Re: [PATCH 0/5] Remove a few hurdles of compiling with clang

[Simon Marchi <simon dot marchi at polymtl dot ca>]

On 2017-06-13 13:06, Pedro Alves wrote:
> On 06/13/2017 11:23 AM, Simon Marchi wrote:
>
> > I have a concrete example that is currently in the pipeline.  I hit 
> > this warning/error:
> >
> > /home/emaisin/src/binutils-gdb/gdb/nat/x86-dregs.c:209:7: error: 
> > variable 'i' is incremented both in the loop header and in the loop 
> > body [-Werror,-Wfor-loop-analysis]
> >       i++;
> >       ^
> > /home/emaisin/src/binutils-gdb/gdb/nat/x86-dregs.c:199:32: note: 
> > incremented here
> >   ALL_DEBUG_ADDRESS_REGISTERS (i)
> >                                ^
> >
> > which would require changing this code:
> >
> >   ALL_DEBUG_ADDRESS_REGISTERS (i)
> >     {
> >       ...
> >       i++;
> >     }
> >
> > to either the expansion of the macro:
> >
> >   for (int i = DR_FIRSTADDR; i <= DR_LASTADDR; i += 2)
> >     {
> >       ...
> >     }
>
> This, IMO.  I think it's just that one place?

It's the only instance of that particular problem, yes.

> > or to a new macro that would take into account the increment:
> >
> >   ITER_DEBUG_ADDRESS_REGISTERS (i, i += 2)  // other users would use 
> > i++
> >     {
> >       ...
> >     }
>
> That'd obfuscate too much for no real benefit, IMO.

Agreed.

Simon