Re: [PATCH] fix PR gdb/19914

[Yunlian Jiang <yunlian at google dot com>]

Yes, this is what I want.
Thanks

On Sun, Apr 24, 2016 at 8:47 PM, Doug Evans <dje@google.com> wrote:
> Yunlian Jiang writes:
>  > ping?
>  >
>  > On Wed, Apr 13, 2016 at 11:18 AM, Yunlian Jiang <yunlian@google.com>
> wrote:
>  > > I have a updated one. It uses separate_debug_objfile_backlink to get
>  > > the real dwp file name if it is a debug file.
>  > >
>  > > --- a/gdb/dwarf2read.c
>  > > +++ b/gdb/dwarf2read.c
>  > > @@ -10835,13 +10835,28 @@ open_and_init_dwp_file (void)
>  > >  {
>  > >    struct objfile *objfile = dwarf2_per_objfile->objfile;
>  > >    struct dwp_file *dwp_file;
>  > > +  char *dwp_base_name;
>  > >    char *dwp_name;
>  > >    bfd *dbfd;
>  > >    struct cleanup *cleanups;
>  > >
>  > >    /* Try to find first .dwp for the binary file before any symbolic
> links
>  > >       resolving.  */
>  > > +
>  > > +  /* If the objfile is a debug file, find the name of the real binary
>  > > +     file and get the name of dwp file from there. */
>  > > +  if (objfile->separate_debug_objfile_backlink)
>  > > +    {
>  > > +      dwp_base_name = xstrprintf ("%s.dwp",
>  > > +        lbasename
> (objfile->separate_debug_objfile_backlink->original_name));
>  > > +    }
>  > > +  else
>  > > +    dwp_base_name = xstrprintf ("%s.dwp", lbasename
> (objfile->original_name));
>  > > +  dwp_name = xstrprintf ("%s%s%s", ldirname(objfile->original_name),
>  > > +                         SLASH_STRING, dwp_base_name);
>  > > +
>  > >    dwp_name = xstrprintf ("%s.dwp", objfile->original_name);
>  > > +  cleanups = make_cleanup (xfree, dwp_base_name);
>  > >    cleanups = make_cleanup (xfree, dwp_name);
>  > >
>  > >    dbfd = open_dwp_file (dwp_name);
>  > >
>  > > On Fri, Apr 8, 2016 at 3:54 PM, Doug Evans <dje@google.com> wrote:
>  > >> Yunlian Jiang writes:
>  > >>  > Hi.
>  > >>  >
>  > >>  > This tries to fix PR gdb/19914. When the object file is not
>  > >>  > a binary but a .debug file, the function to try to find the .dwp
>  > >>  > file in the debug directory does not work. This one tries to solve
>  > >>  > this problem.
>  > >>  >
>  > >>  > 2016-04-05  Yunlian Jiang <yunlian@google.com>
>  > >>  >                * gdb/dwarf2read.c: Try to find .dwp for .debug
>  > >>  >
>  > >>  >
>  > >>  > diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
>  > >>  > index dcd49e3..551376a 100644
>  > >>  > --- a/gdb/dwarf2read.c
>  > >>  > +++ b/gdb/dwarf2read.c
>  > >>  > @@ -10854,6 +10854,18 @@ open_and_init_dwp_file (void)
>  > >>  >        dbfd = open_dwp_file (dwp_name);
>  > >>  >      }
>  > >>  >
>  > >>  > +  if (dbfd == NULL && strlen(dwp_name) > 10)
>  > >>  > +    {
>  > >>  > +      /* Try to find .dwp for the debug file.  */
>  > >>  > +      if (!strcmp(dwp_name + strlen(dwp_name) - 10, ".debug.dwp"))
>  > >>  > +        {
>  > >>  > +           dwp_name[strlen(dwp_name) - 10] = '\0';
>  > >>  > +           dwp_name = xstrprintf ("%s.dwp", dwp_name);
>  > >>  > +           make_cleanup (xfree, dwp_name);
>  > >>  > +           dbfd = open_dwp_file (dwp_name);
>  > >>  > +        }
>  > >>  > +    }
>  > >>  > +
>  > >>  >    if (dbfd == NULL)
>  > >>  >      {
>  > >>  >        if (dwarf_read_debug)
>  > >>
>  > >> Hi.
>  > >>
>  > >> I've looked at this a little bit.
>  > >> I don't have time for a complete review at the moment,
>  > >> but one thing I'm wondering about is whether this extra
>  > >> test should go in open_dwp_file instead.
>  > >>
>  > >> Plus, while we're making the assumption that the separate debug
>  > >> file ends with ".debug" that's not necessarily true.
>  > >> Not sure we can do better, but one thought is to look in
>  > >> separate_debug_objfile_backlink and use that.
>
> Ok, had time to fully dig into this.
>
> There are a couple of problems with the patch.
> E.g., ldirname malloc's its result, so that needs to be freed.
>
> I came up with this (which includes a testcase).
>
> Look ok?
>
> 2016-04-24  Yunlian Jiang <yunlian@google.com>
>             Doug Evans  <dje@google.com>
>
>         PR symtab/19914
>         * dwarf2read.c (open_and_init_dwp_file): Look at backlink if objfile
>         is separate debug file.
>
>         testsuite/
>         * gdb.dwarf2/dwp-sepdebug.c: New file.
>         * gdb.dwarf2/dwp-sepdebug.exp: New file.
>
> diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
> index 7bbf080..eb81151 100644
> --- a/gdb/dwarf2read.c
> +++ b/gdb/dwarf2read.c
> @@ -10838,12 +10838,26 @@ open_and_init_dwp_file (void)
>    struct dwp_file *dwp_file;
>    char *dwp_name;
>    bfd *dbfd;
> -  struct cleanup *cleanups;
> +  struct cleanup *cleanups = make_cleanup (null_cleanup, 0);
>
>    /* Try to find first .dwp for the binary file before any symbolic links
>       resolving.  */
> -  dwp_name = xstrprintf ("%s.dwp", objfile->original_name);
> -  cleanups = make_cleanup (xfree, dwp_name);
> +
> +  /* If the objfile is a debug file, find the name of the real binary
> +     file and get the name of dwp file from there.  */
> +  if (objfile->separate_debug_objfile_backlink != NULL)
> +    {
> +      struct objfile *backlink = objfile->separate_debug_objfile_backlink;
> +      const char *backlink_basename = lbasename (backlink->original_name);
> +      char *debug_dirname = ldirname (objfile->original_name);
> +
> +      make_cleanup (xfree, debug_dirname);
> +      dwp_name = xstrprintf ("%s%s%s.dwp", debug_dirname,
> +                            SLASH_STRING, backlink_basename);
> +    }
> +  else
> +    dwp_name = xstrprintf ("%s.dwp", objfile->original_name);
> +  make_cleanup (xfree, dwp_name);
>
>    dbfd = open_dwp_file (dwp_name);
>    if (dbfd == NULL
> diff --git a/gdb/testsuite/gdb.dwarf2/dwp-sepdebug.c
> b/gdb/testsuite/gdb.dwarf2/dwp-sepdebug.c
> new file mode 100644
> index 0000000..bb11da2
> --- /dev/null
> +++ b/gdb/testsuite/gdb.dwarf2/dwp-sepdebug.c
> @@ -0,0 +1,22 @@
> +/* This testcase is part of GDB, the GNU debugger.
> +
> +   Copyright 2016 Free Software Foundation, Inc.
> +
> +   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, see <http://www.gnu.org/licenses/>.
> */
> +
> +int
> +main (int argc, char **argv)
> +{
> +  return 0;
> +}
> diff --git a/gdb/testsuite/gdb.dwarf2/dwp-sepdebug.exp
> b/gdb/testsuite/gdb.dwarf2/dwp-sepdebug.exp
> new file mode 100644
> index 0000000..a4e7068
> --- /dev/null
> +++ b/gdb/testsuite/gdb.dwarf2/dwp-sepdebug.exp
> @@ -0,0 +1,40 @@
> +# Copyright 2016 Free Software Foundation, Inc.
> +
> +# 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, see <http://www.gnu.org/licenses/>.
> +
> +standard_testfile
> +
> +if { [build_executable ${testfile}.exp ${testfile} ${srcfile}] == -1 } {
> +    return -1
> +}
> +if ![remote_file host exists [standard_output_file ${testfile}.dwp]] {
> +    unsupported "testsuite run does not produce dwp files"
> +    return 0
> +}
> +
> +# Note: the procedure gdb_gnu_strip_debug will produce an executable called
> +# ${binfile}, which is just like the executable ($binfile) but without
> +# the debuginfo. Instead $binfile has a .gnu_debuglink section which
> contains
> +# the name of a debuginfo only file. This file will be stored in the
> +# gdb.base/ subdirectory.
> +
> +if [gdb_gnu_strip_debug $binfile$EXEEXT] {
> +    # check that you have a recent version of strip and objcopy installed
> +    unsupported "cannot produce separate debug info files"
> +    return -1
> +}
> +
> +clean_restart "$testfile"
> +
> +gdb_test "ptype main" {type = int \(int, char \*\*\)}