https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95430
Bug ID: 95430
Summary: [UBSAN] doesn't detect out of bounds in a simple case
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: sanitizer
Assignee: unassigned at gcc dot gnu.org
Reporter: haoxintu at gmail dot com
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: ---
This case test.cc
#include<iostream>
int main () {
int a[10];
int *p1 = a - 100; // UB
int *p2 = a + 100; // UB
std::cout << "ok" << std::endl;
return 0;
}
$g++ -fsanitize=undefined test.cc ; ./a.out
ok
While in Clang
$clang++ -fsanitize=undefined test.cc ; ./a.out
test.cc:5:17: runtime error: index -100 out of bounds for type 'int [10]'
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior test.cc:5:17 in
test.cc:6:17: runtime error: index 100 out of bounds for type 'int [10]'
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior test.cc:6:17 in
ok
My GCC version is
$g++ --version
g++ (GCC) 11.0.0 20200526 (experimental)
Copyright (C) 2020 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
GCC doesn't trigger warning or runtime error in out of bounds in an array.
