Introduce __has_extension macro
__has_extension is a function-like macro which takes the same set
of feature identifiers as __has_feature. It evaluates to 1 if the
feature is supported by Clang in the current language (either as a
language extension or a standard language feature) or 0 if not.
At the same time, add support for the C1X feature identifiers
c_generic_selections (renamed from generic_selections) and
c_static_assert, and document them.
Patch by myself and Jean-Daniel Dupas.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@131308 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Lexer/has_extension_cxx.cpp b/test/Lexer/has_extension_cxx.cpp
new file mode 100644
index 0000000..77efa35
--- /dev/null
+++ b/test/Lexer/has_extension_cxx.cpp
@@ -0,0 +1,36 @@
+// RUN: %clang_cc1 -E %s -o - | FileCheck %s
+
+// CHECK: c_static_assert
+#if __has_extension(c_static_assert)
+int c_static_assert();
+#endif
+
+// CHECK: c_generic_selections
+#if __has_extension(c_generic_selections)
+int c_generic_selections();
+#endif
+
+// CHECK: has_deleted_functions
+#if __has_extension(cxx_deleted_functions)
+int has_deleted_functions();
+#endif
+
+// CHECK: has_inline_namespaces
+#if __has_extension(cxx_inline_namespaces)
+int has_inline_namespaces();
+#endif
+
+// CHECK: has_override_control
+#if __has_extension(cxx_override_control)
+int has_override_control();
+#endif
+
+// CHECK: has_reference_qualified_functions
+#if __has_extension(cxx_reference_qualified_functions)
+int has_reference_qualified_functions();
+#endif
+
+// CHECK: has_rvalue_references
+#if __has_extension(cxx_rvalue_references)
+int has_rvalue_references();
+#endif