Date: Wed, 9 Nov 2011 09:35:51 +0100 From: Stefan Farfeleder <stefanf@FreeBSD.org> To: Jilles Tjoelker <jilles@FreeBSD.org> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r227369 - head/bin/sh Message-ID: <20111109083545.GC1598@mole.fafoe.narf.at> In-Reply-To: <201111082354.pA8NsdhP055080@svn.freebsd.org> References: <201111082354.pA8NsdhP055080@svn.freebsd.org>
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On Tue, Nov 08, 2011 at 11:54:39PM +0000, Jilles Tjoelker wrote: > Author: jilles > Date: Tue Nov 8 23:54:39 2011 > New Revision: 227369 > URL: http://svn.freebsd.org/changeset/base/227369 > > Log: > sh: Remove undefined behaviour due to overflow in +/-/* in arithmetic. > > With i386 base gcc and i386 base clang, arith_yacc.o remains unchanged. > > Modified: > head/bin/sh/arith_yacc.c > > Modified: head/bin/sh/arith_yacc.c > ============================================================================== > --- head/bin/sh/arith_yacc.c Tue Nov 8 23:44:26 2011 (r227368) > +++ head/bin/sh/arith_yacc.c Tue Nov 8 23:54:39 2011 (r227369) > @@ -131,11 +131,11 @@ static arith_t do_binop(int op, arith_t > yyerror("divide error"); > return op == ARITH_REM ? a % b : a / b; > case ARITH_MUL: > - return a * b; > + return (uintmax_t)a * (uintmax_t)b; > case ARITH_ADD: > - return a + b; > + return (uintmax_t)a + (uintmax_t)b; > case ARITH_SUB: > - return a - b; > + return (uintmax_t)a - (uintmax_t)b; > case ARITH_LSHIFT: > return a << b; > case ARITH_RSHIFT: > Isn't the behaviour undefined too when you convert an out-of-range uintmax_t value back into an intmax_t value? Stefan
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