AIX: Disable backtrace API call

AIX: Disable backtrace API call

Backtrace() and backtrace_symbols() API are not supported on
AIX and there are no user-mode equivalent API for the same.
For now, disabling the call to those API.
Currently this is preventing V8 to build on AIX.
This debug functionality was added in
https://codereview.chromium.org/2248393002

R=rmcilroy@chromium.org

BUG=
LOG=N

Committed: https://crrev.com/bc752a0977bf823765aa298fe64670df91e79a29
Cr-Commit-Position: refs/heads/master@{#39356}

[JaideepBajwa, 2016-09-07 17:37:28]

PTAL

[rmcilroy, 2016-09-08 10:10:11]

https://codereview.chromium.org/2324453002/diff/1/src/base/debug/stack_trace_...
File src/base/debug/stack_trace_posix.cc (right):

https://codereview.chromium.org/2324453002/diff/1/src/base/debug/stack_trace_...
src/base/debug/stack_trace_posix.cc:149: // equivalent user-mode API. For now
disabling the call to the API
No need for the comment (there are probably other platforms in a similar
situation and this comment will get stale when #ifdefing out other platforms).

https://codereview.chromium.org/2324453002/diff/1/src/base/debug/stack_trace_...
src/base/debug/stack_trace_posix.cc:150: #if !V8_OS_AIX
Could you instead ifdef out the whole of ProcessBacktrace and the calls to it
(similarly to how __ulibc__ is treated in the chromium version of the file:
https://cs.chromium.org/chromium/src/base/debug/stack_trace_posix.cc?type=cs&...

https://codereview.chromium.org/2324453002/diff/1/src/base/debug/stack_trace_...
src/base/debug/stack_trace_posix.cc:364: // equivalent user-mode API. For now
disabling the call to the API
No need for the comment

https://codereview.chromium.org/2324453002/diff/1/src/base/debug/stack_trace_...
src/base/debug/stack_trace_posix.cc:365: #if V8_OS_AIX
Could you make this #if !V8_OS_AIX and swap the branches around.

[JaideepBajwa, 2016-09-08 14:58:02]

PTAL.
I've updated as suggested. Thank you.

[rmcilroy, 2016-09-12 14:45:38]

LGTM, thanks.

[JaideepBajwa, 2016-09-12 15:09:34]

The CQ bit was checked by bjaideep@ca.ibm.com

[commit-bot: I haz the power, 2016-09-12 15:09:40]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-12 15:32:00]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-09-12 15:32:24]

Description was changed from

==========
AIX: Disable backtrace API call

Backtrace() and backtrace_symbols() API are not supported on
AIX and there are no user-mode equivalent API for the same.
For now, disabling the call to those API.
Currently this is preventing V8 to build on AIX.
This debug functionality was added in
https://codereview.chromium.org/2248393002

R=rmcilroy@chromium.org

BUG=
LOG=N
==========

to

==========
AIX: Disable backtrace API call

Backtrace() and backtrace_symbols() API are not supported on
AIX and there are no user-mode equivalent API for the same.
For now, disabling the call to those API.
Currently this is preventing V8 to build on AIX.
This debug functionality was added in
https://codereview.chromium.org/2248393002

R=rmcilroy@chromium.org

BUG=
LOG=N

Committed: https://crrev.com/bc752a0977bf823765aa298fe64670df91e79a29
Cr-Commit-Position: refs/heads/master@{#39356}
==========

[commit-bot: I haz the power, 2016-09-12 15:32:25]

Patchset 2 (id:??) landed as
https://crrev.com/bc752a0977bf823765aa298fe64670df91e79a29
Cr-Commit-Position: refs/heads/master@{#39356}

[ofrobots, 2016-09-12 19:07:48]

On 2016/09/12 15:32:25, commit-bot: I haz the power wrote:
> Patchset 2 (id:??) landed as
> https://crrev.com/bc752a0977bf823765aa298fe64670df91e79a29
> Cr-Commit-Position: refs/heads/master@{#39356}

Can this be merged back to V8 5.4?

[JaideepBajwa, 2016-09-12 19:22:21]

On 2016/09/12 19:07:48, ofrobots wrote:
> On 2016/09/12 15:32:25, commit-bot: I haz the power wrote:
> > Patchset 2 (id:??) landed as
> > https://crrev.com/bc752a0977bf823765aa298fe64670df91e79a29
> > Cr-Commit-Position: refs/heads/master@{#39356}
> 
> Can this be merged back to V8 5.4?

I've opened a CL to merge this to 5.4.
https://codereview.chromium.org/2333773002/

[ofrobots, 2016-09-12 20:31:24]

On 2016/09/12 19:07:48, ofrobots wrote:
> On 2016/09/12 15:32:25, commit-bot: I haz the power wrote:
> > Patchset 2 (id:??) landed as
> > https://crrev.com/bc752a0977bf823765aa298fe64670df91e79a29
> > Cr-Commit-Position: refs/heads/master@{#39356}
> 
> Can this be merged back to V8 5.4?

Actually I will be following up with a patch that fixes the other platforms that
are also broken (I'm taking over the CL
https://codereview.chromium.org/2321433003/) . I can take care of the merge back
of this together with that.

[ofrobots, 2016-09-12 20:32:29]

On 2016/09/12 20:31:24, ofrobots wrote:
> On 2016/09/12 19:07:48, ofrobots wrote:
> > On 2016/09/12 15:32:25, commit-bot: I haz the power wrote:
> > > Patchset 2 (id:??) landed as
> > > https://crrev.com/bc752a0977bf823765aa298fe64670df91e79a29
> > > Cr-Commit-Position: refs/heads/master@{#39356}
> > 
> > Can this be merged back to V8 5.4?
> 
> Actually I will be following up with a patch that fixes the other platforms
that
> are also broken (I'm taking over the CL
> https://codereview.chromium.org/2321433003/) . I can take care of the merge
back
> of this together with that.

Oh I see that you already opened a bug for the merge. That's fine too.

[JaideepBajwa, 2016-09-12 21:18:39]

On 2016/09/12 20:32:29, ofrobots wrote:
> On 2016/09/12 20:31:24, ofrobots wrote:
> > On 2016/09/12 19:07:48, ofrobots wrote:
> > > On 2016/09/12 15:32:25, commit-bot: I haz the power wrote:
> > > > Patchset 2 (id:??) landed as
> > > > https://crrev.com/bc752a0977bf823765aa298fe64670df91e79a29
> > > > Cr-Commit-Position: refs/heads/master@{#39356}
> > > 
> > > Can this be merged back to V8 5.4?
> > 
> > Actually I will be following up with a patch that fixes the other platforms
> that
> > are also broken (I'm taking over the CL
> > https://codereview.chromium.org/2321433003/) . I can take care of the merge
> back
> > of this together with that.
> 
> Oh I see that you already opened a bug for the merge. That's fine too.

Ok, actually the merge of this CL is not committed yet. I think it would be
better to close that merge CL with a ref to 
https://codereview.chromium.org/2321433003/ (that way the history of 5.4 will be
cleaner).

[ofrobots, 2016-09-12 21:25:52]

On 2016/09/12 21:18:39, JaideepBajwa wrote:
> On 2016/09/12 20:32:29, ofrobots wrote:
> > On 2016/09/12 20:31:24, ofrobots wrote:
> > > On 2016/09/12 19:07:48, ofrobots wrote:
> > > > On 2016/09/12 15:32:25, commit-bot: I haz the power wrote:
> > > > > Patchset 2 (id:??) landed as
> > > > > https://crrev.com/bc752a0977bf823765aa298fe64670df91e79a29
> > > > > Cr-Commit-Position: refs/heads/master@{#39356}
> > > > 
> > > > Can this be merged back to V8 5.4?
> > > 
> > > Actually I will be following up with a patch that fixes the other
platforms
> > that
> > > are also broken (I'm taking over the CL
> > > https://codereview.chromium.org/2321433003/) . I can take care of the
merge
> > back
> > > of this together with that.
> > 
> > Oh I see that you already opened a bug for the merge. That's fine too.
> 
> Ok, actually the merge of this CL is not committed yet. I think it would be
> better to close that merge CL with a ref to 
> https://codereview.chromium.org/2321433003/ (that way the history of 5.4 will
be
> cleaner).

It turns out that we also need to backport
https://codereview.chromium.org/2292973002. It is a mess :(. Feel free to close
your merge CL. I can do all of these in one shot.