cmake_modules/platform.cmake
author Simon McVittie <smcv@debian.org>
Mon, 12 Sep 2022 10:40:53 -0400
branch1.0.0
changeset 15859 7b1d6dfa3173
parent 15312 5b2dec63f4cf
permissions -rw-r--r--
Remove FindSDL2 find-module, use sdl2-config.cmake instead This requires SDL >= 2.0.4. Since <https://bugzilla.libsdl.org/show_bug.cgi?id=2464> was fixed in SDL 2.0.4, SDL behaves as a CMake "config-file package", even if it was not itself built using CMake: it installs a sdl2-config.cmake file to ${libdir}/cmake/SDL2, which tells CMake where to find SDL's headers and library, analogous to a pkg-config .pc file. As a result, we no longer need to copy/paste a "find-module package" to be able to find a system copy of SDL >= 2.0.4 with find_package(SDL2). Find-module packages are now discouraged by the CMake developers, in favour of having upstream projects behave as config-file packages. This results in a small API change: FindSDL2 used to set SDL2_INCLUDE_DIR and SDL2_LIBRARY, but the standard behaviour for config-file packages is to set <name>_INCLUDE_DIRS and <name>_LIBRARIES. Use the CONFIG keyword to make sure we search in config-file package mode, and will not find a FindSDL2.cmake in some other directory that implements the old interface. In addition to deleting redundant code, this avoids some assumptions in FindSDL2 about the layout of a SDL installation. The current libsdl2-dev package in Debian breaks those assumptions; this is considered a bug and will hopefully be fixed soon, but it illustrates how fragile these assumptions can be. We can be more robust against different installation layouts by relying on SDL's own CMake integration. When linking to a copy of CMake in a non-standard location, users can now set the SDL2_DIR or CMAKE_PREFIX_PATH environment variable to point to it; previously, these users would have used the SDL2DIR environment variable. This continues to be unnecessary if using matching system-wide installations of CMake and SDL2, for example both from Debian.


if(APPLE)
    #minimum for macOS.  sorry!
    cmake_minimum_required(VERSION 3.9.0)

    #set c++11 standard for QT requirements
    set(CMAKE_CXX_STANDARD 11)
    set(CMAKE_CXX_STANDARD_REQUIRED ON)
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -stdlib=libc++")

    set(CMAKE_FIND_FRAMEWORK "FIRST")

    #what system are we building for
    set(minimum_macosx_version $ENV{MACOSX_DEPLOYMENT_TARGET})

    #detect on which system we are: if sw_vers cannot be found for any reason (re)use minimum_macosx_version
    find_program(sw_vers sw_vers)
    if(sw_vers)
        execute_process(COMMAND ${sw_vers} "-productVersion"
                        OUTPUT_VARIABLE current_macosx_version
                        OUTPUT_STRIP_TRAILING_WHITESPACE)
        string(REGEX REPLACE "([0-9]+.[0-9]+).[0-9]+" "\\1" current_macosx_version ${current_macosx_version})
    else()
        if(NOT minimum_macosx_version)
            message(FATAL_ERROR "sw_vers not found! Need explicit MACOSX_DEPLOYMENT_TARGET variable set")
        else()
            message("*** sw_vers not found! Fallback to MACOSX_DEPLOYMENT_TARGET variable ***")
            set(current_macosx_version ${minimum_macosx_version})
        endif()
    endif()

    #if nothing is set, we deploy only for the current system
    if(NOT minimum_macosx_version)
        set(minimum_macosx_version ${current_macosx_version})
    endif()

    #minimum OSX version is 10.8.  Earlier versions cannot compile some dependencies anymore
    #(like ffmpeg/libav)
    if(minimum_macosx_version VERSION_LESS "10.8")
        message(FATAL_ERROR "Hedgewars is unsupported on your platform and requires Mac OS X 10.8+")
    endif()

    #parse this system variable and adjust only the powerpc syntax to be compatible with -P
    if(CMAKE_OSX_ARCHITECTURES)
        string(REGEX MATCH "[pP][pP][cC]+" powerpc_build "${CMAKE_OSX_ARCHITECTURES}")
        string(REGEX MATCH "[iI]386+" i386_build "${CMAKE_OSX_ARCHITECTURES}")
        string(REGEX MATCH "[xX]86_64+" x86_64_build "${CMAKE_OSX_ARCHITECTURES}")
        if(x86_64_build)
            add_flag_prepend(CMAKE_Pascal_FLAGS -Px86_64)
        elseif(i386_build)
            add_flag_prepend(CMAKE_Pascal_FLAGS -Pi386)
        elseif(powerpc_build)
            add_flag_prepend(CMAKE_Pascal_FLAGS -Ppowerpc)
        else()
            message(FATAL_ERROR "Unknown architecture present in CMAKE_OSX_ARCHITECTURES (${CMAKE_OSX_ARCHITECTURES})")
        endif()
        list(LENGTH CMAKE_OSX_ARCHITECTURES num_of_archs)
        if(num_of_archs GREATER 1)
            message("*** Only one architecture in CMAKE_OSX_ARCHITECTURES is supported, picking the first one ***")
        endif()
    elseif(CMAKE_SIZEOF_VOID_P MATCHES "8")
        #if that variable is not set check if we are on x86_64 and if so force it, else use default
        add_flag_prepend(CMAKE_Pascal_FLAGS -Px86_64)
    endif()

    #CMAKE_OSX_SYSROOT is set at the system version we are supposed to build on
    #we need to provide the correct one when host and target differ
    if(NOT CMAKE_OSX_SYSROOT AND
       NOT ${minimum_macosx_version} VERSION_EQUAL ${current_macosx_version})
        find_program(xcrun xcrun)
        if(xcrun)
            execute_process(COMMAND ${xcrun} "--show-sdk-path"
                            OUTPUT_VARIABLE current_sdk_path
                            OUTPUT_STRIP_TRAILING_WHITESPACE)
            string(REPLACE "${current_macosx_version}"
                           "${minimum_macosx_version}"
                           CMAKE_OSX_SYSROOT
                           "${current_sdk_path}")
        else()
            message("*** xcrun not found! Build will work on ${current_macosx_version} only ***")
        endif()
    endif()
    if(CMAKE_OSX_SYSROOT)
        add_flag_append(CMAKE_Pascal_FLAGS "-XR${CMAKE_OSX_SYSROOT}")
        add_flag_append(CMAKE_Pascal_FLAGS "-k-macosx_version_min -k${minimum_macosx_version}")
        add_flag_append(CMAKE_Pascal_FLAGS "-k-L${LIBRARY_OUTPUT_PATH} -Fl${LIBRARY_OUTPUT_PATH}")
    endif()

    #add user framework directory
    add_flag_append(CMAKE_Pascal_FLAGS "-Ff~/Library/Frameworks")

endif(APPLE)

if(MINGW)
    #this flags prevents a few dll hell problems
    add_flag_append(CMAKE_C_FLAGS "-static-libgcc")
    add_flag_append(CMAKE_CXX_FLAGS "-static-libgcc")
endif(MINGW)

if(WIN32)
    if(NOT ${BUILD_SHARED_LIB})
        message(FATAL_ERROR "Static linking is not supported on Windows")
    endif()
endif(WIN32)

if(UNIX)
    add_flag_append(CMAKE_C_FLAGS "-fPIC")
    add_flag_append(CMAKE_CXX_FLAGS "-fPIC")
endif(UNIX)