build objc4 runtime

【build objc4 runtime】

　1、Get the latest objc4 project codes from www.opensource.apple.com.

　2、Open the projetct, compile it, you will get compile error.

　3、you need some file to complete the compilation.

　　1) Create Directory: /tmp/objc.dst/usr/include

　　2) from libauto project, get auto_zone.h. Put it in the directory we just created.

　　3) from libclosure project, get Block_private.h. Put it in the directory we just created.

　　4) from libc project, get CrashReporterClient.h. Put it in the directory we just created.

　　    from libc project, get pthreads/pthread_machdep.h. Put it in the directory we just created with dirname of "system".

　　5) from libdispatch project, get private-dir codes. Put it in the directory we just created with dirname of "dispatch".

　　6) from dyld project, get dyld_priv.h. Put it in the directory we just created with dirname of "mach-o".

　　    from dyld project, get objc-shared-cache.h. Put it in the directory we just created.

　　7) from xnu project, get osfmk/machine/cpu_capabilities.h. Put it in the directory we just created with dirname of "system/machine".

　　8) from lanuchd project, get vproc_priv. Put it in the directory we just created.

　　After did all these stuff, you'll get a structure as follow:

　　

　4、In step3, you find alll the header files that you need. Compile the objc project, you still get error. You need do following 3 things:

　　1) add LIBC_NO_LIBCRASHREPORTERCLIENT macro into you configuration.

　　

　　2) add #define CRSetCrashLogMessage2(x) /* nothing */ into CrashReporterClient.h. As follow:

　　

　　3) remove the link to the CrashReporterClient.

　5、Compile objc project, this time you'll success. There're some warning, you can ignore it. 

　　

　　

　6、for convenience，I wrote the code below to help get all the headers.

# $1=src & $2=dst
DST_PATH="./headers/"
function findAndCopyTo
{
    src_path=`find ./.. -path $1`
    if [ -z $src_path ] 2>&-
        then 
        echo "error, cannot find $1"
        exit 0
    fi

    echo "has find $src_path"

    dst_path=${DST_PATH}${2}
    #echo $dst_path

    if [ ! -x $dst_path ]
        then 
        mkdir $dst_path
    fi

    cp $src_path $dst_path 2>&-
}

rm -rf $DST_PATH
mkdir $DST_PATH

#root
findAndCopyTo "*/auto_zone.h" "./"
findAndCopyTo "*/Block_private.h" "./"
findAndCopyTo "*/CrashReporterClient.h" "./"
findAndCopyTo "*/objc-shared-cache.h" "./"
findAndCopyTo "*/vproc_priv.h" "./"

#dispatch
findAndCopyTo "*libdispatch*/benchmark.h" "./dispatch/"
findAndCopyTo "*libdispatch*/data_private.h" "./dispatch"
findAndCopyTo "*libdispatch*/private.h" "./dispatch"
findAndCopyTo "*libdispatch*/queue_private.h" "./dispatch"
findAndCopyTo "*libdispatch*/source_private.h" "./dispatch"

#mach-o
findAndCopyTo "*dyld*/dyld_priv.h" "./mach-o"

#system
findAndCopyTo "*Libc*/pthread_machdep.h" "./system"

#system/machine
findAndCopyTo "*xnu*machine/cpu_capabilities.h" "./system/machine"