From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-483686-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 62632 invoked by alias); 15 Apr 2015 15:56:53 -0000
Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Id: <gcc-bugs.gcc.gnu.org>
List-Archive: <http://gcc.gnu.org/ml/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-help@gcc.gnu.org>
Sender: gcc-bugs-owner@gcc.gnu.org
Received: (qmail 62320 invoked by uid 48); 15 Apr 2015 15:56:48 -0000
From: "ian at airs dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug go/65772] With multiple return values including a function with side effects, incorrect value is returned
Date: Wed, 15 Apr 2015 15:56:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: go
X-Bugzilla-Version: 5.0
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: ian at airs dot com
X-Bugzilla-Status: RESOLVED
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: ian at airs dot com
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags:
X-Bugzilla-Changed-Fields: bug_status resolution
Message-ID: <bug-65772-4-rFdcNLjwFX@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-65772-4@http.gcc.gnu.org/bugzilla/>
References: <bug-65772-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-SW-Source: 2015-04/txt/msg01238.txt.bz2

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65772

Ian Lance Taylor <ian at airs dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |INVALID

--- Comment #3 from Ian Lance Taylor <ian at airs dot com> ---
The test case is invalid.  It works coincidentally with gc.

The order of evaluation rules for Go
(http://golang.org/ref/spec#Order_of_evaluation) do not specify when a variable
is read.  In a case like
    return files, filepath.Walk(dir, visit)
where files is updated by the visit function passed to filepath.Walk, the files
variable may be read either before or after calling filepath.Walk.  The gc
compiler is generating code that reads it after, the gccgo compiler is
generating code that reads it before.  Either is correct according to the
language spec.