In MINIX source code, C function prototypes, say for malloc, are declared in this manner:

_PROTOTYPE( void *malloc, (size_t _size) );

where _PROTOTYPE is defined as:

#define _PROTOTYPE(function, params) function params

But after I built tags for the source, there are no tags generated for the identifier malloc (I'm using VIM with ctags). Could some one please tell me how can I use the -I switch so that ctags could locate function declaration like these? Or is there any other way to work this around?