From 4e1a82c9609fd59afea18f4c0a84819b10b0d13d Mon Sep 17 00:00:00 2001
From: Benjamin Saunders <ben.e.saunders@gmail.com>
Date: Tue, 26 Jun 2018 20:13:06 -0700
Subject: [PATCH] shaderc: 2016-09-08 -> 2018-06-01

---
 .../development/compilers/shaderc/default.nix | 46 +++++++++++++------
 1 file changed, 33 insertions(+), 13 deletions(-)

diff --git a/pkgs/development/compilers/shaderc/default.nix b/pkgs/development/compilers/shaderc/default.nix
index 9df71869491..1176d348d9d 100644
--- a/pkgs/development/compilers/shaderc/default.nix
+++ b/pkgs/development/compilers/shaderc/default.nix
@@ -1,32 +1,52 @@
-{ stdenv, fetchFromGitHub, cmake, glslang, spirv-tools, python }:
+{ stdenv, fetchFromGitHub, cmake, python }:
+# Like many google projects, shaderc doesn't gracefully support separately compiled dependencies, so we can't easily use
+# the versions of glslang and spirv-tools used by vulkan-loader. Exact revisions are taken from
+# https://github.com/google/shaderc/blob/known-good/known_good.json
 
-stdenv.mkDerivation rec {
+# Future work: extract and fetch all revisions automatically based on a revision of shaderc's known-good branch.
+let
+  glslang = fetchFromGitHub {
+    owner = "KhronosGroup";
+    repo = "glslang";
+    rev = "32d3ec319909fcad0b2b308fe1635198773e8316";
+    sha256 = "1kmgjv5kbrjy6azpgwnjcn3cj8vg5i8hnyk3m969sc0gq2j1rbjj";
+  };
+  spirv-tools = fetchFromGitHub {
+    owner = "KhronosGroup";
+    repo = "SPIRV-Tools";
+    rev = "fe2fbee294a8ad4434f828a8b4d99eafe9aac88c";
+    sha256 = "03rq4ypwqnz34n8ip85n95a3b9rxb34j26azzm3b3invaqchv19x";
+  };
+  spirv-headers = fetchFromGitHub {
+    owner = "KhronosGroup";
+    repo = "SPIRV-Headers";
+    rev = "3ce3e49d73b8abbf2ffe33f829f941fb2a40f552";
+    sha256 = "0yk4bzqifdqpmdxkhvrxbdqhf5ngkga0ig1yyz7khr7rklqfz7wp";
+  };
+in stdenv.mkDerivation rec {
   name = "shaderc-git-${version}";
-  version = "2016-09-08";
+  version = "2018-06-01";
 
-  # `vulkan-loader` requires a specific version of `glslang` as specified in
-  # `<vulkan-loader-repo>/glslang_revision`.
   src = fetchFromGitHub {
     owner = "google";
     repo = "shaderc";
-    rev = "e17bb8ba3b8b0b9142b788d988612a40541c54ce";
-    sha256 = "17qfjqkz6j355qi130kixaz51svl09k9b5sfikksgnbmzglzcwki";
+    rev = "be8e0879750303a1de09385465d6b20ecb8b380d";
+    sha256 = "16p25ry2i4zrj00zihfpf210f8xd7g398ffbw25igvi9mbn4nbfd";
   };
 
   patchPhase = ''
-    cp -r ${spirv-tools.src} third_party/spirv-tools
-    chmod -R +w third_party/spirv-tools
-    ln -s ${spirv-tools.headers} third_party/spirv-tools/external/spirv-headers
+    cp -r --no-preserve=mode ${glslang} third_party/glslang
+    cp -r --no-preserve=mode ${spirv-tools} third_party/spirv-tools
+    ln -s ${spirv-headers} third_party/spirv-tools/external/spirv-headers
   '';
 
-  buildInputs = [ cmake glslang python ];
+  buildInputs = [ cmake python ];
   enableParallelBuilding = true;
 
-  cmakeFlags = [ "-DSHADERC_SKIP_TESTS=ON" "-DSHADERC_GLSLANG_DIR=${glslang.src}" ];
+  cmakeFlags = [ "-DSHADERC_SKIP_TESTS=ON" ];
 
   meta = with stdenv.lib; {
     inherit (src.meta) homepage;
     description = "A collection of tools, libraries and tests for shader compilation.";
-    broken = true;
   };
 }