rddbg.c revision 104834 
1/* rddbg.c -- Read debugging information into a generic form.
2   Copyright 1995, 1996, 1997, 2000 Free Software Foundation, Inc.
3   Written by Ian Lance Taylor <ian@cygnus.com>.
4
5   This file is part of GNU Binutils.
6
7   This program is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 2 of the License, or
10   (at your option) any later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program; if not, write to the Free Software
19   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
20   02111-1307, USA.  */
21
22/* This file reads debugging information into a generic form.  This
23   file knows how to dig the debugging information out of an object
24   file.  */
25
26#include "bfd.h"
27#include "bucomm.h"
28#include "libiberty.h"
29#include "debug.h"
30#include "budbg.h"
31
32static boolean read_section_stabs_debugging_info
33  PARAMS ((bfd *, asymbol **, long, PTR, boolean *));
34static boolean read_symbol_stabs_debugging_info
35  PARAMS ((bfd *, asymbol **, long, PTR, boolean *));
36static boolean read_ieee_debugging_info PARAMS ((bfd *, PTR, boolean *));
37static void save_stab PARAMS ((int, int, bfd_vma, const char *));
38static void stab_context PARAMS ((void));
39static void free_saved_stabs PARAMS ((void));
40
41/* Read debugging information from a BFD.  Returns a generic debugging
42   pointer.  */
43
44PTR
45read_debugging_info (abfd, syms, symcount)
46     bfd *abfd;
47     asymbol **syms;
48     long symcount;
49{
50  PTR dhandle;
51  boolean found;
52
53  dhandle = debug_init ();
54  if (dhandle == NULL)
55    return NULL;
56
57  if (! read_section_stabs_debugging_info (abfd, syms, symcount, dhandle,
58					   &found))
59    return NULL;
60
61  if (bfd_get_flavour (abfd) == bfd_target_aout_flavour)
62    {
63      if (! read_symbol_stabs_debugging_info (abfd, syms, symcount, dhandle,
64					      &found))
65	return NULL;
66    }
67
68  if (bfd_get_flavour (abfd) == bfd_target_ieee_flavour)
69    {
70      if (! read_ieee_debugging_info (abfd, dhandle, &found))
71	return NULL;
72    }
73
74  /* Try reading the COFF symbols if we didn't find any stabs in COFF
75     sections.  */
76  if (! found
77      && bfd_get_flavour (abfd) == bfd_target_coff_flavour
78      && symcount > 0)
79    {
80      if (! parse_coff (abfd, syms, symcount, dhandle))
81	return NULL;
82      found = true;
83    }
84
85  if (! found)
86    {
87      non_fatal (_("%s: no recognized debugging information"),
88		 bfd_get_filename (abfd));
89      return NULL;
90    }
91
92  return dhandle;
93}
94
95/* Read stabs in sections debugging information from a BFD.  */
96
97static boolean
98read_section_stabs_debugging_info (abfd, syms, symcount, dhandle, pfound)
99     bfd *abfd;
100     asymbol **syms;
101     long symcount;
102     PTR dhandle;
103     boolean *pfound;
104{
105  static struct
106    {
107      const char *secname;
108      const char *strsecname;
109    } names[] = { { ".stab", ".stabstr" } };
110  unsigned int i;
111  PTR shandle;
112
113  *pfound = false;
114  shandle = NULL;
115
116  for (i = 0; i < sizeof names / sizeof names[0]; i++)
117    {
118      asection *sec, *strsec;
119
120      sec = bfd_get_section_by_name (abfd, names[i].secname);
121      strsec = bfd_get_section_by_name (abfd, names[i].strsecname);
122      if (sec != NULL && strsec != NULL)
123	{
124	  bfd_size_type stabsize, strsize;
125	  bfd_byte *stabs, *strings;
126	  bfd_byte *stab;
127	  bfd_size_type stroff, next_stroff;
128
129	  stabsize = bfd_section_size (abfd, sec);
130	  stabs = (bfd_byte *) xmalloc (stabsize);
131	  if (! bfd_get_section_contents (abfd, sec, stabs, 0, stabsize))
132	    {
133	      fprintf (stderr, "%s: %s: %s\n",
134		       bfd_get_filename (abfd), names[i].secname,
135		       bfd_errmsg (bfd_get_error ()));
136	      return false;
137	    }
138
139	  strsize = bfd_section_size (abfd, strsec);
140	  strings = (bfd_byte *) xmalloc (strsize);
141	  if (! bfd_get_section_contents (abfd, strsec, strings, 0, strsize))
142	    {
143	      fprintf (stderr, "%s: %s: %s\n",
144		       bfd_get_filename (abfd), names[i].strsecname,
145		       bfd_errmsg (bfd_get_error ()));
146	      return false;
147	    }
148
149	  if (shandle == NULL)
150	    {
151	      shandle = start_stab (dhandle, abfd, true, syms, symcount);
152	      if (shandle == NULL)
153		return false;
154	    }
155
156	  *pfound = true;
157
158	  stroff = 0;
159	  next_stroff = 0;
160	  for (stab = stabs; stab < stabs + stabsize; stab += 12)
161	    {
162	      unsigned int strx;
163	      int type;
164	      int other;
165	      int desc;
166	      bfd_vma value;
167
168	      /* This code presumes 32 bit values.  */
169
170	      strx = bfd_get_32 (abfd, stab);
171	      type = bfd_get_8 (abfd, stab + 4);
172	      other = bfd_get_8 (abfd, stab + 5);
173	      desc = bfd_get_16 (abfd, stab + 6);
174	      value = bfd_get_32 (abfd, stab + 8);
175
176	      if (type == 0)
177		{
178		  /* Special type 0 stabs indicate the offset to the
179                     next string table.  */
180		  stroff = next_stroff;
181		  next_stroff += value;
182		}
183	      else
184		{
185		  char *f, *s;
186
187		  f = NULL;
188
189		  if (stroff + strx > strsize)
190		    {
191		      fprintf (stderr, "%s: %s: stab entry %d is corrupt, strx = 0x%x, type = %d\n",
192			       bfd_get_filename (abfd), names[i].secname,
193			       (stab - stabs) / 12, strx, type);
194		      continue;
195		    }
196
197		  s = (char *) strings + stroff + strx;
198
199		  while (s[strlen (s) - 1] == '\\'
200			 && stab + 12 < stabs + stabsize)
201		    {
202		      char *p;
203
204		      stab += 12;
205		      p = s + strlen (s) - 1;
206		      *p = '\0';
207		      s = concat (s,
208				  ((char *) strings
209				   + stroff
210				   + bfd_get_32 (abfd, stab)),
211				  (const char *) NULL);
212
213		      /* We have to restore the backslash, because, if
214                         the linker is hashing stabs strings, we may
215                         see the same string more than once.  */
216		      *p = '\\';
217
218		      if (f != NULL)
219			free (f);
220		      f = s;
221		    }
222
223		  save_stab (type, desc, value, s);
224
225		  if (! parse_stab (dhandle, shandle, type, desc, value, s))
226		    {
227		      stab_context ();
228		      free_saved_stabs ();
229		      return false;
230		    }
231
232		  /* Don't free f, since I think the stabs code
233                     expects strings to hang around.  This should be
234                     straightened out.  FIXME.  */
235		}
236	    }
237
238	  free_saved_stabs ();
239	  free (stabs);
240
241	  /* Don't free strings, since I think the stabs code expects
242             the strings to hang around.  This should be straightened
243             out.  FIXME.  */
244	}
245    }
246
247  if (shandle != NULL)
248    {
249      if (! finish_stab (dhandle, shandle))
250	return false;
251    }
252
253  return true;
254}
255
256/* Read stabs in the symbol table.  */
257
258static boolean
259read_symbol_stabs_debugging_info (abfd, syms, symcount, dhandle, pfound)
260     bfd *abfd;
261     asymbol **syms;
262     long symcount;
263     PTR dhandle;
264     boolean *pfound;
265{
266  PTR shandle;
267  asymbol **ps, **symend;
268
269  shandle = NULL;
270  symend = syms + symcount;
271  for (ps = syms; ps < symend; ps++)
272    {
273      symbol_info i;
274
275      bfd_get_symbol_info (abfd, *ps, &i);
276
277      if (i.type == '-')
278	{
279	  const char *s;
280	  char *f;
281
282	  if (shandle == NULL)
283	    {
284	      shandle = start_stab (dhandle, abfd, false, syms, symcount);
285	      if (shandle == NULL)
286		return false;
287	    }
288
289	  *pfound = true;
290
291	  s = i.name;
292	  f = NULL;
293	  while (s[strlen (s) - 1] == '\\'
294		 && ps + 1 < symend)
295	    {
296	      char *sc, *n;
297
298	      ++ps;
299	      sc = xstrdup (s);
300	      sc[strlen (sc) - 1] = '\0';
301	      n = concat (sc, bfd_asymbol_name (*ps), (const char *) NULL);
302	      free (sc);
303	      if (f != NULL)
304		free (f);
305	      f = n;
306	      s = n;
307	    }
308
309	  save_stab (i.stab_type, i.stab_desc, i.value, s);
310
311	  if (! parse_stab (dhandle, shandle, i.stab_type, i.stab_desc,
312			    i.value, s))
313	    {
314	      stab_context ();
315	      free_saved_stabs ();
316	      return false;
317	    }
318
319	  /* Don't free f, since I think the stabs code expects
320	     strings to hang around.  This should be straightened out.
321	     FIXME.  */
322	}
323    }
324
325  free_saved_stabs ();
326
327  if (shandle != NULL)
328    {
329      if (! finish_stab (dhandle, shandle))
330	return false;
331    }
332
333  return true;
334}
335
336/* Read IEEE debugging information.  */
337
338static boolean
339read_ieee_debugging_info (abfd, dhandle, pfound)
340     bfd *abfd;
341     PTR dhandle;
342     boolean *pfound;
343{
344  asection *dsec;
345  bfd_size_type size;
346  bfd_byte *contents;
347
348  /* The BFD backend puts the debugging information into a section
349     named .debug.  */
350
351  dsec = bfd_get_section_by_name (abfd, ".debug");
352  if (dsec == NULL)
353    return true;
354
355  size = bfd_section_size (abfd, dsec);
356  contents = (bfd_byte *) xmalloc (size);
357  if (! bfd_get_section_contents (abfd, dsec, contents, 0, size))
358    return false;
359
360  if (! parse_ieee (dhandle, abfd, contents, size))
361    return false;
362
363  free (contents);
364
365  *pfound = true;
366
367  return true;
368}
369
370/* Record stabs strings, so that we can give some context for errors.  */
371
372#define SAVE_STABS_COUNT (16)
373
374struct saved_stab
375{
376  int type;
377  int desc;
378  bfd_vma value;
379  char *string;
380};
381
382static struct saved_stab saved_stabs[SAVE_STABS_COUNT];
383static int saved_stabs_index;
384
385/* Save a stabs string.  */
386
387static void
388save_stab (type, desc, value, string)
389     int type;
390     int desc;
391     bfd_vma value;
392     const char *string;
393{
394  if (saved_stabs[saved_stabs_index].string != NULL)
395    free (saved_stabs[saved_stabs_index].string);
396  saved_stabs[saved_stabs_index].type = type;
397  saved_stabs[saved_stabs_index].desc = desc;
398  saved_stabs[saved_stabs_index].value = value;
399  saved_stabs[saved_stabs_index].string = xstrdup (string);
400  saved_stabs_index = (saved_stabs_index + 1) % SAVE_STABS_COUNT;
401}
402
403/* Provide context for an error.  */
404
405static void
406stab_context ()
407{
408  int i;
409
410  fprintf (stderr, _("Last stabs entries before error:\n"));
411  fprintf (stderr, "n_type n_desc n_value  string\n");
412
413  i = saved_stabs_index;
414  do
415    {
416      struct saved_stab *stabp;
417
418      stabp = saved_stabs + i;
419      if (stabp->string != NULL)
420	{
421	  const char *s;
422
423	  s = bfd_get_stab_name (stabp->type);
424	  if (s != NULL)
425	    fprintf (stderr, "%-6s", s);
426	  else if (stabp->type == 0)
427	    fprintf (stderr, "HdrSym");
428	  else
429	    fprintf (stderr, "%-6d", stabp->type);
430	  fprintf (stderr, " %-6d ", stabp->desc);
431	  fprintf_vma (stderr, stabp->value);
432	  if (stabp->type != 0)
433	    fprintf (stderr, " %s", stabp->string);
434	  fprintf (stderr, "\n");
435	}
436      i = (i + 1) % SAVE_STABS_COUNT;
437    }
438  while (i != saved_stabs_index);
439}
440
441/* Free the saved stab strings.  */
442
443static void
444free_saved_stabs ()
445{
446  int i;
447
448  for (i = 0; i < SAVE_STABS_COUNT; i++)
449    {
450      if (saved_stabs[i].string != NULL)
451	{
452	  free (saved_stabs[i].string);
453	  saved_stabs[i].string = NULL;
454	}
455    }
456
457  saved_stabs_index = 0;
458}
459