The GLSL Reference Parser provides a front end for parsing and operating on OpenGL Shading Language code. It was originally developed by 3Dlabs and is being maintained and updated by LunarG. The README has some additional information.
You can download the source from the Khronos public-access Subversion server . For example, using the Subversion command-line client:
svn checkout --username anonymous --password anonymous https://cvs.khronos.org/svn/repos/ogl/trunk/ecosystem/public/sdk/tools/glslang/ glslang
TBD. Builds on Windows and Linux.