Re: [basic-improvements] try/finally support for c/c++ - more tests

[Daniel Jacobowitz <drow at mvista dot com>]

On Thu, Nov 07, 2002 at 09:07:02AM -0800, Mark Mitchell wrote:
> Our goals, then, seem to be:
> 
> (1) Make life easier for C++ programmers by calling cleanups as
>     exceptions propagate.  (This can already be managed explicitly,
>     with try/catch, but if we can fold it into the library, that's
>     a good QOI thing.  We do have to be very careful to document it;)
> 
> (2) Shield GNU libc developers from having to write the few bits of
>     the library that they want to be exception-safe in C++.
> 
> The second bit carries no weight with me at all.  It's no big deal to
> write a few source files in the C++ almost-superset of C.

It is when they're written in gnu99.  It's also a royal pain to require
a C++ compiler when building glibc; bootstrapping gets harder every
day...

> The first bit is, however, a good, user-focused idea.
> 
> But why not just do that at the source level?  In pthread.h:

Then you require that all pthread_cleanup_push's which need to
be unwound properly be written in C++ source files.  In other words,
using these in a library now requires that part of the library to be
converted to C++ in order to be used from C++ safely.  Not just talking
the implementation of GNU libc here; all libraries which use pthreads
cleanups.

I'm sure there are other reasons but I've started to lose track of them
in this discussion, so I'll step back now.  I also approve of the
extension on its own...

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer