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* [Bug c++/32291] New: -Wformat either too picky or not picky enough
@ 2007-06-11 20:29 scovich at gmail dot com
2007-06-11 20:50 ` [Bug c++/32291] " schwab at suse dot de
2010-02-21 0:15 ` manu at gcc dot gnu dot org
0 siblings, 2 replies; 3+ messages in thread
From: scovich at gmail dot com @ 2007-06-11 20:29 UTC (permalink / raw)
To: gcc-bugs
Compiling the following snippet with -Wformat (or -Wall) causes the compiler to
complain: "wformat-bug.C:8: warning: format '%u' expects type 'unsigned int',
but argument 2 has type 'uint32_t'"
The problem seems to be that stdint.h defines uint32_t as "long" in cygwin. I
realize that int != long on some platforms, but i686 isn't one of them. Why
should the user be forced to cast their uint32_t (read: 32-bit unsigned int) to
"unsigned int" before passing it to printf() when they are logically identical?
On the other hand, there's no complaint about passing a signed integer into an
unsigned format or vice-versa, even though the output value might actually
change because of the oversight in those cases.
wformat.C:
=======================================
#include <cstdio>
#include <stdint.h>
int main() {
uint32_t a = ~0;
unsigned int b = a;
uint32_t c = b;
printf("%u\n", c); // warning (?)
int d = c;
unsigned e = d;
printf("%d\n", e); // no warning
printf("%u\n", d); // no warning
}
--
Summary: -Wformat either too picky or not picky enough
Product: gcc
Version: 4.2.0
Status: UNCONFIRMED
Severity: minor
Priority: P3
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: scovich at gmail dot com
GCC target triplet: i686-pc-cygwin
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32291
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug c++/32291] -Wformat either too picky or not picky enough
2007-06-11 20:29 [Bug c++/32291] New: -Wformat either too picky or not picky enough scovich at gmail dot com
@ 2007-06-11 20:50 ` schwab at suse dot de
2010-02-21 0:15 ` manu at gcc dot gnu dot org
1 sibling, 0 replies; 3+ messages in thread
From: schwab at suse dot de @ 2007-06-11 20:50 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from schwab at suse dot de 2007-06-11 20:50 -------
It is not portable to pass a long when an int is expected. But exchanging
unsigned and signed variants of the same type is always possible.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32291
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug c++/32291] -Wformat either too picky or not picky enough
2007-06-11 20:29 [Bug c++/32291] New: -Wformat either too picky or not picky enough scovich at gmail dot com
2007-06-11 20:50 ` [Bug c++/32291] " schwab at suse dot de
@ 2010-02-21 0:15 ` manu at gcc dot gnu dot org
1 sibling, 0 replies; 3+ messages in thread
From: manu at gcc dot gnu dot org @ 2010-02-21 0:15 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from manu at gcc dot gnu dot org 2010-02-21 00:14 -------
Apart from Andrea's answer, you can use PRIu32 to print uint32_type. See
inttypes.h in your system for the complete list.
Closing.
--
manu at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |manu at gcc dot gnu dot org
Status|UNCONFIRMED |RESOLVED
Resolution| |INVALID
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32291
^ permalink raw reply [flat|nested] 3+ messages in thread
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2007-06-11 20:29 [Bug c++/32291] New: -Wformat either too picky or not picky enough scovich at gmail dot com
2007-06-11 20:50 ` [Bug c++/32291] " schwab at suse dot de
2010-02-21 0:15 ` manu at gcc dot gnu dot org
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