Libguestfs - Feb 2015 - Re: [PATCH] gnulib: Define argv[0] as program_name for error.c on Darwin

On Wed, Feb 11, 2015 at 09:52:59PM +0000, Margaret Lewicka
wrote:
> On 11 February 2015 at 19:23, Richard W.M. Jones <rjones@redhat.com>
wrote:
> > On Wed, Feb 11, 2015 at 07:20:33PM +0000, Margaret Lewicka wrote:
> [...]
> >> Proposing a patch to gnulib, even should they accept it, does not
fix
> >> the underlying issue, which is, essentially, that gnulib requires
that
> >> symbol and libguestfs binaries don't supply it. There might be
another
> >> OS that trips over this, after all.
> >
> > But it would fix it for Mac OS X, which is better than nothing.
> >
> > As a test, can you see if adding some variation of:
> >
> >    #if /* this is Mac OS X */
> >    #define program_name (((char **)*_NSGetArgv())[0])
> >    #endif
> >
> > to libguestfs's gnulib/lib/error.h fixes the problem?
> >
> > It'll save you a lot of time if it does work.
> 
> It compiles and libguestfs-test-tool doesn't bomb afterwards, if that
> is a sufficient definition of "working".
Sounds pretty good to me.

Please send a final patch to gnulib/lib/error.h and I'll forward it to
the gnulib people for you (or you can send it yourself if you want).

[In any case, the gnulib error() function is only used in a very few
places in the libguestfs virt-* tools.  I count just 14 uses, ignoring
tests.  The main reason we need all this seems to be because the
gnulib error module is used by other gnulib modules that we actually
care about.]

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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---
 lib/error.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/error.c b/lib/error.c
index 6683197..36a3db7 100644
--- a/lib/error.c
+++ b/lib/error.c
@@ -113,9 +113,13 @@ int strerror_r ();
 #  endif
 # endif
 
+#if defined __APPLE__ && defined __MACH__
+#define program_name (((char **)*_NSGetArgv())[0])
+#else
 /* The calling program should define program_name and set it to the
    name of the executing program.  */
 extern char *program_name;
+#endif
 
 # if HAVE_STRERROR_R || defined strerror_r
 #  define __strerror_r strerror_r
-- 
1.9.3

On Thursday 12 February 2015 17:39:45 Margaret Lewicka
wrote:
> ---
>  lib/error.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/lib/error.c b/lib/error.c
> index 6683197..36a3db7 100644
> --- a/lib/error.c
> +++ b/lib/error.c
> @@ -113,9 +113,13 @@ int strerror_r ();
>  #  endif
>  # endif
>  
> +#if defined __APPLE__ && defined __MACH__
> +#define program_name (((char **)*_NSGetArgv())[0])
> +#else
>  /* The calling program should define program_name and set it to the
>     name of the executing program.  */
>  extern char *program_name;
> +#endif
>  
>  # if HAVE_STRERROR_R || defined strerror_r
>  #  define __strerror_r strerror_r
> 
We import gnulib as git submodule from the upstream gnulib.git, so
this should be sent to its mailing list; see also
  https://www.gnu.org/software/gnulib/

(Personally, I'm not sure that the above patch would help, but I'll
leave the review to gnulib people on the right ml.)

Thanks,
-- 
Pino Toscano