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bazel / crubit / 1750cdcf8329eeda04e7abfc79d56491cc3302ec
commit1750cdcf8329eeda04e7abfc79d56491cc3302ec[log] [tgz]
authorMartin Brænne <mboehme@google.com>Tue Jul 16 06:23:55 2024 -0700
committerCopybara-Service <copybara-worker@google.com>Tue Jul 16 06:25:21 2024 -0700
treebaedff57e91df7e758f67a81535ba34290256858
parent50bfbb83da1709e6e6cdf9a0d88da639f74a306c [diff]
[nullability] Collect evidence from the state before transfer function ran.

As for diagnosis (see a [similar
change](https://github.com/google/crubit/commit/2495238521651a34b79f08c8e13ed457dbfb5474)
made there recently), it makes more sense to perform evidence collection before
the transfer function is run (instead of after), as we know what the
preconditions for the operation are and can therefore, from these preconditions,
collect evidence for what the input values of the operation should be.

This patch not only fixes a regression in
CollectEvidenceFromDefinitionTest.Arithmetic caused by a recent upstream change,
but it also fixes existing wrong behavior in
CollectEvidenceFromDefinitionTest.ReferenceArgsPassed.

It also makes evidence collection for assignment more natural (see the lengthy
comment that previously existed and that this patch now eliminates).

PiperOrigin-RevId: 652814773
Change-Id: Iedf97419beb60a5d628a381e0072370fd755df46
2 files changed
tree: baedff57e91df7e758f67a81535ba34290256858
  1. .bazelci/
  2. bazel/
  3. cc_bindings_from_rs/
  4. common/
  5. docs/
  6. examples/
  7. features/
  8. lifetime_analysis/
  9. lifetime_annotations/
  10. migrator/
  11. nullability/
  12. rs_bindings_from_cc/
  13. support/
  14. .bazelrc
  15. .gitignore
  16. BUILD
  17. Cargo.lock
  18. CODE_OF_CONDUCT
  19. CONTRIBUTING
  20. LICENSE
  21. MODULE.bazel
  22. README.md
  23. WORKSPACE.bzlmod
README.md

Crubit: C++/Rust Bidirectional Interop Tool

Build status

NOTE: Crubit currently expects deep integration with the build system, and is difficult to deploy to environments dissimilar to Google's monorepo. We do not have our tooling set up to accept external contributions at this time.

Crubit is a bidirectional bindings generator for C++ and Rust, with the goal of integrating the C++ and Rust ecosystems.

Status

Support for calling FFI-friendly C++ from Rust is in progress.

Support for calling Rust from C++ will arrive in 2024H2.

Example

Consider the following C++ function:

extern "C" bool IsGreater(int lhs, int rhs);

This function, if present in a header file which is processed by Crubit, becomes callable from Rust as if it were defined as:

pub fn IsGreater(lhs: ffi::c_int, rhs: ffi::c_int) -> bool {...}

Note: There are some temporary restrictions on the API shape. For example, functions that are not extern "C", or that accept a type like std::string, can't be called from Rust directly via Crubit. These restrictions will be relaxed over time.

Getting Started

Here are some resources for getting started with Crubit:

  • Rust Bindings for C++ Libraries is a detailed walkthrough on how to use C++ from Rust using Crubit.

  • The examples/cpp/ directory has copy-pastable examples of calling C++ from Rust, together with snapshots of what the generated Rust interface looks like.

Building Crubit

$ apt install clang lld bazel
$ git clone git@github.com:google/crubit.git
$ cd crubit
$ bazel build --linkopt=-fuse-ld=/usr/bin/ld.lld //rs_bindings_from_cc:rs_bindings_from_cc_impl

Using a prebuilt LLVM tree

$ git clone https://github.com/llvm/llvm-project
$ cd llvm-project
$ CC=clang CXX=clang++ cmake -S llvm -B build -DLLVM_ENABLE_PROJECTS='clang' -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=install
$ cmake --build build -j
$ # wait...
$ cmake --install build
$ cd ../crubit
$ LLVM_INSTALL_PATH=../llvm-project/install bazel build //rs_bindings_from_cc:rs_bindings_from_cc_impl