atomics features in generated code

Author: burrbull

CHANGELOG.md

@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/).
 - Fix escaping <> and & characters in doc attributes
 - Add `interrupt_link_section` config parameter for controlling the `#[link_section = "..."]` attribute of `__INTERRUPTS`
 - Add option to implement Debug for readable registers (#716)
+- Add `atomics-feature`
 
 ## [v0.28.0] - 2022-12-25
 

src/generate/device.rs

@@ -153,6 +153,9 @@ pub fn render(d: &Device, config: &Config, device_x: &mut String) -> Result<Toke
         let mut file = File::create(config.output_dir.join("generic.rs"))?;
         writeln!(file, "{generic_file}")?;
         if config.atomics {
+            if let Some(atomics_feature) = config.atomics_feature.as_ref() {
+                writeln!(file, "#[cfg(feature = \"{atomics_feature}\")]")?;
+            }
             writeln!(file, "\n{generic_atomic_file}")?;
         }
         if config.const_generic {
@@ -170,6 +173,9 @@ pub fn render(d: &Device, config: &Config, device_x: &mut String) -> Result<Toke
     } else {
         let mut tokens = syn::parse_file(generic_file)?.into_token_stream();
         if config.atomics {
+            if let Some(atomics_feature) = config.atomics_feature.as_ref() {
+                quote!(#[cfg(feature = #atomics_feature)]).to_tokens(&mut tokens);
+            }
             syn::parse_file(generic_atomic_file)?.to_tokens(&mut tokens);
         }
         if config.const_generic {

src/lib.rs

@@ -492,6 +492,9 @@
 //! concurrently called on different bits in the same register without data races. This flag won't
 //! work for RISCV chips without the atomic extension.
 //!
+//! The `--atomics_feature` flag can also be specified to include atomics implementations conditionally
+//! behind the supplied feature name.
+//!
 //! `portable-atomic` v0.3.16 must be added to the dependencies, with default features off to
 //! disable the `fallback` feature.
 //!
@@ -503,7 +506,7 @@
 //! register that has read actions will not be read and printed as `(not read/has read action!)`.
 //! Registers that are not readable will have `(write only register)` printed as the value.
 //!
-//! The `--impl_debug_feature` flad can also be specified to include debug implementations conditionally
+//! The `--impl_debug_feature` flag can also be specified to include debug implementations conditionally
 //! behind the supplied feature name.
 //!
 //! Usage examples:

src/main.rs

@@ -72,6 +72,13 @@ fn run() -> Result<()> {
                 .action(ArgAction::SetTrue)
                 .help("Generate atomic register modification API"),
         )
+        .arg(
+            Arg::new("atomics_feature")
+                .long("atomics_feature")
+                .help("add feature gating for atomic register modification API")
+                .action(ArgAction::Set)
+                .value_name("FEATURE"),
+        )
         .arg(
             Arg::new("const_generic")
             .long("const_generic")

src/util.rs

@@ -30,6 +30,8 @@ pub struct Config {
     #[cfg_attr(feature = "serde", serde(default))]
     pub atomics: bool,
     #[cfg_attr(feature = "serde", serde(default))]
+    pub atomics_feature: Option<String>,
+    #[cfg_attr(feature = "serde", serde(default))]
     pub generic_mod: bool,
     #[cfg_attr(feature = "serde", serde(default))]
     pub make_mod: bool,
@@ -111,6 +113,7 @@ impl Default for Config {
         Self {
             target: Target::default(),
             atomics: false,
+            atomics_feature: None,
             generic_mod: false,
             make_mod: false,
             const_generic: false,