RE: port-hp300/50852: src/sys/arch/hp300/stand/common/ite.c:239: bad expression

[David Binderman <dcb314%hotmail.com@localhost>]

The following reply was made to PR port-hp300/50852; it has been noted by GNATS.

From: David Binderman <dcb314%hotmail.com@localhost>
To: "gnats-bugs%NetBSD.org@localhost" <gnats-bugs%netbsd.org@localhost>,
	"port-hp300-maintainer%netbsd.org@localhost" <port-hp300-maintainer%netbsd.org@localhost>,
	"gnats-admin%netbsd.org@localhost" <gnats-admin%netbsd.org@localhost>, "netbsd-bugs%netbsd.org@localhost"
	<netbsd-bugs%netbsd.org@localhost>
Cc: 
Subject: RE: port-hp300/50852: src/sys/arch/hp300/stand/common/ite.c:239:
 bad expression
Date: Fri, 26 Feb 2016 16:45:21 +0000

 Hello there=2C=0A=
 =0A=
 ----------------------------------------=0A=
 > On Fri=2C Feb 26=2C 2016 at 10:55:00AM +0000=2C dcb314%hotmail.com@localhost wrote:=
 =0A=
 >>>Description:=0A=
 >> [src/sys/arch/hp300/stand/common/ite.c:239]: (error) Expression 'whichco=
 nsole=3D++whichconsole%(NITE+1)' depends on order of evaluation of side eff=
 ects=0A=
 >>=0A=
 >> Source code is=0A=
 >>=0A=
 >> whichconsole =3D ++whichconsole % (NITE+1)=3B=0A=
 >>=0A=
 >> Maybe better code=0A=
 >>=0A=
 >> whichconsole =3D (whichconsole + 1) % (NITE+1)=3B=0A=
 >=0A=
 > Independent of the question of which code is better=2C I don't think the=
 =0A=
 > error is correct. =0A=
 =0A=
 False=2C the error is valid.=0A=
 =0A=
 There are two writes to whichconsole=2C one on the left of the assignment=
 =2C=0A=
 one on the right.=0A=
 =0A=
 The ISO standard doesn't define which order those writes occur.=0A=
 See Steve Summit's C FAQ for sequence points=2C section 3.8.=0A=
 =0A=
 =0A=
 Regards=0A=
 =0A=
 David Binderman=0A=
 =0A=
 31 years a C programmer=2C including C and C++ compiler development.=0A=
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