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* [Bug c++/37765] New: Printf of typed null pointer causes a run-time error
@ 2008-10-08 4:33 hosoda-t at palette dot plala dot or dot jp
2008-10-08 7:38 ` [Bug c++/37765] " schwab at suse dot de
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: hosoda-t at palette dot plala dot or dot jp @ 2008-10-08 4:33 UTC (permalink / raw)
To: gcc-bugs
#include <cstdio>
int main()
{
printf("%s\n", (char*)0); // run-time error for g++ 4.3.2,
} // while ok for g++ 3.4.4
run-time error:
10 [main] a 1808 _cygtls::handle_exceptions: Error while dumping state
(probably corrupted stack) Segmentation fault (core dumped)
expexted behavior:print nothing or (null)
workaround: use cout
comment:
Many people still prefer printf to cout. The disabled function make
printf almost useless.
--
Summary: Printf of typed null pointer causes a run-time error
Product: gcc
Version: 4.3.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: hosoda-t at palette dot plala dot or dot jp
GCC host triplet: Microsoft Windows XP
GCC target triplet: i686-pc-cygwin
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37765
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug c++/37765] Printf of typed null pointer causes a run-time error
2008-10-08 4:33 [Bug c++/37765] New: Printf of typed null pointer causes a run-time error hosoda-t at palette dot plala dot or dot jp
@ 2008-10-08 7:38 ` schwab at suse dot de
2008-10-08 23:03 ` hosoda-t at palette dot plala dot or dot jp
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: schwab at suse dot de @ 2008-10-08 7:38 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from schwab at suse dot de 2008-10-08 07:36 -------
"%s" requires a pointer to a string, which (char*)0 isn't.
--
schwab at suse dot de changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |INVALID
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37765
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug c++/37765] Printf of typed null pointer causes a run-time error
2008-10-08 4:33 [Bug c++/37765] New: Printf of typed null pointer causes a run-time error hosoda-t at palette dot plala dot or dot jp
2008-10-08 7:38 ` [Bug c++/37765] " schwab at suse dot de
@ 2008-10-08 23:03 ` hosoda-t at palette dot plala dot or dot jp
2008-10-08 23:07 ` pinskia at gcc dot gnu dot org
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: hosoda-t at palette dot plala dot or dot jp @ 2008-10-08 23:03 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from hosoda-t at palette dot plala dot or dot jp 2008-10-08 23:02 -------
(In reply to comment #1)
> "%s" requires a pointer to a string, which (char*)0 isn't.
"%s" is a c-style string.
try the code below, and please notice that the code works well on g++ 3.4.4 and
also on Microsoft Visual C++ 2005 without a run-time error.
#include <cstdio>
int main()
{
const char* p = "This is a c-syle string.";
printf("%s\n", p);
char* q = 0;
printf("%s\n", q);
}
--
hosoda-t at palette dot plala dot or dot jp changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|RESOLVED |UNCONFIRMED
Resolution|INVALID |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37765
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug c++/37765] Printf of typed null pointer causes a run-time error
2008-10-08 4:33 [Bug c++/37765] New: Printf of typed null pointer causes a run-time error hosoda-t at palette dot plala dot or dot jp
2008-10-08 7:38 ` [Bug c++/37765] " schwab at suse dot de
2008-10-08 23:03 ` hosoda-t at palette dot plala dot or dot jp
@ 2008-10-08 23:07 ` pinskia at gcc dot gnu dot org
2008-10-09 2:42 ` hosoda-t at palette dot plala dot or dot jp
2008-10-09 8:20 ` paolo dot carlini at oracle dot com
4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2008-10-08 23:07 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from pinskia at gcc dot gnu dot org 2008-10-08 23:05 -------
printf ("%s\n", NULL);
is undefined. So GCC is optimizing the printf in this case to puts which
creates smaller and faster code.
--
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=37765
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug c++/37765] Printf of typed null pointer causes a run-time error
2008-10-08 4:33 [Bug c++/37765] New: Printf of typed null pointer causes a run-time error hosoda-t at palette dot plala dot or dot jp
` (2 preceding siblings ...)
2008-10-08 23:07 ` pinskia at gcc dot gnu dot org
@ 2008-10-09 2:42 ` hosoda-t at palette dot plala dot or dot jp
2008-10-09 8:20 ` paolo dot carlini at oracle dot com
4 siblings, 0 replies; 6+ messages in thread
From: hosoda-t at palette dot plala dot or dot jp @ 2008-10-09 2:42 UTC (permalink / raw)
To: gcc-bugs
------- Comment #4 from hosoda-t at palette dot plala dot or dot jp 2008-10-09 02:40 -------
Thank you for your time. I am sure that you are right, because the Null pointer
does not point to a string which must have the terminator '\0' at the end.
However, please kindly adivise me if the folloing code also work on a undefined
behavior or not.
cout << (char*)0;
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37765
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug c++/37765] Printf of typed null pointer causes a run-time error
2008-10-08 4:33 [Bug c++/37765] New: Printf of typed null pointer causes a run-time error hosoda-t at palette dot plala dot or dot jp
` (3 preceding siblings ...)
2008-10-09 2:42 ` hosoda-t at palette dot plala dot or dot jp
@ 2008-10-09 8:20 ` paolo dot carlini at oracle dot com
4 siblings, 0 replies; 6+ messages in thread
From: paolo dot carlini at oracle dot com @ 2008-10-09 8:20 UTC (permalink / raw)
To: gcc-bugs
------- Comment #5 from paolo dot carlini at oracle dot com 2008-10-09 08:19 -------
Yes, all those inserters, per 27.6.2.5.4/3 Require a non-null s.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37765
^ permalink raw reply [flat|nested] 6+ messages in thread
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2008-10-08 4:33 [Bug c++/37765] New: Printf of typed null pointer causes a run-time error hosoda-t at palette dot plala dot or dot jp
2008-10-08 7:38 ` [Bug c++/37765] " schwab at suse dot de
2008-10-08 23:03 ` hosoda-t at palette dot plala dot or dot jp
2008-10-08 23:07 ` pinskia at gcc dot gnu dot org
2008-10-09 2:42 ` hosoda-t at palette dot plala dot or dot jp
2008-10-09 8:20 ` paolo dot carlini at oracle dot com
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