rddbg.c revision 33965 
1/* rddbg.c -- Read debugging information into a generic form.
2   Copyright (C) 1995, 96, 1997 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      fprintf (stderr, "%s: no recognized debugging information\n",
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	      bfd_size_type 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		  s = (char *) strings + stroff + strx;
189		  while (s[strlen (s) - 1] == '\\'
190			 && stab + 12 < stabs + stabsize)
191		    {
192		      char *p;
193
194		      stab += 12;
195		      p = s + strlen (s) - 1;
196		      *p = '\0';
197		      s = concat (s,
198				  ((char *) strings
199				   + stroff
200				   + bfd_get_32 (abfd, stab)),
201				  (const char *) NULL);
202
203		      /* We have to restore the backslash, because, if
204                         the linker is hashing stabs strings, we may
205                         see the same string more than once.  */
206		      *p = '\\';
207
208		      if (f != NULL)
209			free (f);
210		      f = s;
211		    }
212
213		  save_stab (type, desc, value, s);
214
215		  if (! parse_stab (dhandle, shandle, type, desc, value, s))
216		    {
217		      stab_context ();
218		      free_saved_stabs ();
219		      return false;
220		    }
221
222		  /* Don't free f, since I think the stabs code
223                     expects strings to hang around.  This should be
224                     straightened out.  FIXME.  */
225		}
226	    }
227
228	  free_saved_stabs ();
229	  free (stabs);
230
231	  /* Don't free strings, since I think the stabs code expects
232             the strings to hang around.  This should be straightened
233             out.  FIXME.  */
234	}
235    }
236
237  if (shandle != NULL)
238    {
239      if (! finish_stab (dhandle, shandle))
240	return false;
241    }
242
243  return true;
244}
245
246/* Read stabs in the symbol table.  */
247
248static boolean
249read_symbol_stabs_debugging_info (abfd, syms, symcount, dhandle, pfound)
250     bfd *abfd;
251     asymbol **syms;
252     long symcount;
253     PTR dhandle;
254     boolean *pfound;
255{
256  PTR shandle;
257  asymbol **ps, **symend;
258
259  shandle = NULL;
260  symend = syms + symcount;
261  for (ps = syms; ps < symend; ps++)
262    {
263      symbol_info i;
264
265      bfd_get_symbol_info (abfd, *ps, &i);
266
267      if (i.type == '-')
268	{
269	  const char *s;
270	  char *f;
271
272	  if (shandle == NULL)
273	    {
274	      shandle = start_stab (dhandle, abfd, false, syms, symcount);
275	      if (shandle == NULL)
276		return false;
277	    }
278
279	  *pfound = true;
280
281	  s = i.name;
282	  f = NULL;
283	  while (s[strlen (s) - 1] == '\\'
284		 && ps + 1 < symend)
285	    {
286	      char *sc, *n;
287
288	      ++ps;
289	      sc = xstrdup (s);
290	      sc[strlen (sc) - 1] = '\0';
291	      n = concat (sc, bfd_asymbol_name (*ps), (const char *) NULL);
292	      free (sc);
293	      if (f != NULL)
294		free (f);
295	      f = n;
296	      s = n;
297	    }
298
299	  save_stab (i.stab_type, i.stab_desc, i.value, s);
300
301	  if (! parse_stab (dhandle, shandle, i.stab_type, i.stab_desc,
302			    i.value, s))
303	    {
304	      stab_context ();
305	      free_saved_stabs ();
306	      return false;
307	    }
308
309	  /* Don't free f, since I think the stabs code expects
310	     strings to hang around.  This should be straightened out.
311	     FIXME.  */
312	}
313    }
314
315  free_saved_stabs ();
316
317  if (shandle != NULL)
318    {
319      if (! finish_stab (dhandle, shandle))
320	return false;
321    }
322
323  return true;
324}
325
326/* Read IEEE debugging information.  */
327
328static boolean
329read_ieee_debugging_info (abfd, dhandle, pfound)
330     bfd *abfd;
331     PTR dhandle;
332     boolean *pfound;
333{
334  asection *dsec;
335  bfd_size_type size;
336  bfd_byte *contents;
337
338  /* The BFD backend puts the debugging information into a section
339     named .debug.  */
340
341  dsec = bfd_get_section_by_name (abfd, ".debug");
342  if (dsec == NULL)
343    return true;
344
345  size = bfd_section_size (abfd, dsec);
346  contents = (bfd_byte *) xmalloc (size);
347  if (! bfd_get_section_contents (abfd, dsec, contents, 0, size))
348    return false;
349
350  if (! parse_ieee (dhandle, abfd, contents, size))
351    return false;
352
353  free (contents);
354
355  *pfound = true;
356
357  return true;
358}
359
360/* Record stabs strings, so that we can give some context for errors.  */
361
362#define SAVE_STABS_COUNT (16)
363
364struct saved_stab
365{
366  int type;
367  int desc;
368  bfd_vma value;
369  char *string;
370};
371
372static struct saved_stab saved_stabs[SAVE_STABS_COUNT];
373static int saved_stabs_index;
374
375/* Save a stabs string.  */
376
377static void
378save_stab (type, desc, value, string)
379     int type;
380     int desc;
381     bfd_vma value;
382     const char *string;
383{
384  if (saved_stabs[saved_stabs_index].string != NULL)
385    free (saved_stabs[saved_stabs_index].string);
386  saved_stabs[saved_stabs_index].type = type;
387  saved_stabs[saved_stabs_index].desc = desc;
388  saved_stabs[saved_stabs_index].value = value;
389  saved_stabs[saved_stabs_index].string = xstrdup (string);
390  saved_stabs_index = (saved_stabs_index + 1) % SAVE_STABS_COUNT;
391}
392
393/* Provide context for an error.  */
394
395static void
396stab_context ()
397{
398  int i;
399
400  fprintf (stderr, "Last stabs entries before error:\n");
401  fprintf (stderr, "n_type n_desc n_value  string\n");
402
403  i = saved_stabs_index;
404  do
405    {
406      struct saved_stab *stabp;
407
408      stabp = saved_stabs + i;
409      if (stabp->string != NULL)
410	{
411	  const char *s;
412
413	  s = bfd_get_stab_name (stabp->type);
414	  if (s != NULL)
415	    fprintf (stderr, "%-6s", s);
416	  else if (stabp->type == 0)
417	    fprintf (stderr, "HdrSym");
418	  else
419	    fprintf (stderr, "%-6d", stabp->type);
420	  fprintf (stderr, " %-6d ", stabp->desc);
421	  fprintf_vma (stderr, stabp->value);
422	  if (stabp->type != 0)
423	    fprintf (stderr, " %s", stabp->string);
424	  fprintf (stderr, "\n");
425	}
426      i = (i + 1) % SAVE_STABS_COUNT;
427    }
428  while (i != saved_stabs_index);
429}
430
431/* Free the saved stab strings.  */
432
433static void
434free_saved_stabs ()
435{
436  int i;
437
438  for (i = 0; i < SAVE_STABS_COUNT; i++)
439    {
440      if (saved_stabs[i].string != NULL)
441	{
442	  free (saved_stabs[i].string);
443	  saved_stabs[i].string = NULL;
444	}
445    }
446
447  saved_stabs_index = 0;
448}
449