/* rddbg.c -- Read debugging information into a generic form. Copyright 1995, 1996, 1997, 2000, 2002, 2003, 2005, 2007, 2008 Free Software Foundation, Inc. Written by Ian Lance Taylor <ian@cygnus.com>. This file is part of GNU Binutils. 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, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ /* This file reads debugging information into a generic form. This file knows how to dig the debugging information out of an object file. */ #include "sysdep.h" #include "bfd.h" #include "libiberty.h" #include "bucomm.h" #include "debug.h" #include "budbg.h" static bfd_boolean read_section_stabs_debugging_info (bfd *, asymbol **, long, void *, bfd_boolean *); static bfd_boolean read_symbol_stabs_debugging_info (bfd *, asymbol **, long, void *, bfd_boolean *); static bfd_boolean read_ieee_debugging_info (bfd *, void *, bfd_boolean *); static void save_stab (int, int, bfd_vma, const char *); static void stab_context (void); static void free_saved_stabs (void); /* Read debugging information from a BFD. Returns a generic debugging pointer. */ void * read_debugging_info (bfd *abfd, asymbol **syms, long symcount, bfd_boolean no_messages) { void *dhandle; bfd_boolean found; dhandle = debug_init (); if (dhandle == NULL) return NULL; if (! read_section_stabs_debugging_info (abfd, syms, symcount, dhandle, &found)) return NULL; if (bfd_get_flavour (abfd) == bfd_target_aout_flavour) { if (! read_symbol_stabs_debugging_info (abfd, syms, symcount, dhandle, &found)) return NULL; } if (bfd_get_flavour (abfd) == bfd_target_ieee_flavour) { if (! read_ieee_debugging_info (abfd, dhandle, &found)) return NULL; } /* Try reading the COFF symbols if we didn't find any stabs in COFF sections. */ if (! found && bfd_get_flavour (abfd) == bfd_target_coff_flavour && symcount > 0) { if (! parse_coff (abfd, syms, symcount, dhandle)) return NULL; found = TRUE; } if (! found) { if (! no_messages) non_fatal (_("%s: no recognized debugging information"), bfd_get_filename (abfd)); return NULL; } return dhandle; } /* Read stabs in sections debugging information from a BFD. */ static bfd_boolean read_section_stabs_debugging_info (bfd *abfd, asymbol **syms, long symcount, void *dhandle, bfd_boolean *pfound) { static struct { const char *secname; const char *strsecname; } names[] = { { ".stab", ".stabstr" }, { "LC_SYMTAB.stabs", "LC_SYMTAB.stabstr" }, { "$GDB_SYMBOLS$", "$GDB_STRINGS$" } }; unsigned int i; void *shandle; *pfound = FALSE; shandle = NULL; for (i = 0; i < sizeof names / sizeof names[0]; i++) { asection *sec, *strsec; sec = bfd_get_section_by_name (abfd, names[i].secname); strsec = bfd_get_section_by_name (abfd, names[i].strsecname); if (sec != NULL && strsec != NULL) { bfd_size_type stabsize, strsize; bfd_byte *stabs, *strings; bfd_byte *stab; bfd_size_type stroff, next_stroff; stabsize = bfd_section_size (abfd, sec); stabs = (bfd_byte *) xmalloc (stabsize); if (! bfd_get_section_contents (abfd, sec, stabs, 0, stabsize)) { fprintf (stderr, "%s: %s: %s\n", bfd_get_filename (abfd), names[i].secname, bfd_errmsg (bfd_get_error ())); return FALSE; } strsize = bfd_section_size (abfd, strsec); strings = (bfd_byte *) xmalloc (strsize); if (! bfd_get_section_contents (abfd, strsec, strings, 0, strsize)) { fprintf (stderr, "%s: %s: %s\n", bfd_get_filename (abfd), names[i].strsecname, bfd_errmsg (bfd_get_error ())); return FALSE; } if (shandle == NULL) { shandle = start_stab (dhandle, abfd, TRUE, syms, symcount); if (shandle == NULL) return FALSE; } *pfound = TRUE; stroff = 0; next_stroff = 0; for (stab = stabs; stab < stabs + stabsize; stab += 12) { unsigned int strx; int type; int other; int desc; bfd_vma value; /* This code presumes 32 bit values. */ strx = bfd_get_32 (abfd, stab); type = bfd_get_8 (abfd, stab + 4); other = bfd_get_8 (abfd, stab + 5); desc = bfd_get_16 (abfd, stab + 6); value = bfd_get_32 (abfd, stab + 8); if (type == 0) { /* Special type 0 stabs indicate the offset to the next string table. */ stroff = next_stroff; next_stroff += value; } else { char *f, *s; f = NULL; if (stroff + strx > strsize) { fprintf (stderr, "%s: %s: stab entry %ld is corrupt, strx = 0x%x, type = %d\n", bfd_get_filename (abfd), names[i].secname, (long) (stab - stabs) / 12, strx, type); continue; } s = (char *) strings + stroff + strx; while (s[strlen (s) - 1] == '\\' && stab + 12 < stabs + stabsize) { char *p; stab += 12; p = s + strlen (s) - 1; *p = '\0'; s = concat (s, ((char *) strings + stroff + bfd_get_32 (abfd, stab)), (const char *) NULL); /* We have to restore the backslash, because, if the linker is hashing stabs strings, we may see the same string more than once. */ *p = '\\'; if (f != NULL) free (f); f = s; } save_stab (type, desc, value, s); if (! parse_stab (dhandle, shandle, type, desc, value, s)) { stab_context (); free_saved_stabs (); return FALSE; } /* Don't free f, since I think the stabs code expects strings to hang around. This should be straightened out. FIXME. */ } } free_saved_stabs (); free (stabs); /* Don't free strings, since I think the stabs code expects the strings to hang around. This should be straightened out. FIXME. */ } } if (shandle != NULL) { if (! finish_stab (dhandle, shandle)) return FALSE; } return TRUE; } /* Read stabs in the symbol table. */ static bfd_boolean read_symbol_stabs_debugging_info (bfd *abfd, asymbol **syms, long symcount, void *dhandle, bfd_boolean *pfound) { void *shandle; asymbol **ps, **symend; shandle = NULL; symend = syms + symcount; for (ps = syms; ps < symend; ps++) { symbol_info i; bfd_get_symbol_info (abfd, *ps, &i); if (i.type == '-') { const char *s; char *f; if (shandle == NULL) { shandle = start_stab (dhandle, abfd, FALSE, syms, symcount); if (shandle == NULL) return FALSE; } *pfound = TRUE; s = i.name; f = NULL; while (s[strlen (s) - 1] == '\\' && ps + 1 < symend) { char *sc, *n; ++ps; sc = xstrdup (s); sc[strlen (sc) - 1] = '\0'; n = concat (sc, bfd_asymbol_name (*ps), (const char *) NULL); free (sc); if (f != NULL) free (f); f = n; s = n; } save_stab (i.stab_type, i.stab_desc, i.value, s); if (! parse_stab (dhandle, shandle, i.stab_type, i.stab_desc, i.value, s)) { stab_context (); free_saved_stabs (); return FALSE; } /* Don't free f, since I think the stabs code expects strings to hang around. This should be straightened out. FIXME. */ } } free_saved_stabs (); if (shandle != NULL) { if (! finish_stab (dhandle, shandle)) return FALSE; } return TRUE; } /* Read IEEE debugging information. */ static bfd_boolean read_ieee_debugging_info (bfd *abfd, void *dhandle, bfd_boolean *pfound) { asection *dsec; bfd_size_type size; bfd_byte *contents; /* The BFD backend puts the debugging information into a section named .debug. */ dsec = bfd_get_section_by_name (abfd, ".debug"); if (dsec == NULL) return TRUE; size = bfd_section_size (abfd, dsec); contents = (bfd_byte *) xmalloc (size); if (! bfd_get_section_contents (abfd, dsec, contents, 0, size)) return FALSE; if (! parse_ieee (dhandle, abfd, contents, size)) return FALSE; free (contents); *pfound = TRUE; return TRUE; } /* Record stabs strings, so that we can give some context for errors. */ #define SAVE_STABS_COUNT (16) struct saved_stab { int type; int desc; bfd_vma value; char *string; }; static struct saved_stab saved_stabs[SAVE_STABS_COUNT]; static int saved_stabs_index; /* Save a stabs string. */ static void save_stab (int type, int desc, bfd_vma value, const char *string) { if (saved_stabs[saved_stabs_index].string != NULL) free (saved_stabs[saved_stabs_index].string); saved_stabs[saved_stabs_index].type = type; saved_stabs[saved_stabs_index].desc = desc; saved_stabs[saved_stabs_index].value = value; saved_stabs[saved_stabs_index].string = xstrdup (string); saved_stabs_index = (saved_stabs_index + 1) % SAVE_STABS_COUNT; } /* Provide context for an error. */ static void stab_context (void) { int i; fprintf (stderr, _("Last stabs entries before error:\n")); fprintf (stderr, "n_type n_desc n_value string\n"); i = saved_stabs_index; do { struct saved_stab *stabp; stabp = saved_stabs + i; if (stabp->string != NULL) { const char *s; s = bfd_get_stab_name (stabp->type); if (s != NULL) fprintf (stderr, "%-6s", s); else if (stabp->type == 0) fprintf (stderr, "HdrSym"); else fprintf (stderr, "%-6d", stabp->type); fprintf (stderr, " %-6d ", stabp->desc); fprintf_vma (stderr, stabp->value); if (stabp->type != 0) fprintf (stderr, " %s", stabp->string); fprintf (stderr, "\n"); } i = (i + 1) % SAVE_STABS_COUNT; } while (i != saved_stabs_index); } /* Free the saved stab strings. */ static void free_saved_stabs (void) { int i; for (i = 0; i < SAVE_STABS_COUNT; i++) { if (saved_stabs[i].string != NULL) { free (saved_stabs[i].string); saved_stabs[i].string = NULL; } } saved_stabs_index = 0; }