Detect c++ standard unconditionally

Currently select_cxx_standard(), which sets PYBIND11_CPP_STANDARD when
not externally set, is only called from pybind11_add_module(), but the
embed target setup (which runs unconditionally) makes use of
${PYBIND11_CPP_STANDARD}, which isn't set yet.  This commit removes the
`select_cxx_standard` function completely and just always runs the
standard detection code.

This also tweaks the detection code to not bothering checking for the
`-std=c++11` flag when the `-std=c++14` detection succeeded.
This commit is contained in:
Jason Rhinelander 2017-07-12 14:59:16 -04:00
parent 6b51619a7c
commit fad5d3386c
2 changed files with 14 additions and 16 deletions

View File

@ -90,7 +90,6 @@ if(NOT TARGET ${PN}::pybind11)
set_property(TARGET ${PN}::module APPEND PROPERTY INTERFACE_LINK_LIBRARIES ${PYTHON_LIBRARIES})
endif()
select_cxx_standard()
set_property(TARGET ${PN}::pybind11 APPEND PROPERTY INTERFACE_COMPILE_OPTIONS "${PYBIND11_CPP_STANDARD}")
get_property(_iid TARGET ${PN}::pybind11 PROPERTY INTERFACE_INCLUDE_DIRECTORIES)

View File

@ -18,27 +18,27 @@ find_package(PythonLibsNew ${PYBIND11_PYTHON_VERSION} REQUIRED)
include(CheckCXXCompilerFlag)
include(CMakeParseArguments)
function(select_cxx_standard)
if(NOT PYBIND11_CPP_STANDARD)
if(NOT PYBIND11_CPP_STANDARD)
if(NOT MSVC)
check_cxx_compiler_flag("-std=c++14" HAS_CPP14_FLAG)
check_cxx_compiler_flag("-std=c++11" HAS_CPP11_FLAG)
if (HAS_CPP14_FLAG)
set(PYBIND11_CPP_STANDARD -std=c++14)
elseif (HAS_CPP11_FLAG)
else()
check_cxx_compiler_flag("-std=c++11" HAS_CPP11_FLAG)
if (HAS_CPP11_FLAG)
set(PYBIND11_CPP_STANDARD -std=c++11)
else()
message(FATAL_ERROR "Unsupported compiler -- pybind11 requires C++11 support!")
endif()
endif()
elseif(MSVC)
set(PYBIND11_CPP_STANDARD /std:c++14)
endif()
set(PYBIND11_CPP_STANDARD ${PYBIND11_CPP_STANDARD} CACHE STRING
"C++ standard flag, e.g. -std=c++11, -std=c++14, /std:c++14. Defaults to C++14 mode." FORCE)
endif()
endfunction()
endif()
# Checks whether the given CXX/linker flags can compile and link a cxx file. cxxflags and
# linkerflags are lists of flags to use. The result variable is a unique variable name for each set
@ -165,7 +165,6 @@ function(pybind11_add_module target_name)
endif()
endif()
select_cxx_standard()
# Make sure C++11/14 are enabled
target_compile_options(${target_name} PUBLIC ${PYBIND11_CPP_STANDARD})