benchmark/cmake/CXXFeatureCheck.cmake
Kyle Edwards f4f5dba46b Cache RUN_${FEATURE} variable in CXXFeatureCheck.cmake (#886)
When cross-compiling, this variable was not set on the second run
of CMake, resulting in the next check failing even though it shouldn't
be run in the first place. Fix this by caching the variable.
2019-10-04 09:50:53 +01:00

65 lines
2.0 KiB
CMake

# - Compile and run code to check for C++ features
#
# This functions compiles a source file under the `cmake` folder
# and adds the corresponding `HAVE_[FILENAME]` flag to the CMake
# environment
#
# cxx_feature_check(<FLAG> [<VARIANT>])
#
# - Example
#
# include(CXXFeatureCheck)
# cxx_feature_check(STD_REGEX)
# Requires CMake 2.8.12+
if(__cxx_feature_check)
return()
endif()
set(__cxx_feature_check INCLUDED)
function(cxx_feature_check FILE)
string(TOLOWER ${FILE} FILE)
string(TOUPPER ${FILE} VAR)
string(TOUPPER "HAVE_${VAR}" FEATURE)
if (DEFINED HAVE_${VAR})
set(HAVE_${VAR} 1 PARENT_SCOPE)
add_definitions(-DHAVE_${VAR})
return()
endif()
if (NOT DEFINED COMPILE_${FEATURE})
message(STATUS "Performing Test ${FEATURE}")
if(CMAKE_CROSSCOMPILING)
try_compile(COMPILE_${FEATURE}
${CMAKE_BINARY_DIR} ${CMAKE_CURRENT_SOURCE_DIR}/cmake/${FILE}.cpp
CMAKE_FLAGS ${BENCHMARK_CXX_LINKER_FLAGS}
LINK_LIBRARIES ${BENCHMARK_CXX_LIBRARIES})
if(COMPILE_${FEATURE})
message(WARNING
"If you see build failures due to cross compilation, try setting HAVE_${VAR} to 0")
set(RUN_${FEATURE} 0 CACHE INTERNAL "")
else()
set(RUN_${FEATURE} 1 CACHE INTERNAL "")
endif()
else()
message(STATUS "Performing Test ${FEATURE}")
try_run(RUN_${FEATURE} COMPILE_${FEATURE}
${CMAKE_BINARY_DIR} ${CMAKE_CURRENT_SOURCE_DIR}/cmake/${FILE}.cpp
CMAKE_FLAGS ${BENCHMARK_CXX_LINKER_FLAGS}
LINK_LIBRARIES ${BENCHMARK_CXX_LIBRARIES})
endif()
endif()
if(RUN_${FEATURE} EQUAL 0)
message(STATUS "Performing Test ${FEATURE} -- success")
set(HAVE_${VAR} 1 PARENT_SCOPE)
add_definitions(-DHAVE_${VAR})
else()
if(NOT COMPILE_${FEATURE})
message(STATUS "Performing Test ${FEATURE} -- failed to compile")
else()
message(STATUS "Performing Test ${FEATURE} -- compiled but failed to run")
endif()
endif()
endfunction()