objective-c - 带有 clang 和 gnustep 的 Objective-C 中的简单 Hello World 无法编译

Question

系统:

64bit Ubuntu Lucid
GNUStep
clang/LLVM

测试.m

#import <Foundation/Foundation.h>

int main(int argc, char * argv[]){
    NSLog(@"Hello world!\n");
    return 0;
}

编译命令行:

clang -fobjc-gc -I /usr/lib/gcc/x86_64-linux-gnu/4.4.3/include -I /usr/include/GNUstep/ -I /usr/lib/gcc/x86_64-linux-gnu/4.4.3/include-fixed/ -L /usr/lib/GNUstep/ -L /usr/lib64/ -fconstant-string-class=NSConstantString -rpath /usr/lib64 -Xlinker -lgnustep-base  test.m -o Test

错误:

/usr/bin/ld: /usr/lib64//libgnustep-base.so: undefined reference to symbol '__objc_exec_class'
/usr/bin/ld: note: '__objc_exec_class' is defined in DSO /usr/lib64/libobjc.so.2 so try adding it to the linker command line
/usr/lib64/libobjc.so.2: could not read symbols: Invalid operation
clang: error: linker command failed with exit code 1 (use -v to see invocation)

在使用 GCC 时，它编译正常，但 clang 没有。

Answer 1

在全新安装的 Ubuntu 12.10 上，我安装了以下软件包:

$ sudo apt-get install build-essential
$ sudo apt-get install clang
$ sudo apt-get install gnustep
$ sudo apt-get install gnustep-make
$ sudo apt-get install gnustep-devel
$ sudo ln -s /usr/lib/gcc/i686-linux-gnu/4.7/include/objc /usr/local/include/objc

(需要最终符号链接(symbolic link)才能正确定位 objc.h header )

然后我编译了test.m文件如下:

$ clang -o test test.m -I `gnustep-config --variable=GNUSTEP_SYSTEM_HEADERS` \
                       -L `gnustep-config --variable=GNUSTEP_SYSTEM_LIBRARIES` \
                       -lgnustep-base -fconstant-string-class=NSConstantString \
                       -D_NATIVE_OBJC_EXCEPTIONS \
                       -lobjc

tux@ubuntu:~/Desktop$ ./test 
2012-11-20 11:02:08.184 test[11856] Hello world!

* 编辑

在新的 10.04-64 位上，这允许编译得很好:

$ sudo apt-get install build-essential
$ sudo apt-get install clang
$ sudo apt-get install gnustep-devel
$ sudo ln -s /usr/lib/gcc/x86_64-linux-gnu/4.4.3/include/objc/ /usr/local/include/objc