#TESTING TIME

include(CheckCCompilerFlag)

#when you need to check for a linker flag, just leave the argument of "check_c_compiler_flag" empty

# CMAKE_C{XX}_FLAGS is for compiler flags (c and c++)

# CMAKE_EXE_LINKER_FLAGS is for linker flags (also add them to pascal_flags and haskell_flags)

# CMAKE_SHARED_LIBRARY_<lang>_FLAGS same but for shared libraries

#TODO: should there be two different checks for C and CXX?

#stack protection, when found it needs to go in the linker flags too (-lssp is added)

check_c_compiler_flag("-fstack-protector-all -fstack-protector" HAVE_STACKPROTECTOR)

if(HAVE_STACKPROTECTOR)

    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fstack-protector-all -fstack-protector")

    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fstack-protector-all -fstack-protector")

    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -fstack-protector-all -fstack-protector")

endif()

#symbol visibility, not supported on Windows (so we error out to avoid spam)

check_c_compiler_flag("-fvisibility=hidden -Werror" HAVE_VISIBILITY)

if(HAVE_VISIBILITY)

    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fvisibility=hidden")

    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fvisibility=hidden")

endif()

#check for noexecstack on ELF, Gentoo security

set(CMAKE_REQUIRED_FLAGS "-Wl,-z,noexecstack")

check_c_compiler_flag("" HAVE_NOEXECSTACK)

if(HAVE_NOEXECSTACK)

    list(APPEND pascal_flags "-k-z" "-knoexecstack")

    list(APPEND haskell_flags "-optl" "${CMAKE_REQUIRED_FLAGS}")

    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${CMAKE_REQUIRED_FLAGS}")

endif()

#check for full relro on ELF, Debian security

set(CMAKE_REQUIRED_FLAGS "-Wl,-z,relro,-z,now")

check_c_compiler_flag("" HAVE_RELROFULL)

if(HAVE_RELROFULL)

    list(APPEND pascal_flags "-k-z" "-krelro" "-k-z" "-know")

    list(APPEND haskell_flags "-optl" "${CMAKE_REQUIRED_FLAGS}")

    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${CMAKE_REQUIRED_FLAGS}")

else()

    #if full relro is not available, try partial relro

    set(CMAKE_REQUIRED_FLAGS "-Wl,-z,relro")

    check_c_compiler_flag("" HAVE_RELROPARTIAL)

    if(HAVE_RELROPARTIAL)

        list(APPEND pascal_flags "-k-z" "-krelro")

        list(APPEND haskell_flags "-optl" "${CMAKE_REQUIRED_FLAGS}")

        set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${CMAKE_REQUIRED_FLAGS}")

    endif()

endif()

#check for ASLR on Windows Vista or later, requires binutils >= 2.20

set(CMAKE_REQUIRED_FLAGS "-Wl,--nxcompat")

check_c_compiler_flag("" HAVE_WINASLR)

if(HAVE_WINASLR)

    list(APPEND pascal_flags "-k--nxcompat")

    list(APPEND haskell_flags "-optl" "${CMAKE_REQUIRED_FLAGS}")

    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${CMAKE_REQUIRED_FLAGS}")

endif()

#check for DEP on Windows XP SP2 or later, requires binutils >= 2.20

set(CMAKE_REQUIRED_FLAGS "-Wl,--dynamicbase")

check_c_compiler_flag("" HAVE_WINDEP)

if(HAVE_WINDEP)

    list(APPEND pascal_flags "-k--dynamicbase")

    list(APPEND haskell_flags "-optl" "${CMAKE_REQUIRED_FLAGS}")

    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${CMAKE_REQUIRED_FLAGS}")

endif()

#this is actually an optimisation

set(CMAKE_REQUIRED_FLAGS "-Wl,--as-needed")

check_c_compiler_flag("" HAVE_ASNEEDED)

if(HAVE_ASNEEDED)

    list(APPEND pascal_flags "-k--as-needed")

    list(APPEND haskell_flags "-optl" "${CMAKE_REQUIRED_FLAGS}")

    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${CMAKE_REQUIRED_FLAGS}")

endif()

#always unset or these flags will be spread everywhere

unset(CMAKE_REQUIRED_FLAGS)