dbc-codegen 0.3.0

CAN DBC code-gen for embedded Rust
Documentation

CAN DBC code generator for Rust

Generates Rust messages from a dbc file.

⚠️ This is experimental - use with caution. ⚠️

Installation

Install published version using cargo:

cargo install dbc-codegen-cli

Install latest version from the git repository:

cargo install dbc-codegen-cli --git https://github.com/technocreatives/dbc-codegen --branch main

Using dbc-codegen

Generate messages.rs from example.dbc using the CLI:

dbc-codegen testing/dbc-examples/example.dbc dir/where/messages_rs/file/is/written

Or put something like this into your build.rs file:

fn main() {
    let dbc_path = "../dbc-examples/example.dbc";
    let dbc_file = std::fs::read(dbc_path).unwrap();
    println!("cargo:rerun-if-changed={}", dbc_path);

    let mut out = std::io::BufWriter::new(std::fs::File::create("src/messages.rs").unwrap());
    dbc_codegen::codegen("example.dbc", &dbc_file, &mut out, true).unwrap();
}

Using generated Rust code

dbc-codegen generates a Rust file that is expected to be in a cargo project. Here is an example testing/can-messages/Cargo.toml which defines dependencies and features that are used in generated message file.

Project setup

For this to work you need to add following dependencies to Cargo.toml:

bitvec = { version = "1.0", default-features = false }
arbitrary = { version = "1.0", optional = true } # Enable with `arb` feature

To use the code, add mod messages to your lib.rs (or main.rs). You will most likely want to interact with the generated Messages enum, and call Messages::from_can_message(id, &payload).

Note: The generated code contains a lot of documentation. Give it a try:

cargo doc --open

Feature flags

The following (optional) features can be specified:

  • debug: enables #[derive(Debug) for messages
  • range_checked: adds range checks in setters
  • arb: enables implementation of [Arbitrary] trait. Also requires you to add arbitrary crate (version 1.x) as a dependency of the feature, using arb = ["arbitrary"]. [Arbitrary]: https://docs.rs/arbitrary/1.0.0/arbitrary/trait.Arbitrary.html
  • std: Implements std::error::Error for CanError. This makes it easy to use anyhow for error handling.

To enable all features add this to your Cargo.toml:

# features for dbc-codegen `messages.rs` file
[features]
default = ["debug", "arb", "range_checked", "std"]
arb = ["arbitrary"]
debug = []
range_checked = []
std = []

Field/variant rename rules

If some field name starts with a non-alphabetic character or is a Rust keyword then it is prefixed with x.

For example:

VAL_ 512 Five 0 "0Off" 1 "1On" 2 "2Oner" 3 "3Onest";

…is generated as:

pub enum BarFive {
    X0off,
    X1on,
    X2oner,
    X3onest,
    _Other(bool),
}

Type here:

SG_ Type : 30|1@0+ (1,0) [0|1] "boolean" Dolor

…conflicts with the Rust keyword type. Therefore we prefix it with x:

pub fn xtype(&self) -> BarType {
    match self.xtype_raw() {
        false => BarType::X0off,
        true => BarType::X1on,
        x => BarType::_Other(x),
    }
}

License

Licensed under either of

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.