Re: Building GDB 7.3.92 with MinGW

[asmwarrior <asmwarrior at gmail dot com>]

On 2012-1-12 1:48, Doug Evans wrote:
> On Tue, Jan 10, 2012 at 4:35 PM, asmwarrior<asmwarrior@gmail.com>  wrote:
> > On 2012-1-11 5:23, Doug Evans wrote:
> > > For one, remembering to pass -data-directory is a pain.
> >
> > This parameter does not work correctly under MinGW in the case that I would
> > like gdb to automatically run the python script when it startup.
> When you say "run the python script", *which* python script are you
> referring to?
The script code is embedded in c source code in "python.c", in function: voidfinish_python_initialization (void)
> > Normally, my gdb is put in MinGW/bin, and the gdb's own python script is
> > under:
> > MinGW\share\gdb\python\gdb\*.py
> >
> > I need to hard-code the code in gdb/main.c to set the data-directory value.
> > (Because gdb is build from MSYS+MinGW, but it run normally on Windows shell
> > without MSYS)
> >
> > Here are some hard-code modify to the main.c file, if you do not change
> > this, there is no way to load gdb's own python scripts.
> >
> > diff --git a/gdb/main.c b/gdb/main.c
> > index 8b45c25..46b11a8 100644
> > --- a/gdb/main.c
> > +++ b/gdb/main.c
> > @@ -42,6 +42,10 @@
> >   #include "python/python.h"
> >   #include "objfiles.h"
> >   +#ifdef _WIN32
> > +extern int get_app_fullpath(char *location, int length);
> > +#endif
> > +
> >   /* The selected interpreter.  This will be used as a set command
> >     variable, so it should always be malloc'ed - since
> >     do_setshow_command will free it.  */
> > @@ -355,8 +359,27 @@ captured_main (void *data)
> >    debug_file_directory = relocate_gdb_directory (DEBUGDIR,
> >                                                  DEBUGDIR_RELOCATABLE);
> >   +
> > +#ifdef _WIN32
> > +  {
> > +    char location[500];
> > +    int len= get_app_fullpath(location, sizeof (location));
> > +    if (len == 0 || len>  500 - 1)
> > +      gdb_datadir = relocate_gdb_directory
> > (GDB_DATADIR,GDB_DATADIR_RELOCATABLE);
> > +    else
> > +    {
> > +        char *p_slash =strrchr(location,'\\');
> > +        *p_slash = '\000';
> > +        p_slash =strrchr(location,'\\'); /* remove the bin folder*/
> > +        *p_slash = '\000';
> > +        strcat(location,"\\share\\gdb");
> > +        gdb_datadir = xstrdup (location);
> > +    }
> > +  }
> > +#else
> >    gdb_datadir = relocate_gdb_directory (GDB_DATADIR,
> > -                                       GDB_DATADIR_RELOCATABLE);
> > +                                       GDB_DATADIR_RELOCATABLE);
> > +#endif
> >   #ifdef WITH_PYTHON_PATH
> >    {
> >
> > If I remember correctly, I have post it some months ago.
> *If* there is a bug here, and it's not pilot error, it feels like
> perhaps the bug is in relocate_gdb_directory.
> [Why don't all calls to relocate_gdb_directory require similar treatment?
> Thus this feels like the wrong way to go.]
>
> Maybe if you provide a sample session (and complete session please, no
> editing to trim it down), that will help.
I have just look at my notes half years ago(no time to write a complete session right now), the issue is:
In the file:

build\gdb\config.status

The value is hard-coded:

D["DEBUGDIR"]=" \"/mingw/lib/debug\""
D["DEBUGDIR_RELOCATABLE"]=" 1"
D["GDB_DATADIR"]=" \"/mingw/share/gdb\""

There are some code snippet:

gdb_program_name = xstrdup (argv[0]);

 if (! getcwd (gdb_dirbuf, sizeof (gdb_dirbuf)))
    /* Don't use *_filtered or warning() (which relies on
      current_target) until after initialize_all_files().  */
    fprintf_unfiltered (gdb_stderr,
           _("%s: warning: error finding "
             "working directory: %s\n"),
                       argv[0], safe_strerror (errno));

 current_directory = gdb_dirbuf;

 /* Set the sysroot path.  */
 gdb_sysroot = relocate_gdb_directory (TARGET_SYSTEM_ROOT,
                   TARGET_SYSTEM_ROOT_RELOCATABLE);

 debug_file_directory = relocate_gdb_directory (DEBUGDIR,
                        DEBUGDIR_RELOCATABLE);

 gdb_datadir = relocate_gdb_directory (GDB_DATADIR,
                   GDB_DATADIR_RELOCATABLE);

But those values were not set correctly, so I need to hack the path under MinGW.

It is quite simple to test whether GDB set the python path correctly, just run:

python print gdb.PYTHONDIR

If it shows the correct path, then it's good.

PS: I will have a travel in two days, so further response from me will be some bit later.

asmwarrior
ollydbg from codeblocks' forum