Using m4 between the C preprocessor and compiler?

Dear all,

as part of a project I am looking for ways to perform context- 
insensitive but parameterized substitutions on C code.  It happens  
that m4 delivers well for what I need to do. Except for the following.

For now I have used m4 as a front-end before running the C  
preprocessor and compiler. The downside of this is that I can only  
substitute on the "main" source provided to m4, not to the code  
inlined by the C preprocessor through #include.

The other way around (using m4 after the C preprocessor) mostly works,  
but then m4 does not recognize the location markers (#line) inserted  
by the preprocessor and therefore most m4 errors are reported at an  
incorrect location, and multi-line expansions cause m4 to use wrong  
relative numbers in new synclines.


On top of this main issue, I would be interested to disable m4 macro  
expansion within C strings and comments; although I already thought  
about (yet another) filter between CPP and m4 to m4-quote all C  
strings and comments.


Do you have any suggestions on how to solve the #line-problem and more  
elegantly the string/comment problem?

I tried a possible route forward by replacing any occurrence of "#line  
X" in the m4 input by m4_define(`__line__', X), but unfortunately that  
doesn't seem to help. Is there an option to allow __line__ (and  
__file__) to be reset by macros?

Comments would be highly appreciated.



-- 
Raphaël “kena” Poss             [email protected] - +31 20 525 7898
Computer Systems Architecture   http://www.science.uva.nl/research/csa/
Informatics Institute           http://www.science.uva.nl/ii/
Universiteit van Amsterdam      http://www.english.uva.nl/