Merge topic 'minor-cleanups'

bc9a8bba Makefile: Undef FEATURE_STRING iteration define after use.
eb638c75 Tests: Make CompileFeatures feature list lang-specific.
e2f09aff CMakeConfigurableFile: Remove excess newline.
5109b042 Features: Fix GNU 4.8.1 version test.
6a9fdbeb Test: Parameterize the language in the CompileFeature test.
f5bf9d43 Tests: Make CompileFeature tests use highest standard known.

Modules/CMakeConfigurableFile.in

@@ -1,2 +1 @@
 @CMAKE_CONFIGURABLE_FILE_CONTENT@
-

Modules/Compiler/GNU-CXX-FeatureTests.cmake

@@ -3,11 +3,13 @@
 
 set(_oldestSupported "(__GNUC__ * 100 + __GNUC_MINOR__) >= 407")
 # Introduced in GCC 4.8.1
-set(GNU481_CXX11 "((__GNUC__ * 100 + __GNUC_MINOR__) >= 408 && __GNUC_PATCHLEVEL__ >= 1) && __cplusplus >= 201103L")
+set(GNU481_CXX11 "((__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) >= 40801) && __cplusplus >= 201103L")
 set(_cmake_feature_test_cxx_decltype_incomplete_return_types "${GNU481_CXX11}")
 set(_cmake_feature_test_cxx_reference_qualified_functions "${GNU481_CXX11}")
 set(GNU48_CXX11 "(__GNUC__ * 100 + __GNUC_MINOR__) >= 408 && __cplusplus >= 201103L")
 set(_cmake_feature_test_cxx_alignas "${GNU48_CXX11}")
+# The alignof feature works with GNU 4.7 and -std=c++11, but it is documented
+# as available with GNU 4.8, so treat that as true.
 set(_cmake_feature_test_cxx_alignof "${GNU48_CXX11}")
 set(_cmake_feature_test_cxx_attributes "${GNU48_CXX11}")
 set(_cmake_feature_test_cxx_inheriting_constructors "${GNU48_CXX11}")

Source/cmMakefile.cxx

@@ -4978,6 +4978,7 @@ static const char * const CXX_FEATURES[] = {
   0
   FOR_EACH_CXX_FEATURE(FEATURE_STRING)
 };
+#undef FEATURE_STRING
 
 static const char * const CXX_STANDARDS[] = {
     "98"

Tests/CompileFeatures/CMakeLists.txt

@@ -27,17 +27,37 @@ foreach(feature ${cxx_features})
   run_test(${feature} CXX)
 endforeach()
 
-if (CMAKE_CXX_COMPILE_FEATURES)
-  include(CheckCXXSourceCompiles)
-  foreach(feature ${CXX_non_features})
-    check_cxx_source_compiles("#include \"${CMAKE_CURRENT_SOURCE_DIR}/${feature}.cpp\"\nint main() { return 0; }\n" ${feature}_works)
-    if (${feature}_works)
-      message(SEND_ERROR
-        "Feature ${feature} expected not to work for ${CMAKE_CXX_COMPILER_ID}-${CMAKE_CXX_COMPILER_VERSION}.  Update the supported features or blacklist it.")
-    endif()
-  endforeach()
+if (CMAKE_CXX_COMPILER_ID STREQUAL GNU
+    AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.8)
+  list(REMOVE_ITEM CXX_non_features
+    cxx_alignof
+  )
 endif()
 
+set(CXX_ext cpp)
+set(CXX_standard_flag 11)
+foreach(lang CXX)
+  if (CMAKE_${lang}_COMPILE_FEATURES)
+    foreach(feature ${${lang}_non_features})
+      message("Testing feature : ${feature}")
+      try_compile(${feature}_works
+        "${CMAKE_CURRENT_BINARY_DIR}/${feature}_test"
+        "${CMAKE_CURRENT_SOURCE_DIR}/feature_test.${${lang}_ext}"
+        COMPILE_DEFINITIONS "-DTEST=${CMAKE_CURRENT_SOURCE_DIR}/${feature}.${${lang}_ext}"
+        CMAKE_FLAGS "-DCMAKE_${lang}_STANDARD=${${lang}_standard_flag}"
+        OUTPUT_VARIABLE OUTPUT
+      )
+      if (${feature}_works)
+        message(SEND_ERROR
+          "Feature ${feature} expected not to work for ${lang} ${CMAKE_${lang}_COMPILER_ID}-${CMAKE_${lang}_COMPILER_VERSION}.
+  Update the supported features or blacklist it.\n${OUTPUT}")
+      else()
+        message("Testing feature : ${feature} -- Fails, as expected.")
+      endif()
+    endforeach()
+  endif()
+endforeach()
+
 add_executable(CompileFeatures main.cpp)
 set_property(TARGET CompileFeatures
   PROPERTY COMPILE_FEATURES "cxx_auto_type"

Tests/CompileFeatures/feature_test.cpp

@@ -0,0 +1,10 @@
+
+#define STRINGIFY_IMPL(X) #X
+#define STRINGIFY(X) STRINGIFY_IMPL(X)
+
+#include STRINGIFY(TEST)
+
+int main()
+{
+  return 0;
+}

Tests/RunCMake/CompileFeatures/RunCMakeTest.cmake

@@ -10,11 +10,11 @@ run_cmake(NotAFeature_OriginDebug_target_compile_features)
 
 run_cmake(generate_feature_list)
 file(READ
-  "${RunCMake_BINARY_DIR}/generate_feature_list-build/features.txt"
-  FEATURES
+  "${RunCMake_BINARY_DIR}/generate_feature_list-build/cxx_features.txt"
+  CXX_FEATURES
 )
 
-if (NOT FEATURES)
+if (NOT CXX_FEATURES)
   run_cmake(NoSupportedCxxFeatures)
   run_cmake(NoSupportedCxxFeaturesGenex)
 endif()

Tests/RunCMake/CompileFeatures/generate_feature_list.cmake

@@ -1,5 +1,5 @@
 
-file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/features.txt"
+file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/cxx_features.txt"
   "${CMAKE_CXX_COMPILE_FEATURES}"
 )