[PATCH][BINUTILS][AARCH64] Add support for pointer authentication B key

[Christophe Lyon]

On Wed, 12 Dec 2018 at 11:50, Nick Clifton <nickc@redhat.com> wrote:
>
> Hi Sam,
>
> >> One thing did catch my eye:
> >>
> >> +#define tc_output_cie_extra(cie) if (cie->pauth_key == AARCH64_PAUTH_KEY_B) \
> >> +                          out_one ('B');
> >>
> >> Normally this would be written as:
> >>
> >> #define tc_output_cie_extra(cie) \
> >>    do \
> >>      { \
> >>        if (cie->pauth_key == AARCH64_PAUTH_KEY_B) \
> >>          out_one ('B'); \
> >>      } \
> >>    while (0)
> >>
> >> (Note - no semi-colon at the end).
>
> > That's an interesting convention! I don't really see the use of the loop.
>
> It is there so that programmers can do:
>
>   if (foo)
>     tc_output_cie_extra (bar);
>   if (baz)
>      blah;
>
> With your version you might get a warning from the compiler about the "if (baz)"
> conditional not being clearly associated with a previous if() statement.
>
> > I can commit this with the convention if you'd like, otherwise I can get
> > it committed right away.
>
> I think that I prefer my way. :-)  Sorry, but your patch is still approved with this change made.
>
> Cheers
>   Nick
>
>

Hi Sam,
You patch broke the build:
../../gas/dw2gencfi.c: In function 'output_cie':
../../gas/dw2gencfi.c:1868:5: error: expected ';' before '}' token
     }
     ^
../../gas/dw2gencfi.c:1931:1: error: invalid storage class for
function 'output_fde'
 output_fde (struct fde_entry *fde, struct cie_entry *cie,
 ^
../../gas/dw2gencfi.c: In function 'output_fde':
../../gas/dw2gencfi.c:1931:54: error: declaration of 'cie' shadows a
parameter [-Werror=shadow]

[...]

Christophe