Index: clang/include/clang/Basic/Features.def
===================================================================
--- clang/include/clang/Basic/Features.def
+++ clang/include/clang/Basic/Features.def
@@ -248,6 +248,7 @@
 EXTENSION(overloadable_unmarked, true)
 EXTENSION(pragma_clang_attribute_namespaces, true)
 EXTENSION(pragma_clang_attribute_external_declaration, true)
+EXTENSION(gnu_asm, LangOpts.GNUAsm)
 
 #undef EXTENSION
 #undef FEATURE
Index: clang/test/Parser/asm.c
===================================================================
--- clang/test/Parser/asm.c
+++ clang/test/Parser/asm.c
@@ -1,5 +1,9 @@
 // RUN: %clang_cc1 -fsyntax-only -verify %s
 
+#if !__has_extension(gnu_asm)
+#error Extension 'gnu_asm' should be available by default
+#endif
+
 void f1() {
   // PR7673: Some versions of GCC support an empty clobbers section.
   asm ("ret" : : :);
Index: clang/test/Parser/no-gnu-inline-asm.c
===================================================================
--- clang/test/Parser/no-gnu-inline-asm.c
+++ clang/test/Parser/no-gnu-inline-asm.c
@@ -1,5 +1,9 @@
 // RUN: %clang_cc1 %s -triple i686-apple-darwin -verify -fsyntax-only -fno-gnu-inline-asm
 
+#if __has_extension(gnu_asm)
+#error Expected extension 'gnu_asm' to be disabled
+#endif
+
 asm ("INST r1, 0"); // expected-error {{GNU-style inline assembly is disabled}}
 
 void foo() __asm("__foo_func"); // AsmLabel is OK