Merge pull request #832 from rust-embedded/range-set

field::set with range assert
rust-embedded · Apr 17, 2024 · 0138b99 · 0138b99
2 parents 08dd33e + ff15953
commit 0138b99
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Showing 3 changed files with 90 additions and 21 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/).
 
 ## [Unreleased]
 
+- Add checked `set` for not full safe fields
+
 ## [v0.33.0] - 2024-03-26
 
 - Add `IsEnum` constraint for `FieldWriter`s (fix `variant` safety)

diff --git a/src/generate/generic.rs b/src/generate/generic.rs
@@ -476,6 +476,12 @@ impl<FI> BitReader<FI> {
 pub struct Safe;
 /// You should check that value is allowed to pass to register/field writer marked with this
 pub struct Unsafe;
+/// Marker for field writers are safe to write in specified inclusive range
+pub struct Range<const MIN: u64, const MAX: u64>;
+/// Marker for field writers are safe to write in specified inclusive range
+pub struct RangeFrom<const MIN: u64>;
+/// Marker for field writers are safe to write in specified inclusive range
+pub struct RangeTo<const MAX: u64>;
 
 /// Write field Proxy
 pub type FieldWriter<'a, REG, const WI: u8, FI = u8, Safety = Unsafe> = raw::FieldWriter<'a, REG, WI, FI, Safety>;
@@ -533,6 +539,60 @@ where
     }
 }
 
+impl<'a, REG, const WI: u8, FI, const MIN: u64, const MAX: u64> FieldWriter<'a, REG, WI, FI, Range<MIN, MAX>>
+where
+    REG: Writable + RegisterSpec,
+    FI: FieldSpec,
+    REG::Ux: From<FI::Ux>,
+    u64: From<FI::Ux>,
+{
+    /// Writes raw bits to the field
+    #[inline(always)]
+    pub fn set(self, value: FI::Ux) -> &'a mut W<REG> {
+        {
+            let value = u64::from(value);
+            assert!(value >= MIN && value <= MAX);
+        }
+        unsafe { self.bits(value) }
+    }
+}
+
+impl<'a, REG, const WI: u8, FI, const MIN: u64> FieldWriter<'a, REG, WI, FI, RangeFrom<MIN>>
+where
+    REG: Writable + RegisterSpec,
+    FI: FieldSpec,
+    REG::Ux: From<FI::Ux>,
+    u64: From<FI::Ux>,
+{
+    /// Writes raw bits to the field
+    #[inline(always)]
+    pub fn set(self, value: FI::Ux) -> &'a mut W<REG> {
+        {
+            let value = u64::from(value);
+            assert!(value >= MIN);
+        }
+        unsafe { self.bits(value) }
+    }
+}
+
+impl<'a, REG, const WI: u8, FI, const MAX: u64> FieldWriter<'a, REG, WI, FI, RangeTo<MAX>>
+where
+    REG: Writable + RegisterSpec,
+    FI: FieldSpec,
+    REG::Ux: From<FI::Ux>,
+    u64: From<FI::Ux>,
+{
+    /// Writes raw bits to the field
+    #[inline(always)]
+    pub fn set(self, value: FI::Ux) -> &'a mut W<REG> {
+        {
+            let value = u64::from(value);
+            assert!(value <= MAX);
+        }
+        unsafe { self.bits(value) }
+    }
+}
+
 impl<'a, REG, const WI: u8, FI, Safety> FieldWriter<'a, REG, WI, FI, Safety>
 where
     REG: Writable + RegisterSpec,

diff --git a/src/generate/register.rs b/src/generate/register.rs
@@ -1,6 +1,7 @@
 use crate::svd::{
     self, Access, BitRange, DimElement, EnumeratedValue, EnumeratedValues, Field, MaybeArray,
     ModifiedWriteValues, ReadAction, Register, RegisterProperties, Usage, WriteConstraint,
+    WriteConstraintRange,
 };
 use core::u64;
 use log::warn;
@@ -408,7 +409,7 @@ pub fn render_register_mod(
         } else {
             Safety::Unsafe
         };
-        let safe_ty = safe_ty.ident(span);
+        let safe_ty = safe_ty.ident(rsize);
 
         let doc = format!("`write(|w| ..)` method takes [`{mod_ty}::W`](W) writer structure",);
 
@@ -1138,17 +1139,14 @@ pub fn fields(
                                     .map(|v| Variant::from_value(v, def, config))
                             })
                             .transpose()?;
+                        // if the write structure is finite, it can be safely written.
                         if variants.len() == 1 << width {
+                            safety = Safety::Safe;
                         } else if let Some(def) = def.take() {
                             variants.push(def);
                             safety = Safety::Safe;
                         }
 
-                        // if the write structure is finite, it can be safely written.
-                        if variants.len() == 1 << width {
-                            safety = Safety::Safe;
-                        }
-
                         // generate write value structure and From conversation if we can't reuse read value structure.
                         if rwenum.generate_write_enum() {
                             if variants.is_empty() {
@@ -1241,14 +1239,14 @@ pub fn fields(
                         }
                     } else {
                         let wproxy = Ident::new("FieldWriter", span);
-                        let width = &unsuffixed(width);
+                        let uwidth = &unsuffixed(width);
                         if value_write_ty == "u8" && safety != Safety::Safe {
-                            quote! { crate::#wproxy<'a, REG, #width> }
+                            quote! { crate::#wproxy<'a, REG, #uwidth> }
                         } else if safety != Safety::Safe {
-                            quote! { crate::#wproxy<'a, REG, #width, #value_write_ty> }
+                            quote! { crate::#wproxy<'a, REG, #uwidth, #value_write_ty> }
                         } else {
-                            let safe_ty = safety.ident(span);
-                            quote! { crate::#wproxy<'a, REG, #width, #value_write_ty, crate::#safe_ty> }
+                            let safe_ty = safety.ident(width);
+                            quote! { crate::#wproxy<'a, REG, #uwidth, #value_write_ty, crate::#safe_ty> }
                         }
                     };
                     mod_items.extend(quote! {
@@ -1371,9 +1369,10 @@ pub fn fields(
     ))
 }
 
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
 enum Safety {
     Unsafe,
+    Range(WriteConstraintRange),
     Safe,
 }
 
@@ -1393,18 +1392,26 @@ impl Safety {
                 // if a writeConstraint exists then respect it
                 Self::Safe
             }
+            Some(&WriteConstraint::Range(range)) => Self::Range(range),
             _ => Self::Unsafe,
         }
     }
-    fn ident(&self, span: Span) -> Ident {
-        Ident::new(
-            if let Self::Safe = self {
-                "Safe"
-            } else {
-                "Unsafe"
-            },
-            span,
-        )
+    fn ident(&self, width: u32) -> TokenStream {
+        match self {
+            Self::Safe => quote!(Safe),
+            Self::Unsafe => quote!(Unsafe),
+            Self::Range(range) => {
+                let min = unsuffixed(range.min);
+                let max = unsuffixed(range.max);
+                if range.min == 0 {
+                    quote!(RangeTo<#max>)
+                } else if range.max == u64::MAX >> (64 - width) {
+                    quote!(RangeFrom<#min>)
+                } else {
+                    quote!(Range<#min, #max>)
+                }
+            }
+        }
     }
 }