# define system dependent compiler flags

include(CheckCCompilerFlag)

include(CheckCCompilerFlagSSP)

if (UNIX AND NOT WIN32)

    #

    # Define GNUCC compiler flags

    #

    if (${CMAKE_C_COMPILER_ID} MATCHES "(GNU|Clang)")

        # add -Wconversion ?

        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=gnu99 -pedantic -pedantic-errors")

        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -Wshadow -Wmissing-prototypes -Wdeclaration-after-statement")

        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wunused -Wfloat-equal -Wpointer-arith -Wwrite-strings -Wformat-security")

	set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wmissing-format-attribute -fstrict-aliasing -Wbad-function-cast")

	# check -Wstrict-aliasing support

	check_c_compiler_flag("-Wstrict-aliasing=3" WITH_WSTRICT_ALIASING)

	if (WITH_WSTRICT_ALIASING)

            set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wstrict-aliasing=3")

	endif (WITH_WSTRICT_ALIASING)

        # with -fPIC

        check_c_compiler_flag("-fPIC" WITH_FPIC)

        if (WITH_FPIC)

            set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fPIC")

        endif (WITH_FPIC)

	check_c_compiler_flag_ssp("-fstack-protector-strong" WITH_STACK_PROTECTOR_STRONG)

	if (WITH_STACK_PROTECTOR_STRONG)

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

        else (!WITH_STACK_PROTECTOR_STRONG)

	    check_c_compiler_flag_ssp("-fstack-protector" WITH_STACK_PROTECTOR)

	    if (WITH_STACK_PROTECTOR)

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

	    endif (WITH_STACK_PROTECTOR)

	endif (WITH_STACK_PROTECTOR_STRONG)

        if (CMAKE_BUILD_TYPE)

            string(TOLOWER "${CMAKE_BUILD_TYPE}" CMAKE_BUILD_TYPE_LOWER)

            if (CMAKE_BUILD_TYPE_LOWER MATCHES (release|relwithdebinfo|minsizerel))

                check_c_compiler_flag("-Wp,-D_FORTIFY_SOURCE=2" WITH_FORTIFY_SOURCE)

                if (WITH_FORTIFY_SOURCE)

                    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wp,-D_FORTIFY_SOURCE=2")

                endif (WITH_FORTIFY_SOURCE)

            endif()

        endif()

    endif (${CMAKE_C_COMPILER_ID} MATCHES "(GNU|Clang)")

    #

    # Check for large filesystem support

    #

    if (CMAKE_SIZEOF_VOID_P MATCHES "8")

        # with large file support

        execute_process(

            COMMAND

                getconf LFS64_CFLAGS

            OUTPUT_VARIABLE

                _lfs_CFLAGS

            ERROR_QUIET

            OUTPUT_STRIP_TRAILING_WHITESPACE

        )

    else (CMAKE_SIZEOF_VOID_P MATCHES "8")

        # with large file support

        execute_process(

            COMMAND

                getconf LFS_CFLAGS

            OUTPUT_VARIABLE

                _lfs_CFLAGS

            ERROR_QUIET

            OUTPUT_STRIP_TRAILING_WHITESPACE

        )

    endif (CMAKE_SIZEOF_VOID_P MATCHES "8")

    if (_lfs_CFLAGS)

        string(REGEX REPLACE "[\r\n]" " " "${_lfs_CFLAGS}" "${${_lfs_CFLAGS}}")

        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${_lfs_CFLAGS}")

    endif (_lfs_CFLAGS)

endif (UNIX AND NOT WIN32)

if (MSVC)

    # Use secure functions by defaualt and suppress warnings about

    #"deprecated" functions

    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} /D _CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES=1")

    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} /D _CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES_COUNT=1")

    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} /D _CRT_NONSTDC_NO_WARNINGS=1 /D _CRT_SECURE_NO_WARNINGS=1")

endif (MSVC)