https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96447
Bug ID: 96447
Summary: False positive -Wstringop-overflow with -O3
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: other
Assignee: unassigned at gcc dot gnu.org
Reporter: daniel at constexpr dot org
Target Milestone: ---
Created attachment 48990
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48990&action=edit
test.c
The attached reduced test case results in the following false positive warning
at -03 (but not -O2) without any additional compiler flags with both GCC 10.2.0
and GCC 11.0.0 (compiled from git today):
test.c: In function ‘load’:
test.c:23:25: warning: writing 1 byte into a region of size 0
[-Wstringop-overflow=]
23 | data[i] = get8u(s);
| ~~~~~~~~^~~~~~~~~~
test.c:21:23: note: at offset 4 to object ‘data’ with size 4 declared here
21 | unsigned char data[4];
| ^~~~
