tests.cc-wrapper: skip known-broken sanitizer cases

[Ralith]

Motivation for this change

Fixes overly-broad testing due to #41065. Let me know if there's a better way to test for libc++ being in use.

CC @Ericson2314 @LnL7

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option build-use-sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Fits CONTRIBUTING.md.

---

[LnL7]

What about introducing libcxx similar to libc we have now? I think we want to add that in the future anyway to get rid of the default_cxx_stdlib_compile hack.

[Ralith]

Is there documentation anywhere of what exactly the libc we have now is?

[Ericson2314]

Hmm so this doesn't affect the libstdc++ ones? That's very very odd, as the sanitizer runtimes don't come from either.

[Ralith]

Whoops, looks like that's an issue too.

Is there any way to run all the affected tests, so I don't have to keep making slightly inaccurate guesses about what to try?

[Ericson2314]

Sadly I don't know of an easy way to replicate what hydra does, as conceptually simple as it is.

[Ericson2314]

Anyways looks good now. The condition makes sense in theory to me. Thanks for fixing.

[matthewbauer]

@Ralith Do you know what's going on with this latest error:

https://hydra.nixos.org/build/75406498/nixlog/1

ld: file not found: /nix/store/wdiibxx7221iiv8cdgdafgbmkvb58bw9-clang-wrapper-6.0.0/resource-root/lib/darwin/libclang_rt.asan_osx_dynamic.dylib
clang-6.0: error: linker command failed with exit code 1 (use -v to see invocation)
builder for '/nix/store/ih843k6q8xv3xbakp7r370377z18wnci-cc-wrapper-test.drv' failed with exit code 1

[Ralith]

Looks like the test is doing its job and identifying that asan is broken under that configuration, perhaps (but not necessarily) due to changes introduced by #41065. In particular, runtime libraries that at least on linux are provided by compiler-rt aren't being found, though it appears to be looking in at least approximately the right place. The output of find -L /nix/store/wdiibxx7221iiv8cdgdafgbmkvb58bw9-clang-wrapper-6.0.0/resource-root/ would be interesting. I don't have a darwin machine to test on myself.

[orivej]

I have verified that sanitizers did not work on Darwin neither when #39743 was merged in 713d580 [1], nor directly before that in ae99562 [2]. Therefore it is reasonable to disable sanitizer tests on Darwin for now.

[1] With tests.cc-wrapper-clang-6 the error is ld: file not found: /nix/store/2qfdihv2x3m6da4bpv9jpi1qwlnzkns6-clang-wrapper-6.0.0/resource-root/lib/darwin/libclang_rt.asan_osx_dynamic.dylib. File tree:

/nix/store/2qfdihv2x3m6da4bpv9jpi1qwlnzkns6-clang-wrapper-6.0.0/resource-root/lib
└── darwin
    ├── libclang_rt.10.4.a
    ├── libclang_rt.cc_kext.a
    └── libclang_rt.osx.a

With tests.cc-wrapper-gcc, the error is the the same as in [2].

[2] The error is:

/nix/store/3c3vrabg4yy87y4qx8zsy5x2vdg132j5-sanitizers.c:1:10: fatal error: 'sanitizer/asan_interface.h' file not found
#include <sanitizer/asan_interface.h>

[orivej]

Disabled sanitizer tests on Darwin in 07ebb8b.

[Ralith]

Thanks for handling that! I wonder why the asan stuff is missing. Maybe some option we need to pass to the compiler-rt build, or perhaps one of our darwin-specific patches or options is disabling it.