vo_gpu: vulkan: generalize SPIR-V compiler

In addition to the built-in nvidia compiler, we now also support a
backend based on libshaderc. shaderc is sort of like glslang except it
has a C API and is available as a dynamic library.

The generated SPIR-V is now cached alongside the VkPipeline in the
cached_program. We use a special cache header to ensure validity of this
cache before passing it blindly to the vulkan implementation, since
passing invalid SPIR-V can cause all sorts of nasty things. It's also
designed to self-invalidate if the compiler gets better, by offering a
catch-all `int compiler_version` that implementations can use as a cache
invalidation marker.

1 files changed, 4 insertions, 0 deletions

diff --git a/wscript b/wscript
index 964b7878c7..694ead0736 100644
--- a/wscript
+++ b/wscript
@@ -807,6 +807,10 @@ video_output_features = [
         'desc':  'Vulkan context support',
         'func': check_cc(header_name='vulkan/vulkan.h', lib='vulkan'),
     }, {
+        'name': '--shaderc',
+        'desc': 'libshaderc SPIR-V compiler',
+        'func': check_cc(header_name='shaderc/shaderc.h', lib='shaderc_shared'),
+    }, {
         'name': 'egl-helpers',
         'desc': 'EGL helper functions',
         'deps': 'egl-x11 || mali-fbdev || rpi || gl-wayland || egl-drm || ' +