So, what’s the alternative? Not freeing resources is a very common error; it would be nice if the compiler could help detecting it.

A possible explicit solution I can think of is to introduce a new function attribute that gives the name of their ‘cleanup’ function (so that the compiler would know fopen needs a fclose, for example) and a compiler that uses these attributes to issue a warning if a function has a path that calls a function and doesn’t either call its cleanup function or returns its result.

I don’t know whether that would cover all bases, though.