cargo-bench.md

cargo-bench(1)

NAME

cargo-bench - Execute benchmarks of a package

SYNOPSIS

cargo bench [options] [benchname] [-- bench-options]

DESCRIPTION

Compile and execute benchmarks.

The benchmark filtering argument benchname and all the arguments following the two dashes (--) are passed to the benchmark binaries and thus to libtest (rustc's built in unit-test and micro-benchmarking framework). If you are passing arguments to both Cargo and the binary, the ones after -- go to the binary, the ones before go to Cargo. For details about libtest's arguments see the output of cargo bench -- --help and check out the rustc book's chapter on how tests work at https://doc.rust-lang.org/rustc/tests/index.html.

As an example, this will run only the benchmark named foo (and skip other similarly named benchmarks like foobar):

cargo bench -- foo --exact

Benchmarks are built with the --test option to rustc which creates an executable with a main function that automatically runs all functions annotated with the #[bench] attribute. Cargo passes the --bench flag to the test harness to tell it to run only benchmarks.

The libtest harness may be disabled by setting harness = false in the target manifest settings, in which case your code will need to provide its own main function to handle running benchmarks.

Note: The #[bench] attribute is currently unstable and only available on the nightly channel. There are some packages available on crates.io that may help with running benchmarks on the stable channel, such as Criterion.

By default, cargo bench uses the bench profile, which enables optimizations and disables debugging information. If you need to debug a benchmark, you can use the --profile=dev command-line option to switch to the dev profile. You can then run the debug-enabled benchmark within a debugger.

OPTIONS

Benchmark Options

--no-run

Compile, but don't run benchmarks.

--no-fail-fast

Run all benchmarks regardless of failure. Without this flag, Cargo will exit after the first executable fails. The Rust test harness will run all benchmarks within the executable to completion, this flag only applies to the executable as a whole.

选择包

默认情况下，如果没有指定包，则根据清单文件来选择包(如果没有通过--manifest-path给出清单文件路径， 则基于当前工作目录进行寻找)。如果是某个工作区的根清单，则选中该工作区的默认成员；否则仅选中清 单所定义的那个包。

工作区的默认成员可通过清单中workspace.default-members项来显式指定。如果未指定，则其虚拟 工作区会包含全体工作区成员(等同于传递--workspace标志参数时)，而非虚拟工作区则仅包含根部箱自身。

-p spec...

--package spec...

Benchmark指定包. SPEC的格式参见 cargo-pkgid(1) 。 此标志参数可多次使用且支持Unix通配符(*, ? 和 [])。不过，为避免shell可能错误地在Cargo获取到 之前就将通配符展开，应在各个模式串两侧使用单引号或双引号。

--workspace

Benchmark 工作区中的全体成员.

--all

--workspace的已废弃的别名。

--exclude SPEC...

排除指定包。必须与--workspace标志参数共同使用。 此标志参数可多次使用且支持Unix通配符(*, ? 和 [])。不过，为避免shell可能错误地在Cargo获取到 之前就将通配符展开，应在各个模式串两侧使用单引号或双引号。

Target Selection

When no target selection options are given, cargo bench will build the following targets of the selected packages:

• lib — used to link with binaries and benchmarks
• bins (only if benchmark targets are built and required features are available)
• lib as a benchmark
• bins as benchmarks
• benchmark targets

The default behavior can be changed by setting the bench flag for the target in the manifest settings. Setting examples to bench = true will build and run the example as a benchmark. Setting targets to bench = false will stop them from being benchmarked by default. Target selection options that take a target by name ignore the bench flag and will always benchmark the given target.

Passing target selection flags will benchmark only the specified targets.

Note that --bin, --example, --test and --bench flags also support common Unix glob patterns like *, ? and []. However, to avoid your shell accidentally expanding glob patterns before Cargo handles them, you must use single quotes or double quotes around each glob pattern.

--lib

Benchmark the package's library.

--bin name...

Benchmark the specified binary. This flag may be specified multiple times and supports common Unix glob patterns.

--bins

Benchmark all binary targets.

--example name...

Benchmark the specified example. This flag may be specified multiple times and supports common Unix glob patterns.

--examples

Benchmark all example targets.

--test name...

Benchmark the specified integration test. This flag may be specified multiple times and supports common Unix glob patterns.

--tests

Benchmark all targets in test mode that have the test = true manifest flag set. By default this includes the library and binaries built as unittests, and integration tests. Be aware that this will also build any required dependencies, so the lib target may be built twice (once as a unittest, and once as a dependency for binaries, integration tests, etc.). Targets may be enabled or disabled by setting the test flag in the manifest settings for the target.

--bench name...

Benchmark the specified benchmark. This flag may be specified multiple times and supports common Unix glob patterns.

--benches

Benchmark all targets in benchmark mode that have the bench = true manifest flag set. By default this includes the library and binaries built as benchmarks, and bench targets. Be aware that this will also build any required dependencies, so the lib target may be built twice (once as a benchmark, and once as a dependency for binaries, benchmarks, etc.). Targets may be enabled or disabled by setting the bench flag in the manifest settings for the target.

--all-targets

Benchmark all targets. This is equivalent to specifying --lib --bins --tests --benches --examples.

特性选择

可通过传递特性参数来控制启用哪些特性。如果没有给定要使用的特性， 则每个已选择的包都会自动使用default特性。

详见the features documentation。

--features features

传递以空格或者逗号分隔的列表，其中给出要启用的特性。工作区成员的特性可通过包名/特性名的语法启用。 此参数可多次给定，以分别启用给定的特性。

--all-features

为给定的包启用全部可用特性

--no-default-features

不启用给定包的default特性

Compilation Options

--target triple

为指定架构执行 Benchmark 。默认情况下为本机的架构。三元组的格式为 <arch><sub>-<vendor>-<sys>-<abi>。执行 rustc --print target-list 可得到支持的构建目标列表。

也可通过build.target指定(config value)。

注意，指定该标志参数会使Cargo产生的构建工件放在与平常不同的目录下。 详情参见build cache

--profile name

Benchmark with the given profile. See the the reference for more details on profiles.

--ignore-rust-version

Benchmark the target even if the selected Rust compiler is older than the required Rust version as configured in the project's rust-version field.

Output Options

--target-dir directory

用于存放生成的工件以及中间文件的目录。也可通过环境变量CARGO_TARGET_DIR 或 build.target-dir config value指定。

默认情况下为根工作区中的target目录。

Display Options

By default the Rust test harness hides output from benchmark execution to keep results readable. Benchmark output can be recovered (e.g., for debugging) by passing --nocapture to the benchmark binaries:

cargo bench -- --nocapture

-v

--verbose

启用更加详细的输出。可两次使用来显示"非常详细"的输出，其中包含了诸如 依赖警告 以及 构建脚本输出 等额外的输出内容。 也可通过term.verbose指定。 config value.

-q

--quiet

不输出Cargo的日志信息。也可通过term.quiet指定。 config value.

--color when

控制输出内容的颜色。有效取值如下：

• auto (默认)：自动检测终端是否支持带颜色的输出。
• always：总显示带颜色的输出。
• never：从不显示带颜色的输出。

也可通过term.color指定。 config value.

--message-format fmt

The output format for diagnostic messages. Can be specified multiple times and consists of comma-separated values. Valid values:

• human (default): Display in a human-readable text format. Conflicts with short and json.
• short: Emit shorter, human-readable text messages. Conflicts with human and json.
• json: Emit JSON messages to stdout. See the reference for more details. Conflicts with human and short.
• json-diagnostic-short: Ensure the rendered field of JSON messages contains the "short" rendering from rustc. Cannot be used with human or short.
• json-diagnostic-rendered-ansi: Ensure the rendered field of JSON messages contains embedded ANSI color codes for respecting rustc's default color scheme. Cannot be used with human or short.
• json-render-diagnostics: Instruct Cargo to not include rustc diagnostics in in JSON messages printed, but instead Cargo itself should render the JSON diagnostics coming from rustc. Cargo's own JSON diagnostics and others coming from rustc are still emitted. Cannot be used with human or short.

Manifest Options

--manifest-path path

用于指定Cargo.toml文件的路径。默认情况下，Cargo会在当前目录或上级目录中寻找Cargo.toml文件。

--frozen

--locked

这两个选项用于保证Cargo.lock文件是最新的。如果该锁文件不存在，或者不是最新的，Cargo 会报错退出。其中--frozen选项会阻止Cargo访问网络以检查锁文件是否是最新的。

这些选项，可用于保证Cargo.lock文件是最新的(比如持续集成的构建过程)， 或用于避免联网。

--offline

禁止Cargo访问网络。如果不添加此选项，Cargo在需要访问网络但网络不可用的情况下，会报错 并停止工作。添加此选项后，Cargo会尽可能尝试不使用网络来工作。

注意，在此情况下可能会产生与联网状态下不同的依赖解析(Dependency Resolution)结果。 Cargo只会使用本地已下载的crate，即便本地的索引副本中表明可能有新版本crate。在离线前下载 所需依赖的方法，参见 cargo-fetch(1) 。

也可以通过 net.offline config value指定。

Common Options

+toolchain

If Cargo has been installed with rustup, and the first argument to cargo begins with +, it will be interpreted as a rustup toolchain name (such as +stable or +nightly). See the rustup documentation for more information about how toolchain overrides work.

-h

--help

Prints help information.

-Z flag

Unstable (nightly-only) flags to Cargo. Run cargo -Z help for details.

Miscellaneous Options

The --jobs argument affects the building of the benchmark executable but does not affect how many threads are used when running the benchmarks. The Rust test harness runs benchmarks serially in a single thread.

-j N

--jobs N

要并行运行的作业数量。也可通过build.jobs config value指定。 默认为CPU数量。

环境

关于Cargo所读取的环境变量，可参见the reference

退出状态

• 0: Cargo命令执行成功
• 101: Cargo命令未能完成.

EXAMPLES

1. Build and execute all the benchmarks of the current package:

   cargo bench
   

2. Run only a specific benchmark within a specific benchmark target:

   cargo bench --bench bench_name -- modname::some_benchmark
   

SEE ALSO

cargo(1), cargo-test(1)