code review 100870046: cmd/gc: fix handling of for post-condition

cmd/gc: fix handling of for post-condition in -race mode

Fixes issue 8102.

[rsc, 2014-05-31 01:43:33]

Hello golang-codereviews@googlegroups.com (cc: dvyukov),

I'd like you to review this change to
https://code.google.com/p/go/

[rsc, 2014-05-31 01:44:40]

added "in -race mode" to description

[bradfitz, 2014-05-31 01:45:45]

LGTM



On Fri, May 30, 2014 at 6:43 PM, <rsc@golang.org> wrote:

> Reviewers: golang-codereviews,
>
> Message:
> Hello golang-codereviews@googlegroups.com (cc: dvyukov),
>
> I'd like you to review this change to
> https://code.google.com/p/go/
>
>
> Description:
> cmd/gc: fix handling of for post-condition
>
> Fixes issue 8102.
>
> Please review this at https://codereview.appspot.com/100870046/
>
> Affected files (+16, -1 lines):
>   M src/cmd/gc/racewalk.c
>   M src/pkg/runtime/race/race_test.go
>
>
> Index: src/cmd/gc/racewalk.c
> ===================================================================
> --- a/src/cmd/gc/racewalk.c
> +++ b/src/cmd/gc/racewalk.c
> @@ -182,7 +182,7 @@
>                         // x, y := f() becomes BLOCK{CALL f, AS x [SP+0],
> AS y [SP+n]}
>                         // We don't want to instrument between the
> statements because it will
>                         // smash the results.
> -                       racewalknode(&n->list->n, &n->ninit, 0, 0);
> +                       racewalknode(&n->list->n, &n->list->n->ninit, 0,
> 0);
>                         fini = nil;
>                         racewalklist(n->list->next, &fini);
>                         n->list = concat(n->list, fini);
> Index: src/pkg/runtime/race/race_test.go
> ===================================================================
> --- a/src/pkg/runtime/race/race_test.go
> +++ b/src/pkg/runtime/race/race_test.go
> @@ -155,3 +155,18 @@
>         cmd.Env = append(cmd.Env, `GORACE="suppress_equal_stacks=0
> suppress_equal_addresses=0 exitcode=0"`)
>         return cmd.CombinedOutput()
>  }
> +
> +func TestIssue8102(t *testing.T) {
> +       // If this compiles with -race, the test passes.
> +       type S struct {
> +               x interface{}
> +               i int
> +       }
> +       c := make(chan int)
> +       a := [2]*int{}
> +       for ; ; c <- *a[S{}.i] {
> +               if t != nil {
> +                       break
> +               }
> +       }
> +}
>
>
> --
> You received this message because you are subscribed to the Google Groups
> "golang-codereviews" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to golang-codereviews+unsubscribe@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.
>

[dvyukov, 2014-05-31 07:41:37]

LGTM
Thanks for fixing this!

[rsc, 2014-05-31 13:35:30]

*** Submitted as https://code.google.com/p/go/source/detail?r=95cc2b2ebec5 ***

cmd/gc: fix handling of for post-condition in -race mode

Fixes issue 8102.

LGTM=bradfitz, dvyukov
R=golang-codereviews, bradfitz, dvyukov
CC=golang-codereviews
https://codereview.appspot.com/100870046

[gobot, 2014-05-31 13:51:52]

This CL appears to have broken the netbsd-386-minux builder.
See http://build.golang.org/log/c7d9f2891e6200cb6b2091a6170ce3c8f7b3d768