code review 6741044: cmd/gc: escape analysis to track flow of in to out para...

cmd/gc: escape analysis to track flow of in to out parameters.

includes step 0: synthesize outparams, from 6600044
includes step 1,2: give outparams loopdepth 0 and verify unchanged results
         generate esc:$mask tags, but still tie to sink if a param has mask != 0
from 6610054

adds final steps:
- have esccall generate n->escretval, a list of nodes the function results flow to
- use these in esccall and ORETURN/OAS2FUNC/and f(g())
- only tie parameters to sink if tag is absent, otherwise according to mask, tie them to escretval

[lvd, 2012-10-18 15:57:56]

Hello rsc@golang.org (cc: golang-dev@googlegroups.com),

I'd like you to review this change to
https://go.googlecode.com/hg/

[dave_cheney.net, 2012-10-21 10:04:33]

Hi Luuk,

Does this CL address issues like
https://code.google.com/p/go/issues/detail?id=3702 ?

Cheers

Dave

On Fri, Oct 19, 2012 at 2:57 AM,  <lvd@google.com> wrote:
> Reviewers: rsc,
>
> Message:
> Hello rsc@golang.org (cc: golang-dev@googlegroups.com),
>
> I'd like you to review this change to
> https://go.googlecode.com/hg/
>
>
> Description:
> cmd/gc: escape analysis to track flow of in to out parameters.
>
> includes step 0: synthesize outparams, from 6600044
> includes step 1,2: give outparams loopdepth 0 and verify unchanged
> results
>          generate esc:$mask tags, but still tie to sink if a param has
> mask != 0
> from 6610054
>
> adds final steps:
> - have esccall generate n->escretval, a list of nodes the function
> results flow to
> - use these in esccall and ORETURN/OAS2FUNC/and f(g())
> - only tie parameters to sink if tag is absent, otherwise according to
> mask, tie them to escretval
>
> Please review this at http://codereview.appspot.com/6741044/
>
> Affected files:
>   M src/cmd/gc/closure.c
>   M src/cmd/gc/dcl.c
>   M src/cmd/gc/esc.c
>   M src/cmd/gc/fmt.c
>   M src/cmd/gc/go.h
>
>

[rsc, 2012-10-21 22:02:47]

looks good but i'd like to read the diffs again once the other 2 CLs are
submitted. also, please add tests to test/escape*.go.

[gobot, 2012-10-23 18:54:41]

R=bradfitz (assigned by bradfitz)

[gobot, 2012-10-23 18:54:42]

R=iant (assigned by bradfitz)

[gobot, 2012-10-23 18:54:49]

R=rsc (assigned by bradfitz)

[bradfitz, 2012-10-23 18:57:19]

Sorry for the R=spam

Maybe I'm the only person who navigates web pages with the keyboard.

The drop-downs should probably blur once modified or something.

On Tue, Oct 23, 2012 at 11:54 AM, <gobot@golang.org> wrote:

> R=rsc (assigned by bradfitz)
>
>
http://codereview.appspot.com/**6741044/<http://codereview.appspot.com/6741044/>
>

[lvd, 2012-10-24 14:18:59]

Hello rsc@golang.org, bradfitz@golang.org (cc: dave@cheney.net,
gobot@golang.org, golang-dev@googlegroups.com, iant@golang.org, rsc@golang.org),

Please take another look.

[rsc, 2012-10-29 12:31:38]

LGTM

[lvd, 2012-10-29 12:38:27]

*** Submitted as http://code.google.com/p/go/source/detail?r=7df8438a2c41 ***

cmd/gc: escape analysis to track flow of in to out parameters.

includes step 0: synthesize outparams, from 6600044
includes step 1,2: give outparams loopdepth 0 and verify unchanged results
         generate esc:$mask tags, but still tie to sink if a param has mask != 0
from 6610054

adds final steps:
- have esccall generate n->escretval, a list of nodes the function results flow
to
- use these in esccall and ORETURN/OAS2FUNC/and f(g())
- only tie parameters to sink if tag is absent, otherwise according to mask, tie
them to escretval

R=rsc, bradfitz
CC=dave, gobot, golang-dev, iant, rsc
http://codereview.appspot.com/6741044