https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103939
Bug ID: 103939
Summary: memset with sizeof in wrong place not detected ?
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: dcb314 at hotmail dot com
Target Milestone: ---
For this C++ code:
$ more jan7d.cc
#include <cstring>
struct S
{
int a;
int b;
int c;
int d;
};
void f( S * ps)
{
memset(ps, sizeof(S), 0xff);
}
compiled with recent gcc trunk:
$ /home/dcb/gcc/results/bin/gcc -c -g -O2 -Wall -Wextra -pedantic jan7d.cc
$
compiled by clang-13:
$ /usr/bin/clang++ -c -g -O2 -Wall -Wextra -pedantic jan7d.cc
jan7d.cc:14:15: warning: setting buffer to a 'sizeof' expression; did you mean
to transpose the last two arguments? [-Wmemset-transposed-args]
memset(ps, sizeof(S), 0xff);
^
jan7d.cc:14:15: note: cast the second argument to 'int' to silence
1 warning generated.
