https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108497
Bug ID: 108497
Summary: UBsan at -O1 failed to report an integer-overflow
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: sanitizer
Assignee: unassigned at gcc dot gnu.org
Reporter: shaohua.li at inf dot ethz.ch
CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
jakub at gcc dot gnu.org, kcc at gcc dot gnu.org, marxin at
gcc dot gnu.org
Target Milestone: ---
For the following code, UBsan `-fsanitize=undefined -fno-sanitize-recover=all
-O1` failed to report the integer-overflow, while other opt levels reported it.
Interestingly, if you don't specify `-fno-sanitize-recover=all`, UBSAN can
report it normally.
Clang at all opt levels can detect it.
Compiler explorer: https://godbolt.org/z/dE1sfcz5f
% cat a.c
int a, c;
long *b;
int main() {
int d = 0, e = 0;
for (; e < 2; e++)
f:
for (; a; a++)
d % *b;
d = d + 1228455618;
c ^= 0 == 0;
if (c) {
e = 0;
for (; e < 1; e++)
;
goto f;
}
}
%
% gcc-tk -O1 -fsanitize=undefined -fno-sanitize-recover=all a.c && ./a.out
%
% gcc-tk -O2 -fsanitize=undefined -fno-sanitize-recover=all a.c && ./a.out
/a.c:9:5: runtime error: signed integer overflow: 1228455618 + 1228455618
cannot be represented in type 'int'
%
