https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87420
Bug ID: 87420
Summary: missing warning for strcpy of an unterminated array
with variable offset
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
When the source array involves a variable index/offset, GCC 9 issues a warning
for a strcpy call with a single-dimensional unterminated array but fails to
issue the same warning when the array has multiple dimensions, as shown in the
test case below:
$ cat c.c && gcc -O2 -S -Wall -Wextra -Wpedantic c.c
const char a[] = { '1', '2', '3' };
const char b[][3] = { { '1', '2' }, { '1', '2', '3' } };
void f (char *d, int i)
{
__builtin_strcpy (d, &a[i]); // warning (good)
}
void g (char *d, int i)
{
__builtin_strcpy (d, &b[1][i]); // missing warning
}
c.c: In function ‘f’:
c.c:6:3: warning: ‘strcpy’ argument missing terminating nul
[-Wstringop-overflow=]
6 | __builtin_strcpy (d, &a[i]); // warning (good)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~
c.c:1:12: note: referenced argument declared here
1 | const char a[] = { '1', '2', '3' };
| ^
