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pigweed / third_party / github / bazelbuild / rules_rust / a1d8936161beddadddd17d2b1c335ceac77d1d53
commita1d8936161beddadddd17d2b1c335ceac77d1d53[log] [tgz]
authorDavid Freese <dvfreese@gmail.com>Sat Apr 11 16:55:49 2020 -0700
committerGitHub <noreply@github.com>Sat Apr 11 19:55:49 2020 -0400
treef3811f59305e727d9c57610ccb20ba2e3f7cca7e
parentfe50d3b54aecbaeac48abdc2ca7cd00a94969e15 [diff]
Add cfg = proc_macro_host_transition to all rules (#301)

The rust_library rule specifies a cfg option.  This performs transitions
in order to support WASM.  Other rules, such as rust_binary, do not have
this configuration, which causes Bazel to build and link some libraries
into the final binary twice, resulting in compilation errors.  This is
detailed in pull request #294 and issue #300.  The issue was introduced
in commit 7cde1e46.

This adds the example from @colin353 in PR #294 as an example that would
otherwise fail.

Fixes #300
5 files changed
tree: f3811f59305e727d9c57610ccb20ba2e3f7cca7e
  1. .bazelci/
  2. bindgen/
  3. docs/
  4. examples/
  5. proto/
  6. rust/
  7. test/
  8. tools/
  9. util/
  10. wasm_bindgen/
  11. .gitignore
  12. AUTHORS
  13. BUILD
  14. CODEOWNERS
  15. CONTRIBUTING.md
  16. CONTRIBUTORS
  17. libc.BUILD
  18. LICENSE.txt
  19. package-lock.json
  20. package.json
  21. README.md
  22. renovate.json
  23. WORKSPACE
  24. workspace.bzl
README.md

Rust Rules

  • Postsubmit Build status
  • Postsubmit + Current Bazel Incompatible Flags Build status

Overview

This repository provides rules for building Rust projects with Bazel.

Basics

WebAssembly

To build a rust_binary for wasm32-unknown-unknown add the --platforms=//rust/platform:wasm flag.

bazel build @examples//hello_world_wasm --platforms=//rust/platform:wasm

rust_wasm_bindgen will automatically transition to the wasm platform and can be used when building wasm code for the host target.

Protobuf

with an overview here.

Setup

To use the Rust rules, add the following to your WORKSPACE file to add the external repositories for the Rust toolchain:

load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")

http_archive(
    name = "io_bazel_rules_rust",
    sha256 = "b6da34e057a31b8a85e343c732de4af92a762f804fc36b0baa6c001423a70ebc",
    strip_prefix = "rules_rust-55f77017a7f5b08e525ebeab6e11d8896a4499d2",
    urls = [
        # Master branch as of 2019-10-07
        "https://github.com/bazelbuild/rules_rust/archive/55f77017a7f5b08e525ebeab6e11d8896a4499d2.tar.gz",
    ],
)

http_archive(
    name = "bazel_skylib",
    sha256 = "9a737999532daca978a158f94e77e9af6a6a169709c0cee274f0a4c3359519bd",
    strip_prefix = "bazel-skylib-1.0.0",
    url = "https://github.com/bazelbuild/bazel-skylib/archive/1.0.0.tar.gz",
)

load("@io_bazel_rules_rust//rust:repositories.bzl", "rust_repositories")
rust_repositories()

load("@io_bazel_rules_rust//:workspace.bzl", "bazel_version")
bazel_version(name = "bazel_version")

The rules are under active development, as such the lastest commit on the master branch should be used. master currently requires Bazel >= 0.26.0.

External Dependencies

Currently the most common approach to managing external dependencies is using cargo-raze to generate BUILD files for Cargo crates.

Roadmap

  • Improve expressiveness of features and support for Cargo's feature groups.
  • Add cargo_crate workspace rule for pulling crates from Cargo.