These build rules are used for building Rust projects with Bazel.
To use the Rust rules, add the following to your WORKSPACE
file to add the
external repositories for the Rust toolchain:
http_archive(
name = "io_bazel_rules_rust",
sha256 = "615639cfd5459fec4b8a5751112be808ab25ba647c4c1953d29bb554ef865da7",
strip_prefix = "rules_rust-0.0.6",
urls = [
"http://bazel-mirror.storage.googleapis.com/github.com/bazelbuild/rules_rust/archive/0.0.6.tar.gz",
"https://github.com/bazelbuild/rules_rust/archive/0.0.6.tar.gz",
],
)
load("@io_bazel_rules_rust//rust:repositories.bzl", "rust_repositories")
rust_repositories()
The master branch should always be current with the latest bazel, as such you can pin to a recent commit on master.
- Add
rust_toolchain
rule to make it easy to use a custom Rust toolchain. - Add tool for taking
Cargo.toml
and generating aWORKSPACE
file with workspace rules for pulling external dependencies. - Improve expressiveness of features and support for Cargo's feature groups.
- Add
cargo_crate
workspace rule for pulling crates from Cargo.
rust_library(name, srcs, crate_root, crate_type, deps, data, crate_features, rustc_flags, version, out_dir_tar)
Attributes | |
---|---|
name |
Name, required
A unique name for this rule. This name will also be used as the name of the library crate built by this rule. |
srcs |
List of labels, required
List of Rust
If |
crate_root |
Label, optional
The file that will be passed to
If |
crate_type |
String, optional
The type of crate to be produced during library compilation. This list closely matches Cargo's own notion of crate-type, and the available options are "lib", "rlib", "dylib", "cdylib", "staticlib", and "proc-macro".
The exact output depends on the selected toolchain but generally will
match what Cargo would do. If binary compilation is desired, use
|
deps |
List of labels, optional
List of other libraries to be linked to this library target.
These can be either other |
data |
List of labels, optional
List of files used by this rule at runtime.
This attribute can be used to specify any data files that are embedded
into the library, such as via the
|
crate_features |
List of strings, optional
List of features to enable for this crate.
Features are defined in the code using the
|
rustc_flags |
List of strings, optional
List of compiler flags passed to |
version |
String, optional
Version to inject in the cargo environment variable. |
out_dir_tar |
A single compressed tar or tar.gz file
A prepared .tar.gz file to be unpacked and supplied to
|
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("@io_bazel_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
rust_binary(name, srcs, deps, data, crate_features, rustc_flags, version, out_dir_tar)
Attributes | |
---|---|
name |
Name, required
A unique name for this rule. This name will also be used as the name of the binary crate built by this rule. |
srcs |
List of labels, required
List of Rust
If |
crate_root |
Label, optional
The file that will be passed to
If |
deps |
List of labels, optional
List of other libraries to be linked to this library target.
These must be |
data |
List of labels, optional
List of files used by this rule at runtime.
This attribute can be used to specify any data files that are embedded
into the library, such as via the
|
crate_features |
List of strings, optional
List of features to enable for this crate.
Features are defined in the code using the
|
rustc_flags |
List of strings, optional
List of compiler flags passed to |
version |
String, optional
Version to inject in the cargo environment variable. |
out_dir_tar |
A single compressed tar or tar.gz file
A prepared .tar.gz file to be unpacked and supplied to
|
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("@io_bazel_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("@io_bazel_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
rust_test(name, srcs, deps, data, crate_features, rustc_flags, version, out_dir_tar)
Attributes | |
---|---|
name |
Name, required
A unique name for this rule. This name will also be used as the name of the binary test crate built by this rule. |
srcs |
List of labels, required
List of Rust
If |
crate_root |
Label, optional
The file that will be passed to
If |
deps |
List of labels, optional
List of other libraries to be linked to this test target.
These must be |
data |
List of labels, optional
List of files used by this rule at runtime.
This attribute can be used to specify any data files that are embedded
into the library, such as via the
|
crate_features |
List of strings, optional
List of features to enable for this crate.
Features are defined in the code using the
|
rustc_flags |
List of strings, optional
List of compiler flags passed to |
version |
String, optional
Version to inject in the cargo environment variable. |
out_dir_tar |
A single compressed tar or tar.gz file
A prepared .tar.gz file to be unpacked and supplied to
|
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 greeting(&self, thing: &str) -> String {
return format!("{} {}", &self.greeting, thing);
}
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.greeting("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("@io_bazel_rules_rust//rust:rust.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
.
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("@io_bazel_rules_rust//rust:rust.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
.
rust_bench_test(name, srcs, deps, data, crate_features, rustc_flags, out_dir_tar)
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. A
rust_toolchain
rule will be added in the near future to make it
easy to use a custom Rust toolchain, such as a nightly release.
Attributes | |
---|---|
name |
Name, required
A unique name for this rule. This name will also be used as the name of the binary test crate built by this rule. |
srcs |
List of labels, required
List of Rust
If |
crate_root |
Label, optional
The file that will be passed to
If |
deps |
List of labels, optional
List of other libraries to be linked to this test target.
These must be |
data |
List of labels, optional
List of files used by this rule at runtime.
This attribute can be used to specify any data files that are embedded
into the library, such as via the
|
crate_features |
List of strings, optional
List of features to enable for this crate.
Features are defined in the code using the
|
rustc_flags |
List of strings, optional
List of compiler flags passed to |
out_dir_tar |
A single compressed tar or tar.gz file
A prepared .tar.gz file to be unpacked and supplied to
|
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, simply add a rust_bench_test
target:
fibonacci/BUILD
:
package(default_visibility = ["//visibility:public"])
load("@io_bazel_rules_rust//rust:rust.bzl", "rust_library", "rust_bench_test")
rust_library(
name = "fibonacci",
srcs = ["src/lib.rs"],
)
rust_bench_test(
name = "fibonacci_bench",
srcs = ["benches/fibonacci_bench.rs"],
deps = [":fibonacci"],
)
Run the benchmark test using: bazel build //fibonacci:fibonacci_bench
.
rust_doc(name, dep, markdown_css, html_in_header, html_before_content, html_after_content)
Attribute | Description |
---|---|
name |
Name, required
A unique name for this rule. |
dep |
Label, required
The label of the target to generate code documentation for.
|
markdown_css |
List of Labels, optional
CSS files to include via |
html_in_header |
Label, optional
File to add to |
html_before_content |
Label, optional
File to add in |
html_after_content |
Label, optional
File to add in |
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("@io_bazel_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
.
rust_doc_test(name, dep)
Attribute | Description |
---|---|
name |
Name, required
A unique name for this rule. |
dep |
Label, required
The label of the target to run documentation tests for.
|
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("@io_bazel_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.