code review 1612041: bug284: make conversion legal, fix error patterns

bug284: make conversion legal, fix error patterns

[rsc, 2010-06-08 22:29:26]

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

I'd like you to review this change.

[rsc, 2010-06-08 22:30:33]

please check that you agree that the old code
(converting q2 instead of ps1) was not legal.


On Tue, Jun 8, 2010 at 15:29,  <rsc@golang.org> wrote:
> Reviewers: gri,
>
> Message:
> Hello gri (cc: golang-dev@googlegroups.com),
>
> I'd like you to review this change.
>
>
> Description:
> bug284: make conversion legal, fix error patterns
>
> Please review this at http://codereview.appspot.com/1612041/show
>
> Affected files:
>  M test/bugs/bug284.go
>
>
> Index: test/bugs/bug284.go
> ===================================================================
> --- a/test/bugs/bug284.go
> +++ b/test/bugs/bug284.go
> @@ -1,4 +1,4 @@
> -// errchk $G $D/$F.go
> +// errchk $G -e $D/$F.go
>
>  // Copyright 2010 The Go Authors. All rights reserved.
>  // Use of this source code is governed by a BSD-style
> @@ -85,11 +85,12 @@
>        }
>        var q1 Q1
>        var q2 Q2
> +       var ps1 *S1
>        q0 = q0
>        q0 = q1
>        q0 = (*struct {
>                x int
> -       })(q2) // legal because of special conversion exception for pointers
> +       })(ps1) // legal because of special conversion exception for
> pointers
>        q1 = q0
>        q1 = q1
>        q1 = Q1(q2)    // ERROR "cannot"
> @@ -127,12 +128,12 @@
>        x0 = x1
>        x0 = interface {
>                f() int
> -       }(x2) // ERROR "cannot"|"need type assertion"
> +       }(x2) // ERROR "cannot|need type assertion"
>        x1 = x0
>        x1 = x1
> -       x1 = X1(x2) // ERROR "cannot"|"need type assertion"
> -       x2 = X2(x0) // ERROR "cannot"|"need type assertion"
> -       x2 = X2(x1) // ERROR "cannot"|"need type assertion"
> +       x1 = X1(x2) // ERROR "cannot|need type assertion"
> +       x2 = X2(x0) // ERROR "cannot|need type assertion"
> +       x2 = X2(x1) // ERROR "cannot|need type assertion"
>        x2 = x2
>
>        type L1 []int
>
>
>

[gri, 2010-06-08 22:42:15]

LGTM

[rsc, 2010-06-08 22:51:42]

*** Submitted as http://code.google.com/p/go/source/detail?r=933122365329 ***

bug284: make conversion legal, fix error patterns

R=gri
CC=golang-dev
http://codereview.appspot.com/1612041