code review 91590043: syscall: fix Write(nil) on NaCl

syscall: fix Write(nil) on NaCl

Fixes issue 7050.

[rsc, 2014-05-20 05:54:29]

Hello golang-codereviews@googlegroups.com,

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

[crawshaw, 2014-05-20 11:17:05]

LGTM

[r, 2014-05-20 15:27:21]

LGTM

https://codereview.appspot.com/91590043/diff/20002/src/pkg/syscall/fd_nacl.go
File src/pkg/syscall/fd_nacl.go (right):

https://codereview.appspot.com/91590043/diff/20002/src/pkg/syscall/fd_nacl.go...
src/pkg/syscall/fd_nacl.go:165: var zerobuf [0]byte
you could use var zerobuf = make([]byte, 0) or [0]byte{}[:] and avoid the extra
slice op below.
it's not even close to important though

[rsc, 2014-05-20 15:32:27]

On Tue, May 20, 2014 at 11:27 AM, <r@golang.org> wrote:

> LGTM
>
>
> https://codereview.appspot.com/91590043/diff/20002/src/
> pkg/syscall/fd_nacl.go
> File src/pkg/syscall/fd_nacl.go (right):
>
> https://codereview.appspot.com/91590043/diff/20002/src/
> pkg/syscall/fd_nacl.go#newcode165
> src/pkg/syscall/fd_nacl.go:165: var zerobuf [0]byte
> you could use var zerobuf = make([]byte, 0) or [0]byte{}[:] and avoid
> the extra slice op below.
> it's not even close to important though


like you say it doesn't matter, but what's there already is probably
cheaper than those.
(the compiler will turn it into mov $zerobuf, base; mov $0, len, mov $0,
cap.
copying a real slice you'd have to load the fields from the global before
storing them.)

russ

[rsc, 2014-05-20 15:38:35]

*** Submitted as https://code.google.com/p/go/source/detail?r=f735f1992be5 ***

syscall: fix Write(nil) on NaCl

Fixes issue 7050.

LGTM=crawshaw, r
R=golang-codereviews, crawshaw, r
CC=golang-codereviews
https://codereview.appspot.com/91590043