Merge pull request #2989 from dtolnay/pr2987

PR 2987 followup

serde_derive/src/de.rs

@@ -35,7 +35,7 @@ pub fn expand_derive_deserialize(input: &mut syn::DeriveInput) -> syn::Result<To
 
     let ident = &cont.ident;
     let params = Parameters::new(&cont);
-    let (de_impl_generics, _, ty_generics, where_clause) = params.generics();
+    let (de_impl_generics, _, ty_generics, where_clause) = params.generics_with_de_lifetime();
     let body = Stmts(deserialize_body(&cont, &params));
     let delife = params.borrowed.de_lifetime();
     let allow_deprecated = allow_deprecated(input);
@@ -168,10 +168,10 @@ impl Parameters {
         self.this_type.segments.last().unwrap().ident.to_string()
     }
 
-    /// Split a deserialized type's generics into the pieces required for impl'ing
+    /// Split the data structure's generics into the pieces to use for its
-    /// a `Deserialize` trait for that type. Additionally appends the `'de` lifetime
+    /// `Deserialize` impl, augmented with an additional `'de` lifetime for use
-    /// to list of impl generics.
+    /// as the `Deserialize` trait's lifetime.
-    fn generics(
+    fn generics_with_de_lifetime(
         &self,
     ) -> (
         DeImplGenerics,
@@ -312,18 +312,18 @@ fn deserialize_body(cont: &Container, params: &Parameters) -> Fragment {
         deserialize_try_from(type_try_from)
     } else if let attr::Identifier::No = cont.attrs.identifier() {
         match &cont.data {
-            Data::Enum(variants) => enum_::generate_body(params, variants, &cont.attrs),
+            Data::Enum(variants) => enum_::deserialize(params, variants, &cont.attrs),
             Data::Struct(Style::Struct, fields) => {
-                struct_::generate_body(params, fields, &cont.attrs, StructForm::Struct)
+                struct_::deserialize(params, fields, &cont.attrs, StructForm::Struct)
             }
             Data::Struct(Style::Tuple, fields) | Data::Struct(Style::Newtype, fields) => {
-                tuple::generate_body(params, fields, &cont.attrs, TupleForm::Tuple)
+                tuple::deserialize(params, fields, &cont.attrs, TupleForm::Tuple)
             }
-            Data::Struct(Style::Unit, _) => unit::generate_body(params, &cont.attrs),
+            Data::Struct(Style::Unit, _) => unit::deserialize(params, &cont.attrs),
         }
     } else {
         match &cont.data {
-            Data::Enum(variants) => identifier::generate_body(params, variants, &cont.attrs),
+            Data::Enum(variants) => identifier::deserialize_custom(params, variants, &cont.attrs),
             Data::Struct(_, _) => unreachable!("checked in serde_derive_internals"),
         }
     }
@@ -349,10 +349,10 @@ fn deserialize_in_place_body(cont: &Container, params: &Parameters) -> Option<St
 
     let code = match &cont.data {
         Data::Struct(Style::Struct, fields) => {
-            struct_::generate_body_in_place(params, fields, &cont.attrs)?
+            struct_::deserialize_in_place(params, fields, &cont.attrs)?
         }
         Data::Struct(Style::Tuple, fields) | Data::Struct(Style::Newtype, fields) => {
-            tuple::generate_body_in_place(params, fields, &cont.attrs)
+            tuple::deserialize_in_place(params, fields, &cont.attrs)
         }
         Data::Enum(_) | Data::Struct(Style::Unit, _) => {
             return None;
@@ -664,7 +664,8 @@ fn wrap_deserialize_with(
     deserialize_with: &syn::ExprPath,
 ) -> (TokenStream, TokenStream) {
     let this_type = &params.this_type;
-    let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = params.generics();
+    let (de_impl_generics, de_ty_generics, ty_generics, where_clause) =
+        params.generics_with_de_lifetime();
     let delife = params.borrowed.de_lifetime();
     let deserializer_var = quote!(__deserializer);
 

serde_derive/src/de/enum_.rs

@@ -12,7 +12,7 @@ use proc_macro2::TokenStream;
 use quote::quote;
 
 /// Generates `Deserialize::deserialize` body for an `enum Enum {...}`
-pub(super) fn generate_body(
+pub(super) fn deserialize(
     params: &Parameters,
     variants: &[Variant],
     cattrs: &attr::Container,
@@ -25,12 +25,12 @@ pub(super) fn generate_body(
             // Ignore any error associated with non-untagged deserialization so that we
             // can fall through to the untagged variants. This may be infallible so we
             // need to provide the error type.
-            let tagged_frag = quote! {
+            let first_attempt = quote! {
                 if let _serde::#private::Result::<_, __D::Error>::Ok(__ok) = (|| #tagged_frag)() {
                     return _serde::#private::Ok(__ok);
                 }
             };
-            enum_untagged::generate_body(params, untagged, cattrs, Some(tagged_frag))
+            enum_untagged::deserialize(params, untagged, cattrs, Some(first_attempt))
         }
         None => deserialize_homogeneous_enum(params, variants, cattrs),
     }
@@ -42,14 +42,14 @@ fn deserialize_homogeneous_enum(
     cattrs: &attr::Container,
 ) -> Fragment {
     match cattrs.tag() {
-        attr::TagType::External => enum_externally::generate_body(params, variants, cattrs),
+        attr::TagType::External => enum_externally::deserialize(params, variants, cattrs),
         attr::TagType::Internal { tag } => {
-            enum_internally::generate_body(params, variants, cattrs, tag)
+            enum_internally::deserialize(params, variants, cattrs, tag)
         }
         attr::TagType::Adjacent { tag, content } => {
-            enum_adjacently::generate_body(params, variants, cattrs, tag, content)
+            enum_adjacently::deserialize(params, variants, cattrs, tag, content)
         }
-        attr::TagType::None => enum_untagged::generate_body(params, variants, cattrs, None),
+        attr::TagType::None => enum_untagged::deserialize(params, variants, cattrs, None),
     }
 }
 
@@ -84,7 +84,7 @@ pub fn prepare_enum_variant_enum(variants: &[Variant]) -> (TokenStream, Stmts) {
         })
         .collect();
 
-    let variant_visitor = Stmts(identifier::generate_identifier(
+    let variant_visitor = Stmts(identifier::deserialize_generated(
         &deserialized_variants,
         false, // variant identifiers do not depend on the presence of flatten fields
         true,

serde_derive/src/de/enum_adjacently.rs

@@ -1,4 +1,4 @@
-//! Generator of the deserialization code for the adjacently tagged enums:
+//! Deserialization for adjacently tagged enums:
 //!
 //! ```ignore
 //! #[serde(tag = "...", content = "...")]
@@ -16,7 +16,7 @@ use quote::{quote, quote_spanned};
 use syn::spanned::Spanned;
 
 /// Generates `Deserialize::deserialize` body for an `enum Enum {...}` with `#[serde(tag, content)]` attributes
-pub(super) fn generate_body(
+pub(super) fn deserialize(
     params: &Parameters,
     variants: &[Variant],
     cattrs: &attr::Container,
@@ -25,7 +25,8 @@ pub(super) fn generate_body(
 ) -> Fragment {
     let this_type = &params.this_type;
     let this_value = &params.this_value;
-    let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = params.generics();
+    let (de_impl_generics, de_ty_generics, ty_generics, where_clause) =
+        params.generics_with_de_lifetime();
     let delife = params.borrowed.de_lifetime();
 
     let (variants_stmt, variant_visitor) = enum_::prepare_enum_variant_enum(variants);
@@ -37,7 +38,7 @@ pub(super) fn generate_body(
         .map(|(i, variant)| {
             let variant_index = field_i(i);
 
-            let block = Match(enum_untagged::generate_variant(params, variant, cattrs));
+            let block = Match(enum_untagged::deserialize_variant(params, variant, cattrs));
 
             quote! {
                 __Field::#variant_index => #block

serde_derive/src/de/enum_externally.rs

@@ -1,4 +1,4 @@
-//! Generator of the deserialization code for the externally tagged enums:
+//! Deserialization for externally tagged enums:
 //!
 //! ```ignore
 //! enum Enum {}
@@ -20,13 +20,14 @@ use quote::{quote, quote_spanned};
 use syn::spanned::Spanned;
 
 /// Generates `Deserialize::deserialize` body for an `enum Enum {...}` without additional attributes
-pub(super) fn generate_body(
+pub(super) fn deserialize(
     params: &Parameters,
     variants: &[Variant],
     cattrs: &attr::Container,
 ) -> Fragment {
     let this_type = &params.this_type;
-    let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = params.generics();
+    let (de_impl_generics, de_ty_generics, ty_generics, where_clause) =
+        params.generics_with_de_lifetime();
     let delife = params.borrowed.de_lifetime();
 
     let type_name = cattrs.name().deserialize_name();
@@ -143,13 +144,13 @@ fn deserialize_externally_tagged_variant(
             &variant.fields[0],
             cattrs,
         ),
-        Style::Tuple => tuple::generate_body(
+        Style::Tuple => tuple::deserialize(
             params,
             &variant.fields,
             cattrs,
             TupleForm::ExternallyTagged(variant_ident),
         ),
-        Style::Struct => struct_::generate_body(
+        Style::Struct => struct_::deserialize(
             params,
             &variant.fields,
             cattrs,

serde_derive/src/de/enum_internally.rs

@@ -1,4 +1,4 @@
-//! Generator of the deserialization code for the internally tagged enums:
+//! Deserialization for internally tagged enums:
 //!
 //! ```ignore
 //! #[serde(tag = "...")]
@@ -18,7 +18,7 @@ use crate::private;
 use quote::quote;
 
 /// Generates `Deserialize::deserialize` body for an `enum Enum {...}` with `#[serde(tag)]` attribute
-pub(super) fn generate_body(
+pub(super) fn deserialize(
     params: &Parameters,
     variants: &[Variant],
     cattrs: &attr::Container,
@@ -93,9 +93,9 @@ fn deserialize_internally_tagged_variant(
             }
         }
         Style::Newtype => {
-            enum_untagged::generate_newtype_variant(variant_ident, params, &variant.fields[0])
+            enum_untagged::deserialize_newtype_variant(variant_ident, params, &variant.fields[0])
         }
-        Style::Struct => struct_::generate_body(
+        Style::Struct => struct_::deserialize(
             params,
             &variant.fields,
             cattrs,

serde_derive/src/de/enum_untagged.rs

@@ -1,4 +1,4 @@
-//! Generator of the deserialization code for the untagged enums:
+//! Deserialization for untagged enums:
 //!
 //! ```ignore
 //! #[serde(untagged)]
@@ -19,7 +19,7 @@ use quote::{quote, quote_spanned};
 use syn::spanned::Spanned;
 
 /// Generates `Deserialize::deserialize` body for an `enum Enum {...}` with `#[serde(untagged)]` attribute
-pub(super) fn generate_body(
+pub(super) fn deserialize(
     params: &Parameters,
     variants: &[Variant],
     cattrs: &attr::Container,
@@ -28,7 +28,7 @@ pub(super) fn generate_body(
     let attempts = variants
         .iter()
         .filter(|variant| !variant.attrs.skip_deserializing())
-        .map(|variant| Expr(generate_variant(params, variant, cattrs)));
+        .map(|variant| Expr(deserialize_variant(params, variant, cattrs)));
     // TODO this message could be better by saving the errors from the failed
     // attempts. The heuristic used by TOML was to count the number of fields
     // processed before an error, and use the error that happened after the
@@ -59,7 +59,7 @@ pub(super) fn generate_body(
 }
 
 // Also used by adjacently tagged enums
-pub(super) fn generate_variant(
+pub(super) fn deserialize_variant(
     params: &Parameters,
     variant: &Variant,
     cattrs: &attr::Container,
@@ -92,14 +92,14 @@ pub(super) fn generate_variant(
                 }
             }
         }
-        Style::Newtype => generate_newtype_variant(variant_ident, params, &variant.fields[0]),
+        Style::Newtype => deserialize_newtype_variant(variant_ident, params, &variant.fields[0]),
-        Style::Tuple => tuple::generate_body(
+        Style::Tuple => tuple::deserialize(
             params,
             &variant.fields,
             cattrs,
             TupleForm::Untagged(variant_ident),
         ),
-        Style::Struct => struct_::generate_body(
+        Style::Struct => struct_::deserialize(
             params,
             &variant.fields,
             cattrs,
@@ -110,7 +110,7 @@ pub(super) fn generate_variant(
 
 // Also used by internally tagged enums
 // Implicitly (via `generate_variant`) used by adjacently tagged enums
-pub(super) fn generate_newtype_variant(
+pub(super) fn deserialize_newtype_variant(
     variant_ident: &syn::Ident,
     params: &Parameters,
     field: &Field,

serde_derive/src/de/identifier.rs

@@ -1,4 +1,5 @@
-//! Contains generators of enums that represents identifiers of fields in structs or variants in enums.
+//! Deserialization of struct field identifiers and enum variant identifiers by
+//! way of a Rust enum.
 
 use crate::de::{FieldWithAliases, Parameters};
 use crate::fragment::{Fragment, Stmts};
@@ -10,7 +11,7 @@ use quote::{quote, ToTokens};
 
 // Generates `Deserialize::deserialize` body for an enum with
 // `serde(field_identifier)` or `serde(variant_identifier)` attribute.
-pub(super) fn generate_body(
+pub(super) fn deserialize_custom(
     params: &Parameters,
     variants: &[Variant],
     cattrs: &attr::Container,
@@ -84,7 +85,8 @@ pub(super) fn generate_body(
         Some(fields)
     };
 
-    let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = params.generics();
+    let (de_impl_generics, de_ty_generics, ty_generics, where_clause) =
+        params.generics_with_de_lifetime();
     let delife = params.borrowed.de_lifetime();
     let visitor_impl = Stmts(deserialize_identifier(
         &this_value,
@@ -120,7 +122,7 @@ pub(super) fn generate_body(
     }
 }
 
-pub(super) fn generate_identifier(
+pub(super) fn deserialize_generated(
     deserialized_fields: &[FieldWithAliases],
     has_flatten: bool,
     is_variant: bool,

serde_derive/src/de/struct_.rs

@@ -14,7 +14,7 @@ use quote::{quote, quote_spanned};
 use syn::spanned::Spanned;
 
 /// Generates `Deserialize::deserialize` body for a `struct Struct {...}`
-pub(super) fn generate_body(
+pub(super) fn deserialize(
     params: &Parameters,
     fields: &[Field],
     cattrs: &attr::Container,
@@ -22,7 +22,8 @@ pub(super) fn generate_body(
 ) -> Fragment {
     let this_type = &params.this_type;
     let this_value = &params.this_value;
-    let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = params.generics();
+    let (de_impl_generics, de_ty_generics, ty_generics, where_clause) =
+        params.generics_with_de_lifetime();
     let delife = params.borrowed.de_lifetime();
 
     // If there are getters (implying private fields), construct the local type
@@ -419,7 +420,7 @@ fn deserialize_map(
 
 /// Generates `Deserialize::deserialize_in_place` body for a `struct Struct {...}`
 #[cfg(feature = "deserialize_in_place")]
-pub(super) fn generate_body_in_place(
+pub(super) fn deserialize_in_place(
     params: &Parameters,
     fields: &[Field],
     cattrs: &attr::Container,
@@ -431,7 +432,8 @@ pub(super) fn generate_body_in_place(
     }
 
     let this_type = &params.this_type;
-    let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = params.generics();
+    let (de_impl_generics, de_ty_generics, ty_generics, where_clause) =
+        params.generics_with_de_lifetime();
     let delife = params.borrowed.de_lifetime();
 
     let expecting = format!("struct {}", params.type_name());
@@ -633,7 +635,7 @@ fn deserialize_map_in_place(
         });
 
     let this_type = &params.this_type;
-    let (_, _, ty_generics, _) = params.generics();
+    let (_, ty_generics, _) = params.generics.split_for_impl();
 
     let let_default = match cattrs.default() {
         attr::Default::Default => Some(quote!(
@@ -685,7 +687,7 @@ fn deserialize_field_identifier(
         (Some(ignore_variant), Some(fallthrough))
     };
 
-    Stmts(identifier::generate_identifier(
+    Stmts(identifier::deserialize_generated(
         deserialized_fields,
         has_flatten,
         false,

serde_derive/src/de/tuple.rs

@@ -10,7 +10,7 @@ use quote::{quote, quote_spanned};
 use syn::spanned::Spanned;
 
 /// Generates `Deserialize::deserialize` body for a `struct Tuple(...);` including `struct Newtype(T);`
-pub(super) fn generate_body(
+pub(super) fn deserialize(
     params: &Parameters,
     fields: &[Field],
     cattrs: &attr::Container,
@@ -28,7 +28,8 @@ pub(super) fn generate_body(
 
     let this_type = &params.this_type;
     let this_value = &params.this_value;
-    let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = params.generics();
+    let (de_impl_generics, de_ty_generics, ty_generics, where_clause) =
+        params.generics_with_de_lifetime();
     let delife = params.borrowed.de_lifetime();
 
     // If there are getters (implying private fields), construct the local type
@@ -182,7 +183,7 @@ fn deserialize_newtype_struct(
 
 /// Generates `Deserialize::deserialize_in_place` body for a `struct Tuple(...);` including `struct Newtype(T);`
 #[cfg(feature = "deserialize_in_place")]
-pub(super) fn generate_body_in_place(
+pub(super) fn deserialize_in_place(
     params: &Parameters,
     fields: &[Field],
     cattrs: &attr::Container,
@@ -198,7 +199,8 @@ pub(super) fn generate_body_in_place(
         .count();
 
     let this_type = &params.this_type;
-    let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = params.generics();
+    let (de_impl_generics, de_ty_generics, ty_generics, where_clause) =
+        params.generics_with_de_lifetime();
     let delife = params.borrowed.de_lifetime();
 
     let expecting = format!("tuple struct {}", params.type_name());

serde_derive/src/de/unit.rs

@@ -5,11 +5,12 @@ use crate::private;
 use quote::quote;
 
 /// Generates `Deserialize::deserialize` body for a `struct Unit;`
-pub(super) fn generate_body(params: &Parameters, cattrs: &attr::Container) -> Fragment {
+pub(super) fn deserialize(params: &Parameters, cattrs: &attr::Container) -> Fragment {
     let this_type = &params.this_type;
     let this_value = &params.this_value;
     let type_name = cattrs.name().deserialize_name();
-    let (de_impl_generics, de_ty_generics, ty_generics, where_clause) = params.generics();
+    let (de_impl_generics, de_ty_generics, ty_generics, where_clause) =
+        params.generics_with_de_lifetime();
     let delife = params.borrowed.de_lifetime();
 
     let expecting = format!("unit struct {}", params.type_name());