I have a small unit test here which has undefined behaviour.
Source code:
#include <gtest/gtest.h>
TEST(test, test)
{
int k = 0x7fffffff;
k += 1; // cause integer overflow
}
GTEST_API_ int main(int argc, char** argv)
{
testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
I enable UBSAN in my CMakeLists.txt:
cmake_minimum_required (VERSION 3.12)
project(ub CXX)
find_package(GTest REQUIRED)
add_executable (ub_test ub_test.cpp)
target_link_libraries (ub_test GTest::GTest)
target_compile_options(ub_test PRIVATE -fsanitize=undefined)
target_link_options (ub_test PRIVATE -fsanitize=undefined)
UBSAN correctly identifies the undefined behaviour:
/home/steve/src/ub/ub_test.cpp:6:7: runtime error: signed integer overflow: 2147483647 + 1 cannot be represented in type 'int'
However, my test still passes.
[==========] Running 1 test from 1 test suite. [----------] Global test environment set-up. [----------] 1 test from test [ RUN ] test.test /home/steve/src/ub/ub_test.cpp:6:7: runtime error: signed integer overflow: 2147483647 + 1 cannot be represented in type 'int' [ OK ] test.test (0 ms) [----------] 1 test from test (0 ms total) [----------] Global test environment tear-down [==========] 1 test from 1 test suite ran. (0 ms total) [ PASSED ] 1 test.
Is it possible to trigger a test failure (throw an exception, exit 1, etc) when UBSAN finds an issue?
According to the documentation:
-fsanitize=...
: print a verbose error report and continue execution (default);
-fno-sanitize-recover=...
: print a verbose error report and exit the program;
-fsanitize-trap=...
: execute a trap instruction (doesn’t require UBSan run-time support).Note that the
trap
/recover
options do not enable the corresponding sanitizer, and in general need to be accompanied by a suitable-fsanitize=
flag.
It seems like when you use -fsanitize=
the exact same thing happens which you're talking about. It notices the undefined behavior and reports it, but continues execution. So appending a -fno-sanitize-recover=all
should exit the program.
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