Re: __FUNCTION__

Greg KH
2002-01-09T07:25:39Z

On Tue, Jan 08, 2002 at 06:12:02PM -0800, Richard Henderson wrote:
>
> __FUNCTION__ was never a string literal in g++ because you can't decide
> what the name of a template is until you instantiate it.

According to the info page it was:
The compiler automagically replaces the identifiers with a
string literal containing the appropriate name.

This is written right after a lovely C++ example of using __FUNCTION__
and __PRETTY_FUNCTION__. But I can understand the difficulties of
determining this for some C++ cases.

> Having __FUNCTION__ be a magic cpp thingy means there is a translation
> phase violation. Preprocessor macros are expanded in phase 4, string
> concatenation happens in phase 6, syntactic and symantic analysis
> doesn't happen until phase 7.
>
> So changing this allows us to change two things: (1) the integrated
> preprocessor can concatenate adjacent string literals and do lexical
> analysis exactly as described in the standard, and (2) removes an
> irrelevant difference between c and c++ so that at some point we can
> support both with a single front-end.

So, if you are going to change this (well, sounds like it is already
done), what is the timeline from taking a well documented feature and
breaking it (based on the example in the info page)? First a warning,
and then an error, right? What version of the compiler emits a warning,
and what future version will emit an error? I didn't see anything about
these kinds of changes in the gcc development plan, or am I missing some
documentation somewhere?

thanks,

greg k-h