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From: "pinskia at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/32132] bogus warning at -O3 ( 'r' may be used uninitialized in this function ). Date: Mon, 28 May 2007 21:48:00 -0000 [thread overview] Message-ID: <20070528214805.20390.qmail@sourceware.org> (raw) In-Reply-To: <bug-32132-7667@http.gcc.gnu.org/bugzilla/> ------- Comment #5 from pinskia at gcc dot gnu dot org 2007-05-28 21:48 ------- The warning is correct you need to check if str had an error after reading the integer. This is not a GCC bug. The IR looks like: <bb 7>: __comp_ctor (&str, s, 8); this.104 = (struct ios_base *) &str.D.25711; __s = this.104 + *(int *) (str.D.25711._vptr.basic_istream + -12); D.40158 = __s->_M_fmtflags; __s->_M_fmtflags = D.40158 & -57 | 16; _M_get_num (&str.D.25711, &__lval); <bb 8>: if (((this.104 + *(int *) (str.D.25711._vptr.basic_istream + -12))->_M_iostate & 5) != 0) goto <bb 10>; else goto <bb 9>; <bb 9>: __lval.107 = __lval; r = __lval.107; <bb 10>: __comp_dtor (&str); return r; Which shows for sure r may be used unitialized. Note using libstdc++ does not warn about this because we made >> out of line only which means you will not see the warning (even though the warning is correct). -- pinskia at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution| |INVALID http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32132
next prev parent reply other threads:[~2007-05-28 21:48 UTC|newest] Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top 2007-05-28 20:08 [Bug c++/32132] New: " pluto at agmk dot net 2007-05-28 20:09 ` [Bug c++/32132] " pluto at agmk dot net 2007-05-28 20:13 ` pinskia at gcc dot gnu dot org 2007-05-28 20:16 ` pluto at agmk dot net 2007-05-28 20:26 ` pinskia at gcc dot gnu dot org 2007-05-28 21:48 ` pinskia at gcc dot gnu dot org [this message] 2007-05-29 8:51 ` pluto at agmk dot net 2007-05-29 10:18 ` pluto at agmk dot net 2007-05-29 12:31 ` manu at gcc dot gnu dot org 2007-05-29 12:35 ` pluto at agmk dot net 2007-05-29 12:42 ` pluto at agmk dot net 2007-05-29 12:57 ` manu at gcc dot gnu dot org 2007-06-10 3:19 ` pinskia at gcc dot gnu dot org
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