From dff9676c60c51fa7af0749e1cb54305f112183e3 Mon Sep 17 00:00:00 2001
From: Oliver Wolff <oliver.wolff@qt.io>
Date: Mon, 10 Dec 2018 08:33:14 +0100
Subject: [PATCH] ANGLE: Dynamically load D3D compiler from a list

If the default compiler cannot be found, load it from a list of DLL names,
including a non-versioned proxy DLL provided by Qt. On Desktop Windows,
the default compiler can also be specified by an environment variable,
QT_D3DCOMPILER_DLL.
---
 src/3rdparty/angle/src/libANGLE/renderer/d3d/HLSLCompiler.cpp | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/src/3rdparty/angle/src/libANGLE/renderer/d3d/HLSLCompiler.cpp b/src/3rdparty/angle/src/libANGLE/renderer/d3d/HLSLCompiler.cpp
index b38765070..5d47308d6 100644
--- a/src/3rdparty/angle/src/libANGLE/renderer/d3d/HLSLCompiler.cpp
+++ b/src/3rdparty/angle/src/libANGLE/renderer/d3d/HLSLCompiler.cpp
@@ -14,6 +14,10 @@
 #include "libANGLE/histogram_macros.h"
 #include "third_party/trace_event/trace_event.h"
 
+#ifndef QT_D3DCOMPILER_DLL
+#define QT_D3DCOMPILER_DLL D3DCOMPILER_DLL
+#endif
+
 #if ANGLE_APPEND_ASSEMBLY_TO_SHADER_DEBUG_INFO == ANGLE_ENABLED
 namespace
 {
@@ -130,6 +134,27 @@ gl::Error HLSLCompiler::ensureInitialized()
     }
 #endif  // ANGLE_PRELOADED_D3DCOMPILER_MODULE_NAMES
 
+    // Load the compiler DLL specified by the environment, or default to QT_D3DCOMPILER_DLL
+    const wchar_t *defaultCompiler = _wgetenv(L"QT_D3DCOMPILER_DLL");
+    if (!defaultCompiler)
+        defaultCompiler = QT_D3DCOMPILER_DLL;
+
+    const wchar_t *compilerDlls[] = {
+        defaultCompiler,
+        L"d3dcompiler_47.dll",
+        L"d3dcompiler_46.dll",
+        L"d3dcompiler_43.dll",
+        0
+    };
+
+    // Load the first available known compiler DLL
+    for (int i = 0; compilerDlls[i]; ++i)
+    {
+        mD3DCompilerModule = LoadLibrary(compilerDlls[i]);
+        if (mD3DCompilerModule)
+            break;
+    }
+
     if (!mD3DCompilerModule)
     {
         // Load the version of the D3DCompiler DLL associated with the Direct3D version ANGLE was built with.
-- 
2.15.0.windows.1