TensorBoard Support for UchenML

Libraries

Language level: C++20 Language features: everything, except exceptions. Code style guide: Google C++ Style Guide

Please do not add dependencies without discussing them first.

• ABSL - General C++ utilities. Use for logging, flags. Custom types are encouraged to support ABSL stringification.
• Google Test - Testing library

General principles

• Small build targets to allow clients only include functionality they need.
• Executable targets are simple bootstrap/flag parsing. All logic should be in libraries.

Setting up the environment

1. Clone the repository
2. Install Bazelisk: https://github.com/bazelbuild/bazelisk

Setting up Visual Studio Code

Preferred tool chain is Clang/LLVM. Clangd extension is recommended. I would strongly recommend installing the absolute latest version of Clangd from the LLVM website. The version in the Ubuntu repositories is very old and does not support many features.

1. Make sure Microsoft C++ tools are not installed.
2. Install the extensions in .vscode/extensions.json (may need to re)
3. Build compile_commands.json: bazel run @hedron_compile_commands//:refresh_all
4. Restart the Clangd daemon (Ctrl+Shift+P, Clangd: Restart) - only needed when DB is rebuilt.

Recipes

Bazel

• bazel build //... - build everything
• bazel test //... - run all tests. Use --test_output=all to see output from successful runs.
• bazel run //path/to:target - run a binary target
• bazel run //path/to:target -- --flag=value output_file - pass flags to the binary
• bazel test //path/to:target --test_output=all - run a single test with all output
• --config=clang after the verb (build/test/run) builds with Clang on Linux. --config=asan and --config=ubsan enable AddressSanitizer and UBSan, respectively. E.g. bazel test --config=asan --config=clang //... will run all tests with AddressSanitizer and Clang.
• --cxxopt passes flags to the compiler. E.g. --cxxopt=-march=native will build for your CPU, helpful with SIMD. --linkopt passes flags to the linker.

Logging

Rely on ABSL log. LOG(INFO) << "Hello, world!";

End-user binaries need to link with @abseil-cpp//absl/log:flags so logging can be configured with command line flags. E.g. flag --stderrthreshold=0 will log everything to stderr. Every binary should call absl::InitializeLog().

Test main fine should usually call absl::InitializeLog() and absl::SetStderrThreshold(INFO) so everything is logged when tests are ran.

In-depth guide: https://abseil.io/docs/cpp/guides/logging

Command-line flags

Use ABSL flags. See code for examples, refer to ABSL flags documentation.

Some extra build features

Compile with Clang on Linux

bazel build --config=clang //... will enable clang compiler and libc++ on Linux.

Sanitizers

bazel build --config=asan //... will enable AddressSanitizer. bazel build --config=ubsan //... will enable UBSan.

Feel free to add profiles for other sanitizers if necessary.