[Libguestfs] [PATCH 2/5] macosx: Add definition of program_name for gnulib

[Richard W.M. Jones]

On Wed, Feb 11, 2015 at 07:20:33PM +0000, Margaret Lewicka wrote:
> On 11 February 2015 at 13:46, Richard W.M. Jones <rjones at redhat.com> wrote:
> [...]
> > On non-glibc, error.c says:
> >
> >   /* The calling program should define program_name and set it to the
> >      name of the executing program.  */
> >   extern char *program_name;
> >
> > This indicates to me that we shouldn't define `program_name' as a symbol
> > in libguestfs.  Instead every libguestfs-using program should define
> > it.  For example, virt-df (df/main.c) would have:
> >
> >   #if /* this is Mac OS X */
> >   char *program_name = "virt-df";
> >   #endif
> >
> > That sucks a lot.
> 
> That was my first approach, but adding a Darwin-specific ifdef to
> every executable shipped with libguestfs seemed much more intrusive
> than sneaking it in as a symbol in the library. I do see your point,
> though.
> 
> 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.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
Fedora Windows cross-compiler. Compile Windows programs, test, and
build Windows installers. Over 100 libraries supported.
http://fedoraproject.org/wiki/MinGW