diff options
Diffstat (limited to 'macros/src')
| -rw-r--r-- | macros/src/codegen/post_init.rs | 10 | ||||
| -rw-r--r-- | macros/src/codegen/resources.rs | 33 |
2 files changed, 32 insertions, 11 deletions
diff --git a/macros/src/codegen/post_init.rs b/macros/src/codegen/post_init.rs index 96c5df80..eec633ba 100644 --- a/macros/src/codegen/post_init.rs +++ b/macros/src/codegen/post_init.rs @@ -17,10 +17,14 @@ pub fn codegen(app: &App, analysis: &Analysis) -> Vec<TokenStream2> { // If it's live let cfgs = app.late_resources[name].cfgs.clone(); if analysis.locations.get(name).is_some() { - // Need to also include the cfgs stmts.push(quote!( - #(#cfgs)* - #mangled_name.as_mut_ptr().write(late.#name); + // We include the cfgs + #(#cfgs)* + // Late resource is a RacyCell<MaybeUninit<T>> + // - `get_mut_unchecked` to obtain `MaybeUninit<T>` + // - `as_mut_ptr` to obtain a raw pointer to `MaybeUninit<T>` + // - `write` the defined value for the late resource T + #mangled_name.get_mut_unchecked().as_mut_ptr().write(late.#name); )); } } diff --git a/macros/src/codegen/resources.rs b/macros/src/codegen/resources.rs index fa52b86d..89f70f84 100644 --- a/macros/src/codegen/resources.rs +++ b/macros/src/codegen/resources.rs @@ -4,13 +4,20 @@ use rtic_syntax::{analyze::Ownership, ast::App}; use crate::{analyze::Analysis, check::Extra, codegen::util}; -/// Generates `static [mut]` variables and resource proxies +/// Generates `static` variables and resource proxies +/// Early resources are stored in `RacyCell<T>` +/// Late resource are stored in `RacyCell<MaybeUninit<T>>` +/// +/// Safety: +/// - RacyCell<T> access is `unsafe`. +/// - RacyCell<MaybeUninit> is always written to before user access, thus +// the generated code for user access can safely `assume_init`. pub fn codegen( app: &App, analysis: &Analysis, extra: &Extra, ) -> ( - // mod_app -- the `static [mut]` variables behind the proxies + // mod_app -- the `static` variables behind the proxies Vec<TokenStream2>, // mod_resources -- the `resources` module TokenStream2, @@ -24,18 +31,26 @@ pub fn codegen( let mangled_name = util::mark_internal_ident(&name); { + // TODO: do we really need this in the single core case + // late resources in `util::link_section_uninit` let section = if expr.is_none() { util::link_section_uninit(true) } else { None }; + // resource type and assigned value let (ty, expr) = if let Some(expr) = expr { - (quote!(#ty), quote!(#expr)) + // early resource + ( + quote!(rtic::RacyCell<#ty>), + quote!(rtic::RacyCell::new(#expr)), + ) } else { + // late resource ( - quote!(core::mem::MaybeUninit<#ty>), - quote!(core::mem::MaybeUninit::uninit()), + quote!(rtic::RacyCell<core::mem::MaybeUninit<#ty>>), + quote!(rtic::RacyCell::new(core::mem::MaybeUninit::uninit())), ) }; @@ -46,7 +61,7 @@ pub fn codegen( #(#attrs)* #(#cfgs)* #section - static mut #mangled_name: #ty = #expr; + static #mangled_name: #ty = #expr; )); } @@ -74,14 +89,16 @@ pub fn codegen( )); let ptr = if expr.is_none() { + // late resource quote!( #(#cfgs)* - #mangled_name.as_mut_ptr() + &mut #mangled_name.get_mut_unchecked().assume_init() ) } else { + // early resource quote!( #(#cfgs)* - &mut #mangled_name + unsafe { #mangled_name.get_mut_unchecked() } ) }; |