tree: 8f1cd003672058f5c9f1d57079e8299293fa61ef [path history] [tgz]
  1. formal_methods/
  2. inference/
  3. test/
  4. BUILD
  5. pointer_nullability.cc
  6. pointer_nullability.h
  7. pointer_nullability_analysis.cc
  8. pointer_nullability_analysis.h
  9. pointer_nullability_analysis_benchmark.cc
  10. pointer_nullability_analysis_test.cc
  11. pointer_nullability_diagnosis.cc
  12. pointer_nullability_diagnosis.h
  13. pointer_nullability_lattice.cc
  14. pointer_nullability_lattice.h
  15. pointer_nullability_matchers.cc
  16. pointer_nullability_matchers.h
  17. pointer_nullability_matchers_test.cc
  18. pointer_nullability_test.cc
  19. proto_matchers.cc
  20. proto_matchers.h
  21. README.md
  22. type_nullability.cc
  23. type_nullability.h
  24. type_nullability_test.cc
nullability/README.md

C++ nullability analysis

Annotating C++ API boundaries with nullability information can improve their Rust bindings (e.g. binding non-null pointers as T& rather than Option<T&>).

This directory has tools for C++ codebases that use such annotations:

  • Nullability inference suggests annotations to add to APIs, by analyzing the code that implements and uses them.

  • Nullability verification verifies that annotated APIs are used and implemented safely, e.g. checking nullable pointers before dereferencing them. This is a local analysis suitable for use in a clang-tidy check.

They use Clang, its dataflow framework, and its nullability annotations.

Style

This directory mostly uses LLVM-style C++, rather than Google-style C++ used in the rest of crubit/. The goal is to make it easy to upstream into clang-tidy once mature.

Specifically:

  • We follow the LLVM coding standards, with the exceptions listed here.
  • We use absl CHECK() rather than assert(). (This finds bugs more reliably, and is trivial to migrate later.)
  • We otherwise avoid relying on absl, using llvm's Support libraries instead.
  • We write // TODO instead of // FIXME.

This list isn‘t set in stone: we can choose to diverge further from LLVM style, if it’s worth more cost of upstreaming later.