I'm trying to make an application that runs some unit tests using GoogleTest but the tests in the test files outside of the main file are not discovered by GoogleTest.
I have 2 test files:
main_test.cpp:
#include <gtest/gtest.h>
TEST(MainTest, Test1) {
EXPECT_EQ(1,1);
}
int main(int argc, char* argv[]) {
testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
external_test.cpp:
#include <gtest/gtest.h>
TEST(ExternalTest, Test1) {
EXPECT_EQ(1,1);
}
ExternalTest is never discovered and run when I try and build with my build system.
These are the commands that my build system uses to build this app and it seemingly optimizes out the functions in external_test.cpp:
clang++ -c googletest/googletest/src/gtest-all.cc -o build/gtest -Igoogletest/googletest/include/ -Igoogletest/googletest/ -std=c++17
clang++ -c external_test.cpp -o build/external_test -Igoogletest/googletest/include/ -Igoogletest/googletest/ -std=c++17
clang++ -c main_test.cpp -o build/main_test -Igoogletest/googletest/include/ -Igoogletest/googletest/ -std=c++17
cd build
libtool -o test_app.lib main_test gtest external_test
clang++ test_app.lib
Result:
./a.out
[==========] Running 1 test from 1 test suite.
[----------] Global test environment set-up.
[----------] 1 test from MainTest
[ RUN ] MainTest.Test1
[ OK ] MainTest.Test1 (0 ms)
[----------] 1 test from MainTest (0 ms total)
[----------] Global test environment tear-down
[==========] 1 test from 1 test suite ran. (0 ms total)
[ PASSED ] 1 test.
If I build like so:
clang++ -c googletest/googletest/src/gtest-all.cc -o build/gtest -Igoogletest/googletest/include/ -Igoogletest/googletest/ -std=c++17
clang++ -c external_test.cpp -o build/external_test -Igoogletest/googletest/include/ -Igoogletest/googletest/ -std=c++17
clang++ -c main_test.cpp -o build/main_test -Igoogletest/googletest/include/ -Igoogletest/googletest/ -std=c++17
cd build
clang++ external_test gtest main_test
I get the expected result:
./a.out
[==========] Running 2 tests from 2 test suites.
[----------] Global test environment set-up.
[----------] 1 test from ExternalTest
[ RUN ] ExternalTest.Test1
[ OK ] ExternalTest.Test1 (0 ms)
[----------] 1 test from ExternalTest (0 ms total)
[----------] 1 test from MainTest
[ RUN ] MainTest.Test1
[ OK ] MainTest.Test1 (0 ms)
[----------] 1 test from MainTest (0 ms total)
[----------] Global test environment tear-down
[==========] 2 tests from 2 test suites ran. (0 ms total)
[ PASSED ] 2 tests.
But our build system needs to generate the lib file and then link. Also, if I create some function foo in external_test.cpp, and then declare that function as extern in main_test.cpp and call it in the main function - then all tests are discovered correctly.
My theory is that libtool and clang++ somehow preform some link time optimization and remove the tests. I've tried adding the -fno-lto flag to no avail.
Does anyone have any ideas? Any help would be greatly appreciated.
