Issue creating iOS "Fat Library".

Question

I have a bash script that builds my iOS static library for both ARM and i386 architectures. I am then using lipo to combine the binaries into a single "combined" library so that it can be linked to in the simulator as well as on a device. For some reason when I attempt to link against the resulting fat library I still get linker errors complaining that symbols are not found for i386 when debugging. I'm wondering if I am not building the simulator or iphoneos libraries correctly before using lipo. Can someone help me out?

Here is my bash script:

    if [ $1 == "clean" ]
then
    echo -e "Perform Clean\n"
    if [ -d build ]
    then
        rm -r build
        exit 
    fi      
else
    echo -e "Begin combined build process.\n"
    XCODEBUILD_PATH=/Applications/Xcode.app/Contents/Developer/usr/bin
    XCODEBUILD=$XCODEBUILD_PATH/xcodebuild
    echo -e "xcode build executable path: $XCODEBUILD\nBuiding i386 static library.\n"
    $XCODEBUILD -project MyLibrary.xcodeproj -target "MyLibrary" -sdk "iphonesimulator" -configuration "Release" clean build
    echo -e "Buiding ARM static library.\n"
    $XCODEBUILD -project MyLibrary.xcodeproj -target "MyLibrary" -sdk "iphoneos" -configuration "Release" clean build
    echo -e "Combine ARM and i386 libs.\nOutput: build/combined/libMyLibrary.a\n"
    [ -d build/Release-combined ] || mkdir build/Release-combined 
    lipo -create -output "build/Release-combined/libMyLibrary.a" "build/Release-iphoneos/libMyLibrary.a" "build/Release-iphonesimulator/libMyLibrary.a"
    echo -e "Done!\n"
fi
exit

When I add link against the resulting lib "build/Release-combined/libMyLibrary.a". I get linking issues. Am I doing something wrong?

Thanks!

Answer 1

Well there are 2 ways to make gcc/clang build a different arch.

you can pass the -m32 or -m64 flag...

but it is more explicit to use the -arch x86_64 -arch i386 flags which in apple clang and apple gcc can be passed at the same time.