path: root/CMakeLists.txt

cmake_minimum_required (VERSION 2.8.11)


# Use clang on MacOSX. gcc doesn't support __thread key, and Apple has
# abandoned it for clang.  This must be done before the project is defined.
# But DONT force clang if we are cross-compiling to Android.
if (APPLE AND NOT ANDROID_NDK)
    set (CMAKE_C_COMPILER "clang")
    set (CMAKE_CXX_COMPILER "clang++")
endif ()

if (CMAKE_GENERATOR STREQUAL "Xcode")
    message (FATAL_ERROR "Xcode generator is not supported. Please build with \"Unix Makefiles\" or \"Ninja\" generators.")
endif ()

# http://www.cmake.org/cmake/help/v3.0/policy/CMP0042.html
if (POLICY CMP0042)
    cmake_policy (SET CMP0042 NEW)
endif()


project (apitrace)


##############################################################################
# Options

# On Mac OS X build fat binaries with i386 and x86_64 architectures by default.
if (APPLE AND NOT CMAKE_OSX_ARCHITECTURES)
    set (CMAKE_OSX_ARCHITECTURES "i386;x86_64" CACHE STRING "Build architectures for OSX" FORCE)
endif ()

# We use a cached string variable instead of the standard (boolean) OPTION
# command so that we can default to auto-detecting optional depencies, while
# still providing a mechanism to force/disable these optional dependencies, as
# prescribed in http://www.gentoo.org/proj/en/qa/automagic.xml
set (ENABLE_GUI "AUTO" CACHE STRING "Enable Qt GUI.")

option (ENABLE_CLI "Enable command Line interface." ON)

option (ENABLE_EGL "Enable EGL support." ON)

option (ENABLE_WAFFLE "Enable WAFFLE support." OFF)

option (ENABLE_FRAME_POINTER "Disable frame pointer omission" ON)

# Proprietary Linux games often ship their own libraries (zlib, libstdc++,
# etc.) in order to ship a single set of binaries across multiple
# distributions.  Given that apitrace wrapper modules will be loaded into those
# processes, they must not depend on any shared object that could also be
# provided by such applications.  See also
# http://lists.freedesktop.org/archives/mesa-dev/2015-March/079121.html
if (NOT ANDROID)
    option (ENABLE_STATIC_SNAPPY "Statically link against snappy" ON)
    if (CMAKE_SYSTEM_NAME STREQUAL "Linux")
        option (ENABLE_STATIC_LIBGCC "Statically link LD_PRELOAD wrappers against libgcc" ON)
        option (ENABLE_STATIC_LIBSTDCXX "Statically link LD_PRELOAD wrappers against libstdc++" ON)
        if (NOT (ENABLE_STATIC_LIBGCC AND
                 ENABLE_STATIC_LIBSTDCXX AND
                 ENABLE_STATIC_SNAPPY))
            # XXX: Should probably throw a run-time too.
            message (WARNING
                "LD_PRELOAD wrappers not statically linked against all "
                "dependencies, therefore will fail to work with many "
                "third-party applications built on different Linux "
                "distributions and that ship their own shared-object "
                "dependencies."
            )
        endif ()
    endif ()
endif ()


##############################################################################
# Find dependencies

# Check for compiler TLS support.  We don't use compiler TLS support on Windows
# because, even if the compiler supports it, Windows XP does not support TLS on
# DLLs.
if (NOT WIN32)
    include (CheckCXXSourceCompiles)
    check_cxx_source_compiles ("__thread int i; int main() { return 0; }" HAVE_COMPILER_TLS)
    if (NOT HAVE_COMPILER_TLS)
        message (FATAL_ERROR "C++ compiler does not support __thread keyword.")
    endif ()
endif ()

set (CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake)
include (ConvenienceLibrary)
include (InstallPDB)

if (ANDROID)
    set (ENABLE_GUI false)
else ()
    macro (find_host_package)
        find_package (${ARGN})
    endmacro()
endif ()

find_host_package (PythonInterp 2.7 REQUIRED)
if (NOT PYTHON_VERSION_MAJOR EQUAL 2)
    message (FATAL_ERROR "Python 2.x required and requested, but Python ${PYTHON_VERSION_MAJOR}.${PYTHON_VERSION_MINOR} found.")
endif ()

find_package (Threads)

if (CMAKE_SYSTEM_NAME STREQUAL "Linux")
    find_package (procps)
    if (PROCPS_FOUND)
        add_definitions (-DHAVE_READPROC_H)
    endif ()
endif ()

if (ENABLE_GUI)
    if (NOT (ENABLE_GUI STREQUAL "AUTO"))
        set (REQUIRE_GUI REQUIRED)
    endif ()
    if (POLICY CMP0020)
        cmake_policy (SET CMP0020 NEW)
    endif()
    find_package (Qt5Widgets ${REQUIRE_GUI})
    find_package (Qt5WebKitWidgets ${REQUIRE_GUI})
endif ()

if (WIN32)
    find_package (DirectX)
    set (ENABLE_EGL false)
elseif (APPLE)
    set (ENABLE_EGL false)
else ()
    find_package (X11)

    if (X11_FOUND)
        include_directories (${X11_INCLUDE_DIR})
        add_definitions (-DHAVE_X11)
    else ()
        # Print a clear message when X11 is not found
        include (FindPackageMessage)
        find_package_message (X11 "Could not find X11" "")
    endif ()
endif ()

if (ENABLE_EGL AND (ANDROID OR ENABLE_WAFFLE))
    # if waffle is found eglretrace will be built for Android.
    find_package (Waffle)
endif ()


##############################################################################
# Set global build options

include (CheckCXXCompilerFlag)
include (CheckIncludeFileCXX)

macro (add_compiler_flags)
    string (REPLACE ";" " " _FLAGS "${ARGV}")
    set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${_FLAGS}")
    set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${_FLAGS}")
endmacro ()

macro (add_linker_flags)
    string (REPLACE ";" " " _FLAGS "${ARGV}")
    set (CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${_FLAGS}")
    set (CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} ${_FLAGS}")
    set (CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} ${_FLAGS}")
endmacro ()

add_definitions (
    -D__STDC_LIMIT_MACROS
)

if (WIN32)
    # http://msdn.microsoft.com/en-us/library/aa383745.aspx
    if (MINGW OR CMAKE_GENERATOR_TOOLSET MATCHES "_xp$")
        # Windows XP
        add_definitions (-D_WIN32_WINNT=0x0501 -DWINVER=0x0501)
    else ()
        # Windows 7
        add_definitions (-D_WIN32_WINNT=0x0601 -DWINVER=0x0601)
    endif ()
else (WIN32)
    CHECK_CXX_COMPILER_FLAG("-fvisibility=hidden" CXX_COMPILER_FLAG_VISIBILITY)
    if (CXX_COMPILER_FLAG_VISIBILITY)
        add_compiler_flags (-fvisibility=hidden)
    endif ()
endif ()

if (MSVC)
    if (${MSVC_VERSION} LESS 1800)
        message (FATAL_ERROR "Visual Studio 2013 or later required")
    endif ()

    # No RTTI required
    string (REGEX REPLACE "/GR *" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
    set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /GR-")

    # Disable C++ exceptions
    add_definitions (-D_HAS_EXCEPTIONS=0)
    string (REGEX REPLACE "/EHsc *" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
    set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /EHs-c-")

    # Enable math constants defines
    add_definitions (-D_USE_MATH_DEFINES)

    # No min/max macros
    add_definitions (-DNOMINMAX)

    # Adjust warnings
    add_definitions (-D_CRT_SECURE_NO_DEPRECATE -D_CRT_SECURE_NO_WARNINGS -D_CRT_NONSTDC_NO_WARNINGS)
    add_definitions (-D_SCL_SECURE_NO_DEPRECATE -D_SCL_SECURE_NO_WARNINGS)
    add_compiler_flags (-W3)
    # XXX: it's safer to use ssize_t everywhere instead of disabling warning
    add_compiler_flags (-wd4018) # signed/unsigned mismatch
    add_compiler_flags (-wd4063) # not a valid value for switch of enum
    add_compiler_flags (-wd4100) # unreferenced formal parameter
    add_compiler_flags (-wd4127) # conditional expression is constant
    add_compiler_flags (-wd4244) # conversion from 'type1' to 'type2', possible loss of data
    add_compiler_flags (-wd4267) # conversion from 'type1' to 'type2', possible loss of data
    add_compiler_flags (-wd4505) # unreferenced local function has been removed
    add_compiler_flags (-wd4512) # assignment operator could not be generated
    add_compiler_flags (-wd4800) # forcing value to bool 'true' or 'false' (performance warning)
    
    # Use static runtime
    # http://www.cmake.org/Wiki/CMake_FAQ#How_can_I_build_my_MSVC_application_with_a_static_runtime.3F
    foreach (flag_var
        CMAKE_C_FLAGS CMAKE_C_FLAGS_DEBUG CMAKE_C_FLAGS_RELEASE CMAKE_C_FLAGS_MINSIZEREL CMAKE_C_FLAGS_RELWITHDEBINFO
        CMAKE_CXX_FLAGS CMAKE_CXX_FLAGS_DEBUG CMAKE_CXX_FLAGS_RELEASE CMAKE_CXX_FLAGS_MINSIZEREL CMAKE_CXX_FLAGS_RELWITHDEBINFO
    )
        if (${flag_var} MATCHES "/MD")
            string (REGEX REPLACE "/MD" "/MT" ${flag_var} "${${flag_var}}")
        endif ()
    endforeach (flag_var)
else ()
    # Enable and require C++11
    #
    # We must use `-std=gnu++11` instead `-std=c++11` as the latter defines
    # __STRICT_ANSI__ which prevents _isnan from being declared with MinGW.
    #
    # See also:
    # - https://gcc.gnu.org/projects/cxx0x.html
    # - http://clang.llvm.org/cxx_status.html
    check_cxx_compiler_flag ("-std=gnu++11" CXX_COMPILER_FLAG_STD_GNUXX11)
    if (CXX_COMPILER_FLAG_STD_GNUXX11)
        set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=gnu++11")
    elseif (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
        check_cxx_compiler_flag ("-std=gnu++0x" CXX_COMPILER_FLAG_STD_GNUXX0X)
        if (NOT CXX_COMPILER_FLAG_STD_GNUXX0X OR
            CMAKE_CXX_COMPILER_VERSION VERSION_LESS "4.6")
            message (FATAL_ERROR "GCC 4.6 or later required for adequate C++11 support")
        else ()
            set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=gnu++0x")
        endif ()
    else ()
        message (FATAL_ERROR "${CMAKE_CXX_COMPILER_ID} ${CMAKE_CXX_COMPILER_VERSION} compiler does not support C++11")
    endif ()

    # Adjust warnings
    add_compiler_flags (-Wall)
    # XXX: it's safer to use ssize_t everywhere instead of disabling warning
    add_compiler_flags (-Wno-sign-compare) # comparison between signed and unsigned integer expressions

    # Disable strict aliasing assumptions.  We generate a lot of C++ code, and
    # it's not always easy to guarantee or spot when strict aliasing
    # assumptions are violated.  Above all, the benefit is not worth the risk.
    add_compiler_flags (-fno-strict-aliasing)

    # No RTTI required
    # XXX: there's a dynamic_cast in Android
    if (NOT ANDROID)
        set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-rtti")
    endif ()

    # Disable C++ exceptions
    #set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-exceptions")

    # Enable stack protection
    if (CMAKE_COMPILER_IS_GNUCC AND CMAKE_COMPILER_IS_GNUCXX)
        set (CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -fstack-protector-all")
        set (CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -fstack-protector-all")
        if (MINGW)
            # MinGW doesn't link against libssp automatically, and furthermore
            # we want static linking.
            set (SSP_LIBRARY "-Wl,-Bstatic -lssp -Wl,-Bdynamic")
            set (CMAKE_C_STANDARD_LIBRARIES "${SSP_LIBRARY} ${CMAKE_C_STANDARD_LIBRARIES}")
            set (CMAKE_CXX_STANDARD_LIBRARIES "${SSP_LIBRARY} ${CMAKE_CXX_STANDARD_LIBRARIES}")
        endif ()
    endif ()

    # Enable SSE2 intrinsics on x86
    if (CMAKE_SIZEOF_VOID_P EQUAL 4)
        check_cxx_compiler_flag ("-msse2" CXX_COMPILER_FLAG_MSSE2)
        if (CXX_COMPILER_FLAG_MSSE2)
            add_compiler_flags (-msse2 -mfpmath=sse)

            # And tell GCC to assume 4 bytes alignment, many Linux/Windows
            # applications only guarantee that, but not on systems where ABI
            # clearly states otherwise.
            #
            # See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=38496
            if (NOT ANDROID)
                check_cxx_compiler_flag (-mincoming-stack-boundary=2 CXX_COMPILER_FLAG_MINCOMING_STACK_BOUNDARY)
                if (CXX_COMPILER_FLAG_MINCOMING_STACK_BOUNDARY)
                    add_compiler_flags (-mincoming-stack-boundary=2)
                endif ()
            endif ()
        endif ()
    endif ()

    # Be nice to Eclipse
    add_compiler_flags (-fmessage-length=0)
endif ()

if (CMAKE_CXX_COMPILER_ID STREQUAL Clang AND CMAKE_BUILD_TYPE MATCHES Rel)
    message (WARNING
        "\n"
        "  WARNING: NON-DEBUG BUILDS ON CLANG CAN TAKE UP TO 45MIN!\n"
        "  See https://github.com/apitrace/apitrace/issues/346\n"
        ""
    )
    execute_process (COMMAND ${CMAKE_COMMAND} -E sleep 5)
endif ()

if (MINGW)
    # Avoid depending on MinGW runtime DLLs
    add_linker_flags (-static-libgcc -static-libstdc++)
endif ()

if (ENABLE_FRAME_POINTER)
    # disable frame pointer omission
    if (MSVC)
        add_compiler_flags (/Oy-)
    else ()
        add_compiler_flags (-fno-omit-frame-pointer)
    endif ()
endif ()

# Enable Data Execution Prevention and Address Space Layout Randomization
if (WIN32)
    if (MSVC)
        add_linker_flags (/NXCOMPAT /DYNAMICBASE)
    else ()
        add_linker_flags (-Wl,--nxcompat -Wl,--dynamicbase)
    endif ()
endif ()

if (CMAKE_SYSTEM_NAME STREQUAL "Linux")
    # For RTLD_DEFAULT and RTLD_NEXT
    add_definitions (-D_GNU_SOURCE)
endif ()

include (TestBigEndian)
test_big_endian (HAVE_BIGENDIAN)
if (HAVE_BIGENDIAN)
    add_definitions (-DHAVE_BIGENDIAN)
endif ()

# Put all executables into the same top level build directory, regardless of
# which subdirectory they are declared
set (CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR})


##############################################################################
# Installation directories

if (CMAKE_SYSTEM_NAME STREQUAL "Linux")
    # Debian multiarch support
    execute_process(COMMAND dpkg-architecture -qDEB_HOST_MULTIARCH
        OUTPUT_VARIABLE ARCH_SUBDIR
        ERROR_QUIET
        OUTPUT_STRIP_TRAILING_WHITESPACE
    )
endif()

if (WIN32 OR APPLE)
    # On Windows/MacOSX, applications are usually installed on a directory of
    # their own
    set (DOC_INSTALL_DIR doc)
    set (LIB_INSTALL_DIR lib)
    set (LIB_ARCH_INSTALL_DIR lib)
else ()
    set (DOC_INSTALL_DIR share/doc/${CMAKE_PROJECT_NAME})
    set (LIB_INSTALL_DIR lib${LIB_SUFFIX}/${CMAKE_PROJECT_NAME})
    if (ARCH_SUBDIR)
        set (LIB_ARCH_INSTALL_DIR lib/${ARCH_SUBDIR}/${CMAKE_PROJECT_NAME})
    else ()
        set (LIB_ARCH_INSTALL_DIR lib${LIB_SUFFIX}/${CMAKE_PROJECT_NAME})
    endif ()
endif ()

set (SCRIPTS_INSTALL_DIR ${LIB_INSTALL_DIR}/scripts)
set (WRAPPER_INSTALL_DIR ${LIB_ARCH_INSTALL_DIR}/wrappers)


##############################################################################
# Bundled dependencies
#
# We prefer to bundle and statically link against many dependencies:
# - on Windows to make it easy to deploy the wrappers DLLs
# - on unices to prevent symbol collisions when tracing applications that link
# against other versions of these libraries

if (NOT ENABLE_STATIC_SNAPPY)
    find_package (SNAPPY)
endif ()
if (ENABLE_STATIC_SNAPPY OR NOT SNAPPY_FOUND)
    set (SNAPPY_INCLUDE_DIRS ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/snappy)
    set (SNAPPY_LIBRARIES snappy_bundled)
    add_subdirectory (thirdparty/snappy)
endif ()
include_directories (${SNAPPY_INCLUDE_DIRS})

if (NOT WIN32)
    # zlib 1.2.4-1.2.5 made it impossible to read the last block of incomplete
    # gzip traces (e.g., apitrace-tests/traces/zlib-no-eof.trace).
    find_package (ZLIB 1.2.6)
endif ()
if (NOT ZLIB_FOUND)
    set (ZLIB_INCLUDE_DIRS ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/zlib)
    set (ZLIB_LIBRARIES z_bundled)
    add_subdirectory (thirdparty/zlib)
endif ()
include_directories (${ZLIB_INCLUDE_DIRS})

# FindPNG.cmake will search ZLIB internally (without requiring any particular
# version), adding its include dirs and libraries, and overwriting ZLIB_FOUND.
# So if the system's ZLIB was did not meet the our requirements, then there's
# no safe way to use the system's PNG library.
if (NOT WIN32 AND ZLIB_FOUND)
    find_package (PNG)
endif ()
if (NOT PNG_FOUND)
    set (PNG_INCLUDE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/libpng)
    set (PNG_DEFINITIONS "")
    set (PNG_LIBRARIES png_bundled)
    add_subdirectory (thirdparty/libpng)
endif ()

if (MSVC)
    add_subdirectory (thirdparty/getopt)
    include_directories (${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/getopt)
    set (GETOPT_LIBRARIES getopt_bundled)
endif ()

if (WIN32)
    add_subdirectory (thirdparty/dxerr)
    add_subdirectory (thirdparty/directxtex)
    add_subdirectory (thirdparty/devcon)
endif ()

if (CMAKE_EXECUTABLE_FORMAT STREQUAL "ELF")
    add_subdirectory (thirdparty/libbacktrace)
    include_directories (${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/libbacktrace)
    set (LIBBACKTRACE_LIBRARIES ${CMAKE_DL_LIBS} backtrace)
    add_definitions (-DHAVE_BACKTRACE=1)
endif ()

add_subdirectory (thirdparty/md5)
set (MD5_INCLUDE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/md5)
set (MD5_LIBRARIES md5_bundled)

# We use bundled headers for all Khronos APIs, to guarantee support for both
# OpenGL and OpenGL ES at build time, because the OpenGL and OpenGL ES 1 APIs
# are so intertwined that conditional compilation extremely difficult. This
# also avoids missing/inconsistent declarations in system headers.
include_directories (BEFORE ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/khronos)

# We use non-standard C++ flags, so we can't just use GTest's CMakeLists.txt
include_directories (${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/gtest/include)
add_library (gtest ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/gtest/src/gtest-all.cc)
set_property (TARGET gtest APPEND PROPERTY INCLUDE_DIRECTORIES ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/gtest)
target_link_libraries (gtest ${CMAKE_THREAD_LIBS_INIT})

enable_testing ()
add_custom_target (check COMMAND ${CMAKE_CTEST_COMMAND})


##############################################################################
# Common libraries / utilities

include_directories (
    ${CMAKE_CURRENT_SOURCE_DIR}/common
)

if (WIN32)
    set (os os_win32.cpp)
else ()
    set (os os_posix.cpp)
endif ()

add_convenience_library (common
    common/trace_callset.cpp
    common/trace_dump.cpp
    common/trace_fast_callset.cpp
    common/trace_file.cpp
    common/trace_file_read.cpp
    common/trace_file_write.cpp
    common/trace_file_zlib.cpp
    common/trace_file_snappy.cpp
    common/trace_model.cpp
    common/trace_parser.cpp
    common/trace_parser_flags.cpp
    common/trace_writer.cpp
    common/trace_writer_local.cpp
    common/trace_writer_model.cpp
    common/trace_loader.cpp
    common/trace_profiler.cpp
    common/trace_option.cpp
    common/${os}
    common/os_backtrace.cpp
    common/os_crtdbg.cpp
    common/highlight.cpp
)

target_link_libraries (common
    ${LIBBACKTRACE_LIBRARIES}
)
if (WIN32)
    target_link_libraries (common
        shell32
    )
endif ()
if (ANDROID)
    target_link_libraries (common
        log
    )
endif ()


##############################################################################
# Sub-directories

add_subdirectory (dispatch)
add_subdirectory (helpers)
add_subdirectory (wrappers)
add_subdirectory (image)
add_subdirectory (retrace)


##############################################################################
# CLI

if (ENABLE_CLI)
    if (WIN32)
        add_subdirectory (inject)
    endif ()
    add_subdirectory (cli)
endif ()

##############################################################################
# Scripts (to support the CLI)

install (
    PROGRAMS
        scripts/highlight.py
        scripts/jsondiff.py
        scripts/profileshader.py
        scripts/retracediff.py
        scripts/snapdiff.py
        scripts/tracecheck.py
        scripts/tracediff.py
        scripts/unpickle.py
    DESTINATION ${SCRIPTS_INSTALL_DIR}
)
if (WIN32)
    install (
        PROGRAMS scripts/convert.py
        DESTINATION ${SCRIPTS_INSTALL_DIR}
    )
    install (
        FILES scripts/apitrace.PIXExp
        DESTINATION ${SCRIPTS_INSTALL_DIR}
    )
endif ()

##############################################################################
# GUI

if (ENABLE_GUI AND Qt5Widgets_FOUND AND Qt5WebKitWidgets_FOUND)
  add_subdirectory(gui)
endif ()


##############################################################################
# Packaging

install (
    FILES
        README.markdown
        docs/BUGS.markdown
        docs/NEWS.markdown
        docs/USAGE.markdown
    DESTINATION ${DOC_INSTALL_DIR}
)
install (
    FILES LICENSE
    DESTINATION ${DOC_INSTALL_DIR}
    RENAME LICENSE.txt
)

set (CPACK_PACKAGE_VERSION_MAJOR "7")
set (CPACK_PACKAGE_VERSION_MINOR "0")

# Use current date in YYYYMMDD format as patch number 
execute_process (
    COMMAND ${PYTHON_EXECUTABLE} -c "import time, sys; sys.stdout.write(time.strftime('%Y%m%d'))"
    OUTPUT_VARIABLE CPACK_PACKAGE_VERSION_PATCH
)

# cpack mistakenly detects Mingw-w64 as win32
if (MINGW)
    if (CMAKE_SIZEOF_VOID_P EQUAL 8)
        set (CPACK_SYSTEM_NAME win64)
    endif ()
endif ()

# See http://www.vtk.org/Wiki/CMake:CPackPackageGenerators
if (WIN32)
    if (CMAKE_VERSION VERSION_LESS 3.1)
        set (CPACK_GENERATOR "ZIP")
    else ()
        set (CPACK_GENERATOR "7Z")
    endif ()
elseif (APPLE)
    set (CPACK_GENERATOR "DragNDrop")
else ()
    set (CPACK_GENERATOR "TBZ2")
endif ()

include(CPack)