Fix issue LLVM linking with libclamav_rust test executable

[teoberi]

Fix for issue "Clamav 0.105.0 test libclamav_rust failed #569"

[val-ms]

This makes sense to me, and seems like a reasonable solution. I didn't see any adverse effects in testing.

[val-ms]

Actually, I'm not entirely happy with the location where this is stripped. It is stripped before building a specific test executable, (check_fpu_endian), and just happens to propagate down to the libclamav_rust through the LLVM_LIBS environment variable. That makes it feel kind of hacky to me, and easy to accidentally break in the future.

It would be better to either do it:
A) just after LLVM_LIBRARIES is first defined in FindLLVM.cmake, here: https://github.com/Cisco-Talos/clamav/blob/main/cmake/FindLLVM.cmake#L154
or B) to the LLVM_LIBS variable just after LLVM_LIBS is created, here: https://github.com/Cisco-Talos/clamav/blob/main/unit_tests/CMakeLists.txt#L172

@teoberi would you please give one of these options a try to ensure it also resolves the issue and doesn't break anything else in your environment?

If you like, I can make the edit directly to your teoberi-fix-test-libclamav_rust branch.

[teoberi]

I use Slackware64-current (development tree) on all my servers where it has already been switched to LLVM 14.0.6.
I no longer have any server with LLVM 13.0.1 and the build with LLVM 14.0.6 crashes at cmake --build . --config Release before I get to the ctest.
So in conclusion for Slackware I am stuck until problems related to building with LLVM 14 is solved.

[val-ms]

Okay understood. I should've realized that based on our conversations in other issues. Okay I'll tweak it myself and test it as best I can.

[teoberi]

I tested in a virtual machine with Slackware64-current and LLVM 13 the proposed solutions:
A) just after LLVM_LIBRARIES is first defined in FindLLVM.cmake -> it works

Test project /usr/local/src/clamav-0.105.0/build
Start 1: libclamav
1/6 Test 1: libclamav ........................ Passed 42.09 sec
Start 2: libclamav_rust
2/6 Test 2: libclamav_rust ................... Passed 0.38 sec
Start 3: clamscan
3/6 Test 3: clamscan ......................... Passed 10.93 sec
Start 4: clamd
4/6 Test 4: clamd ............................ Passed 29.23 sec
Start 5: freshclam
5/6 Test 5: freshclam ........................ Passed 4.18 sec
Start 6: sigtool
6/6 Test 6: sigtool .......................... Passed 1.00 sec

100% tests passed, 0 tests failed out of 6

Total Test time (real) = 87.83 sec

B) to the LLVM_LIBS variable just after LLVM_LIBS is created -> it works

Test project /usr/local/src/clamav-0.105.0/build
Start 1: libclamav
1/6 Test 1: libclamav ........................ Passed 43.09 sec
Start 2: libclamav_rust
2/6 Test 2: libclamav_rust ................... Passed 0.38 sec
Start 3: clamscan
3/6 Test 3: clamscan ......................... Passed 10.88 sec
Start 4: clamd
4/6 Test 4: clamd ............................ Passed 28.37 sec
Start 5: freshclam
5/6 Test 5: freshclam ........................ Passed 4.15 sec
Start 6: sigtool
6/6 Test 6: sigtool .......................... Passed 0.97 sec

100% tests passed, 0 tests failed out of 6

Total Test time (real) = 87.85 sec

I will test this again after solving the problems related to the build with LLVM 14 as a stage in the process of returning to Clamav.
Clamav was one of the first packages I builded in my early days in Linux I don't know how many years ago.

[val-ms]

Awesome thanks @teoberi for testing.