Parse: Don't crash when trailing return type is missing

Sema::CheckParmsForFunctionDef can't cope with a null TypeSourceInfo.
Don't let the AST contain the malformed lambda.

This fixes PR22122.

llvm-svn: 225505

1 files changed, 4 insertions, 5 deletions

diff --git a/clang/lib/Parse/ParseExprCXX.cpp b/clang/lib/Parse/ParseExprCXX.cpp
index f101d9f1273..355503caa9b 100644
--- a/clang/lib/Parse/ParseExprCXX.cpp
+++ b/clang/lib/Parse/ParseExprCXX.cpp
@@ -1052,6 +1052,7 @@ ExprResult Parser::ParseLambdaExpressionAfterIntroducer(
   TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
   Actions.PushLambdaScope();    
 
+  TypeResult TrailingReturnType;
   if (Tok.is(tok::l_paren)) {
     ParseScope PrototypeScope(this,
                               Scope::FunctionPrototypeScope |
@@ -1112,7 +1113,6 @@ ExprResult Parser::ParseLambdaExpressionAfterIntroducer(
     SourceLocation FunLocalRangeEnd = DeclEndLoc;
 
     // Parse trailing-return-type[opt].
-    TypeResult TrailingReturnType;
     if (Tok.is(tok::arrow)) {
       FunLocalRangeEnd = Tok.getLocation();
       SourceRange Range;
@@ -1182,12 +1182,11 @@ ExprResult Parser::ParseLambdaExpressionAfterIntroducer(
     MaybeParseCXX11Attributes(Attr, &DeclEndLoc);
 
     // Parse the return type, if there is one.
-    TypeResult TrailingReturnType;
     if (Tok.is(tok::arrow)) {
       SourceRange Range;
       TrailingReturnType = ParseTrailingReturnType(Range);
       if (Range.getEnd().isValid())
-        DeclEndLoc = Range.getEnd();      
+        DeclEndLoc = Range.getEnd();
     }
 
     SourceLocation NoLoc;
@@ -1235,9 +1234,9 @@ ExprResult Parser::ParseLambdaExpressionAfterIntroducer(
   StmtResult Stmt(ParseCompoundStatementBody());
   BodyScope.Exit();
 
-  if (!Stmt.isInvalid())
+  if (!Stmt.isInvalid() && !TrailingReturnType.isInvalid())
     return Actions.ActOnLambdaExpr(LambdaBeginLoc, Stmt.get(), getCurScope());
- 
+
   Actions.ActOnLambdaError(LambdaBeginLoc, getCurScope());
   return ExprError();
 }