commit 76117921b9b1ff6e49eab26ed38f6fbda687c7a7
author LoopDawg <sk_opengl@khasekhemwy.net> Wed Sep 06 14:59:06 2017 -0600
committer LoopDawg <sk_opengl@khasekhemwy.net> Wed Sep 06 15:04:52 2017 -0600
tree 8403a0735e20ff77b1cf02b31ade45a9fddbbd4e
parent 3a21c880500eac21cdf79bef5b80f970a55ac6af

Fix lvalue check in SPIR-V generation

There were several locations in TGlslangToSpvTraverser::handleUserFunctionCall testing for
whether a fn argument should be in the lvalue or rvalue array.  They must get the same
result for indexing sanity, but had slightly different logic.

They're now forced into the same test.

SPIRV/GlslangToSpv.cpp

diff --git a/SPIRV/GlslangToSpv.cpp b/SPIRV/GlslangToSpv.cpp
index b6c9705..a82867a 100755
--- a/SPIRV/GlslangToSpv.cpp
+++ b/SPIRV/GlslangToSpv.cpp
@@ -3529,6 +3529,11 @@
     const glslang::TIntermSequence& glslangArgs = node->getSequence();
     const glslang::TQualifierList& qualifiers = node->getQualifierList();
 
+    // Encapsulate lvalue logic, used in two places below, for safety.
+    const auto isLValue = [](int qualifier, const glslang::TType& paramType) -> bool {
+        return qualifier != glslang::EvqConstReadOnly || paramType.containsOpaque();
+    };
+
     //  See comments in makeFunctions() for details about the semantics for parameter passing.
     //
     // These imply we need a four step process:
@@ -3548,7 +3553,7 @@
         glslangArgs[a]->traverse(this);
         argTypes.push_back(&paramType);
         // keep outputs and opaque objects as l-values, evaluate input-only as r-values
-        if (qualifiers[a] != glslang::EvqConstReadOnly || paramType.containsOpaque()) {
+        if (isLValue(qualifiers[a], paramType)) {
             // save l-value
             lValues.push_back(builder.getAccessChain());
         } else {
@@ -3573,7 +3578,7 @@
             builder.setAccessChain(lValues[lValueCount]);
             arg = builder.accessChainGetLValue();
             ++lValueCount;
-        } else if (qualifiers[a] != glslang::EvqConstReadOnly) {
+        } else if (isLValue(qualifiers[a], paramType)) {
             // need space to hold the copy
             arg = builder.createVariable(spv::StorageClassFunction, convertGlslangToSpvType(paramType), "param");
             if (qualifiers[a] == glslang::EvqIn || qualifiers[a] == glslang::EvqInOut) {
@@ -3600,7 +3605,7 @@
     lValueCount = 0;
     for (int a = 0; a < (int)glslangArgs.size(); ++a) {
         const glslang::TType& paramType = glslangArgs[a]->getAsTyped()->getType();
-        if (qualifiers[a] != glslang::EvqConstReadOnly) {
+        if (isLValue(qualifiers[a], paramType)) {
             if (qualifiers[a] == glslang::EvqOut || qualifiers[a] == glslang::EvqInOut) {
                 spv::Id copy = builder.createLoad(spvArgs[a]);
                 builder.setAccessChain(lValues[lValueCount]);