Hi!

I was just building an aarch64 cross-compiler (indeed compiler only:
'make all-gcc'), and then wanted to check something in gimplification
('-S -fdump-tree-gimple'), with '-mabi=ilp32', which told me: "cc1:
error: assembler does not support '-mabi=ilp32'".  That's unexpected, as
for '-S' GCC isn't even going to invoke the assembler.  It's coming from
this change:

On Wed, 11 Dec 2013 13:57:59 +0100, Christophe Lyon <christophe.lyon@linaro.org> wrote:
> Committed on Kugan's behalf as rev 205891.
> 
> On 11 December 2013 13:27, Marcus Shawcroft <marcus.shawcroft@arm.com> wrote:
> > On 10/12/13 20:23, Kugan wrote:
> >
> >> gcc/
> >>
> >> +2013-12-11  Kugan Vivekanandarajah  <kuganv@linaro.org>
> >> +       * configure.ac: Add check for aarch64 assembler -mabi support.
> >> +       * configure: Regenerate.
> >> +       * config.in: Regenerate.
> >> +       * config/aarch64/aarch64-elf.h (ASM_MABI_SPEC): New define.
> >> +       (ASM_SPEC): Update to substitute -mabi with ASM_MABI_SPEC.
> >> +       * config/aarch64/aarch64.h (aarch64_override_options):  Issue
> >> error if
> >> +       assembler does not support -mabi and option ilp32 is selected.
> >> +       * doc/install.texi: Added note that building gcc 4.9 and after
> >> with pre
> >> +       2.24 binutils will not support -mabi=ilp32.
> >> +
> >>
> >
> > Kugan, Thanks for sorting this out. OK to commit.
> >
> > /Marcus

Specifically:

    --- a/gcc/config/aarch64/aarch64.c
    +++ b/gcc/config/aarch64/aarch64.c
    @@ -5187,6 +5187,13 @@ aarch64_override_options (void)
           aarch64_parse_tune ();
         }
    
    +#ifndef HAVE_AS_MABI_OPTION
    +  /* The compiler may have been configured with 2.23.* binutils, which does
    +     not have support for ILP32.  */
    +  if (TARGET_ILP32)
    +    error ("Assembler does not support -mabi=ilp32");
    +#endif

Why is that necessary?  Won't the assembler itself tell the user that it
"does not support -mabi=ilp32", thus this check can be removed?  If not,
can a condition simply be added here to only emit this error if we're
indeed going to invoke the assembler?

(For my own testing, I just locally disabled that, of course.)


Grüße
 Thomas