[Bug target/98139] New: varasm.c fails to compile on AIX 7.2: -Werror=unused-variable

[Bug target/98139] New: varasm.c fails to compile on AIX 7.2: -Werror=unused-variable

[ro at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98139

            Bug ID: 98139
           Summary: varasm.c fails to compile on AIX 7.2:
                    -Werror=unused-variable
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ro at gcc dot gnu.org
                CC: dje at gcc dot gnu.org
  Target Milestone: ---
              Host: powerpc-ibm-aix7.2.4.0
            Target: powerpc-ibm-aix7.2.4.0
             Build: powerpc-ibm-aix7.2.4.0

I've just tried a bootstrap of current master with a self-compiled GCC 8.4.0 on
gcc119 in the cfarm. The build failed compiling varasm.c in stage2:

/home/ro/gcc/src/gcc-master/gcc/varasm.c: In function 'void
output_constant_pool
_contents(rtx_constant_pool*)':
/home/ro/gcc/src/gcc-master/gcc/varasm.c:4254:21: error: unused variable 'name'
[-Werror=unused-variable]
 4254 |         const char *name = targetm.strip_name_encoding (XSTR
(desc->sym,
 0));
      |              

I've used the attached patch to finish the build.  It needs at last proper
formatting and wrapping the args in parens.

However, I wonder why there's no other report of this issue...

[Bug target/98139] varasm.c fails to compile on AIX 7.2: -Werror=unused-variable

[ro at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98139

--- Comment #1 from Rainer Orth <ro at gcc dot gnu.org> ---
Created attachment 49678
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=49678&action=edit
Hacky patch.

[Bug target/98139] varasm.c fails to compile on AIX 7.2: -Werror=unused-variable

[dje at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98139

--- Comment #2 from David Edelsohn <dje at gcc dot gnu.org> ---
I bootstrap GCC on AIX with, and the instructions in the CompileFarm wiki
recommend, --disable-werror.

If that currently is the only problem, we're lucky.  I don't know that this
hack is better.  Shrug.

[Bug target/98139] varasm.c fails to compile on AIX 7.2: -Werror=unused-variable

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98139

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hubicka at gcc dot gnu.org

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Guess the hack already is how xcoff.h defines ASM_OUTPUT_DEF.  Of course the
middle-end should have an alternate way to tell whether a target has alias
support - maybe it already has and the code is just no longer required.

So yeah, why not (the patch).

[Bug target/98139] varasm.c fails to compile on AIX 7.2: -Werror=unused-variable

[ro at CeBiTec dot Uni-Bielefeld.DE]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98139

--- Comment #4 from ro at CeBiTec dot Uni-Bielefeld.DE <ro at CeBiTec dot Uni-Bielefeld.DE> ---
> --- Comment #2 from David Edelsohn <dje at gcc dot gnu.org> ---
> I bootstrap GCC on AIX with, and the instructions in the CompileFarm wiki
> recommend, --disable-werror.

Ah, I missed that.  It's the only instance of target-specific build
instructions in the Wiki.  Shouldn't this go to install.texi, too,
unless it's expected to be fixed before GCC 11?

> If that currently is the only problem, we're lucky.  I don't know that this
> hack is better.  Shrug.

I only tested C,C++, but a couple of months ago I tried with Ada
included and didn't have the issue at all (expect for PR ada/95549).

The big advantage of doing it automatically (either similarly to my
hack, variations of which have been used in the past when target macros
ignore one or more of their args, or by enabling --disable-werror by
default for AIX) is that you avoid wasted time: every time a developer
runs into this, he either starts to hunt down the issue (when she's
diligent) or moves on in disgust (the majority, I guess).

[Bug target/98139] varasm.c fails to compile on AIX 7.2: -Werror=unused-variable

[dje at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98139

--- Comment #5 from David Edelsohn <dje at gcc dot gnu.org> ---
It has nothing to do with the proper way to install GCC on AIX.

It was not the only -Werror failure on AIX.  That is why I said, if that's the
only problem, we're lucky.  The -Werror failures change.

The patch is okay, but it doesn't remove the need to recommend
--disable-werror.

[Bug target/98139] varasm.c fails to compile on AIX 7.2: -Werror=unused-variable

[dje at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98139

David Edelsohn <dje at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |FIXED

--- Comment #6 from David Edelsohn <dje at gcc dot gnu.org> ---
Patch applied.

[Bug target/98139] varasm.c fails to compile on AIX 7.2: -Werror=unused-variable

[ro at CeBiTec dot Uni-Bielefeld.DE]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98139

--- Comment #7 from ro at CeBiTec dot Uni-Bielefeld.DE <ro at CeBiTec dot Uni-Bielefeld.DE> ---
> --- Comment #5 from David Edelsohn <dje at gcc dot gnu.org> ---
> It has nothing to do with the proper way to install GCC on AIX.

Why not?  Consider some developer trying to build trunk on his own AIX
system: he'd run into the same issue, but wouldn't think of (in fact
wouldn't even know about) the cfarm wiki.

> It was not the only -Werror failure on AIX.  That is why I said, if that's the
> only problem, we're lucky.  The -Werror failures change.

FWIW, I've now finished an --enable-languages=all (except ada) build on
gcc119 without --disable-werror and there were no further issues (well,
there are PRs go/98170 and ada/98171).

> The patch is okay, but it doesn't remove the need to recommend
> --disable-werror.

At least for now that need seems to be gone.  Thanks for installing the
patch.