HLSL: Implement 'this' keyword.

hlsl/hlslGrammar.cpp

@@ -75,16 +75,33 @@ void HlslGrammar::unimplemented(const char* error)
     parseContext.error(token.loc, "Unimplemented", error, "");
 }
 
+// IDENTIFIER
+// THIS
+// type that can be used as IDENTIFIER
+//
 // Only process the next token if it is an identifier.
 // Return true if it was an identifier.
 bool HlslGrammar::acceptIdentifier(HlslToken& idToken)
 {
+    // IDENTIFIER
     if (peekTokenClass(EHTokIdentifier)) {
         idToken = token;
         advanceToken();
         return true;
     }
 
+    // THIS
+    // -> maps to the IDENTIFIER spelled with the internal special name for 'this'
+    if (peekTokenClass(EHTokThis)) {
+        idToken = token;
+        advanceToken();
+        idToken.tokenClass = EHTokIdentifier;
+        idToken.string = NewPoolTString(intermediate.implicitThisName);
+        return true;
+    }
+
+    // type that can be used as IDENTIFIER
+
     // Even though "sample", "bool", "float", etc keywords (for types, interpolation modifiers),
     // they ARE still accepted as identifiers.  This is not a dense space: e.g, "void" is not a
     // valid identifier, nor is "linear".  This code special cases the known instances of this, so

hlsl/hlslParseHelper.cpp

@@ -1538,15 +1538,14 @@ TIntermAggregate* HlslParseContext::handleFunctionDefinition(const TSourceLoc& l
             TVariable *variable = new TVariable(param.name, *param.type);
 
             if (i == 0 && function.hasImplicitThis()) {
-                // 'this' members are already in a symbol-table level,
-                // and we need to know what function parameter to map them to
+                // Anonymous 'this' members are already in a symbol-table level,
+                // and we need to know what function parameter to map them to.
                 symbolTable.makeInternalVariable(*variable);
                 pushImplicitThis(variable);
-            } else {
-                // Insert the parameters with name in the symbol table.
-                if (! symbolTable.insert(*variable))
-                    error(loc, "redefinition", variable->getName().c_str(), "");
             }
+            // Insert the parameters with name in the symbol table.
+            if (! symbolTable.insert(*variable))
+                error(loc, "redefinition", variable->getName().c_str(), "");
             // Add the parameter to the AST
             paramNodes = intermediate.growAggregate(paramNodes,
                                                     intermediate.addSymbol(*variable, loc),

hlsl/hlslScanContext.cpp

@@ -333,6 +333,7 @@ void HlslScanContext::fillInKeywordMap()
     (*KeywordMap)["cbuffer"] =                 EHTokCBuffer;
     (*KeywordMap)["tbuffer"] =                 EHTokTBuffer;
     (*KeywordMap)["typedef"] =                 EHTokTypedef;
+    (*KeywordMap)["this"] =                    EHTokThis;
 
     (*KeywordMap)["true"] =                    EHTokBoolConstant;
     (*KeywordMap)["false"] =                   EHTokBoolConstant;
@@ -374,7 +375,6 @@ void HlslScanContext::fillInKeywordMap()
     ReservedSet->insert("sizeof");
     ReservedSet->insert("static_cast");
     ReservedSet->insert("template");
-    ReservedSet->insert("this");
     ReservedSet->insert("throw");
     ReservedSet->insert("try");
     ReservedSet->insert("typename");
@@ -827,6 +827,7 @@ EHlslTokenClass HlslScanContext::tokenizeIdentifier()
     case EHTokTypedef:
     case EHTokCBuffer:
     case EHTokTBuffer:
+    case EHTokThis:
         return keyword;
 
     case EHTokBoolConstant:

hlsl/hlslTokens.h

@@ -273,6 +273,7 @@ enum EHlslTokenClass {
     EHTokCBuffer,
     EHTokTBuffer,
     EHTokTypedef,
+    EHTokThis,
 
     // constant
     EHTokFloatConstant,