But why do you want to replace it in the merge tool if this is how your code is actually written?

Does your IDE does this?

Alternative solution: set of regular expression rules for replace operation.

I personally would imagine this as kind of preprocessor.

You could list set of #defines and before semantic parse all defines would be replaced.

Imagine following example:

interrupt void int_handler(void);

To "semantic_c.conf" you could put:
#define interrupt

Than the code seen by semantic parser will look like:
void int_handler(void);

Other example:
FUNC(void, AUTOMATIC) foo( VAR(uint8, AUTOMATIC) bar);

put to semantic_c.conf:
#define FUNC(rettype, memclass) rettype
#define VAR(type, memclass) type

And voila:
final code will be seen as:
void foo( uint8 bar);

Thanks Christian,

Would you mind elaborating a little bit more?