https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95326
Bug ID: 95326
Summary: UBsan can not detect signed-integer-overflow correctly
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: haoxintu at gmail dot com
Target Milestone: ---
This case example.cpp
#include <iostream>
volatile wchar_t g_volatile_wchar = 2082494266;
volatile unsigned short g_volatile_ushort = 31503U;
int main () {
unsigned long l_var_ulong = 526562505494506029UL;
const wchar_t l_const_wchar = 1188246531;
g_volatile_ushort = l_var_ulong + l_const_wchar * g_volatile_wchar;
std::cout << "hello" << std::endl;
return 0;
}
can not detect signed-integer-overflow runtime error in gcc-trunk
$g++ -fsanitize=signed-integer-overflow example.cpp ; ./a.out
hello
But in clang-trunk
$clang++ -fsanitize=signed-integer-overflow test.cc ; ./a.out
example.cpp:9:53: runtime error: signed integer overflow: 1188246531 *
2082494266 cannot be represented in type 'int'
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior example.cpp:9:53 in
hello
godbolt clang-trunk : https://godbolt.org/z/s4-AqW
godbolt gcc-trunk : https://godbolt.org/z/k7NhG6
