code review 82080044: cmd/gc: check duplicate keys in maps with interface{} k...

cmd/gc: check duplicate keys in maps with interface{} key type

Fixes issue 7214

[atom, 2014-03-29 11:39:35]

Hello golang-codereviews@googlegroups.com (cc: minux.ma@gmail.com),

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

[atom, 2014-04-01 14:20:14]

Please take a look.

[bradfitz, 2014-04-01 15:51:23]

R=rsc



On Sat, Mar 29, 2014 at 4:39 AM, <0xE2.0x9A.0x9B@gmail.com> wrote:

> Reviewers: golang-codereviews,
>
> Message:
> Hello golang-codereviews@googlegroups.com (cc: minux.ma@gmail.com),
>
> I'd like you to review this change to
> https://code.google.com/p/go/
>
>
> Description:
> cmd/gc: check duplicate keys in maps with interface{} key type
>
> Fixes issue 7214
>
> Please review this at https://codereview.appspot.com/82080044/
>
> Affected files (+13, -1 lines):
>   M src/cmd/gc/typecheck.c
>   A test/fixedbugs/issue7214.go
>
>
> Index: src/cmd/gc/typecheck.c
> ===================================================================
> --- a/src/cmd/gc/typecheck.c
> +++ b/src/cmd/gc/typecheck.c
> @@ -2568,9 +2568,9 @@
>
>                         typecheck(&l->left, Erv);
>                         defaultlit(&l->left, t->down);
> -                       l->left = assignconv(l->left, t->down, "map key");
>                         if (l->left->op != OCONV)
>                                 keydup(l->left, hash, nhash);
> +                       l->left = assignconv(l->left, t->down, "map key");
>
>                         r = l->right;
>                         pushtype(r, t->type);
> Index: test/fixedbugs/issue7214.go
> ===================================================================
> new file mode 100644
> --- /dev/null
> +++ b/test/fixedbugs/issue7214.go
> @@ -0,0 +1,12 @@
> +// errorcheck
> +
> +// Copyright 2014 The Go Authors. All rights reserved.
> +// Use of this source code is governed by a BSD-style
> +// license that can be found in the LICENSE file.
> +
> +// Issue 7214: No duplicate key error for maps with interface{} key type
> +
> +package p
> +
> +var _ = map[interface{}]int{2: 1, 2: 1} // ERROR "duplicate key 2 in map
> literal"
> +
>
>
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[rsc, 2014-04-01 16:56:53]

What about map[interface{}]bool{int(1): true, int16(1): true} ?
I think that's legal but I think this code would reject it.

[atom, 2014-04-01 17:25:49]

On 2014/04/01 16:56:53, rsc wrote:
> What about map[interface{}]bool{int(1): true, int16(1): true} ?
> I think that's legal but I think this code would reject it.

The compiler would print:

7214.go:9: illegal constant expression: int16 == int

This needs to be fixed.

[atom, 2014-04-04 06:53:43]

Hello golang-codereviews@googlegroups.com, bradfitz@golang.org, rsc@golang.org
(cc: golang-codereviews@googlegroups.com, minux.ma@gmail.com),

Please take another look.

[rsc, 2014-04-04 14:23:36]

LGTM

nice

[atom, 2014-04-04 14:46:28]

*** Submitted as https://code.google.com/p/go/source/detail?r=3188f9e48f0f ***

cmd/gc: check duplicate keys in maps with interface{} key type

Fixes issue 7214

LGTM=rsc
R=golang-codereviews, bradfitz, rsc
CC=golang-codereviews, minux.ma
https://codereview.appspot.com/82080044