Copy file to the App Resources directory if debug configuration is selected

Question

I need to copy a few files into the App's Resources directory during debug builds. I am thinking about using build rules but don't know how to determine if the build is a debug build. I do have a compiler option of "DEBUG" set.

Answer 1

What you can do is set a compiler flag. In order to do so, go to target>get Info, make sure you have selected the Debug configuration (and not All Configurations), and look for Other C Flags and Other C++ Flags (in Xcode 3.1 these are under GCC 4.2 - Language).

Then add the following as a value: -DDEBUG for both. This will define DEBUG.

Now you can simply do

 #ifdef DEBUG
NSLog(@"Debug mode running");
#endif

Answer 2

You can use a Run Script build phase to do the copying. All build settings applied when building the target are available via environment variables in your script.

You can determine what configuration is being built via the CONFIGURATION environment variable; you can look at other environment variables like BUILT_PRODUCTS_DIR to determine where to put your resource. If you specify your Run Script build phase's output correctly, it will only be run when the output needs to be brought up to date, not every time you build.

More information on Run Script build phases is available here: Xcode Build System Guide: Build Phases: Run Script Build Phase

The same kind of thing can be done with script build rules, which is useful if you have multiple resources you want to apply this to: You can create a script build rule that matches your extension (e.g. *.myresource) and use the build settings and input files that are passed to your script via environment variables to do the actual copying. If you specify your build rule's output correctly, it will only be run when its input is newer than its output, not every time you build.

More information on script build rules is available here: Xcode Build System Guide: Build Phases: Build Rules