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Re: [PATCH]: New warning option -Walloca
On Fri, 31 Aug 2007, Raksit Ashok wrote:
> > > > Dave> Well, there's a thought: maybe poison should behave like warnings (i.e.
> > > > Dave> be suppressed for the most part) when it comes to system headers?
> > >
> > > This sounds like it would work too.
> > >
> >
> > Manuel> But then you won't get any warning when you use alloca through
> > Manuel> another function or through a macro redefinition. Is that what you
> > Manuel> really want?
>
> If we could poison alloca, and ignore alloca's in system headers (for
> example, by making "poison alloca" a warning, and using
> -Wno-system-headers), we would miss cases where alloca is used thru
> another function or macro in system headers.
A simpler approach would be to define alloca to something else *after* you
include system headers. E.g.:
#define alloca dont_use_alloca
Then any time someone uses alloca they get spanked by the compiler and/or
linker. This is stronger than poisoning because it affects the alloca
calls that appear through macro expansions. You can do this in a common
header included across the whole project. Each approach (poison vs macro)
has its uses.
--Kaveh
--
Kaveh R. Ghazi ghazi@caip.rutgers.edu