Re: [PATCH]: Fix compile time warning building ARM port of GAS

[Daniel Jacobowitz <drow at false dot org>]

On Wed, Jun 01, 2005 at 02:42:19AM -0700, Zack Weinberg wrote:
> >   The problem was because of macros like this:
> >
> >     #define TUE(mnem, op, top, nops, ops, ae, te)			\
> >     { #mnem, OPS##nops ops, OT_unconditional, 0x##op, 0x##top, ARM_VARIANT, \
> >       do_##te ? THUMB_VARIANT : 0, do_##ae, do_##te }
> >
> >   where the "do_##te ? THUMB_VARIANT : 0" always evaluates to
> >   THUMB_VARIANT since do_##te must always exist - it is used to
> >   initialise the last field in the structure being set up by the
> >   macro.  Hence the patch just removes the redundant tests.
> 
> Sorry, that's not a redundant test.  Look farther down the file, each
> of the Txx macros has a corresponding non-T macro, that invokes the T
> macro with 0 for the 'te' argument.  Since md_assemble uses the
> tvariant field to decide whether it's got an encoding function to
> call, this patch will cause the assembler to crash on, e.g.
> 
>       .text
>       .syntax unified
>       .thumb
>       rsc       r0, r0, r0
> 
> I can work with you to find another solution, but I'm not seeing these
> warnings.  What compiler are you using?

Since I read Zack's message and didn't quite get it, here's a missing
clue:
#define do_0 0

-- 
Daniel Jacobowitz
CodeSourcery, LLC