[patch] Centralize the handling of install_name and rpath

[Argyrios Kyrtzidis]

LGTM!

On Feb 27, 2014, at 7:32 PM, Rafael Espíndola <rafael.espindola at gmail.com> wrote:

> Currently this is spread over multiple locations and is out of sync
> between Makefile and CMake. For example
> 
> * libclang uses an @rpath install name.
> * libLTO uses @executable_path with Makefile.
> * everything else uses @executable_path when building with cmake.
> 
> For some reason it looks like @rpath is needed by libclang. It seems
> to work for the others too, so what these patches do is centralize the
> logic for using "-install_name @rpath" for shared libraries and
> "-rpath @executable_path/../lib" for binaries.
> 
> Having the logic in one place is cleaner and introduces a single point
> to patch for supporting old OS X versions.
> 
> I now get in a configure build:
> 
> $ otool -l  Debug+Asserts/lib/libLTO.dylib  | grep LC_ID_DYLIB -A2
>          cmd LC_ID_DYLIB
>      cmdsize 48
>         name @rpath/libLTO.dylib (offset 24)
> 
> $ otool -l  Debug+Asserts/lib/libclang.dylib | grep LC_ID_DYLIB -A2
>          cmd LC_ID_DYLIB
>      cmdsize 48
>         name @rpath/libclang.dylib (offset 24)
> 
> $ otool -l Debug+Asserts/bin/llvm-as | grep LC_RPATH -A2
>          cmd LC_RPATH
>      cmdsize 40
>         path @executable_path/../lib (offset 12)
> 
> and in a cmake build
> 
> $ otool -l  lib/libLTO.dylib  | grep LC_ID_DYLIB -A2
>          cmd LC_ID_DYLIB
>      cmdsize 48
>         name @rpath/libLTO.dylib (offset 24)
> 
> $ otool -l  lib/libclang.3.5.dylib  | grep LC_ID_DYLIB -A2
>          cmd LC_ID_DYLIB
>      cmdsize 56
>         name @rpath/libclang.3.5.dylib (offset 24)
> 
> $ otool -l bin/llvm-as | grep LC_RPATH -A2
>          cmd LC_RPATH
>      cmdsize 40
>         path @executable_path/../lib (offset 12)
> 
> Cheers,
> Rafael
> <llvm.patch><clang.patch>