How to build a Fat Framework that includes Mac Catalyst?

Question

How does one build a fat framework that includes the architectures necessary to build to Mac Catalyst apps?

Answer 1

Apple has introduced a (undocumented?) new target: x86_64-apple-ios13.0-macabi

How to build for this target depends on your frameworks build environment.

1) XCFramework

In case your framework is an Xcode project:

• Select the target in Xcode
• Select the "General" tab
• Under "Deployment Info", tick the "Mac" checkbox:
• build

2) External Build

In case you are building your framework outside Xcode, e.g. a C lib, instead of building for x86_64 & iphonesimulator, build for the new target x86_64-apple-ios13.0-macabi & macosx.

Example for C Lib using make:

MIN_IOS_VERSION="10.0"
LIB_NAME= "theNameOfYourLib"

# The build function
build()
{
ARCH=$1
TARGET=$2
HOST=$3
SDK=$4
SDK_PATH=`xcrun -sdk ${SDK} --show-sdk-path`

export PREFIX=build/${ARCH}
export CFLAGS="-arch ${ARCH} -isysroot ${SDK_PATH} -miphoneos-version-min=${MIN_IOS_VERSION} -std=c99 -target ${TARGET}"
export LDFLAGS="-arch ${ARCH}"
export CC="$(xcrun --sdk ${SDK} -f clang) -arch ${ARCH} -isysroot ${SDK_PATH}"

PKG_CONFIG_ALLOW_CROSS=1 PKG_CONFIG_PATH=$PREFIX/lib/pkgconfig ./configure --host=${HOST} --prefix=$PREFIX

make
make install
}

# Build for all required architectures

build "armv7" "armv7-apple-ios" "arm-apple-darwin" "iphoneos" # MIN_IOS_VERSION must be one of arm7 supported ones to. Else remove this line.
build "arm64" "aarch64-apple-ios" "arm-apple-darwin" "iphoneos"
# build "x86_64" "x86_64-apple-ios" "x86_64-apple-darwin" "iphonesimulator" #obsolete due to x86_64-apple-ios13.0-macabi
build "x86_64" "x86_64-apple-ios13.0-macabi" "x86_64-apple-darwin" "macosx"
build "i386" "i386-apple-ios" "i386-apple-darwin" "iphonesimulator" # same as arm7:  MIN_IOS_VERSION must be one of arm7 supported ones.

# Now find all the artefacts created above (e.g. build/arm64/lib/${LIB_NAME}.a,  build/x86_64/lib/${LIB_NAME}.a ...) and merge them together to a fat lib using lipo

OUTPUT_DIR="fatLib"
lipo -create -output $OUTPUT_DIR/lib/${LIB_NAME}.a build/x86_64/lib/${LIB_NAME}.a build/arm64/lib/${LIB_NAME}.a build/armv7/lib/${LIB_NAME}.a build/i386/lib/${LIB_NAME}.a

# You may also need the header files
cp -R build/armv7/include/* $OUTPUT_DIR/include/

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Note: You must/can not add slices for x86_64-apple-ios and x86_64-apple-ios13.0-macabito the fat lib. Both are x86_64. Use only the one for x86_64-apple-ios13.0-macabi.