UCPP

Here is a version of (ifl:)UCPP which I've hacked. (Or rather it would be here. I'm talking to my employers about that.)

From the UCPP page:

ucpp is a C preprocessor and lexer. It has the following goals:

• Strict conformance to the C99 standard (with switches to disable some extensions and mimic C90 behaviour)
• Low memory consumption
• Possibility to use the code as a lexer (that outputs tokens directly)

Some of the hacks that I've made to it:

• Changed the formatting (mainly of -d output) to how I like it.
• Added a -Kmacro switch. This is the important one. It lets you debug preprocessor macros by showing where they're referenced and how the referencing #if[[n]def] evaluated. It needs -d to work.
• Made -? and --help work.

Some example output from -d -KSTRICT:

C:\Program Files\Microsoft Visual Studio\VC98\Include\windef.h: 14:
    #ifndef STRICT   /* true */

C:\Program Files\Microsoft Visual Studio\VC98\Include\windef.h: 15:
    #define STRICT 1

C:\Program Files\Microsoft Visual Studio\VC98\Include\winnt.h: 206:
    #ifdef STRICT   /* true */

Well, that's it for the moment. UCPP seems like a Good Thing to me.