[Bug c++/59248] New: [4.8 regression] pointless -Wconversion warning with sizeof, take 2

[Bug c++/59248] New: [4.8 regression] pointless -Wconversion warning with sizeof, take 2

[jens.maurer at gmx dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59248

            Bug ID: 59248
           Summary: [4.8 regression] pointless -Wconversion warning with
                    sizeof, take 2
           Product: gcc
           Version: 4.8.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jens.maurer at gmx dot net

The simple case was fixed with
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56930 (thanks, Jason), but a
slightly more involved case still warns spuriously:

$ g++ -Wconversion -std=c++11 x.cc 
x.cc: In function ‘int main()’:
x.cc:3:12: warning: conversion to ‘int’ from ‘long unsigned int’ may alter its
value [-Wconversion]
   int x = 2*sizeof(int);
            ^
x.cc:4:12: warning: conversion to ‘int’ from ‘long unsigned int’ may alter its
value [-Wconversion]
   int y { 2* sizeof(int) };
            ^

This didn't produce any warnings with gcc 4.7.3.
>From gcc-bugs-return-435479-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Fri Nov 22 08:15:37 2013
Return-Path: <gcc-bugs-return-435479-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Delivered-To: listarch-gcc-bugs@gcc.gnu.org
Received: (qmail 1121 invoked by alias); 22 Nov 2013 08:15:36 -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
Delivered-To: mailing list gcc-bugs@gcc.gnu.org
Received: (qmail 1083 invoked by uid 48); 22 Nov 2013 08:15:32 -0000
From: "yves.caniou@ens-lyon.fr" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug bootstrap/55915] fails to build lto-compress.c, zlib.h not found
Date: Fri, 22 Nov 2013 08:15:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: bootstrap
X-Bugzilla-Version: 4.8.0
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: yves.caniou@ens-lyon.fr
X-Bugzilla-Status: WAITING
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags:
X-Bugzilla-Changed-Fields:
Message-ID: <bug-55915-4-mFAhITVUBw@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-55915-4@http.gcc.gnu.org/bugzilla/>
References: <bug-55915-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-SW-Source: 2013-11/txt/msg02256.txt.bz2
Content-length: 1735

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55915

--- Comment #6 from Yves Caniou <yves.caniou@ens-lyon.fr> ---
(In reply to Yves Caniou from comment #5)
> Le mardi 19 novembre 2013 02:36:30 pinskia at gcc dot gnu.org a écrit :
> > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55915
> > 
> > Andrew Pinski <pinskia at gcc dot gnu.org> changed:
> > 
> >            What    |Removed                     |Added
> > ----------------------------------------------------------------------------
> > Status|UNCONFIRMED                 |WAITING
> >    Last reconfirmed|                            |2013-11-19
> >      Ever confirmed|0                           |1
> > 
> > --- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
> > (In reply to Yves Caniou from comment #3)
> > 
> > > I have the same problem when compiling gcc-4.8.2 with gcc version 4.6.3
> > > (Ubuntu/Linaro 4.6.3-1ubuntu5) on Xeon(R) CPU W3670  @ 3.20GHz
> > > Note that with the exact same process, I have been able to compile
> > > gcc-4.8.2 with gcc 4.7.2 (debian).
> > 
> > Do you have a zlib.h installed?
> > For the original issue here, I think you need to use BOOT_CFLAGS and maybe
> > BOOT_CXXFLAGS.
> 
> Indeed: /usr/include/zlib.h
> And as I said, I could compile gcc-4.8.2 from 4.7.2 without any problem in
> the 
> first place. Problems only appear when compiling gcc-4.8.2 with the new 
> installation and all environment variables configured (at least as I
> thought: 
> why would I use BOOT_FLAGS and how?)
> 
> .Y

Ok. Wrong machine, I apologize.
I have a /usr/lib/syslinux/com32/include/zlib.h from syslinux-common package,
not /usr/include/zlib.h from zlib1g-dev.
Installing zlib1g-dev does the trick..
>From gcc-bugs-return-435481-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Fri Nov 22 09:17:33 2013
Return-Path: <gcc-bugs-return-435481-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Delivered-To: listarch-gcc-bugs@gcc.gnu.org
Received: (qmail 11591 invoked by alias); 22 Nov 2013 09:17:32 -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
Delivered-To: mailing list gcc-bugs@gcc.gnu.org
Received: (qmail 10023 invoked by uid 48); 22 Nov 2013 09:16:36 -0000
From: "fxcoudert at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libfortran/49024] REAL*16 ERFC_SCALED inaccuracy
Date: Fri, 22 Nov 2013 09:17:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: libfortran
X-Bugzilla-Version: 4.7.0
X-Bugzilla-Keywords: patch
X-Bugzilla-Severity: normal
X-Bugzilla-Who: fxcoudert at gcc dot gnu.org
X-Bugzilla-Status: RESOLVED
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags:
X-Bugzilla-Changed-Fields: bug_status resolution
Message-ID: <bug-49024-4-mOeXp5YUUI@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-49024-4@http.gcc.gnu.org/bugzilla/>
References: <bug-49024-4@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: 2013-11/txt/msg02258.txt.bz2
Content-length: 487

http://gcc.gnu.org/bugzilla/show_bug.cgi?idI024

Bug 49024 depends on bug 59227, which changed state.

Bug 59227 Summary: [4.9 regression] FAIL: gfortran.dg/erf_3.F90  -O0  execution test
http://gcc.gnu.org/bugzilla/show_bug.cgi?idY227

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|REOPENED                    |RESOLVED
         Resolution|---                         |FIXED

[Bug c++/59248] [4.8 regression] pointless -Wconversion warning with sizeof, take 2

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59248

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING
   Last reconfirmed|                            |2013-11-22
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Which "slightly more involved testcase"?

[Bug c++/59248] [4.8 regression] pointless -Wconversion warning with sizeof, take 2

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59248

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.8.3

[Bug c++/59248] [4.8 regression] pointless -Wconversion warning with sizeof, take 2

[jens.maurer at gmx dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59248

--- Comment #2 from Jens Maurer <jens.maurer at gmx dot net> ---
This one:

$ cat ~/x.cc 
int main()
{
  int x = 2*sizeof(int);
  int y { 2* sizeof(int) };
}


(sorry, forgot to attach earlier)

[Bug c++/59248] [4.8 regression] pointless -Wconversion warning with sizeof, take 2

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59248

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW
                 CC|                            |jason at gcc dot gnu.org
      Known to work|                            |4.9.0

--- Comment #3 from Jason Merrill <jason at gcc dot gnu.org> ---
Works better with pre-4.9.

[Bug c++/59248] [4.8 regression] pointless -Wconversion warning with sizeof, take 2

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59248

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.3                       |4.8.4

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 4.8.3 is being released, adjusting target milestone.

[Bug c++/59248] [4.8 regression] pointless -Wconversion warning with sizeof, take 2

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59248

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |diagnostic
           Priority|P3                          |P2

[Bug c++/59248] [4.8 regression] pointless -Wconversion warning with sizeof, take 2

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59248

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.4                       |4.8.5

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.8.4 has been released.

[Bug c++/59248] [4.8 regression] pointless -Wconversion warning with sizeof, take 2

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59248

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED
   Target Milestone|4.8.5                       |4.9.0
      Known to fail|                            |4.8.5

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed for 4.9.0.