c - Building for MacOSX, but linking against dylib built for iOS Simulator file

Question

I've just upgraded to Xcode 5 beta with the April 15 2013 commandline tools and hit the following warning when running a cmake build during the standard CMakeTestCCompiler.cmake attempt to compile a simple test program:

cmake -version
cmake version 2.8.11.2

ld: building for MacOSX, but linking against dylib built for iOS Simulator file '/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator7.0.sdk/usr/lib/libSystem.dylib' for architecture i386

lipo -info /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator7.0.sdk/usr/lib/libSystem.dylib
Non-fat file: libSystem.dylib is architecture: i386

The compile step is:

/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/gcc -arch i386 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator7.0.sdk -o /Users/temp/testCCompiler.c.o -c /Users/temp/testCCompiler.c

lipo -info /Users/temp/testCCompiler.c.o 
Non-fat file: testCCompiler.c.o is architecture: i386

The link step is:

/usr/local/bin/cmake -E cmake_link_script /Users/temp/link.txt --verbose=1

where link.txt contains:

/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/gcc -arch i386 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator7.0.sdk -Wl,-headerpad_max_install_names /Users/temp/testCCompiler.c.o -o testCCompiler

It seems that both testCCompiler.c.o and libSystem.dylib are i386, i386 is specified in link.txt, and i386 is the right architecture for the simulator so i'm not sure why it thinks it is building for MacOSX. Perhaps a commandline option is wrong :(.

thanks for any help!

Answer 1

The problem was that Xcode 5 replaces gcc with clang and adds in a "-triple" option that specifies OSX as the target. If you pass "-miphoneos-version-min=7.0" on both gcc command lines it works. You can see the clang command line if you pass "--verbose" to gcc. It's also necessary to add to the PATH for Xcode 5 so that cmake can find the necessary tools: export PATH=/Applications/Xcode5-DP6.app/Contents/Developer/Toolchains/XcodeDefault.xct??oolchain/usr/bin:/Applications/Xcode5-DP6.app/Contents/Developer/usr/bin:$PATH None of this is official.. but works for me so far.