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-rw-r--r--src/ser.rs1340
1 files changed, 1340 insertions, 0 deletions
diff --git a/src/ser.rs b/src/ser.rs
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index 0000000..43695dd
--- /dev/null
+++ b/src/ser.rs
@@ -0,0 +1,1340 @@
+use proc_macro2::{Span, TokenStream};
+use syn::spanned::Spanned;
+use syn::{self, Ident, Index, Member};
+
+use bound;
+use dummy;
+use fragment::{Fragment, Match, Stmts};
+use internals::ast::{Container, Data, Field, Style, Variant};
+use internals::{attr, replace_receiver, Ctxt, Derive};
+use pretend;
+use this;
+
+pub fn expand_derive_serialize(
+ input: &mut syn::DeriveInput,
+) -> Result<TokenStream, Vec<syn::Error>> {
+ replace_receiver(input);
+
+ let ctxt = Ctxt::new();
+ let cont = match Container::from_ast(&ctxt, input, Derive::Serialize) {
+ Some(cont) => cont,
+ None => return Err(ctxt.check().unwrap_err()),
+ };
+ precondition(&ctxt, &cont);
+ ctxt.check()?;
+
+ let ident = &cont.ident;
+ 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 impl_block = if let Some(remote) = cont.attrs.remote() {
+ let vis = &input.vis;
+ let used = pretend::pretend_used(&cont, params.is_packed);
+ quote! {
+ 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
+ __S: #serde::Serializer,
+ {
+ #used
+ #body
+ }
+ }
+ }
+ } 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>
+ where
+ __S: #serde::Serializer,
+ {
+ #body
+ }
+ }
+ }
+ };
+
+ Ok(dummy::wrap_in_const(
+ cont.attrs.custom_serde_path(),
+ "SERIALIZE",
+ ident,
+ impl_block,
+ ))
+}
+
+fn precondition(cx: &Ctxt, cont: &Container) {
+ match cont.attrs.identifier() {
+ attr::Identifier::No => {}
+ attr::Identifier::Field => {
+ cx.error_spanned_by(cont.original, "field identifiers cannot be serialized");
+ }
+ attr::Identifier::Variant => {
+ cx.error_spanned_by(cont.original, "variant identifiers cannot be serialized");
+ }
+ }
+}
+
+struct Parameters {
+ /// Variable holding the value being serialized. Either `self` for local
+ /// types or `__self` for remote types.
+ self_var: Ident,
+
+ /// Path to the type the impl is for. Either a single `Ident` for local
+ /// types (does not include generic parameters) or `some::remote::Path` for
+ /// remote types.
+ this_type: syn::Path,
+
+ /// Same as `this_type` but using `::<T>` for generic parameters for use in
+ /// expression position.
+ this_value: syn::Path,
+
+ /// Generics including any explicit and inferred bounds for the impl.
+ generics: syn::Generics,
+
+ /// Type has a `serde(remote = "...")` attribute.
+ is_remote: bool,
+
+ /// Type has a repr(packed) attribute.
+ is_packed: bool,
+}
+
+impl Parameters {
+ fn new(cont: &Container) -> Self {
+ let is_remote = cont.attrs.remote().is_some();
+ let self_var = if is_remote {
+ Ident::new("__self", Span::call_site())
+ } else {
+ Ident::new("self", Span::call_site())
+ };
+
+ let this_type = this::this_type(cont);
+ let this_value = this::this_value(cont);
+ let is_packed = cont.attrs.is_packed();
+ let generics = build_generics(cont);
+
+ Parameters {
+ self_var,
+ this_type,
+ this_value,
+ generics,
+ is_remote,
+ is_packed,
+ }
+ }
+
+ /// Type name to use in error messages and `&'static str` arguments to
+ /// various Serializer methods.
+ fn type_name(&self) -> String {
+ self.this_type.segments.last().unwrap().ident.to_string()
+ }
+}
+
+// All the generics in the input, plus a bound `T: Serialize` for each generic
+// field type that will be serialized by us.
+fn build_generics(cont: &Container) -> syn::Generics {
+ let generics = bound::without_defaults(cont.generics);
+
+ let generics =
+ bound::with_where_predicates_from_fields(cont, &generics, attr::Field::ser_bound);
+
+ let generics =
+ bound::with_where_predicates_from_variants(cont, &generics, attr::Variant::ser_bound);
+
+ match cont.attrs.ser_bound() {
+ Some(predicates) => bound::with_where_predicates(&generics, predicates),
+ None => bound::with_bound(
+ cont,
+ &generics,
+ needs_serialize_bound,
+ &parse_quote!(_serde::Serialize),
+ ),
+ }
+}
+
+// Fields with a `skip_serializing` or `serialize_with` attribute, or which
+// belong to a variant with a 'skip_serializing` or `serialize_with` attribute,
+// are not serialized by us so we do not generate a bound. Fields with a `bound`
+// attribute specify their own bound so we do not generate one. All other fields
+// may need a `T: Serialize` bound where T is the type of the field.
+fn needs_serialize_bound(field: &attr::Field, variant: Option<&attr::Variant>) -> bool {
+ !field.skip_serializing()
+ && field.serialize_with().is_none()
+ && field.ser_bound().is_none()
+ && variant.map_or(true, |variant| {
+ !variant.skip_serializing()
+ && variant.serialize_with().is_none()
+ && variant.ser_bound().is_none()
+ })
+}
+
+fn serialize_body(cont: &Container, params: &Parameters) -> Fragment {
+ if cont.attrs.transparent() {
+ serialize_transparent(cont, params)
+ } else if let Some(type_into) = cont.attrs.type_into() {
+ serialize_into(params, type_into)
+ } else {
+ match &cont.data {
+ Data::Enum(variants) => serialize_enum(params, variants, &cont.attrs),
+ Data::Struct(Style::Struct, fields) => serialize_struct(params, fields, &cont.attrs),
+ Data::Struct(Style::Tuple, fields) => {
+ serialize_tuple_struct(params, fields, &cont.attrs)
+ }
+ Data::Struct(Style::Newtype, fields) => {
+ serialize_newtype_struct(params, &fields[0], &cont.attrs)
+ }
+ Data::Struct(Style::Unit, _) => serialize_unit_struct(&cont.attrs),
+ }
+ }
+}
+
+fn serialize_transparent(cont: &Container, params: &Parameters) -> Fragment {
+ let fields = match &cont.data {
+ Data::Struct(_, fields) => fields,
+ Data::Enum(_) => unreachable!(),
+ };
+
+ let self_var = &params.self_var;
+ let transparent_field = fields.iter().find(|f| f.attrs.transparent()).unwrap();
+ let member = &transparent_field.member;
+
+ let path = match transparent_field.attrs.serialize_with() {
+ Some(path) => quote!(#path),
+ None => {
+ let span = transparent_field.original.span();
+ quote_spanned!(span=> _serde::Serialize::serialize)
+ }
+ };
+
+ quote_block! {
+ #path(&#self_var.#member, __serializer)
+ }
+}
+
+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)),
+ __serializer)
+ }
+}
+
+fn serialize_unit_struct(cattrs: &attr::Container) -> Fragment {
+ let type_name = cattrs.name().serialize_name();
+
+ quote_expr! {
+ _serde::Serializer::serialize_unit_struct(__serializer, #type_name)
+ }
+}
+
+fn serialize_newtype_struct(
+ params: &Parameters,
+ field: &Field,
+ cattrs: &attr::Container,
+) -> Fragment {
+ let type_name = cattrs.name().serialize_name();
+
+ let mut field_expr = get_member(
+ params,
+ field,
+ &Member::Unnamed(Index {
+ index: 0,
+ span: Span::call_site(),
+ }),
+ );
+ if let Some(path) = field.attrs.serialize_with() {
+ field_expr = wrap_serialize_field_with(params, field.ty, path, &field_expr);
+ }
+
+ let span = field.original.span();
+ let func = quote_spanned!(span=> _serde::Serializer::serialize_newtype_struct);
+ quote_expr! {
+ #func(__serializer, #type_name, #field_expr)
+ }
+}
+
+fn serialize_tuple_struct(
+ params: &Parameters,
+ fields: &[Field],
+ cattrs: &attr::Container,
+) -> Fragment {
+ let serialize_stmts =
+ serialize_tuple_struct_visitor(fields, params, false, &TupleTrait::SerializeTupleStruct);
+
+ let type_name = cattrs.name().serialize_name();
+
+ let mut serialized_fields = fields
+ .iter()
+ .enumerate()
+ .filter(|(_, field)| !field.attrs.skip_serializing())
+ .peekable();
+
+ let let_mut = mut_if(serialized_fields.peek().is_some());
+
+ let len = serialized_fields
+ .map(|(i, field)| match field.attrs.skip_serializing_if() {
+ None => quote!(1),
+ Some(path) => {
+ let index = syn::Index {
+ index: i as u32,
+ span: Span::call_site(),
+ };
+ let field_expr = get_member(params, field, &Member::Unnamed(index));
+ quote!(if #path(#field_expr) { 0 } else { 1 })
+ }
+ })
+ .fold(quote!(0), |sum, expr| quote!(#sum + #expr));
+
+ quote_block! {
+ let #let_mut __serde_state = try!(_serde::Serializer::serialize_tuple_struct(__serializer, #type_name, #len));
+ #(#serialize_stmts)*
+ _serde::ser::SerializeTupleStruct::end(__serde_state)
+ }
+}
+
+fn serialize_struct(params: &Parameters, fields: &[Field], cattrs: &attr::Container) -> Fragment {
+ assert!(fields.len() as u64 <= u64::from(u32::max_value()));
+
+ if cattrs.has_flatten() {
+ serialize_struct_as_map(params, fields, cattrs)
+ } else {
+ serialize_struct_as_struct(params, fields, cattrs)
+ }
+}
+
+fn serialize_struct_tag_field(cattrs: &attr::Container, struct_trait: &StructTrait) -> TokenStream {
+ match cattrs.tag() {
+ attr::TagType::Internal { tag } => {
+ let type_name = cattrs.name().serialize_name();
+ let func = struct_trait.serialize_field(Span::call_site());
+ quote! {
+ try!(#func(&mut __serde_state, #tag, #type_name));
+ }
+ }
+ _ => quote! {},
+ }
+}
+
+fn serialize_struct_as_struct(
+ params: &Parameters,
+ fields: &[Field],
+ cattrs: &attr::Container,
+) -> Fragment {
+ let serialize_fields =
+ serialize_struct_visitor(fields, params, false, &StructTrait::SerializeStruct);
+
+ let type_name = cattrs.name().serialize_name();
+
+ let tag_field = serialize_struct_tag_field(cattrs, &StructTrait::SerializeStruct);
+ let tag_field_exists = !tag_field.is_empty();
+
+ let mut serialized_fields = fields
+ .iter()
+ .filter(|&field| !field.attrs.skip_serializing())
+ .peekable();
+
+ let let_mut = mut_if(serialized_fields.peek().is_some() || tag_field_exists);
+
+ let len = serialized_fields
+ .map(|field| match field.attrs.skip_serializing_if() {
+ None => quote!(1),
+ Some(path) => {
+ let field_expr = get_member(params, field, &field.member);
+ quote!(if #path(#field_expr) { 0 } else { 1 })
+ }
+ })
+ .fold(
+ quote!(#tag_field_exists as usize),
+ |sum, expr| quote!(#sum + #expr),
+ );
+
+ quote_block! {
+ let #let_mut __serde_state = try!(_serde::Serializer::serialize_struct(__serializer, #type_name, #len));
+ #tag_field
+ #(#serialize_fields)*
+ _serde::ser::SerializeStruct::end(__serde_state)
+ }
+}
+
+fn serialize_struct_as_map(
+ params: &Parameters,
+ fields: &[Field],
+ cattrs: &attr::Container,
+) -> Fragment {
+ let serialize_fields =
+ serialize_struct_visitor(fields, params, false, &StructTrait::SerializeMap);
+
+ let tag_field = serialize_struct_tag_field(cattrs, &StructTrait::SerializeMap);
+ let tag_field_exists = !tag_field.is_empty();
+
+ let mut serialized_fields = fields
+ .iter()
+ .filter(|&field| !field.attrs.skip_serializing())
+ .peekable();
+
+ let let_mut = mut_if(serialized_fields.peek().is_some() || tag_field_exists);
+
+ let len = if cattrs.has_flatten() {
+ quote!(_serde::__private::None)
+ } else {
+ let len = serialized_fields
+ .map(|field| match field.attrs.skip_serializing_if() {
+ None => quote!(1),
+ Some(path) => {
+ let field_expr = get_member(params, field, &field.member);
+ quote!(if #path(#field_expr) { 0 } else { 1 })
+ }
+ })
+ .fold(
+ quote!(#tag_field_exists as usize),
+ |sum, expr| quote!(#sum + #expr),
+ );
+ quote!(_serde::__private::Some(#len))
+ };
+
+ quote_block! {
+ let #let_mut __serde_state = try!(_serde::Serializer::serialize_map(__serializer, #len));
+ #tag_field
+ #(#serialize_fields)*
+ _serde::ser::SerializeMap::end(__serde_state)
+ }
+}
+
+fn serialize_enum(params: &Parameters, variants: &[Variant], cattrs: &attr::Container) -> Fragment {
+ assert!(variants.len() as u64 <= u64::from(u32::max_value()));
+
+ let self_var = &params.self_var;
+
+ let arms: Vec<_> = variants
+ .iter()
+ .enumerate()
+ .map(|(variant_index, variant)| {
+ serialize_variant(params, variant, variant_index as u32, cattrs)
+ })
+ .collect();
+
+ quote_expr! {
+ match *#self_var {
+ #(#arms)*
+ }
+ }
+}
+
+fn serialize_variant(
+ params: &Parameters,
+ variant: &Variant,
+ variant_index: u32,
+ cattrs: &attr::Container,
+) -> TokenStream {
+ let this_value = &params.this_value;
+ let variant_ident = &variant.ident;
+
+ if variant.attrs.skip_serializing() {
+ let skipped_msg = format!(
+ "the enum variant {}::{} cannot be serialized",
+ params.type_name(),
+ variant_ident
+ );
+ let skipped_err = quote! {
+ _serde::__private::Err(_serde::ser::Error::custom(#skipped_msg))
+ };
+ let fields_pat = match variant.style {
+ Style::Unit => quote!(),
+ Style::Newtype | Style::Tuple => quote!((..)),
+ Style::Struct => quote!({ .. }),
+ };
+ quote! {
+ #this_value::#variant_ident #fields_pat => #skipped_err,
+ }
+ } else {
+ // variant wasn't skipped
+ let case = match variant.style {
+ Style::Unit => {
+ quote! {
+ #this_value::#variant_ident
+ }
+ }
+ Style::Newtype => {
+ quote! {
+ #this_value::#variant_ident(ref __field0)
+ }
+ }
+ Style::Tuple => {
+ let field_names = (0..variant.fields.len())
+ .map(|i| Ident::new(&format!("__field{}", i), Span::call_site()));
+ quote! {
+ #this_value::#variant_ident(#(ref #field_names),*)
+ }
+ }
+ Style::Struct => {
+ let members = variant.fields.iter().map(|f| &f.member);
+ quote! {
+ #this_value::#variant_ident { #(ref #members),* }
+ }
+ }
+ };
+
+ let body = Match(match cattrs.tag() {
+ attr::TagType::External => {
+ serialize_externally_tagged_variant(params, variant, variant_index, cattrs)
+ }
+ attr::TagType::Internal { tag } => {
+ serialize_internally_tagged_variant(params, variant, cattrs, tag)
+ }
+ attr::TagType::Adjacent { tag, content } => {
+ serialize_adjacently_tagged_variant(params, variant, cattrs, tag, content)
+ }
+ attr::TagType::None => serialize_untagged_variant(params, variant, cattrs),
+ });
+
+ quote! {
+ #case => #body
+ }
+ }
+}
+
+fn serialize_externally_tagged_variant(
+ params: &Parameters,
+ variant: &Variant,
+ variant_index: u32,
+ cattrs: &attr::Container,
+) -> Fragment {
+ let type_name = cattrs.name().serialize_name();
+ let variant_name = variant.attrs.name().serialize_name();
+
+ if let Some(path) = variant.attrs.serialize_with() {
+ let ser = wrap_serialize_variant_with(params, path, variant);
+ return quote_expr! {
+ _serde::Serializer::serialize_newtype_variant(
+ __serializer,
+ #type_name,
+ #variant_index,
+ #variant_name,
+ #ser,
+ )
+ };
+ }
+
+ match effective_style(variant) {
+ Style::Unit => {
+ quote_expr! {
+ _serde::Serializer::serialize_unit_variant(
+ __serializer,
+ #type_name,
+ #variant_index,
+ #variant_name,
+ )
+ }
+ }
+ Style::Newtype => {
+ let field = &variant.fields[0];
+ let mut field_expr = quote!(__field0);
+ if let Some(path) = field.attrs.serialize_with() {
+ field_expr = wrap_serialize_field_with(params, field.ty, path, &field_expr);
+ }
+
+ let span = field.original.span();
+ let func = quote_spanned!(span=> _serde::Serializer::serialize_newtype_variant);
+ quote_expr! {
+ #func(
+ __serializer,
+ #type_name,
+ #variant_index,
+ #variant_name,
+ #field_expr,
+ )
+ }
+ }
+ Style::Tuple => serialize_tuple_variant(
+ TupleVariant::ExternallyTagged {
+ type_name,
+ variant_index,
+ variant_name,
+ },
+ params,
+ &variant.fields,
+ ),
+ Style::Struct => serialize_struct_variant(
+ StructVariant::ExternallyTagged {
+ variant_index,
+ variant_name,
+ },
+ params,
+ &variant.fields,
+ &type_name,
+ ),
+ }
+}
+
+fn serialize_internally_tagged_variant(
+ params: &Parameters,
+ variant: &Variant,
+ cattrs: &attr::Container,
+ tag: &str,
+) -> Fragment {
+ let type_name = cattrs.name().serialize_name();
+ let variant_name = variant.attrs.name().serialize_name();
+
+ let enum_ident_str = params.type_name();
+ let variant_ident_str = variant.ident.to_string();
+
+ 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(
+ __serializer,
+ #enum_ident_str,
+ #variant_ident_str,
+ #tag,
+ #variant_name,
+ #ser,
+ )
+ };
+ }
+
+ match effective_style(variant) {
+ Style::Unit => {
+ quote_block! {
+ let mut __struct = try!(_serde::Serializer::serialize_struct(
+ __serializer, #type_name, 1));
+ try!(_serde::ser::SerializeStruct::serialize_field(
+ &mut __struct, #tag, #variant_name));
+ _serde::ser::SerializeStruct::end(__struct)
+ }
+ }
+ Style::Newtype => {
+ let field = &variant.fields[0];
+ let mut field_expr = quote!(__field0);
+ if let Some(path) = field.attrs.serialize_with() {
+ field_expr = wrap_serialize_field_with(params, field.ty, path, &field_expr);
+ }
+
+ let span = field.original.span();
+ let func = quote_spanned!(span=> _serde::__private::ser::serialize_tagged_newtype);
+ quote_expr! {
+ #func(
+ __serializer,
+ #enum_ident_str,
+ #variant_ident_str,
+ #tag,
+ #variant_name,
+ #field_expr,
+ )
+ }
+ }
+ Style::Struct => serialize_struct_variant(
+ StructVariant::InternallyTagged { tag, variant_name },
+ params,
+ &variant.fields,
+ &type_name,
+ ),
+ Style::Tuple => unreachable!("checked in serde_derive_internals"),
+ }
+}
+
+fn serialize_adjacently_tagged_variant(
+ params: &Parameters,
+ variant: &Variant,
+ cattrs: &attr::Container,
+ tag: &str,
+ content: &str,
+) -> Fragment {
+ let this_type = &params.this_type;
+ let type_name = cattrs.name().serialize_name();
+ let variant_name = variant.attrs.name().serialize_name();
+
+ let inner = Stmts(if let Some(path) = variant.attrs.serialize_with() {
+ let ser = wrap_serialize_variant_with(params, path, variant);
+ quote_expr! {
+ _serde::Serialize::serialize(#ser, __serializer)
+ }
+ } else {
+ match effective_style(variant) {
+ Style::Unit => {
+ return quote_block! {
+ let mut __struct = try!(_serde::Serializer::serialize_struct(
+ __serializer, #type_name, 1));
+ try!(_serde::ser::SerializeStruct::serialize_field(
+ &mut __struct, #tag, #variant_name));
+ _serde::ser::SerializeStruct::end(__struct)
+ };
+ }
+ Style::Newtype => {
+ let field = &variant.fields[0];
+ let mut field_expr = quote!(__field0);
+ if let Some(path) = field.attrs.serialize_with() {
+ field_expr = wrap_serialize_field_with(params, field.ty, path, &field_expr);
+ }
+
+ let span = field.original.span();
+ let func = quote_spanned!(span=> _serde::ser::SerializeStruct::serialize_field);
+ return quote_block! {
+ let mut __struct = try!(_serde::Serializer::serialize_struct(
+ __serializer, #type_name, 2));
+ try!(_serde::ser::SerializeStruct::serialize_field(
+ &mut __struct, #tag, #variant_name));
+ try!(#func(
+ &mut __struct, #content, #field_expr));
+ _serde::ser::SerializeStruct::end(__struct)
+ };
+ }
+ Style::Tuple => {
+ serialize_tuple_variant(TupleVariant::Untagged, params, &variant.fields)
+ }
+ Style::Struct => serialize_struct_variant(
+ StructVariant::Untagged,
+ params,
+ &variant.fields,
+ &variant_name,
+ ),
+ }
+ });
+
+ let fields_ty = variant.fields.iter().map(|f| &f.ty);
+ let fields_ident: &Vec<_> = &match variant.style {
+ Style::Unit => {
+ if variant.attrs.serialize_with().is_some() {
+ vec![]
+ } else {
+ unreachable!()
+ }
+ }
+ Style::Newtype => vec![Member::Named(Ident::new("__field0", Span::call_site()))],
+ Style::Tuple => (0..variant.fields.len())
+ .map(|i| Member::Named(Ident::new(&format!("__field{}", i), Span::call_site())))
+ .collect(),
+ Style::Struct => variant.fields.iter().map(|f| f.member.clone()).collect(),
+ };
+
+ let (_, ty_generics, where_clause) = params.generics.split_for_impl();
+
+ let wrapper_generics = if fields_ident.is_empty() {
+ params.generics.clone()
+ } else {
+ bound::with_lifetime_bound(&params.generics, "'__a")
+ };
+ let (wrapper_impl_generics, wrapper_ty_generics, _) = wrapper_generics.split_for_impl();
+
+ quote_block! {
+ struct __AdjacentlyTagged #wrapper_generics #where_clause {
+ data: (#(&'__a #fields_ty,)*),
+ phantom: _serde::__private::PhantomData<#this_type #ty_generics>,
+ }
+
+ 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
+ __S: _serde::Serializer,
+ {
+ // Elements that have skip_serializing will be unused.
+ #[allow(unused_variables)]
+ let (#(#fields_ident,)*) = self.data;
+ #inner
+ }
+ }
+
+ let mut __struct = try!(_serde::Serializer::serialize_struct(
+ __serializer, #type_name, 2));
+ try!(_serde::ser::SerializeStruct::serialize_field(
+ &mut __struct, #tag, #variant_name));
+ try!(_serde::ser::SerializeStruct::serialize_field(
+ &mut __struct, #content, &__AdjacentlyTagged {
+ data: (#(#fields_ident,)*),
+ phantom: _serde::__private::PhantomData::<#this_type #ty_generics>,
+ }));
+ _serde::ser::SerializeStruct::end(__struct)
+ }
+}
+
+fn serialize_untagged_variant(
+ params: &Parameters,
+ variant: &Variant,
+ cattrs: &attr::Container,
+) -> Fragment {
+ if let Some(path) = variant.attrs.serialize_with() {
+ let ser = wrap_serialize_variant_with(params, path, variant);
+ return quote_expr! {
+ _serde::Serialize::serialize(#ser, __serializer)
+ };
+ }
+
+ match effective_style(variant) {
+ Style::Unit => {
+ quote_expr! {
+ _serde::Serializer::serialize_unit(__serializer)
+ }
+ }
+ Style::Newtype => {
+ let field = &variant.fields[0];
+ let mut field_expr = quote!(__field0);
+ if let Some(path) = field.attrs.serialize_with() {
+ field_expr = wrap_serialize_field_with(params, field.ty, path, &field_expr);
+ }
+
+ let span = field.original.span();
+ let func = quote_spanned!(span=> _serde::Serialize::serialize);
+ quote_expr! {
+ #func(#field_expr, __serializer)
+ }
+ }
+ Style::Tuple => serialize_tuple_variant(TupleVariant::Untagged, params, &variant.fields),
+ Style::Struct => {
+ let type_name = cattrs.name().serialize_name();
+ serialize_struct_variant(StructVariant::Untagged, params, &variant.fields, &type_name)
+ }
+ }
+}
+
+enum TupleVariant {
+ ExternallyTagged {
+ type_name: String,
+ variant_index: u32,
+ variant_name: String,
+ },
+ Untagged,
+}
+
+fn serialize_tuple_variant(
+ context: TupleVariant,
+ params: &Parameters,
+ fields: &[Field],
+) -> Fragment {
+ let tuple_trait = match context {
+ TupleVariant::ExternallyTagged { .. } => TupleTrait::SerializeTupleVariant,
+ TupleVariant::Untagged => TupleTrait::SerializeTuple,
+ };
+
+ let serialize_stmts = serialize_tuple_struct_visitor(fields, params, true, &tuple_trait);
+
+ let mut serialized_fields = fields
+ .iter()
+ .enumerate()
+ .filter(|(_, field)| !field.attrs.skip_serializing())
+ .peekable();
+
+ let let_mut = mut_if(serialized_fields.peek().is_some());
+
+ let len = serialized_fields
+ .map(|(i, field)| match field.attrs.skip_serializing_if() {
+ None => quote!(1),
+ Some(path) => {
+ let field_expr = Ident::new(&format!("__field{}", i), Span::call_site());
+ quote!(if #path(#field_expr) { 0 } else { 1 })
+ }
+ })
+ .fold(quote!(0), |sum, expr| quote!(#sum + #expr));
+
+ match context {
+ TupleVariant::ExternallyTagged {
+ type_name,
+ variant_index,
+ variant_name,
+ } => {
+ quote_block! {
+ let #let_mut __serde_state = try!(_serde::Serializer::serialize_tuple_variant(
+ __serializer,
+ #type_name,
+ #variant_index,
+ #variant_name,
+ #len));
+ #(#serialize_stmts)*
+ _serde::ser::SerializeTupleVariant::end(__serde_state)
+ }
+ }
+ TupleVariant::Untagged => {
+ quote_block! {
+ let #let_mut __serde_state = try!(_serde::Serializer::serialize_tuple(
+ __serializer,
+ #len));
+ #(#serialize_stmts)*
+ _serde::ser::SerializeTuple::end(__serde_state)
+ }
+ }
+ }
+}
+
+enum StructVariant<'a> {
+ ExternallyTagged {
+ variant_index: u32,
+ variant_name: String,
+ },
+ InternallyTagged {
+ tag: &'a str,
+ variant_name: String,
+ },
+ Untagged,
+}
+
+fn serialize_struct_variant(
+ context: StructVariant,
+ params: &Parameters,
+ fields: &[Field],
+ name: &str,
+) -> Fragment {
+ if fields.iter().any(|field| field.attrs.flatten()) {
+ return serialize_struct_variant_with_flatten(context, params, fields, name);
+ }
+
+ let struct_trait = match context {
+ StructVariant::ExternallyTagged { .. } => StructTrait::SerializeStructVariant,
+ StructVariant::InternallyTagged { .. } | StructVariant::Untagged => {
+ StructTrait::SerializeStruct
+ }
+ };
+
+ let serialize_fields = serialize_struct_visitor(fields, params, true, &struct_trait);
+
+ let mut serialized_fields = fields
+ .iter()
+ .filter(|&field| !field.attrs.skip_serializing())
+ .peekable();
+
+ let let_mut = mut_if(serialized_fields.peek().is_some());
+
+ let len = serialized_fields
+ .map(|field| {
+ let member = &field.member;
+
+ match field.attrs.skip_serializing_if() {
+ Some(path) => quote!(if #path(#member) { 0 } else { 1 }),
+ None => quote!(1),
+ }
+ })
+ .fold(quote!(0), |sum, expr| quote!(#sum + #expr));
+
+ match context {
+ StructVariant::ExternallyTagged {
+ variant_index,
+ variant_name,
+ } => {
+ quote_block! {
+ let #let_mut __serde_state = try!(_serde::Serializer::serialize_struct_variant(
+ __serializer,
+ #name,
+ #variant_index,
+ #variant_name,
+ #len,
+ ));
+ #(#serialize_fields)*
+ _serde::ser::SerializeStructVariant::end(__serde_state)
+ }
+ }
+ StructVariant::InternallyTagged { tag, variant_name } => {
+ quote_block! {
+ let mut __serde_state = try!(_serde::Serializer::serialize_struct(
+ __serializer,
+ #name,
+ #len + 1,
+ ));
+ try!(_serde::ser::SerializeStruct::serialize_field(
+ &mut __serde_state,
+ #tag,
+ #variant_name,
+ ));
+ #(#serialize_fields)*
+ _serde::ser::SerializeStruct::end(__serde_state)
+ }
+ }
+ StructVariant::Untagged => {
+ quote_block! {
+ let #let_mut __serde_state = try!(_serde::Serializer::serialize_struct(
+ __serializer,
+ #name,
+ #len,
+ ));
+ #(#serialize_fields)*
+ _serde::ser::SerializeStruct::end(__serde_state)
+ }
+ }
+ }
+}
+
+fn serialize_struct_variant_with_flatten(
+ context: StructVariant,
+ params: &Parameters,
+ fields: &[Field],
+ name: &str,
+) -> Fragment {
+ let struct_trait = StructTrait::SerializeMap;
+ let serialize_fields = serialize_struct_visitor(fields, params, true, &struct_trait);
+
+ let mut serialized_fields = fields
+ .iter()
+ .filter(|&field| !field.attrs.skip_serializing())
+ .peekable();
+
+ let let_mut = mut_if(serialized_fields.peek().is_some());
+
+ match context {
+ StructVariant::ExternallyTagged {
+ variant_index,
+ variant_name,
+ } => {
+ let this_type = &params.this_type;
+ let fields_ty = fields.iter().map(|f| &f.ty);
+ let members = &fields.iter().map(|f| &f.member).collect::<Vec<_>>();
+
+ let (_, ty_generics, where_clause) = params.generics.split_for_impl();
+ let wrapper_generics = bound::with_lifetime_bound(&params.generics, "'__a");
+ let (wrapper_impl_generics, wrapper_ty_generics, _) = wrapper_generics.split_for_impl();
+
+ quote_block! {
+ struct __EnumFlatten #wrapper_generics #where_clause {
+ data: (#(&'__a #fields_ty,)*),
+ phantom: _serde::__private::PhantomData<#this_type #ty_generics>,
+ }
+
+ 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
+ __S: _serde::Serializer,
+ {
+ let (#(#members,)*) = self.data;
+ let #let_mut __serde_state = try!(_serde::Serializer::serialize_map(
+ __serializer,
+ _serde::__private::None));
+ #(#serialize_fields)*
+ _serde::ser::SerializeMap::end(__serde_state)
+ }
+ }
+
+ _serde::Serializer::serialize_newtype_variant(
+ __serializer,
+ #name,
+ #variant_index,
+ #variant_name,
+ &__EnumFlatten {
+ data: (#(#members,)*),
+ phantom: _serde::__private::PhantomData::<#this_type #ty_generics>,
+ })
+ }
+ }
+ StructVariant::InternallyTagged { tag, variant_name } => {
+ quote_block! {
+ let #let_mut __serde_state = try!(_serde::Serializer::serialize_map(
+ __serializer,
+ _serde::__private::None));
+ try!(_serde::ser::SerializeMap::serialize_entry(
+ &mut __serde_state,
+ #tag,
+ #variant_name,
+ ));
+ #(#serialize_fields)*
+ _serde::ser::SerializeMap::end(__serde_state)
+ }
+ }
+ StructVariant::Untagged => {
+ quote_block! {
+ let #let_mut __serde_state = try!(_serde::Serializer::serialize_map(
+ __serializer,
+ _serde::__private::None));
+ #(#serialize_fields)*
+ _serde::ser::SerializeMap::end(__serde_state)
+ }
+ }
+ }
+}
+
+fn serialize_tuple_struct_visitor(
+ fields: &[Field],
+ params: &Parameters,
+ is_enum: bool,
+ tuple_trait: &TupleTrait,
+) -> Vec<TokenStream> {
+ fields
+ .iter()
+ .enumerate()
+ .filter(|(_, field)| !field.attrs.skip_serializing())
+ .map(|(i, field)| {
+ let mut field_expr = if is_enum {
+ let id = Ident::new(&format!("__field{}", i), Span::call_site());
+ quote!(#id)
+ } else {
+ get_member(
+ params,
+ field,
+ &Member::Unnamed(Index {
+ index: i as u32,
+ span: Span::call_site(),
+ }),
+ )
+ };
+
+ let skip = field
+ .attrs
+ .skip_serializing_if()
+ .map(|path| quote!(#path(#field_expr)));
+
+ if let Some(path) = field.attrs.serialize_with() {
+ field_expr = wrap_serialize_field_with(params, field.ty, path, &field_expr);
+ }
+
+ let span = field.original.span();
+ let func = tuple_trait.serialize_element(span);
+ let ser = quote! {
+ try!(#func(&mut __serde_state, #field_expr));
+ };
+
+ match skip {
+ None => ser,
+ Some(skip) => quote!(if !#skip { #ser }),
+ }
+ })
+ .collect()
+}
+
+fn serialize_struct_visitor(
+ fields: &[Field],
+ params: &Parameters,
+ is_enum: bool,
+ struct_trait: &StructTrait,
+) -> Vec<TokenStream> {
+ fields
+ .iter()
+ .filter(|&field| !field.attrs.skip_serializing())
+ .map(|field| {
+ let member = &field.member;
+
+ let mut field_expr = if is_enum {
+ quote!(#member)
+ } else {
+ get_member(params, field, member)
+ };
+
+ let key_expr = field.attrs.name().serialize_name();
+
+ let skip = field
+ .attrs
+ .skip_serializing_if()
+ .map(|path| quote!(#path(#field_expr)));
+
+ if let Some(path) = field.attrs.serialize_with() {
+ field_expr = wrap_serialize_field_with(params, field.ty, path, &field_expr);
+ }
+
+ let span = field.original.span();
+ let ser = if field.attrs.flatten() {
+ let func = quote_spanned!(span=> _serde::Serialize::serialize);
+ quote! {
+ try!(#func(&#field_expr, _serde::__private::ser::FlatMapSerializer(&mut __serde_state)));
+ }
+ } else {
+ let func = struct_trait.serialize_field(span);
+ quote! {
+ try!(#func(&mut __serde_state, #key_expr, #field_expr));
+ }
+ };
+
+ match skip {
+ None => ser,
+ Some(skip) => {
+ if let Some(skip_func) = struct_trait.skip_field(span) {
+ quote! {
+ if !#skip {
+ #ser
+ } else {
+ try!(#skip_func(&mut __serde_state, #key_expr));
+ }
+ }
+ } else {
+ quote! {
+ if !#skip {
+ #ser
+ }
+ }
+ }
+ }
+ }
+ })
+ .collect()
+}
+
+fn wrap_serialize_field_with(
+ params: &Parameters,
+ field_ty: &syn::Type,
+ serialize_with: &syn::ExprPath,
+ field_expr: &TokenStream,
+) -> TokenStream {
+ wrap_serialize_with(params, serialize_with, &[field_ty], &[quote!(#field_expr)])
+}
+
+fn wrap_serialize_variant_with(
+ params: &Parameters,
+ serialize_with: &syn::ExprPath,
+ variant: &Variant,
+) -> TokenStream {
+ let field_tys: Vec<_> = variant.fields.iter().map(|field| field.ty).collect();
+ let field_exprs: Vec<_> = variant
+ .fields
+ .iter()
+ .map(|field| {
+ let id = match &field.member {
+ Member::Named(ident) => ident.clone(),
+ Member::Unnamed(member) => {
+ Ident::new(&format!("__field{}", member.index), Span::call_site())
+ }
+ };
+ quote!(#id)
+ })
+ .collect();
+ wrap_serialize_with(
+ params,
+ serialize_with,
+ field_tys.as_slice(),
+ field_exprs.as_slice(),
+ )
+}
+
+fn wrap_serialize_with(
+ params: &Parameters,
+ serialize_with: &syn::ExprPath,
+ field_tys: &[&syn::Type],
+ field_exprs: &[TokenStream],
+) -> TokenStream {
+ let this_type = &params.this_type;
+ let (_, ty_generics, where_clause) = params.generics.split_for_impl();
+
+ let wrapper_generics = if field_exprs.is_empty() {
+ params.generics.clone()
+ } else {
+ bound::with_lifetime_bound(&params.generics, "'__a")
+ };
+ let (wrapper_impl_generics, wrapper_ty_generics, _) = wrapper_generics.split_for_impl();
+
+ let field_access = (0..field_exprs.len()).map(|n| {
+ Member::Unnamed(Index {
+ index: n as u32,
+ span: Span::call_site(),
+ })
+ });
+
+ quote!({
+ struct __SerializeWith #wrapper_impl_generics #where_clause {
+ values: (#(&'__a #field_tys, )*),
+ phantom: _serde::__private::PhantomData<#this_type #ty_generics>,
+ }
+
+ impl #wrapper_impl_generics _serde::Serialize for __SerializeWith #wrapper_ty_generics #where_clause {
+ fn serialize<__S>(&self, __s: __S) -> _serde::__private::Result<__S::Ok, __S::Error>
+ where
+ __S: _serde::Serializer,
+ {
+ #serialize_with(#(self.values.#field_access, )* __s)
+ }
+ }
+
+ &__SerializeWith {
+ values: (#(#field_exprs, )*),
+ phantom: _serde::__private::PhantomData::<#this_type #ty_generics>,
+ }
+ })
+}
+
+// Serialization of an empty struct results in code like:
+//
+// let mut __serde_state = try!(serializer.serialize_struct("S", 0));
+// _serde::ser::SerializeStruct::end(__serde_state)
+//
+// where we want to omit the `mut` to avoid a warning.
+fn mut_if(is_mut: bool) -> Option<TokenStream> {
+ if is_mut {
+ Some(quote!(mut))
+ } else {
+ None
+ }
+}
+
+fn get_member(params: &Parameters, field: &Field, member: &Member) -> TokenStream {
+ let self_var = &params.self_var;
+ match (params.is_remote, field.attrs.getter()) {
+ (false, None) => {
+ if params.is_packed {
+ quote!(&{#self_var.#member})
+ } else {
+ quote!(&#self_var.#member)
+ }
+ }
+ (true, None) => {
+ let inner = if params.is_packed {
+ quote!(&{#self_var.#member})
+ } else {
+ quote!(&#self_var.#member)
+ };
+ let ty = field.ty;
+ quote!(_serde::__private::ser::constrain::<#ty>(#inner))
+ }
+ (true, Some(getter)) => {
+ let ty = field.ty;
+ quote!(_serde::__private::ser::constrain::<#ty>(&#getter(#self_var)))
+ }
+ (false, Some(_)) => {
+ unreachable!("getter is only allowed for remote impls");
+ }
+ }
+}
+
+fn effective_style(variant: &Variant) -> Style {
+ match variant.style {
+ Style::Newtype if variant.fields[0].attrs.skip_serializing() => Style::Unit,
+ other => other,
+ }
+}
+
+enum StructTrait {
+ SerializeMap,
+ SerializeStruct,
+ SerializeStructVariant,
+}
+
+impl StructTrait {
+ fn serialize_field(&self, span: Span) -> TokenStream {
+ match *self {
+ StructTrait::SerializeMap => {
+ quote_spanned!(span=> _serde::ser::SerializeMap::serialize_entry)
+ }
+ StructTrait::SerializeStruct => {
+ quote_spanned!(span=> _serde::ser::SerializeStruct::serialize_field)
+ }
+ StructTrait::SerializeStructVariant => {
+ quote_spanned!(span=> _serde::ser::SerializeStructVariant::serialize_field)
+ }
+ }
+ }
+
+ fn skip_field(&self, span: Span) -> Option<TokenStream> {
+ match *self {
+ StructTrait::SerializeMap => None,
+ StructTrait::SerializeStruct => {
+ Some(quote_spanned!(span=> _serde::ser::SerializeStruct::skip_field))
+ }
+ StructTrait::SerializeStructVariant => {
+ Some(quote_spanned!(span=> _serde::ser::SerializeStructVariant::skip_field))
+ }
+ }
+ }
+}
+
+enum TupleTrait {
+ SerializeTuple,
+ SerializeTupleStruct,
+ SerializeTupleVariant,
+}
+
+impl TupleTrait {
+ fn serialize_element(&self, span: Span) -> TokenStream {
+ match *self {
+ TupleTrait::SerializeTuple => {
+ quote_spanned!(span=> _serde::ser::SerializeTuple::serialize_element)
+ }
+ TupleTrait::SerializeTupleStruct => {
+ quote_spanned!(span=> _serde::ser::SerializeTupleStruct::serialize_field)
+ }
+ TupleTrait::SerializeTupleVariant => {
+ quote_spanned!(span=> _serde::ser::SerializeTupleVariant::serialize_field)
+ }
+ }
+ }
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-21 21:19:15 +0000