glaeqen/l0g

Opinionated log/defmt facade meant for no_std libraries

l0g

Opinionated l0gging facade meant for the no_std libraries that are also sometimes used in a std context.

Overview

Logging facilities differ depending on the environment, especially between no_std and std. This facade allows to delegate the decision which l0gging implementation shall be used to the top-level application.

Any call to l0g::{error,warn,info,debug,trace} turns into a

• noop when no feature is set
• log::{error,warn,info,debug,trace} from the log crate when log feature is set
• defmt::{error,warn,info,debug,trace} from the defmt crate when defmt feature is set

Moreover, proc-macro is provided to generalize over which formatting implementation should be used

#[l0g::format]
struct MyStruct {
    value: u8
}

turns into

#[derive(core::fmt::Debug)]
struct MyStruct {
    value: u8
}

if log feature is used or

#[derive(defmt::Format)]
struct MyStruct {
    value: u8
}

if defmt feature is used.

This allows a {:?} formatting to work, regardless of which logging implementation is chosen.

Usage

In the Cargo.toml of your libraries just say

l0g = "1"

In the no_std top-level application specify the dependency with the defmt feature. For how to make defmt work, take a look into its respective documentation.

l0g = { version = "1", features = ["defmt"] }

In the std top-level application specify the dependency with the log feature. For how to make log work, take a look into its respective documentation.

l0g = { version = "1", features = ["log"] }