Rust rules

crate_universe

A rule for downloading Rust dependencies (crates).

WARNING: This rule experimental and subject to change without warning.

Environment Variables:

  • REPIN: Re-pin the lockfile if set (useful for repinning deps from multiple rulesets).
  • RULES_RUST_REPIN: Re-pin the lockfile if set (useful for only repinning Rust deps).
  • RULES_RUST_CRATE_UNIVERSE_RESOLVER_URL_OVERRIDE: Override URL to use to download resolver binary
    • for local paths use a file:// URL.
  • RULES_RUST_CRATE_UNIVERSE_RESOLVER_URL_OVERRIDE_SHA256: An optional sha256 value for the binary at the override url location.

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this repository.Namerequired
cargo_toml_filesA list of Cargo manifests (Cargo.toml files).List of labelsoptional[]
crate_registry_templateA template for where to download crates from for the default crate registry. This must contain {version} and {crate} templates.Stringoptionalhttps://crates.io/api/v1/crates/{crate}/{version}/download
lockfileThe path to a file which stores pinned information about the generated dependency graph. this target must be a file and will be updated by the repository rule when the REPIN environment variable is set. If this is not set, dependencies will be re-resolved more often, setting this allows caching resolves, but will error if the cache is stale.LabeloptionalNone
overridesMapping of crate name to specification overrides. See crate.override for more details.Dictionary: String -> Stringoptional{}
packagesA list of crate specifications. See crate.spec for more details.List of stringsoptional[]
repo_mappingA dictionary from local repository name to global repository name. This allows controls over workspace dependency resolution for dependencies of this repository.<p>For example, an entry “@foo”: “@bar” declares that, for any time this repository depends on @foo (such as a dependency on @foo//some:target, it should actually resolve that dependency within globally-declared @bar (@bar//some:target).Dictionary: String -> Stringrequired
resolver_download_url_templateURL template from which to download the resolver binary. {host_triple} and {extension} will be filled in according to the host platform.Stringoptional“{host_triple}{extension}”
resolver_sha256sDictionary of host_triple -> sha256 for resolver binary.Dictionary: String -> Stringoptional{“aarch64-apple-darwin”: “{aarch64-apple-darwin--sha256}”, “aarch64-unknown-linux-gnu”: “{aarch64-unknown-linux-gnu--sha256}”, “x86_64-apple-darwin”: “{x86_64-apple-darwin--sha256}”, “x86_64-pc-windows-gnu”: “{x86_64-pc-windows-gnu--sha256}”, “x86_64-unknown-linux-gnu”: “{x86_64-unknown-linux-gnu--sha256}”}
supported_targetsA list of supported platform triples to consider when resoliving dependencies.List of stringsoptional[“aarch64-apple-darwin”, “aarch64-unknown-linux-gnu”, “x86_64-apple-darwin”, “x86_64-pc-windows-msvc”, “x86_64-unknown-freebsd”, “x86_64-unknown-linux-gnu”]

rust_analyzer

Produces a rust-project.json for the given targets. Configure rust-analyzer to load the generated file via the linked projects mechanism.

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired
targetsList of all targets to be included in the indexList of labelsoptional[]

rust_benchmark

Builds a Rust benchmark test.

Warning: This rule is currently experimental. Rust Benchmark tests require the Bencher interface in the unstable libtest crate, which is behind the test unstable feature gate. As a result, using this rule would require using a nightly binary release of Rust.

Example:

Suppose you have the following directory structure for a Rust project with a library crate, fibonacci with benchmarks under the benches/ directory:

[workspace]/
WORKSPACE
fibonacci/
    BUILD
    src/
        lib.rs
    benches/
        fibonacci_bench.rs

fibonacci/src/lib.rs:

pub fn fibonacci(n: u64) -> u64 {
    if n < 2 {
        return n;
    }
    let mut n1: u64 = 0;
    let mut n2: u64 = 1;
    for _ in 1..n {
        let sum = n1 + n2;
        n1 = n2;
        n2 = sum;
    }
    n2
}

fibonacci/benches/fibonacci_bench.rs:

#![feature(test)]

extern crate test;
extern crate fibonacci;

use test::Bencher;

#[bench]
fn bench_fibonacci(b: &mut Bencher) {
    b.iter(|| fibonacci::fibonacci(40));
}

To build the benchmark test, add a rust_benchmark target:

fibonacci/BUILD:

package(default_visibility = ["//visibility:public"])

load("@rules_rust//rust:defs.bzl", "rust_library", "rust_benchmark")

rust_library(
name = "fibonacci",
srcs = ["src/lib.rs"],
)

rust_benchmark(
name = "fibonacci_bench",
srcs = ["benches/fibonacci_bench.rs"],
deps = [":fibonacci"],
)

Run the benchmark test using: bazel run //fibonacci:fibonacci_bench.

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired
aliasesRemap crates to a new name or moniker for linkage to this target

These are other rust_library targets and will be presented as the new name given.
Dictionary: Label -> Stringoptional{}
compile_dataList of files used by this rule at compile time.

This attribute can be used to specify any data files that are embedded into the library, such as via the include_str! macro.
List of labelsoptional[]
crate_featuresList of features to enable for this crate.

Features are defined in the code using the #[cfg(feature = “foo”)] configuration option. The features listed here will be passed to rustc with --cfg feature=“${feature_name}” flags.
List of stringsoptional[]
crate_nameCrate name to use for this target.

This must be a valid Rust identifier, i.e. it may contain only alphanumeric characters and underscores. Defaults to the target name, with any hyphens replaced by underscores.
Stringoptional""
crate_rootThe file that will be passed to rustc to be used for building this crate.

If crate_root is not set, then this rule will look for a lib.rs file (or main.rs for rust_binary) or the single file in srcs if srcs contains only one file.
LabeloptionalNone
dataList of files used by this rule at compile time and runtime.

If including data at compile time with include_str!() and similar, prefer compile_data over data, to prevent the data also being included in the runfiles.
List of labelsoptional[]
depsList of other libraries to be linked to this library target.

These can be either other rust_library targets or cc_library targets if linking a native library.
List of labelsoptional[]
editionThe rust edition to use for this crate. Defaults to the edition specified in the rust_toolchain.Stringoptional""
out_dir_tarDeprecated, do not use, see [#cargo_build_script] instead.LabeloptionalNone
proc_macro_depsList of rust_library targets with kind proc-macro used to help build this library target.List of labelsoptional[]
rustc_envDictionary of additional “key”: “value” environment variables to set for rustc.

rust_test()/rust_binary() rules can use $(rootpath //package:target) to pass in the location of a generated file or external tool. Cargo build scripts that wish to expand locations should use cargo_build_script()'s build_script_env argument instead, as build scripts are run in a different environment - see cargo_build_script()'s documentation for more.
Dictionary: String -> Stringoptional{}
rustc_env_filesFiles containing additional environment variables to set for rustc.

These files should contain a single variable per line, of format NAME=value, and newlines may be included in a value by ending a line with a trailing back-slash (</code>).

The order that these files will be processed is unspecified, so multiple definitions of a particular variable are discouraged.
List of labelsoptional[]
rustc_flagsList of compiler flags passed to rustc.List of stringsoptional[]
srcsList of Rust .rs source files used to build the library.

If srcs contains more than one file, then there must be a file either named lib.rs. Otherwise, crate_root must be set to the source file that is the root of the crate to be passed to rustc to build this crate.
List of labelsoptional[]
versionA version to inject in the cargo environment variable.Stringoptional“0.0.0”

rust_binary

Builds a Rust binary crate.

Example:

Suppose you have the following directory structure for a Rust project with a library crate, hello_lib, and a binary crate, hello_world that uses the hello_lib library:

[workspace]/
    WORKSPACE
    hello_lib/
        BUILD
        src/
            lib.rs
    hello_world/
        BUILD
        src/
            main.rs

hello_lib/src/lib.rs:

pub struct Greeter {
    greeting: String,
}

impl Greeter {
    pub fn new(greeting: &str) -> Greeter {
        Greeter { greeting: greeting.to_string(), }
    }

    pub fn greet(&self, thing: &str) {
        println!("{} {}", &self.greeting, thing);
    }
}

hello_lib/BUILD:

package(default_visibility = ["//visibility:public"])

load("@rules_rust//rust:rust.bzl", "rust_library")

rust_library(
    name = "hello_lib",
    srcs = ["src/lib.rs"],
)

hello_world/src/main.rs:

extern crate hello_lib;

fn main() {
    let hello = hello_lib::Greeter::new("Hello");
    hello.greet("world");
}

hello_world/BUILD:

load("@rules_rust//rust:rust.bzl", "rust_binary")

rust_binary(
    name = "hello_world",
    srcs = ["src/main.rs"],
    deps = ["//hello_lib"],
)

Build and run hello_world:

$ bazel run //hello_world
INFO: Found 1 target...
Target //examples/rust/hello_world:hello_world up-to-date:
bazel-bin/examples/rust/hello_world/hello_world
INFO: Elapsed time: 1.308s, Critical Path: 1.22s

INFO: Running command line: bazel-bin/examples/rust/hello_world/hello_world
Hello world

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired
aliasesRemap crates to a new name or moniker for linkage to this target

These are other rust_library targets and will be presented as the new name given.
Dictionary: Label -> Stringoptional{}
compile_dataList of files used by this rule at compile time.

This attribute can be used to specify any data files that are embedded into the library, such as via the include_str! macro.
List of labelsoptional[]
crate_featuresList of features to enable for this crate.

Features are defined in the code using the #[cfg(feature = “foo”)] configuration option. The features listed here will be passed to rustc with --cfg feature=“${feature_name}” flags.
List of stringsoptional[]
crate_nameCrate name to use for this target.

This must be a valid Rust identifier, i.e. it may contain only alphanumeric characters and underscores. Defaults to the target name, with any hyphens replaced by underscores.
Stringoptional""
crate_rootThe file that will be passed to rustc to be used for building this crate.

If crate_root is not set, then this rule will look for a lib.rs file (or main.rs for rust_binary) or the single file in srcs if srcs contains only one file.
LabeloptionalNone
crate_typeCrate type that will be passed to rustc to be used for building this crate.

This option is a temporary workaround and should be used only when building for WebAssembly targets (//rust/platform:wasi and //rust/platform:wasm).
Stringoptional“bin”
dataList of files used by this rule at compile time and runtime.

If including data at compile time with include_str!() and similar, prefer compile_data over data, to prevent the data also being included in the runfiles.
List of labelsoptional[]
depsList of other libraries to be linked to this library target.

These can be either other rust_library targets or cc_library targets if linking a native library.
List of labelsoptional[]
editionThe rust edition to use for this crate. Defaults to the edition specified in the rust_toolchain.Stringoptional""
linker_scriptLink script to forward into linker via rustc options.LabeloptionalNone
out_binary-BooleanoptionalFalse
out_dir_tarDeprecated, do not use, see [#cargo_build_script] instead.LabeloptionalNone
proc_macro_depsList of rust_library targets with kind proc-macro used to help build this library target.List of labelsoptional[]
rustc_envDictionary of additional “key”: “value” environment variables to set for rustc.

rust_test()/rust_binary() rules can use $(rootpath //package:target) to pass in the location of a generated file or external tool. Cargo build scripts that wish to expand locations should use cargo_build_script()'s build_script_env argument instead, as build scripts are run in a different environment - see cargo_build_script()'s documentation for more.
Dictionary: String -> Stringoptional{}
rustc_env_filesFiles containing additional environment variables to set for rustc.

These files should contain a single variable per line, of format NAME=value, and newlines may be included in a value by ending a line with a trailing back-slash (</code>).

The order that these files will be processed is unspecified, so multiple definitions of a particular variable are discouraged.
List of labelsoptional[]
rustc_flagsList of compiler flags passed to rustc.List of stringsoptional[]
srcsList of Rust .rs source files used to build the library.

If srcs contains more than one file, then there must be a file either named lib.rs. Otherwise, crate_root must be set to the source file that is the root of the crate to be passed to rustc to build this crate.
List of labelsoptional[]
versionA version to inject in the cargo environment variable.Stringoptional“0.0.0”

rust_bindgen

Generates a rust source file from a cc_library and a header.

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired
bindgen_flagsFlags to pass directly to the bindgen executable. See https://rust-lang.github.io/rust-bindgen/ for details.List of stringsoptional[]
cc_libThe cc_library that contains the .h file. This is used to find the transitive includes.LabeloptionalNone
clang_flagsFlags to pass directly to the clang executable.List of stringsoptional[]
headerThe .h file to generate bindings for.LabeloptionalNone

rust_bindgen_toolchain

The tools required for the rust_bindgen rule.

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired
bindgenThe label of a bindgen executable.LabeloptionalNone
clangThe label of a clang executable.LabeloptionalNone
libclangA cc_library that provides bindgen's runtime dependency on libclang.LabeloptionalNone
libstdcxxA cc_library that satisfies libclang's libstdc++ dependency.LabeloptionalNone
rustfmtThe label of a rustfmt executable. If this is provided, generated sources will be formatted.LabeloptionalNone

rust_clippy

Executes the clippy checker on a specific target.

Similar to rust_clippy_aspect, but allows specifying a list of dependencies within the build system.

For example, given the following example targets:

load("@rules_rust//rust:defs.bzl", "rust_library", "rust_test")

rust_library(
    name = "hello_lib",
    srcs = ["src/lib.rs"],
)

rust_test(
    name = "greeting_test",
    srcs = ["tests/greeting.rs"],
    deps = [":hello_lib"],
)

Rust clippy can be set as a build target with the following:

load("@rules_rust//rust:defs.bzl", "rust_clippy")

rust_clippy(
    name = "hello_library_clippy",
    testonly = True,
    deps = [
        ":hello_lib",
        ":greeting_test",
    ],
)

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired
depsRust targets to run clippy on.List of labelsoptional[]

rust_doc

Generates code documentation.

Example: Suppose you have the following directory structure for a Rust library crate:

[workspace]/
    WORKSPACE
    hello_lib/
        BUILD
        src/
            lib.rs

To build rustdoc documentation for the hello_lib crate, define a rust_doc rule that depends on the the hello_lib rust_library target:

package(default_visibility = ["//visibility:public"])

load("@rules_rust//rust:rust.bzl", "rust_library", "rust_doc")

rust_library(
    name = "hello_lib",
    srcs = ["src/lib.rs"],
)

rust_doc(
    name = "hello_lib_doc",
    dep = ":hello_lib",
)

Running bazel build //hello_lib:hello_lib_doc will build a zip file containing the documentation for the hello_lib library crate generated by rustdoc.

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired
depThe label of the target to generate code documentation for.

rust_doc can generate HTML code documentation for the source files of rust_library or rust_binary targets.
Labelrequired
html_after_contentFile to add in <body>, after content.LabeloptionalNone
html_before_contentFile to add in <body>, before content.LabeloptionalNone
html_in_headerFile to add to <head>.LabeloptionalNone
markdown_cssCSS files to include via <link> in a rendered Markdown file.List of labelsoptional[]

rust_doc_test

Runs Rust documentation tests.

Example:

Suppose you have the following directory structure for a Rust library crate:

[workspace]/
  WORKSPACE
  hello_lib/
      BUILD
      src/
          lib.rs

To run documentation tests for the hello_lib crate, define a rust_doc_test target that depends on the hello_lib rust_library target:

package(default_visibility = ["//visibility:public"])

load("@rules_rust//rust:rust.bzl", "rust_library", "rust_doc_test")

rust_library(
    name = "hello_lib",
    srcs = ["src/lib.rs"],
)

rust_doc_test(
    name = "hello_lib_doc_test",
    dep = ":hello_lib",
)

Running bazel test //hello_lib:hello_lib_doc_test will run all documentation tests for the hello_lib library crate.

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired
depThe label of the target to run documentation tests for.

rust_doc_test can run documentation tests for the source files of rust_library or rust_binary targets.
Labelrequired

rust_grpc_library

Builds a Rust library crate from a set of proto_librarys suitable for gRPC.

Example:

load("//proto:proto.bzl", "rust_grpc_library")

proto_library(
    name = "my_proto",
    srcs = ["my.proto"]
)

rust_grpc_library(
    name = "rust",
    deps = [":my_proto"],
)

rust_binary(
    name = "my_service",
    srcs = ["my_service.rs"],
    deps = [":rust"],
)

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired
depsList of proto_library dependencies that will be built. One crate for each proto_library will be created with the corresponding gRPC stubs.List of labelsrequired
rust_depsThe crates the generated library depends on.List of labelsoptional[]

rust_library

Builds a Rust library crate.

Example:

Suppose you have the following directory structure for a simple Rust library crate:

[workspace]/
    WORKSPACE
    hello_lib/
        BUILD
        src/
            greeter.rs
            lib.rs

hello_lib/src/greeter.rs:

pub struct Greeter {
    greeting: String,
}

impl Greeter {
    pub fn new(greeting: &str) -> Greeter {
        Greeter { greeting: greeting.to_string(), }
    }

    pub fn greet(&self, thing: &str) {
        println!("{} {}", &self.greeting, thing);
    }
}

hello_lib/src/lib.rs:

pub mod greeter;

hello_lib/BUILD:

package(default_visibility = ["//visibility:public"])

load("@rules_rust//rust:rust.bzl", "rust_library")

rust_library(
    name = "hello_lib",
    srcs = [
        "src/greeter.rs",
        "src/lib.rs",
    ],
)

Build the library:

$ bazel build //hello_lib
INFO: Found 1 target...
Target //examples/rust/hello_lib:hello_lib up-to-date:
bazel-bin/examples/rust/hello_lib/libhello_lib.rlib
INFO: Elapsed time: 1.245s, Critical Path: 1.01s

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired
aliasesRemap crates to a new name or moniker for linkage to this target

These are other rust_library targets and will be presented as the new name given.
Dictionary: Label -> Stringoptional{}
compile_dataList of files used by this rule at compile time.

This attribute can be used to specify any data files that are embedded into the library, such as via the include_str! macro.
List of labelsoptional[]
crate_featuresList of features to enable for this crate.

Features are defined in the code using the #[cfg(feature = “foo”)] configuration option. The features listed here will be passed to rustc with --cfg feature=“${feature_name}” flags.
List of stringsoptional[]
crate_nameCrate name to use for this target.

This must be a valid Rust identifier, i.e. it may contain only alphanumeric characters and underscores. Defaults to the target name, with any hyphens replaced by underscores.
Stringoptional""
crate_rootThe file that will be passed to rustc to be used for building this crate.

If crate_root is not set, then this rule will look for a lib.rs file (or main.rs for rust_binary) or the single file in srcs if srcs contains only one file.
LabeloptionalNone
dataList of files used by this rule at compile time and runtime.

If including data at compile time with include_str!() and similar, prefer compile_data over data, to prevent the data also being included in the runfiles.
List of labelsoptional[]
depsList of other libraries to be linked to this library target.

These can be either other rust_library targets or cc_library targets if linking a native library.
List of labelsoptional[]
editionThe rust edition to use for this crate. Defaults to the edition specified in the rust_toolchain.Stringoptional""
out_dir_tarDeprecated, do not use, see [#cargo_build_script] instead.LabeloptionalNone
proc_macro_depsList of rust_library targets with kind proc-macro used to help build this library target.List of labelsoptional[]
rustc_envDictionary of additional “key”: “value” environment variables to set for rustc.

rust_test()/rust_binary() rules can use $(rootpath //package:target) to pass in the location of a generated file or external tool. Cargo build scripts that wish to expand locations should use cargo_build_script()'s build_script_env argument instead, as build scripts are run in a different environment - see cargo_build_script()'s documentation for more.
Dictionary: String -> Stringoptional{}
rustc_env_filesFiles containing additional environment variables to set for rustc.

These files should contain a single variable per line, of format NAME=value, and newlines may be included in a value by ending a line with a trailing back-slash (</code>).

The order that these files will be processed is unspecified, so multiple definitions of a particular variable are discouraged.
List of labelsoptional[]
rustc_flagsList of compiler flags passed to rustc.List of stringsoptional[]
srcsList of Rust .rs source files used to build the library.

If srcs contains more than one file, then there must be a file either named lib.rs. Otherwise, crate_root must be set to the source file that is the root of the crate to be passed to rustc to build this crate.
List of labelsoptional[]
versionA version to inject in the cargo environment variable.Stringoptional“0.0.0”

rust_proc_macro

Builds a Rust proc-macro crate.

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired
aliasesRemap crates to a new name or moniker for linkage to this target

These are other rust_library targets and will be presented as the new name given.
Dictionary: Label -> Stringoptional{}
compile_dataList of files used by this rule at compile time.

This attribute can be used to specify any data files that are embedded into the library, such as via the include_str! macro.
List of labelsoptional[]
crate_featuresList of features to enable for this crate.

Features are defined in the code using the #[cfg(feature = “foo”)] configuration option. The features listed here will be passed to rustc with --cfg feature=“${feature_name}” flags.
List of stringsoptional[]
crate_nameCrate name to use for this target.

This must be a valid Rust identifier, i.e. it may contain only alphanumeric characters and underscores. Defaults to the target name, with any hyphens replaced by underscores.
Stringoptional""
crate_rootThe file that will be passed to rustc to be used for building this crate.

If crate_root is not set, then this rule will look for a lib.rs file (or main.rs for rust_binary) or the single file in srcs if srcs contains only one file.
LabeloptionalNone
dataList of files used by this rule at compile time and runtime.

If including data at compile time with include_str!() and similar, prefer compile_data over data, to prevent the data also being included in the runfiles.
List of labelsoptional[]
depsList of other libraries to be linked to this library target.

These can be either other rust_library targets or cc_library targets if linking a native library.
List of labelsoptional[]
editionThe rust edition to use for this crate. Defaults to the edition specified in the rust_toolchain.Stringoptional""
out_dir_tarDeprecated, do not use, see [#cargo_build_script] instead.LabeloptionalNone
proc_macro_depsList of rust_library targets with kind proc-macro used to help build this library target.List of labelsoptional[]
rustc_envDictionary of additional “key”: “value” environment variables to set for rustc.

rust_test()/rust_binary() rules can use $(rootpath //package:target) to pass in the location of a generated file or external tool. Cargo build scripts that wish to expand locations should use cargo_build_script()'s build_script_env argument instead, as build scripts are run in a different environment - see cargo_build_script()'s documentation for more.
Dictionary: String -> Stringoptional{}
rustc_env_filesFiles containing additional environment variables to set for rustc.

These files should contain a single variable per line, of format NAME=value, and newlines may be included in a value by ending a line with a trailing back-slash (</code>).

The order that these files will be processed is unspecified, so multiple definitions of a particular variable are discouraged.
List of labelsoptional[]
rustc_flagsList of compiler flags passed to rustc.List of stringsoptional[]
srcsList of Rust .rs source files used to build the library.

If srcs contains more than one file, then there must be a file either named lib.rs. Otherwise, crate_root must be set to the source file that is the root of the crate to be passed to rustc to build this crate.
List of labelsoptional[]
versionA version to inject in the cargo environment variable.Stringoptional“0.0.0”

rust_proto_library

Builds a Rust library crate from a set of proto_librarys.

Example:

load("@rules_rust//proto:proto.bzl", "rust_proto_library")

proto_library(
    name = "my_proto",
    srcs = ["my.proto"]
)

proto_rust_library(
    name = "rust",
    deps = [":my_proto"],
)

rust_binary(
    name = "my_proto_binary",
    srcs = ["my_proto_binary.rs"],
    deps = [":rust"],
)

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired
depsList of proto_library dependencies that will be built. One crate for each proto_library will be created with the corresponding stubs.List of labelsrequired
rust_depsThe crates the generated library depends on.List of labelsoptional[]

rust_proto_toolchain

Declares a Rust Proto toolchain for use.

This is used to configure proto compilation and can be used to set different protobuf compiler plugin.

Example:

Suppose a new nicer gRPC plugin has came out. The new plugin can be used in Bazel by defining a new toolchain definition and declaration:

load('@rules_rust//proto:toolchain.bzl', 'rust_proto_toolchain')

rust_proto_toolchain(
   name="rust_proto_impl",
   grpc_plugin="@rust_grpc//:grpc_plugin",
   grpc_compile_deps=["@rust_grpc//:grpc_deps"],
)

toolchain(
    name="rust_proto",
    exec_compatible_with = [
        "@platforms//cpu:cpuX",
    ],
    target_compatible_with = [
        "@platforms//cpu:cpuX",
    ],
    toolchain = ":rust_proto_impl",
)

Then, either add the label of the toolchain rule to register_toolchains in the WORKSPACE, or pass it to the --extra_toolchains flag for Bazel, and it will be used.

See @rules_rust//proto:BUILD for examples of defining the toolchain.

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired
editionThe edition used by the generated rust source.Stringoptional“2015”
grpc_compile_depsThe crates the generated grpc libraries depends on.List of labelsoptional[Label(“//proto/raze:protobuf”), Label(“//proto/raze:grpc”), Label(“//proto/raze:tls_api”), Label(“//proto/raze:tls_api_stub”)]
grpc_pluginThe location of the Rust protobuf compiler plugin to generate rust gRPC stubs.Labeloptional//proto:protoc_gen_rust_grpc
proto_compile_depsThe crates the generated protobuf libraries depends on.List of labelsoptional[Label(“//proto/raze:protobuf”)]
proto_pluginThe location of the Rust protobuf compiler plugin used to generate rust sources.Labeloptional//proto:protoc_gen_rust
protocThe location of the protoc binary. It should be an executable target.Labeloptional@com_google_protobuf//:protoc

rust_shared_library

Builds a Rust shared library.

This shared library will contain all transitively reachable crates and native objects. It is meant to be used when producing an artifact that is then consumed by some other build system (for example to produce a shared library that Python program links against).

This rule provides CcInfo, so it can be used everywhere Bazel expects rules_cc.

When building the whole binary in Bazel, use rust_library instead.

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired
aliasesRemap crates to a new name or moniker for linkage to this target

These are other rust_library targets and will be presented as the new name given.
Dictionary: Label -> Stringoptional{}
compile_dataList of files used by this rule at compile time.

This attribute can be used to specify any data files that are embedded into the library, such as via the include_str! macro.
List of labelsoptional[]
crate_featuresList of features to enable for this crate.

Features are defined in the code using the #[cfg(feature = “foo”)] configuration option. The features listed here will be passed to rustc with --cfg feature=“${feature_name}” flags.
List of stringsoptional[]
crate_nameCrate name to use for this target.

This must be a valid Rust identifier, i.e. it may contain only alphanumeric characters and underscores. Defaults to the target name, with any hyphens replaced by underscores.
Stringoptional""
crate_rootThe file that will be passed to rustc to be used for building this crate.

If crate_root is not set, then this rule will look for a lib.rs file (or main.rs for rust_binary) or the single file in srcs if srcs contains only one file.
LabeloptionalNone
dataList of files used by this rule at compile time and runtime.

If including data at compile time with include_str!() and similar, prefer compile_data over data, to prevent the data also being included in the runfiles.
List of labelsoptional[]
depsList of other libraries to be linked to this library target.

These can be either other rust_library targets or cc_library targets if linking a native library.
List of labelsoptional[]
editionThe rust edition to use for this crate. Defaults to the edition specified in the rust_toolchain.Stringoptional""
out_dir_tarDeprecated, do not use, see [#cargo_build_script] instead.LabeloptionalNone
proc_macro_depsList of rust_library targets with kind proc-macro used to help build this library target.List of labelsoptional[]
rustc_envDictionary of additional “key”: “value” environment variables to set for rustc.

rust_test()/rust_binary() rules can use $(rootpath //package:target) to pass in the location of a generated file or external tool. Cargo build scripts that wish to expand locations should use cargo_build_script()'s build_script_env argument instead, as build scripts are run in a different environment - see cargo_build_script()'s documentation for more.
Dictionary: String -> Stringoptional{}
rustc_env_filesFiles containing additional environment variables to set for rustc.

These files should contain a single variable per line, of format NAME=value, and newlines may be included in a value by ending a line with a trailing back-slash (</code>).

The order that these files will be processed is unspecified, so multiple definitions of a particular variable are discouraged.
List of labelsoptional[]
rustc_flagsList of compiler flags passed to rustc.List of stringsoptional[]
srcsList of Rust .rs source files used to build the library.

If srcs contains more than one file, then there must be a file either named lib.rs. Otherwise, crate_root must be set to the source file that is the root of the crate to be passed to rustc to build this crate.
List of labelsoptional[]
versionA version to inject in the cargo environment variable.Stringoptional“0.0.0”

rust_static_library

Builds a Rust static library.

This static library will contain all transitively reachable crates and native objects. It is meant to be used when producing an artifact that is then consumed by some other build system (for example to produce an archive that Python program links against).

This rule provides CcInfo, so it can be used everywhere Bazel expects rules_cc.

When building the whole binary in Bazel, use rust_library instead.

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired
aliasesRemap crates to a new name or moniker for linkage to this target

These are other rust_library targets and will be presented as the new name given.
Dictionary: Label -> Stringoptional{}
compile_dataList of files used by this rule at compile time.

This attribute can be used to specify any data files that are embedded into the library, such as via the include_str! macro.
List of labelsoptional[]
crate_featuresList of features to enable for this crate.

Features are defined in the code using the #[cfg(feature = “foo”)] configuration option. The features listed here will be passed to rustc with --cfg feature=“${feature_name}” flags.
List of stringsoptional[]
crate_nameCrate name to use for this target.

This must be a valid Rust identifier, i.e. it may contain only alphanumeric characters and underscores. Defaults to the target name, with any hyphens replaced by underscores.
Stringoptional""
crate_rootThe file that will be passed to rustc to be used for building this crate.

If crate_root is not set, then this rule will look for a lib.rs file (or main.rs for rust_binary) or the single file in srcs if srcs contains only one file.
LabeloptionalNone
dataList of files used by this rule at compile time and runtime.

If including data at compile time with include_str!() and similar, prefer compile_data over data, to prevent the data also being included in the runfiles.
List of labelsoptional[]
depsList of other libraries to be linked to this library target.

These can be either other rust_library targets or cc_library targets if linking a native library.
List of labelsoptional[]
editionThe rust edition to use for this crate. Defaults to the edition specified in the rust_toolchain.Stringoptional""
out_dir_tarDeprecated, do not use, see [#cargo_build_script] instead.LabeloptionalNone
proc_macro_depsList of rust_library targets with kind proc-macro used to help build this library target.List of labelsoptional[]
rustc_envDictionary of additional “key”: “value” environment variables to set for rustc.

rust_test()/rust_binary() rules can use $(rootpath //package:target) to pass in the location of a generated file or external tool. Cargo build scripts that wish to expand locations should use cargo_build_script()'s build_script_env argument instead, as build scripts are run in a different environment - see cargo_build_script()'s documentation for more.
Dictionary: String -> Stringoptional{}
rustc_env_filesFiles containing additional environment variables to set for rustc.

These files should contain a single variable per line, of format NAME=value, and newlines may be included in a value by ending a line with a trailing back-slash (</code>).

The order that these files will be processed is unspecified, so multiple definitions of a particular variable are discouraged.
List of labelsoptional[]
rustc_flagsList of compiler flags passed to rustc.List of stringsoptional[]
srcsList of Rust .rs source files used to build the library.

If srcs contains more than one file, then there must be a file either named lib.rs. Otherwise, crate_root must be set to the source file that is the root of the crate to be passed to rustc to build this crate.
List of labelsoptional[]
versionA version to inject in the cargo environment variable.Stringoptional“0.0.0”

rust_test

Builds a Rust test crate.

Examples:

Suppose you have the following directory structure for a Rust library crate with unit test code in the library sources:

[workspace]/
    WORKSPACE
    hello_lib/
        BUILD
        src/
            lib.rs

hello_lib/src/lib.rs:

pub struct Greeter {
    greeting: String,
}

impl Greeter {
    pub fn new(greeting: &str) -> Greeter {
        Greeter { greeting: greeting.to_string(), }
    }

    pub fn greet(&self, thing: &str) {
        println!("{} {}", &self.greeting, thing);
    }
}

#[cfg(test)]
mod test {
    use super::Greeter;

    #[test]
    fn test_greeting() {
        let hello = Greeter::new("Hi");
        assert_eq!("Hi Rust", hello.greet("Rust"));
    }
}

To build and run the tests, simply add a rust_test rule with no srcs and only depends on the hello_lib rust_library target:

hello_lib/BUILD:

package(default_visibility = ["//visibility:public"])

load("@rules_rust//rust:defs.bzl", "rust_library", "rust_test")

rust_library(
    name = "hello_lib",
    srcs = ["src/lib.rs"],
)

rust_test(
    name = "hello_lib_test",
    deps = [":hello_lib"],
)

Run the test with bazel build //hello_lib:hello_lib_test.

To run a crate or lib with the #[cfg(test)] configuration, handling inline tests, you should specify the crate directly like so.

rust_test(
    name = "hello_lib_test",
    crate = ":hello_lib",
    # You may add other deps that are specific to the test configuration
    deps = ["//some/dev/dep"],
)

Example: test directory

Integration tests that live in the tests directory, they are essentially built as separate crates. Suppose you have the following directory structure where greeting.rs is an integration test for the hello_lib library crate:

[workspace]/
    WORKSPACE
    hello_lib/
        BUILD
        src/
            lib.rs
        tests/
            greeting.rs

hello_lib/tests/greeting.rs:

extern crate hello_lib;

use hello_lib;

#[test]
fn test_greeting() {
    let hello = greeter::Greeter::new("Hello");
    assert_eq!("Hello world", hello.greeting("world"));
}

To build the greeting.rs integration test, simply add a rust_test target with greeting.rs in srcs and a dependency on the hello_lib target:

hello_lib/BUILD:

package(default_visibility = ["//visibility:public"])

load("@rules_rust//rust:defs.bzl", "rust_library", "rust_test")

rust_library(
    name = "hello_lib",
    srcs = ["src/lib.rs"],
)

rust_test(
    name = "greeting_test",
    srcs = ["tests/greeting.rs"],
    deps = [":hello_lib"],
)

Run the test with bazel build //hello_lib:hello_lib_test.

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired
aliasesRemap crates to a new name or moniker for linkage to this target

These are other rust_library targets and will be presented as the new name given.
Dictionary: Label -> Stringoptional{}
compile_dataList of files used by this rule at compile time.

This attribute can be used to specify any data files that are embedded into the library, such as via the include_str! macro.
List of labelsoptional[]
crateTarget inline tests declared in the given crate

These tests are typically those that would be held out under #[cfg(test)] declarations.
LabeloptionalNone
crate_featuresList of features to enable for this crate.

Features are defined in the code using the #[cfg(feature = “foo”)] configuration option. The features listed here will be passed to rustc with --cfg feature=“${feature_name}” flags.
List of stringsoptional[]
crate_nameCrate name to use for this target.

This must be a valid Rust identifier, i.e. it may contain only alphanumeric characters and underscores. Defaults to the target name, with any hyphens replaced by underscores.
Stringoptional""
crate_rootThe file that will be passed to rustc to be used for building this crate.

If crate_root is not set, then this rule will look for a lib.rs file (or main.rs for rust_binary) or the single file in srcs if srcs contains only one file.
LabeloptionalNone
dataList of files used by this rule at compile time and runtime.

If including data at compile time with include_str!() and similar, prefer compile_data over data, to prevent the data also being included in the runfiles.
List of labelsoptional[]
depsList of other libraries to be linked to this library target.

These can be either other rust_library targets or cc_library targets if linking a native library.
List of labelsoptional[]
editionThe rust edition to use for this crate. Defaults to the edition specified in the rust_toolchain.Stringoptional""
envSpecifies additional environment variables to set when the test is executed by bazel test. Values are subject to $(execpath) and “Make variable” substitution.Dictionary: String -> Stringoptional{}
out_dir_tarDeprecated, do not use, see [#cargo_build_script] instead.LabeloptionalNone
proc_macro_depsList of rust_library targets with kind proc-macro used to help build this library target.List of labelsoptional[]
rustc_envDictionary of additional “key”: “value” environment variables to set for rustc.

rust_test()/rust_binary() rules can use $(rootpath //package:target) to pass in the location of a generated file or external tool. Cargo build scripts that wish to expand locations should use cargo_build_script()'s build_script_env argument instead, as build scripts are run in a different environment - see cargo_build_script()'s documentation for more.
Dictionary: String -> Stringoptional{}
rustc_env_filesFiles containing additional environment variables to set for rustc.

These files should contain a single variable per line, of format NAME=value, and newlines may be included in a value by ending a line with a trailing back-slash (</code>).

The order that these files will be processed is unspecified, so multiple definitions of a particular variable are discouraged.
List of labelsoptional[]
rustc_flagsList of compiler flags passed to rustc.List of stringsoptional[]
srcsList of Rust .rs source files used to build the library.

If srcs contains more than one file, then there must be a file either named lib.rs. Otherwise, crate_root must be set to the source file that is the root of the crate to be passed to rustc to build this crate.
List of labelsoptional[]
versionA version to inject in the cargo environment variable.Stringoptional“0.0.0”

rust_toolchain

Declares a Rust toolchain for use.

This is for declaring a custom toolchain, eg. for configuring a particular version of rust or supporting a new platform.

Example:

Suppose the core rust team has ported the compiler to a new target CPU, called cpuX. This support can be used in Bazel by defining a new toolchain definition and declaration:

load('@rules_rust//rust:toolchain.bzl', 'rust_toolchain')

rust_toolchain(
    name = "rust_cpuX_impl",
    rustc = "@rust_cpuX//:rustc",
    rustc_lib = "@rust_cpuX//:rustc_lib",
    rust_lib = "@rust_cpuX//:rust_lib",
    rust_doc = "@rust_cpuX//:rustdoc",
    binary_ext = "",
    staticlib_ext = ".a",
    dylib_ext = ".so",
    stdlib_linkflags = ["-lpthread", "-ldl"],
    os = "linux",
)

toolchain(
    name = "rust_cpuX",
    exec_compatible_with = [
        "@platforms//cpu:cpuX",
    ],
    target_compatible_with = [
        "@platforms//cpu:cpuX",
    ],
    toolchain = ":rust_cpuX_impl",
)

Then, either add the label of the toolchain rule to register_toolchains in the WORKSPACE, or pass it to the "--extra_toolchains" flag for Bazel, and it will be used.

See @rules_rust//rust:repositories.bzl for examples of defining the @rust_cpuX repository with the actual binaries and libraries.

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired
allocator_libraryTarget that provides allocator functions when rust_library targets are embedded in a cc_binary.LabeloptionalNone
binary_extThe extension for binaries created from rustc.Stringrequired
cargoThe location of the cargo binary. Can be a direct source or a filegroup containing one item.LabeloptionalNone
clippy_driverThe location of the clippy-driver binary. Can be a direct source or a filegroup containing one item.LabeloptionalNone
debug_infoRustc debug info levels per opt levelDictionary: String -> Stringoptional{“dbg”: “2”, “fastbuild”: “0”, “opt”: “0”}
default_editionThe edition to use for rust_* rules that don't specify an edition.Stringoptional“2015”
dylib_extThe extension for dynamic libraries created from rustc.Stringrequired
exec_tripleThe platform triple for the toolchains execution environment. For more details see: https://docs.bazel.build/versions/master/skylark/rules.html#configurationsStringoptional""
opt_levelRustc optimization levels.Dictionary: String -> Stringoptional{“dbg”: “0”, “fastbuild”: “0”, “opt”: “3”}
osThe operating system for the current toolchainStringrequired
rust_docThe location of the rustdoc binary. Can be a direct source or a filegroup containing one item.LabeloptionalNone
rust_libThe rust standard library.LabeloptionalNone
rustcThe location of the rustc binary. Can be a direct source or a filegroup containing one item.LabeloptionalNone
rustc_libThe libraries used by rustc during compilation.LabeloptionalNone
rustc_srcThe source code of rustc.LabeloptionalNone
rustfmtThe location of the rustfmt binary. Can be a direct source or a filegroup containing one item.LabeloptionalNone
staticlib_extThe extension for static libraries created from rustc.Stringrequired
stdlib_linkflagsAdditional linker libs used when std lib is linked, see https://github.com/rust-lang/rust/blob/master/src/libstd/build.rsList of stringsrequired
target_tripleThe platform triple for the toolchains target environment. For more details see: https://docs.bazel.build/versions/master/skylark/rules.html#configurationsStringoptional""

rust_toolchain_repository

Composes a single workspace containing the toolchain components for compiling on a given platform to a series of target platforms.

A given instance of this rule should be accompanied by a rust_toolchain_repository_proxy invocation to declare its toolchains to Bazel; the indirection allows separating toolchain selection from toolchain fetching.

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this repository.Namerequired
dev_componentsWhether to download the rustc-dev components (defaults to False). Requires version to be “nightly”.BooleanoptionalFalse
editionThe rust edition to be used by default.Stringoptional“2015”
exec_tripleThe Rust-style target that this compiler runs onStringrequired
extra_target_triplesAdditional rust-style targets that this set of toolchains should support.List of stringsoptional[]
include_rustc_srcWhether to download and unpack the rustc source files. These are very large, and slow to unpack, but are required to support rust analyzer.BooleanoptionalFalse
iso_dateThe date of the tool (or None, if the version is a specific version).Stringoptional""
repo_mappingA dictionary from local repository name to global repository name. This allows controls over workspace dependency resolution for dependencies of this repository.<p>For example, an entry “@foo”: “@bar” declares that, for any time this repository depends on @foo (such as a dependency on @foo//some:target, it should actually resolve that dependency within globally-declared @bar (@bar//some:target).Dictionary: String -> Stringrequired
rustfmt_versionThe version of the tool among “nightly”, “beta”, or an exact version.Stringoptional""
sha256sA dict associating tool subdirectories to sha256 hashes. See rust_repositories for more details.Dictionary: String -> Stringoptional{}
toolchain_name_prefixThe per-target prefix expected for the rust_toolchain declarations in the parent workspace.Stringoptional""
urlsA list of mirror urls containing the tools from the Rust-lang static file server. These must contain the ‘{}’ used to substitute the tool being fetched (using .format).List of stringsoptional[“https://static.rust-lang.org/dist/{}.tar.gz”]
versionThe version of the tool among “nightly”, “beta”, or an exact version.Stringrequired

rust_toolchain_repository_proxy

Generates a toolchain-bearing repository that declares the toolchains from some other rust_toolchain_repository.

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this repository.Namerequired
exec_tripleThe Rust-style target triple for the compilation platformStringrequired
extra_target_triplesThe Rust-style triples for extra compilation targetsList of stringsoptional[]
parent_workspace_nameThe name of the other rust_toolchain_repositoryStringrequired
repo_mappingA dictionary from local repository name to global repository name. This allows controls over workspace dependency resolution for dependencies of this repository.<p>For example, an entry “@foo”: “@bar” declares that, for any time this repository depends on @foo (such as a dependency on @foo//some:target, it should actually resolve that dependency within globally-declared @bar (@bar//some:target).Dictionary: String -> Stringrequired
toolchain_name_prefixThe per-target prefix expected for the rust_toolchain declarations in the parent workspace.Stringoptional""

rust_wasm_bindgen

Generates javascript and typescript bindings for a webassembly module using wasm-bindgen.

To use the Rust WebAssembly bindgen rules, add the following to your WORKSPACE file to add the external repositories for the Rust bindgen toolchain (in addition to the Rust rules setup):

load("@rules_rust//wasm_bindgen:repositories.bzl", "rust_wasm_bindgen_repositories")

rust_wasm_bindgen_repositories()

For more details on rust_wasm_bindgen_repositories, see here.

An example of this rule in use can be seen at @rules_rust//examples/wasm

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired
bindgen_flagsFlags to pass directly to the bindgen executable. See https://github.com/rustwasm/wasm-bindgen/ for details.List of stringsoptional[]
targetThe type of output to generate. See https://rustwasm.github.io/wasm-bindgen/reference/deployment.html for details.Stringoptional“bundler”
wasm_fileThe .wasm file to generate bindings for.LabeloptionalNone

rust_wasm_bindgen_toolchain

The tools required for the rust_wasm_bindgen rule.

In cases where users want to control or change the version of wasm-bindgen used by rust_wasm_bindgen, a unique toolchain can be created as in the example below:

load("@rules_rust//bindgen:bindgen.bzl", "rust_bindgen_toolchain")

rust_bindgen_toolchain(
    bindgen = "//my/cargo_raze:cargo_bin_wasm_bindgen",
)

toolchain(
    name = "wasm_bindgen_toolchain",
    toolchain = "wasm_bindgen_toolchain_impl",
    toolchain_type = "@rules_rust//wasm_bindgen:wasm_bindgen_toolchain",
)

Now that you have your own toolchain, you need to register it by inserting the following statement in your WORKSPACE file:

register_toolchains("//my/toolchains:wasm_bindgen_toolchain")

For additional information, see the Bazel toolchains documentation.

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired
bindgenThe label of a wasm-bindgen-cli executable.LabeloptionalNone

cargo_build_script

Compile and execute a rust build script to generate build attributes

This rules take the same arguments as rust_binary.

Example:

Suppose you have a crate with a cargo build script build.rs:

[workspace]/
    hello_lib/
        BUILD
        build.rs
        src/
            lib.rs

Then you want to use the build script in the following:

hello_lib/BUILD:

package(default_visibility = ["//visibility:public"])

load("@rules_rust//rust:rust.bzl", "rust_binary", "rust_library")
load("@rules_rust//cargo:cargo_build_script.bzl", "cargo_build_script")

# This will run the build script from the root of the workspace, and
# collect the outputs.
cargo_build_script(
    name = "build_script",
    srcs = ["build.rs"],
    # Optional environment variables passed during build.rs compilation
    rustc_env = {
       "CARGO_PKG_VERSION": "0.1.2",
    },
    # Optional environment variables passed during build.rs execution.
    # Note that as the build script's working directory is not execroot,
    # execpath/location will return an absolute path, instead of a relative
    # one.
    build_script_env = {
        "SOME_TOOL_OR_FILE": "$(execpath @tool//:binary)"
    }
    # Optional data/tool dependencies
    data = ["@tool//:binary"],
)

rust_library(
    name = "hello_lib",
    srcs = [
        "src/lib.rs",
    ],
    deps = [":build_script"],
)

The hello_lib target will be build with the flags and the environment variables declared by the build script in addition to the file generated by it.

PARAMETERS

NameDescriptionDefault Value
nameThe name for the underlying rule. This should be the name of the package being compiled, optionally with a suffix of _build_script.none
crate_featuresA list of features to enable for the build script.[]
versionThe semantic version (semver) of the crate.None
depsThe dependencies of the crate.[]
build_script_envEnvironment variables for build scripts.{}
dataFiles or tools needed by the build script.[]
linksName of the native library this crate links against.None
rustc_envEnvironment variables to set in rustc when compiling the build script.{}
kwargsForwards to the underlying rust_binary rule.none

crate.spec

A simple crate definition for use in the crate_universe rule.

WARNING: This rule experimental and subject to change without warning.

Example:

load("@rules_rust//crate_universe:defs.bzl", "crate_universe", "crate")

crate_universe(
    name = "spec_example",
    packages = [
        crate.spec(
            name = "lazy_static",
            semver = "=1.4",
        ),
    ],
)

PARAMETERS

NameDescriptionDefault Value
nameThe name of the crate as it would appear in a crate registry.none
semverThe desired version (semver) of the cratenone
featuresA list of desired features.None

crate.override

A map of overrides for a particular crate

WARNING: This rule experimental and subject to change without warning.

Example:

load("@rules_rust//crate_universe:defs.bzl", "crate_universe", "crate")

crate_universe(
    name = "override_example",
    # [...]
    overrides = {
        "tokio": crate.override(
            extra_rustc_env_vars = {
                "MY_ENV_VAR": "MY_ENV_VALUE",
            },
            extra_build_script_env_vars = {
                "MY_BUILD_SCRIPT_ENV_VAR": "MY_ENV_VALUE",
            },
            extra_bazel_deps = {
                # Extra dependencies are per target. They are additive.
                "cfg(unix)": ["@somerepo//:foo"],  # cfg() predicate.
                "x86_64-apple-darwin": ["@somerepo//:bar"],  # Specific triple.
                "cfg(all())": ["@somerepo//:baz"],  # Applies to all targets ("regular dependency").
            },
            extra_build_script_bazel_deps = {
                # Extra dependencies are per target. They are additive.
                "cfg(unix)": ["@buildscriptdep//:foo"],
                "x86_64-apple-darwin": ["@buildscriptdep//:bar"],
                "cfg(all())": ["@buildscriptdep//:baz"],
            },
            extra_bazel_data_deps = {
                # ...
            },
            extra_build_script_bazel_data_deps = {
                # ...
            },
        ),
    },
)

PARAMETERS

NameDescriptionDefault Value
extra_bazel_data_depsTargets to add to the data attribute of the generated target (eg: rust_library.data).None
extra_bazel_depsTargets to add to the deps attribute of the generated target (eg: rust_library.deps).None
extra_build_script_bazel_data_depsTargets to add to the data attribute of the generated cargo_build_script target.None
extra_build_script_bazel_depsTargets to add to the deps attribute of the generated cargo_build_script target.None
extra_build_script_env_varsEnvironment variables to add to the build_script_env attribute of the generated cargo_build_script target.None
extra_rustc_env_varsEnvironment variables to add to the rustc_env attribute for the generated target (eg: rust_library.rustc_env).None
features_to_removeA list of features to remove from a generated target.[]

rust_bindgen_library

Generates a rust source file for header, and builds a rust_library.

Arguments are the same as rust_bindgen, and kwargs are passed directly to rust_library.

PARAMETERS

NameDescriptionDefault Value
nameA unique name for this target.none
headerThe label of the .h file to generate bindings for.none
cc_libThe label of the cc_library that contains the .h file. This is used to find the transitive includes.none
bindgen_flagsFlags to pass directly to the bindgen executable. See https://rust-lang.github.io/rust-bindgen/ for details.None
clang_flagsFlags to pass directly to the clang executable.None
kwargsArguments to forward to the underlying rust_library rule.none

rust_bindgen_repositories

Declare dependencies needed for bindgen.

rust_proto_repositories

Declare dependencies needed for proto compilation.

PARAMETERS

NameDescriptionDefault Value
register_default_toolchainIf True, the default rust_proto_toolchain (@rules_rust//proto:default-proto-toolchain) is registered. This toolchain requires a set of dependencies that were generated using cargo raze. These will also be loaded.True

rust_repositories

Emits a default set of toolchains for Linux, MacOS, and Freebsd

Skip this macro and call the rust_repository_set macros directly if you need a compiler for other hosts or for additional target triples.

The sha256 attribute represents a dict associating tool subdirectories to sha256 hashes. As an example:

{
    "rust-1.46.0-x86_64-unknown-linux-gnu": "e3b98bc3440fe92817881933f9564389eccb396f5f431f33d48b979fa2fbdcf5",
    "rustfmt-1.4.12-x86_64-unknown-linux-gnu": "1894e76913303d66bf40885a601462844eec15fca9e76a6d13c390d7000d64b0",
    "rust-std-1.46.0-x86_64-unknown-linux-gnu": "ac04aef80423f612c0079829b504902de27a6997214eb58ab0765d02f7ec1dbc",
}

This would match for exec_triple = "x86_64-unknown-linux-gnu". If not specified, rules_rust pulls from a non-exhaustive list of known checksums..

See load_arbitrary_tool in @rules_rust//rust:repositories.bzl for more details.

PARAMETERS

NameDescriptionDefault Value
versionThe version of Rust. Either “nightly”, “beta”, or an exact version. Defaults to a modern version.“1.52.1”
iso_dateThe date of the nightly or beta release (or None, if the version is a specific version).None
rustfmt_versionThe version of rustfmt. Either “nightly”, “beta”, or an exact version. Defaults to version if not specified.None
editionThe rust edition to be used by default (2015 (default) or 2018)None
dev_componentsWhether to download the rustc-dev components (defaults to False). Requires version to be “nightly”.False
sha256sA dict associating tool subdirectories to sha256 hashes. Defaults to None.None
include_rustc_srcWhether to download rustc's src code. This is required in order to use rust-analyzer support. Defaults to False.False
urlsA list of mirror urls containing the tools from the Rust-lang static file server. These must contain the ‘{}’ used to substitute the tool being fetched (using .format). Defaults to [‘https://static.rust-lang.org/dist/{}.tar.gz’][“https://static.rust-lang.org/dist/{}.tar.gz”]

rust_repository_set

Assembles a remote repository for the given toolchain params, produces a proxy repository to contain the toolchain declaration, and registers the toolchains.

N.B. A “proxy repository” is needed to allow for registering the toolchain (with constraints) without actually downloading the toolchain.

PARAMETERS

NameDescriptionDefault Value
nameThe name of the generated repositorynone
versionThe version of the tool among “nightly”, "beta', or an exact version.none
exec_tripleThe Rust-style target that this compiler runs onnone
include_rustc_srcWhether to download rustc's src code. This is required in order to use rust-analyzer support. Defaults to False.False
extra_target_triplesAdditional rust-style targets that this set of toolchains should support. Defaults to [].[]
iso_dateThe date of the tool. Defaults to None.None
rustfmt_versionThe version of rustfmt to be associated with the toolchain. Defaults to None.None
editionThe rust edition to be used by default (2015 (if None) or 2018).None
dev_componentsWhether to download the rustc-dev components. Requires version to be “nightly”. Defaults to False.False
sha256sA dict associating tool subdirectories to sha256 hashes. See rust_repositories for more details.None
urlsA list of mirror urls containing the tools from the Rust-lang static file server. These must contain the ‘{}’ used to substitute the tool being fetched (using .format). Defaults to [‘https://static.rust-lang.org/dist/{}.tar.gz’][“https://static.rust-lang.org/dist/{}.tar.gz”]

rust_test_suite

A rule for creating a test suite for a set of rust_test targets.

This rule can be used for setting up typical rust integration tests. Given the following directory structure:

[crate]/
    BUILD.bazel
    src/
        lib.rs
        main.rs
    tests/
        integrated_test_a.rs
        integrated_test_b.rs
        integrated_test_c.rs
        patterns/
            fibonacci_test.rs

The rule can be used to generate rust_test targets for each source file under tests and a test_suite which encapsulates all tests.

load("//rust:defs.bzl", "rust_binary", "rust_library", "rust_test_suite")

rust_library(
    name = "math_lib",
    srcs = ["src/lib.rs"],
)

rust_binary(
    name = "math_bin",
    srcs = ["src/main.rs"],
)

rust_test_suite(
    name = "integrated_tests_suite",
    srcs = glob(["tests/**"]),
    deps = [":math_lib"],
)

PARAMETERS

NameDescriptionDefault Value
nameThe name of the test_suite.none
srcsAll test sources, typically glob([“tests/**/*.rs”]).none
kwargsAdditional keyword arguments for the underyling rust_test targets. The tags argument is also passed to the generated test_suite target.none

rust_wasm_bindgen_repositories

Declare dependencies needed for rust_wasm_bindgen.

PARAMETERS

NameDescriptionDefault Value
register_default_toolchainIf True, the default rust_wasm_bindgen_toolchain (@rules_rust//wasm_bindgen:default_wasm_bindgen_toolchain) is registered. This toolchain requires a set of dependencies that were generated using cargo raze. These will also be loaded.True

rust_analyzer_aspect

Annotates rust rules with RustAnalyzerInfo later used to build a rust-project.json

ASPECT ATTRIBUTES

NameType
depsString
proc_macro_depsString

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired

rust_clippy_aspect

Executes the clippy checker on specified targets.

This aspect applies to existing rust_library, rust_test, and rust_binary rules.

As an example, if the following is defined in examples/hello_lib/BUILD.bazel:

load("@rules_rust//rust:defs.bzl", "rust_library", "rust_test")

rust_library(
    name = "hello_lib",
    srcs = ["src/lib.rs"],
)

rust_test(
    name = "greeting_test",
    srcs = ["tests/greeting.rs"],
    deps = [":hello_lib"],
)

Then the targets can be analyzed with clippy using the following command:

$ bazel build --aspects=@rules_rust//rust:defs.bzl%rust_clippy_aspect               --output_groups=clippy_checks //hello_lib:all

ASPECT ATTRIBUTES

ATTRIBUTES

NameDescriptionTypeMandatoryDefault
nameA unique name for this target.Namerequired