HLSL: use prefix for builtin functions names to avoid namespace collisions

hlsl/hlslGrammar.cpp

@@ -2785,11 +2785,13 @@ bool HlslGrammar::acceptFunctionCall(HlslToken callToken, TIntermTyped*& node, T
 {
     // name
     TString* functionName = nullptr;
-    if ((baseObject == nullptr && scope == nullptr) ||
-        parseContext.isBuiltInMethod(callToken.loc, baseObject, *callToken.string)) {
+    if ((baseObject == nullptr && scope == nullptr)) {
+        functionName = callToken.string;
+    } else if (parseContext.isBuiltInMethod(callToken.loc, baseObject, *callToken.string)) {
         // Built-in methods are not in the symbol table as methods, but as global functions
         // taking an explicit 'this' as the first argument.
-        functionName = callToken.string;
+        functionName = NewPoolTString(BUILTIN_PREFIX);
+        functionName->append(*callToken.string);
     } else {
         functionName = NewPoolTString("");
         if (baseObject != nullptr)

hlsl/hlslParseHelper.cpp

@@ -956,7 +956,7 @@ TIntermTyped* HlslParseContext::handleDotDereference(const TSourceLoc& loc, TInt
 // Return true if the field should be treated as a built-in method.
 // Return false otherwise.
 //
-bool HlslParseContext::isBuiltInMethod(const TSourceLoc& loc, TIntermTyped* base, const TString& field)
+bool HlslParseContext::isBuiltInMethod(const TSourceLoc&, TIntermTyped* base, const TString& field)
 {
     if (base == nullptr)
         return false;
@@ -3734,7 +3734,10 @@ TIntermTyped* HlslParseContext::handleFunctionCall(const TSourceLoc& loc, TFunct
         // It will have false positives, since it doesn't check arg counts or types.
         if (arguments && arguments->getAsAggregate()) {
             if (isStructBufferType(arguments->getAsAggregate()->getSequence()[0]->getAsTyped()->getType())) {
-                if (isStructBufferMethod(function->getName())) {
+                static const int methodPrefixSize = sizeof(BUILTIN_PREFIX)-1;
+
+                if (function->getName().length() > methodPrefixSize &&
+                    isStructBufferMethod(function->getName().substr(methodPrefixSize))) {
                     const TString mangle = function->getName() + "(";
                     TSymbol* symbol = symbolTable.find(mangle, &builtIn);
 

hlsl/hlslParseHelper.h

@@ -390,6 +390,12 @@ protected:
     TVector<TString> currentTypePrefix;
 };
 
+// This is the prefix we use for builtin methods to avoid namespace collisions with
+// global scope user functions.
+// TODO: this would be better as a nonparseable character, but that would
+// require changing the scanner.
+#define BUILTIN_PREFIX "__BI_"
+
 } // end namespace glslang
 
 #endif // HLSL_PARSE_INCLUDED_