Index: unittests/AST/ASTImporterTest.cpp
===================================================================
--- unittests/AST/ASTImporterTest.cpp
+++ unittests/AST/ASTImporterTest.cpp
@@ -151,6 +151,25 @@
                              Verifier, AMatcher));
 }
 
+template<typename NodeType, typename MatcherType>
+void testImport(const std::string &FromCode,
+                Language FromLang, const ArgVector &FromArgsExtra,
+                const std::string &ToCode,
+                Language ToLang, const ArgVector &ToArgsExtra,
+                MatchVerifier<NodeType> &Verifier,
+                const MatcherType &AMatcher) {
+  auto RunOptsFrom = getRunOptionsForLanguage(FromLang);
+  auto RunOptsTo = getRunOptionsForLanguage(ToLang);
+  for (auto FromArgs : RunOptsFrom) {
+    for (auto ToArgs : RunOptsTo) {
+      FromArgs.insert(FromArgs.end(), FromArgsExtra.begin(), FromArgsExtra.end());
+      ToArgs.insert(ToArgs.end(), ToArgsExtra.begin(), ToArgsExtra.end());
+      EXPECT_TRUE(testImport(FromCode, FromArgs, ToCode, ToArgs,
+                             Verifier, AMatcher));
+    }
+  }
+}
+
 // This class provides generic methods to write tests which can check internal
 // attributes of AST nodes like getPreviousDecl(), isVirtual(), etc.  Also,
 // this fixture makes it possible to import from several "From" contexts.
@@ -428,7 +447,7 @@
 TEST(ImportExpr, ImportStringLiteral) {
   MatchVerifier<Decl> Verifier;
   testImport("void declToImport() { \"foo\"; }",
-             Lang_CXX, "", Lang_CXX, Verifier,
+             Lang_CXX, { "-Wno-unused-value" }, "", Lang_CXX, {}, Verifier,
              functionDecl(
                hasBody(
                  compoundStmt(
@@ -437,7 +456,7 @@
                        hasType(
                          asString("const char [4]"))))))));
   testImport("void declToImport() { L\"foo\"; }",
-             Lang_CXX, "", Lang_CXX, Verifier,
+             Lang_CXX, { "-Wno-unused-value" }, "", Lang_CXX, {}, Verifier,
              functionDecl(
                hasBody(
                  compoundStmt(
@@ -446,7 +465,7 @@
                        hasType(
                         asString("const wchar_t [4]"))))))));
   testImport("void declToImport() { \"foo\" \"bar\"; }",
-             Lang_CXX, "", Lang_CXX, Verifier,
+             Lang_CXX, { "-Wno-unused-value" }, "", Lang_CXX, {}, Verifier,
              functionDecl(
                hasBody(
                  compoundStmt(
@@ -459,7 +478,7 @@
 TEST(ImportExpr, ImportGNUNullExpr) {
   MatchVerifier<Decl> Verifier;
   testImport("void declToImport() { __null; }",
-             Lang_CXX, "", Lang_CXX, Verifier,
+             Lang_CXX, { "-Wno-unused-value" }, "", Lang_CXX, {}, Verifier,
              functionDecl(
                hasBody(
                  compoundStmt(
@@ -471,7 +490,7 @@
 TEST(ImportExpr, ImportCXXNullPtrLiteralExpr) {
   MatchVerifier<Decl> Verifier;
   testImport("void declToImport() { nullptr; }",
-             Lang_CXX11, "", Lang_CXX11, Verifier,
+             Lang_CXX11, { "-Wno-unused-value" }, "", Lang_CXX11, {}, Verifier,
              functionDecl(
                hasBody(
                  compoundStmt(
@@ -483,7 +502,7 @@
 TEST(ImportExpr, ImportFloatinglLiteralExpr) {
   MatchVerifier<Decl> Verifier;
   testImport("void declToImport() { 1.0; }",
-             Lang_C, "", Lang_C, Verifier,
+             Lang_C, { "-Wno-unused-value" }, "", Lang_C, {}, Verifier,
              functionDecl(
                hasBody(
                  compoundStmt(
@@ -492,7 +511,7 @@
                        equals(1.0),
                        hasType(asString("double"))))))));
   testImport("void declToImport() { 1.0e-5f; }",
-              Lang_C, "", Lang_C, Verifier,
+              Lang_C, { "-Wno-unused-value" }, "", Lang_C, {}, Verifier,
               functionDecl(
                 hasBody(
                   compoundStmt(
@@ -507,7 +526,7 @@
   testImport("void declToImport() {"
              "  struct s { int x; long y; unsigned z; }; "
              "  (struct s){ 42, 0L, 1U }; }",
-             Lang_CXX, "", Lang_CXX, Verifier,
+             Lang_CXX, { "-Wno-unused-value" }, "", Lang_CXX, {}, Verifier,
              functionDecl(
                hasBody(
                  compoundStmt(
@@ -529,7 +548,7 @@
 TEST(ImportExpr, ImportCXXThisExpr) {
   MatchVerifier<Decl> Verifier;
   testImport("class declToImport { void f() { this; } };",
-             Lang_CXX, "", Lang_CXX, Verifier,
+             Lang_CXX, { "-Wno-unused-value" }, "", Lang_CXX, {}, Verifier,
              cxxRecordDecl(
                hasMethod(
                  hasBody(
@@ -554,7 +573,8 @@
 TEST(ImportExpr, ImportLabelDeclAndAddrLabelExpr) {
   MatchVerifier<Decl> Verifier;
   testImport(
-      "void declToImport() { loop: goto loop; &&loop; }", Lang_C, "", Lang_C,
+      "void declToImport() { loop: goto loop; &&loop; }",
+      Lang_C, { "-Wno-unused-value" }, "", Lang_C, {},
       Verifier,
       functionDecl(hasBody(compoundStmt(
           has(labelStmt(hasDeclaration(labelDecl(hasName("loop"))))),
@@ -626,7 +646,7 @@
   MatchVerifier<Decl> Verifier;
   testImport(
     "void declToImport() { true ? 1 : -5; }",
-    Lang_CXX, "", Lang_CXX, Verifier,
+    Lang_CXX, { "-Wno-unused-value" }, "", Lang_CXX, {}, Verifier,
     functionDecl(
       hasBody(
         compoundStmt(
@@ -642,7 +662,8 @@
 TEST(ImportExpr, ImportBinaryConditionalOperator) {
   MatchVerifier<Decl> Verifier;
   testImport(
-    "void declToImport() { 1 ?: -5; }", Lang_CXX, "", Lang_CXX, Verifier,
+    "void declToImport() { 1 ?: -5; }",
+    Lang_CXX, { "-Wno-unused-value" }, "", Lang_CXX, {}, Verifier,
     functionDecl(
       hasBody(
         compoundStmt(
@@ -710,7 +731,7 @@
   MatchVerifier<Decl> Verifier;
   // __func__ expands as StringLiteral("declToImport")
   testImport("void declToImport() { __func__; }",
-             Lang_CXX, "", Lang_CXX, Verifier,
+             Lang_CXX, { "-Wno-unused-value" }, "", Lang_CXX, {}, Verifier,
              functionDecl(
                hasBody(
                  compoundStmt(
@@ -817,7 +838,7 @@
              "  d.t;"
              "}"
              "void instantiate() { declToImport<int>(); }",
-             Lang_CXX, "", Lang_CXX, Verifier,
+             Lang_CXX, { "-Wno-unused-value" }, "", Lang_CXX, {}, Verifier,
              functionTemplateDecl(has(functionDecl(
                  has(compoundStmt(has(cxxDependentScopeMemberExpr())))))));
   testImport("template <typename T> struct C { T t; };"
@@ -826,7 +847,7 @@
              "  (&d)->t;"
              "}"
              "void instantiate() { declToImport<int>(); }",
-             Lang_CXX, "", Lang_CXX, Verifier,
+             Lang_CXX, { "-Wno-unused-value" }, "", Lang_CXX, {}, Verifier,
              functionTemplateDecl(has(functionDecl(
                  has(compoundStmt(has(cxxDependentScopeMemberExpr())))))));
 }
@@ -854,7 +875,7 @@
       "template <typename T>"
       "T pi = T(3.1415926535897932385L);"
       "void declToImport() { pi<int>; }",
-      Lang_CXX11, "", Lang_CXX11, Verifier,
+      Lang_CXX14, { "-Wno-unused-value" }, "", Lang_CXX14, {}, Verifier,
       functionDecl(
           hasBody(has(declRefExpr(to(varTemplateSpecializationDecl())))),
           unless(hasAncestor(translationUnitDecl(has(varDecl(
@@ -939,7 +960,7 @@
   testImport("void declToImport() { "
              "  __builtin_types_compatible_p(int, int);"
              "}",
-             Lang_C, "", Lang_C, Verifier,
+             Lang_C, { "-Wno-unused-value" }, "", Lang_C, {}, Verifier,
              functionDecl(
                hasBody(
                  compoundStmt(
@@ -971,7 +992,7 @@
              "  void m() { __is_pod(T); }"
              "};"
              "void f() { declToImport<int>().m(); }",
-             Lang_CXX11, "", Lang_CXX11, Verifier,
+             Lang_CXX11, { "-Wno-unused-value" }, "", Lang_CXX11, {}, Verifier,
              classTemplateDecl(
                has(
                  cxxRecordDecl(
@@ -1043,7 +1064,7 @@
              "  ::template foo<T>;"
              "}"
              "void instantiate() { declToImport<int>(); }",
-             Lang_CXX, "", Lang_CXX, Verifier,
+             Lang_CXX, { "-Wno-unused-value" }, "", Lang_CXX, {}, Verifier,
              functionTemplateDecl(has(functionDecl(
                  has(compoundStmt(has(unresolvedLookupExpr())))))));
 }
@@ -1851,7 +1872,10 @@
              "  (void) S<T>::foo;"
              "}"
              "void instantiate() { declToImport<int>(); }",
-             Lang_CXX11, "", Lang_CXX11, Verifier,
+             Lang_CXX11, { "-Wno-undefined-var-template" },
+             "",
+             Lang_CXX11, {},
+             Verifier,
              functionTemplateDecl(has(functionDecl(has(compoundStmt(
                  has(cStyleCastExpr(has(dependentScopeDeclRefExpr())))))))));
 
@@ -1862,7 +1886,10 @@
              "  S<T>::template foo<T>();"
              "}"
              "void instantiate() { declToImport<int>(); }",
-             Lang_CXX11, "", Lang_CXX11, Verifier,
+             Lang_CXX11, { "-Wno-undefined-var-template" },
+             "",
+             Lang_CXX11, {},
+             Verifier,
              functionTemplateDecl(has(functionDecl(has(compoundStmt(
                  has(callExpr(has(dependentScopeDeclRefExpr())))))))));
 }