CMake need to improve, record ideas

[drelaptop]

• cocos2d-x version: latest in github

• 1. info.plist is always created when -GXcode, it's bad friendly for custom info.plist

  • can't find a method to solve this for now, most cmake use template info.plist

• 2. iOS target and macOS can't be in one project, some complex for switch

  • cmake didn't support, see: https://gitlab.kitware.com/cmake/cmake/issues/17805

• 3. write cmake docs, how to use step by step, add link in main readme.md

  • finished at https://github.com/cocos2d/cocos2d-x/blob/v3/cmake/README.md

• 4. sub-dir tree of header files isn't include in Xcode or VS project

  • finished at cmake add collect headers list, unify the logic of source add #18722

• 5. supply simple python script to execute pre-defined shell command, let cmake easy to use

  • plan to do it, in the future, it's better finish this before 3.17 next milestone released.

• 6. delete the old project build files or not if cmake can do build well

  • the cmake build isn't so good as the older way for iOS platform, need to find a solution
  • might have to wait 4.0 version to do this

• 7. cmake support pre-compiled headers, to increase the compile speed

  • no plan to do it recently, hope cocos2d-x forum help

• 8. What about cmake and cocos2d-x-3rd-party-libs?

  • no plan to do it recently, might do it in future
  • plan do it on 3.18, now new a repo at https://github.com/cocos2d/cocos2d-x-external

• 9. Lua Template project on win32, exist different behavior between run with VS and double-click run on Explorer

refer to: https://stackoverflow.com/questions/23950887/does-cmake-offer-a-method-to-set-the-working-directory-for-a-given-build-system

• 10. using prebuilt libs on Android Gradle Build, we must set COCOS_PREBUILT_ROOT to finger the prebuilt libs root library.

  • might we can get system environment from Gradle, to get the cocos2d-x/prebuilt path, refer to proper-way-to-use-system-environment-variables-in-gradle-using-android-studio
  • Android Studio can't get environment variable in Terminal on macOS, need to do config manually. refer to access-to-environment-variables-from-android-studio-gradle-build

• 11. [High Priority] Resource files didn't update before build a target in Xcode, need to solve this issue,

  • temp solution is re-execute cmake .. in the generated Xcode project folder

• 12. cmake build support mingw on Windows, more than 2 developers asked this

  • no plan yet, might do it in future

• 13. build APK for android on pure cmake build

  • I think it's impossiable until Google support this firstly.

[crazyhappygame]

What about cmake and cocos2d-x-3rd-party-libs?

[drelaptop]

It's a good idea to let cmake support 3rd-party-libs finally. We can finish it in the future, but I have no plan to do it recently.

[crazyhappygame]

@drelaptop Once again great job!
I reviewed current implementation below my comments:

1. Add CI travis/appveyor build for cmake mac/win32
   Without that sooner or later something will stop working for cmake

2. Remove from cocos2d-x\cmake\Modules files Find*.cmake which are delivered with cmake by default (e.g. FindCURL.cmake)
   CMake installation will have more upto-date version.

3. Remove duplicated defines (e.g. remove USE_BOX2D use CC_ENABLE_BOX2D_INTEGRATION everywhere)

  if (USE_BOX2D)
    add_definitions(-DCC_ENABLE_BOX2D_INTEGRATION=1)
  else()
    add_definitions(-DCC_ENABLE_BOX2D_INTEGRATION=0)
  endif()

4. Reduce number of functions (e.g. get_target_depends_ext_dlls). Simplify current implementation
   Current logic is too complicated. Too many variables, functions
   Dll dependencies should be setup by FindPackage.cmake or add_subdirectory
   CMakeLists.txt should looks like below:

if(ANDROID)
    add_library(foo )
else   
    add_executable(foo)
endif()

target_sources(foo file1.cpp ....)
if(ANDROID)
    target_sources(foo android_specific.cpp)
endif()

add_subdirectory(sub)
add_subdirectory(...)

find_package(CURL)
find_package(....)

target_include_directories(foo PRIVATE ${CURL_INCLUDE_DIRS}   .....)
target_link_libraries(foo PRIVATE ${CURL_LIBRARIES} sub ......)

if(MSVC)
    find_package(msvc_specific)
    target_link_libraries(foo msvc_specific)
endif()

5. Do we really need XCode, Visual Studio support?
   Maintaining list of resources and headers and other XCode/Visual Studio specific files make CMakeLists.txt more complicated

6. Modernize current implementation
   We use old syntax, obsolete commands like:
   INCLUDE_DIRECTORIES(), ADD_DEFINITIONS(), LINK_LIBRARIES()

Please see below two documents (there are also videos on youtube)
https://github.com/boostcon/cppnow_presentations_2017/blob/master/05-19-2017_friday/effective_cmake__daniel_pfeifer__cppnow_05-19-2017.pdf

https://github.com/CppCon/CppCon2017/blob/master/Tutorials/Using%20Modern%20CMake%20Patterns%20to%20Enforce%20a%20Good%20Modular%20Design/Using%20Modern%20CMake%20Patterns%20to%20Enforce%20a%20Good%20Modular%20Design%20-%20Mathieu%20Ropert%20-%20CppCon%202017.pdf

[drelaptop]

@crazyhappygame thank you for so detail suggestion, I like you.

1. Add CI travis/appveyor build for cmake mac/win32

   Not need do it now. we should do that after the cmake can replace the older build system. I hope in 3.17 the cmake and older build system both works well.

2. Remove from cocos2d-x\cmake\Modules files Find*.cmake

   Good idea, I will do that in the next days

3. Remove duplicated defines

   Yes, we should do that.

4. Reduce number of functions (e.g. get_target_depends_ext_dlls)

   We should reduce, but about the logic of collect dlls, I can't find a simpler implementation. When consider this issue, we should consider the situation of using prebuilt libs.
   For example, build the cpp-empty-test and use the cocos2d.a prebuilt libs, in this situation we didn't need to add cocos/CMakeLists.txt, and then how we know the dll list of cocos2d lib needed? for we need to copy the dll into app binary dir. The current logic, CocosPickLibs.cmake, CocosUseLibs.cmake and cocos_use_pkg() do this work.

5. Do we really need XCode, Visual Studio support?

   We really need Xcode, I think many users depend Xcode to develop a iOS game, how to Debug if we didn't support IDE, Debug by command line is really hard for most users.

6. Modernize current implementation

   Thanks for this instructions, it's very useful when doing CMake Code refactoring. I will read the document, however I have the plan to research "creator_to_cocos2dx" plugin, and then do some bug fix and improvements. so I am afraid I won't do this work in next days, might do it in recent future. I will ask @minggo suggestion about this task.

[crazyhappygame]

ad1. I was thinking about adding new cmake CI configuration (old CI configs should stay unchanged)

[crazyhappygame]

Could you at least add Travis CI test build for android with prebuilds?
i.e. 3 new projects

cocos new --agreement n -l cpp -p my.pack.test1 test1
cocos new --agreement n -l cpp -p my.pack.test2 test2
cocos new --agreement n -l cpp -p my.pack.test3 test3
.....

[drelaptop]

@crazyhappygame finish 2 items below at PR #18799 , could you review it when you are free?

2. Remove from cocos2d-x\cmake\Modules files Find*.cmake

Good idea, I will do that in the next days

3. Remove duplicated defines

Yes, we should do that.

[crazyhappygame]

@drelaptop
2. Remove from cocos2d-x\cmake\Modules files Find*.cmake - looks good, Linux compilation passed
3. Remove duplicated defines - this looks bad, my idea was about renaming options/defines. In PR #18799 it seems like options are not used at all ..... I think that we should rollback this change and add all add_definitions
Currently it is impossible to enable/disable options/defines by cmake command line. For example below do nothing:
cmake -DUSE_CHIPMUNK=OFF
before it disabled chipmunk and physics integration

[drelaptop]

Thanks for review

For example below do nothing:
cmake -DUSE_CHIPMUNK=OFF

cmake .. -DUSE_CHIPMUNK=OFF this is NOT do nothing, it disable the USE_CHIPMUNK in CMake build, you can find this in CMakeCache.txt

//Use chipmunk for physics library
USE_CHIPMUNK:BOOL=OFF

So I think the issue not can't enable/disable options by cmake command line , but the USE_*** logic. I think the USE_*** logic is awful, for example I can't enable the Box2D Tests in cpp-tests by set USE_BOX2D=ON ONLY. the logic should improved later. rollback this change isn't necessary, for those changes didn't make the cmake build worse.

[crazyhappygame]

@drelaptop Did you run win32/mac/ios/android cmake build after you change? I just run cmake for cocos2d-x\tests\cpp-empty-test for win32 and it fails for me. I think that it worked before... It seems like currently it tries to links to VS2013 libbullet.lib with VS2015 win32 app.

I have following proposition: in travis/appveyor there are android_cocos_new_test, windows32_cocos_new_test CI build configuration. Maybe we may run for them cmake build?

I have below error:

7>libchipmunk.lib(cpArbiter.obj) : MSIL .netmodule or module compiled with /GL found; restarting link with /LTCG; add /LTCG to the link command line to improve linker performance
7>LINK : warning LNK4075: ignoring '/INCREMENTAL' due to '/LTCG' specification
7>libbullet.lib(btAlignedAllocator.obj) : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/OPT:LBR' specification
7>libbullet.lib(btCollisionDispatcher.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btCollisionWorld.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btDefaultCollisionConfiguration.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btDbvtBroadphase.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btDiscreteDynamicsWorld.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btSequentialImpulseConstraintSolver.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btCollisionObject.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btRigidBody.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btGhostObject.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btManifoldResult.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btCollisionShape.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btConvexShape.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btBvhTriangleMeshShape.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btQuickprof.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btConvexConvexAlgorithm.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btEmptyCollisionAlgorithm.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btConvexConcaveCollisionAlgorithm.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btCompoundCollisionAlgorithm.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btCompoundCompoundCollisionAlgorithm.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btConvexPlaneCollisionAlgorithm.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btBoxBoxCollisionAlgorithm.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btSphereSphereCollisionAlgorithm.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btSphereTriangleCollisionAlgorithm.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btDbvt.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btOverlappingPairCache.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btSimulationIslandManager.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btTypedConstraint.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btConeTwistConstraint.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btGeneric6DofConstraint.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btQuantizedBvh.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btOptimizedBvh.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btPolyhedralConvexShape.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btActivatingCollisionAlgorithm.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btPolyhedralContactClipping.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btCollisionAlgorithm.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btHashedSimplePairCache.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btUnionFind.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btConvexPolyhedron.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btConvexHullComputer.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>libbullet.lib(btGeometryUtil.obj) : error LNK2038: mismatch detected for '_MSC_VER': value '1800' doesn't match value '1900' in AppDelegate.obj
7>   Creating library G:/cocos_latest/subrepos/external/cocos2d-x/tests/cpp-empty-test/build2/Debug/cpp-empty-test.lib and object G:/cocos_latest/subrepos/external/cocos2d-x/tests/cpp-empty-test/build2/Debug/cpp-empty-test.exp
7>LINK : warning LNK4098: defaultlib 'LIBCMTD' conflicts with use of other libs; use /NODEFAULTLIB:library
7>glfw3.lib(init.c.obj) : error LNK2001: unresolved external symbol __imp__vsnprintf
7>MSVCRTD.lib(vsnprintf.obj) : error LNK2001: unresolved external symbol __imp__vsnprintf
7>libjpeg.lib(jerror.obj) : error LNK2001: unresolved external symbol ___iob_func
7>libtiff.lib(tif_unix.obj) : error LNK2001: unresolved external symbol __imp____iob_func
7>libpng.lib(pngerror.obj) : error LNK2001: unresolved external symbol __imp____iob_func
7>libchipmunk.lib(chipmunk.obj) : error LNK2001: unresolved external symbol __imp____iob_func
7>libtiff.lib(tif_unix.obj) : error LNK2001: unresolved external symbol __imp__vfprintf
7>libchipmunk.lib(chipmunk.obj) : error LNK2001: unresolved external symbol __imp__vfprintf
7>MSVCRTD.lib(vsnprintf.obj) : error LNK2001: unresolved external symbol __imp___vsnprintf
7>G:\cocos_latest\subrepos\external\cocos2d-x\tests\cpp-empty-test\build2\bin\cpp-empty-test\Debug\cpp-empty-test.exe : fatal error LNK1120: 5 unresolved externals

[drelaptop]

cpp-tests project is tested on mac/iOS/Android. win32 is tested on Windows10 + VS2017.

Did you update you external libs? VS2013 libbullet.lib have been removed 6 months ago. and all vs2013 libs have been removed. @crazyhappygame

[crazyhappygame]

@drelaptop it works for me. I am sorry for false alarm. I had broken build environment.

[drelaptop]

#18816 might fixed

11. [High Priority] Resource files didn't update before build a target in Xcode, need to solve this issue,

not tested yet

[v1993]

Some my ideas (in order of importance decreasing):

1. Add MinGW support (I'm not shure how hard is it, but would be very helpful for me).
2. Icons support for cmake (windows game.ico and add icon for linux (window icon)).
3. Not very important and probably not to be done, but still an idea: build APK for android on pure cmake build (in this case also implement 2nd idea for android).