PR21531: fix crash on invalid with unexpanded pack in case value.

llvm-svn: 222400

2 files changed, 14 insertions, 8 deletions

diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
index 3c4085afe1e..0d2d6032dd2 100644
--- a/clang/lib/Sema/SemaStmt.cpp
+++ b/clang/lib/Sema/SemaStmt.cpp
@@ -388,14 +388,19 @@ Sema::ActOnCaseStmt(SourceLocation CaseLoc, Expr *LHSVal,
     }
   }
 
-  LHSVal = ActOnFinishFullExpr(LHSVal, LHSVal->getExprLoc(), false,
-                               getLangOpts().CPlusPlus11).get();
-  if (RHSVal)
-    RHSVal = ActOnFinishFullExpr(RHSVal, RHSVal->getExprLoc(), false,
-                                 getLangOpts().CPlusPlus11).get();
-
-  CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, CaseLoc, DotDotDotLoc,
-                                        ColonLoc);
+  auto LHS = ActOnFinishFullExpr(LHSVal, LHSVal->getExprLoc(), false,
+                                 getLangOpts().CPlusPlus11);
+  if (LHS.isInvalid())
+    return StmtError();
+
+  auto RHS = RHSVal ? ActOnFinishFullExpr(RHSVal, RHSVal->getExprLoc(), false,
+                                          getLangOpts().CPlusPlus11)
+                    : ExprResult();
+  if (RHS.isInvalid())
+    return StmtError();
+
+  CaseStmt *CS = new (Context)
+      CaseStmt(LHS.get(), RHS.get(), CaseLoc, DotDotDotLoc, ColonLoc);
   getCurFunction()->SwitchStack.back()->addSwitchCase(CS);
   return CS;
 }
diff --git a/clang/test/CXX/temp/temp.decls/temp.variadic/p5.cpp b/clang/test/CXX/temp/temp.decls/temp.variadic/p5.cpp
index 8a70db6789b..4f9368f6b60 100644
--- a/clang/test/CXX/temp/temp.decls/temp.variadic/p5.cpp
+++ b/clang/test/CXX/temp/temp.decls/temp.variadic/p5.cpp
@@ -354,6 +354,7 @@ void test_unexpanded_exprs(Types ...values) {
   for (auto t : values) { } // expected-error{{expression contains unexpanded parameter pack 'values'}}
 
   switch (values) { } // expected-error{{expression contains unexpanded parameter pack 'values'}}
+  switch (0) { case 0: case values: ; } // expected-error{{expression contains unexpanded parameter pack 'values'}}
 
   do { } while (values); // expected-error{{expression contains unexpanded parameter pack 'values'}}