Xcode 4 custom build step before compile

Question

I'm trying to integrate a tool into Xcode 4 that generates a C header from a descriptor file. In Xcode 3 it worked to add a custom build step for files with a specific extension. Those files then get compiled before the .m/.mm/.cpp files that included them. When I try to do this with Xcode 4 it seems like it runs my custom step after compiling the other source. This doesn't work of course. Is there any way to tell Xcode to run the step before?

Here's a simple repro setup:

My main.m contains a:

#include <mytest.h>

and I've added ${DERIVED_FILE_DIR} to the header search path. When I compile this project I get the following:

If I remove the include and build it again I get this:

So the rule is indeed working, but it's executed way too late. Is there any way to change this behavior?

Answer 1

I already have my Revival badge, but here goes :)

I just ran into this problem, and the answer is simple ( now I've spent a half a day staring at it).

The build rule is responding to the source file (.abc), and the source file is being processed in the order it is listed in the 'Compile Sources' build step. Simply go into the build rule and drag the .abc to the top of the list.

One small step towards my archeologist badge, I hope.