Merge #682

682: Not cast if unnecessary r=burrbull a=duskmoon314

In the previous PR #675, some cases of unnecessary casting are eliminated. However, if there is a big field (bigger than 16) with offset, there is still unnecessary generated casting. This PR fixes this case and adjusts the code according to clippy.

Co-authored-by: Campbell He <kp.campbell.he@duskmoon314.com>

Author: bors[bot]

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+- Don't cast fields with width 17-31 and non-zero offset.
+
 ## [v0.27.0] - 2022-10-24
 
 - Manually inline set/clear_bit

build.rs

@@ -35,7 +35,7 @@ fn commit_info() -> String {
 fn commit_hash() -> Result<String, IgnoredError> {
     Ok(String::from_utf8(
         Command::new("git")
-            .args(&["rev-parse", "--short", "HEAD"])
+            .args(["rev-parse", "--short", "HEAD"])
             .output()?
             .stdout,
     )?)
@@ -44,7 +44,7 @@ fn commit_hash() -> Result<String, IgnoredError> {
 fn commit_date() -> Result<String, IgnoredError> {
     Ok(String::from_utf8(
         Command::new("git")
-            .args(&["log", "-1", "--date=short", "--pretty=format:%cd"])
+            .args(["log", "-1", "--date=short", "--pretty=format:%cd"])
             .output()?
             .stdout,
     )?)

src/generate/interrupt.rs

@@ -33,7 +33,7 @@ pub fn render(
         .map(|i| (i.0.value, (i.0, i.1, i.2)))
         .collect::<HashMap<_, _>>();
 
-    let mut interrupts = interrupts.into_iter().map(|(_, v)| v).collect::<Vec<_>>();
+    let mut interrupts = interrupts.into_values().collect::<Vec<_>>();
     interrupts.sort_by_key(|i| i.0.value);
 
     let mut root = TokenStream::new();

src/generate/peripheral.rs

@@ -30,7 +30,7 @@ pub fn render(p_original: &Peripheral, index: &Index, config: &Config) -> Result
     let span = Span::call_site();
     let name_str = name.to_sanitized_constant_case();
     let name_constant_case = Ident::new(&name_str, span);
-    let address = util::hex(p.base_address as u64);
+    let address = util::hex(p.base_address);
     let description = util::respace(p.description.as_ref().unwrap_or(&p.name));
 
     let name_snake_case = name.to_snake_case_ident(span);

src/generate/register.rs

@@ -483,21 +483,16 @@ pub fn fields(
             };
             let value = if offset != 0 {
                 let offset = &util::unsuffixed(offset);
-                quote! {
-                    ((self.bits >> #offset) & #hexmask) #cast
-                }
-            } else if use_cast {
-                quote! {
-                    (self.bits & #hexmask) #cast
-                }
+                quote! { (self.bits >> #offset) }
+            } else {
+                quote! { self.bits }
+            };
+            let value = if use_mask && use_cast {
+                quote! { (#value & #hexmask) #cast }
             } else if use_mask {
-                quote! {
-                    self.bits & #hexmask
-                }
+                quote! { #value & #hexmask }
             } else {
-                quote! {
-                    self.bits
-                }
+                value
             };
 
             // get a brief description for this field
@@ -719,21 +714,16 @@ pub fn fields(
                     let sub_offset = offset + (i as u64) * (increment as u64);
                     let value = if sub_offset != 0 {
                         let sub_offset = &util::unsuffixed(sub_offset);
-                        quote! {
-                            ((self.bits >> #sub_offset) & #hexmask) #cast
-                        }
-                    } else if use_cast {
-                        quote! {
-                            (self.bits & #hexmask) #cast
-                        }
+                        quote! { (self.bits >> #sub_offset) }
+                    } else {
+                        quote! { self.bits }
+                    };
+                    let value = if use_mask && use_cast {
+                        quote! { (#value & #hexmask) #cast }
                     } else if use_mask {
-                        quote! {
-                            self.bits & #hexmask
-                        }
+                        quote! { #value & #hexmask }
                     } else {
-                        quote! {
-                            self.bits
-                        }
+                        value
                     };
                     let name_snake_case_n = util::replace_suffix(&f.name, &suffix)
                         .to_snake_case_ident(Span::call_site());
@@ -963,7 +953,7 @@ pub fn fields(
                         &description_with_bits(description_raw, sub_offset, width),
                         &suffix,
                     );
-                    let sub_offset = util::unsuffixed(sub_offset as u64);
+                    let sub_offset = util::unsuffixed(sub_offset);
 
                     w_impl_items.extend(quote! {
                         #[doc = #doc]
@@ -976,7 +966,7 @@ pub fn fields(
                 }
             } else {
                 let doc = description_with_bits(description_raw, offset, width);
-                let offset = util::unsuffixed(offset as u64);
+                let offset = util::unsuffixed(offset);
                 w_impl_items.extend(quote! {
                     #[doc = #doc]
                     #inline
@@ -1037,7 +1027,7 @@ impl Variant {
             .iter()
             // filter out all reserved variants, as we should not
             // generate code for them
-            .filter(|field| field.name.to_lowercase() != "reserved" && field.is_default == None)
+            .filter(|field| field.name.to_lowercase() != "reserved" && field.is_default.is_none())
             .map(|ev| {
                 let value = ev
                     .value

src/lib.rs

@@ -546,7 +546,7 @@ pub fn generate(input: &str, config: &Config) -> Result<Generation> {
     let device = load_from(input, config)?;
     let mut device_x = String::new();
     let items =
-        generate::device::render(&device, config, &mut device_x).or(Err(SvdError::Render))?;
+        generate::device::render(&device, config, &mut device_x).map_err(|_| SvdError::Render)?;
 
     let mut lib_rs = String::new();
     writeln!(