Introduce a new parser annotation token for primary expressions. When

ClassifyName() builds a primary expression, generate one of these
annotation tokens rather than jumping into the parser.

llvm-svn: 130297

clang/include/clang/Basic/TokenKinds.def

@@ -483,6 +483,7 @@ ANNOTATION(typename)     // annotation for a C typedef name, a C++ (possibly
 ANNOTATION(template_id)  // annotation for a C++ template-id that names a
                          // function template specialization (not a type),
                          // e.g., "std::swap<int>"
+ANNOTATION(primary_expr) // annotation for a primary expression
 
 // Annotation for #pragma unused(...)
 // For each argument inside the parentheses the pragma handler will produce

clang/include/clang/Parse/Parser.h

@@ -392,6 +392,24 @@ private:
   static void setTypeAnnotation(Token &Tok, ParsedType T) {
     Tok.setAnnotationValue(T.getAsOpaquePtr());
   }
+  
+  /// \brief Read an already-translated primary expression out of an annotation
+  /// token.
+  static ExprResult getExprAnnotation(Token &Tok) {
+    if (Tok.getAnnotationValue())
+      return ExprResult((Expr *)Tok.getAnnotationValue());
+    
+    return ExprResult(true);
+  }
+  
+  /// \brief Set the primary expression corresponding to the given annotation
+  /// token.
+  static void setExprAnnotation(Token &Tok, ExprResult ER) {
+    if (ER.isInvalid())
+      Tok.setAnnotationValue(0);
+    else
+      Tok.setAnnotationValue(ER.get());
+  }
 
   /// TryAnnotateTypeOrScopeToken - If the current token position is on a
   /// typename (possibly qualified in C++) or a C++ scope specifier not followed
@@ -1049,10 +1067,10 @@ private:
   //===--------------------------------------------------------------------===//
   // C99 6.5: Expressions.
   
-  ExprResult ParseExpression(ExprResult Primary = ExprResult());
+  ExprResult ParseExpression();
   ExprResult ParseConstantExpression();
   // Expr that doesn't include commas.
-  ExprResult ParseAssignmentExpression(ExprResult Primary = ExprResult());
+  ExprResult ParseAssignmentExpression();
 
   ExprResult ParseExpressionWithLeadingAt(SourceLocation AtLoc);
 
@@ -1258,7 +1276,7 @@ private:
   }
   StmtResult ParseStatementOrDeclaration(StmtVector& Stmts,
                                          bool OnlyStatement = false);
-  StmtResult ParseExprStatement(ParsedAttributes &Attrs, ExprResult Primary);
+  StmtResult ParseExprStatement(ParsedAttributes &Attrs);
   StmtResult ParseLabeledStatement(ParsedAttributes &Attr);
   StmtResult ParseCaseStatement(ParsedAttributes &Attr,
                                 bool MissingCase = false,

clang/lib/Parse/ParseExpr.cpp

@@ -174,11 +174,8 @@ static prec::Level getBinOpPrecedence(tok::TokenKind Kind,
 ///       expression: [C99 6.5.17]
 ///         assignment-expression ...[opt]
 ///         expression ',' assignment-expression ...[opt]
-///
-/// \param Primary if non-empty, an already-parsed expression that will be used
-/// as the first primary expression.
-ExprResult Parser::ParseExpression(ExprResult Primary) {
-  ExprResult LHS(ParseAssignmentExpression(Primary));
+ExprResult Parser::ParseExpression() {
+  ExprResult LHS(ParseAssignmentExpression());
   return ParseRHSOfBinaryExpression(move(LHS), prec::Comma);
 }
 
@@ -214,27 +211,16 @@ Parser::ParseExpressionWithLeadingExtension(SourceLocation ExtLoc) {
 }
 
 /// ParseAssignmentExpression - Parse an expr that doesn't include commas.
-///
-/// \param Primary if non-empty, an already-parsed expression that will be used
-/// as the first primary expression.
-ExprResult Parser::ParseAssignmentExpression(ExprResult Primary) {
+ExprResult Parser::ParseAssignmentExpression() {
   if (Tok.is(tok::code_completion)) {
-    if (Primary.isUsable())
-      Actions.CodeCompletePostfixExpression(getCurScope(), Primary);
-    else
-      Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Expression);
+    Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Expression);
     ConsumeCodeCompletionToken();
   }
 
-  if (!Primary.isUsable() && Tok.is(tok::kw_throw))
+  if (Tok.is(tok::kw_throw))
     return ParseThrowExpression();
 
-  ExprResult LHS;
-  if (Primary.get() || Primary.isInvalid())
-    LHS = ParsePostfixExpressionSuffix(Primary);
-  else
-    LHS = ParseCastExpression(false, false, ParsedType());
-  
+  ExprResult LHS = ParseCastExpression(false, false, ParsedType());
   return ParseRHSOfBinaryExpression(move(LHS), prec::Assignment);
 }
 
@@ -628,6 +614,12 @@ ExprResult Parser::ParseCastExpression(bool isUnaryExpression,
   case tok::kw_nullptr:
     return Actions.ActOnCXXNullPtrLiteral(ConsumeToken());
 
+  case tok::annot_primary_expr:
+    assert(Res.get() == 0 && "Stray primary-expression annotation?");
+    Res = getExprAnnotation(Tok);
+    ConsumeToken();
+    break;
+      
   case tok::identifier: {      // primary-expression: identifier
                                // unqualified-id: identifier
                                // constant: enumeration-constant

clang/lib/Parse/ParseStmt.cpp

@@ -146,13 +146,15 @@ Retry:
         Tok.setKind(tok::annot_typename);
         setTypeAnnotation(Tok, Classification.getType());
         Tok.setAnnotationEndLoc(NameLoc);
-        Tok.setLocation(NameLoc);
         PP.AnnotateCachedTokens(Tok);
         break;
           
       case Sema::NC_Expression:
-        ConsumeToken(); // the identifier
-        return ParseExprStatement(attrs, Classification.getExpression());
+        Tok.setKind(tok::annot_primary_expr);
+        setExprAnnotation(Tok, Classification.getExpression());
+        Tok.setAnnotationEndLoc(NameLoc);
+        PP.AnnotateCachedTokens(Tok);
+        break;
           
       case Sema::NC_TypeTemplate:
       case Sema::NC_FunctionTemplate: {
@@ -210,7 +212,7 @@ Retry:
       return StmtError();
     }
 
-    return ParseExprStatement(attrs, ExprResult());
+    return ParseExprStatement(attrs);
   }
 
   case tok::kw_case:                // C99 6.8.1: labeled-statement
@@ -288,14 +290,13 @@ Retry:
 }
 
 /// \brief Parse an expression statement.
-StmtResult Parser::ParseExprStatement(ParsedAttributes &Attrs, 
-                                      ExprResult Primary) {
+StmtResult Parser::ParseExprStatement(ParsedAttributes &Attrs) {
   // If a case keyword is missing, this is where it should be inserted.
   Token OldToken = Tok;
   
   // FIXME: Use the attributes
   // expression[opt] ';'
-  ExprResult Expr(ParseExpression(Primary));
+  ExprResult Expr(ParseExpression());
   if (Expr.isInvalid()) {
     // If the expression is invalid, skip ahead to the next semicolon or '}'.
     // Not doing this opens us up to the possibility of infinite loops if