437 lines
10 KiB
C
437 lines
10 KiB
C
/* rddbg.c -- Read debugging information into a generic form.
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Copyright (C) 1995-2022 Free Software Foundation, Inc.
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Written by Ian Lance Taylor <ian@cygnus.com>.
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This file is part of GNU Binutils.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA
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02110-1301, USA. */
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/* This file reads debugging information into a generic form. This
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file knows how to dig the debugging information out of an object
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file. */
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#include "sysdep.h"
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#include "bfd.h"
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#include "libiberty.h"
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#include "bucomm.h"
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#include "debug.h"
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#include "budbg.h"
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static bool read_section_stabs_debugging_info
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(bfd *, asymbol **, long, void *, bool *);
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static bool read_symbol_stabs_debugging_info
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(bfd *, asymbol **, long, void *, bool *);
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static void save_stab (int, int, bfd_vma, const char *);
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static void stab_context (void);
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static void free_saved_stabs (void);
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/* Read debugging information from a BFD. Returns a generic debugging
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pointer. */
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void *
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read_debugging_info (bfd *abfd, asymbol **syms, long symcount,
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bool no_messages)
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{
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void *dhandle;
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bool found;
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dhandle = debug_init ();
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if (dhandle == NULL)
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return NULL;
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if (! read_section_stabs_debugging_info (abfd, syms, symcount, dhandle,
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&found))
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goto err_exit;
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if (bfd_get_flavour (abfd) == bfd_target_aout_flavour)
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{
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if (! read_symbol_stabs_debugging_info (abfd, syms, symcount, dhandle,
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&found))
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goto err_exit;
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}
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/* Try reading the COFF symbols if we didn't find any stabs in COFF
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sections. */
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if (! found
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&& bfd_get_flavour (abfd) == bfd_target_coff_flavour
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&& symcount > 0)
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{
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if (! parse_coff (abfd, syms, symcount, dhandle))
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goto err_exit;
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found = true;
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}
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if (! found)
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{
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if (! no_messages)
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non_fatal (_("%s: no recognized debugging information"),
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bfd_get_filename (abfd));
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err_exit:
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free (dhandle);
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return NULL;
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}
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return dhandle;
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}
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/* Read stabs in sections debugging information from a BFD. */
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static bool
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read_section_stabs_debugging_info (bfd *abfd, asymbol **syms, long symcount,
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void *dhandle, bool *pfound)
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{
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static struct
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{
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const char *secname;
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const char *strsecname;
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}
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names[] =
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{
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{ ".stab", ".stabstr" },
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{ "LC_SYMTAB.stabs", "LC_SYMTAB.stabstr" },
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{ "$GDB_SYMBOLS$", "$GDB_STRINGS$" }
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};
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unsigned int i;
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void *shandle;
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*pfound = false;
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shandle = NULL;
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for (i = 0; i < sizeof names / sizeof names[0]; i++)
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{
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asection *sec, *strsec;
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sec = bfd_get_section_by_name (abfd, names[i].secname);
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strsec = bfd_get_section_by_name (abfd, names[i].strsecname);
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if (sec != NULL && strsec != NULL)
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{
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bfd_size_type stabsize, strsize;
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bfd_byte *stabs, *strings;
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bfd_byte *stab;
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bfd_size_type stroff, next_stroff;
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stabsize = bfd_section_size (sec);
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stabs = (bfd_byte *) xmalloc (stabsize);
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if (! bfd_get_section_contents (abfd, sec, stabs, 0, stabsize))
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{
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fprintf (stderr, "%s: %s: %s\n",
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bfd_get_filename (abfd), names[i].secname,
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bfd_errmsg (bfd_get_error ()));
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free (shandle);
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free (stabs);
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return false;
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}
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strsize = bfd_section_size (strsec);
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strings = (bfd_byte *) xmalloc (strsize + 1);
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if (! bfd_get_section_contents (abfd, strsec, strings, 0, strsize))
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{
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fprintf (stderr, "%s: %s: %s\n",
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bfd_get_filename (abfd), names[i].strsecname,
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bfd_errmsg (bfd_get_error ()));
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free (shandle);
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free (strings);
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free (stabs);
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return false;
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}
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/* Zero terminate the strings table, just in case. */
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strings [strsize] = 0;
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if (shandle == NULL)
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{
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shandle = start_stab (dhandle, abfd, true, syms, symcount);
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if (shandle == NULL)
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{
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free (strings);
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free (stabs);
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return false;
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}
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}
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*pfound = true;
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stroff = 0;
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next_stroff = 0;
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/* PR 17512: file: 078-60391-0.001:0.1. */
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for (stab = stabs; stab <= (stabs + stabsize) - 12; stab += 12)
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{
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unsigned int strx;
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int type;
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int other ATTRIBUTE_UNUSED;
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int desc;
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bfd_vma value;
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/* This code presumes 32 bit values. */
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strx = bfd_get_32 (abfd, stab);
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type = bfd_get_8 (abfd, stab + 4);
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other = bfd_get_8 (abfd, stab + 5);
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desc = bfd_get_16 (abfd, stab + 6);
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value = bfd_get_32 (abfd, stab + 8);
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if (type == 0)
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{
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/* Special type 0 stabs indicate the offset to the
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next string table. */
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stroff = next_stroff;
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next_stroff += value;
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}
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else
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{
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size_t len;
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char *f, *s;
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if (stroff + strx >= strsize)
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{
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fprintf (stderr, _("%s: %s: stab entry %ld is corrupt, strx = 0x%x, type = %d\n"),
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bfd_get_filename (abfd), names[i].secname,
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(long) (stab - stabs) / 12, strx, type);
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continue;
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}
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s = (char *) strings + stroff + strx;
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f = NULL;
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/* PR 17512: file: 002-87578-0.001:0.1.
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It is possible to craft a file where, without the 'strlen (s) > 0',
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an attempt to read the byte before 'strings' would occur. */
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while ((len = strlen (s)) > 0
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&& s[len - 1] == '\\'
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&& stab + 16 <= stabs + stabsize)
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{
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char *p;
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stab += 12;
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p = s + len - 1;
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*p = '\0';
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strx = stroff + bfd_get_32 (abfd, stab);
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if (strx >= strsize)
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{
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fprintf (stderr, _("%s: %s: stab entry %ld is corrupt\n"),
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bfd_get_filename (abfd), names[i].secname,
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(long) (stab - stabs) / 12);
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break;
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}
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s = concat (s, (char *) strings + strx,
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(const char *) NULL);
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/* We have to restore the backslash, because, if
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the linker is hashing stabs strings, we may
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see the same string more than once. */
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*p = '\\';
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free (f);
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f = s;
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}
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save_stab (type, desc, value, s);
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if (! parse_stab (dhandle, shandle, type, desc, value, s))
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{
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stab_context ();
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free_saved_stabs ();
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free (f);
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free (shandle);
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free (stabs);
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free (strings);
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return false;
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}
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/* Don't free f, since I think the stabs code
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expects strings to hang around. This should be
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straightened out. FIXME. */
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}
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}
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free_saved_stabs ();
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free (stabs);
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/* Don't free strings, since I think the stabs code expects
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the strings to hang around. This should be straightened
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out. FIXME. */
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}
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}
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if (shandle != NULL)
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{
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if (! finish_stab (dhandle, shandle))
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return false;
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}
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return true;
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}
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/* Read stabs in the symbol table. */
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static bool
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read_symbol_stabs_debugging_info (bfd *abfd, asymbol **syms, long symcount,
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void *dhandle, bool *pfound)
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{
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void *shandle;
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asymbol **ps, **symend;
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shandle = NULL;
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symend = syms + symcount;
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for (ps = syms; ps < symend; ps++)
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{
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symbol_info i;
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bfd_get_symbol_info (abfd, *ps, &i);
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if (i.type == '-')
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{
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const char *s;
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char *f;
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if (shandle == NULL)
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{
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shandle = start_stab (dhandle, abfd, false, syms, symcount);
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if (shandle == NULL)
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return false;
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}
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*pfound = true;
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s = i.name;
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if (s == NULL || strlen (s) < 1)
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return false;
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f = NULL;
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while (strlen (s) > 0
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&& s[strlen (s) - 1] == '\\'
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&& ps + 1 < symend)
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{
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char *sc, *n;
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++ps;
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sc = xstrdup (s);
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sc[strlen (sc) - 1] = '\0';
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n = concat (sc, bfd_asymbol_name (*ps), (const char *) NULL);
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free (sc);
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free (f);
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f = n;
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s = n;
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}
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save_stab (i.stab_type, i.stab_desc, i.value, s);
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if (! parse_stab (dhandle, shandle, i.stab_type, i.stab_desc,
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i.value, s))
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{
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stab_context ();
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free_saved_stabs ();
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return false;
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}
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/* Don't free f, since I think the stabs code expects
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strings to hang around. This should be straightened out.
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FIXME. */
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}
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}
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free_saved_stabs ();
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if (shandle != NULL)
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{
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if (! finish_stab (dhandle, shandle))
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return false;
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}
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return true;
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}
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/* Record stabs strings, so that we can give some context for errors. */
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#define SAVE_STABS_COUNT (16)
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struct saved_stab
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{
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int type;
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int desc;
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bfd_vma value;
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char *string;
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};
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static struct saved_stab saved_stabs[SAVE_STABS_COUNT];
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static int saved_stabs_index;
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/* Save a stabs string. */
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static void
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save_stab (int type, int desc, bfd_vma value, const char *string)
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{
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free (saved_stabs[saved_stabs_index].string);
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saved_stabs[saved_stabs_index].type = type;
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saved_stabs[saved_stabs_index].desc = desc;
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saved_stabs[saved_stabs_index].value = value;
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saved_stabs[saved_stabs_index].string = xstrdup (string);
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saved_stabs_index = (saved_stabs_index + 1) % SAVE_STABS_COUNT;
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}
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/* Provide context for an error. */
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static void
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stab_context (void)
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{
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int i;
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fprintf (stderr, _("Last stabs entries before error:\n"));
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fprintf (stderr, "n_type n_desc n_value string\n");
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i = saved_stabs_index;
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do
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{
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struct saved_stab *stabp;
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stabp = saved_stabs + i;
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if (stabp->string != NULL)
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{
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const char *s;
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s = bfd_get_stab_name (stabp->type);
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if (s != NULL)
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fprintf (stderr, "%-6s", s);
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else if (stabp->type == 0)
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fprintf (stderr, "HdrSym");
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else
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fprintf (stderr, "%-6d", stabp->type);
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fprintf (stderr, " %-6d ", stabp->desc);
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fprintf_vma (stderr, stabp->value);
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if (stabp->type != 0)
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fprintf (stderr, " %s", stabp->string);
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fprintf (stderr, "\n");
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}
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i = (i + 1) % SAVE_STABS_COUNT;
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}
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while (i != saved_stabs_index);
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}
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/* Free the saved stab strings. */
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static void
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free_saved_stabs (void)
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{
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int i;
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for (i = 0; i < SAVE_STABS_COUNT; i++)
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{
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free (saved_stabs[i].string);
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saved_stabs[i].string = NULL;
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}
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saved_stabs_index = 0;
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}
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