[PD-dev] pd-0.43.0 port to NetBSD

[Miller Puckette]

Oh... that's good news.

I think I'd better pump 0.43-1 out first and then apply this for 0.42 since
if there are more tweaks needed it will take time for them to become apparent.

cheers
Miller

On Sat, Sep 17, 2011 at 01:22:21AM +0200, Thomas Klausner wrote:
> Hi Miller,
> 
> > I can't evaluate the changes here that have to do with the build system
> > but can work on getting rid of alloca dependencies.  I didn't know there
> > were any platforms left that didn't support alloca.  (In fact I was celebrating
> > that I would be able to replace more malloc calls with alloca to simplify
> > things here and there.)
> 
> Thanks for the reply.
> 
> The problem is not that alloca() is not supported, it's just that the
> alloca.h header is not available on all systems.
> 
> Gnulib documents it as:
> Portability problems fixed by Gnulib:
> 
>     This header file is missing on some platforms: FreeBSD 6.0, NetBSD
>     5.0, OpenBSD 3.8, AIX 4.3.2, mingw. 
> 
> http://www.gnu.org/software/hello/manual/gnulib/alloca_002eh.html
> 
> The ubuntu man page says:
> 
> 	BUGS
> 
>         The  alloca() function is machine and compiler dependent.  On
> 	many systems its implementation is buggy.  Its use is discouraged.
>  
> The Mac OS X man page claims similarly.
> The NetBSD man page says:
> 
> CAVEATS
>      Few limitations can be mentioned:
> 
>      o   The alloca() function is machine dependent; its use is discouraged.
> 
>      o   The alloca() function is slightly unsafe because it cannot ensure
>          that the pointer returned points to a valid and usable block of mem-
>          ory.  The allocation made may exceed the bounds of the stack, or even
>          go further into other objects in memory, and alloca() cannot deter-
>          mine such an error.  Avoid alloca() with large unbounded allocations.
> 
>      o   Since alloca() modifies the stack at runtime, it causes problems to
>          certain security features.  See security(7) for a discussion.
> 
> On NetBSD, alloca() is provided by stdlib.h.
> 
> Perhaps the easiest way is to let configure check for alloca.h and
> stdlib.h and include one or the other, depending on what's available
> on the system. Would you like diffs for that?
>  Thomas