Try #358:

Author: bors[bot]

CHANGELOG.md

@@ -11,6 +11,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - `variant()` method for field reader and `Variant` enum for fields with reserved values
 
+- Field readers and writers use one enum where it is possible
+
 ## [v0.15.2] - 2019-07-29
 
 - No changes, just fixing the metadata since crates.io didn't like the keywords

src/generate/register.rs

@@ -255,10 +255,10 @@ pub fn fields(
             } = f.bit_range;
             let sc = f.name.to_sanitized_snake_case();
             let pc = f.name.to_sanitized_upper_case();
-            let pc_r = Ident::from(&*format!("{}R", pc));
+            let pc_r = Ident::from(&*format!("{}_A", pc));
             let _pc_r = Ident::from(&*format!("{}_R", pc));
-            let pc_w = Ident::from(&*format!("{}W", pc));
-            let _pc_w = Ident::from(&*format!("_{}W", pc));
+            let pc_w = Ident::from(&*format!("{}_AW", pc));
+            let _pc_w = Ident::from(&*format!("{}_W", pc));
             let _sc = Ident::from(&*format!("_{}", sc));
             let bits = if width == 1 {
                 Ident::from("bit")
@@ -319,6 +319,15 @@ pub fn fields(
             all_peripherals,
         )?;
 
+
+        let pc_r = &f.pc_r;
+        let mut pc_w = &f.pc_r;
+
+        let mut evs_r = None;
+
+        let _pc_r = &f._pc_r;
+        let _pc_w = &f._pc_w;
+
         if can_read {
             let cast = if f.width == 1 {
                 quote! { != 0 }
@@ -336,10 +345,9 @@ pub fn fields(
                 }
             };
 
-            let pc_r = &f.pc_r;
-            let _pc_r = &f._pc_r;
-
             if let Some((evs, base)) = lookup_filter(&lookup_results, Usage::Read) {
+                evs_r = Some(evs.clone());
+
                 let description = &util::escape_brackets(&f.description);
                 let sc = &f.sc;
                 r_impl_items.push(quote! {
@@ -352,8 +360,13 @@ pub fn fields(
 
                 if let Some(base) = &base {
                     let pc = base.field.to_sanitized_upper_case();
-                    let base_pc_r = Ident::from(&*format!("{}_R", pc));
-                    derive_from_base(mod_items, &base, &_pc_r, &base_pc_r, f.name);
+                    let base_pc_r = Ident::from(&*format!("{}_A", pc));
+                    let base_pc_r = derive_from_base(mod_items, &base, &pc_r, &base_pc_r, f.name);
+
+                    mod_items.push(quote! {
+                        ///Reader of the field
+                        pub type #_pc_r = crate::FR<#fty, #base_pc_r>;
+                    });
                 }
 
                 if base.is_none() {
@@ -471,16 +484,19 @@ pub fn fields(
                 if variants.len() == 1 << f.width {
                     unsafety = None;
                 }
-                let pc_w = &f.pc_w;
 
-                let base_pc_w = base.as_ref().map(|base| {
-                    let pc = base.field.to_sanitized_upper_case();
-                    let base_pc_w = Ident::from(&*format!("{}W", pc));
-                    derive_from_base(mod_items, &base, &pc_w, &base_pc_w, f.name)
-                });
+                if Some(evs) != evs_r.as_ref() {
+                    pc_w = &f.pc_w;
 
-                if base.is_none() {
-                    add_from_variants(mod_items, &variants, pc_w, &f);
+                    base.as_ref().map(|base| {
+                        let pc = base.field.to_sanitized_upper_case();
+                        let base_pc_w = Ident::from(&*format!("{}_AW", pc));
+                        derive_from_base(mod_items, &base, &pc_w, &base_pc_w, f.name)
+                    });
+
+                    if base.is_none() {
+                        add_from_variants(mod_items, &variants, pc_w, &f);
+                    }
                 }
 
                 proxy_items.push(quote! {
@@ -499,23 +515,13 @@ pub fn fields(
                     let sc = &v.sc;
 
                     let doc = util::escape_brackets(util::respace(&v.doc).as_ref());
-                    if let Some(enum_) = base_pc_w.as_ref() {
-                        proxy_items.push(quote! {
-                            #[doc = #doc]
-                            #[inline(always)]
-                            pub fn #sc(self) -> &'a mut W {
-                                self.variant(#enum_::#pc)
-                            }
-                        });
-                    } else {
                         proxy_items.push(quote! {
                             #[doc = #doc]
                             #[inline(always)]
                             pub fn #sc(self) -> &'a mut W {
                                 self.variant(#pc_w::#pc)
                             }
                         });
-                    }
                 }
             }
 
@@ -556,7 +562,6 @@ pub fn fields(
                 }
             });
 
-            let _pc_w = &f._pc_w;
             mod_items.push(quote! {
                 ///Proxy
                 pub struct #_pc_w<'a> {
@@ -680,7 +685,7 @@ fn add_from_variants(mod_items: &mut Vec<Tokens>, variants: &Vec<Variant>, pc: &
     });
 }
 
-fn derive_from_base(mod_items: &mut Vec<Tokens>, base: &Base, pc: &Ident, base_pc: &Ident, fname: &str) -> quote::Tokens {
+fn derive_from_base(mod_items: &mut Vec<Tokens>, base: &Base, pc: &Ident, base_pc: &Ident, fname: &str) {
     let desc = format!("Possible values of the field `{}`", fname,);
 
     if let (Some(peripheral), Some(register)) = (&base.peripheral, &base.register) {
@@ -694,10 +699,6 @@ fn derive_from_base(mod_items: &mut Vec<Tokens>, base: &Base, pc: &Ident, base_p
             pub type #pc =
                 crate::#pmod_::#rmod_::#base_pc;
         });
-
-        quote! {
-            crate::#pmod_::#rmod_::#base_pc
-        }
     } else if let Some(register) = &base.register {
         let mod_ = register.to_sanitized_snake_case();
         let mod_ = Ident::from(&*mod_);
@@ -707,19 +708,11 @@ fn derive_from_base(mod_items: &mut Vec<Tokens>, base: &Base, pc: &Ident, base_p
             pub type #pc =
                 super::#mod_::#base_pc;
         });
-
-        quote! {
-            super::#mod_::#base_pc
-        }
     } else {
         mod_items.push(quote! {
             #[doc = #desc]
             pub type #pc = #base_pc;
         });
-
-        quote! {
-            #base_pc
-        }
     }
 }