https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83840
Bug ID: 83840
Summary: missing -Wmemset-elt-size with address of array
element
Product: gcc
Version: 8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
When passing the address of an array to a function that takes a pointer it's
common (if unnecessarily verbose) practice to take the address of the first
element of the array and pass it instead. The test program below shows that
the -Wmemset-elt-size warning doesn't work for this case.
$ cat z.c && gcc -S -Wall z.c
int a[2];
void f (void)
{
__builtin_memset (a, 0, 2); // -Wmemset-elt-size (good)
}
void g (void)
{
__builtin_memset (&a, 0, 2); // -Wmemset-elt-size (good)
}
void h (void)
{
__builtin_memset (&a[0], 0, 2); // missing -Wmemset-elt-size
}
z.c: In function ‘void f()’:
z.c:5:28: warning: ‘memset’ used with length equal to number of elements
without multiplication by element size [-Wmemset-elt-size]
__builtin_memset (a, 0, 2); // -Wmemset-elt-size (good)
^
z.c: In function ‘void g()’:
z.c:10:29: warning: ‘memset’ used with length equal to number of elements
without multiplication by element size [-Wmemset-elt-size]
__builtin_memset (&a, 0, 2); // -Wmemset-elt-size (good)
^
