/* rddbg.c -- Read debugging information into a generic form.
Copyright (C) 1995-2020 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 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))
goto err_exit;
if (bfd_get_flavour (abfd) == bfd_target_aout_flavour)
{
if (! read_symbol_stabs_debugging_info (abfd, syms, symcount, dhandle,
&found))
goto err_exit;
}
/* 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))
goto err_exit;
found = TRUE;
}
if (! found)
{
if (! no_messages)
non_fatal (_("%s: no recognized debugging information"),
bfd_get_filename (abfd));
err_exit:
free (dhandle);
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 (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 ()));
free (shandle);
free (stabs);
return FALSE;
}
strsize = bfd_section_size (strsec);
strings = (bfd_byte *) xmalloc (strsize + 1);
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 ()));
free (shandle);
free (strings);
free (stabs);
return FALSE;
}
/* Zero terminate the strings table, just in case. */
strings [strsize] = 0;
if (shandle == NULL)
{
shandle = start_stab (dhandle, abfd, TRUE, syms, symcount);
if (shandle == NULL)
{
free (strings);
free (stabs);
return FALSE;
}
}
*pfound = TRUE;
stroff = 0;
next_stroff = 0;
/* PR 17512: file: 078-60391-0.001:0.1. */
for (stab = stabs; stab <= (stabs + stabsize) - 12; stab += 12)
{
unsigned int strx;
int type;
int other ATTRIBUTE_UNUSED;
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
{
size_t len;
char *f, *s;
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;
f = NULL;
/* PR 17512: file: 002-87578-0.001:0.1.
It is possible to craft a file where, without the 'strlen (s) > 0',
an attempt to read the byte before 'strings' would occur. */
while ((len = strlen (s)) > 0
&& s[len - 1] == '\\'
&& stab + 12 < stabs + stabsize)
{
char *p;
stab += 12;
p = s + len - 1;
*p = '\0';
strx = stroff + bfd_get_32 (abfd, stab);
if (strx >= strsize)
{
fprintf (stderr, _("%s: %s: stab entry %ld is corrupt\n"),
bfd_get_filename (abfd), names[i].secname,
(long) (stab - stabs) / 12);
break;
}
s = concat (s, (char *) strings + strx,
(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 = '\\';
free (f);
f = s;
}
save_stab (type, desc, value, s);
if (! parse_stab (dhandle, shandle, type, desc, value, s))
{
stab_context ();
free_saved_stabs ();
free (f);
free (shandle);
free (stabs);
free (strings);
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;
if (s == NULL || strlen (s) < 1)
return FALSE;
f = NULL;
while (strlen (s) > 0
&& 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);
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;
}
/* 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)
{
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++)
{
free (saved_stabs[i].string);
saved_stabs[i].string = NULL;
}
saved_stabs_index = 0;
}