Merge #666

666: Mark bits() as safe if a register has no reserved bits r=burrbull a=steelman

If a register has no fields but its write constraints allow full range of values to be written, then mark bits() as safe.

Co-authored-by: Łukasz Stelmach <[email protected]>

Author: bors[bot]

CHANGELOG.md

@@ -10,6 +10,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Update `clap` to 4.0, use `irx-config` instead of `clap_conf`
 - Add #[must_use] to prevent hanging field writers
 - remove explicit deref in `generic.rs` since it's done by auto-deref
+- Make writing raw bits to a whole register safe if the SVD indicates
+  so through the <WriteConstraint> element (see [v0.7.1] too).
 
 ## [v0.26.0] - 2022-10-07
 

src/generate/register.rs

@@ -264,17 +264,16 @@ pub fn render_register_mod(
         // the writer can be safe if:
         // * there is a single field that covers the entire register
         // * that field can represent all values
-        let can_write_safe = match register
-            .fields
-            .as_ref()
-            .and_then(|fields| fields.iter().next())
-            .and_then(|field| field.write_constraint)
-        {
-            Some(WriteConstraint::Range(range)) => {
-                range.min == 0 && range.max == u64::MAX >> (64 - rsize)
-            }
-            _ => false,
-        };
+        // * the write constraints of the register allow full range of values
+        let can_write_safe = !unsafety(
+            register
+                .fields
+                .as_ref()
+                .and_then(|fields| fields.first())
+                .and_then(|field| field.write_constraint)
+                .as_ref(),
+            rsize,
+        ) || !unsafety(register.write_constraint.as_ref(), rsize);
 
         if can_write_safe {
             mod_items.extend(quote! {