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From: Mikael Vidstedt <mikael.vidstedt@bea.com>
To: gcc-help@gcc.gnu.org
Subject: Missing warning about uninitialized variable
Date: Thu, 29 Nov 2007 15:49:00 -0000	[thread overview]
Message-ID: <1196347151.19661.20.camel@cochrane.jrpg.bea.com> (raw)


The following program may make use of an uninitialized variable (gurka):

int
main(int argc, char* argv[])
{
   int gurka;

   if(argc == 10) {
      gurka = 3;
   }

   // gurka isn't necessarily initialized here...
   printf("%d\n", gurka);

   return 0;
}

GCC 4.0 will give a warning when this program is compiled with "-O
-Wall". GCC 4.1 and 4.2 do not give that warning. I haven't had the
possibility to try GCC 4.3.

What say ye?

Thanks,
Mikael


# gcc-4.0 --version
gcc-4.0 (GCC) 4.0.4 20060904 (prerelease) (Debian 4.0.3-7)
Copyright (C) 2006 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is
NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE.

# gcc-4.0 -O -Wall -o foo foo.c
foo.c: In function 'main':
foo.c:6: warning: 'gurka' may be used uninitialized in this function
#


# gcc-4.1 --version
gcc-4.1 (GCC) 4.1.3 20071019 (prerelease) (Debian 4.1.2-17)
Copyright (C) 2006 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is
NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE.

# gcc-4.1 -O -Wall -o foo foo.c
#


# gcc-4.2 --version
gcc-4.2 (GCC) 4.2.3 20071014 (prerelease) (Debian 4.2.2-3)
Copyright (C) 2007 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is
NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE.

# gcc-4.2 -O -Wall -o foo foo.c
#

             reply	other threads:[~2007-11-29 14:44 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-11-29 15:49 Mikael Vidstedt [this message]
2007-11-30 16:31 ` Ian Lance Taylor
2007-11-29 16:01 J.C. Pizarro
2007-11-29 16:18 ` eschenb
2007-11-29 16:32   ` J.C. Pizarro
2007-11-29 16:41     ` eschenb
2007-11-29 16:45       ` J.C. Pizarro
2007-11-29 16:48         ` Tom St Denis
2007-11-29 16:57           ` J.C. Pizarro
2007-11-29 16:58             ` Tom St Denis
2007-11-29 18:11               ` J.C. Pizarro
2007-11-29 18:16                 ` Tom St Denis
2007-11-29 18:20                   ` Mikael Vidstedt
2007-11-29 18:30                     ` Tom St Denis
2007-11-29 18:31                       ` Mikael Vidstedt
2007-11-29 21:12                   ` J.C. Pizarro
2007-11-29 21:10                     ` J.C. Pizarro
2007-11-29 21:30                     ` J.C. Pizarro
2007-11-29 21:42                       ` John Love-Jensen
2007-11-29 21:42                         ` Mikael Vidstedt
2007-11-29 22:12                           ` Tony Wetmore
2007-11-29 22:03                         ` J.C. Pizarro
2007-11-29 17:48         ` John Love-Jensen
2007-11-29 18:02           ` J.C. Pizarro
2007-11-29 16:51       ` J.C. Pizarro
2007-11-29 18:18         ` Sven Eschenberg
2007-11-29 18:22           ` Tom St Denis
2007-11-29 18:57             ` Sven Eschenberg
     [not found] ` <C3743DA6.273A8%eljay@adobe.com>
2007-11-29 16:22   ` J.C. Pizarro
2009-11-25 10:09 David Sveningsson
2009-11-27 14:29 ` Ian Lance Taylor

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