Use CMAKE_IOS_INSTALL_COMBINED CMake Variable for Universal Library Support Out-of-the-Box about ios-cmake HOT 9 CLOSED

I found these two out by looking at the CMake repo, and most of the changes on the iOS build code of CMake come from @ruslo.

The state of this feature is a little bit messy because in fact iOS platform is still not officially supported by CMake :) As far as I know there is some progress there, see this pull request: https://gitlab.kitware.com/cmake/cmake/issues/17870

In practice this feature will not work for random iOS toolchain and require some agreements (e.g. it will work only for Xcode and CMAKE_OSX_SYSROOT should be set to iphoneos), see hints in tests:

• https://github.com/Kitware/CMake/blob/v3.12.2/Tests/RunCMake/XcodeProject/XcodeIOSInstallCombinedPrune.cmake
• https://github.com/Kitware/CMake/blob/v3.12.2/Tests/RunCMake/XcodeProject/XcodeIOSInstallCombined.cmake
• https://github.com/Kitware/CMake/blob/v3.12.2/Tests/RunCMake/XcodeProject/XcodeIOSInstallCombinedSingleArch.cmake

You can find the real-world toolchains in this collection: https://github.com/ruslo/polly

For example:

• https://github.com/ruslo/polly/blob/master/ios-11-4-dep-9-3.cmake
• https://github.com/ruslo/polly/blob/master/os/iphone.cmake

from ios-cmake.

For those interested, here is the CMakeIOSInstallCombined module source code.

from ios-cmake.

Great find! :D
Looking at the CMake tests it actually looks like this has in some form worked since CMake 3.3+ even. At least during development releases.

from ios-cmake.

Ok, so I ended up getting my build to run googletests on iOS XCode (complicated, if you're interested, PM me), but as expected, while my basic build and test targets work as expected, I can't get the install to work correctly. I need to figure it out but it seems that the standard CMake target install with CMAKE_IOS_INSTALL_COMBINED enabled to true with the toolchain conflict with each other. I'll try to see what I can do to fix it.

For people interested, here's my error output (paths stubbed out):

     [exec] 
     [exec] === BUILD AGGREGATE TARGET ALL_BUILD OF PROJECT ${PROJECTNAME} WITH CONFIGURATION Release ===
     [exec] 
     [exec] Check dependencies
     [exec] 
     [exec] Write auxiliary files
     [exec] write-file /Users${ROOT}/build/${PROJECTNAME}.build/Release-iphonesimulator/ALL_BUILD.build/Script-B6C1EA717ACC4EB7AD6F7296.sh
     [exec] chmod 0755 /Users${ROOT}/build/${PROJECTNAME}.build/Release-iphonesimulator/ALL_BUILD.build/Script-B6C1EA717ACC4EB7AD6F7296.sh
     [exec] 
     [exec] PhaseScriptExecution CMake\ Rules build/${PROJECTNAME}.build/Release-iphonesimulator/ALL_BUILD.build/Script-B6C1EA717ACC4EB7AD6F7296.sh
     [exec]     cd /Users${ROOT}
     [exec]     /bin/sh -c /Users${ROOT}/build/${PROJECTNAME}.build/Release-iphonesimulator/ALL_BUILD.build/Script-B6C1EA717ACC4EB7AD6F7296.sh
     [exec] echo ""
     [exec] 
     [exec] echo Build\ all\ projects
     [exec] Build all projects
     [exec] 
     [exec] === BUILD AGGREGATE TARGET install OF PROJECT ${PROJECTNAME} WITH CONFIGURATION Release ===
     [exec] 
     [exec] Check dependencies
     [exec] 
     [exec] Write auxiliary files
     [exec] write-file /Users${ROOT}/build/${PROJECTNAME}.build/Release-iphonesimulator/install.build/Script-1325F327E42D4B51B08E2D23.sh
     [exec] chmod 0755 /Users${ROOT}/build/${PROJECTNAME}.build/Release-iphonesimulator/install.build/Script-1325F327E42D4B51B08E2D23.sh
     [exec] 
     [exec] PhaseScriptExecution CMake\ PostBuild\ Rules build/${PROJECTNAME}.build/Release-iphonesimulator/install.build/Script-1325F327E42D4B51B08E2D23.sh
     [exec]     cd /Users${ROOT}
     [exec]     /bin/sh -c /Users${ROOT}/build/${PROJECTNAME}.build/Release-iphonesimulator/install.build/Script-1325F327E42D4B51B08E2D23.sh
     [exec] /usr/local/Cellar/cmake/3.12.0/bin/cmake -DBUILD_TYPE=Release -DEFFECTIVE_PLATFORM_NAME=-iphonesimulator -P cmake_install.cmake
     [exec] -- Install configuration: "Release"
     [exec] -- Installing: /Users${ROOT}/dist/${PROJECTNAME}-ios/ios/lib/lib${PROJECTNAME}Blas.a
     [exec] [iOS combined] Target: ${PROJECTNAME}Blas
     [exec] [iOS combined] Config: Release
     [exec] [iOS combined] Destination: /Users${ROOT}/dist/${PROJECTNAME}-ios/ios/lib/lib${PROJECTNAME}Blas.a
     [exec] [iOS combined] Architectures (iphoneos): arm64 armv7 armv7s
     [exec] [iOS combined] Architectures (iphonesimulator): i386 x86_64
     [exec] [iOS combined] Build `${PROJECTNAME}Blas` for `iphoneos`
     [exec] Build settings from command line:
     [exec]     SDKROOT = iphoneos11.4
     [exec]     TOOLCHAINS = com.apple.dt.toolchain.XcodeDefault
     [exec] 
     [exec] === BUILD AGGREGATE TARGET ZERO_CHECK OF PROJECT ${PROJECTNAME} WITH CONFIGURATION Release ===
     [exec] 
     [exec] Check dependencies
     [exec] 
     [exec] Write auxiliary files
     [exec] write-file ${BUILD_PATH}/ZERO_CHECK.build/Script-250BDD78B55149C3B04C39C3.sh
     [exec] chmod 0755 ${BUILD_PATH}/ZERO_CHECK.build/Script-250BDD78B55149C3B04C39C3.sh
     [exec] 
     [exec] PhaseScriptExecution CMake\ Rules build/${PROJECTNAME}.build/Release-iphoneos/ZERO_CHECK.build/Script-250BDD78B55149C3B04C39C3.sh
     [exec]     cd /Users${ROOT}
     [exec]     /bin/sh -c ${BUILD_PATH}/ZERO_CHECK.build/Script-250BDD78B55149C3B04C39C3.sh
     [exec] echo ""
     [exec] 
     [exec] make -f /Users${ROOT}/build/CMakeScripts/ReRunCMake.make
     [exec] make[2]: `/Users${ROOT}/build/CMakeFiles/cmake.check_cache' is up to date.
     [exec] 
     [exec] === BUILD TARGET ${PROJECTNAME}Blas OF PROJECT ${PROJECTNAME} WITH CONFIGURATION Release ===
     [exec] 
     [exec] Check dependencies
     [exec] No architectures to compile for (ARCHS=x86_64, VALID_ARCHS=arm64 armv7 armv7s).
     [exec] 
     [exec] ** BUILD FAILED **
     [exec] 
     [exec] 
     [exec] The following build commands failed:
     [exec] 	Check dependencies
     [exec] (1 failure)
     [exec] ** BUILD FAILED **CMake Error at /usr/local/Cellar/cmake/3.12.0/share/cmake/Modules/CMakeIOSInstallCombined.cmake:127 (message):
     [exec]   Build failed
     [exec] Call Stack (most recent call first):
     [exec]   /usr/local/Cellar/cmake/3.12.0/share/cmake/Modules/CMakeIOSInstallCombined.cmake:279 (_ios_install_combined_build)
     [exec]   cmake_install.cmake:49 (ios_install_combined)
     [exec] 
     [exec] 
     [exec] make: *** [install_buildpart_0] Error 1
     [exec] Command /bin/sh failed with exit code 2

Here are the arguments I fed into CMake:

-DCMAKE_TOOLCHAIN_FILE=${basedir}/cmake/toolchain/ios.toolchain.cmake -DIOS_PLATFORM=SIMULATOR64 -DIOS=TRUE

from ios-cmake.

@leetal, I actually got this to work. I tested this by using -DIOS_PLATFORM=OS -DIOS_DEPLOYMENT_TARGET=8.0:

I got this working by doing the following:

1. set CMAKE_OSX_DEVELOPMENT_TARGET to match IOS_DEPLOYMENT_TARGET

• CMAKE_OSX_DEVELOPMENT_TARGET isn't set in the toolchain for some reason (prolly because you're using a CMake version older than 3.11 at your workplace), so whenever I ran the install cmake target, cmake would force a rebuild and set the -mios-${platform}-version-min to whatever the default iOS version is and ignore the one set in
• Note that you no longer need to set that flag I was talking about anymore if using CMake 3.11 since this is automatically added by CMake via this CMake variable

2. You must add the simulator architectures as XCODE_ATTRIBUTES (see below) into your CMakeLists.txt:

if (CMAKE_IOS_INSTALL_COMBINED AND CMAKE_OSX_SYSROOT MATCHES "os")
  set_target_properties(fooTarget bazTarget PROPERTIES
      XCODE_ATTRIBUTE_ARCHS[sdk=iphonesimulator*] i386 x86_64
      XCODE_ATTRIBUTE_VALID_ARCHS[sdk=iphonesimulator*] i386 x86_64
  )
endif()

• This ensures that CMake's install target will pick up the correct architectures when running the ios_install_combined when running the install target
• ios_install_combined looks for both properties on the target
• if you start with -DIOS_PLATFORM=SIMULATOR[64], you will have to set the opposite on the targets. (but this will only build for 1 simulator architecutre, you can't build both simulator architectures with the toolchain, and I decided not to investigate this angle)
• If setting the architectures on the same platform, I get a CRAPTON of linker errors if creating an executable from a library
• I don't fully understand why this works, but it does...

Doing these two things fixes the problems and I'm able to create a nice fat universal static library for the following architectures:

• arm64
• armv7
• armv7s
• i686
• x86_64

I found these two out by looking at the CMake repo, and most of the changes on the iOS build code of CMake come from @ruslo. I believe the code will run a config 2x, and it doesn't directly use the toolchain, but I'm sure it ends up using a lot of the cached values that the toolchain sets (I probably should investigate this, too, but I've spent over a week moving my team's code to use CMake, googletests to run on iOS, and also semi-understand ios_installed_combined enough to make a universal static lib).

I believe (1) is easy to solve by adding 1 simple line to the toolchain (just add flag if cmake is 3.11 or higher, else fall back to current behavior, but this solution will only work for CMake 3.11+). However, (2) will probably only work by changing the documentation since this is dependent on users setting the correct architectures on their targets. Perhaps there is a better solution to this but TBH it's always best to set properties on CMake targets and in addition document the variables that we can set on it (unfortunately CMake doesn't).

This begs a bigger question if CMake should just have 1st party support for iOS like it has for Android. I believe your toolchain is definitely good enough especially if the code is cleaned for the newer versions of CMake. CMake really should clean up their documentation for modern practices, also.

from ios-cmake.

Hi! This question may fit well here. I see in @ruslo's link that the official cmake iOS support is coming along well, but it might not just be 100% there yet.

I'd like to ask, what are the main differences between @ruslo's polly iOS toolchain files, and @leetal's iOS toolchain files in this repository? Both look quite mature and well-working to me. Any hints on what the differences might be and when to best go for one or the other?

Thanks a lot!

from ios-cmake.

I see in @ruslo's link that the official cmake iOS support is coming along well, but it might not just be 100% there yet

I haven't tested it yet, I guess I will need to tweak few variables in Polly to match CMake 3.14 (?) iOS support. In general as far as I understand Polly, CMake iOS support and https://github.com/leetal/ios-cmake are independent things.

the main differences between @ruslo's polly iOS toolchain files, and @leetal's iOS toolchain files in this repository?

According to the README:

• https://github.com/leetal/ios-cmake#options

The resulting binary will consist of only one platform. To combine all
platforms into the same fat-library, use the LIPO tool. More information
on this is available on the net

It's not designed to use both simulator and device simultaneously, if you want such library you have to independently build simulator, then build device, then use lipo.

With Polly, simulator and device architectures can be mixed together without any extra steps (see CMAKE_IOS_INSTALL_COMBINED feature). E.g. build with ios-nocodesign-11-4-dep-9-3 toolchain:

• https://travis-ci.org/ingenue/hunter/jobs/497488024

Will produce the 5 architectures library:

> mkdir __temp && cd __temp
> wget https://github.com/ingenue/hunter-cache/releases/download/cache-19005d5/19005d5e7164d248ee51ba10ac03caf6d0d48645.tar.bz2
> tar xf 19005d5e7164d248ee51ba10ac03caf6d0d48645.tar.bz2
> lipo -info lib/libicui18n.a
Architectures in the fat file: lib/libicui18n.a are: i386 armv7 armv7s x86_64 arm64

This library produced by regular cmake --build _builds --target install command and package can be injected to user code with regular find_package(... CONFIG REQUIRED).

from ios-cmake.

I see! So I would deduce from that that leetal/ios-cmake is quite a basic (while well-working) iOS toolchain file for CMake, while polly's iOS toolchain files offer many more options (like e.g. the mixing of architectures that you mentioned).

Thank you very much, that's a great answer.

from ios-cmake.

Fixed in v3.0.0 🔥 See #27 for more information to official docs.

from ios-cmake.