Release 1.0.217

- deserialization of flatten unit variant is possible
- serialization of such variant gives Err("can only flatten structs and maps (got an enum)")

.github/workflows/ci.yml

@@ -52,6 +52,7 @@ jobs:
           toolchain: ${{matrix.rust}}
       - run: cd serde && cargo build --features rc
       - run: cd serde && cargo build --no-default-features
+      - run: cd test_suite/no_std && cargo build
 
   nightly:
     name: Rust nightly ${{matrix.os == 'windows' && '(windows)' || ''}}

serde/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde"
-version = "1.0.215"
+version = "1.0.217"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 build = "build.rs"
 categories = ["encoding", "no-std", "no-std::no-alloc"]
@@ -37,7 +37,7 @@ rustdoc-args = ["--generate-link-to-definition"]
 # is compatible with exactly one serde release because the generated code
 # involves nonpublic APIs which are not bound by semver.
 [target.'cfg(any())'.dependencies]
-serde_derive = { version = "=1.0.215", path = "../serde_derive" }
+serde_derive = { version = "=1.0.217", path = "../serde_derive" }
 
 
 ### FEATURES #################################################################

serde/build.rs

@@ -1,6 +1,6 @@
 use std::env;
 use std::process::Command;
-use std::str::{self, FromStr};
+use std::str;
 
 // The rustc-cfg strings below are *not* public API. Please let us know by
 // opening a GitHub issue if your build environment requires some way to enable
@@ -108,30 +108,12 @@ fn main() {
 }
 
 fn rustc_minor_version() -> Option<u32> {
-    let rustc = match env::var_os("RUSTC") {
-        Some(rustc) => rustc,
-        None => return None,
-    };
-
-    let output = match Command::new(rustc).arg("--version").output() {
-        Ok(output) => output,
-        Err(_) => return None,
-    };
-
-    let version = match str::from_utf8(&output.stdout) {
-        Ok(version) => version,
-        Err(_) => return None,
-    };
-
+    let rustc = env::var_os("RUSTC")?;
+    let output = Command::new(rustc).arg("--version").output().ok()?;
+    let version = str::from_utf8(&output.stdout).ok()?;
     let mut pieces = version.split('.');
     if pieces.next() != Some("rustc 1") {
         return None;
     }
-
-    let next = match pieces.next() {
-        Some(next) => next,
-        None => return None,
-    };
-
-    u32::from_str(next).ok()
+    pieces.next()?.parse().ok()
 }

serde/src/lib.rs

@@ -95,7 +95,7 @@
 ////////////////////////////////////////////////////////////////////////////////
 
 // Serde types in rustdoc of other crates get linked to here.
-#![doc(html_root_url = "https://docs.rs/serde/1.0.215")]
+#![doc(html_root_url = "https://docs.rs/serde/1.0.217")]
 // Support using Serde without the standard library!
 #![cfg_attr(not(feature = "std"), no_std)]
 // Show which crate feature enables conditionally compiled APIs in documentation.

serde/src/private/ser.rs

@@ -54,6 +54,7 @@ enum Unsupported {
     Sequence,
     Tuple,
     TupleStruct,
+    #[cfg(not(any(feature = "std", feature = "alloc")))]
     Enum,
 }
 
@@ -70,6 +71,7 @@ impl Display for Unsupported {
             Unsupported::Sequence => formatter.write_str("a sequence"),
             Unsupported::Tuple => formatter.write_str("a tuple"),
             Unsupported::TupleStruct => formatter.write_str("a tuple struct"),
+            #[cfg(not(any(feature = "std", feature = "alloc")))]
             Unsupported::Enum => formatter.write_str("an enum"),
         }
     }
@@ -1095,9 +1097,9 @@ where
         self,
         _: &'static str,
         _: u32,
-        _: &'static str,
+        variant: &'static str,
     ) -> Result<Self::Ok, Self::Error> {
-        Err(Self::bad_type(Unsupported::Enum))
+        self.0.serialize_entry(variant, &())
     }
 
     fn serialize_newtype_struct<T>(

serde_derive/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_derive"
-version = "1.0.215"
+version = "1.0.217"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 categories = ["no-std", "no-std::no-alloc"]
 description = "Macros 1.1 implementation of #[derive(Serialize, Deserialize)]"

serde_derive/src/de.rs

@@ -33,6 +33,7 @@ pub fn expand_derive_deserialize(input: &mut syn::DeriveInput) -> syn::Result<To
         let vis = &input.vis;
         let used = pretend::pretend_used(&cont, params.is_packed);
         quote! {
+            #[automatically_derived]
             impl #de_impl_generics #ident #ty_generics #where_clause {
                 #vis fn deserialize<__D>(__deserializer: __D) -> #serde::__private::Result<#remote #ty_generics, __D::Error>
                 where
@@ -424,6 +425,7 @@ fn deserialize_unit_struct(params: &Parameters, cattrs: &attr::Container) -> Fra
             lifetime: _serde::__private::PhantomData<&#delife ()>,
         }
 
+        #[automatically_derived]
         impl #de_impl_generics _serde::de::Visitor<#delife> for __Visitor #de_ty_generics #where_clause {
             type Value = #this_type #ty_generics;
 
@@ -559,6 +561,7 @@ fn deserialize_tuple(
             lifetime: _serde::__private::PhantomData<&#delife ()>,
         }
 
+        #[automatically_derived]
         impl #de_impl_generics _serde::de::Visitor<#delife> for __Visitor #de_ty_generics #where_clause {
             type Value = #this_type #ty_generics;
 
@@ -658,6 +661,7 @@ fn deserialize_tuple_in_place(
             lifetime: _serde::__private::PhantomData<&#delife ()>,
         }
 
+        #[automatically_derived]
         impl #in_place_impl_generics _serde::de::Visitor<#delife> for __Visitor #in_place_ty_generics #where_clause {
             type Value = ();
 
@@ -1020,6 +1024,7 @@ fn deserialize_struct(
 
     let visitor_seed = match form {
         StructForm::ExternallyTagged(..) if has_flatten => Some(quote! {
+            #[automatically_derived]
             impl #de_impl_generics _serde::de::DeserializeSeed<#delife> for __Visitor #de_ty_generics #where_clause {
                 type Value = #this_type #ty_generics;
 
@@ -1084,6 +1089,7 @@ fn deserialize_struct(
             lifetime: _serde::__private::PhantomData<&#delife ()>,
         }
 
+        #[automatically_derived]
         impl #de_impl_generics _serde::de::Visitor<#delife> for __Visitor #de_ty_generics #where_clause {
             type Value = #this_type #ty_generics;
 
@@ -1165,6 +1171,7 @@ fn deserialize_struct_in_place(
             lifetime: _serde::__private::PhantomData<&#delife ()>,
         }
 
+        #[automatically_derived]
         impl #in_place_impl_generics _serde::de::Visitor<#delife> for __Visitor #in_place_ty_generics #where_clause {
             type Value = ();
 
@@ -1338,6 +1345,7 @@ fn deserialize_externally_tagged_enum(
             lifetime: _serde::__private::PhantomData<&#delife ()>,
         }
 
+        #[automatically_derived]
         impl #de_impl_generics _serde::de::Visitor<#delife> for __Visitor #de_ty_generics #where_clause {
             type Value = #this_type #ty_generics;
 
@@ -1599,6 +1607,7 @@ fn deserialize_adjacently_tagged_enum(
             lifetime: _serde::__private::PhantomData<&#delife ()>,
         }
 
+        #[automatically_derived]
         impl #de_impl_generics _serde::de::DeserializeSeed<#delife> for __Seed #de_ty_generics #where_clause {
             type Value = #this_type #ty_generics;
 
@@ -1618,6 +1627,7 @@ fn deserialize_adjacently_tagged_enum(
             lifetime: _serde::__private::PhantomData<&#delife ()>,
         }
 
+        #[automatically_derived]
         impl #de_impl_generics _serde::de::Visitor<#delife> for __Visitor #de_ty_generics #where_clause {
             type Value = #this_type #ty_generics;
 
@@ -2046,12 +2056,14 @@ fn deserialize_generated_identifier(
         #[doc(hidden)]
         struct __FieldVisitor;
 
+        #[automatically_derived]
         impl<'de> _serde::de::Visitor<'de> for __FieldVisitor {
             type Value = __Field #lifetime;
 
             #visitor_impl
         }
 
+        #[automatically_derived]
         impl<'de> _serde::Deserialize<'de> for __Field #lifetime {
             #[inline]
             fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
@@ -2190,6 +2202,7 @@ fn deserialize_custom_identifier(
             lifetime: _serde::__private::PhantomData<&#delife ()>,
         }
 
+        #[automatically_derived]
         impl #de_impl_generics _serde::de::Visitor<#delife> for __FieldVisitor #de_ty_generics #where_clause {
             type Value = #this_type #ty_generics;
 
@@ -2909,6 +2922,7 @@ fn wrap_deserialize_with(
             lifetime: _serde::__private::PhantomData<&#delife ()>,
         }
 
+        #[automatically_derived]
         impl #de_impl_generics _serde::Deserialize<#delife> for __DeserializeWith #de_ty_generics #where_clause {
             fn deserialize<__D>(#deserializer_var: __D) -> _serde::__private::Result<Self, __D::Error>
             where

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/1.0.215")]
+#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.217")]
 #![cfg_attr(not(check_cfg), allow(unexpected_cfgs))]
 // Ignored clippy lints
 #![allow(

serde_derive/src/ser.rs

@@ -29,6 +29,7 @@ pub fn expand_derive_serialize(input: &mut syn::DeriveInput) -> syn::Result<Toke
         let vis = &input.vis;
         let used = pretend::pretend_used(&cont, params.is_packed);
         quote! {
+            #[automatically_derived]
             impl #impl_generics #ident #ty_generics #where_clause {
                 #vis fn serialize<__S>(__self: &#remote #ty_generics, __serializer: __S) -> #serde::__private::Result<__S::Ok, __S::Error>
                 where
@@ -733,6 +734,7 @@ fn serialize_adjacently_tagged_variant(
             phantom: _serde::__private::PhantomData<#this_type #ty_generics>,
         }
 
+        #[automatically_derived]
         impl #wrapper_impl_generics _serde::Serialize for __AdjacentlyTagged #wrapper_ty_generics #where_clause {
             fn serialize<__S>(&self, __serializer: __S) -> _serde::__private::Result<__S::Ok, __S::Error>
             where
@@ -997,6 +999,7 @@ fn serialize_struct_variant_with_flatten(
                     phantom: _serde::__private::PhantomData<#this_type #ty_generics>,
                 }
 
+                #[automatically_derived]
                 impl #wrapper_impl_generics _serde::Serialize for __EnumFlatten #wrapper_ty_generics #where_clause {
                     fn serialize<__S>(&self, __serializer: __S) -> _serde::__private::Result<__S::Ok, __S::Error>
                     where
@@ -1239,6 +1242,7 @@ fn wrap_serialize_with(
             phantom: _serde::__private::PhantomData<#this_type #ty_generics>,
         }
 
+        #[automatically_derived]
         impl #wrapper_impl_generics _serde::Serialize for __SerializeWith #wrapper_ty_generics #where_clause {
             fn serialize<__S>(&#self_var, #serializer_var: __S) -> _serde::__private::Result<__S::Ok, __S::Error>
             where

test_suite/Cargo.toml

@@ -13,7 +13,7 @@ serde = { path = "../serde" }
 
 [dev-dependencies]
 automod = "1.0.1"
-fnv = "1.0"
+foldhash = "0.1"
 rustversion = "1.0"
 serde = { path = "../serde", features = ["rc"] }
 serde_derive = { path = "../serde_derive", features = ["deserialize_in_place"] }

test_suite/no_std/Cargo.toml

@@ -10,4 +10,10 @@ libc = { version = "0.2", default-features = false }
 serde = { path = "../../serde", default-features = false }
 serde_derive = { path = "../../serde_derive" }
 
+[profile.dev]
+panic = "abort"
+
+[profile.release]
+panic = "abort"
+
 [workspace]

test_suite/no_std/src/main.rs

@@ -1,16 +1,13 @@
-#![allow(internal_features)]
-#![feature(lang_items, start)]
 #![no_std]
+#![no_main]
 
-#[start]
-fn start(_argc: isize, _argv: *const *const u8) -> isize {
+use core::ffi::c_int;
+
+#[no_mangle]
+extern "C" fn main(_argc: c_int, _argv: *const *const u8) -> c_int {
     0
 }
 
-#[lang = "eh_personality"]
-#[no_mangle]
-pub extern "C" fn rust_eh_personality() {}
-
 #[panic_handler]
 fn panic(_info: &core::panic::PanicInfo) -> ! {
     unsafe {

test_suite/tests/macros/mod.rs

@@ -34,9 +34,8 @@ macro_rules! hashset {
         $(set.insert($value);)+
         set
     }};
-    ($hasher:ident @ $($value:expr),+) => {{
-        use std::hash::BuildHasherDefault;
-        let mut set = HashSet::with_hasher(BuildHasherDefault::<$hasher>::default());
+    ($hasher:ty; $($value:expr),+) => {{
+        let mut set = HashSet::<_, $hasher>::default();
         $(set.insert($value);)+
         set
     }};
@@ -51,9 +50,8 @@ macro_rules! hashmap {
         $(map.insert($key, $value);)+
         map
     }};
-    ($hasher:ident @ $($key:expr => $value:expr),+) => {{
-        use std::hash::BuildHasherDefault;
-        let mut map = HashMap::with_hasher(BuildHasherDefault::<$hasher>::default());
+    ($hasher:ty; $($key:expr => $value:expr),+) => {{
+        let mut map = HashMap::<_, _, $hasher>::default();
         $(map.insert($key, $value);)+
         map
     }};

test_suite/tests/test_annotations.rs

@@ -2655,11 +2655,46 @@ mod flatten {
 
             #[derive(Debug, PartialEq, Serialize, Deserialize)]
             enum Enum {
+                Unit,
                 Newtype(HashMap<String, String>),
                 Tuple(u32, u32),
                 Struct { index: u32, value: u32 },
             }
 
+            #[test]
+            fn unit() {
+                let value = Flatten {
+                    data: Enum::Unit,
+                    extra: HashMap::from_iter([("extra_key".into(), "extra value".into())]),
+                };
+                assert_tokens(
+                    &value,
+                    &[
+                        Token::Map { len: None },
+                        // data
+                        Token::Str("Unit"), // variant
+                        Token::Unit,
+                        // extra
+                        Token::Str("extra_key"),
+                        Token::Str("extra value"),
+                        Token::MapEnd,
+                    ],
+                );
+                assert_de_tokens(
+                    &value,
+                    &[
+                        Token::Map { len: None },
+                        // extra
+                        Token::Str("extra_key"),
+                        Token::Str("extra value"),
+                        // data
+                        Token::Str("Unit"), // variant
+                        Token::Unit,
+                        Token::MapEnd,
+                    ],
+                );
+            }
+
             #[test]
             fn newtype() {
                 assert_tokens(

test_suite/tests/test_de.rs

@@ -10,7 +10,6 @@
 )]
 #![cfg_attr(feature = "unstable", feature(never_type))]
 
-use fnv::FnvHasher;
 use serde::de::value::{F32Deserializer, F64Deserializer};
 use serde::de::{Deserialize, DeserializeOwned, Deserializer, IntoDeserializer};
 use serde_derive::Deserialize;
@@ -1040,7 +1039,7 @@ fn test_hashset() {
         ],
     );
     test(
-        hashset![FnvHasher @ 1, 2, 3],
+        hashset![foldhash::fast::FixedState; 1, 2, 3],
         &[
             Token::Seq { len: Some(3) },
             Token::I32(1),
@@ -1275,7 +1274,7 @@ fn test_hashmap() {
         ],
     );
     test(
-        hashmap![FnvHasher @ 1 => 2, 3 => 4],
+        hashmap![foldhash::fast::FixedState; 1 => 2, 3 => 4],
         &[
             Token::Map { len: Some(2) },
             Token::I32(1),

test_suite/tests/test_gen.rs

@@ -769,7 +769,7 @@ fn test_gen() {
     }
 
     #[derive(Serialize)]
-    #[repr(packed)]
+    #[repr(C, packed)]
     #[allow(dead_code)]
     struct Packed {
         x: u8,
@@ -915,14 +915,14 @@ where
 
 //////////////////////////////////////////////////////////////////////////
 
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct RemotePacked {
     pub a: u16,
     pub b: u32,
 }
 
 #[derive(Serialize)]
-#[repr(packed)]
+#[repr(C, packed)]
 #[serde(remote = "RemotePacked")]
 pub struct RemotePackedDef {
     a: u16,
@@ -933,14 +933,14 @@ impl Drop for RemotePackedDef {
     fn drop(&mut self) {}
 }
 
-#[repr(packed)]
+#[repr(C, packed)]
 pub struct RemotePackedNonCopy {
     pub a: u16,
     pub b: String,
 }
 
 #[derive(Deserialize)]
-#[repr(packed)]
+#[repr(C, packed)]
 #[serde(remote = "RemotePackedNonCopy")]
 pub struct RemotePackedNonCopyDef {
     a: u16,

test_suite/tests/test_ser.rs

@@ -1,7 +1,6 @@
 #![allow(clippy::derive_partial_eq_without_eq, clippy::unreadable_literal)]
 #![cfg_attr(feature = "unstable", feature(never_type))]
 
-use fnv::FnvHasher;
 use serde_derive::Serialize;
 use serde_test::{assert_ser_tokens, assert_ser_tokens_error, Configure, Token};
 use std::cell::RefCell;
@@ -220,7 +219,7 @@ fn test_hashset() {
         &[Token::Seq { len: Some(1) }, Token::I32(1), Token::SeqEnd],
     );
     assert_ser_tokens(
-        &hashset![FnvHasher @ 1],
+        &hashset![foldhash::fast::FixedState; 1],
         &[Token::Seq { len: Some(1) }, Token::I32(1), Token::SeqEnd],
     );
 }
@@ -300,7 +299,7 @@ fn test_hashmap() {
         ],
     );
     assert_ser_tokens(
-        &hashmap![FnvHasher @ 1 => 2],
+        &hashmap![foldhash::fast::FixedState; 1 => 2],
         &[
             Token::Map { len: Some(1) },
             Token::I32(1),