Mac Catalyst - xcframework support #17929
Description
System information
OpenCV => 4.4.0
Operating System / Platform => macOS Catalina 10.15.5
Compiler => Xcode 11.5 and Xcode 12 beta3
Detailed description
I'm trying to build a Mac Catalyst app using OpenCV. Xcode builds a Mac Catalyst app using the iOS SDK for architecture x86. A Catalyst app looks like an iPad app running on a Mac.
Catalyst requires frameworks to be an xcframework. Apple presented XCFramework as a new binary format of packing libraries.
Steps to reproduce
Here is the commands to create an xcframework, as created by @chrisballinger in #17291
d path/to/opencv
python2 platforms/ios/build_framework.py --iphonesimulator_archs x86_64 --iphoneos_archs arm64 .
mkdir -p build/xcframework
cp build/build-arm64-iphoneos/lib/Release/libopencv_merged.a build/xcframework/libopencv-arm64-iphoneos.a
cp build/build-x86_64-iphonesimulator/lib/Release/libopencv_merged.a build/xcframework/libopencv-x86_64-iphonesimulator.a
# Set project level "Base SDK" to "iOS".
open build/build-x86_64-iphonesimulator/OpenCV.xcodeproj
xcodebuild build -configuration Release -project build/build-x86_64-iphonesimulator/OpenCV.xcodeproj -scheme "ALL_BUILD" -destination 'platform=macOS,arch=x86_64,variant=Mac Catalyst' -UseModernBuildSystem=YES SKIP_INSTALL=NO BUILD_LIBRARY_FOR_DISTRIBUTION=YES TARGETED_DEVICE_FAMILY="1,2" SDKROOT=iphoneos SUPPORTS_MAC_CATALYST=YES
libtool -static -o build/xcframework/libopencv-x86_64-maccatalyst.a build/build-x86_64-iphonesimulator/lib/Release/*.a build/build-x86_64-iphonesimulator/3rdparty/lib/Release/*.a
xcodebuild -create-xcframework -library build/xcframework/libopencv-arm64-iphoneos.a -headers build/build-arm64-iphoneos/install/include/opencv2 -library build/xcframework/libopencv-x86_64-iphonesimulator.a -headers build/build-x86_64-iphonesimulator/install/include/opencv2 -library build/xcframework/libopencv-x86_64-maccatalyst.a -headers build/build-x86_64-iphonesimulator/install/include/opencv2 -output build/xcframework/opencv2.xcframework
The last step fails with this errror:
-error: binaries with multiple platforms are not supported 'build/xcframework/libopencv-x86_64-maccatalyst.a'I was able to create an xcframework manually by doing the following:
1 - Create and xcframework with libopencv-arm64-iphoneos.a and libopencv-x86_64-iphonesimulator.a
2 - opencv2.xcframework is created, which is a folder
3 - Manually add libopencv-x86_64-maccatalyst.a to folder, copy Headers folder, and update plist file in folder.
When adding this to an xcode project, xcode gives this build error:
-Both ios-arm64 and os-x86_64-maccatalyst represent two equivalent library definitions.I tried both Xcode 11.5 and 12 beta3 with same errors.