Release 1.0.85

Implements alias annotation and allow multiple deserialization renames.

README.md

@@ -25,19 +25,17 @@ You may be looking for:
 <details>
 <summary>
 Click to show Cargo.toml.
-<a href="https://play.rust-lang.org/?gist=9003c5b88c1f4989941925d7190c6eec" target="_blank">Run this code in the playground.</a>
+<a href="https://play.rust-lang.org/?edition=2018&gist=72755f28f99afc95e01d63174b28c1f5" target="_blank">Run this code in the playground.</a>
 </summary>
 
 ```toml
 [dependencies]
 
 # The core APIs, including the Serialize and Deserialize traits. Always
-# required when using Serde.
-serde = "1.0"
-
-# Support for #[derive(Serialize, Deserialize)]. Required if you want Serde
-# to work for structs and enums defined in your crate.
-serde_derive = "1.0"
+# required when using Serde. The "derive" feature is only required when
+# using #[derive(Serialize, Deserialize)] to make Serde work with structs
+# and enums defined in your crate.
+serde = { version = "1.0", features = ["derive"] }
 
 # Each data format lives in its own crate; the sample code below uses JSON
 # but you may be using a different one.
@@ -48,11 +46,7 @@ serde_json = "1.0"
 <p></p>
 
 ```rust
-#[macro_use]
-extern crate serde_derive;
-
-extern crate serde;
-extern crate serde_json;
+use serde::{Serialize, Deserialize};
 
 #[derive(Serialize, Deserialize, Debug)]
 struct Point {

crates-io.md

@@ -16,11 +16,7 @@ You may be looking for:
 ## Serde in action
 
 ```rust
-#[macro_use]
-extern crate serde_derive;
-
-extern crate serde;
-extern crate serde_json;
+use serde::{Serialize, Deserialize};
 
 #[derive(Serialize, Deserialize, Debug)]
 struct Point {

serde/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde"
-version = "1.0.84" # remember to update html_root_url
+version = "1.0.85" # remember to update html_root_url
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "A generic serialization/deserialization framework"
@@ -32,30 +32,7 @@ features = ["derive", "rc"]
 [features]
 default = ["std"]
 
-# Re-export the derive(Serialize, Deserialize) macros. This is intended for
-# library crates that provide optional Serde impls behind a Cargo cfg of their
-# own.
-#
-# Mainly this is a workaround for limitations associated with
-# rust-lang/cargo#1286 in which a library crate cannot use one "serde" cfg in
-# Cargo to enable dependencies on both serde and serde_derive crates.
-#
-# The recommended way to provide optional Serde support that requires derive is
-# as follows. In particular, please do not name your library's Serde feature
-# anything other than "serde".
-#
-#     [dependencies]
-#     serde = { version = "1.0", optional = true, features = ["derive"] }
-#
-# Within the library, these optional Serde derives would be written like this.
-#
-#     #[cfg(feature = "serde")]
-#     #[macro_use]
-#     extern crate serde;
-#
-#     #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#     struct ...
-#
+# Provide derive(Serialize, Deserialize) macros.
 derive = ["serde_derive"]
 
 # Provide impls for common standard library types like Vec<T> and HashMap<K, V>.

serde/src/lib.rs

@@ -75,7 +75,7 @@
 ////////////////////////////////////////////////////////////////////////////////
 
 // Serde types in rustdoc of other crates get linked to here.
-#![doc(html_root_url = "https://docs.rs/serde/1.0.84")]
+#![doc(html_root_url = "https://docs.rs/serde/1.0.85")]
 // Support using Serde without the standard library!
 #![cfg_attr(not(feature = "std"), no_std)]
 // Unstable functionality only if the user asks for it. For tracking and
@@ -252,40 +252,6 @@ pub mod private;
 
 // Re-export #[derive(Serialize, Deserialize)].
 //
-// This is a workaround for https://github.com/rust-lang/cargo/issues/1286.
-// Without this re-export, crates that put Serde derives behind a cfg_attr would
-// need to use some silly feature name that depends on both serde and
-// serde_derive.
-//
-//     [features]
-//     serde-impls = ["serde", "serde_derive"]
-//
-//     [dependencies]
-//     serde = { version = "1.0", optional = true }
-//     serde_derive = { version = "1.0", optional = true }
-//
-//     # Used like this:
-//     # #[cfg(feature = "serde-impls")]
-//     # #[macro_use]
-//     # extern crate serde_derive;
-//     #
-//     # #[cfg_attr(feature = "serde-impls", derive(Serialize, Deserialize))]
-//     # struct S { /* ... */ }
-//
-// The re-exported derives allow crates to use "serde" as the name of their
-// Serde feature which is more intuitive.
-//
-//     [dependencies]
-//     serde = { version = "1.0", optional = true, features = ["derive"] }
-//
-//     # Used like this:
-//     # #[cfg(feature = "serde")]
-//     # #[macro_use]
-//     # extern crate serde;
-//     #
-//     # #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-//     # struct S { /* ... */ }
-//
 // The reason re-exporting is not enabled by default is that disabling it would
 // be annoying for crates that provide handwritten impls or data formats. They
 // would need to disable default features and then explicitly re-enable std.

serde_derive/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_derive"
-version = "1.0.84" # remember to update html_root_url
+version = "1.0.85" # remember to update html_root_url
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "Macros 1.1 implementation of #[derive(Serialize, Deserialize)]"

serde_derive/src/de.rs

@@ -1140,25 +1140,17 @@ fn deserialize_enum(
     }
 }
 
-fn deserialize_externally_tagged_enum(
-    params: &Parameters,
+fn prepare_enum_variant_enum(
     variants: &[Variant],
     cattrs: &attr::Container,
-) -> Fragment {
-    let this = &params.this;
-    let (de_impl_generics, de_ty_generics, ty_generics, where_clause) =
-        split_with_de_lifetime(params);
-    let delife = params.borrowed.de_lifetime();
-
-    let type_name = cattrs.name().deserialize_name();
-
-    let expecting = format!("enum {}", params.type_name());
-
+) -> (TokenStream, Stmts) {
     let variant_names_idents: Vec<_> = variants
         .iter()
         .enumerate()
         .filter(|&(_, variant)| !variant.attrs.skip_deserializing())
-        .map(|(i, variant)| (variant.attrs.name().deserialize_name(), field_i(i)))
+        .map(|(i, variant)| {
+            (variant.attrs.name().deserialize_name(), field_i(i), variant.attrs.aliases())
+        })
         .collect();
 
     let other_idx = variants
@@ -1166,7 +1158,7 @@ fn deserialize_externally_tagged_enum(
         .position(|ref variant| variant.attrs.other());
 
     let variants_stmt = {
-        let variant_names = variant_names_idents.iter().map(|&(ref name, _)| name);
+        let variant_names = variant_names_idents.iter().map(|&(ref name, _, _)| name);
         quote! {
             const VARIANTS: &'static [&'static str] = &[ #(#variant_names),* ];
         }
@@ -1179,6 +1171,24 @@ fn deserialize_externally_tagged_enum(
         other_idx,
     ));
 
+    (variants_stmt, variant_visitor)
+}
+
+fn deserialize_externally_tagged_enum(
+    params: &Parameters,
+    variants: &[Variant],
+    cattrs: &attr::Container,
+) -> Fragment {
+    let this = &params.this;
+    let (de_impl_generics, de_ty_generics, ty_generics, where_clause) =
+        split_with_de_lifetime(params);
+    let delife = params.borrowed.de_lifetime();
+
+    let type_name = cattrs.name().deserialize_name();
+    let expecting = format!("enum {}", params.type_name());
+
+    let (variants_stmt, variant_visitor) = prepare_enum_variant_enum(variants, cattrs);
+
     // Match arms to extract a variant from a string
     let variant_arms = variants
         .iter()
@@ -1261,30 +1271,7 @@ fn deserialize_internally_tagged_enum(
     cattrs: &attr::Container,
     tag: &str,
 ) -> Fragment {
-    let variant_names_idents: Vec<_> = variants
-        .iter()
-        .enumerate()
-        .filter(|&(_, variant)| !variant.attrs.skip_deserializing())
-        .map(|(i, variant)| (variant.attrs.name().deserialize_name(), field_i(i)))
-        .collect();
-
-    let other_idx = variants
-        .iter()
-        .position(|ref variant| variant.attrs.other());
-
-    let variants_stmt = {
-        let variant_names = variant_names_idents.iter().map(|&(ref name, _)| name);
-        quote! {
-            const VARIANTS: &'static [&'static str] = &[ #(#variant_names),* ];
-        }
-    };
-
-    let variant_visitor = Stmts(deserialize_generated_identifier(
-        &variant_names_idents,
-        cattrs,
-        true,
-        other_idx,
-    ));
+    let (variants_stmt, variant_visitor) = prepare_enum_variant_enum(variants, cattrs);
 
     // Match arms to extract a variant from a string
     let variant_arms = variants
@@ -1335,30 +1322,7 @@ fn deserialize_adjacently_tagged_enum(
         split_with_de_lifetime(params);
     let delife = params.borrowed.de_lifetime();
 
-    let variant_names_idents: Vec<_> = variants
-        .iter()
-        .enumerate()
-        .filter(|&(_, variant)| !variant.attrs.skip_deserializing())
-        .map(|(i, variant)| (variant.attrs.name().deserialize_name(), field_i(i)))
-        .collect();
-
-    let other_idx = variants
-        .iter()
-        .position(|ref variant| variant.attrs.other());
-
-    let variants_stmt = {
-        let variant_names = variant_names_idents.iter().map(|&(ref name, _)| name);
-        quote! {
-            const VARIANTS: &'static [&'static str] = &[ #(#variant_names),* ];
-        }
-    };
-
-    let variant_visitor = Stmts(deserialize_generated_identifier(
-        &variant_names_idents,
-        cattrs,
-        true,
-        other_idx,
-    ));
+    let (variants_stmt, variant_visitor) = prepare_enum_variant_enum(variants, cattrs);
 
     let variant_arms: &Vec<_> = &variants
         .iter()
@@ -1870,13 +1834,13 @@ fn deserialize_untagged_newtype_variant(
 }
 
 fn deserialize_generated_identifier(
-    fields: &[(String, Ident)],
+    fields: &[(String, Ident, Vec<String>)],
     cattrs: &attr::Container,
     is_variant: bool,
     other_idx: Option<usize>,
 ) -> Fragment {
     let this = quote!(__Field);
-    let field_idents: &Vec<_> = &fields.iter().map(|&(_, ref ident)| ident).collect();
+    let field_idents: &Vec<_> = &fields.iter().map(|&(_, ref ident, _)| ident).collect();
 
     let (ignore_variant, fallthrough) = if !is_variant && cattrs.has_flatten() {
         let ignore_variant = quote!(__other(_serde::private::de::Content<'de>),);
@@ -1977,11 +1941,12 @@ fn deserialize_custom_identifier(
             (
                 variant.attrs.name().deserialize_name(),
                 variant.ident.clone(),
+                variant.attrs.aliases(),
             )
         })
         .collect();
 
-    let names = names_idents.iter().map(|&(ref name, _)| name);
+    let names = names_idents.iter().map(|&(ref name, _, _)| name);
 
     let names_const = if fallthrough.is_some() {
         None
@@ -2032,24 +1997,33 @@ fn deserialize_custom_identifier(
 
 fn deserialize_identifier(
     this: &TokenStream,
-    fields: &[(String, Ident)],
+    fields: &[(String, Ident, Vec<String>)],
     is_variant: bool,
     fallthrough: Option<TokenStream>,
     collect_other_fields: bool,
 ) -> Fragment {
-    let field_strs = fields.iter().map(|&(ref name, _)| name);
-    let field_borrowed_strs = fields.iter().map(|&(ref name, _)| name);
-    let field_bytes = fields
+    let mut flat_fields = Vec::new();
+    for &(_, ref ident, ref aliases) in fields {
+        flat_fields.extend(aliases.iter().map(|alias| (alias, ident)))
+    }
+
+    let field_strs = flat_fields.iter().map(|&(ref name, _)| name);
+    let field_borrowed_strs = flat_fields.iter().map(|&(ref name, _)| name);
+    let field_bytes = flat_fields
         .iter()
         .map(|&(ref name, _)| Literal::byte_string(name.as_bytes()));
-    let field_borrowed_bytes = fields
+    let field_borrowed_bytes = flat_fields
         .iter()
         .map(|&(ref name, _)| Literal::byte_string(name.as_bytes()));
 
-    let constructors: &Vec<_> = &fields
+    let constructors: &Vec<_> = &flat_fields
         .iter()
         .map(|&(_, ref ident)| quote!(#this::#ident))
         .collect();
+    let main_constructors: &Vec<_> = &fields
+        .iter()
+        .map(|&(_, ref ident, _)| quote!(#this::#ident))
+        .collect();
 
     let expecting = if is_variant {
         "variant identifier"
@@ -2237,7 +2211,7 @@ fn deserialize_identifier(
             {
                 match __value {
                     #(
-                        #variant_indices => _serde::export::Ok(#constructors),
+                        #variant_indices => _serde::export::Ok(#main_constructors),
                     )*
                     _ => _serde::export::Err(_serde::de::Error::invalid_value(
                         _serde::de::Unexpected::Unsigned(__value),
@@ -2300,11 +2274,13 @@ fn deserialize_struct_as_struct_visitor(
         .iter()
         .enumerate()
         .filter(|&(_, field)| !field.attrs.skip_deserializing())
-        .map(|(i, field)| (field.attrs.name().deserialize_name(), field_i(i)))
+        .map(|(i, field)| {
+            (field.attrs.name().deserialize_name(), field_i(i), field.attrs.aliases())
+        })
         .collect();
 
     let fields_stmt = {
-        let field_names = field_names_idents.iter().map(|&(ref name, _)| name);
+        let field_names = field_names_idents.iter().map(|&(ref name, _, _)| name);
         quote_block! {
             const FIELDS: &'static [&'static str] = &[ #(#field_names),* ];
         }
@@ -2327,7 +2303,9 @@ fn deserialize_struct_as_map_visitor(
         .iter()
         .enumerate()
         .filter(|&(_, field)| !field.attrs.skip_deserializing() && !field.attrs.flatten())
-        .map(|(i, field)| (field.attrs.name().deserialize_name(), field_i(i)))
+        .map(|(i, field)| {
+            (field.attrs.name().deserialize_name(), field_i(i), field.attrs.aliases())
+        })
         .collect();
 
     let field_visitor = deserialize_generated_identifier(&field_names_idents, cattrs, false, None);
@@ -2558,11 +2536,13 @@ fn deserialize_struct_as_struct_in_place_visitor(
         .iter()
         .enumerate()
         .filter(|&(_, field)| !field.attrs.skip_deserializing())
-        .map(|(i, field)| (field.attrs.name().deserialize_name(), field_i(i)))
+        .map(|(i, field)| {
+            (field.attrs.name().deserialize_name(), field_i(i), field.attrs.aliases())
+        })
         .collect();
 
     let fields_stmt = {
-        let field_names = field_names_idents.iter().map(|&(ref name, _)| name);
+        let field_names = field_names_idents.iter().map(|&(ref name, _, _)| name);
         quote_block! {
             const FIELDS: &'static [&'static str] = &[ #(#field_names),* ];
         }

serde_derive/src/internals/attr.rs

@@ -20,7 +20,6 @@ use syn::NestedMeta::{Literal, Meta};
 
 pub use internals::case::RenameRule;
 
-#[derive(Clone)]
 struct Attr<'c, T> {
     cx: &'c Ctxt,
     name: &'static str,
@@ -90,9 +89,52 @@ impl<'c> BoolAttr<'c> {
     }
 }
 
+struct VecAttr<'c, T> {
+    cx: &'c Ctxt,
+    name: &'static str,
+    first_dup_tokens: TokenStream,
+    values: Vec<T>,
+}
+
+impl<'c, T> VecAttr<'c, T> {
+    fn none(cx: &'c Ctxt, name: &'static str) -> Self {
+        VecAttr {
+            cx: cx,
+            name: name,
+            first_dup_tokens: TokenStream::new(),
+            values: Vec::new(),
+        }
+    }
+
+    fn insert<A: ToTokens>(&mut self, obj: A, value: T) {
+        if self.values.len() == 1 {
+            self.first_dup_tokens = obj.into_token_stream();
+        }
+        self.values.push(value);
+    }
+
+    fn at_most_one(mut self) -> Result<Option<T>, ()> {
+        if self.values.len() > 1 {
+            let dup_token = self.first_dup_tokens;
+            self.cx
+                .error_spanned_by(dup_token, format!("duplicate serde attribute `{}`", self.name));
+            Err(())
+        } else {
+            Ok(self.values.pop())
+        }
+    }
+
+    fn get(self) -> Vec<T> {
+        self.values
+    }
+}
+
 pub struct Name {
     serialize: String,
+    serialize_renamed: bool,
     deserialize: String,
+    deserialize_renamed: bool,
+    deserialize_aliases: Vec<String>,
 }
 
 #[allow(deprecated)]
@@ -104,6 +146,36 @@ fn unraw(ident: &Ident) -> String {
 }
 
 impl Name {
+    fn from_attrs(
+        source_name: String,
+        ser_name: Attr<String>,
+        de_name: Attr<String>,
+        de_aliases: Option<VecAttr<String>>,
+    ) -> Name {
+        let deserialize_aliases = match de_aliases {
+            Some(de_aliases) => {
+                let mut alias_list = BTreeSet::new();
+                for alias_name in de_aliases.get() {
+                    alias_list.insert(alias_name);
+                }
+                alias_list.into_iter().collect()
+            }
+            None => Vec::new(),
+        };
+
+        let ser_name = ser_name.get();
+        let ser_renamed = ser_name.is_some();
+        let de_name = de_name.get();
+        let de_renamed = de_name.is_some();
+        Name {
+            serialize: ser_name.unwrap_or_else(|| source_name.clone()),
+            serialize_renamed: ser_renamed,
+            deserialize: de_name.unwrap_or(source_name),
+            deserialize_renamed: de_renamed,
+            deserialize_aliases: deserialize_aliases,
+        }
+    }
+
     /// Return the container name for the container when serializing.
     pub fn serialize_name(&self) -> String {
         self.serialize.clone()
@@ -113,6 +185,15 @@ impl Name {
     pub fn deserialize_name(&self) -> String {
         self.deserialize.clone()
     }
+
+    fn deserialize_aliases(&self) -> Vec<String> {
+        let mut aliases = self.deserialize_aliases.clone();
+        let main_name = self.deserialize_name();
+        if !aliases.contains(&main_name) {
+            aliases.push(main_name);
+        }
+        aliases
+    }
 }
 
 pub struct RenameAllRules {
@@ -514,10 +595,7 @@ impl Container {
         }
 
         Container {
-            name: Name {
-                serialize: ser_name.get().unwrap_or_else(|| unraw(&item.ident)),
-                deserialize: de_name.get().unwrap_or_else(|| unraw(&item.ident)),
-            },
+            name: Name::from_attrs(unraw(&item.ident), ser_name, de_name, None),
             transparent: transparent.get(),
             deny_unknown_fields: deny_unknown_fields.get(),
             default: default.get().unwrap_or(Default::None),
@@ -762,8 +840,6 @@ fn decide_identifier(
 /// Represents variant attribute information
 pub struct Variant {
     name: Name,
-    ser_renamed: bool,
-    de_renamed: bool,
     rename_all_rules: RenameAllRules,
     ser_bound: Option<Vec<syn::WherePredicate>>,
     de_bound: Option<Vec<syn::WherePredicate>>,
@@ -779,6 +855,7 @@ 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 de_aliases = VecAttr::none(cx, "rename");
         let mut skip_deserializing = BoolAttr::none(cx, "skip_deserializing");
         let mut skip_serializing = BoolAttr::none(cx, "skip_serializing");
         let mut rename_all_ser_rule = Attr::none(cx, "rename_all");
@@ -797,15 +874,26 @@ impl Variant {
                     Meta(NameValue(ref m)) if m.ident == "rename" => {
                         if let Ok(s) = get_lit_str(cx, &m.ident, &m.ident, &m.lit) {
                             ser_name.set(&m.ident, s.value());
-                            de_name.set(&m.ident, s.value());
+                            de_name.set_if_none(s.value());
+                            de_aliases.insert(&m.ident, s.value());
                         }
                     }
 
                     // Parse `#[serde(rename(serialize = "foo", deserialize = "bar"))]`
                     Meta(List(ref m)) if m.ident == "rename" => {
-                        if let Ok((ser, de)) = get_renames(cx, &m.nested) {
+                        if let Ok((ser, de)) = get_multiple_renames(cx, &m.nested) {
                             ser_name.set_opt(&m.ident, ser.map(syn::LitStr::value));
-                            de_name.set_opt(&m.ident, de.map(syn::LitStr::value));
+                            for de_value in de {
+                                de_name.set_if_none(de_value.value());
+                                de_aliases.insert(&m.ident, de_value.value());
+                            }
+                        }
+                    }
+
+                    // Parse `#[serde(alias = "foo")]`
+                    Meta(NameValue(ref m)) if m.ident == "alias" => {
+                        if let Ok(s) = get_lit_str(cx, &m.ident, &m.ident, &m.lit) {
+                            de_aliases.insert(&m.ident, s.value());
                         }
                     }
 
@@ -963,17 +1051,8 @@ impl Variant {
             }
         }
 
-        let ser_name = ser_name.get();
-        let ser_renamed = ser_name.is_some();
-        let de_name = de_name.get();
-        let de_renamed = de_name.is_some();
         Variant {
-            name: Name {
-                serialize: ser_name.unwrap_or_else(|| unraw(&variant.ident)),
-                deserialize: de_name.unwrap_or_else(|| unraw(&variant.ident)),
-            },
-            ser_renamed: ser_renamed,
-            de_renamed: de_renamed,
+            name: Name::from_attrs(unraw(&variant.ident), ser_name, de_name, Some(de_aliases)),
             rename_all_rules: RenameAllRules {
                 serialize: rename_all_ser_rule.get().unwrap_or(RenameRule::None),
                 deserialize: rename_all_de_rule.get().unwrap_or(RenameRule::None),
@@ -993,11 +1072,15 @@ impl Variant {
         &self.name
     }
 
+    pub fn aliases(&self) -> Vec<String> {
+        self.name.deserialize_aliases()
+    }
+
     pub fn rename_by_rules(&mut self, rules: &RenameAllRules) {
-        if !self.ser_renamed {
+        if !self.name.serialize_renamed {
             self.name.serialize = rules.serialize.apply_to_variant(&self.name.serialize);
         }
-        if !self.de_renamed {
+        if !self.name.deserialize_renamed {
             self.name.deserialize = rules.deserialize.apply_to_variant(&self.name.deserialize);
         }
     }
@@ -1038,8 +1121,6 @@ impl Variant {
 /// Represents field attribute information
 pub struct Field {
     name: Name,
-    ser_renamed: bool,
-    de_renamed: bool,
     skip_serializing: bool,
     skip_deserializing: bool,
     skip_serializing_if: Option<syn::ExprPath>,
@@ -1084,6 +1165,7 @@ impl Field {
     ) -> Self {
         let mut ser_name = Attr::none(cx, "rename");
         let mut de_name = Attr::none(cx, "rename");
+        let mut de_aliases = VecAttr::none(cx, "rename");
         let mut skip_serializing = BoolAttr::none(cx, "skip_serializing");
         let mut skip_deserializing = BoolAttr::none(cx, "skip_deserializing");
         let mut skip_serializing_if = Attr::none(cx, "skip_serializing_if");
@@ -1117,15 +1199,26 @@ impl Field {
                     Meta(NameValue(ref m)) if m.ident == "rename" => {
                         if let Ok(s) = get_lit_str(cx, &m.ident, &m.ident, &m.lit) {
                             ser_name.set(&m.ident, s.value());
-                            de_name.set(&m.ident, s.value());
+                            de_name.set_if_none(s.value());
+                            de_aliases.insert(&m.ident, s.value());
                         }
                     }
 
                     // Parse `#[serde(rename(serialize = "foo", deserialize = "bar"))]`
                     Meta(List(ref m)) if m.ident == "rename" => {
-                        if let Ok((ser, de)) = get_renames(cx, &m.nested) {
+                        if let Ok((ser, de)) = get_multiple_renames(cx, &m.nested) {
                             ser_name.set_opt(&m.ident, ser.map(syn::LitStr::value));
-                            de_name.set_opt(&m.ident, de.map(syn::LitStr::value));
+                            for de_value in de {
+                                de_name.set_if_none(de_value.value());
+                                de_aliases.insert(&m.ident, de_value.value());
+                            }
+                        }
+                    }
+
+                    // Parse `#[serde(alias = "foo")]`
+                    Meta(NameValue(ref m)) if m.ident == "alias" => {
+                        if let Ok(s) = get_lit_str(cx, &m.ident, &m.ident, &m.lit) {
+                            de_aliases.insert(&m.ident, s.value());
                         }
                     }
 
@@ -1332,17 +1425,8 @@ impl Field {
             collect_lifetimes(&field.ty, &mut borrowed_lifetimes);
         }
 
-        let ser_name = ser_name.get();
-        let ser_renamed = ser_name.is_some();
-        let de_name = de_name.get();
-        let de_renamed = de_name.is_some();
         Field {
-            name: Name {
-                serialize: ser_name.unwrap_or_else(|| ident.clone()),
-                deserialize: de_name.unwrap_or(ident),
-            },
-            ser_renamed: ser_renamed,
-            de_renamed: de_renamed,
+            name: Name::from_attrs(ident, ser_name, de_name, Some(de_aliases)),
             skip_serializing: skip_serializing.get(),
             skip_deserializing: skip_deserializing.get(),
             skip_serializing_if: skip_serializing_if.get(),
@@ -1362,11 +1446,15 @@ impl Field {
         &self.name
     }
 
+    pub fn aliases(&self) -> Vec<String> {
+        self.name.deserialize_aliases()
+    }
+
     pub fn rename_by_rules(&mut self, rules: &RenameAllRules) {
-        if !self.ser_renamed {
+        if !self.name.serialize_renamed {
             self.name.serialize = rules.serialize.apply_to_field(&self.name.serialize);
         }
-        if !self.de_renamed {
+        if !self.name.deserialize_renamed {
             self.name.deserialize = rules.deserialize.apply_to_field(&self.name.deserialize);
         }
     }
@@ -1426,31 +1514,31 @@ impl Field {
 
 type SerAndDe<T> = (Option<T>, Option<T>);
 
-fn get_ser_and_de<'a, T, F>(
-    cx: &Ctxt,
+fn get_ser_and_de<'a, 'b, T, F>(
+    cx: &'b Ctxt,
     attr_name: &'static str,
     metas: &'a Punctuated<syn::NestedMeta, Token![,]>,
     f: F,
-) -> Result<SerAndDe<T>, ()>
+) -> Result<(VecAttr<'b, T>, VecAttr<'b, T>), ()>
 where
     T: 'a,
     F: Fn(&Ctxt, &Ident, &Ident, &'a syn::Lit) -> Result<T, ()>,
 {
-    let mut ser_meta = Attr::none(cx, attr_name);
-    let mut de_meta = Attr::none(cx, attr_name);
+    let mut ser_meta = VecAttr::none(cx, attr_name);
+    let mut de_meta = VecAttr::none(cx, attr_name);
     let attr_name = Ident::new(attr_name, Span::call_site());
 
     for meta in metas {
         match *meta {
             Meta(NameValue(ref meta)) if meta.ident == "serialize" => {
                 if let Ok(v) = f(cx, &attr_name, &meta.ident, &meta.lit) {
-                    ser_meta.set(&meta.ident, v);
+                    ser_meta.insert(&meta.ident, v);
                 }
             }
 
             Meta(NameValue(ref meta)) if meta.ident == "deserialize" => {
                 if let Ok(v) = f(cx, &attr_name, &meta.ident, &meta.lit) {
-                    de_meta.set(&meta.ident, v);
+                    de_meta.insert(&meta.ident, v);
                 }
             }
 
@@ -1468,21 +1556,31 @@ where
         }
     }
 
-    Ok((ser_meta.get(), de_meta.get()))
+    Ok((ser_meta, de_meta))
 }
 
 fn get_renames<'a>(
     cx: &Ctxt,
     items: &'a Punctuated<syn::NestedMeta, Token![,]>,
 ) -> Result<SerAndDe<&'a syn::LitStr>, ()> {
-    get_ser_and_de(cx, "rename", items, get_lit_str)
+    let (ser, de) = try!(get_ser_and_de(cx, "rename", items, get_lit_str));
+    Ok((try!(ser.at_most_one()), try!(de.at_most_one())))
+}
+
+fn get_multiple_renames<'a>(
+    cx: &Ctxt,
+    items: &'a Punctuated<syn::NestedMeta, Token![,]>,
+) -> Result<(Option<&'a syn::LitStr>, Vec<&'a syn::LitStr>), ()> {
+    let (ser, de) = try!(get_ser_and_de(cx, "rename", items, get_lit_str));
+    Ok((try!(ser.at_most_one()), de.get()))
 }
 
 fn get_where_predicates(
     cx: &Ctxt,
     items: &Punctuated<syn::NestedMeta, Token![,]>,
 ) -> Result<SerAndDe<Vec<syn::WherePredicate>>, ()> {
-    get_ser_and_de(cx, "bound", items, parse_lit_into_where)
+    let (ser, de) = try!(get_ser_and_de(cx, "bound", items, parse_lit_into_where));
+    Ok((try!(ser.at_most_one()), try!(de.at_most_one())))
 }
 
 pub fn get_serde_meta_items(attr: &syn::Attribute) -> Option<Vec<syn::NestedMeta>> {

serde_derive/src/internals/check.rs

@@ -295,12 +295,18 @@ fn check_internal_tag_field_name_conflict(cx: &Ctxt, cont: &Container) {
                     let check_de = !field.attrs.skip_deserializing();
                     let name = field.attrs.name();
                     let ser_name = name.serialize_name();
-                    let de_name = name.deserialize_name();
 
-                    if check_ser && ser_name == tag || check_de && de_name == tag {
+                    if check_ser && ser_name == tag {
                         diagnose_conflict();
                         return;
                     }
+
+                    for de_name in field.attrs.aliases() {
+                        if check_de && de_name == tag {
+                            diagnose_conflict();
+                            return;
+                        }
+                    }
                 }
             }
             Style::Unit | Style::Newtype | Style::Tuple => {}

serde_derive/src/lib.rs

@@ -13,7 +13,7 @@
 //!
 //! [https://serde.rs/derive.html]: https://serde.rs/derive.html
 
-#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.84")]
+#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.85")]
 #![cfg_attr(feature = "cargo-clippy", allow(renamed_and_removed_lints))]
 #![cfg_attr(feature = "cargo-clippy", deny(clippy, clippy_pedantic))]
 // Ignored clippy lints

serde_test/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_test"
-version = "1.0.84" # remember to update html_root_url
+version = "1.0.85" # remember to update html_root_url
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "Token De/Serializer for testing De/Serialize implementations"

serde_test/src/lib.rs

@@ -144,7 +144,7 @@
 //! # }
 //! ```
 
-#![doc(html_root_url = "https://docs.rs/serde_test/1.0.84")]
+#![doc(html_root_url = "https://docs.rs/serde_test/1.0.85")]
 #![cfg_attr(feature = "cargo-clippy", allow(renamed_and_removed_lints))]
 #![cfg_attr(feature = "cargo-clippy", deny(clippy, clippy_pedantic))]
 // Ignored clippy lints

test_suite/tests/compiletest.rs

@@ -4,7 +4,7 @@ use compiletest_rs as compiletest;
 
 #[test]
 fn ui() {
-    let config = compiletest::Config {
+    compiletest::run_tests(&compiletest::Config {
         mode: compiletest::common::Mode::Ui,
         src_base: std::path::PathBuf::from("tests/ui"),
         target_rustcflags: Some(String::from(
@@ -16,7 +16,5 @@ fn ui() {
              ",
         )),
         ..Default::default()
-    };
-
-    compiletest::run_tests(&config);
+    });
 }

test_suite/tests/test_annotations.rs

@@ -516,6 +516,16 @@ struct RenameStructSerializeDeserialize {
     a2: i32,
 }
 
+#[derive(Debug, PartialEq, Deserialize)]
+#[serde(deny_unknown_fields)]
+struct AliasStruct {
+    a1: i32,
+    #[serde(alias = "a3")]
+    a2: i32,
+    #[serde(alias = "a5", rename = "a6")]
+    a4: i32,
+}
+
 #[test]
 fn test_rename_struct() {
     assert_tokens(
@@ -562,6 +572,59 @@ fn test_rename_struct() {
             Token::StructEnd,
         ],
     );
+
+    assert_de_tokens(
+        &AliasStruct { a1: 1, a2: 2, a4: 3 },
+        &[
+            Token::Struct {
+                name: "AliasStruct",
+                len: 3,
+            },
+            Token::Str("a1"),
+            Token::I32(1),
+            Token::Str("a2"),
+            Token::I32(2),
+            Token::Str("a5"),
+            Token::I32(3),
+            Token::StructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &AliasStruct { a1: 1, a2: 2, a4: 3 },
+        &[
+            Token::Struct {
+                name: "AliasStruct",
+                len: 3,
+            },
+            Token::Str("a1"),
+            Token::I32(1),
+            Token::Str("a3"),
+            Token::I32(2),
+            Token::Str("a6"),
+            Token::I32(3),
+            Token::StructEnd,
+        ],
+    );
+}
+
+#[test]
+fn test_unknown_field_rename_struct() {
+    assert_de_tokens_error::<AliasStruct>(
+        &[
+            Token::Struct {
+                name: "AliasStruct",
+                len: 3,
+            },
+            Token::Str("a1"),
+            Token::I32(1),
+            Token::Str("a3"),
+            Token::I32(2),
+            Token::Str("a4"),
+            Token::I32(3),
+        ],
+        "unknown field `a4`, expected one of `a1`, `a2`, `a6`",
+    );
 }
 
 #[derive(Debug, PartialEq, Serialize, Deserialize)]
@@ -592,6 +655,19 @@ enum RenameEnumSerializeDeserialize<A> {
     },
 }
 
+#[derive(Debug, PartialEq, Deserialize)]
+#[serde(deny_unknown_fields)]
+enum AliasEnum {
+    #[serde(rename = "sailor_moon", alias = "usagi_tsukino")]
+    SailorMoon {
+        a: i8,
+        #[serde(alias = "c")]
+        b: i8,
+        #[serde(alias = "e", rename = "f")]
+        d: i8,
+    }
+}
+
 #[test]
 fn test_rename_enum() {
     assert_tokens(
@@ -678,6 +754,81 @@ fn test_rename_enum() {
             Token::StructVariantEnd,
         ],
     );
+
+    assert_de_tokens(
+        &AliasEnum::SailorMoon {
+            a: 0,
+            b: 1,
+            d: 2,
+        },
+        &[
+            Token::StructVariant {
+                name: "AliasEnum",
+                variant: "sailor_moon",
+                len: 3,
+            },
+            Token::Str("a"),
+            Token::I8(0),
+            Token::Str("b"),
+            Token::I8(1),
+            Token::Str("e"),
+            Token::I8(2),
+            Token::StructVariantEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &AliasEnum::SailorMoon {
+            a: 0,
+            b: 1,
+            d: 2,
+        },
+        &[
+            Token::StructVariant {
+                name: "AliasEnum",
+                variant: "usagi_tsukino",
+                len: 3,
+            },
+            Token::Str("a"),
+            Token::I8(0),
+            Token::Str("c"),
+            Token::I8(1),
+            Token::Str("f"),
+            Token::I8(2),
+            Token::StructVariantEnd,
+        ],
+    );
+}
+
+#[test]
+fn test_unknown_field_rename_enum() {
+    assert_de_tokens_error::<AliasEnum>(
+        &[
+            Token::StructVariant {
+                name: "AliasEnum",
+                variant: "SailorMoon",
+                len: 3,
+            },
+        ],
+        "unknown variant `SailorMoon`, expected `sailor_moon`",
+    );
+
+    assert_de_tokens_error::<AliasEnum>(
+        &[
+            Token::StructVariant {
+                name: "AliasEnum",
+                variant: "usagi_tsukino",
+                len: 3,
+            },
+            Token::Str("a"),
+            Token::I8(0),
+            Token::Str("c"),
+            Token::I8(1),
+            Token::Str("d"),
+            Token::I8(2),
+        ],
+        "unknown field `d`, expected one of `a`, `b`, `f`",
+    );
 }
 
 #[derive(Debug, PartialEq, Serialize)]

test_suite/tests/ui/conflict/internal-tag-alias.rs

@@ -0,0 +1,12 @@
+use serde_derive::Serialize;
+
+#[derive(Serialize)]
+#[serde(tag = "conflict")]
+enum E {
+    A {
+        #[serde(alias = "conflict")]
+        x: (),
+    },
+}
+
+fn main() {}

test_suite/tests/ui/conflict/internal-tag-alias.stderr

@@ -0,0 +1,14 @@
+error: variant field name `conflict` conflicts with internal tag
+  --> $DIR/internal-tag-alias.rs:4:1
+   |
+4  | / #[serde(tag = "conflict")]
+5  | | enum E {
+6  | |     A {
+7  | |         #[serde(alias = "conflict")]
+8  | |         x: (),
+9  | |     },
+10 | | }
+   | |_^
+
+error: aborting due to previous error
+

test_suite/tests/ui/duplicate-attribute/rename-rename-de.rs

@@ -1,10 +0,0 @@
-use serde_derive::Serialize;
-
-#[derive(Serialize)]
-struct S {
-    #[serde(rename = "x")]
-    #[serde(rename(deserialize = "y"))]
-    x: (),
-}
-
-fn main() {}

test_suite/tests/ui/duplicate-attribute/rename-rename-de.stderr

@@ -1,8 +0,0 @@
-error: duplicate serde attribute `rename`
- --> $DIR/rename-rename-de.rs:6:13
-  |
-6 |     #[serde(rename(deserialize = "y"))]
-  |             ^^^^^^
-
-error: aborting due to previous error
-