list_chain_line;
		      struct cleanup *ui_out_tuple_chain_line;
		      
		      ui_out_tuple_chain_line
			= make_cleanup_ui_out_tuple_begin_end (uiout,
							       "src_and_asm_line");
		      print_source_lines (symtab, next_line, next_line + 1,
					  psl_flags);
		      ui_out_list_chain_line
			= make_cleanup_ui_out_list_begin_end (uiout,
							      "line_asm_insn");
		      do_cleanups (ui_out_list_chain_line);
		      do_cleanups (ui_out_tuple_chain_line);
		    }
		  /* Print the last line and leave list open for
		     asm instructions to be added.  */
		  ui_out_tuple_chain
		    = make_cleanup_ui_out_tuple_begin_end (uiout,
							   "src_and_asm_line");
		  print_source_lines (symtab, next_line, mle[i].line + 1, psl_flags);
		}
	    }
	  else
	    {
	      ui_out_tuple_chain
		= make_cleanup_ui_out_tuple_begin_end (uiout,
						       "src_and_asm_line");
	      print_source_lines (symtab, mle[i].line, mle[i].line + 1, psl_flags);
	    }

	  next_line = mle[i].line + 1;
	  ui_out_list_chain
	    = make_cleanup_ui_out_list_begin_end (uiout, "line_asm_insn");
	}

      num_displayed += dump_insns (gdbarch, uiout, di,
				   mle[i].start_pc, mle[i].end_pc,
				   how_many, flags, stb, NULL);

      /* When we've reached the end of the mle array, or we've seen the last
         assembly range for this source line, close out the list/tuple.  */
      if (i == (newlines - 1) || mle[i + 1].line > mle[i].line)
	{
	  do_cleanups (ui_out_list_chain);
	  do_cleanups (ui_out_tuple_chain);
	  ui_out_tuple_chain = make_cleanup (null_cleanup, 0);
	  ui_out_list_chain = make_cleanup (null_cleanup, 0);
	  ui_out_text (uiout, "\n");
	}
      if (how_many >= 0 && num_displayed >= how_many)
	break;
    }
  do_cleanups (ui_out_chain);
}

/* The idea here is to present a source-O-centric view of a
   function to the user.  This means that things are presented
   in source order, with (possibly) out of order assembly
   immediately following.  */

static void
do_mixed_source_and_assembly (struct gdbarch *gdbarch, struct ui_out *uiout,
			      struct disassemble_info *di,
			      struct symtab *main_symtab,
			      CORE_ADDR low, CORE_ADDR high,
			      int how_many, int flags, struct ui_file *stb)
{
  int newlines = 0;
  const struct linetable_entry *le, *first_le;
  struct symtab_and_line sal;
  int i, nlines;
  int out_of_order = 0;
  int next_line = 0;
  int num_displayed = 0;
  print_source_lines_flags psl_flags = 0;
  struct cleanup *cleanups;
  struct cleanup *ui_out_chain;
  struct cleanup *ui_out_tuple_chain;
  struct cleanup *ui_out_list_chain;
  CORE_ADDR pc;
  struct symtab *last_symtab;
  int last_line;
  htab_t dis_line_table;

  gdb_assert (main_symtab != NULL && SYMTAB_LINETABLE (main_symtab) != NULL);

  /* First pass: collect the list of all source files and lines.
     We do this so that we can only print lines containing code once.
     We try to print the source text leading up to the next instruction,
     but if that text is for code that will be disassembled later, then
     we'll want to defer printing it until later with its associated code.  */

  dis_line_table = allocate_dis_line_table ();
  cleanups = make_cleanup_htab_delete (dis_line_table);

  pc = low;

  /* The prologue may be empty, but there may still be a line number entry
     for the opening brace which is distinct from the first line of code.
     If the prologue has been eliminated find_pc_line may return the source
     line after the opening brace.  We still want to print this opening brace.
     first_le is used to implement this.  */

  nlines = SYMTAB_LINETABLE (main_symtab)->nitems;
  le = SYMTAB_LINETABLE (main_symtab)->item;
  first_le = NULL;

  /* Skip all the preceding functions.  */
  for (i = 0; i < nlines && le[i].pc < low; i++)
    continue;

  if (i < nlines && le[i].pc < high)
    first_le = &le[i];

  /* Add lines for every pc value.  */
  while (pc < high)
    {
      struct symtab_and_line sal;
      int length;

      sal = find_pc_line (pc, 0);
      length = gdb_insn_length (gdbarch, pc);
      pc += length;

      if (sal.symtab != NULL)
	maybe_add_dis_line_entry (dis_line_table, sal.symtab, sal.line);
    }

  /* Second pass: print the disassembly.

     Output format, from an MI perspective:
       The result is a ui_out list, field name "asm_insns", where elements have
       name "src_and_asm_line".
       Each element is a tuple of source line specs (field names line, file,
       fullname), and field "line_asm_insn" which contains the disassembly.
       Field "line_asm_insn" is a list of tuples: address, func-name, offset,
       opcodes, inst.

     CLI output works on top of this because MI ignores ui_out_text output,
     which is where we put file name and source line contents output.

     Cleanup usage:
     cleanups:
       For things created at the beginning of this function and need to be
       kept until the end of this function.
     ui_out_chain
       Handles the outer "asm_insns" list.
     ui_out_tuple_chain
       The tuples for each group of consecutive disassemblies.
     ui_out_list_chain
       List of consecutive source lines or disassembled insns.  */

  if (flags & DISASSEMBLY_FILENAME)
    psl_flags |= PRINT_SOURCE_LINES_FILENAME;

  ui_out_chain = make_cleanup_ui_out_list_begin_end (uiout, "asm_insns");

  ui_out_tuple_chain = NULL;
  ui_out_list_chain = NULL;

  last_symtab = NULL;
  last_line = 0;
  pc = low;

  while (pc < high)
    {
      struct linetable_entry *le = NULL;
      struct symtab_and_line sal;
      CORE_ADDR end_pc;
      int start_preceding_line_to_display = 0;
      int end_preceding_line_to_display = 0;
      int new_source_line = 0;

      sal = find_pc_line (pc, 0);

      if (sal.symtab != last_symtab)
	{
	  /* New source file.  */
	  new_source_line = 1;

	  /* If this is the first line of output, check for any preceding
	     lines.  */
	  if (last_line == 0
	      && first_le != NULL
	      && first_le->line < sal.line)
	    {
	      start_preceding_line_to_display = first_le->line;
	      end_preceding_line_to_display = sal.line;
	    }
	}
      else
	{
	  /* Same source file as last time.  */
	  if (sal.symtab != NULL)
	    {
	      if (sal.line > last_line + 1 && last_line != 0)
		{
		  int l;

		  /* Several preceding source lines.  Print the trailing ones
		     not associated with code that we'll print later.  */
		  for (l = sal.line - 1; l > last_line; --l)
		    {
		      if (line_has_code_p (dis_line_table, sal.symtab, l))
			break;
		    }
		  if (l < sal.line - 1)
		    {
		      start_preceding_line_to_display = l + 1;
		      end_preceding_line_to_display = sal.line;
		    }
		}
	      if (sal.line != last_line)
		new_source_line = 1;
	      else
		{
		  /* Same source line as last time.  This can happen, depending
		     on the debug info.  */
		}
	    }
	}

      if (new_source_line)
	{
	  /* Skip the newline if this is the first instruction.  */
	  if (pc > low)
	    ui_out_text (uiout, "\n");
	  if (ui_out_tuple_chain != NULL)
	    {
	      gdb_assert (ui_out_list_chain != NULL);
	      do_cleanups (ui_out_list_chain);
	      do_cleanups (ui_out_tuple_chain);
	    }
	  if (sal.symtab != last_symtab
	      && !(flags & DISASSEMBLY_FILENAME))
	    {
	      /* Remember MI ignores ui_out_text.
		 We don't have to do anything here for MI because MI
		 output includes the source specs for each line.  */
	      if (sal.symtab != NULL)
		{
		  ui_out_text (uiout,
			       symtab_to_filename_for_display (sal.symtab));
		}
	      else
		ui_out_text (uiout, "unknown");
	      ui_out_text (uiout, ":\n");
	    }
	  if (start_preceding_line_to_display > 0)
	    {
	      /* Several source lines w/o asm instructions associated.
		 We need to preserve the structure of the output, so output
		 a bunch of line tuples with no asm entries.  */
	      int l;
	      struct cleanup *ui_out_list_chain_line;
	      struct cleanup *ui_out_tuple_chain_line;

	      gdb_assert (sal.symtab != NULL);
	      for (l = start_preceding_line_to_display;
		   l < end_preceding_line_to_display;
		   ++l)
		{
		  ui_out_tuple_chain_line
		    = make_cleanup_ui_out_tuple_begin_end (uiout,
							   "src_and_asm_line");
		  print_source_lines (sal.symtab, l, l + 1, psl_flags);
		  ui_out_list_chain_line
		    = make_cleanup_ui_out_list_begin_end (uiout,
							  "line_asm_insn");
		  do_cleanups (ui_out_list_chain_line);
		  do_cleanups (ui_out_tuple_chain_line);
		}
	    }
	  ui_out_tuple_chain
	    = make_cleanup_ui_out_tuple_begin_end (uiout, "src_and_asm_line");
	  if (sal.symtab != NULL)
	    print_source_lines (sal.symtab, sal.line, sal.line + 1, psl_flags);
	  else
	    ui_out_text (uiout, _("--- no source info for this pc ---\n"));
	  ui_out_list_chain
	    = make_cleanup_ui_out_list_begin_end (uiout, "line_asm_insn");
	}
      else
	{
	  /* Here we're appending instructions to an existing line.
	     By construction the very first insn will have a symtab
	     and follow the new_source_line path above.  */
	  gdb_assert (ui_out_tuple_chain != NULL);
	  gdb_assert (ui_out_list_chain != NULL);
	}

      if (sal.end != 0)
	end_pc = min (sal.end, high);
      else
	end_pc = pc + 1;
      num_displayed += dump_insns (gdbarch, uiout, di, pc, end_pc,
				   how_many, flags, stb, &end_pc);
      pc = end_pc;

      if (how_many >= 0 && num_displayed >= how_many)
	break;

      last_symtab = sal.symtab;
      last_line = sal.line;
    }

  do_cleanups (ui_out_chain);
  do_cleanups (cleanups);
}

static void
do_assembly_only (struct gdbarch *gdbarch, struct ui_out *uiout,
		  struct disassemble_info * di,
		  CORE_ADDR low, CORE_ADDR high,
		  int how_many, int flags, struct ui_file *stb)
{
  int num_displayed = 0;
  struct cleanup *ui_out_chain;

  ui_out_chain = make_cleanup_ui_out_list_begin_end (uiout, "asm_insns");

  num_displayed = dump_insns (gdbarch, uiout, di, low, high, how_many,
                              flags, stb, NULL);

  do_cleanups (ui_out_chain);
}

/* Initialize the disassemble info struct ready for the specified
   stream.  */

static int ATTRIBUTE_PRINTF (2, 3)
fprintf_disasm (void *stream, const char *format, ...)
{
  va_list args;

  va_start (args, format);
  vfprintf_filtered ((struct ui_file *) stream, format, args);
  va_end (args);
  /* Something non -ve.  */
  return 0;
}

struct disassemble_info
gdb_disassemble_info (struct gdbarch *gdbarch, struct ui_file *file)
{
  struct disassemble_info di;

  init_disassemble_info (&di, file, fprintf_disasm);
  di.flavour = bfd_target_unknown_flavour;
  di.memory_error_func = dis_asm_memory_error;
  di.print_address_func = dis_asm_print_address;
  /* NOTE: cagney/2003-04-28: The original code, from the old Insight
     disassembler had a local optomization here.  By default it would
     access the executable file, instead of the target memory (there
     was a growing list of exceptions though).  Unfortunately, the
     heuristic was flawed.  Commands like "disassemble &variable"
     didn't work as they relied on the access going to the target.
     Further, it has been supperseeded by trust-read-only-sections
     (although that should be superseeded by target_trust..._p()).  */
  di.read_memory_func = dis_asm_read_memory;
  di.arch = gdbarch_bfd_arch_info (gdbarch)->arch;
  di.mach = gdbarch_bfd_arch_info (gdbarch)->mach;
  di.endian = gdbarch_byte_order (gdbarch);
  di.endian_code = gdbarch_byte_order_for_code (gdbarch);
  di.application_data = gdbarch;
  disassemble_init_for_target (&di);
  return di;
}

void
gdb_disassembly (struct gdbarch *gdbarch, struct ui_out *uiout,
		 char *file_string, int flags, int how_many,
		 CORE_ADDR low, CORE_ADDR high)
{
  struct ui_file *stb = mem_fileopen ();
  struct cleanup *cleanups = make_cleanup_ui_file_delete (stb);
  struct disassemble_info di = gdb_disassemble_info (gdbarch, stb);
  struct symtab *symtab;
  struct linetable_entry *le = NULL;
  int nlines = -1;

  /* Assume symtab is valid for whole PC range.  */
  symtab = find_pc_line_symtab (low);

  if (symtab != NULL && SYMTAB_LINETABLE (symtab) != NULL)
    nlines = SYMTAB_LINETABLE (symtab)->nitems;

  if (!(flags & (DISASSEMBLY_SOURCE_DEPRECATED | DISASSEMBLY_SOURCE))
      || nlines <= 0)
    do_assembly_only (gdbarch, uiout, &di, low, high, how_many, flags, stb);

  else if (flags & DISASSEMBLY_SOURCE)
    do_mixed_source_and_assembly (gdbarch, uiout, &di, symtab, low, high,
				  how_many, flags, stb);

  else if (flags & DISASSEMBLY_SOURCE_DEPRECATED)
    do_mixed_source_and_assembly_deprecated (gdbarch, uiout, &di, symtab,
					     low, high, how_many, flags, stb);

  do_cleanups (cleanups);
  gdb_flush (gdb_stdout);
}

/* Print the instruction at address MEMADDR in debugged memory,
   on STREAM.  Returns the length of the instruction, in bytes,
   and, if requested, the number of branch delay slot instructions.  */

int
gdb_print_insn (struct gdbarch *gdbarch, CORE_ADDR memaddr,
		struct ui_file *stream, int *branch_delay_insns)
{
  struct disassemble_info di;
  int length;

  di = gdb_disassemble_info (gdbarch, stream);
  length = gdbarch_print_insn (gdbarch, memaddr, &di);
  if (branch_delay_insns)
    {
      if (di.insn_info_valid)
	*branch_delay_insns = di.branch_delay_insns;
      else
	*branch_delay_insns = 0;
    }
  return length;
}

static void
do_ui_file_delete (void *arg)
{
  ui_file_delete ((struct ui_file *) arg);
}

/* Return the length in bytes of the instruction at address MEMADDR in
   debugged memory.  */

int
gdb_insn_length (struct gdbarch *gdbarch, CORE_ADDR addr)
{
  static struct ui_file *null_stream = NULL;

  /* Dummy file descriptor for the disassembler.  */
  if (!null_stream)
    {
      null_stream = ui_file_new ();
      make_final_cleanup (do_ui_file_delete, null_stream);
    }

  return gdb_print_insn (gdbarch, addr, null_stream, NULL);
}

/* fprintf-function for gdb_buffered_insn_length.  This function is a
   nop, we don't want to print anything, we just want to compute the
   length of the insn.  */

static int ATTRIBUTE_PRINTF (2, 3)
gdb_buffered_insn_length_fprintf (void *stream, const char *format, ...)
{
  return 0;
}

/* Initialize a struct disassemble_info for gdb_buffered_insn_length.  */

static void
gdb_buffered_insn_length_init_dis (struct gdbarch *gdbarch,
				   struct disassemble_info *di,
				   const gdb_byte *insn, int max_len,
				   CORE_ADDR addr)
{
  init_disassemble_info (di, NULL, gdb_buffered_insn_length_fprintf);

  /* init_disassemble_info installs buffer_read_memory, etc.
     so we don't need to do that here.
     The cast is necessary until disassemble_info is const-ified.  */
  di->buffer = (gdb_byte *) insn;
  di->buffer_length = max_len;
  di->buffer_vma = addr;

  di->arch = gdbarch_bfd_arch_info (gdbarch)->arch;
  di->mach = gdbarch_bfd_arch_info (gdbarch)->mach;
  di->endian = gdbarch_byte_order (gdbarch);
  di->endian_code = gdbarch_byte_order_for_code (gdbarch);

  disassemble_init_for_target (di);
}

/* Return the length in bytes of INSN.  MAX_LEN is the size of the
   buffer containing INSN.  */

int
gdb_buffered_insn_length (struct gdbarch *gdbarch,
			  const gdb_byte *insn, int max_len, CORE_ADDR addr)
{
  struct disassemble_info di;

  gdb_buffered_insn_length_init_dis (gdbarch, &di, insn, max_len, addr);

  return gdbarch_print_insn (gdbarch, addr, &di);
}