[cfe-dev] PATCH: Cleanup function redeclaration representations

[Neil Booth]

Doug Gregor wrote:-

> On Thu, Apr 24, 2008 at 9:45 AM, Neil Booth <neil at daikokuya.co.uk> wrote:
> >  However, it's nice to complain about / reject the "x" in things like
> >
> >  void foo1 (void) { extern int x(void); }
> >  void foo2 (void) { extern double x(void); }
> >
> >  $ gcc /tmp/bug.c
> >  /tmp/bug.c: In function 'foo2':
> >  /tmp/bug.c:2: error: conflicting types for 'x'
> >  /tmp/bug.c:1: error: previous declaration of 'x' was here
> >
> >  This is undefined behaviour according to the C standard; but there
> >  is little value in letting such stuff pass.
> 
> Very nice... it would definitely be helpful to diagnose this sort of problem.

Agreed.  It's a shame that extern declarations at local scope are
permitted though; it really opens up a huge can of worms with no
satisfactory coding solution (that I found anyway :)); as anyone
trying to implement this stuff properly rapidly discovers :)

Nothing compared to the journeys of C++ though....

Neil.