iMAC:ios$ /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/arm-apple-darwin10-llvm-gcc-4.2 -o hello hello.m -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS6.0.sdk/ -framework Foundation -lobjc
iMAC:ios$ otool -L hello hello: /System/Library/Frameworks/Foundation.framework/Foundation (compatibility version 300.0.0, current version 992.0.0) /usr/lib/libobjc.A.dylib (compatibility version 1.0.0, current version 228.0.0) //包含这个文件则为objective-c编译的文件 /usr/lib/libgcc_s.1.dylib (compatibility version 1.0.0, current version 7.0.0) /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 173.8.0) /System/Library/Frameworks/CoreFoundation.framework/CoreFoundation (compatibility version 150.0.0, current version 793.0.0)