The current ST3 build (3035) has incorrect syntax highlighting for this perfectly valid C code:
int main(int /*argc*/, char /argv*/])
It sees a */ without being in a comment and triggers invalid.illegal.stray-comment-end.c which has the match
The solution is to exclude the case where the / is part of a block comment start, changing the whole pattern to:
Actual use case: When working with -Wall it is not uncommon to use block comments around the names of knowingly unused parameters to silence the warning to actually notice when a parameter was left unused by accident (shadowing etc...).