From b9af4826ebe22c09237a1cbd5b0ed57fa6546dcf Mon Sep 17 00:00:00 2001
From: Neil Roberts <nroberts@igalia.com>
Date: Wed, 14 Mar 2018 19:06:22 +0100
Subject: [PATCH] spirv: Support initializers on uniforms

If a uniform has an initializer it will now be given as the optional
initializer operand to the OpVariable instruction.

Fixes: https://github.com/KhronosGroup/glslang/issues/1259
---
 SPIRV/GlslangToSpv.cpp | 13 ++++++++++++-
 SPIRV/SpvBuilder.cpp   |  5 ++++-
 SPIRV/SpvBuilder.h     |  2 +-
 3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/SPIRV/GlslangToSpv.cpp b/SPIRV/GlslangToSpv.cpp
index 5c00024c69..ad8c854ff4 100755
--- a/SPIRV/GlslangToSpv.cpp
+++ b/SPIRV/GlslangToSpv.cpp
@@ -2843,7 +2843,18 @@ spv::Id TGlslangToSpvTraverser::createSpvVariable(const glslang::TIntermSymbol*
     if (glslang::IsAnonymous(name))
         name = "";
 
-    return builder.createVariable(storageClass, spvType, name);
+    spv::Id initializer = spv::NoResult;
+
+    if (node->getType().getQualifier().storage == glslang::EvqUniform &&
+        !node->getConstArray().empty()) {
+            int nextConst = 0;
+            initializer = createSpvConstantFromConstUnionArray(node->getType(),
+                                                               node->getConstArray(),
+                                                               nextConst,
+                                                               false /* specConst */);
+    }
+
+    return builder.createVariable(storageClass, spvType, name, initializer);
 }
 
 // Return type Id of the sampled type.
diff --git a/SPIRV/SpvBuilder.cpp b/SPIRV/SpvBuilder.cpp
index 8755d9eacf..d726372c12 100644
--- a/SPIRV/SpvBuilder.cpp
+++ b/SPIRV/SpvBuilder.cpp
@@ -1198,7 +1198,7 @@ void Builder::makeDiscard()
 }
 
 // Comments in header
-Id Builder::createVariable(StorageClass storageClass, Id type, const char* name)
+Id Builder::createVariable(StorageClass storageClass, Id type, const char* name, Id initializer)
 {
     Id pointerType = makePointer(storageClass, type);
     Instruction* inst = new Instruction(getUniqueId(), pointerType, OpVariable);
@@ -1219,6 +1219,9 @@ Id Builder::createVariable(StorageClass storageClass, Id type, const char* name)
     if (name)
         addName(inst->getResultId(), name);
 
+    if (initializer != NoResult)
+        inst->addIdOperand(initializer);
+
     return inst->getResultId();
 }
 
diff --git a/SPIRV/SpvBuilder.h b/SPIRV/SpvBuilder.h
index 7c1d421b37..77a14a7bea 100644
--- a/SPIRV/SpvBuilder.h
+++ b/SPIRV/SpvBuilder.h
@@ -271,7 +271,7 @@ class Builder {
     void makeDiscard();
 
     // Create a global or function local or IO variable.
-    Id createVariable(StorageClass, Id type, const char* name = 0);
+    Id createVariable(StorageClass, Id type, const char* name = 0, Id initializer = NoResult);
 
     // Create an intermediate with an undefined value.
     Id createUndefined(Id type);