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authorRaphael Kubo da Costa <rakuco@FreeBSD.org>2015-09-15 14:31:12 (GMT)
committerBrad King <brad.king@kitware.com>2015-09-15 14:51:54 (GMT)
commitffa6f057b4ae07c9dc7b9e1d12ecc0a2e19333a1 (patch)
tree3a18a85325fb2d883b0019a629ef9d69149dd5e8 /Source/Checks
parentcda189356e7e0a897377c3d7ed02ea3a3ad1de5a (diff)
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Avoid using C11 to build CMake if _Thread_local support is broken
Support for C11's _Thread_local was introduced in GCC in the 4.9 series, even though we make the C11 compiler flags available in CMake with GCC >= 4.6. FreeBSD's runetype.h uses _Thread_local, which causes CMake's own build to fail when using GCC < 4.9 and -std=gnu11: /usr/include/runetype.h:92:22: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'const' extern _Thread_local const _RuneLocale *_ThreadRuneLocale; Add a test for _Thread_local support and only build CMake itself with C11 support if it works. Bug: http://www.cmake.org/Bug/view.php?id=15741
Diffstat (limited to 'Source/Checks')
-rw-r--r--Source/Checks/cm_c11_thread_local.c2
-rw-r--r--Source/Checks/cm_c11_thread_local.cmake33
2 files changed, 35 insertions, 0 deletions
diff --git a/Source/Checks/cm_c11_thread_local.c b/Source/Checks/cm_c11_thread_local.c
new file mode 100644
index 0000000..ab780f2
--- /dev/null
+++ b/Source/Checks/cm_c11_thread_local.c
@@ -0,0 +1,2 @@
+_Thread_local int i = 42;
+int main(void) { return 0; }
diff --git a/Source/Checks/cm_c11_thread_local.cmake b/Source/Checks/cm_c11_thread_local.cmake
new file mode 100644
index 0000000..6b8d10b
--- /dev/null
+++ b/Source/Checks/cm_c11_thread_local.cmake
@@ -0,0 +1,33 @@
+set(CMake_C11_THREAD_LOCAL_BROKEN 0)
+if(CMAKE_CXX_COMPILER_ID MATCHES "GNU" AND CMAKE_C11_STANDARD_COMPILE_OPTION)
+ if(NOT DEFINED CMake_C11_THREAD_LOCAL_WORKS)
+ message(STATUS "Checking if compiler supports C11 _Thread_local")
+ try_compile(CMake_C11_THREAD_LOCAL_WORKS
+ ${CMAKE_CURRENT_BINARY_DIR}
+ ${CMAKE_CURRENT_LIST_DIR}/cm_c11_thread_local.c
+ CMAKE_FLAGS -DCMAKE_C_STANDARD=11
+ OUTPUT_VARIABLE OUTPUT
+ )
+ if(CMake_C11_THREAD_LOCAL_WORKS AND "${OUTPUT}" MATCHES "error: expected '=', ',', ';', 'asm' or '__attribute__' before 'int'")
+ set_property(CACHE CMake_C11_THREAD_LOCAL_WORKS PROPERTY VALUE 0)
+ endif()
+ if(CMake_C11_THREAD_LOCAL_WORKS)
+ message(STATUS "Checking if compiler supports C11 _Thread_local - yes")
+ file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
+ "Determining if compiler supports C11 _Thread_local passed with the following output:\n"
+ "${OUTPUT}\n"
+ "\n"
+ )
+ else()
+ message(STATUS "Checking if compiler supports C11 _Thread_local - no")
+ file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
+ "Determining if compiler supports C11 _Thread_local failed with the following output:\n"
+ "${OUTPUT}\n"
+ "\n"
+ )
+ endif()
+ endif()
+ if(NOT CMake_C11_THREAD_LOCAL_WORKS)
+ set(CMake_C11_THREAD_LOCAL_BROKEN 1)
+ endif()
+endif()