How to set up CMake to build an app for the iPhone

Question

This is closely related to my previous question, which was about using CMake to build a static library on the iPhone. I got that to work setting the CMAKE_OSX_SYSROOT.

However, this doesn't work to build an app. My CMakeLists.txt looks like:

project(TEST)  set(CMAKE_OSX_SYSROOT iphoneos2.2.1) set(CMAKE_OSX_ARCHITECTURES "$(ARCHS_STANDARD_32_BIT)") set(CMAKE_EXE_LINKER_FLAGS "-framework Foundation -framework OpenGLES -framework AudioToolbox -framework CoreGraphics -framework QuartzCore -framework UIKit -framework OpenAL" )  set(SRC --my files--)  add_executable(iphone-test MACOSX_BUNDLE ${SRC}) 

A few notes:

• I'm explicitly giving the -framework linking option because find_library didn't work for all of the frameworks (it found most of them, but not OpenGLES). I don't understand why, since they're all in the same folder ${SDK}/System/Library/Frameworks. This leads me to believe that I was doing something wrong, but I don't know what.
• I added MACOSX_BUNDLE to the add_executable command so that the product type generated would be com.apple.product-type.application instead of com.apple.product-type.tool, which apparently doesn't exist on the iPhone.

In any case, the app compiles and links correctly, but when I run it in the simulator, I get the dreaded

Failed to launch simulated application: Unknown error. 

There are lots of reported instances of this problem on google and stackoverflow, but all of the solutions involve cleaning up or creating a new project and moving files; but I'm compiling a fresh copy after CMake does its work, so none of that applies.

I found this thread on the CMake mailing list, but it only reports a success in building a library, and then peters out.

Answer 1

I finally figured out how to do this. Here's what my CMakeLists.txt file looks like:

project(test) set(NAME test)  file(GLOB headers *.h) file(GLOB sources *.cpp)  set(CMAKE_OSX_SYSROOT iphoneos2.2.1) set(CMAKE_OSX_ARCHITECTURES $(ARCHS_STANDARD_32_BIT)) set(CMAKE_CXX_FLAGS "-x objective-c++") set(CMAKE_EXE_LINKER_FLAGS     "-framework AudioToolbox -framework CoreGraphics -framework QuartzCore -framework UIKit" ) link_directories(\${HOME}/\${SDKROOT}/lib)  set(MACOSX_BUNDLE_GUI_IDENTIFIER "com.mycompany.\${PRODUCT_NAME:identifier}") set(APP_TYPE MACOSX_BUNDLE)  add_executable(${NAME}     ${APP_TYPE}     ${headers}     ${sources} )  target_link_libraries(${NAME}     # other libraries to link )  # code signing set_target_properties(${NAME} PROPERTIES XCODE_ATTRIBUTE_CODE_SIGN_IDENTITY "iPhone Developer: My Name") 

Obviously, change mycompany to your company name, and change My Name to your name. I found it's very useful to add the link directory \${HOME}/\${SDKROOT}/lib as above, so that if your app links to a static library (especially a generic (non-iPhone) library), you can build separate iPhoneOS and iPhoneSimulator libraries and easily link to the right one, instead of worrying about a universal binary.

Also, Xcode doesn't seem to properly add resources when you build the project using CMake, so I added this piece to the CMakeLists.txt file. It copies the entire folder /data into my resources folder (as if I had added a "blue" folder link in Xcode).

# copy resource phase  set(APP_NAME \${TARGET_BUILD_DIR}/\${FULL_PRODUCT_NAME}) set(RES_DIR ${test_SOURCE_DIR}/data) add_custom_command(     TARGET ${NAME}     POST_BUILD     COMMAND /Developer/Library/PrivateFrameworks/DevToolsCore.framework/Resources/pbxcp -exclude .DS_Store -exclude CVS -exclude .svn -resolve-src-symlinks ${RES_DIR} ${APP_NAME} )