rules_rust

Rust rules

capture_clippy_output

capture_clippy_output(name)

Control whether to print clippy output or store it to a file, using the configured error_format.

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  

cargo_bootstrap_repository

cargo_bootstrap_repository(name, binary, build_mode, cargo_lockfile, cargo_toml, env, env_label,
                           repo_mapping, rust_toolchain_cargo_template, rust_toolchain_rustc_template,
                           srcs, timeout, version)

A rule for bootstrapping a Rust binary using Cargo

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this repository. Name required  
binary The binary to build (the --bin parameter for Cargo). If left empty, the repository name will be used. String optional ""
build_mode The build mode the binary should be built with String optional "release"
cargo_lockfile The lockfile of the crate_universe resolver Label required  
cargo_toml The path of the crate_universe resolver manifest (Cargo.toml file) Label required  
env A mapping of platform triple to a set of environment variables. See cargo_env for usage details. Additionally, the platform triple * applies to all platforms. Dictionary: String -> String optional {}
env_label A mapping of platform triple to a set of environment variables. This attribute differs from env in that all variables passed here must be fully qualified labels of files. See cargo_env for usage details. Additionally, the platform triple * applies to all platforms. Dictionary: String -> String optional {}
repo_mapping A 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 -> String required  
rust_toolchain_cargo_template The template to use for finding the host cargo binary. {version} (eg. ‘1.53.0’), {triple} (eg. ‘x86_64-unknown-linux-gnu’), {arch} (eg. ‘aarch64’), {vendor} (eg. ‘unknown’), {system} (eg. ‘darwin’), {channel} (eg. ‘stable’), and {tool} (eg. ‘rustc.exe’) will be replaced in the string if present. String optional "@rust_{system}_{arch}__{triple}__{channel}_tools//:bin/{tool}"
rust_toolchain_rustc_template The template to use for finding the host rustc binary. {version} (eg. ‘1.53.0’), {triple} (eg. ‘x86_64-unknown-linux-gnu’), {arch} (eg. ‘aarch64’), {vendor} (eg. ‘unknown’), {system} (eg. ‘darwin’), {channel} (eg. ‘stable’), and {tool} (eg. ‘rustc.exe’) will be replaced in the string if present. String optional "@rust_{system}_{arch}__{triple}__{channel}_tools//:bin/{tool}"
srcs Souce files of the crate to build. Passing source files here can be used to trigger rebuilds when changes are made List of labels optional []
timeout Maximum duration of the Cargo build command in seconds Integer optional 600
version The version of Rust the currently registered toolchain is using. Eg. 1.56.0, or nightly/2021-09-08 String optional "1.78.0"

cargo_dep_env

cargo_dep_env(name, out_dir, src)

A rule for generating variables for dependent cargo_build_scripts without a build script. This is useful for using Bazel rules instead of a build script, while also generating configuration information for build scripts which depend on this crate.

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  
out_dir Folder containing additional inputs when building all direct dependencies.

This has the same effect as a cargo_build_script which prints puts files into $OUT_DIR, but without requiring a build script.
Label optional None
src File containing additional environment variables to set for build scripts of direct dependencies.

This has the same effect as a cargo_build_script which prints cargo:VAR=VALUE lines, but without requiring a build script.

This 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 (\\).
Label required  

error_format

error_format(name)

Change the –error-format flag from the command line with --@rules_rust//:error_format. See rustc documentation for valid values.

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  

extra_rustc_flag

extra_rustc_flag(name)

Add additional rustc_flag from the command line with --@rules_rust//:extra_rustc_flag. Multiple uses are accumulated and appended after the extra_rustc_flags.

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  

extra_rustc_flags

extra_rustc_flags(name)

Add additional rustc_flags from the command line with --@rules_rust//:extra_rustc_flags. This flag should only be used for flags that need to be applied across the entire build. For options that apply to individual crates, use the rustc_flags attribute on the individual crate’s rule instead. NOTE: These flags not applied to the exec configuration (proc-macros, cargo_build_script, etc); use --@rules_rust//:extra_exec_rustc_flags to apply flags to the exec configuration.

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  

incompatible_flag

incompatible_flag(name, issue)

A rule defining an incompatible flag.

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  
issue The link to the github issue associated with this flag String required  

rust_analyzer_toolchain

rust_analyzer_toolchain(name, proc_macro_srv, rustc, rustc_srcs)

A toolchain for rust-analyzer.

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  
proc_macro_srv The path to a rust_analyzer_proc_macro_srv binary. Label optional None
rustc The path to a rustc binary. Label required  
rustc_srcs The source code of rustc. Label required  

rust_binary

rust_binary(name, aliases, compile_data, crate_features, crate_name, crate_root, crate_type, data,
            deps, edition, env, experimental_use_cc_common_link, linker_script, malloc, out_binary,
            platform, proc_macro_deps, rustc_env, rustc_env_files, rustc_flags, srcs, stamp, version)

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) -&gt; 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:defs.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:defs.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

On Windows, a PDB file containing debugging information is available under the key pdb_file in OutputGroupInfo. Similarly on macOS, a dSYM folder is available under the key dsym_folder in OutputGroupInfo.

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  
aliases Remap 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 -> String optional {}
compile_data List 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 labels optional []
crate_features List 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 strings optional []
crate_name Crate 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.
String optional ""
crate_root The 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.
Label optional None
crate_type Crate 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).
String optional "bin"
data List 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 labels optional []
deps List 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 labels optional []
edition The rust edition to use for this crate. Defaults to the edition specified in the rust_toolchain. String optional ""
env Specifies additional environment variables to set when the target is executed by bazel run. Values are subject to $(rootpath), $(execpath), location, and “Make variable” substitution.

Execpath returns absolute path, and in order to be able to construct the absolute path we need to wrap the test binary in a launcher. Using a launcher comes with complications, such as more complicated debugger attachment.
Dictionary: String -> String optional {}
experimental_use_cc_common_link Whether to use cc_common.link to link rust binaries. Possible values: [-1, 0, 1]. -1 means use the value of the toolchain.experimental_use_cc_common_link boolean build setting to determine. 0 means do not use cc_common.link (use rustc instead). 1 means use cc_common.link. Integer optional -1
linker_script Link script to forward into linker via rustc options. Label optional None
malloc Override the default dependency on malloc.

By default, Rust binaries linked with cc_common.link are linked against @bazel_tools//tools/cpp:malloc", which is an empty library and the resulting binary will use libc’s malloc. This label must refer to a cc_library rule.
Label optional @bazel_tools//tools/cpp:malloc
out_binary Force a target, regardless of it’s crate_type, to always mark the file as executable. This attribute is only used to support wasm targets but is expected to be removed following a resolution to https://github.com/bazelbuild/rules_rust/issues/771. Boolean optional False
platform Optional platform to transition the binary to. Label optional None
proc_macro_deps List of rust_proc_macro targets used to help build this library target. List of labels optional []
rustc_env Dictionary 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 -> String optional {}
rustc_env_files Files 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 (\\).

The order that these files will be processed is unspecified, so multiple definitions of a particular variable are discouraged.

Note that the variables here are subject to workspace status stamping should the stamp attribute be enabled. Stamp variables should be wrapped in brackets in order to be resolved. E.g. NAME={WORKSPACE_STATUS_VARIABLE}.
List of labels optional []
rustc_flags List of compiler flags passed to rustc.

These strings are subject to Make variable expansion for predefined source/output path variables like $location, $execpath, and $rootpath. This expansion is useful if you wish to pass a generated file of arguments to rustc: @$(location //package:target).
List of strings optional []
srcs List 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 labels optional []
stamp Whether to encode build information into the Rustc action. Possible values:

- stamp = 1: Always stamp the build information into the Rustc action, even in –nostamp builds. This setting should be avoided, since it potentially kills remote caching for the target and any downstream actions that depend on it.

- stamp = 0: Always replace build information by constant values. This gives good build result caching.

- stamp = -1: Embedding of build information is controlled by the –[no]stamp flag.

Stamped targets are not rebuilt unless their dependencies change.

For example if a rust_library is stamped, and a rust_binary depends on that library, the stamped library won’t be rebuilt when we change sources of the rust_binary. This is different from how cc_library.linkstamps behaves.
Integer optional -1
version A version to inject in the cargo environment variable. String optional "0.0.0"

rust_bindgen

rust_bindgen(name, bindgen_flags, cc_lib, clang_flags, header)

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

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  
bindgen_flags Flags to pass directly to the bindgen executable. See https://rust-lang.github.io/rust-bindgen/ for details. List of strings optional []
cc_lib The cc_library that contains the .h file. This is used to find the transitive includes. Label required  
clang_flags Flags to pass directly to the clang executable. List of strings optional []
header The .h file to generate bindings for. Label required  

rust_bindgen_toolchain

rust_bindgen_toolchain(name, bindgen, clang, default_rustfmt, libclang, libstdcxx)

The tools required for the rust_bindgen rule.

This rule depends on the bindgen binary crate, and it in turn depends on both a clang binary and the clang library. To obtain these dependencies, rust_bindgen_dependencies imports bindgen and its dependencies.

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

rust_bindgen_toolchain(
    name = "bindgen_toolchain_impl",
    bindgen = "//my/rust:bindgen",
    clang = "//my/clang:clang",
    libclang = "//my/clang:libclang.so",
    libstdcxx = "//my/cpp:libstdc++",
)

toolchain(
    name = "bindgen_toolchain",
    toolchain = "bindgen_toolchain_impl",
    toolchain_type = "@rules_rust//bindgen:toolchain_type",
)

This toolchain will then need to be registered in the current WORKSPACE. For additional information, see the Bazel toolchains documentation.

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  
bindgen The label of a bindgen executable. Label optional None
clang The label of a clang executable. Label optional None
default_rustfmt If set, rust_bindgen targets will always format generated sources with rustfmt. Boolean optional True
libclang A cc_library that provides bindgen’s runtime dependency on libclang. Label optional None
libstdcxx A cc_library that satisfies libclang’s libstdc++ dependency. This is used to make the execution of clang hermetic. If None, system libraries will be used instead. Label optional None

rust_clippy

rust_clippy(name, deps)

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

Name Description Type Mandatory Default
name A unique name for this target. Name required  
deps Rust targets to run clippy on. List of labels optional []

rust_doc

rust_doc(name, crate, html_after_content, html_before_content, html_in_header, markdown_css,
         rustc_flags, rustdoc_flags)

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:defs.bzl", "rust_library", "rust_doc")

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

rust_doc(
    name = "hello_lib_doc",
    crate = ":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

Name Description Type Mandatory Default
name A unique name for this target. Name required  
crate The 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.
Label required  
html_after_content File to add in <body>, after content. Label optional None
html_before_content File to add in <body>, before content. Label optional None
html_in_header File to add to <head>. Label optional None
markdown_css CSS files to include via <link> in a rendered Markdown file. List of labels optional []
rustc_flags Deprecated: use rustdoc_flags instead List of strings optional []
rustdoc_flags List of flags passed to rustdoc.

These strings are subject to Make variable expansion for predefined source/output path variables like $location, $execpath, and $rootpath. This expansion is useful if you wish to pass a generated file of arguments to rustc: @$(location //package:target).
List of strings optional []

rust_doc_test

rust_doc_test(name, crate, deps)

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:defs.bzl", "rust_library", "rust_doc_test")

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

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

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

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  
crate The label of the target to generate code documentation for. rust_doc_test can generate HTML code documentation for the source files of rust_library or rust_binary targets. Label required  
deps List 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 labels optional []

rust_grpc_library

rust_grpc_library(name, crate_name, deps, rust_deps, rustc_flags)

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

Example:

load("@rules_rust//proto/protobuf:defs.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

Name Description Type Mandatory Default
name A unique name for this target. Name required  
crate_name Crate 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.
String optional ""
deps List of proto_library dependencies that will be built. One crate for each proto_library will be created with the corresponding gRPC stubs. List of labels required  
rust_deps The crates the generated library depends on. List of labels optional []
rustc_flags List of compiler flags passed to rustc.

These strings are subject to Make variable expansion for predefined source/output path variables like $location, $execpath, and $rootpath. This expansion is useful if you wish to pass a generated file of arguments to rustc: @$(location //package:target).
List of strings optional []

rust_library

rust_library(name, aliases, compile_data, crate_features, crate_name, crate_root, data, deps,
             disable_pipelining, edition, proc_macro_deps, rustc_env, rustc_env_files, rustc_flags,
             srcs, stamp, version)

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) -&gt; 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:defs.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

Name Description Type Mandatory Default
name A unique name for this target. Name required  
aliases Remap 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 -> String optional {}
compile_data List 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 labels optional []
crate_features List 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 strings optional []
crate_name Crate 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.
String optional ""
crate_root The 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.
Label optional None
data List 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 labels optional []
deps List 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 labels optional []
disable_pipelining Disables pipelining for this rule if it is globally enabled. This will cause this rule to not produce a .rmeta file and all the dependent crates will instead use the .rlib file. Boolean optional False
edition The rust edition to use for this crate. Defaults to the edition specified in the rust_toolchain. String optional ""
proc_macro_deps List of rust_proc_macro targets used to help build this library target. List of labels optional []
rustc_env Dictionary 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 -> String optional {}
rustc_env_files Files 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 (\\).

The order that these files will be processed is unspecified, so multiple definitions of a particular variable are discouraged.

Note that the variables here are subject to workspace status stamping should the stamp attribute be enabled. Stamp variables should be wrapped in brackets in order to be resolved. E.g. NAME={WORKSPACE_STATUS_VARIABLE}.
List of labels optional []
rustc_flags List of compiler flags passed to rustc.

These strings are subject to Make variable expansion for predefined source/output path variables like $location, $execpath, and $rootpath. This expansion is useful if you wish to pass a generated file of arguments to rustc: @$(location //package:target).
List of strings optional []
srcs List 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 labels optional []
stamp Whether to encode build information into the Rustc action. Possible values:

- stamp = 1: Always stamp the build information into the Rustc action, even in –nostamp builds. This setting should be avoided, since it potentially kills remote caching for the target and any downstream actions that depend on it.

- stamp = 0: Always replace build information by constant values. This gives good build result caching.

- stamp = -1: Embedding of build information is controlled by the –[no]stamp flag.

Stamped targets are not rebuilt unless their dependencies change.

For example if a rust_library is stamped, and a rust_binary depends on that library, the stamped library won’t be rebuilt when we change sources of the rust_binary. This is different from how cc_library.linkstamps behaves.
Integer optional 0
version A version to inject in the cargo environment variable. String optional "0.0.0"

rust_library_group

rust_library_group(name, deps)

Functions as an alias for a set of dependencies.

Specifically, the following are equivalent:

rust_library_group(
    name = "crate_group",
    deps = [
        ":crate1",
        ":crate2",
    ],
)

rust_library(
    name = "foobar",
    deps = [":crate_group"],
    ...
)

and

rust_library(
    name = "foobar",
    deps = [
        ":crate1",
        ":crate2",
    ],
    ...
)

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  
deps Other dependencies to forward through this crate group. List of labels optional []

rust_proc_macro

rust_proc_macro(name, aliases, compile_data, crate_features, crate_name, crate_root, data, deps,
                edition, proc_macro_deps, rustc_env, rustc_env_files, rustc_flags, srcs, stamp,
                version)

Builds a Rust proc-macro crate.

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  
aliases Remap 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 -> String optional {}
compile_data List 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 labels optional []
crate_features List 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 strings optional []
crate_name Crate 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.
String optional ""
crate_root The 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.
Label optional None
data List 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 labels optional []
deps List 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 labels optional []
edition The rust edition to use for this crate. Defaults to the edition specified in the rust_toolchain. String optional ""
proc_macro_deps List of rust_proc_macro targets used to help build this library target. List of labels optional []
rustc_env Dictionary 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 -> String optional {}
rustc_env_files Files 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 (\\).

The order that these files will be processed is unspecified, so multiple definitions of a particular variable are discouraged.

Note that the variables here are subject to workspace status stamping should the stamp attribute be enabled. Stamp variables should be wrapped in brackets in order to be resolved. E.g. NAME={WORKSPACE_STATUS_VARIABLE}.
List of labels optional []
rustc_flags List of compiler flags passed to rustc.

These strings are subject to Make variable expansion for predefined source/output path variables like $location, $execpath, and $rootpath. This expansion is useful if you wish to pass a generated file of arguments to rustc: @$(location //package:target).
List of strings optional []
srcs List 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 labels optional []
stamp Whether to encode build information into the Rustc action. Possible values:

- stamp = 1: Always stamp the build information into the Rustc action, even in –nostamp builds. This setting should be avoided, since it potentially kills remote caching for the target and any downstream actions that depend on it.

- stamp = 0: Always replace build information by constant values. This gives good build result caching.

- stamp = -1: Embedding of build information is controlled by the –[no]stamp flag.

Stamped targets are not rebuilt unless their dependencies change.

For example if a rust_library is stamped, and a rust_binary depends on that library, the stamped library won’t be rebuilt when we change sources of the rust_binary. This is different from how cc_library.linkstamps behaves.
Integer optional 0
version A version to inject in the cargo environment variable. String optional "0.0.0"

rust_prost_toolchain

rust_prost_toolchain(name, prost_opts, prost_plugin, prost_plugin_flag, prost_runtime, prost_types,
                     proto_compiler, tonic_opts, tonic_plugin, tonic_plugin_flag, tonic_runtime)

Rust Prost toolchain rule.

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  
prost_opts Additional options to add to Prost. List of strings optional []
prost_plugin Additional plugins to add to Prost. Label required  
prost_plugin_flag Prost plugin flag format. (e.g. --plugin=protoc-gen-prost=%s) String optional "--plugin=protoc-gen-prost=%s"
prost_runtime The Prost runtime crates to use. Label required  
prost_types The Prost types crates to use. Label required  
proto_compiler The protoc compiler to use. Label required  
tonic_opts Additional options to add to Tonic. List of strings optional []
tonic_plugin Additional plugins to add to Tonic. Label optional None
tonic_plugin_flag Tonic plugin flag format. (e.g. --plugin=protoc-gen-tonic=%s)) String optional "--plugin=protoc-gen-tonic=%s"
tonic_runtime The Tonic runtime crates to use. Label optional None

rust_proto_library

rust_proto_library(name, crate_name, deps, rust_deps, rustc_flags)

Builds a Rust library crate from a set of proto_librarys.

Example:

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

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

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

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

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  
crate_name Crate 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.
String optional ""
deps List of proto_library dependencies that will be built. One crate for each proto_library will be created with the corresponding stubs. List of labels required  
rust_deps The crates the generated library depends on. List of labels optional []
rustc_flags List of compiler flags passed to rustc.

These strings are subject to Make variable expansion for predefined source/output path variables like $location, $execpath, and $rootpath. This expansion is useful if you wish to pass a generated file of arguments to rustc: @$(location //package:target).
List of strings optional []

rust_shared_library

rust_shared_library(name, aliases, compile_data, crate_features, crate_name, crate_root, data, deps,
                    edition, experimental_use_cc_common_link, malloc, platform, proc_macro_deps,
                    rustc_env, rustc_env_files, rustc_flags, srcs, stamp, version)

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

Name Description Type Mandatory Default
name A unique name for this target. Name required  
aliases Remap 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 -> String optional {}
compile_data List 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 labels optional []
crate_features List 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 strings optional []
crate_name Crate 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.
String optional ""
crate_root The 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.
Label optional None
data List 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 labels optional []
deps List 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 labels optional []
edition The rust edition to use for this crate. Defaults to the edition specified in the rust_toolchain. String optional ""
experimental_use_cc_common_link Whether to use cc_common.link to link rust binaries. Possible values: [-1, 0, 1]. -1 means use the value of the toolchain.experimental_use_cc_common_link boolean build setting to determine. 0 means do not use cc_common.link (use rustc instead). 1 means use cc_common.link. Integer optional -1
malloc Override the default dependency on malloc.

By default, Rust binaries linked with cc_common.link are linked against @bazel_tools//tools/cpp:malloc", which is an empty library and the resulting binary will use libc’s malloc. This label must refer to a cc_library rule.
Label optional @bazel_tools//tools/cpp:malloc
platform Optional platform to transition the shared library to. Label optional None
proc_macro_deps List of rust_proc_macro targets used to help build this library target. List of labels optional []
rustc_env Dictionary 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 -> String optional {}
rustc_env_files Files 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 (\\).

The order that these files will be processed is unspecified, so multiple definitions of a particular variable are discouraged.

Note that the variables here are subject to workspace status stamping should the stamp attribute be enabled. Stamp variables should be wrapped in brackets in order to be resolved. E.g. NAME={WORKSPACE_STATUS_VARIABLE}.
List of labels optional []
rustc_flags List of compiler flags passed to rustc.

These strings are subject to Make variable expansion for predefined source/output path variables like $location, $execpath, and $rootpath. This expansion is useful if you wish to pass a generated file of arguments to rustc: @$(location //package:target).
List of strings optional []
srcs List 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 labels optional []
stamp Whether to encode build information into the Rustc action. Possible values:

- stamp = 1: Always stamp the build information into the Rustc action, even in –nostamp builds. This setting should be avoided, since it potentially kills remote caching for the target and any downstream actions that depend on it.

- stamp = 0: Always replace build information by constant values. This gives good build result caching.

- stamp = -1: Embedding of build information is controlled by the –[no]stamp flag.

Stamped targets are not rebuilt unless their dependencies change.

For example if a rust_library is stamped, and a rust_binary depends on that library, the stamped library won’t be rebuilt when we change sources of the rust_binary. This is different from how cc_library.linkstamps behaves.
Integer optional 0
version A version to inject in the cargo environment variable. String optional "0.0.0"

rust_static_library

rust_static_library(name, aliases, compile_data, crate_features, crate_name, crate_root, data, deps,
                    edition, platform, proc_macro_deps, rustc_env, rustc_env_files, rustc_flags, srcs,
                    stamp, version)

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

Name Description Type Mandatory Default
name A unique name for this target. Name required  
aliases Remap 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 -> String optional {}
compile_data List 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 labels optional []
crate_features List 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 strings optional []
crate_name Crate 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.
String optional ""
crate_root The 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.
Label optional None
data List 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 labels optional []
deps List 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 labels optional []
edition The rust edition to use for this crate. Defaults to the edition specified in the rust_toolchain. String optional ""
platform Optional platform to transition the static library to. Label optional None
proc_macro_deps List of rust_proc_macro targets used to help build this library target. List of labels optional []
rustc_env Dictionary 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 -> String optional {}
rustc_env_files Files 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 (\\).

The order that these files will be processed is unspecified, so multiple definitions of a particular variable are discouraged.

Note that the variables here are subject to workspace status stamping should the stamp attribute be enabled. Stamp variables should be wrapped in brackets in order to be resolved. E.g. NAME={WORKSPACE_STATUS_VARIABLE}.
List of labels optional []
rustc_flags List of compiler flags passed to rustc.

These strings are subject to Make variable expansion for predefined source/output path variables like $location, $execpath, and $rootpath. This expansion is useful if you wish to pass a generated file of arguments to rustc: @$(location //package:target).
List of strings optional []
srcs List 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 labels optional []
stamp Whether to encode build information into the Rustc action. Possible values:

- stamp = 1: Always stamp the build information into the Rustc action, even in –nostamp builds. This setting should be avoided, since it potentially kills remote caching for the target and any downstream actions that depend on it.

- stamp = 0: Always replace build information by constant values. This gives good build result caching.

- stamp = -1: Embedding of build information is controlled by the –[no]stamp flag.

Stamped targets are not rebuilt unless their dependencies change.

For example if a rust_library is stamped, and a rust_binary depends on that library, the stamped library won’t be rebuilt when we change sources of the rust_binary. This is different from how cc_library.linkstamps behaves.
Integer optional 0
version A version to inject in the cargo environment variable. String optional "0.0.0"

rust_stdlib_filegroup

rust_stdlib_filegroup(name, srcs)

A dedicated filegroup-like rule for Rust stdlib artifacts.

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  
srcs The list of targets/files that are components of the rust-stdlib file group List of labels required  

rust_test

rust_test(name, aliases, compile_data, crate, crate_features, crate_name, crate_root, data, deps,
          edition, env, experimental_use_cc_common_link, malloc, platform, proc_macro_deps, rustc_env,
          rustc_env_files, rustc_flags, srcs, stamp, use_libtest_harness, version)

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) -&gt; Greeter {
        Greeter { greeting: greeting.to_string(), }
    }

    pub fn greet(&self, thing: &str) -&gt; String {
        format!("{} {}", &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 via the crate attribute:

hello_lib/BUILD:

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

Run the test with bazel test //hello_lib:hello_lib_test. The crate will be built using the same crate name as the underlying “:hello_lib” crate.

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:

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 test //hello_lib:greeting_test.

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  
aliases Remap 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 -> String optional {}
compile_data List 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 labels optional []
crate Target inline tests declared in the given crate

These tests are typically those that would be held out under #[cfg(test)] declarations.
Label optional None
crate_features List 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 strings optional []
crate_name Crate 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.
String optional ""
crate_root The 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.
Label optional None
data List 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 labels optional []
deps List 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 labels optional []
edition The rust edition to use for this crate. Defaults to the edition specified in the rust_toolchain. String optional ""
env Specifies additional environment variables to set when the test is executed by bazel test. Values are subject to $(rootpath), $(execpath), location, and “Make variable” substitution. Dictionary: String -> String optional {}
experimental_use_cc_common_link Whether to use cc_common.link to link rust binaries. Possible values: [-1, 0, 1]. -1 means use the value of the toolchain.experimental_use_cc_common_link boolean build setting to determine. 0 means do not use cc_common.link (use rustc instead). 1 means use cc_common.link. Integer optional -1
malloc Override the default dependency on malloc.

By default, Rust binaries linked with cc_common.link are linked against @bazel_tools//tools/cpp:malloc", which is an empty library and the resulting binary will use libc’s malloc. This label must refer to a cc_library rule.
Label optional @bazel_tools//tools/cpp:malloc
platform Optional platform to transition the test to. Label optional None
proc_macro_deps List of rust_proc_macro targets used to help build this library target. List of labels optional []
rustc_env Dictionary 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 -> String optional {}
rustc_env_files Files 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 (\\).

The order that these files will be processed is unspecified, so multiple definitions of a particular variable are discouraged.

Note that the variables here are subject to workspace status stamping should the stamp attribute be enabled. Stamp variables should be wrapped in brackets in order to be resolved. E.g. NAME={WORKSPACE_STATUS_VARIABLE}.
List of labels optional []
rustc_flags List of compiler flags passed to rustc.

These strings are subject to Make variable expansion for predefined source/output path variables like $location, $execpath, and $rootpath. This expansion is useful if you wish to pass a generated file of arguments to rustc: @$(location //package:target).
List of strings optional []
srcs List 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 labels optional []
stamp Whether to encode build information into the Rustc action. Possible values:

- stamp = 1: Always stamp the build information into the Rustc action, even in –nostamp builds. This setting should be avoided, since it potentially kills remote caching for the target and any downstream actions that depend on it.

- stamp = 0: Always replace build information by constant values. This gives good build result caching.

- stamp = -1: Embedding of build information is controlled by the –[no]stamp flag.

Stamped targets are not rebuilt unless their dependencies change.

For example if a rust_library is stamped, and a rust_binary depends on that library, the stamped library won’t be rebuilt when we change sources of the rust_binary. This is different from how cc_library.linkstamps behaves.
Integer optional 0
use_libtest_harness Whether to use libtest. For targets using this flag, individual tests can be run by using the –test_arg flag. E.g. bazel test //src:rust_test --test_arg=foo::test::test_fn. Boolean optional True
version A version to inject in the cargo environment variable. String optional "0.0.0"

rust_toolchain

rust_toolchain(name, allocator_library, binary_ext, cargo, clippy_driver, debug_info,
               default_edition, dylib_ext, env, exec_triple, experimental_link_std_dylib,
               experimental_use_cc_common_link, extra_exec_rustc_flags, extra_rustc_flags,
               extra_rustc_flags_for_crate_types, global_allocator_library, llvm_cov, llvm_profdata,
               llvm_tools, opt_level, per_crate_rustc_flags, rust_doc, rust_std, rustc, rustc_lib,
               rustfmt, staticlib_ext, stdlib_linkflags, strip_level, target_json, target_triple)

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",
    binary_ext = "",
    dylib_ext = ".so",
    exec_triple = "cpuX-unknown-linux-gnu",
    rust_doc = "@rust_cpuX//:rustdoc",
    rust_std = "@rust_cpuX//:rust_std",
    rustc = "@rust_cpuX//:rustc",
    rustc_lib = "@rust_cpuX//:rustc_lib",
    staticlib_ext = ".a",
    stdlib_linkflags = ["-lpthread", "-ldl"],
    target_triple = "cpuX-unknown-linux-gnu",
)

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

Name Description Type Mandatory Default
name A unique name for this target. Name required  
allocator_library Target that provides allocator functions when rust_library targets are embedded in a cc_binary. Label optional @rules_rust//ffi/cc/allocator_library
binary_ext The extension for binaries created from rustc. String required  
cargo The location of the cargo binary. Can be a direct source or a filegroup containing one item. Label optional None
clippy_driver The location of the clippy-driver binary. Can be a direct source or a filegroup containing one item. Label optional None
debug_info Rustc debug info levels per opt level Dictionary: String -> String optional {"dbg": "2", "fastbuild": "0", "opt": "0"}
default_edition The edition to use for rust_* rules that don’t specify an edition. If absent, every rule is required to specify its edition attribute. String optional ""
dylib_ext The extension for dynamic libraries created from rustc. String required  
env Environment variables to set in actions. Dictionary: String -> String optional {}
exec_triple The platform triple for the toolchains execution environment. For more details see: https://docs.bazel.build/versions/master/skylark/rules.html#configurations String required  
experimental_link_std_dylib Label to a boolean build setting that controls whether whether to link libstd dynamically. Label optional @rules_rust//rust/settings:experimental_link_std_dylib
experimental_use_cc_common_link Label to a boolean build setting that controls whether cc_common.link is used to link rust binaries. Label optional //rust/settings:experimental_use_cc_common_link
extra_exec_rustc_flags Extra flags to pass to rustc in exec configuration List of strings optional []
extra_rustc_flags Extra flags to pass to rustc in non-exec configuration List of strings optional []
extra_rustc_flags_for_crate_types Extra flags to pass to rustc based on crate type Dictionary: String -> List of strings optional {}
global_allocator_library Target that provides allocator functions for when a global allocator is present. Label optional @rules_rust//ffi/cc/global_allocator_library
llvm_cov The location of the llvm-cov binary. Can be a direct source or a filegroup containing one item. If None, rust code is not instrumented for coverage. Label optional None
llvm_profdata The location of the llvm-profdata binary. Can be a direct source or a filegroup containing one item. If llvm_cov is None, this can be None as well and rust code is not instrumented for coverage. Label optional None
llvm_tools LLVM tools that are shipped with the Rust toolchain. Label optional None
opt_level Rustc optimization levels. Dictionary: String -> String optional {"dbg": "0", "fastbuild": "0", "opt": "3"}
per_crate_rustc_flags Extra flags to pass to rustc in non-exec configuration List of strings optional []
rust_doc The location of the rustdoc binary. Can be a direct source or a filegroup containing one item. Label required  
rust_std The Rust standard library. Label required  
rustc The location of the rustc binary. Can be a direct source or a filegroup containing one item. Label required  
rustc_lib The libraries used by rustc during compilation. Label optional None
rustfmt Deprecated: Instead see rustfmt_toolchain Label optional None
staticlib_ext The extension for static libraries created from rustc. String required  
stdlib_linkflags Additional linker flags to use when Rust standard library is linked by a C++ linker (rustc will deal with these automatically). Subject to location expansion with respect to the srcs of the rust_std attribute. List of strings required  
strip_level Rustc strip levels. For all potential options, see https://doc.rust-lang.org/rustc/codegen-options/index.html#strip Dictionary: String -> String optional {"dbg": "none", "fastbuild": "none", "opt": "debuginfo"}
target_json Override the target_triple with a custom target specification. For more details see: https://doc.rust-lang.org/rustc/targets/custom.html String optional ""
target_triple The platform triple for the toolchains target environment. For more details see: https://docs.bazel.build/versions/master/skylark/rules.html#configurations String optional ""

rust_toolchain_repository_proxy

rust_toolchain_repository_proxy(name, exec_compatible_with, repo_mapping, target_compatible_with,
                                target_settings, toolchain, toolchain_type)

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

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this repository. Name required  
exec_compatible_with A list of constraints for the execution platform for this toolchain. List of strings optional []
repo_mapping A 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 -> String required  
target_compatible_with A list of constraints for the target platform for this toolchain. List of strings optional []
target_settings A list of config_settings that must be satisfied by the target configuration in order for this toolchain to be selected during toolchain resolution. List of strings optional []
toolchain The name of the toolchain implementation target. String required  
toolchain_type The toolchain type of the toolchain to declare String required  

rust_toolchain_tools_repository

rust_toolchain_tools_repository(name, allocator_library, auth, auth_patterns, dev_components,
                                edition, exec_triple, extra_exec_rustc_flags, extra_rustc_flags,
                                global_allocator_library, iso_date, netrc, opt_level, repo_mapping,
                                rustfmt_version, sha256s, target_triple, urls, version)

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 toolchain_repository_proxy invocation to declare its toolchains to Bazel; the indirection allows separating toolchain selection from toolchain fetching.

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this repository. Name required  
allocator_library Target that provides allocator functions when rust_library targets are embedded in a cc_binary. String optional "@rules_rust//ffi/cc/allocator_library"
auth Auth object compatible with repository_ctx.download to use when downloading files. See repository_ctx.download for more details. Dictionary: String -> String optional {}
auth_patterns A list of patterns to match against urls for which the auth object should be used. List of strings optional []
dev_components Whether to download the rustc-dev components (defaults to False). Requires version to be “nightly”. Boolean optional False
edition The rust edition to be used by default (2015, 2018, or 2021). If absent, every rule is required to specify its edition attribute. String optional ""
exec_triple The Rust-style target that this compiler runs on String required  
extra_exec_rustc_flags Extra flags to pass to rustc in exec configuration List of strings optional []
extra_rustc_flags Extra flags to pass to rustc in non-exec configuration List of strings optional []
global_allocator_library Target that provides allocator functions when a global allocator is used with cc_common.link. String optional "@rules_rust//ffi/cc/global_allocator_library"
iso_date The date of the tool (or None, if the version is a specific version). String optional ""
netrc .netrc file to use for authentication; mirrors the eponymous attribute from http_archive String optional ""
opt_level Rustc optimization levels. For more details see the documentation for rust_toolchain.opt_level. Dictionary: String -> String optional {}
repo_mapping A 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 -> String required  
rustfmt_version The version of the tool among “nightly”, “beta”, or an exact version. String optional ""
sha256s A dict associating tool subdirectories to sha256 hashes. See rust_register_toolchains for more details. Dictionary: String -> String optional {}
target_triple The Rust-style target that this compiler builds for. String required  
urls A 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 strings optional ["https://static.rust-lang.org/dist/{}.tar.xz"]
version The version of the tool among “nightly”, “beta”, or an exact version. String required  

rust_wasm_bindgen

rust_wasm_bindgen(name, bindgen_flags, target, wasm_file)

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

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

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  
bindgen_flags Flags to pass directly to the bindgen executable. See https://github.com/rustwasm/wasm-bindgen/ for details. List of strings optional []
target The type of output to generate. See https://rustwasm.github.io/wasm-bindgen/reference/deployment.html for details. String optional "bundler"
wasm_file The .wasm file or crate to generate bindings for. Label required  

rust_wasm_bindgen_toolchain

rust_wasm_bindgen_toolchain(name, bindgen)

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 = "//3rdparty/crates:wasm_bindgen_cli__bin",
)

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

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

Name Description Type Mandatory Default
name A unique name for this target. Name required  
bindgen The label of a wasm-bindgen-cli executable. Label optional None

rustfmt_test

rustfmt_test(name, targets)

A test rule for performing rustfmt --check on a set of targets

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  
targets Rust targets to run rustfmt --check on. List of labels optional []

rustfmt_toolchain

rustfmt_toolchain(name, rustc, rustc_lib, rustfmt)

A toolchain for rustfmt

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  
rustc The location of the rustc binary. Can be a direct source or a filegroup containing one item. Label optional None
rustc_lib The libraries used by rustc during compilation. Label optional None
rustfmt The location of the rustfmt binary. Can be a direct source or a filegroup containing one item. Label required  

CrateInfo

CrateInfo(aliases, compile_data, compile_data_targets, data, deps, edition, is_test, metadata, name,
          output, owner, proc_macro_deps, root, rustc_env, rustc_env_files, rustc_output,
          rustc_rmeta_output, srcs, std_dylib, type, wrapped_crate_type)

A provider containing general Crate information.

FIELDS

Name Description
aliases Dict[Label, String]: Renamed and aliased crates
compile_data depset[File]: Compile data required by this crate.
compile_data_targets depset[Label]: Compile data targets required by this crate.
data depset[File]: Compile data required by crates that use the current crate as a proc-macro.
deps depset[DepVariantInfo]: This crate’s (rust or cc) dependencies’ providers.
edition str: The edition of this crate.
is_test bool: If the crate is being compiled in a test context
metadata File: The output from rustc from producing the output file. It is optional.
name str: The name of this crate.
output File: The output File that will be produced, depends on crate type.
owner Label: The label of the target that produced this CrateInfo
proc_macro_deps depset[DepVariantInfo]: This crate’s rust proc_macro dependencies’ providers.
root File: The source File entrypoint to this crate, eg. lib.rs
rustc_env Dict[String, String]: Additional "key": "value" environment variables to set for rustc.
rustc_env_files [File]: Files containing additional environment variables to set for rustc.
rustc_output File: The output from rustc from producing the output file. It is optional.
rustc_rmeta_output File: The rmeta file produced for this crate. It is optional.
srcs depset[File]: All source Files that are part of the crate.
std_dylib File: libstd.so file
type str: The type of this crate (see rustc –crate-type).
wrapped_crate_type str, optional: The original crate type for targets generated using a previously defined crate (typically tests using the rust_test::crate attribute)

DepInfo

DepInfo(dep_env, direct_crates, link_search_path_files, transitive_build_infos,
        transitive_crate_outputs, transitive_crates, transitive_data, transitive_metadata_outputs,
        transitive_noncrates, transitive_proc_macro_data)

A provider containing information about a Crate’s dependencies.

FIELDS

Name Description
dep_env File: File with environment variables direct dependencies build scripts rely upon.
direct_crates depset[AliasableDepInfo]
link_search_path_files depset[File]: All transitive files containing search paths to pass to the linker
transitive_build_infos depset[BuildInfo]
transitive_crate_outputs depset[File]: All transitive crate outputs.
transitive_crates depset[CrateInfo]
transitive_data depset[File]: Data of all transitive non-macro dependencies.
transitive_metadata_outputs depset[File]: All transitive metadata dependencies (.rmeta, for crates that provide them) and all transitive object dependencies (.rlib) for crates that don’t provide metadata.
transitive_noncrates depset[LinkerInput]: All transitive dependencies that aren’t crates.
transitive_proc_macro_data depset[File]: Data of all transitive proc-macro dependencies, and non-macro dependencies of those macros.

RustWasmBindgenInfo

RustWasmBindgenInfo(js, ts, wasm)

Info about wasm-bindgen outputs.

FIELDS

Name Description
js Depset[File]: The Javascript files produced by wasm-bindgen.
ts Depset[File]: The Typescript files produced by wasm-bindgen.
wasm File: The .wasm file generated by wasm-bindgen.

StdLibInfo

StdLibInfo(alloc_files, between_alloc_and_core_files, between_core_and_std_files, core_files,
           dot_a_files, memchr_files, panic_files, self_contained_files, srcs, std_dylib, std_files,
           std_rlibs, test_files)

A collection of files either found within the rust-stdlib artifact or generated based on existing files.

FIELDS

Name Description
alloc_files List[File]: .a files related to the alloc module.
between_alloc_and_core_files List[File]: .a files related to the compiler_builtins module.
between_core_and_std_files List[File]: .a files related to all modules except adler, alloc, compiler_builtins, core, and std.
core_files List[File]: .a files related to the core and adler modules
dot_a_files Depset[File]: Generated .a files
memchr_files Depset[File]: .a files associated with the memchr module.
panic_files Depset[File]: .a files associated with panic_unwind and panic_abort.
self_contained_files List[File]: All .o files from the self-contained directory.
srcs List[Target]: All targets from the original srcs attribute.
std_dylib File: libstd.so file
std_files Depset[File]: .a files associated with the std module.
std_rlibs List[File]: All .rlib files
test_files Depset[File]: .a files associated with the test module.

cargo_build_script

cargo_build_script(name, edition, crate_name, crate_root, srcs, crate_features, version, deps,
                   link_deps, proc_macro_deps, build_script_env, data, compile_data, tools, links,
                   rundir, rustc_env, rustc_env_files, rustc_flags, visibility, tags, aliases, kwargs)

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

Name Description Default Value
name The name for the underlying rule. This should be the name of the package being compiled, optionally with a suffix of _build_script. none
edition The rust edition to use for the internal binary crate. None
crate_name Crate name to use for build script. None
crate_root The file that will be passed to rustc to be used for building this crate. None
srcs Souce files of the crate to build. Passing source files here can be used to trigger rebuilds when changes are made. []
crate_features A list of features to enable for the build script. []
version The semantic version (semver) of the crate. None
deps The build-dependencies of the crate. []
link_deps The subset of the (normal) dependencies of the crate that have the links attribute and therefore provide environment variables to this build script. []
proc_macro_deps List of rust_proc_macro targets used to build the script. []
build_script_env Environment variables for build scripts. {}
data Files needed by the build script. []
compile_data Files needed for the compilation of the build script. []
tools Tools (executables) needed by the build script. []
links Name of the native library this crate links against. None
rundir A directory to cd to before the cargo_build_script is run. This should be a path relative to the exec root.

The default behaviour (and the behaviour if rundir is set to the empty string) is to change to the relative path corresponding to the cargo manifest directory, which replicates the normal behaviour of cargo so it is easy to write compatible build scripts.

If set to ., the cargo build script will run in the exec root.
None
rustc_env Environment variables to set in rustc when compiling the build script. {}
rustc_env_files Files containing additional environment variables to set for rustc when building the build script. []
rustc_flags List of compiler flags passed to rustc. []
visibility Visibility to apply to the generated build script output. None
tags (list of str, optional): Tags to apply to the generated build script output. None
aliases Remap 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. None
kwargs Forwards to the underlying rust_binary rule. An exception is the compatible_with attribute, which shouldn’t be forwarded to the rust_binary, as the rust_binary is only built and used in exec mode. We propagate the compatible_with attribute to the _build_scirpt_run target. none

cargo_env

cargo_env(env)

A helper for generating platform specific environment variables

load("@rules_rust//rust:defs.bzl", "rust_common")
load("@rules_rust//cargo:defs.bzl", "cargo_bootstrap_repository", "cargo_env")

cargo_bootstrap_repository(
    name = "bootstrapped_bin",
    cargo_lockfile = "//:Cargo.lock",
    cargo_toml = "//:Cargo.toml",
    srcs = ["//:resolver_srcs"],
    version = rust_common.default_version,
    binary = "my-crate-binary",
    env = {
        "x86_64-unknown-linux-gnu": cargo_env({
            "FOO": "BAR",
        }),
    },
    env_label = {
        "aarch64-unknown-linux-musl": cargo_env({
            "DOC": "//:README.md",
        }),
    }
)

PARAMETERS

Name Description Default Value
env A map of environment variables none

RETURNS

str: A json encoded string of the environment variables

rules_rust_dependencies

rules_rust_dependencies()

Dependencies used in the implementation of rules_rust.

rust_analyzer_toolchain_repository

rust_analyzer_toolchain_repository(name, version, exec_compatible_with, target_compatible_with,
                                   iso_date, sha256s, urls, auth, netrc, auth_patterns)

Assemble a remote rust_analyzer_toolchain target based on the given params.

PARAMETERS

Name Description Default Value
name The name of the toolchain proxy repository contianing the registerable toolchain. none
version The version of the tool among “nightly”, “beta’, or an exact version. none
exec_compatible_with A list of constraints for the execution platform for this toolchain. []
target_compatible_with A list of constraints for the target platform for this toolchain. []
iso_date The date of the tool. None
sha256s A dict associating tool subdirectories to sha256 hashes. See rust_register_toolchains for more details. None
urls A 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.xz’] None
auth Auth object compatible with repository_ctx.download to use when downloading files. See repository_ctx.download for more details. None
netrc .netrc file to use for authentication; mirrors the eponymous attribute from http_archive None
auth_patterns Override mapping of hostnames to authorization patterns; mirrors the eponymous attribute from http_archive None

RETURNS

str: The name of a registerable rust_analyzer_toolchain.

rust_bindgen_dependencies

rust_bindgen_dependencies()

Declare dependencies needed for bindgen.

RETURNS

list[struct(repo=str, is_dev_dep=bool)]: A list of the repositories defined by this macro.

rust_bindgen_library

rust_bindgen_library(name, header, cc_lib, bindgen_flags, bindgen_features, clang_flags, kwargs)

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

Name Description Default Value
name A unique name for this target. none
header The label of the .h file to generate bindings for. none
cc_lib The label of the cc_library that contains the .h file. This is used to find the transitive includes. none
bindgen_flags Flags to pass directly to the bindgen executable. See https://rust-lang.github.io/rust-bindgen/ for details. None
bindgen_features The features attribute for the rust_bindgen target. None
clang_flags Flags to pass directly to the clang executable. None
kwargs Arguments to forward to the underlying rust_library rule. none

rust_bindgen_register_toolchains

rust_bindgen_register_toolchains(register_toolchains)

Registers the default toolchains for the rules_rust bindgen rules.

PARAMETERS

Name Description Default Value
register_toolchains Whether or not to register toolchains. True

rust_prost_dependencies

rust_prost_dependencies(bzlmod)

Declares repositories needed for prost.

PARAMETERS

Name Description Default Value
bzlmod Whether bzlmod is enabled. False

RETURNS

list[struct(repo=str, is_dev_dep=bool)]: A list of the repositories defined by this macro.

rust_prost_library

rust_prost_library(name, kwargs)

A rule for generating a Rust library using Prost.

PARAMETERS

Name Description Default Value
name The name of the target. none
kwargs Additional keyword arguments for the underlying rust_prost_library rule. none

rust_prost_transitive_repositories

rust_prost_transitive_repositories()

Load transitive dependencies of the @rules_rust//proto/protobuf rules.

This macro should be called immediately after the rust_protobuf_dependencies macro.

rust_proto_protobuf_dependencies

rust_proto_protobuf_dependencies(bzlmod)

PARAMETERS

Name Description Default Value
bzlmod <p align="center"> - </p> False

rust_proto_protobuf_register_toolchains

rust_proto_protobuf_register_toolchains(register_toolchains)

Register toolchains for proto compilation.

PARAMETERS

Name Description Default Value
register_toolchains <p align="center"> - </p> True

rust_proto_protobuf_transitive_repositories

rust_proto_protobuf_transitive_repositories()

Load transitive dependencies of the @rules_rust//proto/protobuf rules.

This macro should be called immediately after the rust_protobuf_dependencies macro.

rust_register_toolchains

rust_register_toolchains(dev_components, edition, allocator_library, global_allocator_library,
                         iso_date, register_toolchains, rustfmt_version, rust_analyzer_version,
                         sha256s, extra_target_triples, extra_rustc_flags, extra_exec_rustc_flags,
                         urls, version, versions)

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 sha256s 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

Name Description Default Value
dev_components Whether to download the rustc-dev components (defaults to False). Requires version to be “nightly”. False
edition The rust edition to be used by default (2015, 2018, or 2021). If absent, every target is required to specify its edition attribute. None
allocator_library Target that provides allocator functions when rust_library targets are embedded in a cc_binary. None
global_allocator_library Target that provides allocator functions when global allocator is used with cc_common.link. None
iso_date Deprecated: Use versions instead. None
register_toolchains If true, repositories will be generated to produce and register rust_toolchain targets. True
rustfmt_version The version of rustfmt. If none is supplied and only a single version in versions is given, then this defaults to that version, otherwise will default to the default nightly version. None
rust_analyzer_version The version of Rustc to pair with rust-analyzer. None
sha256s A dict associating tool subdirectories to sha256 hashes. None
extra_target_triples Additional rust-style targets that rust toolchains should support. ["wasm32-unknown-unknown", "wasm32-wasi"]
extra_rustc_flags Dictionary of target triples to list of extra flags to pass to rustc in non-exec configuration. None
extra_exec_rustc_flags Extra flags to pass to rustc in exec configuration. None
urls A 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). ["https://static.rust-lang.org/dist/{}.tar.xz"]
version Deprecated: Use versions instead. None
versions A list of toolchain versions to download. This paramter only accepts one versions per channel. E.g. ["1.65.0", "nightly/2022-11-02", "beta/2020-12-30"]. []

rust_repositories

rust_repositories(kwargs)

Deprecated: Use rules_rust_dependencies and rust_register_toolchains directly.

PARAMETERS

Name Description Default Value
kwargs Keyword arguments for the rust_register_toolchains macro. none

rust_repository_set

rust_repository_set(name, exec_triple, target_settings, version, versions, allocator_library,
                    global_allocator_library, extra_target_triples, iso_date, rustfmt_version,
                    edition, dev_components, extra_rustc_flags, extra_exec_rustc_flags, opt_level,
                    sha256s, urls, auth, netrc, auth_patterns, register_toolchain,
                    exec_compatible_with, default_target_compatible_with)

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

PARAMETERS

Name Description Default Value
name The name of the generated repository none
exec_triple The Rust-style target that this compiler runs on none
target_settings A list of config_settings that must be satisfied by the target configuration in order for this set of toolchains to be selected during toolchain resolution. []
version The version of the tool among “nightly”, “beta’, or an exact version. None
versions A list of toolchain versions to download. This paramter only accepts one versions per channel. E.g. ["1.65.0", "nightly/2022-11-02", "beta/2020-12-30"]. []
allocator_library Target that provides allocator functions when rust_library targets are embedded in a cc_binary. None
global_allocator_library Target that provides allocator functions a global allocator is used with cc_common.link. None
extra_target_triples Additional rust-style targets that this set of toolchains should support. If a map, values should be (optional) target_compatible_with lists for that particular target triple. {}
iso_date The date of the tool. None
rustfmt_version The version of rustfmt to be associated with the toolchain. None
edition The rust edition to be used by default (2015, 2018, or 2021). If absent, every rule is required to specify its edition attribute. None
dev_components Whether to download the rustc-dev components. Requires version to be “nightly”. False
extra_rustc_flags Dictionary of target triples to list of extra flags to pass to rustc in non-exec configuration. None
extra_exec_rustc_flags Extra flags to pass to rustc in exec configuration. None
opt_level Dictionary of target triples to optimiztion config. None
sha256s A dict associating tool subdirectories to sha256 hashes. See rust_register_toolchains for more details. None
urls A 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). ["https://static.rust-lang.org/dist/{}.tar.xz"]
auth Auth object compatible with repository_ctx.download to use when downloading files. See repository_ctx.download for more details. None
netrc .netrc file to use for authentication; mirrors the eponymous attribute from http_archive None
auth_patterns Override mapping of hostnames to authorization patterns; mirrors the eponymous attribute from http_archive None
register_toolchain If True, the generated rust_toolchain target will become a registered toolchain. True
exec_compatible_with A list of constraints for the execution platform for this toolchain. None
default_target_compatible_with A list of constraints for the target platform for this toolchain when the exec platform is the same as the target platform. None

rust_test_suite

rust_test_suite(name, srcs, kwargs)

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

Name Description Default Value
name The name of the test_suite. none
srcs All test sources, typically glob(["tests/**/*.rs"]). none
kwargs Additional keyword arguments for the underyling rust_test targets. The tags argument is also passed to the generated test_suite target. none

rust_toolchain_repository

rust_toolchain_repository(name, version, exec_triple, target_triple, exec_compatible_with,
                          target_compatible_with, target_settings, channel, allocator_library,
                          global_allocator_library, iso_date, rustfmt_version, edition,
                          dev_components, extra_rustc_flags, extra_exec_rustc_flags, opt_level,
                          sha256s, urls, auth, netrc, auth_patterns)

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

PARAMETERS

Name Description Default Value
name The name of the generated repository none
version The version of the tool among “nightly”, “beta”, or an exact version. none
exec_triple The Rust-style target that this compiler runs on. none
target_triple The Rust-style target to build for. none
exec_compatible_with A list of constraints for the execution platform for this toolchain. None
target_compatible_with A list of constraints for the target platform for this toolchain. None
target_settings A list of config_settings that must be satisfied by the target configuration in order for this toolchain to be selected during toolchain resolution. []
channel The channel of the Rust toolchain. None
allocator_library Target that provides allocator functions when rust_library targets are embedded in a cc_binary. None
global_allocator_library Target that provides allocator functions when a global allocator is used with cc_common.link. None
iso_date The date of the tool. None
rustfmt_version The version of rustfmt to be associated with the toolchain. None
edition The rust edition to be used by default (2015, 2018, or 2021). If absent, every rule is required to specify its edition attribute. None
dev_components Whether to download the rustc-dev components. Requires version to be “nightly”. Defaults to False. False
extra_rustc_flags Extra flags to pass to rustc in non-exec configuration. None
extra_exec_rustc_flags Extra flags to pass to rustc in exec configuration. None
opt_level Optimization level config for this toolchain. None
sha256s A dict associating tool subdirectories to sha256 hashes. See rust_register_toolchains for more details. None
urls A 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.xz’] ["https://static.rust-lang.org/dist/{}.tar.xz"]
auth Auth object compatible with repository_ctx.download to use when downloading files. See repository_ctx.download for more details. None
netrc .netrc file to use for authentication; mirrors the eponymous attribute from http_archive None
auth_patterns A list of patterns to match against urls for which the auth object should be used. None

RETURNS

str: The name of the registerable toolchain created by this rule.

rust_wasm_bindgen_dependencies

rust_wasm_bindgen_dependencies()

Declare dependencies needed for the rules_rust wasm-bindgen rules.

RETURNS

list[struct(repo=str, is_dev_dep=bool)]: A list of the repositories defined by this macro.

rust_wasm_bindgen_register_toolchains

rust_wasm_bindgen_register_toolchains(register_toolchains)

Registers the default toolchains for the rules_rust wasm-bindgen rules.

PARAMETERS

Name Description Default Value
register_toolchains Whether or not to register toolchains. True

rust_analyzer_aspect

rust_analyzer_aspect(name)

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

ASPECT ATTRIBUTES

Name Type
deps String
proc_macro_deps String
crate String
actual String
proto String

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required  

rust_clippy_aspect

rust_clippy_aspect(name)

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

Name Description Type Mandatory Default
name A unique name for this target. Name required  

rustfmt_aspect

rustfmt_aspect(name)

This aspect is used to gather information about a crate for use in rustfmt and perform rustfmt checks

Output Groups:

The build setting @rules_rust//:rustfmt.toml is used to control the Rustfmt configuration settings used at runtime.

This aspect is executed on any target which provides the CrateInfo provider. However users may tag a target with no-rustfmt or no-format to have it skipped. Additionally, generated source files are also ignored by this aspect.

ASPECT ATTRIBUTES

ATTRIBUTES

Name Description Type Mandatory Default
name A unique name for this target. Name required