diff options
Diffstat (limited to 'cmake')
-rwxr-xr-x | cmake/config-ix.cmake | 3 | ||||
-rw-r--r-- | cmake/modules/CheckAtomic.cmake | 18 |
2 files changed, 21 insertions, 0 deletions
diff --git a/cmake/config-ix.cmake b/cmake/config-ix.cmake index 731071e..5833119 100755 --- a/cmake/config-ix.cmake +++ b/cmake/config-ix.cmake @@ -76,6 +76,9 @@ if( LLVM_USING_GLIBC ) add_llvm_definitions( -D_GNU_SOURCE ) endif() +# Define LLVM_MULTITHREADED if gcc atomic builtins exists. +include(CheckAtomic) + include(CheckCXXCompilerFlag) check_cxx_compiler_flag("-fPIC" SUPPORTS_FPIC_FLAG) diff --git a/cmake/modules/CheckAtomic.cmake b/cmake/modules/CheckAtomic.cmake new file mode 100644 index 0000000..27bbaba --- /dev/null +++ b/cmake/modules/CheckAtomic.cmake @@ -0,0 +1,18 @@ +# atomic builtins are required for threading support. + +INCLUDE(CheckCXXSourceCompiles) + +CHECK_CXX_SOURCE_COMPILES(" +int main() { + volatile unsigned long val = 1; + __sync_synchronize(); + __sync_val_compare_and_swap(&val, 1, 0); + __sync_add_and_fetch(&val, 1); + __sync_sub_and_fetch(&val, 1); + return 0; + } +" LLVM_MULTITHREADED) + +if( NOT LLVM_MULTITHREADED ) + message(STATUS "Warning: LLVM will be built thread-unsafe because atomic builtins are missing") +endif() |