1 /* rddbg.c -- Read debugging information into a generic form.
2 Copyright 1995, 1996, 1997, 2000, 2002, 2003, 2005, 2007
3 Free Software Foundation, Inc.
4 Written by Ian Lance Taylor <[email protected]>.
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., 51 Franklin Street - Fifth Floor, Boston, MA
21 02110-1301, 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 "sysdep.h"
28 #include "bfd.h"
29 #include "libiberty.h"
30 #include "bucomm.h"
31 #include "debug.h"
32 #include "budbg.h"
33
34 static bfd_boolean read_section_stabs_debugging_info
35 (bfd *, asymbol **, long, void *, bfd_boolean *);
36 static bfd_boolean read_symbol_stabs_debugging_info
37 (bfd *, asymbol **, long, void *, bfd_boolean *);
38 static bfd_boolean read_ieee_debugging_info (bfd *, void *, bfd_boolean *);
39 static void save_stab (int, int, bfd_vma, const char *);
40 static void stab_context (void);
41 static void free_saved_stabs (void);
42
43 /* Read debugging information from a BFD. Returns a generic debugging
44 pointer. */
45
46 void *
read_debugging_info(bfd * abfd,asymbol ** syms,long symcount)47 read_debugging_info (bfd *abfd, asymbol **syms, long symcount)
48 {
49 void *dhandle;
50 bfd_boolean found;
51
52 dhandle = debug_init ();
53 if (dhandle == NULL)
54 return NULL;
55
56 if (! read_section_stabs_debugging_info (abfd, syms, symcount, dhandle,
57 &found))
58 return NULL;
59
60 if (bfd_get_flavour (abfd) == bfd_target_aout_flavour)
61 {
62 if (! read_symbol_stabs_debugging_info (abfd, syms, symcount, dhandle,
63 &found))
64 return NULL;
65 }
66
67 if (bfd_get_flavour (abfd) == bfd_target_ieee_flavour)
68 {
69 if (! read_ieee_debugging_info (abfd, dhandle, &found))
70 return NULL;
71 }
72
73 /* Try reading the COFF symbols if we didn't find any stabs in COFF
74 sections. */
75 if (! found
76 && bfd_get_flavour (abfd) == bfd_target_coff_flavour
77 && symcount > 0)
78 {
79 if (! parse_coff (abfd, syms, symcount, dhandle))
80 return NULL;
81 found = TRUE;
82 }
83
84 if (! found)
85 {
86 non_fatal (_("%s: no recognized debugging information"),
87 bfd_get_filename (abfd));
88 return NULL;
89 }
90
91 return dhandle;
92 }
93
94 /* Read stabs in sections debugging information from a BFD. */
95
96 static bfd_boolean
read_section_stabs_debugging_info(bfd * abfd,asymbol ** syms,long symcount,void * dhandle,bfd_boolean * pfound)97 read_section_stabs_debugging_info (bfd *abfd, asymbol **syms, long symcount,
98 void *dhandle, bfd_boolean *pfound)
99 {
100 static struct
101 {
102 const char *secname;
103 const char *strsecname;
104 }
105 names[] =
106 {
107 { ".stab", ".stabstr" },
108 { "LC_SYMTAB.stabs", "LC_SYMTAB.stabstr" },
109 { "$GDB_SYMBOLS$", "$GDB_STRINGS$" }
110 };
111 unsigned int i;
112 void *shandle;
113
114 *pfound = FALSE;
115 shandle = NULL;
116
117 for (i = 0; i < sizeof names / sizeof names[0]; i++)
118 {
119 asection *sec, *strsec;
120
121 sec = bfd_get_section_by_name (abfd, names[i].secname);
122 strsec = bfd_get_section_by_name (abfd, names[i].strsecname);
123 if (sec != NULL && strsec != NULL)
124 {
125 bfd_size_type stabsize, strsize;
126 bfd_byte *stabs, *strings;
127 bfd_byte *stab;
128 bfd_size_type stroff, next_stroff;
129
130 stabsize = bfd_section_size (abfd, sec);
131 stabs = (bfd_byte *) xmalloc (stabsize);
132 if (! bfd_get_section_contents (abfd, sec, stabs, 0, stabsize))
133 {
134 fprintf (stderr, "%s: %s: %s\n",
135 bfd_get_filename (abfd), names[i].secname,
136 bfd_errmsg (bfd_get_error ()));
137 return FALSE;
138 }
139
140 strsize = bfd_section_size (abfd, strsec);
141 strings = (bfd_byte *) xmalloc (strsize);
142 if (! bfd_get_section_contents (abfd, strsec, strings, 0, strsize))
143 {
144 fprintf (stderr, "%s: %s: %s\n",
145 bfd_get_filename (abfd), names[i].strsecname,
146 bfd_errmsg (bfd_get_error ()));
147 return FALSE;
148 }
149
150 if (shandle == NULL)
151 {
152 shandle = start_stab (dhandle, abfd, TRUE, syms, symcount);
153 if (shandle == NULL)
154 return FALSE;
155 }
156
157 *pfound = TRUE;
158
159 stroff = 0;
160 next_stroff = 0;
161 for (stab = stabs; stab < stabs + stabsize; stab += 12)
162 {
163 unsigned int strx;
164 int type;
165 int other;
166 int desc;
167 bfd_vma value;
168
169 /* This code presumes 32 bit values. */
170
171 strx = bfd_get_32 (abfd, stab);
172 type = bfd_get_8 (abfd, stab + 4);
173 other = bfd_get_8 (abfd, stab + 5);
174 desc = bfd_get_16 (abfd, stab + 6);
175 value = bfd_get_32 (abfd, stab + 8);
176
177 if (type == 0)
178 {
179 /* Special type 0 stabs indicate the offset to the
180 next string table. */
181 stroff = next_stroff;
182 next_stroff += value;
183 }
184 else
185 {
186 char *f, *s;
187
188 f = NULL;
189
190 if (stroff + strx > strsize)
191 {
192 fprintf (stderr, "%s: %s: stab entry %ld is corrupt, strx = 0x%x, type = %d\n",
193 bfd_get_filename (abfd), names[i].secname,
194 (long) (stab - stabs) / 12, strx, type);
195 continue;
196 }
197
198 s = (char *) strings + stroff + strx;
199
200 while (s[strlen (s) - 1] == '\\'
201 && stab + 12 < stabs + stabsize)
202 {
203 char *p;
204
205 stab += 12;
206 p = s + strlen (s) - 1;
207 *p = '\0';
208 s = concat (s,
209 ((char *) strings
210 + stroff
211 + bfd_get_32 (abfd, stab)),
212 (const char *) NULL);
213
214 /* We have to restore the backslash, because, if
215 the linker is hashing stabs strings, we may
216 see the same string more than once. */
217 *p = '\\';
218
219 if (f != NULL)
220 free (f);
221 f = s;
222 }
223
224 save_stab (type, desc, value, s);
225
226 if (! parse_stab (dhandle, shandle, type, desc, value, s))
227 {
228 stab_context ();
229 free_saved_stabs ();
230 return FALSE;
231 }
232
233 /* Don't free f, since I think the stabs code
234 expects strings to hang around. This should be
235 straightened out. FIXME. */
236 }
237 }
238
239 free_saved_stabs ();
240 free (stabs);
241
242 /* Don't free strings, since I think the stabs code expects
243 the strings to hang around. This should be straightened
244 out. FIXME. */
245 }
246 }
247
248 if (shandle != NULL)
249 {
250 if (! finish_stab (dhandle, shandle))
251 return FALSE;
252 }
253
254 return TRUE;
255 }
256
257 /* Read stabs in the symbol table. */
258
259 static bfd_boolean
read_symbol_stabs_debugging_info(bfd * abfd,asymbol ** syms,long symcount,void * dhandle,bfd_boolean * pfound)260 read_symbol_stabs_debugging_info (bfd *abfd, asymbol **syms, long symcount,
261 void *dhandle, bfd_boolean *pfound)
262 {
263 void *shandle;
264 asymbol **ps, **symend;
265
266 shandle = NULL;
267 symend = syms + symcount;
268 for (ps = syms; ps < symend; ps++)
269 {
270 symbol_info i;
271
272 bfd_get_symbol_info (abfd, *ps, &i);
273
274 if (i.type == '-')
275 {
276 const char *s;
277 char *f;
278
279 if (shandle == NULL)
280 {
281 shandle = start_stab (dhandle, abfd, FALSE, syms, symcount);
282 if (shandle == NULL)
283 return FALSE;
284 }
285
286 *pfound = TRUE;
287
288 s = i.name;
289 f = NULL;
290 while (s[strlen (s) - 1] == '\\'
291 && ps + 1 < symend)
292 {
293 char *sc, *n;
294
295 ++ps;
296 sc = xstrdup (s);
297 sc[strlen (sc) - 1] = '\0';
298 n = concat (sc, bfd_asymbol_name (*ps), (const char *) NULL);
299 free (sc);
300 if (f != NULL)
301 free (f);
302 f = n;
303 s = n;
304 }
305
306 save_stab (i.stab_type, i.stab_desc, i.value, s);
307
308 if (! parse_stab (dhandle, shandle, i.stab_type, i.stab_desc,
309 i.value, s))
310 {
311 stab_context ();
312 free_saved_stabs ();
313 return FALSE;
314 }
315
316 /* Don't free f, since I think the stabs code expects
317 strings to hang around. This should be straightened out.
318 FIXME. */
319 }
320 }
321
322 free_saved_stabs ();
323
324 if (shandle != NULL)
325 {
326 if (! finish_stab (dhandle, shandle))
327 return FALSE;
328 }
329
330 return TRUE;
331 }
332
333 /* Read IEEE debugging information. */
334
335 static bfd_boolean
read_ieee_debugging_info(bfd * abfd,void * dhandle,bfd_boolean * pfound)336 read_ieee_debugging_info (bfd *abfd, void *dhandle, bfd_boolean *pfound)
337 {
338 asection *dsec;
339 bfd_size_type size;
340 bfd_byte *contents;
341
342 /* The BFD backend puts the debugging information into a section
343 named .debug. */
344
345 dsec = bfd_get_section_by_name (abfd, ".debug");
346 if (dsec == NULL)
347 return TRUE;
348
349 size = bfd_section_size (abfd, dsec);
350 contents = (bfd_byte *) xmalloc (size);
351 if (! bfd_get_section_contents (abfd, dsec, contents, 0, size))
352 return FALSE;
353
354 if (! parse_ieee (dhandle, abfd, contents, size))
355 return FALSE;
356
357 free (contents);
358
359 *pfound = TRUE;
360
361 return TRUE;
362 }
363
364 /* Record stabs strings, so that we can give some context for errors. */
365
366 #define SAVE_STABS_COUNT (16)
367
368 struct saved_stab
369 {
370 int type;
371 int desc;
372 bfd_vma value;
373 char *string;
374 };
375
376 static struct saved_stab saved_stabs[SAVE_STABS_COUNT];
377 static int saved_stabs_index;
378
379 /* Save a stabs string. */
380
381 static void
save_stab(int type,int desc,bfd_vma value,const char * string)382 save_stab (int type, int desc, bfd_vma value, 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
395 static void
stab_context(void)396 stab_context (void)
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
433 static void
free_saved_stabs(void)434 free_saved_stabs (void)
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