Fix cmake clang build for sanitizers

[mellery451]

This fixes the cmake clang sanitizer build. I've tried both sanitizers on mac and linux and all of them fail for me in some way, so I'm not adding either build to jenkins until I can resolve that.

[seelabs]

We should keep the SConstruct in sync too. Adding a conditional to line 448 should work.

[ripplelabs-jenkins]

Jenkins Build Summary

Built from this commit

Built at 20180109 - 17:22:34

Test Results

Build Type	Result	Status
clang.debug.unity	970 cases, 0 failed, t: 386s	PASS ✅
coverage	970 cases, 0 failed, t: 609s	PASS ✅
gcc.debug.unity	970 cases, 0 failed, t: 432s	PASS ✅
clang.debug.nounity	968 cases, 0 failed, t: 754s	PASS ✅
gcc.debug.nounity	968 cases, 0 failed, t: 303s	PASS ✅
clang.release.unity	969 cases, 0 failed, t: 465s	PASS ✅
gcc.release.unity	969 cases, 0 failed, t: 505s	PASS ✅

[MarkusTeufelberger]

See also #2082 for ASAN/TSAN related problems

[seelabs]

👍

[scottschurr]

What's the correct way to enable one of the sanitizers? I tried

cmake -Dtarget=${BUILD_TYPE} -DSANITIZE_ADDRESS=On -Dassert=true ../../..

as suggested here: https://github.com/arsenm/sanitizers-cmake. Cmake responded:

CMake Warning:
  Manually-specified variables were not used by the project:

    SANITIZE_ADDRESS

so apparently that's not it.

I have the same question for scons as well...

[mellery451]

@scottschurr ... for cmake, add this during generation -Dsan=thread or -Dsan=address. For scons, I'm guessing it's --sanitize=thread or --sanitize=address, although I haven't tried it.

[scottschurr]

👍 Successfully built using cmake for TSAN and with scons for ASAN. Ran both resulting executables against the Flow unit test.

[seelabs]

In 0.90.0-b5