Release 1.0.225

Use differently named __private module per patch release

serde/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde"
-version = "1.0.222"
+version = "1.0.225"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 build = "build.rs"
 categories = ["encoding", "no-std", "no-std::no-alloc"]
@@ -15,7 +15,7 @@ repository = "https://github.com/serde-rs/serde"
 rust-version = "1.56"
 
 [dependencies]
-serde_core = { version = "=1.0.222", path = "../serde_core", default-features = false, features = ["result"] }
+serde_core = { version = "=1.0.225", path = "../serde_core", default-features = false, features = ["result"] }
 serde_derive = { version = "1", optional = true, path = "../serde_derive" }
 
 [package.metadata.playground]

serde/build.rs

@@ -1,19 +1,36 @@
 use std::env;
+use std::fs;
+use std::path::PathBuf;
 use std::process::Command;
 use std::str;
 
+const PRIVATE: &str = "\
+#[doc(hidden)]
+pub mod __private$$ {
+    #[doc(hidden)]
+    pub use crate::private::*;
+}
+use serde_core::__private$$ as serde_core_private;
+";
+
 // 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
 // these cfgs other than by executing our build script.
 fn main() {
     println!("cargo:rerun-if-changed=build.rs");
 
+    let out_dir = PathBuf::from(env::var_os("OUT_DIR").unwrap());
+    let patch_version = env::var("CARGO_PKG_VERSION_PATCH").unwrap();
+    let module = PRIVATE.replace("$$", &patch_version);
+    fs::write(out_dir.join("private.rs"), module).unwrap();
+
     let minor = match rustc_minor_version() {
         Some(minor) => minor,
         None => return,
     };
 
     if minor >= 77 {
+        println!("cargo:rustc-check-cfg=cfg(no_diagnostic_namespace)");
         println!("cargo:rustc-check-cfg=cfg(no_serde_derive)");
     }
 
@@ -21,6 +38,12 @@ fn main() {
     if minor < 61 {
         println!("cargo:rustc-cfg=no_serde_derive");
     }
+
+    // Support for the `#[diagnostic]` tool attribute namespace
+    // https://blog.rust-lang.org/2024/05/02/Rust-1.78.0.html#diagnostic-attributes
+    if minor < 78 {
+        println!("cargo:rustc-cfg=no_diagnostic_namespace");
+    }
 }
 
 fn rustc_minor_version() -> Option<u32> {

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/1.0.222")]
+#![doc(html_root_url = "https://docs.rs/serde/1.0.225")]
 // Support using Serde without the standard library!
 #![cfg_attr(not(feature = "std"), no_std)]
 // Show which crate feature enables conditionally compiled APIs in documentation.
@@ -239,8 +239,9 @@ mod integer128;
 
 // Used by generated code and doc tests. Not public API.
 #[doc(hidden)]
-#[path = "private/mod.rs"]
-pub mod __private;
+mod private;
+
+include!(concat!(env!("OUT_DIR"), "/private.rs"));
 
 // Re-export #[derive(Serialize, Deserialize)].
 //

serde/src/private/de.rs

@@ -17,7 +17,7 @@ pub use self::content::{
     UntaggedUnitVisitor,
 };
 
-pub use serde_core::__private::InPlaceSeed;
+pub use crate::serde_core_private::InPlaceSeed;
 
 /// If the missing field is of type `Option<T>` then treat is as `None`,
 /// otherwise it is an error.
@@ -28,6 +28,7 @@ where
 {
     struct MissingFieldDeserializer<E>(&'static str, PhantomData<E>);
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de, E> Deserializer<'de> for MissingFieldDeserializer<E>
     where
         E: Error,
@@ -67,6 +68,7 @@ where
 {
     struct CowStrVisitor;
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'a> Visitor<'a> for CowStrVisitor {
         type Value = Cow<'a, str>;
 
@@ -140,6 +142,7 @@ where
 {
     struct CowBytesVisitor;
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'a> Visitor<'a> for CowBytesVisitor {
         type Value = Cow<'a, [u8]>;
 
@@ -213,8 +216,8 @@ mod content {
         self, Deserialize, DeserializeSeed, Deserializer, EnumAccess, Expected, IgnoredAny,
         MapAccess, SeqAccess, Unexpected, Visitor,
     };
-    use serde_core::__private::size_hint;
-    pub use serde_core::__private::Content;
+    use crate::serde_core_private::size_hint;
+    pub use crate::serde_core_private::Content;
 
     pub fn content_as_str<'a, 'de>(content: &'a Content<'de>) -> Option<&'a str> {
         match *content {
@@ -294,6 +297,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de> DeserializeSeed<'de> for ContentVisitor<'de> {
         type Value = Content<'de>;
 
@@ -305,6 +309,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de> Visitor<'de> for ContentVisitor<'de> {
         type Value = Content<'de>;
 
@@ -530,6 +535,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de> DeserializeSeed<'de> for TagOrContentVisitor<'de> {
         type Value = TagOrContent<'de>;
 
@@ -543,6 +549,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de> Visitor<'de> for TagOrContentVisitor<'de> {
         type Value = TagOrContent<'de>;
 
@@ -824,6 +831,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de, T> Visitor<'de> for TaggedContentVisitor<T>
     where
         T: Deserialize<'de>,
@@ -894,6 +902,7 @@ mod content {
         pub content: &'static str,
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de> DeserializeSeed<'de> for TagOrContentFieldVisitor {
         type Value = TagOrContentField;
 
@@ -905,6 +914,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de> Visitor<'de> for TagOrContentFieldVisitor {
         type Value = TagOrContentField;
 
@@ -971,6 +981,7 @@ mod content {
         pub content: &'static str,
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de> DeserializeSeed<'de> for TagContentOtherFieldVisitor {
         type Value = TagContentOtherField;
 
@@ -982,6 +993,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de> Visitor<'de> for TagContentOtherFieldVisitor {
         type Value = TagContentOtherField;
 
@@ -1104,6 +1116,7 @@ mod content {
 
     /// Used when deserializing an internally tagged enum because the content
     /// will be used exactly once.
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de, E> Deserializer<'de> for ContentDeserializer<'de, E>
     where
         E: de::Error,
@@ -1523,6 +1536,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de, E> Deserializer<'de> for SeqDeserializer<'de, E>
     where
         E: de::Error,
@@ -1545,6 +1559,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de, E> SeqAccess<'de> for SeqDeserializer<'de, E>
     where
         E: de::Error,
@@ -1571,6 +1586,7 @@ mod content {
 
     struct ExpectedInSeq(usize);
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl Expected for ExpectedInSeq {
         fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
             if self.0 == 1 {
@@ -1630,6 +1646,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de, E> Deserializer<'de> for MapDeserializer<'de, E>
     where
         E: de::Error,
@@ -1669,6 +1686,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de, E> MapAccess<'de> for MapDeserializer<'de, E>
     where
         E: de::Error,
@@ -1723,6 +1741,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de, E> SeqAccess<'de> for MapDeserializer<'de, E>
     where
         E: de::Error,
@@ -1749,6 +1768,7 @@ mod content {
 
     struct PairDeserializer<'de, E>(Content<'de>, Content<'de>, PhantomData<E>);
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de, E> Deserializer<'de> for PairDeserializer<'de, E>
     where
         E: de::Error,
@@ -1800,6 +1820,7 @@ mod content {
 
     struct PairVisitor<'de, E>(Option<Content<'de>>, Option<Content<'de>>, PhantomData<E>);
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de, E> SeqAccess<'de> for PairVisitor<'de, E>
     where
         E: de::Error,
@@ -1832,6 +1853,7 @@ mod content {
 
     struct ExpectedInMap(usize);
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl Expected for ExpectedInMap {
         fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
             if self.0 == 1 {
@@ -1864,6 +1886,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de, E> de::EnumAccess<'de> for EnumDeserializer<'de, E>
     where
         E: de::Error,
@@ -1892,6 +1915,7 @@ mod content {
         err: PhantomData<E>,
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de, E> de::VariantAccess<'de> for VariantDeserializer<'de, E>
     where
         E: de::Error,
@@ -2046,6 +2070,7 @@ mod content {
 
     /// Used when deserializing an untagged enum because the content may need
     /// to be used more than once.
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de, 'a, E> Deserializer<'de> for ContentRefDeserializer<'a, 'de, E>
     where
         E: de::Error,
@@ -2424,8 +2449,10 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'a, 'de: 'a, E> Copy for ContentRefDeserializer<'a, 'de, E> {}
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'a, 'de: 'a, E> Clone for ContentRefDeserializer<'a, 'de, E> {
         fn clone(&self) -> Self {
             *self
@@ -2467,6 +2494,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'a, 'de, E> Deserializer<'de> for SeqRefDeserializer<'a, 'de, E>
     where
         E: de::Error,
@@ -2489,6 +2517,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'a, 'de, E> SeqAccess<'de> for SeqRefDeserializer<'a, 'de, E>
     where
         E: de::Error,
@@ -2563,6 +2592,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'a, 'de, E> Deserializer<'de> for MapRefDeserializer<'a, 'de, E>
     where
         E: de::Error,
@@ -2602,6 +2632,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'a, 'de, E> MapAccess<'de> for MapRefDeserializer<'a, 'de, E>
     where
         E: de::Error,
@@ -2656,6 +2687,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'a, 'de, E> SeqAccess<'de> for MapRefDeserializer<'a, 'de, E>
     where
         E: de::Error,
@@ -2682,6 +2714,7 @@ mod content {
 
     struct PairRefDeserializer<'a, 'de, E>(&'a Content<'de>, &'a Content<'de>, PhantomData<E>);
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'a, 'de, E> Deserializer<'de> for PairRefDeserializer<'a, 'de, E>
     where
         E: de::Error,
@@ -2737,6 +2770,7 @@ mod content {
         PhantomData<E>,
     );
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'a, 'de, E> SeqAccess<'de> for PairRefVisitor<'a, 'de, E>
     where
         E: de::Error,
@@ -2776,6 +2810,7 @@ mod content {
         err: PhantomData<E>,
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de, 'a, E> de::EnumAccess<'de> for EnumRefDeserializer<'a, 'de, E>
     where
         E: de::Error,
@@ -2804,6 +2839,7 @@ mod content {
         err: PhantomData<E>,
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de, 'a, E> de::VariantAccess<'de> for VariantRefDeserializer<'a, 'de, E>
     where
         E: de::Error,
@@ -2890,6 +2926,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de, E> de::IntoDeserializer<'de, E> for ContentDeserializer<'de, E>
     where
         E: de::Error,
@@ -2901,6 +2938,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de, 'a, E> de::IntoDeserializer<'de, E> for ContentRefDeserializer<'a, 'de, E>
     where
         E: de::Error,
@@ -2930,6 +2968,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de, 'a> Visitor<'de> for InternallyTaggedUnitVisitor<'a> {
         type Value = ();
 
@@ -2975,6 +3014,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<'de, 'a> Visitor<'de> for UntaggedUnitVisitor<'a> {
         type Value = ();
 
@@ -3022,6 +3062,7 @@ pub trait IdentifierDeserializer<'de, E: Error> {
 
 pub struct Borrowed<'de, T: 'de + ?Sized>(pub &'de T);
 
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl<'de, E> IdentifierDeserializer<'de, E> for u64
 where
     E: Error,
@@ -3038,6 +3079,7 @@ pub struct StrDeserializer<'a, E> {
     marker: PhantomData<E>,
 }
 
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl<'de, 'a, E> Deserializer<'de> for StrDeserializer<'a, E>
 where
     E: Error,
@@ -3063,6 +3105,7 @@ pub struct BorrowedStrDeserializer<'de, E> {
     marker: PhantomData<E>,
 }
 
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl<'de, E> Deserializer<'de> for BorrowedStrDeserializer<'de, E>
 where
     E: Error,
@@ -3083,6 +3126,7 @@ where
     }
 }
 
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl<'a, E> IdentifierDeserializer<'a, E> for &'a str
 where
     E: Error,
@@ -3097,6 +3141,7 @@ where
     }
 }
 
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl<'de, E> IdentifierDeserializer<'de, E> for Borrowed<'de, str>
 where
     E: Error,
@@ -3111,6 +3156,7 @@ where
     }
 }
 
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl<'a, E> IdentifierDeserializer<'a, E> for &'a [u8]
 where
     E: Error,
@@ -3122,6 +3168,7 @@ where
     }
 }
 
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl<'de, E> IdentifierDeserializer<'de, E> for Borrowed<'de, [u8]>
 where
     E: Error,
@@ -3164,6 +3211,7 @@ macro_rules! forward_to_deserialize_other {
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl<'a, 'de, E> Deserializer<'de> for FlatMapDeserializer<'a, 'de, E>
 where
     E: Error,
@@ -3300,6 +3348,7 @@ struct FlatMapAccess<'a, 'de: 'a, E> {
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl<'a, 'de, E> MapAccess<'de> for FlatMapAccess<'a, 'de, E>
 where
     E: Error,
@@ -3344,6 +3393,7 @@ struct FlatStructAccess<'a, 'de: 'a, E> {
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl<'a, 'de, E> MapAccess<'de> for FlatStructAccess<'a, 'de, E>
 where
     E: Error,
@@ -3407,6 +3457,7 @@ pub struct AdjacentlyTaggedEnumVariantVisitor<F> {
     fields_enum: PhantomData<F>,
 }
 
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl<'de, F> Visitor<'de> for AdjacentlyTaggedEnumVariantVisitor<F>
 where
     F: Deserialize<'de>,
@@ -3427,6 +3478,7 @@ where
     }
 }
 
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl<'de, F> DeserializeSeed<'de> for AdjacentlyTaggedEnumVariantSeed<F>
 where
     F: Deserialize<'de>,

serde/src/private/mod.rs

@@ -12,7 +12,7 @@ pub use crate::lib::option::Option::{self, None, Some};
 pub use crate::lib::ptr;
 pub use crate::lib::result::Result::{self, Err, Ok};
 
-pub use serde_core::__private::string::from_utf8_lossy;
+pub use crate::serde_core_private::string::from_utf8_lossy;
 
 #[cfg(any(feature = "alloc", feature = "std"))]
 pub use crate::lib::{ToString, Vec};

serde/src/private/ser.rs

@@ -58,6 +58,7 @@ enum Unsupported {
     Enum,
 }
 
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl Display for Unsupported {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
         match *self {
@@ -89,6 +90,7 @@ where
     }
 }
 
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl<S> Serializer for TaggedSerializer<S>
 where
     S: Serializer,
@@ -355,6 +357,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<M> ser::SerializeTupleVariant for SerializeTupleVariantAsMapValue<M>
     where
         M: ser::SerializeMap,
@@ -395,6 +398,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<M> ser::SerializeStructVariant for SerializeStructVariantAsMapValue<M>
     where
         M: ser::SerializeMap,
@@ -462,6 +466,7 @@ mod content {
         ),
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl Serialize for Content {
         fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where
@@ -554,6 +559,7 @@ mod content {
         }
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<E> Serializer for ContentSerializer<E>
     where
         E: ser::Error,
@@ -765,6 +771,7 @@ mod content {
         error: PhantomData<E>,
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<E> ser::SerializeSeq for SerializeSeq<E>
     where
         E: ser::Error,
@@ -791,6 +798,7 @@ mod content {
         error: PhantomData<E>,
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<E> ser::SerializeTuple for SerializeTuple<E>
     where
         E: ser::Error,
@@ -818,6 +826,7 @@ mod content {
         error: PhantomData<E>,
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<E> ser::SerializeTupleStruct for SerializeTupleStruct<E>
     where
         E: ser::Error,
@@ -847,6 +856,7 @@ mod content {
         error: PhantomData<E>,
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<E> ser::SerializeTupleVariant for SerializeTupleVariant<E>
     where
         E: ser::Error,
@@ -879,6 +889,7 @@ mod content {
         error: PhantomData<E>,
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<E> ser::SerializeMap for SerializeMap<E>
     where
         E: ser::Error,
@@ -930,6 +941,7 @@ mod content {
         error: PhantomData<E>,
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<E> ser::SerializeStruct for SerializeStruct<E>
     where
         E: ser::Error,
@@ -959,6 +971,7 @@ mod content {
         error: PhantomData<E>,
     }
 
+    #[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
     impl<E> ser::SerializeStructVariant for SerializeStructVariant<E>
     where
         E: ser::Error,
@@ -1003,6 +1016,7 @@ where
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl<'a, M> Serializer for FlatMapSerializer<'a, M>
 where
     M: SerializeMap + 'a,
@@ -1184,6 +1198,7 @@ where
 pub struct FlatMapSerializeMap<'a, M: 'a>(&'a mut M);
 
 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl<'a, M> ser::SerializeMap for FlatMapSerializeMap<'a, M>
 where
     M: SerializeMap + 'a,
@@ -1222,6 +1237,7 @@ where
 pub struct FlatMapSerializeStruct<'a, M: 'a>(&'a mut M);
 
 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl<'a, M> ser::SerializeStruct for FlatMapSerializeStruct<'a, M>
 where
     M: SerializeMap + 'a,
@@ -1263,6 +1279,7 @@ where
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl<'a, M> ser::SerializeTupleVariant for FlatMapSerializeTupleVariantAsMapValue<'a, M>
 where
     M: SerializeMap + 'a,
@@ -1309,6 +1326,7 @@ where
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl<'a, M> ser::SerializeStructVariant for FlatMapSerializeStructVariantAsMapValue<'a, M>
 where
     M: SerializeMap + 'a,
@@ -1339,6 +1357,7 @@ pub struct AdjacentlyTaggedEnumVariant {
     pub variant_name: &'static str,
 }
 
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl Serialize for AdjacentlyTaggedEnumVariant {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -1352,6 +1371,7 @@ impl Serialize for AdjacentlyTaggedEnumVariant {
 // that is not recognized.
 pub struct CannotSerializeVariant<T>(pub T);
 
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl<T> Display for CannotSerializeVariant<T>
 where
     T: Debug,

serde_core/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_core"
-version = "1.0.222"
+version = "1.0.225"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 build = "build.rs"
 categories = ["encoding", "no-std", "no-std::no-alloc"]
@@ -36,7 +36,7 @@ rustdoc-args = [
 # 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 = "=1.0.222", path = "../serde_derive" }
+serde_derive = { version = "=1.0.225", path = "../serde_derive" }
 
 
 ### FEATURES #################################################################

serde_core/build.rs

@@ -1,13 +1,28 @@
 use std::env;
+use std::fs;
+use std::path::PathBuf;
 use std::process::Command;
 use std::str;
 
+const PRIVATE: &str = "\
+#[doc(hidden)]
+pub mod __private$$ {
+    #[doc(hidden)]
+    pub use crate::private::*;
+}
+";
+
 // 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
 // these cfgs other than by executing our build script.
 fn main() {
     println!("cargo:rerun-if-changed=build.rs");
 
+    let out_dir = PathBuf::from(env::var_os("OUT_DIR").unwrap());
+    let patch_version = env::var("CARGO_PKG_VERSION_PATCH").unwrap();
+    let module = PRIVATE.replace("$$", &patch_version);
+    fs::write(out_dir.join("private.rs"), module).unwrap();
+
     let minor = match rustc_minor_version() {
         Some(minor) => minor,
         None => return,

serde_core/src/lib.rs

@@ -35,7 +35,7 @@
 ////////////////////////////////////////////////////////////////////////////////
 
 // Serde types in rustdoc of other crates get linked to here.
-#![doc(html_root_url = "https://docs.rs/serde/1.0.222")]
+#![doc(html_root_url = "https://docs.rs/serde_core/1.0.225")]
 // Support using Serde without the standard library!
 #![cfg_attr(not(feature = "std"), no_std)]
 // Show which crate feature enables conditionally compiled APIs in documentation.
@@ -252,9 +252,18 @@ pub use crate::ser::{Serialize, Serializer};
 
 // Used by generated code. Not public API.
 #[doc(hidden)]
-#[path = "private/mod.rs"]
-pub mod __private;
-use self::__private as private;
+mod private;
+
+// Used by declarative macro generated code. Not public API.
+#[doc(hidden)]
+pub mod __private {
+    #[doc(hidden)]
+    pub use crate::private::doc;
+    #[doc(hidden)]
+    pub use core::result::Result;
+}
+
+include!(concat!(env!("OUT_DIR"), "/private.rs"));
 
 #[cfg(all(not(feature = "std"), no_core_error))]
 mod std_error;

serde_core/src/private/doc.rs

@@ -8,6 +8,7 @@ use crate::ser;
 #[derive(Debug)]
 pub struct Error;
 
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl ser::Error for Error {
     fn custom<T>(_: T) -> Self
     where
@@ -18,12 +19,14 @@ impl ser::Error for Error {
 }
 
 #[cfg(feature = "std")]
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl error::Error for Error {
     fn description(&self) -> &str {
         unimplemented!()
     }
 }
 
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl Display for Error {
     fn fmt(&self, _: &mut fmt::Formatter) -> fmt::Result {
         unimplemented!()

serde_core/src/private/seed.rs

@@ -5,6 +5,7 @@ use crate::de::{Deserialize, DeserializeSeed, Deserializer};
 /// Wraps a mutable reference and calls deserialize_in_place on it.
 pub struct InPlaceSeed<'a, T: 'a>(pub &'a mut T);
 
+#[cfg_attr(not(no_diagnostic_namespace), diagnostic::do_not_recommend)]
 impl<'a, 'de, T> DeserializeSeed<'de> for InPlaceSeed<'a, T>
 where
     T: Deserialize<'de>,

serde_derive/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_derive"
-version = "1.0.222"
+version = "1.0.225"
 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/deprecated.rs

@@ -0,0 +1,56 @@
+use proc_macro2::TokenStream;
+use quote::quote;
+
+pub fn allow_deprecated(input: &syn::DeriveInput) -> Option<TokenStream> {
+    if should_allow_deprecated(input) {
+        Some(quote! { #[allow(deprecated)] })
+    } else {
+        None
+    }
+}
+
+/// Determine if an `#[allow(deprecated)]` should be added to the derived impl.
+///
+/// This should happen if the derive input or an enum variant it contains has
+/// one of:
+///   - `#[deprecated]`
+///   - `#[allow(deprecated)]`
+fn should_allow_deprecated(input: &syn::DeriveInput) -> bool {
+    if contains_deprecated(&input.attrs) {
+        return true;
+    }
+    if let syn::Data::Enum(data_enum) = &input.data {
+        for variant in &data_enum.variants {
+            if contains_deprecated(&variant.attrs) {
+                return true;
+            }
+        }
+    }
+    false
+}
+
+/// Check whether the given attributes contains one of:
+///   - `#[deprecated]`
+///   - `#[allow(deprecated)]`
+fn contains_deprecated(attrs: &[syn::Attribute]) -> bool {
+    for attr in attrs {
+        if attr.path().is_ident("deprecated") {
+            return true;
+        }
+        if let syn::Meta::List(meta_list) = &attr.meta {
+            if meta_list.path.is_ident("allow") {
+                let mut allow_deprecated = false;
+                let _ = meta_list.parse_nested_meta(|meta| {
+                    if meta.path.is_ident("deprecated") {
+                        allow_deprecated = true;
+                    }
+                    Ok(())
+                });
+                if allow_deprecated {
+                    return true;
+                }
+            }
+        }
+    }
+    false
+}

serde_derive/src/internals/ast.rs

@@ -1,6 +1,7 @@
 //! A Serde ast, parsed from the Syn ast and ready to generate Rust code.
 
 use crate::internals::{attr, check, Ctxt, Derive};
+use proc_macro2::Ident;
 use syn::punctuated::Punctuated;
 use syn::Token;
 
@@ -62,13 +63,17 @@ impl<'a> Container<'a> {
         cx: &Ctxt,
         item: &'a syn::DeriveInput,
         derive: Derive,
+        private: &Ident,
     ) -> Option<Container<'a>> {
         let attrs = attr::Container::from_ast(cx, item);
 
         let mut data = match &item.data {
-            syn::Data::Enum(data) => Data::Enum(enum_from_ast(cx, &data.variants, attrs.default())),
+            syn::Data::Enum(data) => {
+                Data::Enum(enum_from_ast(cx, &data.variants, attrs.default(), private))
+            }
             syn::Data::Struct(data) => {
-                let (style, fields) = struct_from_ast(cx, &data.fields, None, attrs.default());
+                let (style, fields) =
+                    struct_from_ast(cx, &data.fields, None, attrs.default(), private);
                 Data::Struct(style, fields)
             }
             syn::Data::Union(_) => {
@@ -129,13 +134,19 @@ fn enum_from_ast<'a>(
     cx: &Ctxt,
     variants: &'a Punctuated<syn::Variant, Token![,]>,
     container_default: &attr::Default,
+    private: &Ident,
 ) -> Vec<Variant<'a>> {
     let variants: Vec<Variant> = variants
         .iter()
         .map(|variant| {
             let attrs = attr::Variant::from_ast(cx, variant);
-            let (style, fields) =
-                struct_from_ast(cx, &variant.fields, Some(&attrs), container_default);
+            let (style, fields) = struct_from_ast(
+                cx,
+                &variant.fields,
+                Some(&attrs),
+                container_default,
+                private,
+            );
             Variant {
                 ident: variant.ident.clone(),
                 attrs,
@@ -165,19 +176,20 @@ fn struct_from_ast<'a>(
     fields: &'a syn::Fields,
     attrs: Option<&attr::Variant>,
     container_default: &attr::Default,
+    private: &Ident,
 ) -> (Style, Vec<Field<'a>>) {
     match fields {
         syn::Fields::Named(fields) => (
             Style::Struct,
-            fields_from_ast(cx, &fields.named, attrs, container_default),
+            fields_from_ast(cx, &fields.named, attrs, container_default, private),
         ),
         syn::Fields::Unnamed(fields) if fields.unnamed.len() == 1 => (
             Style::Newtype,
-            fields_from_ast(cx, &fields.unnamed, attrs, container_default),
+            fields_from_ast(cx, &fields.unnamed, attrs, container_default, private),
         ),
         syn::Fields::Unnamed(fields) => (
             Style::Tuple,
-            fields_from_ast(cx, &fields.unnamed, attrs, container_default),
+            fields_from_ast(cx, &fields.unnamed, attrs, container_default, private),
         ),
         syn::Fields::Unit => (Style::Unit, Vec::new()),
     }
@@ -188,6 +200,7 @@ fn fields_from_ast<'a>(
     fields: &'a Punctuated<syn::Field, Token![,]>,
     attrs: Option<&attr::Variant>,
     container_default: &attr::Default,
+    private: &Ident,
 ) -> Vec<Field<'a>> {
     fields
         .iter()
@@ -197,7 +210,7 @@ fn fields_from_ast<'a>(
                 Some(ident) => syn::Member::Named(ident.clone()),
                 None => syn::Member::Unnamed(i.into()),
             },
-            attrs: attr::Field::from_ast(cx, i, field, attrs, container_default),
+            attrs: attr::Field::from_ast(cx, i, field, attrs, container_default, private),
             ty: &field.ty,
             original: field,
         })

serde_derive/src/internals/attr.rs

@@ -3,14 +3,13 @@ use crate::internals::symbol::*;
 use crate::internals::{ungroup, Ctxt};
 use proc_macro2::{Spacing, Span, TokenStream, TokenTree};
 use quote::ToTokens;
-use std::borrow::Cow;
 use std::collections::BTreeSet;
 use std::iter::FromIterator;
 use syn::meta::ParseNestedMeta;
 use syn::parse::ParseStream;
 use syn::punctuated::Punctuated;
 use syn::spanned::Spanned;
-use syn::{parse_quote, token, Ident, Lifetime, Token};
+use syn::{token, Ident, Lifetime, Token};
 
 // This module handles parsing of `#[serde(...)]` attributes. The entrypoints
 // are `attr::Container::from_ast`, `attr::Variant::from_ast`, and
@@ -609,11 +608,6 @@ impl Container {
         self.serde_path.as_ref()
     }
 
-    pub fn serde_path(&self) -> Cow<syn::Path> {
-        self.custom_serde_path()
-            .map_or_else(|| Cow::Owned(parse_quote!(_serde)), Cow::Borrowed)
-    }
-
     /// Error message generated when type can't be deserialized.
     /// If `None`, default message will be used
     pub fn expecting(&self) -> Option<&str> {
@@ -1024,6 +1018,7 @@ impl Field {
         field: &syn::Field,
         attrs: Option<&Variant>,
         container_default: &Default,
+        private: &Ident,
     ) -> Self {
         let mut ser_name = Attr::none(cx, RENAME);
         let mut de_name = Attr::none(cx, RENAME);
@@ -1217,7 +1212,7 @@ impl Field {
                 };
                 let span = Span::call_site();
                 path.segments.push(Ident::new("_serde", span).into());
-                path.segments.push(Ident::new("__private", span).into());
+                path.segments.push(private.clone().into());
                 path.segments.push(Ident::new("de", span).into());
                 path.segments
                     .push(Ident::new("borrow_cow_str", span).into());
@@ -1234,7 +1229,7 @@ impl Field {
                 };
                 let span = Span::call_site();
                 path.segments.push(Ident::new("_serde", span).into());
-                path.segments.push(Ident::new("__private", span).into());
+                path.segments.push(private.clone().into());
                 path.segments.push(Ident::new("de", span).into());
                 path.segments
                     .push(Ident::new("borrow_cow_bytes", span).into());

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/1.0.222")]
+#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.225")]
 #![cfg_attr(not(check_cfg), allow(unexpected_cfgs))]
 // Ignored clippy lints
 #![allow(
@@ -75,6 +75,8 @@ extern crate proc_macro;
 mod internals;
 
 use proc_macro::TokenStream;
+use proc_macro2::{Ident, Span};
+use quote::{ToTokens, TokenStreamExt as _};
 use syn::parse_macro_input;
 use syn::DeriveInput;
 
@@ -84,11 +86,30 @@ mod bound;
 mod fragment;
 
 mod de;
+mod deprecated;
 mod dummy;
 mod pretend;
 mod ser;
 mod this;
 
+#[allow(non_camel_case_types)]
+struct private;
+
+impl private {
+    fn ident(&self) -> Ident {
+        Ident::new(
+            concat!("__private", env!("CARGO_PKG_VERSION_PATCH")),
+            Span::call_site(),
+        )
+    }
+}
+
+impl ToTokens for private {
+    fn to_tokens(&self, tokens: &mut proc_macro2::TokenStream) {
+        tokens.append(self.ident());
+    }
+}
+
 #[proc_macro_derive(Serialize, attributes(serde))]
 pub fn derive_serialize(input: TokenStream) -> TokenStream {
     let mut input = parse_macro_input!(input as DeriveInput);

serde_derive/src/pretend.rs

@@ -1,4 +1,5 @@
 use crate::internals::ast::{Container, Data, Field, Style, Variant};
+use crate::private;
 use proc_macro2::TokenStream;
 use quote::{format_ident, quote};
 
@@ -83,8 +84,8 @@ fn pretend_fields_used_struct(cont: &Container, fields: &[Field]) -> TokenStream
     let placeholders = (0usize..).map(|i| format_ident!("__v{}", i));
 
     quote! {
-        match _serde::__private::None::<&#type_ident #ty_generics> {
-            _serde::__private::Some(#type_ident { #(#members: #placeholders),* }) => {}
+        match _serde::#private::None::<&#type_ident #ty_generics> {
+            _serde::#private::Some(#type_ident { #(#members: #placeholders),* }) => {}
             _ => {}
         }
     }
@@ -96,11 +97,12 @@ fn pretend_fields_used_struct_packed(cont: &Container, fields: &[Field]) -> Toke
 
     let members = fields.iter().map(|field| &field.member).collect::<Vec<_>>();
 
+    let private2 = private;
     quote! {
-        match _serde::__private::None::<&#type_ident #ty_generics> {
-            _serde::__private::Some(__v @ #type_ident { #(#members: _),* }) => {
+        match _serde::#private::None::<&#type_ident #ty_generics> {
+            _serde::#private::Some(__v @ #type_ident { #(#members: _),* }) => {
                 #(
-                    let _ = _serde::__private::ptr::addr_of!(__v.#members);
+                    let _ = _serde::#private2::ptr::addr_of!(__v.#members);
                 )*
             }
             _ => {}
@@ -125,10 +127,11 @@ fn pretend_fields_used_enum(cont: &Container, variants: &[Variant]) -> TokenStre
         })
         .collect::<Vec<_>>();
 
+    let private2 = private;
     quote! {
-        match _serde::__private::None::<&#type_ident #ty_generics> {
+        match _serde::#private::None::<&#type_ident #ty_generics> {
             #(
-                _serde::__private::Some(#patterns) => {}
+                _serde::#private2::Some(#patterns) => {}
             )*
             _ => {}
         }
@@ -172,8 +175,8 @@ fn pretend_variants_used(cont: &Container) -> TokenStream {
         };
 
         quote! {
-            match _serde::__private::None {
-                _serde::__private::Some((#(#placeholders,)*)) => {
+            match _serde::#private::None {
+                _serde::#private::Some((#(#placeholders,)*)) => {
                     let _ = #type_ident::#variant_ident #turbofish #pat;
                 }
                 _ => {}

serde_derive/src/ser.rs

@@ -1,8 +1,9 @@
+use crate::deprecated::allow_deprecated;
 use crate::fragment::{Fragment, Match, Stmts};
 use crate::internals::ast::{Container, Data, Field, Style, Variant};
 use crate::internals::name::Name;
 use crate::internals::{attr, replace_receiver, Ctxt, Derive};
-use crate::{bound, dummy, pretend, this};
+use crate::{bound, dummy, pretend, private, this};
 use proc_macro2::{Span, TokenStream};
 use quote::{quote, quote_spanned};
 use syn::spanned::Spanned;
@@ -12,7 +13,7 @@ pub fn expand_derive_serialize(input: &mut syn::DeriveInput) -> syn::Result<Toke
     replace_receiver(input);
 
     let ctxt = Ctxt::new();
-    let cont = match Container::from_ast(&ctxt, input, Derive::Serialize) {
+    let cont = match Container::from_ast(&ctxt, input, Derive::Serialize, &private.ident()) {
         Some(cont) => cont,
         None => return Err(ctxt.check().unwrap_err()),
     };
@@ -23,17 +24,18 @@ pub fn expand_derive_serialize(input: &mut syn::DeriveInput) -> syn::Result<Toke
     let params = Parameters::new(&cont);
     let (impl_generics, ty_generics, where_clause) = params.generics.split_for_impl();
     let body = Stmts(serialize_body(&cont, &params));
-    let serde = cont.attrs.serde_path();
+    let allow_deprecated = allow_deprecated(input);
 
     let impl_block = if let Some(remote) = cont.attrs.remote() {
         let vis = &input.vis;
         let used = pretend::pretend_used(&cont, params.is_packed);
         quote! {
             #[automatically_derived]
+            #allow_deprecated
             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>
+                #vis fn serialize<__S>(__self: &#remote #ty_generics, __serializer: __S) -> _serde::#private::Result<__S::Ok, __S::Error>
                 where
-                    __S: #serde::Serializer,
+                    __S: _serde::Serializer,
                 {
                     #used
                     #body
@@ -43,10 +45,11 @@ pub fn expand_derive_serialize(input: &mut syn::DeriveInput) -> syn::Result<Toke
     } else {
         quote! {
             #[automatically_derived]
-            impl #impl_generics #serde::Serialize for #ident #ty_generics #where_clause {
-                fn serialize<__S>(&self, __serializer: __S) -> #serde::__private::Result<__S::Ok, __S::Error>
+            #allow_deprecated
+            impl #impl_generics _serde::Serialize for #ident #ty_generics #where_clause {
+                fn serialize<__S>(&self, __serializer: __S) -> _serde::#private::Result<__S::Ok, __S::Error>
                 where
-                    __S: #serde::Serializer,
+                    __S: _serde::Serializer,
                 {
                     #body
                 }
@@ -212,7 +215,7 @@ fn serialize_into(params: &Parameters, type_into: &syn::Type) -> Fragment {
     let self_var = &params.self_var;
     quote_block! {
         _serde::Serialize::serialize(
-            &_serde::__private::Into::<#type_into>::into(_serde::__private::Clone::clone(#self_var)),
+            &_serde::#private::Into::<#type_into>::into(_serde::#private::Clone::clone(#self_var)),
             __serializer)
     }
 }
@@ -382,7 +385,7 @@ fn serialize_struct_as_map(
     let let_mut = mut_if(serialized_fields.peek().is_some() || tag_field_exists);
 
     quote_block! {
-        let #let_mut __serde_state = _serde::Serializer::serialize_map(__serializer, _serde::__private::None)?;
+        let #let_mut __serde_state = _serde::Serializer::serialize_map(__serializer, _serde::#private::None)?;
         #tag_field
         #(#serialize_fields)*
         _serde::ser::SerializeMap::end(__serde_state)
@@ -404,7 +407,7 @@ fn serialize_enum(params: &Parameters, variants: &[Variant], cattrs: &attr::Cont
 
     if cattrs.remote().is_some() && cattrs.non_exhaustive() {
         arms.push(quote! {
-            ref unrecognized => _serde::__private::Err(_serde::ser::Error::custom(_serde::__private::ser::CannotSerializeVariant(unrecognized))),
+            ref unrecognized => _serde::#private::Err(_serde::ser::Error::custom(_serde::#private::ser::CannotSerializeVariant(unrecognized))),
         });
     }
 
@@ -431,7 +434,7 @@ fn serialize_variant(
             variant_ident
         );
         let skipped_err = quote! {
-            _serde::__private::Err(_serde::ser::Error::custom(#skipped_msg))
+            _serde::#private::Err(_serde::ser::Error::custom(#skipped_msg))
         };
         let fields_pat = match variant.style {
             Style::Unit => quote!(),
@@ -585,7 +588,7 @@ fn serialize_internally_tagged_variant(
     if let Some(path) = variant.attrs.serialize_with() {
         let ser = wrap_serialize_variant_with(params, path, variant);
         return quote_expr! {
-            _serde::__private::ser::serialize_tagged_newtype(
+            _serde::#private::ser::serialize_tagged_newtype(
                 __serializer,
                 #enum_ident_str,
                 #variant_ident_str,
@@ -614,7 +617,7 @@ fn serialize_internally_tagged_variant(
             }
 
             let span = field.original.span();
-            let func = quote_spanned!(span=> _serde::__private::ser::serialize_tagged_newtype);
+            let func = quote_spanned!(span=> _serde::#private::ser::serialize_tagged_newtype);
             quote_expr! {
                 #func(
                     __serializer,
@@ -648,7 +651,7 @@ fn serialize_adjacently_tagged_variant(
     let type_name = cattrs.name().serialize_name();
     let variant_name = variant.attrs.name().serialize_name();
     let serialize_variant = quote! {
-        &_serde::__private::ser::AdjacentlyTaggedEnumVariant {
+        &_serde::#private::ser::AdjacentlyTaggedEnumVariant {
             enum_name: #type_name,
             variant_index: #variant_index,
             variant_name: #variant_name,
@@ -731,12 +734,12 @@ fn serialize_adjacently_tagged_variant(
         #[doc(hidden)]
         struct __AdjacentlyTagged #wrapper_generics #where_clause {
             data: (#(&'__a #fields_ty,)*),
-            phantom: _serde::__private::PhantomData<#this_type #ty_generics>,
+            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>
+            fn serialize<__S>(&self, __serializer: __S) -> _serde::#private::Result<__S::Ok, __S::Error>
             where
                 __S: _serde::Serializer,
             {
@@ -754,7 +757,7 @@ fn serialize_adjacently_tagged_variant(
         _serde::ser::SerializeStruct::serialize_field(
             &mut __struct, #content, &__AdjacentlyTagged {
                 data: (#(#fields_ident,)*),
-                phantom: _serde::__private::PhantomData::<#this_type #ty_generics>,
+                phantom: _serde::#private::PhantomData::<#this_type #ty_generics>,
             })?;
         _serde::ser::SerializeStruct::end(__struct)
     }
@@ -996,19 +999,19 @@ fn serialize_struct_variant_with_flatten(
                 #[doc(hidden)]
                 struct __EnumFlatten #wrapper_generics #where_clause {
                     data: (#(&'__a #fields_ty,)*),
-                    phantom: _serde::__private::PhantomData<#this_type #ty_generics>,
+                    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>
+                    fn serialize<__S>(&self, __serializer: __S) -> _serde::#private::Result<__S::Ok, __S::Error>
                     where
                         __S: _serde::Serializer,
                     {
                         let (#(#members,)*) = self.data;
                         let #let_mut __serde_state = _serde::Serializer::serialize_map(
                             __serializer,
-                            _serde::__private::None)?;
+                            _serde::#private::None)?;
                         #(#serialize_fields)*
                         _serde::ser::SerializeMap::end(__serde_state)
                     }
@@ -1021,7 +1024,7 @@ fn serialize_struct_variant_with_flatten(
                     #variant_name,
                     &__EnumFlatten {
                         data: (#(#members,)*),
-                        phantom: _serde::__private::PhantomData::<#this_type #ty_generics>,
+                        phantom: _serde::#private::PhantomData::<#this_type #ty_generics>,
                     })
             }
         }
@@ -1029,7 +1032,7 @@ fn serialize_struct_variant_with_flatten(
             quote_block! {
                 let #let_mut __serde_state = _serde::Serializer::serialize_map(
                     __serializer,
-                    _serde::__private::None)?;
+                    _serde::#private::None)?;
                 _serde::ser::SerializeMap::serialize_entry(
                     &mut __serde_state,
                     #tag,
@@ -1043,7 +1046,7 @@ fn serialize_struct_variant_with_flatten(
             quote_block! {
                 let #let_mut __serde_state = _serde::Serializer::serialize_map(
                     __serializer,
-                    _serde::__private::None)?;
+                    _serde::#private::None)?;
                 #(#serialize_fields)*
                 _serde::ser::SerializeMap::end(__serde_state)
             }
@@ -1132,7 +1135,7 @@ fn serialize_struct_visitor(
             let ser = if field.attrs.flatten() {
                 let func = quote_spanned!(span=> _serde::Serialize::serialize);
                 quote! {
-                    #func(&#field_expr, _serde::__private::ser::FlatMapSerializer(&mut __serde_state))?;
+                    #func(&#field_expr, _serde::#private::ser::FlatMapSerializer(&mut __serde_state))?;
                 }
             } else {
                 let func = struct_trait.serialize_field(span);
@@ -1239,12 +1242,12 @@ fn wrap_serialize_with(
         #[doc(hidden)]
         struct __SerializeWith #wrapper_impl_generics #where_clause {
             values: (#(&'__a #field_tys, )*),
-            phantom: _serde::__private::PhantomData<#this_type #ty_generics>,
+            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>
+            fn serialize<__S>(&#self_var, #serializer_var: __S) -> _serde::#private::Result<__S::Ok, __S::Error>
             where
                 __S: _serde::Serializer,
             {
@@ -1254,7 +1257,7 @@ fn wrap_serialize_with(
 
         __SerializeWith {
             values: (#(#field_exprs, )*),
-            phantom: _serde::__private::PhantomData::<#this_type #ty_generics>,
+            phantom: _serde::#private::PhantomData::<#this_type #ty_generics>,
         }
     })
 }
@@ -1290,11 +1293,11 @@ fn get_member(params: &Parameters, field: &Field, member: &Member) -> TokenStrea
                 quote!(&#self_var.#member)
             };
             let ty = field.ty;
-            quote!(_serde::__private::ser::constrain::<#ty>(#inner))
+            quote!(_serde::#private::ser::constrain::<#ty>(#inner))
         }
         (true, Some(getter)) => {
             let ty = field.ty;
-            quote!(_serde::__private::ser::constrain::<#ty>(&#getter(#self_var)))
+            quote!(_serde::#private::ser::constrain::<#ty>(&#getter(#self_var)))
         }
         (false, Some(_)) => {
             unreachable!("getter is only allowed for remote impls");

test_suite/tests/test_deprecated.rs

@@ -0,0 +1,30 @@
+#![deny(deprecated)]
+#![allow(dead_code)]
+
+use serde_derive::{Deserialize, Serialize};
+
+#[derive(Serialize, Deserialize)]
+#[deprecated]
+enum DeprecatedEnum {
+    A,
+    B,
+}
+
+#[derive(Serialize, Deserialize)]
+#[deprecated]
+struct DeprecatedStruct {
+    a: bool,
+}
+
+#[derive(Serialize, Deserialize)]
+enum DeprecatedVariant {
+    A,
+    #[deprecated]
+    B,
+}
+
+#[derive(Serialize, Deserialize)]
+struct DeprecatedField {
+    #[deprecated]
+    a: bool,
+}

test_suite/tests/ui/deprecated/deprecated_de_with.rs

@@ -0,0 +1,20 @@
+#![deny(deprecated)]
+
+use serde::Deserializer;
+use serde_derive::Deserialize;
+
+#[derive(Deserialize)]
+pub struct Struct {
+    #[serde(deserialize_with = "deprecated_with")]
+    pub field: i32,
+}
+
+#[deprecated]
+fn deprecated_with<'de, D>(_deserializer: D) -> Result<i32, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    unimplemented!()
+}
+
+fn main() {}

test_suite/tests/ui/deprecated/deprecated_de_with.stderr

@@ -0,0 +1,11 @@
+error: use of deprecated function `deprecated_with`
+ --> tests/ui/deprecated/deprecated_de_with.rs:8:32
+  |
+8 |     #[serde(deserialize_with = "deprecated_with")]
+  |                                ^^^^^^^^^^^^^^^^^
+  |
+note: the lint level is defined here
+ --> tests/ui/deprecated/deprecated_de_with.rs:1:9
+  |
+1 | #![deny(deprecated)]
+  |         ^^^^^^^^^^

test_suite/tests/ui/deprecated/deprecated_ser_with.rs

@@ -0,0 +1,20 @@
+#![deny(deprecated)]
+
+use serde::Serializer;
+use serde_derive::Serialize;
+
+#[derive(Serialize)]
+pub struct Struct {
+    #[serde(serialize_with = "deprecated_with")]
+    pub field: i32,
+}
+
+#[deprecated]
+fn deprecated_with<S>(_field: &i32, _serializer: S) -> Result<S::Ok, S::Error>
+where
+    S: Serializer,
+{
+    unimplemented!()
+}
+
+fn main() {}

test_suite/tests/ui/deprecated/deprecated_ser_with.stderr

@@ -0,0 +1,11 @@
+error: use of deprecated function `deprecated_with`
+ --> tests/ui/deprecated/deprecated_ser_with.rs:8:30
+  |
+8 |     #[serde(serialize_with = "deprecated_with")]
+  |                              ^^^^^^^^^^^^^^^^^
+  |
+note: the lint level is defined here
+ --> tests/ui/deprecated/deprecated_ser_with.rs:1:9
+  |
+1 | #![deny(deprecated)]
+  |         ^^^^^^^^^^

test_suite/tests/ui/with/incorrect_type.stderr

@@ -6,10 +6,7 @@ error[E0277]: the trait bound `&u8: serde::Serializer` is not satisfied
 15 | struct W(#[serde(with = "w")] u8, u8);
    |                         --- required by a bound introduced by this call
    |
-   = help: the following other types implement trait `Serializer`:
-             &mut Formatter<'a>
-             FlatMapSerializer<'a, M>
-             _::_serde::__private::ser::content::ContentSerializer<E>
+   = help: the trait `Serializer` is implemented for `&mut Formatter<'a>`
 note: required by a bound in `w::serialize`
   --> tests/ui/with/incorrect_type.rs:9:28
    |
@@ -36,10 +33,7 @@ error[E0277]: the trait bound `&u8: serde::Serializer` is not satisfied
 15 | struct W(#[serde(with = "w")] u8, u8);
    |                         ^^^ the trait `Serializer` is not implemented for `&u8`
    |
-   = help: the following other types implement trait `Serializer`:
-             &mut Formatter<'a>
-             FlatMapSerializer<'a, M>
-             _::_serde::__private::ser::content::ContentSerializer<E>
+   = help: the trait `Serializer` is implemented for `&mut Formatter<'a>`
 
 error[E0308]: `?` operator has incompatible types
   --> tests/ui/with/incorrect_type.rs:15:25
@@ -57,10 +51,7 @@ error[E0277]: the trait bound `&u8: serde::Serializer` is not satisfied
 18 | struct S(#[serde(serialize_with = "w::serialize")] u8, u8);
    |                                   -------------- required by a bound introduced by this call
    |
-   = help: the following other types implement trait `Serializer`:
-             &mut Formatter<'a>
-             FlatMapSerializer<'a, M>
-             _::_serde::__private::ser::content::ContentSerializer<E>
+   = help: the trait `Serializer` is implemented for `&mut Formatter<'a>`
 note: required by a bound in `w::serialize`
   --> tests/ui/with/incorrect_type.rs:9:28
    |
@@ -87,10 +78,7 @@ error[E0277]: the trait bound `&u8: serde::Serializer` is not satisfied
 18 | struct S(#[serde(serialize_with = "w::serialize")] u8, u8);
    |                                   ^^^^^^^^^^^^^^ the trait `Serializer` is not implemented for `&u8`
    |
-   = help: the following other types implement trait `Serializer`:
-             &mut Formatter<'a>
-             FlatMapSerializer<'a, M>
-             _::_serde::__private::ser::content::ContentSerializer<E>
+   = help: the trait `Serializer` is implemented for `&mut Formatter<'a>`
 
 error[E0308]: `?` operator has incompatible types
   --> tests/ui/with/incorrect_type.rs:21:37