Compiling a Carbon app w/library that supports Cocoa as well

Question

We are linking to a library that supports video rendering in both Cocoa and Carbon/AGL environments. I can compile and link with a Cocoa application. That works fine. I just had to include the Carbon and AGL frameworks. No problem.
Where I am running into trouble is with our Carbon application. I have included the frameworks that are necessary for Cocoa to run (cocoa, foundataion, appkit, etc...). Here is where the trouble starts:
The compiler is, of course, confused by the objective-c directives. Okay, so I go into the build settings and add "-x\ objective-c++" to the cflags. I compile again and it no longer complains about objective-c++, the compilation finishes fine. Now the linker complains:
"File not found: /Developer/....path...../Debug/...projectName.build..../Objects-normal/i386/mai n.o"
Sure enough there is no file, main.o, but there is a file, projName.LinkFileList.
Why (even though the compiler output says that main.o exists) isn't main.o sticking around? Is there anything obvious that I am doing wrong?
Excuse me if this is hazy. I'll clarify anything you ask.
NOTE: I cannot change this static lib to use only Carbon OR Cocoa. It (only) supports both and (I think) must be linked to both frameworks.
Thanks for reading.

Answer 1

Why would the compiler be looking at Objective-C directives? It is one thing to link with a library that supports different languages. It is something else to #include headers from that other language. Do the Carbon headers have Cocoa in them? Are they not surrounded by macro guards?