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authorStephen Kelly <steveire@gmail.com>2015-01-01 17:56:01 +0100
committerStephen Kelly <steveire@gmail.com>2015-01-01 18:20:10 +0100
commit998e9c10943ef361785e6f15cab1fa61172b1c24 (patch)
tree72a5c04f01d72672586c66ede0e5ec912f65df0d /Modules
parentec31926d24ac2cf9a8aef4cfbcbeaaca0c99b717 (diff)
downloadcmake-998e9c10943ef361785e6f15cab1fa61172b1c24.tar.gz
WCDH: Add feature portability for thread_local.
AppleClang does not support the cxx_thread_local feature, even though it is based on a Clang version which does support the feature. http://stackoverflow.com/a/23850891/2428389 A possible reason for that is that thread_local might be used as a variable in existing Apple SDK headers. Extend the WriteCompilerDetectionHeader module to generate a define for that feature with portability fallbacks. For the avoidance of making it easy to write code which looks correct but which has odd runtime behavior, don't set the define symbol at all if no equivalent keyword is known.
Diffstat (limited to 'Modules')
-rw-r--r--Modules/WriteCompilerDetectionHeader.cmake15
1 files changed, 15 insertions, 0 deletions
diff --git a/Modules/WriteCompilerDetectionHeader.cmake b/Modules/WriteCompilerDetectionHeader.cmake
index 36b9706e01..d61358fa2e 100644
--- a/Modules/WriteCompilerDetectionHeader.cmake
+++ b/Modules/WriteCompilerDetectionHeader.cmake
@@ -194,6 +194,7 @@
# ``cxx_static_assert`` ``<PREFIX>_STATIC_ASSERT_MSG`` ``static_assert``
# ``cxx_attribute_deprecated`` ``<PREFIX>_DEPRECATED`` ``[[deprecated]]``
# ``cxx_attribute_deprecated`` ``<PREFIX>_DEPRECATED_MSG`` ``[[deprecated]]``
+# ``cxx_thread_local`` ``<PREFIX>_THREAD_LOCAL`` ``thread_local``
# ============================= ================================ =====================
#
# A use-case which arises with such deprecation macros is the deprecation
@@ -573,6 +574,20 @@ function(write_compiler_detection_header
# endif
\n")
endif()
+ if (feature STREQUAL cxx_thread_local)
+ set(def_value "${prefix_arg}_THREAD_LOCAL")
+ set(file_content "${file_content}
+# if ${def_name}
+# define ${def_value} thread_local
+# elif ${prefix_arg}_COMPILER_IS_GNU || ${prefix_arg}_COMPILER_IS_Clang || ${prefix_arg}_COMPILER_IS_AppleClang
+# define ${def_value} __thread
+# elif ${prefix_arg}_COMPILER_IS_MSVC
+# define ${def_value} __declspec(thread)
+# else
+// ${def_value} not defined for this configuration.
+# endif
+\n")
+ endif()
if (feature STREQUAL cxx_attribute_deprecated)
set(def_name ${prefix_arg}_${feature_PP})
set(def_value "${prefix_arg}_DEPRECATED")