Re: changing "configure" to default to "gcc -g -O2 -fwrapv ..."

[Bernd Schmidt]

Paul Eggert wrote:
> "Richard Guenther" <address@hidden> writes:
>
> > Authors of the affected programs should adjust their makefiles
>
> That is what the proposed patch is for.  It gives a way for
> developers to adjust their makefiles.
>
> A developer of portable software cannot simply put something
> like this into a makefile:
>
>   CFLAGS = -g -O2 -fwrapv
>
> as -fwrapv won't work with most other compilers.  So the
> developer needs some Autoconfish help anyway, to address the
> problem.  The proposed help is only rudimentary, but it does
> adjust makefiles to address the issue, and it's better than
> nothing.  Further improvements would of course be welcome.

So rather than changing the default to -fwrapv for all programs, which I 
would find most unwelcome, how about adding a macro
  AC_THIS_PROGRAM_IS_BROKEN_AND_THE_MAINTAINER_DOESNT_CARE
which could add -fwrapv and maybe -fno-strict-aliasing if the compiler 
supports them?  Then anyone who knows their program is affected, or is 
just worried that it might be, could add that macro to their configure.in.


Bernd