https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86972
Bug ID: 86972
Summary: Incorrect array-bounds warning with -O2 when creating
pointer from array
Product: gcc
Version: 8.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: aes368 at cornell dot edu
Target Milestone: ---
int *p;
int main() {
int a[1];
p = a - 1;
}
The above code raises the warning:
warning: array subscript -1 is below array bounds of ‘int [1]’ [-Warray-bounds]
p = a - 1;
~~^~~
when compiled with
gcc -O2 -Wall
I see this both on 7.3.0 and 8.2.0.
The subscript detected seems to always be the term added to a, though it does
not raise a warning with 0 or +1.
