Vim syntax match changes based on function type name keyword

Question

I've written a C code syntax rule to highlight function names in function definitions as such:

This is the syntax rule written in ~/.vim/syntax/c.vim:

syntax match cCustomFunc /\w\+\s\+\zs\w\+(/he=e-1
highlight default link cCustomFunc Function

However, when the type in the function definition is a C keyword, the syntax highlighting fails. For example:

Any keyword type such as char, int, void, etc. causes it to fail.

I've tried putting "contains=Type" at the end of the syntax match rule, but it did not work.

How can I make my syntax highlighting rule work when the type in the function definition is a keyword?

Answer 1

The problem is that the keyword is preventing your regex from matching, since the regex you're using needs to match the whole line, even though you're using \zs to start the capture only at the function name, after the keyword...

You can solve that by using a look-behind regex with \@<=, rather than \zs.

This seems to work ok:

syntax match cCustomFunc /\(\w\+\s\+\)\@<=\w\+(/he=e-1