RFR (M): 8024265: Enable new build on AIX (top level part)

Mon Sep 9 14:32:09 UTC 2013

Hi Magnus,

thanks again for the review. Please see my comments inline:

On Mon, Sep 9, 2013 at 12:23 PM, Magnus Ihse Bursie <
magnus.ihse.bursie at oracle.com> wrote:

>  Hi Volker,
>
> Some more comments inlined.
>
>  OK, common/autoconf/build-aux/autoconf-config.guess was too old and
> didn't knew about AIX 7 so it returned the default AIX fallback which is
> 'rs6000-ibm-aix'. I have now fixed 'autoconf-config.guess' to know about
> AIX 7 (a one character change which is already in autoconf-2.69 so we won't
> have problems if you should ever update autoconf-config.guess).
>
>
> Hmm... While more elegant, the idea was that autoconf-config.guess should
> be a strict copy of the config.guess file from the autoconf package. The
> whole idea of wrapping it in a custom config.guess was to avoid "forking"
> the autoconf config.guess, with small changes (like this) that would be
> hard to track and might get lost if we update to a newer version from the
> upstream autoconf file.
>
> That being said, since we settled on autoconf 2.69, we really should
> update the file to config.guess from autoconf-2.69. I've started a test run
> on our internal test system with the config.guess from 2.69 to see if it
> breaks any existing platforms. If not, I suggest we do a fast integration
> of the new config.guess.
>
> Can you hold on with your changes until a new config.guess comes in? Even
> if you're just making a small change that will be reverted soon after, I
> think it would set a unfortunate precedent.
>

That's OK for me. Actually my change still works without the changes in
"config.guess" on AIX 5.3. And it will automatically start working once we
get the new "config.guess".

>  Ahrgh, all these proud compilers with their own ways of expressing the
>> same functionality. :( I assume that you are using the COMP_MODE_OPTION in
>> the jdk projct? I couldn't find any references to it in the Hotspot build
>> changes, and otherwise there seems to be no reason to export it in the
>> spec.gmk file.
>>
>>
>  Yes, exactly. It is used in 'jdk/makefiles/GensrcX11Wrappers.gmk'
> (MEMORY_MODEL_FLAG="$(COMP_MODE_OPTION)$*").
>
> Once again the X11 wrappers. We should really make an effort and get rid
> of them. :-/
>
>
> I don't mind:)

>   I fully agree with the criticism on the name:) After we already have
> 'COMPILER_SUPPORTS_TARGET_BITS_FLAG' I've simply renamed it to
> 'COMPILER_TARGET_BITS_FLAG'. I think that's much more appropriate and if
> you don't like it we should ask the one who invented
> 'COMPILER_SUPPORTS_TARGET_BITS_FLAG' :) And I had to set
> 'COMPILER_TARGET_BITS_FLAG' a little earlier  such that is availabel in
> PLATFORM_SET_COMPILER_TARGET_BITS_FLAGS.
>
> Sounds good! Nice aligning with the existing macro.
>
> However, you forgot to change the name in spec.gmk.in. (At least in the
> webrev you published.)
>

Good catch! I didn't realize it because the build in the stage repositories
currently doesn’t reach the X11 wrappers.
I've changed it and moved it near the definition of
'COMPILER_SUPPORTS_TARGET_BITS_FLAG'

>   2. After you pointed out that setting '-q64' as extra flags on the
> configure command line is not the way it is supposed to work I recalled
> that we also have this problem on older Linux/PPC64 boxes (e.g. SLES 10)
> where the default compiler produces 32-bit objects by default. To fix this
> problem as well, I've inserted a call to
> PLATFORM_SET_COMPILER_TARGET_BITS_FLAGS followed by a second call to
> AC_CHECK_SIZEOF([int *], [1111]) in the case where we would otherwise have
> bailed out because the "TESTED_TARGET_CPU_BITS" differs from the actual
> "OPENJDK_TARGET_CPU_BITS". I think this change should not affect any
> existing platforms because it will only be triggered where we woould have
> bailed out with an error anyway.
>
>  Also, the workaround for autoconf bug
> http://lists.gnu.org/archive/html/autoconf/2010-07/msg00004.html in
> AC_CHECK_SIZEOF isn't needed any more now that we require at least
> autoconf-2.69 because the problem was fixed in 2.67. And if I looked at it
> more carefully I must say that I don't understand the workaround at all. In
> my opinion, the test "x$SIZEOF_INT_P" != "x$ac_cv_sizeof_int_p" will always
> fail, because the AC_CHECK_SIZEOF macro only writes a define for
> SIZEOF_INT_P into "confdefs.h" (as can be seen in generated-configure.h)
> but it never defines it in the shell. And defining SIZEOF_INT_P in the
> configure shell script wouldn't help if the define written by the
> AC_CHECK_SIZEOF macro was wrong (as described in the bug). So Ithink the
> best is to remove the workaround and use "ac_cv_sizeof_int_p" in the places
> where we used AC_CHECK_SIZEOF before.
>
>
> Good to get rid of the old workaround. I agree, it looks kind of weird. I
> think I might have been behind some of the weirdness; I think I interpreted
> the autoconf documentation as if it should assign a variable SIZEOF_INT_P
> in the configure script, and that the $ac_* variables were internal
> variables that should not be directly accessed. In the current
> documentation, at least, the $ac_cv_sizeof* macro is officially mentioned
> so it should be safe to use.
>
> However, your second relies on some internal autoconf magic, by unsetting
> variables and defines. We've tried to avoid that, but at times there were
> no choice. Since we're about to fail anyway, and the code is more in place
> for future, strange platforms, it's probably no harm.
>
>
Exactly.

Is it OK if I push it now to
http://hg.openjdk.java.net/ppc-aix-port/ppc-aix-port/stage or is there
anything you want to test first?

> /Magnus
>