Features: Add cxx_attributes.

Help/variable/CMAKE_CXX_KNOWN_FEATURES.rst

@@ -27,6 +27,11 @@ The features known to this version of CMake are:
 
   .. _N2341: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2341.pdf
 
+``cxx_attributes``
+  Generic attributes, as defined in N2761_.
+
+  .. _N2761: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2761.pdf
+
 ``cxx_auto_type``
   Automatic type deduction, as defined in N1984_.
 

Modules/Compiler/GNU-CXX-FeatureTests.cmake

@@ -8,6 +8,7 @@ set(_cmake_feature_test_cxx_reference_qualified_functions
 set(GNU48_CXX11 "(__GNUC__ * 100 + __GNUC_MINOR__) >= 408 && __cplusplus >= 201103L")
 set(_cmake_feature_test_cxx_alignas "${GNU48_CXX11}")
 set(_cmake_feature_test_cxx_alignof "${GNU48_CXX11}")
+set(_cmake_feature_test_cxx_attributes "${GNU48_CXX11}")
 set(_cmake_feature_test_cxx_inheriting_constructors "${GNU48_CXX11}")
 # TODO: Should be supported by GNU 4.7
 set(GNU47_CXX11 "${_oldestSupported} && __cplusplus >= 201103L")

Source/cmMakefile.cxx

@@ -45,6 +45,7 @@
   F(cxx_alias_templates) \
   F(cxx_alignas) \
   F(cxx_alignof) \
+  F(cxx_attributes) \
   F(cxx_auto_type) \
   F(cxx_constexpr) \
   F(cxx_decltype) \

Tests/CompileFeatures/cxx_attributes.cpp

@@ -0,0 +1,2 @@
+
+void unusedFunc [[noreturn]] () { throw 1; }