Re: [PATCH] fix PR gdb/19914

[Yunlian Jiang <yunlian at google dot com>]

Could this be pushed to upstream?

Thanks

On Mon, Apr 25, 2016 at 8:53 AM, Yunlian Jiang <yunlian@google.com> wrote:
> 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 \(int, char \*\*\)}