[perl #121505] Can't build perl with gcc4.9 due to UB in sv.c

On Thu Apr 10 00:03:05 2014, shay wrote:
> On 10 April 2014 00:57, Tony Cook via RT <perlbug-followup@perl.org>
> wrote:
> > On Wed Apr 09 14:55:54 2014, tonyc wrote:
> >> I still need to produce an update for win32/makefile.mk.
> >
> > Though op/numconvert.t doesn't fail, nor does any other relevant
> > test, with 4.9.0 20140218.
> >
> > I don't really see a way to pick out a version in makefile.mk either,
> > the only real solution I see is to always add it.
> >
> 
> Add a new CCTYPE, as is done for different MSVC++ versions? GCC49 or
> GCC490 if you're using gcc-4.9.0 or higher?

Adding extra CCTYPE values means touching every place that looks at CCTYPE.

I tried to add GCCVERSION and then parse that using findstr, but it was unwieldly[1] and didn't work, since dmake treats the non-zero exit from findstr when it doesn't find the string as a build-time error.

I ended up adding a GCCWRAPV macro that can be overridden from the dmake command-line which enables -fwrapv by default.

This builds and tests ok with the gcc 4.7.3 included with the strawberry perl I have installed.

It builds perl successfully with a mingw gcc-4.9 snapshot, but I suspect testing would fail due to some strangeness in the built Errno.pm (the errno codes have l (lowercase L) suffixes.

For review/comment.

Tony

[1] findstr supports regexps - but the regexps don't support alternation


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via perlbug:  queue: perl5 status: open
https://rt.perl.org/Ticket/Display.html?id=121505

• [perl #121505] Can't build perl with gcc4.9 due to UB in sv.c by Tony Cook via RT