Adapting cmake build system for c++11 code on Windows with MingW

Question

I have been using an open source library that builds fine on OSX, and I am trying to build it on Windows. The developer has little Windows experience himself, and is aware that others have done it in the past, but is not sure how.

The roadblock I'm running into is how to tell MingW to use C++11.

CMakeLists.txt (from this repo):

cmake_minimum_required(VERSION 2.8)

set(ENTITYX_MAJOR_VERSION 0)
set(ENTITYX_MINOR_VERSION 8)
set(ENTITYX_PATCH_VERSION 1)
set(ENTITYX_VERSION ${ENTITYX_MAJOR_VERSION}.${ENTITYX_MINOR_VERSION}.${ENTITYX_PATCH_VERSION})


include_directories(${CMAKE_CURRENT_LIST_DIR})

set(ENTITYX_BUILD_TESTING false CACHE BOOL "Enable building of tests.")
set(ENTITYX_RUN_BENCHMARKS false CACHE BOOL "Run benchmarks (in conjunction with -DENTITYX_BUILD_TESTING=1).")
set(ENTITYX_MAX_COMPONENTS 64 CACHE STRING "Set the maximum number of components.")
set(ENTITYX_USE_CPP11_STDLIB true CACHE BOOL "For Clang, specify whether to use libc++ (-stdlib=libc++).")
set(ENTITYX_BUILD_SHARED false CACHE BOOL "Build shared libraries?")

include(${CMAKE_ROOT}/Modules/CheckIncludeFile.cmake)
include(CheckCXXSourceCompiles)

# Default compiler args
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -pedantic -Werror -Wall -Wextra -Wno-unused-parameter -Wno-error=unused-variable -Wno-error=sign-compare -std=c++11")
set(CMAKE_CXX_FLAGS_DEBUG "-O0 -g")
set(CMAKE_CXX_FLAGS_MINSIZEREL "-Os -DNDEBUG")
set(CMAKE_CXX_FLAGS_RELEASE "-O2 -DNDEBUG")
set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-O2 -g")

# C++11 feature checks
include(CheckCXX11Features.cmake)

add_definitions(-DGTEST_USE_OWN_TR1_TUPLE=1)
set(OLD_CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
check_cxx_source_compiles(
"
#include <memory>

int main() {
    std::shared_ptr<int>();
}
"
ENTITYX_HAVE_CXX11_STDLIB
)

if (NOT ENTITYX_HAVE_CXX11_STDLIB)
    message("-- Not using -stdlib=libc++ (test failed to build)")
    set(CMAKE_CXX_FLAGS "${OLD_CMAKE_CXX_FLAGS}")
else ()
    message("-- Using -stdlib=libc++")
endif ()


# Misc features
check_include_file("stdint.h" HAVE_STDINT_H)

macro(require FEATURE_NAME MESSAGE_STRING)
    if (NOT ${${FEATURE_NAME}})
        message(FATAL_ERROR "${MESSAGE_STRING} required -- ${${FEATURE_NAME}}")
    else()
        message("--   ${MESSAGE_STRING} found")
    endif()
endmacro(require)

macro(create_test TARGET_NAME SOURCE)
    add_executable(${TARGET_NAME} ${SOURCE})
    target_link_libraries(
        ${TARGET_NAME}
        entityx
        gtest
        gtest_main
        ${ARGN}
        )
    add_test(${TARGET_NAME} ${TARGET_NAME})
endmacro()

if (NOT CMAKE_BUILD_TYPE)
    message("-- Defaulting to release build (use -DCMAKE_BUILD_TYPE:STRING=Debug for debug build)")
    set(CMAKE_BUILD_TYPE "Release")
endif()

message("-- Checking C++ features")
require(HAS_CXX11_AUTO "C++11 auto support")
require(HAS_CXX11_NULLPTR "C++11 nullptr support")
require(HAS_CXX11_RVALUE_REFERENCES "C++11 rvalue reference support")
#require(HAS_CXX11_CSTDINT_H "C++11 stdint support")
require(HAS_CXX11_VARIADIC_TEMPLATES "C++11 variadic templates")
require(HAS_CXX11_RVALUE_REFERENCES "C++11 rvalue references")
require(HAS_CXX11_LONG_LONG "C++11 long long")
require(HAS_CXX11_LONG_LONG "C++11 lambdas")

message("-- Checking misc features")
require(HAVE_STDINT_H "stdint.h")

set(CMAKE_CXX_FLAGS_DEBUG "-O0 -g")
set(CMAKE_CXX_FLAGS_MINSIZEREL "-Os -DNDEBUG")
set(CMAKE_CXX_FLAGS_RELEASE "-O2 -DNDEBUG")
set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-O2 -g")

# Things to install
set(install_libs entityx)

set(sources entityx/tags/TagsComponent.cc entityx/deps/Dependencies.cc entityx/System.cc entityx/Event.cc entityx/Entity.cc entityx/Manager.cc entityx/help/Timer.cc)
add_library(entityx STATIC ${sources})

if (ENTITYX_BUILD_SHARED)
    message("-- Building shared libraries (-DENTITYX_BUILD_SHARED=0 to only build static librarires)")
    add_library(entityx_shared SHARED ${sources})
    target_link_libraries(
        entityx_shared
        )
    set_target_properties(entityx_shared PROPERTIES OUTPUT_NAME entityx)
    list(APPEND install_libs entityx_shared)
endif (ENTITYX_BUILD_SHARED)

if (ENTITYX_BUILD_TESTING)
    #find_package(Boost 1.48.0 REQUIRED COMPONENTS timer system)
    add_subdirectory(gtest-1.6.0)
    include_directories(${gtest_SOURCE_DIR}/include ${gtest_SOURCE_DIR})
    enable_testing()
    create_test(entity_test entityx/Entity_test.cc)
    create_test(event_test entityx/Event_test.cc)
    create_test(system_test entityx/System_test.cc)
    create_test(tags_component_test entityx/tags/TagsComponent_test.cc)
    create_test(dependencies_test entityx/deps/Dependencies_test.cc)
    if (ENTITYX_RUN_BENCHMARKS)
        message("-- Running benchmarks")
        add_definitions(-DGTEST_USE_OWN_TR1_TUPLE=1 -DBOOST_NO_CXX11_NUMERIC_LIMITS=1)
        create_test(benchmarks_test entityx/Benchmarks_test.cc)
    else ()
        message("-- Not running benchmarks (use -DENTITYX_RUN_BENCHMARKS=1 to enable)")
    endif ()
endif (ENTITYX_BUILD_TESTING)


configure_file(
    ${CMAKE_CURRENT_SOURCE_DIR}/entityx/config.h.in
    ${CMAKE_CURRENT_SOURCE_DIR}/entityx/config.h
)

install(
    DIRECTORY "entityx"
    DESTINATION "include"
    FILES_MATCHING PATTERN "*.h"
    )

install(
    TARGETS ${install_libs}
    LIBRARY DESTINATION lib
    ARCHIVE DESTINATION lib
    )

Here is the output of a build attempt:

PS C:\Code\entityx\build> cmake -G "MinGW Makefiles" -DENTITYX_BUILD_SHARED=1 -DENTITYX_BUILD_TESTING=1 -DENTITYX_BUILD_PYTHON=0 ..
-- The C compiler identification is GNU 4.8.1
-- The CXX compiler identification is GNU 4.8.1
-- Check for working C compiler: C:/MinGW/bin/gcc.exe
-- Check for working C compiler: C:/MinGW/bin/gcc.exe -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working CXX compiler: C:/MinGW/bin/g++.exe
-- Check for working CXX compiler: C:/MinGW/bin/g++.exe -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Checking C++11 support for "auto" (N2546)
-- Checking C++11 support for "auto" (N2546) -- works
-- Checking C++11 support for "nullptr" (N2431)
-- Checking C++11 support for "nullptr" (N2431) -- works
-- Checking C++11 support for "lambda" (N2927)
-- Checking C++11 support for "lambda" (N2927) -- works
-- Checking C++11 support for "static_assert" (N1720)
-- Checking C++11 support for "static_assert" (N1720) -- works
-- Checking C++11 support for "rvalue_references" (N2118)
-- Checking C++11 support for "rvalue_references" (N2118) -- works
-- Checking C++11 support for "decltype" (N2343)
-- Checking C++11 support for "decltype" (N2343) -- works
-- Checking C++11 support for "cstdint"
-- Checking C++11 support for "cstdint" -- works
-- Checking C++11 support for "long_long" (N1811)
-- Checking C++11 support for "long_long" (N1811) -- works
-- Checking C++11 support for "variadic_templates" (N2555)
-- Checking C++11 support for "variadic_templates" (N2555) -- works
-- Checking C++11 support for "constexpr" (N2235)
-- Checking C++11 support for "constexpr" (N2235) -- works
-- Checking C++11 support for "sizeof_member" (N2253)
-- Checking C++11 support for "sizeof_member" (N2253) -- works
-- Checking C++11 support for "__func__" (N2340)
-- Checking C++11 support for "__func__" (N2340) -- works
-- Performing Test ENTITYX_HAVE_CXX11_STDLIB
-- Performing Test ENTITYX_HAVE_CXX11_STDLIB - Failed
-- Not using -stdlib=libc++ (test failed to build)
-- Looking for stdint.h
-- Looking for stdint.h - found
-- Defaulting to release build (use -DCMAKE_BUILD_TYPE:STRING=Debug for debug build)
-- Checking C++ features
--   C++11 auto support found
--   C++11 nullptr support found
--   C++11 rvalue reference support found
--   C++11 variadic templates found
--   C++11 rvalue references found
--   C++11 long long found
--   C++11 lambdas found
-- Checking misc features
--   stdint.h found
-- Python support disabled
-- Building shared libraries (-DENTITYX_BUILD_SHARED=0 to only build static libraries)
-- Found PythonInterp: G:/Python27/python.exe (found version "2.7.5")
-- Looking for include file pthread.h
-- Looking for include file pthread.h - not found
-- Found Threads: TRUE
-- Not running benchmarks (use -DENTITYX_RUN_BENCHMARKS=1 to enable)
-- Configuring done
-- Generating done
-- Build files have been written to: C:/Code/entityx/build

And here is CMakeError.log

Performing C++ SOURCE FILE Test ENTITYX_HAVE_CXX11_STDLIB failed with the following output:
Change Dir: C:/Code/entityx/build/CMakeFiles/CMakeTmp

Run Build Command:C:/MinGW/bin/mingw32-make.exe "cmTryCompileExec424246307/fast"
C:/MinGW/bin/mingw32-make.exe -f CMakeFiles\cmTryCompileExec424246307.dir\build.make CMakeFiles/cmTryCompileExec424246307.dir/build

mingw32-make.exe[1]: Entering directory 'C:/Code/entityx/build/CMakeFiles/CMakeTmp'

"G:\Program Files (x86)\CMake 2.8\bin\cmake.exe" -E cmake_progress_report C:\Code\entityx\build\CMakeFiles\CMakeTmp\CMakeFiles 1

Building CXX object CMakeFiles/cmTryCompileExec424246307.dir/src.cxx.obj

C:\MinGW\bin\g++.exe    -pedantic -Werror -Wall -Wextra -Wno-unused-parameter -Wno-error=unused-variable -Wno-error=sign-compare -std=c++11 -std=gnu++11 -stdlib=libc++ -DENTITYX_HAVE_CXX11_STDLIB   -o CMakeFiles\cmTryCompileExec424246307.dir\src.cxx.obj -c C:\Code\entityx\build\CMakeFiles\CMakeTmp\src.cxx

g++.exe: error: unrecognized command line option '-stdlib=libc++'

CMakeFiles\cmTryCompileExec424246307.dir\build.make:59: recipe for target 'CMakeFiles/cmTryCompileExec424246307.dir/src.cxx.obj' failed

mingw32-make.exe[1]: *** [CMakeFiles/cmTryCompileExec424246307.dir/src.cxx.obj] Error 1

mingw32-make.exe[1]: Leaving directory 'C:/Code/entityx/build/CMakeFiles/CMakeTmp'

Makefile:116: recipe for target 'cmTryCompileExec424246307/fast' failed

mingw32-make.exe: *** [cmTryCompileExec424246307/fast] Error 2


Source file was:

#include <memory>

int main() {
    std::shared_ptr<int>();
}

So the problem appears that -stdlib=libc++ is a valid option when I run cmake on OSX, but not under MingW on Windows. How should I fix this? Note that on OSX I am building with Clang 5.0.0

Note: I'm aware I'm going to have to get a pthread.h Windows version later, but I wanted to tackle the bigger problem first.

Answer 1

It's because libc++ is the normal standard C++ library for Clang, which is the default on OSX, but MinGW uses GCC which have its own standard library.