Assert fails in llvm::BitcodeWriter::~BitcodeWriter() during some tests

[sogartar]

🐛 Bug

When running some of the tests and LLVM is built in debug, an assert in fails llvm::BitcodeWriter::~BitcodeWriter().

I encountered this when doing the CMake build PR. There LLVM could be built in debug, wheres it seems the Bazel build uses a prebuilt release version, so the assert is suppressed.
It appears in tests related to SHA.

To Reproduce

Steps to reproduce the behavior:

1. Checkout https://github.com/sogartar/CompilerGym/tree/boian-cmake-2 and build with CMake in debug. Use -DCMAKE_BUILD_TYPE=debug as an argument during configuration.
2. Run the tests from the binary directory with

   ctest -j5 -R tests/fuzzing/llvm_stress_fuzz_test\|tests/llvm/fresh_environment_observation_reward_test\|tests/llvm/llvm_env_test\|tests/llvm/observation_spaces_test\|tests/llvm/validation_regression_test
   

One of the errors that appears:

compiler_gym-llvm-service: /home/petkantchin/ws/nodlabs/compiler_gym/build/ninja/debug/external/llvm/llvm/src/llvm/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp:4370: llvm::BitcodeWriter::~BitcodeWriter(): Assertion `WroteStrtab' failed.

LastTest.log

Expected behavior

No assert should be triggered.
It may be the case that there should be no assert in the LLVM code.

Environment

Please fill in this checklist:

• CompilerGym: https://github.com/sogartar/CompilerGym/tree/boian-cmake-2
• How you installed CompilerGym (conda, pip, source): source
• OS: Ubuntu 20.04
• Python version: 3.8
• Build command you used (if compiling from source): build instructions for CMake from INSTALL.md
• GCC/clang version (if compiling from source): clang-9
• Bazel version (if compiling from source):
• Versions of any other relevant libraries: LLVM in debug

[ChrisCummins]

Hi @sogartar, thanks for the report!

Without being familiar with the code, I had a bit of a hard time understanding why this assert is thrown given the lack of comments: https://github.com/llvm/llvm-project/blob/d32170dbd5b0d54436537b6b75beaf44324e0c28/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp#L4370

However it seems like the problem will go away if I just swap one API call for another. I'm going to post a PR, would you mind checking if this fixes the debug build?

Cheers,
Chris

[sogartar]

I just ran the failing tests against the PR. Here is the log LastTest.log.

I noticed that this assert does not fail. The tests/llvm/llvm_env_test test now passes.

The other tests are still failing. Namely,

• tests/fuzzing/llvm_stress_fuzz_test
• tests/llvm/fresh_environment_observation_reward_test
• tests/llvm/observation_spaces_test
• tests/llvm/validation_regression_test

Most likely the other errors are unrelated to BitcodeWriter's destructor.

All tests "generally" pass under release build.

tests/llvm/validation_regression_test occasionally hangs under release.
On one occasion tests/fuzzing/llvm_stress_fuzz_test failed with LastTest.log.
I am not sure these problems are related only to this PR.

[ChrisCummins]

Hi @sogartar, I'm just going back over some issues. Was this one fixed? I'm not sure why I closed it :)

[sogartar]

This is fixed.

[ChrisCummins]

Ok thanks!