diff --git a/include/clang/AST/Stmt.h b/include/clang/AST/Stmt.h
index dae7fbf..e92c4fa 100644
--- a/include/clang/AST/Stmt.h
+++ b/include/clang/AST/Stmt.h
@@ -722,7 +722,14 @@
 };
 
 
-/// ReturnStmt - This represents a return, optionally of an expression.
+/// ReturnStmt - This represents a return, optionally of an expression:
+///   return;
+///   return 4;
+///
+/// Note that GCC allows return with no argument in a function declared to
+/// return a value, and it allows returning a value in functions declared to
+/// return void.  We explicitly model this in the AST, which means you can't
+/// depend on the return type of the function and the presence of an argument.
 ///
 class ReturnStmt : public Stmt {
   Expr *RetExpr;
diff --git a/test/CodeGen/statements.c b/test/CodeGen/statements.c
index 46d19db..4092121 100644
--- a/test/CodeGen/statements.c
+++ b/test/CodeGen/statements.c
@@ -1,9 +1,13 @@
-// RUN: clang %s -emit-llvm
+// RUN: clang < %s -emit-llvm
 
-void foo(int x) {
+void test1(int x) {
 switch (x) {
 case 111111111111111111111111111111111111111:
 bar();
 }
 }
 
+// Mismatched type between return and function result.
+int test2() { return; }
+void test3() { return 4; }
+