allow renaming of shader entry point when creating SPIR-V

Use "--source-entrypoint name" on the command line, or the
TShader::setSourceEntryPoint(char*) API.

When the name given to the above interfaces is detected in the
shader source, it will be renamed to the entry point name supplied
to the -e option or the TShader::setEntryPoint() method.

hlsl/hlslGrammar.cpp

@@ -308,8 +308,13 @@ bool HlslGrammar::acceptDeclaration(TIntermNode*& node)
     // identifier
     HlslToken idToken;
     while (acceptIdentifier(idToken)) {
+        TString* fnName = idToken.string;
+
+        // Potentially rename shader entry point function.  No-op most of the time.
+        parseContext.renameShaderFunction(fnName);
+
         // function_parameters
-        TFunction& function = *new TFunction(idToken.string, declaredType);
+        TFunction& function = *new TFunction(fnName, declaredType);
         if (acceptFunctionParameters(function)) {
             // post_decls
             acceptPostDecls(function.getWritableType().getQualifier());

hlsl/hlslParseHelper.cpp

@@ -51,6 +51,7 @@ namespace glslang {
 
 HlslParseContext::HlslParseContext(TSymbolTable& symbolTable, TIntermediate& interm, bool parsingBuiltins,
                                    int version, EProfile profile, const SpvVersion& spvVersion, EShLanguage language, TInfoSink& infoSink,
+                                   const TString sourceEntryPointName,
                                    bool forwardCompatible, EShMessages messages) :
     TParseContextBase(symbolTable, interm, parsingBuiltins, version, profile, spvVersion, language, infoSink, forwardCompatible, messages),
     contextPragma(true, false),
@@ -58,7 +59,8 @@ HlslParseContext::HlslParseContext(TSymbolTable& symbolTable, TIntermediate& int
     postEntryPointReturn(false),
     limits(resources.limits),
     entryPointOutput(nullptr),
-    nextInLocation(0), nextOutLocation(0)
+    nextInLocation(0), nextOutLocation(0),
+    sourceEntryPointName(sourceEntryPointName)
 {
     globalUniformDefaults.clear();
     globalUniformDefaults.layoutMatrix = ElmRowMajor;
@@ -5539,4 +5541,13 @@ TIntermNode* HlslParseContext::addSwitch(const TSourceLoc& loc, TIntermTyped* ex
     return switchNode;
 }
 
+// Potentially rename shader entry point function
+void HlslParseContext::renameShaderFunction(TString*& name) const
+{
+    // Replace the entry point name given in the shader with the real entry point name,
+    // if there is a substitution.
+    if (name != nullptr && *name == sourceEntryPointName)
+        name = new TString(intermediate.getEntryPointName().c_str());
+}
+
 } // end namespace glslang

hlsl/hlslParseHelper.h

@@ -47,6 +47,7 @@ class HlslParseContext : public TParseContextBase {
 public:
     HlslParseContext(TSymbolTable&, TIntermediate&, bool parsingBuiltins,
                      int version, EProfile, const SpvVersion& spvVersion, EShLanguage, TInfoSink&,
+                     const TString sourceEntryPointName,
                      bool forwardCompatible = false, EShMessages messages = EShMsgDefault);
     virtual ~HlslParseContext();
     void initializeExtensionBehavior();
@@ -165,6 +166,9 @@ public:
     bool handleOutputGeometry(const TSourceLoc&, const TLayoutGeometry& geometry);
     bool handleInputGeometry(const TSourceLoc&, const TLayoutGeometry& geometry);
 
+    // Potentially rename shader entry point function
+    void renameShaderFunction(TString*& name) const;
+
 protected:
     void inheritGlobalDefaults(TQualifier& dst) const;
     TVariable* makeInternalVariable(const char* name, const TType&) const;
@@ -251,6 +255,8 @@ protected:
     TMap<int, TVector<TVariable*>> flattenMap;
     unsigned int nextInLocation;
     unsigned int nextOutLocation;
+
+    TString sourceEntryPointName;
 };
 
 } // end namespace glslang