`shadow-rs`: Build-time information stored in your Rust project (binary, lib, cdylib, dylib).

shadow-rs allows you to access properties of the build process and environment at runtime, including:

Cargo.toml information, such as the project version
Dependency information
Git information, such as the commit that produced the build artifact
What version of the Rust toolchain was used in compilation
The build variant, e.g. debug or release
... And more!

You can use this crate to programmatically check where a binary came from and how it was built.

Currently, integration into wasm is also supported. For detailed settings, please refer to the link example_wasm.

Note on Caching

shadow-rs build information is not always rebuilt when you build a project. shadow-rs outputs several hints to Cargo in order to force rebuilds when required, but this does not always work. You can enforce up-to-date build information by running cargo clean before the build, or use a CI/CD pipeline tool. For more details, see #95.

Examples

Check out the example_shadow for a simple demonstration of how shadow-rs might be used to provide build-time information at run-time.
Check out the example_shadow_hook for a demonstration of how custom hooks can be used to add extra information to shadow-rs's output.
Check out the builtin_fn example for a simple demonstration of the built-in functions that shadow-rs provides.

Setup

1) Modify `Cargo.toml` fields

Modify your Cargo.toml like so:

[package]
build = "build.rs"

[dependencies]
shadow-rs = "{latest version}"

[build-dependencies]
shadow-rs = "{latest version}"

About build = "build.rs",this is an optional addition where, by default, build points to the build.rs file. It is recommended to use it as such. However, if your build script file is not named build.rs, please manually specify it. For example: build = "gen.rs".

2) Create `build.rs` file

Now in the root of your project (same directory as Cargo.toml) add a file build.rs:

fn main() -> shadow_rs::SdResult<()> {
    shadow_rs::new()
}

If you want to exclude some build constants, you can use [new_deny] instead of [new].

3) Integrate Shadow

In your main Rust file (usually main.rs or lib.rs), add this:

use shadow_rs::shadow;

shadow!(build);

The shadow! macro uses the given identifier to create a module with that name.

4) Use Shadow Constants

You can now use the module defined with shadow! to access build-time information.

fn main(){
    println!("debug:{}", shadow_rs::is_debug()); // check if this is a debug build. e.g 'true/false'
    println!("branch:{}", shadow_rs::branch()); // get current project branch. e.g 'master/develop'
    println!("tag:{}", shadow_rs::tag()); // get current project tag. e.g 'v1.3.5'
    println!("git_clean:{}", shadow_rs::git_clean()); // get current project clean. e.g 'true/false'
    println!("git_status_file:{}", shadow_rs::git_status_file()); // get current project statue file. e.g '  * examples/builtin_fn.rs (dirty)'

    println!("{}", build::VERSION); //print version const
    println!("{}", build::CLAP_LONG_VERSION); //print CLAP_LONG_VERSION const
    println!("{}", build::BRANCH); //master
    println!("{}", build::SHORT_COMMIT);//8405e28e
    println!("{}", build::COMMIT_HASH);//8405e28e64080a09525a6cf1b07c22fcaf71a5c5
    println!("{}", build::COMMIT_DATE);//2021-08-04 12:34:03 +00:00
    println!("{}", build::COMMIT_AUTHOR);//baoyachi
    println!("{}", build::COMMIT_EMAIL);//xxx@gmail.com

    println!("{}", build::BUILD_OS);//macos-x86_64
    println!("{}", build::RUST_VERSION);//rustc 1.45.0 (5c1f21c3b 2020-07-13)
    println!("{}", build::RUST_CHANNEL);//stable-x86_64-apple-darwin (default)
    println!("{}", build::CARGO_VERSION);//cargo 1.45.0 (744bd1fbb 2020-06-15)
    println!("{}", build::PKG_VERSION);//0.3.13
    println!("{}", build::CARGO_TREE); //like command:cargo tree
    println!("{}", build::CARGO_MANIFEST_DIR); // /User/baoyachi/shadow-rs/ |

    println!("{}", build::PROJECT_NAME);//shadow-rs
    println!("{}", build::BUILD_TIME);//2020-08-16 14:50:25
    println!("{}", build::BUILD_RUST_CHANNEL);//debug
    println!("{}", build::GIT_CLEAN);//false
    println!("{}", build::GIT_STATUS_FILE);//* src/lib.rs (dirty)
}

Reproducibility

This tool includes the current time in the binary which would normally make it non-reproducible. However, it respects the SOURCE_DATE_EPOCH variable - if set to a Unix timestamp it will override the value of build time.

Clap

You can also use shadow-rs to provide information to command-line interface crates such as clap. An example of this can be found in example_shadow.

List of Constants and Functions

Functions

Function	Description
`is_debug()`	`true` if this is a build with debug assertions.
`branch()`	Git branch at build time.
`tag()`	Current Git tag at build time.
`git_clean()`	Whether Git working tree was clean at build time.
`git_status_file()`	`git status`-like output, e.g. `* examples/builtin_fn.rs (dirty)`

Constants

Constant	Example
VERSION	3.4.5
CLAP_LONG_VERSION	(A multi-line string containing branch, commit hash, build time, Rust version and toolchain channel)
BRANCH	master
TAG	v1.0.0
SHORT_COMMIT	8405e28e
COMMIT_HASH	8405e28e64080a09525a6cf1b07c22fcaf71a5c5
COMMIT_DATE	2021-08-04 12:34:03 +00:00
COMMIT_DATE_2822	Thu, 24 Jun 2021 21:33:59 +0800
COMMIT_DATE_3339	2021-06-24T21:33:59.972494+08:00
COMMIT_AUTHOR	baoyachi
COMMIT_EMAIL	xxx@gmail.com
BUILD_OS	macos-x86_64
BUILD_TARGET	x86_64-apple-darwin
BUILD_TARGET_ARCH	x86_64
RUST_VERSION	rustc 1.45.0 (5c1f21c3b 2020-07-13)
RUST_CHANNEL	stable-x86_64-apple-darwin (default)
CARGO_VERSION	cargo 1.45.0 (744bd1fbb 2020-06-15)
PKG_VERSION	0.3.13
CARGO_TREE	(Output of `cargo tree`)
CARGO_MANIFEST_DIR	/User/baoyachi/shadow-rs/
PROJECT_NAME	shadow-rs
BUILD_TIME	2021-06-24 21:33:59
BUILD_TIME_2822	Thu, 24 Jun 2021 21:33:59 +0800
BUILD_TIME_3339	2021-06-24T15:53:55+08:00
BUILD_RUST_CHANNEL	release
GIT_CLEAN	true
GIT_STATUS_FILE	* src/lib.rs (dirty)