bevy/crates/bevy_macro_utils/src/fq_std.rs
Zachary Harrold d70595b667
Add core and alloc over std Lints (#15281)
# Objective

- Fixes #6370
- Closes #6581

## Solution

- Added the following lints to the workspace:
  - `std_instead_of_core`
  - `std_instead_of_alloc`
  - `alloc_instead_of_core`
- Used `cargo +nightly fmt` with [item level use
formatting](https://rust-lang.github.io/rustfmt/?version=v1.6.0&search=#Item%5C%3A)
to split all `use` statements into single items.
- Used `cargo clippy --workspace --all-targets --all-features --fix
--allow-dirty` to _attempt_ to resolve the new linting issues, and
intervened where the lint was unable to resolve the issue automatically
(usually due to needing an `extern crate alloc;` statement in a crate
root).
- Manually removed certain uses of `std` where negative feature gating
prevented `--all-features` from finding the offending uses.
- Used `cargo +nightly fmt` with [crate level use
formatting](https://rust-lang.github.io/rustfmt/?version=v1.6.0&search=#Crate%5C%3A)
to re-merge all `use` statements matching Bevy's previous styling.
- Manually fixed cases where the `fmt` tool could not re-merge `use`
statements due to conditional compilation attributes.

## Testing

- Ran CI locally

## Migration Guide

The MSRV is now 1.81. Please update to this version or higher.

## Notes

- This is a _massive_ change to try and push through, which is why I've
outlined the semi-automatic steps I used to create this PR, in case this
fails and someone else tries again in the future.
- Making this change has no impact on user code, but does mean Bevy
contributors will be warned to use `core` and `alloc` instead of `std`
where possible.
- This lint is a critical first step towards investigating `no_std`
options for Bevy.

---------

Co-authored-by: François Mockers <francois.mockers@vleue.com>
2024-09-27 00:59:59 +00:00

105 lines
2.7 KiB
Rust

//! This module contains unit structs that should be used inside `quote!` and `spanned_quote!`
//! using the variable interpolation syntax in place of their equivalent structs and traits
//! present in `std`.
//!
//! To create hygienic proc macros, all the names must be its fully qualified form. These
//! unit structs help us to not specify the fully qualified name every single time.
//!
//! # Example
//! Instead of writing this:
//! ```
//! # use quote::quote;
//! quote!(
//! fn get_id() -> Option<i32> {
//! Some(0)
//! }
//! );
//! ```
//! Or this:
//! ```
//! # use quote::quote;
//! quote!(
//! fn get_id() -> ::core::option::Option<i32> {
//! ::core::option::Option::Some(0)
//! }
//! );
//! ```
//! We should write this:
//! ```
//! use bevy_macro_utils::fq_std::FQOption;
//! # use quote::quote;
//!
//! quote!(
//! fn get_id() -> #FQOption<i32> {
//! #FQOption::Some(0)
//! }
//! );
//! ```
use proc_macro2::TokenStream;
use quote::{quote, ToTokens};
/// Fully Qualified (FQ) short name for [`std::any::Any`]
pub struct FQAny;
/// Fully Qualified (FQ) short name for [`Box`]
pub struct FQBox;
/// Fully Qualified (FQ) short name for [`Clone`]
pub struct FQClone;
/// Fully Qualified (FQ) short name for [`Default`]
pub struct FQDefault;
/// Fully Qualified (FQ) short name for [`Option`]
pub struct FQOption;
/// Fully Qualified (FQ) short name for [`Result`]
pub struct FQResult;
/// Fully Qualified (FQ) short name for [`Send`]
pub struct FQSend;
/// Fully Qualified (FQ) short name for [`Sync`]
pub struct FQSync;
impl ToTokens for FQAny {
fn to_tokens(&self, tokens: &mut TokenStream) {
quote!(::core::any::Any).to_tokens(tokens);
}
}
impl ToTokens for FQBox {
fn to_tokens(&self, tokens: &mut TokenStream) {
quote!(::std::boxed::Box).to_tokens(tokens);
}
}
impl ToTokens for FQClone {
fn to_tokens(&self, tokens: &mut TokenStream) {
quote!(::core::clone::Clone).to_tokens(tokens);
}
}
impl ToTokens for FQDefault {
fn to_tokens(&self, tokens: &mut TokenStream) {
quote!(::core::default::Default).to_tokens(tokens);
}
}
impl ToTokens for FQOption {
fn to_tokens(&self, tokens: &mut TokenStream) {
quote!(::core::option::Option).to_tokens(tokens);
}
}
impl ToTokens for FQResult {
fn to_tokens(&self, tokens: &mut TokenStream) {
quote!(::core::result::Result).to_tokens(tokens);
}
}
impl ToTokens for FQSend {
fn to_tokens(&self, tokens: &mut TokenStream) {
quote!(::core::marker::Send).to_tokens(tokens);
}
}
impl ToTokens for FQSync {
fn to_tokens(&self, tokens: &mut TokenStream) {
quote!(::core::marker::Sync).to_tokens(tokens);
}
}