Re: Patch: install libgtkpeer.so and libjawt.so in versioned library directory

[Thomas Fitzsimmons <fitzsim at redhat dot com>]

Andrew Haley wrote:
> Thomas Fitzsimmons writes:
>  > 
>  > Andrew Haley wrote:
>  > > Thomas Fitzsimmons writes:
>  > > 
>  > >  > +
>  > >  > +  // Check if LD_LIBRARY_PATH is already prefixed with
>  > >  > +  // GCJ_VERSIONED_LIBDIR.  If not, export LD_LIBRARY_PATH prefixed
>  > >  > +  // with GCJ_VERSIONED_LIBDIR and re-spawn gij.
>  > >  > +  char *libpath = getenv (LTDL_SHLIBPATH_VAR);
>  > >  > +  char *newpath = _Jv_PrependVersionedLibdir (libpath);
>  > >  > +
>  > >  > +  if (! libpath || strcmp (libpath, newpath))
>  > >  > +    {
>  > >  > +      setenv (LTDL_SHLIBPATH_VAR, newpath, 1);
>  > >  > +      JvFree (newpath);
>  > >  > +
>  > >  > +      int error_code = execv (GIJ_EXECUTABLE, (char* const*) argv);
>  > > 
>  > > But, as discussed with Bryce, the version in svn is
>  > > 
>  > >      int error_code = execvp (argv[0], (char* const*) argv);
>  > > 
>  > > This can break java-1.4.2-gcj-compat.
>  > > 
>  > > /usr/bin/java prefixes the LD_LIBRARY_PATH with the gij install dir.
>  > > Then, /usr/bin/java does an execv of PREFIX/gij, but it leaves argv[0]
>  > > pointing to /usr/bin/java rather than PREFIX/gij.
>  > 
>  > Yes, /usr/bin/java must now be symlinked to gij, rather than being a binary 
>  > wrapper itself.  The idea of this patch was to merge the functionality from 
>  > java-gcj-compat's java.c into gij itself, so that we could get rid of java.c in 
>  > favour of a symlink.
>
> Can we not have a version of this that works correctly with
> already-installed systems?

We could, but that would need GIJ_EXECUTABLE, which Bryce didn't like.  FWIW, to 
avoid confusion, and problems like the one you've encountered, I prefer 
hard-coding executables that I intend to exec.  But doing so would compromise 
Bryce's vision of a relocatable libgcj.

>  > > So, when you call execvp(), the /usr/bin/java wrapper is re-executed,
>  > > not gij.  This in turn, re-executes gij, ad nauseam.
>  > > 
>  > > So, to make this clear:
>  > > 
>  > > /usr/bin/java prefixes LD_LIBRARY_PATH and execs gij
>  > > gij prefixes LD_LIBRARY_PATH and execs /usr/bin/java
>  > > /usr/bin/java prefixes LD_LIBRARY_PATH and execs gij
>  > > gij prefixes LD_LIBRARY_PATH and execs /usr/bin/java
>  > > ...
>  > 
>  > This only happens because each tool execs the other.  This won't
>  > happen when java symlinks to gij.
>
> Is there a version of java-1.4.2-gcj-compat to do this?

I've committed the required changes to java-gcj-compat HEAD.

Tom