rddbg.c revision 130561 
1/* rddbg.c -- Read debugging information into a generic form.
2   Copyright 1995, 1996, 1997, 2000, 2002, 2003
3   Free Software Foundation, Inc.
4   Written by Ian Lance Taylor <ian@cygnus.com>.
5
6   This file is part of GNU Binutils.
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, Boston, MA
21   02111-1307, USA.  */
22
23/* This file reads debugging information into a generic form.  This
24   file knows how to dig the debugging information out of an object
25   file.  */
26
27#include "bfd.h"
28#include "bucomm.h"
29#include "libiberty.h"
30#include "debug.h"
31#include "budbg.h"
32
33static bfd_boolean read_section_stabs_debugging_info
34  (bfd *, asymbol **, long, void *, bfd_boolean *);
35static bfd_boolean read_symbol_stabs_debugging_info
36  (bfd *, asymbol **, long, void *, bfd_boolean *);
37static bfd_boolean read_ieee_debugging_info (bfd *, void *, bfd_boolean *);
38static void save_stab (int, int, bfd_vma, const char *);
39static void stab_context (void);
40static void free_saved_stabs (void);
41
42/* Read debugging information from a BFD.  Returns a generic debugging
43   pointer.  */
44
45void *
46read_debugging_info (bfd *abfd, asymbol **syms, long symcount)
47{
48  void *dhandle;
49  bfd_boolean found;
50
51  dhandle = debug_init ();
52  if (dhandle == NULL)
53    return NULL;
54
55  if (! read_section_stabs_debugging_info (abfd, syms, symcount, dhandle,
56					   &found))
57    return NULL;
58
59  if (bfd_get_flavour (abfd) == bfd_target_aout_flavour)
60    {
61      if (! read_symbol_stabs_debugging_info (abfd, syms, symcount, dhandle,
62					      &found))
63	return NULL;
64    }
65
66  if (bfd_get_flavour (abfd) == bfd_target_ieee_flavour)
67    {
68      if (! read_ieee_debugging_info (abfd, dhandle, &found))
69	return NULL;
70    }
71
72  /* Try reading the COFF symbols if we didn't find any stabs in COFF
73     sections.  */
74  if (! found
75      && bfd_get_flavour (abfd) == bfd_target_coff_flavour
76      && symcount > 0)
77    {
78      if (! parse_coff (abfd, syms, symcount, dhandle))
79	return NULL;
80      found = TRUE;
81    }
82
83  if (! found)
84    {
85      non_fatal (_("%s: no recognized debugging information"),
86		 bfd_get_filename (abfd));
87      return NULL;
88    }
89
90  return dhandle;
91}
92
93/* Read stabs in sections debugging information from a BFD.  */
94
95static bfd_boolean
96read_section_stabs_debugging_info (bfd *abfd, asymbol **syms, long symcount,
97				   void *dhandle, bfd_boolean *pfound)
98{
99  static struct
100    {
101      const char *secname;
102      const char *strsecname;
103    } names[] = { { ".stab", ".stabstr" },
104		  { "LC_SYMTAB.stabs", "LC_SYMTAB.stabstr" } };
105  unsigned int i;
106  void *shandle;
107
108  *pfound = FALSE;
109  shandle = NULL;
110
111  for (i = 0; i < sizeof names / sizeof names[0]; i++)
112    {
113      asection *sec, *strsec;
114
115      sec = bfd_get_section_by_name (abfd, names[i].secname);
116      strsec = bfd_get_section_by_name (abfd, names[i].strsecname);
117      if (sec != NULL && strsec != NULL)
118	{
119	  bfd_size_type stabsize, strsize;
120	  bfd_byte *stabs, *strings;
121	  bfd_byte *stab;
122	  bfd_size_type stroff, next_stroff;
123
124	  stabsize = bfd_section_size (abfd, sec);
125	  stabs = (bfd_byte *) xmalloc (stabsize);
126	  if (! bfd_get_section_contents (abfd, sec, stabs, 0, stabsize))
127	    {
128	      fprintf (stderr, "%s: %s: %s\n",
129		       bfd_get_filename (abfd), names[i].secname,
130		       bfd_errmsg (bfd_get_error ()));
131	      return FALSE;
132	    }
133
134	  strsize = bfd_section_size (abfd, strsec);
135	  strings = (bfd_byte *) xmalloc (strsize);
136	  if (! bfd_get_section_contents (abfd, strsec, strings, 0, strsize))
137	    {
138	      fprintf (stderr, "%s: %s: %s\n",
139		       bfd_get_filename (abfd), names[i].strsecname,
140		       bfd_errmsg (bfd_get_error ()));
141	      return FALSE;
142	    }
143
144	  if (shandle == NULL)
145	    {
146	      shandle = start_stab (dhandle, abfd, TRUE, syms, symcount);
147	      if (shandle == NULL)
148		return FALSE;
149	    }
150
151	  *pfound = TRUE;
152
153	  stroff = 0;
154	  next_stroff = 0;
155	  for (stab = stabs; stab < stabs + stabsize; stab += 12)
156	    {
157	      unsigned int strx;
158	      int type;
159	      int other;
160	      int desc;
161	      bfd_vma value;
162
163	      /* This code presumes 32 bit values.  */
164
165	      strx = bfd_get_32 (abfd, stab);
166	      type = bfd_get_8 (abfd, stab + 4);
167	      other = bfd_get_8 (abfd, stab + 5);
168	      desc = bfd_get_16 (abfd, stab + 6);
169	      value = bfd_get_32 (abfd, stab + 8);
170
171	      if (type == 0)
172		{
173		  /* Special type 0 stabs indicate the offset to the
174		     next string table.  */
175		  stroff = next_stroff;
176		  next_stroff += value;
177		}
178	      else
179		{
180		  char *f, *s;
181
182		  f = NULL;
183
184		  if (stroff + strx > strsize)
185		    {
186		      fprintf (stderr, "%s: %s: stab entry %ld is corrupt, strx = 0x%x, type = %d\n",
187			       bfd_get_filename (abfd), names[i].secname,
188			       (long) (stab - stabs) / 12, strx, type);
189		      continue;
190		    }
191
192		  s = (char *) strings + stroff + strx;
193
194		  while (s[strlen (s) - 1] == '\\'
195			 && stab + 12 < stabs + stabsize)
196		    {
197		      char *p;
198
199		      stab += 12;
200		      p = s + strlen (s) - 1;
201		      *p = '\0';
202		      s = concat (s,
203				  ((char *) strings
204				   + stroff
205				   + bfd_get_32 (abfd, stab)),
206				  (const char *) NULL);
207
208		      /* We have to restore the backslash, because, if
209			 the linker is hashing stabs strings, we may
210			 see the same string more than once.  */
211		      *p = '\\';
212
213		      if (f != NULL)
214			free (f);
215		      f = s;
216		    }
217
218		  save_stab (type, desc, value, s);
219
220		  if (! parse_stab (dhandle, shandle, type, desc, value, s))
221		    {
222		      stab_context ();
223		      free_saved_stabs ();
224		      return FALSE;
225		    }
226
227		  /* Don't free f, since I think the stabs code
228		     expects strings to hang around.  This should be
229		     straightened out.  FIXME.  */
230		}
231	    }
232
233	  free_saved_stabs ();
234	  free (stabs);
235
236	  /* Don't free strings, since I think the stabs code expects
237	     the strings to hang around.  This should be straightened
238	     out.  FIXME.  */
239	}
240    }
241
242  if (shandle != NULL)
243    {
244      if (! finish_stab (dhandle, shandle))
245	return FALSE;
246    }
247
248  return TRUE;
249}
250
251/* Read stabs in the symbol table.  */
252
253static bfd_boolean
254read_symbol_stabs_debugging_info (bfd *abfd, asymbol **syms, long symcount,
255				  void *dhandle, bfd_boolean *pfound)
256{
257  void *shandle;
258  asymbol **ps, **symend;
259
260  shandle = NULL;
261  symend = syms + symcount;
262  for (ps = syms; ps < symend; ps++)
263    {
264      symbol_info i;
265
266      bfd_get_symbol_info (abfd, *ps, &i);
267
268      if (i.type == '-')
269	{
270	  const char *s;
271	  char *f;
272
273	  if (shandle == NULL)
274	    {
275	      shandle = start_stab (dhandle, abfd, FALSE, syms, symcount);
276	      if (shandle == NULL)
277		return FALSE;
278	    }
279
280	  *pfound = TRUE;
281
282	  s = i.name;
283	  f = NULL;
284	  while (s[strlen (s) - 1] == '\\'
285		 && ps + 1 < symend)
286	    {
287	      char *sc, *n;
288
289	      ++ps;
290	      sc = xstrdup (s);
291	      sc[strlen (sc) - 1] = '\0';
292	      n = concat (sc, bfd_asymbol_name (*ps), (const char *) NULL);
293	      free (sc);
294	      if (f != NULL)
295		free (f);
296	      f = n;
297	      s = n;
298	    }
299
300	  save_stab (i.stab_type, i.stab_desc, i.value, s);
301
302	  if (! parse_stab (dhandle, shandle, i.stab_type, i.stab_desc,
303			    i.value, s))
304	    {
305	      stab_context ();
306	      free_saved_stabs ();
307	      return FALSE;
308	    }
309
310	  /* Don't free f, since I think the stabs code expects
311	     strings to hang around.  This should be straightened out.
312	     FIXME.  */
313	}
314    }
315
316  free_saved_stabs ();
317
318  if (shandle != NULL)
319    {
320      if (! finish_stab (dhandle, shandle))
321	return FALSE;
322    }
323
324  return TRUE;
325}
326
327/* Read IEEE debugging information.  */
328
329static bfd_boolean
330read_ieee_debugging_info (bfd *abfd, void *dhandle, bfd_boolean *pfound)
331{
332  asection *dsec;
333  bfd_size_type size;
334  bfd_byte *contents;
335
336  /* The BFD backend puts the debugging information into a section
337     named .debug.  */
338
339  dsec = bfd_get_section_by_name (abfd, ".debug");
340  if (dsec == NULL)
341    return TRUE;
342
343  size = bfd_section_size (abfd, dsec);
344  contents = (bfd_byte *) xmalloc (size);
345  if (! bfd_get_section_contents (abfd, dsec, contents, 0, size))
346    return FALSE;
347
348  if (! parse_ieee (dhandle, abfd, contents, size))
349    return FALSE;
350
351  free (contents);
352
353  *pfound = TRUE;
354
355  return TRUE;
356}
357
358/* Record stabs strings, so that we can give some context for errors.  */
359
360#define SAVE_STABS_COUNT (16)
361
362struct saved_stab
363{
364  int type;
365  int desc;
366  bfd_vma value;
367  char *string;
368};
369
370static struct saved_stab saved_stabs[SAVE_STABS_COUNT];
371static int saved_stabs_index;
372
373/* Save a stabs string.  */
374
375static void
376save_stab (int type, int desc, bfd_vma value, const char *string)
377{
378  if (saved_stabs[saved_stabs_index].string != NULL)
379    free (saved_stabs[saved_stabs_index].string);
380  saved_stabs[saved_stabs_index].type = type;
381  saved_stabs[saved_stabs_index].desc = desc;
382  saved_stabs[saved_stabs_index].value = value;
383  saved_stabs[saved_stabs_index].string = xstrdup (string);
384  saved_stabs_index = (saved_stabs_index + 1) % SAVE_STABS_COUNT;
385}
386
387/* Provide context for an error.  */
388
389static void
390stab_context (void)
391{
392  int i;
393
394  fprintf (stderr, _("Last stabs entries before error:\n"));
395  fprintf (stderr, "n_type n_desc n_value  string\n");
396
397  i = saved_stabs_index;
398  do
399    {
400      struct saved_stab *stabp;
401
402      stabp = saved_stabs + i;
403      if (stabp->string != NULL)
404	{
405	  const char *s;
406
407	  s = bfd_get_stab_name (stabp->type);
408	  if (s != NULL)
409	    fprintf (stderr, "%-6s", s);
410	  else if (stabp->type == 0)
411	    fprintf (stderr, "HdrSym");
412	  else
413	    fprintf (stderr, "%-6d", stabp->type);
414	  fprintf (stderr, " %-6d ", stabp->desc);
415	  fprintf_vma (stderr, stabp->value);
416	  if (stabp->type != 0)
417	    fprintf (stderr, " %s", stabp->string);
418	  fprintf (stderr, "\n");
419	}
420      i = (i + 1) % SAVE_STABS_COUNT;
421    }
422  while (i != saved_stabs_index);
423}
424
425/* Free the saved stab strings.  */
426
427static void
428free_saved_stabs (void)
429{
430  int i;
431
432  for (i = 0; i < SAVE_STABS_COUNT; i++)
433    {
434      if (saved_stabs[i].string != NULL)
435	{
436	  free (saved_stabs[i].string);
437	  saved_stabs[i].string = NULL;
438	}
439    }
440
441  saved_stabs_index = 0;
442}
443