chore: allow generated file to be used with include!

[nyurik]

• Due to a compiler limitation, inner attributes are not allowed with the include! macro. This PR removes all #![...] and //! ... from the generated code, and adds many explicit allow to individual functions and use statements where relevant.

mod messages {
    include!(concat!(env!("OUT_DIR"), "/messages.rs"));
}

• Do not place generated code inside the user's code - not a good practice. All generated code should go into OUT_DIR.
• Remove allow_dead_code configuration
• Consolidate all documentation in the README, and use it as docs
• Minor Cargo.toml cleanup

[Copilot]

Pull request overview

This PR refactors the code generation to make generated files compatible with Rust's include! macro by removing inner attributes (#![...] and //! ...), which are not allowed due to a compiler limitation. Generated code is now written to OUT_DIR during the build process and included via include! in user code, following Rust best practices for build-time code generation.

Key changes:

• Generated code now omits all inner attributes and doc comments, moving lint suppressions to module-level #[expect(...)] attributes
• All generated code is written to OUT_DIR instead of the source tree
• Removed the allow_dead_code configuration option
• Updated error trait implementation from std::error::Error to core::error::Error for better no_std compatibility

Reviewed changes

Copilot reviewed 11 out of 13 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
testing/can-messages/src/messages.rs	Entire generated file removed from source tree
testing/can-messages/src/lib.rs	Replaced static module with include! from OUT_DIR, added module-level lint suppressions
testing/can-messages/build.rs	Simplified to write generated code directly to OUT_DIR instead of src/
testing/can-embedded/src/messages.rs	Stub file removed as it's now generated during build
testing/can-embedded/src/lib.rs	Added include! macro to load generated code from OUT_DIR
testing/can-embedded/build.rs	New build script to generate messages.rs for embedded target
testing/can-embedded/Cargo.toml	Added build dependencies for code generation
src/lib.rs	Removed inner attributes and doc comments from generated code, changed error trait to core::error::Error, removed allow_dead_code config
README.md	Removed reference to allow_dead_code configuration option
Cargo.lock	Dependency version updates
.github/workflows/ci.yml	Updated cargo commands to use --workspace instead of --all

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[tegimeki]

These changes look good to me and address issues I've considered important, namely having generated code in OUT_DIR rather than within the source tree. However, not being a user of this crate currently it seems best to ping some of the recent committers to get their take: @killercup @scootermon @projectgus @trnila @cpctaylo

This seems like a breaking change, not necessarily at the API level but in terms of how dependent projects might use the generated files... what kind of version bump is anticipated?

[trnila]

can we add imports to have working example in README?

use dbc_codegen::Config;
use std::fs::write;
use std::{env::var, path::PathBuf};

dbc_file should be as a string now:

let dbc_file = std::fs::read_to_string(dbc_path).unwrap();

[nyurik]

@trnila I made README to be the only documentation for the crate, and for it to be auto-compiled as part of the doc tests.

[Copilot]

Pull request overview

Copilot reviewed 14 out of 17 changed files in this pull request and generated 3 comments.

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[nyurik]

@trnila are you able to compile everything with the new changes? Anything else blocking this? thx!

[trnila]

@nyurik Just having this last issue in my app:

warning: variant `InvalidMultiplexor` is never constructed
   --> out/messages.rs:469:5
    |
459 | pub enum CanError {
    |          -------- variant in this enum
...
469 |     InvalidMultiplexor {
    = note: `CanError` has derived impls for the traits `Debug` and `Clone`, but these are intentionally ignored during dead code analysis
    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default

Can be reproduced by using the same minimalistic dbc testing/dbc-examples/example.dbc:

BO_ 256 msg1: 1 tx
 SG_ test : 0|8@1+ (1,0) [0|255] ""  rx

and commenting out pub use messages::*; in testing/can-messages/src/lib.rs.
This line exports everything including CanError and somebody else in different location could construct InvalidMultiplexor.

We are using dbc-codegen directly in our binary without any libs, so rust detects this dead code correctly...

[nyurik]

@trnila thx, fixed