Implemented skip_deserializing for enum

serde_codegen/src/de.rs

@@ -496,6 +496,7 @@ fn deserialize_item_enum(
 
     let variant_visitor = deserialize_field_visitor(
         variants.iter()
+            .filter(|variant| !variant.attrs.skip_deserializing())
             .map(|variant| variant.attrs.name().deserialize_name())
             .collect(),
         item_attrs,
@@ -518,7 +519,7 @@ fn deserialize_item_enum(
 
     // Match arms to extract a variant from a string
     let mut variant_arms = vec![];
-    for (i, variant) in variants.iter().enumerate() {
+    for (i, variant) in variants.iter().filter(|variant| !variant.attrs.skip_deserializing()).enumerate() {
         let variant_name = aster::id(format!("__field{}", i));
         let variant_name = quote!(__Field::#variant_name);
 

serde_codegen_internals/src/attr.rs

@@ -187,12 +187,14 @@ impl Item {
 #[derive(Debug)]
 pub struct Variant {
     name: Name,
+    skip_deserializing: bool,
 }
 
 impl Variant {
     pub fn from_ast(cx: &Ctxt, variant: &syn::Variant) -> Self {
         let mut ser_name = Attr::none(cx, "rename");
         let mut de_name = Attr::none(cx, "rename");
+        let mut skip_deserializing = BoolAttr::none(cx, "skip_deserializing");
 
         for meta_items in variant.attrs.iter().filter_map(get_serde_meta_items) {
             for meta_item in meta_items {
@@ -212,6 +214,10 @@ impl Variant {
                             de_name.set_opt(de);
                         }
                     }
+                    // Parse `#[serde(skip_deserializing)]`
+                    MetaItem(Word(ref name)) if name == "skip_deserializing" => {
+                        skip_deserializing.set_true();
+                    }
 
                     MetaItem(ref meta_item) => {
                         cx.error(format!("unknown serde variant attribute `{}`",
@@ -230,12 +236,17 @@ impl Variant {
                 serialize: ser_name.get().unwrap_or_else(|| variant.ident.to_string()),
                 deserialize: de_name.get().unwrap_or_else(|| variant.ident.to_string()),
             },
+            skip_deserializing: skip_deserializing.get(),
         }
     }
 
     pub fn name(&self) -> &Name {
         &self.name
     }
+
+    pub fn skip_deserializing(&self) -> bool {
+        self.skip_deserializing
+    }
 }
 
 /// Represents field attribute information

testing/tests/test_de.rs

@@ -37,7 +37,9 @@ enum Enum {
     Unit,
     Simple(i32),
     Seq(i32, i32, i32),
-    Map { a: i32, b: i32, c: i32 }
+    Map { a: i32, b: i32, c: i32 },
+    #[serde(skip_deserializing)]
+    Skipped,
 }
 
 //////////////////////////////////////////////////////////////////////////
@@ -805,6 +807,12 @@ declare_error_tests! {
         ],
         Error::UnknownVariant("Foo".to_owned()),
     }
+    test_enum_skipped_variant<Enum> {
+        &[
+            Token::EnumUnit("Enum", "Skipped"),
+        ],
+        Error::UnknownVariant("Skipped".to_owned()),
+    }
     test_struct_seq_too_long<Struct> {
         &[
             Token::SeqStart(Some(4)),