GL_VERSION        693 src/runtime/opengl.cpp     const char *version = (const char *)global_state.GetString(GL_VERSION);
GL_VERSION        183 src/runtime/openglcompute.cpp     debug(user_context) << "Halide running on "<< global_state.GetString(GL_VERSION) << "\n";
GL_VERSION        226 test/opengl/save_state.cpp         const char *version = (const char *)glGetString(GL_VERSION);